JPH01231055A - Photosensitive lithographic printing block requiring no dampening water and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve ink repellency and durability for printing of a silicone rubber layer by incorporating microcapsules housing a photosetting compsn. in the inside into a positive photosensitive layer. CONSTITUTION:A photosensitive layer contains microcapsules housing a photo- solubilizing compsn. and a photosetting compsn. in the inside. Said photo- solubilizing compsn. is not critically restricted so far as it is suited to a usual photosensitive lithographic printing block, but a compsn. contg. an ortho quinonediazide compd., or a compsn. contg. a compd. which generates an acid by the irradiation with active rays or a compd. decomposed by an acid, is preferred. Preferred photosetting compsn. to be encapsulated in the microcapsule is a photopolymerizable compsn. contg. an ethylenic unsatd. compd. and a photopolymn. initiator, or a compsn. contg. a photosensitive diazonium compd. Thus, a printing block having superior ink repellency and durability for printing of a silicon rubber layer is provided.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a positive type photosensitive lithographic printing plate that does not require dampening water and has a silicone rubber layer as an ink repellent layer, and a method for producing a photosensitive lithographic printing plate that does not require dampening water. This article concerns a method for producing a lithographic printing plate that does not require dampening water to obtain a printing plate that can be printed on.

(Prior Art) Many photosensitive lithographic printing plates that do not require dampening water have been proposed, which are comprised of a substrate, a silicone rubber layer provided on the substrate, and a photosensitive layer provided on the silicone rubber layer.

Among these known techniques, regarding positive type photosensitive lithographic printing plates that do not require dampening water, for example, Japanese Patent Publication No. 53-'l'7
3g3, JP Sho AI-b/, 3, JP Sho kA-23
It is described in No. 7'IO, etc.

(Problems to be Solved by the Invention) However, these positive type photosensitive lithographic printing plates that do not require dampening water have insufficient adhesive strength between the photosensitive layer and the silicone rubber layer, and are inferior in printing durability. For example, Tokuko Sho 55-'
Publication No. 173gJ discloses that the photosensitive layer can be photosensitive by containing a silane coupling agent or a silicone primer in the silicone rubber layer or by providing an adhesive layer of a silane coupling agent or silicone primer between the photosensitive layer and the silicone rubber layer. It has been proposed to improve the adhesive force between the silicone rubber layer and the silicone rubber layer, but if these methods are followed, the ink repellency of the silicone rubber layer in the non-image area is reduced, resulting in scumming.

In this way, with conventional technology, improving the printing durability results in poorer ink repellency of the silicone rubber layer, and conversely, improving the ink repellency of the silicone rubber layer results in poorer printing durability. It was difficult to satisfy both requirements of ink repulsion.

On the other hand, a printing plate material that does not require dampening water and uses microcapsules containing a photocurable composition in its inner phase was disclosed in JP-A-2-1g.
It is disclosed in Japanese Patent No. 7331. This is on the board,
A microcapsule layer and a silicone rubber layer are coated in this order, and the microcapsules are destroyed by applying heat and/or pressure, and the contents of the unexposed areas of the microcapsules are transferred to the upper silicone rubber layer. leached,
This forms an ink-receptive image area. With this method, a printing plate material that does not require dampening water can be easily obtained through dry processing. However, if the thickness of the silicone rubber layer is too thick, the contents of the microcapsules will not be leached to the surface of the silicone rubber layer, and sufficient ink receptivity will not be obtained, which will limit the thickness of the silicone rubber layer. Therefore, if the silicone rubber layer is thinned, sufficient ink repellency cannot be obtained, and sufficient printing durability cannot be obtained.

(Means for Solving the Problems) As a result of extensive research to solve the above problems, the present inventor has discovered that microcapsules containing a photocurable composition in the inner phase are contained in a positive photosensitive layer. By doing so, a positive type dampening water-free photosensitive planographic printing plate can be produced which has excellent ink repulsion in the silicone rubber layer and has significantly improved printing durability. The present invention was achieved by discovering that the present invention can be obtained.

That is, the gist of the present invention is to provide a positive type photosensitive lithographic printing plate that does not require dampening water and includes a substrate, a silicone rubber layer provided on the substrate, and a photosensitive layer provided on the silicone rubber layer. a dampening water-free photosensitive lithographic printing plate, characterized in that it contains microcapsules containing (a) a previously dissolved composition, and (b) a photocurable composition as an internal phase;
In addition, in the method for producing a dampening water-free lithographic printing plate from the dampening water-free light-sensitive lithographic printing plate, image exposure is performed on the dampening water-free light-sensitive lithographic printing plate, and unexposed areas are exposed by pressure. A method for producing a lithographic printing plate that does not require dampening water, which comprises exposing the entire surface to light after destroying the microcapsules, and performing development at an arbitrary stage after the image exposure to remove the photosensitive layer in the exposed area. exists in

The present invention will be explained in detail below.

The substrate used in the present invention is not particularly limited as long as it can be attached to a lithographic printing machine, has flexibility, and can withstand the load applied during printing.

For example, paper such as coated paper; metal plates such as aluminum, iron, and zinc; organic polymer films such as polyolefin (e.g., polyethylene and polypropylene), polyester (e.g., polyethylene terephthalate, etc.), and polyamide; Further, examples include composites of materials other than the above-mentioned metal plates and metal foils such as aluminum foil. Further coating may be applied to these surfaces for the purpose of preventing halation, or the substrate may be paper, organic polymer film, etc. impregnated with or dispersed with an ultraviolet absorber for the purpose of preventing halation. is also possible.

The silicone rubber layer preferably used in the present invention is
It also consists of a silicone rubber obtained by crosslinking an organopolysiloxane having the following repeating units as a main component.

(In the formula, n is an integer of 1 or more, Hl and R2 are hydrogen atoms, unsubstituted or substituted (e.g., halogen atoms, cyano groups, amine groups) alkyl groups, alkenyl groups, or phenyl groups having 1 to IO carbon atoms. Randomly selected from
In particular, it is preferred that 60% or more of R1 and R2 be methyl groups. ) The molecular weight is arbitrary, but the viscosity at 25°C is /~/0. Preferably, θOO Stokes.

