US4230614A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stop-off compound and method of making
Assignee: Boeing Commercial Airplane Co
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Filing: 1977-11-23
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Granted: 1980-10-28
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Expires: 1997-11-23
Abstract
Abstract A filler of polyisobutylene dissolved in a solvent is combined with boron nitride to form a stop-off compound used as a parting agent when diffusion bonding metals. A uniform coating of the compound is applied with screen printing methods prior to bonding.
Inventors
- 👤 Charles R. Arnold
- 👤 Donald A. Pennington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:07
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/224; B23K20/00; B23K20/18; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24851; Y10T428/24868; Y10T428/24876; Y10T428/24884; Y10T428/31504; Y10T428/31678; Y10T428/31692
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
82 words
A stop-off composition as a parting agent during diffusion bonding of metals comprising: about 48 weight percent of a release agent of boron nitride dispersed in about 52 weight percent of a binder consisting of polyisobutylene dissolved in a solvent consisting essentially of an aliphatic or aromatic hydrocarbon to form a stop-off coating composition having a consistency to permit silkscreen application of the composition to a metal part to provide a coating having uniform thickness and sharply defined lines in intricate patterns.
Claim 2
Dependent Claim
82 words
A stop-off composition as a parting agent during diffusion bonding of metals comprising: about 48 weight percent of a release agent of boron nitride dispersed in about 52 weight percent of a binder consisting of polyisobutylene dissolved in a solvent consisting essentially of an aliphatic or aromatic hydrocarbon to form a stop-off coating composition having a consistency to permit silkscreen application of the composition to a metal part to provide a coating having uniform thickness and sharply defined lines in intricate patterns.
Claim 3
Dependent Claim
107 words
A stop-off composition as a parting agent during diffusion bonding of metals comprising: a release agent of boron nitride dispersed in a binder consisting of polyisobutylene dissolved in a solvent consisting of xylene and toluene to form a stop-off coating composition having a consistency to permit silkscreen application of the composition to a metal part to provide a coating having a uniform thickness and sharply defined lines in intricate patterns wherein the release agent comprises about 11 to 14 parts, the polyisobutylene about 1 part, the xylene about 6 to 8 parts and the toluene about 5 to 7 parts with all the parts being by weight.
Claim 4
Dependent Claim
107 words
A stop-off composition as a parting agent during diffusion bonding of metals comprising: a release agent of boron nitride dispersed in a binder consisting of polyisobutylene dissolved in a solvent consisting of xylene and toluene to form a stop-off coating composition having a consistency to permit silkscreen application of the composition to a metal part to provide a coating having a uniform thickness and sharply defined lines in intricate patterns wherein the release agent comprises about 11 to 14 parts, the polyisobutylene about 1 part, the xylene about 6 to 8 parts and the toluene about 5 to 7 parts with all the parts being by weight.
Claim 5
Independent Claim
90 words
A method of preparing a stop-off compound for diffusion bonding of metals, the steps comprising: forming a binder by placing about 1 part by weight polyisobutylene into a container, adding solvents consisting of about 6 to 8 parts xylene and about 5 to 7 parts toluene and stirring until the polyisobutylene is completely dissolved; adding a release agent of about 11 to 14 parts of boron nitride powder to the binder and mixing to disperse the powder throughout the binder for providing a viscous stop-off compound suitable for silkscreen application.
Claim 6
Independent Claim
90 words
A method of preparing a stop-off compound for diffusion bonding of metals, the steps comprising: forming a binder by placing about 1 part by weight polyisobutylene into a container, adding solvents consisting of about 6 to 8 parts xylene and about 5 to 7 parts toluene and stirring until the polyisobutylene is completely dissolved; adding a release agent of about 11 to 14 parts of boron nitride powder to the binder and mixing to disperse the powder throughout the binder for providing a viscous stop-off compound suitable for silkscreen application.
Claim 7
Dependent Claim
43 words
A method of preparing a stop-off compound as in claim 3, with further steps of preparing the binder well ahead of the need for the stop-off compound, sealing the binder in a tight container, and storing until needed to make the stop-off compound.
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) | 1983-10-28 | 1984-04-28 | 1984-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-28 | 1988-04-28 | 1988-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-28 | 1992-04-28 | 1992-10-28 | $7700.00 | Window Closed / Lapsed |