JPS603646A - Production of toner - Google Patents

Abstract

PURPOSE:To obtain a toner which is easy to grind and produce and has good electrostatic charge exchangeable, developing and transfer characteristics and excellent fixability by adding a microcapsulated foaming agent to a toner raw material and kneading the mixture thereof. CONSTITUTION:A microcapsuled foaming agent, more particularly, a solvent type foaming agent is added to a toner raw material and the mixture thereof is kneaded. A microcapsulated foaming agent or the like consisting of, for example, n-hexane, etc. as a core and having a polyurethane wall formed by an interfacial polymn. method, etc. is used for such microcapsulated solvent type foaming agent. A slab having numerous foam is obtd. by kneading such foaming agent with the other toner raw material. Such slab is easily ground as it is porous and the toner having much micro-ruggedness and a large surface area is obtainable. The electrostatic exchange in the stage of development is thus accelerated and stable developing property is obtd. Since the surface area is large, the toner is susceptible to the effect of heat and pressure and good fixability is obtd. in a heat fixing process and pressure fixing process.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a dry toner for developing electrical latent images in electrophotography, electrostatic recording, and electrostatic printing.

(Prior art) I¥? - Methods for forming electrostatic latent images are well known in the art; for example, in electrophotography, after charging a photoconductor layer,
A light image based on the original drawing is irradiated to reduce or eliminate static charges in the light irradiated area to form a Seitunura image. This latent image is then developed with a developer called Toboo. As you know,
Development methods are broadly divided into methods using wet developers and methods using dry developers, and the latter are further classified into one-component development methods that use two particles of carrier and toner, and component development methods that use only toner. be done.

Furthermore, images developed by such a developing method are
Depending on the safety, the toner is transferred to Nagi etc., and then the toner is melted by heating, the calculus resin of the toner is softened by a solvent, or the toner is simply deformed by pressure. will be established.

In any of these conventional toner development and fixing systems, toners with many microscopic irregularities on the toner surface and a large surface area tend to promote charge exchange during development and exhibit stable developability. Furthermore, in terms of fixability, toners with a larger surface area are more susceptible to the effects of heat and pressure, and the fixability is better regardless of whether it is a heat fixing method or a pressure fixing method.

As a method for producing a toner having many minute irregularities on the surface, a method can be considered in which the toner material is foamed at the time of cross-crossing, and then pulverized and classified. In other words, when the toner is mixed, the toner material is foamed, creating countless small spaces in the toner slab.
Furthermore, by uniformly producing and pulverizing the particles, a controlled fine uneven structure is formed on the surface of the B toner particles.

The method of foaming the toner mixture is (h) a method in which gas is generated by causing a chemical reaction with heat or subcomponents:
: Key agent [degradable blowing agent: azobisformamide, azodicarbonamide, diazoaminobenzene, N,N'-tumethyl-N,N'-dinitronoterephthalamide, N
, N'-dinitrosopencumethylenetetramine, benzenesulfonylhydrazide, toluene-(lJQ-sulfonyl-hydrazide, 4t'-oxybis(benzenesulfonyl-hydrazide)) Method: () Mechanically converting the material How to foam and foam; (,
71 A method of absorbing an inert gas (e.g. pentane, hexane, etc.) into a material under high pressure and foaming it at normal pressure.
The blowing agent itself contains tono-functional groups such as amine groups and sulfonyl groups, and if it remains undecomposed and remains in the toner mixture, it is thought that it will have a significant impact on the electrical properties of the toner. It is unsuitable for use in manufacturing due to the control of toner properties. In addition, the mechanical foaming method of (,,21) is unsuitable for equipment reasons in the case of highly viscous substances exceeding 705 poise, such as toner?ll! or kneaded materials. The method of absorbing inert gas and foaming at normal pressure is (1) to (ω,
Although this seems to be the most effective method, it poses many problems, such as the introduction of a pressurizing 4J tip and setting of pressurizing conditions.

Therefore, the method currently considered to be the simplest and most effective is to uniformly disperse a solvent-based foaming agent in the toner mixture and foam it with the heat generated during kneading. It's a way of getting things.

Methods of using a solvent-based blowing agent include: (a) Mixing the solvent-based blowing agent directly into the toner raw material and mixing it; (b) Mixing the solvent-based foaming agent with the toner raw material and causing it to absorb. Possible methods include: (C) A method of mixing a microencapsulated solvent-based foaming agent with toner raw materials for crosstalk.

Here, in the methods (a) and (b), it is difficult to uniformly disperse the solvent-based blowing agent in the toner mixture;
The most suitable method is to use a microencapsulated solvent-based blowing agent (c).