In order to crosslink these organopolysiloxanes to form a silicone rubber, a hydroxyl group, a hydrolyzable group (for example, an acyloxy group, an alkoxy group,
Crosslinking is carried out by a condensation reaction using an organopolysiloxane bonded with ketoximate groups, amino groups, amide groups, etc.

In the present invention, organopolysiloxanes having hydroxyl groups bonded to both ends are particularly preferably used, and specific examples thereof include α,ω-dihydroxydimethylpolysiloxane.

These have two hydrolyzable groups directly bonded to the silicon atom.
It is preferable to add a silicon compound having at least 1 silicon compound, a so-called crosslinking agent.

Specific examples of crosslinking agents include γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, methyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, and methyltrimethoxysilane. Examples include acetoxysilane, vinyltris(methylethylketoxime)silane, and methyltris(methylethylketoxime)silane.

Furthermore, organopolysiloxanes in which a hydrogen atom is directly bonded to a silicon atom, such as α,ω-dihydroxypolyhydrodienemethylsiloxane, α,ω-bis(trimethylsilyl)polynohydrodienemethylsiloxane, /
, ,7. S,? , q-hentamethylcyclopentasiloxane, etc. may be added.

Generally known metal catalysts such as organic tin compounds and organic titanium compounds are added as catalysts for curing silicone rubber, and these catalysts may also be added for curing the silicone rubber of the present invention. is preferred.

Specific examples include dibutyltin dilaurate, tributyltin acetate, dibutyltin dilaurate, tetraethyl orthotitanate, and tetraethyl orthotitanate. These catalysts are preferably used in an amount of 0.07 to 5% by weight, particularly preferably 0.02 to 2% by weight, based on the total weight of the silicone rubber.

It is also useful to add inorganic fillers such as silica and calcium carbonate for reinforcement purposes.

In order to form the silicone rubber layer of the present invention, each of the above components is mixed with cyclohexane, methylsifumi hexane,
Silicone made into a solution by dissolving it in a mixed solvent of aliphatic hydrocarbons such as n-hexane, n-hebutane, co-methylhexane, or a small amount of aromatic hydrocarbons such as benzene, toluene, xylene, etc. When a rubber solution is applied according to a conventional method and dried for a short time, usually at 90°C to 100°C,
The solvent evaporates and a still sticky silicone rubber layer forms. When this is further heat-treated at a temperature ranging from 150 DEG C. to 150 DEG C. for several minutes or more, a fully cured non-adhesive silicone rubber layer is formed.

In the present invention, the preferred thickness of the silicone rubber layer is 0.
．． The thickness is 7 to 200 μm, more preferably 7 to 7003 m1, and even more preferably λ to SO μm.

The pre-solubilized composition used in the photosensitive layer of the present invention is not particularly limited as long as it is used in ordinary photosensitive lithographic printing plates, but preferred examples include the following (1) and (2).
can be mentioned.

(11 Compositions Containing Orthoquinone Diazide Compounds Examples of orthoquinone diazide compounds include, for example, those described in Japanese Patent Publication No. Sho q3-Yug'103 (11), polycondensate of pyrogallol and acetone, and eunaphthoquinone-codiazide. -q-, l@-ter-sulfonic acid ester, % open 13E!; Examples include -2-diazide-q- or -S-sulfonic acid esters of polycondensation resins of phenols and aldehydes or ketones such as -2-diazide-q- or -ter-sulfonic acid esters. The esterification rate of orthonaphthoquinonediazide group is /!
;-KO% is preferred.

As an orthoquinonediazide compound, Tokuko Sho 5O-5θ
The condensation product of para-substituted phenol/formalin resin and sulfonyl chloride of orthobenzoquinonediazide or orthonaphthoquinonediazide described in Publication No. S3 may also be used.

The para-substituted phenols used in this para-substituted phenol/formalin resin include para-cresol, para-substituted phenol,
1-Butylphenol, paraethylphenol, paraethylphenol, paraisopropylphenol, para-
Examples include n-butylphenol, paraoctylphenol, parabenzylphenol, paraphenylphenol, paramethoxyphenol, parabenzyloxyphenol, paracarboxyethylphenol, parahydroxybenzenesulfonate ethylphenol, and paraacetophenol.

Furthermore, examples of the orthoquinone diazide compound include polyhydroxybenzophenone/2-naphthoquinone-2-diazide-gu or -5-sulfonic acid ester.

This polyhydroxybenzophenone is a compound obtained by substituting two or more hydrogen atoms of benzophenone with hydroxyl groups, such as dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, pentahydroxybenzophenone, octahydroxybenzophenone, or a derivative thereof (such as a halogen atom, substituents of alkyl groups, aryl groups, aralkyl groups, carboxyl groups, etc.). Preferably trihydroxybenzophenone or tetrahydroxybenzophenone, more preferably λ, J, p-1-lyhydroxybenzophenone, 2.3. +, 9'-tetrahydroxybenzophenone.

The esterification rate is preferably 30 to 100%.

In addition, "Light-8 sensitive System" written by J. Kosar.
s”) No. 339-3 Octopus (/qbs), John Wiley & Sons
5ons) (New York) and double knee varnish.
Day Forest (W, S, D, Forest
) Author [Photoresist J (” Photores
ist”) Volume 50.

(1973), McGraw-H
New York), Special Publications No. 37-7753, No. 37-3627, No. 77-73109, No. 77-73109, No. 9θ-3g01, No. 11S-5
6olI issue, same%5-273daS issue, same! ;/ -73
No. 073, JP-A-1Ig-qA57! i No., same g-Otsu 3g02, same Ig-Otsu 3g03, same 3g-da 3
The orthogynondiazide compounds described in the '13/issue publications can also be praised.

As the orthoquinonediazide compound, each of the above compounds may be used alone, or two or more thereof may be used in combination.

