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US5338594A Expired / Lapsed US ⏱️ 0.0 years remaining

Foam filled honeycomb and methods for their production

Assignee: Hexcel Corp
•
Filing: 1992-02-07
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Granted: 1994-08-16
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Expires: 2012-02-07
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Abstract

Abstract High strength foam-filled materials and methods for their production are disclosed. The high strength materials include cellular structures comprising a plurality of open-ended cells containing polycyanurate foam. The polycyanurate foam-filled cellular structures have synergistically high mechanical properties and improved resistance to moisture. When cyanate ester foamable precursors in the form of tough films are foamed to fill honeycomb cells, the resulting foam-filled honeycomb has uniformly fine foam cell structure and improved bonding between the foam and the honeycomb.

Inventors

  • 👤 Yen-Seine Wang
  • 👤 Frank Lee
  • 👤 Ching-Chi Kuo
  • 👤 Ken Baron

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 21:45
CPC Classifications
B; B32; B32B; B32B3/00; B32B3/10; B32B3/12; B32B7/00; B32B7/04; B32B7/06; B32B2266/00; B32B2266/02; B32B2266/0214; B32B2307/00; B32B2307/70; B32B2307/718; B32B2419/00; B32B2605/00; B32B2605/18; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1003; Y10T428/00; Y10T428/23; Y10T428/233; Y10T428/234; Y10T428/236; Y10T428/239; Y10T428/24; Y10T428/24149; Y10T428/24157; Y10T428/24165; Y10T428/24174; Y10T428/31504; Y10T428/31678; Y10T428/31681; Y10T428/31721

