Patent ID: 11873385
Assignee: NIPPON SHEET GLASS COMPANY, LIMITED
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C  G | IPC C  G

Claim 0:
1. An infrared-cut filter comprising:
a first infrared-absorbing layer comprising:
a compound including a copper ion and a phosphonic acid represented by the following formula (a); and at least one phosphoric acid ester selected from the group consisting of phosphoric acid esters represented by the following formulae (b1) and (b2), wherein
a first molar ratio of a content of phosphorus to a content of copper is within a range of 1.22 to 1.53,
a second molar ratio of a content of the phosphonic acid to a content of the phosphoric acid esters is 0.85 or more and less than 2.50, and
a third molar ratio of a content of the phosphonic acid to a content of copper is within a range of 0.45 to 0.9,, wherein R1 is an alkyl group with 2 to 4 carbon atoms, R21, R22 and R3 are each a monovalent functional group represented by —(CH2CH2O)nR4, n is an integer of 1 to 25, R4 is an alkyl group with 6 to 25 carbon atoms, and R21, R22 and R3 are same or different functional group.