JPH06332246A - High-density packable toner - Google Patents

Abstract

PURPOSE:To obtain an excellent flow property, heat fixability and offset resistance performance even at the time of high-speed copying by selecting a specific styrene resin and olefin resin and forming a uniform interdispersion state between both resins. CONSTITUTION:The styrene resin having the number reference mol.wt. of a low mol.wt. side peak in a 350 to 100000 range, the maximal value of the mol.wt. at the peak in an 8000 or over and <=160000 range and the content of the high mol.wt. component per 100 pts.wt. low mol.wt. component in a 25 to 40 pts.wt. range and the olefin resin having the storage modulus of elasticity (G') at 150 deg.C within a 1.0X10<3> to 1.0X10<5>dyne/cm<2> range and tangent loss (tandelta) in a 0.3 to 3.0 range are used. The olefin resin is incorporated at a ratio of 1 to 5 pts.wt. per 100 pts.wt. styrene resin. As a result, the high-density filling of the toner into a container is possible without flocculation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used for developing an electrostatic image in electrophotography or the like,
More specifically, the present invention relates to an electrostatic charge image toner that enables high-density filling into a toner container or the like without deteriorating various characteristics of the toner.

[0002]

2. Description of the Related Art As a developer for developing an electrostatic image formed on an electrophotographic photosensitive member, a composition comprising a fixing resin, a releasing agent such as a low molecular weight olefin resin and a coloring agent such as carbon black. A powder toner obtained by molding an object into a certain particle size is widely used. If necessary, the powder toner is charged in combination with a magnetic carrier or the like, conveyed to the surface of the photoconductor, formed a toner image on the surface of the photoconductor, and then transferred to copy paper or the like, and finally on a copy paper by a heat roller or the like. Is fixed in.

Release agents such as low molecular weight olefin resins are
For example, as described in JP-B-52-3304, it is intended to prevent the occurrence of offset development during heat roller fixing and to impart excellent fixing performance, but on the other hand, it is contained in the toner composition. It is known that the releasing agent promotes the aggregation of the toner particles with each other, resulting in the deterioration of the fluidity and the contamination of the copy paper due to the fluffing.

In order to solve this drawback, JP-A-58-1
No. 89647 (Prior Art I), a styrene-acrylic resin having an acid value of 2 to 15 is selected as a resin to be mixed with an olefin resin mold release agent, and 10 to 50 mμ is selected as a carbon black to be mixed therein. It has been shown to use those having a particle size of 100 and an oil absorption of 200 to 800%.

Also, Japanese Patent Laid-Open No. 63-183452.
(Prior Art II) includes a weight as a medium for fixing toner.
GPC with an average molecular weight / number average molecular weight of 40 or more
Number standard molecular weight by 4 × 10³ Through 7 × 10³ Low of
Sub-region and 2 × 10^Five Through 5 × 10 ^Five In the high molecular region of
It has a maximum value and the ratio of the low molecular weight region is 65 to
By using a polymer that is 85% by weight,
From high to high speed machines, storage stability and offset resistance
It is described that a developer excellent in fixing property and fixing property can be obtained.
It

[0006]

[Problems to be Solved by the Invention]
II has achieved some success for the purpose of improving anti-offset property and fixing property while preventing toner aggregation tendency, but still aims at high-speed copying and enhances toner productivity. However, the purpose of reducing distribution costs was not yet satisfactory. That is, in high-speed copying, since the flow velocity of the developer in the developing device is naturally high, the toner is required to have an excellent flow velocity, while the contact time with the fixing roller is shortened at the time of heat fixing. Although it is required that the offset preventing action is performed within an extremely short time, a releasing agent excellent in the offset preventing action easily causes aggregation of toner particles, which becomes a factor of impairing fluidity.

Further, the toner is filled in a bottle or a container of other shape after manufacture, and is stored and transported. However, since the toner is fine and each particle is an independent powder, a large amount of toner is contained inside. It contains air, and attempts have been made to fill the toner with a high density in order to reduce the distribution cost and enable high-speed filling. That is, JP-A-60-
As disclosed in Japanese Patent No. 68201 and Japanese Unexamined Patent Publication No. 1-124503, there is a system in which the inside of a container to be filled with toner is decompressed and toner powder is filled therein. If such high density filling is performed, the toner particles are remarkably aggregated with each other, resulting in deterioration of toner fluidity and deterioration of image quality due to occurrence of white spots.

Therefore, an object of the present invention is to provide an electrostatic charge image toner having excellent fluidity and heat fixing property suitable for high speed copying, and enabling high density filling by a pressure reduction method or the like without toner aggregation. To provide.

