JP2899181B2 - Electrostatic image developing toner and heat fixing 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 toner for developing an electrostatic image suitable for heat fixing used in electrophotography, electrostatic recording and magnetic recording, and a heat fixing method for fixing the toner by heating. .

[0002]

2. Description of the Related Art Conventionally, electrophotography has been disclosed in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910.
Many methods are known as described in Japanese Patent Publication No. JP-A-Heisei, 43-24878 and Japanese Patent Publication No. 43-24748. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means. Forming and then developing the latent image with toner,
After transferring the toner image to a transfer material such as paper as necessary,
The copy is obtained by fixing by heating, pressure, heating and pressurizing, or solvent vapor, and the toner remaining on the photoreceptor without being transferred is cleaned by various methods, and the above steps are repeated.

In recent years, such copying apparatuses have begun to be used not only as office work copying machines for simply copying original documents, but also as printers as personal computer outputs or personal copying machines for individuals. .

[0004] For this reason, smaller, lighter, faster, and more reliable devices have been strictly pursued, and machines have become simpler in various respects. As a result, the performance required of the toner has become higher, and if the performance of the toner cannot be improved, a better machine cannot be realized.

For example, various methods and apparatuses have been developed for fixing a toner image to a sheet such as paper. For example, there are a pressure bonding heating method using a heat roller and a heat fixing method in which a heating member and a pressing member are brought into close contact with each other via a film.

In the heating method using a heating roller or a film, the toner is fixed by allowing the toner image surface of the sheet to be fixed to pass through the surface of the heat roller or the film formed of a material having a releasable property to the toner. Is performed. In this method, since the surface of the heat roller or the film comes into contact with the toner image of the sheet to be fixed, the thermal efficiency at the time of fusing the toner image onto the sheet to be fixed is extremely good, and the fixing can be performed quickly. It is very effective in an electrophotographic copying machine. However, in the above method, a part of the toner image adheres to and transfers to the fixing roller or film surface because the heat roller or the film surface and the toner image come into contact in a molten state, and the toner image re-transfers to the next sheet to be fixed. A so-called offset phenomenon occurs, and the sheet to be fixed may be stained. Preventing the toner from adhering to the heat fixing roller and the film surface is one of the essential conditions of the heat fixing method.

Conventionally, for the purpose of preventing toner from adhering to the surface of a fixing roller, for example, the surface of the roller is formed of a material having excellent releasability with respect to the toner, such as silicone rubber or a fluorine-based resin, and the surface of the roller is further prevented from offsetting. In order to prevent the roller surface from being fatigued, the roller surface is coated with a thin film of a liquid having good releasability such as silicone oil. However, this method is extremely effective in preventing toner offset, but has a problem that a fixing device is complicated because a device for supplying an anti-offset liquid is required. .

[0008] This is in the opposite direction of miniaturization and weight reduction, and moreover, silicone oil and the like may evaporate due to heat and contaminate the inside of the machine. Therefore, instead of using a silicone oil supply device, instead of supplying the anti-offset liquid during heating from the toner, a method of adding a release agent such as low molecular weight polyethylene or low molecular weight polypropylene to the toner is proposed. Have been. If a large amount of such an additive is added in order to obtain a sufficient effect, filming on a photoreceptor or contamination of the surface of a toner carrier such as a carrier or a sleeve will cause deterioration of an image and pose a practical problem. Therefore, a device is used in which a small amount of a release agent is added to the toner so as not to deteriorate the image, and a small amount of release oil is supplied or the offset toner is wound up with a device using a web-type member such as a web. It has been used in combination.

However, in view of recent demands for miniaturization, weight reduction, and high reliability, it is necessary and preferable to remove even these auxiliary devices. Therefore, if there is no further performance improvement such as toner fixing and offset,
It is difficult to realize this without further improvement of the binder resin of the toner, the release agent and the like.

It is known that a wax is contained in a toner as a release agent. For example, JP-A-52-330
No. 4, JP-A-52-3305, JP-A-57-5-5
The technology is disclosed in 2574 and the like.

Further, JP-A-3-50559, JP-A-2-79860, JP-A-1-109359, JP-A-62-14166, and JP-A-61-27
No. 3554, No. 61-94062, Japanese Unexamined Patent Publication No. Sho 61
-138259, JP-A-60-252361, JP-A-60-252360, JP-A-60-2
No. 17366 discloses a technique for containing waxes.

[0012] Waxes are used for improving the offset resistance of the toner at low and high temperatures and for improving the fixing property at low temperatures. However, while improving these performances, the blocking resistance is deteriorated, the developability is deteriorated when exposed to heat due to the temperature rise of a copying machine, etc., and the developability is deteriorated due to the blooming of wax when left for a long period of time. Or worse.

No conventional toner satisfies all of these aspects, causing some problems. For example, high-temperature offset and developability are excellent, but low-temperature fixability is just one step away, or low-temperature offset and low-temperature fixability are excellent, but blocking resistance is slightly inferior, and developability decreases when the temperature rises in the machine. And the offset resistance at low and high temperatures cannot be compatible.

Also, low molecular weight polypropylene (for example,
Viscole 550P, 660 manufactured by Sanyo Chemical Industry Co., Ltd.
P, etc.) are commercially available, but toners with further improved low-temperature offset properties and improved fixability have been desired.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner which solves the above-mentioned problems and a method for fixing the toner by heating.

That is, an object of the present invention is to provide a toner excellent in fixing property at low temperature and anti-offset property, and a method for heat-fixing the toner.

It is another object of the present invention to provide a toner having excellent offset resistance at high temperatures and a method for fixing the toner by heating.

It is a further object of the present invention to provide a toner which is excellent in blocking resistance and does not deteriorate in developability even after being left for a long period of time, and a method for heating and fixing the toner.

Another object of the present invention is to provide a toner excellent in durability against temperature rise of a machine main body, and a method for heating and fixing the toner.

