DE2002562A1 - Offset printing plates - Google Patents

Description

The. The invention relates to printing plates for the offset process, in particular with paper as the carrier material, on which there is a coating with a surface which is insoluble in water but is water-repellent but repels printing ink. In the offset process, the image areas are oleophilic and therefore accept oily printing ink, whereas dle ^; non-image parts are hydrophilic and therefore wettable with water. This printing plate provided with printing ink can now be used in the usual way, either directly or via a rubber blanket, to produce a number of printed products.

Such layers were previously made of a hydrophilic Binder or colloid built up, such as starch, casein, polyvinyl alcohol, "alginates, carboxymethyl cellulose> Polyacrylates and: the like which have been made insoluble with an acid

BATH ORIGINAL ² ~

003830/1 SS3

IA-37 081

or a salt and are pigmented with a fine, inorganic Substance such as kaolinite, barium sulfate, colloidal silica, zinc oxide or titanium dioxide.

If a paper is used as the carrier material in the production of an offset printing plate, this is generally first provided with a coating in order to seal it against the ingress of water, to improve the wet strength of the paper and the adhesion of the printing layer. The trend now is that the number of layers to be applied to the paper is as small as possible. The present invention also goes in this direction, because it provides a printing plate for the offset printing process with only 2 layers and an upper layer with an area effective for the printing process. and an underlayer on the paper support. The printing plates according to the invention are characterized by particularly great usability, good storability and particularly balanced hydrophobic and hydrophilic properties, the oily or greasy printing ink is very firmly bound, so a large number of prints of excellent quality can be produced. For the printing process. even the most diverse products as printing ink and wiping means (wetout material) may be used on, so as to obtain a universally applicable reproductive material. The printing plates according to the invention can be presensitized with sensitizers in order to print an image which accepts printing ink by exposure. The invention also relates to a method for producing these new printing plates for the offset process.

The printing plate according to the invention (see Pig.) Is built up from a 2-layer system, whereby the printing

009830/1363 ORIGINAL BATHROOM

LA-37, 081 "

Upper layer I ² J- consists of a binder, such as polyvinyl alcohol or hydroxyethylated star.ke as the only hydrophilic ^ .colloid with customary pigments or fillers * The lower layer 12 between paper layer 10 and "upper layer contains Ik as an essential component in the binder, in particular polyvinyl alcohol, together with pigments or fillers salts of polyvalent metals which serve to make the printing surface of the top layer insoluble from below / "without the need to provide acidic, catalyzing salts in or on the printing surface itself"

This principle is exactly the opposite of the previous one Construction of offset printing plates using paper carriers, wherein salts of polyvalent metals are usually either in situ in the top layer or through

€ n ■ optionally be coated with binder in this area, where an extra surface treatment with a _t Sal_zlösung.

Another essential feature of the printing plates according to the invention is the presence of phosphates the ammonium or monovalent metals in the top layer that serve. Anions for reaction with the polyvalent ones To provide metal ions of the sublayer available to a pore-closing deposit in the sublayer and at the interface of the sublayer with the To generate upper class. '- ·

In that the salts of the polyvalent metal are not provided in the effective area but at a distance from this area, their pH value can be adjusted to the most favorable value with regard to the drying of an oleophilic or lacquer-like printing ink, without the; pre - parts of pigmented pressure-forming layers containing salts ■ - ·· '-meh-rvrertiger metals lost - ■ 4 - *.

009830/1363 bad original /

LA-37 081

About the mode of action of these salts of polyvalent metals, US Pat. No. 2,535,650 shows that a water-soluble and water-stable, divalent metal-containing salt into the pores and cavities of the Penetrate layer and can clog it, so the capillaries that seal in or around the fine mineral particles are present within the colloid of the layer, especially when a mopping water is used, which is able to react with the salt of the divalent metal to form a voluminous precipitate. A Part of widely used wiping solutions is a monovalent metal phosphate, particularly sodium dihydrogen phosphate. There is reason to believe that this substance of the cleaning water reacts with the zinc ions and a flocculent precipitate, as in this patent mentioned, forms.

