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

Claim 2

In a method for cross-linking thermoplastic or elastomeric material wherein cross-linking is preceded by grafting of silane and is carried out in the presence of moistures, the combination of steps comprising: providing the thermoplastic or elastomeric material as dry, fluid powder; agitating the powder to obtain fluidization thereof and raising the temperature by operation of the agitating; adding a silane compound to the material prior to completion of the agitation, the silane compound being of the variety that permits grafting on the molecules of said powder; providing for a temperature below the crystallite melting range, between 80° C. and 100° C., so that the silane or silane compound as agitated together with the said material fluid is caused to diffuse into the fluid particles without grafting; and providing for grafting of the silane or silane compound molecules to the molecules of the thermoplastic or elastomeric material.

Claim 3

In a method as in claim 1, wherein the silane compound is added at a temperature below the crystallite melting range of the said powder.

Claim 4

In a method as in claim 1, wherein the silane is added at a temperature between 60° and 100° C.

Claim 5

In a method as in claim 1, wherein the grafting occurs with mechanical-thermal treatment of the powder.

Claim 6

In a method as in claim 4, wherein said treatment is carried out at a temperature between 160° and 250° C.

Claim 7

In a method as in claim 4, wherein the powder is extruded.

Claim 8

In a method for cross-linking thermoplastic or elastomeric material, wherein cross-linking is preceded by grafting of silane and is carried out in the presence of moistures, the combination of steps comprising: providing the thermoplastic or elastomeric material as a dry, fluid powder; agitating the powder to obtain fluidization thereof and raising the temperature by operation of the agitation; adding a silane compound to the material prior to completion of the agitation, the silane compound being of a variety that permits grafting on the molecules of said powder; providing for a temperature below the crystallite's melting range, so that the silane or silane compound, as agitated, together with the said material fluid is caused to diffuse into the fluid particles without grafting; and subjecting the material to a high energy radiation for grafting the silane or silane compound molecules upon the molecules of the thermoplastic or elastomeric material.

Claim 9

In a method for cross-linking thermoplastic or elastomeric material, wherein cross-linking is preceded by grafting of silane and is carried out in the presence of moistures, the combination of steps comprising: providing the thermoplastic or elastomeric material as a dry, fluid powder; agitating the powder to obtain fluidization thereof and raising the temperature by operation of the agitation; adding a silane compound to the material prior to completion of the agitation, the silane compound being of a variety that permits grafting on the molecules of said powder; providing for a temperature below the crystallite's melting range, so that the silane or silane compound, as agitated, together with the said material fluid is caused to diffuse into the fluid particles without grafting; and subjecting the material to a high energy radiation for grafting the silane or silane compound molecules upon the molecules of the thermoplastic or elastomeric material.

Claim 10

In a method as in claim 7 wherein the material has a temperature below 180° C. during said radiation.

Claim 11

In a method as in claim 1 wherein the silane compound is added to the powder prior to agitation.

Claim 12

In a method for cross-linking thermoplastic or elastomeric material, wherein cross-linking is preceded by grafting of silane and is carried out in the presence of moistures, the combination of steps comprising: providing the thermoplastic or elastomeric material as a dry, fluid powder; agitating the powder to obtain fluidization thereof and raising the temperature by operation of the agitation; adding a silane compound when the temperature of the powder has risen to 60° C. to 100° C. prior to completion of the agitation, the silane compound being of a variety that permits grafting on the molecules of said powder; providing for a temperature below the crystallite's melting range, so that the silane or silane compound, as agitated, together with the said material fluid is caused to diffuse into the fluid particles without grafting; and providing for grafting of the silane or silane compound molecules on the molecules of the thermoplastic or elastomeric material.

Claim 13

In a method for cross-linking thermoplastic or elastomeric material, wherein cross-linking is preceded by grafting of silane and is carried out in the presence of moistures, the combination of steps comprising: providing the thermoplastic or elastomeric material as a dry, fluid powder; agitating the powder to obtain fluidization thereof and raising the temperature by operation of the agitation; adding a silane compound when the temperature of the powder has risen to 60° C. to 100° C. prior to completion of the agitation, the silane compound being of a variety that permits grafting on the molecules of said powder; providing for a temperature below the crystallite's melting range, so that the silane or silane compound, as agitated, together with the said material fluid is caused to diffuse into the fluid particles without grafting; and providing for grafting of the silane or silane compound molecules on the molecules of the thermoplastic or elastomeric material.

Claim 14

In a method as in claim 1 or 10 wherein the silane compound is added when the temperature of the powder has risen to 80° to 90°.

Claim 15

In a method as in claim 1, and including pre-drying the powder before adding the silane compound.

Claim 16

In a method as in claim 1, wherein the silane compound is added to the powder under conditions of low pressure to obtain evaporation.

Claim 17

In a method as in claim 13, wherein the diffusion occurs from the liquidous as well as from the gaseous phase of the silane compound.

Claim 18

In a method as in claim 1, wherein the mixture is formed and subsequently placed in intimate contact with water.

Claim 19

In a method as in claim 15, and including adding to the water a substance which reduces surface tension.

Claim 20

In a method as in claim 1, wherein the silane compound is mixed with peroxide.

Claim 21

In a method as in claim 17, wherein the silane compound is additionally mixed with an activator.

Claim 22

In a method as in claim 17, wherein the silane compound is additionally mixed with an anti-oxidant.

Claim 23

In a method as in claim 1, wherein a condensation catalyst is added to the mixture subsequent to diffusion.

Claim 24

In a method as in claim 20, wherein the condensation catalyst is added under temporary continuation of the agitation.

Claim 25

In a method as in claim 20, wherein the mixture is extruded, the catalyst being added to the hot mixture as it is being extruded.

Claim 26

In a method as in claim 20, wherein the mixture is applied to an elongated object, the catalyst being sprayed on.

Claim 27

In a method as in claim 20, wherein a batch of the powder and of the catalyst is prepared to obtain diffusion of the catalyst into the latter powder and adding the batch as mixed to the mixture.

Claim 28

In a method as in claim 1, wherein the silane compound is mixed with a anti-oxidant.

Claim 29

In a method as in claim 25, wherein the oxidant is a monomer or oligomer of the 2,2,4 trimethyl-dihydroquinoline.

Claim 30

In a method as in claim 25, wherein the oxidant is also grafted onto the polymer.

Claim 31

In a method as in claim 1, wherein 0.05 to 0.5 parts per 100 parts (by weight) of powder, of a peroxide is added to the silane as solution therein.

Claim 32

In a method as in claim 28, wherein the peroxide is an ester-peroxide.

Claim 33

In a method as in claim 29, wherein the esteroxide is tert.-butylperoxy-isonanoate.

Claim 34

In a method as in claim 28, wherein the peroxide is a blend of 1, 3 bis(tert.-butylperoxy-isopropy) benzene and tert.-butylperoxy-3,3,5-trimethylhexanoate.

Claim 35

Method as in claim 1, wherein the silane compound is vinyltriacetoxy silane.

Claim 36

Method as in claim 1, wherein the fluid is higher molecular polyethylene with a melting index of about 2.

Claim 37

Method as in claim 1, and including mixing the fluidizable polymer with higher condendated substances.

Claim 38

Method as in claim 1, and including mixing the fluidizable polymer with ethylene propylene terpolymer elastomer or ethylene-propylene elastomer at 5 to 20 parts by weight per 100 parts fluidizable polymer.