Claims Analysis

Total Claims: 32
Claim 1
Independent Claim 66 words
A high strength structural material having improved mechanical properties, said structural material comprising: a cellular material comprising a plurality of open-ended cells arranged side-by-side defining a geometric shape; said open-ended cells filled with polycyanurate foam wherein said cellular material containing the foam exhibits a compressive strength greater than that obtained by adding the compressive strength of said cellular material to the compressive strength of said foam.
Claim 2
Dependent Claim 66 words
A high strength structural material having improved mechanical properties, said structural material comprising: a cellular material comprising a plurality of open-ended cells arranged side-by-side defining a geometric shape; said open-ended cells filled with polycyanurate foam wherein said cellular material containing the foam exhibits a compressive strength greater than that obtained by adding the compressive strength of said cellular material to the compressive strength of said foam.
Claim 3
Dependent Claim 43 words
The high strength structural material of claim 1 wherein said polycyanurate foam includes from about 5 w/w % to about 95 w/w % of a polymerized cyanate ester and from about 1 w/w % to about 90 w/w % of a thermoplastic polymer.
Claim 4
Dependent Claim 79 words
The high strength structural material of claim 2 wherein said cyanate ester has the formula: ##STR4## wherein R', R", R'", and R"" are selected from the group consisting of H, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, phenyl, mono-substituted phenyl, di-substituted phenyl and tri-substituted phenyl, haloaryl, aryloxy, nitro, thio and carboxy; and X is a biphenol linking group selected from the group consisting of alkyl, cycloalkyl, S, O, N, phenyl, phenylalkyl, and divalent fused ring systems.
Claim 5
Dependent Claim 32 words
The high strength structural material of claim 2 wherein said thermoplastic polymer is selected from the group consisting of polyvinyl butyrals, polysulfones, polyethersulfones, polyimides, polyacrylates, polyetherethylketones, polyetherimides, polyvinylformals, polyethylene oxides, and copolyesters.
Claim 6
Dependent Claim 15 words
The high strength structural material of claim 4 wherein said thermoplastic polymer is a polyethersulfone.
Claim 7
Dependent Claim 24 words
The high strength structural material of claim 1 wherein said polycyanurate foam comprises a polymerized cyanate ester, said cyanate ester having the formula: ##STR5##
Claim 8
Dependent Claim 22 words
The high strength structural material of claim 1 wherein said plurality of open-ended cells defining a geometric shape is a honeycomb structure.
Claim 9
Dependent Claim 37 words
The high strength structural material of claim 1 wherein the foam containing cellular material has a room temperature compressive strength ranging from about 500 psi to about 1000 psi and a density of less than 15 pcf.
Claim 10
Dependent Claim 45 words
The high strength structural material of claim 1 wherein said polycyanurate foam containing cells form a series and said series is spliced to at least one additional series of polycyanurate foam containing cells, said at least two series of polycyanurate foam containing cells positioned side-by-side.
Claim 11
Dependent Claim 76 words
A high strength structural material having improved mechanical properties, said structural material comprising: a plurality of open-ended cells forming a honeycomb shaped structure; and a quantity of foam contained in each open-ended cell, said foam comprising a polycyanurate, a thermoplastic, and a surfactant wherein said honeycomb shaped structure containing said foam exhibits a compressive strength greater than that obtained by adding the compressive strength of said honeycomb shaped structure to the compressive strength of said foam.
Claim 12
Dependent Claim 76 words
A high strength structural material having improved mechanical properties, said structural material comprising: a plurality of open-ended cells forming a honeycomb shaped structure; and a quantity of foam contained in each open-ended cell, said foam comprising a polycyanurate, a thermoplastic, and a surfactant wherein said honeycomb shaped structure containing said foam exhibits a compressive strength greater than that obtained by adding the compressive strength of said honeycomb shaped structure to the compressive strength of said foam.
Claim 13
Dependent Claim 53 words
The high strength structural material of claim 10 wherein said foam includes from about 5 w/w % to about 95 w/w % of a polycyanurate, from about 1 w/w % to about 90 w/w % of a thermoplastic polymer, and from about 0.01 w/w % to about 5 w/w % of a surfactant.
Claim 14
Dependent Claim 31 words
The high strength structural material of claim 11 wherein said thermoplastic is selected from the group consisting of polyvinyl butyrals, polysulfones, polyethersulfones, polyimides, polyacrylates, polyetherethylketones, polyetherimides, polyvinylformals, polyethylene oxides, and copolyesters.
Claim 15
Dependent Claim 61 words
The high strength structural material of claim 10 wherein said foam includes from about 30 w/w % to about 60 w/w % of a polymerized cyanate ester, said cyanate ester having the formula: ##STR6## from about 5 w/w % to about 60 w/w % of a polyethersulfone, and from about 0.1 w/w % to about 5 w/w % of a surfactant.
Claim 16
Dependent Claim 14 words
The high strength structural material of claim 13 wherein said surfactant is a polysiloxane.
Claim 17
Independent Claim 74 words
A method for preparing foam filled structural material, said structural material having a plurality of open-ended cells arranged side-by-side forming a geometric shape, said method comprising the steps of: providing a cyanate ester foamable precursor composition on a substrate; positioning said structural material over said foamable precursor composition so that said series of open-ended cells is adjacent to said foamable precursor composition; and causing said foamable precursor composition to foam into said open-ended cells.
