JPS61177459A - Original plate for waterless lithographic printing - Google Patents

Abstract

PURPOSE:To eliminate the influence of temp. and oxygen concn. in an engraving and exposing stage by constituting a photosetting adhesive layer of a mixture composed of a monomer, oligomer or polymer having >=2 unsatd. carbon-carbon bonds in one molecule and a monomer, oligomer or polymer having >=2 mercapto groups in one molecule. CONSTITUTION:The original plate for lithographic printing is constituted of a substrate 1, the photosetting adhesive layer 2 and a silicone rubber layer 3 provided thereon. The photosetting adhesive layer consists of the mixture contg. (a): the monomer, oligomer or polymer having >=2 unsatd. carbon-carbon bonds in one molecule and (b): the monomer, oligomer or polymer having >=2 mercapto groups in 1mol in which part or the whole of (a) or (b) has a hydroxyl group. Since the photosetting adhesive layer is formed by the addition reaction of the mercapto groups and the unsatd. carbon-carbon bonds, the printed matter having stable and excellent image reproducibility is obtd. without receiving the influence of the temp. and oxygen concn. during engraving and exposing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an original plate for waterless lithographic printing that can be printed without using dampening water.

[Conventional technology]

Regarding lithographic printing plates that can be printed without using dampening water,
Several inventions have been made in the past.

For example, Tokuko Sho 54-26925. Special Public Service 1986-231
The lithographic printing plate and lithographic printing original plate disclosed in No. 50 provide a waterless lithographic printing plate that has excellent printing durability and is highly practical.

[Problems to be solved by the present invention]

Japanese Patent Publication No. 54-26923 discloses photosensitive layer compositions such as (1) a photopolymerizable composition containing an ethylenically unsaturated monomer, (2) a composition containing a photocurable diazo resin or an azide resin, etc. However, in these photosensitive layer compositions, printing plates using azide resin components are susceptible to changes over time due to the photosensitive layer components, and the development latitude is There are some problems such as narrow space and poor workability.
A photopolymerizable composition containing an ethylenically unsaturated monomer of +11 as a photosensitive layer component is superior in practicality.

Also, in Japanese Patent Publication No. 56-23150, substrates.

A photopolymerizable adhesive layer containing an ethylenically unsaturated monomer or oligomer and a photoinitiator provided on the substrate, and a silicone rubber layer obtained by crosslinking a mesh mold provided on the photopolymerizable adhesive layer. A waterless lithographic printing original plate consisting of the following is disclosed, and due to these basic structures, a waterless lithographic printing plate with particularly high practicality is provided.

However, when such ethylenically unsaturated monomers or oligomers are used as components of the photopolymerizable adhesive layer, the speed of the photocuring reaction is affected by temperature and oxygen concentration.
If the temperature is too low or the oxygen concentration is too high in the plate-making exposure process, there is a problem that sufficient sensitivity and halftone dot reproducibility cannot be obtained.

An object of the present invention is to provide a waterless lithographic printing original plate which is not affected by temperature and oxygen concentration during the plate-making exposure process without impairing the advantages of this original printing plate.

Means for Solving Problems] The present invention provides a substrate, a photocurable adhesive layer provided on the substrate, and a silicone rubber obtained by condensation type crosslinking provided on the photocurable adhesive layer. In a waterless lithographic printing plate consisting of layers, a photocurable adhesive layer is used.

(a) Monomers, oligomers, or polymers containing two or more carbon-carbon unsaturated bonds in one molecule ('b) Monomers, oligomers, or polymers containing two or more mercapto groups in one molecule. The original plate for waterless lithographic printing is characterized in that part or all of (a) or (b) has a hydroxyl group.

The present invention will be explained in detail according to the drawings. FIG. 1 shows a lithographic printing original plate according to the present invention, and shows a substrate 1. Photocurable adhesive layer 2
and a silicone rubber layer 3 provided thereon, and a protective film 4 may be further provided thereon if necessary.

