Back to results
US 4,230,614 AGranted
Stop-off compound and method of making
AssigneeBoeing Commercial Airplane Company
InventorsCharles R. Arnold, Donald A. Pennington
Life of this patent
Estimating the term…
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.
Claims4
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.
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.
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.
Dependencies are inferred from the claim text.