Grafting of silane on thermoplastics or elastomers for purposes of cross-linking

Claim 2

In a method for providing a sheathing of cross-linking thermoplastic or elastomeric material, wherein the powdery or granular material is mixed with silane to be diffused into the material under conditions of obtaining a homogenic mixture and wherein the silane is grafted upon the molecules of the material, the improvement of adding water-containing additives to the mixture, and extruding a sheath, the water being released at an elevated temperature pursuant to the extrusion to cause cross-linking of the silane grafted material in the presence of moisture.

Claim 3

Method as in claim 1, including adding about 0.05 to 5 parts (by weight) per 100 parts fluidizable polymer, of additives which develop water on decompositioning.

Claim 4

Method as in claim 2 wherein the additive is a polyvinyl alcohol.

Claim 5

Method as in claim 2 wherein the additive is beta-hydroxycarbon acid or gamma hydroxycarbon acid or a derivative of such acid.

Claim 6

Method as in claim 2 wherein the additive is a hydrate water containing an organic compound such as aluminumoxidehydrate, or gypsum.

Claim 7

In a method as in claim 1, wherein the split off of water results in residue which is indifferent to the cross-linking.

Claim 8

In a method for cross-linking thermoplastic or elastomeric material wherein a thermoplastic or elastomeric material is provided as dry, fluid powder, and to obtain fluidization thereof and raising the temperature by operation of the agitating, but below the crystallite melting range; and wherein a silane compound is added to the material prior to completion of the agitation to diffuse into the fluid particles, the silane compound being of the variety that permits grafting on the molecules of said powder; and wherein the silane or silane compound molecules are grafted onto the molecules of the thermoplastic or elastomeric material, the improvement comprising: adding about 0.05 to 5 parts by weight of at least one additive which develops water on decompositioning at elevated temperature, and extruding the silane grafted material to obtain internal release of water and cross-linking in an extruded product.

Claim 9

In a method for cross-linking thermoplastic or elastomeric material wherein a thermoplastic or elastomeric material is provided as dry, fluid powder, and to obtain fluidization thereof and raising the temperature by operation of the agitating, but below the crystallite melting range; and wherein a silane compound is added to the material prior to completion of the agitation to diffuse into the fluid particles, the silane compound being of the variety that permits grafting on the molecules of said powder; and wherein the silane or silane compound molecules are grafted onto the molecules of the thermoplastic or elastomeric material, the improvement comprising: adding about 0.05 to 5 parts by weight of at least one additive which develops water on decompositioning at elevated temperature, and extruding the silane grafted material to obtain internal release of water and cross-linking in an extruded product.

Claim 10

In a method as in claim 7, wherein the silane grafted material is extruded around a cable to obtain insulating sheathing as the extruded product, cross-linking occurring in situ pursuant to the internal release of water in the sheathing as extruded.

Claim 11

Method as in claim 8, wherein the additive is a polyvinyl alcohol.

Claim 12

Method as in claim 8, wherein the additive is beta-hydroxycarbon acid or gamma hydroxycarbon acid or a derivative of such acid.

Claim 13

Method as in claim 8, wherein the additive is a hydrate water containing an organic compound such as aluminumoxidehydrate, or gypsum.

Claim 14

Method as in claim 8, wherein the additive is added to the powder prior to completion of agitation to obtain homogenic diffusion into the powder prior to extrusion.