(2) Composition containing a compound that can generate an acid when irradiated with actinic rays and a compound that can be decomposed by an acid. Examples of compounds that can be decomposed by an acid include, for example, Japanese Patent Application Laid-Open No. Sho'Ig-9003. Acetal or O as described,
N-acetal compound, a compound having an orthocarboxylic acid ester group and/or a carboxylic acid amide acetal group described in JP-A No. 5/-/2θ7/'I, JP-A-Sho 5
3-/, a polymer having an acetal group or a ketal group in the main chain as described in JP-A No. 33'129, or JP-A-Sho!
;b-/')3'l! ; A polymer having an orthocarboxylic acid ester group in its main chain as described in Japanese Patent Application Publication No. 1986, a compound having the following structural unit as described in JP-A No. 1987-1999, Euco θ9&, S-/, -C-Y " (where X and (Y is each 10- or / -N, and X and Y may be the same or different.) A compound having the following structural unit described in JP-A-10-10.2Q7 .

11/ -C-0-8i- \ Compound -C-0-8L- having a silyl ether group represented by the following structural unit described in JP-A No. 1.0-/l/lI'lA .

These acid-decomposable compounds may be used alone or in combination of 1.2 or more.

Compounds that can generate acid upon irradiation with actinic rays include:
Various known compounds and mixtures may be mentioned. For example, diazonium salts, phosphonium salts, sulfonium salts, and hyotonium BF, -1PF6-1S b F6-1
Salts such as SiF6-, CIO4-, organic compounds, orthoquinone-diazide sulfonyl chloride, and organometallic/organic compounds are also actinic radiation-sensitive components that form or separate acids upon irradiation with actinic radiation. and can be used as an acid-generating compound. In principle, all organic hydrogenic compounds which are known as free-radical-forming photoinitiators are compounds which form hydrogenic acid and can be used as acid-generating compounds.

Examples of the aforementioned hydrohalic acid-forming compounds can be found in US Patent Specification Box 3.5/&! ; No. 52, same No. 3.
334 #g No. 9 and the same No.? , 779? 7
g and West German Patent Publication No. 2. Ori No. 6.27, for example, and also, for example, West German Patent Publication No. QA/0. g Id , a compound that generates an acid under photolysis pressure as described in No. 2 can also be used.

Furthermore, JP-A-55-7477.2A', JP-A-55-2'l//3, JP-A-55-7774.2
Publication No. 0-3626, Japanese Unexamined Patent Publication No. 1986-
/3g! ; Co-halomethyl-/, as described in Publication No. 39;
3. 'I-oxadiazole compounds and the like can also be used.

Specific examples of acid-generating compounds include JP-A-5A-/') J
The following can be mentioned as described in 'lj publication.

t-(di-n-propylamine)-benzenediazonium tetrafluoroborate, da-11-) lylumeryl pyctochloride, S-jetoxy-benzenediazonium hexafluorophosphate and tetrafluoroborate,
diphenylamine-ta-cyazonium sulfate),
4'-Methyl-A -1-IJ Chlormethyl-neepilone, 'I-(3,'l,!;-)rimethoxystyryl)-6-dolychloromethylulone, +-(II-methoxy-styryl)- A-(,3
,,3,,3-)lichlorobropenyl)-1-pyrone, 2-trichloromethyl-benzimidazole, cotribromomethyl-quinolone, λ,j-dimethyl-/-tribromoacetyl-benzene, 3-nitro-/- trifuromeacetyl-benzene, goo-dibromoacetyl-benzoe,/, cubis-dibromomethyl-benzene, tris-sifuromemethyl-S-)riazine, 2-(ot-methoxy-naphthyl-niyl)-, ni(naphthi-/-yl) )-, Ni(naphthoxy-niyl)-, -1(derethoxyethylnaphthi/-yl)-, 2-(benzobilani-3-yl)-, Ni(gumethoxy-anthracy/
-yl)- and ni(phenanthyl)-9,bis-trichloromethyl-S-)riazine, and also 0 as described in JP-A-30-31.209.
-Naphthoquinone diazidoke sulfonic acid halides can also be used.

It is preferable to further mix an alkali-soluble resin and/or an organic solvent-soluble resin with the previously solubilized compositions (1) and (2).

Examples of the alkali-soluble resin include phenol, 0
Examples include novolac resins comprising at least seven types of -cresol, m-cresol, and p-cresol and formaldehyde.

Specifically, for example, m-cresol, p-cresol,
Examples include formaldehyde, novolak resin, phenol, m-cresol, p-cresol, formaldehyde, and the like.

Examples of organic solvent-soluble resins include epoxy resins;
Acrylic resins such as methyl methacrylate-methacrylic acid copolymers; polyvinyl acetals such as polyvinyl formal and polyvinyl butyral; polymers having aliphatic hydroxyl groups such as polymers having dihydroxyethyl methacrylate units; N (''-hydroxyphenyl) methacrylate Examples include polymers having aromatic hydroxyl groups such as polymers having amide units.

The last-mentioned organic solvent-soluble resins are particularly preferred, and those having a structural unit represented by the following general formula are preferred.

CONR4YuY-〇H (In the formula, R1 and R2 are hydrogen atoms,) ・Rogen atom, alkyl group, aryl group or carboxyl group, R3
is a hydrogen atom, a halogen atom, an alkyl group, or an aryl group, R4 is a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, Y is an aromatic group that may have a substituent, and X is a nitrogen atom and a carbon atom of the aromatic group, and n is 0 or the number of /. ) Specifically, for example, N-(v-hydroxyphenyl)
Methacrylamide, N-(4-hydroxyphenylcoacrylamide, N-(j-methyl-guhydroxyphenyl)methacrylamide, N-(3,5-dihydroxyphenyl)methacrylamide, N'-(2-hydroxy-gucciano) The structural unit is derived from N-(+-hydroxyphenylethyl)methacrylamide, N-(+-hydroxyphenylethyl)methacrylamide, and the like, and among these, N-(g-hydroxyphenyl)methacrylamide is particularly preferred.

This organic solvent soluble resin may be a homopolymer of the above monomers, but preferably a copolymer with other copolymerizable monomers. Examples of the monomers to be copolymerized include acrylonitrile, methacrylonitrile, Methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate,
Acrylic acid, methacrylic acid, etc. are preferred, and multi-component copolymers with these are preferred.

In the case of the composition containing an orthoquinonediazide compound (1), the orthoquinonediazide compound is preferably contained in an amount of 5 to 60% by weight based on the total solid content in the pre-solubilized composition of the present invention. ! It is more preferable to contain 0% by weight.

