JP2001305778A - Toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner excellent in blocking resistance during storage of the toner and excellent in low temperature fixing property. SOLUTION: The toner having improved blocking property during storage of the toner and having good low temperature fixing property is obtained by incorporating a styrene resin and 0.5 to 10 wt.% of 12-hydroxystearic acid into the binder resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used for developing an electrostatic image or a magnetic latent image in electrophotography, electrostatic recording, electrostatic printing, and the like. It relates to a toner having excellent properties.

[0002]

2. Description of the Related Art In a typical image forming process by an electrophotographic method or an electrostatic printing method, a photoconductive insulating layer is uniformly charged, the insulating layer is exposed, and then a charge on an exposed portion is obtained. To form an electric latent image by dissipating the toner, and a developing step of visualizing the latent image by adhering a finely charged toner to the latent image, and transferring the obtained visible image to a transfer material such as transfer paper. It comprises a transfer step of transferring and a fixing step of permanently fixing by heating or pressing.

[0003] The toner used in such an electrophotographic method or the electrostatic printing method is required to have various performances in each of the above steps. For example, the toner is required to have blocking resistance so that the toner does not block during storage in a copying machine and a printer. It must maintain a charge amount suitable for copiers and printers without being affected by the environment.

[0004] In the fixing step by the heat roller fixing method, non-offset properties in which molten toner does not adhere to the heat roller and low-temperature fixability of toner to paper must be good. In recent years, as the energy saving and the speeding up of copiers and printers have been rapidly progressing, the requirements for the fixing characteristics of toner have become stricter year by year, and various studies have been made.

[0005] For example, Japanese Patent Application Laid-Open No. 62-195683 describes that a low molecular wax is added to prevent hot offset (adhesion of a molten toner to a heat roller).

[0006]

However, in this method, although hot offset can be suppressed, there is a problem that it is difficult to improve low-temperature fixability.

The present invention has been made to solve this problem, and an object of the present invention is to provide a toner having excellent low-temperature fixability.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies with the aim of solving the above problems, and as a result, the inclusion of 12-hydroxystearic acid in the toner improves the low-temperature fixability of the toner. Find things,
The present invention has been completed.

That is, the present invention relates to a toner containing 12-hydroxystearic acid.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the content of 12-hydroxystearic acid in a toner is 0.5 to 0.5.
It is preferably in the range of 10% by mass. This is because when the content is 0.5% by mass or more, excellent low-temperature fixability tends to be imparted to the obtained toner. This is because the blocking property tends to be good. More preferably, it is in the range of 0.5 to 5% by mass, and still more preferably 0.5 to 3% by mass.

The method of adding 12-hydroxystearic acid to the toner is not particularly limited. When kneading the binder resin and other materials constituting the toner, a predetermined amount is put into an extruder or the like and kneaded. do it.

Examples of the binder resin used in the toner of the present invention include a polyester resin and a styrene- (meth) acrylic resin, and a styrene resin is preferable. This is because, when a styrene resin is used as the binder resin, even when 12-hydroxystearic acid is added, the Tg of the toner tends to be small and the blocking resistance of the toner tends not to be impaired.

In the present invention, the styrene resin preferably used as a binder resin comprises a styrene monomer or a styrene monomer and a (meth) acrylate monomer as essential components. Is what you do.

Examples of the styrene monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn -Butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-densylstyrene, pn-dodecylstyrene, p-phenyl Examples thereof include styrene and 3,4-dicyclostyrene. Examples of the (meth) acrylate-based monomer include methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylic acid. n-butyl, isobutyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) a Mention may be made of acrylic acid stearyl. These monomers can be appropriately selected and used as needed, and among them, styrene and n-
Butyl (meth) acrylate is preferred.

[0015] Further, monomers other than the above-mentioned styrene-based monomer and (meth) acrylate-based monomer can also be used as constituent components of the styrene-based resin, if necessary.

For example, unsaturated dicarboxylic acid diesters such as dimethyl maleate, diethyl maleate, dibutyl maleate, dimethyl fumarate, diethyl fumarate, dibutyl fumarate and the like unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and cinnamic acid Acids, maleic acid, fumaric acid, unsaturated dicarboxylic acids such as itaconic acid, monomethyl maleate,
Carboxylic acid-containing vinyl monomers such as monoesters of unsaturated dicarboxylic acids such as monoethyl maleate, monobutyl maleate, monomethyl fumarate, monoethyl fumarate and monobutyl fumarate can be mentioned.

The copolymerization ratio of the monomer which is a component of the styrene resin is not particularly limited, but the binder resin obtained preferably has a Tg (glass transition temperature) of 40 to 70 ° C.
, More preferably in the range of 50 to 65 ° C. When the Tg of the binder resin for toner is set to 40 ° C. or higher, the obtained toner has good blocking resistance, and when the Tg is set to 70 ° C. or lower, the fixability of the obtained toner tends to be improved. That's why. In addition, Tg can be measured by a method such as a DSC method.

