JP2003337408A - Positive photosensitive composition, positive photosensitive image forming material and positive image forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive photosensitive composition in which peeling of an image is suppressed even in the case of low adhesion of a photosensitive layer to a support. <P>SOLUTION: The positive photosensitive composition comprises (A) a photothermal conversion material which absorbs light of a light source for imagewise exposure and converts it to heat, (B) an alkali-soluble resin and (C) a heterocyclic thiol compound. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to lithographic printing plate making, laser gravure plate making, or printed wiring board,
Used to form conductor circuits and electrode substrates in liquid crystal display devices, plasma displays, color filters, organic electroluminescence, thin transistors, etc.
A positive photosensitive composition which is mainly highly sensitive to light in the infrared region, and is particularly suitable for directly forming an image with a semiconductor laser, a YAG laser, or the like, a positive photosensitive composition. The present invention relates to an image forming material and a positive image forming method using the same.

[0002]

2. Description of the Related Art With the progress of computer image processing technology, an image is directly formed by a laser beam from digital image information without outputting to a silver salt mask film.
A TP (Computer to Plate) system is drawing attention. Especially high-power semiconductor lasers and Y
A CTP system using an AG laser, etc., has a shortened manufacturing process, ambient light during work, and manufacturing costs.
Its practical application is progressing rapidly.

Along with this, in recent years, as a lithographic printing plate for a CTP system, an infrared laser beam has been used to form a positive image by increasing the solubility of an exposed portion in a developing solution mainly due to changes other than chemical changes. Photosensitive lithographic printing plates having a layer of a photosensitive composition on the surface of a support have been proposed (for example, JP-A-10-268512, JP-A-11-84657, JP-A-11-174681,
JP-A-11-194504, JP-A-11-22393
No. 6, etc., WO97 / 39894, WO98 / 4
See each specification, such as No. 2507. ).

These positive-working photosensitive lithographic printing plates are different from the conventional positive-working photosensitive lithographic printing plates in that the solubility of the exposed area in a developing solution is typically changed by a chemical change such as photolysis of an o-quinonediazide compound. While a positive image was formed by increasing the amount, a substance that absorbs infrared light such as an infrared absorbing dye and converts it into heat and an alkali-soluble resin such as a novolac resin were used as the main photosensitive components. , A substance that increases the solubility of the exposed portion in a developing solution by a physical change such as structural transition of the resin due to heat generated by exposure to infrared laser light, and is a substance sensitive to white light such as an o-quinonediazide compound It is known that the photosensitive lithographic printing plate has an advantage that it can be handled even under a white light because it does not need to be contained. However, according to the studies by the present inventors, these positive-type photosensitive compositions have a tendency that the image to be formed is easily peeled off and the desired image cannot be obtained when the adhesion on the surface of the support is low. It turned out to have weaknesses.

[0005]

The present invention has been made in view of the above-mentioned prior art. Therefore, the present invention provides a positive type photosensitive composition comprising a photothermal conversion substance and an alkali-soluble resin in a support. A positive photosensitive composition capable of forming a desired image on the surface of a support in which peeling of an image is suppressed even when the adhesion between the surface and the photosensitive layer is low, a positive photosensitive image forming material, and the same are used. It is an object to provide a positive image forming method.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, by incorporating a specific heterocyclic thiol compound into a positive photosensitive composition, the above object was achieved. The present invention has been completed by finding out what is possible, that is, the present invention comprises the following component (A):
A positive photosensitive composition containing the component (B) and the component (C), and a positive photosensitive image forming material having a layer of the positive photosensitive composition formed on the surface of a support, And
The positive type photosensitive image forming material is used in the wavelength range of 650 to 1,30
A gist is a positive image forming method in which scanning exposure is performed with a laser beam of 0 nm, and then development processing is performed with an alkali developing solution. (A) Photothermal conversion substance that absorbs light from an image exposure light source and converts it into heat (B) Alkali-soluble resin (C) Heterocyclic thiol compound

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The photothermal conversion substance of the component (A) which constitutes the positive photosensitive composition of the present invention is particularly limited as long as it is a compound capable of absorbing the light of the image exposure light source and converting it into heat. However, the light-absorbing dye is particularly effective among the organic or inorganic dyes and pigments, organic dyes, metals, metal oxides, metal carbides, metal borides, etc. that have absorption maximums in the wavelength range of 650 to 1,300 nm. Is. While these light-absorbing dyes efficiently absorb light in the wavelength range, they hardly absorb light in the ultraviolet region, or they are substantially insensitive to absorption, and are weakly affected by the weak ultraviolet light contained in white lamps. Is a compound that does not act to modify the photosensitive composition.

These light absorbing dyes include nitrogen atoms,
A heteroatom such as an oxygen atom or a sulfur atom is a polymethine (-
CH =) _n- chain-bonded structure, typically, a so-called cyanine dye in a broad sense having a structure in which the heteroatom forms a heterocycle and the heterocycle is bonded via a polymethine chain. Specifically, for example, quinoline type (so-called cyanine type in a narrow sense), indole type (so-called indocyanine type), benzothiazole type (so-called thiocyanine type),
Pyrylium-based, thiopyrylium-based, squarylium-based,
Examples include croconium dyes, azurenium dyes, and so-called polymethine dyes having a structure in which an acyclic heteroatom is bonded via a polymethine chain. Among them, quinoline dyes, indole dyes, benzothiazole dyes, pyrylium dyes are included. , Cyanine dyes such as thiopyrylium dyes, and polymethine dyes are preferable.

Other typical light absorbing dyes include diiminium dyes and phthalocyanine dyes. Of these, diiminium dyes are preferred.

In the present invention, among the above-mentioned cyanine dyes, the quinoline dyes are particularly represented by the following general formula (I
Those represented by a), (Ib), or (Ic) are preferable.

