JP2002341589A - MICR toner - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a MICR that has resistance to rubbing against a magnetic head, does not cause a reading error due to appropriate signal strength, and has no problem in image quality such as image density and fog. The purpose of the present invention is to provide a toner. SOLUTION: The present invention relates to a toner containing a binder resin, magnetite particles and a wax, wherein the magnetite particles are composed of granular magnetite and acicular magnetite, and the weight ratio of the acicular magnetite to the granular magnetite is 1.0. 0.5
0 to 15% by weight or less in the toner, and the wax has a melting point of 60 to 10% by DSC.
A MICR toner characterized in that the temperature is 0 ° C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a MICR (Magnetic Ink Char) used for magnetic reading printing in a magnetic one-component developing system printer or copier.
actor Recognition).

[0002]

2. Description of the Related Art In recent years, magnetic ink character recognition (MIC)
It has become very easy to prepare a document capable of R), in particular, a check and a bill by a magnetic one-component developing method using a magnetic toner. MICR is a method in which an image is magnetized and read out by a magnetic head. Usually, an image is created by offset printing or the like using magnetic ink, so that it is not simple. Although a printing method using a two-component developing method has also been put into practical use, it cannot be said that it is simple because the machine becomes larger than a one-component developing method. Although there is a thermal transfer type as a small printing machine, most of the single function machines print only MICR characters. Therefore, there is a demand for a small printer capable of simultaneously printing characters and graphics other than MICR characters. In that respect, the magnetic one-component developing system is compact in size and easy to maintain.
Since printing other than CR characters can be easily performed, applications for MICR have been developed.

It has been attempted to use a magnetic material having a large magnetization itself as the conventional MICR toner, and JP-A-6-282100 and JP-A-7-271085 disclose the use of acicular magnetite. . However, there is a problem that acicular magnetite is easily exposed on the toner surface and is easily rubbed off by rubbing with a magnetic head.
In addition, an appropriate saturation magnetization is required for the magnetic one-component development, but if needle magnetite is contained in an amount required for the development, the signal intensity becomes too high. Further, the use amount of acicular magnetite is limited due to poor dispersibility, and it has been difficult to satisfy both the saturation magnetization required for development and the residual magnetization required for signal intensity. The use of magnetites of other shapes did not satisfy all the conditions.

Further, in order to improve the rubbing property, MI
Various waxes can be added to the CR toner,
JP-A-6-282100, JP-A-6-43689,
Although disclosed in Japanese Patent Application Laid-Open No. Hei 7-270855, even if there is no problem as a mere image, there are many cases where a problem occurs in magnetic reading, and it has been difficult to sufficiently satisfy the demand.

As described above, none of the conventional MICR toners satisfies the rub resistance against the magnetic head and the appropriate signal strength without impairing the image quality such as image density and fog.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a MICR which has resistance to rubbing against a magnetic head, does not cause a reading error due to an appropriate signal strength, and has no problem in image quality such as image density and fog. The purpose of the present invention is to provide a toner.

[0007]

The present invention relates to a toner containing a binder resin, magnetite particles and wax, wherein the magnetite particles are composed of granular magnetite and acicular magnetite, and the ratio of granular magnetite is not limited to 1: 1. 0
15 to 5 in the toner so as to have a needle shape of 0.50 or less.
A MICR toner containing 0% by weight and having a melting point of DSC of the wax of 60 to 100 ° C. Magnetite has a residual magnetization of granular magnetite of 5 to 15 emu / g and a saturation magnetization of 70 to 95 emu.
mu / g, residual magnetization of acicular magnetite is 20-50 e
It is preferable that the mu / g and the saturation magnetization be 70 to 95 emu / g. Preferably, the wax is a natural gas-based Fischer-Tropsch wax.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The MICR toner of the present invention contains a binder resin, a magnetic substance, and a wax as main components.
Further, if necessary, a charge controlling agent, a coloring agent, and other additives may be contained, and a fluidizing agent may be attached to the surface.
Examples of the binder resin of the toner of the present invention include styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene, styrene-p-chlorostyrene copolymer, and styrene-vinyltoluene copolymer; Copolymers and copolymers thereof; styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer,
Copolymer of styrene and acrylic acid ester such as styrene-acrylic acid-n-butyl copolymer; styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-n-butyl methacrylate Copolymers of styrene and methacrylate such as copolymers; multi-component copolymers of styrene with acrylates and methacrylates; other styrene-acrylonitrile copolymers, styrene-vinyl methyl ether copolymers, styrene Styrene copolymers of styrene and other vinyl monomers such as butadiene copolymer, styrene-vinyl methyl ketone copolymer, styrene-acrylonitrile indene copolymer, styrene-maleic acid ester copolymer; poly Methyl methacrylate, polybutyl methacrylate, poly Crylate ester resin, polyester resin, polyvinyl acetate, polyamide resin, epoxy resin, polyvinyl butyral resin, polyacrylate phenol resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, petroleum resin, chlorinated paraffin, polychlorinated Vinyl, polyvinylidene chloride, etc. can be used alone or in combination. In the present invention, among these, styrene-acrylate copolymer resins and polyester resins are preferably used.