[0009]

According to the present invention, the number standard molecular weight of the low molecular weight peak is 350 to 100,000.
And the maximum value of the molecular weight at the peak is more than 8000 and not more than 16000, and the content of the high molecular weight component per 100 parts by weight of the low molecular weight component is in the range of 25 to 40 parts by weight. A styrene resin and a storage elastic modulus (G ') at a temperature of 150 ° C are 1.
An olefin resin having 0 × 10 ^{3 to} 1.0 × 10 ⁵ dyne / cm ² and a tangent loss (tan δ) in the range of 0.3 to 3.0 is added per 100 parts by weight of styrene resin.
There is provided a high density filling type electrostatic image toner characterized by being contained in an amount of 5 to 5 parts by weight.

[0010]

The toner of the present invention contains a styrene resin as a fixing agent and an olefin resin as a releasing agent as essential components. First, as the styrene resin, the number standard molecular weight of the low molecular weight side peak is 350. To 100,000, the maximum value of the molecular weight at this peak is more than 8,000 and not more than 16,000, and the content of the high molecular weight component is 25 to 40 parts by weight per 100 parts by weight of the low molecular weight component. Select and use one within the range.

In the present invention, of the molecular weight distribution of the fixing resin (styrene resin), the peak on the low molecular weight side is particularly problematic because the peak on the low molecular weight side is the heat fixing property and offset resistance of the toner particles. It has a significant influence on the fluidity and the like, and is closely related to the mutual dispersibility (hereinafter simply referred to as mutual dispersibility) with the olefin resin (release agent).

The lower limit of the peak on the low molecular weight side is defined as 350, because when a component below 350 is contained, this component remarkably increases the aggregation tendency of the toner particles. In the present invention, the maximum value of this low molecular weight peak is 8
Greater than 000 and in the range of 16000 or less,
Particularly preferably, it is important to be in the range of 10,000 to 15,000.

It has been found that the maximum value of the peak on the low molecular weight side affects the cohesive force, heat fixing property and mutual dispersibility of the toner particles. That is, when the peak maximum value is lower than the above range, the cohesive force is too small to easily cause offset, and at the same time, high density packing, particularly high density packing with a bulk density of 0.4 g / cm ³ or more, results in mutual interference of toner particles. Agglomeration will occur. On the other hand, when the peak maximum value is larger than the above range, the cohesive force is increased and the offset is also decreased, but the heat fixing property is also decreased, and it becomes difficult to sufficiently disperse the olefin resin, As a result, the inconvenience described later tends to occur.

In the present invention, an olefin resin and a temperature of 15 are used.
Storage elastic modulus (G ′) at 0 ° C. of 1.0 × 10 ^{3 to} 1.0 × 10 ⁵ dyne / cm ² and tangent loss (ta
The second characteristic is to select an olefin resin having nδ) in the range of 0.3 to 3.0 and combine the olefin resin in an amount of 1 to 5 parts by weight per 100 parts by weight of the styrene resin.

Storage modulus (G ') and tangent loss (tan)
δ) is a rheological property and is a tangent loss (tan).
δ) is represented by the ratio of loss elastic modulus (G ″) / storage elastic modulus (G ′), and these are determined by the method described later.
Among these properties, the storage elastic modulus is related to the cohesive force of the olefin resin, while the loss elastic modulus is related to the viscosity of the olefin resin, and the tangent loss represents the balance between them. .

According to the present invention, the combination of the styrene resin and the olefin resin makes it possible to uniformly disperse the olefin resin in the styrene resin medium and prevent interparticle aggregation during high density packing. However, it is based on a new finding that offset resistance during high-speed copying can be improved.

When the storage modulus (G ') of the olefin resin is smaller than the above range, or the tangent loss (tan)
If δ) is larger than the above range, the dispersion of the olefin resin in the styrene resin becomes non-uniform, and the cohesive force of the olefin resin itself becomes small, and the adhesive tendency tends to increase. There is a tendency that the fluidity of the toner in the paper is lowered and the agglomeration between particles at the time of high density packing is increased.

On the other hand, when the storage modulus (G ') of the olefin resin is larger than the above range, or when the tangent loss (tan δ) is smaller than the above range, the olefin resin is dispersed in the styrene resin. The state becomes coarse and uniform dispersion becomes difficult, and further, the cohesive force of the olefin resin itself is too large, and offset tends to occur during high-speed copying.

