JPS61118758A - Production of toner - Google Patents

Abstract

PURPOSE:To fix a toner at a low temp. and to obtain a toner having an excellent shelf life by adsorbing a monomer contg. Tg at a higher ratio than in a core material and having high hydrophilicity to soft particles and subjecting the same to a seed polymn. CONSTITUTION:The pulverous particles contg. a resin and coloring agent are suspended in water and with such particles as core particles, a vinyl resin monomer is adsorbed thereto and is grown to produce the toner. The vinyl monomer which contains Tg at the higher ratio than in the resin of the core particles and has the hydrophilicity equal to and/or higher than the hydrophilicity of the resin to be used for the core particles is used as the vinyl monomer to be added after the dispersion of the core particles into the water in the stage of producing the toner on the above-mentioned manner. The toner which is fixed at a low temp. and has the excellent shelf life is thus produced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing toner using a seed polymerization method.
Specifically, the present invention relates to a method for producing a capsule toner that can be fixed at low temperatures and has excellent storage stability.

[Prior art]

In recent years, electrophotographic methods, electrostatic printing methods, electrostatic recording methods, etc. are used to form electrostatic images based on image information, and this is converted into a 3A image using developer toner to form a toner image. It is widely practiced to form a visible image by transferring the image onto a transfer paper or the like, tightening it, and then fixing it.

Conventionally, toner for electrostatic image development has been widely used in powder form, which is obtained by finely pulverizing a mixture of a thermoplastic resin as a binder and a colorant such as carbon black dispersed therein. , if it is a two-component toner, iron powder,
By mixing and stirring the carrier such as glass beads, S
Also, it is a one-component toner containing fine magnetic powder.
If so, by stirring itself, friction #fiE is applied and the electrostatic force is used to develop the electrostatic image, and the obtained toner image is transferred, for example, and then heated with a heating roller or the like to fix it. That's what I do.

However, in such toners, toner particles are crushed during agitation due to linear and frictional charging, resulting in fine powder toner, resulting in poor visible image quality, or the need to replace the toner with a new one early. Not only is it necessary to do this, but since fusing is achieved by a heating fixing method, a long waiting time is required until the temperature of the fixing device rises to the required installation temperature Kt, and due to excessive heating. In addition, problems such as the rapid deterioration of the photoreceptor and the like arise due to the fact that a large amount of energy is required for the process, and a high-temperature heat source is incorporated into the machine.

Therefore, the temperature at which the toner is softened and fixed is lowered.

The above-mentioned problem will not occur if low temperature fixing is used, but in return,
The storage stability of the toner is poor, and phenomena such as plotting occur easily at high temperatures. Therefore, there is a strong desire to develop toners that have good storage stability and are fixed at low temperatures.

Conventionally, in order to meet this requirement, IW capsule toner, which is a toner made of a soft resin wrapped in a hard resin, has been known. For example, JP-A-58-176642,
It is described in No. 48-90977, Special Publication No. 53-8493, Koto, etc.

However, the production by the spray drying method described in these places a burden on the production equipment, and the synthesis by the coacel pacigon method and phase separation method has drawbacks such as the limited composition of the polymer and the use of a large amount of solvent.

Therefore, seed polymerization is a simple encapsulation method that does not use these methods. All seed polymerization methods are described in JP-A-59-62870 and JP-A-59-61843.

[Problem that the invention seeks to solve]

However, the reality is that toners that are fixed at low temperatures and have good storage stability have not been obtained using known methods.

Therefore, the technical object of the present invention is to provide a method for manufacturing a toner that is fixed at low temperatures and has excellent storage stability, and also to provide a method for manufacturing a toner that does not require complicated equipment.

[Means for solving problems]

As a result of extensive research, the inventor of the present invention has found that a toner can be manufactured which has a process of suspending fine particles containing a resin and a colorant in water, using this as a core particle, and allowing a vinyl resin monomer to adsorb and grow on this core particle. In the method.