As shown in FIG. 2, when exposed through the positive film 5, the photocurable adhesive layer in the non-image areas is cured, and the silicone rubber layer in the unexposed areas is immersed in a developer to lower the upper layer and lightly rubbed on the printing plate. is stripped away, exposing the surface 2' of the underlying photocurable adhesive layer, as shown in FIG. 6, to provide a sharp image area with excellent ink receptivity. On the other hand, the silicone rubber layer 3' in the exposed area is strongly adhered by the curing of the photocurable adhesive layer, and remains on one plate surface to provide an ink-repellent non-image area.

The substrate 1 in the present invention is made of aluminum, steel, plastic such as polyester and polyamide, rubber,
Known substrates for waterless planography, such as coated paper or composite nails thereof, are used.

The photocurable adhesive layer 2 used in the present invention is:

It is photocured by irradiation with active light and has the property of strongly adhering to the upper silicone rubber layer. The photocurable adhesive layer can have any thickness as long as it is uniformly applied to the substrate and is in close contact with the substrate.

Preferably, the diameter is 100 microns or less, and 50 microns or less is even more useful. If necessary.

° It is also useful to provide an anchor coat layer between the substrate and the photocurable adhesive layer for the purpose of improving the adhesion between the photocurable adhesive layer and the substrate or preventing halation during plate-making exposure.

The photocurable adhesive layer used in the present invention preferably has the composition shown below.

(1) Monomers, oligomers, or polymers having two or more carbon-carbon unsaturated bonds in the same molecule
100 parts by weight (2) Monomer having two or more mercapto groups in the same molecule,
Oligomer, polymer 10 to 1.000 parts by weight (3) If necessary, one or more carbon-carbon unsaturated bonds in the same molecule and one or more merca 7
') group-containing monomer, oligomer, or polymer 0 to 1.000 parts by weight (4) Furthermore, if necessary, a sensitizer [0 to 20 parts based on the total of 11, (2], and (3))
Weight% (5) If necessary, as a filler +
11. (Polymer that does not have the group shown in 21 or inorganic powder + 11, (0 to 1 for the sum of 21 and (3)
,000% by weight It is essential that some or all of (a) and (1) above have hydroxyl groups in terms of stability of adhesive strength with the silicone rubber layer, and in particular (a) having hydroxyl groups. The total number of molecules of I (b) is t (a) #
It is effective that the total number of molecules in (b) is 10 or more, and more preferably 30 or more. Here (a
Only component () may have a hydroxyl group, or only component (b) may have a hydroxyl group.

It is also optional that both components have hydroxyl groups.

Here, the above carbon-carbon unsaturated bond-containing compound.

The mercapto group-containing compound is essential as a photocurable adhesive component of the present invention, and contributes to increasing the adhesive strength with the upper silicone rubber layer upon irradiation with actinic rays.

A carbon-carbon unsaturated bond is usually reactive with a mercapto group, and typically has the general formula (in the formula R', R2, Rs, R' hydrogen, ), o) Z
N W child.

(respectively means a substituted or unsubstituted alkyl group, aryl group, aralkyl group, or alkoxy group having 1 to 10 carbon atoms).

The above carbon-carbon unsaturated bond-containing monomers, oligomers, and polymers have a molecular weight of 9 from 200 to 100,000.
For example, (1) diene monomers, oligomers thereof, and the above-mentioned polymers having a po group.

(2) Polymers of monomers having two unsaturated bonds in one molecule, for example, polymers containing allyl (meth)acrylate as a monomer component. Examples of those having hydroxyl groups include copolymers of the above monomers with hydroxystyrene, 2-hydroxyethyl (meth)acrylate, and the like.

(3) A reaction product of an unsaturated bond-containing alcohol and a polyvalent incyanate compound.

For example, there may be mentioned a reaction product of allyl alcohol and tolylene diisocyanate.

(4) A reaction product of an unsaturated bond-containing incyanate and a polyhydric hydroxyl group-containing compound.

Products having hydroxyl groups include products obtained by reacting under conditions where the number of hydroxyl groups is in excess of the number of isocyanate groups.

To give a few specific examples, a typical example is a reaction product of allyl isocyanate and glycerin.

