JP2002046362A - Computer to plate method through ink jet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple method for manufacturing a lithographic printing plate at low cost. SOLUTION: In the manufacturing method of the lithographic printing plate, in which the distribution of small liquid droplets on the surface of a lithographic acceptor executed strictly to the information realized by ink jet printing is included, the liquid includes an olephilizing turning compound represented by formula (I), wherein Y represents C or N, Q represents atoms necessary for completing an aromatic or a hetero-aromatic five-membered or six-membered ring, X represents atoms necessary for completing a hetero-aromatic five- membered or six-membered ring. Z is selected from oxygen or sulfur and M is selected from a proton or a pair of ions for canceling a negative charge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate by ink jet printing.
late) manufacturing method.

[0002]

2. Description of the Related Art The traditional techniques of printing are letterpress printing, gravure printing and offset lithography.
ographies). All of these printing methods transfer ink in a pattern of images (tr
plate cylinder of a rotary press, usually for efficiency.
requires a plate mounted on the ylinder. In letterpress printing, an image pattern is a raised area that accepts ink and transfers it onto a recording medium by impression.
ed areas) on the plate. Gravure printing cylinders, in contrast, are a series of wells that receive ink for deposition on a recording medium.
s) or indentations.

In the case of traditional offset lithographic printing,
The image to be printed is ink-repellent (ink repellent).
ent) [oleophobic or hydrophilic] ink receptivity on the background (ink ac
present on the plate as a pattern of cepting (lipophilic) areas. In a wet system, the required ink repellency is determined by dampening solution [dampin] prior to inking.
g (or “fountain”) solution]
Given by the first application of. Conventional presensitized lithographic printing plates
An optical printing plate is a UV-sensitive coating based on photopolymer or diazonium chemistry.
ing). The plate must be UV exposed through a mask that carries the image. The mask is based on silver halide chemistry and can be used with a camera or imagesetter (im
FIG. 2 is a graphic art film produced by photographic technology with an exposure by an ag-setter and further with a wet process. Depending on the type of plate used (negative or positive), the non-image areas or image areas are solubilized, thereby distinguishing the plate into lipophilic and hydrophilic areas. A disadvantage of this conventional method is that it requires cumbersome production of photographic intermediate films with wet processing. A further disadvantage is the wet treatment of the printing plate itself.

[0004] With the advent of computers in revolutionizing the graphics design process leading to printing, convenient and inexpensive computer-to-plates where photographic intermediates are no longer needed.
Extensive efforts have been made to develop systems. In recent years, some of these systems have been introduced to the market based on different chemical systems and exposure methods. For example, the SETPRTINT material (trademark of Agfa-Gevaert NV) is a silver halide DTR
It is based on chemistry and consists of a polyethylene terephthalate base carrying a photographic coating that produces complementary lipophilic and hydrophilic areas after photomode exposure and processing. Other systems based on photo mode exposure but with a hydrophilic aluminum base are described in LITHOSTAR (Agfa-Gevaert N. et al.
V. trademark). A system based on thermal mode exposure with an intense infrared laser is THERMOSTAR (also a
Agfa-Gevaert NV).

[0005] Many of the new computer tow plate systems are large, complex, and expensive. They are a pre-press process for large printing companies' printing operations.
It is designed for use by large printing companies as a means of simplifying the process and taking advantage of the rapid exchange and response to digital information in graphic designs provided by their customers. There remains a strong demand for an economical and efficient computer tow plate system for many small printers utilizing lithographic printing.

To satisfy the needs of these small printers, a number of electronic non-impact printing systems have been investigated for use in the production of lithographic printing plates. The most important of these was the laser printing system described, for example, in US Pat. No. 5,304,443 and its references. Other non-impact printing systems of interest for economical and convenient computer tow plate manufacturing for lithographic printing are described, for example, in US Pat.
No. 958,564.

In recent years, ink jet printers have replaced laser printers as the most popular hard copy output printers for computers. Some of the competitive advantages of ink jet printers are low cost and reliability. Ink jet printing systems are relatively fast image output systems and have a simple structure. Because it does not require any complex optical system. Recently, there have been several reports in the literature advocating the use of ink jet printers to produce lithographic printing plates.

In Japanese Patent Application Laid-Open No. 62-25081, a lipophilic liquid or fluid ink is printed on a hydrophilic aluminum surface of a lithographic printing plate by ink jet printing. Titanate or silane coupling agent was present in the ink.