In the reverse arrangement of the present invention, there are aluminum and zinc salts or other polyvalent metals in the lower layer, whereas there is a soluble phosphate in the upper layer. The reaction mechanism this arrangement is easy if you consider that there is a flaky, mixed precipitate of both aluminum and zinc salts at the interface forms between the lower and upper layers when the upper layer is in contact with the lower layer as part of its application comes. This curly material presumably fills in completely the pores of the underlayer and increases their effectiveness and their ability to prevent excessive migration of free aluminum, Zinc and / or chloride retard up through the top layer, creating the printing surface for fingerprints can become sensitive or have a higher acidity. gets like it is greasy or normal for normal drying

009830/1363 bad original

LA-37 081

tr __

'Is beneficial to oily printing inks, especially during manufacture of intermediate originals, e.g. for forms, Checks or the like can be used ».

The essential aspects of the invention Printing plates lie in the following points:>

1.) Contrary to common practice, the. Salts of the polyvalent metals in the lower layer »2.) In the upper layer and thus in the printing surface there are no salts of polyvalent metals 3) In the top layer there is a water-soluble one Phosphate, which with some of the polyvalent metal salts in the lower class able to react and obviously for any compatible, hydrophilic, colloidal binder can be selected. For example, instead of polyvinyl alcohol Use hydroxyethylated starch.

It has been found that polyphosphates, such as sodium. hydrogen pyrophosphate and hexametaphosphate, give the best results, but in principle any soluble phosphate according to the invention can be used which provides anions that interact with the aluminum and zinc ions with the formation of the pores in the underlayer and at the interface between the underlayer and upper class / ¥ ieaer impact is able to react, especially the ammonium and alkali phosphates, " ^: . ...... · ■

In principle, any colloidal binder can be used, provided that it is able to retain the salts of the polyvalent metals in solution until the layer is applied to the paper and the water is removed during drying without coagulating. Since "binder for the upper class · should also serve metal salt Compatible his

.r-iy ■■ > :. · ■ '". -

- BAD ORIGINAL

0Ö983Q / 13S3

LA-37 081 _ 6 -

and connect properly to the underlayer. Sodium alginate is unsuitable for this because it coagulates with metal ions and creates a poor bond with the underlayer leads to the formation of a weak intermediate layer of zinc and / or aluminum alginate.

The pigments for the top layer are selected in the customary manner in order to use as many of the customary printing inks as possible and to obtain labeling means accepting printing surface. Is preferred according to the invention as a filler or Pigment for the top layer an aluminum-modified silica, thereby a better adhesion of the greasy ink achieved vdrd, as it is in usual ribbons of typewriters or ballpoint pens. Such a ratio of kaolinite to silica is particularly preferred, that the porosity and the anchoring effect for firmly adhering pictures or writing made of wax material, like it when writing on carbon paper or plastic tape is present, is guaranteed. It is desirable to incorporate silica in the top layer in order to be easy as a result rubbing effect better absorption and adhesion of image and characters like those with copier and drawing pens can be applied to achieve. However, other commonly used fillers and pigments can also be used.

The printing plates according to the invention are the first, true "all-purpose plates" and are suitable for the following, for example Application areas:

1.) direct lettering: the plate directly takes pictures or writing from any Pei-ichriftuiip: nvorrichtun _t '·;, as it is generally an {ev: andt, and holds the picture, based on

- 7 009830/1363 ⁶ ^ ° ™

- ■ _'-. ..- '1 & -37 G81

- 7- '■■■■■' ■:

of the above properties as well as the fact that the Pictograms or characters also on places where an eraser has been used to erase the surface, keep them, because by erasing surface areas in chemical Are a little more active than the original surface. This support, in chemical terms, which is known to be the salts for fixing the image or of the characters cause, compensates for the partial. Loss of anchoring possibility and porosity due to the j | erasing and smoothing action of the eraser.

2.) Copying with the help of the thermal copying process (Xerox). The thermosetting underlayer as well as a top layer and a back layer that are not hygroscopic or unstable Containing substances allow wrinkle-free and generally high quality xerographic transfer.

3 «) Between o% inal and test print for reproduction work (repro preprint work). Since the area is generally neutral, and contains no substances that a printing ink cause a delay or obstruction of. Antroctaeis of oily or lacquer-like, the new material is particularly suitable for these purposes.

h.) For the processes known under the name "Verifax" or "Ektalith",.