On the other hand, according to the present invention, as the styrene resin forming the continuous medium, a styrene resin having a cohesive force in an appropriate range with respect to offset resistance, heat fixing property and non-cohesion between particles is selected. As the olefin resin forming the dispersed phase, an olefin resin having a rheological property within a certain range with respect to adhesive strength and offset resistance was selected, and a uniform mutual dispersion state was formed between both resins. As a result, high density toner filling in the container is possible without agglomeration, and excellent fluidity, even during high-speed copying,
The heat fixing property and the offset resistance can be obtained.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION "FIG. 1" shows a molecular weight distribution of an example of a styrene resin used in the present invention [corresponding to a binder resin (A) in Examples described later]. Low molecular weight peak number standard molecular weight is 350 to 10
In addition to being in the range of 0000, the maximum value of this peak is in the range of more than 8,000 and 16,000 or less, particularly 10,000 to 15,000. The low molecular weight side peak means that the peak is on the low molecular weight side when there are a plurality of peaks, and may be the peak when there is a single peak. Generally, those having a molecular weight distribution having two or more peaks are preferable.

In this case, as the styrene resin, the content ratio of the high molecular weight component per 100 parts by weight of the low molecular weight component is in the range of 25 to 40 parts by weight, particularly 30 to 35 parts by weight. It is desirable in terms of high density packing. That is, if the content of the high molecular weight component is more than the above range, the heat fixing property tends to be lowered, and conversely, if it is less, the tendency to aggregate at the time of high density packing is also observed. The number average molecular weight (Mn) of the styrene resin is 7,000 to 900.
It is desirable that it is in the range of 0, and the molecular weight distribution (Mw
/ Mn) is conveniently in the range 16 to 26.

The styrene resin may be polystyrene, that is, a homopolymer of styrene, or a copolymer of styrene and another ethylenically unsaturated monomer. As the styrene copolymer, a copolymer of styrene and an acrylic monomer is suitable. As an acrylic monomer,
(Meth) acrylic acid alkyl ester such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; acrylic acid, meta Acrylic acid; (meth) acrylonitrile: (meth) acrylic amide; (meth) acrylic hydroxyalkyl ester such as (meth) acrylic-2-hydroxyethyl, (meth) acrylic-3-hydroxypropyl; (meth) acrylic-2- Aminoethyl, (meth) acrylic-
3-aminopropyl, N-ethyl (meth) acrylic-2
-(Meth) acryl-aminoalkyl ester such as aminoethyl; glycidyl (meth) acrylate and the like can be mentioned, but the main component of the acrylic monomer is preferably composed of (meth) acrylic acid alkyl ester.

The ratio of styrene to acrylic monomer in the copolymer may vary, but is generally 60: 4.
It is preferably present in a molar ratio of 0 to 98: 2, especially 75:25 to 85:15. A particularly suitable styrene-acrylic copolymer has a composition of styrene 75 to 85% by weight methyl methacrylate 0.5 to 5% by weight n-butyl acrylate 10 to 20% by weight.

As the olefin resin, any resin having a storage elastic modulus (G ') and a tangent loss (tan δ) within the above ranges can be used. Since these viscoelastic properties depend on the molecular weight, molecular weight distribution and crystallographic properties of the olefin resin, those having a combination of properties satisfying these properties are used. First, the olefin resin has a number average molecular weight (Mn) of 7,000 to 15,000, particularly 800.
It is preferably in the range of 0 to 15,000. When Mn is lower than this range, the tangent loss tends to be higher than the range of the present invention when the storage elastic modulus is lower than the range of the present invention, and the number average molecular weight (Mn) is At higher than the range, there is a tendency opposite to the above. As olefin resin, polypropylene, polyethylene,
Propylene-ethylene copolymers are used, but polypropylene is particularly preferred.

In the present invention, the olefin resin is preferably used in an amount of 1 to 5 parts by weight, particularly 2 to 4 parts by weight, based on 100 parts by weight of the styrene resin. If the amount of the olefin resin is less than the above range, sufficient offset preventing ability may not be obtained during high-speed copying. On the other hand, if it is more than the above range, high-density packing may be difficult due to aggregation between toner particles, or Poor toner fluidity may occur during high-speed copying.

In addition to the above essential components, the toner of the present invention contains various toner compounding components, such as charge control dyes,
A colorant or the like can be added. As the charge control dye, it is preferable to use a metal-containing complex salt dye, particularly a 2: 1 type metal-containing complex salt dye (dye molecule: metal = 2: 1). ,formula

[0027]

[Chemical 1] In the formula, rings A and B may have a condensed ring, may have a substituent such as a halogen atom, a nitro group, an alkyl group and an amide group, and M represents a transition metal. As the transition metal M, Cr, Co, C
Although u, Fe, Ni, etc. can be mentioned, those containing Cr are preferable.

