Water base erasable ink compositions
AssigneeSakura Color Products Corporation
InventorsKeiko Nakamura, Norihiro Hirano, Kenichi Shibuya
Life of this patent
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Abstract
A water base erasable ink composition for use in marking pens which comprises: (a) water as a solvent; (b) a coloring agent; (c) an aqueous emulsion of at least one nonvolatile oily material which is liquid at room temperatures and is selected from the group consisting of aliphatic carboxylic acid esters, higher hydrocarbons and higher alcohols in a dry amount of 1-50% by weight; (d) a cyclodextrin or its derivative in an amount of 0.1-20% by weight; and (e) a resin which is film-forming at room temperatures. The ink composition has improved storability over a long period of time.
Claims9
A water base erasable ink composition for use in marking pens which comprises:
- (a) water as a solvent;
- (b) a coloring agent;
- (c) an aqueous emulsion of at least one oily material
- which is liquid and nonvolatile at room temperature and is selected from the group consisting of aliphatic carboxylic acid esters, higher hydrocarbons selected from the group consisting of liquid paraffin, squalane and oxidized polyethylene wax, and aliphatic alcohols having 6 to 12 carbon atoms in a dry amount of 1-50% by weight based on the ink composition;
- (d) a cyclodextrin or a modified cyclodextrin in an amount of 0.1-20% by weight based on the ink composition;
- and
- (e) a resin which is film-forming at room temperatures.
A process for the preparation of a water base erasable ink composition for use in marking pens which comprises:
- (a) water as a solvent;
- (b) a water insoluble pigment;
- (c) an aqueous emulsion of at least one oily material which is liquid and nonvolatile at room temperatures and is selected from the group consisting of aliphatic carboxylic acid esters, higher hydrocarbons selected from the group, consisting of paraffin wax, squalane and oxidized polyethylene wax, and aliphatic alcohols having 6 to 12 carbon atoms in a dry amount of 1-50% by weight based on the ink composition;
- (d) a cyclodextrin or a modified cyclodextrin in an amount of 0.5-10% by weight based on the ink composition;
- (e) a water soluble resin which is film-forming at room temperatures;
- and
- (f) a surfactant;
- the process comprising:
- adding the surfactant and the pigment to water, and then adding the cyclodextrin or the modified cyclodextrin to the water to form a mixture, and then adding the emulsion of the oily material to the mixture;
- and then finally adding the water soluble resin to the mixture.
Dependencies are inferred from the claim text.