JP2001312113A - Image forming method and toner used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method which is capable of well forming images by using a contactless heat fixing system. SOLUTION: The coating weights of the respective color toners in the image forming method for superposing yellow, cyan, magenta and black toners images on each other, then subjecting the images to contactless heat fixing are specified to yellow <=5 g/cm2, cyan <=6 g/cm2, magenta <=6 g/cm2 and black <=6 g/cm2. The respective color toner having melt viscosity of <=120 mm Pas.sec at 140 deg.C are preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-sided or double-sided simultaneous image forming method using a non-contact heat fixing system such as an oven, and a toner in the fields of electrophotography, electrostatic recording, facsimile and the like.

[0002]

2. Description of the Related Art The fixing of powder toner in an electrophotographic process can be roughly classified into (1) a non-heating fixing method using pressure and a solvent, and (2) air heated on an image holding member (transfer material). A non-contact heat fixing method in which a toner image is not directly heated, such as an oven fixing method for supplying and fixing or a radiation fixing method for supplying heat by light, and (3) heat and pressure are simultaneously supplied by a heat roll. There are three types of contact heating methods.

[0003] In the field of high-speed double-sided copying or printing, a non-contact heat fixing method is widely adopted. However, when fixing paper of 190 g / m ² or more, the fixing quality was sometimes inferior to the case of using hot roll fixing in terms of thermal efficiency. In addition, even though fixing on only one side does not cause much problem, it is remarkable when fixing is performed on both sides simultaneously.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a non-contact heat fixing system capable of simultaneously printing or copying both sides of a sheet, not only when fixing to a paper of 190 g / m ² or more, but also using a hot roll. An object of the present invention is to provide an image forming method capable of obtaining an average fixing quality and a toner therefor.

[0005]

Means for Solving the Problems The present inventors have conducted various studies from various angles in order to achieve the above-mentioned object. As a result, in the non-contact heat fixing system, the amount of toner adhering to the transfer material is reduced. It was found that a good image was formed depending on the situation. It has also been found that the toner used here also affects the formation of a good image depending on the melt viscosity.

Therefore, according to the present invention, in an image forming method in which yellow, cyan, magenta and black toner images are superimposed and fixed using a non-contact heat fixing method, the amount of each toner adhered to a transfer material Is yellow: 5 g /
m ² or less, cyan: 6 g / m ² or less, magenta: 6 g / m
² or less, black: 6 g / m ² or less.

According to the present invention, there is provided a toner for use in an image forming method for fixing after superimposing yellow, cyan, magenta and black toner images by using a non-contact heat fixing method. An image forming toner having a melt viscosity at 120 ° C. of 120 mmPa · sec or less is provided.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
According to the present invention, when the adhesion amount of the toner of each color at a predetermined image density is in the following range, even when the toner is fixed on paper of 190 g / m ² or more, a fixed image quality comparable to the hot roll fixing is obtained. Things became possible. Yellow: 5 g / m when the image density is 1.3
² or less Cyan: 6 g / m when the image density is 1.4
² or less is possible Magenta: adhesion amount when the image density is 1.4 6 g / m
² or less Black: 6 g / m when the image density is 1.8
Must be ² or less

Further, according to the present invention, 14
Focusing on the melt viscosity at 0 ° C, the melt viscosity is 120 mPas.
-When it was less than sec, more favorable fixed image quality was obtained.

The image density used in the present invention is GRET.
Determined using GRETAG D19C manufactured by AG. The filter used was Filter set 47B.

The toner material used in the present invention is not limited, and all known materials can be used as long as the conditions are satisfied.

As the binder resin, polystyrene,
Polymers of styrene such as poly-p-chlorostyrene and polyvinyltoluene and their substituted products; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer Styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-
Butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethacrylic acid Methyl copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer Coalescence, styrene-
Styrene-based copolymers such as maleic ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, Polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax and the like can be used alone or in combination.

