JPS60222867A - Microcapsule type toner - Google Patents

Abstract

PURPOSE:To obtain a microcapsule type toner having good fluidity, good strength of an outside wall and excellent pressure fixability by using a mixture composed of >=2 kinds of amines consisting of bifunctional amine and tri- or higher functional amine as the component for a resin constituting the outside wall. CONSTITUTION:The polyurethane resin or polyurea resin formed by bringing isocyanate into reaction with the mixed amines composed of the bifunctional amine such as ethylene diamine, phenylene diamine or 4,4'-diaminostylbene-2,2'-sulfonic acid (Na salt) and the tri- or higher functional amine such as diethylene triamine or triaminobenzene as the amine component in the resin constituting the outside wall of the microcapsule type toner at a suitably selected molar ratio or the polyamide resin formed by bringing polybasic acid halide into such mixed amines is used for said outside wall. The toner which is fixable under low pressure, obviates blocking, etc. during production and storage of the toner and has high strength and excellent fluidity is thus obtd.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a toner for developing electrostatic images, and more particularly to a microcapsule toner that can be suitably used as a pressure fixing type toner. be.

[Prior art]

In recent years, electrophotographic methods, electrostatic printing methods, and electrostatic recording methods are used to form an electrostatic charge image based on image information and develop it with toner as a developer to form a toner image. Generally, a visible image is formed by transferring this toner image onto a transfer paper or the like and then fixing the toner image.

Conventionally, as toner for developing electrostatic images, powdered toner obtained by finely pulverizing a thermoplastic resin as a binder and a colorant such as 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 beads, or if it is a one-component toner containing fine magnetic powder, it is stirred by itself. The toner image is triboelectrically charged, an electrostatic charge image is developed using the electrostatic force, and the resulting toner image is transferred, for example, and then heated with a heating roller or the like to be fixed.

However, in such toners, the toner particles are crushed during agitation for frictional charging and fine powder toner is generated, resulting in poor visible image quality, or the toner must be replaced with a new one early. Not only is it necessary to do this, but also because fixing is achieved by a heat fixing method,
A long waiting time is required for the temperature of the fuser to rise to the required set temperature, and a large amount of energy is required for heating, which can also cause a fire if paper jam occurs. Moreover, in order to achieve reliable fixing, it is necessary to satisfy fairly strict conditions such as temperature conditions.

Under these 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 has the advantage that it does not cause various problems, does not require warm-up time, and requires less energy for fixing.

However, the pressure fixing method described above has poor fixing properties compared to fixing methods using heat, etc., and is easy to peel off when rubbed, and requires high pressure, which can destroy the fibers of the image forming support, such as copy paper, and cause the paper to deteriorate. There were drawbacks such as the paper becoming weak and the surface of the copy paper becoming excessively glossy and sticky.

In order to solve these drawbacks, research has recently begun on the use of so-called microcapsules as toners for developing electrostatic images. This microcapsule type toner is a powder type toner in which a liquid substance or soft solid exhibiting pressure fixability and a colorant are enclosed as core materials in fine particle resin capsules.

This microcapsule type toner can encapsulate sticky soft solids, etc. in the core, so it has better powder characteristics than conventional pressure foot toners made of a single resin.
It is expected to have advantages such as being able to fix at low pressure and not causing aggregation, blocking, etc. during toner production or storage.

However, the reality is that conventional microcapsule toners have not yet provided satisfactory results. For example, JP-A-54-76233 discloses a technique for obtaining a polyamide film by polycondensation of acid chloride and a trifunctional amine such as diethyltriamine, but microcapsule type toner is manufactured using acid chloride. However, there is a problem in that the acid chloride is hydrolyzed when it is made into small particles, making it difficult to carry out the film-forming reaction stably, and the rate of hydrolysis becomes particularly high at pH 7 or higher during emulsion production.

This becomes a big problem when small particles of 8 to 25 microns are required, such as microcapsule toner.

Furthermore, Japanese Patent Application Laid-open No. 56-64349 discloses a technique using a cross-linked resin for the outer wall, and Japanese Patent Application Laid-Open No. 57-179860
The publication discloses a technique in which polyurethane resin or polyurea resin is obtained by polyaddition or condensation of isocyanate and diamine, etc., and this is used as an outer wall. According to such techniques.

It is true that crosslinking increases the film strength and rigidity of the outer wall resin, but on the other hand, when used as a toner, the impact strength decreases and it becomes brittle, making it difficult to stir the toner particles in the '-C1 developer, or When mechanical force such as classification is applied, a part of the outer wall tends to be easily destroyed, which has the disadvantage of causing a decrease in fluidity.

