JPH02266363A - Magnetic toner - Google Patents

Abstract

PURPOSE:To improve fixability and to facilitate the treatment of the magnetic powder to be used by internally adding org. matter which varies in solubility parameter by >=1 from a binder resin into the toner and further dispersing the magnetic powder into the org. matter. CONSTITUTION:The org. matter which varies in the solubility parameter by >=1 from the binder resin is internally added to the toner and further, the magnetic powder is dispersed mainly in the org. matter. Public known processes as the processes for producing ordinary toners are applicable as the production process. As an example, the magnetic toner may be produced by a melt kneading, grinding and dispersing. The magnetic powder itself is incorporated into the added org. matter in this case and, therefore, the direct viscosity increase is prevented at the time of the melting. The fixability is improved in this way and the treatment of the magnetic powder to be used is facilitated.

Description

[Detailed description of the invention] [j! ! Business field of use] The present invention relates to a magnetic toner.

[Prior Art] Compared to two-component development using a carrier, one-component development has various advantages, such as not requiring management of the mixture ratio of carrier and toner, and no deterioration of toner due to friction with carrier. ing. However, the magnetic toner used in -component development has problems such as the high moisture absorption of the magnetic powder and the dispersibility of the magnetic powder into the toner, which tends to cause problems such as poor fixing and agglomeration. For toners with magnetic properties, as in Japanese Patent Publication No. 63-26380, a method of coating magnetic powder with a silane coupling agent improves moisture resistance and improves the dispersibility of magnetic powder in the binder resin. There is something that makes it better.

[Problems to be Solved by the Invention] However, in the magnetic toner having this configuration, surface treatment of the magnetic powder requires time and effort. The surface layer of the magnetic powder is coated with resin to prevent the magnetic powder from coagulating with each other, and the dispersion of the magnetic powder into the toner is homogeneous. If the toner is made finer, the fluidity of the toner will deteriorate.

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and an object of the present invention is to provide a powder ink that uses magnetic powder to further improve fixing properties. Furthermore, it is an object of the present invention to provide a donor that can be easily produced without complicated processing of the magnetic powder used.

[Means for Solving the Problems] The magnetic toner of the present invention is a magnetic toner composed of a binder resin and a magnetic powder, in which an organic substance having a solubility parameter of 1 or more is added to the binder resin, and a magnetic toner is further added. It is characterized by the fact that the powder is mainly dispersed in organic matter.

[Function] According to the above configuration of the present invention, since the magnetic powder itself is contained in the added organic substance, a direct increase in viscosity during melting is prevented, so that fixing properties are dramatically increased.

[Example] Hereinafter, the present invention will be explained in detail with reference to Examples.

As the binder resin used in the toner of the present invention, known polystyrene and copolymers thereof, such as IF, hydrogenated styrene resin, styrene-isobutylene copolymer, styrene-butadiene copolymer, ABS resin, ASA resin,
AS resin, AAS resin, AC8 resin, AES resin, styrene/P-chlorostyrene copolymer, styrene/
Propylene copolymer, styrene/butadiene crosslinked polymer Styrene/butadiene/chlorinated paraffin copolymer, styrene/allyl/alcohol copolymer, styrene/butadiene/chlorinated paraffin copolymer, styrene/butadiene/chlorinated paraffin copolymer,
Butadiene rubber emulsion, styrene, maleic ester copolymer, styrene/isobutylene copolymer, styrene/maleic anhydride copolymer, acrylate resin or methacrylate resin and its copolymer, styrene/acrylic resin, The copolymer, for example,
Styrene/acrylic copolymer, styrene/diethylamino/ethyl methacrylate copolymer, styrene/butadiene/acrylic ester copolymer, styrene/methyl methacrylate copolymer, styrene/n/butyl methacrylate copolymer, styrene・Diethylamino・
Ethyl methacrylate copolymer, styrene/methyl methacrylate/n-butyl acrylate copolymer, styrene/methyl methacrylate/butyl arylate/
N-(ethoxymethyl)acrylamide copolymer, styrene/glycidyl methacrylate copolymer, styrene/butadiene/dimethyl/aminoethyl methacrylate copolymer, styrene/acrylic acid ester/maleic ester copolymer, styrene/methacrylate copolymer Methyl acrylate/2-ethylhexyl acrylate copolymer, styrene/
n-butyl arylate/ethyl glycol methacrylate copolymer, styrene/n-butyl methacrylate/acrylic copolymer, styrene/n-butyl methacrylate/maleic anhydride copolymer, styrene/butyl acrylate/isobutyl maleic acid Half ester
Divinylbenzene copolymer, polyester and its copolymer, polyethylene and its copolymer, epoxy resin,
Silicone resins, polypropylene and its copolymers, waxes, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, fluororesins, polyamide resins, polyvinyl alcohol resins, polyurethane resins, polycarbonate resins, cellulose resins, Arylate resin, butyral resin, and polyvinyl butyral may be used alone or in combination. Furthermore, wax-like compounds can be added to the binder resin, such as plant-based natural waxes such as candelilla wax, carnauba wax, and rice wax.
Animal-based natural waxes such as beeswax and lanolin, mineral-based natural waxes such as montan wax and osikelite, paraffin wax, microcrystalline wax, natural petroleum waxes such as petrolatum, synthetic hydrocarbon waxes such as polyethylene wax and Fischer-Tropsch wax, and montan waxes. One or two types of wax selected from among wax derivatives, modified waxes such as paraffin wax-recognized conductors, hydrogenated waxes such as hydrogenated castor oil and hydrogenated castor oil derivatives, and synthetic waxes such as fatty acids, acid amides, esters, and ketones. The above can be used as a blend.