(5) A reaction product of an epoxy compound containing an unsaturated bond and a polycarboxylic acid or an amine.

For example, glycidyl allyl ether and ethylamine,
Reactants with amines such as butylamine, ethylenediamine, and aniline, and polyhydric carboxylic acids such as adipic acid and phthalic acid.

(6) A reaction product of an alcohol having an unsaturated bond and a polyhydric carboxylic acid.

Typical examples include reaction products of allyl alcohol and adipic acid or phthalic acid.

(7) A reaction product of a carboxylic acid having an unsaturated bond and a polyhydric alcohol.

Products having hydroxyl groups include products obtained by reacting under conditions where the number of hydroxyl groups is in excess of the number of carboxylic acids.

A typical example is a reaction product of vinyl acetic acid and glycerin.

(8) A reaction product of an unsaturated bond-containing halide and an amine.

Typical examples include reaction products of allyl chloride and butylamine or ethylenediamine.

etc.

The monomer oligomer or polymer having a mercapto group in the present invention has a structure represented by the first-order general formula (1).

Fj + SR). (I)(
In the formula, n is an integer of 2 or more; US is a polyvalent hydrocarbon group having 2 or more carbon atoms; and may contain a heteroatom such as ')*NeStOs'') Contained in 9 molecules of compound (1) It is effective in terms of image reproducibility that the number n of mercapto groups is 2 or more and 1.000 or less.The structure of R5 can be arbitrary such as aliphatic or aromatic, an ester bond, or an amide bond.

It can have an ether bond, etc., and it is effective if the number of carbon atoms is 2 or more, and preferably 2 to 10,000.

Such compounds include polyvalent mercapto group-containing aliphatic hydrocarbons such as 1,6-dimercaptohexane and 1,10-dimercaptodecane, thioglycolic acid, α
Examples include esterification products of mercapto group-containing carboxylic acid compounds such as -mercaptopropionic acid and β-mercaptopropionic acid with polyhydric alcohols such as glycerin, trimethylolpropane lapentaerythritol, and glucose. Examples of these compounds having a hydroxyl group include aliphatic derivatives such as 1,3-dimercaptoglycerin, and esterified products obtained by reacting a mercapto group-containing carboxylic acid with a polyhydric alcohol under conditions with an excess of hydroxyl groups. .

Although it is essential that a part or all of T2+ in the composition of these photocurable adhesive layers (11, T2+) have a hydroxyl group, it is possible to arbitrarily select a compound having a hydroxyl group or a compound having no hydroxyl group as exemplified above. I can do it.

A sensitizer is added to these compositions as necessary, and such a sensitizer is benzophenone.

Examples include acetophenone and acetonaphthoquinone. In addition, for the purpose of maintaining the shape of the photocurable adhesive layer and controlling the sensitivity to light, the above-mentioned component (5) is polyolefin, polyamide, or polyester.

Polymers without carbon-carbon unsaturated bonds and mercapto groups, such as polyethers and polyurethanes.

Alternatively, it is also effective to add powders of inorganic compounds such as silicon oxide, calcium carbonate, carbon powder, and titanium oxide.

In the present invention, if the silicone rubber layer 3 is too thick, it is not only economically disadvantageous, but also because it is difficult to peel off the silicone rubber layer in the area that should become the developed image area. If the size is small.

The problem is that it is easily scratched.The thickness of the foot is 0.5.
~50 microns, preferably 1-10 microns.

One typical example of the silicone rubber obtained by condensation type crosslinking in the present invention is as follows.

(1) has two or more hydroxyl groups directly bonded to a silicon atom, and has the following formula (11) % formula % () (wherein RZ R7 means a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms) (2) A silicon compound having two or more hydrolyzable groups in one molecule directly bonded to a silicon atom (hydrolyzable groups include hydrogen atoms, halogen atoms, alkoxy Examples include those that have a crosslinked structure by reaction with hydrolyzable groups such as acyloxy group, acyloxy group, ketoximate group, amino group, amide group, aminooxy group, and alkenyloxy group.