It is a primary object of the present invention to provide a toner and a method for fixing the toner by heating, which satisfy the above objects without contradiction.

[0021]

SUMMARY OF THE INVENTION The present invention relates to a toner for developing an electrostatic image containing at least a binder resin and a hydrocarbon wax, wherein the toner is measured by the following differential scanning calorimeter. In the DSC curve, with respect to the endothermic peak at the time of temperature rise, the rising temperature at the endothermic peak is 80 ° C. or more, the onset temperature at the endotherm is 105 ° C. or less, the endothermic peak temperature is in the range of 100 to 120 ° C., Exothermic peak temperature, the exothermic peak temperature is in the range of 62 to 75 ° C., and the exothermic peak intensity ratio is 5 × 10 ⁻³ or more, and the hydrocarbon wax is used in an amount of 100% by weight of the binder resin. To 0.5 parts by weight per part by weight of the toner for developing an electrostatic image.

[0022]

Further, according to the present invention, in a DSC curve for a toner measured by a differential scanning calorimeter, the rising temperature at the endothermic peak is 80 ° C. or more, and the onset temperature at the endothermic peak is 105 ° C. ° C or less, and the endothermic peak temperature is 100 to 120.
° C, the exothermic peak at the time of temperature decrease, the exothermic peak temperature is in the range of 62 to 75 ° C, and the intensity ratio of the exothermic peak is 5 × 10 ^-3 or more.
A toner image formed with a toner for developing an electrostatic image containing 0.5 to 10 parts by weight of hydrocarbon wax with respect to 00 parts by weight is fixed to a transfer material by a contact heating fixing unit. To a heat fixing method.

[0024]

Further, the present invention will be described in detail.

The behavior between the heat and the toner can be found by analyzing the data of the toner measured by the differential scanning calorimeter. That is, it is possible to know the exchange of heat with the toner and the change in the state of the toner from the data. For example, it is possible to know whether the offset phenomenon can be prevented, and to know the effect of heat during storage or actual use, for example, what is the anti-blocking property, and how much the temperature increase affects the developability. it can.

At the time of temperature rise, changes in the state when heat is applied to the toner can be seen, and the transfer, melting,
An endothermic peak due to dissolution is observed. The present invention is characterized in that the rising endothermic peak is 80 ° C or higher,
Excellent blocking resistance. On the other hand, when the temperature is lower than 80 ° C., the toner starts to undergo a plastic change in a long-term range from a relatively low temperature, and is inferior in storability or deteriorates in developability with increasing temperature. Further, the endothermic onset temperature is 105 ° C or less (preferably in the range of 90 to 102 ° C).
Which is excellent in low-temperature fixability. On the other hand, when the temperature exceeds 105 ° C., the temperature of the plastic change in a short time range becomes high, and the low-temperature offset resistance and the fixing property become poor.

Further, the endothermic peak temperature is 100 to 120 ° C.
(Preferably 102 to 115 ° C.), whereby good fixability and high-temperature offset resistance can be obtained. On the other hand, when the temperature is lower than 100 ° C., the wax component dissolves in the binder resin before the temperature becomes high, and it is difficult to obtain sufficient offset resistance at high temperatures. On the other hand, when the temperature exceeds 120 ° C., it is difficult to obtain a sufficient fixing property.

That is, since the binder resin for toner used for heat fixing enters a viscoelastic region where fixation is possible from about 100 ° C., melting of the wax component in this temperature region causes a plasticizing effect on the resin. Thus, the fixing property can be improved, the releasing effect can be sufficiently exhibited, and the offset resistance can be improved. Therefore, there is no wrapping around the fixing roller or film, and there is no need to rely on the separation claw, so that there is no trace of the claw or the like, there is no contamination of the pressure roller, and no wrapping around the pressure roller occurs. As long as the above condition is satisfied, peaks may be present in other regions.

When the temperature is lowered, changes in the state of the toner at normal temperature and in the state of cooling can be observed, and an exothermic peak accompanying the transition, coagulation and crystallization of the wax component is observed. In the present invention, the exothermic peak temperature is 62 to 75 ° C (preferably 65 to 75 ° C).
-72 ° C), thereby exhibiting good fixability and blocking resistance. On the other hand, 7
If the temperature exceeds 5 ° C., the temperature range in which the wax is in a molten state is narrowed, and the fixability is poor. If the temperature is lower than 62 ° C., blocking, fusing, and the like are likely to occur, and the plasticizing effect of the binder resin is maintained until a low temperature. May occur.

The peak intensity ratio is at least 10 × 10 ⁻³ (preferably at least 12 × 10 ⁻³ , particularly preferably at least 15 × 1 ^−3).
0 ^-3 or more). The larger the peak intensity ratio, the higher the density of the wax component, the higher the crystallinity, the higher the hardness, the less the occurrence of blocking, and the better the triboelectric chargeability. If it is less than 10 × 10 ⁻³ , the blocking resistance deteriorates or the developability is affected, and the developability deteriorates particularly when the temperature rises, and especially the peak temperature decreases. Easy to appear when
Further, fusion on the photoreceptor easily occurs.

In the DSC measurement according to the present invention, since the exchange of heat of the toner is measured and its behavior is observed, it is necessary to measure with a high-precision internal heating input compensation type differential scanning calorimeter from the measurement principle. For example, DSC-7 manufactured by PerkinElmer can be used.

The measuring method is as described in ASTM D3418-82.
Perform according to. The DSC curve used in the present invention has a temperature rate of 10 ° C./min after heating once to take a pre-history.
A DSC curve measured when the temperature is lowered and raised in a temperature range of 0 to 200 ° C. is used. The definition of each temperature is defined as follows.

