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:
Dec. 11, 2012
Filed:
Mar. 30, 2010
Raymond M. Robertson, Blacksburg, VA (US);
William C. Thomas, Pembroke, VA (US);
Raymond M. Robertson, Blacksburg, VA (US);
William C. Thomas, Pembroke, VA (US);
Celanese Acetate LLC, Dallas, TX (US);
Abstract
An environmentally degradable cigarette filter includes a filter element of a bloomed cellulose acetate tow and a plug wrap surrounding said filter element. A weak organic acid and a pH adjusted inorganic ester salt are encapsulated in a matrix material which is in contact with the tow. The pH adjusted inorganic ester salt has a pH less than or equal to 8. When the cigarette filter is discarded into the environment, water liberates the weak acid and the ester salt from the matrix material. The weak acid hydrolyzes the ester liberating a strong acid. The strong acid catalyzes the degradation of the cellulose acetate tow. (The weak acid also hydrolyzes the cellulose acetate tow, but after the strong acid is generated, the strong acid becomes the dominant acid catalyst for the cellulose acetate tow degradation.)