Further, the alkali-soluble resin is preferably contained in an amount of 5 to IIo weight %, more preferably 70 to 30 weight %. The organic solvent soluble resin is preferably contained in an amount of 0 to 93% by weight, and more preferably in an amount of Sθ to 90M.

(2) A compound capable of generating an acid upon irradiation with actinic rays;
In the case of a composition containing a compound that can be decomposed by an acid and a compound that can generate an acid, the compound that can generate an acid is contained in the pre-solubilized composition of the present invention in an amount of 0.7 to 1OM% based on the total solid content. is preferable. Compounds that can be decomposed by acids are 5 to 70
Preferably, the content is % by weight. The content of the alkali-soluble resin and/or organic solvent-soluble resin is preferably 30-95% by weight.

It is advantageous to include known exposure-visible image-imparting agents and dyes in the presolubilized composition used in the present invention. As the exposure visible image imparting agent, a substance that generates an acid upon exposure to light is generally used, and as the dye, a compound that forms a salt with this acid is generally used.

As a compound that generates an acid upon exposure to light, a trihaloalkyl compound represented by the following general formula is preferred.

(However, Xa is a trihaloalkyl group having 7 to 3 carbon atoms, W is N or P, Z is 0, S or Se, and Y cyclizes W and Z and forms a chromophore. ) Specific compounds include oxadiazole compounds having a benzofuran ring such as
Tokukai Akira! ; Q-7 (quattrichloromethyl ether (p-methoxystyryl) described in Publication No. 172g)
Examples include '+ 3+ lI-oxadiazole compounds.

Also, Tokukai Akira! ; U-(U, dimethoxy q-styryl)-A described in 3-36:223 publication
-) 'J chloromethyl-corbilon compound, Kotsugubis-(trichloromethyl)-A-p-methoxystyryl-5-) riazine compound, co.

l-bis-()IJdichlorotyl)-A-p~dimethylaminostyryl-5-) riazine compounds and the like.

The amount of the exposed visible image imparting agent added is preferably 0.0 to 20% by weight, more preferably 0.00 to 20% by weight based on the total solid content in the previously dissolved composition. /~10% by weight.

On the other hand, as the dye, any compound that generally forms a salt with an acid can be used, such as triphenylmethane dyes, cyanine dyes, diazo dyes, styryl dyes, and the like.

Specifically, Victoria Pure Blue BOH, Ethyl Violet, Crystal Violet, Brilliant Green, Peisinoku Fuchsin, Eosin, Phenolphthalein, Xylenol Blue, Congo Red, Malachite Green, Oil Blue +603, Oil Pink≠
372, cresol red, auramine, coup-diethylaminophenylimino naphthoquinone, leucomalachite green, leuco crystal violet, and the like. The amount of the dye added is preferably θ, 07 to IOM amount %, more preferably o, o s -g M amount %, based on the total solid content in the photo-solubilized composition.

The photo-solubilizing composition used in the present invention may contain various additives depending on the purpose. For example, surfactants to improve coating properties, various sensitizers to improve sensitivity, such as tetrahydrophthalic anhydride,
Organic acid anhydrides such as glutaric anhydride, organic acids such as glutaric acid, benzoic acid, and tetrahydrophthalic acid, plasticizers, etc. to improve the physical properties of the coating film, and to improve the print ink receptivity of images. , various additives having a hydrophobic group, such as p-octylphenol-formalin novolac resin having an alkyl group with a carbon number of Da or more, p-t-butylphenol-formalin novolak resin, p-t-butylphenol-benzaldehyde resin, etc. can be added.

These components vary depending on the purpose of use, but are usually 0.07 to 30% of the total solid content of the previously dissolved composition.
Preferably, the content is % by weight.

Preferred examples of the photocurable composition encapsulated in microcapsules used in the present invention include the following (3) and (4).
), but is not limited to this.

(3) Photopolymerizable composition containing an ethylenically unsaturated compound and a photopolymerization initiator The ethylenically unsaturated compound includes the following (1) to (V).
There are compounds having a boiling point of 700° C. or higher under normal pressure and having two or more polymerizable terminal ethylene groups such as.

(1) Esters of unsaturated carboxylic acids and aliphatic polyhydroxy compounds and esters of unsaturated carboxylic acids and aromatic polyhydroxy compounds For example, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, diethylene glycol di (meth)acrylate, triethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol triacrylate, hydroquinone di(meth)acrylate
Acrylate, pyrogallol triacrylate, Tip 2
'-bis(cuacryloxydiethoxyphenyl)propane and the like.

<+1)<meth)acrylamide derivatives Examples include ethylene bis(meth)acrylamide, hexamethylene bis(
Examples include meth)acrylamide.

(111) (meth)acrylic acid glycidyl ester and adducts such as amines or carboxylic acids, such as N, N,
N', N'-tetrakis(cohydroxy-3-(
meth)acryloyloxypropyl)xylylenediamine, /,2-bis(2-hydroxy-3-(meth)acryloyloxypropyl)-t,2-dihydroxyethane (adduct of (meth)acrylic acid glycidyl ester and tartaric acid ), etc.

GV) Ring-opened polymer of glycidyl group of (meth)acrylic acid glycidyl ester (in the formula, n is an integer of 2 or more) (V) Side chain as described in JP-A-59-7IO'1g Alternatively, the photopolymerizable photosensitive resin polyfunctional ethylenically unsaturated group having a polyfunctional ethylenically unsaturated group at the terminal may be, for example, the general formula, (wherein R1 is a hydrogen atom, a methyl group, ethyl, l ) represents an alkyl group or a hydroxyalkyl group such as a hydroxymethyl group or a hydroxyethyl group, R2 is a methylene group,
Indicates alkylene groups such as ethylene group and trimethylene group,
R3 represents a hydrogen atom or a methyl group, m is O or/, n
represents m + n = J, and p represents the number /~3. ) include those containing a structural part.

The photopolymerizable photosensitive resin has, for example, the general formula (wherein R', R2, R3, m, n, and p have the same meanings as above, R4 represents a hydrogen atom or a methyl group, and R5
represents a hydrogen atom or a carboxyl group, and q represents the number of θ to 3. ) Examples include resins having units represented by:

Such a resin can be easily obtained by subjecting a polymer having a carboxyl group or a carboxylic anhydride group to a side chain or end to an ester reaction with a polyfunctional ethylenically unsaturated compound having a hydroxyl group by a known method.

