JPH025071A - Heat fixing dry process toner - Google Patents

Abstract

PURPOSE:To suppress the generation of a high-temp. offset and to allow efficient fixing at a high speed by incorporating a resin contg. a specific acrylate monomer as a polymer constituting unit into the toner. CONSTITUTION:The resin which consists essentially of a binder resin and coloring agent and contains the monomer expressed by formula I as the polymer constituting unit is incorporated into the toner. In formula I, R denotes a hydrogen atom or methyl group; (n) denotes 15 or larger integer. Namely, the resin contg. the monomer unit expressed by formula I consists of the monomer having a long chain alkyl group and, therefore, exhibits the behavior of the crystal body and since the long chain alkyl group is of >=15 (n), the resin exhibits the sharp melting behavior at the temp. above ordinary temp., thus constituting the binder resin material for low-temp. fixing. The high release property is obtd. in this way and the generation of the offset is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electrostatic image developing toner used for developing an electrostatic latent image in electrophotography, electrostatic recording, etc. Related to dry toner for heat fixing.

Conventional technology In electrophotography, an electrostatic latent image formed on a photoreceptor is usually developed with a resin powder containing a pigment, and the resulting visible image is transferred onto a transfer paper using heat, pressure, or a combination thereof. etc.,
High efficiency is required, and from these points of view, the hot roll fixing method is often adopted.

In the hot roll fixing method, in order to perform high-speed fixing with low power consumption, it is effective to lower the softening point and melt viscosity of the toner binding material. When lowering the softening point of the binder polymer used as a material, toner fluidity tends to decrease due to caking during storage, while lowering the melt viscosity
Due to the Off-Sera 1 phenomenon, etc., stains on images are likely to occur.

For this reason, it is necessary to install a device that supplies a release agent such as silicone oil to the heated roll to prevent the occurrence of offset, or to increase the glass transition point of the binder polymer, or to add inorganic fine powder such as silica to the toner surface. A method has been proposed for using it as an external additive to prevent caking during storage.

Problems to be Solved by the Invention However, in order to supply the cylinder oil to the heat roll, a supply mechanism is required, which complicates the apparatus and leads to losses. Maintenance such as oil replenishment is also required.

Further, when the glass transition point of the binder polymer is set high, the softening temperature becomes high, which tends to make low-temperature fixing difficult.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a dry type 1-ner which can perform fixing at high speed and efficiently.

Another object of the present invention is to provide a dry toner that is less prone to caking during storage.

Still another object of the present invention is to provide a dry toner that is less likely to cause high temperature offset.

Means for Solving the Problems The present invention provides a heat fixing dry toner containing a binder resin and a colorant as main components, which contains a resin containing a monomer represented by the following general formula (1) as a polymer constitutional unit. It is characterized by

Hard Cl-12=c (I
>000-(CH) -CH3 n (wherein, R represents a hydrogen atom or a methyl group, and r) is 1
(represents an integer of 5 or more) The resin containing a monomer unit represented by the above general formula (I> as a polymer constitutional unit) may be a homopolymer of the monomer represented by the above general formula (1), or It may also be a copolymer. In the case of a copolymer, the copolymerization ratio of the monomers represented by general formula (I) is 0.
．． It needs to be 5% or more, preferably 2% or more.

In the present invention, the resin containing the monomer unit represented by the above general formula (I) as a polymer constitutional unit has an average molecular weight of 1×
10 to 5×105 is preferable, and the crow transition point is 30
Preferably it is ~80°C.

Examples of the monomer represented by the general formula (I>) in the present invention include stearyl methacrylate, stearyl acrylate, hexadecyl acrylate, hexadecyl methacrylate, and hebutadecyl acrylate.

In addition, examples of monomers copolymerizable with these monomers include styrenes such as styrene and p-chlorostyrene;
Vinylnaphthalene, such as vinyl chloride, vinyl bromide,
Vinyl esters such as vinyl fluoride, vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate, for example,
Methyl allicrylate, ethyl acrylate, acrylic 1jl
n-butyl, i-butyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, etc. Methylene aliphatic carboxylic acid esters, acrylonitrile, methacrylonitrile, acrylamide, vinyl ethers such as vinyl ethyl ether, vinyl isobutyl ether, vinyl ethyl ether, vinyl ethers such as vinyl methyl ketone, vinyl hexyl ketone, etc. Examples include vinyl monomers such as N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone.

In the dry toner of the present invention, the resin containing the monomer unit represented by the above general formula (I) as a polymer constitutional unit is
It can be used in combination with other resins commonly used as binder resins. Other resins that can be used in combination include homopolymers or copolymers of the monomers listed above as copolymerizable monomers and polyester resins. These resins account for 99%, preferably 97%, of the total resin mixture.
% can be mixed.

