DD218482A1 - PHOTOPOLYMERIZABLE COMPOSITION - Google Patents

Abstract

The invention relates to a photopolymerizable composition for the production of relief images for information recording materials, printing plates, printed circuits and coatings. The aim and object is to develop a photopolymerisable composition which exhibits improved developability in aqueous development baths. The object is achieved in that the photopolymerizable composition consisting of at least one photopolymerizable compound, at least one initiator which forms free radicals upon irradiation with light and optionally binder at least one ethylenically ungesettigte compound of the general structure in the RH or CH3 and n is 1 to 10 , contains.

Description

The invention relates to a photopolymerizable composition for the production of relief images for information recording materials, printing plates, printed circuits and coatings.

Characteristic of the known technical solutions

It is known to generate by irradiation with light from organic or inorganic compounds radicals which initiate a polymerization in the presence of ethylenically unsaturated compounds. By this light-induced polymerization, there is a change in the physical properties necessary for the production of information recording materials. Printing plates, printed! Circuits, coatings or for high quality inks is technically used. Common photopolymerizable compositions usually contain at least one photoinitiator, a photopolymerizable compound and a binder. In addition, sensitizers, thermal polymerization stabilizers, plasticizers and pigments may be included.

& MA! 1983 * 088 131

Initiators of ethylenically unsaturated compounds are benzophenone and benzophenone derivatives (DE-OS 1 949 010), Michler's ketone, anthraquinone, oxime ester (DE-OS 1 795 089), benzoin and benzoin derivatives (DE-OS 2 232 365), hexaacrylbisiraidazole (US Pat. PS 3 615 454), metal complexes (US Pat. No. 3,297,440) or dye redox systems (US Pat. No. 3,092,096). As binders usually find high molecular weight synthetic polymers application. In the production of relief images their solubility determines the type of development. For photopolymerizable compositions which are developed by means of organic solvents, butadiene polymers (US Pat. No. 4,052,231), chlorinated polyolefins (US Pat. No. 4,058,443), polymethacrylic acid esters (US Pat. No. 2,760,363), vinyl chloride polymers (DE-OS 2 759 164) or polyamides (US Pat. No. 4,145,222).

Suitable binders which permit aqueous development are polyvinyl alcohol (DS-OS 2 510 873), copolymers based on styrene and maleic acid half ester (US Pat. No. 4,092,172) or copolymers of acrylic or methacrylic acid with vinyl monoranes (DE-OS 2 320 859). A significant influence on the applicability of the photopolymerizable composition has the structure of the ethylenically unsaturated compounds used. They must meet the following requirements:

a) high polymerization rate

b) good compatibility with the binders

c) complete demolition in the development baths

d) good solubility in the application solution

e) no negative influence on the physico-mechanical properties of the photosensitive layer.

As ethylenically unsaturated compounds are both crystalline monomers, such as acrylamide, N-vinylsuccin

imid (US Patent 3,871,885, 3,899,338) as well as liquid known.

In order to achieve optimum property changes between polymerizing and unpolymerized areas, preference is given to using polyfunctional compounds which polymerize on irradiation into insoluble networks. Examples of these are di-, tri- or tetraacrylic acid esters (DE-OS 2,651,507, 2,205,146), bisacrylamides, (US Pat. No. 3,081,168), divinyl sulfones (US Pat. No. 3,865,594), urethane acrylates (DE-OS 2 121 253), polyvalent metal acrylates (US Pat. No. 3,531,282), unsaturated polyesters (US Pat. No. 3,615,628) or oligomers based on butadiene (DE-OS 2,610,206).

These known ethylenically unsaturated compounds only partially meet these requirements. Acrylic acid esters, such as, for example, trimethyloltriacrylate, hexanediol diacrylate or pentaerythritol tetraacrylate, can not be completely removed in aqueous development baths, as a result of which a high level of fog is produced in the production of relief images.

Oligomers based on butadiene and urethane acrylates show a low rate of polymerization and are therefore not suitable for the preparation of highly sensitive photopolymerizable compositions. Another disadvantage of these compounds is the required development with organic solvents. Polyvalent acrylic acid salts, such as barium diacrylate, zinc diacrylate, aluminum triacrylate, are difficult to dissolve in organic solvents, limiting their use to water-soluble binders and initiator systems. ^v

Object of the invention

The aim of the invention is a photopolymerizable composition which has improved developability in aqueous developing baths.

