JPS59135191A - Lithography with rubber intermediate layer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION In general, photosensitive printing plates are classified into lithography, intaglio and letterpress.
planographic printing plat
e) The surface of the support is chemically or physically treated to render it hydrophilic, or the surface is coated with a hydrophilic polymer, and then the hydrophilic polymer thus prepared is 1 by applying a photosensitive material to the surface.

Typical surface treatments include mechanical surface treatments such as brushing and graining, with or without chemical surface treatments such as electrolytic graining and/or etching, and/or anodizing. There are chemical surface treatments in which additional layers such as alkali metal salts or phosphonic acids, silicates, potassium fluorozirconates are applied.

During this period, most lithographic plates were made from grained/zinc sheets, in which case the lead-lined plates were coated with a suitable photosensitive composition, dried, and rapidly exposed to obtain the desired image. Developing ink is then applied to the entire surface of the zinc plate, and the zinc plate is then rinsed to remove the water-soluble material and developing ink. The printing surface of the plate is then applied with an arabicum bath to protect it until it is ready for use. The gum arabic provided chemical protection to the image, yet was easily washed off by the water when the plate was desired to be used.

U.S. Pat. No. 2,714,066 discloses a lithographic plate made from a thin sheet of metal, in which at least one surface of the sheet has a thin, preferably inorganic, alkali bond bonded to it. Formed from solutions of metal silicates, salicylic acid or other treatment agents. treated to provide a hydrophilic surface treatment, thereby forming a permanent hydrophilic stain-reducing-tone-reducing film coated with a firm bonding contact on the surface of the plate; It will have a coating layer of photosensitive organic material over the hydrophilic treated surface of its L embossment, ie the exposed surface of the stain prevention-tone reduction film. A preferred substrate is an aluminum foil material or sheet material thereof that has been cleaned, for example by immersion in a sodium phosphate solution.

Rauner U.S. Patent No. 5.511
, No. 661, Mr. Cunningll
am)), as well as U.S. Pat. No. 3,860,426 and U.S. Pat. Although coatings have been disclosed, they still utilize processing methods and additives that are not required for the present invention.

The present invention relates in particular to PS plate systems in which metal substrates are prepared by an anodizing method for the application of photosensitive materials. A problem that has traditionally plagued anodized PS plate systems has been backclarand contamination from resins, dyes, photosensitive materials, additives, and the like. Due to the necessary porosity of the layer immediately after the anodization treatment, absorption of the photosensitive material layer occurs in the oxidized layer, and if the layer is sealed with a suitable agent such as sodium silicate during the manufacturing process. However, if no intermediate layer is formed, the area becomes oleophilic and the ink will adhere to the absorbent material or the like. However, it is well known that when such inorganic interlayers are used, the organic nature of the sensitizers, resins, additives and dyes can result in shorter print life.

In order to avoid background contamination as much as possible without adversely affecting print life, anodizing ps
Various solutions have been taken by plate manufacturers. Such solutions include choosing a dye that does not cause visible stains when observed with the naked eye, and choosing a dye that does not penetrate the pores during anodizing and that stands out during development and processing. You may choose a resin like this. However, such solutions limit the selection of dyes, resins, photosensitive materials, and additives, and can sometimes lead to differences in the ink/water balance during the printing operation. Also, attempts have been made to use relatively low concentrations of dye, but this generally limits the printout between image and non-image areas and the contrast between image and background areas. receive. Yet another solution is to optimize the anodizing conditions to avoid the formation of porous JN.

None of these compromises can be added to as a whole.

One attempt to circumvent the various compromise solutions mentioned above is to treat the PS version with an aqueous solution of kepolyvinylphosphonic acid after anodization. In such a system, the high printout properties of the plate preserve the high contrast properties, and contamination is totally eliminated, as well as image deletion, water/ink balance (print smear), exposure and storage. Overall lifespan is improved. However, the print life is about 25 times shorter. The main reason is
It is therefore an object of the present invention to improve print life and other desirable printing plate properties by preventing sealing or interlayer chemicals from forming weak adhesion between the anodic oxide and the covering layer in the image area. It is an object of the present invention to provide a new lithographic plate that largely overcomes the background contamination problem without any substantial adverse effects.