Endothermic peak in toner (positive direction is endothermic) Peak rising temperature (LP) in toner: temperature at which the peak curve is clearly deviated from the baseline. That is, the temperature at which the differential value of the peak curve is positive and the increase of the differential value starts to increase or the temperature at which the differential value changes from negative to positive. (Specific examples are shown in FIG. 1 and FIGS. 3 to 6.) Onset temperature (OP) of heat absorption of toner: A tangent of the curve is drawn at the point where the differential value of the peak curve is maximum, and the tangent and the baseline are drawn. (A specific example is shown in FIG. 1). In the case of a toner containing a wax, an endothermic peak having a peak at a temperature of 70 ° C. or higher is targeted. Endothermic peak temperature (PP) in the toner: peak top temperature (maximum peak in a region of 120 ° C. or lower)

Heat generation peak in toner (heat is defined in the minus direction) Temperature of heat generation peak in toner: temperature of peak top of maximum peak Heat generation peak intensity ratio in toner: differential value of curve before and after peak top of the above peak Are drawn at the points where the peaks are maximum and minimum, and the temperature difference between each tangent and the baseline intersection is ΔT, and the height from the baseline to the peak top per unit weight is ΔH (the height of the measured peak). ΔH / ΔT (ΔH, ΔT in FIG. 2 and FIG. 7 to FIG. 10) assuming a value mW / mg divided by the weight of the measurement sample.
T shows a specific example). That is, a large value indicates that the peak is sharp.

The hydrocarbon wax used in the present invention is a low molecular weight alkylene polymer obtained by radical polymerization of alkylene under high pressure or a Ziegler catalyst under low pressure, or an alkylene polymer obtained by thermally decomposing a high molecular weight alkylene polymer. A hydrocarbon wax obtained by extracting and separating a specific component from, for example, a synthetic hydrocarbon obtained by hydrogenating a distillation residue of a hydrocarbon obtained from the synthesis gas consisting of carbon monoxide and hydrogen by the Age method is used.
The hydrocarbon wax is separated by a separation crystallization method using a press sweating method, a solvent method, and vacuum distillation. That is, those obtained by removing the low molecular weight components by these methods, those obtained by extracting the low molecular weight components, and those obtained by further removing the low molecular weight components therefrom.

The hydrocarbon as a base is synthesized by a reaction between carbon monoxide and hydrogen using a metal oxide catalyst (often a multi-component system of two or more types), for example, a zincol method, a hydrochol method ( Hydrocarbons using a fluidized catalyst bed) or hydrocarbons with a carbon number of up to several hundreds obtained by the Aggé method (using a fixed catalyst bed), which produces a large amount of waxy hydrocarbons (finally, hydrogenated and ) Or a hydrocarbon obtained by polymerizing an alkylene such as ethylene with a Ziegler catalyst is preferred because it is a branched, small and saturated long-chain linear hydrocarbon. In particular, a hydrocarbon wax synthesized by a method that does not rely on the polymerization of alkylene is preferable because of its structure and a molecular weight distribution that can be easily separated. Further, a preferable range in the molecular weight distribution is
Number average molecular weight (Mn) is 550 to 1200, preferably 600 to 1000, and weight average molecular weight (Mw) is 800 to
3600, preferably 900 to 3000, Mw / Mn is 3 or less, preferably 2.5 or less, particularly preferably 2.
0 or less. Further, a molecular weight of 700 to 2400 (preferably a molecular weight of 750 to 2000, particularly preferably a molecular weight of 8
00 to 1600). By having such a molecular weight distribution, the toner can have favorable thermal characteristics. That is, if the molecular weight is smaller than the above range, the thermal effect is excessively susceptible, blocking resistance and developability are deteriorated, and if the molecular weight is larger than the above range, heat from the outside cannot be effectively used, Excellent fixability and offset resistance cannot be obtained.

As other physical properties, the density at 25 ° C. is 0.95 (g / cm ³ ) or more and the penetration is 1.5 (10 ^−1).
mm) or less, preferably 1.0 (10 ^-1 mm) or less. If the ratio is out of these ranges, it tends to change at low temperatures and tends to be inferior in storage stability and developability.

The melt viscosity at 140 ° C. is 10
It is 0 cp or less, preferably 50 cp or less, particularly preferably 20 cp or less. When the melt viscosity exceeds 100 cp, the plasticity and the releasability become inferior, and the excellent fixability and the offset resistance are affected. Further, the softening point is preferably 130 ° C. or lower, particularly preferably 120 ° C. or lower. When the softening point exceeds 130 ° C., the temperature at which the mold releasability works particularly effectively becomes high, which affects the excellent offset resistance.

Further, the acid value is less than 2.0 mgKOH / g, preferably less than 1.0 mgKOH / g. When the ratio exceeds this range, the interfacial adhesive strength with the binder resin, which is one of the components constituting the toner, is large, and the phase separation at the time of melting tends to be insufficient, so that good releasability is hardly obtained, The offset resistance at high temperatures is not good, and the triboelectricity of the toner is adversely affected, which may cause problems in developability and durability.

The content of these hydrocarbon waxes is within 20 parts by weight based on 100 parts by weight of the binder resin.
It is effective to use 0.5 to 10 parts by weight.

In the present invention, the molecular weight distribution of the hydrocarbon wax is determined by gel permeation chromatography (G
PC) under the following conditions.

(GPC measurement conditions) Apparatus: GPC-150
C (Waters) Column: GMH-HT 30 cm 2 columns (manufactured by Tosoh Corporation) Temperature: 135 ° C Solvent: o-dichlorobenzene (0.1% ionol added) Flow rate: 1.0 ml / min Sample: 0.15% sample 0.4 ml injection

Measurement is performed under the above conditions, and a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample is used in calculating the molecular weight of the sample. In addition, Mark-Hou
It is calculated by converting to polyethylene using a conversion formula derived from the wink viscosity formula.

