JPH0690578B2 - Heat roller fixing method and fixing device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a heat roller fixing method and a fixing device which are generally applied to copying machines for electrostatic recording devices such as electrophotography or magnetophotographic devices.

[Problems to be solved with conventional technology]

2. Description of the Related Art Conventionally, in a fixing device for fixing a toner image, there are a melt fixing of toner by heat or a pressure fixing by only pressure, and a roller fixing for contacting and fixing toner by heat mainly.

Among these fixing devices, the pressure fixing device holds the image support under pressure between two fixing rollers, and usually has a length of 1 cm in the roller longitudinal direction.
The toner image is fixed on the image support by a pressure of 10 kg or more, and a hard chrome plated coating layer is used as the surface material of the fixing roller. This is because the hard chrome plated coating layer is excellent in that it enhances the surface strength of the roller and improves the releasability of the image support from the surface. However, since a high pressure of 10 kg or more per 1 cm in the longitudinal direction is applied, the weight of the fixing device becomes heavy, the image support such as paper has gloss due to the pressure, and double-sided copying becomes difficult. is there. For this reason, efforts have been made to reduce the pressure, but so far, when the surface temperature of the fixing roller is room temperature or lower, a fixing device for fixing with a pressure of 1 cm to 10 kg or less has not been developed so far.

For this reason, the fixing method which is widely used in general is thermal fixing, for example, a chamber fixing device, a heat roller fixing device: a flash fixing device and the like. However, in the chamber fixing device, a large amount of energy is required for non-contact heating of the paper having the toner image using a sheathed heater that heats red to fuse the toner made of resin to fix the toner on the paper, and further, when jamming, There is a problem that the paper is ignited by heating. In addition, a flash fixing device requires a large capacitor to instantly apply a high voltage to a flash lamp to ignite it, which leads to an increase in size of the device and also requires a time to charge the capacitor. It has a problem that it is difficult to make it. For this reason, the fixing device in the current electrophotographic apparatus has a fixing roller that comes into contact with a recording material carrying a toner image and fixes the toner image on the recording material, and a pressure roller that is in pressure contact with the fixing roller. The heat roller fixing device is the mainstream. However, this heat roller fixing device is also a fixing roller in which the surface of a steel cylinder is coated with fluorine resin such as PTFE or PFA to about 150 to 200 ° C from the inside with a halogen heater etc. This is also in pressure contact with the roller. This is because the toner image is fixed by passing the paper between pressure rollers that are coated with silicon rubber on a steel cylinder, so the efficiency of energy used for fixing is low. There is.

In other words, the thermal efficiency of the halogen lamp heater, which is a heat source, is as low as about 80 to 85% of the infrared radiation that can be extracted as heat,
Furthermore, because this heat is transferred to the steel or aluminum cylinder, heat escape from the cylinder end occurs,
The heat that can actually be used for fixing is less than 70% of the total. For this reason, an end heat insulating means is considered, but sufficient heat insulation causes complication of the device and cost increase.

Further, in the conventional fixing method and apparatus, since the pressure roller is formed of rubber having low hardness on the metal cylinder, the contact width with the fixing roller is increased, especially 60 sheets per minute (A4) It is 10 mm or more in the above copying equipment. Therefore, not only the toner is heated, but also a large amount of heat is taken by the paper as the transfer material. Further, the fixing roller, which is deprived of heat, is rapidly cooled by continuous copying, and the fixing property is deteriorated.

On the other hand, efforts are being made to lower the fixing temperature and increase the fixing efficiency by lowering the softening point of the toner used, but the toner can be pulverized to a suitable particle size to maintain image quality. In practice, it is difficult to lower the softening point because it is necessary to prevent solidification called blocking, which is caused by solidification.

As described above, so far, a fixing method and a fixing device which are energy-saving and can cope with high speed have not been obtained.

[Technical means and method for solving the problems]

The present invention has been made to cope with the above situation, and an object of the present invention is to provide a fixing system which consumes less energy and can cope with high speed.

That is, an object of the present invention is to sandwich and convey a final transfer material having a toner image between a pair of heat rollers having a heat source inside and at least one roller heated and heated by the heat source. In the heat roller fixing method for fixing an image, the pressure applied between the heat roller pair is 20 kg / cm ² or more and 150 kg /
cm ² or less, and the toner for forming the toner image, 50 to 3000 parts by weight of a low softening point compound having a softening point of 40 to 130 ° C. with respect to 100 parts by weight of a polymer formed from a polymerizable monomer. It is an object of the present invention to provide a heat roller fixing method characterized by containing a polymerized toner.

It is another object of the present invention to sandwich and convey the final transfer material having a toner image between a pair of heat rollers having a heat source inside and at least one roller heated and heated by the heat source. In a heat roller fixing device that fixes an image,
Fixes a toner image formed from a polymerized toner containing 50 to 3000 parts by weight of a low softening point compound having a softening point of 40 to 130 ° C. with respect to 100 parts by weight of a polymer formed from a polymerizable monomer. A heat roller fixing device characterized by having a heat roller pair for adjusting the pressure applied between the heat roller pairs to 20 kg / cm ² or more and 150 kg / cm ² or less. Especially.

In the present invention, it allowed increasing the heat fluidity by adding pressing force 20kg / cm ² ~150kg / cm ² on the toner, and is characterized in city that allowed more reduced the temperature during the aforementioned fixing.

[Explanation of Examples]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows an electrophotographic apparatus to which the fixing device of the present invention is applied.
When a copy button (not shown) is pressed, the photosensitive drum 1 starts rotating in the arrow direction.

