US4900387A
Expired / Lapsed
US
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Method of bonding via electrorheological adhesives
Assignee: Boeing Co
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Filing: 1988-02-24
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Granted: 1990-02-13
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Expires: 2008-02-24
Abstract
Abstract Adhesives and coating are formulated with electrorheological materials to thicken when subjected to an electric field. The adhesives are thin and easy to apply, but thicken to prevent running while the adhesive cures or sets. A uniform bond along the joint is formed, thereby eliminating the uneven or discontinuous adhesive bonds made with conventional adhesives that reduce the strength and integrity of the joint.
Inventors
- 👤 Joseph C. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:51
CPC Classifications
C; C09; C09J; C09J5/00
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
135 words
A method for bonding a first surface to a second surface by applying a curable adhesive composition containing a fluid adhesive component to at least one surface wherein the improvement comprises: (a) using an adhesive composition containing an electrorheological material, said electroheological material present in an amount serving to increase the viscosity of the adhesive composition to a gel state when an electric field is applied to the adhesive composition; (b) applying the adhesive composition to at least one surface; (c) positioning the first surface immediately adjacent to the second surface such that said adhesive composition contacts both surfaces; (d) applying the electric field to the adhesive composition, said electric field cooperating with the electrorheological material to increase the viscosity of the adhesive composition to a gel state; and (e) curing the fluid adhesive component.
Claim 2
Independent Claim
135 words
A method for bonding a first surface to a second surface by applying a curable adhesive composition containing a fluid adhesive component to at least one surface wherein the improvement comprises: (a) using an adhesive composition containing an electrorheological material, said electroheological material present in an amount serving to increase the viscosity of the adhesive composition to a gel state when an electric field is applied to the adhesive composition; (b) applying the adhesive composition to at least one surface; (c) positioning the first surface immediately adjacent to the second surface such that said adhesive composition contacts both surfaces; (d) applying the electric field to the adhesive composition, said electric field cooperating with the electrorheological material to increase the viscosity of the adhesive composition to a gel state; and (e) curing the fluid adhesive component.
Claim 3
Dependent Claim
31 words
The method of claim 1, wherein the viscosity of the adhesive composition in step (d) with the electric field applied is such that the adhesive composition is in a nonflowable, gel-state.
Claim 4
Dependent Claim
26 words
The method of claim 1, wherein the electrorheological material is selected from the group consisting of finely divided silica, silica gel, glass spheres and silica spheres.
Claim 5
Dependent Claim
13 words
The method of claim 1, wherein the electrorheological material is a polar material.
Claim 6
Dependent Claim
13 words
The method of claim 1, wherein the fluid adhesive component is a nonconductor.
Claim 7
Dependent Claim
22 words
The method of claim 1, wherein the fluid adhesive component is selected from the group consisting of epoxy, polyurethane and silicone adhesives.
Claim 8
Dependent Claim
20 words
The method of claim 1, wherein the potential of the electric field ranges from about 2000 to about 2500 volts/mm.
Claim 9
Dependent Claim
26 words
The method of claim 2, wherein the viscosity of the adhesive composition in step (d) with the electric field applied is at least about 12,000 centipoise.
Claim 10
Dependent Claim
56 words
The method of claim 1, wherein the viscosity increase caused by application of the electric field is from a first viscosity low enough to permit application of the adhesive composition in fluid form, to a second viscosity high enough to prevent the adhesive composition from flowing under its own weight when applied to a nonhorizontal surface.
Claim 11
Dependent Claim
41 words
The method of claim 1, wherein said electrorheological material comprises about 0.5 to about 5.0 weight percent based on the total weight of the adhesive composition and the electric field is in the range of about 2000 to about 2500 volts/mm.
Claim 12
Dependent Claim
45 words
The method of claim 1, wherein the adhesive composition comprises: a fluid adhesive component; and an electrorheological material present in an amount effective to increase the viscosity of the adhesive composition to a gel state when an electric field is applied to the adhesive composition.
Claim 13
Dependent Claim
21 words
The method of claim 1, wherein the fluid adhesive component is selected from the group consisting of epoxy, polyurethane,and silicone adhesives.
Claim 14
Dependent Claim
26 words
The method of claim 1, wherein the electrorheological material is selected from the group consisting of finely divided silica, silica gel, glass spheres, and silica spheres.
Claim 15
Independent Claim
74 words
A method for bonding two surfaces together comprising the steps of: (a) applying a fluid adhesive in a bondline between the two surfaces to be bonded, the adhesive including an effective amount of an electrorheological fluid sufficient for gelling the adhesive when an electric field is applied to the adhesive; (b) applying the electric field to the adhesive to gel the adhesive; and, (c) curing the adhesive while continuing to apply the electric field.
Claim 16
Independent Claim
74 words
A method for bonding two surfaces together comprising the steps of: (a) applying a fluid adhesive in a bondline between the two surfaces to be bonded, the adhesive including an effective amount of an electrorheological fluid sufficient for gelling the adhesive when an electric field is applied to the adhesive; (b) applying the electric field to the adhesive to gel the adhesive; and, (c) curing the adhesive while continuing to apply the electric field.
Claim 17
Dependent Claim
27 words
The method of claim 14 wherein, in the absence of an electric field, the adhesive has a viscosity in the range of 50-4000 centipoise at 25° C.
Claim 18
Dependent Claim
29 words
The method of claim 15, wherein the adhesive has a dielectric constant in the range of about 2.0-5.5 and an electrical resistivity of at least about 10 -14 ohm-cm.
Claim 19
Dependent Claim
18 words
The method of claim 14, wherein the step of curing involves heating the adhesive to an elevated temperature.
Claim 20
Dependent Claim
10 words
The method of claim 17, wherein the adhesive is thermosettable.
Claim 21
Dependent Claim
17 words
The method of claim 14, wherein the electrorheological fluid comprises about 0.5-5.0 wt. % of the adhesive.
Claim 22
Dependent Claim
20 words
The method of claim 14, wherein the electrorheological fluid is an anhydrous polymer and the adhesive is an organic resin.
Claim 23
Dependent Claim
21 words
The method of claim 14, wherein the adhesive also includes a hydroxy or an amino compound, water, and an organic resin.
Claim 24
Dependent Claim
17 words
The method of claim 14, wherein the electric field is in the range of about 2000-2500 volts/mm.
Claim 25
Dependent Claim
21 words
The method of claim 14, wherein the gelled adhesive of step (b) has a viscosity of at least about 12,000 centipoise.
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) | 1993-02-12 | 1993-08-14 | 1994-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-12 | 1997-08-14 | 1998-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-12 | 2001-08-14 | 2002-02-13 | $7700.00 | Window Closed / Lapsed |