JPS6156355A - Microcapsule type toner - Google Patents

Abstract

PURPOSE:To improve the pressure fixability, offset resistance and winding resistance of a microcapsule type toner by incorporating a specific vinyl polymer having a specific ratio of weight average mol.wt./number average mol.wt. into a core material. CONSTITUTION:The vinyl polymer to be used for the core material, for exmaple, lauryl polymethacrylate is so formed as to consist of a high mol.wt. component and low mol.wt. compolent. The ratio of the weight average mol.wt. Mw/number average mol.wt. Mn of the polymer is made in a 3.5-20 range in which the weight average mol.wt. is made >=150000 and is incorporated at 5-50wt% of the entire vinyl polymer of the core material for the above-mentioned purpose. A coloring agent is added to the monomer in the stage of polymn. and the monomer is polymerized. Such polymer is incorported into the core material. The outside wall is coated with a hard resin such as epoxy resin, by which the capsule type toner is obtd. The mol.wt. distribution of the vinyl polymer of the core material is made in the prescribed range and therefore, the pressure fixability of the toner is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a toner for electrostatic image development,
More specifically, the present invention relates to a microcapsule type toner which can be suitably used as a pressure fixing type toner.

[Conventional technology]

In recent years, electrophotographic methods, layered printing methods, electrostatic recording methods, etc. are used to form an electrostatic image based on the image 11'1 report, and this is developed with a developer toner to form a toner image. 2. Description of the Related Art It is widely practiced to form a visible image by transferring a toner image onto a transfer paper or the like and then fixing it.

Conventionally, as a toner for electrostatic image development, a powdered toner obtained by finely pulverizing thermoplastic A1 resin containing a coloring agent such as a carbon blank dispersed therein has been widely used. If it is a two-component toner, it is mixed and stirred with a carrier such as iron powder or glass, or if it is a one-component toner containing fine magnetic powder, it is stirred itself. By this, the toner image is triboelectrically charged and the static electricity is used to develop an electrostatic image, and the resulting toner image is, for example, transferred and then heated and fixed by a heating roller or the like.
However, in such toners, toner particles are crushed during agitation for triboelectrification to produce fine powder toner, resulting in a visible image.

Not only will the quality of the image be poor, or the toner will need to be replaced early, but also the temperature of the fuser will rise to the required set temperature since fusing is accomplished by a heat fusing method. It takes a long time to open the paper, requires a lot of energy to heat up, and can even cause a fire if paper jams occur. It is necessary to satisfy fairly strict conditions such as temperature conditions.

Under such circumstances, a method of fixing using pressure has been proposed. That is, a pressure fixing method has been proposed in which toner particles are fixed to an image forming support by applying pressure to the toner, and for example, the method described in U.S. Pat. No. 3,269,626 is known. . Since this method does not require the use of heat or solvent, it is free from various obstacles, does not require 7 ohm fuse time, and has the advantage of requiring less energy for fixing.

However, the above-mentioned pressure fixing method has poor fixing properties compared to fixing methods using heat, etc., and may peel off or sag when rubbed, and requires high pressure, which may destroy the fibers of the image forming support, such as copy paper. There were drawbacks such as the copy paper becoming brittle and having an excessively glossy surface.

In order to solve the problem of Cl deficiency, research has recently been conducted on the use of so-called microcapsules as toners for developing electrostatic images. This microcapsule type toner is a microcapsule type toner that contains fine particles in resin capsules.
It is a powder-like material containing a liquid substance or soft solid exhibiting pressure fixability and a coloring agent as a core material.

This microcapsule type toner can encapsulate sticky soft solids etc. in the core material, so it has better powder characteristics than conventional pressure fixing toners made of a single resin.
Fixing can be done with low pressure, and toner [, 2, 1, 4, 1]. ,a. 2e2□7. It is expected to have benefits such as not requiring one oyu.

[Disadvantages of conventional technology]

Regarding such microcapsule type toner that can be fixed under pressure, Japanese Patent Application Laid-open Nos. 51-91724 and 52-1199 disclose
No. 37, No. 54-118249 and No. 55-6425
The techniques described in the specifications of each publication No. 1 are known. However, the above-mentioned technique still has problems such as the toner offset phenomenon to the pressure roller and the paper wrapping phenomenon to the pressure roller.