The penetration of the wax in the present invention is J
It is a value measured according to IS K-2207. Specifically, it is a numerical value representing the penetration depth when a needle having a conical tip having a diameter of about 1 mm and a vertex angle of 9 ° is penetrated with a constant load in a unit of 0.1 mm. The test conditions in the present invention are a sample temperature of 25 ° C., a load of 100 g, and a penetration time of 5 seconds.

The melt viscosity is a value measured using a Brookfield viscometer. The conditions are a measurement temperature of 140 ° C., a shear rate of 1.32 rpm, and a sample of 10 ml.

The acid value is the number of mg of potassium hydroxide required to neutralize the acid groups contained in 1 g of a sample,
According to SK5902. The density is JIS K6 at 25 ° C.
The softening point of 760 is a value measured according to JIS K2207.

Further, according to the present invention, the hydrocarbon wax has the following characteristics, a DSC curve measured by a differential scanning calorimeter, an endothermic peak at the time of temperature rise, and an endothermic onset temperature of 50 to 110 ° C. Wherein at least one endothermic peak P ₁ exists in the range of 70 to 130 ° C.,
Maximum exothermic peak at the time of cooling is within the range of endothermic peak temperature ± 9 ° C. peak P _1, it is better to satisfy.

At the time of raising the temperature, a change when the wax is heated can be seen, and an endothermic peak accompanying the transition and melting of the wax is observed. Endothermic onset temperature is 50-11
0 ° C (preferably 50 to 90 ° C, more preferably 6 ° C
(0 to 90 ° C.), developability, blocking resistance, and low-temperature fixability can be satisfied. If the peak onset temperature is less than 50 ° C., the change temperature of the wax is too low, resulting in a toner having poor blocking resistance or poor developability at elevated temperatures. Is too high, and sufficient fixability cannot be obtained. Good fixing due to the presence of an endothermic peak in the range of 70 to 130 ° C, preferably in the range of 70 to 120 ° C, more preferably in the range of 95 to 120 ° C, and particularly preferably in the range of 97 to 115 ° C. Properties and offset resistance. When the peak temperature exists only at less than 90 ° C., the melting temperature of the wax is too low, sufficient hot offset resistance cannot be obtained, and when the peak temperature exists only in the region exceeding 130 ° C., the wax The melting temperature is too high and sufficient low-temperature offset resistance and low-temperature fixability cannot be obtained. That is, the presence of the peak temperature in this region makes it easier to balance the offset resistance and the fixability. Here, when the peak below 90 ° C. becomes the maximum peak, the same behavior as when there is a peak only in this region is present. Therefore, a peak in this region may be present. It must be smaller than the peak in the region of ° C.

When the temperature is lowered, the change during cooling of the wax and the state at normal temperature can be observed, and an exothermic peak accompanying the solidification, crystallization, and transition of the wax is observed. Among the exothermic peaks at the time of temperature decrease, the largest exothermic peak is an exothermic peak accompanying solidification and crystallization of wax. The existence of an endothermic peak accompanying melting at the time of heating to a temperature close to this exothermic peak temperature,
It shows that the wax is more homogeneous, such as the structure of the wax and the molecular weight distribution, and the difference is preferably within 9 ° C, more preferably within 7 ° C, and particularly preferably,
It is within 5 ° C. That is, by reducing this difference, the wax is sharp-melted, that is, the wax is hard at low temperatures, melts quickly at the time of melting, and the melt viscosity is greatly reduced, so that the developing property, the blocking resistance, the fixing property, and the offset resistance are reduced. A good balance of properties can be achieved. The maximum exothermic peak is at a temperature of 85 to 115 ° C (preferably 90 to 115 ° C).
(110 ° C.).

The DSC measurement of the wax is based on the above-mentioned toner, and the definition of each temperature is defined as follows.

Endothermic peak of wax: Onset temperature of endothermic wax: The lowest temperature at which the differential value of the curve is maximized. Therefore, the definition of the endothermic onset temperature differs from that of the toner. Endothermic peak temperature of wax: peak top temperature Exothermic peak of wax: exothermic peak temperature of wax: peak top temperature of maximum peak

The content of these hydrocarbon waxes is within 20 parts by weight based on 100 parts by weight of the binder resin.
It is effective to use it in an amount of 0.5 to 10 parts by weight, and it may be used in combination with other waxes as long as the wax is not adversely affected.

As the binder resin used in the toner of the present invention, the following binder resins can be used.

For example, homopolymers of styrene such as polystyrene, poly-p-chlorostyrene and polyvinyltoluene and their substituted products; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene Copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer -Based copolymer; polyvinyl chloride, phenolic resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin , Xylene resin, polyvinyl butyral, terpene resin, coumarone indene resin, petroleum resin and the like can be used. Preferred binders include styrene copolymers or polyester resins.

Examples of comonomers for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and the like.
Double such as dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. A monocarboxylic acid having a bond or a substituted product thereof;
For example, dicarboxylic acids having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like;
Vinyl esters such as vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene, butylene; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; vinyl methyl ether and vinyl Vinyl monomers such as ethyl ether, vinyl isobutyl ether and the like; and vinyl monomers such as one or two or more are used.

The styrene-based polymer or styrene-based copolymer may be crosslinked, or may be a resin mixture thereof.

As a crosslinking agent for the binder resin, a compound having two or more polymerizable double bonds may be mainly used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; Carboxylic acid esters having two double bonds such as glycol diacrylate, ethylene glycol dimethacrylate, 1,3-butadiol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; and 3
Compounds having at least two vinyl groups are used alone or as a mixture.

The toner of the present invention may contain a charge control agent.

The following substances control the toner to be negatively charged.

For example, an organic metal complex and a chelate compound are effective, and examples thereof include a monoazo metal complex, an acetylacetone metal complex, an aromatic hydroxycarboxylic acid, and an aromatic dicarboxylic acid-based metal complex. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

The following substances control the toner to be positively charged.

