US4956393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Structures exhibiting improved transmission of ultrahigh frequency electromagnetic radiation and structural materials which allow their construction
Assignee: Cytec Technology Corp
•
Filing: 1988-08-29
•
Granted: 1990-09-11
•
Expires: 2008-08-29
Abstract
Abstract Radomes having increased transparency and reduced reflectivity and refractivity to radar waves may be prepared or repaired utilizing heat-curable resin-containing structural materials in which the heat-curable resin contains greater than about 70 weight percent of cyanate functional monomers. The structural materials take the form of matrix resin impregnated prepegs and composites, film adhesives, paste adhesives, syntactic foams, and expandable foams, and may be used to prepare numerous useful structural features including honeycomb materials and leading edge radomes containing syntactic foams.
Inventors
- 👤 Jack D. Boyd
- 👤 Hermann Sitt
- 👤 Hong-Son Ryang
- 👤 Theodore F. Biermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:49
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/42; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24149; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2938; Y10T428/2964; Y10T428/2967; Y10T428/31504; Y10T428/31551; Y10T428/31605
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
117 words
In a process for the manufacture or repair of radomes in which matrix resins, structural adhesives, and foams containing heat curable resin systems are utilized, the improvement comprising employing as said heat curable resin system, a resin system comprising, in weight percent relative to the total resin system weight, (a) about 70 percent or more of a cyanate resin; (b) from 0 to about 25 weight percent of a bismaleimide resin; (c) from 0 to about 20 weight percent of an epoxy resin; (d) from 0 to about 20 weight percent of an engineering thermoplastic selected from the group consisting of the polyimides, polyetherimides, and polyamideimides; and (e) an effective amount of a cyanate cure promoting catalyst
Claim 2
Dependent Claim
117 words
In a process for the manufacture or repair of radomes in which matrix resins, structural adhesives, and foams containing heat curable resin systems are utilized, the improvement comprising employing as said heat curable resin system, a resin system comprising, in weight percent relative to the total resin system weight, (a) about 70 percent or more of a cyanate resin; (b) from 0 to about 25 weight percent of a bismaleimide resin; (c) from 0 to about 20 weight percent of an epoxy resin; (d) from 0 to about 20 weight percent of an engineering thermoplastic selected from the group consisting of the polyimides, polyetherimides, and polyamideimides; and (e) an effective amount of a cyanate cure promoting catalyst
Claim 3
Dependent Claim
9 words
A radome prepared by the process of claim 1.
Claim 4
Dependent Claim
65 words
A syntactic foam having increased transparency to radar waves, comprising: (a) from 90 to about 40 weight percent of a heat curable resin system component, comprising: (i) about 70 weight percent or more of a heat curable cyanate resin; and (ii) an amount of a catalyst effective to cure said cyanate resin; and from 10 to about 60 weight percent of (b) a microsphere component
Claim 5
Dependent Claim
65 words
A syntactic foam having increased transparency to radar waves, comprising: (a) from 90 to about 40 weight percent of a heat curable resin system component, comprising: (i) about 70 weight percent or more of a heat curable cyanate resin; and (ii) an amount of a catalyst effective to cure said cyanate resin; and from 10 to about 60 weight percent of (b) a microsphere component
Claim 6
Dependent Claim
21 words
The syntactic foam of claim 3 wherein said resin system component (a) comprises in excess of 90 weight percent cyanate resin.
Claim 7
Dependent Claim
16 words
The syntactic foam of claim 3 wherein said microspheres comprise borosilicate glass or fused quartz microspheres.
Claim 8
Dependent Claim
25 words
The syntactic foam of claim 3 wherein the loss tangent at 10 Ghz is less than about 0.008 as measured in accordance with ASTM D2520.
Claim 9
Dependent Claim
56 words
A heat-curable cyanate adhesive composition, comprising: (a) a cyanate functional monomer and/or prepolymer; (b) an epoxy functional polysiloxane; and (c) an amount of a catalyst effective to promote the elevated temperature cure of said composition, wherein the loss tangent of the neat resin as measured by ASTM D2520 is less than about 0.007 at 25° C.
Claim 10
Dependent Claim
56 words
A heat-curable cyanate adhesive composition, comprising: (a) a cyanate functional monomer and/or prepolymer; (b) an epoxy functional polysiloxane; and (c) an amount of a catalyst effective to promote the elevated temperature cure of said composition, wherein the loss tangent of the neat resin as measured by ASTM D2520 is less than about 0.007 at 25° C.
Claim 11
Dependent Claim
11 words
The adhesive composition of claim 7 which is a paste adhesive.
Claim 12
Dependent Claim
11 words
The adhesive composition of claim 7 which is a paste adhesive.
Claim 13
Dependent Claim
11 words
The adhesive composition of claim 7 further comprising a blowing agent.
Claim 14
Dependent Claim
11 words
The adhesive composition of claim 7 further comprising a blowing agent.
References Cited (Backward Citations)
US3553244A
Cited
US3740348A
Cited
US3536734A
Cited
US4110364A
Cited
US4370467A
Cited
US4393195A
Cited
US4369304A
Cited
US4369302A
Cited
US4396745A
Cited
US4364884A
Cited
US4353769A
Cited
US4615859A
Cited
US4436569A
Cited
US4645805A
Cited
US4568603A
Cited
US4728962A
Cited
US4731420A
Cited
US4777226A
Cited
US4709008A
Cited
US4774316A
Cited
US4740584A
Cited
US4785075A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-10 | 1994-03-12 | 1994-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-10 | 1998-03-12 | 1998-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-10 | 2002-03-12 | 2002-09-11 | $7700.00 | Window Closed / Lapsed |