The magnetite particles to be incorporated in the MICR toner of the present invention are composed of at least granular magnetite and acicular magnetite. In this case, the weight ratio between the two is 1.0 for the granular magnetite and 0.1 for the acicular magnetite.
50 or less is required. Further, the latter is preferably 0.10 to 0.50 for the former 1.0, and more preferably the latter 0.20 to 0.45 for the former 1.0. In the weight ratio of both, granular magnetite
If the ratio of acicular magnetite to zero is greater than 0.50, the signal strength exceeds the appropriate level, causing a problem that a reading error occurs in the reader sorter of the reader of the MICR system. Furthermore, it is necessary that the content of the magnetite particles blended in the MICR toner of the present invention is 15 to 50% by weight in the toner. The content is preferably 20 to 40% by weight.
In this case, if the content of the magnetite particles is 15% by weight or less, the saturation magnetization required for development and the residual magnetization required for the signal intensity cannot be obtained. This causes problems such as deterioration of performance, exceeding a saturation magnetization required for development, and a signal intensity exceeding an appropriate level. The granular magnetite in the present invention includes irregular, spherical, hexahedral, octahedral, and the like. The residual magnetism of the granular magnetite used in the present invention is 5 to 15 em
u / g is preferable, and 8-13 emu / g is more preferable. The saturation magnetization is preferably from 70 to 95 emu / g,
-85 emu / g is more preferred. Particle size 0.2 ~
In general, the aspect ratio is about 0.3 μm and the aspect ratio is 2.0 or less. If the residual magnetization exceeds 15 emu / g, the magnetization and the signal intensity become excessive, while if it is less than 5 emu / g, the signal intensity becomes insufficient and causes a reading error. When the saturation magnetization is less than 70 emu / g, the saturation magnetization required for development cannot be obtained. When the saturation magnetization exceeds 95 emu / g, the saturation magnetization required for development tends to exceed the residual magnetization of the acicular magnetite used in the present invention. Is 20
-50 emu / g is preferable, and 25-40 emu / g is more preferable. The saturation magnetization is preferably from 70 to 95 emu / g, more preferably from 75 to 85 emu / g. Generally, the particle diameter is about 0.6 μm and the aspect ratio is 2.0 or more. When the residual magnetization is less than 20 emu / g, the signal intensity becomes insufficient, and when it exceeds 50 emu / g, the signal intensity becomes excessive. If the saturation magnetization is less than 70 emu / g, the saturation magnetization required for development cannot be obtained, and if it exceeds 95 emu / g, the saturation magnetization tends to exceed the saturation magnetization required for development. You can also.