These and other objects of the invention will become apparent to those skilled in the art from the following description.

The present invention is a planographic printing plate.
In particular, the present invention relates to a lithographic plate comprising an anodized metal substrate having an intermediate layer of sugar rubber and a photosensitive layer provided on the intermediate layer.

When the anodic oxide is newly formed, its surface is highly active and dyes and gases are particularly prone to absorption into the pores of the oxide. These absorption properties naturally deteriorate over time, which is attributed to the reaction of the anodic aluminum oxide with water vapor in the air. For industrial purposes, especially for structural purposes, most of the anodic oxides are prepared using hot water, steam, dichromate, sodium silicate, nickel acetate, cobalt acetate, etc. This increases corrosion resistance.

Therefore, most sealed anodic oxides have excellent alkali resistance, which is a measure of corrosion resistance. In the present invention, the intermediate layer has the effect of sealing the photosensitive coating layer and the reaction between the organic dye in the developer and the anodic oxide; It does not become a corrosion coating.

The substrate used in the production of the positive or negative treated lithographic plates of the present invention may be any metal substrate hitherto used for such purposes. Among the various support materials available are zinc, iron or steel, copper, lead,
These include tin, chromium, manganese, tantalum, titanium and preferably aluminum, and also aluminum alloys, such as alloys of predominant aluminum with silicon, iron, zinc, copper, manganese, magnesium, chromium, zirconium, etc. Such substrates may be subjected to conventional methods, such as chemical etching, electrolytic etching or mechanical graining, if desired, and then anodized using conventional methods. For example, an aluminum plate can be anodized by undergoing anodization, in which case the aluminum plate is treated with an aqueous or solvent-based acid, such as sulfuric acid at a concentration of 1 to 80% by weight. It is used as an anode in oxalic acid, boric acid, phosphoric acid, sulfamino acid, chromic acid, etc., and the electrolyte temperature is 5 to 70℃, 0
．． Current densities of 5 to 6 QA/dm2, voltages of 1 to 100 volts, and times of 30 seconds to 50 minutes are used.

To overcome the inherent porosity problems with anodized substrates, the substrates are made of water-soluble saccharide rubber (5acch).
aride gum) solution.

A typical example is Hercules (10
Carboxymethyl cellulose gum, hydroxypropyl cellulose gum, gatch gum, ja Burgum, locust bean gum (10Cuθt bean gum), gum arabic, guar gum (guar), such as sodium carboxymethyl cellulose salt 7L and 7M sold by gum), protein-type rubber, etc. Mixtures of interlayer agents can be used if desired. Generally, the amount of rubber in the solution is approximately 0.1 to ! IO10% by weight
Preferably, it is about 0.5 to 10% by weight. There is no restriction as to the nature of the solvent, as long as it is substantially inert, and it may be water or even an organic solvent such as, for example, methanol. Aqueous solvents are preferred. A preferred sugar gum is sodium carboxymethylcellulose in the ammonium or alkali metal salt form, especially in the sodium or potassium salt form.

If the water consists of sugar gum, 1. It is advantageous to include small amounts of oxidizing or complexing agents in the solution.

When sodium carboxymethylcellulose rubber is used, crystals of the water-insoluble aluminum salt of carboxymethylcellulose form upon contact with bare, non-oxidized aluminum. Such crystals are eliminated by adding citric acid, phosphoric acid, sulfuric acid, sulfonic acid, sodium nitrate, potassium nitrate and preferably nitric acid. in general,
] of the additive may be about 0.01 to 1.0% by weight, preferably about 0.1 to 0.4% by weight, ie a pH of 3 to 8 is desired. Similar results were also obtained for potassium fluorozirconium, potassium fluoride,
It can also be obtained using hydrofluoric acid, potassium trifluorozincate, and other water-soluble inorganic fluorides.

