US5358675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlling heterogeneous nucleation and growth of foams
Assignee: CASTLE ASSOCIATES
•
Filing: 1992-05-13
•
Granted: 1994-10-25
•
Expires: 2012-05-13
Abstract
Abstract A method of controlling the nucleation of cells in a polymeric foam material includes blending a matrix material with a second phase material which provides sites for bubble nucleation. The selection of the second phase material controls the size and density of the cells.
Inventors
- 👤 Gregory A. Campbell
- 👤 Don H. Rasmussen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:26
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/34; B29C44/3469; B29C44/60; Y; Y10; Y10S; Y10S264/00; Y10S264/13; Y10S521/00; Y10S521/908
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
149 words
A method for producing closed cell foamed structures, comprising: blending a polymeric matrix material with a second phase material which has a transition temperature below that of said polymeric matrix material to form an unfoamed composition, said second phase material being present in said unfoamed composition in a concentration between 0.001 and 18 volume percent; heating said unfoamed composition to a temperature above the transition temperature of the matrix material; cooling said unfoamed composition to a temperature below the transition temperature of the polymeric matrix material to provide sites which can be activated for bubble nucleation, whereby said sites are provided by voids resulting from stresses caused by differing thermal expansion coefficients between the second phase material and the polymeric phase material; impregnating said unfoamed composition with gas at an elevated pressure; and heating said impregnated unfoamed composition to expand cells at said sites to form a foamed structure.
Claim 2
Independent Claim
149 words
A method for producing closed cell foamed structures, comprising: blending a polymeric matrix material with a second phase material which has a transition temperature below that of said polymeric matrix material to form an unfoamed composition, said second phase material being present in said unfoamed composition in a concentration between 0.001 and 18 volume percent; heating said unfoamed composition to a temperature above the transition temperature of the matrix material; cooling said unfoamed composition to a temperature below the transition temperature of the polymeric matrix material to provide sites which can be activated for bubble nucleation, whereby said sites are provided by voids resulting from stresses caused by differing thermal expansion coefficients between the second phase material and the polymeric phase material; impregnating said unfoamed composition with gas at an elevated pressure; and heating said impregnated unfoamed composition to expand cells at said sites to form a foamed structure.
Claim 3
Dependent Claim
32 words
The method recited in claim 1 further comprising: selecting said second phase material to limit the expansion of said cells by the physical size of the particles in said second phase material.
Claim 4
Dependent Claim
33 words
The method recited in claim 1 further comprising: controlling the density of cells in said foamed structures by adjusting the amount of said second phase material added to said matrix material during blending.
Claim 5
Dependent Claim
21 words
The method recited in claim 1 wherein said second phase polymeric material has particles of rubber which act as nucleation sites.
Claim 6
Dependent Claim
15 words
The method recited in claim 1 wherein said second phase material is high impact polystyrene.
Claim 7
Dependent Claim
13 words
The method recited in claim 1 wherein said second phase material is latex.
Claim 8
Dependent Claim
14 words
The method recited in claim 1 wherein said matrix material is an amorphous polymer.
Claim 9
Dependent Claim
23 words
The method recited in claim 1 wherein said matrix material is an amorphous polymer and said second phase material is an amorphous polymer.
Claim 10
Dependent Claim
20 words
The method recited in claim 1 wherein said polymeric matrix material is polystyrene and said second phase material is rubber.
Claim 11
Dependent Claim
20 words
The method recited in claim 1 wherein said polymeric matrix material is polycarbonate and said second phase material is rubber.
Claim 12
Dependent Claim
20 words
The method recited in claim 1 wherein said polymeric matrix material is polyester and said second phase material is rubber.
Claim 13
Dependent Claim
20 words
The method recited in claim 1 wherein said polymeric matrix material is polyethylene and said second phase material is rubber.
Claim 14
Dependent Claim
12 words
The method recited in claim 4 wherein said foamed structures are microcellular.
Claim 15
Dependent Claim
20 words
The method recited in claim 1 wherein said polymeric matrix material is polyetherimide and said second phase material is rubber.
Claim 16
Dependent Claim
13 words
The method recited in claim 4 wherein said matrix material is polyphenylene oxide/polystyrene.
Claim 17
Dependent Claim
21 words
The method recited in claim 1 wherein said polymeric matrix material is polyethylene oxide/polystyrene and said second phase material is rubber.
Claim 18
Dependent Claim
14 words
The method recited in claim 4 wherein said polymeric matrix material is semicrystalline polymer.
Claim 19
Dependent Claim
22 words
The method recited in claim 1 wherein said matrix material is semicrystalline polymer and said second phase material is an amorphous polymer.
Claim 20
Dependent Claim
22 words
The method recited in claim 1 wherein said matrix material is semicrystalline polymer and said second phase material is an semicrystalline polymer.
