Films scratch resistance

The resulting films are usually hard and scratch-resistant but often show considerable stress (152). Such films can be used as corrosion-resistant coatings on metals or as membranes in gas sensor devices (153,154)... 

Sputtering i s presently the maj or thin-film process for the production of deicing coatings. The coating is satisfactory from an optical standpoint although transmission could still be improved, but it has poor scratch resistance and must be sandwiched between the two layers of safety glass. The CVD oxides films shown in Table 16.1 are particularly attractive since they are inherently abrasion resistant and could be used on the outer surface of the glass. 

Each method and application requires specific formulation with specific properties, such as solids content, density, viscosity, color, finished film thickness, scratch resistance, gloss, etc. An example of a UV curable formulation is in Table 7.1. 

The data obtained clearly demonstrate that the scratch resistance of polyacrylate coating materials can be strongly enhanced by incorporation of methacryloyloxymethylsilanes (the reasons for the low value of gloss retention observed for 3c are not yet fully understood). As an additional benefit, the cured clearcoats revealed an extremely high chemical resistance no change in the films were observed after a 500 h exposure to 30% aq. H2SO4 test or after 100 cycles in the MEK rub test [4]. 

Diamond-like carbon since its inception in 1962 has found applications in some very important areas. These applications include coatings used in scratch-resistant optics, razor blades, prosthesis in medical applications electron emission surfaces in electronics as an insulator material for copper heat sinks in semiconductors such as solar cells and sensors for visible to infrared radiations and as structural materials such as deuterated DLC film used for neutron storage in advanced research instrumentation. As technology matures the unique properties of DLC will find new and important applications. 

In plastics, the addition of talc improves their heat distortion temperature, dimensional stability, scratch resistance, impact resistance, and reduces the process cycle due to nucleation. Other important properties include high brightness, blocking of infrared in agricultural film, anti-blocking properties, and low absorption of packaged components. 

Owing to remarkable mechanical properties Hke great hardness, scratch resistance and a low frictional coefficient in combination with a high tolerance for aggressive environmental conditions, diamond-coated objects have been developed soon after the first preparation of diamond films. Today the respective products are employed in many technical apphcations. 

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