Photosensitive resin composition, ink jet head using photosensitive resin composition, and process for manufacturing ink jet head

A process for manufacturing an ink jet head comprising a discharge port for discharging an ink, an ink flow path communicated with said discharge port, and a substrate provided with an energy generating element for generating energy for discharging ink from the discharge port, characterized in that the process comprises:

• providing a precursor comprising a first photosensitive resin layer laminated by a second photosensitive resin layer on said substrate, the second photosensitive resin layer including a composition comprising (a) a polyacrylate resin having structural unit represented by the following general formula (1), wherein the first photosensitive resin layer is positioned on the side of the substrate
• wherein, X represents a hydroxyl group or a methylolamino group;
• R1 and R2 independently represent a hydrogen atom, or an alkyl group having 1 to 3 carbon atoms;
• R3 represents an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, or an aralkyl group having an aryl group or alkyl group with 1 to 2 carbon atoms;
• n represents a positive integer;
• and m represents 0 or a positive integer, and (b) a compound represented by the following general formula (2)
• wherein R1 to R6 independently represents a hydrogen atom, a methylol group, or an alkoxymethyl group to which an alkoxy group having 1 to 4 carbon atoms is bonded;
• provided that, at least two of R1 to R6 represent methylol groups, or alkoxymethyl groups to which an alkoxy group having 1 to 4 carbon atoms is bonded;
• patterning, by a photolithographic process, said second photosensitive resin layer to form a second ink flow path pattern which has a shape of a portion of the ink flow path;
• patterning said first photosensitive resin layer to form a first ink flow path pattern which has a shape of another portion of the ink flow path;
• providing a coating resin layer for forming the wall of the ink flow path on said first ink flow path pattern and the second flow path pattern;
• forming an ink discharge port in the coating resin layer;
• and
• removing the first ink flow path pattern and the second ink flow path pattern to form the ink flow path.