[0011]

[Chemical 1]

[In the formulas (Ia), (Ib) and (Ic), R ¹ and R
² are each independently an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, or a substituent. Optionally represents a phenyl group, L ¹ represents an optionally substituted tri, penta, hepta, nona, or undecamethine group, and the two substituents on the penta, hepta, nona, or undecamethine group Are connected to each other and have 5 to 7 carbon atoms
May form a cycloalkene ring, and the quinoline ring may have a substituent. In that case, two adjacent substituents may be linked to each other to form a condensed benzene ring. X ⁻ represents a counter anion. ]

Here, R ¹ in the formulas (Ia), (Ib), and (Ic)
And when R ² is an alkyl group, the number of carbon atoms is usually 1 to 1.
5, preferably 1 to 10, the number of carbon atoms in the case of an alkenyl group or an alkynyl group is usually 2 to 15, preferably 2-1.
0, as those substituents including phenyl groups, from 1 to 15 carbon atoms, preferably 1 to 10 alkoxy group, a phenoxy group, hydroxy group, or a phenyl group and the like, in L ¹ Examples of the substituent include an alkyl group having the same number of carbon atoms, an amino group, a halogen atom, and the like, and examples of the substituent in the quinoline ring include an alkyl group having the same number of carbon atoms, an alkoxy group having the same number of carbon atoms, a nitro group, or a halogen atom. An atom etc. are mentioned.

As the indole and benzothiazole dyes, those represented by the following general formula (II) are particularly preferable.

[0015]

[Chemical 2]

[In the formula (II), Y ¹ and Y ² each independently represent a dialkylmethylene group or a sulfur atom, and R ³ and R ⁴ each independently may have a substituent. An alkyl group, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, or a phenyl group which may have a substituent, and L ² has a substituent Optionally represents a tri, penta, hepta, nona, or undecamethine group, and two substituents on the penta, hepta, nona, or undecamethine group are linked to each other to have 5 carbon atoms.
~ 7 cycloalkene ring may be formed, the condensed benzene ring may have a substituent, in which case two adjacent substituents are linked to each other to form a condensed benzene ring. Good. X ⁻ represents a counter anion. ]

Here, when R ³ and R ⁴ in the formula (II) are alkyl groups, the number of carbon atoms is usually 1 to 15, preferably 1
-10, an alkenyl group, or an alkynyl group has usually 2 to 15, preferably 2 to 10 carbon atoms, and those substituents including a phenyl group usually have 1 carbon atom.
To 15, preferably 1 to 10 alkoxy group, phenoxy group, hydroxy group, phenyl group and the like, L
^As the substituent in ² , an alkyl group having the same carbon number as above,
Examples of the substituent on the condensed benzene ring include an alkyl group having the same number of carbon atoms, an alkoxy group having the same number of carbon atoms, a nitro group, and a halogen atom.

As the pyrylium-based and thiopyrylium-based dyes, in particular, the following general formulas (IIIa), (IIIb), or
What is represented by (IIIc) is preferable.

[0019]

[Chemical 3]

[In the formulas (IIIa), (IIIb), and (IIIc), Z ¹
And Z ² each independently represents an oxygen atom or a sulfur atom, and R ⁵ , R ⁶ , R ⁷ , and R ⁸ are each independently a hydrogen atom or an alkyl group, or R ⁵ and R ⁷ , and R ⁶ and R
⁸ may be linked to each other to form a cycloalkene ring having 5 or 6 carbon atoms, L ³ represents a mono-, tri-, penta-, or heptamethine group which may have a substituent. Two substituents on the penta or heptamethine group may be linked to each other to form a cycloalkene ring having 5 to 7 carbon atoms, and the pyrylium ring and thiapyrylium ring may have a substituent. In this case, two adjacent substituents may be linked to each other to form a condensed benzene ring. X ⁻ represents a counter anion. ]

Here, when R ⁵ , R ⁶ , R ⁷ and R ⁸ in the formulas (IIIa), (IIIb) and (IIIc) are alkyl groups, the number of carbon atoms is usually 1 to 15, preferably 1-10,
Examples of the substituent for L ³ include an alkyl group having the same number of carbon atoms, an amino group, and a halogen atom as described above. Examples of the substituent for the pyrylium ring and thiapyrylium ring include
Examples thereof include aryl groups such as phenyl group and naphthyl group.

Further, as the polymethine dye, those represented by the following general formula (IV) are particularly preferable.

[0023]

[Chemical 4]

[In the formula (IV), R⁹, R^Ten, R¹¹, And R¹²
Each independently represents an alkyl group, R¹³And R¹⁴Is each
Each independently, an aryl group which may have a substituent, a group
Represents a ryl group or a thienyl group, L^FourHas a substituent
You can use mono, tri, penta, or heptamethine groups
Shown on the tri, penta, or heptamethine group
Cycloalkene having 5 to 7 carbon atoms in which substituents are connected to each other
It may form a ring, and the quinone ring and the benzene ring are
It may have a substituent. X^- Represents a counter anion. ]

Here, the carbon number of the alkyl group of R ⁹ , R ¹⁰ , R ¹¹ and R ¹² in the formula (IV) is usually 1 to 15, preferably 1 to 10, and R ¹³ and R ¹⁴ are aryl groups. And the number of carbon atoms is usually 6 to 20, preferably 6 to 15, R ¹³
And R ¹⁴ is specifically a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-furyl group, a 3-furyl group, 2
-Thienyl group, 3-thienyl group and the like, and the substituents thereof include an alkyl group having the same carbon number as above, an alkoxy group having the same carbon number as above, a dialkylamino group, a hydroxy group,
Or a halogen atom and the like, and the substituent in L ⁴ includes an alkyl group having the same carbon number as above, an amino group, a halogen atom and the like, and the substituent in the quinone ring and the benzene ring includes an alkyl having the same carbon number as above. Group, an alkoxy group having the same number of carbon atoms, a nitro group, a halogen atom and the like.

Further, as the diiminium dye, those represented by the following general formula (Va) or (Vb) having at least one N, N-diaryliminium salt skeleton are particularly preferable.

