Negative photosensitive composition, partition walls for optical device using it and optical device having the partition walls

A negative photosensitive composition, comprising:

• ink repellent (A),
• a photosensitive resin (B) having an acidic group and an ethylenic double bond in one molecule, and
• a photopolymerization initiator (C),
• wherein
• the proportion of the ink repellent (A) is from 0.01 to 10 mass % to the total solid content of the composition,
• ink repellent (A) has a fluorine atom content of from 10 to 55 mass %, and
• said ink repellent (A) comprises a hydrolyzed condensate of at least three hydrolysable silane compounds, the three hydrolysable silane compounds respectively selected from the group consisting of:
• a hydrolysable silane compound (a-1) having an organic group having one C3-10 perfluoroalkyl group which may contain an etheric oxygen atom and three hydrolysable groups bonded to a silicon atom;
• a hydrolysable silane compound (a-2) having p pieces of a hydrocarbon group(s) and (4-p) pieces of hydrolysable groups bonded to a silicon atom, where p is 0, 1, or 2;
• and
• a hydrolysable silane compound (a-3) having q pieces of an organic group(s) having a polymerizable functional group selected from an acryloyl group and a methacryloyl group, r piece of a hydrocarbon group, and (4-q-r) pieces of hydrolysable groups bonded to a silicon atom, where q is 1 or 2, r is 0 or 1, and q+r=1 or 2.