The photoconductor drum 1 is uniformly charged by the charger 3 as it rotates. On the other hand, the document illumination system 2 starts moving from the home position as the photosensitive drum 1 rotates. The original document on the original table 4 is illuminated by the original illumination lamp 5, and the optical image of the original document is sequentially exposed at the exposure position 7 onto the uniformly charged photoconductor drum 1 through the lens system 6. As a result, an electrostatic latent image is formed on the photosensitive drum 1. Then, the electrostatic latent image is developed into a toner image by the developing device 8, and the toner image is fed by the paper feed roller 9 and the registration roller 10 in synchronization with the leading edge of the toner image, and the transfer paper P as a recording material. Is transferred by the transfer charger 11. The transfer paper P on which the toner image has been transferred is further conveyed by the conveyor belt 12 and reaches the fixing device F of the present invention. The transfer paper P includes a fixing roller 13 having a heat source inside, and a pressure roller that is in pressure contact with the fixing roller 13.
It is held and conveyed by a pair of rotating bodies with 14. At this time, it is softened by heat conduction from the fixing roller 13 and pressure from the pressure roller 14 and is fixed on the transfer paper P. After fixing, the transfer paper P is separated from the roller pair by the separating claw 15 and discharged to the outside of the machine. After the toner image has been transferred, the residual toner is removed from the photosensitive drum by the cleaner 17 to prepare for the next image formation.

Next, the fixing device F of the present invention will be described in detail with reference to FIG. The fixing roller 13 is formed by coating a rigid cylinder made of aluminum, stainless steel or the like with a fluorine resin having a high mold release property such as PFA or PTFE. Further, a heat source such as a halogen lamp is installed inside the fixing roller to raise the surface of the fixing roller 13 to a predetermined temperature.

The pressure roller 14 is formed by coating a cylinder of aluminum or stainless steel with a rubber having releasability such as silicon rubber or fluorine rubber.

The two rolls are pressed against each other by a spring 16 at the nip portion N.

Next, the detailed conditions will be described. The pressure in the nip portion N is 20 kg / cm ² or more and 120 kg / cm ² or less, preferably 25 kg / cm ² or more and 80 kg / cm ² or less, 20 kg / cm ² If the pressure is below, the fixing rate will be significantly reduced to 60% or less, and if it is 120 kg / cm ² or more, the surface of the transfer paper will be glossy, and inevitably because the core metal of the roll pair will withstand the pressure. It must be made thick, and as a result, the heat capacity of the roll increases, and it takes a lot of time to start.

The contact width (nip width) of the roll pair at the nip portion N cannot be unconditionally determined because it depends on the pressure and the thickness and hardness of the silicone rubber and fluorine rubber described later, but the peripheral speed of the roll (V _P mm / sec ) Relationship between Nip width (N _P mm) 0.01
It should be set so that> N _P / V _P > 0.002.

Further, the temperature of the fixing roll 13 varies depending on the pressure of the nip portion and the nip width, but may be appropriately set in the range of 85 ° C. to 140 ° C. in consideration of other various conditions. Further, the surface of the fixing roller 13 should be as smooth as possible because it affects the quality of the finished image, and the surface roughness is 3 μmr.
mS or less is preferable.

Next, regarding the rubber that can be used for the pressure roller 14, as the silicone rubber, KE-16,1091,1092,109
3, KE-119, KE-1205, 1206, 1300, 1600 (RTV silicone rubber), KE-106, KE-1201, 1202, 1204, KE-1212, KE-1800
(LTV silicone rubber), KE-530,540,550, KE-860,870 (H
TV silicone rubber) [manufactured by Shin-Etsu Silicone Co., Ltd.], and fluorocarbon rubbers such as G-201, 501, G-602, 603, 701, 751, 702 [manufactured by Daikin Industries, Ltd.] are used. However, when the HTV silicone rubber is used, it is preferable to apply or impregnate a releasing agent such as silicone oil on the surface of the silicone rubber of the pressure roll 14 in order to prevent toner offset during fixing. The thickness of the rubber is appropriately determined depending on the pressure applied to the nip portion N and the rubber hardness, but it tends to be thicker when the rubber hardness is high, and becomes thinner as the rubber hardness becomes lower. However, if the thickness is less than 0.1 mm, the durability is actually poor, and the nip portion N due to the skew of the transfer paper, etc.
When the transfer paper is wrinkled or bent, local pressure is applied to the rubber, and as a result, cracking or peeling occurs. For this reason, the thickness of the rubber used must be at least 0.2 mm or more, preferably 0.3 mm or more. Further, when the pressure required for fixing is applied with a thickness of 5 mm or more, the transfer paper and the fixing roller in the nip portion N are
The contact width of 13 becomes large and extra heat is transferred to the transfer paper, resulting in significant energy loss. The proper thickness is preferably set to a value of 0.3 to 1 mm when the hardness of the rubber used is 50 degrees, and a value of 2 to 3 mm when the hardness is 70 degrees. However, this value is when using the above-mentioned silicone rubber,
In practice, it may be appropriately determined according to the tensile strength and hardness of the rubber used and the above-mentioned various conditions.

Next, the toner that can be used in the present invention will be described in detail.

The toner according to the present invention is a polymerized toner produced in an aqueous medium by using a polymerization initiator from a monomer composition having at least a polymerizable monomer and a colorant by a suspension polymerization method. 50 to 3000 low softening point compound having a softening point of 40 to 130 ° C. with respect to 100 parts by weight of a polymer formed from a polymer.
It is a polymerized toner containing a part by weight.