An ink jet printing apparatus for producing a lithographic printing plate is described in PCT WO 94/11191. It is directed to depositing hydrophobic or hydrophilic substances on hydrophobic printing plates.

In US Pat. No. 5,501,150, a silver reducible image (silver) is formed by ink jet printing.
It is said to provide a lithographic printing plate after wet processing to render the silver image sufficiently hydrophobic using a fluid ink and a hydrophilic media set containing materials to produce r-reducible image). Produces a metallic silver image.

In order to deposit hot wax on the surface of an offset plate, ink jet printing, in which the ink is a solid or phase change ink instead of a liquid or fluid ink, is described in US Pat. No. 4,833,486. ing. As the wax cools, it solidifies, thereby giving the printing plate. Solid ink-jet printing is a process in which a wax or resin image has limited durability due to its thermoplastic, chemical and adhesive properties, and the amount of solidified ink-jet droplets and the round shape on the medium is liquid ink-jet printing. Have significant disadvantages with lithographic printing plates in that they do not have the inherent image resolution characteristics found in US Pat.

There is also the prior art in the use of ink jet printing to apply an opaque image or mask pattern to a photosensitive lithographic printing plate blank, as for example in JP-A-63-109,052. The blank is then exposed through an ink jet imaged mask pattern and then processed by conventional means to give a lithographic printing plate. This method retains the materials and processing of a conventional lithographic printing plate and only uses ink jet printing as an alternative to a photomask that exposes the conventional plate. Thus, this method increases the complexity and cost of the plate making process and does not rely on an ink jet ink image for the hydrophobic image of the plate. US Patent No. 5,495,
No. 803 describes a solid or phase change ink jet printing to form a photomask for a printing plate.

As a further example of a method for producing a printing plate by using an ink jet printing system, JP-A-56-113456 discloses an ink-repellent material (eg, curable silicones). We propose a printing plate manufacturing method for printing on a printing plate by jet printing. The printing plate obtained by this method is a substrate (subs
The intaglio printing plate in which the ink-repellent material formed on the surface of the plate serves as a non-image portion (intagli)
o printing plate). As a result, the resolution of the printed image in shadow areas or reversed lines is not so good. Furthermore, this method requires a large amount of ink since the ink-repellent material must be deposited on the entire non-image area, which occupies a large part of the printing plate surface, thereby slowing down the printing process.

US Pat. No. 5,511,477 discloses forming a positive or negative image on a substrate by ink jet printing with a photopolymer ink composition optionally preheated to a temperature of about 30 ° to 260 ° C. Disclosed is a method of making a photopolymer relief printing plate comprising exposing a printed substrate to ultraviolet radiation, thereby curing the ink composition to form the image. This is an unpleasant process due to the higher vapor pressure and toxicity of the ink.

US Pat. No. 5,312,654 discloses ink jet printing using a photopolymerizable ink composition on a substrate having an ink absorbing layer and a hydrophilized layer between the substrate and the absorbing layer. Discloses a method of making a lithographic printing plate comprising curing the image by exposing it to actinic light in the wavelength region of the ink composition which is sensitized. . The printing durability of the printing plate is low.

Japanese Patent Application Laid-Open No. 4-69244 discloses that a printed image is formed on a recording material which has been subjected to a hydrophilic treatment by ink jet printing using a hydrophobic ink containing a photocurable component, and A method of making a printing plate comprising exposing the entire surface to actinic light is disclosed. However, the surface of the substrate to be used in the lithographic printing plate is usually subjected to various treatments such as mechanical polishing, anodizing or hydrophilic treatment to obtain good hydrophilicity and water retention. Therefore, even the use of ink compositions having very high surface tensions results in poor images on the surface of the substrate due to ink spreading and low print durability.

EP-A-533168 is an ink-absorbing layer that is removed after printing an ink, using a lithographic base.
A method is disclosed which avoids spreading of the ink by coating with a graphic base.
This is an uneconomic and cumbersome method.

Research Di, May 1988
No. 289118 discloses a method of making a printing plate by using an ink jet where the ink is a hydrophobic polymer latex. However, the printing plate has poor ink acceptance and low printing durability.

EP-A-003789 discloses a method for producing an offset printing plate by an ink-jet method using a lipophilic ink. It is not shown how the ink is made, but it is clear from the examples that it is with an artificial latex that is difficult to make.