The vinyl resin monomer has hydrophilicity equal to and/or greater than that of the resin contained in the core particle, and the Tg when the vinyl resin monomer is polymerized is higher than the Tg of the resin in the core particle. The inventors have discovered that the above problems can be solved by a toner production method characterized by a high toner production method, and have thus arrived at the present invention.

In other words, fine particles (toner) containing soft resin are used as seeds.
And that's poly with high Tg! It is an extremely simple idea to drop the seven particles and grow one particle in order to wrap it with -. However, the added vinyl monomer may penetrate into the interior of the particles, and as a result, a clear core-shell structure may not be formed, or even the core and wall may be reversed. For example, Tsunetaka Matsumoto et al.
(1974)), when emulsion-polymerized ethyl acrylate (particle size 0.1 μm) is used as a core and styrene is added dropwise to the core to grow particles, the resulting particles become polystyrene in the opposite order of addition. It is reported that the core was made of polyacrylate and the outer wall was made of polyacrylate. When methyl methacrylate, which has approximately the same hydrophilicity as polymethyl acrylate, is used instead of styrene as a monomer to be added later, Jika Juntsu DK is obtained.

It has been reported that particles with polyethyl acrylate in the core and methyl methacrylate in the outer wall are formed.

The inventor conducted research based on these four sentences.

A similar effect is exhibited for toner particles with a diameter of 5 to 15 μm, and the core material also has high Tg and highly hydrophilic monomers that are adsorbed onto soft particles and subjected to seed polymerization, resulting in low-temperature fixing and durability. It was particularly successful to obtain a toner with good properties, which led to the present invention.

The present invention will be explained in detail below.

The core particles used in the present invention contain a resin and a colorant.

Dyes, pigments, magnetic materials, etc. are used as coloring agents.
In the case of a two-component developer using toner and carrier, dyes and pigments are used, and a magnetic material may be added if necessary. Furthermore, in the case of a one-component image agent that does not use a carrier, it is necessary to use a magnetic material to make a one-component magnetic toner.

Specific examples of dyes and #I materials include carbon black, nigronon dye ((3,1,Na50415B),
Aniline blue (50405 to 0,1,I', force) b
Kooilup # - (0,1, NcLazoic Blu
e3).

Chromeixa-(0,1,Nal 4090),
'l Ruto2 Marinep# - (0,1,Na77103
)s Debon Oil Red ((J, 1. Wind 26105)
, Orient Oil Red #330 (0,1, Kaze 605
05), Quinoline Yellow (0,1, Kan 47005).

Methylene blue chloride (0,1,Na52015)
% Phthalocyanine Blue ((J, 1. Arashi 74160).

72 Kite Green Oxalate (0, I. Arashi 4200
0), lamp black (0, 1, NLL77266)
.

Rose Bengal (0, 1, Kaze 45435), oil black, azo oil black, and others can be used alone or in combination. These colorants are used in toner as a final product.

It may be contained in a proportion of about 3 to 20% by weight.

Magnetic materials include ferrite, magnetite, iron, cobalt, nickel, and other ferromagnetic metals or alloys, or compounds containing these elements, or materials that do not contain ferromagnetic elements but can be made by applying appropriate heat treatment. Mention may be made of alloys which become ferromagnetic, such as alloys of the type called Heusler alloys containing manganese and copper, such as manganese-copper-aluminum, manganese-copper-tin, or chromium dioxide, among others.

Specifically, as magnetite, EFT-1000,
EPT-500, M MB-450 (manufactured by Toda Kogyo Co., Ltd.), BL-100, BL-120, BL-200, B
L-220, BL-500, BL-520, Bl, -8
P, B-BL, I'LB-j20 (manufactured by Titan Kogyo Co., Ltd.), etc. are preferably used. These colorants may be dissolved and added not only to the core particles but also to the vinyl resin monomer added later.