[0027]

[Chemical 5]

[In the formulas (Va) and (Vb), R ¹⁵ , R ¹⁶ and
R ¹⁷ and R ¹⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an alkyl group which may have a substituent. Represents a good alkynyl group or an alkoxy group which may have a substituent, and R ¹⁹ and R ²⁰ each independently represent an alkyl group which may have a substituent or a substituent which may have a substituent. An alkenyl group which may have a substituent, an alkynyl group which may have a substituent, an alkoxy group which may have a substituent, an acyloxy group which may have a substituent, or a substituent which may have a substituent. It represents a good phenyl group, and the benzene ring and iminoquinone ring may have a substituent. X ⁻ represents a counter anion. The electronic bond (dotted line) in the formula (Vb) shows a resonance state with other electronic bonds. ]

Here, R ¹⁵ in the formulas (Va) and (Vb),
When R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , and R ²⁰ are an alkyl group or an alkoxy group, the number of carbon atoms is usually 1 to 15, preferably 1 to 10, an alkenyl group, or an alkynyl group. Is usually 2 to 15, preferably 2 to 10, and as the substituents therefor, an alkyl group having the same number of carbon atoms, an alkoxy group having the same number of carbon atoms, a carboxy group, an acyloxy group, an alkoxycarbonyl group, a hydroxy group, and an amino group are the same. , An alkylamino group, a halogenated alkyl group, or a halogen atom, and the like, as the substituent on the benzene ring and the iminoquinone ring, an alkyl group having the same number of carbon atoms, an alkoxy group having the same number of carbon atoms, an acyl group, a nitro group,
Or a halogen atom etc. are mentioned.

Among these diiminium dyes, R ¹⁵ , R ¹⁶ , R ¹⁷ and R in the above general formulas (Va) and (Vb) are included.
It is particularly preferable that ¹⁸ is an alkyl group and R ¹⁹ and R ²⁰ are also alkyl groups, or that R ¹⁹ and R ²⁰ are phenyl groups having a dialkylamino group as a substituent.

The above general formulas (Ia to c), (II), (IIIa to
Counter anion X in c), (IV), and (Va-b)^-As
Is, for example, Cl^-, Br^-, I^-, ClO_Four ^- , PF
₆ ^-, SbF₆ ^-, AsF₆ ^-, And BF_Four ^-, BC
l_Four ^-Inorganic boric acid and other inorganic acid anions, and
Zensulfonic acid, toluenesulfonic acid, naphthalene sulphate
Fonic acid, acetic acid, and methyl, ethyl, propyl, butyric acid
Ru, phenyl, methoxyphenyl, naphthyl, fluoro
Phenyl, difluorophenyl, pentafluorophenyl
Organic boric acid having organic groups such as ruthel, thienyl and pyrrolyl
The organic acid anion of

Further, the above general formulas (Ia to c), (II) and (IIIa to
In c) and (IV), L¹, L ², L³, And L^Four
On the polymethine chain of the formula (VIa)
A bituric acid anion group or a thiobarbituric acid anion group
Having as a substituent, or L¹, L², L
³, And L^FourIn the polymethine chain of the following general formula (VIb)
The represented square acid anion group or thiosquare acid ani
An on group or a black compound represented by the following general formula (VIc)
Form an acid anion group or thiocroconate anion group
As a result, an inner salt may be formed.

[0033]

[Chemical 6]

[In formulas (VIa), (VIb), and (VIc),
Z³, Z^Four, Z^Five, Z⁶, Z⁷ , And Z⁸Each independently
Represents an oxygen atom or a sulfur atom, R^{twenty one}And R^{twenty two}Are each
Independently, a hydrogen atom and an optionally substituted alkyl group
Group, an alkenyl group which may have a substituent, a substituent
Having an alkoxy group which may have, or a substituent
Indicates a phenyl group which may be present. ]

When R ²¹ and R ²² in the formula (VIa) are an alkyl group or an alkoxy group, the number of carbon atoms is usually 1 to 1.
5, preferably 1 to 5, the number of carbon atoms in the case of an alkenyl group is usually 2 to 15, preferably 2 to 5, but is preferably an alkyl group, and the alkyl group is specifically a methyl group. , Ethyl group, propyl group, butyl group and the like.

The quinoline type represented by the above general formulas (Ia to c), the indole type or benzothiazole type represented by the above general formula (II), and the pyrylium represented by the above general formulas (IIIa to c). Type or thiopyrylium type cyanine type dyes,
Among the polymethine dyes represented by the general formula (IV), and the diiminium dyes represented by the general formula (Va to b),
In the present invention, the indole-type or benzothiazole-type cyanine dye represented by the general formula (II) is particularly preferable.

In the present invention, the content ratio of the photothermal conversion substance of the component (A) in the positive photosensitive composition is 0.
It is preferably 5 to 30% by weight, more preferably 1 to 20% by weight, and particularly preferably 2 to 10% by weight.

Further, the alkali-soluble resin as the component (B) constituting the positive photosensitive composition of the present invention is a resin having a phenolic hydroxyl group, specifically, phenol such as novolac resin and resol resin. Resins, polyvinylphenol resins, copolymers of acrylic acid derivatives having a phenolic hydroxyl group, polyvinyl acetal resins and the like are preferable, and among them, novolak resins, phenol resins such as resole resins, or polyvinylphenol resins are preferable, and phenol resins are more preferable. Novolak resins are particularly preferred.

The novolac resin is, for example, phenol,
o-cresol, m-cresol, p-cresol,
2,5-xylenol, 3,5-xylenol, o-ethylphenol, m-ethylphenol, p-ethylphenol, propylphenol, n-butylphenol, t-butylphenol, 1-naphthol, 2-naphthol, 4,4 '. At least one of phenols such as biphenyldiol, bisphenol-A, pyrocatechol, resorcinol, hydroquinone, pyrogallol, 1,2,4-benzenetriol and phloroglucinol under acid catalysis, for example formaldehyde, acetaldehyde, propion Aldehydes such as aldehyde, benzaldehyde and furfural (paraformaldehyde may be used in place of formaldehyde and paraaldehyde in place of acetaldehyde), or acetone, methylethyl A resin obtained by polycondensation with at least one kind of a ketone, a ketone such as methyl isobutyl ketone, and in the present invention, phenol as a phenol, o-cresol, m-cresol, p-cresol, 2,5-xylenol, 3,5-
Xylenol, resorcinol and formaldehyde, acetaldehyde as aldehydes or ketones,
Polycondensates with propionaldehyde are preferred.

