Abstract: The present invention discloses a process for the production of 2-methyl-1,4-naphthoquinone and its bisulfite adducts, comprising the following steps: a) oxidizing 2-methyl-naphthalene (2-MNA) to achieve an organic phase containing 2-methyl-naphthoquinone (2-MNQ) and 6-methyl-naphthoquinone (6-MNQ); b) subjecting said organic phase to treatment with an aqueous solution of a bisulfite salt to extract preferentially the 6-MNQ isomer from the organic phase; c) separating said organic phase from the aqueous phase; d) subjecting the organic phase of process step c) to a second bisulfitation step with an aqueous solution of a bisulfite salt, resulting in an organic phase containing 2-MNA and trace amounts of 2-MNQ and an aqueous phase containing 2-MSB and trace amounts of 6-MSB; e) optionally removing interfering bisulfite ions from the aqueous phase of process step c); f) raising the pH of the aqueous phase from step c) or e) to higher than 8.

Abstract: The present invention discloses a process for the production of 2-methyl-1,4-naphthoquinone and its bisulfite adducts, comprising the following steps: a) oxidizing 2-methyl-naphthalene (2-MNA) to achieve an organic phase containing 2-methyl-naphthoquinone (2-MNQ) and 6-methyl-naphthoquinone (6-MNQ); b) subjecting said organic phase to treatment with an aqueous solution of a bisulfite salt to extract preferentially the 6-MNQ isomer from the organic phase; c) separating said organic phase from the aqueous phase; d) subjecting the organic phase of process step c) to a second bisulfidation step with an aqueous solution of a bisulfite salt, resulting in an organic phase containing 2-MNA and trace amounts of 2-MNQ and an aqueous phase containing 2-MSB and trace amounts of 6-MSB; e) optionally removing interfering bisulfite ions from the aqueous phase of process step c); f) raising the pH of the aqueous phase from step c) or e) to higher than 8.

Abstract: The present invention discloses a process for the production of 2-methyl-1,4-naphthoquinone and its bisulfite adducts, comprising the following steps: a) oxidizing 2-methyl-naphthalene (2-MNA) to achieve an organic phase containing 2-methyl-naphthoquinone (2-MNQ) and 6-methyl-naphthoquinone (6-MNQ); b) subjecting said organic phase to treatment with an aqueous solution of a bisulfite salt to extract preferentially the 6-MNQ isomer from the organic phase; c) separating said organic phase from the aqueous phase; d) subjecting the organic phase of process step c) to a second bisulfidation step with an aqueous solution of a bisulfite salt, resulting in an organic phase containing 2-MNA and trace amounts of 2-MNQ and an aqueous phase containing 2-MSB and trace amounts of 6-MSB; e) optionally removing interfering bisulfite ions from the aqueous phase of process step c); f) raising the pH of the aqueous phase from step c) or e) to higher than 8.

Abstract: The present invention discloses highly stabilized nicotinamide (NA) formulated vitamin K3 derivative particles, whereby the NA forms a physical protective layer (both continuous and discontinuous) leading to highly stabilized vitamin K3 derivative particles, as well as a process for their production.

Abstract: A light-emitting handpiece for curing light-curable dental resins and similar materials. In general appearance, the handpiece is designed to resemble a conventional dental drill. Preferably, the handpiece comprises a housing defining a tubular handle portion that is adapted to contain a power pack for energizing an LED light source, a head portion for supporting an LED in a position to project radiation outwardly therefrom; and (iii) a neck portion that serves to interconnect the head and handle portions. Preferably, at least the head and neck portions of the housing are integrally formed from a common, thermally conductive material, preferably aluminum. In use, the head and neck portions of the handpiece housing operate to provide a heat sink for the LED. Circuitry within the handpiece housing operates to prevent overheating of the housing and the LED source.

Abstract: A vacuum forming apparatus to allow a tray containing a sheet, to be molded into a prescribed shape, to be moved manually in a very rapid manner in a rearward diagonal upward direction from a horizontally positioned vacuum table that is at one level into horizontal engagement with a heating element that is at a higher level, When in this latter position the tray is retained by a magnet until the sheet is heated to a moldable condition. The tray is then manually withdrawn from the magnet without harm to an operator's fingers while the tray is being moved rapidly in a forward diagonal downward direction away from the heating element into engagement with the vacuum tables In this position the moldable sheet is formed into the prescribed molded shape. To accomplish this very rapid diagonal movement of the tray parallel linkages are employed that are each pivotally connected to the rear central portion of the tray at one end and to a post at its other end.