Disclosed is a coating composition suitable for coating onto a wall or other substrate to yield a dry-erase coating. The composition may be prepared by providing an aminoalkoxysilane, and in the substantial absence of water, reacting a portion of the aminoalkoxysilane with a carbonate and reacting a portion of the aminoalkoxysilane with an epoxy compound. These reactions will result in a coating composition that comprises a mixture of alkoxysilylamines and alkoxysilylcarbamates. The coating composition can also include an alkyl amine in an amount effective to catalytically deprotect alkoxy groups to yield silanol groups, facilitating fast crosslinking.

The present invention provides trisazo dyes of formula (V), wherein A, M and R.sub.1, R.sub.2, R.sub.3, R.sub.4 are as defined in the specification, processes for their preparation, recording liquids and liquid dye preparations containing them and their use in inks as well as processes for applying them and printed articles comprising them.

##STR00001##

The present invention provides trisazo dyes of formula (V), wherein A, M and R.sub.1, R.sub.2, R.sub.3, R.sub.4 are as defined in the specification, processes for their preparation, recording liquids and liquid dye preparations containing them and their use in inks as well as processes for applying them and printed articles comprising them.

##STR00001##

The present disclosure relates to a method for preparing a thermochromic water-based gel ink composition, as well as a thermochromic water-based gel ink composition thereof comprising a specific monocarboxylic or polycarboxylic acid. The present disclosure also concerns a writing instrument, such as a ballpoint pen, a brush pen, a marker, a highlighter, and a felt pen, comprising a thermochromic water-based gel ink composition according to the disclosure.

The present disclosure relates to a method for preparing a thermochromic water-based gel ink composition, as well as a thermochromic water-based gel ink composition thereof comprising a specific monocarboxylic or polycarboxylic acid. The present disclosure also concerns a writing instrument, such as a ballpoint pen, a brush pen, a marker, a highlighter, and a felt pen, comprising a thermochromic water-based gel ink composition according to the disclosure.

An ink composition includes a fluid and a plurality of microcapsules suspended in the fluid. The fluid includes a first chemical compound that exhibits a first color characteristic in a first pH range and exhibits a second color characteristic in a second pH range, where the first color characteristic is visually distinct from the second color characteristic. A second chemical compound is contained within the microcapsules, such that rupturing at least a subset of the plurality of microcapsules releases the second chemical compound. Releasing the second chemical compound shifts a pH of the fluid from a first pH in the first pH range to a second pH in the second pH range.

An ink composition includes a fluid and a plurality of microcapsules suspended in the fluid. The fluid includes a first chemical compound that exhibits a first color characteristic in a first pH range and exhibits a second color characteristic in a second pH range, where the first color characteristic is visually distinct from the second color characteristic. A second chemical compound is contained within the microcapsules, such that rupturing at least a subset of the plurality of microcapsules releases the second chemical compound. Releasing the second chemical compound shifts a pH of the fluid from a first pH in the first pH range to a second pH in the second pH range.

An ink composition for a water-based ballpoint pen including at least a black pigment and borneol, the black pigment satisfying requirements X to Z below: X: 50% particle size (D50) in a cumulative particle size distribution in terms of volume being 0.2 to 1.0 μm, Y: 10% particle size (D10) in a cumulative particle size distribution in terms of volume being 0.1 to 0.3 μm, and Z: 90% particle size (D90) in a cumulative particle size distribution in terms of volume being 1.0 to 5.0 μm.

An ink composition for a water-based ballpoint pen including at least a black pigment and borneol, the black pigment satisfying requirements X to Z below: X: 50% particle size (D50) in a cumulative particle size distribution in terms of volume being 0.2 to 1.0 μm, Y: 10% particle size (D10) in a cumulative particle size distribution in terms of volume being 0.1 to 0.3 μm, and Z: 90% particle size (D90) in a cumulative particle size distribution in terms of volume being 1.0 to 5.0 μm.

Provided are an ink composition for writing instruments which has a good solubility of a coloring material in an ink solvent and which is less liable to cause bleeding and feathering on the written lines and is improved in a water resistance, and a coloring material used for preparing the above ink composition. The coloring material includes a material obtained by adding at least one selected from a leuco dye, a halochromic dye and a photochromic compound to a compound represented by the following Formula (I): ##STR00001##
The ink composition for writing instruments is characterized by containing the coloring material described above.