009830/1363, bathroom

IA-37 081 - 8 -

Briefly summarized is the printing plate according to the invention or master copy constructed in such a way that the printing surface of the top layer is polyvinyl alcohol as the only hydrophilic surface Contains colloid and is pigmented with one or more fillers in the form of kaolinite or colloidal silica. Is, but other pigments and fillers can also be obtained, such as titanium dioxide or zinc oxide. In this upper class with the The printing surface does not contain a salt of polyvalent metals in order to increase their hydrophobic-hydrophilic properties modify. Likewise, there are no mixing liquids for the printing area required, the multiple metal salts in Solution included to make the colloid insoluble and to modify the hydrophobic-hydrophilic properties. Through this is also a layering of the printing surface with excess Avoided water-soluble metal salts detrimental to the solid penetration of the printing inks on the surface and / or could lead to an uneven reaction of the insolubilizer. This affects everything as is well known, the drying of the printing ink for templates or Zv / ischenoriginale for the production of e.g. forms or Checks.

Generally speaking, the underlayer is composed of an adhesive bonding system in which Polyvinyl alcohol is an essential component and, according to a preferred embodiment of the invention, also melamine-formaldehyde resins and melamine are included. The lower layer can also be kaolin or clay or other abovementioned, lucid- • contain wisely applied fillers. In addition, however, it also contains a water-soluble salt of a polyvalent one Metal, which reduces the adhesion of the symbols on the printing Area is affected.

- 9 -

BATH ORIGfNAL 009830/1363

/ 20O2B62

IA-37

According to the invention, polyvinyl alcohol is preferred as the binder, but the overall structure of the printing plate or template according to the invention is independent of the binder system used, so that any colloidal, hydrophilic, adhesive product can be used which does not irreversibly coagulate ^{by adding salts of polyvalent metals 1, or does so already} does when it comes into contact with a surface that contains a polyvalent metal salt. These binders can therefore be used instead of polyvinyl alcohol in both the upper and lower layers. An example of this is hydroxyethylated starch.

Both layers can contain small amounts of substances be introduced ",, such as surface-active agents, Anti-foaming agents, fungicides and the like, which are only used for Stabilization and preservation of the layers serve and on the printing properties and the like, none Have influence. ,: "■■ -

The invention is explained in more detail using the following examples:

B-.e i β ρ 1 e- 1. 1

The lower layer was built up from the following mass!

7.7 Polyvinyl alcohol (Gelvafcol 3 «9i) 1.5 melamine (recrystallized). '

5.8 Gypel resin emulsion . bU% solids 29.4 clay slurry, 68 ₁ % solids content

1.8 Mel.amrn-Forniald: ehyd-Har2; kO% solid ¹ © '(Parex resin Wr> 613 - American Cyanamid :)

1.0 equal parts tributyl phosphate and butanol

as: Anti-Haumers

0.5 40 % solids in the anti-foamer '- 10 -

iFoamlGifie Jr. J8l - Coilolds Ine)

000830/1303 bathroom ORIGINAL

lA-37

- 10 -

123.7 water

!, *! · Aluminum chloride solution 5 °

6, ^ zinc acetate solution 25 % ~ i &

20.7 water

In the above-Cypel resin emulsion is mentioned it is a resin emulsion with a Peststoffgehalt of 44%, "the about 63 wt -.% Ethyl acrylate, 35% acrylonitrile and contains 2% Methacyrylsäure.

The polyvinyl alcohol is in the 1st serving of water dispersed and dissolved by heating to about 90 C. then the other ingredients with the exception of the metal salts and the 2nd amount of water are added to a mixer and finally the salts and the remaining amount of water are added to form the application compound.

A paper, about 81.5 g / m (50 lbs / ream), was used as the support; the application takes place in the usual way, for example with the aid of an application roller or by pouring on, an application rate of about 118 g / m (8 lbs / 3300 sq.ft) being used. Excessive mass was removed with the help of a blade. The layer was then dried in the air in an oven at a temperature of about 100 to 200 ^° C. for 1 to 30 minutes. It is also possible to apply a layer without "Cypel resin".

The following recipe was used for the top layer:

5, yy. Polyvinyl alcohol (Gelvatol 3-91) 36.0 clay slurry ^ % solids 43.2 colloidal silica 30 % pesticides

BATH ORIGINAL

009830/1363

2002582

IA-37 081

- 11 -

3.3 Melamine formaldehyde resin emulsion 40 # "solids .0.6 Tributyl phosphate and butanol equal parts 0.2 Aro oil OT as surface-active agent 75% solids"

in water (dioctyl ester of sodium sulfosuceinate) 8,9 acid sodium pyrophosphate .75 $ solution

• 102.4 water

! The polyvinyl alcohol was itfieder first dispersed in cold water and dissolved by heating to about 90 ⁰ G. Then the remaining ingredients were mixed in.

