IP Library Granted Patent US 8,735,035
Granted Patent B2
US 8,735,035 · App. 13/355,117 · Granted May 27, 2014

Electrophotographic toner and process of preparing the same

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Quick Facts
Patent No.
US 8,735,035
App. No.
13/355,117
Granted
May 27, 2014
Kind
B2
Abstract

An electrophotographic toner and a process for preparing the same. The electrophotographic toner includes a binder, a coloring agent, and a release agent. The binder includes two resins having different weight average molecular weights.

Claims (17)

1. An electrophotographic toner comprising a binder with two resins having different weight average molecular weights, a coloring agent, and a release agent, wherein:

the toner comprises a ratio of sulfur strength [S] to iron strength [Fe] ([S]/[Fe]) measured by fluorescence x-ray in the toner is about 5.0×10 −4 to about 5.0×10 −2 ;

the toner has, on a Gel Permeation Chromatography (GPC) chromatogram, a molecular weight distribution curve including a main peak in a region of about 8.0×10 3 g/mol to about 4.0×10 4 g/mol and a shoulder starting point in a region of equal to or greater than about 1.0×10 5 g/mol;

the toner has a weight average molecular weight of about 5.0×10 4 g/mol to about 4.0×10 5 g/mol and a Z average molecular weight of about 1.0×10 5 g/mol to about 6.0×10 6 g/mol;

an average circularity of the toner is about 0.960 to about 0.985;

a coefficient of variation (C.V) of the average circularity of the toner is about 1.5% to about 3.3%; and

the toner has a Brunauer, Emmett & Teller (BET) surface area of about 1.5 m 2 /g to about 3.5 m 2 /g.

2. The toner of claim 1 , wherein the toner further comprises about 1.0×10 3 ppm to about 1.0×10 4 ppm of iron (Fe) and about 1.0×10 3 ppm to about 5.0×10 3 ppm of silicon (Si).

3. The toner of claim 1 , wherein a volume average particle diameter of the toner is about 4.0 μm to about 9.0 μm.

4. The toner of claim 1 , wherein the toner has a GSDp value of about 1.0 to about 1.35 and a GSDv value of about 1.0 to about 1.3.

5. An electrophotographic toner comprising:

a primary binder agent comprising a low molecular weight resin latex having a weight average molecular weight of about 1.3×10 4 g/mol to about 3.0×10 4 g/mol and a high molecular weight resin latex having a weight average molecular weight of about 1.0×10 5 g/mol to about 5.0×10 6 g/mol;

a coloring agent to provide the toner with color;

a release agent adhered to the toner particles without being covalently bonded to the toner particles allowing the toner to be fused onto a final image receptor at a low fixation temperature; and

a charging control agent allowing the toner to be supported on a developing roller;

wherein the ratio of the low molecular weight resin to the high molecular weight resin is about 80:20 to about 85:15;

wherein the toner comprises a ratio of sulfur strength [S] to iron strength [Fe] ([S]/[Fe]) measured by fluorescence x-ray in the toner is about 5.0×10 −4 to about 5.0×10 −2 .

Assignments (6)
CONFIRMATORY ASSIGNMENT EFFECTIVE NOVEMBER 1, 2018 Recorded Oct 17, 2019
From: HP PRINTING KOREA CO., LTD.
To: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P.
Reel/Frame 050747/0080 →
CHANGE OF LEGAL ENTITY EFFECTIVE AUG. 31, 2018 Recorded Oct 16, 2019
From: HP PRINTING KOREA CO., LTD.
To: HP PRINTING KOREA CO., LTD.
Reel/Frame 050938/0139 →
CORRECTIVE ASSIGNMENT TO CORRECT THE DOCUMENTATION EVIDENCING THE CHANGE OF NAME PREVIOUSLY RECORDED ON REEL 047370 FRAME 0405. ASSIGNOR(S) HEREBY CONFIRMS THE CHANGE OF NAME. Recorded Nov 21, 2018
From: S-PRINTING SOLUTION CO., LTD.
To: HP PRINTING KOREA CO., LTD.
Reel/Frame 047769/0001 →
CHANGE OF NAME Recorded Aug 17, 2018
From: S-PRINTING SOLUTION CO., LTD.
To: HP PRINTING KOREA CO., LTD.
Reel/Frame 047370/0405 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 21, 2017
From: SAMSUNG ELECTRONICS CO., LTD
To: S-PRINTING SOLUTION CO., LTD.
Reel/Frame 041852/0125 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 23, 2012
From: LEE, JU-YEON; LEE, JUN-YOUNG; PANG, KYEONG; KOO, TAE-HOE; PARK, SU-BUM
To: SAMSUNG ELECTRONICS CO., LTD.
Reel/Frame 027714/0612 →