Of these, polyester resins and epoxy polyol resins are preferred in view of manufacturability and the like.
Further, since non-contact heat fixing is exposed to a high temperature for a long time as compared with hot roll fixing, odor due to generated gas becomes a problem as compared with hot roll fixing. Styrene-acrylic copolymers are not suitable because they produce styrene odor.
As for the polyester resin, the content of trimellitic acid (including anhydride and esterified product) in the constituent monomer is 3 mol%, and the content of dodecenyl succinic acid is 2 mol%.
% Or more, odor tends to be generated at the time of fixing.

As the coloring agent, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (1
0G, 5G, G), cadmium yellow, yellow iron oxide,
Loess, graphite, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G) , R), Tartrazine lake, Quinoline yellow lake, Anthrazan yellow BGL, Isoindolinone yellow, Bengala, Lead red, Lead red, Cadmium red, Cadmium mercury red, Antimon red, Permanent red 4R, Para red, Phisa red, Parachlororthonitroaniline red, lysole fast scarlet G, brilliant fast scarlet, brilliant carmine BS, permanent red (F2R, F4R, FRL, FRLL, F4R
H), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Lisor Rubin G
X, permanent red F5R, brilliant carmine 6B, pigment scarlet 3B, bordeaux 5B, toluidine maroon, permanent bordeaux F2K, helio bordeaux BL, bordeaux 10B, bon maroon light, bon maroon medium, eosin lake, rhodamine lake B, rhodamine lake Y , Alizarin rake,
Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC),
Indigo, ultramarine, navy blue, anthraquinone blue, fast violet B, methyl violet lake, cobalt violet, manganese violet, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B, naphthol green B , Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Titanium Oxide, Zinc White, Lithobon and mixtures thereof can be used.

The amount of the colorant used is generally the amount of the binder resin 1
It is 0.1 to 50 parts by weight with respect to 00 parts by weight.

The toner of the present invention may contain a charge controlling agent, if necessary. As the charge control agent, any known charge control agents can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified) Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds,
Tungsten alone or compound, fluorine-based activator, metal salt of salicylic acid, metal salt of salicylic acid derivative and the like.

In the present invention, the amount of the charge controlling agent used is determined by the type of the binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is uniquely limited. However, preferably, 0.1 to 100 parts by weight of the binder resin
It is used in the range of 10 parts by weight, preferably in the range of 2 to 5 parts by weight. If the amount is less than 0.1 part by weight, the negative charge of the toner is insufficient, which is not practical. If the amount exceeds 10 parts by weight, the chargeability of the toner is too large, and the electrostatic attraction with the carrier is increased, so that the fluidity of the developer is reduced and the image density is reduced.

As additives, for example, silica fine particles, hydrophobic silica, fatty acid metal salts (eg, zinc stearate, aluminum stearate), metal oxides (eg, titania, alumina, tin oxide, antimony oxide), and fluoropolymers are contained. May be. Particularly preferred additives include:
Hydrophobized silica, titania and alumina fine particles can be used.

As the silica fine particles, HDK H20
00, HDK H 2000/4, HDK H 205
0EP, HVK21 (both from Hoechst) and R97
2, R974, RX200, RY200, R202, R
805 and R812 (Nippon Aerosil). Further, as titania fine particles, P-25 (manufactured by Nippon Aerosil Co., Ltd.), STT-30, STT-65C-S (above,
TAF-140 (manufactured by Titanium Industry Co., Ltd.), MT-150W, MT-500B, MT-600
B (all manufactured by Teica).

In particular, titanium oxide fine particles subjected to hydrophobic treatment include T-805 (manufactured by Nippon Aerosil Co., Ltd.) and STT-
30A, STT-65S-S (manufactured by Titanium Industry Co., Ltd.), TAF-500T, TAF-1500T (above,
MT-100S, MT-100
T (above, manufactured by Teika), IT-S (manufactured by Ishihara Sangyo) and the like.

In order to obtain hydrophobized silica fine particles, titania fine particles and alumina fine particles, hydrophilic fine particles are treated with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane or octyltrimethoxysilane. Can be obtained.

