IP Library › Granted Patent US 12,019,394
Granted Patent B2
US 12,019,394 · App. 17/459,134 · Granted Jun 25, 2024

Toner, developer, toner set, toner receiving unit, image forming apparatus, and image forming method

Inventors: Toyoshi Sawada (Shizuoka, JP); Kazumi Suzuki (Shizuoka, JP); Katsunori Kurose (Shizuoka, JP); Akihiro Kaneko (Kanagawa, JP); Motoshi Iizuka (Shizuoka, JP)
Assignee: Ricoh Company, Ltd.
G03G9/09733G03G9/08704G03G15/201
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Quick Facts
Patent No.
US 12,019,394
App. No.
17/459,134
Granted
Jun 25, 2024
Kind
B2
Abstract

A toner includes polyolefin and has an exothermic peak in a range from 40° C. to 70° C. in a cooling process of the polyolefin by the DSC after a first heating process of the polyolefin by DSC. The polyolefin does not have an exothermic peak in the cooling process of the polyolefin by the DSC after the first heating process of the polyolefin by the DSC, and has an exothermic peak in a range from 0° C. to 30° C. in a second heating process of the polyolefin by the DSC.

Claims (38)

1. A toner comprising polyolefin, wherein

the toner has an exothermic peak in a range from 40° C. to 70° C. in a cooling process of the polyolefin by differential scanning calorimetry (DSC) after a first heating process of the polyolefin by the DSC, and

the polyolefin does not have an exothermic peak in the cooling process of the polyolefin by the DSC after the first heating process of the polyolefin by the DSC, and has an exothermic peak in a range from 0° C. to 30° C. in a second heating process of the polyolefin by the DSC,

wherein

the polyolefin is a maleic acid modified polyolefin having at least a polypropylene block in a main chain and having a melting point within a range from 65° C. to 90° C.;

a maleic acid modification rate of the maleic acid modified polyolefin with a polypropylene block in a main chain is within a range from 0.5 wt. % to 8.0 wt. %; and

a content of the maleic acid modified polyolefin with a polpropylene block in a main chain in the toner is within a range from 2.1 wt. % to 30.0 wt. % further comprising at least one component selected from the group consisting of a release agent, a colorant, a charge control agent, an external additive, a fluidity improver, a cleanability improver and a magnetic material.

2. The toner according to claim 1 , wherein

a weight average molecular weight of the maleic acid modified polyolefin is within a range from 60000 to 100000.

3. The toner according to claim 1 , wherein

the toner is transparent or white.

4. A developer comprising:

the toner according to claim 1 ; and

a carrier.

5. A toner set comprising:

a color toner containing a bonding resin and a colorant; and

the toner according to claim 1 .

6. A toner receiving unit receiving the toner according to claim 1 .

7. An image forming apparatus comprising:

an electrostatic latent image carrier;

an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier;

a developing unit that develops the electrostatic latent image using a toner to form a toner image;

a transfer unit that transfers the toner image to a recording medium; and

a fixing unit that fixes an image transferred to the recording medium, wherein

the toner is the toner according to claim 1 .

8. The image forming apparatus according to claim 7 , wherein the toner image is formed on a side nearest to the recording medium.

9. The image forming apparatus according to claim 7 , wherein

the recording medium is a plastic film.

10. An image forming method comprising:

forming an electrostatic latent image on an electrostatic latent image carrier;

developing the electrostatic latent image using a toner to form a toner image;

transferring the toner image to a recording medium; and

fixing an image transferred to the recording medium, wherein

the toner is the toner according to claim 1 .

11. The toner according to claim 1 , further comprising a polyester resin.

12. The toner according to claim 11 , wherein said polyester resin has a glass transition temperature within a range from 50° C. to 75° C.

13. The toner according to claim 11 , further comprising at least one resin selected from the group consisting of styrene, poly-α-styrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-methyl chloroacrylate copolymer, and styrene-acrylonitrile-acrylate copolymer, epoxy resin, vinyl chloride resin, rosin modified maleic acid resin, phenolic resin polyethylene resin, polypropylene resin, petroleum resin, polyurethane resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, and polyvinyl butyrate resin.

14. The toner according to claim 1 , further comprising at least one release agent selected from the group consisting of liquid paraffin, microcrystalline wax, natural paraffin, synthetic paraffin, polyolefin wax, and partial oxides, fluorides, and chlorides thereof; beef fat, fish oil; coconut oil, soybean oil, rapeseed oil, rice bran wax, camauba wax; montan wax, higher aliphatic acids, aliphatic acid amide, aliphatic acid bisamide; zinc stearate, calcium stearate, magnesium stearate, aluminum stearate, zinc oleate, zinc palmitate, magnesium palmitate, zinc myristate, zinc laurate, zinc behenate, aliphatic acid esters, and polyvinylidene fluoride.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 27, 2021
From: SAWADA, TOYOSHI; SUZUKI, KAZUMI; KUROSE, KATSUNORI; KANEKO, AKIHIRO; IIZUKA, MOTOSHI
To: RICOH COMPANY, LTD.
Reel/Frame 057310/0348 →
Priority Claims (1)
JP 2020-146620 · Sep 1, 2020 · national
Continuity (1)
Related Publication 20220066344A1 · Mar 3, 2022