Patent US4472229A successfully refreshed from Google Patents.
US4472229A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a laminated sheet product
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1981-07-13
•
Granted: 1984-09-18
•
Expires: 2001-07-13
Abstract
Abstract Sheet products are made from amino-aldehyde, e.g. urea-formaldehyde, resin fibres in admixture with other non-cellulosic fibres, e.g. glass fibres, and optionally cellulosic fibres. Multiply products may be made from plies having the above constitution and plies of, for example, amino-aldehyde resin fibres, alone or in admixture with cellulosic and/or non-cellulosic fibres. The paper-like sheet materials may be used e.g. as filter papers. Laminated products may be made by pressing at an elevated temperature, a stack of plies of paper made from a mixture of amino-aldehyde resin fibres and another fibrous material, e.g. cellulosic fibres.
Inventors
- 👤 Graham E. Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:48
CPC Classifications
B; B32; B32B; B32B29/00; B32B29/002; B32B29/005; B01; B01D; B01D39/00; B01D39/08; B01D39/14; D; D21; D21H; D21H13/00; D21H13/10; D21H13/20; D21H13/22; D21H13/36; D21H13/38; D21H13/40; D21H27/00; D21H27/08; D21H27/30; D21H27/38; D21H5/00; D21H5/12; D21H5/20; B01D2239/00; B01D2239/04; B01D2239/0464; B01D2239/06; B01D2239/065; B01D2239/0654; B01D2239/0668; B01D2239/0681; B01D2239/08; B01D2239/12; B01D2239/1233; B01D2239/1291; B32B2262/00; B32B2262/06; B32B2262/062; B32B2262/10; B32B2262/101; B32B2262/12; B32B2307/00; B32B2307/70; B32B2307/724; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31942; Y10T428/31946; Y10T428/31949; Y10T428/31964; Y10T442/00; Y10T442/50; Y10T442/59; Y10T442/60; Y10T442/654; Y10T442/693
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
141 words
A method of making a laminated sheet product comprising the steps of: (a) forming fibers from an amino-aldehyde resin; (b) curing said fibers by heating at between 80° C. and 200° C. until said fibers have a degree of cure between 50% and 96%; (c) forming said cured fibers, in admixture with fibers other than amino-aldehyde resin fibers having a degree of cure below 96%, into paper, the fibrous material of said paper containing 10% to 90% by weight of said amino-aldehyde resin fibers having a degree of cure between 50% and 96%; (d) forming a stack containing superimposed plies of said paper; and (e) pressing said stack at a temperature of at least 100° C., the pressing conditions being such that said amino-aldehyde resin fibers having a degree of cure between 50% and 96% fuse to bond together adjacent plies.
Claim 2
Independent Claim
141 words
A method of making a laminated sheet product comprising the steps of: (a) forming fibers from an amino-aldehyde resin; (b) curing said fibers by heating at between 80° C. and 200° C. until said fibers have a degree of cure between 50% and 96%; (c) forming said cured fibers, in admixture with fibers other than amino-aldehyde resin fibers having a degree of cure below 96%, into paper, the fibrous material of said paper containing 10% to 90% by weight of said amino-aldehyde resin fibers having a degree of cure between 50% and 96%; (d) forming a stack containing superimposed plies of said paper; and (e) pressing said stack at a temperature of at least 100° C., the pressing conditions being such that said amino-aldehyde resin fibers having a degree of cure between 50% and 96% fuse to bond together adjacent plies.
Claim 3
Dependent Claim
16 words
A method according to claim 1 wherein the plies are free of any thermosetting resin impregnant.
Claim 4
Dependent Claim
22 words
A method according to claim 1 wherein the amino-aldehyde resin fibres have a degree of cure in the range 75 to 93%.
Claim 5
Dependent Claim
24 words
A method according to claim 1 wherein the fibrous material of the paper plies contains 20 to 65% by weight of amino-aldehyde resin fibres.
Claim 6
Dependent Claim
16 words
A method according to claim 1 wherein the stack is pressed at 120° to 200° C.
Claim 7
Dependent Claim
22 words
A method according to claim 1 wherein the stack is pressed at a pressure of 10 to 500 kg cm -2 .
Claim 8
Dependent Claim
32 words
A method according to claim 1 wherein the paper plies, before pressing, contain at least 10% by weight of water, based on the weight of the fibrous material in the paper plies.
Claim 9
Dependent Claim
16 words
A method according to claim 7 wherein the stack is pressed against a gas permeable member.
Claim 10
Dependent Claim
19 words
A method according to claim 8 wherein the gas permeable member is a felt pad or a wire mesh.
References Cited (Backward Citations)
GB573115A
Cited
GB572962A
Cited
US3101294A
Cited
US3592767A
Cited
US4032457A
Cited
GB1574344A
Cited
US4202959A
Cited
GB1573116A
Cited
EP0009322A1
Cited
EP0014026A1
Cited
EP0019383A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-18 | 1988-03-19 | 1988-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-18 | 1992-03-19 | 1992-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-18 | 1996-03-19 | 1996-09-18 | $7700.00 | Window Closed / Lapsed |