The melt viscosity of the toner of the present invention is measured by an isothermal method using an elevated flow tester (CFT-500, manufactured by Shimadzu Corporation) under the conditions of a die having a pore diameter of 1 mm and a pressure of 20 kg / cm ^2. Can be.

In the present invention, the toner may be developed by a so-called one-component developing method in which an electrostatic latent image is visualized by itself, or may be developed by using a two-component developer obtained by mixing a toner and a carrier. The latent image may be developed by a two-component developing method for visualizing the latent image.

The carrier used in the two-component developing method is the same as a conventional carrier such as iron powder, ferrite, and glass beads. These carriers may be coated with a resin. The resin used in this case is carbon fluoride, polyvinyl chloride, polyvinylidene chloride, phenol resin, polyvinyl acetal, silicone resin and the like. In any case, the mixing ratio of the toner and the carrier is generally about 0.5 to 6.0 parts by weight of the toner per 100 parts by weight of the carrier.

The toner particle size distribution used in the present invention can be measured by various methods. In the present invention, the toner particle size distribution was measured using a coater counter. That is, a coulter counter TA-II type (manufactured by Coulter Inc.) is used as a measuring device, and an interface (manufactured by Nikkaki Co., Ltd.) for outputting a number distribution and a volume distribution and a PC 9801 personal computer are used. A computer (manufactured by NEC) is connected, and a 1% NaCl aqueous solution is prepared using primary grade sodium chloride as an electrolyte.

The measuring method is as follows.
In 5 ml, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersing agent, and 2 to 20 mg of a measurement sample is further added.
Perform split distribution processing. Electrolyte solution 100 in another beaker
２００200 ml, and the sample dispersion is added thereto to a predetermined concentration.
The particle size distribution of particles of 2 to 40 μm is measured based on the number by using a 100 μm aperture as an aperture by TA-II type, and the volume distribution and number distribution of particles of 2 to 40 μm are calculated. The volume average particle size determined from the distribution was determined.

As an example of the method for producing the toner according to the present invention, first, the binder resin, the pigment or dye as a colorant, the charge controlling agent, the lubricant, and other additives are used, such as a Henschel mixer. After sufficiently mixing with a mixer, a batch type twin roll, Banbury mixer or continuous twin screw extruder, for example, KTK type 2 manufactured by Kobe Steel, Ltd.
Screw extruder, TEM twin screw extruder manufactured by Toshiba Machine Co., Ltd., K
A twin screw extruder manufactured by CK, a PCM type twin screw extruder manufactured by Ikegai Iron Works, a KEX type twin screw extruder manufactured by Kurimoto Iron Works,
The constituent materials are kneaded well using a continuous single-shaft kneader, for example, a hot kneader such as a co-kneader manufactured by Buss Co., Ltd., and after cooling, coarsely pulverized using a hammer mill or the like. In addition, color toner
In the case of (1), in order to improve the dispersion of the pigment, a master batch obtained by previously melting and kneading a part of the binder resin and the pigment is generally used as a coloring agent. Furthermore, these coarsely pulverized materials are finely pulverized using a fine pulverizer using a jet stream or a mechanical pulverizer alone or in combination, and are classified using a classifier using a swirling stream or a classifier using the Coanda effect. To obtain a toner having a circularity and a particle size of

[0028]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples. All parts are parts by weight. First, some examples of the production of toner according to the present invention will be described below.