Furthermore, known carbon black, various metals, metal oxides, metal salts, and the like may be used alone or in combination as conductive materials for the toner of the present invention.

The above-mentioned resins as organic substances used in the toner of the present invention,
Wax etc. are used. At that time, since it is not compatible with the binder resin and does not disperse the conductive material, the solubility parameter, which is the square root of the evaporation energy per mole of the substance divided by the molar volume, is determined by the binder resin and the conductive material. If they are separated by 1 or more, they will be difficult to dissolve.

As a method for manufacturing the magnetic toner of the present invention, a method known as a general method for manufacturing toner can be applied. - For example, magnetic toners may be produced by melt mixing, crushing, and classification.

[Example 1] 80 parts by weight of 0.3 μm Fe5O4 and a solubility parameter of 11. 0 [c a 1/c m']”
20 parts by weight of polymethyl methacrylate were placed in cyclohexane and spray-dried to produce fine particles with an average particle size of 2 μm. The softening point of polymethyl methacrylate is 8
It is 7℃. 60 parts by weight of the fine particles, 201 parts by weight of polyethylene with a solubility parameter of 8.0 [cal/Cm ']', and 4 parts by weight of conductive carbon black.
volume, and solubility parameter is 8.5 [cal
By mixing, crushing, and classifying 20 parts by weight of styrene oligomer of /cmJ ``'', a powder with an average particle size of 10.2 μm was obtained.
An ink AI was prepared. The volume resistivity of the toner is 10
An image was formed using the toner A1, which had a viscosity of 2 ΩCm and a viscosity at 140° C. of 3×10 cm, p, as measured by a rotational viscometer, using an electrophotographic image forming apparatus. At this time, A1 was fixed at a fixing temperature of 90°C, and an image with an optical temperature (hereinafter referred to as OD value) of 1°6 was obtained. Furthermore, even when images were formed at a relative temperature of 60 wt %, no deterioration in image quality was observed.

[Comparative Example 1] 20 parts by weight of the same styrene oligomer as in Example 1, 20 parts by weight of polyethylene, 12 parts by weight of polymethyl methacrylate, γ-methacryloxypropylmethoxysilane and 0.3 μm Fe50'a coated with polyethylene.
1 part of 48 parts by weight of 48 parts by weight and 4 parts by weight of conductive carbon black were mixed, and the mixture was crushed and classified to produce toner B1 having an average particle size of 10.2 μm. In addition, styrene oligomer 20
parts by weight, 20 parts by weight of polyethylene, 1231 parts by weight of polymethyl methacrylate, 48 parts by weight of 0.3 μm Fe5On
1 part by weight of carbon black and 4 parts by weight of conductive carbon black were kneaded, crushed and classified to produce toner B2 having an average particle size of 10.degree. 2 .mu.m. The volume resistivity of both Bl and B2 is 1
0"0cm, and the viscosity at 140°C measured with a rotational viscometer is 6xlO"c for B1.

p,, B2 was 8X10"c, P,.

When an image was formed using the prepared toner B1, it was fixed at a fixing temperature of 115° C., and an image with an OD value of 1.6 was obtained. Further, even when images were formed at a relative humidity of 60 wt%, no deterioration in image quality was observed. Further, when an image was formed using toner B2, it was fixed at a fixing temperature of 130° C., and an image with an OD value of 1.6 was obtained. Furthermore, when images were formed at a relative temperature of 60 wt %, a significant decrease in image quality was observed.

As described above, it has been found that the fixing temperature can be reduced by the method of the present invention.