The application was carried out in such a way that a dry weight of 59 g / m (4 lbs / 3; Q00sqf t) was obtained again with the aid of an applicator roller or by pouring on, the excess amount being drawn off with the aid of a doctor blade or a blade. The surface \ -mröe then smoothed and the whole at an oven temperature of about 100 to 25O ⁰ C in. 0.5 to 15 minutes in air dried.

In addition to polyvinyl alcohol, the binder in the two layers can also contain a small amount of polyvinyl acetate, for example 2 to 10 % by weight, as is the case with the above-mentioned commercial products. For the lower layer, the polyvinyl alcohol can account for 7 to 35% by weight , preferably 15 to 29% by weight , calculated on the solid polyvinyl alcohol in the application compound, for the upper layer 4 to 20% by weight, preferably 8 to 16 #. ■

With the melamine-formaldehyde resins of the lower layer it can are various commercially available products (Resloora M-80, Parez 613). However, other aminoplasts such as 'Dimethylol urea or urea-formaldehyde resins are used will. The proportion of these resins in the underlayer is 0.4

009 8 30/1363 ^{BAD W}

• LA-37 081

- 12 -

. up to k wt .- #, preferably 1.3 to 2.6 wt .- # solids. In the top layer, melamine-formaldehyde resins can be used in an amount of 0.5 to 5% by weight, preferably 2 to 10% by weight , based on dry pesticides of the melamine-formaldehyde resins in the coating composition.

The ratio of units Ä'thylacrylat, acrylonitrile, and methacrylic acid in the "Cypel resin" can zwisehen 85 and 55 parts by weight Athylacrylat, 20 to 4-5 parts by weight of acrylonitrile m and 0.5 to 4 parts by weight Methacrylic acid. The proportion of Cypel resin in the lower layer is 3 to 15% by weight, preferably 5 to 10% by weight, calculated on dry solids.

In the two layers you can instead of clay or Kaolin can also use other pigments such as barium sulfate, titanium dioxide or colloidal silica. The amount of filler is 1 to 3 parts by weight of pigment or filler in the

; Sub-layer per part by weight of binder or based on

Pigment or fillers in the coating composition 40 to 80% by weight, preferably 5 ° to 70% by weight . The topsheet may be the 1 to 8 parts of filler per part of polyvinyl alcohol, preferably "the 6 to 7-fold amount by weight included, that is, in the Auftragsamsse 75 to 90 wt .- #, preferably 81 to 86 wt -.% [Solid.

j The colloidal silica used for the upper class

ί acid is preferably one in which

■ At least part of the silicon has been replaced by aluminum.

; Such a product is as a colloidal system in aqueous

Apply medium with a Feststoffgeh'alt of 30% on the market (Ludox AM), you can, however, other commercially available colloidal silica ■■ "sätiröpräparat The Merge of colloidal silica in the upper layer may between 8 and 40 percent -..%, Preferably -

0 0 9 8 3 0/1363 BAD ORIGINAL

■ IA-37 ° Bl · "

wise 10 to 35 Gett - $ - calculated on the silica solids in the coating mass - be. ^;

The antifoams and surface-active agents serve to stabilize the coating composition and its application to the paper carrier. It can natürIi ^- Ch other customary .Substanzen as anti-foaming agents, surface active agent be applied oder'Netzmittel.

Instead of the aluminum chloride and zinc acetate in the lower layer, other water-soluble salts of polyvalent MdB-IIe can be used, such as the chlorides, nitrates, pormates, acetates or propionates of bivalent metals, such as zinc, calcium: nickel, copper, cobalt, barium , Strontium and 3-valent metals such as aluminum. A combination of 2- and 3-finished metal salts such as zinc chloride and zinc acetate or aluminum halide, in a ratio of 1 to k parts by weight of divalent metal salt to 1 part by weight of trivalent metal salt is preferred. In the lower layer, the amount of polyvalent metal salts can be 2 to 15% by weight, preferably 5 to 8% by weight . the coating compound. \

At s τ? i e 1 2

A mass of the following composition was used for the lower layer applied. · · '.

123.7 water

1.5 melamine (, recrystallized)

7.7 polyvinyl alcohol.