Examples of resins contained in the core particles include polyethylene,
Thermoplastic resins such as polyglopylene, vinyl acetate, ethylene-vinyl acetate copolymer, polyester, and vinyl resin are preferred.
The glass transition point of the thermoplastic resin is preferably 50°C or lower, more preferably 40°C or lower. The optimum temperature for pressure fixing toner is -30℃ to 40℃.
The one is good.

The Tg of the vinyl resin that is later added with foil to form the outer wall is 60° C. or higher, preferably 70 to 120° C.; preferred. In the case of vinyl resin, Tg can be substituted with an approximate solution obtained based on values described in polymer handbooks, etc., without relying on actual measurement. For example, in the case of styrene-ethyl acrylate copolymer (70:30 volume ratio), St (Tgtoo℃)
, Bk (Tg-24℃), so calculate Tg6 by volume ratio
It becomes 2.8℃.

Examples of vinyl-based resins include styrene, p-methylstyrene, p-tart-7''tylstyrene, p-7'
) * Cystyrene, p-phenylstyrene, 3゜4-dichlorostyrene, methyl acrylate, ethyl acrylate,
Acrylic [n-butyl, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate.

Methyl α-chloroacrylate, methyl methacrylate, methacrylate is ethyl, propyl methacrylate.

n-butyl methacrylate, inobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, ucryl methacrylate,
Examples include stearyl methacrylate and phenyl methacrylate. By combining these monomers, the glass transition point, R
The degree of aqueousness may be adjusted.

In addition, the vinyl resin contained in the core particles is divinylbenzene,
A portion may be crosslinked using a crosslinking agent such as ethylene glycol dimethacrylate. Alternatively, a graft polymer may be obtained by polymerizing in the presence of liquid butadiene or unsaturated polyester. Furthermore, a wax such as low molecular weight polyethylene or Carna Power wax, or a release agent such as silicone oil (to prevent part of the melted toner from adhering to the surface of the electrodeposition roller) may be added to the core particle shell. .

In the present invention, the core particles are suspended in water, and later the monomer t-=
Eruto-Useed Teiho. A dispersion stabilizer is used to stably suspend the core particles9.

For this purpose, anti-aging agent or inorganic fine powder can be used. For example, sodium dodecylbenzenesulfonate, sodium pentadecyl sulfate, sodium octyl sulfate A, 7! There are active agents such as sodium J-alkyl-pholyether sulfonate, sodium lavalate, sodium glycolate, and calcium oleate, and inorganic fine powders such as tricalcicum phosphate, barifum sulfate, aluminum hydroxide, and silica.

To make the core particles, a vinyl monocap is mixed with a coloring agent and a suspension polymerization method (for example, JP-A-57-229641, JP-A-57-57) is used.
- If you adopt the method described in Publication No. 233363 etc.),
This is advantageous in terms of synthesis because the seed polymerization step can be performed continuously.

As the vinyl monomer added later after dispersing the core particles in water, the above vinyl monomer can be used, but the Tg is higher than that of the resin of the core particles, preferably 60 ° C. or higher, and Since the resin used for the core particles is also hydrophilic, copolymers mainly composed of methyl methacrylate, ether methacrylate, methyl acrylate, acrylonitrile, p-cyanostyrene I-styrene, etc. are preferred.

Here, hydrophilicity is 6D compared to the resin of the core particle, for example, if the core particle is made using a hydrophobic monomer such as #-12-ethylhexyl acrylate. Even substances generally known as hydrophobic substances such as styrene can be used in the present invention as they have relatively high hydrophilic properties. The hydrophilicity of the monomers added later must be compared with that of the resin in the core particles, but the hydrophilicity of the monomers that make up the resin contained in the core particles and the monomers added later can be compared and substituted. Relative hydrophilicity can be compared based on the solubility of each monomer in water, but Hansh et al.
LevievgVol 71, 525 (1971)
, the partition coefficient logP is calculated from the hydrophobic parameter π of each substituent, as done by Noriku Kubota-1 Hiroshi Terada et al.
It is also possible to obtain 'li- and use that as a substitute.

Here, the distribution coefficient PF is defined as 1st order.