Examples of polymers having carboxylic acid or carboxylic anhydride groups in side chains or terminals include (meth)acrylic acid homopolymers, (meth)acrylic acid/(meth)acrylic acid ester copolymers, and styrene/(meth)acrylic acid ester copolymers. Examples include meth)acrylic acid copolymers, styrene/maleic anhydride copolymers, and the like.

The molecular weight of these (co)polymers is /, 000 ~ so
, o o o range is preferred.

Specific examples of the polyfunctional ethylenically unsaturated compound include pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, trimethylo,-ruethane diacrylate, trimethylolethane dimethacrylate, and trimethylol. Propane diacrylate, trimethylolpropane dimethacrylate, dimethylolmethanol diacrylate (glycerin-/, 3-diacrylate), dimethylolmethanol dimethacrylate (glycerin-/, 3-dimethacrylate), trimethylolmethane diacrylate,
Examples include trimethylolmethane dimethacrylate.

As the photopolymerization initiator, conventionally known ones can be used, such as benzoin, benzoin alkyl ether, penzofunone, 2. -2-dimethoxycophenylacetophenone, /-hydroxycyclohexylphenylketone, comethyl-c<'-<methylthio)phenyl]
-Eumorpholino/-propanone, +,lI'-bisdimethylaminobenzophenone, anthraquinone, benzyl, Michler's ketone, a complex system of biimidazole and Michler's ketone, etc. can all be suitably used. In order to effectively sensitize the visible light of an argon ion laser, for example, a composite system of biimidazole and a dialkylaminostyryl derivative, <t,
A-) Lis(trichloromethyl)-/, 3.3-)
Complex system of riazine and cyanine dye derivative, Co, G, A
-ToIJS(trichloromethyl) -/, ,,7.
! -) Composite systems of riazine and thiapyrylium derivatives are preferred.

The amount of the photopolymerization initiator to be used is 0.00% based on the total weight of the ethylenically unsaturated compound. It is preferable to select from the range of / to 2ON amount%.

(4) Composition Containing Photosensitive Diazonium Compound Examples of the photosensitive diazonium compound include the following aromatic diazonium salts.

Gouphenylaminobenzenediazonium salt -morpholinoyu, S-dibutoxybenzenediazonium salt Gouphenylaminobenzenediazonium salt 4-N,N-dimethylaminobenzenediazonium salt 9-N,N-diethylaminobenzenediazonium salt 9-(4I'-methoxy phenylamino)benzenediazonium salt 9-(N-ethyl-N-hydroxyethylamine)benzenediazonium salt q -(q'-methylbenzoylamino)-1,S-jethoxybenzenediazonium salt dianisidine diazonium salt These aromatic diazoniums Examples of the salt include hydrochloride, sulfate, phosphate, double salt of zinc chloride, hexafluorophosphate, or tetrafluoroborate.

As the photosensitive diazonium compound, the following diazo resins are particularly preferred.

Diazo resins contain aromatic diazonium salts such as Hiro-diazodiphenylamine, 3-methoxy-q-diazodiphenylamine, and Gumethoxy-q'-diazodiphenylamine, and activated carbonyl salts such as formaldehyde, acetaldehyde, and benzaldehyde. It is a condensate with a group-containing compound.

Furthermore, aromatic diazonium salts and compounds that do not contain diazonium groups (aromatic amines, phenols, thiophenols, phenol ethers, aromatic thioethers, aromatic heterocyclic Also useful are diazonium salt polycondensation products in which compounds of the formula (selected from aromatic hydrocarbons and organic acid amides) are interconnected by intermediate links derived from condensable carbonyl compounds.

These diazo resins may be water-soluble diazo resins such as hydrochloride, sulfate, phosphate, or double salt of zinc chloride, but organic solvent-soluble diazo resins are preferred from the viewpoint of storage stability. Particularly preferred.

As a diazo resin soluble in organic solvents, Japanese Patent Publication No. 39-7
No. 7 & 02, Tokuko Showa Otsu-/21031, Tokuko Showa 6/
-Goodiazodiphenylamine or q-diazodiphenylamine derivatives such as 3-methoxy-Goodiazodiphenylamine, q-methoxyg'-diazodiphenylamine, and formaldehyde, acetaldehyde, benzaldehyde, etc., as described in Dani No. 23/publications. Reaction products of condensates with active carbonyl group-containing compounds and hexafluorophosphates, tetrafluoroborates, and other Lewis acid salts are useful.

Also, U.S. Patent No. 3.300. J09, the above condensate, sulfonic acids such as para-toluenesulfonic acid or its salts, phosphinic acids such as benzenephosphinic acid or its salts, coaccu dihydroxybenzophenone, 2-hydroxy- Also included are organic solvent-soluble diazo resin organic acid salts which are reaction products with hydroxyl group-containing compounds such as 7-medoxybenzophenone-5-sulfonic acid or its salts.

Further, examples of the diazo resins described in Japanese Patent Publication No. 19-I1gooi that are soluble in organic solvents include, for example, diazodiphenylamine/p-hydroxybenzoic acid/baraformaldehyde polycondensate, diazodiphenylamine・Bis(hydroxymethyl)urea polycondensate, 3-methoxydardiazodiphenylamine・
z, +'-bis(methoxymethyl)diphenyl ether polycondensate, 3-methoxy-p-diazodiphenylamine goomethyl-y'-methoxymethyldiphenyl ether, t'-bis(methoxymethyl)diphenyl ether polycondensate, etc. Examples include hexafluorophosphate, cohydroxy-gumethine benzophenone ter-sulfonate, and mesitylene sulfonate.

The molecular weight of these photosensitive diazonium compounds is, for example,
After separating it as a condensate with β-naphthol under alkaline conditions, it can be measured by gel permeation chromatography (hereinafter abbreviated as GPC).

In the present invention, those having a weight average molecular weight (hereinafter abbreviated as Mw) of 100 to /θ, θ00 in terms of standard polystyrene can be suitably used, and those having SθO to 7,000 are particularly preferred.