The method for producing the styrene resin suitably used as the binder resin of the toner of the present invention is not particularly limited. For example, from the viewpoint of the odor of the obtained toner, the remaining monomer and solvent Can be produced by a method in which the content of the compound in the binder resin is 500 ppm or less. For example, it can be produced by an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, or a solution polymerization method, and can also be produced by mixing resins produced by these various polymerization methods.

The toner of the present invention has a Tg of 40 to 70 ° C.
Is preferably within the range. This is because when the Tg of the toner is 40 ° C. or more, the obtained toner tends to have good blocking resistance, and when the Tg is 70 ° C. or less, the fixability of the obtained toner tends to be good. . Preferably it is in the range of 45 to 70C, more preferably in the range of 50 to 65C.

The toner of the present invention has a fixing temperature lower limit of about 130 ° C. and is excellent in low-temperature fixing property, a fixing temperature upper limit of 220 ° C. or more, is excellent in non-hot offset property, and has a wide fixing temperature range. .

The toner of the present invention is magnetic, non-magnetic, one-component,
It can be widely used regardless of the type of component. Further, for the purpose of imparting non-offset properties, a known wax or the like can be further appropriately added as an additive. Although the type of wax is not limited, a polyolefin wax, particularly a low molecular weight polyolefin wax, is preferred.
The amount of the wax added is preferably in the range of 0.5 to 5% by mass based on the toner. This means that the amount of wax added is 0.
When the content is 5% by mass or more, the non-offset property of the obtained toner tends to be improved, and when the content is 5% by mass or less, the fluidity of the obtained toner tends to be good. More preferably, 1 to 3% by mass
Range.

In the toner of the present invention, in addition to the wax described above,
If necessary, a colorant, a charge control agent, a magnetic powder, and the like can be added.

The toner of the present invention can be prepared, for example, by mixing a mixture of 12-hydroxystearic acid and the above-mentioned binder resin and additives with a kneader such as a twin-screw extruder at a temperature of 80 to 200.
After kneading in the range of about ° C, it can be manufactured by finely pulverizing and classifying using a jet mill or the like.
The obtained toner particles preferably have an average particle size of about 5 to 15 μm.

[0024]

The present invention will be described below in detail with reference to examples.

The fixing temperature range, blocking resistance, and glass transition temperature (Tg) were evaluated by the following methods.

(1) Fixing Temperature Range An unfixed image obtained by a commercial copying machine PREMAGE 251 (manufactured by TOSHIBA) was evaluated using a fixing tester with variable roller temperature. The fixed image obtained under the conditions of a process speed of a fixing tester of 50 mm / sec was rubbed nine times with a sand eraser (JIS 512), and the image density before and after the rubbing was measured with a Macbeth densitometer. 20 drops in concentration
% Was defined as the lower limit of the fixing temperature range, and the lowest temperature at which hot offset occurred was defined as the upper limit of the fixing temperature range.

From the lower limit of the fixing temperature range, the low-temperature fixability of the toner was determined as follows. (Lower limit of fixing temperature range)-Less than 145 ° C: very good low-temperature fixability-145 ° C or more and less than 155 ° C: excellent in low-temperature fixability-155 ° C or more and less than 165 ° C: Low-temperature fixability is slightly inferior but practical 165 ° C or higher: poor in low-temperature fixability

(2) Blocking Resistance The toner was placed in a glass bottle and left at 50 ° C. for 16 hours, and the state of blocking of the toner was visually evaluated.

(3) Glass transition temperature After the sample was heated to 100 ° C., the temperature was raised at a rate of 10 /
It is shown by the shoulder value measured under the condition of min.

(Synthesis Example 1) Deionization obtained by dissolving 75 parts by mass of styrene, 25 parts by mass of n-butyl acrylate, 0.48 parts by mass of divinylbenzene, and 3 parts by mass of benzoyl peroxide in 0.1 part by mass of partially saponified polyvinyl alcohol. After adding to 200 parts by mass of water and raising the temperature to 85 ° C.,
After a period of time, the polymerization was completed. Next, the mixture was filtered, washed with water, and dried to obtain a styrene- (meth) acrylic resin (A). The Tg of the obtained resin (A) was 54 ° C.

