The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 09, 1998
Filed:
Jun. 07, 1995
Herman Abber, Brockton, MA (US);
Robert H Lussier, Weymouth, MA (US);
Dianne E Porter, Southboro, MA (US);
Avery Dennison Corporation, Pasadena, CA (US);
Abstract
A marking composition erasable from both porous and non-porous marking substrates using substantially non-abrasive mechanical erasers. The marking composition preferably has a viscosity of less than about 10 cps and a surface tension between about 20 dynes/cm and about 40 dynes/cm and is particularly well-suited for use in capillary feed markers and similar writing instruments. In a first preferred embodiment, the marking composition comprises a water-insoluble colorant and a blend of two different non-carboxylated styrene-butadiene latex emulsions. The first latex emulsion, an embodiment of which is commercially available as PLIOLITE.RTM. LPF-2108, contains about 40% total solids by weight and has a viscosity of about 30 cps, a pH of about 11.2, a Mooney value of about 150-160, a surface tension of about 55-60 dynes/cm, and a bound styrene content of about 21-29%. The second non-carboxylated styrene-butadiene latex emulsion, an embodiment of which is commercially available as Butofan.RTM. NS 103, contains about 47% total solids by weight and has a viscosity of about 200 cps, a pH of about 9.7, a Mooney value of about 70-75, a surface tension of about 62 dynes/cm and a bound styrene content of about 24%. Preferably, the latex emulsion blend has a viscosity greater than about 50 cps, and the ratio of the second latex emulsion to the first latex emulsion is greater than or equal to about 75:25 and less than 100:0. The marking composition preferably further includes a shear-stabilizing agent, such as potassium oleate, as well as a preservative, an antioxidant, a fluorochemical surfactant and one or more anti-drying agents.