Coating technology for plastic containers
AssigneeIonkraft GmbH
InventorMontgomery JARITZ
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Abstract
Methods for plastic coating by means of plasma-enhanced chemical vapor deposition (PECVD) are described. In particular, the methods described can be used to coat recyclable plastic containers for storing aggressive chemicals with a stable migration barrier. A process and a coating are described. With the process, a coating can be deposited from a process gas mixture of at least one precursor and a reactive gas which is excited to form a plasma. By adjusting the reactive gas content in the process gas mixture and varying the mass-related excitation energy, a gradient coat can be deposited on the plastic substrate to produce a chemically resistant migration barrier.
Claims28
A method for production of a coating for producing a chemically resistant migration barrier on a plastic substrate, in particular a plastic container, by means of plasma-enhanced chemical vapor deposition (PECVD) wherein a process gas mixture is fed into a reaction space;
- and is excited by means of an energy source with an excitation energy to form a plasma, the process gas mixture having an adjustable composition of one or more precursors and/or one or more reactive gases, characterized in that a gradient coat with an adhesion zone, a barrier zone and a passivation zone or a gradient coat with a barrier zone and a passivation zone is deposited on the plastic substrate, wherein the deposition of the gradient coat is controlled by varying a reactive gas content in the process gas mixtures, and wherein the excitation energy is controlled on a mass-related basis as a function of a precursor gas mass flow and a reactive gas mass flow, the mass-related excitation energy being gradually reduced for a deposition of an organically characterized passivation zone on an oxidically characterized barrier zone.
(canceled)
A coating on a plastic substrate for producing a chemically resistant migration barrier, wherein the coating comprises:
- one or more gradient coats, wherein the one or more gradient coats contain organosilicon compounds (SiOxCyHz) which have been deposited from one or more silicon-containing precursors, in particular at least one of siloxanes, silazanes, or silanes, wherein at least one gradient coat comprises:
- at least one oxidically characterized barrier zone;
- and
- an organically characterized passivation zone, wherein a chemical configuration of the at least one gradient coat changes gradually starting from a substrate face of the coating along a layer build-up direction and changes from at least one barrier zone to a passivation zone, wherein a chemical structure of the gradient coat is determined by a structural parameter V measured using Fourier-transform-infrared-spectroscopy (FT-IR):
- V
- =
- (
- A
- +
- B
- +
- E
- )
- /
- (
- C
- +
- D
- )
- A:
- Extinction an W=1376 cm−1
- B:
- Extinction an W=1257 cm−1
- E:
- Extinction an W=839 cm−1
- C:
- Extinction an W=440 cm−1, 1010 cm−1 bis 1035 cm−1, 1070 cm−1
- D:
- Extinction an W=930 cm−1,
- wherein the structural parameter V at its maximum in the passivation zone is V>0.2.
Dependencies are inferred from the claim text.