Synthesis Example 2 64 parts by mass of styrene, 16 parts by mass of n-butyl acrylate, 2,2 bis (4,4-di-t
0.032 parts by mass of -butylperoxycyclohexyl) propane (“PARCADOX 12” manufactured by Kayaku Akzo Co., Ltd.) was mixed and added to 200 parts by mass of deionized water in which 0.2 parts by mass of partially saponified polyvinyl alcohol was dissolved, After the temperature was raised to 130 ° C., suspension polymerization was performed for 2.5 hours, and cooled to 40 ° C. Then, 16 parts by mass of styrene, 4 parts by mass of n-butyl acrylate, 4 parts by mass of benzoyl peroxide, t
1 part by weight of -butyl peroxybenzoate was charged into the dispersion, the temperature was raised to 130 ° C., and suspension polymerization was performed for 2 hours.
The polymerization was completed. Thereafter, the resultant was separated by filtration, washed with water and dried to obtain a styrene- (meth) acrylic resin (B). The Tg of the obtained resin (B) was 62 ° C.

(Example 1) 92.5 parts by mass of resin (A), 12
-0.5 parts by mass of hydroxystearic acid, 4 parts by mass of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), 1 part by mass of a charge control agent (Bontron S-34 manufactured by Orient Chemical Co., Ltd.), polypropylene wax (manufactured by Sanyo Chemical Co., Ltd.) 660P) 2 parts by mass were melt-kneaded at 190 ° C. using a twin-screw extruder.
Next, it was pulverized by a jet mill pulverizer and classified to obtain a toner having an average particle diameter of 10 μm and a Tg of 57 ° C. The blocking resistance of the obtained toner was good. The fixing temperature range of the obtained toner was 160 to 240 ° C.

(Example 2) 92 parts by mass of resin (A), 1 part by mass of 12-hydroxystearic acid, 4 parts by mass of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), a charge control agent (Bontron S- manufactured by Orient Chemical Co., Ltd.) 34) 1 part by mass and 2 parts by mass of a polypropylene wax (660P manufactured by Sanyo Kasei) were melt-kneaded at 190 ° C. using a twin-screw extruder. Then
Pulverize with a jet mill pulverizer, classify and average particle size 10
μm and a toner having a Tg of 57 ° C. were obtained. The blocking resistance of the obtained toner was good. The fixing temperature range of the obtained toner was 155 to 240 ° C.

(Example 3) 90 parts by mass of resin (A), 3 parts by mass of 12-hydroxystearic acid, 4 parts by mass of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), a charge control agent (Bontron S- manufactured by Orient Chemical Co., Ltd.) 34) 1 part by mass and 2 parts by mass of a polypropylene wax (660P manufactured by Sanyo Kasei) were melt-kneaded at 190 ° C. using a twin-screw extruder. Then
Pulverize with a jet mill pulverizer, classify and average particle size 10
A toner having a μm of Tg of 56 ° C. was obtained. The blocking resistance of the obtained toner was good. The fixing temperature range of the obtained toner was 145 to 240 ° C.

Example 4 88 parts by mass of resin (A), 5 parts by mass of 12-hydroxystearic acid, 4 parts by mass of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), a charge control agent (Bontron S- manufactured by Orient Chemical Co., Ltd.) 34) 1 part by mass and 2 parts by mass of a polypropylene wax (660P manufactured by Sanyo Kasei) were melt-kneaded at 190 ° C. using a twin-screw extruder. Then
Pulverize with a jet mill pulverizer, classify and average particle size 10
A toner having a μm and a Tg of 54 ° C. was obtained. Although very slight blocking was confirmed in the obtained toner, it was at a usable level. The fixing temperature range of the obtained toner is 140
２４０240 ° C.

(Example 5) 90 parts by mass of resin (A), 5 parts by mass of 12-hydroxystearic acid, 4 parts by mass of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), a charge control agent (Bontron S- manufactured by Orient Chemical Co., Ltd.) 34) One part by mass was melt-kneaded at 190 ° C. using a twin-screw extruder. Then, it is pulverized by a jet mill pulverizer, classified and average particle diameter 10 μm,
A toner having a Tg of 54 ° C. was obtained. Although the obtained toner was confirmed to have very slight blocking, it was at a usable level. The fixing temperature range of the obtained toner is 140 to 23.
It was 0 ° C.

(Example 6) 84 parts by mass of resin (A), 9 parts by mass of 12-hydroxystearic acid, 4 parts by mass of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), and a charge control agent (Bontron S- manufactured by Orient Chemical Co., Ltd.) 34) 1 part by mass and 2 parts by mass of a polypropylene wax (660P manufactured by Sanyo Chemical Industries) were melt-kneaded at 190 ° C. using a twin-screw extruder. Then
Pulverize with a jet mill pulverizer, classify and average particle size 10
A toner having a μm and a Tg of 53 ° C. was obtained. Although the obtained toner was slightly blocked, it was at a usable level. The fixing temperature range of the obtained toner is 135 to 240 ° C.
Met.