JP 57-038422 discloses a printing plate by forming an ink image on a blank printing plate and also thermally fixing the image by depositing toner on the imaged area. A method of manufacturing is disclosed. The composition of the ink is not described, only the composition of the toner is disclosed.

JP-A-7-108667 discloses an electrostatic attraction type ink setting system (e) in which an ink image containing a hydrophilic substance is placed on a conductive support whose surface layer is made hydrophilic.
electrostatic attraction t
a plate making method for drying or curing an ink image by forming the ink image by using an ink set system.
Ink jet writing
ng), discloses a plate making method for applying a bias voltage to the conductive support. This is a cumbersome method.

US Pat. No. 5,213,041 discloses an ejectable containing a heat-fusible component.
Disclosed is a method of making a reusable printing plate for printing by using the substance to project an imaging deposit on the plate surface by jet printing. The image forms an imageable deposit that is fused to the surface of the printing plate using a variable frequency and variable power induction heater.

In WO 97/43122, a lithographic printing plate is produced by an ink jet fluid comprising a reactive component selected from the group consisting of a transition metal complex and an organic carbonyl compound. In a preferred embodiment, the reactive compound comprises a chromium complex of one or more organic acids.

The present invention provides a lithographic receiver by ink jet printing.
r) on top of the oleophilizing fluid
luid) directly to the teaching of the production of lithographic printing plates.

[0025]

It is an object of the present invention to provide a simple and inexpensive method for the production of a lithographic printing plate.

It is a further object of the present invention to provide an intermediate graphic film.
(c film) is not required.

A further object of the present invention is to provide a process.
It is an object of the present invention to provide a method for producing a lithographic printing plate that does not require ssing.

It is a further object of the present invention to provide a method for producing a lithographic printing plate that produces little or no waste and is therefore advantageous from an ecological point of view.

It is a further object of the present invention to provide a method for producing a lithographic printing plate wherein the production steps can be performed in daylight.

[0030] Further objects will become apparent from the description hereinafter.

[0031]

SUMMARY OF THE INVENTION An object of the present invention is to provide a lithographic receiver.
A method for producing a lithographic printing plate comprising dispensing, by ink-jet printing, droplets of a fluid on the surface of a lithographic printing plate, wherein the fluid has the following general formula (I):

[0032]

Embedded image

Wherein Y represents C or N; Q represents an atom necessary to complete an aromatic or heteroaromatic 5- or 6-membered ring; X is a heteroaromatic 5- or 6-membered ring. Represents the atoms necessary to complete: Z is selected from oxygen or sulfur;
M is selected from a proton or a counter ion for canceling a negative charge.
This is achieved by providing a method characterized by containing a chilling compound.

The various components used in accordance with the method of the present invention will now be described in detail.

I. The essence of the present invention is
The presence of the lipophilic compound represented by the above general formula (I) in the ink jet fluid.

Preferred compounds are 8-hydroxyquinolines, 7-hydroxybenzimidazoles and 7-hydroxybenzotriazoles and their corresponding thio-analogues.
The most preferred compounds are 8-hydroxyquinolines.

Typical examples of the compounds corresponding to the general formula (I) are shown below.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

[Table 3]

The compounds described above are commercially available or can be synthesized according to well-known simple methods.

The lipophilic agent can be present in the ink in an amount of 0.01 to 6% by weight, preferably 0.02 to 3% by weight.

The lipophilic agent must be in the form of a homogeneous solution or a stable colloidal dispersion so that it can pass through the nozzles of the printer head.

The liquid carrier is water or an organic solvent or a combination thereof. The choice of a particular liquid carrier will depend on the particular ink jet printer and its compatibility with the ink jet print head and cartridge used for ink jet printing. Inkjet technology used: piezo, heat,
Aqueous-based fluids and solvent-based fluids can be used in the present invention, depending on the bubble jet or continuous ink jet.

While water is a preferred medium for aqueous inks, the aqueous composition may be one or more water-miscible solvents such as polyhydric alcohols, for example, ethylene glycol, diethylene glycol, triethylene glycol. Or it can comprise trimethylolpropane. Aqueous carrier medium (aqueousca) in aqueous composition
rr. medium) is 30 to 99.995.
%, Preferably in the range of 50-95% by weight.

Organic solvents such as alcohols, ketones or acetates can also be used as carrier media for the ink jet fluid.

