JP2010146013A - Development acceleration of radiation-sensitive element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive active radiation-sensitive composition having a sensitive and excellent development latitude, excellent in a handling property, and used with an irradiation source. <P>SOLUTION: The positive active radiation-sensitive composition and a radiation-sensitive element include one or more polyvinyl acetal polymers and development acceleration compounds which can be solved within an alkaline aqueous solution. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to the field of radiation sensitive compositions, in particular its use in imaging elements.

  The lithographic process involves building an image (printed) region and a non-image (non-printed) region on substantially the same surface on the substrate. When such a process is used in the printing industry, non-image areas and image areas are adjusted to have different affinity for printing ink. For example, non-image areas may generally be hydrophilic or oleophobic and image areas may be oleophilic.

  Certain types of electronic components can be manufactured using lithographic manufacturing techniques. The types of electronic components that can use radiation sensitive compositions in their manufacture include printed circuit boards, thick film and thin film circuits, including passive elements such as resistors, capacitors and inductors; multichip devices; integrated circuits And active semiconductor devices. Preferably, the electronic component may include a conductor, such as a copper substrate; a semiconductor and an insulator, for example, silica as a surface layer having silicon underneath, and the silica may be selectively etched away to Expose the underlying silicon part. In the context of masks, a desired pattern in the form of a coating is formed on a mask precursor, such as a plastic film, which is then used in subsequent processing steps, such as a printing substrate or electronic component substrate. A pattern can be formed on the material.

  In the past, laser direct imaging (LDI) has been known, which directly forms an offset printing plate or printed circuit board based on digital data from a computer. LDI provides various merits such as better drawing quality, just-in-time processing, improved production yield, no film forming cost, and other known advantages. Significant developments have been observed in the area of lasers. Specifically, solid lasers and semiconductor lasers having a light emission band from near infrared wavelengths to infrared wavelengths, small size, and high energy output have become available as commercial products. These lasers are extremely useful as exposure light sources when LDI is required.

  A heat-sensitive imaging element is classified as a composition that is exposed to a suitable amount of thermal energy and undergoes chemical conversion (s) in response to absorbing that energy. The essence of a chemical transformation induced by heat is the ablation of the composition, or a change in the solubility of the composition in a specific developer, or a change in adhesion to the surface, or a heat-sensitive layer. It is considered that the change of the hydrophilicity or hydrophobicity of the surface of the surface is caused. As such, in the fabrication of printed circuit boards, or in the manufacture of lithographic printing plates, by selectively exposing predetermined areas of a heat sensitive film or layer to heat (distributing thermal energy imagewise). In which a suitably imaged film or layer used as a resist pattern can be produced directly or indirectly. Positive working systems based on novolak-diazoquinone resins are the leading technology for imaging in the computer chip industry (eg, RR Dammel “diazonaphthoquinone-based resists”). (Diazonophothionone-based Resists), Tutorial text No. 11, (SPIE Press, Bellingham, WA 993)).

Photosensitive novolac-diazoquinone resin compositions are also widely used in the production of printing plates. The photosensitive diazonaphthoquinone derivative (DNQ) added to the novolak resin (phenol-formaldehyde condensation polymer) delays the dissolution of the resin. It has been proposed to improve the molecular mechanism of Novolak-DNQ imaging materials (A. Reiser, Journal of Imaging Science and Technology, No. 1). 42, No. 1, January / February 1998, p. 15-22). The report teaches that the fundamental feature of the imaging phenomenon in novolak-diazonaphthoquinone compositions is that the dissolution of the resin is observed to be inhibited, which strongly acts as a dissolution inhibitor. This is because the hydrogen acceptor interacts with the OH group of the resin to form a phenolic chain. Upon exposure, the hydrogen bonds between the phenolic chains are cleaved by a reaction called the Wolff rearrangement, followed by photolysis of the diazoquinone residues of the inhibitor molecule. This rearrangement reaction is not only very fast but also highly exothermic. (ΔH ⁰ is at least −66 kcal / mol). The sudden appearance of such a large heat pulse at the position of the dissolution inhibitor causes a large temperature jump of about 220 ° C. or more. Due to the high temperature generated at the position of the dissolution inhibitor, the phenolic chain is cleaved at the point of attachment to DNQ and becomes inactive (dispersed). This occurs because it cannot be retained by the inducing effect of the dissolution inhibitor. A positive working, direct laser addressable printing form precursor based on a phenolic resin sensitive to UV, visible and / or infrared radiation has already been described. See, for example, US Pat. No. 4,708,925, US Pat. No. 5,372,907 and US Pat. No. 5,491,046.

  In US Pat. No. 4,708,925, the solubility of the phenolic resin in alkaline solution is reduced by using a radiation sensitive onium salt such as triphenylsulfonium hexafluorophosphate instead of DNQ. However, when the onium salt is photolyzed, the original solubility of the resin is restored. The onium salt composition is inherently highly sensitive to UV irradiation and can also be sensitive to infrared irradiation. In US Pat. No. 6,037,085 and US Pat. No. 5,962,192, a thermal laser sensitive composition based on an azide material and having a dye component added to obtain the required sensitivity. Things are described.

  A wide range of heat-inducing compositions useful as heat-sensitive recording materials are disclosed in British Patent 1,245,924, in which predetermined regions of the imageable layer are defined at various locations. Solubility in a given solvent is determined by indirect exposure to short-term transmission or reflection of high-intensity visible and / or infrared radiation from the background area of the image originally in contact with the recording material. Can be raised by heating. Several systems have been described that operate in many different mechanisms and use a variety of developing materials, from water to chlorinated organic solvents. The range of water developable compositions disclosed includes those containing novolac type phenolic resins. That patent describes a coating film of such a resin whose solubility increases when heated. The composition may contain a light-absorbing compound such as carbon black or miloli blue (CI Pigment Blue 27), the raw materials of which are further images for its use as a recording medium. Coloring.

  Other compositions containing dissolution-inhibiting raw materials are also described in the patent literature. Examples of such patents include WO 97/39894, WO 98/42507, WO 99/08879, WO 99/01795, WO 99. / 21725 pamphlet, US Pat. No. 6,117,623, US Pat. No. 6,124,425, EP 940266, and WO 99/11458. However, infrared dyes or the like function primarily as radiation absorbers and have a minimal binder dissolution function in the exposed areas.

  U.S. Pat. No. 5,840,467 (Kitatani et al.) Describes a positive working image recording material that absorbs heat by absorbing a binder, infrared or near infrared. Includes light-to-heat conversion materials that can be generated, and materials that can be thermally decomposed, which can substantially reduce the solubility of the material when the material is in an undegraded state. Specific examples of the thermally decomposable substance include diazonium salts and quinonediazides. Specific examples of the binder include phenol resin, acrylic resin, and polyurethane resin. Various pigments and dyes can be specifically mentioned as potential light-to-heat conversion materials such as cyanine dyes. An image recording material can also be coated on a suitable substrate to create an imageable element. The element thus fabricated can be irradiated imagewise using laser light and the irradiated area can be removed using an alkaline developer.

  Several substances have been reported that can improve the sensitivity of positive working compositions. Cyclic acid anhydrides as sensitizers are described in US Pat. No. 4,115,128, examples of which include phthalic anhydride, succinic anhydride and pyromellitic anhydride. . Phenols and organic acids are also described in JP-A-60-88942 and JP-A-2-96755. Specific examples include bisphenol A, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid, terephthalic acid Examples include acids, lauric acid, and ascorbic acid.

  A positive radiation-sensitive composition for use with an irradiation source includes one or more polymers that can be dissolved in an alkaline aqueous solution, and a development accelerating compound. The present invention is a positive working, radiation sensitive composition with good sensitivity for use with an illumination source in lithographic applications such as conventional imaging systems, computer platemaking systems, or other direct imaging elements and applications. Offer things. The composition is stable in that state until exposed to light and has excellent handling properties.

  In a first broad aspect of the invention, a radiation sensitive composition is provided comprising at least one aqueous alkali soluble polymer and a development accelerating compound. The composition preferably includes a radiation-to-heat compound that matches the sensitivity range of the composition to the wavelength of the radiation source.

  In a second broad aspect of the invention, a positive working imageable element is provided, which includes a coating (including a composition as described above) on a substrate. . The imageable element is capable of forming an image by irradiation, preferably infrared irradiation, and can be developed using an aqueous alkaline developer solution.

  The present invention further provides a positive working lithographic printing precursor comprising a coating on a hydrophilic lithographic substrate having a hydrophilic lithographic printing surface, the coating comprising a composition as described above. Including product). The precursor can form an image by irradiation, preferably infrared irradiation, and can be developed using an aqueous alkaline developer solution. In a further aspect of the invention, there is provided a positive working lithographic printing master comprising a precursor as described above, which is imaged and developed. As a further aspect of the invention, a method is provided for preparing the precursors and masters thereof.

  As a result of intensive studies on positive working radiation sensitive compositions, the inventors have shown that certain combinations of aqueous alkaline soluble polymer compounds and certain development accelerating compounds provide the desired level of developability. In addition, it has been found that it is possible to produce a positive working lithographic printing precursor that requires less total irradiation energy compared to the absence of such development promoting compounds.

  In the present invention, the positive-type radiation-sensitive composition for use with an irradiation source includes one or more polymer compounds that can be dissolved in an alkaline aqueous solution as the polymer component (A), and a component ( B), that is, what is referred to herein as a development promoting compound (B).

  This polymer component (A) has some solubility in an alkaline aqueous solution, but preferably has low solubility. In the radiation-sensitive layer formed from the composition of the present invention, the polymer is either due to its inherent low solubility or to the interaction of parts within its own molecule, such as by hydrogen bonding, or to the composition. Low solubility due to any interaction with other substances involved.

  The positive working radiation sensitive composition of the present invention can be coated onto a substrate and dried to form a radiation sensitive imageable layer, thereby creating an imageable element. In a preferred embodiment of the present invention, the positive working radiation sensitive composition is coated onto a hydrophilic lithographic substrate and dried, thereby forming a positive working lithographic printing precursor. When the imageable layer is exposed to light, it is easily dissolved by the alkaline aqueous solution. By adding the development accelerating compound (B) (see below for details), the energy required for exposure to give the composition the desired level of developability is in the case of a coating that does not contain the development accelerating compound (B). Compared to lower. The areas of the coating that are not exposed to radiation (and therefore not heated by absorption and conversion of radiation to heat) do not show a significant change in the dissolution rate in the developer. In fact, the addition of the development accelerating compound (B) increases the solubility of the coated and dried composition in an alkaline aqueous solution to some extent, whereas the coating and drying upon irradiation is increased. The improvement in solubility of the resulting composition is significantly accelerated. Thereby, the developability of the image formed by irradiation is improved. The solubility of the irradiated area does not return to its pre-irradiation value no matter how much time passes after such irradiation.