The inventors of the present invention have made intensive studies to solve the drawbacks of the conventional technology, and have found that although the outer wall of the conventional microcapsule toner uses a crosslinking resin, the degree of crosslinking is not controlled. Therefore, mechanical strength is weak,
In particular, it was found that this caused a decline in liquidity.

That is, it was discovered that there is a certain correlation between the degree of crosslinking of the outer wall and the mechanical strength of the resin, and this led to the completion of the present invention.

[Purpose of the invention]

An object of the present invention is to provide a microcapsule type toner in which the degree of crosslinking of the outer wall resin can be controlled and, as a result, the mechanical strength of the resin can be adjusted to appropriate physical properties.

[Structure of the invention]

The above-mentioned object of the present invention is to provide a microcapsule type toner having a core material containing a pressure-fixable substance and an outer wall of a reservoir covering the core material, in which an amine component in a resin constituting the outer wall contains two or more plants. This was achieved by a microcapsule type toner characterized in that it consists of a mixture of amines.

The present invention will be explained in detail below.

The microcapsule toner of the present invention is composed of an outer wall and a core material. The outer wall has the above structure, and the core material contains a pressure fixing substance and a coloring agent. Note that the coloring agent may be contained in the outer wall instead of the core material, or may be contained in both the core material and the outer wall.

One of the features of the present invention is that it provides a novel technical concept of controlling the degree of crosslinking of the outer wall, and as a means for controlling this, a mixture of two or more types of amines is used, and as a result, the mechanical strength is improved. The purpose is to form a microcapsule type toner having appropriate physical properties and to improve fluidity, which is extremely important as a toner physical property.

As the mixture of 2a1 or higher amines, a mixture of a difunctional 113 amine and a trifunctional or higher amine is used.

Examples of difunctional amines include ethylenediamine, hemethylenediamine, and phenylenediamine.

Xylylenediamine, diamino/chlorhexane, hyherazine, 4.4'-diaminodiphenylmethane, 4.4'
-diaminodiphenyl ether, 4,4'-diaminostilbene-2,2'-sulfonic acid and its sodium salt.

Further, examples of trifunctional or higher functional amines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine, and triaminobenzene.

One or more of the above amines may be arbitrarily selected and used, and other polyamines having different molecular chain lengths may be mixed in order to impart elasticity.

The mixing ratio of two or more types of amines is preferably 1 to 50 mol%, more preferably 2 to 30 mol%, of trifunctional or higher polyfunctional amines in the total amines.

The amines are reacted with incyanates to give polyurethane or polyurea resins as the outer wall resin, and with polybasic acid halides, preferably acid chlorides, to give polyamides. Although the present invention is particularly effective in the reaction of the above-mentioned amine with incyanate, it is of course not applicable to the reaction with acid chloride.

As the above-mentioned incyanate, for example, the following can be mentioned as suitable ones.

1) Hexamethylene diincyanate 0ON (UH2) aNo (J Commercial product name: "Sumidur H" (manufactured by Sumitomo Bayer Urethane) 2) Hexamethylene diincyanate adduct Commercial product name =
"Sumidur N" (manufactured by Sumitomo Bayer Urethane) 3) Metaphenylene diisocyanate C0 4) Toluylene diisocyanate OO Commercial product name: "Suminate 80" (manufactured by Ousui Kagaku Kogyo) "Hiren TMJ (manufactured by DuPont) 5 ) 2.4-) Rylene diisocyanate Commercial product name: “
6) Reaction product of toluylene incyanate and trimethylolpropane Commercial product name: ``Sumidur ■□'' (Manufactured by Sumitomo Bayer Urethane) Commercial product name: ``Coronate L'' (manufactured by Nippon Polyurethane Kogyo Co., Ltd.) 7) 3,3'-dimethyl-diphenyl-4,4'-diincyanate Commercial product name: "Hyren H" (manufactured by DuPont) [Suminate BTJ (manufactured by Ousui Kagaku Kogyo Co., Ltd.) 8) Diphenylmethane-4,4'-diisocyanate Commercial product name: "Millionate MTJ (manufactured by Nippon Polyurethane Industries, Ltd.) r l5onate 125 M J (manufactured by Kasei Upjohn Co., Ltd.) "Sumidur 44S" (manufactured by Sumitomo Bayer Urethane Co., Ltd.) 9) 3.3 '-dimethyl-diphenylmethane-4,4
'-diisocyanate Commercial product name: "NO-ILENE DMM J (manufactured by Devon Co., Ltd.) 10)) Liphenylmethane-triincyanate CO Commercial product name: "Sumidur Rin" (manufactured by Sumitomo Bayer Urethane Co., Ltd.) 11) Polymethylene phenyl isocyanate Commercial product name =
“Sumidur 44V-10” (manufactured by Sumitomo Bayer Urethane Co., Ltd.) “Millionate M” (manufactured by Nippon Polyurethane Industries Co., Ltd.) 12) So-7talene-1,5-diisocyanate OO OO Commercial product name: “Sumijil 15” (Sumitomo Bayer Urethane Co., Ltd.) (manufactured by Urethane Co., Ltd.) 13) Dicyclohexylmethane diisocyanate commercial product name = "Desmodur W" (manufactured by Sumitomo Bayer Urethane Co., Ltd.) 14) Diphenyl ether-4,4'-diisocyanate commercial product name = "Suminate E" (manufactured by Ousui Kagaku Kogyo Co., Ltd.) As the modified polyvalent incyanate, for example, the product name [Sumidur 44P-90J] is used.