Claim 18
Independent Claim 74 words
A method for preparing foam filled structural material, said structural material having a plurality of open-ended cells arranged side-by-side forming a geometric shape, said method comprising the steps of: providing a cyanate ester foamable precursor composition on a substrate; positioning said structural material over said foamable precursor composition so that said series of open-ended cells is adjacent to said foamable precursor composition; and causing said foamable precursor composition to foam into said open-ended cells.
Claim 19
Dependent Claim 61 words
The method of claim 15 wherein said cyanate ester based foamable precursor composition includes from about 5 w/w % to about 95 w/w % cyanate ester, from about 1 w/w % to about 90 w/w % thermoplastic polymer, from about 0.05 w/w % to about 5 w/w % catalyst, and from about 0.1 w/w % to about 5 w/w % surfactant.
Claim 20
Dependent Claim 18 words
The method of claim 16 wherein said cyanate ester based foamable precursor composition further includes a blowing agent.
Claim 21
Dependent Claim 13 words
The method of claim 15 wherein said cyanate ester has the formula: ##STR7##
Claim 22
Dependent Claim 30 words
The method of claim 16 wherein said thermoplastic polymer is selected from the group consisting of polyvinyl butyrals, polysulfones, polyether sulfones, polyimides, polyacrylates, polyetherethylketones, polyetherimides, polyvinylformals, polyethylene oxides, and copolyester.
Claim 23
Dependent Claim 75 words
The method of claim 15 wherein said cyanate ester foamable precursor composition includes from about 30 w/w % to about 60 w/w % cyanate ester having the formula: ##STR8## from about 5 w/w % to about 60 w/w % polyethersulfone, from about 0.01 w/w % to about 0.5 w/w % surfactant, from about 0.1 w/w % to about 2 w/w % catalyst, and from about 0.1 w/w % to about 2 w/w % blowing agent.
Claim 24
Dependent Claim 10 words
The method of claim 20 wherein said catalyst is azodicarbonamide.
Claim 25
Dependent Claim 19 words
The method of claim 20 wherein said blowing agent is selected from the group consisting of azodicarbonamide and ethylenecarbonate.
Claim 26
Dependent Claim 45 words
The method of claim 15 wherein providing said cyanate based foamable precursor composition on said release material is accomplished by heating said cyanate based foamable precursor composition, forming a film of said heated cyanate based foamable precursor, and positioning said film on said release material.
Claim 27
Dependent Claim 42 words
The method of claim 15 further including the steps of positioning a layer of release material over said open-ended cells opposite said cyanate based foamable precursor composition, and applying heat and pressure to said series of open-ended cells and foamable precursor composition.
Claim 28
Dependent Claim 30 words
The method of claim 24 wherein said heat is sufficient to provide a temperature of between about 150° C. to about 220° C., and said pressure is about 35 psi.
Claim 29
Independent Claim 101 words
A method for filling honeycomb cells with foam, said method comprising the steps of: heating a foamable precursor composition of about 54 w/w % cyanate ester having the formula: ##STR9## about 43 w/w % polyethersulfone, about 2 w/w % azocarbonamide, about 1 w/w % ethylenecarbonate, and about 0.1 w/w % polysiloxane surfactant; forming a film of said heated foamable precursor composition; layering said film on porous release cloth; placing a honeycomb structure adjacent said film so that said honeycomb cells are positioned over said film; and applying sufficient heat and pressure to said honeycomb and film to foam said foamable precursor.
Claim 30
Independent Claim 101 words
A method for filling honeycomb cells with foam, said method comprising the steps of: heating a foamable precursor composition of about 54 w/w % cyanate ester having the formula: ##STR9## about 43 w/w % polyethersulfone, about 2 w/w % azocarbonamide, about 1 w/w % ethylenecarbonate, and about 0.1 w/w % polysiloxane surfactant; forming a film of said heated foamable precursor composition; layering said film on porous release cloth; placing a honeycomb structure adjacent said film so that said honeycomb cells are positioned over said film; and applying sufficient heat and pressure to said honeycomb and film to foam said foamable precursor.
Claim 31
Dependent Claim 37 words
The high strength structural material of claim 1 wherein the foam containing cellular material has a room temperature compressive strength ranging from about 800 psi to about 900 psi and a density of less than 15 pcf.
Claim 32
Dependent Claim 86 words
The high strength structural material of claim 11 wherein said polycyanurate is a polymerized cyanate ester, said cyanate ester having the formula: ##STR10## wherein R', R", R'", and R"" are selected from the group consisting of H, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, phenyl, mono-substituted phenyl, di-substituted phenyl and tri-substituted phenyl, haloaryl, aryloxy, nitro, thio and carboxy; and X is a biphenol linking group selected from the group consisting of alkyl, cycloalkyl, S, O, N, phenyl, phenylalkyl, and divalent fused ring systems.

References Cited (Backward Citations)

US2744042A Cited
US3644158A Cited
US3644168A Cited
US3834962A Cited
US3970324A Cited
US4162341A Cited
US4088723A Cited
US4970276A Cited
US4983683A Cited
US4917742A Cited
US4956393A Cited
US5077319A Cited
US5188879A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-08-15 1998-02-14 1998-08-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-08-15 2002-02-14 2002-08-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-08-15 2006-02-14 2006-08-16 $7700.00 Window Closed / Lapsed

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