JPS58144838A - Pressure-fixable microencapsulated toner - Google Patents

Abstract

PURPOSE:To provide a pressure-fixable microenpsulated toner fixable with low pressure and capable of forming a sharp image, by microencapsulating a core material contg. a reactive resin and a colorant, and having specified ranges of complex elasticity and viscosity. CONSTITUTION:A reactive resin polymerizable and hardenable by aerial oxidation, such as linseed oil or maleic acid-modified oil, or that consisting of a compsn. of at least 2 kinds of resins polymerizable and hardenable by mixing, such as a compsn. of epoxy resin and phenol resin, is mixed with a polymerization initiator, a hardening catalyst, a colorant, and a viscosity-increasing agent, etc. to prepare a core material having 5X10<3>-5X10<7>dyne/cm<3> complex elasticity at 25 deg.C and in 10Hz condition, and 10-10<5> poises viscosity. An intended microencapsulated pressure-fixable toner is obtained by microencapsulating this core material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a pressure fixable microcapsule toner,
More specifically, it relates to a pressure-fixable microcapsule toner that can be fixed at low pressure and provides clear images.

[Technical background of the invention and its problems]

Conventionally, in electrophotography, etc., a required electrostatic charge image or electrostatic charge pattern (latent GL) is formed on the surface of a photoconductor, and colored powder (toner) having an opposite charge is deposited on this electrostatic charge image.
By contacting the photoconductor with a developer containing the toner, the toner is deposited on the photoconductor surface and a visible or developed image is obtained. Visualization of the electrostatic charge, that is, development, can be achieved by, for example, a cascade development method using a mixed developer of toner and carrier, a magnetic brush development method, or a current development method consisting only of toner. This is done by a fur brush development method or touch development method using a chemical agent. In this way 3jl
The S9 wounds are transferred to a transfer material such as paper as necessary and fixed.

Conventionally, the following methods have been adopted for fixing toner images. That is, (1) a method in which the toner is heated and melted using a heater or a heat roller, etc., to fuse and assimilate it to the transfer material; (2) a method in which the binder resin in the toner is softened or dissolved with an organic solvent, and the toner is melted on the transfer material; and (3) a method of fixing the toner on the transfer material by applying pressure to the toner.

Among Hire et al.'s methods, method (1) requires a heat source;
Furthermore, method (2) has problems such as generation of vapors from organic solvents and the like. On the other hand, the method (3) of fixing toner by pressure does not have the above-mentioned problems, but is energy-saving and pollution-free, and can copy immediately when the copying machine is turned on. , has the advantage of being capable of high-speed fixing.

Several proposals have been made in the past regarding methods of fixing such toner by pressure. For example, Japanese Patent Publication No. 44-9880 discloses pressure fixing toner compositions comprising aliphatic components K IaCn to C1m, and Japanese Patent Publication Nos. 48-75033 and 48-7
No. 8936 discloses an electrostatic photographic toner made of a hard polymer.

However, these pressure fixable toners are manufactured by a pulverization method. Therefore, if the binder resin used in the toner is soft, the manufacturing process will be difficult, and the manufactured toner will also tend to aggregate, making it difficult to store it for a long time. Can not. Therefore, it is necessary to use a somewhat hard Ingu resin, and in order to fix toner using such Ingu resin, 300 to 9/ctl is required.
This method has a problem in that a high fixing pressure of 1 or more must be applied.

On the other hand, Japanese Patent Publication No. 34-8561 discloses a pressure-adhesive toner comprising an encapsulated oil-based colorant).
Also, Japanese Patent Laid-Open No. 48-71648 discloses a pressure fixable toner comprising a capsule containing a solvent. In these toners, since the capsule core material is liquid, they exhibit good fixing properties without applying high fixing pressure, but the images formed may smear or flow, and the bleed resistance is poor. It also has problems such as a low viscosity and offset during fixing.

Also, Special Publication No. 48-75032 and No. 49-177
No. 39, etc., discloses a nine-pressure fixable toner in which a soft polymer is encapsulated. However, when manufacturing the core material, such a toner requires the same processing steps as the toner using the pulverization method, so the single core material must be somewhat hard. In order to do this, a high pressure of 5001 v/c- or higher is required, and the toner fixing properties are still insufficient.

In this way, capsule toners that use a housing as the core material have good pressure fixing properties, but they suffer from the problems that the formed images lack sharpness and have poor offset resistance and bleed resistance. have.