' Component (1) has a molecular weight of 1. OOO~1. OO0
,000, the resulting silicone rubber has excellent physical properties, and R4 and R7 in formula (II)
It is economical that 60 or more of the total numbers are methyl groups.
From the standpoint of ease of synthesis, the preferred nine-molecule structure is generally a linear structure having hydroxyl groups at both ends. Component (2) is generally a compound having the structure of linear formula (2), (2) or (V) or a hydrolyzed wire mesh thereof.

R8R10 (In the formula 4≧l≧2.m≧0.n≧2.R', R'.

R? , RTo is a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, and Y is a group arbitrarily selected from R@, R9, Rlo, and x. In (5) and (V), the structural unit may have a block or random structure.) The silicone rubber produced by the reaction between the silicone rubber component (1) and the component (2) is determined by the number of hydroxyl groups in component (1) and the component (2).
) can be obtained by making the number of hydrolyzable groups in component (2) almost the same, and it can also be obtained by supplying water so that the number of hydrolyzable groups in component (2) is in excess.

It is also effective to add a known curing catalyst or a known adhesion promoter such as aminoalkyltrialkoxysilane to the silicone rubber composition before curing in the present invention. It is also useful to add inorganic fillers to the extent that they do not impair the properties.

It is also effective to apply a transparent organic film laminate, plastic coating, etc. on the silicone rubber layer obtained here for the purpose of surface protection.

〔Example〕

Examples are shown below. In the examples, 1 part indicates a part by weight. In addition, in the examples, the reaction product of isocyanate and alcohol is described, but the 9 reaction was performed at a concentration of 10 in dioxane.
% by weight, 0.01% by weight based on incyanate compound
Diptyltin silaurylate was used as a catalyst, and the reaction was carried out at 60°C.

Example 1 On a grained aluminum plate.

(a) 2-incyanatoethyl 2,6-dicyanatohexanoate (T-100J manufactured by Toshi Co., Ltd.) 53
, 46 g (0.2 mol) of aliphatic polyester with hydroxyl groups at both ends (Plaxel 208J manufactured by Chisso Co., Ltd.)
) 85.0 g (0.1 mol), allyl alcohol, 11.6 g (0.2 mol), and 1,2.6-hexanetriol, 26.8 g (0.2 mol) were reacted in this order. Compound 30 Part (b) 1
．． 20 parts of 10-dimercapto normal decane (C)
Benzophenone 5 parts (d)
Bayer polyurethane [IMPLANIL ELNJ
50 parts of the dioxane solution was coated with a one-turn coating machine to form a photocurable adhesive layer (thickness: 6 microns).

on this photocurable adhesive layer.

(e) α,ω-dihydroxypolydimethylsiloxane (number average molecular weight 40,000) 100 parts (f
) Ethyltriacetoxysilane 10 parts (2
) A composition consisting of 0.5 parts of dibutyltin diacetate was applied as a solution in n-hexane using a spin coater and cured to form a silicone rubber layer (thickness: 3 microns).

A polypropylene film with a thickness of 6 microns was applied to the surface of the silicone rubber layer thus obtained.A positive film was vacuum-adhered to the printing base plate thus obtained, and
Exposure was carried out for 1 minute from a distance of 1 m using a Metal No. 1 Ride lamp and Idolfin 2000J manufactured by Iwasaki Electric Co., Ltd. under the conditions of When developed by immersing it in a developer consisting of 5 parts of polypropylene glycol (molecular weight 400) and rubbing it with a non-woven fabric "Sofpad" manufactured by Dynic Co., Ltd., only the silicone rubber layer in the unexposed area was peeled off, and the photocurable adhesive layer was removed. Exposed. On the other hand, the silicone rubber layer in the exposed area was strongly photo-adhesive.

When the developed printing plate was set in an offset printing machine and printed using Toyo Ink Co., Ltd.'s printing ink "TKU Aquares G" without adding dampening water, printed matter with excellent image reproducibility was obtained. Ta.

Further, the obtained printing original plate was vacuum-adhered to an original positive film, exposed to light at a plate surface temperature of 15° C., developed and printed, and a printed matter with excellent image reproducibility was obtained. Grayscale sensitivity.

