JP3360527B2 - Thermal fixing toner composition, method for producing the same, and image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing toner composition used for developing an electric latent image or a magnetic latent image, a method for producing the same, and an image forming method using the heat fixing toner composition. It is.

[0002]

2. Description of the Related Art There are known various methods for obtaining a copy or print by developing an electric latent image or a magnetic latent image using toner, and then transferring and fixing the latent image to a transfer member such as paper.
The toner is a powder containing a binder resin and a colorant as essential components, and the necessary materials are kneaded, cooled and pulverized, so-called kneading and pulverization method, or the binder resin is finely divided in the presence of a colorant or the like. Although it can be produced by a polymerization method of polymerizing into a state, a kneading and pulverizing method is generally used conventionally. In order to impart good chargeability, fluidity, transferability, and the like to toner particles, organic and inorganic fine particles, so-called external additives, are often mixed.

When an electric latent image is developed, the toner generally obtains an electric charge by charging between a developing machine member and a carrier.
The latent image on the latent image carrier is developed by the charge. In the case of a magnetic latent image, the magnetic force of the toner is used. The developed toner image is transferred to a transfer body such as paper, and further fixed on the transfer body. Various fixing methods are known. That is, the fixing technique uses heat, light, pressure, a solvent, and the like and various combinations thereof. Among them, a heat roll fixing method in which a transfer member having a toner image is inserted and fixed between a pair of rolls including a heating roll and a pressure roll is common. It is also known as a similar technique to change one or both of the rolls to a belt.

[0004] These methods can provide a fast and robust fixed image, have high energy efficiency, and are less harmful to the environment due to evaporation of a solvent or the like, as compared with other fixing methods. However, because the toner image directly contacts the roll or belt,
A so-called offset in which a part of the toner adheres to a roll or a belt during fixing is likely to occur. In particular, when the temperature of the fixing device is high, the cohesive force of the molten toner is reduced and offset is likely to occur.

[0005] Further, since the temperature of the fixing machine quickly rises to the operating temperature after the power is turned on, it is desired that the fixing be performed at a lower temperature in order to shorten the waiting time and reduce the energy consumption. In particular, in recent years, in order to thoroughly save energy, it has been desired to stop energizing the fixing device except during use, and it is necessary that the temperature of the fixing device be instantaneously increased to the operating temperature upon energization. For this purpose, it is desirable to reduce the heat capacity of the fixing device as much as possible, but in this case, the fluctuation width of the fixing device temperature tends to be larger than before. That is, the overshoot of the temperature after the start of energization becomes large, and the temperature drop due to paper passing also becomes large. Further, the temperature difference between the paper passing portion and the non-paper passing portion when paper having a width smaller than the width of the fixing device is continuously passed becomes large. In particular, when used in high-speed copiers and printers, the power capacity tends to be insufficient, and the above tendency is strong. Therefore, a toner having a wide fixing latitude, which fixes at a low temperature and does not cause offset to a higher temperature region, is desired.

In order to lower the fixing temperature and prevent the occurrence of offset, it is known to blend a low molecular weight polymer and a high molecular weight polymer and use a resin having an appropriate molecular weight distribution as a binder resin for toner. (Japanese Patent Application Laid-Open No. 50-1)
No. 34652), and the use of a crosslinked resin is also known (JP-A-51-23354).
However, with these methods, it is not possible to obtain a fixing latitude that is wide enough to satisfy recent requirements.
When a large amount of a high molecular weight polymer or a crosslinked polymer is used, offset hardly occurs, but the fixing temperature rises. On the other hand, when the molecular weight of the low molecular weight polymer is reduced or the amount is increased to lower the fixing temperature, the temperature at which the offset occurs decreases. Although the fixing temperature can be lowered by lowering the glass transition temperature of the binder resin or by using a plasticizer, a phenomenon called so-called blocking, in which the toner is aggregated and solidified during storage or in a developing machine, occurs. I do.

As another method for lowering the fixing temperature and preventing the offset phenomenon, it is known to use a crystalline polymer (Japanese Patent Publication No. 57-36586;
-79049). Below the melting temperature of the crystals, the solidity of the toner is maintained, and the viscosity sharply decreases with the melting of the crystals, so that low-temperature fixing is achieved. Further, by setting the molecular weight to be high, occurrence of offset can be prevented. However, because the crystalline polymer is soft,
Blocking easily occurs, and a filming phenomenon in which a part of the toner adheres to a developing member, a carrier, or a latent image holding member easily occurs. Also, particularly when copying or printing at a high speed, the toner gradually deforms due to the pressure or shear force received from the developing machine member or carrier, or obtains stable developing characteristics by embedding an external additive on the surface of the toner particles. Can not. Further, since the fluidity of the toner powder is poor, the mixing of the toner and the carrier becomes insufficient, and a phenomenon that charging is poor occurs.
JP-A-63-116166 describes that some of the above-mentioned problems can be solved by using a crystal polymer having a crystal block having a difference in melting point in combination with a release agent. In particular, it is said that the softening properties of the crystalline resin can be suppressed by the release agent, but the problem has not been fundamentally solved.

To solve these problems, many techniques have been proposed in which a crystalline polymer is not used alone as a binder resin, but is used in combination with an amorphous polymer. It is also known that when a toner is produced by a kneading and pulverizing method, pulverization is facilitated by the presence of an amorphous portion. For example, the use of a crystalline polymer and an amorphous polymer in combination is described in JP-A-2-79860 and the like. 163756, JP-A-1-163
JP-A-757, JP-A-4-81770, JP-A-4-81
It is described in, for example, JP-A-155351.