The polymerized toner of the present invention usually has a volume average particle size of about 0.1 to about 30μ.
50 to 3000 parts by weight of a low softening point compound having a softening point of 40 to 130 ° C. is included with respect to 100 parts by weight of a polymer having a particle size of 100 μm and produced from a polymerizable monomer by suspension polymerization. As described above, the polymerized toner of the present invention is excellent in blocking resistance as compared with the conventional polymerized toner, although it contains a large amount of the low softening point compound. This is because the low softening point compound is well encapsulated in the polymer obtained by polymerizing the polymerizable monomer, and the low softening point compound is not exposed on the surface of the polymerized toner particles. In the present invention, to confirm whether or not the low softening point compound is substantially encapsulated in the polymer, the obtained polymerized toner is melt-kneaded, cooled and solidified and then pulverized, and then classified and polymerized. This is done by preparing a pulverized powder having an average particle diameter similar to that of the toner and comparing the blocking resistance of the prepared pulverized powder with the blocking resistance of the polymerized toner used as a raw material. The anti-blocking property is that the temperature of 50
20 after being left for one day in an environment of ℃ and relative humidity of about 60 ± 5%
Approximately 1 mm long particle size remaining on the mesh screen (Taylor mesh)
It can be measured depending on the presence or absence of the above aggregated substances.

In the present invention, a plurality of low softening point compounds may be mixed and used. The softening points (40 to 130 ° C) and the amounts of use of the multiple low softening point compounds used are (T1, W1), (T
2, W2) …… (Tn−1, Wn−1), (Tn, Wn),
It is preferable to satisfy the following conditions.

The amount of the low softening point compound used is a value assuming the case where the added polymerizable monomer is polymerized by almost 100% to produce a polymer, and 50 ≦ 100 parts by weight of the polymer. W1 ＋ W2 ＋…
... Wn-1 + Wn ≤ 3000 is satisfied. Polymer 100
In other words, “parts by weight” means 100 parts by weight of the polymeric monomer that is effectively used to produce the polymer forming the polymerized toner. Therefore, 100 parts by weight of the polymer may be produced by using 100 parts by weight or more of the polymerizable monomer in consideration of the amount dissolved in the aqueous medium and the unreacted amount.

When the value deviates from the above conditions and becomes a value of 0.05 or less, the amount of the low softening point compound used is too large, the blocking resistance is lowered, and the mechanical strength of the polymerized toner tends to be insufficient. On the other hand, when the value is 0.8 or more, the low temperature fixability and / or the low pressure fixability is less improved.

The polymerized toner of the present invention can be produced by the following production method.

That is, at least a polymerizable monomer, low softening point 40-130
A monomer composition containing a low softening point compound having a temperature of ℃ and a colorant is dispersed and granulated in an aqueous medium heated to a high temperature, and after the granulation step is substantially completed, In this method, a polymerization initiator is added to an aqueous medium containing the monomer composition particles and adjusted to a polymerization temperature to carry out suspension polymerization.
In this case, the liquid temperature during the granulation step of the aqueous medium is preferably higher than the softening point of the low softening point compound in terms of easiness of granulation and sharpness of particle size distribution.

In the above production method, a polymerization initiator for polymerizing the polymerizable monomer is added to the aqueous medium after granulating the monomer composition. Therefore, it is possible to carry out the granulation by making the temperature of the aqueous medium, which is the dispersion medium of the monomer composition, higher than the conventional temperature.

Furthermore, a classification step is provided after granulation to classify the monomer composition particles having a predetermined particle size and the monomer composition particles having a non-specified particle size, and then a polymerization initiator is added to carry out polymerization. On the other hand, it is also possible to mix the separated monomer composition particles having a non-specified particle size with the monomer composition before the polymerization step, and to re-disperse and granulate again. .

Further, during the granulation step, it is possible to raise the temperature of the aqueous medium without considering the decomposition temperature of the polymerization initiator, so that it is possible to substantially reduce the temperature in the monomer composition such as paraffin or low molecular weight polyolefin. Even a low softening point compound that is insoluble in the polymerizable monomer can be added in a large amount for granulation, and even if a large amount is added, granulation can be performed at a high temperature. Energy-saving polymerized toners having a distribution that can be cold-fixed and / or low-pressure fixed can be produced.

According to the knowledge of the present inventors, when a water-soluble polymerization initiator is used, the generated polymerized toner has reduced moisture resistance, and thus the development characteristics and blocking resistance at high temperature and high humidity deteriorate. In order to produce a polymerized toner having excellent environmental characteristics, it is preferable to use a substantially water-insoluble polymerization initiator. When a substantially water-insoluble polymerization initiator is used, in a system in which the monomer composition is previously dissolved and mixed as in the conventional case, the polymerization initiator should be evenly distributed to each monomer composition particle. However, even in a system in which a monomer composition is granulated in an aqueous medium as in the above production method, and then a substantially water-insoluble polymerization initiator is added, a good polymerization reaction can be obtained in each particle. What happens is surprising.

As described above, it is preferable that the polymerization initiator used in the above production method is substantially water-insoluble.

