Plastic composite moulded bodies obtainable by welding in an electromagnetic alternating field

1. A plastics composite molding, obtained by a process comprising welding in an alternating electromagnetic field,

wherein a weld is obtained with the aid of a plastics material which comprises a nano-scale, magnetic oxidic particle, and

wherein the plastics material that generates the weld is thermoplastically softenable,

wherein the nano-scale, magnetic oxidic particle comprises aggregated primary particles, and

wherein the primary particles comprise (i) magnetic metal oxide domains whose diameter is from 2 to 100 nm, in (ii) a non-magnetic metal oxide matrix or non-magnetic metalloid oxide matrix.

2. The molding of claim 1 , wherein the nano-scale, magnetic oxidic particle comprises aggregated primary particles, and

wherein an aggregate size of the primary particles is greater than 100 nm and smaller than 1 μm.

3. The molding of claim 1 , wherein the magnetic domains of the nano-scale magnetic oxidic particle comprise iron oxide.

4. The molding of claim 1 , wherein the nano-scale, magnetic oxidic particle comprises a non-agglomerated superparamagnetic domain.

5. The molding of claim 1 , wherein at least one nano-scale, magnetic oxidic particle is a supermagnetic oxidic particle comprising magnetic domains,

wherein the magnetic domains superparamagnetic oxidic particle comprise a ferrite.

6. The molding of claim 5 , wherein the magnetic domains of the superparamagnetic oxidic particle comprise a ternary system of formula (I)

(M a 1-x-y M b x Fe y ) II Fe 2 III O 4   (I),

wherein M a or M b is manganese, cobalt, nickel, zinc, copper, barium, yttrium, tin, lithium, cadmium, magnesium, calcium, strontium, titanium, chromium, vanadium, niobium, or molybdenum,

x is from 0.05 to 0.95,

y is from 0 to 0.95, and

x+y≦1.

7. The molding of claim 1 , wherein a proportion of the magnetic domains in the nano-scale, magnetic oxidic particle is from 10 to 90% by weight.

8. The molding of claim 1 , wherein a proportion of the nano-scale, magnetic oxidic particles in the plastics material that generates the weld is from 0.1 to 40% by weight.

9. The molding of claim 1 , wherein the plastics material that generates the weld comprises at least one selected from the group consisting of a single-component polyurethane, a two-component polyurethane, a single- or two-component polyepoxide, a single- or two-component silicone polymer, a silane-modified polymer, a polyamide, a (meth)acrylate-functional polymer, a polyester, a polycarbonate, a cycloolefin copolymer, a polysiloxane, a poly(ether) sulphone, a polyether ketone, a polystyrene, a polyoxymethylene, a polyamideimide, a polytetrafluoroethylene, a polyvinylidene fluoride, a polyfluoroethylene-propylene copolymer, a perfluoroalkoxy copolymer, a methacrylate/butadiene/styrene copolymer, and a liquid-crystalline copolyester.

10. The molding of claim 1 , in the form of an assembled hollow body, which has been welded directly or by a connecting element.

11. The molding of claim 1 , in the form of a multilayer composite comprising an element welded in the manner of at least one of a sheet and a foil.

12. A process for producing the plastics composite molding according to claim 1 , the process comprising:

welding a plastics material in an alternating electromagnetic field,

wherein the plastics material comprises a nano-scale, magnetic oxidic particle comprising aggregated primary particles,

wherein the primary particles comprise magnetic metal oxide domains whose diameter is from 2 to 100 nm, in a non-magnetic metal oxide matrix or non-magnetic metalloid oxide matrix, and

wherein the plastics material of the welding is thermoplastically softenable.

13. The process of claim 12 , wherein at least one molding to be joined comprises at least in a region of a joint area, a plastics material which comprises a nano-scale, magnetic oxidic particle comprising aggregated primary particles,

wherein the primary particles comprise magnetic metal oxide domains whose diameter is from 2 to 100 nm, in a non-magnetic metal oxide matrix or non-magnetic metalloid oxide matrix.

14. The process of claim 12 , wherein the plastics molding to be joined is exposed at least in a region of a joint area to an alternating electrical, magnetic, or electromagnetic field,

wherein the plastics material that generates a weld is heated to melting point.

15. The molding of claim 10 , in the form of a container, tube, or line.

16. The molding of claim 1 , wherein the plastics material that generates the weld comprises at least one selected from the group consisting of a polyamide, a polyester, a polycarbonate, a cycloolefin copolymer, a poly(ether) sulphone, a polyether ketone, a polystyrene, a polyoxymethylene, a polytetrafluoroethylene, a polyvinylidene fluoride, a polyfluoroethylene-propylene copolymer, a perfluoroalkoxy copolymer, a methacrylate/butadiene/styrene copolymer, and a liquid-crystalline copolyester.

17. The molding of claim 1 , wherein the plastics material that generates the weld comprises a polyamide.

18. The molding of claim 1 , wherein the plastics material that generates the weld comprises a polyester.