MULTI-LAYER COMPOSITE MATERIAL FOR PRODUCING PLASTIC MOLDED PARTS, CONTAINER COMPOSED OF SUCH A COMPOSITE MATERIAL, AND METHOD FOR PRODUCING THE CONTAINER

Abstract

The invention relates to a multilayer composite material for the production of plastics moldings, to a container made of this composite material, and also to a process for the production of the container. The composite material comprises a first structure-providing self-supporting rigid external layer made of a fiber composite material, a second structure-providing external layer, a first intermediate layer made of a barrier plastic and a second cracking-resistant intermediate layer made of a thin cracking-resistant film, and also at least one adhesion promoter layer, where the intermediate layers and the adhesion promoter layer have been embedded between the structure-providing external layers and form an adhesion bond with the structure-forming external layers, and where the thickness of each of the structure-providing external layers is many times the thickness of each of the intermediate layers or of the adhesion promoter layer.

Claims

1. A multilayer composite material comprising: a first structure-providing, self-supporting rigid external layer made of a fiber composite material; a second structure-providing external layer; a cracking-resistant intermediate layer made of a plastic selected from a group, comprising cracking-resistance-modified polyethylene, polyisobutylene, prestretched polypropylene, polyvinyl butyral, ethylene-vinyl acetate, polyacrylate, polymethylene acrylate, polyurethane, polyvinyl acetate and ethylene-vinyl acetate; and at least one adhesion promoter layer, where the cracking-resistant intermediate layer and the adhesion promoter layer are embedded between the structure-providing external layers and form an adhesion bond with the structure-providing external layers, and where a thickness of each of the structure-providing external layers is greater than a thickness of at least one of the cracking-resistant intermediate layer or of the adhesion promoter layer.

2. The multilayer composite material as claimed in claim 1, wherein there is a further intermediate layer provided, made of a barrier plastic.

3. The multiplayer composite material as claimed in claim 1, wherein the second structure-providing external layer comprises one or more thermoplastics selected from a group comprising polyethylene, polyamide, polyphenylene sulfide, polybutylene terephthalate, polyketone, polyether-etherketone, liquid-crystal polymer and polyphthalamide.

4. The multilayer composite material as claimed in claim 1, wherein the fiber composite material comprises a material with a matrix with at least one of long fibers or continuous-filament fibers embedded therein, where the long fibers or the continuous-filament fibers are selected from a group comprising at least one of glass fibers, carbon fibers or aramid fibers, and the long fibers or continuous-filament fibers have been at least one of woven or laid.

5. The multilayer composite material as claimed in claim 2, wherein the barrier plastic is selected from a group comprising polyvinylidene chloride, ethylene-vinyl alcohol copolymer, a liquid-crystalline plastic, polyamide, cellulose and biaxially oriented polypropylene.

6. The multilayer composite material as claimed in claim 1, wherein the adhesion promoter layer comprises a maleic-anhydride-modified LDPE or an LLDPE.

7. The multilayer composite material as claimed in claim 1, comprises a layer structure comprising, in the following sequence, an exterior layer made of a thermoplastic selected from a group comprising polyethylene, polyamides, polyphenylene sulfides, polybutylene terephthalates, polyketones, polyetheretherketones, liquid-crystal polymers and polyphthalamides, a cracking-resistant intermediate layer and a structure-providing external layer made of a fiber composite material.

8. The multilayer composite material as claimed in claim 1, comprises a layer structure comprising, in the following sequence, an exterior layer made of a thermoplastic selected from a group comprising polyethylene, polyamides, polyphenylene sulfides, polybutylene terephthalates, polyketones, polyetheretherketones, liquid-crystal polymers and polyphthalamides, an adjoining first adhesion promoter layer, an intermediate layer made of a barrier plastic, a second adhesion promoter layer, a cracking-resistant intermediate layer, a third adhesion promoter layer, and a structure-providing external layer made of a fiber composite material.

9. The multilayer composite material as claimed in claim 1, wherein the thickness of the structure-providing external layers is from 0.5 to 2 mm, and that the thickness of the cracking-resistant intermediate layer, and also of the adhesion promoter layer is from 50 m to 1520 m.

10. A container made of a multilayer composite material with the features of claim 1, where the first structure-providing external layer is an external layer of the container and the second structure-providing external layer is an internal layer of the container.

11. The container as claimed in claim 10 is a fuel container for a motor vehicle.

12. The container as claimed in claim 10, wherein this is composed of two shell-shaped moldings comprising an upper shell and a lower shell.

