Near-infrared absorbing composition, near-infrared absorbing film, and image sensor for solid-state imaging element

Abstract

The present invention addresses the problem of providing: a near-infrared absorbing composition having low haze, excellent near-infrared absorptivity, improved dispersion stability (moisture resistance) of a metal complex when there is moisture, and improved thermostability of the metal complex; a near-infrared absorbing film formed using the same; and an image sensor for a solid-state imaging element, said image sensor being equipped with the near-infrared absorbing film. The near-infrared absorbing composition is characterized by containing at least a near-infrared absorbent, a metal compound, and a solvent, wherein the near-infrared absorbent contains metal ions, and the metal compound has a structure represented by general formula (1), general formula (2), or general formula (3). General formula (I): M(OR1)n; general formula (II): M<n+>(O=R2-O<->)n; and general formula (III): (OR3)n-mM<n+>(<->OCOR4)m.

Description

Technical field[0001]The present invention relates to a near-infrared absorbing composition, a near-infrared absorbing film using the same, and an image sensor for a solid-state imaging element. More specifically, it relates to excellent near-infrared absorbing ability and dispersion stability (moisture resistance) when water is mixed. The improved near-infrared absorbing composition, the near-infrared absorbing film using the same, and the image sensor for solid-state imaging devices provided with this near-infrared absorbing film.Background technique[0002]In recent years, CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor) image sensors are used as solid-state image sensors for color images in video cameras, digital cameras, and mobile phones with camera functions. In other words, since a silicon photodiode that is sensitive to light in the near-infrared wavelength region is used in its light-receiving section, it is necessary to correct the visual sensi...

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Problems solved by technology

[0004] In each of the above-mentioned patent documents, in order to improve the quality, the use of a specific solvent as a dispersion medium, the addition of a solubilizing agent, etc., have achieved improvement in storage stability. object, addressing the stability of the copper phosphonate salt after adding a resin component as a binder, but did not mention the stability of the near-infrared-absorbing composition in a state without a binder component, the present inventors As a result of research, it was found that the dispersion stability of the near-infrared-absorbing composition in the stage before the addition of the binder resin has a large influence on the final quality of the near-infrared cut filter

[0005] In addition, there is a problem that aggregation occurs in a film containing a binder even if it is a dispersion liquid that does not contain a binder because moisture enters the copper complex.

In Patent Document 4, an optical filter is disclosed, which includes a near-infrared light absorbing layer containing a phosphate ester having an ethylene oxide structure, a phosphate ester compound having a propylene oxide structure, and copper. However, it has been found that even when such a copper complex is used, the dispersibility of the copper complex and the dispersion stability (moisture resistance) at the time of water mixing are insufficient.

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