On the other hand, in a toner using a soft resin as a core material, the image formed is clear, but there is a problem in that the fixing property of the toner is not required.

[Object of the Invention] The object of the present invention is to eliminate the above-mentioned problems, to provide a pressure fixing microphone that exhibits good surface fixing properties at low pressure, has excellent offset resistance and bleed resistance, and provides sharp images. Our goal is to provide four capsule toners.

[Summary of the invention]

The pressure fixable microcapsule toner of the present invention is a microcapsule toner comprising a reactive resin, a reaction initiator for the reactive resin or a curing catalyst, and a colorant as a core material, wherein the core material is heated at 26°C. It is characterized by having a complex modulus of elasticity of 5 x 10'' to S x 10 madyne/cd and a viscosity of 10 to 10'Pols* under the condition of 10Hi.

In the following, the invention will be explained in more detail.

The complex modulus and viscosity of the core material used in the present invention are measured as follows.

That is, the complex modulus of elasticity G'' is determined by dynamic viscoelasticity measurement at 10 Hz, and the measurement is performed by first placing a sample into a shallow cup-shaped lower cell to a certain thickness. A disk-shaped upper cell is attached to the frame, and a constant load is applied to the lower cell through a mechanism.Next, a sinusoidal vibration of a constant amplitude is applied to the lower cell by an electromagnetic vibrator for 10 hours.This vibration causes The stress generated in the sample is detected by the load cell through the upper cell and sent to the amplifier calculation circuit.The calculation circuit separates the stress and strain into components in the same phase, and from each component, the storage modulus E' and the loss The elastic modulus Bi is determined.Therefore, the multiple index tensile modulus E'' is determined using the following formula. In the material of the present invention, the -Ason ratio is close to 0.5, so the complex elastic modulus can be obtained from the following equation.

G~Top E'E' 2 (Eη+1 In addition, there are no particular restrictions on the equipment used for viscosity measurement as long as it is one that is normally used for measuring the viscosity of resins, etc.; Examples include testers. It is particularly preferable to use the Koka Type 74 tester because it allows measurement over a wide viscosity range, usually 1 to 10'poise.

Viscosity measurement using Koka type flow tester, for example,
The test can be carried out using a Koka-type flow tester manufactured by Takasu Seisakusho ■ in a manner similar to that described in Ohka Journal 63@A3 (1960) p. 427.

The core material used in the pressure-fixable micro-bag cell toner of the present invention has a complex modulus of 5 x 10' to 5 x 10' dyne/c-dyne obtained by the above measurement method, and a viscosity of is 10~""poise". If the complex elastic modulus is less than 5 x 10'dyne/cJ, offset will occur when pressure fixing is performed, and S
The statue also bleeds. On the other hand, 5 X 10' dyn
If the viscosity exceeds 10 pols, high pressure is required for fixing and the fixing performance deteriorates.If the viscosity is less than 10 pols, the sharpness of the image formed will be poor, and the setting resistance and bleed resistance will deteriorate. On the other hand, if it exceeds 10'poig@, the isn formed is clear but the toner fixability becomes poor.

The curing or polymerization of the reactive resin during pressure fixing of the pressure fixable microcapsule tonano of the present invention can be carried out by the following method. That is, for example, (1) a reactive resin having an unsaturated bond is used, a drying aid (dryer) is added as necessary,
A method of curing by oxidative polymerization of the resin by oxygen in the air by breaking the capsule during pressure fixing, (2) using two or more types of resins that react and harden when mixed as reactive resins, Each of the seven resins is filled into separate microcapsules.

(3) Reaction of a polymerization initiator or latent curing catalyst for reactive resins, which functions in the presence of oxygen, by breaking the capsule during pressure fixing to bring the respective resins into contact and curing the reaction. The initiator or the latent curing catalyst is filled in microcapsules together with a reactive resin, and when the capsule is destroyed during pressure fixing, the initiator or the latent curing catalyst comes into contact with oxygen in the air and develops its function, causing the resin to polymerize or curing method, and (4) at least 28i class latent curing catalysts for reactive resins that exhibit their functions when mixed are separately filled in microcapsules together with reactive resins, etc.; Due to the destruction of the capsule during pressure fixing,
The above-mentioned latent curing contact #IQI 7+; brought into contact,
The method for curing the resin to express its function can be cited.