Modified products such as nigrosine and fatty acid metal salts, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate;
Onium salts such as phosphonium salts, which are analogs thereof, and their lake pigments, triphenylmethane dyes and these lake pigments (as the lake-forming agent, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannin Acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.) metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyltin borate Diorganotin borates; these can be used alone or in combination of two or more. Among these, charge control agents such as nigrosine and quaternary ammonium salts are particularly preferably used.

In the toner of the present invention, charging stability,
In order to improve developability, fluidity and durability, it is preferable to add silica fine powder.

The silica fine powder used in the present invention is BE
The specific surface area by nitrogen adsorption measured by the T method is 30 m ² / g
Those within the above range (particularly 50 to 400 m ² / g) give good results. It is preferable to use 0.01 to 8 parts by weight, preferably 0.1 to 5 parts by weight of silica fine powder with respect to 100 parts by weight of the toner.

The silica fine powder used in the present invention is:
Silicon varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, and other organosilicon compounds for purposes such as hydrophobicity and charge control, if necessary It is also preferable that the composition is treated with such a treating agent or in combination with various treating agents.

As other additives, lubricant powders such as Teflon powder, zinc stearate powder and polyvinylidene fluoride powder are preferable, and polyvinylidene fluoride is particularly preferable.
Alternatively, abrasives such as cerium oxide powder, silicon carbide powder, and strontium titanate powder, among which strontium titanate is preferred. Or, for example, titanium oxide powder,
Fluidity-imparting agents such as aluminum oxide powder, particularly hydrophobic ones are preferred. A small amount of a caking inhibitor, a conductivity imparting agent such as a carbon black powder, a zinc oxide powder, an antimony oxide powder, a tin oxide powder, and the like, and fine particles of white and black having opposite polarities can also be used as a developing property improver.

Further, when the toner of the present invention is used as a two-component developer, it is used by mixing with a carrier powder. In this case, the mixing ratio of the toner and the carrier powder is 0.1 to 50% by weight as the toner concentration, preferably 0.5%.
It is preferably from 10 to 10% by weight, more preferably from 3 to 10% by weight.

As the carrier that can be used in the present invention, known carriers can be used. For example, magnetic powders such as iron powder, ferrite powder and nickel powder, glass beads, etc. And those treated with a vinyl resin or a silicone resin.

Further, the toner of the present invention can be used as a magnetic toner by further containing a magnetic material. In this case, the magnetic material can also serve as a colorant. In the present invention, the magnetic material contained in the magnetic toner includes iron oxide such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; and aluminum, cobalt, copper, lead, magnesium, and tin of these metals. ,
Examples include alloys of metals such as zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium, and mixtures thereof.

These ferromagnetic materials preferably have an average particle size of 2 μm or less, preferably about 0.1 to 0.5 μm. The amount contained in the toner is preferably about 20 to 200 parts by weight, particularly preferably 40 to 150 parts by weight, per 100 parts by weight of the resin component.

Also,

[0073]

[Outside 1] The magnetic properties upon application are the coercive force ratio (Hc)

[0074]

[Outside 2] Those having a saturation magnetization (σs) of 50 to 200 emu / g and a residual magnetization (σr) of 2 to 20 emu / g are preferable.

The colorant that can be used in the toner of the present invention includes any suitable pigment or dye. As a colorant of the toner, for example, carbon black as a pigment,
Examples include alinine black, acetylene black, naphthol yellow, hansa yellow, rhodamine lake, alizarin lake, bengala, phthalocyanine blue, indanthrene blue and the like. These are used in an amount necessary and sufficient to maintain the optical density of the fixed image, and 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, per 100 parts by weight of the resin.
Good addition amount by weight. A dye is further used for the same purpose. Examples include azo dyes, anthraquinone dyes, xanthene dyes, methine dyes and the like.
0.1 to 20 parts by weight, preferably 0.1 part by weight, per 0 parts by weight.
The addition amount of 3 to 10 parts by weight is good.

To prepare the toner for developing an electrostatic image according to the present invention, a binder resin, a wax, a metal salt or a metal complex, a pigment or dye as a colorant, a magnetic substance, a charge control agent if necessary, While the other additives, etc. are thoroughly mixed by a mixer such as a Henschel mixer, a ball mill, and then melt-kneaded using a heat kneader such as a heating roll, a kneader, or an extruder to make the resins compatible with each other. The toner according to the present invention can be obtained by dispersing or dissolving a metal compound, a pigment, a dye, and a magnetic substance, and performing cooling and solidification followed by pulverization and classification.

Further, if necessary, desired additives are sufficiently mixed by a mixer such as a Henschel mixer to obtain the toner for developing an electrostatic image according to the present invention.

The toner of the present invention can be applied to plain paper or an overhead projector (OH
The sheet is heat-fixed to a transfer material such as a transparent sheet for P).

As the contact heating fixing means, a heating / pressing roll fixing device or a fixedly supported heating body is brought into pressure contact with the heating body, and the transfer material is brought into close contact with the heating body via a film. A fixing unit that heats and fixes the toner with the pressing member can be used.

FIG. 15 shows an example of the fixing means.

In the fixing device shown in FIG.
It has a smaller heat capacity than conventional heat rolls and has a linear heating part, and the maximum temperature of the heating part is 100 to 30
Preferably it is 0 ° C.

The film located between the heating element and the pressing member is preferably a heat-resistant sheet having a thickness of 1 to 100 μm. Examples of the heat-resistant sheet include polyester, PET (polyethylene) having high heat resistance. Terephthalate), PFA (tetrafluoroethylene-perfluoroalkylvinyl ether copolymer), PTFE (polytetrafluoroethylene), polyimide, polymer sheet such as polyamide, metal sheet such as aluminum, and metal sheet and polymer sheet. A laminate sheet is used.

A more preferable structure of the film is that these heat-resistant sheets have a release layer and / or a low-resistance layer.

A specific example of the fixing device will be described with reference to FIG.