However, although these methods have some effects, they do not sufficiently solve the problem caused by the softness of the crystalline resin while maintaining the low-temperature fixability of the crystalline resin. When the amount of the crystalline polymer is larger than that of the amorphous polymer, the crystalline polymer basically forms a continuous phase in the binder resin, and the amorphous polymer forms a dispersed phase. In that case,
Although low-temperature fixability can be achieved, the problem caused by being soft because the crystalline polymer is exposed on the surface of the toner particles is not sufficiently improved. On the other hand, when the amorphous polymer is larger than the crystalline polymer, the amorphous polymer becomes a continuous phase and the crystalline polymer becomes a dispersed phase. In this case, since the crystalline polymer is covered with the amorphous polymer, the problem due to the crystalline polymer does not appear, but the melting of the entire toner is controlled by the softening temperature of the amorphous polymer. Therefore, low-temperature fixability is not obtained.

JP-A-63-174061, JP-A-63-174062, JP-A-63-174063
In the publication, resin using isocyanate, in the molecule-
It is described that a resin containing an NHCO- atomic group, a crystalline resin having a low molecular weight and a high cohesive energy in the form of an amide wax is used. According to the study of the present inventors,
In these cases, although low-temperature fixing is achieved, the offset resistance is not always sufficient. That is, when the molten toner permeates the paper, it has the effect of preventing the occurrence of offset, but there is a problem that a uniform high-density image cannot be obtained.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and has as its object to solve the problems. That is, an object of the present invention is to provide a heat fixing toner composition which can fix at a low temperature, can reduce energy consumption in a fixing step, hardly cause offset to a fixing machine, and has a wide fixing latitude. . Furthermore, an object of the present invention is to prevent blocking during storage or use in a developing machine, to have good fluidity, to mix well with a carrier, to have excellent chargeability, and to provide a developing machine member, a carrier and a latent image holding member. It is an object of the present invention to provide a heat fixing toner composition that does not cause problems such as filming. A further object of the present invention is to provide a heat fixing toner composition which is not deformed by pressure or shear force received from a developing machine or a carrier, does not change its characteristics due to embedding of an external additive, and exhibits stable developing characteristics. It is in. Still another object of the present invention is to provide a method for producing a heat fixing toner composition having the above-mentioned properties.
Another object of the present invention is to provide an image forming method for forming an image using the toner composition for heat fixing having the above-mentioned characteristics.

[0012]

The above objects of the present invention can be attained by producing and using a heat fixing toner composition having the following constitution. That is, the heat fixing toner composition of the present invention comprises a binder resin, a colorant, and a nonmagnetic inorganic compound fine powder, and the main component of the binder resin has a durometer D at room temperature. A crystalline resin having a hardness of 20 or more, a melting point of 40 ° C. to 120 ° C., and a melt viscosity in a range of 10 ² Pa · s to 10 ⁶ Pa · s, and a nonmagnetic inorganic compound It is characterized by using a toner composition containing 0.1% by weight to 30% by weight of fine powder inside toner particles. Preferably it is in the range of 1% to 20% by weight. Further, it is preferable that the toner particles have a surface layer, since a better effect can be obtained.

The method for producing a toner composition for heat fixing according to the present invention has a durometer D hardness of 2 at room temperature.
0 or more, the melting point is 40 ° C. to 120 ° C., and the melt viscosity is colored in a binder resin mainly composed of a crystalline resin having a rubbery region in a range of 10 ² Pa · s to 10 ⁶ Pa · s. Dispersing an agent and a nonmagnetic inorganic fine powder to form toner particles containing the nonmagnetic inorganic compound fine powder in an amount of 0.1% by weight to 30% by weight inside the toner particles; Forming a layer. The toner particles formed in the above step are preferably made of a nonmagnetic inorganic oxide fine powder of 1% by weight to 2% by weight.
The toner particles are contained in a range of 0% by weight.

Further, according to the image forming method of the present invention, there is provided a step of forming an electrostatic latent image on a latent image holding member, and developing the electrostatic latent image by using a developer carried on a developer carrying member. The process of
A step of transferring the toner image formed on the latent image holding member onto a transfer member, and a step of thermally fixing the toner image on the transfer member, and a binder resin as a developer. A binder containing a colorant and a nonmagnetic inorganic compound fine powder, wherein the main component of the binder resin has a hardness at room temperature of durometer D hardness of 20 or more, a melting point of 40 ° C to 120 ° C, and a melt viscosity of Contains a crystalline resin having a rubbery region in the range of 10 ² Pa · s to 10 ⁶ Pa · s as a main component, and contains the nonmagnetic inorganic compound fine powder in an amount of 0.1% by weight to 30% by weight inside the toner particles. It is characterized in that a toner composition is used. Preferably, a toner composition containing 1% by weight to 20% by weight is used. In that case, it is preferable that the toner has a surface layer because a more favorable effect can be obtained.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the binder resin in the toner composition for heat fixing needs to have a main component of a crystalline resin having the above-mentioned specific characteristics. This means that the melt viscoelastic properties are governed by the properties of the crystalline resin. That is, the main component specifically means that the crystalline resin in the present invention accounts for 60% or more by weight of the entire binder resin including the surface layer and the release agent. When the content of the crystalline resin in the total binder resin is less than 60% by weight, the crystalline resin does not form a continuous phase in the binder resin, or the content of the surface layer is too large, so that it is substantially sufficient. Low temperature fixing cannot be achieved.