In particular, m-cresol: p-cresol:
The mixing ratio of 2,5-xylenol: 3,5-xylenol: resorcinol is 40 to 100: 0 to 5 in molar ratio.
A mixed phenol of 0: 0 to 20: 0 to 20: 0 to 20 or a mixing ratio of phenol: m-cresol: p-cresol in a molar ratio of 1 to 100: 0 to 70: 0 to 6.
0 is preferably a polycondensate of mixed phenols and formaldehyde, and the photosensitive composition of the present invention may contain a dissolution inhibitor as described below.
The mixing ratio of m-cresol: p-cresol: 2,5-xylenol: 3,5-xylenol: resorcinol is 70 to 100: 0 to 30: 0 to 20: 0 to 2 in a molar ratio.
Mixed phenols of 0: 0 to 20 or phenol:
A polycondensate of mixed phenols having a molar ratio of m-cresol: p-cresol of 10 to 100: 0 to 60: 0 to 40 and formaldehyde is preferable.

The novolak resin has a polystyrene-equivalent weight average molecular weight (M _W ) of 1,000 to 15,000 as measured by gel permeation chromatography.
Those having 1,500 to 10,000 are more preferable.

Further, the resole resin is a resin polycondensed in the same manner except that an alkali catalyst is used instead of the acid catalyst in the polycondensation of the novolak resin, and in the present invention, it is the same as in the novolak resin. , Phenols and mixed compositions thereof, and aldehydes or ketones are preferable, and those having similar weight average molecular weight (M _W ) are also preferable.

The polyvinylphenol resin is, for example, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, dihydroxystyrene,
Trihydroxystyrene, tetrahydroxystyrene,
Hydroxystyrenes such as pentahydroxystyrene, 2- (o-hydroxyphenyl) propylene, 2- (m-hydroxyphenyl) propylene, 2- (p-hydroxyphenyl) propylene (these are chlorine, bromine in the benzene ring). , Or a halogen atom such as iodine or fluorine, or an alkyl group having 1 to 4 carbon atoms as a substituent.) In the presence of a radical polymerization initiator or a cationic polymerization initiator. In the present invention, the benzene ring has 1 to 1 carbon atoms.
Polymers of hydroxystyrenes which may have the alkyl group of 4 as a substituent are preferable, and polymers of hydroxystyrenes having an unsubstituted benzene ring are particularly preferable.
The weight average molecular weight (M _W ) is 1,000 to 100,
000 is preferable, and 1,500 to 50,000 is more preferable.

In the present invention, the content of the alkali-soluble resin as the component (B) in the positive photosensitive composition is preferably 50 to 99% by weight, and 60 to 98% by weight.
More preferably, it is 70% by weight, and particularly preferably 70 to 97% by weight.

The positive photosensitive composition of the present invention is
In addition to the photothermal conversion substance as the component (A) and the alkali-soluble resin as the component (B), it is essential to contain a heterocyclic thiol compound as the component (C). The heterocyclic thiol compound is a compound having a structure in which a mercapto group is substituted on the heterocyclic compound, and preferred heterocyclic thiol compounds are exemplified by, for example, 2-mercaptothiazole, 2-mercaptooxazole, and 2-mercaptoimidazole. , 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2,4,6-trimercapto-s-triazine, 2-dibutylamino-4,6-dimercapto-s.
-Triazine, 2,4,6-trimercapto-s-triazine monosodium salt, 2,4,6-trimercapto-s-triazine trisodium salt, 2-anilino-
Mention may be made of 4,6-dimercapto-s-triazine.

In the present invention, the content ratio of the heterocyclic thiol compound as the component (C) in the positive photosensitive composition is preferably 0.01 to 50% by weight, and 0.0
It is more preferably 5 to 40% by weight, and 0.1 to 30
It is particularly preferred that it is% by weight. When the content ratio of the component (C) is less than the above range, peeling of an image tends to occur when the adhesion of the surface of the support is low as a positive photosensitive composition, while when it exceeds the above range, a homogeneous composition is obtained. It is difficult to get things.

In the present invention, the positive-type photosensitive composition containing the photothermal conversion substance as the component (A), the alkali-soluble resin as the component (B), and the heterocyclic thiol compound as the component (C). Preferably contains a dissolution inhibitor (D) component that is not decomposed by light in the infrared region for the purpose of increasing the difference in solubility between the exposed and unexposed parts in an alkaline developer. Examples of the depressant include JP-A-10-268512 and JP-A-11-28.
Sulfonic acid esters, phosphoric acid esters, aromatic carboxylic acid esters, aromatic disulfones, carboxylic acid anhydrides, aromatic ketones, aromatic aldehydes, and aromatic compounds described in detail in each publication of No. 8089. Amines, aromatic ethers, compounds having a triarylmethane skeleton, and the like, having a lactone skeleton, an N, N-diarylamide skeleton, and a diarylmethylimino skeleton, which are described in detail in JP-A No. 11-190903. Examples thereof include acid-coloring dyes and base-coloring dyes having a lactone skeleton, a thiolactone skeleton, and a sulfolactone skeleton, which are described in detail in JP-A No. 11-143076.

In the present invention, the content ratio of the dissolution inhibitor of the component (D) in the positive photosensitive composition is preferably 50% by weight or less, more preferably 0.01 to 30% by weight. It is preferably 0.1 to 20% by weight, and particularly preferably.

