Preparation method for shear-thinning water-based ball-point pen inks, shear-thinning water-based ball-point pen ink compositions, and ball-point pens employing the same
CA 2196512 C · Owner: Kito, Tsutomu · Inventors: Senga, Kuniyuki; Kito, Tsutomu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A shear-thinning water-based ball-point pen ink composition comprising from 1% by weight to 35% by weight of a colorant, from 2% by weight to 35% by weight of a water-soluble polar solvent from 1% by, weight to 30% by weight of a nonionic surface active agent having an HLB value within the range of from 8 to 12, and the balance being water and adjusting additives, and having a viscosity within the range of from 25 mPa.s to 160 mPa.s (a value at the number of revolution of 100 rpm in an EM type rotational viscometer, 25°C) and a shear thinning index within the range of from 0.1 to 0.6; the nonionic surface active agent having a mixed phase comprising a phase standing dispersed in the form of …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed January 31, 1997 and granted September 16, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 31, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 31, 2019.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.