The crystalline resin used in the present invention must have sufficient hardness at room temperature. Specifically, the durometer D hardness needs to be 20 or more, preferably 30 or more. If the durometer D hardness is less than 20, the toner particles are deformed by the pressure or shear force received from the carrier when mixed with the carrier in the developing machine, so that stable charge development characteristics cannot be maintained. Further, when the toner on the latent image holding member is cleaned, the toner is deformed by the shearing force received from the cleaning blade, and cleaning failure occurs. Durometer D hardness is 30
The above case is preferable because the characteristics are further stabilized even when used in a high-speed machine. The durometer D hardness is J
It is a value measured in the range of 21 ° C to 25 ° C according to IS K7215-1986.

In the present invention, the hardness of a material contained in the toner other than the crystalline resin is a durometer D hardness 2
Although it may be 0 or less, it is desirable that the hardness of the entire toner is 20 or more in durometer D hardness.

The crystalline resin used in the present invention has a melting point of:
It is necessary to be in the range of 40 ° C to 120 ° C, and preferably in the range of 60 ° C to 90 ° C. Since the viscosity of the crystalline resin sharply decreases from the melting point, blocking occurs when stored at a temperature higher than the melting point. Therefore, the temperature exposed during storage and use, that is, 40 ° C.
As described above, desirably, it is necessary to have a melting point of 60 ° C. or more. On the other hand, when the melting point is higher than 120 ° C., low-temperature fixing cannot be achieved. The melting point is measured by JI
It can be determined as the melting peak temperature of the input compensation differential scanning calorimetry shown in SK-7121. Note that the crystalline resin may show a plurality of melting peaks, and the maximum peak is regarded as the melting point.

The crystalline resin used in the present invention needs to have a rubbery region in a range of a melt viscosity of 10 ² Pa · s to 10 ⁶ Pa · s, preferably 10 ³ to 10 ⁵ P
It is sufficient that a rubber-like region, that is, a region where the temperature dependence of the viscosity is moderate is present in the range of a · s. Thereby, occurrence of an offset can be prevented. Slow temperature dependence of viscosity means that the viscosity that decreases with temperature as the crystal melts has an inflection point, and the temperature dependence of viscosity becomes lower. FIG. 1 is a characteristic diagram of the crystalline resin. The rubbery region where the viscosity decreases almost linearly with temperature is a region indicated by a to b in the figure, and the melt viscosity is 1
0 ² to 10 ⁶ Pa · s, preferably 10 ³ to 10 ⁵ Pa
・ It is in the range of s. The slope [log viscosity (Pa · s)
/ Temperature (° C.)] is a range of inclination of c to d in the figure,
It must be greater than zero (the slope of c in the figure) and lower than the slope of the viscosity accompanying the crystal melting (the slope of d in the figure).
More preferably, log viscosity (Pa · s) / temperature (° C.)
When the value is in the range of -0.05 to 0, the offset does not occur in a wide viscosity range, so that it can be preferably used.

The rubbery region is generated when the crystalline resin has a high molecular weight and causes entanglement of molecular chains. If the molecular chains are sufficiently entangled, an elastic force is generated in the entire binder resin to exert a cohesive force, so that a part of the toner is not torn off and adheres to the fixing member. The molecular weight at which the entanglement of the molecular chains occurs depends on the type of the resin. For example, in the case of polystyrene, the weight average molecular weight is about 30,000. Even if the type of resin is different, if the molecular weight in terms of polystyrene measured by gel permeation chromatography is 50,000 or more, preferably 100,000 or more in weight, offset can be prevented. The melt viscosity was measured by Shimadzu Corporation.
It can be measured using a flow tester CFT-500.

The crystalline resin used in the present invention may be any resin as long as it satisfies the above conditions.
Among them, polyolefin polymers and copolymers can be preferably used. For example, polybutene, poly-3-methyl-1-butene, polypentene, poly-5-methyl-
1-hexene, polytetradecene, polypentadecene,
It is selected from polyhexadecene, polyheptadecene, polyoctadecene, polynonadecene, polyeicosene, polycycloheptene-alt-ethylene and the like. Further, a copolymer of monomers constituting the polymer may be used. In addition, in the case of polyolefins whose melting points are too low or too high for homopolymers, for example, in the case of polyethylene or polypropylene, monomers forming those homopolymers are copolymerized with other olefin components, or acrylic acid or acrylic acid is used. By copolymerizing with an acid ester, methacrylic acid, methacrylic acid ester, vinyl alcohol, vinyl acetate, maleic anhydride or the like, it can be used as a crystalline resin in the present invention.

In the present invention, as the crystalline resin,
Polydienes and diene copolymers can also be used. Specifically, for example, trans-1,4-poly-
1,3-butadiene, cis-2-t-butyl-1,4-
Poly-1,3-butadiene, trans-1-methoxy-
1,4-poly-1,3-butadiene, transchloroprene, trans-1,4-polyisoprene, isotactic-trans-1,4-poly-1,3-pentadiene, isotactic-trans-1, 4-poly-1,
3-heptadiene, isotactic-trans-6-
Methyl-1,4-poly-1,3-heptadiene, isotactic-trans-1,4-poly-1,3-hexadiene, isotactic-trans-5-methyl-
1,4-poly-1,3-hexadiene, trans-erythro-di-isotactic-2,5-poly-2,4-
Hexadiene, isotactic-trans-1,4-
It can be selected from poly-1,3-octadiene and the like.

The crystalline resin used in the present invention includes polyester resins. Specifically, for example, poly-1,2-cyclopropene dimethylene isophthalate, polydecamethylene adipate, polydecamethylene azelate, polydecamethylene oxalate, polydecamethylene sebacate, polydecamethylene succinate, Eicosamethylene malonate, polyethylene-p- (carbophenoxy) butyrate, polyethylene-p- (carbophenoxy) undecanoate,
Polyethylene-p-phenylenediacetate, polyethylene sebacate, polyethylene succinate, polyhexamethylene carbonate, polyhexamethylene-p-
(Carbophenoxy) undecanoate, polyhexamethylene oxalate, polyhexamethylene sebacate,
Polyhexamethylene suberate, polyhexamethylene succinate, poly-4,4-isopropylidene diphenylene adipate, poly-4,4-isopropylidene diphenylene malonate, trans-poly-4,4-isopropylidene diphenylene- 1-methylcyclopropane dicarboxylate, polynonamethylene azelate, polynonamethylene terephthalate, polyoctamethylene dodecane diate, polypentamethylene terephthalate, trans-poly-m-phenylenecyclopropane dicarboxylate, cis-poly-m -Phenylenecyclopropanedicarboxylate, polytetramethylene carbonate, polytetramethylene-p-phenylenediacetate, polytetramethylene sebacate, polytrimethylene dodecandioate Polytrimethylene octadecanedioate, polytrimethylene oxalate, polytrimethylene undecandioate, poly-p-xylene adipate, poly-p-xylene azelate, poly-p-xylene sebacate, polydiethylene glycol terephthalate, cis-poly It can be selected from -1,4- (2-butene) sebacate, polycaprolactone, and the like, and copolycondensates thereof.

In the present invention, when the above crystalline resin is used, fixing at a low temperature can be sufficiently achieved. Therefore, it is not necessary to include a component having a low molecular weight. May be included in a small amount. Vinyl aromatic monomer, acrylic monomer, vinyl ester monomer,
A polymer or copolymer composed of a vinyl ether monomer or the like is preferably used. Examples of the vinyl aromatic monomer include styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, o-chlorostyrene, m
-Chlorostyrene, p-chlorostyrene, p-ethylstyrene and divinylbenzene. Examples of acrylic monomers include, for example, methyl acrylate, ethyl acrylate, butyl acrylate, phenyl acrylate, methyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, β-ethyl hydroxyacrylate, γ- Examples include propyl hydroxyacrylate, butyl σ-hydroxyacrylate, ethyl β-hydroxymethacrylate, and ethylene glycol dimethacrylate. Examples of the vinyl ester monomer include vinyl formate, vinyl acetate, vinyl propionate and the like. Examples of the vinyl ether monomer include vinyl-n-butyl ether, vinyl phenyl ether, vinyl cyclohexyl ether and the like. Also, styrene-butadiene copolymer, epoxy resin, polyester, rubber, polyvinylpyrrolidone, polyamide, coumarone-indene copolymer, methyl vinyl ether-maleic anhydride copolymer, amino resin, polyurethane, polyurea, polyvinyl chloride, etc. Can also be used. Further, a petroleum resin or a rosin-based resin may be contained.
Examples of the petroleum resin include an aliphatic resin, an aromatic resin, a copolymer resin, an alicyclic hydrogenated petroleum resin, an alkyl phenol resin, and a cumarone indene resin. Examples of the rosin-based resin include rosin, modified rosin, glycerin esters of these rosins, and pentaerythritol esters of these rosins. If these resins are used, they should not be used in more than 40% by weight of the binder resin.

The nonmagnetic inorganic compound fine powder is used for compensating the softness of the crystalline resin. That is, even when the hardness of the crystalline resin at room temperature is durometer D hardness of 20 or more, for example, 30 or more, due to the softness of the amorphous portion contained in the crystalline resin, during storage or development. Although problems such as blocking in the machine, poor fluidity, poor charging due to poor mixing with the carrier, and filming of the developing machine members, the carrier or the latent image holding member cannot be avoided, non-magnetic inorganic fine powder is added internally. By doing so, those problems can be solved. Adsorption of resin molecules on the particle surface of the non-magnetic inorganic compound fine powder inhibits thermal motion of the resin molecules at room temperature, or the non-magnetic inorganic compound fine powder becomes a crystal nucleus, thereby improving the crystallinity. This is because the softness of the toner particle surface decreases.

The non-magnetic inorganic compound fine powder used in the present invention includes the following. That is, as oxides, silica, alumina, titanium oxide, zinc oxide,
Chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, tin oxide, copper oxide, manganese oxide, spinel, etc., hydroxides, such as aluminum hydroxide and magnesium hydroxide, and carbonates, barium carbonate, carbonate Calcium, strontium carbonate, magnesium carbonate, etc. as silicates, such as aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, zinc silicate, calcium silicate, mica, etc .; titanates as barium titanate, magnesium titanate, calcium titanate , Strontium titanate, potassium titanate,
Examples of sulfates such as lead titanate and the like include barium sulfate and the like, and silicon carbide, silicon nitride, boron carbide, boron nitride and the like.

The shape of the nonmagnetic inorganic compound fine powder may be flake, fibrous, balun, or porous. Further, the surface may be treated with a surface treating agent such as heat, oil, or organic substance. As the surface treatment agent, higher fatty acids such as stearic acid, acrylic acid and derivatives thereof, titanate coupling agents, silane coupling agents, silicone oil, modified silicone oil and the like are preferably used. The average particle diameter of the nonmagnetic inorganic compound fine powder may be 1 μm or less in the major axis, but is preferably 0.1 μm or less.