Examples of the reactive resin used in the present invention include ole-/Y-, polymers, and oils having unsaturated groups such as vinyl groups, functional groups such as epoxy groups, carboxyl groups, or amide groups; They can be used in appropriate combinations.

Specifically, substances that can be used in the method (1) include 1, for example, linseed oil, linseed oil, soybean oil, poppy seed oil, dehydrated castor oil, and K stand oil, Gail oil, etc. that have been heat-treated with these oils. natural drying oils; synthetic drying oils such as styrenated oils, vinyltoluenated oils, and i-reinated oils; or modified phenolic resins and modified alkyd resins that are dissolved and recombined with these drying oils. At this time, as a dryer added as necessary, for example, an acid such as boric acid, naphthenic acid, fatty acid, rosin acid, etc. is combined with metal such as cobalt, manganese, lead, zinc, calcium, iron, or steel. Also, the reactive resin used in the method (2) is an acid anhydride, etc. Combinations with lyamide, polyamine, phenol resin, silicone resin, etc. may be mentioned. Any epoxy resin having one or more epoxy groups in its molecule can be used, and all commercially available resins from liquid to solid can be used.

Examples of acid anhydrides include maleic anhydride resin, trimellitic anhydride, pyramellitic anhydride, etc.
Examples of lyamide include persamide (manufactured by General Ken's ■) (V@rsamld*, Gen@ra1m).
il1g), Sunmide (8unmid, made by Sanwa Kagaku ■), Lacquakendo N-153 (Lukamid)
e N-153, manufactured by Dainippon Ink■), 4-rear construction L
-15-(Po1)'aml-d/L-15, manufactured by Sanyo Oil & Fats ■), etc. As the polyamine, for example,
Examples include adducts of aliphatic polyamines such as diethylenetriamine and triethylenetetraone with ethylene oxide, propylene oxide, or edoxy resins, and aliphatic amine siloxanes. In this method,
Not limited to the above-mentioned resins, any resin can be used as long as it reacts with the resin.

Furthermore, the resins used in methods (3) and (4) include, in addition to the resins used in (1) and (2),
For example, liquid polybutadiene, those having a vinyl group such as ester acrylate, urethane acrylate, epoxy acrylate, phenolic resin, unsaturated I
Examples include polyester resins, alkyd resins, urethane resins, silicone resins, and modified products of these resins.

In the present invention, examples of the polymerization initiator or latent curing catalyst used in the method (3) include redox catalysts and organometallic compound catalysts. As the redox catalyst, for example, 0-dimethylaniline-m-tolylmethylsulfone or p-)
Rylzosulfoxide, can-α“-aminothioether-
C1-, Ol-α-hydroxythioether-C1-, Ol-mercagutan-CI-, and the like. In addition, examples of organometallic compound catalysts include Heto, B Rs
,BRt C/,A/R,,Zn&,Cd&,CdZn
One type selected from the group consisting of R*, 8bRs, BIRs, and LiR (wherein R represents an alkyl group such as a methyl group or an ethyl group, an alkenyl group, an alkynyl group, or an allyl group). Species or more□, to-Zn&-alcohol or amine (wherein R has the same meaning as above.)
and Ox -BRIOR'0BR4NHR' @BF
sON (wherein R has the same meaning as above, and R' represents a methyl group, an alkyl group such as ethyl group, an alkenyl group, an alkynyl group, or an allyl group), and the like.

In addition, as the latent curing catalyst used in the method (4), for example, when the reactive resin has a vinyl group, a catalyst derived from an oxidizing agent-reducing agent may be mentioned, When the resin has an epoxy group, an alkalidenium chelate-silanol catalyst may be used. Among the above, examples of oxidizing agents include hydro(ruoxides), such as organic (ruoxides) such as dialkyl peroxide and diacyl peroxide, and examples of reducing agents include tertiary adenates, naphthene Examples of aluminum chelates include acid groups, mercagutans, and organic metal compounds such as A/(CJs)s・B(Cd(s)3 and Zn(C*Ha)).On the other hand, examples of aluminum chelates include, for example, aluminum Examples include β-diketone compounds such as cum acetylacetonate, in which an alkyl group is bonded to the α-position carbon of an aluminum atom as a ligand; Examples include silicon compounds.