The substantially water-insoluble polymerization initiator in the present invention has a solubility of 1 g or less with respect to 100 g of water at room temperature, preferably 0.5 g or less with respect to 100 g of water, and particularly preferably 100 g of water. It has a low solubility of 0.2 g or less. When it has a solubility of 1 g or more in 100 g of water,
A decomposition product of the polymerization initiator remaining on the surface of the polymerized toner particles after the completion of the polymerization undesirably reduces the moisture resistance of the polymerized toner. Further, the polymerization initiator used in the above-mentioned production method is soluble in the polymerizable monomer, and usually used in an amount range (2 to 5 parts by weight of the polymerization initiator relative to 100 parts by weight of the monomer).
Has a property of being dissolved in a polymerizable monomer. As the polymerization initiator usable in the above production method, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane- 1-carbonitrile), 2,2'-azobis-4
-Azo- or diazo-type polymerization initiators such as methoxy-2,4-dimethylvaleronitrile and other azobisisobutyronitriles (AIBN): benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate, kyumen hydroper oxide,
Examples thereof include peroxide-based polymerization initiators such as 2,4-dichlorylbenzoyl peroxide and lauroyl peroxide. In the production method of the present invention, the polymerization initiator preferably has a melting point equal to or lower than the polymerization temperature (usually 50 ° C. or higher). It is also preferable to use a mixture of two or more polymerization initiators for the purpose of controlling the molecular weight and molecular weight distribution of the polymer or the reaction time. In that case, it is preferable to use at least one having a melting point at a temperature corresponding to the liquid temperature in the aqueous medium at the time of polymerization or at a temperature lower than that. This is because the polymerization initiator is oiled at the liquid temperature during the polymerization reaction, so that the polymerization initiator or the radicals generated from the polymerization initiator is added to each of the monomer composition particles dispersed after being added to the aqueous medium. It is because it is imparted more favorably. By the way, 2,2'-azobis- used in Examples described later
(2,4-Dimethylvaleronitrile) is a meso form (mp55-5
7 ° C.) and dl form (mp74-77 ° C.), the mixture starts melting at about 45 ° C. and ends melting at about 70 ° C. The amount of the polymerization initiator used is 0.1 with respect to 100 parts by weight of the polymerized monomer.
-20 parts by weight, preferably 1-10 parts by weight.

At 0.1 parts by weight or less, it is difficult to uniformly apply the polymerization initiator to each of the monomer composition particles, and at 20 parts by weight or more, the molecular weight of the polymerization product becomes too low and the polymerization reaction becomes unsatisfactory. The tendency to occur uniformly increases.

The suspension polymerization reaction is usually performed at a polymerization temperature of 50 ° C or higher,
The upper limit temperature is set in consideration of the decomposition rate of the polymerization initiator. If the set polymerization temperature is too high, the polymerization initiator will be rapidly decomposed, which is not preferable. In the above production method, since it is not necessary to allow the polymerization initiator to be present in the monomer composition during suspension granulation, the liquid temperature of the aqueous medium during granulation is, for example, 75 ° C. or higher and the monomer composition Granulation can be easily carried out by lowering the melt viscosity of.

After confirming that the formed monomer composition particles have a predetermined particle size, lower the liquid temperature of the aqueous medium containing the particles to the polymerization temperature (for example, 55 to 70 ° C), and then start the polymerization. Add agent. By lowering the liquid temperature of the aqueous medium, the retention of the monomer composition particles is improved and the coalescence of the particles is suppressed. The polymerization reaction time varies depending on the type of polymerization initiator and the polymerization temperature, but is usually 2 to 30 hours.

In the above production method, since dispersion granulation at high temperature is possible, it is possible to produce a polymerization product usable as a toner even if a low softening point compound is added to the monomer composition in a large amount as an additive. Is possible. In the polymerized toner of the present invention, the low softening point compound can also serve as a binder resin. The low softening point compound in the present invention has a softening point of 40 to 130 ° C., preferably 50 to 120 ° C., measured by a ring and ball method (see JIS K 2531 etc.). If the softening point is 40 ° C. or lower, the blocking resistance and shape retention of the toner are insufficient, and if the softening point is 130 ° C. or higher, the effect of lowering the fixing temperature or fixing pressure is small. Low softening point compounds include paraffins, waxes, low molecular weight polyolefins, modified waxes having an aromatic group, hydrocarbon compounds having an alicyclic group, natural waxes, and long-chain hydrocarbon chains having 12 or more carbon atoms [CH ₃ CH _{2 11} or CH _{2 12} or more aliphatic carbon chain], a long-chain carboxylic acid, an ester thereof, or the like. Different low softening point compounds may be mixed and used. Specifically, Paraffin Wax (made by Nippon Oil Co., Ltd.),
Paraffin wax (manufactured by Nippon Seiro), Microwax (manufactured by Nippon Oil), Microcrystalline Wax (manufactured by Nihon Seiwa), Hard Paraffin wax (manufactured by Nihon Seiwa), PE
-130 (Made by Hoechst), Mitsui High-Wax 110P (Mitsui Petrochemical), Mitsui High-Wax 220P (Mitsui Petrochemical), Mitsui High-Wax 660P (Mitsui Petrochemical), Mitsui High-Wax 210P (Mitsui Petrochemical), Mitsui High-Wax 320P (Mitsui Petrochemical), Mitsui Hiwax 410P (Mitsui Petrochemical), Mitsui Hiwax 420P (Mitsui Petrochemical), Hiretsu T-100X (Mitsui Petrochemical), Hiretsu T-200X (Mitsui Petrochemical), Hiretsu T-300X
(Mitsui Petrochemical); Petrosin 80 (Mitsui Petrochemical); Petrosin 100 (Mitsui Petrochemical), Petrosin 1
20 (manufactured by Mitsui Petrochemical), Tatsuku Ace A-100 (manufactured by Mitsui Petrochemical), Tatsuku Ace F-100 (manufactured by Mitsui Petrochemical), Tatsuku Ace B-60 (manufactured by Mitsui Petrochemical), Modified Wax JC-1141 (Mitsui Petrochemical) Made), modified wax JC-
2130 (Mitsui Petrochemical), Modified Wax JC-4020 (Mitsui Petrochemical), Modified Wax JC-1142 (Mitsui Petrochemical), Modified Wax JC-5020 (Mitsui Petrochemical); Mitsuwa, Karunawawax , Montan Wax, etc. can be mentioned. In addition, when using a low softening point compound having a softening point of 100 ° C. or higher, the liquid noise of the aqueous medium is 100 ° C. under pressure.
In some cases, it may be preferable to carry out dispersion granulation as described above.