Toner Production Example 1 (Black toner) Water 1200 parts Phthalocyanine green water-containing cake (solid content 30%) 200 parts Carbon black (MA60, manufactured by Mitsubishi Chemical Corporation) 540 parts is thoroughly stirred with a flasher. Here, a polyester resin (acid value; 3, hydroxyl value; 25, Mn; 45000,
(Mw / Mn; 4.0, Tg; 60 ° C.) 1200 parts were added and kneaded at 150 ° C. for 30 minutes. Then, 1000 parts of xylene was added and kneaded for 1 hour. Thus, a master batch pigment was obtained. Polyester resin 100 parts (acid value; 3, hydroxyl value; 25, Mn; 45000, Mw / Mn; 4.0, Tg; 60 ° C.) 5 parts of the above master batch 5 parts zinc salicylate derivative (Bontron E84, manufactured by Orient Chemical Co.) 4 Part The above materials were mixed by a mixer, melt-kneaded by a two-roll mill, and the kneaded product was rolled and cooled. Thereafter, pulverization and classification were performed to obtain a toner having a volume average particle size of 7.5 μm and a circularity of 0.95. Further, 0.8 wt% of hydrophobic silica (H2000, Hoechst, primary particle diameter 20 nm) was added and mixed with a mixer to obtain a black toner. Here, the melt viscosity at 140 ° C. of the black toner was 96 mPas · sec.

(Yellow Toner) 600 parts of water 1200 parts of Pigment Yellow 17 water-containing cake (50% of solid content) are thoroughly stirred with a flasher. Here, a polyester resin (acid value; 3, hydroxyl value; 25, Mn; 45000,
(Mw / Mn; 4.0, Tg; 60 ° C.) 1200 parts were added and kneaded at 150 ° C. for 30 minutes. Then, 1000 parts of xylene was added and kneaded for 1 hour. Then, two passes were performed with three rolls to obtain a master batch pigment. Polyester resin 100 parts (acid value; 3, hydroxyl value; 25, Mn; 45000, Mw / Mn; 4.0, Tg; 60 ° C.) 5 parts of the above master batch 5 parts zinc salicylate derivative (Bontron E84, manufactured by Orient Chemical Co.) 4 Part The above materials were mixed by a mixer, melt-kneaded by a two-roll mill, and the kneaded product was rolled and cooled. Thereafter, pulverization and classification were performed to obtain a toner having a volume average particle size of 7.5 μm and a circularity of 0.95. Further, an additive was added in the same manner as in the above black toner, and mixed with a mixer to obtain a yellow toner. Here, the melt viscosity of the yellow toner at 140 ° C. is 98 mP.
as sec.

(Magenta Toner) 600 parts of water 1200 parts of Pigment Red 57 water-containing cake (50% of solid content) are thoroughly stirred with a flasher. Here, a polyester resin (acid value; 3, hydroxyl value; 25, Mn; 45000,
(Mw / Mn; 4.0, Tg; 60 ° C.) 1200 parts were added and kneaded at 150 ° C. for 30 minutes. Then, 1000 parts of xylene was added and kneaded for 1 hour. The mixture was further passed through a three-roll mill for two passes to obtain a master batch pigment. Polyester resin 100 parts (acid value; 3, hydroxyl value; 25, Mn; 45000, Mw / Mn; 4.0, Tg; 60 ° C.) 5 parts of the master batch 5 parts zinc salicylate derivative (Bontron E84, manufactured by Orient Chemical Co.) 4 Part The above materials were mixed by a mixer, melt-kneaded by a two-roll mill, and the kneaded product was rolled and cooled. Thereafter, pulverization and classification were performed to obtain a toner having a volume average particle size of 7.5 μm and a circularity of 0.95. Further, an additive was added in the same manner as in the above black toner and mixed with a mixer to obtain a magenta toner. Here, the melt viscosity of the magenta toner at 140 ° C. is 17 mP.
as sec.

Cyan toner 600 parts of water 1200 parts of Pigment Blue 15: 3 water-containing cake (50% of solid content) is thoroughly stirred with a flasher. Here, a polyester resin (acid value; 3, hydroxyl value; 25, Mn; 45000,
(Mw / Mn; 4.0, Tg; 60 ° C.) 1200 parts were added and kneaded at 150 ° C. for 30 minutes. Then, 1000 parts of xylene was added and kneaded for 1 hour. The mixture was further passed through a three-roll mill for two passes to obtain a master batch pigment. 100 parts of polyester resin (acid value; 3, hydroxyl value; 25, Mn; 45000, Mw / Mn; 4.0, Tg; 60 ° C) 3 parts of the above master batch 3 parts zinc salicylate derivative (Bontron E84, manufactured by Orient Chemical Co., Ltd.) 4 Part The above materials were mixed by a mixer, melt-kneaded by a two-roll mill, and the kneaded product was rolled and cooled. Here, the maximum diameter of the pigment was 0.4 μm. Thereafter, pulverization and classification were performed to obtain a toner having a volume average particle size of 7.5 μm and a circularity of 0.95. Further, additives were added in the same manner as in the case of the above black toner, and mixed with a mixer to obtain a cyan toner. Here, the melt viscosity of the cyan toner at 140 ° C. was 34 mPas · sec.