The photocurable composition encapsulated in the microcapsules used in the present invention may be a mixture of the components (3) and (4) above.

The photocurable composition encapsulated in microcapsules used in the present invention contains known additives, such as hydroquinone, p-methoxyphenol, di-t-butyl-p-
Cresol, pyrogallol, t-butylcatechol, benzoquinone, 9. Add thermal polymerization inhibitors such as lI'-thiobis(3-methyl-t-t-butylphenol) 1.2'-methylenebis(coumethyl-4-t-butylphenol), coloring agents such as pigments and dyes, etc. be able to.

The microcapsules used in the present invention can be produced by methods known in the art. For example, U.S. Patent No. 2 g 00.4
A method using coacervation of a hydrophilic wall-forming material as described in No. 57, No. zgoθ95g, etc.; US Patent Box J, 2g? ! / jS-'I, British Patent No. 99U13, Tokkosho, 3g-/957tI, same Q,
Interfacial polymerization methods described in U.S. Pat. A
A method by polymer precipitation described in US Patent No. 3.79 & A +23071 etc.; Filtration method using incyanate polyol wall material described in A Otsu No. 9; US Patent Box 3.9/K! ; Method of using isocyanate wall materials as described in US Patent No. 007/
No. 90, same No. OG'137b, same? JII, Og'
Method using urea-formaldehyde-based or urea-formaldehyde-resorcinol-based wall-forming materials described in No. 1g02; wall-forming materials such as melamine-formaltehyde resin, hydroxyglobil cellulose, etc. described in U.S. Patent No. 11.02s, Yss. Method using forming materials; Japanese Patent Publication No. 31. -9/43 issue, Tokukai Akira! ; British Patent No. 952g07, British Patent No. 91. ．． No. 50711; Electrolytic Dispersion Cooling Method; US Patent Box 3. / / No. 7907, British patent cylinder 9.70. Examples include the spray drying method described in No. 22 of F. Although not limited thereto, it is preferable to emulsify the core material and then form a monopolymer film as the microcapsule wall. The particle size of the microcapsules is preferably adjusted to 0.07 to 30 μm, particularly preferably O0S to 10 μm.

When making capsules, water-soluble polymers and surfactants can be used.Water-soluble polymers include water-soluble anionic polymers, nonionic polymers, and amphoteric polymers. Both natural and synthetic compounds can be used, and examples thereof include those having a COO-1sO3- group. Specific anionic natural polymers include gum arabic, alginate,
Semi-synthetic products include carboxymethyl cellulose, phthalated gelatin, sulfated starch, sulfated cellulose, and lignin sulfonic acid.

Synthetic products include maleic anhydride-based (including hydrolyzed) copolymers, acrylic acid-based (including methacrylic acid-based) polymers and copolymers, vinylbenzenesulfonic acid-based polymers and copolymers. , carboxy-modified polyvinyl alcohol, etc.

Examples of amphoteric compounds include gelatin.

As surfactants, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers,
Nonionic surfactants such as polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, glycerin fatty acid esters: fatty acid salts, alkyl sulfate ester salts,
Anionic surfactants such as alkylbenzene sulfonates, alkylnaphthalene sulfone salts, dialkyl sulfosuccinate salts, alkyl phosphate salts, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl sulfate salts; and alkylamine salts, Examples include cationic surfactants such as 9th class ammonium salts and polyoxyethylene alkylamine salts; fluorine-based surfactants.

These dispersion stabilizers may be used alone or in combination of two or more.

As the emulsifying device used for emulsifying and dispersing, one that applies a large shearing force to the processing liquid or one that applies high-intensity ultrasonic energy is suitable. Especially colloid mills, homogenizers, capillary emulsifiers, liquid sirens,
An emulsifying device with an electrostrictive ultrasonic generator and a Pohlmann whistle can give good results.

In the photosensitive layer used in the present invention, the microcapsules containing the photocurable composition in the inner phase preferably have a content of 30 to 93% by weight.1. ! It is more preferable to contain iθ to 90% by weight.

In order to form a photosensitive layer in the present invention, microcapsules containing (a) the pre-solubilized composition and (b) the photocurable composition as an internal phase, and if necessary, other components are mixed with various solvents, e.g. , comethoxyethanol, coethoxyethanol, methyl cellosolve acetate, ethyl cellosolve acetate, /-methoxy-coprobanol, dioxane, tetrahydrofuran, acetone,
Methyl ethyl ketone, cyclohexanone, acetylacetone, dimethylformamide, dimethyl sulfoxide,
Dissolve or disperse in a single solvent such as trichloroethane, or a mixed solvent of two or more solvents. At this time, the coating solvent must not dissolve the microcapsule walls. This is applied according to a conventional method, and usually tI0℃~iso
Dry at °C.

The thickness of the photosensitive layer of the present invention is 0. /~Yθθμm is preferable, 7~100μm is more preferable, and even 2~Sθμm
m is preferred.

The method for producing a photosensitive lithographic printing plate that does not require dampening water of the present invention usually involves the following steps: It is manufactured according to the method (1) or (2) shown below.

(]) A photosensitive layer and a silicone rubber layer are coated on a polymer film in this order, and the substrate and silicone rubber layer are pressed together so that they are in close contact with each other.

(2) The silicone rubber layer provided on the substrate and the photosensitive layer provided on the polymer film are pressed together so that the silicone rubber layer and the photosensitive layer are in close contact with each other.

The polymer film has a thickness of 0. /~SOOμm
of polyethylene, polypropylene, acrylonitrile,
Films include butadiene-styrene copolymer, polystyrene, acrylonitrile-styrene copolymer, polymethyl methacrylate, nylon 6, polyvinyl chloride, polyvinylidene chloride, polyethylene terephthalate, etc., and the surface is subjected to discharge treatment and roughening treatment. It may be a film whose wettability has been improved.

Furthermore, to the extent that the effects of the present invention are not impaired, a silane coupling agent or a silicone primer may be added to the photosensitive layer or the silicone rubber layer for the purpose of improving the adhesion between the photosensitive layer and the silicone rubber layer. good. Similarly, for the purpose of improving the adhesion between the silicone rubber layer and the substrate,
A silane coupling agent, a silicone primer, etc. may be applied onto the substrate, or a silane coupling agent, a silicone primer, etc. may be added to the silicone rubber layer.