As is known in the ink jet art, the jet velocity, the separation length of the droplets (separati
On length, drop size and flow stability are greatly affected by the surface tension and viscosity of the aqueous composition. Ink jet fluids suitable for use with an ink jet printing system can have a surface tension in the range of 20 to 60 dynes / cm, preferably 30 to 50 dynes / cm. Control of the surface tension of the aqueous ink jet fluid can be achieved by the addition of small amounts of surfactants. The level of surfactant to be used can be determined by simple trial and error experiments. Several anionic and nonionic surfactants are known in the ink jet art. Commercially available surfactants are SUR
FYNOLTM series (trademark of Air Products), ZONYLTM series (trademark of DuPont), FLUORADTM series (trademark of 3M) and AEROSOLTM series (Cyanam)
id trademark). The viscosity of the fluid is preferably 20 mPa.s at room temperature. s or less, for example, 1 to 10, preferably 1 to 5 mPa.s. s.

[0048] The ink jet fluid may further comprise other components. A cosolvent can be included to help prevent the ink from drying in the orifices of the printhead. Biocides can be added to prevent unwanted microbial growth that may occur in the ink over time. Additional additives that may optionally be present in the ink include thickeners, pH adjusters, buffers, conductivity enhancers, desiccants and defoamers.

Dyes can be added to increase the contrast of the image after it has been jetted onto the lithographic receiver. Many dyes and pigments are known to be suitable for ink jet technology. Suitable dyes further include their compatibility in a carrier medium (ie, aqueous-based or solvent-based) and their compatibility with lipophilic agents, that is, when they are coagulatio
n) should not occur. Particularly advantageous for aqueous inks is acid black (acid
black).

II. The lithographic receiver support can be any support suitable for printing plates. Typical supports include metal and polymer sheets or foils. Preferably, a support having a metal surface is used. Preferably, the metal surface is oxidized. In a particularly preferred embodiment of the present invention, a support having an anodized aluminum surface is used. The support for a lithographic printing plate is typically polished, for example, by electrochemical grinding, and then anodized by an anodization technique using, for example, sulfuric acid and / or phosphoric acid.
ed) formed from aluminum. Both polishing and anodizing methods are well known in the art and need not be described further here. After writing the image, the printing plate is inked with printing ink in the usual way (inke
d) and the plate can be used on a printing press. Prior to inking, the plate can be treated with an aqueous solution of a natural gum such as gum arabic or a synthetic gum such as carboxymethyl cellulose, as is well known in the printing art.

According to another mode of the present invention, a lithographic base having a hydrophilic surface is provided.
base) comprises a flexible support, such as paper or plastic film, with a cross-linked hydrophilic layer. Particularly suitable cross-linked hydrophilic layers are formaldehyde, glyoxal, polyisocyanate, melamine-type cross-linking agents, ammonium zirconyl carbonate (ammonium carbonate).
zirconyl carbonate, a hydrophilic binder cross-linked with a cross-linking agent such as a titanate cross-linking agent or a hydrolyzed tetraalkyl orthosilicate. Hydrolyzed tetraalkyl orthosilicate is particularly preferred.

Examples of the hydrophilic binder include vinyl alcohol, acrylamide, methylolacrylamide,
Hydrophilic (co) polymers such as methylol methacrylamide, acrylate acid, methacrylate acid, hydroxyethyl acrylate, hydroxyethyl methacrylate homopolymers and copolymers or maleic anhydride / vinyl methyl ether copolymer can be used.
The hydrophilicity of the (co) polymer or (co) polymer mixture used is at least 60% by weight, preferably higher than the hydrophilicity of the hydrolyzed polyvinyl acetate to the extent of 80% by weight. Is preferred.

The crosslinked hydrophilic binder in the thermosensitive layer used according to the embodiment of the present invention is a colloidal inorganic pigment, such as titanium dioxide or other metal, which increases the mechanical strength and porosity of the layer. Metal oxide particles that are oxide particles are also contained. It is believed that the incorporation of these particles gives the surface of the crosslinked hydrophilic layer a uniform rough texture consisting of microscopic hills and valleys that serve as storage for water in the background area. Preferably, these particles are beryllium, magnesium, aluminum, silicon, gadolinium, germanium, arsenic,
Indium, tin, antimony, tellurium, lead, bismuth,
It is an oxide or hydroxide of titanium or a transition metal. Particularly preferred inorganic particles are oxides or hydroxides of aluminum, silicon, zirconium or titanium used in at most 75% by weight of the hydrophilic layer. The amount of inorganic pigment is 0.
Particle size in the range of 005 μm to 10 μm
size).

