Composition for reflective film, reflective film, and X-ray detector
Provided is a composition for reflective film comprising a polyvinyl acetal resin, an epoxidized vegetable oil, a solvent, a coupling agent and titanium oxide.
1. An X-ray detector comprising:
a substrate;
a photoelectric conversion element which is formed on the substrate and which converts incident light to signal charges;
a scintillator layer which is formed on the photoelectric conversion element and which converts incident X-ray to fluorescence; and
a reflective film which is formed on the scintillator layer using a composition for reflective film, and which reflects the fluorescence radiated from the scintillator layer,
wherein the composition comprises a polyvinyl acetal resin; an epoxidized vegetable oil; a solvent; a silane coupling agent; and titanium oxide in an amount of at least 50% by weight of the total solids content, the solids content being components of the composition except the solvent.
2. The X-ray detector according to claim 1 , wherein the epoxidized vegetable oil is an epoxidized linseed oil.
3. The X-ray detector according to claim 2 , wherein the epoxidized linseed oil has an oxirane oxygen concentration of 5% or greater.
4. The X-ray detector according to claim 2 , wherein the epoxidized linseed oil is present in an amount of 0.5% to 30% by weight of the total solids content.
5. The X-ray detector according to claim 1 , wherein the polyvinyl acetal resin is a polyvinyl butyral resin.
6. The X-ray detector according to claim 5 , wherein the weight average molecular weight of the polyvinyl butyral resin is equal to or more than 3×10 4 .
7. The X-ray detector according to claim 1 , wherein the coupling agent is an epoxysilane.
8. The X-ray detector according to claim 7 , wherein the epoxysilane coupling agent is at least one of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidyloxypropyl(dimethoxy)methylsilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, and diethoxy(3-glycidyloxypropyl)methylsilane.
9. The X-ray detector according to claim 1 , wherein the average particle size of the titanium oxide is equal to or less than 5 μm.
10. The X-ray detector according to claim 1 , wherein the titanium oxide has a rutile crystal structure.
11. The X-ray detector according to claim 1 , wherein the titanium oxide is present in an amount of 50% to 98% by weight of the total solids content.
12. The X-ray detector according to claim 1 , wherein the titanium oxide is present in an amount of 70% to 98% by weight of the total solids content.
13. The X-ray detector according to claim 1 , wherein the solvent is at least one of cyclohexanone, methylcyclohexanone, toluene, and xylene.
14. The X-ray detector according to claim 1 , wherein the polyvinyl acetal resin is present in an amount of 5% to 30% by weight of the total solids content.