Helmets are used for personal protection, used when driving a motorbike, when doing sports like skiing, or by the police or soldiers if on (heavy) duty. Self-evident, the helmets have a transparent sections for visibility. Generally, the transparent section is pivotable connected to the helmet, as to allow it to be turned away from before the face. If turned away, a human has a completely free view. The transparent section often is called a visor. Visors in time have become sophisticated, having a plurality of layers, that may be detachable. Also, the visor may be treated on sides, for example to prevent fogging on the inside of helmets visor. Visors have become lightweight, but yet double- or multi-layered, as for example described in WO

2009/040581 , WO 2008/096178 or WO 2008/075953. Visors are equally used in ski-goggles and the like, which may not take the form of a helmet.

With respect to the characteristic of being repellent to water or snow at the outside of the visor, several options have been suggested. For example, it has been proposed to apply a layer of siliconpolymer to increase the hydrophobicity character, as for example described in EP 264821. WO 2009/1 13978 suggests to apply a coating of perfluorocarbosilane to render a glass surface water repellent. These suggested measures to render the outside part of the visor water- repellent generally are not at all scratch resistant. Also the inside of the visor, which is often rendered fog resistant with a coating, could be improved with respect to ease of application and wear resistance.

The invention relates to a visor with a water repelling layer that has improved scratch resistance. According to the invention, the visor is provided with a plastic film of a polyfluorinated polyolefin.

The invention furthermore relates to the use of a polyfluorinated polyolefin film on a visor for a helmet to prevent or lower the adherence of water, snow or ice to the surface of the visor. The use of such polyfluorinated polyolefin film on a visor may also be advantageous because of an easy manner that such a film can be applied. Further, the film may have improved strength with respect to the prior art solutions.

The present invention provides a surface treatment whereby water, snow or ice cannot adhere anymore (or at least substantially reduced) to the visor by making the surface extremely hydrophobic. As far as some residual adhesion is present, the layer of ice and/or frozen snow can be easily wiped away with for example a hand, cloth or glove, without damaging the film. If, after some time the film may become scratched or damaged, it is possible to remove the old film, and attach a new film to the surface of the visor.

A further advantage is, that rain is blown away from the visor when a motor drives at a speed of about 20-30 km/hr or more, or when a sportsman or -woman has such velocity. Hence, vision is improved. Police or soldiers can - as far as necessary - wipe the visor with a glove without damaging the layer.

In a preferred embodiment, a film of fluorinated polymer is applied on the outside of the visor.

In another preferred embodiment, the film is applied to the inside of the inner part of the visor, as that allows more easy cleaning on the inside of the visor, and it may prevent fogging.

The film has high transparency, in order to assure that the transparency of the visor is not or barely affected. The transparency preferably is about 95% or more for the visible wave length of 400-800 nm. Preferably, the transparency is about 97% or higher, like for example 98% or higher.

The most appropriate fluorinated materials are Dupont's Teflon FEP and Teflon PFA films.

Teflon® FEP is a fluorinated ethylene propylene resin that meets the ASTM Standard

Specification for FEP— Fluorocarbon Molding and Extrusion Materials under ASTM Designation D21 16-95a. It is available as pellets or as stabilized aqueous dispersions. Applications for this family of resins include coating, melt extrusion, and impregnating. Products made from Teflon® FEP are known for their excellent chemical resistance, superior electrical properties, and high service temperatures of up to 200 °C (392 °F). In addition, Teflon® FEP provides outstanding low-temperature toughness and unique flame resistance.

Teflon® PFA is a perfluoroalkoxy copolymer resin available in pellet or powder. Teflon® PFA combines the processing ease of conventional thermoplastic resins with the excellent properties of Teflon® polytetrafluoroethylene (PTFE). Products manufactured from Teflon® PFA can offer continuous service temperatures up to 260 °C (500 °F). What's more, Teflon® PFA provides superior creep resistance at high temperatures, excellent low-temperature toughness, and exceptional flame resistance.

Teflon® PFA or FEP fluoropolymer resins are processed by conventional melt-extrusion techniques and by injection, compression, rotational, transfer, and blow-molding processes. The high melt strength and heat stability of these resins permit the use of relatively large die openings and ig -temperature draw-down techniques, which increase processing rates.

Reciprocating screw injection molding machines are recommended. Corrosion-resistant metals should be used in contact with the molten resin. Long extruder barrels, relative to diameter, are used to provide residence time for heating the resin to 316° to 427^ (600° to 800 °F).

More specific one can apply a Teflon® FEP or PFA foils, which have a self adhesive site. These foils can be easily applied on a visor and have a transparency of >98%. The surface thus obtained is highly water repellent. As a result the surface will not keep water drops attached that may hamper visibility. Snow which would tend to adhere to the visor is easily wiped of without damaging the layer.

Teflon ® FEP or PFA films are commercially available, for example from Dupont. Films of FEP are preferred, because they are cheaper. The commercial available FEP or PFA films generally have a thickness of between about 25 micron and 250 micron, but this is not very critical. Suitable thicknesses are values 50 and 150 micron.

In one embodiment, it is preferred to cover the whole of the visor with the plastic film. However, this is not necessary. Hence, it can be preferable, to adhere the film to e.g. between 95 and 60% of the visor. The film would be placed in the middle of the visor, leaving a strip of uncovered visor at the edges of the visor.

In another embodiment of the invention, the film is applied on the inside of the visor. In particular in cold climates, also the inside can become iced, and a visor provided with a film on the inside allows easy wiping away of any material adhered to the visor.

Example 1 On the surface of a visor of a motor helmet, a FEP foil was applied. When using this helmet in the rain when driving a motorbike, the visor remained clean even at low speed. The visor did not showed wear, even after a month of use, while regularly polishing the outside of the visor with cloth. Also, wiping with a glove did not detoriate the film layer.

Example 2

The visor of ski goggles were provided with PFA foil. When using these goggles in the rainy snow, no snow or water adhered to the outside of the goggles. In an comparable way, motorbike goggles were used in a roug -terrain race. During the race, the goggles remained clearer than without the layer. Further, even when wiped with paper, the anti-adherence layer was not damaged.