Method of using a foamable hot-melt adhesive for sealing

Claim 1

A method of producing a foamable hot-melt adhesive, comprising: admixing a per se known granulated hot-melt thermoplastic adhesive having a melting temperature in the range of about 100° C. with a thermally decomposable powdered foaming additive having a decomposition temperature above the melting temperature of said adhesive; said foaming additive being selected from the group consisting of 1,1'-diacetoxy-1,1'-azocyclohexane; 2,2'-diacetoxy-2,2'-azopropane; and 4,4'-dimethyl-4,4'-azobutyrolactone; and heating the resultant admixture to a temperature above the melting temperature of said adhesive and below the decomposition temperature of said foaming additive so as to provide a molten adhesive together with a foaming additive therein which evidences substantially no foaming at said temperature to achieve a substantially uniform admixture.

Claim 2

A method of producing a foamable hot-melt adhesive, comprising: admixing a per se known granulated hot-melt thermoplastic adhesive having a melting temperature in the range of about 100° C. with a thermally decomposable powdered foaming additive having a decomposition temperature above the melting temperature of said adhesive; said foaming additive being selected from the group consisting of 1,1'-diacetoxy-1,1'-azocyclohexane; 2,2'-diacetoxy-2,2'-azopropane; and 4,4'-dimethyl-4,4'-azobutyrolactone; and heating the resultant admixture to a temperature above the melting temperature of said adhesive and below the decomposition temperature of said foaming additive so as to provide a molten adhesive together with a foaming additive therein which evidences substantially no foaming at said temperature to achieve a substantially uniform admixture.

Claim 3

A method of sealing communication cable structure ends comprising: coating a foamable hot-melt adhesive, comprised of substantially uniform admixture of a per se known molten thermoplastic adhesive having a melting temperature in the range of about 100° C. and a thermally decomposable solid foaming additive in said molten adhesive having a decomposition temperature above the melting range of said adhesive, onto end portion to be sealed; said foaming additive being selected from the group consisting of 1,1'-diacetoxy-1,1'-azocyclohexane; 2,2'-diacetoxy-2,2'-azopropane; and 4,4'-dimethyl-4,4'-azobutyrolactone; and heating the so-coated end portions to a temperature above the decomposition temperature of said foaming additive so that a foam is generated on said end portions and, which bonds and seals said end portions.

Claim 4

A method of sealing communication cable structure ends comprising: coating a foamable hot-melt adhesive, comprised of substantially uniform admixture of a per se known molten thermoplastic adhesive having a melting temperature in the range of about 100° C. and a thermally decomposable solid foaming additive in said molten adhesive having a decomposition temperature above the melting range of said adhesive, onto end portion to be sealed; said foaming additive being selected from the group consisting of 1,1'-diacetoxy-1,1'-azocyclohexane; 2,2'-diacetoxy-2,2'-azopropane; and 4,4'-dimethyl-4,4'-azobutyrolactone; and heating the so-coated end portions to a temperature above the decomposition temperature of said foaming additive so that a foam is generated on said end portions and, which bonds and seals said end portions.

Claim 5

A method for joining cable structure ends wherein a filler piece composed of a heat-shrinkable plastic material and having recesses for insertion of cable structure end portions is coated with a foamable hot-melt adhesive composed of a substantially uniform admixture of a thermoplastic adhesive having a melting temperature of about 100° C. and a thermally decomposable foaming additive having a decomposition temperature above the melting temperature of said adhesive, said foaming additive being selected from the group consisting of 1,1'-diacetoxy-1,1'-azocyclohexane; 2,2'-diacetoxy-2,2'-azopropane; and 4,4'-dimethyl-4,4'-azobutyrolactone, said cable end portions are inserted into said filler piece and in contact with said foamable hot-melt adhesive in the molten state, and the resultant assembly is heated to a temperature sufficient to shrink said filler piece about said cable ends and to decompose said foaming additive so that a foam is generated between said end portions and filler piece and which bonds and seals said end portions with said filler piece.

Claim 6

A method for joining cable structure ends wherein a filler piece composed of a heat-shrinkable plastic material and having recesses for insertion of cable structure end portions is coated with a foamable hot-melt adhesive composed of a substantially uniform admixture of a thermoplastic adhesive having a melting temperature of about 100° C. and a thermally decomposable foaming additive having a decomposition temperature above the melting temperature of said adhesive, said foaming additive being selected from the group consisting of 1,1'-diacetoxy-1,1'-azocyclohexane; 2,2'-diacetoxy-2,2'-azopropane; and 4,4'-dimethyl-4,4'-azobutyrolactone, said cable end portions are inserted into said filler piece and in contact with said foamable hot-melt adhesive in the molten state, and the resultant assembly is heated to a temperature sufficient to shrink said filler piece about said cable ends and to decompose said foaming additive so that a foam is generated between said end portions and filler piece and which bonds and seals said end portions with said filler piece.

Claim 13

A method of filling apertures and the like in the construction field, comprising: applying a foamable hot-melt adhesive comprised of a substantially uniform admixture of a per se known molten thermoplastic adhesive having a melting range of about 100° C. and a thermally decomposable solid foaming additive having a decomposition temperature above the melting range of said adhesive on surfaces containing an aperture to be sealed; said foaming additive being selected from the group consisting of 1,1'-diacetoxy-1,1'-azocyclohexane; 2,2'-diacetoxy-2,2'-azopropane; and 4,4'-dimethyl-4,4'-azobutyrolactone; and heating the so-applied foamable hot-melt adhesive to a temperature above the decomposition temperature of said forming additive so that the foam is generated which fills the aperture and bonds to surrounding surfaces.

Claim 14

A method of filling apertures and the like in the construction field, comprising: applying a foamable hot-melt adhesive comprised of a substantially uniform admixture of a per se known molten thermoplastic adhesive having a melting range of about 100° C. and a thermally decomposable solid foaming additive having a decomposition temperature above the melting range of said adhesive on surfaces containing an aperture to be sealed; said foaming additive being selected from the group consisting of 1,1'-diacetoxy-1,1'-azocyclohexane; 2,2'-diacetoxy-2,2'-azopropane; and 4,4'-dimethyl-4,4'-azobutyrolactone; and heating the so-applied foamable hot-melt adhesive to a temperature above the decomposition temperature of said forming additive so that the foam is generated which fills the aperture and bonds to surrounding surfaces.