The toner of the present invention may contain a wax having a melting point of DSC of 60 to 110 ° C. in order to ensure the releasability between the fixing heat roll and the toner and the abrasion resistance of the magnetic head. It is necessary, and the melting point of DSC is preferably 85 to 100 ° C. If the melting point of DSC is lower than 60 ° C., a problem is likely to occur in the storage stability of the toner, and the fluidity tends to deteriorate. When the temperature exceeds 110 ° C., the effect of lowering the melt viscosity of the toner is small, so that the low-temperature fixing property is inferior, the fixing strength is weakened, and the image is easily peeled off by being rubbed with a magnetic head. Also,
Images tend to be missing when in contact with other objects or when a tape is applied. Here, the melting point by DSC refers to the peak temperature of the amount of heat absorbed, and is a value of SSC-
The process of raising the temperature between 20 to 150 ° C. at a rate of 10 ° C./min using a 5200 and then rapidly cooling from 150 ° C. to 20 ° C. is repeated twice to measure the peak temperature of the second heat absorption. . As the wax, low-molecular-weight polyethylene, polypolyolefin-based wax such as low-molecular-weight polypropylene, paraffin wax, Fischer-Tropsch wax, carnauba wax, candelilla wax,
Rice wax and the like. These waxes can be used alone or as a mixture. As the wax, a natural gas-based or coal-based Fischer-Tropsch wax is preferable. The Fischer-Tropsch wax has a lower melting point than olefin-based wax, and thus has excellent low-temperature fixability. Further, it has excellent storage stability because it has a very low melting point component compared to general petroleum or coal paraffin wax. In the present invention, among the Fischer-Tropsch waxes, a natural gas-based Fischer-Tropsch wax is particularly preferred.
The natural gas type is superior to the coal type in prevention of offset to the heat fixing roll and the storage stability of the toner, and has a low cost because there is no step of extracting a water gas unlike the coal type. The above two types of Fischer-Tropsch wax preferably have a penetration at 25 ° C. of 2 or less as measured by JIS K-2235, and if it is larger than 2, the fluidity of the toner is deteriorated, and the storage stability and triboelectric chargeability are deteriorated. Prone to problems. The content of the wax was 2.0 to the toner.
-15% by weight is preferred, and 4.0-10% by weight is more preferred. If the amount of the wax is less than 2.0% by weight, the effect as a release agent is small, and there is a problem in offset resistance and rubbing resistance. If the amount exceeds 15% by weight, a problem in storage stability occurs.

It is preferable to add a charge control agent to the toner of the present invention. Examples of positively chargeable charge control agents include, for example, denatured products such as nigrosine and fatty acid metal salts, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, and tetrabutylammonium tetrafluoroborate;
Dibutyltin oxide, dioctyltin oxide,
Diorganotin oxides such as dicyclohexyltin oxide and diorganotin borates such as dibutyltin borate, dioctyltin borate and dicyclohexyltin borate can be used alone or in combination of two or more. Among them, especially nigrosine compounds,
Quaternary ammonium salts are preferably used. The preferred addition amount is 0.1 to 5% by weight. As the negative charge control agent, for example, an acetylacetone metal complex, a monoazo metal complex, an organic metal compound such as a naphthoic acid or salicylic acid-based metal complex or a salt, a chelate compound, or the like can be used alone or in combination of two or more kinds. . Of these, salicylic acid-based metal complexes and monoazo metal complexes are particularly preferably used. The preferred addition amount is 0.1
~ 5% by weight. These may be used alone or as a mixture. The toner of the present invention is preferably negatively chargeable, but can be adjusted by appropriately using the charge control agent.

Since the MICR toner of the present invention contains black magnetite, there is usually no problem if a colorant is not used, but a colorant can be used if necessary. Colorants include carbon black, aniline blue, calco oil blue, chrome yellow, ultramarine blue, quinoline yellow, methylene blue chloride,
Examples include phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, rhodamine dyes, anthraquinone dyes, monoazo and disazo pigments, mixtures thereof, and others.
These colorants need to be contained in such a ratio that a visible image having a sufficient image density is formed.
A ratio of 20 parts by weight or less to 00 parts by weight is preferable.

The toner of the present invention may contain a higher fatty acid, an olefin-maleic anhydride copolymer or the like in order to protect the photoreceptor and obtain a high-quality image without deteriorating the developing characteristics. It may be added. further,
The toner of the present invention preferably has a fluidizing agent attached to the toner surface. The fluidizing agent is typified by silica or titanium oxide, but hydrophobic silica is preferred. The present invention can be applied not only to the melt-kneading / pulverizing method but also to a toner produced by a polymerization method. Further, the present invention can be used not only for MICR but also for general printers.