Reference numeral 10 denotes a low-heat-capacity linear heating element fixedly supported by the apparatus, and has, for example, a thickness of 1.0 mm and a width of 10 mm.
mm, an alumina substrate 9 having a longitudinal length of 240 mm
Is applied to a width of 1.0 mm, and is energized from both ends in the longitudinal direction. The energization is performed by applying a pulse corresponding to a desired temperature and energy release amount controlled by the temperature detecting element 11 by changing the pulse width in a pulse-like waveform of DC 100 V and a cycle of 20 msec. Approximate pulse width is 0.5msec ~
5 msec. The fixing film 2 moves in the direction of the arrow in the figure by contacting the heating element 10 whose energy and temperature are controlled in this manner.

An example of the fixing film has a thickness of 20 μm.
m is a heat-resistant film (for example, polyimide, polyetherimide, PES or PFA, at least on the image contact surface side, a fluororesin such as PTFE or PAF) coated with a release layer having a thickness of 10 μm and coated with a release layer. Generally, the total thickness is less than 100μ, more preferably 4
Less than 0μ is good. The film is driven without wrinkles in the direction of the arrow by the driving and tension of the driving roller 3 and the driven roller 4.

Reference numeral 5 denotes a pressure roller having a rubber elastic layer having good releasability such as silicone rubber.
The heating element is pressurized through the film with g, and is rotated by pressing against the film. The unfixed toner 7 on the transfer material 6 is guided to a fixing unit by an entrance guide 8 and obtains a fixed image by the above-described heating.

In the above description, the endless belt has been described.
A sheet feeding shaft and a winding shaft are used, and the fixing film may be an edged film.

The image forming apparatus is applicable to a fixing device of an apparatus for forming an image using a toner such as a copying machine, a printer, and a facsimile.

[0090]

The present invention will be described below with reference to specific examples.

First, the hydrocarbon wax used in the present invention will be described.

A hydrocarbon wax F synthesized by the Age method (Comparative Example) was used, and wax A (the present invention), wax B (the present invention) and wax C (the present invention) were prepared therefrom.
Was obtained by fractional crystallization. The hydrocarbon synthesized by the Age method was oxidized to obtain wax G (comparative example). FIG. 11 shows a DSC curve of wax A (invention) when the temperature was raised, and FIG. 12 shows a DSC curve when the temperature was lowered.
FIG. 13 shows a DSC curve at the time of temperature rise (Comparative Example), and FIG. 13 shows a DSC curve at the time of temperature fall.

Using a Ziegler catalyst, ethylene was polymerized at a low pressure to obtain wax H having a relatively low molecular weight (comparative example).
Wax D (the present invention) from which low molecular weight components had been removed to some extent by fractional crystallization was obtained. Wax H by similar polymerization
Higher molecular weight wax I (Comparative Example) was obtained, and low molecular weight components were extracted by fractional crystallization to obtain wax E (the present invention).
I got These physical properties are shown in Tables 1, 2 and 3.

Example 1 100 parts by weight of styrene-butyl acrylate copolymer (copolymerization weight ratio: 80:20; number average molecular weight: about 10,000) Magnetic iron oxide (average particle diameter: 0.25 μm; saturation magnetization: 80 emu under 10K Oersted) / G, remanent magnetization 10 emu /
g, coercive force 120 Oersted) 80 parts by weight Nigrosine 2 parts by weight Wax A 4 parts by weight

After premixing the above materials, melt kneading was carried out by a twin screw extruder set at 130 ° C.
After cooling the kneaded material, coarsely pulverized, finely pulverized by a pulverizer using a jet stream, and further classified using an air classifier,
Toner 1 having a weight average particle size of 8 μm was obtained. This toner 10
0 parts by weight, and positively charged hydrophobic colloidal silica fine powder
And 6 parts by weight (externally added) to obtain a toner having colloidal silica fine powder on the surface of toner particles. The DSC measurement result of the toner 1 is shown in Table 4, the DSC curve when the temperature of the toner 1 is raised is shown in FIG. 1, and the DSC curve when the temperature is lowered is shown in FIG.

Examples 2 to 5 Toners 2 to 5 were prepared in the same manner as in Example 1 except that waxes B to E were used. DS of each toner
Table 4 shows the C measurement results.

Comparative Examples 1 to 4 Toners 6 to 9 were prepared in the same manner as in Example 1 except that the waxes F to I were used. Table 4 shows the DSC measurement results of these toners.

Comparative Example 5 A toner 10 was prepared in the same manner as in Example 1 except that no wax was used. Table 4 shows the DSC measurement result of the toner 10. This endothermic peak is derived from the binder resin and is also found in other toners.

Comparative Example 6 A toner 14 was prepared in the same manner as in Example 1 except that a low molecular weight polypropylene wax (Viscol 550P) manufactured by Sanyo Chemical Industries, Ltd. was used. Toner 14
Is shown in Table 4.

Fixing and offset test Commercially available electrophotographic copying machine NP-1215 (manufactured by Canon Inc.)
An unfixed image was obtained, and an unfixed toner image was fixed and an offset test was performed using a temperature-variable heat roller external fixing machine using a Teflon coat as an upper roller and a silicone rubber as a lower roller. Nip 4.0mm, linear pressure 0.4kg / cm, process speed 45mm / se
The temperature was adjusted every 5 ° C. in a temperature range of 100 to 230 ° C. as c. 8 for low temperature offset and fixability testing
0 g / m ² paper was used. 5 tests for hot offset
Evaluation was performed using ² g / m ² paper. The fixability was measured by applying a load of 50 g / cm ² to the fixed image and applying the material to silbon paper [lenz c.
leaning paper "dasper (R)"
(Ozu Paper Co. Ltd)], and the temperature at which the density reduction rate before and after rubbing was less than 10% was defined as the fixing start point. For the offset, the temperature at which the offset disappeared visually was set as the low-temperature offset-free starting point, the temperature was raised, and the highest temperature without offset was set as the high-temperature offset-free end point. The test results are summarized in Table 5. Table 5 shows a fixing start temperature, a density reduction rate at 150 ° C., a low-temperature offset free start point, a high-temperature offset free end point, and a non-offset area.