  For purposes of the present invention, increasing the dissolution rate of the coating means should be understood to mean increasing the amount effective in the imaging process. It does not include an increase that is less than an effective amount in the image forming process. The present invention provides a positive radiation sensitive composition for use with an irradiation source in lithographic applications such as conventional imaging systems, computer platemaking systems, or other direct imaging elements and applications. It is stable in that state until it is exposed and has excellent handleability.

  US Pat. No. 6,255,033 (Levanon et al.) Describes polyvinyl acetal polymers having phenolic groups, and further grafts or condenses aldehydes on polyvinyl alcohol by an acetalization reaction. The synthesis method is also described. In the present invention, this polyvinyl acetal polymer can be used alone or in combination with another resin, for example, the polymer component (A) of the present invention. All of US Pat. No. 6,255,033 is incorporated herein. The general structure of the polymer is represented by the following formula:

Here, R ¹ is —C _n H _{2n + 1} (where n = 1 to 12), and R ² is

here,
R ⁴ = —OH;
R ⁵ = —OH or —OCH ₃ or Br— or —O—CH ₂ —C≡CH, and R ⁶ = Br— or NO ₂ ;
R ³ = — (CH ₂ ) _t —COOH, —C≡CH, or

Where R ⁷ = COOH, — (CH ₂ ) _t —COOH, —O— (CH ₂ ) _t —COOH,
And here t = 1-4, and where
b = 5-40 mol%, preferably 15-35 mol%
c = 10-60 mol%, preferably 20-40 mol%
d = 0 to 20 mol%, preferably 0 to 10 mol%
e = 2 to 20 mol%, preferably 1 to 10 mol%, and f = 5 to 50 mol%, preferably 15 to 40 mol%.

The polyvinyl acetal polymer of US Pat. No. 6,255,033 used in the present invention can be represented as follows:
(I) a tetrafunctional polymer in which the repeating units comprise vinyl acetate and vinyl alcohol residues and first and second cyclic acetal groups, or (ii) the repeating units therein are vinyl acetate A pentafunctional polymer comprising a residue, a vinyl alcohol residue, and first, second and third cyclic acetal groups. All three acetal groups are 6-membered cyclic acetal groups. One of them is substituted with an alkyl group and the other is substituted with an aromatic group having hydroxyl-, or hydroxyl- and alkoxyl-, or hydroxyl-, and nitro- and bromine-groups. And the third is substituted with a carboxylic acid group, a carboxylic acid substituted alkyl group, or a carboxylic acid substituted aryl group.

  Examples of suitable aldehydes that can be used to prepare the first cyclic acetal group of the polyvinyl acetal polymer used in the present invention include: acetaldehyde, propionaldehyde, n-butyraldehyde, n-valeraldehyde, n-carbaldehyde. Proaldehyde, n-heptaldehyde, isobutyraldehyde and isovaleraldehyde, mixtures thereof, and the like.

  Examples of suitable aldehydes that can be used to prepare the second cyclic acetal group of the polyvinyl acetal polymer used in the present invention include 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 2-hydroxy -1-naphthaldehyde, 2,4-dihydroxybenzaldehyde, 3,5-dibromo-4-hydroxybenzaldehyde (hydroxybenzaldehyde), 4-oxypropynyl-3-hydroxybenzaldehyde, vanillin, isovanillin and cinnamaldehyde, mixtures thereof, and the like It is.

  Examples of suitable aldehydes that can be used to prepare the third cyclic acetal group of the polyvinyl acetal polymer used in the present invention include glyoxylic acid, 2-formylphenoxyacetic acid, 3-methoxy-4-formylphenoxyacetic acid. And propargyl aldehyde, mixtures thereof, and the like.

  This polymer is advantageous in that a large number of different functional groups can be incorporated therein to provide properties tailored to a particular application. Long chain alkyl aldehydes can be used to lower the softening point (Tg) of the polymer and facilitate the lamination of dry film photoresists. Aromatic aldehydes such as cinnamaldehyde can be used to increase the lipophilicity of the composition used in the printing plate. The polymer compound used as the polymer component (A) in the present specification has a weight average molecular weight of 2,000 to 300,000 and a polydispersity index (weight average molecular weight / number average molecular weight) of 1.1 to 10. Preferably there is.

  As the polymer component (A), a single polymer may be used by itself, or two or more polymers may be used in combination. The amount is 30 to 95% by weight, preferably 40 to 95% by weight, particularly preferably 50 to 90% by weight, of the total solid content in the composition. When the amount of the polymer component (A) added is less than 30% by weight, the durability of the imageable layer made from the composition becomes inferior. When the addition amount exceeds 95% by weight, the sensitivity to radiation decreases.

The development accelerating compound used as component (B) may be any one or more of the following classes of compounds:
1. Hydroxyl and thiol-containing compounds such as alcohols, phenols, naphthols, thiols and thiophenols. The alcohol may have an alkyl radical containing 12 to 60 carbon atoms, or a fluoroalkyl containing 4 to 60 carbon atoms, or a fluoroalkylaryl containing 7 to 60 carbon atoms. One example of a suitable polyol is dimethicone copolyol SF1488. One example of a monohydric phenol is nonylphenol. Examples of dihydric phenols are resorcinol and alkylresorcinol, such as 4-hexylresorcinol and n-dodecylresorcinol. Examples of trihydric phenols include pyrogallol, phloroglucinol, 1,2,4-benzenetriol, and their alkyl or fluoroalkyl derivatives. One example of a suitable thiol-containing compound is 1-phenyl-1H-tetrazole-5-thiol. One example of naphthol is 1-naphthol.

2. Anionic lithium salt, one of carboxylate, thiocarboxylate, sulfate, sulfonate, phosphate, phosphite, nitrate and nitrite. Examples of lithium salts of organic acids include lithium 3- (1H, 1H, 2H, 2H-fluoroalkyl) propionate and lithium 3-[(1H, 1H, 2H, 2H-fluoroalkyl) thio] propionate, Examples include lithium trifluoromethanesulfonate and lithium perfluorooctylethylsulfonate.

3. Esters and amides of phosphorus-containing acids, preferably having a free hydroxyl group. Examples of phosphorus-containing esters are P (OH) (OR) ₂ , P (OH) ₂ (OR), P (OH) ₂ [O—R—N (CH ₂ —CH ₂ —OH) ₂ ], P ( OR) ₂ [O—R—NH (CH ₂ —CH ₂ —OH) ₂ ], wherein R is alkyl, aryl, alkylaryl, polyethylene oxide, polypropylene oxide, or combinations thereof In addition, here, the R radical may contain a fluorine atom. Other suitable compounds include alkylphosphonic acids, R—P (O) (OH) ₂ , and esters and salts thereof, where R is as defined above. Examples of suitable phosphorus-containing amides include P (OH) (ONHR) ₂ , P (OH) ₂ (ONHR), P (OR) ₂ [O—NH (CH ₂ —CH ₂ —OH) ₂ ], P (OR) [O—NH (CH ₂ —CH ₂ —OH) ₂ ] _{2 and the} like, where R is alkyl, aryl, polyethylene oxide, polypropylene oxide, and combinations thereof, where R The radical may contain a fluorine atom.

4). Polysiloxane containing free hydroxyl groups. The free hydroxyl group is preferably terminal. Examples of suitable compounds include those of the structure R [OSi (OCH ₃ ) ₂ ] _n —Si (OCH ₃ ) (OH) ₂ , where R is alkyl (alkyl), aryl , Polyethylene oxide, polypropylene oxide groups, or combinations thereof, n is between 2 and 1000.

5. A quaternary ammonium salt of a phosphorus-containing acid, preferably containing a free hydroxyl group. An example of a quaternary ammonium salt containing a hydroxyl group is the diethanolamine salt of perfluoroalkyl-substituted polyethylene oxide phosphorous acid.

6). A compound containing an azo functional group -N = N-.
Examples of this type of compound include:
-Azonitrile, for example 2-[(1-cyano-1-methyl) azo] formamide,
Azoamide compounds such as 2,2′-azobis (2-methyl-N- [1,1-bis (hydroxyethyl) -2-hydroxyethyl] propionamide),
Azoamidine and cyclic azoamidine compounds such as 2,2′-azobis (2-amidinopropane) dihydrochloride,
-Other azo compounds such as 2,2'-azobis (2-methylpropionamidooxime).

7). Linear and cyclic compounds containing the following groups:

Examples of linear compounds include the following:

Where R ¹⁰ = CH ₃ —C ₆ H ₄ —SO ₂ — or C ₆ H ₅ —SO ₂ —, and R ¹¹ , R ¹² = —C _n H _{2n + 1} (where n = 1 to 20), And where R ¹ and R ² are present as one of the following combinations:
R ⁸ = H and R ⁹ is one of the following: C ₆ H ₅ —SO ₂ —, CH ₃ —C ₆ H ₄ —SO ₂ —, —SO ₂ —C ₆ H ₄ —O—C ₆ H ₄ —SO ₂ —NH—NH ₂ , and —SO ₂ —C ₆ H ₃ (CH ₃ ) —O—C ₆ H ₃ (CH ₃ ) —SO ₂ —NH—NH ₂ , and R ⁸ = —CONH ₂ and R ⁹ is one of C ₆ H ₅ —SO ₂ — and CH ₃ —C ₆ H ₄ —SO ₂ —.
Examples of cyclic compounds include benzotriazole, 5-phenyl-1H-tetrazole, and 1-phenyl-1H-tetrazole-5-thiol.
Some of the above compounds are also used as blowing agents.

8). A compound having the following structure:

Where X is one of -S-, S = O, C = O, C-O (NH) or C = O (O), wherein R ¹³ is H or C ₁ -C ₁₂ alkyl, benzyl or structure E, where E is given by:

And here, R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ may be one of Br, Cl, F, NO ₂ , H or OH. .
Examples of such compounds include 2,2 ′, 4,4′-tetrahydroxy-diphenyl sulfide and 2,2 ′, 4,4′-tetrahydroxy-diphenyl sulfoxide.