The thickness of the crosslinked hydrophilic layer in the lithographic base according to this embodiment can vary from 0.2 to 25 μm, preferably from 1 to 10 μm.

Specific examples of suitable cross-linked hydrophilic layers for use in accordance with the invention are EP-A 601 240, GB 1419512, FR 23003.
No. 54, U.S. Pat. No. 3,971,660, U.S. Pat. No. 4,284,705 and EP-A 514 490.

As a lithographic base flexible support in connection with the embodiment of the present invention, a plastic film such as a subbed polyethylene terephthalate film, a subbed polyethylene naphthalate film, a cellulose acetate film, a polystyrene film, It is particularly preferable to use a polycarbonate film or the like. The plastic film support can be opaque or transparent.

III. Ink Jet Printing Process In ink jet printing, droplets of ink fluid are projected directly onto the ink receiver surface without physical contact between the printing device and the receiver. The printing device stores the printing data electronically and stores the drops image-wise (i
mage-wise) ejecting
Control mechanism for Printing is achieved by moving the print head across the paper or vice versa.
Earlier patents relating to ink jet printers include U.S. Pat. No. 3,739,393 and U.S. Pat. No. 3,805,27.
No. 3 and U.S. Pat. No. 3,891,121.

The ejection of the ink droplets can be performed in several different ways. In the first type of method, a continuous droplet stream is created by applying pressure in a wave pattern. This process is known as continuous ink jet printing. In a first embodiment, the droplet stream is electrostatically charged, deflected and re-collected droplets and droplets which are uncharged and continue their path undeflected and form an image. Divided into drops. Alternatively, the charged, deflected stream forms an image and the uncharged, undeflected jet is collected again. In this variant of continuous ink jet printing, several jets are deflected to different degrees, thus recording an image [multi-deflection system.
system].

According to the second method, it can be generated "on demand"("DOD" or "drop on demand" method), so that the printing device allows the droplet Ejects droplets only when used to image on,
Thereby, the complexity of drop charging, deflection hardware and ink recollection is avoided. In drop-on-demand, ink droplets are generated by pressure waves generated by the mechanical movement of a piezoelectric transducer (so-called "piezo method") or by discrete thermal pushes.
[The so-called “bubble jet” method (“bubble j
et "method) or thermal jet method (" ther "
mal jet "method)].

[0060]

The present invention will now be described by way of the following non-limiting examples.

EXAMPLES A representative of the various chemicals described above was tested for their lipophilic ability using the following procedure. 0.1 to 2 lipophilic agents
Dissolved in isopropanol or N-methylpyrrolidone at a concentration of% w / w. A 6 μl droplet of the ink fluid is then applied to a lithographic electrochemically polished and anodized aluminum receptor as described above.
electrochemically grained
andanodised aluminum rec
eir). Abdick Edition (ABD
ICK) Installed on a 360 printing press and used as ink VAN SON RUBB
ERBASE) (registered trademark of vanson Co.) and 2% TAME as a fountain (Anchor / Lithchemko)
Co. Was used to test local lipophilicity.
The ink uptake of the droplet images was evaluated.

The results for some of the compounds described above are summarized in Table II.

[0063]

[Table 4]

The results in Table II clearly show the excellent lipophilicity of the compounds used according to the invention.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Marc van Dame Belgium B2640 Malt Cell Septes Trat 27 Agfa-Gevuert Na Mrose Fennoutapp F-term (reference) 2C056 EA24 FB01 2H084 AA25 AE05 CC05 2H086 BA18 BA59 2H114 AA04 AA21 BA10 DA41 EA01 EA08 GA01 4J039 BC49 BC50 BC51 BC52 BC55 BC73 BC76 BC79 BE33 CA01 EA46 EA48 GA24

Claims (2)

[Claims] 1. A method for producing a lithographic printing plate, comprising distributing information-wise droplets of a fluid onto the surface of a lithographic receiver by ink jet printing, wherein the fluid has the following general formula (I): ] Wherein Y represents C or N; Q represents the atoms necessary to complete an aromatic or heteroaromatic 5- or 6-membered ring;
Represents the atoms necessary to complete a 5- or 6-membered heteroaromatic ring; Z is selected from oxygen or sulfur; M is selected from a proton or counter ion to offset a negative charge;
A lipophilic compound represented by the formula: 2. The method according to claim 1, wherein said lipophilic compound is 8-hydroxyquinoline.