Messer Griesheim Gmbh

L'air Liquide, Soci&#xe9;t&#xe9; Anonyme Pour L'etude Et L'exploitation Des Proc&#xe9;d&#xe9;s Georges Claude

Mg Industries

Mexxer Griesheim Gmbh

Messer Group Gmbh

Air Liquide Deutschland Gmbh

Rolf Van Bonn

Manfred Eschwey

Horst Neumann

Joachim Barbe

Ludwig Bohm

ManfredNeumann Eschwey

Eckard Raddatz

Rainer Kaps

Siegfried Rödel

The gas-phase fluorination of plastic articles is effected in a reaction chamberinto which the plastic articles to be fluorinated are introduced. The gas-phase fluorination is effected at normal or atmospheric ambient pressure of about 1 kPa in the reaction chamber. The gas-phase fluorination can be carried out statically or dynamically. The flushing carried out before the gas-phase fluorination for complete or partial removal of atmospheric oxygen from the reaction chambercan also be effected at atmospheric pressure in the reaction chamber. The reaction chamberis equipped with a coverand metering valves V, V, Vfor air, inert gas and gas mixture comprising fluorine and one or more inert gases are present on the entrance side of the reaction chamber, which is not vacuum-tight and hence also cannot be evacuated. The metering valves are connected to the reaction chambervia a flow meter. A release valve Vand a flow-through/shut-off valve Vare arranged in an exhaust gas lineof the reaction chamber

Method and apparatus for the fluorination of plastics

The invention relates to a method for the modification of the surface of shaped parts made of plastic by treatment with a gas mixture which comprises fluorine and oxygen. The surface tension of the modified surface of the shaped part is more than 25 mN/m greater than that of a surface comprising non-modified plastic material. The ratio of the partial pressure of fluorine to the partial pressure of oxygen is 1:10 or lower and the shaped part has a fluorine occupancy of less than 0.5 &#x3bc;g/cmas a result of the treatment.

Method for the modification of the surface of shaped parts made of plastic by fluorine-initialized oxidation

Organic substrate surfaces, particularly of industrial polymers, are provided by fluorination or chlorination with corresponding layers so as to obtain certain properties; for the purpose of improving the application of a layer, the surfaces are exposed beforehand at temperatures between 25.degree. C. and 300.degree. C. to hydrogen or a gas containing at least 0.1% by volume of hydrogen.

Process for conditioning organic substrate surfaces

For purposes of producing barrier layers on the surfaces of thermoplastics, the surfaces are exposed to a treatment gas containing fluorine. The barrier layers are effective against mixtures of polar or non-polar substances such as, for instance, fuels containing methanol. In order to improve the barrier effect, the cooled-off treatment gas is left to act upon the surface, whose temperature at the beginning of exposure is kept between 60.degree. C. and 250.degree. C. [140.degree. F. and 482.degree. F.].

Process for the production of barrier layers for admixtures of polar and

Plastic objects are exposed to a gas mixture containing fluorine and a gaseous oxidizing agent, to produce an extremely smooth surface on the objects. The oxidizing agent can be oxygen, and the object is preferably exposed to the gaseous mixture for about 10-30 seconds. The surface of the object treated according to the present invention is found to be considerably more smooth and glossy than objects treated with fluorine alone, without the oxidizing agent. The surface formed according to the present invention therefore minimizes the contact area between the treated object and the surrounding media.

Method for producing smooth surfaces on plastics

A process for blow molding and fluorination of a hollow thermoplastic article includes bringing a blank to rest against the inside wall of the blow mold as a result of introducing an inert blow gas. An inert gas/reaction mixture is then introduced in the hollow article for fluorinating the inside surface of the hollow article. After the inside surface of the hollow article has cooled off, the inert gas/reaction gas mixture is blown in below the melting point of the thermoplastic material.

Process for the production of fluorinated surfaces of polymers

A process for preparing fluoridated surfaces of polymers includes exposing the surfaces for a period of time to the influence of a fluorine containing a treatment gas of defininte proportion for forming fluoridated hydrocarbons. A small portion of the treatment gas is drawn off during the exposure period and channeled via an activated aluminum oxide contact for carrying out the reaction Al.sub.2 O.sub.3 +3F.sub.2 .fwdarw.2AlF.sub.3 +3/20.sub.2 to determine the fluorine concentration in the residual gas by means of quantitative determination of the released oxygen and therewith the degree of fluorine coating of the surface.

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Duisburg, Germany

Rolf Van Bonn