In order to create a microcapsule type toner that does not cause offset and wrapping phenomena, it is preferable to use a polymer with as high a molecular weight as possible as the core material. However, a polymer with a high molecular weight naturally has poor pressure fixing properties. There is a problem. Furthermore, if the molecular weight is too low, the core material is likely to be deformed not only during pressure fixing but also after pressure fixing, causing toner to peel off from paper or the like, resulting in poor fixing.

[Purpose of the invention]

An object of the present invention is to provide a microcapsule type toner which has good pressure fixability, offset resistance, and excellent wrapping resistance.

[Invented shrinking machine 1 work Ff1. and Effects] The above object of the present invention is to provide a microcapsule type toner having a core material and an outer wall for covering the core material, wherein the core material has a value of ff1JB average molecular weight/number average molecular weight of 3.5 to 3.5.
This was achieved by using a microcapsule type toner which is characterized by containing 20 vinyl polymers as a main component.

The present invention will be explained in detail below.

The method for producing the microcapsule type toner of the present invention can utilize various known encapsulation techniques. A method in which a resin film is formed by a polymerization reaction with the components inside), a coacervage tan method, i
n-5 itu polymerization method, phase separation method, etc., and U.S. Patent Nos. 3 and 3
No. 38,991, No. 3.326.848 and No. 3
, No. 502.582 and the like can be used. Among them, interfacial polymerization method can be effectively used. This is because it is easy to form the outer wall and it is easy to separate the functions of the core material and wall material.

The outer wall material forming h1 of the microcapsule type toner is not particularly limited, but may include Evokin ml resin, polyamide ljt plate, polyurethane resin Nagi, polyurea resin, epoxyurea resin, epoxyurethane resin, vinyl resin, and Other resins are preferably used for practical purposes; polyurethane resins and polyurea 111111! It is particularly preferable to use epoxy urea resin, epoxy urea resin, and epoxy urethane resin.

Epoxy resin is a υi fat produced by the reaction between an epoxy resin or a compound containing an epoxy group and a curing agent.

Examples of these epoxy resins or compounds containing epoxy groups include the following, but are not particularly limited as long as they have 2 or more epoxy groups in the molecule.

A-1) Screw 7E/-1 and A type epoxy m plate nmo 0
Commercial product name: ``Ebihuto 801'' Sea Epicote δ15''
.

"Epicote 819" (Epifuu) 828J.

"Evinia-1534J (manufactured by Yuka Shell Epokin Co., Ltd.) A-2) Resorcin type epoxy 113 (fat n = integer greater than or equal to 0 A-3) Bis7 El/-F type Evokin If fat n = integer greater than or equal to o, An example of a commercially available product is “Epicote 807J.

“Epicote 827J.

“Epicote 190J.

[Ebihut YX-310J.

“Ebihut DX-255J (manufactured by Yuka Shell Epoxy Co., Ltd.)
Examples include j.

In addition, the above-mentioned curing agents include ethylenenoamine, noethylenetriamine, triethylenetriamine, tetraethylenepentamine, hexamethylenezamine, iminobispropylamine, other aliphatic polyamine compounds, xylene ν amine, and Dilennoamine and other aromatic polyamine compounds are typical, and commercially available products include 1, Epicure T, Ebicure U1 Epiquier 103
, evo/-) B-001, 2f, i-t LX-IN,
Ebihut PX-3 (Yuka Shell Epoxy Co., Ltd. + I
J1) J, and others generally known as epoxy curing agents.

The polyamide resin is obtained by the reaction of a carboxylic acid chloride such as sebacic acid chloride, thenic acid chloride, and divic acid chloride, and the above-mentioned epoxy tB (aliphatic polyamine, aromatic polyamine, etc. exemplified as a fat hardening agent). A so-called polyamide resin can be used.

Polyurethane resins are obtained by the reaction of polyincyanates and polyols, and polyurethane resins are obtained by the reaction of polyisocyanates and polyamines. As a specific example of the polyisocyanate, for example, dog polyisocyanate can be mentioned.

B-1) Hex → t methylene isocyanine) OCN
(CHz) aN CO Commercial product name: "Desmonyl H" (Sumitomo Bayer Urethane Industries, Ltd. v1) B-2) Diphenylmethane-4,4'-noisocyanate Commercial product name: "Millionate MTJ (manufactured by Nippon Polyurethane Industries, Ltd.) "Isone) 125MJ (manufactured by Kasei Anopunoyon Co., Ltd.) "Suminate M" (manufactured by Sumitomo Chemical Co., Ltd.) The following is just one example of a polyol or polyamine that reacts with the above-mentioned polyinsyanate to give a polyurethane resin or polyurea υ1 fat. can be mentioned.