[Smijl 3062j, "Smijl PFj,"
Sumidur ODj, r Sumidji, -ru 0632J, "Sumidur PC" (manufactured by Osui Bayer Urethane Co., Ltd.)
, "Coronate EHj, r Coronate HLJ, [Coronate 2014J, r Near 0 Ne-) APJ, l'-Coronate 1-2501J, r Millionate MS-50J, [Coronate 3041J (and above.

manufactured by Nippon Polyurethane Industry Co., Ltd.), [Duranate 24A-
900XJ% "Duranate EXPD-101" (manufactured by Asahi Kasei Industries, Ltd.), "Takenate M-402", "
Takene 1-F-513'', r Takene D-102J
, rTakenate L-1150'' (manufactured by Kurade Yakuhin Kogyo Co., Ltd.) and the like are preferably used. It goes without saying that even compounds other than those mentioned above can be used as the polyvalent incyanate as long as they have a plurality of incyanate groups.

The mixing ratio of the above incyanate and amine is l:1 to 50 equivalents, preferably l:1.1 to 40 equivalents.

Acid chlorides that can react with the above amines to obtain polyamides include adipoyl chloride, sebacoyl chloride, phthaloyl chloride, inphthaloyl chloride, terinophthaloyl chloride, fumaroyl chloride, and 1,4-cyclohexane. Examples include diacid halides such as dicarbonyl chloride, 4,4'-biphenyldicarbonyl chloride, and 4,4'-sulfonyldibenzoyl chloride, and trifunctional acid halides such as trimesoyl chloride, and two or more It may also be used as a mixture of difunctional and trifunctional acid chlorides, and mixtures with difunctional and trifunctional acid chlorides are also preferably used. The mixing ratio at this time is 2
Functionality = trifunctionality = 99:l to 60:40°, preferably 99
: 1 to 80 : 20.

In the present invention, another third resin may be copolymerized or blended with the outer wall containing the polyurethane resin, polyurea resin, and/or polyamide resin. Examples of the third resin include polyester resin, acrylic resin, styrene resin, and styrene-acrylic resin.

As the core material constituting the microcapsule type toner of the present invention, a pressure fixing material such as a liquid material or a soft solid material containing a colorant is used. Any material may be used as long as it has fluidity or plasticity, and the viscosity is 10 to 1 at a temperature of 60°C.
0,000,000 cps is preferred. Specific examples include liquid polybutene, liquid polychloroprene, liquid polybutadiene, epoxidized soybean oil, and epoxy7ated triglyceride.

Epoxidized monoester, adipic acid polyester,
Liquid polyester, chlorinated paraffin, trimellitic acid ester, vegetable oils such as soybean oil, silicone oil, mineral oil, polymethyl acrylate, polybutyl acrylate, and polylauryl methacrylate.

Acrylic acid ester oligomers, styrene monomer oligomers, styrene and furkyl acrylate copolymer oligomers, styrene and alkyl methacrylate copolymer oligomers, petroleum residues such as polyvinyl acetate, asphalt, and kiltnide, as well as linoleic acid and linolenic acid. ,oleic acid.

Esters of unsaturated fatty acids such as elaidic acid, eleostearic acid, lyrinelaidic acid, gadolenic acid, erucic acid, arachidonic acid, curbanodonic acid, α-lycanic acid, linseed oil, eno oil, tung oil.

Castor oil, hemp oil, kapok oil, poppy oil, sesame oil,
Vegetable oils that are drying or semi-drying oils such as rice bran oil, safflower oil, soybean oil, corn oil, rapeseed oil, sunflower oil, cottonseed oil, copolymers of acetylene and butadiene, synchropentadiene oligomers such as 1- Examples include synthetic drying oils such as "Finton" (manufactured by Nippon Zeon Co., Ltd.), and others.

