IP Library Granted Patent US 8,557,380
Granted Patent B2
US 8,557,380 · App. 12/306,660 · Granted Oct 15, 2013

Form of hydroquinone and production thereof

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Quick Facts
Patent No.
US 8,557,380
App. No.
12/306,660
Granted
Oct 15, 2013
Kind
B2
Abstract

Novel hydroquinone flakes are prepared from a powder thereof, by, if necessary, melting the hydroquinone powder, depositing the hydroquinone in the liquid state as a film on a support made of a material or coated with a material which conducts heat, solidifying the hydroquinone by adjusting the support to an appropriate temperature, and recovering the solidified product in the form of flakes.

Claims (8)

1. Flakes of hydroquinone, comprising particles having a platelet shape and having a length ranging from 0.5 to 6 cm, a width ranging from 0.5 to 3 cm and a thickness ranging from 400 μm to 1,500 μm, said flakes having a level of fine particles, particles having dimensions of less than 100 μm, of less than 3% by weight thereof, wherein said flakes are formed by depositing hydroquinone in a molten liquid state as a film on a support made of a thermally conductive material or coated with a thermally conductive material, solidifying the hydroquinone by bringing the support to the appropriate temperature, recovering the solidified product in the form of flakes using any appropriate means.

2. The hydroquinone flakes as defined by claim 1 , having a morphology as shown in FIG. 1 or FIG. 4.

3. The hydroquinone flakes as defined by claim 1 , wherein from 20% to 40% of the particles, by weight, are able to pass through a sieve having a mesh size of 2.5 mm.

4. The hydroquinone flakes as defined by claim 1 , having a (loose) bulk density of the flakes of at least 0.4 g/cm 3 .

5. The hydroquinone flakes as defined by claim 1 , having a (tapped) bulk density of the flakes of at least 0.5 g/cm 3 .

6. The hydroquinone flakes as defined by claim 1 , having a length ranging from 1 to 3 cm.

7. The hydroquinone flakes as defined by claim 1 , having a thickness ranging from 500 to 750 μm.

8. The hydroquinone flakes as defined by claim 1 , having a level of fine particles ranging from 0.7 to 1% by weight thereof.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 26, 2024
From: RHODIA OPERATIONS
To: SPECIALTY OPERATIONS FRANCE
Reel/Frame 066374/0642 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 7, 2023
From: RHODIA OPERATIONS
To: SPECIALTY OPERATIONS FRANCE
Reel/Frame 065488/0365 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 5, 2009
From: LE THIESSE, JEAN-CLAUDE
To: RHODIA OPERATIONS
Reel/Frame 022787/0798 →