Patent US4476285A successfully refreshed from Google Patents.
US4476285A
Expired / Lapsed
US
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Rubber modified epoxy adhesive
Assignee: Northrop Grumman Systems Corp
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Filing: 1983-03-02
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Granted: 1984-10-09
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Expires: 2003-03-02
Abstract
Abstract A rubber-modified epoxy adhesive and the method of making the same is dissed for use in bonding graphite-epoxy composite structures. The adhesive comprises a two-part formulation, one part being a reaction product of a carboxyl terminated reactive liquid rubber prereacted with a bisphenol A epoxy resin so that linear epoxy-rubber chains are developed. The second part of the adhesive is an amine curing agent. One effective example of the adhesive is formulated as follows: approximately 4 parts by weight of the bisphenol A epoxy resin is mixed per part of a carboxyl terminated butadiene acrylonitrile rubber and heated to 170° C. At 160° C., a catalyst of approximately 0.01 parts by weight of triphenyl phosphene per part of the rubber is added and the mixture stirred for one hour at 170°-175° C. to provide the reaction product. After cooling to room temperature, the reaction product may be packaged in premeasured quantities for mixture, when required, with a curing agent of cycloaliphatic diamine at a ratio of approximately 4:1.
Inventors
- 👤 David J. Crabtree
- 👤 Elizabeth Y. Park
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:18
CPC Classifications
C; C08; C08G; C08G59/00; C08G59/18; C08G59/20; C08G59/32; C08G59/38; C08G59/02; C08G59/12; C08G59/40; C08G59/50; C08G59/5026
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
84 words
An adhesive composition, comprising: a reaction product consisting essentially of a bisphenol A epoxy resin and a carboxyl terminated butadiene-acrylonitrile rubber mixed in the ratio of about 4:1 parts by weight of said epoxy resin to said rubber, said reaction product being characterized by linear epoxy-rubber chains produced by a carboxyl-epoxide reaction; and a curing agent consisting essentially of a cycloaliphatic diamine composed of bis (p-amine-cyclohexyl) methane isomers, the ratio of said reaction product to said curing agent being in the range of 3.5-5.0:1.
Claim 2
Dependent Claim
84 words
An adhesive composition, comprising: a reaction product consisting essentially of a bisphenol A epoxy resin and a carboxyl terminated butadiene-acrylonitrile rubber mixed in the ratio of about 4:1 parts by weight of said epoxy resin to said rubber, said reaction product being characterized by linear epoxy-rubber chains produced by a carboxyl-epoxide reaction; and a curing agent consisting essentially of a cycloaliphatic diamine composed of bis (p-amine-cyclohexyl) methane isomers, the ratio of said reaction product to said curing agent being in the range of 3.5-5.0:1.
Claim 3
Dependent Claim
29 words
An adhesive composition according to claim 1, further comprising: a catalyst consisting essentially of triphenyl phosphene in a sufficient amount to accelerate the carboxyl-epoxide reaction of said reaction product.
Claim 4
Dependent Claim
36 words
An adhesive composition according to claim 2, further comprising: an additional epoxy resin selected from the group consisting of trifunctional and tetrafunctional epoxy resins in a sufficient amount to increase the thermal stability of the composition.
Claim 5
Dependent Claim
17 words
An adhesive composition according to claim 3 wherein said additional epoxy resin is a trifunctional epoxy resin.
Claim 6
Dependent Claim
17 words
An adhesive composition according to claim 3 wherein said additional epoxy resin is a tetrafunctional epoxy resin.
Claim 7
Independent Claim
79 words
A method of preparing a rubber-modified epoxy adhesive, comprising the steps of: reacting a bisphenol A epoxy resin with a carboxyl terminated butadiene-acrylonitrile rubber, the ratio of the resin to the rubber being about 4:1, to produce a reaction product having linear epoxy-rubber chains; and mixing the reaction product with a curing agent of a cycloaliphatic diamine composed of bis (p-amine-cyclohexyl) methane isomers, the ratio of the reaction product to the curing agent being in the range of 3.5-5.0:1.
Claim 8
Independent Claim
79 words
A method of preparing a rubber-modified epoxy adhesive, comprising the steps of: reacting a bisphenol A epoxy resin with a carboxyl terminated butadiene-acrylonitrile rubber, the ratio of the resin to the rubber being about 4:1, to produce a reaction product having linear epoxy-rubber chains; and mixing the reaction product with a curing agent of a cycloaliphatic diamine composed of bis (p-amine-cyclohexyl) methane isomers, the ratio of the reaction product to the curing agent being in the range of 3.5-5.0:1.
Claim 9
Dependent Claim
83 words
A method of preparing an adhesive according to claim 6, wherein said step of reacting comprises: mixing the resin and the rubber in proper ratio; heating the resin and rubber mixture to about 170° C.; stirring the mixture constantly while heating; adding a small quantity of triphenyl phosphene as a catalyst to accelerate the reaction product; stirring for one hour after adding the phosphene catalyst, the temperature being maintained in the range of 170°-175° C.; and cooling the reaction product to room temperature.
Claim 10
Dependent Claim
40 words
A method of preparing an adhesive according to claim 7, further comprising: blending an additional epoxy resin selected from the group consisting of trifunctional and tetrafunctional epoxy resins in a sufficient amount to increase the thermal stability of the adhesive.
References Cited (Backward Citations)
US2858291A
Cited
GB999383A
Cited
US3894113A
Cited
US3678131A
Cited
US3823107A
Cited
US3707583A
Cited
US3859239A
Cited
US3892819A
Cited
US3926903A
Cited
SU653282A1
Cited
SU696038A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |