JP2002365840A - Nonmagnetic one-component developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonmagnetic one-component developing toner having such superior durability and stable electrostatic charge performance as to enable long-time printing, having both anti-offsetting property and fixability in a wide temperature range, giving a fixed image excellent in wear and peeling resistances and suitable for a high-speed developing system and a high-speed fixing system. SOLUTION: The nonmagnetic one-component developing toner contains at least a polyester resin and a colorant, the outflow starting temperature Tfb of the toner measured with a constant load extrusion type capillary rheometer is 95-110 deg.C, the melting temperature T1/2 of the toner measured by a 1/2 method is 135-155 deg.C and the toner has been surface-treated with a silicone oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-magnetic one-component developing toner used in an electrophotographic method, an electrostatic recording method, or an electrostatic printing method.

[0002]

2. Description of the Related Art The processing speed of a copying machine or a printer using an electrophotographic method varies depending on a maker and a type. For example, when converted into the number of processed A4 sheets, about 10 to 30 sheets / min. Many office copiers have a processing speed of about 60 to 100 sheets / min. Further, in recent years, machines having higher-speed developing devices and fixing devices have been oriented, and many models have been developed. At the same time, power is saved, and the amount of heat given from the heat roll to the toner during fixing tends to decrease. As the speeding up of the machine and the saving of power have progressed in this way, as a result, the toner has good sharp-melt properties and low-temperature fixing properties because the pressurization by the heat roll and the heating time are shortened. Become indispensable. Further, a machine maker generally sells a series of machines having different processing speeds, and mounts the same toner on each model. In this case, the toner requires developing characteristics and fixing characteristics suitable for all models having different developing speeds, fixing temperatures, and fixing speeds. As described above, recently, there has been a demand for a toner which has not only low-temperature fixing characteristics but also anti-offset characteristics at high temperatures and can be used in a wide temperature range.

Hitherto, polyester, polystyrene, styrene (meth) acrylate copolymer, styrene butadiene copolymer, epoxy resin and the like have been researched and used as resin materials for powder toners. Various proposals have been made according to use conditions.

In particular, a number of design examples have been proposed for a resin for toner which is fixed by a heat roll, with the aim of improving the fixing performance and the anti-offset performance. In order to improve the viscoelastic behavior during heating and melting, Alternatively, the molecular weight distribution is expanded in order to suppress the change in melt viscosity due to temperature change,
Various techniques such as providing a crosslinked structure and applying a rubber elastic material have been studied.

[0005] Recently, polyester resins have attracted attention due to the increasing demand for low-temperature fixing performance due to energy saving or high speed at the time of heat roll fixing. It has been widely known from previous studies that a polyester resin can be used as a heat roll fixing resin. However, in the conventionally known techniques, when the hot offset resistance is to be improved, the softening point and the molecular weight of the resin must be increased, and the cold offset resistance and the low-temperature fixability are deteriorated. Conversely, when trying to improve the cold offset resistance and the low-temperature fixing property, the softening point or the glass transition point of the resin is lowered, and the hot offset resistance and the blocking resistance are deteriorated.

In particular, when an image is formed by using a developing device for a non-magnetic one-component developing toner having a toner conveying member such as a developing sleeve roll and a toner layer thickness regulating member such as a metal blade pressed against the developing roller, the initial development of the image is prevented. In this method, a uniform thin layer of toner particles is formed on the conveying member, and a good image can be obtained. However, if the toner is used continuously for a long time, an image having fog or streaks will be formed. this is,
If the developing process is repeated continuously for a long time, the toner partially fuses on the layer thickness regulating member and the conveying member due to friction between the toner and the layer thickness regulating member, and a uniform toner layer cannot be formed. As a result, non-uniform charging of the toner is likely to occur when a resin having a low softening point is used. In order to maintain the print image quality at a certain level,
It is necessary to stabilize the charge amount of the toner during printing,
By simply adding a particulate additive such as silica, which has been conventionally performed, the external additive such as silica is buried in the toner during printing, and as a result, the charging performance of the toner is reduced, and printing is performed. This causes deterioration of image quality.

As described above, the non-magnetic one-component developing toner is required to have durability and charge stability associated with continuous printing. In order to ensure this durability, it is necessary to increase the softening point or glass transition point of the resin, but this is in a direction opposite to the above-described direction of improving the cold offset resistance and the low-temperature fixing property, It is important to design these in a well-balanced manner. Further, in order to obtain a stable image in long-term printing, it is necessary to provide stable charging characteristics.

As a means for easily measuring the properties such as the thermal properties and viscosity properties of a resin for toner, there is a constant load extrusion type capillary rheometer. The constant load extrusion type thin tube rheometer measures the viscous resistance of the melt as it passes through the thin tube, and specifically includes a flow tester “CFT-500” manufactured by Shimadzu Corporation.

FIG. 1 shows the structure of a cylinder unit of the "CFT-500" type. In the measurement by the temperature rise method using this device, the test is performed while raising the temperature at a constant rate over the course of the test time, so that the sample goes from the solid region to the transition region, through the rubbery elastic region to the flow region. The process can be measured continuously. With this device, the shear rate and the viscosity at each temperature in the flow region can be easily measured.

FIG. 2 shows a flow curve obtained by the heating method. A
Region B (softening curve) shows the stage in which the sample is deformed under compression load and the internal voids are gradually reduced. Point B is the temperature at which the internal voids disappear and the transparent body or phase becomes uniform in appearance while having a non-uniform stress distribution, and indicates an inflection point from the solid region to the transition region. This temperature is defined as the softening temperature Ts. The area of the BC (stop curve) shows the area where there is no apparent change in the position of the piston within a finite time and the sample begins to flow out of the die, including the rubbery elastic area of the sample. In the case of a crystalline polymer, this region is short, and the softening temperature shows a value close to the outflow start temperature described in the next section. C
The point indicates the temperature at which the sample begins to flow out of the die due to the decrease in viscosity, and this temperature is defined as the flow start temperature Tfb.
The area of CDE (outflow curve) indicates an area where the sample flows out of the die, and irreversible viscous flow is mainly performed.

The melting temperature T1 / 2 according to the 1/2 method indicates the temperature at a point corresponding to 1/2 of the stroke of the movement of the piston between Tfb and the outflow end temperature Tend in the outflow curve.

The softening temperature Ts, the outflow start temperature Tfb, the melting temperature T1 / 2 by the 1/2 method, and the outflow end temperature Tend specified here all affect the offset resistance and the low-temperature fixability at the time of fixing. If anything, the softening temperature T
s, the outflow start temperature Tfb greatly contributes to the low-temperature fixing property and the cold offset resistance, and the melting temperature T by the 1/2 method is large.
1/2, outflow end temperature Tend is hot offset resistance,
Large contribution to grindability.

As an invention based on the viscosity characteristics obtained by such a measuring method, for example, Japanese Patent Laid-Open No. 11-1
No. 90913. However, this publication does not describe a toner used in a non-magnetic one-component development method and a non-magnetic one-component development method, and even if the toner described in the publication is used as a non-magnetic one-component development toner. However, the toner described in the above publication cannot withstand the share received when the toner passes through the gap between the toner transport member specific to the non-magnetic one-component developing system and the toner layer thickness regulating member pressed against the toner transport member. As described above, the prior art does not disclose a non-magnetic one-component developing toner having mechanical strength and thermal characteristics suitable for the recent high-speed developing system and high-speed fixing system.

[0014]

SUMMARY OF THE INVENTION The present invention has excellent durability and stable charging performance enabling long-time printing, and has both offset resistance and fixing performance in a wide temperature range. It is another object of the present invention to provide a high-speed developing method excellent in abrasion resistance and peeling resistance of a fixed image, and a non-magnetic one-component developing toner suitable for a high-speed fixing method.

[0015]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, have reached the present invention. That is, the present invention relates to a non-magnetic one-component developing toner containing at least a polyester resin and a colorant, wherein the outflow starting temperature Tfb of a constant load extrusion type capillary rheometer is 95 ° C to 115 ° C, 1/2. Another object of the present invention is to provide a toner for non-magnetic one-component development, wherein the melting temperature T1 / 2 by the method is 135 ° C. to 155 ° C., and the surface of the toner particles is treated with silicone oil.

The use of the resin having the melting properties specified in the present invention enables low-temperature fixing in a heat roll fixing system and suppresses the occurrence of offset at high temperatures. Further, the abrasion resistance and peeling resistance of the fixed image are improved. By the way, in order to maintain the charging performance and stably secure the image quality, an external additive such as silica is attached to the toner surface in the conventional non-magnetic one-component developer. May be buried in the toner by printing for a long time or separated from the toner surface. Since the toner surface of the non-magnetic one-component developing toner of the present invention is treated with the silicone oil, the appropriate charge is maintained even when the external additive is embedded in or separated from the toner surface during long-time printing. Things become possible.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Ts, Tfb, T1 / 2, Ten by a constant load extrusion type capillary rheometer according to the present invention.
d is a value obtained by measuring under the following conditions. <Measurement conditions of constant load extrusion type thin tube rheometer> ・ Piston cross-sectional area 1cm ²・ Cylinder pressure 0.98MPa ・ Die length 1mm, die hole diameter 1mm ・ Measurement start temperature 50 ° C ・ Temperature increase rate 6 ° C / min・ Sample weight 1.5g

The binder resin of the non-magnetic one-component developing toner of the present invention is not particularly limited in molecular structure or composition as long as it exhibits the above-mentioned melting characteristics as a toner compound. And a diol obtained by dehydration-condensation of a diol with an ordinary method.

(1) Dicarboxylic acids Examples of dicarboxylic acids include phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, adipic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, and hexahydrophthalic anhydride. And dihydrocarboxylic acids such as tetrahydrophthalic anhydride, cyclohexanedicarboxylic acid, succinic acid, malonic acid, glutaric acid, azelaic acid, and sebacic acid, and derivatives or esterified products thereof.

(2) Diols The diols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, bisphenol A, Polyoxyethylene- (2.0) -2,2-
Bis (4-hydroxyphenyl) propane and its derivatives, polyoxypropylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.2) -polyoxyethylene- ( 2.0)
-2,2-bis (4-hydroxyphenyl) propane,
Polyoxypropylene- (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene-
(2.2) -2,2-bis (4-hydroxyphenyl)
Propane, polyoxypropylene- (2.4) -2,2
-Bis (4-hydroxyphenyl) propane, polyoxypropylene- (3.3) -2,2-bis (4-hydroxyphenyl) propane and its derivatives, polyethylene glycol, polypropylene glycol, ethylene oxide-propylene oxide random copolymer Coalescent diol, ethylene oxide-propylene oxide block copolymer diol, ethylene oxide-tetrahydrofuran copolymer diol, polycaprolactone diol, and the like.

(3) Trivalent or higher polyvalent monomer In addition to the above dicarboxylic acids and diols, trifunctional or higher polyfunctional monomers such as trimellitic acid, trimellitic anhydride, pyromellitic acid, and pyromellitic anhydride. A polyvalent carboxylic acid or a derivative or esterified product thereof, or
Sorbitol, 1,2,3,6-hexanetetraol, 1,4-sorbitan, pentaerythritol, 1,
2,4-butanetriol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol,
2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-
Trimethylolbenzene, trifunctional or higher polyhydric alcohol, or cresol novolak type epoxy resin, phenol novolak type epoxy resin, polymer or copolymer of vinyl compound having epoxy group, epoxidized resorcinol-acetone condensation Products, partially epoxidized polybutadiene or other pentavalent epoxy compound,
Further, divalent to tetravalent bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, pentaerythritol tetraglycidyl ether, etc. Epoxy compounds and the like can be used as needed.

The polyester resin in the present invention can be obtained by performing a dehydration condensation reaction or a transesterification reaction using the above-mentioned raw material components in the presence of a catalyst.
The reaction temperature and reaction time at this time are not particularly limited, but are usually 150 to 300 ° C. and 2 to 24 hours.

As the catalyst for carrying out the above reaction, for example, zinc oxide, stannous oxide, tetrabutyl titanate, monobutyltin oxide, dibutyltin oxide, dibutyltin dilaurate, paratoluenesulfonic acid and the like can be used as appropriate. .

The binder resin for the toner in the present invention is not particularly limited in its molecular structure and the like as long as it satisfies the melting characteristics of the toner specified in the present invention by using the compounds and production methods exemplified above. Although not a particular example, a particularly preferred embodiment includes the following method.

That is, the most preferred embodiment as the binder resin of the non-magnetic one-component developing toner of the present invention is as follows:
A linear polyester resin (A) (hereinafter referred to as resin (A)) containing two or more polyester resins having different melting temperatures T1 / 2, and the resin having the lowest melting temperature T1 / 2 among them. A mixed polyester resin in which the resin having a higher melting temperature T1 / 2 than the linear polyester resin is a crosslinked polyester resin (B) (hereinafter referred to as resin (B)). The weight ratio (A) / (B) of the linear polyester resin (A) and the crosslinked polyester resin (B) is preferably 1/9 to 9/1, and is preferably 2/8 to 8/2. Is more preferred. In particular, it is preferably 3/7 to 7/3. By blending the resin (A) and the resin (B) in a well-balanced manner, it is possible to provide a toner that sufficiently satisfies the anti-offset performance and the fixing performance in a wide temperature range.

In the above method, the resin (A) mainly has cold offset resistance and low-temperature fixing property, and the resin (B) mainly has hot offset resistance and toughness.

The linear polyester resin used for the resin (A) includes the above-mentioned dicarboxylic acids (1) and diols (2)
Can be obtained by dehydration-condensation. Further, a resin (A) or (B) having a branched or crosslinked structure
Can be further obtained by appropriately using a trivalent or higher polyvalent monomer (3).

The outflow starting temperature Tfb of the non-magnetic one-component developing toner of the present invention is 95 ° C. to 115 ° C. It is more preferably 100 ° C to 115 ° C, and 100 ° C to 11 ° C.
It is particularly preferred that the temperature is 0 ° C. Further, the melting temperature T1 / 2 according to the １ ／ method in the present invention is 135 ° C. to 155 ° C.
It is. More preferably 135 to 150 ° C, 14
It is particularly preferred that the temperature be 0 to 150 ° C. Softening temperature Ts
Is preferably 65 ° C to 80 ° C, and 70 ° C to 80 ° C.
C. is more preferable. Outflow end temperature Tend is 1
50 ° C to 165 ° C, preferably 155 ° C to 165 ° C
Is more preferable. Melting temperature T by 1/2 method
If the 1/2 and / or the end-of-flow temperature Tend is too high, the pulverizability deteriorates and the productivity decreases. Ts and / or
Alternatively, if Tfb is low, the toner may cause blocking or the like, which is not preferable.

The softening temperature Ts (A) of the resin (A) is 55 ° C.
To 75 ° C, more preferably 60 ° C to 75 ° C. Above all, it is particularly preferable that the temperature is 65 ° C to 75 ° C. The outflow start temperature Tfb (A) is 60 ° C.
To 90 ° C, more preferably 65 ° C to 90 ° C, and particularly preferably 68 ° C to 85 ° C. Melting temperature T1 / 2 by 1/2 method
(A) is preferably 80 ° C to 110 ° C or lower, more preferably 85 ° C to 110 ° C, and particularly preferably 85 ° C to 105 ° C. The outflow end temperature Tend (A) is mainly determined by the Tenn of the resin (B).
d (B) greatly affects the toner characteristics, and therefore Tend (A) of the resin (A) is not particularly limited. However, the range of 90 ° C. to 115 ° C. is considered in consideration of a mixed system of the two. Is preferable, and it is more preferable that it is in the range of 90 ° C to 110 ° C. Above all, it is particularly preferable that the temperature is 90 ° C to 105 ° C.

Since the resin (A) having the above physical property values has a low softening temperature and a high crystallinity, in the fixing process using a heat roll, the heat applied by lowering the fixing temperature or increasing the process speed is given. Even if the energy is reduced, it melts sufficiently and exhibits excellent performance in cold offset resistance and fixing strength.

The Ts (A) of the resin (A) greatly affects the Ts of the toner. Therefore, the Ts (B) of the resin (B) is not particularly limited. ) Is desirably in a temperature range where the Ts of the toner does not deviate from the above range when used as a mixture. Therefore, Ts (B) of the resin (B) is preferably in the range of 70C to 90C, more preferably in the range of 70C to 85C. Particularly, the temperature is desirably 75 ° C to 85 ° C.

If the difference between the softening temperature Ts (B) of the resin (B) and the outflow starting temperature Tfb (B) is too small, the viscosity of the toner melted at the time of fixing decreases, and the melted toner layer Tfb (B) is 100 ° C.
It is preferably in the range of 170 ° C, and 110 ° C to 17 ° C.
A range of 0 ° C. is more preferred. In particular, the temperature is desirably 110 ° C to 160 ° C. Furthermore, Tfb (B) is Ts (B)
It is preferably higher by 30 ° C. or higher, and more preferably higher by 40 ° C. or higher.

If the melting temperature T1 / 2 (B) of the resin (B) by the 1/2 method and the outflow end temperature Tend (B) are both too low, hot offset is likely to occur, and If it is too much, the pulverizability deteriorates and the productivity decreases, so T1 / 2 (B) is 130 ° C. to 210 ° C.
Is preferably 140 ° C. to 205 ° C., and more preferably 150 ° C. to 205 ° C. Outflow end temperature Tend (B) is 160 ° C to 23
It is preferably 0 ° C, more preferably 165 ° C to 230 ° C. In particular, the temperature is desirably 169 ° C to 230 ° C. In the present invention, such a crosslinked polyester resin (B) may be of one type, but it is preferable to use two or more types of resins (B) having different T1 / 2 in order to achieve the effects of the present invention.

The melting temperatures of the resin (A) and the resin (B) according to the 法 method are T1 / 2 (A) and T1 / 2, respectively.
(B), T1 / 2 (A) <T1 / 2 (B)
In particular, from the viewpoint of compatibility between low-temperature fixability and offset resistance, and in order to facilitate uniform mixing when performing melt-kneading without causing a problem due to a difference in viscosity between resins, , T1 / 2 (B) -T1 / 2 (A) is preferably 20 ° C. to 110 ° C., and 30 ° C. to 1 ° C.
More preferably, 00 ゜ C. Especially 40 ° C-10
Preferably it is 0 ° C.

With respect to the glass transition temperature Tg of the resin, if the Tg is too low, the heat storage stability and the blocking resistance decrease, and if the Tg is too high, the low-temperature fixability is affected. The glass transition temperature of the resin (A) and the resin (B) used in the present invention is 50 to 70 ° C. in either case of a mixed resin or a single resin. Those having a Tg of 55 ° C to 65 ° C are particularly preferred.

Regarding the acid value, the resin (A) and the resin (B) do not cause a decrease in the charge amount due to an increase in the hygroscopicity, and from the viewpoint of storage stability and developability, It is preferably 20 or less, and particularly preferably 15 or less. Further, the resin used in the present invention may contain a THF-insoluble component. The measurement of the THF insoluble content was performed as follows. Take 1 g of the synthesized resin powder on a special filter paper and add THF
Refers to the residue on the filter paper after refluxing for 8 hours in a Soxhlet reflux apparatus using as a solvent. In addition, the crosslinked structure referred to in the present invention includes both a branched structure in which the polyester main chain is branched and a structure in which the polyester main chain is connected in a network. Usually, the content of the THF-insoluble component defined in the present invention is small in the polyester having a branched structure, and the content of the THF-insoluble component increases as the network structure increases.

As the colorant that can be used in the present invention, well-known colorants can be mentioned. Carbon blacks such as furnace black, channel black, acetylene black, thermal black, and lamp black classified according to the production method are used as black colorants, and phthalocyanine C.I. I. PigmentBl
ue 15-3, an indanthrone C.I. I. Pigm
ent Blue 60 and the like, and quinacridone C.I. I. Pigment Red 122,
Azo-based C.I. I. Pigment Red 22, C.I.
I. Pigment Red 48: 1, C.I. I. Pig
Ment Red 48: 3, C.I. I. Pigment
Red 57: 1, etc., and azo C.I. I. Pigment Yellow 12, C.I. I.
Pigment Yellow 13, C.I. I. Pigm
ent Yellow 14, C.I. I. Pigment
Yellow 17, C.I. I. Pigment Yellow
ow 97, C.I. I. Pigment Yellow 1
55, isoindolinone-based C.I. I. Pigment
Yellow 110, a benzimidazolone C.I.
I. Pigment Yellow 151, C.I. I. P
pigment yellow 154, C.I. I. Pigm
ent Yellow 180, and the like. The colorant content is in the range from 1 part by weight to 20 parts by weight. These colorants can be used alone or in combination of two or more.

The positively chargeable charge control agent used in the present invention is not particularly limited as long as it is a compound that imparts positive chargeability to the toner, but is preferably a triphenylmethane dye, a nigrosine dye, or a quaternary ammonium salt. And a resin containing a quaternary ammonium group and / or an amino group. These compounds may be used alone or in combination of two or more charge control agents. Examples of the positively chargeable charge control agent include the following products, but are not limited to the examples.

Examples of triphenylmethane dyes include “OIL BLUE” (Orient Chemical Co., Ltd.),
"Copy Blue PR" (Clariant Co., Ltd.)
And the like. Nigrosine dyes include “NIG
ROSINE BASE EX ”,“ OIL BRAC ”
KBS "," BONTORON N-01 "," BO
Notoron N-04 "," Bontoron N-
07 "," BONTORON N-21 "(all Orient Chemical Co., Ltd.) and the like. As a quaternary ammonium salt compound, "BONTORON P-51"
(Orient Chemical Co., Ltd.), "TP-302", "TP
-610 "," TP-415 "(above, Hodogaya Chemical Co., Ltd.)," COPY CHARGE PSY "(Clariant, Inc.) and the like. Examples of the resin containing a quaternary ammonium group and / or an amino group include “FCA
-201-PS "(Fujikura Kasei Co., Ltd.) and the like.

The negatively chargeable charge control agent used in the present invention is not particularly limited as long as it is a compound that imparts negative chargeability to the toner. Examples of the azo metal complex (salt) and salicylic acid metal complex ( Salts), benzyl acid metal complexes (salts), tetraphenyl metal complexes (salts), calixarene-type phenol condensates, cyclic polysaccharides, and resin charge control agents are preferred.

As the azo metal complex (salt), “BON
TORON S-34 "," BONTORON S-4 "
4 "(all Orient Chemical Co., Ltd.) and the like.
As salicylic acid-based metal complexes, "BONTORON"
E-81 "," BONTORON E-84 "," BO
NTORON E-88 "(orient Chemical Co., Ltd.) and the like. Examples of the benzyl acid metal complex include “LR-147” (Nippon Carlit Co., Ltd.). Examples of tetraphenyl-based metal complexes include “CO
PY CHARGE NX "(Clariant Co., Ltd.). As calixarene type compounds,
"BONTORON E-89", "BONTORON E-89"
F-21 "(all Orient Chemical Co., Ltd.). As the cyclic polysaccharide, “COPY C
HARGE NCA "(Clariant Co., Ltd.). As the resin-based charge control agent, "FCA-1001"
-NS "(Fujikura Kasei Co., Ltd.)," COPY LEVEL
NCS "(Clariant Co., Ltd.) and the like.

The content of the charge controlling agent is 10
It is preferably used in an amount of 0.3 to 10 parts by weight, more preferably 1 to 5 parts by weight, per 0 parts by weight.

The release agent used in the toner for developing an electrostatic image of the present invention includes known polypropylene wax, polyethylene wax, modified polyolefin wax, higher fatty acid ester, Fischer-Tropsch wax,
Graft polymerized waxes, higher aliphatic alcohols, amide waxes, natural waxes, etc. can be used. Among them, a release agent containing a higher fatty acid ester compound and / or an aliphatic alcohol compound as a main component is dispersible in a polyester resin. And good releasability and slidability are preferable. When a higher fatty acid ester wax and / or an aliphatic alcohol are added to the toner,
Better hot offset resistance and fixing strength can be obtained as compared with the same amount of polyolefin wax such as polypropylene wax and polyethylene wax.

Examples of the wax mainly containing a higher fatty acid ester compound include natural waxes such as carnauba wax, montan wax, candelilla wax, rice wax and botaro wax. These waxes are purified and pulverized. Thus, the dispersion in the resin is further improved. Examples of the synthetic ester wax include higher fatty acid esters such as pentaerythritol.
As higher fatty acid esters, for example, "WEP-
5 "and" WEP-6 "(both Nippon Oil & Fats Co., Ltd.).

Examples of the release agent mainly containing an aliphatic alcohol compound include those mainly containing a higher alcohol obtained by an oxidation reaction of paraffin, olefin or the like. Examples of the release agent containing an aliphatic alcohol as a main component include “Unilin 425”, “Unilin 550” (both by Petrolite), “NPS-9210”,
“PARACOL 5070” (Nippon Seiro Co., Ltd.) and the like.

Among the release agents containing a higher fatty acid ester compound or an aliphatic alcohol compound as a main component, those having a melting point in the range of 65 ° C. to 130 ° C. are particularly preferred because they greatly contribute to the offset resistance. The release agent may be used alone or in combination. A good fixing offset performance can be obtained by adding 0.3 to 15 parts by weight, preferably 1 to 5 parts by weight, to the binder resin.
If less than 0.3 parts by weight, the offset resistance is impaired,
If the amount is more than 15 parts by weight, the fluidity of the toner deteriorates, and the image density becomes non-uniform or toner leakage occurs with printing, which is not preferable.

As an example of the silicone oil used in the present invention, dimethyl silicone oil is preferable, but a so-called modified silicone oil modified with various functional groups according to the chargeability can also be used. Examples of the modified silicone oil include alkyl-modified silicone oil, methylstyrene or olefin-modified silicone oil,
Polyether-modified silicone oil, alcohol-modified silicone oil, fluorine-modified silicone oil, chlorophenyl silicone oil, mercapto-modified silicone oil, epoxy-modified silicone oil, carboxyl-modified silicone oil, higher fatty acid-modified silicone oil, carnauba-modified silicone oil, amide-modified silicone oil And the like.

These silicone oils can be used alone, but in order to adjust the toner properties such as the electrical properties and fluidity of the toner to a desired level, two or more silicone oils may be used in a mixture. It is possible. The viscosity at 25 ° C. of the silicone oil used in the present invention is more preferably from 10 to 6,000 centistokes, and particularly preferably from 30 to 3,000 centistokes. If the viscosity of the silicone oil exceeds 6000 centistokes, it is not preferable because uneven distribution easily occurs when the silicone oil is directly added to the toner.

In the present invention, the amount of the silicone oil adhered to the surface of the toner base is preferably 0.001 to 0.5 part by weight based on 100 parts by weight of the toner particles. Moreover, it is more preferable that it is 0.001-0.2 weight part, and it is especially preferable that it is 0.001-0.1 weight part. If the amount of the silicone oil is less than 0.001 part by weight, the effect of the present invention cannot be obtained, and if it exceeds 0.5 part by weight, the fluidity becomes poor, which is not preferable.

The toner for developing an electrostatic image according to the present invention comprises:
A binder resin comprising a polyester resin as described above,
Although a coloring agent is constituted as an essential component, other additives may be included. As an example, a lubricant such as metal soap and zinc stearate can be used, and as an abrasive, for example, cerium oxide and silicon carbide can be used.

The toner of the present invention can be obtained by an extremely general manufacturing method regardless of a specific manufacturing method.
For example, it can be obtained by melt-kneading a resin, a colorant, and a charge control agent at a temperature equal to or higher than the melting point (softening point) of the resin, followed by pulverization and classification.

Specifically, for example, the above resin, colorant,
Prior to melt-kneading, the mixture is uniformly mixed in advance with a Henschel mixer or the like, using a release agent and a charge control agent as essential components. The conditions for the mixing are not particularly limited, but the mixing may be performed in several stages so as to obtain a desired uniformity. The coloring agent and / or the charge controlling agent used here may be previously subjected to a flushing treatment so as to be uniformly dispersed in the resin, or a master batch melt-kneaded with the resin at a high concentration.

The above mixture is mixed by kneading means such as a two-roll, three-roll, pressure kneader or a twin-screw extruder. At this time, the colorant or the like may be uniformly dispersed in the resin, and the conditions for the melt-kneading are not particularly limited, but are usually from 80 to 200 ° C. for 30 seconds to 2 hours.

If necessary, coarse pulverization is performed for the purpose of reducing the load in the fine pulverization step and improving the pulverization efficiency. The apparatus and conditions used for the coarse pulverization are not particularly limited, but the coarse pulverization is generally performed using a rotoplex, a pulperizer, or the like to a particle size of 3 mm mesh pass or less.

Then, fine pulverization is performed with a mechanical pulverizer such as a turbo mill or a kryptron, or an air pulverizer such as a spiral jet mill, a counter jet mill, or an impinging plate jet mill, and then classified using an air classifier or the like. No. Fine grinding and classification equipment, conditions are the desired particle size,
What is necessary is just to select and set so that it may become a particle size distribution and a particle shape. The volume average particle diameter of the particles constituting the toner is not particularly limited, but is usually adjusted to be 5 to 15 μm.

The silicone oil according to the present invention is characterized in that it is applied to the toner. The application method is the same as the method of applying and adhering an ordinary external additive, using a mixer such as a Henschel mixer. If necessary, an external additive is mixed with the toner thus obtained using a mixer such as a Henschel mixer. In the present invention, various additives (referred to as external additives) can be used for modifying the surface of the toner such as improving the fluidity of the toner and improving the charging characteristics. Examples of the external additives that can be used in the present invention include inorganic fine powders such as silicon dioxide, titanium oxide, and alumina, and those obtained by surface-treating them with a hydrophobizing agent such as silicone oil, organic fine particles, and resin fine powders. Is used.

Among them, hydrophobic silica obtained by surface-treating silicon dioxide with various polyorganosiloxanes, silane coupling agents and the like is preferably used as an external additive.

Specifically, there is one that is commercially available under the following trade names. AEROSIL; R972, R974, R202, R8
05, R812, RX200, RY200, R80
9, RX50, NAX50, RA200HS, RA20
0H [Nippon Aerosil Co., Ltd.] WORKER; HDK H2000, H2050, H3
050, HVK2150, H05TM, H05TX, H
05TD, H05TA, H13TM, H13TX, H1
3TD, H13TA, H20TD, H30TM, H30
TX, H30TD, T30TA (Wacker Chemicals Co., Ltd.), Nipsil; SS-10, SS-15, SS-20,
SS-50, SS-60, SS-100, SS-50
B, SS-50F, SS-10F, SS-40, SS-
70, SS-72F, [Nippon Silica Industry Co., Ltd.], CABOSIL; TS-500, TS-530, TS-
610, TS-720, TG-308F, TG-709
F, TG-810G, TG-811F, TG820F
[Cabot Specialty Chemicals, Inc.].

The titanium oxide may be a hydrophilic grade or a hydrophobic grade surface-treated with octylsilane or the like. For example, there is one that is commercially available under the following trade names. Titanium oxide T
805 (Degussa Co., Ltd.), titanium oxide P25 (Nippon Aerosil Co., Ltd.) and the like.

Examples of the alumina include aluminum oxide C (Degussa Co., Ltd.).

The particle size of these external additives is preferably not more than 1/3 of the diameter of the toner, particularly preferably 1/1.
0 or less. It is preferable that two or more kinds of these external additives having different average particle diameters are used in combination. The use ratio of silica is usually 0.05 to 5% by weight, and preferably 0.1 to 3% by weight, based on the toner.

The thus-obtained non-magnetic one-component developing toner of the present invention is developed and fixed on a recording medium by a known and usual method. As a fixing method, a heat roll fixing method is adopted. preferable. As a heat roll,
A cylindrical body which can be heated to a temperature at which the toner can be melted and fixed is coated with a coating resin having both releasability and heat resistance, such as a silicone resin or a fluororesin. In the heat-roll fixing method, the toner is fixed by the printing medium passing between two rolls having at least one heat roll and pressed at an appropriate pressure as described above.

The remarkable technical effect of the non-magnetic one-component developing toner of the present invention is exhibited in a developing and fixing device in which development is performed at a higher speed and heat roll fixing is performed. As the recording medium in the present invention, any known and commonly used medium can be used, and examples thereof include papers such as plain paper and resin-coated paper, and synthetic resin films and sheets such as PET films and OHP sheets.

As a non-magnetic one-component developing method, there is a contact type non-magnetic one-component developing method in which a developing sleeve carrying a developer is brought into contact with a photosensitive drum having an electrostatic latent image for development. . The non-magnetic one-component developing toner of the present invention is an electrostatic latent image formed on the surface of a photoreceptor by allowing the toner to pass between a developing sleeve and a charging member pressed against the developing sleeve and frictionally charging the toner. Can be particularly effectively used in a contact-type non-magnetic one-component developing method for developing a toner.

[0065]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. In the following, numerical values in the composition table represent "parts by weight".

A constant load extrusion type capillary rheometer was used to measure the piston cross-sectional area 1 cm ² , cylinder pressure 0.98 M
Pa, die length 1 mm, die hole diameter 1 mm, measurement start temperature 50 ° C, heating rate 6 ° C / min, sample weight 1.5 g
Was performed under the following conditions.

First, an example of the synthesis of the binder resin used in preparing the toner is shown below.

(Synthesis of Linear Polyester A) Terephthalic acid: 664 parts by weight Ethylene glycol: 150 parts by weight Polyoxyethylene- (2.2) -2,2-bis (4
-Hydroxyphenyl) propane: 632 parts by weight

The above-mentioned materials were placed in a two-liter four-necked flask equipped with a stirrer, a condenser and a thermometer, and 4 parts by weight of tetrabutyl titanate was added under a stream of nitrogen gas to remove water generated by dehydration condensation. While 240
The reaction was carried out at normal pressure for 15 hours at ゜ C. Thereafter, the pressure was sequentially reduced, and the reaction was continued at 5 mmHg. Reaction is ASTM E28
The reaction was followed by a softening point according to -517, and the reaction was terminated when the softening point reached 80 ° C. Table 1 shows the softening temperature Ts of the obtained polyester resin A by a constant load extrusion type capillary rheometer, the outflow start temperature Tfb, the melting temperature T1 / 2 by the 1/2 method, the outflow end temperature Tend, and the Tg by the DSC measurement method. Show.

(Synthesis of Linear Polyester B) Terephthalic acid: 664 parts by weight Polyoxypropylene- (2.2) -2.2-bis (4-hydroxyphenyl) propane: 688 parts by weight Ethylene glycol: 150 parts by weight

A linear polyester A was used, except that the above-mentioned materials were used and the reaction was terminated when the softening point reached 90 ° C.
As a result, a polyester resin B as shown in Table 1 was obtained.

(Synthesis of linear polyester C) Terephthalic acid: 332 parts by weight Isophthalic acid: 332 parts by weight Polyoxypropylene- (2.2) -2.2-bis (4-hydroxyphenyl) propane: 460 parts by weight polyoxyethylene- (2.2) -2.2-bis (4
-Hydroxyphenyl) propane: 210 parts by weight Ethylene glycol: 150 parts by weight

The synthesis was performed in the same manner as in the linear polyester A except that the reaction was terminated when the softening point reached 100 ° C. using the above-mentioned materials. As a result, a polyester resin C as shown in Table 1 was obtained. Obtained.

(Synthesis of Linear Polyester D) Using the same raw materials as for linear polyester A, the softening point was 100 ° C.
The synthesis was carried out in the same manner as for the linear polyester A except that the reaction was terminated when the reaction time became as a result. As a result, a polyester resin D as shown in Table 1 was obtained.

(Synthesis of Crosslinked Polyester E) Terephthalic acid: 664 parts by weight Ethylene glycol: 150 parts by weight Neopentyl glycol: 166 parts by weight Trimethylolpropane: 80 parts by weight

The above materials were placed in a two-liter four-necked flask equipped with a stirrer, a condenser and a thermometer, and 4 parts by weight of tetrabutyl titanate was added under a nitrogen gas stream to remove water generated by dehydration condensation. While 230
The reaction was performed at normal pressure for 10 hours at ゜ C. Thereafter, the pressure was sequentially reduced, and the reaction was continued at 5 mmHg. Reaction is ASTM E28
Tracking was performed using a softening point according to −517, and the softening point was 190
When the temperature reached ゜ C, the reaction was terminated. Table 1 shows the softening temperature Ts of the obtained polyester resin E by a constant load extrusion type capillary rheometer, the outflow start temperature Tfb, the melting temperature T1 / 2 by the 1/2 method, the outflow end temperature Tend, and the Tg by the DSC measurement method. Show.

(Synthesis of Crosslinked Polyester F) Terephthalic acid: 498 parts by weight Isophthalic acid: 166 parts by weight Polyoxypropylene- (2.2) -2,2-bis (4-hydroxyphenyl) propane: 550 parts by weight Parts ・ Ethylene glycol: 150 parts by weight ・ Trimethylolpropane: 80 parts by weight

Using the above materials, the synthesis was carried out in the same manner as in the case of the crosslinked polyester E. As a result, a polyester resin F as shown in Table 1 was obtained.

(Synthesis of Crosslinked Polyester G) Terephthalic acid: 332 parts by weight Isophthalic acid: 266 parts by weight Trimellitic acid: 115 parts by weight Polyoxypropylene- (2.2) -2,2-bis (4 -Hydroxyphenyl) propane: 688 parts by weight ・ Ethylene glycol: 150 parts by weight

Using the above materials, except that the reaction was terminated when the softening point reached 180 ° C.,
As a result of performing synthesis in the same manner as in Example 1, a polyester resin G as shown in Table 1 was obtained.

(Synthesis of Crosslinked Polyester H) Terephthalic acid: 332 parts by weight Isophthalic acid: 232 parts by weight Trimellitic acid: 154 parts by weight Polyoxypropylene- (2.2) -2,2-bis (4 -Hydroxyphenyl) propane: 688 parts by weight ・ Ethylene glycol: 150 parts by weight

Using the above materials, except that the reaction was terminated when the softening point reached 160 ° C.,
As a result of performing synthesis in the same manner as in Example 1, a polyester resin H as shown in Table 1 was obtained.

[0083]

[Table 1]

<Production of Toner> (Example 1) Linear polyester resin A: 27.6 parts by weight Crosslinked polyester resin G: 27.6 parts by weight Crosslinked polyester resin F: 36.8 parts by weight Carbon black Mogal L: 5 parts by weight (manufactured by Cabot Specialty Chemicals, Inc.) Charge control agent (negative charge control agent) Bontron S-34: 1 part by weight (manufactured by Orient Chemical Industry Co., Ltd.) Wax Biscol 550P (Sanyo) 2 parts by weight The above materials are mixed with a Henschel mixer and kneaded with a twin-screw kneader. The kneaded material thus obtained was pulverized and classified to obtain a toner base having a volume average particle size of 9.1 μm.

Next, 100 parts by weight of the toner raw material dimethyl silicone oil (KF-96-100CS) (manufactured by Shin-Etsu Chemical Co., Ltd., viscosity: 100 centistokes) 0.05 part by weight Hydrophobic silica NAX50 1.0 part by weight ( R972 1.0 part by weight (average particle diameter of silica primary particles manufactured by Nippon Aerosil Co., Ltd .; 16 nm) The above "toner base material" and dimethyl silicone oil KF
-96-100CS was mixed at the above mixing ratio, and thereafter, hydrophobic silica was added at the above mixing ratio to perform uniform mixing. Thereafter, the mixture was sieved to obtain the toner of Example 1 (non-magnetic one-component developing toner).

(Examples 2 to 4) Toners were produced according to the resin ratios shown in Table 2 in place of the resin of Example 1. Other raw materials are the same as in Example 1.

(Examples 5 to 7) The resin ratio shown in Table 2 was used instead of the resin used in Example 1, and the wax was WE
A toner was manufactured in the same manner as in Example 1 except that P-5 (higher fatty acid ester wax manufactured by NOF CORPORATION) was used.

Example 8 A toner was produced according to the resin ratio shown in Table 2 in place of the resin of Example 1. Other raw materials are the same as in Example 1.

Comparative Example 1 A toner was produced in the same manner as in Example 1 except that no silicone oil was adhered to the toner surface of Example 1.

(Comparative Examples 2 to 4) The toner of Example 1 was prepared by changing the resin of Example 1 to those shown in Table 2. Silica was externally added in the same manner as in Example 1 except that silicone oil was not adhered to the toner surface to prepare a toner.

Comparative Example 5 A toner was produced in the same manner as in Comparative Example 2 except that silicone oil was adhered to the toner surface in Comparative Example 2 in the same manner as in Example 1.

[0092]

[Table 2]

The viscosity characteristics (Ts, Tfb, T1 / 2, Tend) and Tg of the toners obtained in the above Examples and Comparative Examples were measured by a constant load extrusion type capillary rheometer. Table 3 shows the measurement results.

[0094]

[Table 3]

(Low-temperature fixability and offset property test) An unfixed sample of A4 paper (55 kg paper) was prepared using a test machine modified from a commercially available non-magnetic one-component developing system printer, and a heat roll fixing unit having the following specifications was used. Was used to evaluate low-temperature fixability and offset property under the following test conditions. The fixed image sample for evaluating the low-temperature fixability was prepared at 100 ° C., and the fixed image sample for performing the offset property evaluation was prepared at 180 ° C. to 200 ° C. at 10 ° C. intervals. The fixed image for evaluation was a solid image of a square having a side of 2 cm. In order to evaluate low-temperature fixability, a mending tape (Sumitomo 3M, 81
0) was rubbed back and forth at a pressure of 5.0 KPa, and peeled off at an angle of 180 ° at a speed of 5 mm / sec to determine an image density remaining ratio. The image density was measured with a Macbeth image densitometer RD-918. Residual image density = Image density after peel test / Image density before peel test × 100 Low when the image density residual ratio is 90% or more, ◎ when less than 90% and 80% or more, and X when less than 80%. It was used as an index for evaluation of fixability. The offset start temperature was determined by observing the fixed image sample and visually confirming the presence or absence of the offset phenomenon. The evaluation criteria for the offset property is 180 ° C
When no offset occurs at 200 ° C., 180 ° C.
○, 180 ° C when no offset occurs up to 190 ° C
Only when no offset occurs (within the practical range), 18
When an offset occurs at 0 ° C., it is evaluated as x. Table 4 shows the results
Shown in

<Image Characteristics> A black solid image was printed by a commercially available non-magnetic one-component developing system printer, and the image density was measured by a Macbeth densitometer. The case where the measured value was 1.3 or more was evaluated as ○, the case where the measured value was 1.2 or more and less than 1.3 was evaluated as Δ (within the practical range), and the case where the measured value was less than 1.2 was evaluated as ×. Table 4 shows the results.

<Print Durability Test> Continuous printing was performed using a commercially available non-magnetic one-component developing system printer and the toners of the examples and comparative examples. The toner layer on the developing sleeve was uniform and no defects were found. The state where no occurrences were observed was judged as “○”, and the case where uneven portions such as streaks occurred were judged as “×”. The results are shown in Table 4. <Number of prints> In continuous printing in the print durability test, evaluation was made based on the number of prints until the image was blurred when 350 g of toner was filled. Table 4 shows the results.

<Evaluation of Charging Characteristics> Tenth print and 8000th print
A suction type small charge measuring device (Model 21) manufactured by Trek, which measures the charge by taking in the toner on the developing roller into the Faraday gauge with a suction nozzle.
0HS-2A). Table 5 shows the results.

[0099]

[Table 4]

[0100]

[Table 5]

[0101]

According to the present invention, it has excellent durability and image stability capable of continuous printing for a long time, has both offset resistance and fixing performance in a wide temperature range, and has a fixed image quality. A non-magnetic one-component developing toner suitable for a high-speed developing system and a high-speed fixing system having excellent wear resistance and peeling resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a structure of a cylinder portion of a constant load extrusion type thin tube rheometer.

FIG. 2 is an example of a flow curve obtained by a heating method.

[Explanation of symbols]

 1 Piston 2 Cylinder 3 Heater 4 Die 5 Die holder 6 Sample

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsuyuki Ogura, Inventor 1-1662-9, Owada-cho, Saitama City, Saitama Prefecture (72) Shinji Ameya 1-4-604, Minamiurawa, Saitama City, Saitama Prefecture F-term (reference) 2H005 AA06 AA08 CA08 CA12 CA14 CA17 EA03 EA05 EA10 FA07

Claims (9)

[Claims] 1. A non-magnetic one-component developing toner containing at least a polyester resin and a colorant, and a flow start temperature Tf measured by a constant load extrusion type capillary rheometer.
b is 95 ° C to 115 ° C, melting temperature T by 1/2 method
A toner for non-magnetic one-component development, wherein 1/2 is 135 ° C. to 155 ° C., and the toner base material is surface-treated with silicone oil. 2. The non-magnetic one-component developing toner according to claim 1, wherein the polyester resin contains a linear polyester resin (A) and a crosslinked polyester resin (B). 3. A weight ratio (A) / (B) of the linear polyester resin (A) and the crosslinked polyester resin (B).
3. The non-magnetic one-component developing toner according to claim 2, wherein the ratio is 1/9 to 9/1. 4. An outflow starting temperature T of the linear polyester resin (A) measured by a constant load extrusion type capillary rheometer.
fb is 60 to 90 ° C., and the outflow end temperature Tend of the crosslinked polyester resin (B) is 160 to 23.
The non-magnetic one-component developing toner according to claim 2, wherein the temperature is 0 ° C. 5. 5. The melting temperature T1 / 2 of the linear polyester resin (A) and the crosslinked polyester resin (B) measured by a constant load extrusion type capillary rheometer is T1 / 2.
(A) When T1 / 2 (B), 20 ° C ≦ T1 / 2 (B) −T1 / 2 (A) ≦ 110 °
The non-magnetic one-component developing toner according to claim 2, wherein the toner is C 1. 6. The non-magnetic one-component developing toner according to claim 2, wherein the crosslinked polyester resin (B) contains two or more polyester resins having different melting temperatures T1 / 2. 7. A higher fatty acid ester compound and / or
2. The non-magnetic one-component developing toner according to claim 1, further comprising a release agent containing an aliphatic alcohol compound as a main component. 8. The non-magnetic one-component developing toner according to claim 1, wherein two or more external additives having different average particle diameters are further attached to the surface of the toner. 9. The silicone oil has a viscosity of 25 ° C.
2. The non-magnetic one-component developing toner according to claim 1, wherein the toner has a density of 10 to 6000 centistokes.