Background and summary of the invention

This invention concerns the ink to be filled into writing tools, e.g. pens, felt pens, roller pens, liner pens, markers, highlight pens etc. The inks currently in use are characterized by application properties on which their development focuses. This means they can be removed from textiles by washing, they can be washed off from skin, they cannot be wiped off from nonporous materials, they are resistant against wear etc. These main application characteristics of the inks have some negative properties which the solution under this invention seeks to eliminate. The property to be eliminated is the tendency to dry out, which is demonstrated particularly in alcohol-based inks consisting of a mixture of low aliphatic alcohols, pigments and other components, but also in water-based inks containing organic dyes and other components (examples of water-based inks are described in the patent No. 289465 "Washable inks easily removable from skin").

The disadvantage of the known writing liquids consists in the fact that the writing tools need to have their writing tips protected against drying. If the tip is not covered with a protective cap for a while it relatively quickly dries out, its function deteriorates and after a longer period of time it is completely degraded.

The mentioned disadvantage is eliminated by the ink under this invention with the increased resistance against drying.

The subject matter of the invention consists in the composition of the ink containing 0.1 to 25 wt. % of organic dye or pigment, 0.1 to 40 wt. % of glycols or polyethylene glycols with molecule weights from 100 to 6 000, 0.1 to 20 wt. % of glycol ethers with boiling points over 150° C and up to 15 wt. % of additives and admixtures such as biocides, defoamers, leveling agents, film formers or separators, while the balance to 100 wt. % is water or low aliphatic alcohols or their mixtures.

When filled into writing tools, the inks under this invention do not dry out even if the tool is not used for writing and left for a long time without a protective cap, which significantly improves capabilities of the products. The increased resistance against drying is created particularly by a combination of polyethylene glycols and glycol ethers with high boiling points, which form a layer on the ink surface and prevent evaporation of low-boiling solvents and gradual drying of the ink in the writing tool tip. The ink under this invention lasts up to 60 days in an open tip without drying out.

Detailed description of the preferred embodiments

It is understood that specific examples of realization of the invention, as described and depicted below, are provided only as an illustration and that they in no way limit realization of the invention to such examples. Experts proficient in the state of the art will find and will be able to identify through routine experimenting one or more equivalents of the realizations of the invention as specifically described herein. Such equivalents shall be covered by the scope of patent claims contained herein.

Example 1 - non-drying ink, black

Acid blue 9 (under Color Index) 2.22% wt.

Acid orange 7 (under Color Index) 4.00% wt.

Acid red 1 (under Color Index) 1.78% wt. natrium-dioctyl sulphosuccinate 0.02% wt. water - polyglycol - ether solution of a mixture of quarter ammonium salts 0.27% wt. propylene glycol phenyl ether 0.44% wt. tetraethylene glycol 26.87% wt. water 64.40% wt.

Example 2 - non-drying ink, red

Acid red 18 (under Color Index) 1.22% wt.

Acid red 1 (under Color Index) 0.94% wt.

Food yellow 4 (under Color Index) 0.47% wt. natrium-dioctyl sulphosuccinate 0.02% wt. water - polyglycol - ether solution of a mixture of quarter ammonium salts 0.28% wt. propylene glycol phenyl ether 0.47% wt. tetraethylene glycol 26.39% wt water 70.21% wt.

Example 3 - non-drying ink, blue

Acid red 52 (under Color Index) 0.43% wt.

Acid blue 9 (under Color Index) 0.77% wt. natrium-dioctyl sulphosuccinate 0.02% wt. water - polyglycol - ether solution of a mixture of quarter ammonium salts 0.29% wt. propylene glycol phenyl ether 0.48% wt. tetraethylene glycol 26.78% wt. water 71.23% wt.

Example 4 - non-drying ink, red

Solvent red 160 (under Color Index) 4.00% wt. triglyceride of caprylic and capric acids 0.50% wt. propylene glycol phenyl ether 2.00% wt. n-propanol balance to 100% wt.

Example 5 - non-drying ink, blue

Basic blue 26 (under Color Index) 4.00% wt. triglyceride of caprylic and capric acids 0.50% wt. propylene glycol phenyl ether 1.50% wt. n-propanol 50.00% wt. butanol balance to 100% wt.

Example 6 - non-drying ink, blue

Solvent blue 44 (under Color Index) 7.00% wt. Basic violet 1 (under Color Index) 1.00% wt. triglyceride of caprylic and capric acids 2.50% wt. tripropylene glycol-n-butyl ether 0.50% wt. n-propanol balance to l00% wt.

Example 7 - non-drying ink, green

mixture of Solvent yellow 83:1,

Solvent blue 44 (under Color Index) 8.00% wt. triglyceride of caprylic and capric acids 3.20% wt. propylene glycol phenyl ether 1.80% wt. n-propanol 47.00% wt. butanol balance to 100% wt.

Example 8 - non-drying ink, black

mixture of Basic violet 10, Basic orange 59,

Basic violet 3, Basic blue 26 (under Color Index) 9.00% wt. triglyceride of caprylic and capric acids 2.70% wt. propylene glycol phenyl ether 3.30% wt. n-propanol balance to 100% wt.

The ink with increased resistance against drying under this invention can be used particularly as a filling in writing tools, such as pens, felt pens, roller pens, liner pens, markers, highlight pens etc.