Negative type photosensitive composition curable at low temperature
To provide a negative type photosensitive composition curable at a low temperature and capable of forming a cured film excellent in transparency, in chemical resistance and in environmental durability, and also to provide a pattern-formation method employing the composition. [Means] The present invention provides a negative type photosensitive composition comprising: an alkali-soluble resin, a compound having two or more (meth)acryloyloxy groups, a polysiloxane, a polymerization initiator, and a solvent. The alkali-soluble resin is a polymer comprising a carboxyl-containing polymerization unit and an alkoxysilyl-containing polymerization unit.
1. A negative type photosensitive composition comprising:
an alkali-soluble resin which is a polymer comprising a carboxyl-containing polymerization unit, a hydroxyl-containing polymerization unit and an alkoxysilyl-containing polymerization unit,
a compound having two or more (meth)acryloyloxy groups,
a polysiloxane,
a polymerization initiator, and
a solvent and
wherein said hydroxyl-containing polymerization unit is selected from the group consisting of polyethylene glycol derivative; a polypropylene glycol derivative; an oxyalkylene-modified monomer and glycerol (meth)acrylate.
2. The composition according to claim 1 , wherein said carboxyl-containing polymerization unit is derived from an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof.
3. The composition according to claim 1 , wherein said alkoxysilyl-containing polymerization unit is derived from a monomer represented by the following formula (I):
X—(CH 2 ) a —Si(OR) b (CH 3 ) 3-b
in which
X is vinyl, styryl, or (meth)acryloyloxy group,
R is methyl or ethyl group,
a is an integer of 0 to 3, and
b is an integer of 1 to 3.
4. The composition according to claim 1 , wherein said alkali-soluble resin has a weight average molecular weight of 3000 to 50000.
5. The composition according to claim 1 , wherein said polysiloxane has a weight average molecular weight of 1200 to 5000.
6. The composition according to claim 1 , wherein said compound having two or more (meth)acryloyloxy groups is contained in an amount of 3 to 50 weight parts based on 100 weight parts in total of said alkali-soluble resin and said polysiloxane.
7. The composition according to claim 1 , wherein said polymerization initiator is a photo-radical generator.
8. A cured film-producing method, comprising the steps of:
coating a substrate with the composition according to claim 1 , to form a coating film, exposing the coating film to light, and then
developing the exposed coating film.
9. The cured film-producing method according to claim 8 , which further comprises the step of heating to cure the coating film at a temperature of 70 to 360° C. after developing.
10. A cured film formed from the composition according to claim 1 .
11. A device comprising the cured film according to claim 10 .
12. The composition according to claim 1 , wherein said alkali-soluble resin, the content of said hydroxyl-containing polymerization unit in the polymer is 3 wt % or more and 40 wt % or less.
13. The composition according to claim 1 , wherein said hydroxyl-containing polymerization unit is selected from the group consisting of diethylene glycol (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, poly(ethylene glycol-polypropylene glycol) mono(meth)acrylate, poly(ethylene glycol-tetramethylene glycol) mono(meth)acrylate, or poly(polypropylene glycol-tetramethylene glycol) mono(meth)acrylate and glycerol (meth)acrylate.
14. The composition according to claim 12 , wherein said hydroxyl-containing polymerization unit is selected from the group consisting of diethylene glycol (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, poly(ethylene glycol-polypropylene glycol) mono(meth)acrylate, poly(ethylene glycol-tetramethylene glycol) mono(meth)acrylate, or poly(polypropylene glycol-tetramethylene glycol) mono(meth)acrylate and glycerol (meth)acrylate.
15. The composition according to claim 1 , wherein the polysiloxane has a dissolution rate in a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution is 50 to 5000 Å/second for a thickness of 0.1 to 10 μm.