Positive type photosensitive composition

A positive type photosensitive composition which comprises a support, and a recording layer provided thereon containing a polymer soluble in an alkaline developer, a compound represented by the formula (I):

• ##STR24## wherein R.sub.1 and R.sub.5 may be the same or different from each other and each represent an alkyl group;
• R.sub.2 and R.sub.4 may be the same or different from each other and each represent --COOR' group, --COR' group or --CN group where R' represents an alkyl group, an aralkyl group or an aryl group;
• and R.sub.3 represents an alkyl group, an alkenyl group, an aralkyl group, an aralkenyl group, an aryl group or an aromatic heterocyclic residue,
• and a near infrared rays-absorbing dye,
• wherein, by irradiating near infrared rays to said recording layer, a solubility in the developer at a portion to which near infrared rays are irradiated is increased than a solubility in the developer at a portion to which no near infrared rays is irradiated, and
• wherein said near infrared rays-absorbing dye is a cyanine dye represented by the formula (X):
• ##STR25## wherein R.sub.24 represents a hydrogen atom, a halogen atom, an alkyl group or a diphenylamino group;
• R.sub.25 and R.sub.26 may be the same or different from each other and each represent an alkyl group, an alkoxyalkyl group, an acyloxyalkyl group or a sulfoalkyl group;
• R.sub.27 and R.sub.28 may be the same or different from each other end each represent a hydrogen atom, a halogen atom, an alkoxy group or a phenyl group, and when R.sub.27 or R.sub.28 represents a phenyl group, it may be fused with the phenyl group of the dye skeleton to form a naphthalene ring;
• Z.sub.1 is a substituent on carbon atoms of the dye skeleton, and represents a divalent hydrocarbon group forming a cyclohexene ring or a cyclopentene ring with the carbon atoms of the dye skeleton, or independent two substituents selected from a hydrogen atom and an alkyl group;
• X.sub.1 and X.sub.2 may be the same or different from each other and each represent a sulfur atom, a methylene group which may have one or two substituents, or an unsubstituted vinylene group, and the substituent(s) of the methylene group is selected from an alkyl group having 1 to 6 carbon atoms or a hydrocarbon residue which forms a spiro ring having 3 to 6 carbon atoms;
• Y.sup.- represents a pair anion of the dye, but when R.sub.25 and R.sub.26 both represent sulfoalkyl groups, the dye itself becomes a neutral molecule so that it is not necessary.