The positive photosensitive composition of the present invention preferably contains an organic acid having a pKa of 2 or more or its anhydride (E) component for the purpose of improving developability such as imparting underdeveloping property. The organic acid or its anhydride is preferably contained, for example, as disclosed in JP-A-60-88.
942, JP-A-63-276048, JP-A-2-9.
Nos. 6754 and the like, specifically glyceric acid, methylmalonic acid, dimethylmalonic acid, propylmalonic acid, succinic acid, malic acid, mesotartaric acid, glutaric acid, β-methylglutaric acid, β , Β-dimethyl glutaric acid, β-ethyl glutaric acid, β, β-diethyl glutaric acid, β-propyl glutaric acid, β, β-methyl propyl glutaric acid, pimelic acid, suberic acid, sebacic acid, etc. Acids, maleic acid, fumaric acid, aliphatic unsaturated carboxylic acids such as glutaconic acid, 1,1-cyclobutanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1,1-cyclopentanedicarboxylic acid, 1,2-
Cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid,
Carbocyclic saturated carboxylic acids such as 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid,
1,2-cyclohexene dicarboxylic acid, 2,3-dihydroxybenzoic acid, 3,4-dimethylbenzoic acid, 3,4-
Dimethoxybenzoic acid, 3,5-dimethoxybenzoic acid, p
-Toluic acid, 2-hydroxy-p-toluic acid, 2-
Carbocyclic unsaturated carboxylic acids such as hydroxy-m-toluic acid, 2-hydroxy-o-toluic acid, mandelic acid, gallic acid, phthalic acid, isophthalic acid and terephthalic acid, and Meldrum's acid, ascorbic acid, succinic anhydride Examples thereof include anhydrides such as acids, glutaric anhydride, maleic anhydride, cyclohexenedicarboxylic acid anhydride, cyclohexanedicarboxylic acid anhydride, and phthalic anhydride. Among them, in the present invention, cyclohexanedicarboxylic acid or its anhydride is particularly preferable.

In the present invention, the content of the organic acid or the anhydride thereof as the component (E) in the positive photosensitive composition is preferably 0.1 to 30% by weight, and 0.5
Is more preferably from 20 to 20% by weight, more preferably from 1 to 10% by weight.
Is particularly preferable.

The positive type photosensitive composition of the present invention has a nonionic property, for the purpose of improving sensitivity and developing property.
It is preferable to contain a surfactant (F) component such as anionic, cationic, amphoteric or fluorine-based.

Examples of the nonionic surfactant include polyethylene glycols such as polyethylene glycol and polyethylene glycol polypropylene glycol block copolymers, polyethylene glycol cetyl ether, polyethylene glycol stearyl ether, polyethylene glycol oleyl ether, polyethylene glycol behenyl ether and the like. Polyethylene glycol polypropylene glycol alkyl ethers such as polyethylene glycol polypropylene glycol cetyl ether, polyethylene glycol polypropylene glycol decyl tetradecyl ether, polyethylene glycol octyl phenyl ether, polyethylene glycol nonyl phenyl ether Polyethylene glycol alkyl phenyl ethers such as tellurium, ethylene glycol monostearate, ethylene glycol distearate, diethylene glycol stearate, polyethylene glycol distearate, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monooleate, etc. Fatty acid esters, glyceryl monomyristate, glyceryl monostearate, glyceryl monoisostearate, glyceryl monostearate, glyceryl monostearate, glyceryl monooleate, glyceryl dioleate, and the like, and polyethylene oxide adducts thereof, polyglycerin fatty acid ester Kind, Pentaerythritol monostearate, Tri Stearate pentaerythritol monooleate and pentaerythritol,
Pentaerythrite fatty acid esters such as pentaerythritol trioleate, and polyethylene oxide adducts thereof, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, sorbitan trioleate, etc. Fatty acid esters and polyethylene oxide adducts thereof, sorbit fatty acid esters such as sorbitol monolaurate sorbit, sorbit tetrastearate sorbit hexasorbate, sorbit tetraoleate and the like, polyethylene oxide adducts thereof, polyethylene glycol alkylamines Polyethylene glycol alkyl amino ethers, castor oil polyethylene oxide adducts, lanolin polyethylene oxide Thing, and the like can be mentioned.

As the anionic surfactant,
For example, higher fatty acid salts such as sodium laurate, sodium stearate and sodium oleate, alkyl sulfonates such as sodium lauryl sulfonate,
Alkylbenzenesulfonates such as sodium dodecylbenzenesulfonate, alkylnaphthalenesulfonates such as sodium isopropylnaphthalenesulfonate, alkyldiphenyletherdisulfonates such as sodium alkyldiphenyletherdisulfonate,
Polyoxyethylene alkyl ether sulfonates such as sodium polyoxyethylene lauryl ether sulfonate, alkyl sulfate ester salts such as sodium lauryl sulfate and sodium stearyl sulfate, sodium octyl alcohol sulfate ester, sodium lauryl alcohol sulfate ester, ammonium lauryl alcohol sulfate ester Higher alcohol sulfate ester salts such as, acetyl alcohol sulfate sodium salts such as aliphatic alcohol sulfate salts, sodium polyoxyethylene lauryl ether sulfate, ammonium polyoxyethylene lauryl ether sulfate, polyoxyethylene lauryl ether sulfate such as triethanolamine Ethylene alkyl ether sulfates, polyoxyethylene nonylphenyl Sodium ether sulfate and other polyoxyethylene alkyl phenyl ether sulfates, sodium lauryl phosphate, sodium stearyl phosphate and other alkyl phosphate ester salts, polyoxyethylene lauryl ether sodium phosphate, polyoxyethylene stearyl ether sodium phosphate and other polyoxyethylene alkyl ethers Examples thereof include phosphates, polyoxyethylene alkylphenyl ether phosphates such as sodium polyoxyethylene nonylphenyl ether phosphate, sulfosuccinic acids, unsaturated fatty acid sulfated oils, taurine salts, castor oil sulfate ester salts and the like.

Further, as the cationic surfactant,
For example, lauryl trimethyl ammonium chloride,
Quaternary ammonium chlorides such as cetyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, similar quaternary ammonium sulfates, similar quaternary ammonium nitrates, 2- Examples thereof include imidazoline derivatives such as octadecyl-hydroxyethyl-2-imidazoline, N, N-diethyl-stearoamide-methylamine hydrochloride, amine salts such as polyoxyethylene stearylamine, and the like.

