CN-114556229-B - Toner and method for producing the same

Abstract

A toner comprising toner particles comprising a binder resin and a crystalline polyester, characterized in that the binder resin comprises a polyester having a structure represented by formula (1). In the formula (1), R each independently represents hydrogen, methyl, or phenyl, A represents a polyester segment, B represents a polyester segment or any functional group selected from the group consisting of-R 1 OH、-R 1 COOH, a group of the formula (2), and-R 1 NH 2 , R 1 represents a single bond or an alkylene group having 1 to 4 carbon atoms, and the average number of repetition n is a number of 10 to 80.

Inventors

• GAO QIAOCHE
• SUGAHARA NOBUYOSHI
• Sano Nisi
• OOYAMA KAZUNARI
• NISHIMURA YU
• TAKENAKA KOHJI
• SHI SHANGHENG

Assignees

• 佳能株式会社

Dates

Publication Date

20260512

Application Date

20201007

Priority Date

20191007

Claims (6)

1. 1. A toner comprising toner particles including a binder resin and a crystalline polyester, wherein The binder resin comprises a polyester having a structure represented by the following formula (1): in the formula (1), R independently represents hydrogen, methyl or phenyl; a represents a polyester segment; B represents a polyester segment or is selected from the group consisting of-R 1 OH、-R 1 COOH, And-R 1 NH 2 , wherein R 1 represents a single bond or C 1-4 alkylene, and An average repetition number n of 10 to 80, and In the polyester having the structure represented by the formula (1), the content of the structure represented by the following formula (2) is 0.5 to 5.0 mass%: in formula (2), R each independently represents hydrogen, methyl, or phenyl, and n is an average value of the number of repetitions of the siloxane unit, and is 10 to 80, and The content of the polyester having the structure of formula (1) in the binder resin is 70 mass% or more.
2. 2. The toner according to claim 1, having a glass transition temperature of 45 ℃ to 60 ℃ during the second temperature increase measured by a differential scanning calorimeter.
3. 3. The toner according to claim 1 or 2, wherein Using Δh1 as an amount of heat absorption of the toner, measured by a differential scanning calorimeter, derived from the crystalline polyester during a first temperature increase, and ΔH2 is used as an amount of heat absorption of the toner measured by a differential scanning calorimeter and derived from the crystalline polyester during the second temperature rising process, ΔH2 is 1.0J/g to 10.0J/g, and The ratio of Δh2 to Δh1, i.e., Δh2/Δh1, is 0.50 to 1.00.
4. 4. The toner according to claim 1 or 2, wherein the content of the crystalline polyester in the toner is 2.0 parts by mass to 12.0 parts by mass with respect to 100 parts by mass of the binder resin.
5. 5. The toner according to claim 1 or 2, wherein each of the R is a methyl group.
6. 6. The toner according to claim 1 or 2, wherein the crystalline polyester is a polycondensate of an aliphatic diol having 6 to 18 carbons and an aliphatic dicarboxylic acid compound having 6 to 18 carbons.

Description

Toner and method for producing the same Technical Field The present invention relates to a toner for developing an electrostatic image used in, for example, an electrophotographic process and an electrostatic recording process. Background In recent years, full-color copying machines based on electrophotography have been widely spread and even started to be applied in the printing market. The printing market demands high speed, high image quality, and high productivity, while accommodating a wide range of media (types of paper). For example, even when the kind of paper is changed from thick paper to thin paper, uniform medium speed performance is required to enable printing to continue without changing the process speed or the heating temperature setting of the fixing unit according to the kind of paper. In order to accommodate uniform media velocity performance, the toner must support proper fusing over a wide fusing temperature range from low to high temperatures. In order to achieve sufficient fixing in a wide fixing temperature range, various studies have been made to improve low-temperature fixing ability by adding a sharply meltable crystalline polyester to a toner to cause the effect of a plasticizer as a binder resin. Various studies have been conducted to improve the problem of toner storage properties associated therewith. For example, patent document 1 discloses a toner having an improvement in low-temperature fixability caused by miscibility of a crystalline polyester resin in an amorphous polyester resin and having an improvement in toner storability caused by formation of a shell on the toner surface. On the other hand, in the printing market, the storage of images on printed materials is also considered important. In the case of forming an image from a toner exhibiting good low-temperature fixability, even if the toner exhibits good storability, the printed materials adhere to each other while being kept in a high-temperature environment due to softening of the fixed image. When the bonded printed material is peeled off, uneven gloss is generated, and the image undergoes peeling off. Patent document 2 discloses a toner which controls compatibility between crystalline polyester and amorphous polyester in order to improve both low-temperature fixability and image storability. [ Prior Art literature ] [ Patent literature ] Patent document 1 Japanese patent application laid-open No.2015-036723 [ Patent document 2] Japanese patent application laid-open No.2016-080934 Disclosure of Invention Problems to be solved by the invention The toner described in patent document 1 does exhibit good toner storage properties, however, image storage properties are not satisfactory due to softening after image fixation. The toner described in patent document 2 exhibits unsatisfactory low-temperature fixability when image storability is improved, because it has a constitution in which compatibility between amorphous polyester and crystalline polyester is suppressed. In addition, although good image storability is shown at a temperature of 30 ℃ and a humidity of 60% rh, during transportation of a printing material by, for example, a vehicle or a ship, high temperatures above the outside air temperature may occur depending on the loading position, and thus there is room for improvement in image storability. The present invention provides a toner exhibiting excellent low-temperature fixability and excellent image storability. Solution for solving the problem The present invention relates to a toner comprising toner particles including a binder resin and a crystalline polyester, wherein the binder resin comprises a polyester having a structure represented by the following formula (1). In the formula (1), R independently represents hydrogen, methyl or phenyl, A represents a polyester segment, B represents a polyester segment or is selected from the group consisting of-R 1OH、-R1 COOH, And-R 1NH2, wherein R 1 represents a single bond or an alkylene group of C 1-4, and the average number of repetitions n is from 10 to 80. ADVANTAGEOUS EFFECTS OF INVENTION The present invention can thus provide a toner exhibiting excellent low-temperature fixability and excellent image storability. Detailed Description The expressions "from XX to YY" and "XX to YY" showing numerical ranges are meant to include the numerical ranges of the lower and upper limits as endpoints unless specifically stated otherwise. When numerical ranges are set in segments, the upper and lower limits of the respective numerical ranges may be combined in any combination. The present inventors have conducted intensive studies with a view to achieving further improvement in low-temperature fixability and image storability. As a result, it was found that excellent low-temperature fixability and excellent image storability were obtained by using a toner comprising a crystalline polyester and a binder resin comprising a polyester having a structure represented by the