In order to obtain a microcapsule type toner suitable as a magnetic toner used as a -component toner, for example, the core material contains a colorant.

Fine magnetic powder is contained as part or all of the colorant.

As a coloring agent, carbon black, nigrosine dye (
0, 1, 50415B), Aniline Blue (U, 1.
50405), Calco Oil Blue (0°1-N
azoic Blue 3), Kurumi x o
-(0,1,Ni114090), Ultramarine k
(0, I-N (L77103), DuPont Oil Red (0,1,, NCL26105), Quinoline Yellow o
f (0,1, NCL47005), methylene blue chloride (0,i, Na52015), phthalocyanine blue (0,1, No.

74160), malachite green offsalate (0,
1, Nα42000), Langblack (C・■・隘7
7266), Rose Bengal (0,1, NIIL454
35), mixtures thereof, and others. These colorants need to be contained in a sufficient proportion to form a visible image with sufficient concentration, and are usually 1 to 20 parts by weight per 100 parts by weight of the liquid substance. It is said that

The magnetic material may be a ferromagnetic metal or alloy such as iron, cobalt, or nickel, including ferrite and magnetite, or a compound containing these elements, or a material that does not contain a ferromagnetic element or is subjected to appropriate heat treatment. Examples of alloys 1 that exhibit ferromagnetism include alloys called Heusler alloys containing manganese and copper such as manganese-copper-aluminum, manganese-copper-tin, chromium dioxide, and others. These magnetic materials have an average particle size of 0. It is uniformly dispersed in a liquid substance etc. in the form of a fine powder of l -1 μm. The content thereof is 20 to 70 parts by weight, preferably 40 to 70 parts by weight of 4Q' per 100 parts by weight of toner.

The microcapsule type toner of the present invention can be suitably produced, for example, as follows. That is.

For example, an example of a manufacturing method preferably used in the present invention is as follows.

(υ After uniformly mixing the incyanate (oil-soluble monomer), the pressure fixing substance, and the colorant, pouring this mixture into a dispersion medium such as water containing an appropriate dispersion stabilizer, Stirring, etc. 9 Disperse and suspend the above mixture (it is preferable to carry out the process up to this point below room temperature)
. Thereafter, the temperature of the yarn is raised (there are two ways to raise the temperature: either suddenly or gradually. The degree of reactivity is maintained at Q1, and an amine (water-soluble monomer) that reacts with the isocyanate is added to the water. Stirring is continued until the reaction is completed.Then, the solid matter is separated from P and dried to produce a microcapsule type toner.

(2) When the pressure-fixable substance is a polymeric substance in method 0 above, the monomer of the pressure-fixable substance and its polymerization initiator are added, and the monomers are first encapsulated in flare or urethane resin. It may also be made into a pressure fixable material by first polymerization.

[When adding 312 or more types of amines, they may be added simultaneously or separately. For example 2
K at the same time as adding the functional amine.

Alternatively, a trifunctional or higher polyfunctional amine may be added after the addition.

In the methods such as [υ~(3) above], in order to control the particle size of the obtained donor, it is sufficient to control the particle size of the fine particles of the mixture in the reaction system.

For example, this can be achieved by controlling the stirring force while monitoring the particle size and dispersion degree of the fine particles using a microscope or the like.

Further, in order to mix and disperse the colorant into the mixture, a ball mill, an atrique, a sand grinder, etc. may be used, but the colorant may be treated with a silane coupling agent, a titanium coupling agent, etc. ,
Alternatively, a dispersion improver such as lecithin for dispersing inorganic substances into organic substances may be added.

As a means for dispersing the mixture of the liquid substances and the like in the dispersion medium, mechanical stirring means such as a homomixer, homojetter, Waring blender, etc., or ultrasonic dispersion is used. It is actually necessary to add a dispersion stabilizer to the dispersion medium, thereby maintaining a stable suspension state during the polymerization reaction.

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 inorganic materials such as colloidal silica, alumina, tricalcium 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.

Note that the particle size of the microcapsule toner according to the present invention is not subject to any special restrictions, but the average particle size is usually 5 to 5.
The thickness is 50 μm, 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,
When the developer does not contain magnetic fine powder, it can be mixed with a carrier to prepare a two-component developer.

Although the carrier is not limited to 1%, iron powder, glass beads, etc., or resin-coated versions thereof are used, and the toner concentration in the developer consisting of the carrier and toner is 0.
It is 2 to 1Qwt%, preferably 1 to 5wt%. Further, the particle size of the carrier used is 25 to 1000 μm, preferably 30 to 500 μm.