9. Substituted aromatic amides, acids and their esters such as 2,4-dichlorobenzamide, 3-nitrobenzamide, 2-nitrobenzoic acid, 3-nitrobenzoic acid, 2,4-dinitrobenzoic acid, 2,4-dichloro Benzoic acid, 2-hydroxy-1-naphthoic acid, 2,4-dihydroxybenzoic acid, methyl salicylate, phenyl salicylate, methyl 4-hydroxybenzoate (methyl-4-hydroxybenzoate), butyl 4-hydroxybenzoate, etc. .

10. Sulfone, for example dimethyl sulfone.

  In order to provide light absorption of laser energy in the composition of the present invention, a radiation-to-heat conversion compound (C) capable of absorbing incident radiation, preferably infrared radiation, and converting it to heat. ) Is preferably included in the coating composition. The radiation-to-heat conversion compound suitable for the heat-sensitive composition of the present invention can be selected from a wide range of organic and inorganic pigments such as carbon black, phthalocyanine or metal oxides. Green pigments Heliogen Green D8730, D9360, and Fanal Green D8330 (manufactured by BASF); Predisol 64H-CAB678 (manufactured by Sun Chemicals), and black pigment Predisol CAB2604, Predisol N1203, Predisol Black CB-C9558 (manufactured by Sun Chemicals Corp.) and the like are effective heat absorbing pigments. By way of example, other types of materials having absorption in the near infrared region are known to those skilled in the art. Infrared absorbing materials suitable for use as radiation-to-heat conversion compounds are those having absorption at wavelengths longer than 700 nm, for example about 700-1300 nm, where near infrared (about 700-1000 nm) absorbing materials are Generally used.

  The dyes that can be used as the infrared laser-sensitive composition are various known infrared dyes. Specific examples of dyes that absorb infrared light or near infrared light include cyanine dyes (Japanese Patent Laid-Open Nos. 58-125246, 59-84356, and 59-202829). , And disclosed in JP-A-60-78787); methine dyes (disclosed in JP-A-58-173696, JP-A-58-181690, and JP-A-58-194595); naphthoquinone dyes (Japanese Patent Laid-Open Nos. 58-112793, 58-224793, 59-48187, 59-73996, 60-52940, and 60) Disclosed in JP-A-63744); squarylium colorant (disclosed in JP-A-58-112792); substituted arylbenzo (thio) pyrylium salt (US Pat. No. 3) 881,924); Trimethine thiapyrylium salt (described in JP-A-57-142645 (US Pat. No. 4,327,169)); 181051, JP 58-220143, JP 59-41363, JP 59-84248, JP 59-84249, JP 59-146063, and JP-A-59-146061); cyanine colorant (described in JP-A-59-216146); pentamethine thiopyrylium salt (described in US Pat. No. 4,283,475); And pyrylium compounds, Epolite III-178, Epolite III-130 and Epolite (Epol) ght) III-125 (described in KOKOKU 5-13514 and JP fair 5-19702 JP), and cyanine dyes (described in British Patent No. 434,875), and the like.

  The pigment or dye is contained in a radiation sensitive layer or other composition for the printing plate, such as an etching resist, in an amount of 0.01 to 30% by weight, based on the total solids in the raw material for the printing plate, The amount is preferably 0.1 to 10% by weight, particularly preferably 0.5 to 10% by weight in the case of dyes and 3 to 13% by weight in the case of pigments. When the pigment or dye content is less than 0.01% by weight, the sensitivity is lowered. If the amount is more than 30% by weight, the homogeneity of the photosensitive layer is lost, and the durability and other properties of the imageable layer such as etching resistance are lowered.

  In a further embodiment of the invention, the positive radiation-sensitive medium of the invention is prepared without the radiation-to-heat conversion compound (C). The radiation-sensitive medium is separate from the layer containing the converting compound (C) but can be incorporated into a positive working lithographic printing precursor in an immediately imageable layer. Although it is possible to coat the layer containing the conversion compound (C) on the imageable layer containing the medium capable of being imaged by radiation, the layer containing the conversion compound (C) is imaged. It is preferred to be placed between the formable layer and the hydrophilic lithographic substrate, provided that the imageable layer is transparent to the radiation used for image formation. And When light is applied to such a combination layer structure, the layer containing the conversion compound (C) generates heat in the irradiated area, and then the heat contains the adjacent radiation-sensitive medium. Imagewise transfer to formable layer. Then, the radiation sensitive medium is easily dissolved by the alkaline aqueous solution in the image-heated region. As a result, less energy is required to expose the composition to obtain the desired level of developability as compared to the coating without component (B). As used herein, the term “hydrophilic lithographic substrate” means that at least one surface thereof is hydrophilic so that it can retain water or an aqueous medium, such as fountain solution. Refers to a substrate or sheet of material.

  Instead of the polymer (A) and the infrared absorbing compound being separate, it is also possible to obtain a polymer in which an infrared absorbing substance is bound to the polymer. Examples of these materials are described in US Pat. No. 6,124,425.

  In some cases, a compound that inhibits the solubility of the polymer in an alkaline aqueous solution (referred to herein as a “dissolution inhibitor”) can also be added to the coating composition. Such compounds include dyes, particularly infrared dyes such as ADS830A dyes (CAS # 134127-48-3, manufactured by American Dye Source, Montreal, Canada), and the like. Examples of image colorants include, but are not limited to, Victoria Pure Blue BO (Basic Blue, CAS # 2390-60-5). It is preferred to use such compounds where the inherent solubility of the polymer is relatively high.

  In order to achieve processing stability under wider processing conditions, a surfactant may optionally be added to the composition of the present invention. Suitable nonionic surfactants are described in JP-A-62-251740 and JP-A-3-208514, and amphoteric surfactants are described in JP-A-59-121044 and JP-A-4-13149. There is description in the gazette. The amount of nonionic or amphoteric surfactant is preferably 0.05 to 10 weight percent, more preferably 0.1 to 5 weight percent of the material of the composition.

  Surfactants to improve coatability, such as Zonyl (DuPont) or FC-430 or FC-431 (Minnesota Mining and Manufacturing Co.) Various fluorine-containing surfactants such as manufactured by (.)), Or polysiloxane such as Byk333 (manufactured by Byk Chemie) may be added to the infrared-sensitive layer. The amount of surfactant added is preferably 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight of the total material of the composition.

  In some cases, an image colorant can be added to the composition of the present invention to provide a visible image on the printing plate exposed prior to inking. As the image colorant, dyes other than the above-mentioned salt-forming organic dyes may be used. Examples of suitable dyes are oil-soluble dyes and basic dyes, including salt-forming organic dyes. Specific examples include Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (all of these from Oriental Chemical Industries Co., Ltd.), Victoria Pure Blue BO, Basic Blue Tetrafluoroborate, etc. Specific examples include Victoria Pure Blue BO (7), Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000). And methylene blue (CI52015). The dyes described in JP-A-62-293247 are particularly preferred. The dye is added to the material for the printing plate in an amount of preferably 0.01 to 10% by weight, more preferably 0.5 to 8% by weight of the total solids content of the composition material. Is good.

  A plasticizer for imparting flexibility to the formed film can be added as required in the material for the composition of the present invention. Examples of the plasticizer include sorbitan such as butylphthalyl, polyethylene glycol, tributyl citrate, dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, tetrahydrofurfuryl oleate, an oligomer or polymer of acrylic acid or methacrylic acid, etc. Tristearate, sorbitan monopalmitate, sorbitan trioleate, monoglyceride stearate, polyoxyethylene-nonylphenyl ether alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N -Hydroxyethylimidazolium betaine, N-tetradecyl-N, N-betaine (for example, Dai-ichi Kogyo Co., Ltd.). Ltd.) under the trade name Amogen (Amogen) and the like.

  In some cases, suitable adhesion promoters may be added to the compositions of the present invention. Suitable examples include diacid, triazole, thiazole and alkyne-containing raw materials. The usage-amount of an adhesion promoter is 0.01 to 3 weight%. Other polymers may be added to reduce compounding costs. Examples thereof include urethane resins and ketone resins. The amount of these raw materials can vary between 0.5% and 25% solids, preferably between 2% and 20% by weight.

  In general, the composition ratio of polymer component (A) to component (B) is preferably from 99/1 to 60/40. The development accelerator compound (B) is present in an amount effective to significantly improve the sensitivity of the coating to the developer, i.e., an amount useful in the imaging process, in the area of the coating exposed to radiation. Must be. If the amount of component (B) is less than this lower limit, component (B) cannot significantly improve the sensitivity of the coating. When the amount of the component (B) is larger than the above upper limit, the tolerance of the coating portion where an image is not formed with respect to the developer is significantly reduced. Therefore, neither case is preferable. A more preferred range of component (B) is 1.5% to 20%, and the most preferred range is 5% to 15%, as measured by weight percent relative to the total solids of the coating composition.

  To produce a positive working lithographic printing precursor of the present invention, the individual components described above are dissolved in a suitable solvent, filtered if necessary, and in a liquid state on a hydrophilic lithographic substrate. For example, bar coating, spin coating, rotating coating, spray coating, flow coating, dip coating, air knife coating, blade coating, roll coating, etc. There is. Suitable solvents include methylene chloride, ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate. , Dimethoxyethane, methyl lactate, ethyl lactate, and toluene. A single solvent may be used alone, or two or more solvents may be used in combination. The concentration of the above-described components (all solid components including additives) in the solvent is preferably 1 to 50% by weight. The coating amount (solid content) on the hydrophilic lithographic substrate obtained after coating and drying varies depending on the application, but is generally 0.3-12.0 grams / square meter depending on the application. preferable. Although it is possible to apply a smaller amount to the hydrophilic lithographic substrate to make it appear to have a higher sensitivity, the film properties of the material are reduced.

  The radiation sensitive compositions of the present invention are suitable for other direct imaging including, but not limited to, printed circuit boards for lithographic printing plates and laser direct imaging (LDI). It is useful for manufacturing a conductive element. In the case of lithographic printing, the positive working lithographic printing precursor of the present invention uses a hydrophilic lithographic substrate, which generally has a separate hydrophilic layer on the substrate. Thus, when the precursor is developed, the hydrophilic coating layer remains and can be used to retain an aqueous medium such as fountain solution in the printing process. In such a case, the range of choice of the substrate on which the hydrophilic layer is coated becomes very wide. Alternatively, the hydrophilic lithographic substrate may be a single material, which is typically aluminum but is treated to ensure hydrophilic surface properties. be able to.