As the colorant, a coloring pigment, an extender pigment,
One kind or a combination of two or more kinds of magnetic pigments and conductive pigments can be used. Of course, these pigments may be pigments having two or more of the above-mentioned functions. For example, carbon black has a function as a conductive pigment together with a black pigment, and iron tetroxide has a function as a magnetic pigment. As is clear from the so-called iron black name, it also has a function as a black pigment.

Suitable examples of color pigments are: Black pigment carbon black, acetylene black, lamp black, aniline black. Yellow pigment Yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navels yellow, naphthol yellow S, Hansa yellow G, Hansa yellow 10G, benzidine yellow G,
Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake. Orange pigment Red lead yellow molybdenum, Molybden orange, Permanent orange GTR, Pyrazolone orange, Balkan orange, Induslen brilliant orange RK, Benzidine orange G, Induslen brilliant orange GK.

Red pigment Red iron oxide, cadmium red, red lead, cadmium mercuric sulfide, permanent red 4R, resole red, pyrazolone red, watching red calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, alizarin lake. , Brilliant Carmine 3B. Purple pigment Manganese purple, fast violet B, methyl violet lake. Blue pigment Navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated compound, fast sky blue, indanthrene blue B
C. Green pigment chrome green, chrome oxide, pigment green B,
Malachite Green Rake, Fanal Yellow Green G. White pigment Zinc white, titanium oxide, antimony white, zinc sulfide. Extender barite powder, barium carbonate, clay, silica, white carbon, talc, alumina white.

Conventional magnetic material pigments include, for example,
Iron oxide (Fe₃ O_Four ), Ferric oxide (γ-Fe)₂ O
₃ ), Zinc iron oxide (ZnFe₂ O_Four ), Iron oxide yttria
Umm (Y ₃ Fe_Five O₁₂), Cadmium iron oxide (CdFe
₂ O_Four ), Gadolinium iron oxide (Gd₃ Fe_Five O₁₂),acid
Copper iron chloride (CuFe₂ O_Four ), Iron oxide lead (PbFe)₁₂O
₁₉), Iron oxide nickel (NiFe₂ O_Four ), Iron oxide neo
Dium (NdFeO₃ ), Iron oxide barium (BaFe
₁₂O₁₉), Magnesium iron oxide (MgFe₂ O_Four ),
Iron manganese oxide (MnFe₂ O_Four ), Lanthanum iron oxide
(LaFeO₃ ), Iron powder (Fe), cobalt powder (C
o), nickel powder (Ni), etc. are known.
Also in any of these known fine powders of magnetic materials
Can be used. Magnetic properties particularly suitable for the purposes of the invention
The material pigment is ferric oxide.

As the conductive pigment, in addition to the above-mentioned carbon black, any conductive fine particles such as non-conductive inorganic fine powder and various metal powders may be used.

The charge control dye is preferably used in an amount of 0.5 to 5 parts by weight, particularly 1.5 to 3 parts by weight, and 5 to 15 parts by weight, especially 8 parts by weight, per 100 parts by weight of the fixing resin.
Used in an amount of from 12 to 12 parts by weight.

These toner components are pre-mixed with a mixer such as a Henschel mixer, and then kneaded with a kneading device such as a twin-screw extruder. The kneaded composition is cooled, pulverized and classified. To make toner. The toner particle size is generally 5 to 20 μm based on the Coulter counter.
m, especially in the range of 7 to 15 μm. If necessary, the surface of the toner particles is sprinkled with a fluidity improving agent such as hydrophobic vapor phase silica in an amount of 0.05 to 1.0% by weight to obtain a final toner.

The toner according to the present invention has a remarkable advantage that it can be densely packed in a toner container for distribution without agglomeration between particles. When the inside of the container is decompressed and filled with high density, the speed of the powder falling into the container is high, and the amount of air in the container is small, so the degree of compression of the powder filled in the container is large. . Especially at the initial stage of filling, where there is a large difference between the pressure in the powder feeder and the pressure in the container, the powder entering the container collides violently with the inner bottom surface and the toner particle layer above it, resulting in a large compressive force on the powder. However, in the present invention, since the toner particles have a dispersion structure that does not easily agglomerate, the degree of pressure reduction in the container is increased to perform high-speed, high-density filling. However, interparticle coagulation does not easily occur, high density packing with a bulk density of 0.4 g / cm ³ or more is possible, the cost of the container is saved, and the volume per toner weight is reduced to reduce distribution cost. It becomes possible.

