Photocopying materials
AssigneeOce-van der Grinten N.V.
InventorsAntonius H. I. Houtermans, Johannes G. Kamphuis
Life of this patent
Estimating the term…
Abstract
A photocopying material is provided having a light-sensitive layer comprising an oleophilic resin and a resinous diazonium compound, which both are soluble in an organic solvent but substantially insoluble in water, in admixture with a surface active agent which, after imagewise exposure, renders the layer developable with plain water such as ordinary tap water so as to yield an excellent photocopy and in particular a printing form from which many thousands of fine prints can be made on an offset machine.
Claims21
Photocopying material comprising a support carrying a light-sensitive layer which consists essentially of a negative-working, light-sensitive diazonium resin salt and an oleophilic, filmforming resin, both of which are soluble in organic solvents and at most sparingly soluble in water, and at least 10% by weight of water-soluble surfactant which renders said diazonium resin salt soluble in water so that said layer is developable into an image by plain water after imagewise exposure of said layer to light;
- said resin salt being selected from the group consisting of p-toluene sulfonic acid, napththalene-2-sulfonic acid, BF4- and 1-chloro-4-benzene sulfonic acid salts of the condensation product of p-diazo-diphenylamine and formaldehyde;
- said surfactant being selected from the group consisting of:
- a. alkyl-quaternary ammonium salts of the general formula ##STR4## in which R represents a hydrocarbon chain, which salts comprise predominantly at least one compound of formula I wherein R is an alkyl chain having 12 to 18 carbon atoms;
- b. ethylene oxide amines of the general formula ##STR5## R represents an alkyl chain, which amines comprise at least one compound of formula II wherein the alkyl chain has 18 carbon atoms and the sum of x and y is 15;
- c. water-soluble quaternary ammonium salts of the general formula ##STR6## wherein R.sub.1 and R.sub.2 each is a methylol or ethylol group, R.sub.3 is hydrogen or a methylol or ethylol group, and R.sub.4 is an alkyl chain having 9-18 carbon atoms;
- d. sodium and sodium-2-ethyl dodecyl sulfates, sodium decyl sulfate and sodium tridecyl sulfate;
- and
- e. polyvinyl pyrrolidone surfactants.
Light-sensitive composition for the production of photocopy material, consisting essentially of a solution in an organic solvent of a negative-working light-sensitive diazonium resin salt and an oleophilic filmforming resin, each of which is soluble in organic solvents and at most sparingly soluble in water, and at least 10% by weight, calculated on the dissolved dry matter, of water-soluble surfactant which renders said diazonium resin salt soluble in water,
- said resin salt being selected from the group consisting of p-toluene sulfonic acid, napththalene-2-sulfonic acid, BF4-and 1-chloro-4-benzene sulfonic acid salts of the condensation product of p-diazo-diphenylamine and formaldehyde;
- said surfactant being selected from the group consisting of:
- a. alkyl-quaternary ammonium salts of the general formula ##STR9## in which R represents a hydrocarbon chain, which salts comprise predominantly at least one compound of formula I wherein R is an alkyl chain having 12 to 18 carbon atoms;
- b. ethylene oxide amines of the general formula ##STR10## in which R represents an alkyl chain, which amines comprise at least one compound of formula II wherein the alkyl chain has 18 carbon atoms and the sum of x and y is 15;
- c. water-soluble quaternary ammonium salts of the general formula ##STR11## wherein R.sub.1 and R.sub.2 each is a methylol or ethylol group, R.sub.3 is hydrogen or a methylol or ethylol group and R.sub.4 is an alkyl chain having 9-18 carbon atoms;
- d. sodium and sodium-2-ethyl dodecyl sulfates, sodium decyl sulfate and sodium tridecyl sulfate;
- and
- e. polyvinyl pyrrolidone surfactants.
Photocopying material for producing an offset printing plate, comprising a support carrying a light-sensitive layer consisting essentially of negative-working light-sensitive diazonium resin salt selected from the group consisting of naphththalene-2-sulfonic acid, BF.sub.4 - and 1-chloro-4-benzene sulfonic acid salts of the condensation product of p-diazodiphenylamine and formaldehyde, oleophilic filmforming epoxy resin and at least 10% by weight of water-soluble surfactant that renders said resin salt soluble in water, said resin salt and said epoxy resin being present in a weight ratio, resin salt to resin, of between 0.3 and 4 to 1, the quantity of said surfactant being sufficient to render said layer developable into an image by plain water after imagewise exposure of said layer to light, said surfactant being selected from the group consisting of:
- a. alkyl-quaternary ammonium salts of the general formula ##STR12## in which R represents a hydrocarbon chain, which salts comprise predominantly at least one compound of formula I wherein R is an alkyl chain having 12 to 18 carbon atoms;
- b. ethylene oxide amines of the general formula ##STR13## in which R represents an alkyl chain, which amines comprise at least one compound of formula II wherein the alkyl chain has 18 carbon atoms and the sum of x and y is 15;
- c. diethanolamine and triethanolamine dodecyl sulfates;
- d. sodium and sodium-2-ethyl dodecyl sulfates, sodium decyl sulfate and sodium tridecyl sulfate;
- and
- e. polyvinyl pyrrolidone surfactants.
Dependencies are inferred from the claim text.