Claim 21
Dependent Claim
23 words
The method recited in claim 1 wherein said matrix material is an amorphous polymer and said second phase material is a semicrystalline polymer.
Claim 22
Dependent Claim
30 words
The method of claim 4 wherein said polymeric matrix material is selected from the group consisting of polyester, polyethylene, polystyrene acrylo nitril, polyphenylene oxide/polystyrene, polycarbonate, polyetherimide, polypropylene, nylon, and teflon.
Claim 23
Dependent Claim
23 words
The method of claim 1 further comprising cooling said foamed structure to about room temperature, provided that said cooling does not encompass quenching.
Claim 24
Dependent Claim
20 words
The method of claim 1 wherein the particle size of the second phase material is from 0.02 to 10 microns.
Claim 25
Dependent Claim
14 words
The method of claim 23 wherein said second phase material comprises high impact polystyrene.
Claim 26
Dependent Claim
12 words
The method of claim 23 wherein said second phase material comprises rubber.
Claim 27
Dependent Claim
19 words
The method of claim 23 wherein said polymeric matrix material comprises polystyrene and said second phase material comprises rubber.
Claim 28
Independent Claim
164 words
A method of producing foamed structures with predictable cell size and density, comprising: blending a polymeric matrix material selected from the group consisting of polyester, polyethylene, polystyrene acrylo nitril, polyphenylene oxide/polystyrene, polycarbonate, polyetherimide, polypropylene, nylon and teflon with a second phase material having a lower transition temperature than said matrix material, said second phase material being present in said blend at a concentration of from 0.001 to 18 volume percent of said blend; heating said blend to a temperature above the transition temperature of the matrix material; cooling said heated blend to a temperature below the transition temperature of the polymeric matrix material to provide sites which can be activated for bubble nucleation, whereby said sites are provided by voids resulting from stresses caused by differing thermal expansion coefficients between the second phase material and the polymeric matrix material; impregnating said blend with gas at an elevated pressure; and heating said impregnated blend to expand cells at said sites to form a foamed structure.
Claim 29
Independent Claim
164 words
A method of producing foamed structures with predictable cell size and density, comprising: blending a polymeric matrix material selected from the group consisting of polyester, polyethylene, polystyrene acrylo nitril, polyphenylene oxide/polystyrene, polycarbonate, polyetherimide, polypropylene, nylon and teflon with a second phase material having a lower transition temperature than said matrix material, said second phase material being present in said blend at a concentration of from 0.001 to 18 volume percent of said blend; heating said blend to a temperature above the transition temperature of the matrix material; cooling said heated blend to a temperature below the transition temperature of the polymeric matrix material to provide sites which can be activated for bubble nucleation, whereby said sites are provided by voids resulting from stresses caused by differing thermal expansion coefficients between the second phase material and the polymeric matrix material; impregnating said blend with gas at an elevated pressure; and heating said impregnated blend to expand cells at said sites to form a foamed structure.
Claim 30
Dependent Claim
16 words
The method recited in claim 27 wherein the expanded cell size is less than 10 microns.
Claim 31
Dependent Claim
20 words
The method recited in claim 27 wherein said matrix material is amorphous and said second phase material includes rubber particles.
Claim 32
Dependent Claim
21 words
The method recited in claim 27 wherein said matrix material is amorphous and said second phase material is high impact polystyrene.
Claim 33
Dependent Claim
19 words
The method recited in claim 27 wherein said matrix material is semicrystalline and said second phase material includes rubber.
Claim 34
Dependent Claim
21 words
The method recited in claim 27 wherein said matrix material is semicrystalline and said second phase material is high impact polystyrene.
Claim 35
Independent Claim
179 words
A method of producing foamed structures with predictable cell size and density, comprising: blending a polymeric matrix material with a second phase material to form an unfoamed composition, said second phase material having a preselected particle size and a transition temperature below that of said polymeric matrix material, said second phase material being present in said unfoamed composition at a concentration between 0.001 and 18 volume percent; heating said unfoamed composition to a temperature above the transition temperature of the matrix material; cooling said heated unfoamed composition to a temperature below the transition temperature of the polymeric matrix material to provide sites which can be activated for bubble nucleation, whereby said sites are provided by voids resulting from stresses caused by differing thermal expansion coefficients between the second phase material and the polymeric matrix material; impregnating said unfoamed composition with gas at an elevated pressure; reducing said process pressure; and heating said impregnated material to a process temperature to expand said cells to a size dependent on the particle size of the second phase material, thereby foaming the material.
