JPS5926139A - Preparation of microcapsule toner - Google Patents

Abstract

PURPOSE:To prepare toner good in pressure fixability, by a method wherein a sulfonic acid derivative as a catalyst is added to a mixed solution having a core substance and fine silica suspended therein and coating resin further dissolved therein and the surface of the core substance is coated with the coating resin which is, in turn, cured. CONSTITUTION:To a mixed solution having a soft core substance (e.g., polyethylene) and fine silica suspended therein and coating resin such as butyral resin further dissolved therein, a catalyst shown by formula (wherein R is 1-4 alkyl group or H)(e.g., benzene sulfonic acid) is added and the surface of the core substance is coated with the coating resin which is, in turn, cured and, at the same time, fine silica is pref. contained. Thus prepard microcapsule toner is good in pressure fixability with respect to plain paper and the development capacity and the fixability thereof are stable even if plural numbers of copyings are repeatedly carried out. In addition, this capsule toner generates no offset to a pressure roller and no welding to a development sleeve and the surface of a photosensitive element.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capsule toner used to develop an electrical latent image in electrophotography, and more particularly to a method for producing a microcapsule toner using a novel coating material. .

Conventionally, 7F, U.S. Patent No. 229769 for child photography method
No. 1 helmet, ll? Publication No. 42-23910 and
Many methods are known, as described in Japanese Patent Publication No. 43-24748. Generally, a photoconductive material is used to form an electrical latent image on a photoreceptor by various means, and then a photoconductive material is used to form an electrical latent image on a photoreceptor. +! 1! The image is developed using toner, and if necessary, the toner image is transferred to a transfer sheet such as paper, and then fixed by heat, pressure, solvent vapor, etc. to obtain a copy.

Furthermore, a developing method for visualizing sTM and atmospheric pressure using toner is also widely known. For example, US Inl / ('4
jπl' The magnetic brush method described in EEL No. 2874063, the J skate development method described in EEL No. 2618552, the powder cloud method described in EEL No. 2221776, and fur brush development. A large number of developing methods are known, such as the method and the acid development method. The developed toner image is transferred and fixed onto a transfer medium such as paper, if necessary.

Methods for fixing toner images include heating and melting the toner with a heater or hot roller and fixing it on the support, softening or dissolving the binder resin of the toner with a solvent and fixing it on the support, and applying pressure. There are known methods for fixing toner on a support.

The method of applying pressure to fix the toner is described in US Patent No. 2269.
It is described in No. 626 Mei 111 Layer Lt 15876 Publication, etc., and it is energy saving, non-polluting, there is no fear of copy failure, high-speed fixing is possible, and the fixing device is simple. There are also many advantages.

However, problems such as toner fixability and offset development to the pressure roller have been identified, and various studies are being conducted to improve the pressure fixing V1 unit.
Publication No. 44-91380 describes a pressure fixing toner containing an aliphatic component and a thermoplastic resin;
No. 13-75032 and the like describes a capsule-type pressure fixing toner containing a soft material in the core. However, the pressure fixing performance is sufficient, and the development performance and
A practical pressure fixing toner that has stable fixing performance and does not cause fusion to the metal sleeve or photoreceptor surface is 10
It has not been done.

For example, pressure-fixed toners made of soft materials tend to fuse to the surface of the color sensitive element, and there are many problems such as being susceptible to false positives during storage. The above-mentioned drawbacks have been significantly improved by the manufacturing method of microcapsules (1), which uses a material that is easily pressure-fixed and uses a hard and highly abrasion-resistant material as a coating material. Ruru.

OBJECTS OF THE INVENTION & j: It is an object of the present invention to provide a method for producing a microcapsule toner that exhibits good fixability to paper through pressurization.

The object of the present invention is to provide a method for producing a pressure-fixable microcapsule toner that has stable developing performance and fixing performance even after repeated copying of a large number of sheets.

Another object of the present invention is to provide a method for producing a pressure-fixable microcapsule toner that does not cause offset to a pressure roller or fuse to the surface of a developing sleeve or photoreceptor.

The feature of the present invention is that a soft core substance and fine silica are suspended, a coating resin is further dissolved, and the general formula % formula % (ItIJ, (,!, ~C4) is added to the fc mixed solution. Alkyl group or 1()
Add the catalyst shown in the above mixed solution, and add the human blood 1 of the core substance.
1C for covering 4fflj resin (preferably butyral resin)
), and preferably contains fine silica dispersed therein at the same time.

In order to apply a cured coating of butyral resin to the core material using a hot V, it is necessary to apply a temperature of 180° C. or more for the entire length IL5. This flat Ire of 180"C or more is tl
, the core material whose main phase is a very common synthetic or natural resin softens or flows, and when the core material is coated with butyral resin, +lS, the material t becomes unable to maintain a constant toner particle size. Part of the striped butyral resin itself undergoes thermal decomposition, causing yellowing and changes in ej' rostral properties.

By using the catalyst of the present invention, a transparent and highly abrasion-resistant microcapsule toner can be obtained, which can provide a sufficient coating by heating at low temperatures and in a short time, and does not cause softening of the core material or yellowing of the butyral resin. Ta.

What kind of reaction occurs with the addition of such a catalyst?
At present, it is not fully clear whether a coating with high wear resistance can be obtained, but it is thought to be as follows.

The durability of the microcapsule toner containing fine silica on its surface during continuous copying is significantly improved, which is several orders of magnitude higher in performance than the case of coating with butyral resin alone. In addition, the microcapsule toner without the addition of a catalyst has extremely poor performance as an electrophotographic toner of only 11 points. From these facts, due to the additive force 11 of the catalyst of the present invention, some kind of bond is generated between the terminal silano-Jv group of the fine silica and the hydroxyl group of the butyral resin, and a bond between the inorganic substance and the resin is formed on the surface of the core material. It is inferred that a highly abrasion-resistant composite partially having chemical bonds was formed, resulting in a toner with good durability. Of course, the use of catalysts and the formation of these coatings at low temperatures are especially effective in the sense that the physical properties of the electrophotographic toner are not impaired.