It is necessary that the nonmagnetic inorganic compound fine powder is contained in the toner particles in an amount of 0.1% by weight or more. If the amount added to the inside of the toner particles is less than 0.1% by weight, the effect of addition is not exhibited. The upper limit of the amount of addition is determined by the fact that the melt viscosity of the toner becomes so high that it is not suitable for fixing.
It can be contained up to the range of weight%. Preferably it is in the range of 1% to 20% by weight.

Known coloring agents can be used, such as carbon blacks such as furnace black, channel black, acetylene black and thermal black, inorganic pigments such as red iron oxide, navy blue and titanium oxide, fast yellow, disazo yellow, and the like. Pyrazolone red,
Azo pigments such as chelate red, brilliant carmine, and para brown; phthalocyanine pigments such as copper phthalocyanine and metal-free phthalocyanine; flavantron yellow;
And condensed polycyclic pigments such as dibromoanthrone orange, perylene red, quinacridone red, and dioxazine violet. In addition, disperse dyes, oil-soluble dyes and the like can also be used. The compounding amount of these colorants is preferably in the range of 0.1 to 30% by weight based on the toner particles.

A magnetic powder can be contained as a colorant or for the purpose of imparting a magnetic force to the toner. As the magnetic powder, magnetite, ferrite, a simple metal such as cobalt, iron, nickel, or an alloy thereof can be used. These magnetic powders may be surface-treated with a silane coupling agent, a titanium coupling agent, or another organic or inorganic substance before use. It is preferable that the amount of the magnetic powder is in the range of 0.1 to 80% by weight based on the toner particles.

Further, the toner composition of the present invention may contain wax or silicone oil as a lubricant. Examples of waxes include animal waxes such as beeswax, whale wax, Chinese wax, lanolin, plant waxes such as candelilla wax, carnauba wax, wood wax, rice wax, sugar cane wax, montan wax, ozokerite, ceresin, rig. Mineral waxes such as night wax, petroleum waxes such as paraffin wax and microcrystalline wax, modified waxes such as montan wax derivatives, paraffin wax derivatives, microcrystalline wax derivatives, hydrogenated waxes such as caster wax and opal wax, low molecular weight Polyethylene and its derivatives, acura wax,
Synthetic wax such as distearyl ketone, caproic amide, caprylic amide, beralgonamide, capric amide, lauric amide, tridecyl amide, myristic amide, stearic amide, behenic amide, ethylene bis stearamide, etc. Saturated fatty acid amide wax, caproleic acid amide, myristoleic acid amide, oleic acid amide, elaidic acid amide,
Examples include unsaturated fatty acid amide waxes such as linoleic acid amide, erucic acid amide, ricinoleic acid amide, and linolenic acid amide.

The toner particles are formed by dispersing a colorant, a non-magnetic inorganic fine powder and other optional materials in the above-mentioned binder resin to form toner particles and, if desired, a surface of the toner particles. It is manufactured by a process of forming a layer. Specifically, a known method of pulverizing a toner material composed of a binder resin mainly composed of a crystalline resin, a colorant, non-magnetic inorganic fine particles and other materials is used.

That is, toner particles are formed by a kneading and pulverizing method, a method of polymerizing particles in which a binder resin monomer, a colorant, a nonmagnetic inorganic fine powder and other materials are dispersed in an aqueous medium. The suspension polymerization method, emulsified particles of the binder resin,
An emulsion aggregation method in which the colorant, nonmagnetic inorganic fine powder and other materials are aggregated and fixed together may be used. In the case of the emulsion aggregation method, the emulsified particles may be those produced by an emulsion polymerization method, or those obtained by dissolving a binder resin in a solvent and finely dispersing the same in an aqueous medium. Also, binder resin,
A method of dissolving and dispersing a colorant, non-magnetic inorganic fine particles and other materials in a solvent, suspending and dispersing in a water-based medium, and then removing the solvent may be employed. Alternatively, a method of dissolving and dispersing a binder resin, a colorant, non-magnetic inorganic fine particles, and other materials in a solvent, dispersing the binder resin in a gas with a spray dryer or the like, and simultaneously removing the solvent may be employed. Further, a method of precipitating the binder resin dissolved in the solvent by lowering the temperature or adding a poor solvent may be adopted. Further, a method of dispersing and cooling a molten material in a medium may be employed. Further, a technique of dispersion polymerization or seed polymerization may be used. Among these methods, a method in which a binder resin, a colorant, non-magnetic inorganic fine particles and other materials are dissolved and dispersed in a solvent, suspended and dispersed in an aqueous medium, and then the solvent is removed is appropriately. By selecting a solvent, particles can be generally formed irrespective of the type of resin, and thus it is suitable as the production method of the present invention.

The toner particles formed as described above preferably have a particle diameter in the range of 1 to 20 μm.

In the present invention, the surface of the toner particles is desirably covered with a surface layer. By providing the surface layer, the disadvantage that the binder resin is soft can be reliably avoided. It is desirable that the surface layer does not significantly affect the mechanical properties and melt viscoelastic properties of the entire toner. For example, if the non-melting or high-melting surface layer covers the toner thickly, it is difficult to make use of the low-temperature fixability of the crystalline resin. Therefore, a three-dimensionally crosslinked material is not desirable as a material constituting the surface layer. On the other hand, the thickness of the surface layer is desirably small. The preferred thickness of the surface layer is in the range of 0.001 to 0.5 μm.