Explanation of the essence of the invention

The object of the invention is a photopolymerizable composition with a new ethylenically unsaturated compound

to develop, which is characterized by high PolymerisatiOnsgeschwindigkeit, good compatibility with the known binders and by a good solubility in aqueous developing baths. The object is achieved in that the photopolymerizable composition consisting of at least one photopolymerizable compound, at least one initiator which forms free radicals upon irradiation with light and optionally binder as the photopolymerizable compound, an ethylenically unsaturated compound of the general structure

9 ft

in which R is H or CH, and η is 1 to 10 ^.

Preferably, the photopolymerizable composition contains 1 to 15 wt .-% of an initiator, 40 - 50 wt - - 80 wt, -% of binder and 20.% Ethylenically unsaturated compound. In addition, stabilizers and pigments or dyes may be included. It is possible to use the new ethylenically unsaturated compound in admixture with known photopolymerizable compounds. For special applications, the photopolymerizable compound according to the invention can also be used without a binder. The Herstellung.der new ethylenically unsaturated compound in a known manner by the alkoxylation of 4,4 ¹ dihydroxydiphenyl sulfone as described by G.Gawalek, "surfactants", Akademie Verlag, Berlin, 1975, is described and subsequent acrylation (acrylic acid or acrylic acid chloride US- PS 3 427 161, 3,380,831). As initiators, it is possible to use all known initiators which, on irradiation with light, form free radicals and can initiate a free-radical polymerization.

Suitable compounds are

- organic carbonyl compounds

- azo compounds

- sulfur compounds

- halogen compounds

- heterocyclic compounds

- Metal carbonyls

and dyes. ^ι

Examples of these are benzoin isopropyl ether, benzoichloroethyl ether, benzophenone, Michler's ketone or 9,10 anthraquinone. "

As binders it is possible to use both organically soluble and water-soluble polymers. Examples of these are polyamides, ethylene-vinyl acetate copolymers, polyvinyl chloride, polystyrene, butadiene-styrene copolymers or polymethyl methacrylate. Preference is given to using alkali-soluble polymers, such as copolymers of maleic acid monoesters with ethylene, propylene or styrene, or copolymers of acrylic and methacrylic acid with vinyl monomers, which permit aqueous development. To improve the storage stability, it is preferred to use from 0.01 to 0.1% by weight of a stabilizer, such as, for example, hydroquinone, p-methoxyphenol or 2,6-di-tert. Added butylcresol. Furthermore, pigments such as carbon black may be included in the composition for contrasting the relief images. In the production of high-sensitive information recording materials or printing plates, it is advantageous to exclude interfering atmospheric oxygen by applying a protective layer of polyvinyl alcohol or polyvinylpyrrolidone.

For coating the photopolymerizable composition are organic solvents such as acetone, methyl ethyl ketone, tetrahydrofuran, methanol, ethanol or methylene chloride. The photopolymerizable composition according to the invention is characterized in that it has a high sensitivity

result in layers with good physico-mechanical properties and are completely removable in aqueous development baths. , ,

Sxä is suitable i.a. for the production of information recording materials and negative plates with low fog and improved detail reproduction properties.

embodiments example 1

On a 100% thick polyethylene terephthalate film (PETP

, /. , ι

Foil), the following compositions are coated and the solid layer is irradiated at a distance of 20 cm with a 500 W high-pressure mercury lamp for 2 min. As the ethylenically unsaturated compound, the compound A becomes the structure

0 O 0

used.

-; , Connection a b C Benzoin chloroethyl ether (g) 1 - 1 Benzophenone / Michler's ketone (1: 1) - 1.5 - Acrylic acid-ethyl acrylate (15:85) - 15 15 Styrene-Maleinsäurebutylhalbester (L: l) ^: 15 - - Connection A 10 10 - hexanediol - - 10 Methyl ethyl ketone (ml) 80 80 80 Methylene chloride (ml) 20 20 20

There are according to the variant a - c. tack-free, solvent-resistant coatings obtained.