The above-mentioned low softening point compound is a fixing temperature of the polymerized toner and / or
Alternatively, 50 to 3,000 parts by weight is mixed with 100 parts by weight of the polymerizable monomer for lowering the fixing pressure. It is particularly preferable to mix 70 to 1,000 parts by weight. If it is 50 parts by weight or less, it is not sufficient to lower the fixing temperature or fixing pressure of the fixing roller.
If it is more than 3,000 parts by weight, the product is made of anti-blocking material and the durability tends to decrease.

The polymerizable monomer applicable to form the polymerized toner of the present invention is a monomer having a CH ₂ ═C <group as a reactive group, such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene. , p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-
Butyl styrene, p-tert-butyl styrene, p-n-hexyl styrene, p-n-octyl styrene, p-n-nonyl styrene, p-n-decyl styrene, p-n-dodecyl styrene, and other styrenes and the like. Derivatives: vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, etc .; acrylic acid, methacrylic acid, maleic acid, maleic acid half ester; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-methacrylic acid
Α-Methylene aliphatic monocarboxylic acids such as butyl, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc. Acid esters; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate,
Dodecyl acrylate, 2-ethylhexyl acrylate,
Stearyl acrylate, 2-chloroethyl acrylate,
Acrylic esters such as phenyl acrylate; Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N-vinyl pyrrole, N- N-vinyl compounds such as vinylcarbazole, N-vinylindole and N-vinylpyrrolidone; vinylnaphthalene compounds;
There are monomers having a reactive double bond such as vinyl groups such as acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide.

These may be used alone or in combination of two or more. You may use a crosslinking agent as needed. Examples of the cross-linking agent include divinylbenzene, divinylnaphthalene, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate and the like. The addition amount of the crosslinking agent is usually 0.1 to 5 parts by weight based on 100 parts by weight of the polymerizable monomer. Further, a polymer of these polymerizable monomers may be added in a small amount in the monomer composition. Among the above-mentioned monomers, a polymerized toner produced from styrene, styrene having a substituent such as an alkyl group, or a mixed monomer of styrene and another monomer is considered in terms of developability and durability. It is preferable when doing.

Further, a preferable polymerized toner can be obtained by adding a polar polymer having a polar group, a polar copolymer or a cyclized rubber as an additive at the time of polymerizing the monomer to polymerize the polymerizable monomer. The polar polymer, polar copolymer or cyclized rubber should be added in an amount of 0.5 to 50 parts by weight, preferably 1 to 40 parts by weight, withstanding 100 parts by weight of the polymerizable monomer. If it is 0.5% by weight or less, it is difficult to obtain a sufficient pseudocapsule structure, and if it is 50 parts by weight or more, the amount of the polymerizable monomer becomes insufficient and the properties as a polymerized toner tend to deteriorate. Polar polymer,
It is preferable to polymerize by suspending a polymerizable monomer composition containing a polar copolymer or a cyclized rubber in an aqueous phase of an aqueous medium in which the polar polymer and a dispersant having an opposite charge property are dispersed. . That is, the cationic or anionic polymer, the cationic or anionic copolymer or the anionic cyclized rubber contained in the polymerizable monomer composition is a reversely charged anionic polymer dispersed in an aqueous medium. Alternatively, the cationic dispersant and the toner particle surface are electrostatically attracted to each other, and the particle surface is covered with the dispersant to prevent the particles from coalescing with each other and stabilize, and at the same time, the added polar polymer, polar copolymer or Since the cyclized rubber gathers on the surface layer of the toner particles, it becomes a kind of shell-like morphology, and the obtained particles become pseudo capsules. Since the relatively high molecular weight polar polymer, polar copolymer or cyclized rubber collected in the surface layer of the particles encloses a large amount of the low softening point compound inside the toner particles, the polymerized toner particles of the present invention have a blocking property. Imparts excellent developability and abrasion resistance. The polar polymers (including polar copolymers and cyclized rubbers) and reversely-charged dispersants that can be used in the present invention are exemplified below. The polar polymer is GPC.
Those having a weight average molecular weight of 5,000 to 500,000 as measured in (3) are dissolved in the polymerizable monomer satisfactorily and have durability, and thus are preferably used.

(I) As the cationic polymer, a polymer of nitrogen-containing monomer such as dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, a copolymer of styrene and the nitrogen-containing monomer or styrene, unsaturated carboxylic acid ester Etc. and the nitrogen-containing monomer.

(Ii) Examples of the anionic polymer include nitrile-based monomers such as acrylonitrile, halogen-containing monomers such as vinyl chloride,
There are polymers of unsaturated carboxylic acids such as acrylic acid, unsaturated dibasic acids, anhydrides of unsaturated dibasic acids, and copolymers of styrene and the monomers.

As the dispersant, an inorganic fine powder which has the ability to disperse and stabilize the monomer composition particles in an aqueous medium and is sparingly soluble in water is preferable. The amount of dispersant added to the aqueous medium is based on water.
It is preferable to add 0.1 to 50% by weight (preferably 1 to 20% by weight).

(Iii) Examples of anionic dispersants include Aerosil # 200,
There are colloidal silica such as # 300 (manufactured by Nippon Aerosil Co., Ltd.).

(Iv) Examples of the cationic dispersant include fine particles of hydrophilic positively charged silica such as aluminum oxide, magnesium hydroxide, and aminoalkyl-modified colloidal silica.

Instead of the above polar polymer or copolymer, a cyclized rubber having anionic property may be used.