[Example 2] Styrene oligomer: A composition of polyethylene=9=1 was prepared and used as binder resin A. 4.8 wt % of conductive carbon black was added thereto, passed through a Henschel mixer, kneaded in a three-roll mill, cooled, and then crushed and classified to produce a fine powder with an average particle size of 1.1 μm. 40 parts by weight of this fine powder, 20 parts by weight of polymethyl methacrylate, F
40 parts by weight of e5Os was further mixed, mixed, and pulverized to produce toner C1 having an average particle size of 10.9 μm. Volume resistance at this time! II O2Ωam. The viscosity at 140°C was 8 x 103. When an image is formed using toner C1, it is fixed at a fixing temperature of 115°C and O
An image with a D value of 1.6 was obtained. Furthermore, the relative humidity aow
Even if image formation is performed at t%, the image quality will deteriorate.
Not observed.

[Comparative Example 2] A composition containing styrene oligomer and polyethylene of 9:1 was prepared and used as binder resin A. 19 parts by weight of this, 1 wt% of conductive carbon black, and 20 m of polymethyl methacrylate! 40 parts by weight of Fe5Oa were further mixed, mixed, and pulverized to prepare toner D1 having an average particle size of 10.9 μm. The volume resistivity of this toner DI was 102 Ωcm. The viscosity at 140°C was I x 10'. When an image was formed using toner D1, it was fixed at a fixing temperature of 130° C., and an image with an OD value of 1.6 was obtained.

Furthermore, when images were formed at a relative humidity of 60 wt%, a significant deterioration in image quality was observed.

[Example 3] Solubility parameter is 12.7 [cal/cm11]
10 parts by weight of 1/2 paraffin wax and Fe3
After mixing and dispersing 0460 parts by weight in cyclohexane and drying the solvent, 70 parts by weight of a styrene-acrylic copolymer with a solubility parameter of 9.5 [cal/cm']"' was ground to an average particle size of 1 μm. , 5!! parts of conductive carbon black are mixed, crossed, and crushed in toluene.
A toner having an average particle size of 10.5 μm was produced. styrene,
The softening point of acrylic copolymer is 1.65°C, the softening point of paraffin wax is 90°C, and the volume resistivity is 102
Ωam, and the viscosity at 140°C is 9×1°*c
, p, when forming an image with the toner,
An image with an OD value of 1.6 was formed at a fixing temperature of 100°C.

Furthermore, even when images were formed at a relative temperature of 60 wt %, no deterioration in image quality was observed.

[Comparative Example 3] Solubility parameter is 10.5 [cal/cm1] 1
72 paraffin wax 10 parts by weight and Fe5O460
! 70 parts by weight of styrene and acrylic copolymer with a solubility parameter of 9.5 [cal/cm'] ``'', after drying the solvent and pulverizing to an average particle size of 1 μm, were mixed and dispersed in cyclohexane. By mixing, cross-mixing, and pulverizing 5 parts by weight of carbon black in toluene, the average particle size is 1.
The softening point of the styrene-acrylic copolymer from which the 0.5 μm toner was made is 165°C, the softening point of paraffin wax is 110°C, the volume resistivity is 102ΩCm, and the viscosity at 140°C is 2.
xlO'c,p, When an image was formed using the above toner, an image with an OD value of 1.6 was formed at a fixing temperature of 160°C. Furthermore, when images were formed at a relative humidity of 60 wt%, a significant deterioration in image quality was observed. Compared to Example 3, the fixing temperature at the same resistance value is higher and the solubility parameters are similar, so the resins are compatible with each other and the magnetic powder is dispersed in the binder resin, as observed through a microscope. Confirmed by.

Although the present invention has been described above with reference to several examples, it is clear from the above examples that the present invention can be applied to other combinations of resins that are not compatible with each other.

[Effects of the Invention] As described above, according to the present invention, a conductive material, a binder resin,
In a magnetic toner composed of magnetic powder, an organic substance having a solubility parameter different from that of a binder resin by one or more is internally added,
Furthermore, since the magnetic powder is mainly dispersed in the organic substance, fixing can be performed at a lower temperature, and when used in an image forming apparatus, the running cost can be reduced.

In particular, if it is used as a toner for an image forming method that includes a step of forming an image using a thermal transfer method and a step of recycling an ink sheet, it is possible to provide an image forming apparatus with significantly reduced running costs. Become. Also,
Even when used in other image forming apparatuses, the effect of reducing the fixing temperature has been recognized. For example, it can be applied as a toner for use in apparatuses such as printers, copiers, and facsimile machines using electrophotography.

that's all Applicant: Seiko Epson Corporation

Claims (2)

[Claims] (1) A magnetic toner composed of a binder resin and magnetic powder is characterized in that an organic substance having a solubility parameter different from that of the binder resin by one or more is added therein, and further, the magnetic powder is mainly dispersed in the organic substance. magnetic toner. (2) A magnetic toner, characterized in that the binder resin according to claim 1 and the organic substance added therein have a softening point of 70 to 180°C.