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US4929319A Expired / Lapsed US ⏱️ 0.0 years remaining

Process and device for surface pre-treatment of plastic by means of an electrical corona discharge

Assignee: Hoechst AG
•
Filing: 1988-02-17
•
Granted: 1990-05-29
•
Expires: 2008-02-17
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Abstract

Abstract For surface pre-treatment of a plastic article, such as a film sheet or the interior of a plastic molded article, by means of electrical corona-discharge, a device is provided having a generator 5 and a corona discharge device 11. The generator applied a high-frequency, high-voltage alternating current to the discharge electrodes 4 of the corona-discharge device 11. The grounded counterelectrode used is the metal core 2 of a roller 10 over whose peripheral coating 3 a film sheet 1 is transported. A housing 6 encompasses the electrodes 4 of the corona-discharge device 11 and is connected via a line 7 to an atomizer 8 in which a liquid is atomized to form an aerosol by means of a piezoelectrically operating ultrasonic vibration system or by two-component atomizer nozzles which operate at ultrasonic speed. A fan 9, the throughput rate of which can be regulated, is connected to the atomizer 8 and pushes the carrier gas, for example, air, for the aerosol through the atomizer into the corona-discharge device 11. Further corona-discharge devices can be present into which an aerosol of another liquid or only a reactive gas are fed.

Inventors

  • 👤 Peter Dinter
  • 👤 Lothar Bothe
  • 👤 John D. Gribbin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 21:15
CPC Classifications
B; B29; B29C; B29C59/00; B29C59/10; B29C59/12; B29C59/103; B29C71/00; B29C71/04; H; H01; H01T; H01T19/00; H01T19/04

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 68 words
A process for corona-discharge surface pre-treatment of plastic, comprising the steps of: producing an electrical corona discharge in a corona-discharge zone between at least one voltage-conducting electrode and a grounded counter-electrode; placing a plastic article in the corona-discharge zone onto the surface of said grounded counter-electrode; atomizing a liquid to produce an aerosol; and introducing the aerosol into the corona-discharge zone by means of a stream of gas.
Claim 2
Dependent Claim 68 words
A process for corona-discharge surface pre-treatment of plastic, comprising the steps of: producing an electrical corona discharge in a corona-discharge zone between at least one voltage-conducting electrode and a grounded counter-electrode; placing a plastic article in the corona-discharge zone onto the surface of said grounded counter-electrode; atomizing a liquid to produce an aerosol; and introducing the aerosol into the corona-discharge zone by means of a stream of gas.
Claim 3
Dependent Claim 24 words
A process as claimed in claim 1, further comprising the step of surface-activating the plastic article in a preliminary step by a corona discharge.
Claim 4
Dependent Claim 36 words
A process as claimed in claim 1, comprising the steps of subjecting the plastic article to at least two corona discharges in sequence, each of the corona discharges being carried out in a different aerosol atmosphere.
Claim 5
Dependent Claim 22 words
A process at claimed in claim 1, wherein the gas comprises a carrier gas comprising air, a noble gas or mixtures thereof.
Claim 6
Dependent Claim 31 words
A process as claimed in claim 1, wherein said aerosols comprise monomers, dispersions or solutions of low- and/or high-molecular-weight polymer compounds and/or colloidal systems in aqueous form or dissolved in solvents.
Claim 7
Dependent Claim 41 words
A process as claimed in claim 1, comprising the steps of treating the surfaces of two plastic articles, independently of one another, by said steps in two different aerosol atmospheres, and thereafter bringing the treated surfaces into contact with one another.
Claim 8
Dependent Claim 50 words
A process as claimed in claim 1, wherein the plastic article comprises an extruded plastic melt film which is applied in air-free form to a base, wherein said corona discharge is produced by means of an alternating current, and wherein said aerosol is produced by ultrasound atomization of a liquid.
Claim 9
Dependent Claim 41 words
A process as claimed in claim 1, further comprising the step of warming the plastic article, the liquid to be atomized to form the aerosol and the gas used for aerosol transport to a temperature between about 20° and 95° C.
Claim 10
Dependent Claim 25 words
A process as claimed in claim 8, wherein the plastic article comprises a film sheet having an outside surface to which the aerosol is applied.
Claim 11
Dependent Claim 35 words
A process as claimed in claim 9, wherein the surface resistance of the outside surface of the film sheet to which the aerosol has been applied is between 10 8 and 10 9 ohm.sup.. m.
Claim 12
Dependent Claim 25 words
A process as claimed in claim 1, wherein the plastic article comprises a hollow container having an inside surface to which the aerosol is applied.

References Cited (Backward Citations)

US3142630A Cited
GB938325A Cited
DE1284620B Cited
US3274089A Cited
GB1095837A Cited
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EP0160889A2 Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-05-28 1993-11-27 1994-05-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-05-28 1997-11-27 1998-05-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-05-28 2001-11-27 2002-05-29 $7700.00 Window Closed / Lapsed

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