C-1) Polyol ethylene glycol, fluoropylene gellicol, hexamethylene glycol, water, and others.

C-2) Polyamines ethylenenoamine, hexamethylenenoamine, phenylenenoamine, xylylenediamine, and others.

According to a preferred embodiment of the present invention, the microcapsule type toner contains a vinyl polymer consisting of a high molecular weight component and a low molecular weight component as a main component in the core material, and the weight average of the vinyl polymer is Molecule ffi/r & average molecule fl
A high molecular weight component having a value of (M w / M n ) of 3.5 to 2.0 and a weight average molecular weight of 150.000 or more is contained in an amount of 5 to 50% by weight based on the total vinyl polymer of the core material. It is to contain.

As mentioned above, the vinyl polymer of the present invention has a molecular weight distribution consisting of a low molecular weight component and a high molecular weight component, and has a molecular weight distribution of M w / M
n is 3.5 to 20. When the vinyl polymer of the present invention is composed of a homopolymer or a copolymer of I Ml, this value is the value that each of these polymers has, and also the value of the vinyl polymer of the present invention. When the combined polymer is a mixed polymer, this is the value for the entire mixed polymer.

That is, in the case of mixed polymers, the value of Mud/Mn is not necessarily 3.5 to 20 for each individual polymer to be mixed.
It is not necessary that the value of the mixed polymer as a whole obtained by mixing is within the above range, and the molecular weight of the low molecular weight component of the polymer of the present invention is
Weight average molecular weight is 150.000 or less, preferably 10
,000 to 150,000, and the 5i of the high molecular weight component
Regarding the molecular weight, the ff1 plate average molecular weight is 150°000 or more, preferably Zoo,000 to 500,000, and the proportion of high molecular weight components contained in the resin of the present invention is 5 to 50,000.
50fi% by weight, preferably 10-40″% by weight,
95 to 50% by weight of low molecular weight components, preferably 90 to 6%
It is 0 times 2%.

Weight average molecule fl M w of the vinyl polymer of the present invention
11. ,. oo~zoo, oooon
(* e 'fit 7J 4s f) h'. ,
. 1. : Furthermore, M w , M n and M w /
Mn values can be measured by various methods, and there are some variations due to differences in the method of definition. Therefore, in the present invention, M w , M n and M W/M
The value of n is defined as that measured by the following measurement method.

That is, all of these values are measured by gel permeability chromatography (GPC) under the conditions described below. At a temperature of 40°C,
7 g medium (tetrahydro 7 run) was flowed at a flow rate of 1.2 mQ per minute, and 3108 samples of tetrahydro 7 run sample i8 with a concentration of 0.2 g/20- were injected as an equal sample amount, and no measurements were taken.

When measuring the molecular weight of a sample, the molecular weight distribution of the sample is included in the range where the logarithm of molecule 1 and the count number of the prepared calibration curve are a straight line, using several different polystyrene filter samples. Select the measurement conditions.

The reliability of this measurement was confirmed by using a quasi-sample made of NB570G polystyrene under the above-mentioned measurement conditions.

Any GPC column may be used as long as it satisfies the above conditions, such as TSK-GEL and 0MH6 (Toyo Soda Co., Ltd.!!).

By using the microcapsule type toner according to the present invention, it has become possible to obtain an image that exhibits good fixability due to the pressure fixing time without causing the toner offset phenomenon.

Examples of the vinyl monomer used in the core material for shrinking the microcapsule toner of the present invention include styrene, p
-methylstyrene, p-tert-butylstyrene, p-
Methoxystyrene, p-phenylstyrene, 3.4-7
Chlorstyrene, methyl acrylate, ethyl acrylate, lobutyl acrylate, inbutyl acrylate, propyl acrylate, lobutyl acrylate, dodenyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, acrylic phenyl methacrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, 11-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, tothyl methacrylate,
Examples include 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, and phenyl methacrylate.

Further, the core material preferably contains a coloring agent, but in order to obtain a microcapsule toner suitable as a magnetic toner used as a -component toner, for example, magnetic toner may be included as part or all of the coloring agent. Contains fine body powder.

As a coloring agent, carbon black, nigrosine dye (
C, l No. 50415B), 7 Nirin Blue (C, l
No.