Claim 36
Independent Claim
179 words
A method of producing foamed structures with predictable cell size and density, comprising: blending a polymeric matrix material with a second phase material to form an unfoamed composition, said second phase material having a preselected particle size and a transition temperature below that of said polymeric matrix material, said second phase material being present in said unfoamed composition at a concentration between 0.001 and 18 volume percent; heating said unfoamed composition to a temperature above the transition temperature of the matrix material; cooling said heated unfoamed composition to a temperature below the transition temperature of the polymeric matrix material to provide sites which can be activated for bubble nucleation, whereby said sites are provided by voids resulting from stresses caused by differing thermal expansion coefficients between the second phase material and the polymeric matrix material; impregnating said unfoamed composition with gas at an elevated pressure; reducing said process pressure; and heating said impregnated material to a process temperature to expand said cells to a size dependent on the particle size of the second phase material, thereby foaming the material.
Claim 37
Dependent Claim
12 words
The method of claim 33 wherein said second phase material comprises rubber.
Claim 38
Dependent Claim
27 words
The method of claim 34 further comprising blending said matrix material and said second phase material at a temperature above the transition temperature of the matrix material.
Claim 39
Dependent Claim
24 words
The method of claim 34 further comprising selecting the particle size of said second phase material to provide a predetermined size of said cells.
Claim 40
Dependent Claim
12 words
The method of claim 36 wherein said polymeric matrix material comprises polystyrene.
Claim 41
Dependent Claim
30 words
The method of claim 34 wherein said polymeric matrix material is selected from the group consisting of polyester, polyethylene, polystyrene acrylo nitril, polyphenylene oxide/polystyrene, polycarbonate, polyetherimide, polypropylene, nylon, and teflon.
Claim 42
Independent Claim
179 words
A method for producing a microcellular foamed polymer composition comprising: (a) providing a matrix polymeric material; (b) blending a second phase material having a particle size of from 0.02 to 10 microns and having a transition temperature below the transition temperature of said matrix polymeric material with said matrix polymeric material to form an unfoamed composition, said second phase material being present in an amount of from 0.001 to 18 volume percent of said unfoamed composition; (c) heating said unfoamed composition to a temperature above the transition temperature of the matrix polymeric material; (d) cooling said heated unfoamed composition to a temperature below the transition temperature of the matrix polymeric material to provide sites that can be activated for bubble nucleation, whereby said sites are provided by voids resulting from stresses caused by differing thermal expansion coefficients between the second phase material and the matrix polymeric material; (e) impregnating said cooled unfoamed composition with a gas at an elevated pressure; and (f) heating said impregnated unfoamed composition to expand cells at said sites to form the foamed polymer composition.
Claim 43
Independent Claim
179 words
A method for producing a microcellular foamed polymer composition comprising: (a) providing a matrix polymeric material; (b) blending a second phase material having a particle size of from 0.02 to 10 microns and having a transition temperature below the transition temperature of said matrix polymeric material with said matrix polymeric material to form an unfoamed composition, said second phase material being present in an amount of from 0.001 to 18 volume percent of said unfoamed composition; (c) heating said unfoamed composition to a temperature above the transition temperature of the matrix polymeric material; (d) cooling said heated unfoamed composition to a temperature below the transition temperature of the matrix polymeric material to provide sites that can be activated for bubble nucleation, whereby said sites are provided by voids resulting from stresses caused by differing thermal expansion coefficients between the second phase material and the matrix polymeric material; (e) impregnating said cooled unfoamed composition with a gas at an elevated pressure; and (f) heating said impregnated unfoamed composition to expand cells at said sites to form the foamed polymer composition.
Claim 44
Dependent Claim
18 words
The method of claim 39 wherein the average size of the expanded cells is below about 40 microns.
Claim 45
Dependent Claim
18 words
The method of claim 39 wherein the average size of the expanded cells is below about 10 microns.
Claim 46
Dependent Claim
12 words
The method of claim 41 wherein the matrix polymeric material comprises polystyrene.
Claim 47
Dependent Claim
25 words
The method of claim 42 wherein the second phase material comprises rubber in an amount of from 0.1-10% by volume of the unfoamed matrix composition.
Claim 48
Dependent Claim
30 words
The method of claim 41 wherein the matrix polymeric material is selected from the group consisting of polyester, polyethylene, polystyrene acrylo nitril, polyphenylene oxide/polystyrene, polycarbonate, polyetherimide, polypropylene, nylon, and teflon.
References Cited (Backward Citations)
US3608005A
Cited
US3929686A
Cited
GB1439438A
Cited
US4075265A
Cited
US4473665A
Cited
US4598101A
Cited
US4696776A
Cited
US4761256A
Cited
US5160674A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-24 | 1998-04-25 | 1998-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-24 | 2002-04-25 | 2002-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-24 | 2006-04-25 | 2006-10-25 | $7700.00 | Window Closed / Lapsed |