29.4 clay slurry 68% pests -

5f8 "C; yp el" resin emulsion kk% pesticides

0-Q983U71363

2002S62

IiU37 081 - 14 -

'' kg

1.8 Melamine Förraaldehyde Resin 40 % Pest Substances' 1.0 Antifoam
0.5 poamicids

1.4 aluminum chloride 50 % solution

6.5 Zinc chloride 25 # solution
10.7 water

Composition as a mass of the following / upper-

layer applied.

kg

104.0 water

5 _t 5 polyvinyl alcohol

31.4 colloidal silica 30 % pesticides 9.4 colloidal silica 40 % pesticides

36.5 clay slurry 68 % solids

3.4 melamine formaldehyde resin emulsion 40 % pesticides

1.1 melamine

0.6 antifoam

0.2 wetting agent (Xrosol OT)

9.0 sodium hydrogen pyrophosphate 7 ^ solution

The printing plate or template obtained in this way is distinguished by its long working life.

Example 3

For a medium-time sheet, the following can be used Lower layer can be applied.

- 15 -

009830/1363

BATH ORIGINAL

; · ■ - 2ÖQ2562

lÄ-37 081 '

kg ·.

123.7 haters

1.5 melamine (recrystallized) "V

7.7 Polyvinyl alcohol:. - "/ ..- 29, ^ clay slurry 68 % solids - _.:

5.8 "Cypel" resin emulsion, hk% pesticides. . ; 1.8 melamine formaldehyde resin k-0% pesticides

1.0 Antifoam "· '0.5 Foamicide.' Λ

3.1 "aluminum chloride 50 # solution.

13.5 2ane acetate, 25 % solution. · ·

25.6 water,; - ■ "

^: Instead of the zinc acetate solution used here, you can also use an equivalent amount of cobalt acetate or nickel. : apply acetate. , ^r .: '

By combining a Cypel resin, polyvinyl alcohol,; With the amine-formaldehyde resin and melamine in the mass for the underlayer, a self-hardening system is obtained which ensures good binding of the mineral pigments and uniqueness of adhesion to the paper carrier. This layer '.'hyd'rophile has certain properties and is viasser-impene- \ casual The present in the underlayer amount an'vpölyvalenten metal salts sufficient to provide the desired balance between hydrophilic and hydrophobic properties, main-; '.:. ■' obtain and . Upper class always the desired for the ■■ '; Ratio required amount of polyvalent metal salt to. Make available, despite the amounts in Eahraen of arrival: application of the plate by Pre-etch and wisehlösungen, · which ·: .- '<the plate surface vfährend' the pressure is moistened continuously, be-removes. The lower class can maintain its functionality for a long time because it is supported by the upper class. is protected from the effects of solutions, but 'despite- ■ · ■ which the-optimal printing properties are made usable' - l6 -

009830/1363

. ■ BATHROOM

U-37 081

can be. This differs from the one according to the invention Printing plate or template very much different from the "known" ones.

Another advantage of the arrangement according to the invention which is practically the opposite of the previous arrangement, lies in the simplification of the regulation of the insolubilization of the layers while at the same time ensuring optimal printing properties. The polyvalent ones have usually been used up to now Metal salts applied to the printing surface of the layer in the form of a solution, the amount of salt being particularly had to be adjusted carefully as excessive salt content had to be removed by brushing or the like. Nevertheless, there are wide fluctuations in the salt concentration; in any case, a layer of metal salt remains as a coating and impairs the adhesion and anchoring of the greasy printing ink in the printing areas.

Another benefit after the. Invention is that corrections to the image-bearing printing plate by erasing or removal of parts of the image is possible and the surface properties sufficient for a new label. In the previous methods with coating solutions Contains polyvalent metal salts for the removal of parts of the image by erasing not only to remove the printing ink but also to remove this essential component in the for the Offset printing is an important layer so that such a material is not re-written or over-typed after correction can be.

A printing plate or template according to the invention with the reverse arrangement of the active components without melamine in the top layer or with a bottom layer without the polyvalent metal salt is useful, but not as effective as the embodiments described above.

- 17 009830/1363 bad original

1A-37 081 - 17 -

In this case, the amide-aldehyde resin acts as the underlayer the desired insolubilization of the immediately adjacent Upper class.

B is ρ ie 1 4 '

An example of an application mass for the lower layer in the above sense consists of

1.5 melamine ■

7.7 -polyvinyl alcohol

29.4 dew slurry $ 68. Solids.