[0014]

The present invention will be described below based on examples and comparative examples. In addition, all the compounding parts number means a weight part. <Example 1>-54.0 parts of styrene-acrylic acid ester copolymer resin (trade name: CPR-100, manufactured by Mitsui Chemicals, Inc.)-1.5 parts of negatively chargeable charge control agent (products, manufactured by Hodogaya Chemical Industry Co., Ltd.) Name: TRH)-Granular magnetite 30.0 parts (trade name: BL-100, residual magnetization 8.5 emu / g, saturation magnetization 85 emu / g, manufactured by Titanium Industry Co., Ltd.)-Acicular magnetite 12.0 parts (manufactured by Toda Industry Co., Ltd.) Trade name: MAT-230, residual magnetization 30 emu / g, saturation magnetization 81.8 emu / g)-2.5 parts of natural gas-based Fischer-Tropsch wax (trade name: FT-100, melting point 91 ° C, manufactured by Nippon Seiro) The raw materials were dry-mixed with a super mixer, hot-melted and kneaded with a twin-screw extruder to obtain a kneaded product, pulverized with a jet mill, and classified with a dry-type air classifier to obtain a volume average particle diameter of 8 μm.
m was obtained. Hydrophobic silica (trade name: R972, manufactured by Nippon Aerosil Co., Ltd.) is used for 100 parts of the toner.
Add 5 parts, stir in a Henschel mixer for 5 minutes,
The toner for MICR of the present invention was prepared by adhering to the toner surface. <Example 2>-54.0 parts of polyester resin (trade name: FC-1198, manufactured by Mitsubishi Rayon Co., Ltd.)-1.5 parts of negative charge control agent (trade name: Bontron S-44, manufactured by Orient Chemical Industries, Ltd.)・ 30.0 parts of granular magnetite (trade name: BL-200, manufactured by Titanium Industry Co., Ltd .; 8.5 emu / g, residual magnetization: 85 emu / g) ・ 12.0 parts of acicular magnetite (trade name, manufactured by Kanto Denka Kogyo Co., Ltd.) CJ-3000B, residual magnetization 34.3 emu / g, saturation magnetization 83.2 emu / g)-2.5 parts of natural gas-based Fischer-Tropsch wax (trade name: FT-100, manufactured by Nippon Seiro Co., Ltd., melting point 91 ° C) Was dry-mixed with a super mixer, hot-melted and kneaded with a twin-screw extruder to obtain a kneaded product, pulverized with a jet mill, and then classified with a dry air classifier to obtain a volume average particle. 8μ diameter
m was obtained. To 100 parts of the toner, hydrophobic silica (trade name: R9, manufactured by Nippon Aerosil Co., Ltd.)
72) 2.5 parts were added, and the mixture was stirred in a Henschel mixer for 5 minutes to adhere to the surface of the toner to prepare a MICR toner of the present invention.

Comparative Example 1 Forty parts of the granular magnetite BL-100 of Example 1 were used, and acicular magnetite MAT-23.
0 and 16 parts of styrene-acrylate resin.
A toner for comparison was prepared in the same manner as in Example 1 except that the toner was used as a part. Comparative Example 2 Granular magnetite BL-100 of Example 1
7.5 parts, 3 parts of acicular magnetite MAT-230,
A comparative toner was prepared in the same manner as in Example 1 except that the amount of the styrene-acrylate resin was changed to 85.5 parts. Comparative Example 3 Granular magnetite BL-100 of Example 1
Was prepared in the same manner as in Example 1, except that 27 parts were used and 15 parts of the acicular magnetite MAT-230 were used. Comparative Example 4 A comparative toner was prepared in the same manner as in Example 1 except that the magnetite of Example 1 was changed to 42 parts of the granular magnetite BL-100 alone. Comparative Example 5 A comparative toner was prepared in the same manner as in Example 1 except that the magnetite of Example 1 was replaced with 42 parts of the acicular magnetite MAT-230 alone. <Comparative Example 6> The wax of Example 1 was replaced with polypropylene wax (trade name: Viscol P55, manufactured by Sanyo Chemical Industries, Ltd.)
0, melting point 145 ° C.), and a comparative toner was prepared in the same manner as in Example 1.