The anodized metal substrate is contacted with the sugar rubber for a sufficient period of time to form an intermediate layer thereon, which intermediate layer is likely to be on the order of a monolayer. Generally, times of about 5 to 120 seconds are used, and longer times may be used if desired. The specific contact length depends on the specific sugar rubber used,
It will vary depending on its concentration in the solvent, the nature of the solvent, temperature, and other additives to the system. The appropriate length of time can be easily optimized for a given system. The method of contacting is not particularly limited, and the saccharide rubber may be sprayed onto an anodized metal substrate, the substrate may be immersed in a saccharide rubber solution,
The solution can also be applied to the substrate with a roller if necessary. Following such contact, the substrate surface is washed with water or rinsed with water or other solvent and dried under ambient temperature conditions.

A suitable photosensitive layer is deposited onto the anodized substrate having an interlayer formed thereon and processed in a conventional manner. Positive-type photosensitive compositions often have a 0-
The quinonediazide type photosensitive material alone or the addition of appropriate additives. When exposing the photosensitive layer to actinic radiation with an image-supported lithographic flat, the O in the exposed areas
- Photosensitive materials of the quinonediazide type convert into alkali-soluble compounds, which are then easily removed by aqueous alkaline solutions to obtain positive images. In areas where the alkali-soluble photosensitive material has been removed by the aqueous alkaline solution, a hydrophilic surface is exposed that receives water and repels ink. The areas left as an image are oleophilic and will accept ink. Many positive type photosensitive materials are known and can be used in the present invention without limitation. It is also possible to use photosensitive diazo materials of the negative type, in which the areas not exposed to actinic radiation are removed with an alkali or otherwise, leaving a hydrophilic surface and the plate thus treated. , which is prepared for use in a lithographic printing press without further processing to print or reproduce the desired document or image. however,
It is conventional to treat the printed side of the plate with what is known in the art as an "image developer" before the plate is installed in a lithographic printing press. Various types of image developers can be used - for example, resin emulsions which adhere to the ink-receiving areas but not to the hydrophilic areas of the plate, e.g. Lacquer for side plate systems (add, ative plate systems). Further, developing ink from a printing press can also be used as an image developer. As a result of the intermediate forming process of the present invention, Hoechets R
The background contamination typically encountered when using inks such as C43 is avoided. Other conventional post-treatments include applying rubber to the entire plate, which protects the plate from air oxidation and hydration of the anodic oxide due to moisture in the air during storage. .

To further illustrate the invention, various examples are presented below.

In these examples, and throughout this specification, all amounts and percentages are in degrees Celsius, unless otherwise noted.

Example ■ (A) An aluminum plate that has been grained with stone and etched immediately after anodization is thoroughly rinsed, water is removed using a squeegee, and then dried in air at 97°C for 15 seconds. I did it. after that,
A positive type photosensitive composition, that is, an alkali aJ-soluble phenolic resin (AJnova3-PN-43Q)
), 1 part of 634 weight, 2-siacy 1,2-naphthoquinone-5-sulfonyl chloride and phenol resin (same A
lnoval PN-433)
1 part by weight, 2 parts by weight of polyurethane resin, and 1 part of acid-sensitive organic dye dissolved in 601 parts by weight of methyl isobutyl ketone.
A composition containing 6 parts by weight of primary amyl acetate, 30 parts by weight of primary amyl acetate, 20 parts by weight of methyl ethyl ketone, and 20 parts by weight of ethylene glycol monoethyl was applied to the plate and processed in a conventional manner. After processing with a conventional image remover and washing with water, the plate is rubbed with developer ink. For the background difference between the image remover area and the unprocessed area, MacBθth
It can be measured using a reflection densitometer and using a black filter on a plate acceleratedly aged at 100°C. The difference in optical density between the two regions indicates the degree of contamination. The lower the optical density difference, the smaller the degree of contamination. The optical density difference (ΔO, D, ) was 0.06.