The dampening water-free photosensitive lithographic printing plate of the present invention produced as described above is image-wise exposed, and then the microcapsules in the unexposed areas are destroyed by pressure, and then the entire surface of the photosensitive layer is exposed. and after exposing the image,
It can be manufactured by performing development either before or after the pressurization and before or after the entire surface exposure to remove the photosensitive layer in the exposed area. Specifically, the following (1) to (3)
method can be adopted.

(1) After imagewise exposure and development to form a positive image, pressure is applied to destroy the microcapsules, and the entire surface is further exposed.

(2) Image exposure is carried out, the microcapsules in the unexposed areas are destroyed by applying pressure, and a positive image is formed by development, and then the entire surface is exposed to light.

(3) Imagewise exposure is performed, the microcapsules in the unexposed area are destroyed by applying pressure, and after the entire surface is exposed, a positive image is formed by development.

Among the manufacturing methods (1) to (3) above, (1) and (2)
) is a more preferable manufacturing method, and method (1) is particularly preferable because it provides effects such as no background smearing of printed matter.

The above-mentioned image exposure can be performed by a conventional method. Usually, the original film is passed over the photosensitive layer from above the polymer film of the dampening water-free photosensitive lithographic printing plate of the present invention, or after the polymer film is peeled off, the original film is passed through the photosensitive layer using a carbon arc, high-pressure mercury lamp, xenon lamp, or metal halide lamp. A general-purpose light source including ultraviolet rays of 1 gOnm or more and visible light, such as a fluorescent lamp, a tungsten lamp, an argon ion laser, a helium cadmium laser, and a krypton laser, is suitably used.

In the above-mentioned development, when the polymer film is imagewise exposed using a developer, the development process is performed after peeling off the polymer film. This development process dissolves or swells the photosensitive layer in the exposed area, and removes it by rubbing lightly with a sponge or brush, exposing the surface of the ink-repellent silicone rubber layer and forming a non-image area. Although the inclusions in the microcapsules present in the photosensitive layer in the exposed areas are hardened, they are removed together with the surrounding previously dissolved composition by the development process.

The developer used in the development process may be any known developer, but the following are preferred. That is, the developer contains an alkaline agent, water, and if necessary, a specific organic solvent. The specific organic solvent herein refers to a solvent that can dissolve or swell the exposed area (non-image area) of the photosensitive layer when contained in the developer, and that is
An organic solvent having a solubility in water of 70% by weight or less at 0°C). Such organic solvents only need to have the above characteristics. For example, ethyl acetate, propyl acetate, butyl acetate, amyl acetate, benzyl acetate, ethylene glycol monobutylacetate f-
Carboxylic acid esters such as butyl lactate, butyl levulinate; ethyl butyl ketone, methyl butyl ketone,
Ketones such as cyclohexanone; Alcohols such as ethylene glycol monobutyl ether, ethylene glycol benzyl ether, ethylene glycol monophenyl ether, benzyl alcohol, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol; Alkyl substitution such as xylene Aromatic hydrocarbons include halogenated hydrocarbons such as methylene dichloride, ethylene dichloride, and monochlorobenzene. Two or more kinds of these organic solvents may be used. Among these organic solvents, ethylene glycol monophenyl ether and benzyl alcohol are particularly effective. Further, the content of these organic solvents in the developing solution is generally 20% by weight or less, and more preferable results are obtained especially when the content is 70% by weight or less.

On the other hand, the alkaline agents contained in the developer include (A) sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium or ammonium salt of dibasic or tertiary phosphoric acid; Inorganic alkaline agents (B) such as sodium metasilicate, sodium carbonate, ammonia, etc. Mono-, di- or trimethylamine, mono-, di- or triethylamine, mono- or diisopropylamine,
Examples include organic compounds such as n-butylamine, mono-, di-, or triethanolamine, mono-, di-, or triisopropanolamine, ethyleneimine, and ethylenediamine.

The content of these alkaline agents in the developer is usually o,
o o s to 10% by weight, preferably 0103 to 6
Weight%.

Further, the developer may contain a surfactant if necessary. Suitable surfactants include, for example, nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, and monoglyceride alkyl esters; alkylbenzene sulfones; Anionic surfactants such as acid salts, alkylnaphthalene sulfonates, alkyl sulfates, alkylphenyl polyoxyethylene ether sulfates, alkyl sulfonates, sulfosuccinic acid ester salts; amphoteric surfactants such as alkyl betaines, amino acids, etc. agent can be used and 0. The content is suitably within the range of / to 30% by weight.

The above-mentioned pressurizing method is a method of destroying the microcapsules in the unexposed areas and causing the photocurable composition contained in the internal phase to ooze out of the capsules. For example, this can be easily done by passing it between two rolls, or it can also be done by passing it between heated rolls. The applied pressure is not limited to a specific value, but is approximately SO ~ 500 kg/
c! It is preferable to destroy it with a pressure of about rr2.

The above-mentioned full-surface exposure can be carried out in the same manner as the above-mentioned image exposure except that the original film is not used.

(Examples) The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

Note that all parts used in the examples indicate parts by weight.

Example 1 Water 2Sθi in a 50θ-ml stainless steel beaker
, Zonyl-A (surfactant manufactured by DuPont) 7
2.3jj, and pectin3. / g mixture was stirred at room temperature for 20 min, and the pH was adjusted to g, θ using 20% dilute sulfuric acid.
After adjusting this water solution to 70% using a homogenizer
While stirring at θ00 rpm, the following composition sog was added, and stirring was continued for further 7 hours to obtain an emulsion.

Next, in the above emulsion, 75 g of urea in water iog,
Resorcinol in water/θJ 0. lIg, 37% formalin aqueous solution/0. g was added, the temperature was brought to 43° C., and stirring was continued with heating for 3 hours.

Next, the pH was adjusted to 9.0 using a 20% aqueous sodium hydroxide solution, and then allowed to cool to room temperature.

After filtering this, it was washed using water and methyl cellosolve to obtain microcapsules (particle size 1 to IO μm).