50405), Rose Bengal (C0I, No. 454)
35>, mixtures thereof, and ponds thereof.

The magnetic material may be a metal or alloy showing ferromagnetism such as 7-elite, magnetite, iron, fpartite, nickel, etc., or a compound containing these elements, or a material that does not contain a ferromagnetic element but is subjected to appropriate heat treatment. Alloys that exhibit ferromagnetism due to
Mention may be made of aluminum, alloys of the type called Heusler alloys containing manganese and copper, such as manganese-tin, or chromium dioxide, among others.

Specifically, as magnetite, EPT-1000,
EPT-500, MRMB-450C or higher, manufactured by Toda Kogyo Co., Ltd.), BL-520, [1L-SP, Its-BL,
RB-20 (manufactured by Titane Co., Ltd.) and the like are preferably used.

The mixing ratio of each of the Shinsei materials in the microcapsule type toner of the present invention is preferably as shown in the table below.

(wL% with respect to the total amount of toner) In case of two components 5-60 10-90 -
0～20j
In the present invention, it is preferable to use epoxy urethane resin or epoxy urethane resin as the outer wall. Examples of manufacturing methods preferably used in this case are as follows.

[1] The polyvalent isoneanate compound, the epoxy group-containing compound, the polymeric vinyl monomer, the vinyl monomer, the polymerization initiator, and the colorant are mixed and mixed uniformly. The mixture is poured into a dispersion medium consisting of water containing an appropriate dispersion stabilizer, and the mixture is divided into fine particles by stirring etc. to make the mixture repellent. The toner is encapsulated in the form of microcapsules, then polymerized, and stirring is continued until the polymerization is completed.6 After that, the solid matter is filtered off and dried to produce a microcapsule type toner.

Examples of dispersion stabilizers include water-soluble polymer substances such as gelatin, gelatin/derivatives, polyvinyl alcohol, polystyrene sulfonic acid, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium carboxymethyl cellulose, and sodium polyacrylate, and anionic interfaces. Surfactants such as surfactants, nonionic surfactants, and cationic surfactants, hydrophilic inorganics such as colloidal surfactants, alumina, tricarium phosphate, ferric hydroxide, titanium hydroxide, and aluminum hydroxide. Colloidal substances, etc. can be used effectively. Of course, two or more of these dispersion stabilizers may be used in combination, and appropriate auxiliary agents may also be used together.

Although the particle size of the microcapsule toner according to the present invention is not subject to any particular restrictions, the average particle size is usually 5 to 50 μm.
m1 is preferably 5 to 30 μm.

Further, the thickness of the outer wall and the particle size of the core material may be the same as in the case of conventional microcapsule type toner.

When the microcapsule type toner of the present invention contains magnetic fine powder, it can be used alone as a developer,
If it does not contain magnetic fine powder, it can be mixed with a carrier to form a two-component system. It can be used by adjusting the sharpness.

The toner of the present invention is easily torn by a pressure roller with a linear pressure of, for example, 10 to 30 kg/cm, although it varies depending on the size of its outer wall, particle size, etc.; By doing so, the toner image made of the toner can be easily fixed onto a supporting paper, for example, a transfer paper. Further, auxiliary heating may be performed at that time.

〔Example〕

Examples of the present invention will be described below, and the present invention will be carried out using these examples! l! ! It is not limited to
Note that "parts" represent parts by weight unless otherwise specified.

Example-1 100 parts of lauryl methacrylate and 2 parts of 2.2'-7zobis-(2,4-trimethylvaleronitrile) were polymerized at a temperature of 60°C for 5 hours in a nitrogen-substituted container to obtain a high molecular weight polymer ( A) was obtained.

The above high molecular weight polymer [37 parts A, 23 parts lauryl methacrylate, 0.915 parts 2,2'-azobis-(2,4-trimethylvaleronitrile), 50 parts magnetic powder εshi-520 (manufactured by Titan Kogyo Co., Ltd.), and Nophenylmethane-4,4-neuson 7ate (commercial product name: Millione) MT.

(manufactured by Nippon Polyurethane Industries Co., Ltd.) and uniformly mixed and dispersed for about 1 hour using a sand grinder to prepare the magnetic ink.1) Next, 20 g of tricarium phosphate in the form of floid and dodecylbenzene sulfone were added as a dispersion stabilizer. In an aqueous Li containing 0.2 FK of sodium chloride, using a Homono Esoter (specially manufactured by N Kako), 400 g of the above uniformly mixed drink was mixed at the rotation speed of the Homo Esoter so that the average particle size was 15 μIn. was prepared and suspended and dispersed in water.