Compared to the case where the exposure temperature was 30° C., it was only decreased by 0.2 steps, and it was confirmed that the image reproducibility hardly changed even when the temperature changed during exposure.

Further, the obtained printing plate was simultaneously exposed to light using an original positive film in an air atmosphere at 30° C. without being subjected to reduced pressure vacuum, and when it was developed and printed, printed matter with excellent image reproducibility was obtained. Therefore, it was confirmed that the oxygen concentration during exposure did not affect image reproducibility.

Comparative example 1 On a grained aluminum plate.

(a) Polyurethane manufactured by Bayer “Inplanil E”
IJNJ 60 copies (13
) 40 parts of 4:1 molar reaction product of glycidyl methacrylate and xylylene diamine (e)
An ethyl cellosolve solution having a composition of 5 parts of Michler's ketone was applied using a spin coater to form a photocurable adhesive layer (thickness: 6 microns). on this photocurable adhesive layer.

(d) α,ω-dihydroxypolydimethylsiloxane (number average molecular weight 40,000) 100 parts (e
) -r-Tiltriacetoxysilane 10 parts (f) A composition consisting of 0.5 parts of dibutyltin diacetate was applied as an n-hexane solution using a spin coater and cured to form a silicone rubber layer (3 micron thick). ). The obtained laminate was treated with "Trefan" in the same manner as in Example 1.
Laminate it.

A printing original plate was obtained.

The obtained printing original plate was brought into close contact with the original positive film under reduced pressure in the same manner as in Example 1, exposed to light at 30C and 15C, and developed. As a result, the gray scale sensitivity was as follows: The value was 1.8 steps lower than that exposed at 30°C.

Furthermore, when the obtained printing original plate was exposed to light at 30° C. in the air instead of under reduced pressure and developed, the silicone rubber layer also peeled off in the exposed areas.

A plate that could not be used as a printing plate was obtained.

Example 2 The composition of the photocurable adhesive layer in Example 1.

(a) Compound 4 (a) in Example 1
Part 5 (b) Pentaerythritol tetrakis (β-
Mercaptopropionate) 15 parts (C) Benzophenone 5 parts (ω Bayer's polyurethane "Inplanil ELN"
When a printing original plate was prepared in the same manner as in Example 1, exposed and developed, except for using a composition consisting of 40 parts of J, printed matter with excellent image reproducibility was obtained under each exposure condition.

Example 3 A printing original plate was prepared using pentaerythritol tetrathioglycolate in place of (1)) pentaerythritol tetrakis (β-mercaptopropionate) in the composition of the photocurable adhesive layer of Example 2.

When the obtained printing original plate was exposed, developed and printed in the same manner as in Example 1, printed matter having excellent image reproducibility under each exposure condition was obtained.

Example 4 In Example 1, the composition of the photocurable adhesive layer.

(a) Allyl methacrylate/2-hydroxyethyl methacrylate copolymer (copolymerization molar ratio 2/1°, number average molecular weight 8,000) 70 parts (b)
1.30 parts of 10-dimercapto-normal decane (Q)
A printing original plate was prepared using 5 parts of benzophenone.

The obtained printing original plate was exposed in the same manner as in Example 1.

When developed and printed, printed matter with excellent image reproducibility under each exposure condition was obtained.

Example 5 In Example 1, the composition of the photocurable adhesive layer.

(a) 40 parts of a reaction product of 4 moles of riIJ sidyl allyl ether and 1 mole of p-xylylene diamine (b
) 1.20 parts of 10-dimercapto normal decane (C)
Benzophenone 5 parts (→
Poly(n-butyl acrylate) (number average molecular weight 49.
OOO) 40 copies of printing original plates were created.

The obtained printing original plate was exposed in the same manner as in Example 1.

When developed and printed, printed matter with excellent image reproducibility under each exposure condition was obtained.

Example 6 In Example 1, the composition of the photocurable adhesive layer.