Examples of the amphoteric surfactant include N-lauryl-N, N-dimethyl-N-carboxymethylammonium, N-stearyl-N, N-dimethyl-N-carboxymethylammonium and N-lauryl. Betaine-type compounds such as -N, N-dihydroxyethyl-N-carboxymethylammonium, N-lauryl-N, N, N-tris (carboxymethyl) ammonium, 2-alkyl-N-carboxymethyl-N-hydroxyethyl Examples thereof include imidazolium salts such as imidazolium, imidazolines such as imidazoline-N-sodium ethylsulfonate, imidazoline-N-sodium ethylsulfate, aminocarboxylic acids, aminosulfates and the like.

In the present invention, the content ratio of the surfactant as the component (F) in the positive photosensitive composition is 0.0
It is preferably from 01 to 20% by weight, and 0.002-1
It is more preferably 0% by weight, and particularly preferably 0.005 to 5% by weight. Further, two or more kinds of these (F) components may be used at the same time.

Further, the positive photosensitive composition of the present invention includes, for example, Victoria Pure Blue (42595), Crystal Violet (42555) and Auramine O (41).
000), Catillon Brilliant Flavin (Basic 13), Rhodamine 6GCP (45160), Rhodamine B (45170), Safranine OK 70: 100 (5
0240), Erioglaucine X (42080), Fast Black HB (26150), No. 120 / Rionol Yellow (21090), Rionol Yellow GRO (21090), Shimla First Yellow 8
GF (21105), Benzidine Yellow 4T-564
D (21095), Shimla Fast Red 4015
(12355), Lionol Red B4401 (158
50), Fastgen Blue TGR-L (7416)
0), and a colorant (G) component such as a dye or pigment such as Lionol Blue SM (26150) may be contained. Here, the numbers in parentheses are color indexes (CI).
Means

In the present invention, the content of the colorant as the component (G) in the positive photosensitive composition is 50% by weight.
It is preferably below, more preferably from 0.5 to 30% by weight, particularly preferably from 2 to 20% by weight.

Further, the positive photosensitive composition of the present invention comprises
When the alkali-soluble resin as the component (B) is the above-mentioned phenol resin, phenol is used for the purpose of imparting chemical resistance, printing durability, etc. to the positive image by crosslinking the resin by post-heating after exposure and development. A cross-linking agent (H) component having an action of cross-linking the resin may be contained, and as the cross-linking agent, typically, a methylol group as a functional group,
Examples thereof include an alkoxymethyl group obtained by subjecting it to alcohol condensation modification, and other amino compounds having at least two acetoxymethyl groups and the like. Specifically, a melamine derivative,
For example, methoxymethylated melamine [manufactured by Mitsui Cytec, Cymel 300 series (1), etc.], benzoguanamine derivative [methyl / ethyl mixed alkoxylated benzoguanamine resin (manufactured by Mitsui Cytec, Cymel 1100).
Series (2) and the like], glycoluril derivative [tetramethylol glycoluril resin (manufactured by Mitsui Cytec, Cymel 1100 series (3) and the like]), urea resin derivative, resole resin and the like.

In the present invention, the content of the above-mentioned (H) crosslinking agent in the positive photosensitive composition is 20% by weight.
It is preferably below, more preferably below 10% by weight, especially below 5% by weight.

In addition to the above-mentioned components, the positive-type photosensitive composition of the present invention contains, for example, dyes, pigments, coatability improvers, adhesion improvers, sensitivity improvers, oil sensitizers, and developability improvers. Various additives usually used in photosensitive compositions such as agents are further added.
It may be contained in an amount of not more than 10% by weight, preferably not more than 10% by weight.

In general, when the positive photosensitive composition does not contain a compound sensitive to light in the ultraviolet region, the sensitivity and the contrast between the image area and the non-image area tend to be poor. Therefore, the positive-type photosensitive composition of the present invention does not include a compound sensitive to light in the ultraviolet region, such as an onium salt, a diazonium salt, or a quinonediazide group-containing compound, and is substantially free from light in the ultraviolet region. When it is not sensitive to, the effects of the present invention in terms of the sensitivity, the contrast between the image area and the non-image area, and the resistance to peeling of the image from the support are more remarkably exhibited. Therefore, it is preferable. Incidentally, here, having substantially no sensitivity to light in the ultraviolet region,
Before and after irradiation with light having a wavelength of 360 to 450 nm, there is no substantial difference in solubility in an alkaline developer,
It means that it has no image forming ability in a practical sense.

The positive photosensitive composition of the present invention is usually prepared by coating the surface of the support with a coating solution prepared by dissolving or dispersing each of the above components in a suitable solvent, followed by heating and drying. To form a positive type photosensitive image forming material having a layer of the positive type photosensitive composition formed thereon.

Here, examples of the support include thermosetting resins such as epoxy resin, polyimide resin, bismaleimide resin, unsaturated polyester resin, phenol resin and melamine resin, saturated polyester resin, polycarbonate resin, Resin sheet such as polysulfone resin, acrylic resin, polyamide resin, polystyrene resin, polyvinyl chloride resin, polyolefin resin, fluororesin or other thermoplastic resin, paper, paper coated with the resin, glass plate, and alumina, silica Inorganic plates such as barium sulfate and calcium carbonate, and composite sheet such as glass woven fabric base epoxy resin, glass nonwoven fabric base epoxy resin, paper base epoxy resin, paper base phenol resin, etc. An insulating substrate with a thickness of 0.02 to 10 mm is used. Is suitably used as a conductive layer is formed, as the material of the conductive layer, for example,
Examples of the metal include copper, gold, silver, chromium, zinc, tin, aluminum, lead, nickel, indium oxide, tin oxide, indium oxide-doped tin oxide (ITO), and solder. still,
As a method for forming a conductive layer on the surface of the insulating substrate, for example, a method of heating the foil of the metal, laminating by pressure bonding, sputtering the metal, vapor deposition, plating, or the like is adopted, and the thickness thereof is usually It is about 1 to 100 μm.

Further, as the support in the present invention, the metal plate mentioned as the constituent material of the conductive layer, and the resin sheet, the paper mentioned as the insulating substrate, on the surface of which the conductive layer is not formed, Paper coated with the resin, a glass plate,
An inorganic board, a composite material sheet, etc. can also be used.