(Object of the Invention) Accordingly, an object of the present invention is to provide a toner that improves the pulverizability of the toner and is highly manufacturable by evenly dispersing fine spaces in the toner mixture.

Another object of the present invention is to provide a toner that has excellent charge exchange properties and exhibits extremely stable development and transfer properties.

Furthermore, another object of the present invention is to provide a toner that has good fixability in both heat fixing and pressure fixing by forming a controlled fine uneven structure on the surface of the toner particles. As a result of intensive studies, the present inventors added a microencapsulated foaming agent, particularly a solvent-based foaming agent, to toner raw materials such as a binder resin, colorant, and other additives, and by mixing them. The present invention has been completed by finding that the above object can be achieved.

The configuration of the honor invention will be explained in detail below.

As the toner binder resin of the present invention, materials conventionally used as adhesives for toners can be used.1 For example, styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene, etc. monopolymer of Ka body, styrene-p-chlorostyrene co-ni polymer, styrene-propylene co-m polymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, Styrene-methacrylic acid ester copolymer, Sunalene-alpha chloromethacrylic methyl copolymer, Styrene-acrylonitrile copolymer, Styrene-vinyl methyl ether copolymer, Styrene-vinyl ethyl ether copolymer, Styrene-vinyl methyl ketone Copolymers, styrene copolymers such as styrene-butatsuene copolymer, styrene-inzolene copolymer, styrene-acrylonitrile-indene copolymer, polyvinyl chloride, natural resin-modified phenol, natural fecal fat-modified malein Play resin, acrylic resin,
Polyvinyl acetate, silicone resin, polyethylene, polyzolopyrene, polyester 414 resin, polyurethane, polyamide resin, ionomer resin, 7 run resin, yJ9 xy resin, 7 xylene resin, polyvinyl butyral, terpene resin, coumaron indene resin, petroleum resin , chlorinated paraffin, paraffin wax, etc. can be used.The coloring agent used in the toner of the present invention may be dyes conventionally used in toners for electrostatic image development, such as q5F, but charge control agents and the like may also be used. Of course you can use it. Further, if it is desired to obtain a magnetic toner, a magnetic fine powder such as magnetite may be mixed.

In addition, surfactants, antioxidants, organic fillers, etc. may be added as necessary.

The microencapsulated foaming agent used in the present invention refers to one in which a solvent-based foaming agent is used as a core material, and the outer wall of the foaming agent is made of a natural or synthetic resin. Here T, *lW[! 5b
f@l? H: 1. lld,, 'A400 ~ "1)
It is desirable that the material be thermally stable, chemically inert, and have a high evaporation rate and a low specific heat and latent heat of vaporization.

Conventionally, for the purpose of Braille copying, 3D rooting, etc.,
There have been attempts to add V′c to the toner, or to mix evaporating foaming agents into the toner.
This invention is completely different in purpose and structure from the present invention.

Further, the boiling point of the solvent-based blowing agent is desirably within the 6.h range of 700°C to 700°C, taking into consideration the stability when microencapsulated.

For example, in general, a solvent-based foaming agent such as hexane, isohexane, isohbutane or heptane is suspended in a gelatin-Arabic water bath solution, and the amount of solvent is added to the inside by the coacervation method. Agent? ! - It is possible to create microcuff zero cells that stagnate.

Okay, another possible method is to use benzene in hexamethylene bischloroformate? 8 + 11 It is possible to emulsify the emulsified product in water, add hegisamethylenesoamine to the emulsified product, and use the shogoton condensation method to produce microcapsules containing a foaming agent inside.

Yet another method is to create microcapsules containing a solvent-based foaming agent inside by adding a solvent-based foaming agent to R'4i 1iTl in the R'4i 1iTl layer and evaporating the resin solvent using the spray drying method. This is possible.

The microcapsules thus obtained are added to toner raw materials such as a binder resin, a colorant, and other additives, and then kneaded.

Regarding the situation ratio, the amount of the solvent-based blowing agent is 0.7 to 15, preferably 7 to 70, relative to the toner oil binding agent/θ0 ton placement part.
The department is good. If it is less than 0.7 parts, the foaming effect will be small, and /
It takes time to completely foam the IT foaming agent above the left side, and the toner material may be deteriorated by heat during cross-talk, which is not preferable. (Example) Examples will be described below.

``Part'', 1%'' indicates the amount of stable space %.