5.8 "Cypel" resin. . . - '. 1.8 · Melamine-formaldehyde resin solution 40 $ - Ag. ■■ ■ ' 1.0 antifoam

As in Example T, "the polyvinyl alcohol is first dispersed in cold water and then dissolved by heating." Then the other ingredients are mixed in.. Application weight 147.5 g / m ² (10 lbs / 3000 , sqft) The layer was dried at 150 ° C for 10 min.

If this lower class can, nn now an upper class of previous examples are applied. In this system there are no polyvalent metal salts, the desired hydrophilic / hydrophobic properties are achieved Melamine formaldehyde "achieved. '· ■

BATH

1A-37 081 - 18 -

Example 5

A top layer was produced from a composition from Example 1, but without the melamine-formaldehyde component In this case, "the metal salts of the sub-layer cause the previous examples the insolubilization of the binder and clogging of the pores.

It can be seen from the above that the offset printing plate according to the invention or template a permanent setting of optimal printing properties with regard to image adhesion and production allow a large number of good quality copies. The principle according to the invention can be applied to a apply a large number of materials. Corrections can be made on the already provided with text or picture without any disadvantages Plate to be made.

; Patent claims

8195

009830/1363

Claims (1)

P ate η ta n- s ρ rüche Offset printing plate or template consisting of: Support material and 2 layers containing polyvalent metal salts, thereby g e k e η η ze i c h η e t that the am Carrier material made of paper overlying lower layer the polyvalent metal salts and the upper layer with the printing Area _a. contains soluble phosphate, which with the more- ' valuable metal ions with the formation of a voluminous precipitate in the pores of the underlayer and on the interface of the upper and lower classes able to react " 2. Offset printing plate or - template according to claim 1> dadurch -g ek en η ζ eic h "η et that the lower layer contains 2 to 15 Gexi.-f polyvalent metal salts. 3. offset printing plate according to claim 1 or 2, characterized geke η η ζ ei ch net that the polyvalent metal salts 1 to 4 Gei't Part 2 vjertige and 1 part by weight of 3-valent, Me tall sal ζ are .. k. Offset printing plate or template according to claims 1 to 3, characterized in that the polyvalent metal salts are the chlorides, nitrate ^ pormates, acetates or propionates of zinc, calcium, nickel, copper, cobalt, .Bariuni or strontium and the trivalent metal salts as chloride, nitrate, pormate or acetate of aluminum are * 5.
until Offset printing plate or template according to claim 1 thereby g e ken η ζ ei c h η e t; that the soluble 00983071363 BATH ORIGINAL IA-37 081 Upper class phosphate Sodium dihydrogen phosphate, disodium hydrogen phosphate, Tetrasodium pyrophosphate, sodium hydrogen pyrophosphate, sodium tripolyphosphate, sodium hexamethaphosphate or the corresponding ammonium or potassium phosphates. •. 6. offset printing plate or template according to claim 1 to 5, characterized by the fact that the hydrophilic, colloidal binder of the two layers polyvinyl alcohol t at hy is α or hydroxylated starch. 7. Offset printing plate according to claim 1 to 5, characterized labeled that the binder is one or both layers contain an amidaldehyde resin. 8. Offset printing plate according to claim 7, characterized in that the lower layer is 0.4 to h by weight and the upper layer is 0.5 to 5 parts by weight of a melamine formaldehyde ^: contains hyd resin. 9. Offset printing plate according to Claims 1 to 8, characterized characterized in that the binder of the lower ψ layer additionally contains a resin containing ethyl acrylate, Comprising,% - Aerylonitril and methacrylic acid, preferably 3 to 15 wt.. OK Offset printing plate according to Claims 1 to 9, characterized characterized in that the top layer and / or the bottom layer contains fillers or pigments, in particular kaolin and colloidal silica, optionally modified with aluminum oxide. ·. · 11. Offset printing plate according to claim 10, 'thereby g e- 'indicates that the proportion of fillers in 009830/1363 ^BAD ORIGINAL 2002662 lA-37 of the top layer 5 Ms 8 parts by weight to 1 part by weight of polyvinyl alcohol matters. 12. Offset printing plate according to claim 11, characterized in that - ke η η ζ e ic h η et that the top layer 50 to 60 wt. %. ; Clay or kaolin, and 5 to ^ O wt -.% Colloidal silica contains •. ·. ■■ "-" -.-. 13 'offset printing plate according to claim 10, characterized denotes overall M, that the proportion of filler in the undercoat layer 1 to k parts by weight per 1 part by weight of polyvinyl alcohol by weight.' 9830/136 3 Blank page