To produce the magnetically polymerized toner, magnetic particles are added to the monomer composition. In this case, the magnetic particles also serve as a coloring agent. As the magnetic particles that can be used in the present invention, substances that are placed in the field and magnetized are used, such as iron,
Powders of ferromagnetic metals such as cobalt and nickel, and powders of alloys and compounds such as magnetite, hematite, and ferrite are given. Magnetic fine particles having a particle size of 0.05 to 5 μm, preferably 0.1 to 1 μm are used. The content of the magnetic particles is 10 to 60% by weight, preferably 20 to 50% by weight, based on the weight of the toner. Further, these magnetic fine particles may be treated with a treating agent such as a silane coupling agent, a titanium coupling agent or the like, or an appropriate reactive resin or the like. In this case, depending on the surface area of the magnetic fine particles and the density of hydroxyl groups existing on the surface, it is 5% by weight or less (preferably 0.1% by weight).
(3 wt% to 3 wt%), sufficient dispersibility in the polymerizable monomer and the low softening point compound is obtained, and the physical properties of the toner are not adversely affected. The polymerized toner contains a colorant, and as the colorant, a dye such as a conventionally known dye, carbon black, or a pigment such as a grafted carbon black in which the surface of the carbon black is coated with a resin can be used. . The colorant is contained in an amount of 0.5 to 30% by weight based on the polymer and the low softening point compound. A charge control agent and a fluidity modifier may be added (internally added) to the toner, if necessary. The charge control agent and the homogeneity modifier may be mixed (externally added) with the toner particles and used. Examples of the charge control agent include metal complexes of organic compounds having a carboxyl group or a nitrogen-containing group, metal-containing dyes, nigrosine and the like. Examples of fluidity modifiers and auxiliary agents for cleaning the surface of the latent image bearing member (photoreceptor) include colloidal silica and fatty acid metal salts.
Further, for the purpose of increasing the amount, a filler such as calcium carbonate or fine powder silica may be blended in the toner in the range of 0.5 to 20% by weight. Further, in order to prevent the mutual aggregation of the toner particles and improve the fluidity, a fluidity improver such as Teflon fine powder or zinc thraphosphate powder may be added. When a low molecular weight hydrocarbon compound (for example, a weight average molecular weight of 500 to 5000) or carnauba wax that improves releasability at the time of heat roll fixing is used as a low softening point compound, for example, a hydrocarbon compound is hydrophobic. Since it has a low molecular weight, it is less likely to mix with the polymer produced by the polymerization, and is less likely to be exposed on the particle surface as compared with a polar polymer, a polar copolymer or a cyclized rubber, and will be pushed into the polymerized toner. As a result, even if it contains a large amount of the low softening point compound, it is excellent in durability and blocking resistance because it is encapsulated. Then, the toner comes out from the inside at the time of fixing and remarkably improves the fixing property and the offset property. In other words, it serves as an offsetting agent and a fixing agent.

When the polymerized toner of the present invention is applied to a two-component developer, it can be applied in a compounding ratio of a normal toner and a carrier, for example, 1 to 500 parts by weight of the carrier is mixed with 1 part by weight of the toner. .

The suspension method is a colorant (including a magnetic material in the present invention), 50 to 3000 parts by weight of the low-softening point compound and 100 parts by weight of the polymerizable monomer are uniformly dissolved, Alternatively, the dispersed monomer composition is used in an aqueous medium containing 0.1 to 50% by weight of a suspension stabilizer (for example, a sparingly soluble inorganic dispersant) (for example, 5 ° C or higher than the polymerization temperature, preferably 10 ° C or higher). 30
It is heated to a temperature of ℃ or more) by a usual stirrer, homomixer, homogenizer or the like. Preferably the agitation speed, time and aqueous medium so that the particles of the melted or softened monomer composition have the desired toner particle size, generally less than 30 μm (eg volume average particle size 0.1-20 μm). Adjust the temperature. Then, the liquid temperature of the aqueous medium is lowered to the polymerization temperature while stirring is carried out to the extent that the sedimentation of the particles is prevented so that the state of the dispersion stabilizer is almost maintained by the action of the dispersion stabilizer. The polymerization temperature is set to 50 ° C. or higher, preferably 55 to 80 ° C., particularly preferably 60 to 75 ° C., and the polymerization is carried out by adding a substantially water-insoluble polymerization initiator while stirring. After completion of the reaction, the polymerized toner of the present invention can be obtained by collecting and drying the produced toner particles by an appropriate method such as washing, removal of the dispersion stabilizer, filtration, decantation and centrifugation. In the suspension polymerization method, usually 200 to 3000 parts by weight of water is used as an aqueous dispersion medium with respect to 100 parts by weight of the polymerizable monomer and the low softening point compound.

Also suitable stabilizers such as polyvinyl alcohol,
Gelatin, methyl cellulose, methyl hydropropyl cellulose, ethyl cellulose, carboxymethyl cellulose sodium salt, polyacrylic acid and salts thereof, starch, gum alginate, zein, casein,
Any one or a mixture of tricalcium phosphate, talc, barium sulfate, bentonite, aluminum hydroxide, ferric hydroxide, titanium hydroxide, thorium hydroxide, etc. is adversely affected in the production method of the present invention in an aqueous medium. You may use the thing contained to the extent that there is not.

Further, in order to uniformly disperse the inorganic dispersion stabilizer, a surfactant may be used to the extent that it does not adversely affect the production method of the present invention. This is to accelerate the initial action of the dispersion stabilizer, and specific examples thereof include sodium dodecylbenzenesulfonate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, and allyl-alkyl-polyether. Sodium sulfonate, sodium oleate, sodium laurate, sodium caprate, sodium caprate, sodium caproate, potassium stearate, calcium oleate, 3,3-disulfondi, phenylurea-4,4-diazo-bis-amino -8-Naphthol-6
-Sodium sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-sodium disulfonate, etc. You can However, it should be noted that when a hydrophilic organic stabilizer or surfactant is used, the moisture resistance of the polymerized toner decreases.

