Resins for toners, toners, developers, image forming devices, and process cartridges

A technology of toner and resin, which is applied to the equipment, developer, and electrical recording process using charge patterns, etc., which can solve the problems of gloss change, time-consuming, and rapid melting of crystalline segments To avoid problems such as poor retention of pigment properties, and to achieve excellent pigment dispersibility

Active Publication Date: 2019-11-01
RICOH KK
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when the crystalline resin becomes exposed on the surface of the toner, there is a problem that the toner particles are aggregated due to the stress of stirring in the developing device, constituting the cause of white voids
[0008] These proposed technologies are all excellent in simultaneously satisfying low-temperature fixability and heat-resistant storage stability, but do not fundamentally remedy the softness attributed to the crystalline segment and cannot solve the problem with the mechanical durability of the toner related questions
[0009] In addition, as a major problem of toners using crystalline resins, there is a problem of scratch resistance of images
Since it takes time from when the toner melts on the fixing medium during heat fixing until the crystalline resin in the toner becomes recrystallized, the surface of the image cannot quickly recover the hardness
Therefore, there arises a problem that scratches are generated on the surface of the image or glossiness is changed due to contact and sliding friction with discharge rollers, conveying members, etc. in the discharge step after fixing
[0010] In addition, when using a resin in which a crystalline segment and an amorphous segment are chemically bonded to each other, depending on the composition and bond used, the rapid meltability of the crystalline segment may not be well maintained
Also, there is a problem that pigments tend to concentrate unevenly in resins like crystalline resins

Method used

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  • Resins for toners, toners, developers, image forming devices, and process cartridges
  • Resins for toners, toners, developers, image forming devices, and process cartridges
  • Resins for toners, toners, developers, image forming devices, and process cartridges

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0367] In the preparation of the aqueous medium phase, celluloses may be used as a dispersant. Examples of the celluloses include methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and sodium carboxymethylcellulose.

[0368] --Emulsion or dispersion preparation steps--

[0369] The emulsion or dispersion liquid preparation step is not particularly limited, and an appropriate step can be selected according to the purpose as long as it is mixing the solution or dispersion liquid (toner material phase) of the toner material with the aqueous medium , and emulsifying or dispersing the former to prepare an emulsion or a dispersion.

[0370] The emulsification or dispersion method is not particularly limited, and an appropriate method can be selected according to purposes. For example, emulsification or dispersion can be performed with a known disperser. Examples of the disperser include low-speed shear dispersers, and high-speed shear dispersers.

[0371] The usage ...

Embodiment

[0479] Embodiments of the present invention will be explained below. However, the present invention is by no means limited to the following Examples. "Parts" means "parts by mass", unless otherwise expressly specified. "%" means "% mass", unless expressly stated otherwise.

[0480]

[0481] The glass transition temperature and melting point of the resin were measured with a DSC system (differential scanning calorimeter) ("DSC-60" manufactured by Shimadzu Corporation).

[0482] Specifically, according to the following procedure, the maximum endothermic peak temperature among the endothermic peak temperatures of the target sample was measured as the melting point of the resin.

[0483] From the obtained DSC curve, the DSC curve of the second temperature rise was selected with the analysis program "Endothermic Peak Temperature (Endothermic Peak Temperature)" of the DSC-60 system, and the endothermic peak in the second temperature rise of the target sample was obtained.

[04...

manufacture Embodiment 1-1

[0500]

[0501] Into a 5 L four-necked flask equipped with a nitrogen gas introduction tube, a dehydration tube, a stirrer, and a thermocouple, propylene glycol (1,2-propanediol) and 1,3-propanediol ( Propylene glycol / 1,3-propanediol in a ratio of 95 / 5 (by mole)) with dimethyl terephthalate as dicarboxylic acid (OH group (OH group of diol ) to COOH groups (COOH groups of terephthalic acid) in a molar ratio (OH / COOH) of 1.2), and titanium tetraisopropoxide in an amount of 300 ppm relative to the mass of the charged material. The material was reacted while letting methanol flow out, and the reaction was maintained until finally the material was warmed to 230° C. and the resin acid value became 5 mgKOH / g or less. After that, they were reacted under a reduced pressure of 20 mmHg to 30 mmHg for 4 hours, thereby obtaining [amorphous segment A1], which is a linear polyester resin.

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PUM

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Abstract

Provided is a resin for a toner, which is a copolymer including a crystalline segment, and having a maximum elastic stress value at 100° C. (ES100) of 1,000 Pa or less, and a maximum elastic stress value at 70° C. (ES70) of 1,000 Pa or greater when the temperature is lowered from 100° C. to 70° C., where the maximum elastic stress values are measured according to a large amplitude oscillatory shear procedure.

Description

technical field [0001] The present invention relates to a resin for toner, a toner, a developer, an image forming apparatus, and a process cartridge. Background technique [0002] Conventionally, a latent image formed electrically or magnetically in an electrophotographic image forming apparatus or the like is developed with an electrophotographic toner (hereinafter may be simply referred to as "toner"). In electrophotography, for example, an electrostatic charge image (latent image) is formed on a photoreceptor, and then developed with a toner, thereby forming a toner image. Typically, the toner image is transferred onto a transfer material such as paper, and then fixed on the transfer material such as paper. In the fixing step of fixing the toner image on the transfer paper, thermal fixing techniques such as heating roller fixing technique and heating belt fixing technique are generally used due to their high energy efficiency. [0003] Recently, demands for faster and m...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G03G9/087
CPCG03G9/0821G03G9/08764G03G9/08788G03G9/08795G03G9/08797G03G9/087G03G15/08
Inventor 宫明杏实朝比奈大辅泽田豊志山下裕士杉本强中山慎也千叶晋关口圣之
Owner RICOH KK
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