Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N3/00—Preparing for use and conserving printing surfaces
  • B41N3/08—Damping; Neutralising or similar differentiation treatments for lithographic printing formes; Gumming or finishing solutions, fountain solutions, correction or deletion fluids, or on-press development

Definitions

• the present invention relates to a fountain solution additive for offset printing, which contains wetting agents, pH-regulating substances, humectants, optionally film-forming agents, softening agents and preservatives.
• fountain solution additives have already proven their worth, but it is particularly useful in film dampening systems, such as Dahlgreen and Alcolor, necessary to add large amounts of alcohols such as isopropanol or ethanol to the fountain solution, which is undesirable for work and environmental reasons.
• the invention has also set itself the task of further improving fountain solution additives, in particular those according to EP-A-0 111 136.
• the fountain solution additive improved according to the invention can also be in paste, powder or tablet form.
• the substances in group B are able, on the one hand, to make the addition of solvents, in particular alcohols such as isopropyl alcohol or ethanol, superfluous, and, on the other hand, to prevent undesirable foaming or emulsification of the fountain solution additive with the printing inks.
• solvents in particular alcohols such as isopropyl alcohol or ethanol
• they are able to make the partially poorly or insufficiently water-soluble components of group A better water-soluble, but without reducing their effectiveness as a fountain solution additive.
• Suitable aliphatic or aromatic sulfonic acids or sulfonates with hydrocarbon chains with a maximum of 10 carbon atoms are, in particular, the relatively short-chain derivatives such as sodium cumene sulfonate and sodium toluenesulfonate.
• Long chain sulfonic acids and sulfonates such as sodium lauryl sulfate have proven to be much less suitable because they act as strong wetting agents and foaming agents and, at the required concentration, lead to undesired emulsification of the printing inks with the fountain solution. According to the invention, however, sodium isooctyl sulfate can be used without further ado.
• the relatively short-chain derivatives have also proven particularly useful as optionally alkoxylated ether sulfonic acids or ether sulfonates.
• optionally alkoxylated ether sulfonic acids or ether sulfonates For example, sodium butyl monoglycol sulfate is excellent.
• Alkylphenol ethoxylates and theirs have been found to be optionally sulfonated alkylphenol ethoxylates Sulphates have proven successful, the ethoxylate chain containing 1 to 6 ethoxy groups and the alkyl group containing a maximum of 10 carbon atoms.
• the relatively short-chain derivatives are preferably used as the alkoxylated carboxylic acid with a maximum of 10 carbon atoms, since these are less likely to foam and emulsify.
• the esters of short-chain carboxylic acids of ethylene glycol and oligoethylene glycols with up to 6 ethylene glycol units are particularly suitable.
• a liquid fountain solution concentrate can contain 0.1 to 50 parts of group A wetting agent and 1 to 90 parts by weight of group B in addition to 0.1 to 50 parts.
• a dampening solution additive according to the invention in powder form can thus contain 0.05 to 5 parts of group A wetting agent and 1 to 50 parts by weight of group B in addition to 2 to 90 parts of buffer salt, 0 to 60 parts of softening agent, 0 to 80 parts of humectant and 0 to 80 parts of film former and 0.2 to 5 parts preservative.
• Such a powder can also be easily compressed into tablets. These tablets dissolve quickly and easily in water, allowing easy and simple dosing and preparation of the fountain solution for offset printing.
• the powder can also be dissolved directly in water without difficulty or offered in the form of a paste with only a low water content.
• the advantage of the powder and tablet form, but also the paste form, is the small storage volume, the smaller packaging, the reduction in freight costs and the stability.
• a content of 0.001 to 1.0 g of wetting agent and / or 0.1 to 2 g of substances of group B per liter of fountain solution leads to the advantages of fountain solution compared to conventional formulations, namely the improvement of the color / water emulsification behavior, which can be achieved according to the invention Enabling uniform water flow and the resulting printing advantages.
• the dampening rollers can be cleaned faster and more thoroughly, and the re-contamination of related dampening rollers is reduced.
• the printing plates run free extremely quickly, thereby reducing the amount of waste. In particular, color deposits on the rubber blanket in the non-image area are reduced even more.
• Typical formulations thus contain 0.0 1 to 20 parts, preferably 2 to 5 parts, of group A wetting agent. They are mixed with 1 to 70 parts, preferably 5 to 20 parts, of substances in group B and 2 to 20 parts of buffer salt (trisodium citrate / citric acid in Weight ratio 5: 1 to 2: 1), 0.1 to 5 parts of preservative and 10 to 90 parts of water dissolved.
• 0 to 50 parts preferably 3 to 10 parts of humectant, in particular sorbitol
• 0 to 20 parts preferably 2 to 10 parts of softening agent such as sodium ethylenediaminetetraacetic acid sodium salt and 0 to 50 parts, preferably 2 to 5 parts, of film former such as gum arabic are added and mixed intimately .
• These concentrates can be filled and used immediately.
• 1 to 100 g, preferably about 10 g / l, of the concentrate are added to the fountain solution.
• Powder formulations contain 0.05 to 5 parts, preferably 0.5 to 2 parts, of group A wetting agent and 1 to 50 parts, preferably 10 to 40 parts of group B, with 2 to 90 parts of buffer salt (trisodium citrate / citric acid in a weight ratio of 5: 1 up to 2: 1). They also contain 0.2 to 5 parts, preferably 1 to 3 parts of potassium sorbate, 0 to 80 parts, preferably 20 to 40 parts of sorbitol as a humectant, 0 to 60 parts, preferably 2 to 20 parts of sodium ethylenediaminetetraacetic acid as a softening agent and 0 to 80 Parts, preferably 0 to 5 parts of gum arabic as a film former.
• the components are mixed homogeneously as powder and, if desired, instantized or compressed into tablets.
• the powder or the tablets are added in amounts of 1 to 100 g, preferably 10 g / l of dampening water.

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Cited By (3)

Citations (9)

• 1986
  • 1986-12-02 EP EP86116744A patent/EP0269760A1/fr not_active Ceased

Patent Citations (9)

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