The solvent is not particularly limited as long as it has a sufficient solubility for the components used and gives a good coating property. For example, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, Cellosolve solvents such as ethyl cellosolve acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol dimethyl ether, etc. Propylene glycol solvent, butyl acetate, amyl acetate, ethyl butyrate, butyl butyrate, diethyl oxalate,
Ester-based solvents such as ethyl pyruvate, ethyl-2-hydroxybutyrate, ethyl acetoacetate, methyl lactate, ethyl lactate, and methyl 3-methoxypropionate, isopropanol, n-propanol, heptanol, hexanol, diacetone alcohol, furfuryl. Alcohol solvents such as alcohol, cyclohexanone,
Ketone solvents such as methyl ethyl ketone and methyl amyl ketone, dimethylformamide, dimethylacetamide,
Examples thereof include highly polar solvents such as N-methylpyrrolidone, mixed solvents thereof, and those obtained by adding an aromatic hydrocarbon to these. The use ratio of the solvent is usually in the range of about 1 to 150 times by weight with respect to the total amount of the photosensitive composition.

As the coating method, conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, and curtain coating can be used. The coating amount varies depending on the application, but the dry film thickness is usually 0.3 to 7 μm.
m, preferably 0.5 to 5 μm, particularly preferably 1 to 3
The range is μm. The drying temperature at that time is, for example, about 60 to 170 ° C., preferably 70 to 150 ° C.
The drying time is about 5 seconds to 10 minutes, preferably about 10 seconds to 5 minutes.

In the positive image-forming method of the present invention, the positive-type photosensitive image-forming material having the layer of the positive-type photosensitive composition on the surface of a support is imagewise exposed and then developed with an alkali developing solution. Forming a positive image.

Here, the light source for imagewise exposing the positive photosensitive composition layer is mainly a HeNe laser,
Examples thereof include laser light sources such as an argon ion laser, a YAG laser, a HeCd laser, a semiconductor laser, and a ruby laser. In particular, when an image is formed by heat generated by absorbing light, the wavelength range is 650 to 1,30.
A light source that generates infrared laser light in the range of 0 nm is preferable, and specific examples thereof include a semiconductor laser that oscillates 830 nm and a YAG laser that oscillates 1064 nm. The scanning exposure method is also not particularly limited, and examples thereof include a plane scanning exposure method, an outer surface drum scanning exposure method, and an inner surface drum scanning exposure method.

The laser light source is usually a lens.
Photosensitive composition as concentrated high-intensity light beam
Photosensitivity in the present invention which scans the layer surface but is sensitive to it
Sensitivity characteristics of composition layer (mJ / cm²) Is a laser that receives light
-Light intensity of beam (mJ / s · cm²) Depends on
There is. Here, the light intensity of the laser beam is the optical power
Hit the unit time of the laser beam measured by the meter
Energy (mJ / s) on the surface of the photosensitive composition layer
Laser beam irradiation area (cm² )
It can be obtained by and. Laser beam irradiation surface
The product is usually 1 / e of the laser peak intensity²Beyond strength
It is defined by the area of the part which is
It can also be measured by exposing the photosensitive composition to light.

In the present invention, the light intensity of the light source is
2.0 x 10⁶mJ / s · cm² It is preferable to be above
Correctly, 1.0 × 10⁷mJ / s · cm²What to do
Is more preferable. In the present invention, if the light intensity is in the above range
Can improve the sensitivity characteristics of the positive photosensitive composition layer of
The inspection exposure time can be shortened and it has a great advantage in practical use.
Become.

Examples of the developing solution used for developing the positive photosensitive member obtained by imagewise exposing the positive photosensitive image forming material of the present invention include sodium silicate, potassium silicate, lithium silicate, ammonium silicate, sodium metasilicate, Potassium metasilicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, sodium diphosphate, sodium triphosphate, ammonium diphosphate, ammonium triphosphate, sodium borate, boric acid Inorganic alkali salts such as potassium and ammonium borate, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine,
Organic amine compounds such as triethylamine, monoisopropylamine, diisopropylamine, monobutylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine and diisopropanolamine, or water such as tetramethylammonium hydroxide and tetraethylammonium hydroxide. An alkali developing solution which is an aqueous solution of about 0.1 to 5% by weight of a tetraalkylammonium oxide compound or the like is used. Among them, alkali metal silicates such as inorganic silicates such as sodium silicate and potassium silicate are preferable. Incidentally, in the developer, from the viewpoint that the range of development conditions can be stably widened, the same nonionic surfactants, anionic surfactants and amphoteric surfactants as those mentioned as the surfactant component of the photosensitive composition can be used. A surfactant such as a surfactant or an organic solvent such as alcohol can be added.

The development treatment is carried out by a conventionally known method, for example, dip development, spray development, spin development, brush development, ultrasonic development, etc., preferably about 10 to 50 ° C., particularly preferably about 15 to 45 ° C. At a temperature of 5
It takes about 2 seconds to 3 minutes. After development, it may be dried, and then, if necessary, post-baking treatment may be performed at a temperature range of about 100 to 250 ° C. for the purpose of improving the adhesiveness of the formed image. Further, for example, as described in JP-A No. 11-10827, the above-mentioned alkali developing solution, or the above-mentioned surfactant or water-soluble organic solvent added thereto, or a solution thereof is used. Permeation into the photosensitive layer after exposure as a penetrant, by applying a physical stimulus if necessary, peeling the exposed portion from the support surface to develop, a so-called penetration development method, or
As described in JP-A-10-333321 and the like, printing ink is supplied onto the photosensitive layer, and the adhesive force of the ink is used to transfer the ink to an adherend together with the exposed portion, thereby exposing the exposed portion. Is peeled off from the support surface and developed,
A method such as a so-called print development method can also be adopted.