  Suitable substrates include, for example, paper; paper on which plastics such as polyethylene, polypropylene, and polystyrene are laminated; metal plate such as aluminum, anodized aluminum, zinc or copper plate; copper foil, reverse-treated copper foil, drum Side-treated copper foil, and double-treated copper foil coated on a plastic laminate, the plastic film is, for example, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, nitric acid Made of cellulose, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, or polyvinyl acetal; paper or plastic film on which the above metals are deposited or laminated Lum; glass deposited glass or metal or metal oxide, and the like.

  The substrate in the embodiment of the present invention for the printing plate is preferably a polyester film or an aluminum plate, particularly preferably an aluminum plate, because it is dimensionally stable and relatively inexpensive. is there. A plastic film in which aluminum is laminated or vapor-deposited can also be used. There is no restriction | limiting in particular in the composition of the aluminum plate applied to this invention, The aluminum plate may be manufactured in accordance with various well-known methods, such as roughening, anodizing, and the process after anodizing, for example. The thickness of the aluminum plate used in the embodiment of the present invention is 0.1 to 0.6 mm, preferably 0.15 to 0.5 mm.

  The positive working lithographic printing precursor produced as described above is typically subjected to an image exposure and development process. In a preferred embodiment, a radiation sensitive composition as described above is applied as a coating on a hydrophilic lithographic substrate (eg, an aluminum plate) to form a lithographic printing precursor. The precursor can be imaged (eg, by imagewise exposure to infrared radiation), and the imaged precursor can be developed by using a normal aqueous alkaline developer solution for positive working. A lithographic printing plate is formed. If the precursor has a separate imageable layer and a layer containing a conversion material, the development process removes both layers and exposes the underlying hydrophilic surface. .

  In a preferred embodiment of the present invention, the light source for the actinic ray beam used in the imagewise exposure is a light source that generates light having an emission wavelength in the range from the near infrared wavelength region to the infrared wavelength region. Is preferable, and a solid laser or a semiconductor laser is particularly preferable. The positive working lithographic printing precursor based on the radiation sensitive medium of the present invention is preferably highly sensitive to irradiation with wavelengths between 700 nm and 1300 nm, more preferably between 700 nm and 1000 nm.

  The developer solution and replenisher solution for the positive working lithographic printing precursor of the present invention may be a commonly known alkaline aqueous solution such as sodium metasilicate, tertiary potassium phosphate, secondary ammonium phosphate, sodium carbonate, And potassium borate, sodium hydroxide, ammonium hydroxide, potassium hydroxide, tetraalkylammonium hydroxide; and organic alkaline agents such as alkylamines, alkylethanolamines or diamines. This alkaline agent may be used alone or in combination of two or more.

  Of these, particularly preferred developing solutions are aqueous solutions of silicates and hydroxides. When developing using an automatic developing machine, an aqueous solution having a basicity higher than the basicity of the developing solution (replenishing solution) is added to the developing solution, thereby developing the developing solution in the developing tank over a long period of time. It is known to be able to process a large number of printing plates and printed pieces without replacing. It is preferable to use such a replenishment method also in the embodiment of the present invention. In some cases, various surfactants or organic solvents may be added to the developer and replenisher solutions to accelerate or adjust developability, improve the dispersibility of the developer scum, and / or on the printing plate. The affinity of the image portion for the ink can be improved. Other agents commonly used in positive printing plate developers can also be used in this developer solution.

  This composition is usually post-treated with water, but in some cases, for example, a surfactant may be included. In the case of printing plates, a desensitizing solution containing gum arabic or starch derivatives is used. When the imageable medium of the embodiments of the present invention is used in various applications, post-processing can be performed using various combinations of these processes.

Preparation of Acetal Polymers for Use in the Invention The acetalization reaction of polyvinyl alcohol can be effected according to known standard methods, for example, US Pat. No. 4,665,124; US Pat. U.S. Pat. No. 4,940,646; U.S. Pat. No. 5,169,898; U.S. Pat. No. 5,700,619; U.S. Pat. No. 5,792,823; It is described in the gazette. US Pat. No. 6,255,033 (Levanon et al.) Describes in detail examples of the synthesis of acetal polymers used in the present invention.

Polymer 1
In a preferred embodiment of the present invention, the polymer used as the polymer component (A) is a polyvinyl derivative derived from 3-hydroxybenzaldehyde and butyraldehyde by the following process and having a butyral acetal group and a hydroxy-substituted aromatic acetal group. An acetal resin (referred to herein as polymer 1) is obtained, where the hydroxy substitution is at the 3-position of the aromatic ring:

  A water-cooled condenser containing 100 grams of Airvol 103 polyvinyl alcohol (98% hydrolyzed polyvinyl acetate having a number average molecular weight of about 15,000), 150 grams of deionized water and 25 grams of methanol. In a closed reactor fitted with a dropping funnel and thermometer. With continuous stirring, the mixture was heated at 90 ° C. for 0.5 hour to give a clear solution. The temperature was then adjusted to 60 ° C. and 3 grams of concentrated sulfuric acid dissolved in 50 grams of methanol was added. Over a period of 15 minutes, 60 grams of 3-hydroxybenzaldehyde and 1.4 grams of 2,6-di-tert-butyl-4-methylphenol in 450 grams of Dowanol PM ™ The solution dissolved in was added dropwise. The reaction mixture is diluted with the addition of 200 grams of Dowanol PM ™, and then 23.2 grams of 200 grams of n-butyraldehyde is dissolved in Dowanol PM ™. The solution was added dropwise and the reaction was continued at 50 ° C. for an additional 3 hours after the aldehyde addition was complete. At this stage, the conversion of butyraldehyde is complete and the conversion of 3-hydroxybenzaldehyde is about 50%. A water-Dowanol PM (TM) azeotrope is distilled from the reaction mixture under vacuum, but Dowanol PM (TM) is added to the reaction mixture during the distillation. When the water content of the reaction mixture is less than 0.1%, the distillation is finished. The conversion of 3-hydroxybenzaldehyde is higher than 97%. The reaction mixture is precipitated in water. The polymer obtained is filtered, washed with water and then dried at 60 ° C. for 3 days, resulting in a moisture content of 2%.

Polymer 2
In a preferred embodiment of the invention, the polymer used as polymer component (A) is derived from 3-hydroxybenzaldehyde, butyraldehyde and cinnamaldehyde by the following process, butyral acetal group, cinnamacetal group, and hydroxy substituted A polyvinyl acetal resin having aromatic acetal groups (referred to herein as polymer 2) is obtained, where the hydroxy substitution is at the 3-position of the aromatic ring. The preparation of polymer 2 is similar to that of polymer 1 except that after the addition of 3-hydroxybenzaldehyde, 14.7 grams of cinnamaldehyde in 150 g of Dowanol PM ™, then Add 16 grams of butyraldehyde in 200 g of Dowanol PM ™. The presence of cinnamaldehyde in the composition of polymer 2 is believed to improve the ink adhesion of the imageable areas of the printing plate.

Polymer 3
In a preferred embodiment of the present invention, the polymer used as the polymer component (A) is a polyvinyl acetal resin (this is derived from 2-hydroxybenzaldehyde and butyraldehyde and has a butyral acetal group and a hydroxy-substituted aromatic acetal group. (Referred to herein as polymer 3), where the hydroxy substitution is at the 2-position of the aromatic ring. The preparation of polymer 3 is similar to that of polymer 1, except that Airvol 103 polyvinyl alcohol is replaced with Poval 103, instead of 3-hydroxybenzaldehyde, 2-hydroxybenzaldehyde (90 grams). , 500 grams of Dowanol PM (dissolved in Dowanol PM ™), and 12 grams of butyraldehyde dissolved in 200 grams of Dowanol PM ™ were added.

Polymer 4
In a preferred embodiment of the present invention, the polymer used as the polymer component (A) is a polyvinyl acetal resin (this is derived from 2-hydroxybenzaldehyde and butyraldehyde and has a butyral acetal group and a hydroxy-substituted aromatic acetal group. (Referred to herein as polymer 4), where the hydroxy substitution is at the 2-position of the aromatic ring. The preparation method for polymer 4 was the same as for polymer 3, except that the amount of 2-hydroxybenzaldehyde used was 68 grams and the amount of n-butyraldehyde was 23.2 grams.

The following examples illustrate aspects of the present invention. The raw material was obtained from the following sources:
Airbol 103 (Airvol 103 ™), polyvinyl alcohol product, Hoechst, Germany, Clariant, USA.
Tween 80K (manufactured by Avecia) in Manchester, UK.
ADS830A and ADS830WS ™, IR dye, manufactured by American Dye Source, Montreal, Quebec, Canada.
Phosphate esters, Zelec 8172 and 8175 ™, manufactured by Stepan UK Ltd., Cheshire, UK.
Zonyl FSA ™, manufactured by DuPont Canada Inc. of Mississauga, ON, Canada.
Silicone acrylate VS-80 (TM), manufactured by 3M (3M), St. Paul, MN, USA.
Dimethicone copolyol SF1488 ™, manufactured by GE Silicones of Waterford, NY, USA.
Goldstar Plus (trademark), a positive printing plate developer, manufactured by Kodak Polychrome, Mississauga, ON, Canada.

Comparative Example 1
This comparative example shows the results when no development promoting compound is added to the composition of the present invention.
Ingredient Weight%
Polymer 3 or 4 75
Development accelerator compound 0
Resole resin LB9900 * 20
IR dye 2
Colorant-Victoria Blue R 2.5
N, N-diethylaniline 0.5

The components of this composition were dissolved in a mixture of MEK: Dowanol PM ™, filtered and applied onto the surface of anodized aluminum. After drying, the resulting printing plate has a dry coating weight of 1.5 grams / m ² . The printing plate was imaged at 490 rpm in a Creo Lotem 400 Quantum at a power density of 6-18 W. The printing plate was developed in an 8.4% aqueous potassium metasilicate solution for 30 seconds, washed with water and dried. The energy density required to obtain a clear background is 230 mJ / cm ² (dry 2.5 minutes / 100 ° C.) for polymer 3 and 240 mJ / cm ² (dry 3 minutes / 95 ° C.) for polymer 4. The weight loss% coating from the unexposed areas of the printing plate was less than 15.

Application examples 1-15
Ingredient Weight%
Polymer 3 or 4 55
Development accelerating compound (see Table 1) 20
Resole resin LB9900 * 20
IR dye 2
Colorant-Victoria Blue R 2.5
N, N-diethylaniline 0.5

The components of this composition were dissolved in a mixture of MEK: Dowanol PM ™, filtered and applied onto the surface of anodized aluminum. After drying, the resulting printing plate has a dry coating weight of 1.5 grams / m ² . The printing plate was imaged at 490 rpm in a Creo Lotem 400 Quantum at a power density of 6-18 W. The printing plate was developed in an 8.4% aqueous potassium metasilicate solution for 30 seconds, washed with water and dried. The energy required to obtain a clear background is as shown in Table 1.