(B) Treatment (A) was repeated. After drying the aluminum plate in hot air, it has a pH of 4.7.
The specimens were immersed in an aqueous gum arabic solution at 20° C. for 60 seconds, then rinsed with cold water and dried.

A photosensitive layer was then applied.

The optical density difference in this case was 002.

(C) Process (B) was repeated. However, rinsing with cold water was omitted. In the case of nickel, the adhesion of the photosensitive composition to the substrate on which nickel was formed was weak.

Example ■ Processes (A) and (B) of Example I were repeated. However, the photosensitive composition is of the negative type, and is a condensation polymer of 4-phenylaminobenzenediazonium salt and formaldehyde as a salt of 2-hydroxy-4-menoxybenzophenone-5-sulfonic acid. Epoxy resin Epon 1031 dissolved in 1 part by weight of diazo polymer and 150 parts by weight of methyl selon
(Epon1031) [Nijinirsha (5hell)
) containing 10 Ni parts. The optical densities obtained were similar to those for treatments (A) and (B) of Example (2).

Processing (B) in Example 3 was repeated. However, rinsing with cold water was omitted.

In the first treatment of the six treatments in Example (2), the adhesion of the photosensitive layer to the substrate was weak, in the second treatment good adhesion was obtained, and in the sixth treatment No adhesion was obtained at all.

The process (B) of Example (2) and the process (A) of Example (2) were repeated five times for Example (2), and the intermediate layer forming process was changed as shown in the table below. Nitric acid was used to prepare pl.

Processing Parameter change (A) 6L℃ (B) 750℃, pH 1,55 (C) 1
% solution, 60°C, p) (i, 55 (D) 1% solution, 60°C, pH 5,45 (B) 2% solution, p
H5, 0, 3, 6 o 0 C In a storage life test of up to 5 days, d: The plate was clean.

Example tV The process (B) of Example ■ and the process (A) of Example ■ were reversed again. However, instead of the gum arabic aqueous solution, saccharide gums as shown in the table below were used, and the intermediate layer forming process parameters were changed as shown in the table below. Contamination i1 is reduced and shelf life is improved.

Processing Parameter change (A) 0.5% Inakomamecom (Locust
Bean Gum; Locust Bean Gum),
pH6,78 (B) 2% -)-t)umcarboxymethylcellulose (7L), 1(7,14 (C) 1s Sodium carboxymethylcellulose (7L), 1)H7,60 (D) 1% Sodium carboxy Methyl cellulose (7 L), H4 (E) 1% Sodium carboxymethyl cellulose (7 L), pH 4, immersed for 10 seconds (F) o, 3 s% Guar gum, pH 6,9M (G) D, 33 guar gum, immersed for 5 seconds ( H) 0.15% guar gum, (1) 0
．． 15% guar gum, soaked for 5 seconds (J) 1% sodium carboxymethylcellulose (7L), 0.15% guar gum added, at 60°C, pH 7.6 (K) 2% sodium carboxymethylcellulose (7L), at 60°C, pH 9 ,14 (L) 1% Sodium carboxymethylcellulose (7M), 1) H7.15, immersion 10 seconds (M) 1% Sodium carboxymethylcellulose (7M), at 60°C, pI (7,15 (N) Protein gum, 1) H74 (0) Floating rubber, pH 7.4, immersion for 10 seconds (P)
2% Hydroxypropyl cellulose, 1) I(7, filter (Q) 2% Sodium carboxymethylcellulose (7L), 0.5% Potassium hexafluorodyrnate, 0.10 Potassium polynitrate, 60 ℃, pH 5.7, immersion time 15 seconds (R)'
2% sodium carboxymethylcellulose (7L
), 0.5% Potassium trifluorozincate, 0.10
Sodium carboxymethylcellulose (7L), potassium nitrate, 2% Sodium carboxymethylcellulose (7L), immersion 15 seconds (T) 2% Sodium carboxymethyl cellulose (7L), 0026% hydrofluoric acid, pH 4, immersion 15 seconds (T) H Potassium fluoride, soaked fff15 seconds, pHB Various modifications and variations can be made to the methods and products of the invention without departing from the spirit and scope of the invention. The various embodiments of the invention described above are merely illustrative of the invention and are not intended to limit the invention.

