Provided are a curable composition including a sail compound having a) an organic anion in which, in Hansen, solubility parameter, d is 16 or more, p is 16 or more and 32 or less, and H is 60% or less of p and b) a counter cation, a lithographic printing plate precursor having an image-recording layer containing the curable composition, a method for producing a lithographic printing plate using the lithographic printing plate precursor, and a compound that is used in the image-recording layer in the lithographic printing plate precursor.

A polymerizable composition is provided, including an infrared absorber, a polymerization initiator, a polymerizable compound, and a polymer binder, wherein the polymer binder is a particulate random copolymer, and the polymer binder has structural units derived from a polymerizable polyalkylene oxide-based monomer and a polymerizable nitrogen-free non-polyalkylene oxide-based monomer. The polymerizable composition may be used in the production of imageable elements or printing plates.

Provided are a lithographic printing plate precursor including a hydrophilized aluminum support, and a water-soluble or water-dispersible negative type image recording layer provided on the aluminum support, in which an arithmetic average height Sa of a surface of an outermost layer on a side where the image recording layer is provided is in a range of 0.3 m to 20 m or in which Expression (1) and Expression (2) are satisfied in a case where a Bekk smoothness of a surface of an outermost layer on a side where the image recording layer is provided is set as a seconds and a Bekk smoothness of a surface of an outermost layer on a side opposite to a side where the image recording layer is provided is set as b seconds; a method of producing the same; a lithographic printing plate precursor laminate formed of the lithographic printing plate precursor; a plate-making method for a lithographic printing plate; and a lithographic printing method.

a1000,b1000(1)

1/a+1/b0.002(2)

Provided are a positive type planographic printing plate precursor including: a support which has a hydrophilic surface; and an image recording layer on the support, the image recording layer containing: a polymer compound 1 having at least one bond selected from the group consisting of a urea bond, a urethane bond, and a carbonate bond in a main chain and containing a sulfonamide group in the main chain; a polymer compound 2-1 having at least one of a constitutional unit represented by Formula S-1 or a constitutional unit represented by Formula S-2 or a polymer compound 2-2 having a constitutional unit represented by Formula EV-1 and a constitutional unit represented by Formula EV-2; and an infrared absorbent, and a method of producing a planographic printing plate obtained by using the positive type planographic printing plate precursor.

##STR00001##

Provided is a positive type photosensitive resin composition including: a polymer compound which contains, in a main chain thereof, a sulfonamide group and a structure represented by Formula A-1; and an infrared absorbent. In Formula A-1, X represents NR.sup.1, S, or O, R.sup.1 represents a hydrogen atom or an alkyl group, and each symbol * independently represents a bonding position with respect to another structure.

##STR00001##

A lithographic printing plate precursor is disclosed including a support and a coating comprising (i) a photopolymerisable layer including a polymerisable compound and a photoinitiator, and a toplayer provided above the photopolymerisable layer: characterized in that the toplayer includes a halogenated polymer and a nitrite and/or nitrate salt.

Provided are: a positive type photosensitive resin composition including a polyester containing a sulfonamide group in a main chain thereof, and an infrared absorbent; a positive type planographic printing plate precursor obtained by using the positive type photosensitive resin composition; and a method of producing a planographic printing plate.

A negative type photosensitive resin composition includes a polymer compound which contains a linking group represented by Formula A-1 in a main chain and an ethylenically unsaturated group; and a polymerization initiator. In Formula A-1, R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a monovalent organic group, and X.sup.1 represents a linking group represented by any of Formulae A-2 to A-6.

A negative type planographic printing plate precursor includes an image recording layer containing the negative type photosensitive resin composition.

A method of preparing a planographic printing plate includes, in order, an exposure step of image-exposing the negative type planographic printing plate precursor; and a development step of performing development by removing a non-exposed portion of the exposed negative type planographic printing plate precursor using a developer.

##STR00001##

There are free radical scavengers of formula (P.sub.m-L).sub.n-T.sub.q. Also provided are negative-working lithographic printing plate precursors comprising a hydrophilic substrate and a NIR photopolymerizable or UV-violet photopolymerizable imageable layer coated on the hydrophilic layer, the imageable layer also being photopolymerizable by visible light, the imageable layer having an outer surface and a thickness, the outer surface of the imageable layer being uniformly, and partially or completely crosslinked down to a depth corresponding to at most about 70% of the thickness of the imageable layer.

Provided are a photosensitive resin composition which enables production of a lithographic printing plate precursor having a non-image portion which has good solubility in an alkali aqueous solution and which enables production of a lithographic printing plate having excellent chemical resistance and excellent printing durability, a lithographic printing plate precursor obtained by using the photosensitive resin composition, a method for producing a lithographic printing plate, and a new polymer compound. The photosensitive resin composition of the present invention contains: a polymer compound which has an amine bond or a quaternary ammonium salt bond, and at least one bond selected from the group consisting of a urea bond, a urethane bond, and a carbonate bond in the main chain and has a sulfonamide group or a phenolic hydroxyl group in the main chain and/or the side chain; and an infrared absorbing material.