In the electrostatographic copying method using the toner of the present invention, the electrostatic latent image can be formed by any method known per se, for example, the photoconductive layer on the conductive substrate is uniformly charged. After that, imagewise exposure can be performed to form an electrostatic latent image. The development of the electrostatic image is easily carried out by mixing the magnetic brush as it is in the case of the one-component magnetic toner and the magnetic carrier in the case of the two-component toner, and bringing the magnetic brush into contact with the substrate. The toner image formed by the development is transferred onto a copy sheet, and the toner image is fixed by bringing it into contact with a heating roll.

When the toner for electrostatic images of the present invention is used, the toner has good fluidity even in an electrophotographic method with a process speed per minute of 200 mm / sec or more, and the fixing failure and the offset development at the time of heat fixing are also possible. There is also an advantage that it does not occur.

[0038]

The present invention will be described in more detail by the following examples. Binder resin [styrene (St) / butyl acrylate (B
A) Copolymer] (A) St: BA = 88: 12 (weight ratio), molecular weight 10000
35 parts by weight of components exceeding 0 (per 100 parts by weight of low molecular weight component) Molecular weight distribution Number standard molecular weight range on the low molecular weight side: 521 to 99225 Peak on the low molecular weight side: 14925 Number average molecular weight: 8800 Mw / Mn (Mw = weight Average molecular weight, Mn = number average molecular weight): 24.7

(B) St: BA = 80: 20 (weight ratio), molecular weight 90,000
30 parts by weight (per 100 parts by weight of low molecular weight component) Molecular weight distribution Number standard molecular weight range on low molecular weight side: 385-88435 Peak on low molecular weight side: 11166 Number average molecular weight: 7300 Mw / Mn (Mw = weight average) Molecular weight, Mn = number average molecular weight): 17.7

(C) St: BA = 72: 28 (weight ratio), molecular weight 90000
More than 27 parts by weight (per 100 parts by weight of low molecular weight component) Molecular weight distribution Number standard molecular weight range on low molecular weight side: 382-91858 Peak on low molecular weight side: 10779 Number average molecular weight: 7400 Mw / Mn (Mw = weight average) Molecular weight, Mn = number average molecular weight): 21.4

(D) St: BA = 91: 9 (weight ratio), molecular weight 120,000
42 parts by weight (per 100 parts by weight of low molecular weight component) Molecular weight distribution Number standard molecular weight range on low molecular weight side: 439 to 12052
5 Peak on low molecular weight side: 16715 Number average molecular weight: 11200 Mw / Mn (Mw = weight average molecular weight, Mn = number average molecular weight): 15.0

(E) St: BA = 93: 7 (weight ratio), 45 parts by weight of a component having a molecular weight of more than 40,000 (per 100 parts by weight of a low molecular weight component) Molecular weight distribution Number standard molecular weight range on the low molecular weight side: 902-38639 Low molecular weight peak: 13060 Number average molecular weight: 11700 Mw / Mn (Mw = weight average molecular weight, Mn = number average molecular weight): 26.9

(F) St: BA = 65: 35 (weight ratio), molecular weight 30,000
More than 20 parts by weight (per 100 parts by weight of low molecular weight component) Molecular weight distribution Number standard molecular weight range on low molecular weight side: 333 to 3076 Peak on low molecular weight side: 5080 Number average molecular weight: 3600 Mw / Mn (Mw = weight average) Molecular weight, Mn = number average molecular weight): 32.3

Release agent (polypropylene) (a) G = 4.0 × 10 ³ dyne / cm ² tan δ = 2.5 Mn (number average molecular weight) = 8000 (b) G = 6.0 × 10 ⁴ dyne / cm ² tan δ = 0.3 Mn (number average molecular weight) = 15000 (c) G = 1.0 × 10 ⁴ dyne / cm ² tan δ = 1.0 Mn (number average molecular weight) = 9000 (d) G = 3. 0 × 10 dyne / cm ² tan δ = 8.5 Mn (number average molecular weight) = 4000 (e) G = 1.0 × 10 dyne / cm ² tan δ = 11.0 Mn (number average molecular weight) = 3000 (f) G = 2.5 × 10 ⁵ dyne / cm ² tan δ = 0.2 Mn (number average molecular weight) = 20,000

The tangent loss (tan δ) is represented by the ratio of loss elastic modulus (G ″) / storage elastic modulus (G ′), and these values are obtained by the method described below: polypropylene is heated. A sample is prepared by molding into a sheet of 20 mm × 20 mm square and 2 mm thick by a press.
Using a DVE type Rheospectler manufactured by Rheology Co., Ltd. as a measuring device, the sample was varied in the range of 50 ° C. to 200 ° C., and sinusoidal vibration (measurement frequency 1 Hz) was applied in the shearing direction by the forced vibration non-resonance method. , The stress response under ultra-small displacement is measured, and the storage elastic modulus (G ′), loss elastic modulus (G ″) and tangent loss (tan δ) are calculated from the power and dynamic strain by known methods. It was