As the colorant used in the core material of the pressure-fixable microcapsule toner of the present invention, any pigment such as caseno black or various dyes that have been conventionally used as a colorant in toners can be used. It's possible to make a difference. Furthermore, if it is desired to obtain a magnetic toner, this can be achieved by adding magnetic powder to the toner. It is preferable that the amount of the colorant to be blended is appropriately selected depending on the use of the pressure-fixable microcapsule toner.

The core material of the pressure-fixable microcapsule toner of the present invention having the composition described above may contain various thickeners or diluents in order to adjust its viscosity and complex modulus. As the thickener, any substance can be used as long as it is a relatively high viscosity resin that is compatible with the reactive resin component or a substance that becomes spherical when swollen by the reactive resin. rubber, tetrazine-modified phenol resin, etc. In addition, as a diluent, any type of monomer or dimer having a functional group such as a vinyl group or an epoxy group, or a low-viscosity oligomer can be used. For example, acrylic acid ester, methacrylic acid, etc. Examples include monomers such as esters and dimers.

The pressure fixable microcapsule toner of the present invention can be manufactured by conventionally known techniques. Examples of such manufacturing methods include a spray dryer method, an interfacial polymerization method, a coacervation method, a phase separation method, and an in 5ttu polymerization method, which can be appropriately selected depending on the purpose. The encapsulant is not particularly limited as long as it is a substance that is normally used in microcapsulation.

[Effects of invention]

The pressure fixable microcapsule toner of the present invention is stable without causing aggregation or the like during storage. Further, this microcapsule toner exhibits good fixing properties without requiring high fixing pressure unlike conventional microcapsule toners. Furthermore, since the microcapsule toner has excellent offset resistance and bleed resistance, the images obtained by using the pressure fixable microcapsule toner of the present invention are clear and free from smearing. EXAMPLES Below, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

In the examples, all parts represent parts by weight.

Example 1 A core material having the following composition was prepared. Using a roll building, the above mixture was heated at 50° C. under a nitrogen atmosphere of π.
After kneading for 0 minutes, this mixture was emulsified and dispersed in 250 parts of 511 gelatin aqueous solution at 60°C. While stirring this emulsified dispersion, the temperature was lowered to 40 ± 1°C, and 250 parts of a 5% by weight aqueous Arabic ♡um solution and 50 parts of 40°C warm water were added.
After adding 0 part of each one after another, a 10% acetic acid aqueous solution was gradually added dropwise to adjust the pH of the emulsified dispersion to 4.0 to 4.3K.
i! II was set up. Then, the liquid was cooled to 5°C and 3
After adding 4 parts of 7% formalin, a 10% NaOH aqueous solution was gradually added dropwise to adjust the pH of the liquid to 9.

Further stirring was continued, and the temperature of the liquid was raised to 50°C at a heating rate of 1°C/min to harden the capsule wall. To this capsule dispersion, 15 parts of solid polystyrene latex emulsion (0602 Latex Emulsion manufactured by Nippon Gosei Rubber) was added, and dried using a spray dryer at an inlet temperature of 200°C and an outlet temperature of 150°C.
It was dried under conditions of 0.degree. C. to obtain a pressure-fixable microcapsule toner.

To 100 parts of the micro capsule toner thus obtained, 0.5 parts of hydrophobic silica was added and mixed to improve fluidity to remove latent electrostatic charges, and then pressure fixing was carried out. Ta. As a result, a clear image without smearing was obtained, no offset to the pressure roll occurred, and no set-off occurred even when the copies were stacked. In addition, the fixed image slightly adhered to the finger when touched immediately after fixing, but 3
After 0 minutes, it was confirmed that it was dry to the touch.

Example 2 A core material having the following composition was prepared.

By performing the same operation as in Example 1 using the above mixture, a pressure fixable microcab toner was obtained.

Got it like Jin! In the same manner as in Example 1, 0.5 part of hydrophobic silica was added and mixed to 100 parts of Ikro Kaguseru toner, and this was used to create electrostatic latent scratches and pressure fixing was performed. As a result, a clear image without smearing was obtained, no offset to the pressure roll occurred, and no set-off occurred even when the copies were stacked. Also, the fixed image is
It was confirmed that it was dry to the touch after 10 minutes.

Example 3 Core materials having the following two compositions were prepared.