For forming the surface layer on the surface of the toner particles, a known technique can be used. For example, "Particle design"
(Interface polymerization method, as shown in "Microcapsules-Functions and Applications", edited by Masazumi Koishi, Industrial Research Institute, 1987)
A situ polymerization method, a liquid curing coating method, a coacervation method, a liquid drying method, a melt dispersion cooling method, a spray drying method, a dry mixing method and the like can be used. The surface layer may be formed after forming the toner particles using the above-described method, or the surface layer may be formed simultaneously with the formation of the toner particles.

In order to form a thin surface layer so as to achieve the object of the present invention, a method of chemically treating the surface of toner particles containing a binder resin, a colorant, non-magnetic inorganic fine particles and other materials is used. Is preferably used. Further, it is preferable that a polar group is introduced into a component constituting the surface layer, and the bonding strength between the toner and a transfer body such as paper increases by chemically bonding. The polar group may be any polar functional group, for example, a carboxyl group, a carbonyl group, an epoxy group, an ether group, a hydroxyl group, an amino group, an imino group, a cyano group, an amide group,
Examples include an imide group, an ester group, and a sulfone group. For chemical treatment, for example, strong oxidizing substances such as peroxides,
Examples thereof include a method of oxidizing by ozone oxidation and plasma oxidation, and a method of bonding a polymerizable monomer containing a polar group by graft polymerization. By the chemical treatment, the polar group is firmly bonded to the molecular chain of the crystalline resin by a covalent bond.

In the toner composition of the present invention, a chargeable substance may be further chemically or physically attached to the surface of the toner particles. Further, fine particles such as a metal, a metal oxide, a metal salt, a ceramic, a resin, and carbon black may be externally added to improve chargeability, conductivity, powder fluidity, lubricity, and the like.

Next, an image forming method using the toner composition of the present invention will be described. The image forming method includes a step of forming an electrostatic latent image on an image latent image holding member, a step of developing the electrostatic latent image using a developer carried on a developer carrier, and a step of developing the latent image. The method comprises the steps of: transferring a toner image formed on a holding member onto a transfer member such as paper; and thermally fixing a toner image on the transfer member. Things are used. In each of the above steps in the present invention, known steps in an image forming method can be used. As the latent image holding member, an electrophotographic photosensitive member and a dielectric recording member can be used.For example, in the case of an electrophotographic photosensitive member, after being uniformly charged by a corotron charger, a contact charger, etc., exposure is performed, An electrostatic latent image is formed. Next, the toner particles are attached to the electrostatic latent image by contacting or approaching a developing roll having a developer layer formed on the surface to form a toner image on the electrophotographic photosensitive member. The formed toner image is transferred onto a transfer body such as paper using a corotron charger or the like, and is heated and fixed by a fixing device to form a toner image.

[0040]

EXAMPLES Examples of the present invention will be described below, but needless to say, the present invention is not limited to the following examples. (Example 1) As a crystalline resin, an ethylene-ethyl acrylate copolymer (manufactured by Du Pont-Mitsui Polychemicals, E
VAFLEX-EEAA707) (22 g) was dissolved in 218 g of hexane at 60 ° C. 1.4 g of the obtained solution and carbon black (R330R, manufactured by Cabot Corporation)
And silica fine powder (R972, manufactured by Nippon Aerosil Co., Ltd.)
The mixture was mixed with 2.2 g and subjected to a dispersion treatment at 40 ° C. for 4 hours by a sand mill (this liquid is referred to as “liquid A”). On the other hand, 7.6 g of hydroxypropyl methylcellulose (Metroze 65SH50, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 190 g of ion-exchanged water.
Was dissolved and cooled to 5 ° C. (This solution is referred to as solution B.) While stirring the solution B with a stirrer (manufactured by Tokushu Kika Kogyo Co., Ltd., Auto Homo Mixer), 120 g of solution A is slowly added, and the mixture is suspended and suspended. A liquid was obtained. This suspension was an O / W emulsion having an average oil droplet size of about 20 μm (this suspension is referred to as “liquid C”).

Next, the solution C was placed in a 2-liter separable flask, and the solution was reduced under reduced pressure by a stirrer (Three One Motor, manufactured by Shinto Kagaku) with a propeller type stirring blade.
Stirring at 3 ° C. for 3 hours removed hexane. The obtained liquid was mixed with 2 liters of ion-exchanged water and suction-filtered to obtain toner particles. This operation was repeated seven more times to wash the toner particles. The above-described particle production operation was further repeated four times, and the obtained toner particles were mixed to obtain a slurry of toner particles. This was poured into a stainless steel vat and dried at 40 ° C. for 24 hours using a dryer (manufactured by Yamato Kagaku). One part by weight of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RA-200H) was added to 100 parts by weight of the obtained toner and sufficiently stirred. The average particle size of the toner particles in the obtained toner composition was 10 μm.

The above crystalline resin has a durometer D hardness of 27, a melting point of 84 ° C., and a melt viscosity of 5.6 × at 96 ° C.
It was 10 ³ Pa · s and showed a rubbery region with a slope of −0.025 expressed as log viscosity (Pa · s) / temperature (° C.).