[0074]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Example 1 As a support, a copper clad laminate (manufactured by Sanhayato Co.) in which a conductive layer of electrolytic copper foil having a thickness of 18 μm was laminated on the surface of a polyimide resin insulating substrate having a thickness of 0.1 mm was used. On the copper foil, as a light-heat converting substance of the component (A), 3.5 parts by weight of the following (a) dye and 3.5 parts by weight of the following (b) dye,
As the alkali-soluble resin as the component (B), phenol:
m- cresol: p-condensation consisting coalescence novolak resin mixing ratio of cresol mixed phenols and formaldehyde 50:30:20 molar ratio (M _W 9,40
0) 100 parts by weight, 1 part by weight of 2-mercaptobenzimidazole as the heterocyclic thiol compound of the component (C),
10 parts by weight of crystal violet lactone as a dissolution inhibitor of the component (D) and 1,2-cyclohexanedicarboxylic acid 3.5 as the organic acid of the component (E) or its anhydride
4 parts by weight of a polyethylene oxide adduct of sorbitol tetraoleate as a surfactant of the component (F) (“NIKKOL GO-4” manufactured by Nikko Chemicals Co., Ltd.) and a fluorine-based surfactant (“Surflon S- manufactured by Asahi Glass Co., Ltd.” 38
1 ") 0.2 part by weight is applied to 930 parts by weight of propylene glycol monomethyl ether at room temperature to apply a positive photosensitive composition coating solution using a wire bar, and air-dry at room temperature for 2 minutes. Then, by further drying in a convection oven at 80 ° C. for 2 minutes, a positive type photosensitive image forming material having a positive type photosensitive composition layer having a film thickness of 1.5 μm was produced.

[0076]

[Chemical 7]

With respect to the obtained positive type photosensitive image forming material,
An exposure device using a semiconductor laser having a wavelength of 830 nm as a light source (“Trend Setter 3244” manufactured by Creo)
T ”), the exposure amount on the surface of the photosensitive layer is 200 mJ /
Scanning exposure was carried out with an exposure energy of ² cm2, and then an alkaline developing solution ("DR-6" manufactured by Mitsubishi Kagaku Media Co., Ltd.
A double-fold diluted solution) was contacted at 25 ° C. to develop and wash with water to form a positive image of fine line image. At that time, the development time for obtaining a good image is in the range of 60 to 180 seconds, and the adhesion of the photosensitive composition layer to the surface of the support is good in the range of the development time, which is easy to use with a nail. Even when scratched, the photosensitive composition layer was not peeled off.

Example 2 A positive type photosensitive image was prepared in the same manner as in Example 1 except that 1 part by weight of 2-mercaptoimidazole was used as the heterocyclic thiol compound as the component (C) in the positive type photosensitive composition. A forming material was prepared and a positive image was formed. At that time, the development time for obtaining a good image is in the range of 60 seconds to 180 seconds, and in the development time of that range, the adhesion of the photosensitive composition layer to the surface of the support is the same as in Example 1. It was good.

Example 3 Positive type photosensitive composition was prepared in the same manner as in Example 1 except that 1 part by weight of 2-mercaptobenzothiazole was used as the heterocyclic thiol compound as the component (C) in the positive type photosensitive composition. An image forming material was prepared and a positive image was formed. At that time, the development time for obtaining a good image is in the range of 60 seconds to 180 seconds, and in the development time of that range, the adhesion of the photosensitive composition layer to the surface of the support is the same as in Example 1. It was good.

Example 4 In the same manner as in Example 1, except that 1 part by weight of 2-mercaptobenzoxazole was used as the heterocyclic thiol compound as the component (C) in the positive photosensitive composition, the positive photosensitive composition was used. An image forming material was prepared and a positive image was formed. At that time, the development time for obtaining a good image is in the range of 60 seconds to 180 seconds, and in the development time of that range, the adhesion of the photosensitive composition layer to the surface of the support is the same as in Example 1. It was good.

Example 5 As the heterocyclic thiol compound of the component (C) in the positive photosensitive composition, 2-dibutylamino-4,6-
A positive type photosensitive image forming material was prepared in the same manner as in Example 1 except that 1 part by weight of dimercapto-s-triazine was used, and a positive image was formed. At that time, the development time for obtaining a good image is in the range of 60 seconds to 180 seconds, and in the development time of that range, the adhesion of the photosensitive composition layer to the surface of the support is the same as in Example 1. It was good.

Comparative Example 1 A positive type photosensitive image forming material was prepared in the same manner as in Example 1 except that the heterocyclic thiol compound as the component (C) was not used as the positive type photosensitive composition. Formed. At that time, the development time for obtaining a good image is from 60 seconds to 18
Although it was in the range of 0 seconds, when the photosensitive composition layer on the surface of the support was rubbed with a nail during the development time of 120 seconds as the central time, part of the photosensitive composition layer was peeled off.

[0083]

According to the present invention, in a positive type photosensitive composition comprising a photothermal conversion substance and an alkali-soluble resin,
A positive photosensitive composition capable of forming a desired image on the surface of a support, suppressing peeling of the image even when the adhesion between the surface of the support and the photosensitive layer is low, a positive photosensitive image forming material, and the use thereof It is possible to provide a positive image forming method.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takuya Uematsu             1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa             Within Mitsubishi Chemical Corporation F-term (reference) 2H025 AA14 AB03 AB13 AB15 AB17                       AC08 AD03 CB29 CC06 CC20                       FA10 FA17

Claims (6)

[Claims] 1. A positive photosensitive composition comprising the following component (A), component (B), and component (C). (A) Photothermal conversion substance that absorbs light from an image exposure light source and converts it into heat (B) Alkali-soluble resin (C) Heterocyclic thiol compound 2. The (A) component photothermal conversion substance has a wavelength range of 6
The positive photosensitive composition according to claim 1, which is a light absorbing dye having an absorption maximum at 50 to 1,300 nm. 3. The positive photosensitive composition according to claim 2, wherein the light absorbing dye as the light-heat converting substance of the component (A) is a cyanine dye having a structure in which a heterocycle is bonded via a polymethine chain. . 4. The positive photosensitive composition according to claim 1, wherein the alkali-soluble resin as the component (B) is a novolac resin. 5. A positive-type photosensitive image-forming material comprising a support and a layer of the positive-type photosensitive composition according to claim 1 formed on the surface of the support. 6. A positive image, which comprises subjecting the positive-type photosensitive image-forming material according to claim 5 to scanning exposure with a laser beam in the wavelength range of 650 to 1,300 nm, and then developing with an alkali developer. Forming method.