Procedural amendment (method) 1. Indication of the case Patent Application No. 175167 filed in 1982 3. Relationship with the person making the amendment Patent applicant address New York, New York, United States of America 6. Patent applicant column in the application to be amended , Translation of power of attorney and specification 7, Contents of amendment

Claims (1)

[Scope of Claims] (1) An anodized metal substrate, an intermediate layer provided on the substrate, which is subsequently cleaned, and a diazo photosensitive layer provided on the intermediate layer after cleaning. A P8 lithographic plate comprising: and wherein the intermediate layer comprises a saccharide rubber. (2) The PS lithographic plate according to claim 1, wherein the metal substrate is an aluminum substrate. (3) The PS lithographic plate according to claim 2, wherein the anodized aluminum substrate is grained and/or etched. (4) Saccharide gums include cellulose gum, gum arabic,
The PS lithographic plate according to claim 2 or 3, wherein the PS lithographic plate is selected from the group consisting of locust bean gum, guar gum, gatsuchi rubber, and jacquard rubber. (5) P according to claim 2 or 6, characterized in that the sugar a rubber is cellulose rubber.
s flat plate. The PS lithographic plate according to claim 5, wherein the (S)sa rubber is an ammonium salt or an alkali metal salt of carboxymethylcellulose. (7) Includes a metal substrate subjected to anodizing treatment, an intermediate layer provided on the substrate, which is subsequently cleaned, and a diazo photosensitive layer provided on the intermediate layer after cleaning; The one with an image is a lithographic plate characterized in that the intermediate layer contains sugar rubber. (8) The image-attached lithographic plate according to claim 7, wherein the metal substrate is an aluminum substrate. (9) The image-attached lithographic plate according to claim 8, wherein the anodized aluminum substrate is subjected to a grain treatment and/or an etching treatment. (1o) lfFMM rubber is cellulose rubber, gum arabic, carob rubber (1ocu8t bean gum)
m) The image-attached lithographic plate according to claim 8 or 9, characterized in that it is selected from the group consisting of guar gum, guar gum, and jaguar gum. (11) jl? The image attachment according to claim 8 or 9, wherein the tBfinium is cellulose rubber, is a lithographic plate. (12) The 413i rubber is an ammonium salt of carboxymethylcellulose or an alkali metal. The image attached according to claim 8 or 9, which is a salt, is a lithographic plate. (13) The anodized metal substrate is brought into contact with a sugar rubber solution, and then the reading of the metal substrate is carried out. A method for producing a PS lithographic plate according to claim 1, comprising applying a photosensitive layer to the treated surface. (14) The anodized metal substrate is subjected to graining and/or etching treatment before the anodizing treatment. The manufacturing method according to claim 13, characterized in that the saccharide gum is selected from the group consisting of cellulose gum, acacia gum, locust bean gum, guar gum, gatsuchi gum and jaggery gum in an aqueous solution. ) The manufacturing method according to claim 14, wherein the afacono. The manufacturing method according to claim 15. (17) The aqueous solution contains nitric acid, phosphoric acid, sulfuric acid, sulfonic acid,
17. The manufacturing method according to claim 16, which comprises an alkali metal nitrate or a water-soluble fluoride.