  All the weight loss percentages in the unexposed areas of the printing plate shown in Table 1 were less than 15.

Application examples 16-31
Ingredient Weight%
Polymer 3 or 4 or 1 65
Development accelerating compound (see Table 1) 10
Resole resin LB9900 * 20
IR dye 2
Colorant-Victoria Blue R 2.5
N, N-diethylaniline 0.5

The components of this composition were dissolved in a mixture of MEK: Dowanol PM ™, filtered and applied onto the surface of anodized aluminum. After drying, the coating weight of the resulting printing plate is 1.5 grams / m ² · dry thickness. The printing plate was imaged at 490 rpm in a Creo Lotem 400 Quantum at a power density of 6-18 W. The printing plate was developed in an 8.4% aqueous sodium metasilicate solution for 30 seconds, washed with water and dried. The energy density necessary to obtain a clear background is as shown in Table 2.

  All the weight loss percentages in the unexposed areas of the printing plates shown in Table 2 were less than 15.

Application examples 32-35
Ingredient Weight%
Polymer 3 or 4 60
Development accelerating compound (see Table 1) 15
Resole resin LB9900 * 20
IR dye 2
Colorant-Victoria Blue R 2.5
N, N-diethylaniline 0.5

The components of this composition were dissolved in a mixture of MEK: Dowanol PM ™, filtered and applied onto the surface of anodized aluminum. After drying, the coating weight of the resulting printing plate is 1.5 grams / m ² · dry thickness. The printing plate was imaged at 490 rpm in a Creo Lotem 400 Quantum at a power density of 6-18 W. The printing plate was developed in an 8.4% aqueous potassium metasilicate solution for 30 seconds, washed with water and dried. The energy density necessary to obtain a clear background is as shown in Table 2.

  All the weight loss percentages in the unexposed areas of the printing plates shown in Table 3 were less than 15.

Application Example 36
Ingredient Weight%
Polymer 4 79.2
Hydroxyphenol tetrazole-thiol 10
IR dye 2
Colorant-Victoria Blue R 3.5
Benzoflex 2160 5
N, N-diethylaniline 0.3

The components of this composition were dissolved in a mixture of MEK: Dowanol PM ™, filtered and applied onto the surface of anodized aluminum. After drying at 90 ° C. for 3 minutes, the coating weight of the resulting printing plate is 1.5 grams / m ² · dry thickness. The printing plate was imaged at 490 rpm in a Creo Lotem 400 Quantum at a power density of 6-18 W. The printing plate was developed in a 5.5% aqueous sodium metasilicate solution for 30 seconds, washed with water and dried. The energy density required to obtain a clear background was 70 mJ / cm ² . The weight loss% coating from the unexposed areas of the printing plate was less than 15.

Comparative Example 37
This comparative example is an example for reference that does not contain a development accelerating compound.
The coating solution was made using the following additives (wt%):
-Polymer 1: Polymer 2, 45:55, 87.5%;
- formula C ₄₇ H ₄₇ ClN cyanine dyes having _{2 O 3 S (CAS # 134127-48-3} ), 1% ( as an infrared absorbing agent);
-Image colorant Victoria Pure Blue BO (Victoria Pure Blue BO) (Basic Blue 7, CAS # 2390-60-5), 6.5%;
Polyethylene glycol sorbitan ester, Tween-80 (degree of polymerization 80), 5%.

The coating solution was made in acetone: methoxypropanol (Dowanol PM) 75:25, with a solids percentage of 10%. The printing plate was cast on the anodized aluminum substrate by hand using casting rod # 12 (coating weight 1.75 to 1.8 g / m ² ). The printing plate was dried in a mobile oven (Wisconsin SPCMINI-34 / 121 type) at 130 ° C. for 3 minutes.

The printing plate is then used with a Creo Quantum 800 ™ image setter, with an output of 12 W, a wavelength of 830 nm, and an energy density series between 180 and 400 mJ / cm ² . Images were formed in the form of a rectangular solid image at intervals of 20 mJ / cm ² . The printing plate was developed using a Glunz-Jensen 85HD developer in an alkaline developer containing 7% sodium metasilicate and having a conductivity of 66 mS / cm. Development conditions were 24 ° C., passage time 30 seconds, and drying 50 ° C. The developed printing plate had a square with a bare substrate, and the optical density was measured using an optical densitometer. The clearing point was defined as the energy at which the optical density (OD) difference between the cleared area of the substrate and the original uncoated substrate was 0.01 or less. The printing plate prepared in this example had a clearing point of 350 mJ / cm ^{2 and} the% weight loss in the developer was less than 50. The weight loss in the developer represents that for the non-irradiated areas.

Example 38
The following coating composition was prepared:
Polymer 1: Polymer 2, 45: 55, 84.5% (all prepared in the same manner as in Example 28)
・ Infrared dye, 1%
・ Basic Blue 7 (Basic Blue 7), 6.5%
・ Tween-80, 5%
・ Lithium trifluoromethanesulfonate, 3%

A coating solution containing 10% solids was prepared by the above formulation. The printing plate was hand cast on an anodized aluminum substrate using the solution in Example 28 (reference example) and the solution described above. The printing plates were dried at 125 ° C. for 3 minutes. A coating weight of 1.8 g / m ² was obtained. An image was formed on the printing plate using a Creo Quantum 800 image setter with an irradiation of 12 W and a wavelength of 830 nm. The image was a series of 20 mJ / cm ² by the spacing between the energy density of 120~360mJ / cm ^2. The printing plate was developed at 23 ° C. in a developer containing 7% sodium metasilicate (conductivity 66 mS / cm), and the residence time in the developer was 30 seconds. The clearing point of a printing plate using a lithium trifluoromethanesulfonate development accelerator was 140 mJ / cm ² , and the weight loss% in the developer was less than 50, whereas no development accelerator compound was used. In the reference example, the clearing point was 320 mJ / cm ² and the coating weight loss without irradiation was less than 50.

Example 39
The coating was made using the following composition:
Polymer 1: Polymer 2, 1: 1, 77.5%
・ Basic Blue 7 (Basic Blue 7), 6.5%
・ IR dye, 1%
・ Tween-80, 5%
・ Zelec 8175, 10%

A coating solution having a solid content of 10% was prepared in acetone: Dowanol PM (75:25). The solution was cast to obtain a printing plate having a coating weight of 1.65 to 1.75 g / m ² . A reference printing plate using the reference solution described in Example 28 was also cast at the same time. The two printing plates were dried at 125 ° C. for 2 minutes. Those of the printing plate, the Quantum 800 (Quantum 800) imagesetter Cleo (Creo), 12W irradiation at a wavelength of 830 nm, the energy density series of 20 mJ / cm ² by the distance between the 120~360mJ / cm ² images Formed. The printing plates were developed for 30 seconds at 23 ° C. using a Goldstar positive printing plate developer diluted to 90% of the original density. In the printing plate using Zelec 8175 development accelerator, the clearing point was 110 mJ / cm ² , and the weight loss% in the developer was less than 50. The reference printing plate not used had a clearing point of 320 mJ / cm ² and a non-irradiated coating weight loss percentage of less than 50.

Example 40
The coating was made using the following composition:
Polymer 1: Polymer 2, 1: 1, 77.5%
・ Basic Blue 7 (Basic Blue 7), 6.5%
・ IR dye, 1%
・ Tween-80, 5%
・ Zelec 8172, 10%

See Example 28, in which two printing plates were cast by hand, one of which uses the above solution containing Zelec 8172 as a development accelerator and the other one does not contain a development accelerator. A working solution was used. The coating weight of these printing plates was 1.7~1.8g / m ^2. The printing plate was dried at 125 ° C. for 2 minutes and imaged using an energy series between 12 W and 80-300 mJ / cm ² . The printing plates were developed in 60% Goldstar at 23 ° C. for 30 seconds. Its clearing point and% weight loss in the developer were 140 mJ / cm ² and less than 50, respectively, for the printing plate containing Zelec 8172, but no reference to a development accelerator compound. The printing plate was not clear up to 300 mJ / cm ² .

Example 41
A coating was made containing the following additives:
Polymer 1: Polymer 2, 1: 1, 86%
・ IR dye, 1%
・ Basic Blue 7 (Basic Blue 7), 6.5%
・ Tween-80, 5%
-Lithium 3-[(1H, 1H, 2H, 2H-fluoroalkyl) thio] propionate (Zonyl FSA, manufactured by DuPont), 1.5%.

A coating of the above formulation and a reference coating of Example 28 containing the same ingredients but no Zonyl FSA were prepared. These coating solutions were prepared to 10% solids in Dowanol PM. A printing plate was cast by hand on the anodized aluminum substrate and baked at 125 ° C. for 2.5 minutes. The measured coating weight was 1.7~1.8g / m ^2. Images were formed on these printing plates under the same conditions (output 11 W, energy density series 100 to 350 mJ / cm ² ). The printing plates were developed in a developer containing 7.2% sodium metasilicate (conductivity 66 mS) at 24 ° C. and a residence time of 30 seconds in the developer. The reference printing plate containing no development accelerator compound has a clearing point of 320 mJ / cm ² and a weight loss percentage in the developer of less than 50, whereas it contains 1.5% FSA. In the printing plate, the clearing point was 130 mJ / cm ² , and the coating weight loss% without irradiation was less than 50.

Example 42
A printing plate was made with a coating containing 7% n-dodecylresorcinol and compared to a reference printing plate.

The coating in this example had the following composition:
Polymer 1: Polymer 2, 1: 1, 80.5%
・ Basic Blue 7 (Basic Blue 7), 6.5%
・ IR dye, 1%
・ Tween-80, 5%
N-dodecylresorcinol, 7%

The coating solution and reference coating in this example (similar to Example 28) were made in acetone: Dowanol PM 75:25 to a solids content of 10%. The solution was cast on an anodized aluminum substrate using a rod. The obtained printing plate was baked at 130 ° C. for 3 minutes. The coating weight was 1.7 g / m ² . The printing plate was exposed to 830 nm IR laser irradiation with an output of 8 W and an energy density series of 90 to 400 mJ / cm ² . The printing plate was developed in a DuPont-Hawson developer containing 7% sodium metasilicate (conductivity 71 mS / cm) at 23 ° C. and a residence time of 30 seconds. . In the printing plate using n-dodecylresorcinol, the clearing point was 160 mJ / cm ² and the coating weight loss% without irradiation was less than 50, whereas in the reference printing plate, the clearing point was Was 350 mJ / cm ² and the coating weight loss% without irradiation was less than 50.