Comparison 1" Toner A Styrene-n-butyl methacrylate copolymer (type bone average molecular weight approximately Sθ, 000) 22 parts, Styrene Kenka SI
23 parts of B polymer, 5 parts of low molecular weight 1Lt polyglobylene wax (weight and average molecular size θθ0), and 30 parts of triiron tetroxide (granular, average particle size θ, 5μ) were melted and mixed, and then Although pulverization was performed, the pulverization properties were poor and the average particle size/g/Z
I could only crush it to a certain extent. This was further classified to obtain a magnetic toner with an average particle size of /Sμ.1 The thus obtained toner contained carbon black (average particle size of 0.
0.3% of θλμ) was added and stirred with a high-speed rotating device (a stirring device with n stirring blades) 1 to form a kerf J! on the surface of the toner particles. Toner A with black attached 4: Iq
Puhi.

Using toner A-C Fuji Xerox Co., Ltd. Entertainment FX-
When I made a copy using 2g30 with 111 /components/fH shadows, the /θ copy position of Kaki's first image was 6'4
I was out of control. After the 10th copy, an image with a somewhat stable density was obtained, but the degree of reflection was a little low at /, /. Further, when the temperature after constant temperature was determined by K''1, a reasonably good constant; τi level was obtained at 770°C.

Shiko PL Example / Toner B Toner B, which is the same as Toner A, add the encapsulated solvent L11 foaming agent to the core material and add Otobe to the M base material, and add γt'r! 1. Toner B was obtained in exactly the same manner as "Abi1, Revival, A1".

n-hexane was used as the core agent for the encapsulated solvent-based blowing agent. Dissolve hexamethylene bischloroformate in n-hexane and disperse it in the whole water of the periwinkle liquid.
It was emulsified by high-speed stirring. Add hexamethylenezamine water bath solution to this, and interface 1 [legal, average particle size 10μ]
Polyurethane-walled microcapsules were obtained using n-hexane.

All of the encapsulated blowing agent was added and kneading was carried out.

Numerous air bubbles were formed in the toner B slab.

Toner Be1 - When crushed under the same moxibustion conditions as Toner A,
The crushability of Toner B is superior to Toner 8, with an average particle size of /,2
A .mu.m toner was obtained.

In addition, when copy B was tested in the same manner as toner A, the density was stable from the first copy (lD-/, 3
) images were obtained. Satisfactory Beppu image strength was still obtained at a fixing temperature of 15°C.

"f B OJ) gt (#"22"・"'17""
d-Aj, 9° The reason for the improvement is that by adding a foaming agent, the toner slab becomes porous, and by crushing the slab, a toner with a large surface area is created.7
It is estimated that she is Y-ish.

Toner B has a shape rich in minute irregularities (l'
i added 3 (y-q and run-1!f plastic electron microscope spider 4+7i
I conducted an i-certification. ssou a example, 2 toss - C month? 23 parts of listyrene barrel fat, 72 parts of low-molecular IX sepolyethylene wax, styrene-butadiene copolymer S, and 0 parts of 43-p compound were weighed out as toner materials.

On the other hand, according to the coacervation method, n-hexane was applied over the core material, and the outer F was coated with gelatin-'r rubia rubber.
Microcapsules with a uniform diameter of 14 μm were prepared, and 4 parts of Ji-6 toner material were mixed with 7 parts of microcassicle (calculated as n-hexane), and then kneaded with a melting door. When pulverization was carried out in the same manner as in the comparative example, the average particle size/3μm
of toner was obtained. Using this toner, copy evaluation was performed in exactly the same manner as toner 8, and a score of 1/1/3 was obtained with a safe score of 1/1/3. Furthermore, when this image was fixed by passing it between rollers to which hQ pressure λθFf/ca was applied, 7
A fixed image intensity of 11 points was obtained. - Example 3 Toner D Styrene-n-butyl methacrylate co-AfK (,@
'in average molecular weight force 60. Examples/
70 parts of the encapsulated solvent-type foaming agent used in the above was added in terms of core material, and after melting and kneading, the mixture was pulverized and classified to obtain a toner having an average particle size of 3 μm. Next, 2 parts of this toner was mixed with 100 parts of iron powder (particle size/θθμ) to form a developer.
When I performed a copy evaluation using commercially available Fx-, 2g, and 30 using this developer, +i! i
i 1:# The density is 1st (ID-/,, 2), so if you get a copy that you can drink enough, it's J'L. When the fixed Δ temperature was examined, a satisfactory fixing efficiency was achieved at 770°C.

Claims (1)

[Claims] (1) Microencapsulated foaming agents are added to toner raw materials such as binder resins, colorants, and other additives, and mixed with
j! 3. A toner manufacturing method that uses 7 as an 11" character.