US4056587A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for expanding
Assignee: WR Grace and Co
•
Filing: 1975-10-20
•
Granted: 1977-11-01
•
Expires: 1995-10-20
Abstract
Abstract Foam styrene polymer sheet is expanded to form foam products having lower density by a process which includes (a) contacting the foam styrene polymer sheet with an aqueous composition, (b) maintaining the aqueous composition in contact with the sheet to effect impregnation of the sheet by the aqueous composition, and thereafter (c) heating the impregnated sheet to expand the sheet. The expanded products are useful as thermal insulation and packaging material.
Inventors
- 👤 Arvid Honkanen
- 👤 Paul Joonase
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:27
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/34; B29C44/56; B29C44/5618; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S264/15
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
110 words
A process for further expanding a previously expanded styrene polymer foam sheet comprising the steps of: impregnating the previously expanded styrene polymer foam sheet with an aqueous composition to the extent of at least 0.3 parts of aqueous composition per 100 parts of styrene polymer; and heating the thus impregnated sheet to at least the softening point of said styrene polymer to soften said polymer and to volatilize said aqueous composition within the porosity of said foam sheet to thus expand said foam sheet by the action of said volatilized aqueous composition to a greater extent than any expansion which would be produced in the absence of said aqueous composition.
Claim 2
Dependent Claim
110 words
A process for further expanding a previously expanded styrene polymer foam sheet comprising the steps of: impregnating the previously expanded styrene polymer foam sheet with an aqueous composition to the extent of at least 0.3 parts of aqueous composition per 100 parts of styrene polymer; and heating the thus impregnated sheet to at least the softening point of said styrene polymer to soften said polymer and to volatilize said aqueous composition within the porosity of said foam sheet to thus expand said foam sheet by the action of said volatilized aqueous composition to a greater extent than any expansion which would be produced in the absence of said aqueous composition.
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein the temperatures of the aqueous composition and the sheet are less than 90° C. in said step of impregnating.
Claim 4
Dependent Claim
17 words
The process of claim 1 wherein the aqueous composition in said step of impregnating is a liquid.
Claim 5
Dependent Claim
10 words
The process of claim 3 wherein the liquid is water.
Claim 6
Dependent Claim
17 words
The process of claim 3 wherein the liquid is a mixture of water with a wetting agent.
Claim 7
Dependent Claim
15 words
The process of claim 5 wherein the wetting agent is a linear alkyl aryl sulfonate.
Claim 8
Dependent Claim
22 words
The process of claim 3 wherein the liquid composition is at a temperature of from about 20° C to about 30° C.
Claim 9
Dependent Claim
17 words
The process of claim 1 wherein the aqueous composition in said step of impregnating is water vapor.
Claim 10
Dependent Claim
16 words
The process of claim 8 wherein the water vapor is at a temperature below 90° C.
Claim 11
Dependent Claim
21 words
The process of claim 1 wherein the foam styrene polymer sheet is impregnated with at least 0.3 percent by weight water.
Claim 12
Dependent Claim
21 words
The process of claim 1 wherein the foam styrene polymer sheet is impregnated with at least 0.6 percent by weight water.
Claim 13
Dependent Claim
21 words
The process of claim 1 wherein the sheet is maintained in contact with the aqueous composition for at least 6 hours.
Claim 14
Dependent Claim
21 words
The process of claim 3 wherein the sheet is maintained in contact with the aqueous composition for at least 6 hours.
Claim 15
Dependent Claim
13 words
The process of claim 3 wherein the liquid is sprayed onto the sheet.
Claim 16
Dependent Claim
13 words
The process of claim 3 wherein the sheet is immersed in the liquid.
Claim 17
Dependent Claim
24 words
The process of claim 1 wherein said expansion of the sheet in step (c) is effected while the sheet is disposed in a mold.
Claim 18
Dependent Claim
15 words
The process of claim 1 wherein contact is maintained with the sheet rolled upon itself.
Claim 19
Dependent Claim
23 words
The process of claim 17 wherein the rolled sheet is wrapped in a packaging material having high resistance to transmission of water vapor.
Claim 20
Dependent Claim
24 words
The process of claim 17 wherein the contact is maintained with the sheet at a temperature of from about 20° to about 30° C.
Claim 21
Dependent Claim
33 words
The process of claim 1 wherein the sheet is impregnated with water in an amount effective for expanding the sheet to a bulk density of not more than 2 pounds per cubic foot.
Claim 22
Dependent Claim
27 words
The process of claim 20 wherein the sheet is expanded to not more than 2 pounds per cubic foot by heating for not more than 10 seconds.
Claim 23
Dependent Claim
27 words
The process of claim 20 wherein the sheet is expanded to not more than 2 pounds per cubic foot by heating for not more than 5 seconds.
Claim 24
Dependent Claim
12 words
The process of claim 1 wherein the sheet is an extruded sheet.
Claim 25
Dependent Claim
17 words
The process of claim 1 wherein the sheet is in a substantially water-free environment during said heating.
Claim 26
Dependent Claim
21 words
The process of claim 1 wherein the sequence of said steps is repeated to effect a second expansion of the sheet.
Claim 27
Dependent Claim
44 words
The process of claim 5 wherein the wetting agent is selected from the group consisting of alkali metal soaps; anionic, nonionic, cationic, ampholytic and zwitterionic synthetic surfactants; long chain tertiary amine oxides; long chain tertiary phosphine oxides; long chain dialkyl sulfoxides; and mixtures thereof.
Claim 28
Dependent Claim
56 words
The process of claim 5 wherein the wetting agent is selected from the group consisting of naphthalene sulfonates, sulfosuccinates, sorbitan derivatives, alkyl sulfonates (sulfonated fatty esters), phosphated derivatives, glycerol fatty esters, fatty esters, aryl sulfonates, alkyl aryl sulfonates, diphenyl sulfonates, fatty ester sulfates, alcohol sulfates, ethoxylated or propoxylated alcohols, fatty glycols, polyethoxylated glycols, and mixtures thereof.
References Cited (Backward Citations)
US2857625A
Cited
US3010157A
Cited
GB854586A
Cited
US3060513A
Cited
US3082483A
Cited
US3242238A
Cited
US3119147A
Cited
US3200437A
Cited
US3262625A
Cited
US3335207A
Cited
US3334169A
Cited
US3300551A
Cited
US3364519A
Cited
US3823047A
Cited
US3853972A
Cited
US3848038A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-31 | 1981-05-02 | 1981-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-31 | 1985-05-02 | 1985-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-31 | 1989-05-02 | 1989-11-01 | $7700.00 | Window Closed / Lapsed |