0o=concentration of the substance in the n-octatool phase; Ow=concentration of the substance in the aqueous phase, that is, the distribution coefficient when an equilibrium state between the slow substance n-octatool and water is reached. The difference πX between the common logarithms of the distribution coefficients of the substance AI and the substance AX with the Kfit substituent X is called the hydrophobic parameter of the substituent.

πx= log FAX - log PAR compound l
If og P has not been measured, an approximate solution can be calculated by combining π.

Just 6 in this table includes methyl, ethyl, propyl and about 0
．． It can be seen that the values are added by 50 (value of -OH2-). Applying this to monomers, for example, styrene (-
0)1=OH2)+(-06)(,)=0.82+
1.96 = 2.78, and 2-etherhexyl acrylate and butyl acrylate are as follows.

(H20=OH-C000H20HOH20H20H,
0H3) log P0H20H3: (-CH=CH2)+(-COOCH3)+6(-O
H2)-)-OH3=OJ2+(-0,01)+6X0
50+0.56=439(H20=OH-0000H2
(,!H20H2CH3) log P= (-0H=
OH2)+(-000083)+3(-CI-12)=
0.82+(-0,01)+3X0.50=2.31 In the case of a copolymer, it can be determined by adding the volume ratio of log P of each monomer. This applies not only to the core particles but also to the monomers added later. That is, styrene-2-
of ethylhexyl acrylate (50: 50 v/v
) Since the log P of the copolymer is estimated to be 3.58, styrene t- may be used as a monomer to be added later. When the core particle is made of styrene-butyl acrylate (tsO: 40v/y) copolymer, l
The monomer added later was methyl methacrylate (log P==1.4
2) or a mixture of styrene and methyl methacrylate.

As the 1-coinitiator used in the present invention, typical free radical initiators and redox catalysts can be used. For example, hydrogen peroxide, t-butyl peroxide, lauroyl peroxide, azobisin butyronitrile, potassium persulfate.

Examples include hydrogen peroxide-as; lupic acid.

The polymerization initiator may be added after being dissolved in the monomer to be added, or the monomer may be adsorbed onto the core particles, then dissolved in water and added to the aqueous phase. In addition, when the core particles themselves are made by suspension polymerization, two initiators with a decomposition temperature of 1 and 2 are used together.

It is also possible to polymerize the core particles at a low temperature, then add a wall monomer and then raise the temperature.

The particle size of the toner produced by the seed polymerization method of the present invention is not subject to any lateral restrictions, but the average particle size is 5 to 50 μm, preferably 5 to 30 μm. Furthermore, this manufacturing method is applicable to both two-component toners and one-component magnetic toners. Furthermore, if a core material with a Tg of 5° C. or less is used and a plasticizer, wax, etc. are further used in the core, it can also be applied to toners for pressure fixing.

〔Example〕

Examples of the present invention will be described below, but the embodiments of the present invention are not limited by these K.

Example 1 Styrene (Tg 100°C) 9511% 2-ethylhexyl 7 acrylate (Tg - 50°C) 70 JIS carbon black r MONARO) 1880 J (manufactured by Capot) 15+Jz-z'-azobis(2,4-dimethylvalero) Nitrirun 5I was mixed and dispersed in Santos fi-:ly- to obtain a 5-polymerizable composition.This was added to an aqueous colloidal solution containing 0.02% by weight of sodium dodecylbenzenesulfonate and 15% by weight of phosphoric acid lucicum zitx. %, add TK homojetter (manufactured by Tokushu Kika Kogyo Co., Ltd.)
was used to disperse the particles to a particle size of 6 to 12 μm to obtain a suspension. Thereafter, this suspension was heated at 60° C. for 20 hours to polymerize.

A dispersion of core particles was obtained. Next, to this was added styrene 35.0 in which 1.0.9 m of benzoyl peroxide was dissolved. pi80℃
The mixture was added dropwise over a period of 3 hours, and the reaction was continued for an additional 10 hours to complete the polymerization. After cooling, treat with hydrochloric acid.

