Blow moulded containers and moulded parts consisting of synthetic material and having improved antistatic properties

• US 20030021926A1
• Filed: 09/16/2002
• Published: 01/30/2003
• Est. Priority Date: 03/16/2000
• Status: Active Grant

• Current Assignee: Basell Polyolefine GmbH (Lyondellbasell Industries NV)
• Original Assignee: Basell Polyolefine GmbH (Lyondellbasell Industries NV)
• Inventors: Rohde, Wolfgang, Haufe, Andreas, Springholz, Bernhard
• Granted Patent: US 6,855,388 B2
• Time in Patent Office: Days
• US Class Current: 428/36.1
• CPC Class Codes: B29C 2949/074 having ribs or protrusions
• CPC Class Codes: B29C 2949/0741 longitudinal, e.g. from top to bottom
• CPC Class Codes: B29C 49/04 Extrusion blow-moulding
• CPC Class Codes: B29K 2995/0013 Conductive
• CPC Class Codes: B60K 2015/03401 for preventing electrostatic charges
• CPC Class Codes: B65D 25/385 with means for preventing inflammation or explosion during discharging of inflammable or explosive substances from containers, e.g. from petroleum cans
• CPC Class Codes: B65D 90/46 Arrangements for carrying off, or preventing the formation of electrostatic charges carrying-off, or preventing the formation of electrostatic charges in general H05F
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1362 Textile, fabric, cloth, or pile containing [e.g., web, net, woven, knitted, mesh, nonwoven, matted, etc.]
• CPC Class Codes: Y10T 428/24124 Fibers
• CPC Class Codes: Y10T 428/24174 including sheet or component perpendicular to plane of web or sheet
• CPC Class Codes: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix
• CPC Class Codes: Y10T 428/249942 Fibers are aligned substantially parallel
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers

Abstract

The present invention relates to plastic containers or mouldings which have been produced by blow moulding and have improved antistatic properties. The containers or mouldings have an outer wall and an inner wall and contain webs of electrically conducting material running along the inner wall. The invention also relates to a process for the production of the containers or mouldings and to their use.

Claims

1. Plastic containers or mouldings which have been produced by blow moulding and have improved antistatic properties, characterized in that the containers or mouldings have an outer wall and an inner wall, and in that the containers or mouldings contain webs of electrically conductive material running along the inner wall.

2. Containers or mouldings according to claim 1, characterized in that they contain, as electrically conducting materials, materials which have a specific electrical volume resistance of at most 10⁶ Ω

·

cm, preferably at most 10⁵ Ω

·

cm.

3. Containers or mouldings according to claim 1 or 2, characterized in that they contain, as electrically conducting materials, metals or intrinsically non-conducting plastics which are filled with metal turnings or metal filaments or carbon fibres or conductive carbon black in sufficient amount or intrinsically electrically conducting plastics, such as substituted polythiophenes or other polymers having conjugated double bonds.

4. Containers or mouldings according to one of claims 1 to 3, characterized in that the webs are arranged on the inner wall of the containers or mouldings crosswise in the form of networks or in parallel, where the maximum separation between the individual parallel webs is 20 mm, preferably at most 15 mm.

5. Containers or mouldings according to one of claims 1 to 4, characterized in that, in the case of crosswise running of the webs, the maximum coherent, non-electrically conducting grid area does not exceed a size of 100 cm², preferably 80 cm².

6. Containers or mouldings according to one of claims 1 to 5, characterized in that the total area of the inner wall of the containers or mouldings which is covered by the webs of electrically conducting material is at least 10%, preferably at least 20%, based on the total area of the inner wall.

7. Containers or mouldings according to one of claims 1 to 6, characterized in that the plastics employed are polyolefins obtained by polymerization of monomers having from 2 to 10 carbon atoms, where the polymerization can be carried out by the gas-phase process, in high-pressure reactors, in loop reactors or by the slurry process in the presence of suitable polymerization catalysts, preferably polyethylene.

8. Process for the production of containers or mouldings according to one of claims 1 to 7, in which the plastic is firstly melted in an extruder, then discharged in the molten state into a blow mould to give a parison, and then inflated by compressed air and cooled, characterized in that the webs of electrically conducting material are applied directly to the inner wall of the parison during discharge of the plastic melt from the extruder into the blow mould in a modified coextrusion process and are inflated together with the parison to form the finished container or moulding.

9. Process according to claim 8, characterized in that the position of the webs in the extrusion direction and at the periphery of the moulding is controlled in such a way that the webs do not run through pinch-off welds or meet one another in pinch-off welds.

10. Use of containers or mouldings according to one of claims 1 to 7 for antistatically finished containers, such as bottles, canisters, drums, IBCs, or industrial mouldings, such as fuel canisters made of plastic or fill necks for fuel tanks in motor vehicles.