The blocking property of the toner was evaluated by placing the toner composition in an oven at 50 ° C. for 24 hours, and it was confirmed that there was no problem. Next, 3 parts by weight of the toner composition was mixed with 100 parts by weight of a carrier having iron powder as a core and the surface of which was resin-coated with a styrene-n-butyl acrylate copolymer to obtain a developer. This developer is put into a copying machine (manufactured by Fuji Xerox Co., Ltd., an evaluation machine with a fixing device removed from Vivace 500), charged amount, filming of photoconductor and carrier, embedding of external additives in toner particles, toner particles The deformation was evaluated. The copying operation was performed continuously for 20,000 sheets. The charge amount is measured by blow-off tribo, filming is performed visually and by observation with a scanning electron microscope, changes in the charge amount are monitored, and copier troubles are observed. This was performed through a monitor for the amount change. The charge amount of the toner is 15 microcoulombs / g up to 20,000 sheets.
There was no problem. Also, no filming on the photoreceptor and carrier was observed. Observation of the toner particles after copying 20,000 sheets revealed that the external additive was embedded and that the toner particles were slightly deformed in a rounded direction. However, there was no change in image quality.

The evaluation of the fixing property was carried out using a Vivace 500 copier manufactured by Fuji Xerox Co., Ltd. with the fixing device removed, and the minimum fixing temperature and the presence or absence of an offset were evaluated. The minimum fixing temperature refers to the minimum temperature of the surface of the heat roll at which the image is hardly peeled off even if the paper having the fixed image of the character image is squeezed and the character can be distinguished. As a result of the evaluation, the minimum fixing temperature was 135 ° C., and no offset occurred even at a high temperature of 240 ° C. Incidentally, the minimum fixing temperature of the toner for the Vivace 500 copying machine was 170 ° C. under the same evaluation conditions, indicating that a significant decrease in the fixing temperature was achieved.

The results are summarized in Table 1. In the table, ○ means that there was no problem, 多少 means that some change was observed but no practical problem, and × means that a large change was observed. .

(Examples 2 and 3) The amount of the fine silica powder added to the ethylene-ethyl acrylate copolymer was 0.1%.
A toner composition was prepared in the same manner as in Example 1 except that the amount was changed to 24 g (Example 2) or 5.85 g (Example 3), and evaluated under the same evaluation conditions as in Example 1. Table 1 shows the evaluation results.

Example 4 A surface layer was formed on toner particles produced in the same manner as in Example 1 as follows. Ion-exchanged water was added to the prepared slurry of toner particles to adjust the solid content concentration to 20%, and the solid content was adjusted to 20% with a stirrer equipped with a propeller-type stirring blade (Three One Motor, manufactured by Shinto Kagaku).
Stir at 0 revolutions / min. Next, 0.4 g of potassium persulfate, 0.26 g of n-butyl acrylate, 1.25 g of styrene, and 0.1 g of sodium bisulfite were sequentially added thereto, and reacted at 25 ° C. for 4 hours. After the reaction, the obtained liquid was mixed with 2 liters of ion-exchanged water, and suction-filtered. This operation was repeated four more times to wash the polymer particles.
Open the obtained polymer particles in a stainless steel vat,
It was dried at 40 ° C. for 24 hours with a drier (manufactured by Yamato Scientific Co., Ltd.). One part by weight of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RA-200H) was added to 100 parts by weight of the obtained toner and sufficiently stirred. Evaluation of the obtained toner composition was performed in the same manner as in Example 1. Table 1 shows the evaluation results.
Shown in

Example 5 A surface layer was formed in the same manner as in Example 4 on toner particles produced in the same manner as in Example 2.
Evaluation was performed in the same manner as in Example 1. Table 1 shows the evaluation results. (Example 6) A surface layer was formed in the same manner as in Example 4 on toner particles produced in the same manner as in Example 3, and evaluation was performed as in Example 1. Table 1 shows the evaluation results. (Example 7) A toner was produced in the same manner as in Example 1 except that 2.2 g of alumina fine powder (AOC, Nippon Aerosil Co., Ltd.) was included in the ethylene-ethyl acrylate copolymer instead of silica fine powder. And evaluated similarly. Table 1 shows the evaluation results.

Example 8 As a crystalline resin, polycaprolactone (Placcel H5, manufactured by Daicel Chemical Industries, Ltd.)
11 g and polycaprolactone (manufactured by Daicel Chemical Industries, Ltd.
11 g of Praxel H7) was dissolved in 218 g of ethyl acetate, and carbon black (R3, manufactured by Cabot Corp.)
30R) and 2.2 g of alumina fine powder (Nippon Aerosil Co., Ltd., AOC) were added and dispersed in a ball mill for 20 hours (this liquid is referred to as Liquid A). On the other hand, 11.4 g of hydroxypropyl methylcellulose (manufactured by Shin-Etsu Chemical Co., Ltd., Metroose 65SH50) was added to 285 g of ion-exchanged water.
Was dissolved and cooled to 5 ° C. (this solution is referred to as solution B). Solution A is slowly added to solution B while stirring with a stirrer (manufactured by Tokushu Kika Kogyo Co., Ltd., auto homomixer)
The mixture was suspended to give a suspension. The resulting suspension is
The O / W emulsion had an average oil droplet size of about 17 μm (this liquid is referred to as Liquid C). Next, the liquid C is put into a 2-liter separable flask, and a stirrer equipped with a propeller type stirring blade (Shinto Kagaku Co., Ltd., Three One Motor)
Was stirred at 50 ° C. for 3 hours under reduced pressure to remove ethyl acetate. The obtained liquid was mixed with 2 liters of ion-exchanged water and suction-filtered to obtain toner particles. This operation was repeated seven more times to wash the toner particles.