Examples 1 to 17 and Comparative Examples 1 to 18 100 parts by weight of a styrene (St) / butyl acrylate (BA) copolymer as a binder resin, polypropylene as a release agent, and carbon black as a colorant. After mixing the metal-containing complex salt dye as a charge control agent and melt-kneading,
The volume-based median diameter is 1 after cooling, crushing, and classification.
An electrophotographic toner having a size of 0 μm was produced.

The type of binder resin, the type and amount of release agent used (parts by weight), and the amounts of carbon black and metal complex salt dye (parts by weight) used in each of the above Examples and Comparative Examples are as follows:
The details are shown in Tables 1 and 2. The electrophotographic toner obtained as described above was mixed with 0.3% of hydrophobic silica and then filled in the toner cartridge by the high-density filling machine shown in FIG. (The filling state is shown as bulk density in Tables 1 and 2.)

A method of filling toner using the high-density filling machine shown in FIG. 2 will be described below. The on-off valve 12 arranged below the toner hopper 11 is kept closed, and the decompression casing 20 is closed.
The air cylinder 70 is operated to lower the lower half body 22, and the lower half body 22 is divided from the upper half body 21. In such a state, the toner cartridge 80 is mounted on the support base 62 of the container holder 60 arranged in the lower half body 22 so that the opening 81 is located on the upper side.
Then, the air cylinder 70 is operated to move the lower half 22.
Sealing member 22a and sealing member 21a of the upper half 21
The lower half body 22 is raised so as to join and airtightly. When the lower half body 22 and the upper half body 21 are joined together, the on-off valve 52 interposed in the atmosphere introduction pipe 51 is closed,
The inside of the decompression casing 20 is made airtight. In this case, the lower half 2
The toner cartridge 80 held inside the toner cartridge 80 has an opening 81 separated from the fitting portion 21 b of the upper half body 21, and the inside of the toner cartridge 80 is a decompression casing 2.
It is in communication with the inside of 0.

In this state, the on-off valve 42 provided in the pressure reducing conduit 41 is opened and the vacuum pump 44 is driven. As a result, the air inside the decompression casing 20 is sucked and the inside of the decompression casing 20 is decompressed, and at the same time, the inside of the toner cartridge 80 is decompressed. Then, when the pressure inside the toner cartridge 80 and the pressure inside the decompression casing 20 surrounding the toner cartridge 80 are reduced in an equilibrium state and both are brought into a substantially vacuum state, the on-off valve 4 interposed in the decompression pipe line 41.
2 is closed and the driving of the vacuum pump 44 is stopped. As a result, the inside of the decompression casing 20 becomes airtight. In such a state, the air cylinder 61 in the decompression casing 20 is operated to raise the support base 62. As a result, the opening 81 of the toner cartridge 80 held by the support base 62 is inserted into the fitting portion 21 as indicated by the chain double-dashed line in FIG.
It is airtightly fitted to b through a packing 21c.

Next, the open / close valve 12 disposed below the toner hopper 11 in the toner supply device 10 is opened, and the open / close valve 52 interposed in the atmosphere introducing pipe 51 is opened. As a result, a predetermined amount of toner stored in the toner hopper 11 is transferred to the decompression casing 2 via the connecting pipe 30.
The toner cartridge 80 in 0 is collectively dropped. At this time, in the decompression casing 20, from the air introduction pipe 51,
Atmosphere of a predetermined flow rate defined by the flow rate adjusting valve 53 provided in the atmosphere introducing pipe 51 flows in, and the pressure in the decompression casing 20 rises. Therefore, when the toner falls into the toner cartridge 80, the toner cartridge 80
Even if the internal pressure rises, the pressure inside and outside the toner cartridge 80 is balanced and the toner cartridge 80 is not damaged.

When all the toner in the toner hopper 11 is filled in the toner cartridge 80, the air cylinder 61 in the decompression casing 20 is driven to lower the support base 62 and the opening 81 of the toner cartridge 80 is fitted. Joint part 21
It is separated from b. Next, the air cylinder 70 is driven to lower the lower half body 22 of the decompression casing 20. When the lower half body 22 is separated from the upper half body 21, the toner cartridge 80 filled with toner is taken out from the lower half body 22.