The toner of the present invention is easily torn by a suppression roller with a linear pressure of, for example, 10 to 30 kg/aT+, although this varies depending on the thickness of its outer wall, particle size, etc. 1For example, a fixing device may be configured with such a suppression roller. By forcing
A toner image made of the toner can be easily fixed onto a supporting paper, for example, a transfer paper.

That is, when the capsule is ruptured, the core material sealed inside is released, but since this core material is a pressure-fixable material containing a colorant, it has sufficient visibility.
Moreover, since pressure is applied to areas that have fluidity or plasticity, the image pressure fixing substance enters or is pushed between the fibers of paper such as transfer paper and is captured.
As a result, the toner image is obtained without being disturbed, ie without sacrificing resolution.

〔Effect of the invention〕

According to the present invention, since a mixture of two or more types of amines is used, the degree of crosslinking can be freely controlled, and as a result, a microcapsule type toner can be obtained that provides appropriate physical properties such as mechanical strength. In particular, the content of crosslinking components is 2 to 30
It has been found that when the degree of crosslinking is controlled to be mol %, the fluidity of the toner becomes extremely good.

〔Example〕

Examples of the present invention will be described below, but the embodiments of the present invention are not limited to these. In addition"
"Part" means 1 part by weight unless otherwise specified.

Preparation of the toner kite 1 of the present invention The above materials were mixed and stirred in a sand grinder for about 1 hour to uniformly mix and disperse to obtain a magnetic ink.

Separately, a dispersion liquid was prepared by uniformly dispersing 0.06 g of colloidal tricalcium phosphate 14.9° sodium dodecylbenzenesulfonate A prepared with trisodium phosphate and calcium chloride in 800 d of water.

Next, the magnetic ink was added to this dispersion.

Using a homogenter (manufactured by Tokushu Kika Kogyo Co., Ltd.), the number of revolutions is 8.
Approximately 5-2 000-9000 rpm under optical microscope observation
The mixture was dispersed for about 10 minutes to form fine oil droplets with a diameter of 0 μm.

Next, the dispersion was transferred to a second four-bottle flask, and under low-speed stirring, an aqueous solution 7 in which (0+) and (C2) were dissolved was added.
0 was added over about 15 minutes at room temperature. Next, the temperature was gradually raised and the mixture was reacted at 80° C. for 7 hours to obtain i-microcapsules having the core material as the core material and the urea polymer as the outer wall.

Next, it was cooled and 40 liters of concentrated hydrochloric acid was added.

Tricalcium phosphate, which is a dispersion stabilizer, was removed by dispersion, filtered with F+, washed with water, and dried to obtain a microcapsule type toner of the present invention.

In the above, (5), CB), (01), (0
2) using the substances shown in Table 1, toner N of the present invention
αl was obtained.

Production of Toner Nα2 of the Present Invention In the production of toner NCL1 of the present invention, the two amine components (C1) and (0□) are added separately, that is, after adding (C1), (02) is added to (C1). Toner Nα2 of the present invention was obtained in the same manner, except that the above was added in the same manner.

Manufacture of Comparative Toners Nα1 and 2 In the manufacture of toner ml of the present invention, comparative toner NcL was prepared in the same manner as toner 41 of the present invention using the substances shown in Table-1.
1 and tooth 2 were manufactured.

Experimental example Liquidity assessment Toner NCL 1 of the present invention obtained as described above.

Flowability was measured for each of Comparative Toner No. 2 and Comparative Toner NcLl, 2. The evaluation method was based on the quietness density described below. This method is one of the liquidity evaluation methods.
This is a simple method for evaluating fluidity in a system where there is no large difference in density, such as an L-book system, and the larger the value, the better the fluidity.

(Measurement method) To make it simple for a laboratory, a cone-shaped funnel was placed on top of a 20 mIL graduated cylinder, and microcapsule-type toner was gently dropped through a 100-mesh sieve from above.
Toner 2otni at that time! The weight was measured and the quietness density was calculated.

(Measurement Results) The results are shown in Table 1. υ1 It can be seen that the toner of the present invention has good fluidity.

Toner style of the present invention 1. 2 and comparative toner N11l, 2 were visually inspected for the presence or absence of cohesiveness. The results are shown in Table-1.

Claims (1)

[Claims] A microcapsule type toner having a core material containing a pressure fixing substance and an outer wall for covering the core material,
A microcapsule type toner, wherein the amine component in the resin constituting the outer wall is a mixture of two or more types of amines.