[Problem]

To provide an oil-based ink composition for ballpoint pens and also an oil-based ballpoint pen employing the composition. The ink composition inhibits a ball seat from wearing under high pen pressure (writing load: 300 to 500 gf), improves writing feeling, and is excellent in writing performance at the beginning of handwriting, in temporal stability and in ink followability.

[means to solve the problem]

An oil-based ink composition for ballpoint pens, comprising a colorant, an organic solvent, and a polyoxy-alkylene glyceryl ether.

[Problem]

To provide an oil-based ink composition for ballpoint pens and also an oil-based ballpoint pen employing the composition. The ink composition inhibits a ball seat from wearing under high pen pressure (writing load: 300 to 500 gf), improves writing feeling, and is excellent in writing performance at the beginning of handwriting, in temporal stability and in ink followability.

[means to solve the problem]

An oil-based ink composition for ballpoint pens, comprising a colorant, an organic solvent, and a polyoxy-alkylene glyceryl ether.

The ink composition contains titanium oxide particles having an average particle size of 0.1 μm or more and 0.4 μm or less, hollow resin particles having an average particle size of 1.0 μm or more and 2.0 μm or less, a polysaccharide and water, wherein the titanium oxide particles and the hollow resin particles are negatively charged.

The ink composition contains titanium oxide particles having an average particle size of 0.1 μm or more and 0.4 μm or less, hollow resin particles having an average particle size of 1.0 μm or more and 2.0 μm or less, a polysaccharide and water, wherein the titanium oxide particles and the hollow resin particles are negatively charged.

A writing instrument having a writing tip, the writing instrument comprising a non-aqueous writing ink which is contained in a tubular ink cartridge, wherein the tubular ink cartridge has an inner diameter of between about 1 mm and about 2.5 mm, and two open ends, wherein the first open end is connected with the writing tip and the second open end is connected with the external surroundings of the writing instrument, wherein the non-aqueous writing ink contained in a tubular ink cartridge is in fluid communication with the writing tip via the first open end and with the external surroundings of the writing instrument via the second open end, and wherein the non-aqueous writing ink comprises a solvent, a resin, a coloring agent, and a gelling agent.

A writing instrument having a writing tip, the writing instrument comprising a non-aqueous writing ink which is contained in a tubular ink cartridge, wherein the tubular ink cartridge has an inner diameter of between about 1 mm and about 2.5 mm, and two open ends, wherein the first open end is connected with the writing tip and the second open end is connected with the external surroundings of the writing instrument, wherein the non-aqueous writing ink contained in a tubular ink cartridge is in fluid communication with the writing tip via the first open end and with the external surroundings of the writing instrument via the second open end, and wherein the non-aqueous writing ink comprises a solvent, a resin, a coloring agent, and a gelling agent.

A coloring tablet may have excellent solubility and redispersibility and a water-based ink composition for a writing instrument. Such a coloring tablet may contain at least a colorant and a dispersing agent. The dispersing agent may include a hydroxide neutralization product of an (meth)acrylic resin, a hydroxide neutralization product of a styrene-maleic acid copolymer resin, a polyoxyethylene-based surfactant, an alkyl condensed ring sulfonate, an amine ethylene oxide propylene oxide adduct, and/or a isobutylene-based polymer.

A coloring tablet may have excellent solubility and redispersibility and a water-based ink composition for a writing instrument. Such a coloring tablet may contain at least a colorant and a dispersing agent. The dispersing agent may include a hydroxide neutralization product of an (meth)acrylic resin, a hydroxide neutralization product of a styrene-maleic acid copolymer resin, a polyoxyethylene-based surfactant, an alkyl condensed ring sulfonate, an amine ethylene oxide propylene oxide adduct, and/or a isobutylene-based polymer.

To provide an aqueous ink composition for ballpoint pen having excellent ink discharge properties at the initial writing (initial touch) even after exposure of the pen tip for a long period of time. The aqueous ink composition for ballpoint pen contains at least 0.1 to 5% by mass of a graft compound of an allyl alcohol-maleic anhydride-styrene copolymer composed of: (a) a polyoxyalkylene alkyl ether unit represented by Formula (I), (b) a maleic anhydride unit, and (c) a styrene unit, the allyl alcohol-maleic anhydride-styrene copolymer having the composition ratio (a):(b):(c) of 25 to 75:25 to 75:0 to 50% by mol and having a mass average molecular weight from 1000 to 50000, and polyoxyalkylene monoalkyl alcohol; 5 to 40% by mass of resin particles; and water; wherein in Formula (I), R represents an alkyl group having 1 to 5 carbons, and m is a positive number of 5 to 50. ##STR00001##

To provide an aqueous ink composition for ballpoint pen having excellent ink discharge properties at the initial writing (initial touch) even after exposure of the pen tip for a long period of time. The aqueous ink composition for ballpoint pen contains at least 0.1 to 5% by mass of a graft compound of an allyl alcohol-maleic anhydride-styrene copolymer composed of: (a) a polyoxyalkylene alkyl ether unit represented by Formula (I), (b) a maleic anhydride unit, and (c) a styrene unit, the allyl alcohol-maleic anhydride-styrene copolymer having the composition ratio (a):(b):(c) of 25 to 75:25 to 75:0 to 50% by mol and having a mass average molecular weight from 1000 to 50000, and polyoxyalkylene monoalkyl alcohol; 5 to 40% by mass of resin particles; and water; wherein in Formula (I), R represents an alkyl group having 1 to 5 carbons, and m is a positive number of 5 to 50. ##STR00001##