Examples 18 to 19 and Comparative Examples 19 to 20 Types of binder resin, type and amount of release agent (parts by weight), carbon black and metal-containing complex salt dye, which are concretely shown in Tables 1 and 2. An electrophotographic toner was prepared in the same manner as in Example 1 except that the used amount (part by weight) of was used. After 0.3% of hydrophobic silica was mixed with the electrophotographic toner obtained as described above, the toner cartridge was filled by gravity dropping. (The filling state is shown as bulk density in Tables 1 and 2.) The following evaluations were performed using the electrophotographic toners obtained in the above Examples and Comparative Examples, and the results are shown in Tables 3 and 4.
It was shown to.

Toner Aggregation The toner densely packed in the toner cartridge described above
Take out 0 g, metal mesh (250 mesh, opening 6
(3 μm), the toner was suctioned off from the back surface of the metal mesh with an air volume of 4 liters / cm ² per minute, and the number of blocking toner remaining on the metal mesh was observed. The above results were evaluated according to the following criteria. ○: None at all △: 1 to 5 occurred ×: 6 or more occurred

Preparation of Developer A high-density filled electrophotographic toner was taken out from the above toner cartridge, and an acrylic-coated ferrite carrier having an average particle size of 90 μm was blended and uniformly stirred and mixed,
A two-component developer having a toner concentration of 4.5% was prepared.

Image formation The above developer was used as a copying machine (manufactured by Mita Kogyo Co., Ltd., DC-8).
585), and an image was formed using an A3 size original having a character area ratio of 20%. The following tests were carried out using the obtained copy.

Measurement of Fixing Ratio Five copies were continuously made by the above copying machine, and the fourth and fifth sheets were used as copy samples. The measurement points were black solid portions existing in the central part and the lower part of the above copy sample, and the image densities (ID) of each were measured using a reflection densitometer (manufactured by Tokyo Denshoku Co., Ltd., Photo Bottle White Photometer TC-6D). , And the average value was defined as (A ′). Next, the exposed weight (mild steel:
400 g, 26 mm × 50 mmφ), the sample was reciprocated 5 times so as to slide on the sample, and the image density was measured in the same manner as described above, and the average value was defined as (B ′).

Observation of offset: Five copies were continuously made by the above copying machine, and the copy samples of the fourth and fifth copies were visually observed to find an offset phenomenon (the surface of the fixing roller comes into pressure contact with the toner image in a heated and melted state). Therefore, a part of the toner image adheres to the surface of the fixing roller, and the presence of this adhered toner is fixed on the transfer paper in the next copying).

Observation of toner loss The first copying machine, the 500th printing machine, and the 1st printing machine were continuously copied by the above copying machine.
From the 000th sheet, the 2000th sheet, the 3000th sheet, the 4000th sheet, and the 5000th sheet, five copy sheets of the original document were sampled, and the presence or absence of toner loss was observed. The above results were evaluated according to the following criteria. ◯: It did not occur. △: 1-3 occurrences ×: 4 occurrences or more

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

[Table 3]

[0062]

[Table 4]

As is clear from Table 3, the toners of the respective examples of the present invention can provide good results as the toner for high-density filling electrostatic image.

On the other hand, as is clear from Table 4,
The toners of Comparative Examples 1, 2, 7, and 8 in which the olefin resin having a storage elastic modulus of 1.0 × 10 ³ dyne / cm ² or less and a tangent loss (tan δ) of 3 or more was used as a release agent were high in density. When the toner is filled, the fixing ratio is good, but toner aggregation occurs, and even offset and toner loss occur. In the toners of Comparative Examples 3 and 9 in which an olefin resin having a storage elastic modulus of 1.0 × 10 ⁵ dyne / cm ² or more and a tangent loss (tan δ) of 0.3 or less was used as a release agent,
Although high-density packing can prevent toner aggregation, it was not possible to have a fixing rate higher than 95%, which is necessary for image quality.

Further, Comparative Example 4 in which a styrene resin having a number standard molecular weight of the low molecular weight side peak exceeding the range of 350 to 100,000 and a high molecular weight component exceeding 40 parts by weight was used as a binder resin, With the toner of No. 10, when the high-density filling was performed, it was not possible to have a fixing rate exceeding 95% required for image quality. In the toners of Comparative Examples 6 and 12, in which the number-based molecular weight of the peak on the low molecular weight side was below the range of 350 to 100,000, and the styrene resin having a high molecular weight component content of 20 parts by weight or less was used as the binder resin, When the high-density filling was performed, the fixing rate was good, but toner aggregation occurred, causing offset and toner loss. In the toners of Comparative Examples 5 and 11 in which the styrene-based resin having the content of the high molecular weight component exceeding 40 parts by weight was used as the binder resin, the toner aggregation could be prevented by the high density filling, but the fixing required for the image quality. 95%
Could not have a value above.