(Example 7) 78 parts by mass of resin (A), 11 parts by mass of 12-hydroxystearic acid, 4 parts by mass of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), a charge control agent (Bontron S- manufactured by Orient Chemical Co., Ltd.) 34) 1 part by mass and 2 parts by mass of a polypropylene wax (660P manufactured by Sanyo Chemical Industries, Ltd.)
The mixture was melt-kneaded at 190 ° C. using a twin-screw extruder. Next, it was pulverized by a jet mill pulverizer and classified to obtain a toner having an average particle diameter of 10 μm and a Tg of 51 ° C. The resulting toner showed severe blocking, but was barely usable. The fixing temperature range of the obtained toner is 1
35-220 ° C.

(Example 8) 92 parts by mass of resin (B), 1 part by mass of 12-hydroxystearic acid, 4 parts by mass of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), a charge control agent (Bontron S- manufactured by Orient Chemical Company) 34) 1 part by mass and 2 parts by mass of polypropylene wax (660P manufactured by Sanyo Chemical Industries) were melt-kneaded at 170 ° C. using a twin-screw extruder. Then
Pulverize with a jet mill pulverizer, classify and average particle size 10
A toner having a μm and a Tg of 61 ° C. was obtained. The blocking resistance of the obtained toner was good. The fixing temperature range of the obtained toner was 150 to 240 ° C.

(Example 9) 90 parts by mass of resin (B), 3 parts by mass of 12-hydroxystearic acid, 4 parts by mass of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), a charge control agent (Bontron S- manufactured by Orient Chemical Co., Ltd.) 34) 1 part by mass and 2 parts by mass of polypropylene wax (660P manufactured by Sanyo Chemical Industries) were melt-kneaded at 170 ° C. using a twin-screw extruder. Then
Pulverize with a jet mill pulverizer, classify and average particle size 10
A toner having a μm of Tg of 60 ° C. was obtained. The blocking resistance of the obtained toner was good. The fixing temperature range of the obtained toner was 140 to 240 ° C.

Example 10 88 parts by mass of resin (B), 12-
5 parts by mass of hydroxystearic acid, 4 parts by mass of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), 1 part by mass of a charge control agent (Bontron S-34 manufactured by Orient Chemical Co., Ltd.), 2 parts by mass of polypropylene wax (660P manufactured by Sanyo Chemical Co., Ltd.) To
Melt kneading was performed at 170 ° C. using a twin screw extruder. Next, it was pulverized by a jet mill pulverizer and classified to obtain a toner having an average particle diameter of 10 μm and a Tg of 58 ° C. Although the obtained toner was confirmed to have very slight blocking, it was at a usable level. The fixing temperature range of the obtained toner is 1
35-240 ° C.

(Comparative Example 1) 93 parts by mass of resin (A), 4 parts by mass of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), 1 part by mass of charge control agent (Bontron S-34 manufactured by Orient Chemical Co., Ltd.)
2 parts by mass of a polypropylene wax (660P manufactured by Sanyo Chemical Co., Ltd.) was melt-kneaded at 190 ° C. using a twin-screw extruder. Next, it was pulverized by a jet mill pulverizer and classified to obtain a toner having an average particle diameter of 10 μm and a Tg of 57 ° C. The blocking resistance of the obtained toner was good. The fixing temperature range of the obtained toner was 175 to 240 ° C.

(Comparative Example 2) 93 parts by weight of resin (B), 4 parts by weight of carbon black (# 40 manufactured by Mitsubishi Chemical Corporation), 1 part by weight of a charge control agent (Bontron S-34 manufactured by Orient Chemical Company),
Two parts by mass of a polypropylene wax (660P, manufactured by Sanyo Chemical Co., Ltd.) were melt-kneaded at 170 ° C. using a twin-screw extruder. Next, it was pulverized by a jet mill pulverizer and classified to obtain a toner having an average particle diameter of 10 μm and a Tg of 64 ° C. The blocking resistance of the obtained toner was good. The fixing temperature range of the obtained toner was 170 to 240 ° C.

[0044]

As is apparent from the above description, according to the present invention, a toner excellent in low-temperature fixability can be provided, which is extremely useful industrially.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masaru Sugiura 2-1-1, Ushikawa-dori, Toyohashi-shi, Aichi F-term in Mitsubishi Rayon Co., Ltd. Toyohashi Works (reference) 2H005 AA01 AA06 CA03 CA30 DA06 DA10 FB02

Claims (3)

[Claims] 1. A toner comprising 12-hydroxystearic acid. 2. The method according to claim 1, wherein the content of 12-hydroxystearic acid is 0.5 to 10% by mass.
The toner described in the above. 3. The toner according to claim 1, wherein a styrene resin is contained as the binder resin.