If a chemical bond is formed between the butyral resin and the fine silica, the ratio of the number of reactive groups between the two naturally affects the properties of the αI target. When the number of 7-ranol groups in the fine silica is larger than the number of hydroxyl groups in the butyral resin, unreacted silanol groups remain on the surface of the seedlings, resulting in a toner that is hygroscopic. On the other hand, if the number of hydroxyl groups in the butyral resin is in excess of 7 ranol groups, only the hydroxyl groups will be consumed by the crosslinking reaction in the polymer nail 1, and in order to obtain the toner, all the silanol groups of the fine silica will be consumed. Moreover, it must have a ratio of the amount of polymer tin in the butyral resin to crosslink with a suitable density. As for the range.

Butyral resin is 30-2% M0% for the mixed solution,
Preferably 20 to 5 layers, and fine silica is 20 to 0
．． 5 weight scale, preferably 15 to 0.5 weight scale.

The fine silica used in the present invention has a particle size of 0.5
All known products in the range of ~120μ can be used; for example, Aerosil, -200.

-300,'-MOX80. -Mox 170, -1
4972, Shiba-Nut-22,-17, Fine Seal-1id-50°'r-32. -i3.1)
Tsukusu-500, Kyahoshiru M-5, -MS-7, I
! There are IH-5, 8-17, etc.

The core material to be used in the present invention is preferably one that easily fixes to paper fibers when pressure is applied.

Particularly preferable examples include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-acrylic copolymer, ethylene-vinyl acetate, and the like.
Rubbers such as ethylene polymers having a melt viscosity of 10-10' cps at 40°C, styrene-isoprene copolymers, styrene-pucdiene copolymers, polyurekne elastomers, Ha; 4u linear polyesters, etc. These include fatty acids and derivatives thereof such as stearic acid, oleic acid, myristic acid, stearic acid amide, oleic acid amide, zinc stearate, and waxes such as paraffin wax and carnauba wax.

Furthermore, suspending these core substances and fine 1j1 silica,
As a solvent for dissolving butyral resin, it is preferable to use a solvent that does not have an adverse effect on suspended substances, such as alcohols such as methanol, ethanol, gropanol, butanol, cellosolves such as methyl cellosolve, ethyl cellosolve, methyl cellosolve, etc. alone or Can be used in combination.

As a catalyst, it is necessary to add 0.1 to 20 Mfd of a substance represented by the general formula % formula % (1L is an alkyl group of 01 to C4 or 1 () to 414 fat, and the above catalyst and Teha, I+!lif
, benzenesulfone flll, o-)/reninsulfone l'fl, ITI-) reninsulfone enemy %
p-ToluenesulfoneriL O-xylenesulfonic acid.

■-Xylene sulfonic acid, p-xylene sulfonic acid, 0
-Propylbenzenesulfone CI, In~Propylbenzenesulfone ftj? s'p ”ropylbenzenesulfonic acid, o-isopropylbenzenesulfonetWtm-
Isopropylbenzenesulfonic acid, p-isopropylbenzenesulfonic acid.

0-Butylbenzenesulfonic acid, m-butylbenzenesulfone AL p-butylbenzenesulfonic acid, 0-isobutylbenzenesulfone vsm-isobutylbenzenesulfonic acid, p-isobutylbenzenesulfone fis
Examples include p-tertphterbenzenesulfonic acid.

In order to obtain the core material, known toner manufacturing methods can be used. For example, a suitably selected resin that is easily pressure-fixed is kneaded in a roll mill, and then finely pulverized and classified to obtain a soft core *' having an average particle size of 5 to 20 μm. There is no problem in adding a coloring agent, a magnetic substance, or a load control agent to this core material as necessary.

Hereinafter, the present invention will be described in detail with reference to examples. ○ [Example 1] (Manufacture of core material) 100 parts by weight of polyethylene resin (70M of polyethylene resin, 2 parts by weight of ill charge control agent) were mixed, and 150 parts by weight of polyethylene resin was mixed with 70M of polyethylene resin and 2 parts by weight of ill charge control agent. Knead for 20 minutes using a cutter mill or jet mill.
After fine pulverization and further classification process, the average particle size is 10.
tt core material is obtained.

(Manufacture of microcapsules) Core material 10.0 liters 11 butyral resin 30 〃 and butanol 3301 ηl! Add Fc and stir with a homomixer at room temperature until all the butyral resin is dissolved. To this mixed solution, add 511 g, f of 0-toluenesulfonic acid.
Add i++ and stir slowly for 1 hour at 6 (1"G).

Thereafter, drying was performed to obtain a -component magnetic microcapsule toner. This toner is transferred to the electronic copying machine NP-120.
(manufactured by Canon), and even after 20,000 copies, the images were as good as the initial one. In addition, a fixing test was conducted using an unfixed image using a separate fixing device with variable pressure.

[Examples 2 to 6] [Comparative Examples 1 to 2] The same core material as in Example 1 was used, and the microcapsules were manufactured in the same manner as in Example 1 with the following formulation. (Manufactured by Canon) m: The results of continuous copying using a slave copying device are shown below.

The pressure fixability was evaluated using a variable pressure test fixing device having two rigid rollers after fixing an unfixed image.

Claims (1)

[Claims] The general formula (it is C2-04
A method for producing a microcapsule toner, which comprises adding an alkyl group or a catalyst represented by 1() to the above mixed solution, and then hardening and coating a coating resin on the surface of a core material.