Abstract: An inkjet ink is provided, which includes a solvent and a pigment having an average particle diameter of not larger than 250 nm. The number of flocculates of pigment particles having a diameter of 1 ?m or more is 1.6×108/cm3 or less.

Abstract: It is made possible to improve a recording density by leaps and bounds. An information recording and reproducing apparatus includes: a control portion including a record-erase circuit which causes electrons to be emitted from the electron emission end to a recording portion on a recording medium by applying a first voltage to the first electrode in a state in which a second voltage is applied to the second electrode at time of information recording or erasing, and a reproducing circuit which causes a reproducing current to flow from the electron emission end to the recording portion on the recording medium by applying a third voltage which is lower than the first voltage to the first electrode in a state in which the second voltage is applied to the second electrode at time of reproducing, the control portion detecting an electric resistance change caused by a change in a recording state in the recording portion.

Abstract: An inkjet ink is provided, which includes a solvent and a pigment having an average particle diameter of not larger than 250 nm. The number of flocculates of pigment particles having a diameter of 1 ?m or more is 1.6×108/cm3 or less.

Abstract: There is disclosed an ink for ink jet recording, comprising a photo-acid generating agent which is capable of generating an acid as it is irradiated with light, a colorant, and an acid-polymerizable solvent which can be polymerized in the presence of an acid. In this ink, the content of the photo-acid generating agent is not less than 2.5 [5] parts by weight per 100 parts by weight of the acid-polymerizable solvent, and the acid-polymerizable solvent comprises an aliphatic epoxy compound represented by the following general formula (1) and an oxetane ring-containing compound: R1-CH2—C CH3)2—CH2—R1 ??(1) (wherein R1 is glycidyl ether group).

Abstract: A photosensitive composition for forming a pattern through a light-exposure with either one of ArF excimer laser and F.sub.2 excimer laser, which comprises a compound having either an acid-decomposable or acid-crosslinkable group, and a compound represented by the following general formula (1): ##STR1## wherein Ar.sup.1 and Ar.sup.2 are individually an aromatic ring or condensed aromatic ring, R.sup.1 and R.sup.2 are individually halogen atoms or monovalent organic group, X is a group selected from the group consisting of CF.sub.3 SO.sub.3, CH.sub.3 SO.sub.3, CF.sub.3 COOH, ClO.sub.4, SbF.sub.6 and AsF.sub.6, Z is a group selected from the group consisting of Cl, Br, I, S--R and Se--R (R is an alkyl group having 1 to 10 carbon atoms or perfluoroalkyl group having 1 to 10 carbon atoms), and m and n are 0 or a positive integer.