Blocking Test Approximately 20 g of the developer was placed in a 100 cc plastic
After leaving it at 3 ° C. for 3 days, it was visually evaluated. This result is the fifth
It is described in the table. Excellent: No aggregates were observed. Good: Aggregates are seen but easily collapse. OK: Aggregates are observed, but collapse when shaken. Impossible: Aggregates can be caught and do not collapse easily.

(Developability test) About 100 g of developer was added to 50
After placing in a 0 cc polyethylene cup and allowed to stand at 45 ° C. for 3 days, developability was evaluated using a commercially available electrophotographic copying machine FC-5II (manufactured by Canon Inc.). Table 6 shows the results (image density, fog) of the test. By this test, it is possible to obtain a simulation for observing the durability against the temperature rise of the machine and the safety after long-term storage.

[0103]

[Table 1]

[0104]

[Table 2]

[0105]

[Table 3]

[0106]

[Table 4]

[0107]

[Table 5]

[0108]

[Table 6] Examples 6 to 10, Comparative Examples 7 to 12 Unfixed images of toner 1 to toner 10 and toner 14 (1
0) is pressed against the heating element (1) as shown in FIG. 15, and a pressing member (5) for bringing the transfer material (6) into close contact with the heating element (1) via the film (2). And an offset test were carried out using an external fixing machine consisting of As a material of the fixing film (2), an endless film obtained by coating a release layer of a fluororesin obtained by adding a conductive material to a polyimide film by 10 μm was used. As the pressure roller (5), silicone rubber was used, and the test was performed with a nip of 3.5 mm, a total pressure of 8 kg between the heating body (1) and the pressure roller (5), and a process speed of 50 mm / sec. .
The film was driven by driving and tension by a driving roller (3) and a driven roller (4), and energy was applied to the heating element (1) having a low heat capacity linear shape in pulses to control the temperature. The evaluation method was the same as in Example 1, and the results are shown in Table 7.

As can be seen from Tables 5 to 7, the toners containing waxes A, B or C were even better overall than the toners containing alkylene polymer waxes D or E.

[0110]

[Table 7]

Example 11 Styrene-butyl acrylate copolymer (copolymer weight ratio = 80: 20; number average molecular weight: about 10,000) 100
Parts by weight Copper phthalocyanine (colorant) 4 parts by weight Quaternary organic ammonium salt (positive charge control agent) 1 part by weight Wax A 3 parts by weight

After premixing the above materials, a toner 11 having a weight average particle size of 8 μm was obtained in the same manner as in Example 1. 100 parts by weight of the above toner and 1.0 part by weight of positively charged hydrophobic colloidal silica fine powder were mixed (externally added) to prepare a toner having fine silica powder on the toner particle surface. 100 parts by weight of a ferrite carrier coated with a mixed resin of a styrene acrylic resin and a fluororesin,
0 parts by weight were mixed to obtain a developer. Table 7 shows the DSC measurement result of the toner 11.

This developer was evaluated using a commercially available electrophotographic copying machine FC-2 (manufactured by Canon Inc., fixing device configuration as shown in FIG. 15). At an environmental temperature of 7.5 ° C., in the first copy immediately after the power was turned on, there was no low-temperature offset, and the fixability (the density reduction rate was 5% by the evaluation method according to Example 1) was good.

At a temperature of 23.5.degree.
After copying the sheets, no offset was observed due to the temperature rise at the end of the fixing device even when copying was performed with 52 g / m ² paper.

When a copying test was performed in an environment of a temperature of 32.5 ° C., a clear blue image was always obtained, the toner could be used up in the good state until the end, no fusing occurred, and There was no blocking. When the temperature inside the apparatus was measured on the way, it was 48 ° C. near the developing device and 52 ° C. near the cleaner. Further, when the cartridge is heated
When the image was allowed to stand at 0 ° C. for 2 weeks, the image was evaluated. As a result, a clear blue image without fog was obtained.

Example 12 100 parts by weight of a styrene-butyl acrylate copolymer (copolymerization ratio = 82: 18; number average molecular weight: about 10,000) 60 parts by weight of magnetic iron oxide (average particle size: 0.25 μm) Monoazochrome complex ( Negative charge control agent) 1 part by weight Wax A 4 parts by weight

After the above materials were preliminarily mixed, a magnetic toner 12 having a weight average particle diameter of 12 μm was obtained in the same manner as in Example 1. 100 parts by weight of this magnetic toner and 0.4 parts by weight of hydrophobic colloidal silica fine powder were mixed (externally added), and a toner having colloidal silica fine powder on the surface of magnetic toner particles was used as a developer. The DSC data is shown in Table 7.

The developer was tested by removing the cleaning pad of the fixing roller of a commercially available laser beam printer, Laser Shot B406 (manufactured by Canon Inc., hot roll fixing machine).

In the first copy test at an environmental temperature of 7.5 ° C., there was no offset and the fixability (density reduction rate 3%) was good.

When the cartridge was left at a temperature of 40 ° C. for 2 weeks and subjected to a durability test in an environment of 32.5 ° C., a toner image having an image density of 1.35 to 1.40 and no fogging was obtained. Printout was possible up to the use up without occurrence of wearing and no offset, and no stain was observed on both the heating roller and the pressure roller.