13. A process for the production of a container made of a multilayer composite material with the features of claim 1, comprising the following steps: provision of semifinished fiber-matrix products as fiber composite material; heating and plastification of the semifinished fiber-matrix products; molding of the semifinished fiber-matrix products to give shell-shaped intermediate products; provision of a multilayer plastified extrudate comprising a structure-providing external layer made of a thermoplastic selected from a group comprising polyethylene, polyamides; polyphenylene sulfides, polybutylene terephthalates, polyketones, polyetheretherketones, liquid-crystal polymers and polyphthalamides and a cracking-resistant intermediate layer; and introduction of the plastic extrudate into the plastified and molded semifinished fiber-matrix product and coherent bonding of the semifinished fiber-matrix product and of the extrudate with utilization of the heat of plastification and/or by an adhesion promoter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The invention is explained below with reference to an embodiment depicted in the drawings.

[0060] FIG. 1 shows a layer structure of a multilayer composite material of a first embodiment of the invention and

[0061] FIG. 2 shows a layer structure of a multilayer composite material of a second embodiment of the invention.

[0062] A layer structure of a multilayer composite material of the invention is depicted by way of example in the attached FIG. 1.

DETAILED DESCRIPTION

[0063] FIG. 1 shows a diagrammatic layer structure of a composite material 1 of the invention comprising a first structure-providing external layer 2 made of a fiber composite material and a second structure-providing external layer 3 made of an HDPE. The layer section depicted in FIG. 1 also shows the wall structure of a container of the invention. The first and second structure-providing external layers 2 and 3 are respectively outermost layers of the container wall, where the first structure-providing external layer 2 forms an external side of the container and the second structure-providing external layer 3 forms an internal side of the container.

[0064] Between the first structure-providing external layer 2 and the second structure-providing external layer 3, the arrangement has first and second intermediate layers 4 and 5, respectively designed as thin films with layer thickness from 50 to 300 m. These layers are correspondingly flexible and are not structure-providing layers for the purposes of the invention. The second intermediate layer 5 is designed as cracking-resistant intermediate layer for the purposes of present invention, whereas the first intermediate layer 4 consists of a barrier plastic.

[0065] The first structure-providing external layer 2 consists of a fiber composite material with continuous-filament fiber embedded in a thermoplastic matrix, and the second structure-providing external layer 3, which forms the internal layer of the container, consists of an HDPE. The first structure-providing external layer 2 and the structure-providing external layer 3 of self-supporting rigid design and respectively have a layer thickness of about 0.5 to 2 mm

[0066] Although the first structure-providing external layer 2 forms the external side of the container, the invention is to be understood as providing the possibility of a protecting coating externally provided to this first structure-providing external layer 2.

[0067] In the embodiment described it is preferable that the first intermediate layer 4 is an EVOH layer (ethylene-vinyl alcohol copolymer), embedded into a first and second adhesion promoter layer 6, 7.

[0068] The second intermediate layer 5 consists by way of example of a polyisobutylene, and is designed as cracking-resistant intermediate layer or film for the purposes of the invention.

[0069] The second intermediate layer 5 has been embedded between the second adhesion promoter layer 7 and a third adhesion promoter layer 8, so that adhesion bonding of the laminate is achieved across the second intermediate layer 5.

[0070] The second intermediate layer 5, as thin, cracking-resistant film, absorbs the deformation fracture energy by way of example when the first structure-providing external layer 2 is exposed to an impact, so that the cracks that form cannot propagate into the first intermediate layer 4 and into the second structure-providing external layer 3.

[0071] FIG. 2 depicts a second embodiment of the invention. Layers corresponding to those of the embodiment of FIG. 1 have the same reference signs in this embodiment. The second embodiment of the invention differs from the first embodiment in that the first structure-providing external layer 2 is itself of multilayer design. This layer consists of a fiber composite material comprising a first fiber layer 9 and a second fiber layer 10 respectively embedded into a matrix material in the form of a thermoplastic or thermoset plastic and separated from one another by an intermediate layer 5 as cracking-resistant intermediate layer. The intermediate layer 5 has adhesive bonding to the fiber layers 9, 10, optionally by way of further adhesion promoter layers.

KEY

[0072] 1 Multilayer composite material [0073] 2 First structure-providing external layer [0074] 3 Second structure-providing external layer [0075] 4 First intermediate layer [0076] 5 Second intermediate layer [0077] 6 First adhesion promoting layer [0078] 7 Second adhesion promoting layer [0079] 8 Third adhesion promoting layer [0080] 9 First fiber layer [0081] 10 Second fiber layer