After filtering and washing, it was dried to obtain a toner. This toner 2
Prepare a developer consisting of 100 parts of iron powder carrier and 100 parts of iron powder carrier,
- An unfixed toner image was obtained using a modified BixV machine (manufactured by Konishiroku Photo Industry Co., Ltd.).

A heated roller whose surface layer is made of Teflon (manufactured by DuPont, polytetrafluoroethylene) and a
ffi'/! j core com r KE-1300R
When the temperature of the heat roller was changed every 10 degrees Celsius and the temperature of the heat roller was changed at every 10 degrees Celsius, the temperature of the heat roller was changed to 1.
A good fixed image was obtained at 20°C. Also, this toner t-
No aggregation was observed even after 2 hours at a high temperature of 55° C. and 60% humidity.

Comparative Example 1 Styrene 130, 9.2-ethylhexyl acrylate 70! i, carbon black rMONAI'LO) 18
80J (manufactured by Cabot) 15JF, 2,2'-azobis(2,4-dimethylvaleronitrile) 5I and benzoyl peroxide 1. Add OI and Sandstar? −
After dispersing in a calcium phosphate dispersion, suspension polymerization was performed. After reacting at 60°C for 20 hours, 1 at 80°C.
The mixture was allowed to react for 0 hours, and after cooling, hydrochloric acid was added, followed by filtration and washing with water to obtain a toner. When this toner was evaluated in the same manner as in Example 1, it was found that although it was fixed at 120°C, aggregation of the toner was observed after 2 hours at a high temperature of 550°C.

Comparative Example 2 Styrene IUOJil, n-methyl acrylate (Tg
-54℃) 65p, carbon black rMONAROH
After mixing and dispersing the mixture in 880 J l 5&, 2,27-azobis(2,4-dimethylvaleronitrile) 59 using a sand stirrer, suspension polymerization was carried out in a calcium phosphate dispersion in the same manner as in Example 1. After reacting at 60°C for 20 hours, 35% of styrene containing 1.09% of benzoyl peroxide was dissolved. if
: Added. After reacting at 80° C. for 10 hours, the mixture was treated with hydrochloric acid, filtered, and washed with water to obtain a toner. When this toner gold was evaluated in the same manner as in Example 1, although the fixing was performed at a roller temperature of 120°C, the toner agglomerated in the environmental resistance test at 55°C and 2 yen PMJ.

Comparative Example 3 Composition of the resin in Comparative Example IK (130 g of styrene, 2-
ethyl acrylate 70 II) to styrene 15
5II, 2-ethylhexyl 7ri! jL/-)45. N
I got toner instead of K. This toner has been tested for environmental resistance (5
As in Example 1, no aggregation was observed when the temperature of the heat roller was 150°C.
A satisfactory fixed image could not be obtained unless it exceeded .

Example 2 In Comparative Example 2, the monomer added later was styrene 35
Styrene 20J, methyl methacrylate (instead of J)
Tg l l 3°C) Perform the same operation instead of using a mixture of 15I to obtain a toner. This toner gave a good fixed gli image at 120° C., and no aggregation occurred in the environmental resistance test.

Patent applicant: Konishiroku Photo Industry Co., Ltd. Agent: Nobuaki Sakaguchi (and one other person)

Claims (2)

[Claims] (1) A toner manufacturing method comprising a step of suspending fine particles containing a resin and a colorant in water, using the core particles as core particles, and allowing a vinyl resin monomer to adsorb and grow on the core particles,
The vinyl resin monomer has hydrophilicity equal to and/or equal to or higher than that of the resin contained in the core particle, and the Tg when the vinyl resin monomer is polymerized is higher than the Tg of the resin in the core particle. A method for manufacturing a toner characterized by the following. (2) A method for producing a toner according to claim 1, wherein the core particles are obtained by suspension polymerizing a toner material containing a vinyl resin monomer, a polymerization initiator, and a colorant in water. .