Aqueous-based, shear-thinning, erasable ink and roller-ball pen containing same
US5629363A · kind A · utility
Inventors
Key dates
| Filing date | Nov 1, 1995 |
| Grant date | May 13, 1997 |
| Priority date | — |
| Expiry date | Nov 1, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB43K1/082
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An aqueous-based, shear-thinning, erasable ink and a roller-ball pen containing same. In a preferred embodiment, the ink comprises a blend of three different non-carboxylated, styrene-butadiene aqueous emulsions, a water-insoluble or water-dispersible pigment and a shear-thinning, viscosity-adjustment agent in the form of a silicate clay. The ink further comprises an antioxidant preparation, which includes tocopherol and vitamin C, for use in extending the time period over which the ink remains erasable after being applied to a substrate, a shear-stabilizing agent in the form of potassium oleate for use in preventing unwanted coagulation of the styrene-butadiene copolymer due to shear, a pH-adjusting agent in the form of triethanolamine for shifting the pH of the ink to a pH of about 9-10, and an anti-drying agent in the form of a 3:1 mixture of sorbitol to glycerine. The pen comprises a barrel for storing a quantity of the ink, the barrel being made of polypropylene and having an open top end; a hollow tip made of a stainless steel, a nickel-silver alloy or a polyoxymethylene and having a top end and a bottom end, the top end being shaped to define a ball socket; a ball rotatably …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.