Polyethylene composition for improving adhesion to polyurethane resins
The present invention concerns a polyethylene composition comprising (A) an ethylene co-polymer containing monomer units with hydrolysable silane-groups, and (B) one or more ethylene co-polymers selected from the group of (B1) an ethylene co-polymer containing monomer units with hydroxyl groups, (B2) an ethylene co-polymer containing monomer units with (meth-)acrylate groups, and (B3) an ethylene co-polymer containing monomer units with hydroxyl groups and (meth-)acrylate groups, a cable comprising a layer (1) which comprises one or more ethylene copolymers selected from the group of (B1), (B2) and (B3) and to the use of one or more ethylene co-polymers selected from the group of (B1), (B2) and (B3) for improving the adhesion between a layer of a cable comprising the ethylene co-polymer(s) and a polyurethane resin.
1. A polyethylene composition comprising
(A) an ethylene co-polymer containing monomer units with hydrolysable silane groups, and
(B) one or more ethylene co-polymers wherein at least one hydroxyl group and at least one (meth-)acrylate group are present in the same monomer;
wherein component (B) is present in the polyethylene composition in an amount so that the monomer units having at least one hydroxyl group and at least one (meth-) acrylate groups are present in the polyethylene composition in an amount of 0.14 mol % or more and 7 mol % or less; and
wherein components (A) and (B) may be present in the composition as separate ethylene co-polymers or as one ethylene co-polymer containing the respective groups simultaneously wherein component (B) is present in an amount of 4 wt % of more of the total polyethylene composition.
2. Polyethylene composition according to claim 1 , wherein component (B) is present in an amount of 35 wt % or less in the total polyethylene composition.
3. Cable comprising a first layer which comprises the polyethylene composition according to claim 1 .
4. The cable according to claim 3 , wherein the first layer is a skin layer and/or insulation layer.
5. The cable according to claim 3 , wherein a second layer which comprises a polyethylene containing hydrolysable silane-groups is present adjacent to the first layer.
6. The cable according to claim 3 , wherein the cable is a power cable.
7. A polyethylene composition comprising
(A) an ethylene copolymer containing 76.1 wt % to 98.8 wt % ethylene and monomer units with hydrolysable silane groups, and
(B) one or more ethylene co-polymers wherein at least one hydroxyl group and at least one (meth-)acrylate group are present in the same monomer;
wherein component (B) is present in the polyethylene composition in an amount so that the monomer units having at least one hydroxyl group and at least one (meth) acrylate group are present in the polyethylene composition in an amount of 0.14 mol % or more and 7 mol % or less; and
wherein components (A) and (B) may be present in the composition as separate ethylene co-polymers or as one ethylene co-polymer containing the respective groups simultaneously and wherein component (B) is present in an amount of 4 wt % or more of the total polyethylene composition.
8. A method for producing a cable, comprising:
producing a first cable layer comprising a polyethylene composition comprising an ethylene co-polymer wherein at least one hydroxyl group and at least one (meth-)acrylate group are present in the same monomer; wherein the monomer units having at least one hydroxyl group and at least one (alkyl-)acrylate groups are present in the polyethylene composition in an amount of 0.14 mol % or more and 7 mol % or less;
adhering the first cable layer to a second cable layer comprising a polyurethane resin.
9. The method of claim 8 , wherein the ethylene co-polymer contains monomers having methyl-, ethyl-, propyl- or butyl acrylate groups.
10. The method of claim 8 , wherein the ethylene co-polymer further contains monomer units with hydrolysable silane groups.
11. The method of claim 10 , wherein in the ethylene co-polymer the monomer units with hydrolysable silane groups are present in an amount of 0.1 to 1 mol. %.
12. The method of claim 10 , wherein the monomer units with hydrolysable silane groups comprise vinyl trimethoxysilane, vinyl dimethoxyethoxysilane, vinyl triethoxysilane, gamma-(meth) acryloxypropyltrimethoxysilane, gamma(meth)acryloxypropyltriethoxysilane, and/or vinyl triacetoxysilane.
13. The method of claim 10 , wherein the monomer units with hydrolysable silane groups comprise vinyl trimethoxysilane.