Capsule 1 Capsule■ The above mixtures were mixed in a nitrogen atmosphere at 50°C for 40 minutes using a P-ru sample.
The mixture was emulsified and dispersed in 1,000 parts of an aqueous solution of 5tisgelatin at 0°C. While stirring this emulsified dispersion, the temperature was increased to 40°C.
Lower the temperature to ±1°C, and add 100 g
After sequentially adding 0 parts and 2000 parts of 40°C hot water, a 10-thiacetic acid aqueous solution was gradually added dropwise to adjust the emulsified dispersion to a temperature of 4.0 to 4.3. After cooling to 5°C and adding 15 s of 37% formalin,
104 Gradually drop the NaOH aqueous solution to adjust the pH of the liquid.
was adjusted to 9. Further, while stirring was continued, the temperature of the liquid was raised to 50°C at a rate of 1°C/- to cure the capsule acid. This capsule dispersion was further added with -Restyrene latex emulsion (manufactured by Nippon Gosei F.M., 06).
02 Latex Emulsion) was added in solid form and dried using a spray dryer at an inlet temperature of 200°C and an outlet temperature of 150°C to obtain two types of pressure-fixable microcapsule toners. .

Using the mixture of the Tokumou micro-bag cell toner in this manner, electrostatic charge latent was created and pressure fixing was carried out. As a result, a clear image without bleeding was obtained.

Example 4 Core materials having the following two compositions were prepared as v4.

Capsule I Capsule I Two types of pressure fixable micro capsule toners were obtained by carrying out the same operations as in Example 3 using the above mixtures.

Using a mixture of the microcapsule toner thus obtained, electrostatic charge was developed and pressure fixing was performed. As a result, a clear wound without bleeding was obtained.

Comparative example 1 A core material having the following composition was prepared.

A mixture consisting of the above composition was prepared using a roll mill for 12 hours.
After mixing for 40 minutes at 0°C, it was cooled.

The powder was coarsely pulverized, then pulverized in a hammer mill, further pulverized in a 1-set jet mill, and then classified to obtain a pressure fixable toner having a particle size of 5 to 20 firt.

Comparative example 2 A core material having the following composition was prepared.

A pressure fixable toner having a particle size of 5 to 20 μm was obtained by using a mixture having the above composition and performing the same treatment as Comparative PAI 1.

Using the pressure fixable toners obtained in Examples 1 to 4 and Comparative Examples 1 to 2 above, an electrostatic latent image is developed, and then pressure fixed by passing between rollers to which a constant pressure is applied. I did this. At this time, fixing was performed while changing the fixing pressure, and the peel strength was measured.

The pressure during fixing was measured using a pressure f, y discrimination paper prescale (for high pressure) manufactured by Fuji Photo Film ■.

In addition, to measure the peel strength, prepare a black peta part (with a density of 1.6 or more using a Kubes reflection densitometer) with a width of 5 m and a length of 15 cIIL, and after fixing it under pressure, An adhesive tube with a width of 1.8 clIt was adhered to the longitudinal direction of the section, and the adhesive tube was peeled off at a peeling rate of 10 mm/see %.
The force when peeled off at a peeling angle of 90° was determined, and this value was divided by the tape width.

The results are shown in the table.

The peel strengths of Examples 1 to 4 were measured immediately after pressure fixing, and the values increased as time passed and became constant after 12 hours.

As is clear from the table, it was confirmed that the pressure fixable microcapsule toner of the present invention can be fixed even at a lower fixing pressure and has better adhesion than conventional ones. Ta.

Claims (4)

[Claims] (1) A microcapsule toner comprising a core material containing a reactive resin and a colorant, and a capsule enclosing the core material, in which the core material has a 5XIO" to 5X 1 G'd7n・/
A pressure-fixable microcapsule toner having a complex modulus of elasticity of cf and a viscosity of 10 to 10'' p·II·. (2) The pressure fixable microcapsule toner according to claim 1, wherein the reactive resin is polymerized by air oxidation. (3) The method according to claim 1, wherein the reactive resin is composed of two or more types of resins that react and cure when mixed, and each reactive resin is filled in separate microcapsules. Pressure fixing microcapsule toner. (4) The pressure-fixable microcapsule according to claim 1, wherein the core material further contains a reactive tree polymerization initiator or a latent curing catalyst that exhibits its function in the presence of oxygen. Toner 0 (5) The core substance further contains two or more types of latent curing catalysts for reactive resins that exhibit their functions, and each latent curing catalyst has a separate microorganism. 9. The pressure-fixable i-exposure capsule toner according to claim 1, which is filled into a capsule.