Toner Production Example 2 The resin used in Toner Production Example 1 was a polyol resin (M
n; 5600; Mw / Mn; 5.8; Tg; 63 ° C.). The melt viscosity of each toner at 140 ° C.
5 mPas · sec, 121 mPas for yellow toner
-Sec, magenta toner is 123mPas-sec,
Cyan toner was 122 mPas · sec.

Toner Production Example 3 Toner Production Example 1 except that the addition amount of the master batch used in toner production example 1 was changed to 3 parts for black, 3 parts for yellow, 3 parts for magenta, and 1 part for cyan. Manufactured similarly.

Toner Production Example 4 Toner Production Example 2 except that the addition amount of the master batch used in Toner Production Example 2 was changed to 3 parts for black, 3 parts for yellow, 3 parts for magenta, and 1 part for cyan. Manufactured similarly.

Carrier Production Example 1 Silicon resin solution (manufactured by Shin-Etsu Chemical Co., Ltd., KR50) 100 parts γ- (2-aminoethyl) aminopropyltrimethoxysilane 3 parts Toluene 100 parts The above formulation is dispersed by a homomixer for 30 minutes and coated. A layer forming liquid was prepared. This coating layer forming solution was used to obtain a carrier A in which a coating layer was formed on the surface of 1,000 parts of spherical ferrite having an average particle size of 50 μm using a fluidized bed type coating apparatus.

Example 1 1.75 kg of the carrier A and 70 g of the toner of Production Example 1 were placed in a ball mill and stirred for 30 minutes to obtain a developer. The obtained developer is developed so as to obtain a predetermined image density of each color.
The image was fixed in an oven-type non-contact fixing unit at 0 ° C. The fixed image was evaluated by the smear method and the clock meter method, and the results are shown in Table 1. The meaning of the rank is as follows. Rank 5: Excellent, Rank 4: Good, Rank 3: Acceptable, Rank 2: Poor, Rank 1: Very poor

Example 2 1.75 kg of the carrier A and 70 g of the toner of Production Example 2 were placed in a ball mill and stirred for 30 minutes to obtain a developer. The obtained developer was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 1.75 kg of the carrier A and 70 g of the toner of Production Example 3 were placed in a ball mill and stirred for 30 minutes to obtain a developer. The obtained developer was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2 1.75 kg of the carrier A and 70 g of the toner of Production Example 4 were placed in a ball mill and stirred for 30 minutes to obtain a developer. The obtained developer was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0041]

[Table 1]

[0042]

According to the present invention, the fixing quality can be as good as that of a hot roll even when fixing to paper of 190 g / m ² or more in a non-contact fixing method capable of printing or copying simultaneously on both sides as well as on one side. Can be obtained.

Claims (3)

[Claims] 1. An image forming method in which yellow, cyan, magenta and black toner images are superimposed and fixed by using a non-contact heat fixing method, wherein the adhesion amount of each toner is 5 g / m ² or less for yellow, and : 6 g / m ² or less, magenta: 6 g / m ² or less, black: 6 g / m ² or less. 2. The image forming method according to claim 1, wherein
The melt viscosity at 140 ° C of the used toner is 120mm
An image forming method characterized by Pas · sec or less. 3. The toner used in the image forming method according to claim 1, wherein the melt viscosity at 140 ° C. is 120 mm.
An image forming toner having a Pa · sec or less.