Patent US11634A successfully refreshed from Google Patents.
EP0246074A2
Expired / Lapsed
EP
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Process for producing toner for developing electrostatic images
Assignee: Canon Inc
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Filing: 1987-05-12
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Granted: —
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Expires: 2007-05-12
Abstract
Abstract A toner for developing electrostatic latent images is produced by classifying feed toner particles supplied through a supply nozzle (16) into at least three fractions in a classifying chamber divided into at least three sections (11,12,13) and placed under a reduced pressure under the action of the inertia force of the toner particles supplied together with a gas stream and the centrifugal force of the curved gas stream due to Coanda effect. A first gas introduction pipe (14) and a second gas introduction pipe (15) are disposed above the classifying chamber so as to provide a first inlet and a second inlet opening with the first inlet being disposed closer to the supply nozzle than the second inlet. The magnitudes of the static pressures Pi and P 2 in the first and second gas introduction pipes are controlled so as to satisfy the relations of: |P 1 | ≧ 150 mm.aq., |P 2 | ≧ 40 mm.aq. and |P 1 | - |P 2 | ≧ 100 mm.aq.
Inventors
- 👤 Hitoshi Kanda
- 👤 Masayoshi Kato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 20:02
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/16; B; B07; B07B; B07B7/00; B07B7/08; B07B7/086; B07B7/0865; G03G9/00; G03G9/08
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
359 words
A process for producing a toner for developing electrostatic latent image, comprising: generating a reduced pressure in a classifying chamber which is divided into at least three sections including a coarse powder section having a first outlet for withdrawing a coarse powder, a medium powder section having a second outlet for withdrawing a medium powder, and a fine powder section having a third outlet for withdrawing a fine powder, by sucking the classifying chamber through at least one of the first to third outlets; supplying to the classifying chamber a feed toner material comprising toner particles of 20 µm or less in particle size in a proportion of 50 % or more by number through a supply pipe having a supply nozzle opening into the classifying chamber at a velocity of 50 m/sec to 300 m/sec along with a gas stream flowing through the pipe; controlling the absolute value of a static pressure P i to 150 mm.aq. or above in a first gas introduction pipe having a first gas inlet opening into the classifying chamber at a position upstream of the first gas inlet by a first gas introduction control means; controlling the absolute value of a static pressure P 2 to 40 mm.aq. or above in a second gas introduction pipe having a second gas inlet opening into the classifying chamber at a position just upstream of the second gas inlet by a second gas introduction control means, the second gas inlet being disposed farther than the first gas inlet with respect to the supply nozzle; and distributing the feed toner material supplied to the classifying chamber into at least the coarse powder section, the medium powder section and the fine powder section under the action of the inertia force of the feed toner particles in the gas stream and the centrifugal force of the curved gas stream due to Coanda effect and under a condition where the absolute value |P 1 | of the static pressure P 1 and the absolute value I P 2 1 of the static pressure P 2 satisfying the relation of |P 1 | - |P 2 | ≧ 100 (mm.aq.).
Claim 2
Dependent Claim
359 words
A process for producing a toner for developing electrostatic latent image, comprising: generating a reduced pressure in a classifying chamber which is divided into at least three sections including a coarse powder section having a first outlet for withdrawing a coarse powder, a medium powder section having a second outlet for withdrawing a medium powder, and a fine powder section having a third outlet for withdrawing a fine powder, by sucking the classifying chamber through at least one of the first to third outlets; supplying to the classifying chamber a feed toner material comprising toner particles of 20 µm or less in particle size in a proportion of 50 % or more by number through a supply pipe having a supply nozzle opening into the classifying chamber at a velocity of 50 m/sec to 300 m/sec along with a gas stream flowing through the pipe; controlling the absolute value of a static pressure P i to 150 mm.aq. or above in a first gas introduction pipe having a first gas inlet opening into the classifying chamber at a position upstream of the first gas inlet by a first gas introduction control means; controlling the absolute value of a static pressure P 2 to 40 mm.aq. or above in a second gas introduction pipe having a second gas inlet opening into the classifying chamber at a position just upstream of the second gas inlet by a second gas introduction control means, the second gas inlet being disposed farther than the first gas inlet with respect to the supply nozzle; and distributing the feed toner material supplied to the classifying chamber into at least the coarse powder section, the medium powder section and the fine powder section under the action of the inertia force of the feed toner particles in the gas stream and the centrifugal force of the curved gas stream due to Coanda effect and under a condition where the absolute value |P 1 | of the static pressure P 1 and the absolute value I P 2 1 of the static pressure P 2 satisfying the relation of |P 1 | - |P 2 | ≧ 100 (mm.aq.).
Claim 3
Dependent Claim
29 words
A process according to Claim 1, wherein the reduced pressure in the classification chamber is generated by sucking the classification chamber through all of the first to third outlets.
Claim 4
Dependent Claim
29 words
A process according to Claim 1, wherein the feed toner material is supplied to the classifying chamber at a velocity of 70 - 200 m/sec through the supply nozzle.
Claim 5
Dependent Claim
23 words
A process according to Claim 1, wherein the absolute value I Pi of the static pressure P 1 is 200 mm.aq. or above.
Claim 6
Dependent Claim
24 words
A process according to Claim 4, wherein the absolute value |P 1 | of the static pressure P 1 is 210 to 1000 mm.aq.
Claim 7
Dependent Claim
24 words
A process according to Claim 1, wherein the absolute value I P 21 of the static pressure P 2 is 45 to 400 mm.aq.
Claim 8
Dependent Claim
24 words
A process according to Claim 6, wherein the absolute value I P 21 of the static pressure P 2 is 45 to 70 mm.aq.
Claim 9
Dependent Claim
56 words
A process according to Claim 1, wherein the absolute value |P 1 | of the static pressure P 1 and the absolute value I P 21 of the static pressure P 2 satisfy the relations of: 150 ≦ |P 1 | - |P 2 | ≦ 700, and |P 1 |/|P 2 | =2 to 10.
Claim 10
Dependent Claim
24 words
A process according to Claim 1, wherein the toner particles comprise a binder resin, a colorant, an antioffset agent, and a charge control agent.
Claim 11
Dependent Claim
15 words
A process according to Claim 1, wherein the toner particles have been prepared through pulverization.
Claim 12
Dependent Claim
16 words
A process according to Claim 1, wherein the toner particles have been prepared through suspension polymerization.
Claim 13
Dependent Claim
19 words
A process according to Claim 2, wherein the sucking of the classifying chamber is effected by a collecting cyclone.
Claim 14
Dependent Claim
21 words
A process according to Claim 1, wherein the static pressures P i and P 2 are respectively controlled by a damper.
References Cited (Backward Citations)
No citation records indexed.
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