Example 2 '

The following composition is coated analogously to Example 1, wherein the photopolymerizable compound B of the structure

/ - $ - / \ -0- / CH _o -CH _o -r07, -C-CH = CH ₀ \ / 1 V , / ^{2 2 Λ}

is used.

Styrene-maleic acid butadiene half-ester copolymer acetonic carbon black dispersion (4% carbon black, 8 % binder based on styrene-maleic acid methyl half-ester copolymer) Compound B benzoin isopropyl ether acetone-methylene chloride (5: 1)

In order to prevent the influence of oxygen, a protective layer of 2% polyvinyl alcohol solution is poured onto the dried layer. The thus coated film is exposed for 30 seconds in a contact step under a photographic step wedge with a blackening increase of ~ f 2 with a 500 W high pressure mercury lamp at a distance of 25 cm ,

The exposed material is then at 25 ⁰ C in the following solution

900 ml water 50 ml isopropanol 1 G Na tium hydroxide

developed, rinsed with distilled water and dried. There are.8 steps recognizable. The comparative example with hexanediol diacrylate gives only 7 stages.

- 8th ·-

Example 3

The procedure of Example 2 is repeated, wherein as the ethylenically unsaturated compound 4 g of the compound C. "

0 ^ 0 0

CH ₂ -CH-C-5 / O-CH ₂ -CH ₂ ZO- / \ -S- \ \ -O- / CH ₂ -CH ₂ -o7 ₅ -C-CH = CH ₂

be used. After development, 9 levels are visible.

Example 4.

The procedure of Example 2 is repeated with the following casting composition.

8 g of methacrylic acid-methyl methacrylate-ethyl acrylate mixed

polymerizate (20:40:40).

0.075 g crystal violet

3g compound D of the structure

° 0 · 0

-S- / \ -O- / CH-CH _o -O /, - C-CH = CH "CH ₃ ' ^u CH ₃

0.45 g of benzoin ethyl ether.

100 ml of methyl ethyl ketone / acetone / methanol = (30:50:20)

After development, 10 levels are recognizable.

Example 5

On a prepared aluminum plate, the following compositions are coated and passed through a template for 2 min. Illuminated with a 500 W high-pressure mercury lamp at a distance of 40 cm. The exposed plate is left in an aqueous solution for 60 seconds,

930 ml of water

70 ml of isopropanol

1 g Na OH '

1 g of Na dodecylbenzenesulfonate

developed, rinsed with distilled water and dried.

connection d e f G 1 Benzophenone / Michler's ketone (g) 0.5 0.5 - 0.6 1 (1: 1) Benzoin ethyl ether (g) - - 0.6 10 Acrylic acid-methyl methacrylate 2.0 Ethyl acrylate (18:50:32) (g) 10 10 10 - Compound B (g) - 2.5 3.0 1.5 Pentaerythritol tetraacrylate (g) 2.5 - - 0.1 Trimethylolpropane triacrylate (g) - - - 70 Crystal violet (g) 0.1 0.1 0.1 .20 Methyl ethyl ketone (ml) 70 -.70 70 10 Acetone (ml) 20 · .- 20 ^f \ 20 Methanol (ml) - 10, 1 ¹⁰ i 10

Relie'fbilder are obtained, which can be stained with hydrophobic printing inks. Comparative variant D still has monomer residues in the unexposed areas, which can also be stained and result in high fog and reduced detail reproduction.

- 10 -

Claims (3)

invention claim -C-CH = CH ₂ 1. A photopolymerizable composition consisting of at least one photopolymerizable compound, at least one initiator which forms free radicals upon irradiation with light and optionally binders, characterized in that they are as ethylenic photopolymerizable compound ( unsaturated compound of the general structure - / \ -0- CH-O-U-O _ - - R in the RH or CH ₃
'' η 1 to 10 - / .. Λ mean,
contains. 2. A photopolymerizable composition according to item 1, characterized in that they preferably 1 to 15 Gevv .-% of initiator, 40 - 50 wt .-% contains the ethylenically unsaturated compound - wt -.% Of binder and 20. 3. Photopolymerizable composition according to item 1 to 2, characterized in that the binder contains alkali-soluble polymers, ¹