(Composition contained in the internal phase of microcapsules)・
Trimethylolpropane triacrylate ioθ part/λ
-Methyl-/-(+-(methylthio)phenyl]-comorpholinopropanone-l 3 parts,
7 parts of terdiethylthioxanthone Next, the following photosensitive solution was applied to a polypropylene film SO-λ with a thickness of approximately SOμm.
Coat it on the inner surface of O/Nako θlu1 paper ■ using Percoater rot and dry it at 60℃ for S minutes to a thickness of about 3μm.
A photosensitive layer was provided.

(Photosensitive liquid) ・Microcapsule 65 parts・N
-(<t-hydroxyphenyl)methacrylamide/acrylonitrile/methyl acrylate/ethyl acrylate/acrylic acid copolymer (mole ratio/0/10//-7/10/J, Mw?2.OθO)
25% by weight ethyl hepteracellosolve solution
ioo part/m-talesol-formalin-novolac resin/2-naphthoquinofucodiazide-
S-sulfonic acid ester (esterification rate 25%, Mw 2.A 00 )
20 parts Victoria Pure Blue BOH/, 2 parts Methyl Cellosolve 200 parts Next,
On this photosensitive layer, the following silicone rubber solution was coated using a spin coater at room temperature and /00 rpm, and then heated at 60°C.
Dry for 3 minutes. After drying, the silicone rubber layer was still sticky.

(Silicone rubber solution) - Dimethylpolysiloxane with hydroxyl groups at both ends (viscosity: OOθStokes, BY/A-g/7 manufactured by Tone Silicone)...
700 parts・Methyltriacetoxysilane・・
・・・・70 parts・Dibutyltin diacetate・
...0.2 parts methylcyclohexane
・・・・・・300 parts On the other hand, on an aluminum plate with a thickness of 0.211 m, using a spin coater, coated at room temperature, / 0
Apply S H-,2:24θ brimer (silicone brimer made by Tone Silicone) at 0 rI)m,
Air-dried for 3 minutes at room temperature.

A polypropylene film on which the photosensitive layer and silicone rubber layer are laminated is placed on top of the polypropylene film using a laminator so that the brimer layer on the aluminum plate and the adhesive silicone rubber layer are in close contact with each other. 0' to 9/cr! L2, / 00 cm was crimped for 1 minute. This was heat-treated at 60° C. for 2 minutes, and then the polypropylene film was peeled off and heat-treated at 60° C. for 20 minutes to fully cure the silicone rubber layer and obtain a photosensitive lithographic printing plate that did not require dampening water.

The thickness of the fully cured silicone rubber layer is approximately 5.
It was μm.

This is passed through a positive original film according to the usual method, and 3K
7 with W high pressure mercury lamp UMH-3ooθ (manufactured by Ushio Inc.)
Image exposure was carried out for 9 minutes from a distance of m.

This was immersed in the following developer at -5° C. for 30 seconds and developed by rubbing lightly. The photosensitive layer was removed in the exposed area, and the ink-repellent silicone rubber layer was exposed.

(Genzuka liquid) Sodium carbonate 73
Part: Polyoxyethylene, nonylphenyl ether, sodium sulfate (manufactured by Nippon Nyukazai ■, product name: Nucor s b O8N)...
...70 copies, Wednesday
.../000 copies using a laminator at 700℃, 200kg/Crn2, /θ0crrL
/min with a heating roller. The entire surface of the plate was exposed to light for a minute from a distance of 7 m using the high-pressure mercury lamp to obtain a lithographic printing plate that did not require dampening water.

Using this plate, printing was carried out with Toyo King Ultra TKU Aquares G sumi ink (manufactured by Toyo Ink Seisakusho) K (manufactured by Toyo Ink Mfg. ■) without supplying dampening water using a printing machine manufactured by San Printing Machinery ■ and a San Offcent 220E. As a result, 500 beautiful prints with no background stains were obtained.

Example λ A dampening water-free photosensitive lithographic printing plate obtained in the same manner as in Example was subjected to image exposure,
Pressure, development, and full-surface exposure were performed in this order to obtain a lithographic printing plate that did not require dampening water.

When printing was carried out under the same conditions as Example/, Example/
obtained similar results.

Example 3 A dampening water-free photosensitive lithographic printing plate obtained in the same manner as in Example 1 was subjected to image exposure,
Pressure, full-surface exposure, and development were performed in this order to obtain a lithographic printing plate that did not require dampening water.

When printing was carried out under the same conditions as Example/, Example/
obtained similar results.

Comparative Example/Example/The photosensitive solution of Example/ was pressed in the same manner as in Example/ without using microcapsules to obtain a photosensitive lithographic printing plate that does not require dampening water.

After image exposure, this was developed using the developer solution, and then printed under the same conditions as in Example 1.
After printing 000 sheets, one part of the print had come off.

(Effects of the Invention) The photosensitive lithographic printing plate that does not require dampening water of the present invention can provide a lithographic printing plate that does not require dampening water and has a silicone rubber layer that has excellent ink repulsion properties and printing durability. , you can print beautiful prints without using dampening water. Therefore,
The present invention is extremely useful industrially.

Claims (2)

[Claims] (1) In a positive type photosensitive lithographic printing plate that does not require dampening water and includes a substrate, a silicone rubber layer provided on the substrate, and a photosensitive layer provided on the silicone rubber layer, the photosensitive layer is (a) 1. A photosensitive lithographic printing plate that does not require dampening water and comprises microcapsules containing a photo-solubilized composition and (b) a photo-curable composition as an internal phase. (2) consisting of a substrate, a silicone rubber layer provided on the substrate, and a photosensitive layer provided on the silicone rubber layer,
From a positive dampening water-less photosensitive lithographic printing plate to a dampening water-less lithographic printing plate, the photosensitive layer comprises microcapsules containing (a) a photo-solubilized composition and (b) a photo-curable composition as an internal phase. In the method for producing a printing plate, the photosensitive lithographic printing plate that does not require dampening water is subjected to image exposure, and after the microcapsules in the unexposed areas are destroyed by pressure, the entire surface is exposed to light, and the A method for producing a lithographic printing plate that does not require dampening water, characterized in that the photosensitive layer in exposed areas is removed by developing at an arbitrary stage.