The above-described particle preparation operation was further repeated four times, and the obtained toner particles were mixed to obtain a toner particle slurry. This was poured into a stainless steel vat and dried at 40 ° C. for 24 hours using a dryer (manufactured by Yamato Kagaku). 1 part by weight of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RA-200H) was added to 100 parts by weight of the obtained toner and sufficiently stirred. The average particle size of the toner particles in the obtained toner composition was 8 μm. Evaluation,
Performed in the same manner as in Example 1.

The above crystalline resin has a durometer D hardness of 53, a melting point of 62 ° C., a melt viscosity of 90 × 10 ³ Pa · s at 90 ° C., and a log viscosity (Pa ·
s) / temperature (° C.) showed a rubbery region with a slope of −0.011.

As a result of the evaluation, there was no problem in the blocking property of the toner. The charge amount of the toner is 12 up to 20,000 sheets.
There was microcoulomb / g, there was no change on the image and there was no problem. Filming on the photoreceptor or carrier was not observed. Also, neither embedding of the external additive nor deformation of the toner particles was observed. The minimum fixing temperature was 110 ° C., and no offset occurred even at a high temperature of 240 ° C. Table 1 shows the results.

Comparative Example 1 A toner was prepared and evaluated in the same manner as in Example 1 except that fine silica powder was not added to the ethylene-ethyl acrylate copolymer. Table 1 shows the evaluation results.

[0054]

[Table 1]

[0055]

As described above, according to the present invention, while utilizing the low-temperature fixing property and the offset resistance of the high molecular weight crystalline resin, the deformation due to the pressure and shearing force in the copying machine or the printer is suppressed. On the other hand, the internal addition of the nonmagnetic inorganic compound fine powder can eliminate the disadvantages of the crystalline resin,
Wide fixing latitude at low temperature, hardly blocking during storage and use in developing machine, good flowability, good mixing with carrier, excellent chargeability, developing member, carrier and latent image holder It is possible to provide a heat fixing toner composition which does not cause problems such as filming and exhibits stable development characteristics. Therefore, by forming an image using the toner composition for heat fixing having such characteristics, an image having excellent image quality can be stably formed.

[Brief description of the drawings]

FIG. 1 is a characteristic diagram of a crystalline resin according to the present invention.

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI G03G 15/08 507L (56) References JP-A-1-188864 (JP, A) JP-A-6-168648 (JP, A) JP-A Sho 62-70860 (JP, A) JP-A-3-202856 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/08

Claims (6)

(57) [Claims] 1. A thermal fixing toner composition containing a binder resin, a colorant and a nonmagnetic inorganic compound fine powder, wherein the main component of the binder resin has a durometer D hardness of 20 or more at room temperature. A crystalline resin having a melting point of 40 ° C. to 120 ° C. and a rubbery region in a melt viscosity range of 10 ² Pa · s to 10 ⁶ Pa · s; 0.1% by weight to 3% inside the particle
A heat fixing toner composition containing 0% by weight. 2. The heat fixing toner composition according to claim 1, wherein the toner particles have a surface layer. 3. A rubber-like region having a hardness at room temperature of durometer D hardness of 20 or more, a melting point of 40 ° C. to 120 ° C., and a melt viscosity of 10 ² Pa · s to 10 ⁶ Pa · s. A step of dispersing a colorant and a nonmagnetic inorganic fine powder in a binder resin mainly composed of a crystalline resin to form toner particles containing 0.1% to 30% by weight of the nonmagnetic inorganic compound fine powder. A method for producing a heat fixing toner composition, comprising: 4. A rubber-like region having a hardness at room temperature of durometer D hardness of 20 or more, a melting point of 40 ° C. to 120 ° C., and a melt viscosity of 10 ² Pa · s to 10 ⁶ Pa · s. A colorant and a non-magnetic inorganic fine powder are dispersed in a binder resin containing a crystalline resin as a main component, and toner particles containing 0.1% to 30% by weight of the non-magnetic inorganic compound fine powder are dispersed. A method for producing a toner composition for heat fixing, comprising a step of forming and a step of forming a surface layer on the surface of the toner particles. 5. A step of forming an electrostatic latent image on a latent image holding member, a step of developing the electrostatic latent image using a developer carried on a developer carrying member, and a step of holding the latent image. A step of transferring a toner image formed on the body onto a transfer body, and a step of heat-fixing the toner image on the transfer body, wherein, as the developer, a binder resin and a colorant; A nonmagnetic inorganic compound fine powder, wherein the main component of the binder resin has a hardness at room temperature of durometer D hardness of 20 or more, a melting point of 40 ° C to 120 ° C, and a melt viscosity of A toner composition comprising a crystalline resin having a rubbery region in the range of 10 ² Pa · s to 10 ⁶ Pa · s, and containing the nonmagnetic inorganic compound fine powder in an amount of 0.1% by weight to 30% by weight inside the toner particles. An image forming method, comprising using an object. 6. A step of forming an electrostatic latent image on a latent image holding member, a step of developing the electrostatic latent image using a developer carried on a developer carrying member, and the step of holding the latent image A step of transferring a toner image formed on the body onto a transfer body, and a step of heat-fixing the toner image on the transfer body, wherein, as the developer, a binder resin and a colorant; A nonmagnetic inorganic compound fine powder, wherein the main component of the binder resin has a hardness at room temperature of durometer D hardness of 20 or more, a melting point of 40 ° C to 120 ° C, and a melt viscosity of A crystalline resin having a rubbery region in the range of 10 ² Pa · s to 10 ⁶ Pa · s, wherein the nonmagnetic inorganic compound fine powder is contained in the toner particles in an amount of 0.1% by weight to 30% by weight. And a toner composition having toner particles having a surface layer. Image forming method.