Further, there are no particular limitations on the colorant for the toner as long as it is a known colorant, such as carbon black, oil black, graphite, nigrosine dye, aniline blue, chrome yellow, ultramarine blue DuPont oillet, etc.
Quinoline yellow methylene blue chloride, cyanine blue malachite green oxalate, lamp black, rose bengal, C,1, pigment red d
8:1, C,1, Pigment Red 122, C,1
, Pigment Red 57:1 , C,1, Pigment Yellow 97 , C,1, Pigment Yellow 12
, C,1, Pigment Blue 15:1, C,1, Pigment Blue 15:3, etc. can be exemplified as representative examples.

In addition to the binder resin and colorant, the toner particles may contain, for example,
As a mold release agent, polyethylene wax, polypropylene wax, etc. may be used in combination, and magnetic powder may also be added.

Conventionally, high-molecular-weight resins have been used as binding materials for working toners, and pigments such as Chikarabon black and charge control agents are mixed into the resins using a kneading method, and the toners are made by finely pulverizing the resin. In this case, the binder resin holds and fixes elemental materials such as pigments, and for fixing, the toner is softened by heat, pressure, or a combination of both, giving it the ability to adhere along the unevenness of the paper surface. are doing. It is preferable that the softening behavior of the toner changes rapidly with respect to temperature, and even if the binding resin is easily softened, the softening behavior at low temperatures poses a problem in caking property during storage.

Since the resin containing the monomer unit represented by the general formula (I) used in the present invention is composed of a monomer having a long-chain alkyl group, it exhibits crystalline behavior, and the long-chain alkyl group , n is 15 or more, it exhibits sharp melting behavior at temperatures above room temperature, and is therefore useful as a low-temperature, low-wear binder resin material. Furthermore, since it has a long-chain alkyl group, it exhibits high mold releasability and is also effective in preventing the occurrence of offset.

The dry toner of the present invention can be used either as a one-component developer or as a two-component developer, and since it has the physical property of having a low viscosity when melted, it can be used not only for hot roll fixing but also for flash fixing. It can also be used in various known thermal tube methods such as the method, radiant method, or oven method.

Example The present invention will be explained below with reference to Examples.

Example 1 Styrene/n-butyl meth 80 parts acrylate copolymer (Tg=63°C, Mw=200,000, Mn=7.
000) Stearyl polymethacrylate 10 parts (melting point (DSC method); 30°C, Hw=12.000°Hn=6.000) Carbon black (Cabot 10 parts BPL) After kneading the above mixture with a Banbury mixer,
A toner with an average particle size of 11 μm was obtained by pulverization (Toner A).
).

A toner was obtained in the same manner as above except that polystearyl methacrylate was not used in the above composition (Toner B).

Each of these toners was mixed with iron powder coated with polymethyl methacrylate, and fixing tests 1 to 1 were performed using a copying machine (modified FX3500, manufactured by Fuji Xerox IQ). The minimum fixing temperature by rubbing with a cloth is
140°C1 Toner B was heated to 155°C. Also, high temperature offset did not occur for toner A even at temperatures above 220°C, but for toner B at temperatures above 200°C.
It occurred in There was very little caking in both cases when left at 40°C for 24 hours.

Example 2 Bisphenol A-Fumaric acid 85 parts Polyester (Tg-60°CX Mw=6e,000, ) I
n=4,000) Stearyl polyacrylate
5 parts (melting point (DSC method): 41°C, Hw = 9,00
0°Hn=5,000) Carbon black (Cahot 10 parts BPL) Using the above mixture, a toner having an average particle size of 11 μm was obtained in the same manner as in Example 1 (Toner C).

A toner was obtained in the same manner as described above except that stearyl polyacmonolate was not used in the above composition (Toner D).

Using these toners, a fixing test was conducted in the same manner as in Example 1. The lowest fixing temperature by rubbing with a cloth was 125°C for Toner C and 145°C for Toner D. Also, high temperature offset is for toner C.
It occurred at 200°C, and for Toner D it occurred at 180°C. Caking hardly occurred in both cases when left at 40°C for 24 hours.

Effects of the Invention As is clear from the above comparison, the dry toner of the present invention contains a resin containing the monomer represented by the above general formula (I) as a polymer constituent unit, so high temperature offset does not occur. It is difficult to fix, it can be fixed efficiently at high speed, and
It has an excellent effect of being less likely to cause caking during storage.

Patent applicant Fuji Xerox Co., Ltd. Agent
Patent attorney Tsuyoshi Watanabe

Claims (1)

[Claims] (1) A heat-fixable dry toner containing a binder resin and a colorant as main components, which is characterized by containing a resin containing a monomer represented by the following general formula as a polymer constituent unit. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R represents a hydrogen atom or a methyl group, and n is 15
or a larger integer)