The storage elastic modulus is 1.0 × 10 ³ dyn.
In the range of e / cm ^{2 to} 1.0 × 10 ⁵ dyne / cm ² , an olefin resin having a tangent loss (tan δ) of 0.3 to 3 is used as a release agent, and the binder resin 100 is used.
Comparative Examples 13, 1 used in an amount of 1 part by weight or less per part by weight.
With the toners Nos. 5 and 17, when high density filling was performed, not only the fixing rate required for image quality could not exceed a value of 95%, but also toner aggregation occurred, resulting in offset and toner loss. On the contrary, Comparative Example 14 using the release agent in an amount of 5 parts by weight or more per 100 parts by weight of the binder resin,
With respect to the toners 16 and 18, when the high-density filling was performed, the fixing ratio was good, but toner aggregation occurred, resulting in offset and toner loss.

Further, Comparative Examples 19 (the toner prescription is the same as Comparative Example 1) and 20 (the toner prescription is the same as Comparative Example 2).
However, since the filling by spontaneous dropping is good in all aspects of the fixing ratio, toner aggregation, offset and toner loss, it can be seen how strict conditions are required for the toner for high-density filling electrostatic image.

[0068]

According to the present invention, as the styrene resin forming the continuous medium, a styrene resin having a specific molecular weight distribution having a cohesive force in an appropriate range with respect to offset resistance, heat fixing property and non-cohesiveness between particles. As the olefin resin that forms the dispersed phase, select an olefin resin that has a certain rheological property in terms of adhesive strength and offset resistance, and form a uniform interdispersion state between both resins. As a result, high-density filling of the toner into the container is possible without agglomeration, and excellent fluidity, heat fixing property and offset resistance can be obtained even at high speed copying.

That is, according to the present invention, since the toner particles have a dispersion structure in which aggregation is difficult to occur, interparticle aggregation is unlikely to occur even if the degree of decompression in the container is increased and high-speed and high-density filling is performed, resulting in bulky particles. High density packing with a density of 0.4 g / cm ³ or more is possible, the cost of the container can be saved, and the distribution cost can be reduced by reducing the volume per toner weight. When the electrostatic image toner of the present invention is used, the process speed per minute is 200 mm / sec.
The electrophotographic method described above also has the advantage that the toner has good fluidity and that no fixing failure or offset phenomenon occurs during thermal fixing.

[Brief description of drawings]

FIG. 1 is a diagram showing the molecular weight distribution of a styrene resin used in the present invention [binder resin (A) in Examples].

FIG. 2 is a diagram showing a high-density filling machine used in the present invention.

[Explanation of symbols]

 11 Toner Hopper 12 Opening / Closing Valve 20 Decompression Casing 21 Upper Half of Decompression Casing 22 Lower Half of Decompression Casing 30 Connecting Pipe 41 Decompression Pipeline 42 Opening / Closing Valve 44 Vacuum Pump 51 Atmosphere Introduction Pipe 52 Opening / Closing Valve 60 Container Holder 61 Air Cylinder 62 Support 70 Air Cylinder 80 Toner Cartridge 81 Opening

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Horio 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Engineering Co., Ltd.

Claims (4)

[Claims] 1. The number standard molecular weight of the peak on the low molecular weight side is 35.
In the range of 0 to 100,000, the maximum value of the molecular weight in the peak is more than 8,000 and in the range of 16,000 or less, and the content of the high molecular weight component is 25 to 40 parts by weight per 100 parts by weight of the low molecular weight component. And a storage elastic modulus (G ′) at a temperature of 150 ° C. of 1.0 × 10 ^{3 to} 1.0 × 10 ⁵ dy.
A high content of an olefin resin having ne / cm ² and a tangent loss (tan δ) of 0.3 to 3.0 in an amount of 1 to 5 parts by weight per 100 parts by weight of a styrene resin. Density filling type toner for electrostatic image. 2. The static resin according to claim 1, wherein the styrene resin is a styrene-acrylic copolymer containing a styrene monomer and an acrylic monomer in a weight ratio of 70:30 to 90:10. Toner for charge images. 3. The number average molecular weight (M
The toner for electrostatic charge images according to claim 1, which comprises n) a styrene-acrylic copolymer of 7,000 to 9000. 4. The olefin resin is 7000 to 1
The electrostatic charge image toner according to claim 1, which is polypropylene or polyethylene having a number average molecular weight (Mn) of 5,000.