Method for forming pattern, and optical element
There is provided a method for forming a pattern comprising two regions of different refractive indices easily, that is, a method comprising the steps of forming a pattern having a water-shedding oil-shedding region by use of a radiation sensitive resin composition and coating the pattern with a high refractive index resin solution using a solvent having low wettability to the water-shedding oil-shedding region so as to form two regions of different refractive indices.
1. A method for forming a pattern having two regions of different refractive indices which comprises the steps of:
(1) coating a substrate with a radiation sensitive resin composition, to form a coating film;
(2) exposing a portion of the coating film to radiation to form an exposed coating film;
(3) developing the exposed coating film to form a pattern comprising a first coating film region and a non-coating film region; and
(4) coating the pattern with a resin solution prepared by dissolving a resin having a higher refractive index than that of the first coating film region in a solvent having low wettability to the first coating film region, thereby converting the non-coating film region into a second coating film region, to form two different refractive index regions which are the first coating film region and the second coating film region,
wherein said resin having a higher refractive index than that of the first coating film region is selected from the group consisting of acrylic resin, urethane resin, polyester resin, polycarbonate resin, norbornene resin, styrene resin, polyether resin, silicon resin, polyamide resin, polyimide resin, polysiloxane resin, fluorine resin, polybutadiene resin, vinyl ether resin, and vinyl ester resin.
2. The method of claim 1 , wherein the refractive index of the first coating film region is 1.5 or lower, and the refractive index of the second coating film region is from 1.6 to 1.71.
3. The method of claim 1 , wherein the solvent of the resin solution has a contact angle to the first coating film region of 30° or larger.