Example 43
The composition of the coating containing the silicone compound is as follows:
Polymer 1: Polymer 2, 1: 1, 82.5%
・ Basic Blue 7 (Basic Blue 7), 6.5%
・ IR dye, 1%
・ Tween-80, 5%
・ Silicone acrylate, VS-80, 5%

For comparison, a reference coating containing no development accelerator compound, as in Example 28, was used. The solution was prepared such that the solid content was 10% in 75:25 of acetone: Dowanol PM. The printing plate was cast by hand and baked at 130 ° C./3 minutes. The coating weight was 1.8~1.85g / m ^2. An image was formed on the printing plate at 12 W and an energy series of 90 to 350 mJ / cm ² . The printing plate was used in a DuPont-Hawson developer using a Goldstar (Kodak) positive printing plate developer at 23 ° C. and a residence time of 30 seconds. Developed. In the printing plate using the silicone acrylate development accelerating compound, the clearing point was 150 mJ / cm ² and the non-irradiation coating weight loss% was less than 50, whereas in the reference one, 300 mJ / cm ² , the coating weight loss% in non-irradiation was less than 50.

Example 44
A coating composition having the following composition was prepared:
Polymer 1: Polymer 2, 1: 1, 77.5%
-Basic Blue 7 tetrafluoroborate, 6.5%
・ IR dye, 1%
・ Tween-80, 5%
・ Resorcinol, 10%

For comparison, a reference coating containing no development accelerator compound, as in Example 28, was used. The coating solution was prepared such that the solid content was 10% in 75:25 of acetone: Dowanol PM. In this example, a dye based on the triarylmethane dye Basic Blue 7 (CAS No. 371231-05-9) was prepared and used. Specifically, tetrafluoroborate Basic Blue · 7 (Basic Blue 7) - was used (BF _4). The printing plate was cast by hand using a casting rod and dried at 130 ° C./3 minutes. The coating weight was 1.8~1.85g / m ^2. An image was formed on the printing plate at 12 W and an energy series of 90 to 350 mJ / cm ² . The printing plate was developed using a developer containing 7% sodium metasilicate (conductivity 66 mS / cm) in a DuPont-Hawson developer at 26 ° C. and a passage time of 30 seconds. Developed. In the printing plate using the resorcinol development accelerator compound, the clearing point was 150 mJ / cm ² and the coating weight loss% in non-irradiation was less than 50, whereas in the reference printing plate, 350 mJ / cm ^2. The coating weight loss% in non-irradiation was less than 50.

Example 45
A printing plate was made with a coating containing 5% 4-hexylresorcinol and having the composition of Table 4. A reference coating with the composition of Table 1 and no development accelerator compound was also prepared. The coating solution was prepared such that the solid content was 10% in 75:25 of acetone: Dowanol PM. The solution was cast on an anodized aluminum substrate using a rod. The obtained printing plate was baked at 130 ° C. for 3 minutes. The printing plate was exposed to 830 nm IR laser irradiation with an output of 8 W and an energy density series of 90 to 350 mJ / cm ² . The printing plate was developed in a DuPont-Hawson developer containing 7% sodium metasilicate (conductivity 71 mS / cm) at 23 ° C. and a residence time of 30 seconds. . The printing plate containing 4-hexylresorcinol had a clearing point of 150 mJ / cm ² and a non-irradiation coating weight loss percentage of less than 50. In contrast, the reference printing plate containing no development accelerator compound was clear even at 320 mJ / cm ² , and the coating weight loss% without irradiation was less than 50.

Example 46
Two printing plates were made, one of which contains 5% dimethicone copolyol SF1488 in the composition and the reference printing plate does not contain a development accelerating compound (Table 5).

The solution was prepared such that the solid content was 10% in 75:25 of acetone: Dowanol PM. The printing plate was cast by hand and baked at 130 ° C./3 minutes. The coating weight was 1.8~1.85g / m ^2. An image was formed on the printing plate at 12 W and an energy series of 90 to 350 mJ / cm ² . The printing plate was developed using a Goldstar positive printing plate developer in a DuPont-Hawson developer at 23 ° C. and a residence time of 30 seconds. From Table 5, when 5% level of SF1488 is added, the clearing point is 160 mJ / cm ² and the non-irradiated coating weight loss% is less than 50 for the reference one. It can be seen that at 320 mJ / cm ² , the coating weight loss% without irradiation is less than 50.

Example 47
Two coating solutions were prepared as follows.
Solution 1:
Polymer 1: Polymer 2, 1: 1, 78%
Hexyl resorcinol, 10%
Basic Blue 7 (Basic Blue 7), 7%
Tween-80, 5%
This solution was prepared to have a solid content of 10% in Dowanol PM.
Solution 2:
1 kg of phenol formaldehyde resin was homemade using acid catalyzed sulfuric acid at a phenol: formaldehyde molar ratio of 0.9: 1. The resin solution had pH = 5 and a solid content of 10%. 1 g of IR dye ADS830WS was dissolved in 100 g of ethanol and added to the phenol-formaldehyde resin solution with stirring.

Solution 1 was coated on an anodized aluminum substrate by spraying. The coating weight was 1.6 g / m ² . Solution 2 was then spray coated over the coating from Solution 1 so that the additional coating weight was 0.5 g / cm ² . The obtained printing plate was baked at 125 ° C. for 2.5 minutes. The printing plate was imaged at 830 nm using a Creo Quantum 800 image setter with an energy density series of 90-300 mJ / cm ² and an output of 12 W. The printing plate was developed using a DuPont developer containing an alkaline developer (66 mS / cm) made from 7% sodium silicate solution. The printing plate was developed at 26 ° C. for 30 seconds. The clearing point of the printing plate was 150 mJ / cm ² and the coating weight loss% without irradiation was less than 50.

  The foregoing has outlined important features of the invention so that the invention may be better understood and in order to better appreciate the contribution of the invention to the industry. Those skilled in the art will recognize that the concepts underlying the present invention can be readily utilized as a basis for the design of other methods and apparatus for the purpose of carrying out some objects of the present invention. I will. Therefore, most importantly, the disclosure herein should be considered to include such equivalent methods and apparatus without departing from the spirit and scope of the present invention.

Claims (68)

A radiation sensitive composition comprising:
a. An acetal resin derived by condensing polyvinyl alcohol with an aldehyde,
And b. A radiation sensitive composition comprising a development accelerating compound.   The composition of claim 1 further comprising a radiation-to-heat converting compound.   The composition according to claim 2, wherein the radiation-thermal conversion compound is an infrared light-thermal conversion compound.   The composition according to claim 3, further comprising a dissolution inhibitor. The composition according to claim 1, wherein the development accelerating compound is at least one of the following.
a. An alcohol containing at least one of an alkyl radical containing 12 to 60 carbon atoms, a fluoroalkyl radical containing 4 to 60 carbon atoms, and a fluoroalkylaryl radical containing 7 to 60 carbon atoms;
b. Polyols;
c. Monohydric phenol;
d. Polyphenols;
e. A compound containing a thiol functional group;
f. An anionic lithium salt which is one of carboxylate, thiocarboxylate, sulfate, sulfonate, phosphate, phosphite, nitrate and nitrite;
g. Esters of phosphorus-containing acids;
h. An amide of a phosphorus-containing acid;
i. Polysiloxane;
j. A quaternary ammonium salt having a free hydroxyl group;
k. An azo compound;
l. A compound containing an NH-NH-functional group;
m. Compounds containing functional groups of the formula

;
n. A compound containing the structure

(Wherein X is one of —S—, S═O, C═O or CO ₂ , and R ¹³ may be C ₁ -C ₁₂ alkyl, benzyl or structure E, Where E is given by:

Here, R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ may be one of H and OH)
o. Substituted aromatic acids;
p. Substituted aromatic esters;
q. A substituted aromatic amide; and r. A compound containing a sulfone functional group.   6. The composition of claim 5, wherein the polyol is dimethicone copolyol.   The composition according to claim 5, wherein the polyhydric phenol is at least one of resorcinol, 4-hexylresorcinol, n-dodecylresorcinol, and 1-naphthol.   6. The composition of claim 5, wherein the polyhydric phenol is one of pyrogallol, phloroglucinol, 1,2,4-benzenetriol, and their alkyl and fluoroalkyl derivatives.   The anionic lithium salt is lithium 3- (1H, 1H, 2H, 2H-fluoroalkyl) propionate and lithium 3-[(1H, 1H, 2H, 2H-fluoroalkyl) thiopropionate, lithium trifluoromethanesulfonate. And the composition of claim 5 which is one of lithium perfluorooctylethylsulfonate. The ester of the phosphorus-containing acid is P (OH) (OR) ₂ , P (OH) ₂ (OR), P (OH) ₂ [ORN (CH ₂ —CH ₂ —OH) ₂ ], P (OR) ₂ [O—R—NH (CH ₂ —CH ₂ —OH) ₂ ] (where R is alkyl, aryl, alkylaryl, polyethylene oxide, polypropylene oxide, or combinations thereof) 6. The composition of claim 5, wherein:   The composition according to claim 5, wherein the ester of the phosphorus-containing acid is nonylphenol phosphate. The amide of the phosphorus-containing acid is P (OH) (ONHR) ₂ , P (OH) ₂ (ONHR), P (OR) ₂ [O—NH (CH ₂ —CH ₂ —OH) ₂ ], P (OR _{) [O-NH (CH 2} -CH 2 -OH) 2] 2 ( where R is alkyl, aryl, polyethylene oxide, one of the polypropylene oxide or their combinations), according to claim 5 Composition. The polysiloxane is R [OSi (OCH ₃ ) ₂ ] _n —Si (OCH ₃ ) (OH) ₂ (where R is an alkyl (alkyl), aryl, polyethylene oxide, polypropylene oxide group or a combination thereof). , N = 2 to 1000).   The substituted aromatic acid is 2-nitrobenzoic acid, 3-nitrobenzoic acid, 4-nitrobenzoic acid, 2,4-dinitrobenzoic acid, 2,4-dichlorobenzoic acid, 2-hydroxy-1-naphthoic acid and The composition according to claim 5, wherein the composition is at least one of 3-hydroxy-2-naphthoic acid.   6. The composition of claim 5, wherein the substituted aromatic ester is methyl salicylate, phenyl salicylate, benzyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate and methyl 4-hydroxybenzoate.   6. The composition of claim 5, wherein the substituted aromatic amide is 3-nitrobenzamide and (2'-hydroxyethyl) -2,4-dihydroxybenzamide. The acetal resin has the following structure:

Here, R ¹ is —C _n H _{2n + 1} (where n = 1 to 12), and R ² is

here,
R ⁴ = —OH;
R ⁵ = —OH or —OCH ₃ or Br— or —O—CH ₂ —C≡CH, and B ⁶ = Br— or NO ₂ ;
R ³ = — (CH ₂ ) _t —COOH, —C≡CH, or

Where R ⁷ = COOH, — (CH ₂ ) _t —COOH, —O— (CH ₂ ) _t —COOH,
And where t = 1-4 and where b = 5-40 mol%, preferably 15-35 mol%
c = 10-60 mol%, preferably 20-40 mol%
d = 0 to 20 mol%, preferably 0 to 10 mol%
e = 2 to 20 mol%, preferably 1 to 10 mol%, and f = 5 to 50 mol%, preferably 15 to 40 mol%,
The composition of claim 1. The composition according to claim 17, wherein the development accelerating compound is at least one of the following.
a. An alcohol containing at least one of an alkyl radical containing 12 to 60 carbon atoms, a fluoroalkyl radical containing 4 to 60 carbon atoms, and a fluoroalkylaryl radical containing 7 to 60 carbon atoms;
b. Polyols;
c. Monohydric phenol;
d. Polyphenols;
e. A compound containing a thiol functional group;
f. An anionic lithium salt which is one of carboxylate, thiocarboxylate, sulfate, sulfonate, phosphate, phosphite, nitrate and nitrite;
g. Esters of phosphorus-containing acids;
h. An amide of a phosphorus-containing acid;
i. Polysiloxane;
j. A quaternary ammonium salt having a free hydroxyl group;
k. An azo compound;
l. A compound containing an NH-NH-functional group;
m. Compounds containing functional groups of the formula

;
n. A compound containing the structure

(Wherein X is one of —S—, S═O, C═O or CO ₂ , and R ¹³ may be C ₁ -C ₁₂ alkyl, benzyl or structure E, Where E is given by:

Wherein R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ may be one of H and OH);
o. Substituted aromatic acids;
p. Substituted aromatic esters;
q. A substituted aromatic amide; and r. A compound containing a sulfone functional group,   The composition according to claim 18, wherein the polyhydric phenol is at least one of resorcinol, 4-hexylresorcinol, n-dodecylresorcinol, and 1-naphthol. A radiation sensitive composition comprising:
a. At least one of resorcinol, n-dodecylresorcinol, 4-hexylresorcinol and 1-naphthol,
b. An acetal resin formed by condensing polyvinyl alcohol with an aldehyde,
c. A dissolution inhibitor, and d. Infrared light-heat conversion compound,
A composition comprising An image-forming element,
a. A substrate, and b. A layer coated with the composition according to claim 2 and dried on the surface of the substrate,
Including the element. An image-forming element,
a. A substrate, and b. A layer coated on the surface of the substrate with the composition of claim 5 and dried;
Including the element. An image-forming element,
a. A substrate, and b. A layer coated with the composition of claim 18 and dried on a surface of the substrate,
Containing element. An image-forming element,
a. A substrate, and b. A layer coated on the surface of the substrate with the composition of claim 20 and dried,
Including the element. A positive working lithographic printing precursor comprising a layer of a radiation sensitive composition on a hydrophilic lithographic printing surface, the composition comprising:
a. An acetal resin derived by condensing polyvinyl alcohol with an aldehyde, and b. Development accelerator compounds,
A precursor comprising   26. The precursor of claim 25, wherein the composition further comprises an infrared light-thermal conversion compound.   27. The precursor of claim 26, wherein the composition further comprises a dissolution inhibitor. The precursor according to claim 25, wherein the precursor is at least one of the following.
a. An alcohol containing at least one of an alkyl radical containing 12 to 60 carbon atoms, a fluoroalkyl radical containing 4 to 60 carbon atoms, and a fluoroalkylaryl radical containing 7 to 60 carbon atoms;
b. Polyols;
c. Monohydric phenol;
d. Polyphenols;
e. A compound containing a thiol functional group;
f. An anionic lithium salt which is one of carboxylate, thiocarboxylate, sulfate, sulfonate, phosphate, phosphite, nitrate and nitrite;
g. Esters of phosphorus-containing acids;
h. An amide of a phosphorus-containing acid;
i. Polysiloxane;
j. A quaternary ammonium salt having a free hydroxyl group;
k. An azo compound;
l. A compound containing an NH-NH-functional group;
m. Compounds containing functional groups of the formula

;
n. A compound containing the structure

(Wherein X is one of —S—, S═O, C═O or CO ₂ , and R ¹³ may be C ₁ -C ₁₂ alkyl, benzyl or structure E, Where E is given by:

Here, R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ may be one of H and OH)
o. Substituted aromatic acids;
p. Substituted aromatic esters;
q. A substituted aromatic amide; and r. A compound containing a sulfone functional group.   29. Precursor according to claim 28, wherein the polyol is a dimethicone copolyol.   The precursor according to claim 28, wherein the polyhydric phenol is at least one of resorcinol, 4-hexylresorcinol, n-dodecylresorcinol, and 1-naphthol.   29. The precursor of claim 28, wherein the polyhydric phenol is one of pyrogallol, phloroglucinol, 1,2,4-benzenetriol, and their alkyl and fluoroalkyl derivatives.   The anionic lithium salt is lithium 3- (1H, 1H, 2H, 2H-fluoroalkyl) propionate and lithium 3-[(1H, 1H, 2H, 2H-fluoroalkyl) thiopropionate, lithium trifluoromethanesulfonate. And the precursor of claim 28, which is one of lithium perfluorooctylethylsulfonate. The ester of the phosphorus-containing acid is P (OH) (OR) ₂ , P (OH) ₂ (OR), P (OH) ₂ [ORN (CH ₂ —CH ₂ —OH) ₂ ], P (OR) ₂ [O—R—NH (CH ₂ —CH ₂ —OH) ₂ ] (where R is alkyl, aryl, alkylaryl, polyethylene oxide, polypropylene oxide, or combinations thereof) 29. The precursor of claim 28.   29. Precursor according to claim 28, wherein the ester of phosphorus-containing acid is nonylphenol phosphate. The amide of the phosphorus-containing acid is P (OH) (ONHR) ₂ , P (OH) ₂ (ONHR), P (OR) ₂ [O—NH (CH ₂ —CH ₂ —OH) ₂ ], P (OR _{) [O-NH (CH 2} -CH 2 -OH) 2] 2 ( where R is alkyl, aryl, polyethylene oxide, one of the polypropylene oxide or their combinations), according to claim 28 Precursor. The polysiloxane is R [OSi (OCH ₃ ) ₂ ] _n —Si (OCH ₃ ) (OH) ₂ (where R is an alkyl (alkyl), aryl, polyethylene oxide, polypropylene oxide group or a combination thereof). 29. The precursor according to claim 28, wherein n = 2 to 1000).   The substituted aromatic acid is 2-nitrobenzoic acid, 3-nitrobenzoic acid, 4-nitrobenzoic acid, 2,4-dinitrobenzoic acid, 2,4-dichlorobenzoic acid, 2-hydroxy-1-naphthoic acid and 30. The composition of claim 28, wherein the composition is at least one of 3-hydroxy-2-naphthoic acid.   30. The composition of claim 28, wherein the substituted aromatic ester is methyl salicylate, phenyl salicylate, benzyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate and methyl 4-hydroxybenzoate.   29. The composition of claim 28, wherein the substituted aromatic amide is 3-nitrobenzamide and (2'-hydroxyethyl) -2,4-dihydroxybenzamide. A positive working lithographic printing precursor comprising a layer of radiation sensitive composition on a hydrophilic lithographic printing surface, wherein said composition comprises a. An acetal resin derived by condensing polyvinyl alcohol with an aldehyde,
And b. A development accelerator compound,
The positive working lithographic printing precursor, wherein the acetal resin has the structure:

Here, R ¹ is —C _n H _{2n + 1} (where n = 1 to 12), and R ² is

here,
R ⁴ = —OH;
R ⁵ = —OH or —OCH ₃ or Br— or —O—CH ₂ —C≡CH, and B ⁶ = Br— or NO ₂ ;
R ³ = — (CH ₂ ) _t —COOH, —C≡CH, or

Where R ⁷ = COOH, — (CH ₂ ) _t —COOH, —O— (CH ₂ ) _t —COOH,
And where t = 1-4 and where b = 5-40 mol%, preferably 15-35 mol%
c = 10-60 mol%, preferably 20-40 mol%
d = 0 to 20 mol%, preferably 0 to 10 mol%
e = 2 to 20 mol%, preferably 1 to 10 mol%, and f = 5 to 50 mol%, preferably 15 to 40 mol%, 41. The precursor of claim 40, wherein the development promoting compound is at least one of the following.
a. An alcohol containing at least one of an alkyl radical containing 12 to 60 carbon atoms, a fluoroalkyl radical containing 4 to 60 carbon atoms, and a fluoroalkylaryl radical containing 7 to 60 carbon atoms;
b. Polyols;
c. Monohydric phenol;
d. Polyphenols;
e. A compound containing a thiol functional group;
f. An anionic lithium salt which is one of carboxylate, thiocarboxylate, sulfate, sulfonate, phosphate, phosphite, nitrate and nitrite;
g. Esters of phosphorus-containing acids;
h. An amide of a phosphorus-containing acid;
i. Polysiloxane;
j. A quaternary ammonium salt having a free hydroxyl group;
k. An azo compound;
l. A compound containing an NH-NH-functional group;
m. Compounds containing functional groups of the formula

;
n. A compound containing the structure

(Wherein X is one of —S—, S═O, C═O or CO ₂ , and R ¹³ may be C ₁ -C ₁₂ alkyl, benzyl or structure E, Where E is given by:

Here, R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ may be one of H and OH)
o. Substituted aromatic acids;
p. Substituted aromatic esters;
q. A substituted aromatic amide; and r. A compound containing a sulfone functional group.   42. The precursor of claim 41, wherein the polyhydric phenol is at least one of resorcinol, 4-hexylresorcinol, n-dodecylresorcinol, and 1-naphthol. A positive working lithographic printing precursor comprising a layer of a radiation sensitive composition on a hydrophilic lithographic printing surface, the composition comprising: a. At least one of resorcinol, n-dodecylresorcinol, 4-hexylresorcinol and 1-naphthol,
b. An acetal resin formed by condensing polyvinyl alcohol with an aldehyde,
c. A dissolution inhibitor, and d. Infrared light-heat conversion compound,
A positive working lithographic printing precursor. A method for making a positive working lithographic printing precursor, the method comprising: coating a hydrophilic lithographic printing surface with a layer of radiation sensitive composition; and drying the layer. ,
Wherein the composition is
a. An acetal resin derived by condensing polyvinyl alcohol with an aldehyde, and b. A development accelerator compound,
Method.   45. The method of claim 44, wherein the composition further comprises an infrared light-to-heat converting compound.   46. The method of claim 45, wherein the composition further comprises a dissolution inhibitor. 46. The method of claim 45, wherein the development promoting compound is at least one of the following.
a. An alcohol containing at least one of an alkyl radical containing 12 to 60 carbon atoms, a fluoroalkyl radical containing 4 to 60 carbon atoms, and a fluoroalkylaryl radical containing 7 to 60 carbon atoms;
b. Polyols;
c. Monohydric phenol;
d. Polyphenols;
e. A compound containing a thiol functional group;
f. An anionic lithium salt which is one of carboxylate, thiocarboxylate, sulfate, sulfonate, phosphate, phosphite, nitrate and nitrite;
g. Esters of phosphorus-containing acids;
h. An amide of a phosphorus-containing acid;
i. Polysiloxane;
j. A quaternary ammonium salt having a free hydroxyl group;
k. An azo compound;
l. A compound containing an NH-NH-functional group;
m. Compounds containing functional groups of the formula

;
n. A compound containing the structure

(Wherein X is one of —S—, S═O, C═O or CO ₂ , and R ¹³ may be C ₁ -C ₁₂ alkyl, benzyl or structure E, Where E is given by:

Here, R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ may be one of H and OH)
o. Substituted aromatic acids;
p. Substituted aromatic esters;
q. A substituted aromatic amide; and r. A compound containing a sulfone functional group.   48. The method of claim 47, wherein the polyol is dimethicone copolyol.   48. The method of claim 47, wherein the polyhydric phenol is at least one of resorcinol, 4-hexylresorcinol, n-dodecylresorcinol, and 1-naphthol.   48. The method of claim 47, wherein the polyhydric phenol is one of pyrogallol, phloroglucinol, 1,2,4-benzenetriol, and their alkyl and fluoroalkyl derivatives.   The anionic lithium salt is lithium 3- (1H, 1H, 2H, 2H-fluoroalkyl) propionate and lithium 3-[(1H, 1H, 2H, 2H-fluoroalkyl) thiopropionate, lithium trifluoromethanesulfonate. 48. The method of claim 47, wherein the method is one of lithium perfluorooctylethylsulfonate. The ester of the phosphorus-containing acid is P (OH) (OR) ₂ , P (OH) ₂ (OR), P (OH) ₂ [ORN (CH ₂ —CH ₂ —OH) ₂ ], P (OR) ₂ [O—R—NH (CH ₂ —CH ₂ —OH) ₂ ] (where R is alkyl, aryl, alkylaryl, polyethylene oxide, polypropylene oxide, or combinations thereof) 48. The method of claim 47, wherein:   48. The method of claim 47, wherein the ester of phosphorus-containing acid is nonylphenol phosphate. The amide of the phosphorus-containing acid is P (OH) (ONHR) ₂ , P (OH) ₂ (ONHR), P (OR) ₂ [O—NH (CH ₂ —CH ₂ —OH) ₂ ], P (OR 48. The method of claim 47, wherein R is one of [O—NH (CH ₂ —CH ₂ —OH) ₂ ] _2, wherein R is alkyl, aryl, polyethylene oxide, polypropylene oxide, or combinations thereof. the method of. The polysiloxane is R [OSi (OCH ₃ ) ₂ ] _n —Si (OCH ₃ ) (OH) ₂ (where R is an alkyl (alkyl), aryl, polyethylene oxide, polypropylene oxide group or a combination thereof). 48. The method of claim 47, wherein n = 2 to 1000).   The substituted aromatic acid is 2-nitrobenzoic acid, 3-nitrobenzoic acid, 4-nitrobenzoic acid, 2,4-dinitrobenzoic acid, 2,4-dichlorobenzoic acid, 2-hydroxy-1-naphthoic acid and 48. The composition of claim 47, wherein the composition is at least one of 3-hydroxy-2-naphthoic acid.   48. The composition of claim 47, wherein the substituted aromatic ester is methyl salicylate, phenyl salicylate, benzyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate and methyl 4-hydroxybenzoate.   48. The composition of claim 47, wherein the substituted aromatic amide is 3-nitrobenzamide and (2'-hydroxyethyl) -2,4-dihydroxybenzamide. A method for making a positive working lithographic printing precursor, the method comprising: coating a hydrophilic lithographic printing surface with a layer of radiation sensitive composition; and drying the layer. Wherein the composition is a. An acetal resin derived by condensing polyvinyl alcohol with an aldehyde,
And b. A development accelerator compound,
The method, wherein the acetal resin has a structure of the following formula:

Here, R ¹ is —C _n H _{2n + 1} (where n = 1 to 12), and R ² is

here,
R ⁴ = —OH;
R ⁵ = —OH or —OCH ₃ or Br— or —O—CH ₂ —C≡CH, and B ⁶ = Br— or NO ₂ ;
R ³ = — (CH ₂ ) _t —COOH, —C≡CH, or

Where R ⁷ = COOH, — (CH ₂ ) _t —COOH, —O— (CH ₂ ) _t —COOH,
And where t = 1-4 and where b = 5-40 mol%, preferably 15-35 mol%
c = 10-60 mol%, preferably 20-40 mol%
d = 0 to 20 mol%, preferably 0 to 10 mol%
e = 2 to 20 mol%, preferably 1 to 10 mol%, and f = 5 to 50 mol%, preferably 15 to 40 mol%, 60. The method of claim 59, wherein the development promoting compound is at least one of the following.
a. An alcohol containing at least one of an alkyl radical containing 12 to 60 carbon atoms, a fluoroalkyl radical containing 4 to 60 carbon atoms, and a fluoroalkylaryl radical containing 7 to 60 carbon atoms;
b. Polyols;
c. Monohydric phenol;
d. Polyphenols;
e. A compound containing a thiol functional group;
f. An anionic lithium salt which is one of carboxylate, thiocarboxylate, sulfate, sulfonate, phosphate, phosphite, nitrate and nitrite;
g. Esters of phosphorus-containing acids;
h. An amide of a phosphorus-containing acid;
i. Polysiloxane;
j. A quaternary ammonium salt having a free hydroxyl group;
k. An azo compound;
l. A compound containing an NH-NH-functional group;
m. Compounds containing functional groups of the formula

;
n. A compound containing the structure

(Wherein X is one of —S—, S═O, C═O or CO ₂ , and R ¹³ may be C ₁ -C ₁₂ alkyl, benzyl or structure E, Where E is given by:

Here, R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ may be one of H and OH)
o. Substituted aromatic acids;
p. Substituted aromatic esters;
q. A substituted aromatic amide; and r. A compound containing a sulfone functional group.   61. The method of claim 60, wherein the polyhydric phenol is at least one of resorcinol, 4-hexyl resorcinol, n-dodecyl resorcinol, and 1-naphthol. A method for making a positive working lithographic printing precursor, the method comprising: coating a hydrophilic lithographic printing surface with a layer of radiation sensitive composition; and drying the layer. Wherein the composition is a. At least one of resorcinol, n-dodecylresorcinol, 4-hexylresorcinol and 1-naphthol,
b. An acetal resin formed by condensing polyvinyl alcohol with an aldehyde,
c. A dissolution inhibitor, and d. Infrared light-heat conversion compound,
Said method. A method for making a lithographic printing master, the method comprising:
a. Comprising a lithographic printing precursor comprising a layer of a radiation sensitive composition on a hydrophilic lithographic printing surface, the composition comprising:
i. An acetal resin derived by condensing polyvinyl alcohol with an aldehyde,
And ii. The step, which is a composition comprising a development accelerating compound;
b. Irradiating the region of the layer imagewise using image forming radiation to facilitate dissolution of the layer in the irradiated region with an alkaline aqueous solution;
Including said method.   64. The method of claim 63, wherein the composition further comprises an infrared light-to-thermal conversion compound.   65. The method of claim 64, wherein the composition further comprises a dissolution inhibitor. 65. The method of claim 64, wherein the development promoting compound is at least one of the following.
a. An alcohol containing at least one of an alkyl radical containing 12 to 60 carbon atoms, a fluoroalkyl radical containing 4 to 60 carbon atoms, and a fluoroalkylaryl radical containing 7 to 60 carbon atoms;
b. Polyols;
c. Monohydric phenol;
d. Polyphenols;
e. A compound containing a thiol functional group;
f. An anionic lithium salt which is one of carboxylate, thiocarboxylate, sulfate, sulfonate, phosphate, phosphite, nitrate and nitrite;
g. Esters of phosphorus-containing acids;
h. An amide of a phosphorus-containing acid;
i. Polysiloxane;
j. A quaternary ammonium salt having a free hydroxyl group;
k. An azo compound;
l. A compound containing an NH-NH-functional group;
m. Compounds containing functional groups of the formula

;
n. A compound containing the structure

(Where X is -S-, S = O, one of a C = O or CO _2, and wherein R ¹³ is C ₁ -C ₁₂ alkyl, may be benzyl or structure E, Where E is given by:

Here, R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ may be one of H and OH)
o. Substituted aromatic acids;
p. Substituted aromatic esters;
q. A substituted aromatic amide; and r. A compound containing a sulfone functional group.   The precursor according to claim 66, wherein the polyhydric phenol is at least one of resorcinol, 4-hexylresorcinol, n-dodecylresorcinol, and 1-naphthol. A method for making a lithographic printing master, the method comprising:
a. Providing a lithographic printing precursor comprising a layer of radiation sensitive composition on a hydrophilic lithographic printing surface, wherein the composition comprises:
i. An acetal resin formed by condensing polyvinyl alcohol with an aldehyde,
ii. At least one of resorcinol, n-dodecylresorcinol, 4-hexylresorcinol and 1-naphthol,
iii. A dissolution inhibitor, and iv. Infrared light-heat conversion compound,
A process including:
b. Irradiating the region of the layer imagewise using image forming radiation to facilitate dissolution of the layer in the irradiated region with an alkaline aqueous solution;
Including said method.