(a) Reactant of pentaerythritol (1 mol) and totalyl incyanate (2 mol) 30 parts (t)
) 1.10-dimercapto-normaldecane 30 parts (C)
Benzophenone 5 parts (d) Bayer polyurethane "Inplanil ELN"
When 40 copies of a printing original plate were prepared and exposed, developed and printed in the same manner as in Example 1, printed matter with excellent image reproducibility under each exposure condition was obtained.

Example 7 In Example 1, the composition of the photocurable adhesive layer.

(a) Allyl methacrylate/lauryl methacrylate copolymer (copolymerization molar ratio 5/1, number average molecular weight 1
9.000) 50 parts (b) Pe/taerythritol (1 mol) and thioglycolic acid (2
When a printing original plate was prepared using 5 parts of SO part (C) and 5 parts of benzophenone and exposed, developed and printed in the same manner as in Example 1, printed matter with excellent image reproducibility under each exposure condition was obtained. Ta.

Example 8 In Example 1, the composition of the photocurable adhesive layer.

(a) Triisocyanate “T-1” manufactured by Toshi Co., Ltd.
00J53.5g (0.2 mol) is an aliphatic polyester with hydroxyl groups at both ends, "Plaxel 208" manufactured by Chisso Corporation.
J85. Og (0.1 mol), allyl alcohol 2
Compound obtained by reacting 3.2g (0.4 mol)
40 parts ('b) Esterified product of pentaerythritol (1 mol) and thioglycolic acid (2 mol) 20 parts (C) Benzophenone 5 parts (d) Bayer's polyurethane "Inplanil ELNJ"
A printing original plate was prepared as 40 copies, and Example 1
When exposed, developed and printed in the same manner as above, printed matter with excellent image reproducibility was obtained under each exposure condition.

Example 9 In Example 1, the composition of the photocurable adhesive layer.

(a) Reactant of pentaerythritol (1 mol) and totalyl incyanate (4 mol) 3-0 parts (1
)) Esterified product of pentaerythritol (1 mol) and thioglycolic acid (2 mol) 30 parts (e)
Benzophenone 5 parts (d)
Poly(n-butyl acrylate) (number average molecular weight 49
．． 000 ) A printing original plate was prepared as 40 copies, and when exposed, developed and printed in the same manner as in Example 1, printed matter with excellent image reproducibility under each exposure condition was obtained.

Example 10 In Example 1, the composition of the photocurable adhesive layer.

(a) 1.2.4.5-tetrakis(diallylamino)benzene 30
Part (b) 30 parts (C
) 5 parts of benzophenone (d)
Bayer's polyurethane "Inplanil ELNJ"
When 40 copies of a printing original plate were prepared and exposed, developed and printed in the same manner as in Example 1, printed matter having excellent image reproducibility under each exposure condition was obtained.

〔Effect of the invention〕

According to the original plate for waterless planographic printing according to the present invention.

Because the photocurable adhesive layer is based on an addition reaction between a mercapto group and a carbon-carbon unsaturated bond, it is less sensitive to temperature and oxygen during plate-making exposure than the previously proposed polymerization using ethylenically unsaturated monomers or oligomers. without being affected by concentration.

Printed matter with stable and excellent image reproducibility can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional structural diagram of a planographic printing original plate according to the present invention. FIG. 2 is a conceptual diagram of the exposure process of the lithographic printing original plate. FIG. 3 is a cross-sectional view of the present lithographic printing plate obtained after plate making. 1: Substrate 2: Photocurable adhesive layer 3: Silicone rubber layer 4: Protective film 5: Positive film

Claims (1)

[Claims] (1) In a waterless planographic original plate comprising a substrate, a photocurable adhesive layer provided on the substrate, and a silicone rubber layer obtained by condensation type crosslinking provided on the photocurable adhesive layer, The photocurable adhesive layer is made of (a) a monomer or oligomer containing two or more carbon-carbon unsaturated bonds in one molecule, or a polymer (b) a monomer containing two or more mercapto groups in one molecule. , an oligomer, or a mixture containing a polymer, in which part or all of (a) or (b) has a hydroxyl group.