Further, a water-soluble polymerizable monomer simultaneously undergoes emulsion polymerization in water and contaminates the resulting suspension polymer with small emulsion-polymerized particles.Therefore, a water-soluble polymerization inhibitor such as a metal salt may be added. It is also possible to prevent emulsion polymerization in the aqueous phase. It is also possible to add glycerin, glycol or the like to water in order to reduce the viscosity of the aqueous medium and prevent the particles from coalescing during polymerization.
Also, due to the phenomenon of solubility of easily soluble polymerizable monomers in water, Na
Salts such as Cl, KCl and Na ₂ So ₄ may be added to the aqueous medium.
It is also possible to add Brnsted acid such as hydrochloric acid to the aqueous medium in order to enhance the ionization of the polar groups of the polar polymer or cyclized rubber in the monomer composition. In particular, the addition of Bronsted acid, such as hydrochloric acid, to the aqueous medium is effective in further enhancing the effect of the anionic polymer, anionic copolymer or cyclized rubber.

The polymerized toner of the present invention can be applied to a known dry electrostatic image developing method. For example, two-component developing method such as cascade method, magnetic brush method, microtoning method; one-component developing method using magnetic toner such as conductive-component developing method, insulating one-component developing method, jumping developing method; powder cloud Method and far flash method; non-magnetic one-component developing method in which the toner is conveyed to the developing section and developed by being held on the toner carrier by electrostatic force; electric field curtain development in which the toner is conveyed to the developing section and developed by the electric field curtain method. It is applicable to the law. Although it is particularly preferably applicable to the dry developing method, it may optionally be used as a toner for the wet developing method.

〔Example〕

 Hereinafter, the present invention will be described in detail based on examples.

[Example 1] The above components were mixed with an attritor at a temperature of 80 ° C. for 4 hours to prepare a monomer composition. Obtained monomer composition 254
20 parts by weight of amino-modified silica (100 parts by weight of Aerosil 200 treated with 5 parts by weight of aminopropyltriethoxysilane) and 25 parts by weight of 0.1N hydrochloric acid.
The mixture was put into an aqueous medium of 1200 parts by weight of distilled water heated to 85 ° C. while stirring with a TK homomixer, and after the addition, the mixture was stirred at 10,000 rpm for 15 minutes to carry out dispersion granulation.

After granulation, the liquid temperature was lowered to 60 ° C, and 3 parts by weight of 2,2'-azobis- (2,4-dimethylvaleronitrile) and 1.5 parts by weight of 2,2'-azobisisobutyronitrile were used as a polymerization initiator. It was added to the aqueous medium and stirred for 30 minutes. Further, the stirring was changed to a paddle blade stirring, and stirring was carried out at 60 ° C. for 10 hours to complete the polymerization.

The obtained polymerized toner-containing aqueous medium is cooled and dehydrated,
Amino-modified silica is dissolved and removed by washing with a sodium hydroxide solution, water-based, dehydrated, and dried (if necessary, fine particles of unnecessary component particles are removed to remove), and a volume average particle diameter of 6.5 μm ( A polymerized toner (measured with a Coulter counter using a 100 μm aperture) was obtained. The polymerized toner obtained contained about 180 parts by weight of paraffin wax based on 100 parts by weight of polystyrene. The resulting toner did not cause blocking even if left in an environment of 50 ° C for one day. From this, it was found that the paraffin wax was encapsulated inside the polymerized toner particles.

10 parts by weight of the obtained polymerized toner, zinc stearate powder 0.
1 part by weight, hydrophobic silica (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) 0.1 part by weight, and insulating carrier particles having an average particle size of 40 μm (formed from 75 parts by weight of triiron tetraoxide and 25 parts by weight of epoxy resin) 90 parts by weight Were mixed to prepare a developer, and the development and fixing tests were carried out under the following conditions.

Photoconductor: Amorphous silicon photoconductor Copy speed: 600 mm / sec Electrostatic latent image forming conditions Dark potential: +450 v Sleeve diameter: 32 mm (peripheral speed: 600 mm / sec) Magnetic surface of N, S magnetic pole sleeve surface Magnetic velocity density in the vertical direction …… 1000 gauss Developer layer thickness …… 0.2mm Distance between sleeve and photoconductor surface …… 300μm Development bias …… ＋ 150v (DC) 3.0KHz, 1.4KVpp (AC) Fixing condition ・fixing roller steel core metal on PFA30myuemu · pressure roller onto a silicone rubber (rubber hardness 90 °) ...... KE-550 thickness ...... 1 mm Nitsupu width ...... 2 mm fixing pressure ^{...... 30kg / cm 2 ~40kg / cm} 2 the Under the conditions, the electrostatic latent image formed on the amorphous silicon photoconductor was well developed by the developer shown in Example 1 above. Further, this developed toner image was electrostatically transferred onto plain paper, and under the above-mentioned fixing conditions, the fixing roll surface temperature was 120 ° C., and good fixing property was obtained.

[Example 2] Paraffin wax 140 ° F (softening point 60 ° C) 500 parts by weight and paraffin, instead of paraffin 155 ° F3 500 parts by weight
A polymerized toner having a volume average particle diameter of 5.8μ was produced in the same manner as in Example 1 except that 2000 parts by weight of 155 ° (softening point 69 ° C.) was used and the temperature of the aqueous medium during dispersion granulation was 90 ° C. The polymerized toner thus obtained contained about 125 parts by weight of paraffin wax based on 100 parts by weight of polystyrene. The toner image on plain paper obtained in the same manner as in Example 1 was fixed by the same fixing device as in Example 1 at a fixing temperature of 130 ° C., and was well fixed.