<Evaluation Test> Using a commercially available magnetic one-component printer (printing speed A4: 16 sheets / min.), Printing was performed with the toners of Examples and Comparative Examples, and image density, fog, rub fixing strength, and tape peeling were evaluated. The strength and signal strength were evaluated. Table 1 shows the results. It was shown to.

[Table 1] In Examples 1 and 2, there was no problem in image density, fog, rub fixing strength, tape peeling strength, and signal strength. Comparative Example 1
Since the magnetite content was large, the rub fixing strength and the tape peeling strength were weak, and the initial signal strength exceeded an appropriate range. In Comparative Example 2, since the content of magnetite was small, the signal intensity was below the appropriate range. In Comparative Example 3, since the ratio of acicular magnetite was large, the initial signal intensity exceeded the appropriate range. In Comparative Example 4, since only granular magnetite was used, the signal intensity was below the appropriate range. Comparative Example 5
Since only acicular magnetite was used, the rub fixing strength and the tape peeling strength were weak, and the signal strength greatly exceeded the appropriate range. In Comparative Example 6, since the wax having a high melting point of DSC was used, the rub fixing strength and the tape peeling strength were weak,
The signal intensity was reduced by rubbing with the magnetic head.

* The evaluation method is as follows. 1) Image density: Macbeth reflection densitometer (RD91
In 4), the initial density of the 25 mm × 25 mm solid image and the density after 10,000 sheets were measured. 2) Fog: The whiteness of the non-image area was measured with a color difference meter ZE2000 manufactured by Nippon Denshoku Co., Ltd., and the value of (whiteness before printing minus whiteness after printing) was defined as the fog value. 3) Rubbing fixing strength (residual rate%): 25 mm × 25 mm
3 of a solid image with sand eraser under pressure of 500 g / cm ²
Reciprocating rubbing was calculated from the image density X before rubbing and the image density Y after rubbing according to the following equation. The characteristics were substituted for the strength of the magnetic head against sliding. Rubbing fixation strength (%) = Y / X × 100 4) Tape peeling strength (residual rate%): A cellophane tape was stuck on a 25 mm × 25 mm solid image, peeled off, and the image density P before peeling and the image density Q after peeling. From the following equation. It was used as a substitute for the fixing strength when touching other things or applying a tape. Tape peeling strength (%) = Q / P × 100 5) Signal strength (%): M is used for MICR character reader
Signal strength was measured using Agtek's MINIMACR RS232. If the signal strength is 70 to 200%, no reading error occurs in the reader sorter of the reader of the MICR system. 5-1) Signal strength: The signal strength was measured at the initial stage and after 10,000 copies. 5-2) Signal strength: The signal strength was measured by repeating one image 20 times, and the signal strength at the first time and the signal strength at the 20th time were described. 5-3) Signal strength: After a cellophane tape was attached to the MICR character, the signal strength was measured before and after peeling and peeling.

[0018]

The toner for MICR of the present invention contains a particulate magnetite and a needle magnetite in a specific amount and ratio, and contains a wax having a specific melting point by DSC, so that it can be read by a magnetic head. MICR characters are not peeled off by repeated rubbing with the magnetic head, and the magnetic head and the surroundings of the MICR character are contaminated, causing a reading error in the reader sorter of the reader of the MICR system. Since it has the MICR suitability of not allowing it to be used and the printer suitability that can be used with existing magnetic one-component printers and has no problem in image quality such as image density and fog, it is extremely easy to use MICR documents (prints , Checks, etc.).

Claims (3)

[Claims] 1. A toner containing a binder resin, magnetite particles and wax, wherein the magnetite particles are composed of granular magnetite and acicular magnetite, and the weight ratio of acicular 0.50 to granular magnetite 1.0 is 1.0. A toner for MICR, which is contained in the toner in an amount of 15 to 50% by weight as follows, and the melting point of the wax by DSC is 60 to 100 ° C. 2. The granular magnetite has a residual magnetization of 5 to 15.
The MICR toner according to claim 1, wherein the emu / g, the saturation magnetization is 70 to 95 emu / g, the residual magnetization of the acicular magnetite is 20 to 50 emu / g, and the saturation magnetization is 70 to 95 emu / g. . 3. The MICR toner according to claim 1, wherein the wax is a natural gas-based Fischer-Tropsch wax.