Example 13 Polyester resin (Bisferrule A-based diol-terephthalic acid-trimellitic acid condensate) (monomer mixture weight ratio = 50: 45: 5; number average molecular weight: about 5000) 10
0 parts by weight Magnetic iron oxide (average particle size 0.25μ) 80 parts by weight Chromium 3,5-di-t-butylsalicylate complex 1 part by weight Wax A 3 parts by weight

After premixing the above materials, a magnetic toner 13 having a weight average particle size of 8 μm was obtained in the same manner as in Example 1. 0.6 parts by weight of hydrophobic colloidal silica fine powder was externally added to 100 parts by weight of this toner, and a toner having colloidal silica fine powder on the surface of toner particles was used as a developer. The DSC data is shown in Table 8.

This developer was used in a commercially available electrophotographic copying machine NP-
The test was performed using 8582 (manufactured by Canon Inc., heat roll fixing).

In an environment with a temperature of 15 ° C., when the copier is sufficiently cooled, the power is turned on, and the A3 is started 5 minutes after the standby.
(80g) transfer paper was copied 200 times,
No offset was generated, and the fixing property of the 200th sheet (density reduction rate: 8%) was good. In addition, when solid black was continuously copied, no wrapping occurred and nail marks were also slight.

When a copy test was performed on 20,000 sheets in an environment of 32.5 ° C., an image without fog having an image density of 1.38 to 1.40 was obtained, and no fusing or the like occurred.

[0126]

[Table 8]

Example 14 Toner 1 was evaluated using a commercially available electrophotographic copying machine NP-4835 (manufactured by Canon Inc.). Environmental temperature 7.5 ° C
In the first copy test, the sample had no offset and good fixability (density reduction rate: 7%).

When a durability test was performed on 10,000 sheets in an environment of 32.5 ° C., the image density was 1.36 to 1.4.
At 1, the image without fogging was continuously obtained. No fusing occurred, and the cleaning web of the fixing roller was very little stained. Immediately after 200 sheets of B5 (80 g / m ² ) transfer paper were continuously taken, A3 (52 g / m ² )
was copied transfer paper m ^2), it did not occur hot offset by an end portion Atsushi Nobori.

[0129]

According to the present invention, by including a specific hydrocarbon-based wax in a toner, favorable thermal characteristics can be imparted to the toner, and the following excellent effects are exhibited.

The present invention can provide a toner excellent in fixing property at low temperature and anti-offset property and a heat fixing method.

The present invention can provide a toner excellent in offset resistance at high temperatures and a heat fixing method.

The present invention can provide a toner which is excellent in blocking resistance and does not deteriorate in developability even when left for a long period of time.

The present invention can provide a toner excellent in durability against temperature rise of a machine body such as a copying machine or a printer.

The present invention can provide a toner that achieves the above effects without contradiction.

[Brief description of the drawings]

FIG. 1 is a view showing a DSC curve when a temperature of a toner 1 of the present invention is raised.

FIG. 2 is a view showing a DSC curve when the temperature of the toner 1 of the present invention is lowered.

FIG. 3 is a diagram showing an endothermic peak portion of a DSC curve at the time of temperature rise.

FIG. 4 is a diagram showing an endothermic peak portion of a DSC curve at the time of temperature rise.

FIG. 5 is a diagram showing an endothermic peak portion of a DSC curve at the time of temperature rise.

FIG. 6 is a diagram showing an endothermic peak portion of a DSC curve at the time of temperature rise.

FIG. 7 is a diagram showing an exothermic peak portion of a DSC curve at the time of temperature decrease.

FIG. 8 is a diagram showing an exothermic peak portion of a DSC curve at the time of temperature decrease.

FIG. 9 is a diagram showing an exothermic peak portion of a DSC curve at the time of temperature decrease.

FIG. 10 is a diagram showing an exothermic peak portion of a DSC curve at the time of temperature decrease.

FIG. 11 is a graph showing the relationship between D and D of the wax A according to the present invention when the temperature is increased.
It is a figure which shows a SC curve.

FIG. 12 shows the relationship between D and D of wax A according to the present invention when the temperature is lowered.
It is a figure which shows a SC curve.

FIG. 13 shows DS when wax F (comparative example) was heated.
It is a figure showing a C curve.

FIG. 14 shows DS of wax F (comparative example) when the temperature is lowered.
It is a figure showing a C curve.

FIG. 15 is a schematic explanatory view showing a specific example of a fixing device for performing the heat fixing method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 heating element 2 fixing film 3 drive roller 4 driven roller 5 pressure roller 6 transfer material 7 toner 8 entrance guide 9 resistance material 10 alumina substrate 11 detection element

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaji Fujiwara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tsutomu Onuma 3-30-2 Shimomaruko, Ota-ku, Tokyo (56) References JP-A-5-346678 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 9/08

Claims (2)

(57) [Claims] 1. A toner for developing an electrostatic image containing at least a binder resin and a hydrocarbon-based wax, wherein the toner is a DSC related to a toner measured by the following differential scanning calorimeter.
In the curve, with respect to the endothermic peak at the time of temperature rise, the rising temperature at the endothermic peak is 80 ° C. or more, the onset temperature at the endotherm is 105 ° C. or less, and the endothermic peak temperature is 100 to
It is in the range of 120 ° C., and the exothermic peak temperature is 62 to 7
In the range of 5 ° C. and an exothermic peak intensity ratio of 5 × 10 ⁻³ or more, wherein the hydrocarbon wax is contained in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the binder resin. A toner for developing electrostatic images, characterized in that: 2. In a DSC curve of a toner measured by a differential scanning calorimeter, a rising temperature at an endothermic peak is 80 ° C. or more and an onset temperature at an endothermic peak is 105 ° C. or less with respect to an endothermic peak at the time of temperature rise. The endothermic peak temperature is 100 ~
It is in the range of 120 ° C., and the exothermic peak temperature is 62 to 7
It is in the range of 5 ° C., and the intensity ratio of the exothermic peak is 5 × 10 ⁻³ or more.
A heat fixing method comprising: fixing a toner image formed by an electrostatic image developing toner containing 10 parts by weight of a hydrocarbon wax to a transfer material by a contact heat fixing unit.