Transfer the suspension dispersion to a four-way flask and add 40. After adding 1 drop at room temperature for about 15 minutes, 8
The temperature was raised to 0° C. and stirring was continued for 5 hours to polymerize the core material to obtain microcapsules having outer walls made of urea nails.

Next, it was cooled, 40 mQ of concentrated hydrochloric acid was added, and the
Tricalcium phosphate, which is a dispersion stabilizer, was decomposed and removed, filtered, washed with water, and dried to obtain a microcapsule type toner of the present invention.

Vinyl polymer in the core material of the obtained microcapsule type toner f) M w/ M n 13.5, M wh'
It was 110,000.

Using this toner as a developer, electrophotographic copying + mrU-B ix 1200J (manufactured by Konishiroku Photo Industry Co., Ltd.) was applied to a pressure fixing type (pressure fixing TFFI 20!l/
When image formation was performed using the modified version of am), the fixing properties were good and neither offset nor wrapping occurred.

Example 2 10 parts of the high molecular weight polymer (A) of Example-1, 20 parts of lauryl methacrylate, 2.2'-azobis (2.4
A microcapsule type toner of the present invention was obtained in exactly the same manner as in Example 1, except that 0.8 part of methylvaleronitrile) was used. The richness of vinyl polymer in this toner -/
The sword was 17.0111 and 130.000.

When an image was formed using this toner in the same manner as in Example 1, the fixing properties were good, and neither offset nor wrapping occurred.

Comparative Example-1 Example-1 except that the high molecular weight polymer of Example-1 [11 parts of A, 29 parts of lauryl methacrylate, and 1.2 parts of 2.2′-azobis(2゜4-trimethylvaleronitrile) were used]
A microcapsule type toner was obtained in the same manner as in Example 1. Mw/Mn of the vinyl polymer in this toner is 3.
1, Mw was 450,000.

When an image was formed using this toner in the same manner as in Example 1, offset occurred and image staining was observed.

Also, the fixing properties were poor, and the toner peeled off when I rubbed it with my fingers. In addition, the paper was wrinkled due to the phenomenon in which the paper was wrapped around the roller.

Comparative Example-2 Except for using 18 parts of the high molecular weight polymer (A) of Example-1, 12 parts of lauryl methacrylate, and 0.5 parts of 2.2'-7zobis(2゜4-trimethylvaleronitrile). A microcapsule type toner was obtained in the same manner as in Example-1. M + u / kio of the vinyl polymer in this toner
is 3.0. Mt+ is 250,000.

When this toner was used to form an image on the studs of Example 1, no offset occurred, but the fixing properties were poor and the toner peeled off from the paper when rubbed with a finger.

Evaluation of fixing properties Apart from the qualitative evaluation of fixing properties by finger rubbing, quantitative evaluation of fixing properties was carried out as follows.

Solid black part of the sample fixed on paper (reflection density = 1.0
) to test the friction resistance of dyed products Iso A-3010
(manufactured by Daiei Scientific Precision Manufacturing Co., Ltd.) to adjust the load to 2 kg, and
It was rubbed five times with 5 kg paper (manufactured by Konishiroku Photo Industry Co., Ltd.), and the change in reflection density (residual rate) was evaluated in percentage. Show the results to barley.

As described above, the fixing properties of the microcapsule type toner of the present invention are good.

〔Effect of the invention〕

As is clear from the above examples, according to the present invention, it is possible to provide a microcapsule type toner that has good pressure fixing properties, excellent offset resistance, and excellent secondary winding properties.

Claims (3)

[Claims] (1) In a microcapsule type toner having a core material and an outer wall for covering the core material, the core material is mainly made of a vinyl polymer having a weight average molecular weight/number average molecular weight value of 3.5 to 20. A microcapsule type toner characterized by containing it as an ingredient. (2) The microcapsule type toner according to claim 1, wherein the vinyl polymer consists of a high molecular weight component and a low molecular weight component. (3) The microorganism according to claim 2, which contains a high molecular weight component having a weight average molecular weight of 150,000 or more in an amount of 5 to 50% by weight based on the total vinyl polymer of the core material. Capsule type toner.