Oleophobic polyolefin fiber materials

A fabric composed of polyolefin fiber, obtainable by a process comprising the following steps a) to c) of

• a) treating an untreated textile fabric consisting of polyolefin fiber to an extent in the range from 90% to 100% by weight in a plasma under such conditions that, after step a) has been carried out, the fabric has a surface tension in the range from 35 to 60 mN/m,
• b) treating the fabric obtained after step a) with a polyorganosiloxane containing R3Si—O— units as end groups and, within the polyorganosiloxane chain, units of the formula (I)
• —Si(R)2—O— (I)
• and units of the formula (II)
• —Si(R)(X)—O— (II)
• where
• each R is independently CH3, CH2—CH3 or phenyl, and
• each X is a radical of the formula (III)
• where t is from 1 to 4, z is from 5 to 60,
• in each unit of the formula
• —O—CHR1—CHR2—
• one of R1 and R2 is H and the other is H or CH3 and every R3 present is H or is R,
• c) treating the fabric with a polymer containing perfluoroalkyl (RF) groups, this polymer being a polyacrylic polymer having RF groups or a polyurethane having RF groups or a mixture of such polymers,
• this step c) being carried out concurrently with step b) or later than step b).