摘要 |
<p>A method of providing the surface area of a substrate with a first zone which is solvent-wettable and a second zone which is solvent-non-wettable, and which is particularly suitable for application to the printheads and nozzle plates of drop-on-demand ink jet printers or like products where the spacing between zones of the same kind can be as little as just tens of microns, and wherein the solvent-non-wettable zone displays excellent abrasion resistance and resistance to solvents, is virtually non-wettable by a wide range of solvents and bonds well even to plastics substrates, comprises: (i) providing a surface having good solvent wettability at least over that part of the area of the substrate (2) which is to form said first zone; (ii) providing said area with a first layer (4) which comprises siloxic material which bonds to the substrate (2) and which is in contact with the substrate (2) over at least that part of the area which is to form said second zone; (iii) providing said area with an overlayer (8) comprising organic fluorocompound which bonds to said first layer (4) and provides a surface of poor solvent wettability, said overlayer (8) being in contact with said first layer (4) over at least that part of the area which is to form said second zone; and (iv) by etching or washing, removing overlying material from said surface having good solvent wettability over that part of the area which is to form said first zone whereby to expose said surface. h</p> |