[Example 3] The above components were mixed with an attritor for 4 hours to prepare a monomer composition. Separately amino modified silica 20 parts by weight, 0.1N hydrochloric acid
75 parts by weight of an aqueous medium consisting of 25 parts by weight and 1200 parts by weight of distilled water
The mixture was heated to ℃, 254 parts by weight of the above monomer composition was added to an aqueous medium under stirring with a TK homomixer, and after the addition, 30 rpm at 10,000 rpm.
After stirring for a minute and after granulation, the aqueous medium was cooled to 60 ° C. As polymerization initiators, 5 parts by weight of 2,2'-azobis- (2,4-dimethylvaleronitrile) and 2 parts by weight of 2,2'-azobisisobutyronitrile were added, and the mixture was further stirred for 30 minutes. Then, while stirring at 100 rpm with a normal stirrer, 60
The reaction was carried out at 0 ° C for 10 hours. After that, when post-treatment was carried out in the same manner as in Example 1, the volume average particle size was 5.5 with a sharp particle size distribution.
A polymerized toner having a size of μm was obtained. The polymerized toner obtained is
Approximately 5 paraffin waxes per 100 parts by weight of polystyrene
It contained 5 parts by weight.

The toner image on the plain paper obtained in the same manner as in Example 1 was fixed well when the roller surface temperature was fixed at 160 ° C.

[Comparative Example 1] The above components were mixed with an attritor at a temperature of 60 ° C. for 4 hours to prepare a monomer composition.

2,2'-azobis- was added to 254 parts by weight of the obtained monomer composition.
6 parts by weight of (2,4-dimethylvaleronitrile) and 2,2 '
Amino-modified silica (100 parts by weight of Aerosil 200 treated with 5 parts by weight of aminopropyltriethoxysilane) and 20 parts by weight of 0.1N hydrochloric acid were added and mixed with 3 parts by weight of azobisisobutyronitrile. Contains parts by weight
The mixture was put into an aqueous medium of 1200 parts by weight of distilled water heated to 60 ° C. while stirring with a TK homomixer, and after the addition, the mixture was stirred at 10,000 rpm for 15 minutes to carry out dispersion granulation.

Further, the stirring was changed to a paddle blade stirring, and stirring was carried out at 60 ° C. for 10 hours to complete the polymerization. Then, post-treatment is carried out in the same manner as in Example 1 to obtain a polymerized toner having a volume average particle diameter of 5.3 μm.
The polymerized toner obtained contained about 20 parts by weight of paraffin wax based on 100 parts by weight of polystyrene. 10 parts by weight of the obtained polymerized toner, 0.1 part by weight of zinc stearate powder, 0.1 part by weight of hydrophobic silica (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) and carrier particles having an average particle size of 40 μm (the same as in Example 1). A developer was prepared by mixing 90 parts by weight. When the developing agent thus prepared was used for development, transfer and fixing in the same manner as in Example 1, a fixed image which could be put to practical use could not be obtained even at a fixing temperature of 180 ° C. or higher.

[Comparative Example 2] The above components were mixed with an attritor at a temperature of 60 ° C. for 4 hours to prepare a monomer composition.

2,2'-azobis- was added to 254 parts by weight of the obtained monomer composition.
0.5 parts by weight of (2,4-dimethylvaleronitrile) and 2,
A mixture of 0.2 parts by weight of 2'-azobisisobutyronitrile was mixed with amino-modified silica (Aerosil 200 100
(Parts treated with 5 parts by weight of aminopropyltriethoxysilane) 20 parts by weight and 25 parts by weight of 0.1N hydrochloric acid 1200 parts by weight of distilled water heated to 60 ° C. to an aqueous medium TK
Add under stirring with a homomixer, 10,000 rp for 15 minutes after adding
The mixture was stirred at m and dispersed and granulated.

Further, the stirring was changed to a paddle blade stirring, and stirring was carried out at 60 ° C. for 10 hours to carry out polymerization. Then, when post-treatment was carried out in the same manner as in Example 1, a large number of particles having a particle size of 100 μm or more could not be practically used as they were as toner for developing an electrostatic image. Therefore, it is classified and the volume average particle size is about 8μ.
m particles were obtained, but the anti-blocking product was insufficient.

〔The invention's effect〕

Since the present invention uses the above apparatus and developer,
Transfer paper does not remove excess heat during fixing, and since the developer can be fixed at a temperature much lower than the softening point under normal pressure, there is little energy loss and a system that enables high-speed fixing is obtained. It was

[Brief description of drawings]

FIG. 1 is a schematic side view showing a fixing device as an embodiment of the present invention, and FIG. 2 is a schematic side view of an electrophotographic device using the fixing device of the present invention. 13 …… Heat roll, 14 …… Pressure roll 15 …… Separating claw, 16 …… Pressure spring

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroshi Fukumoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroshi Satomura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (56) Reference JP 49-5636 (JP, A) JP 58-16250 (JP, A) JP 61-62057 (JP, A) JP 60-134250 (JP, A) JP 59-77468 (JP, A) JP 62-280784 (JP, A) JP 62-273584 (JP, A) JP 58-168071 (JP, A) JP 63 -113482 (JP, A) JP 61-260252 (JP, A) JP 63-78155 (JP, A)

Claims (2)

[Claims] 1. A final transfer material having a toner image is nipped and conveyed between a pair of heat rollers having a heat source inside and at least one roller heated and heated by the heat source, and the toner image is fixed. In the heat roller fixing method, the pressure applied between the heat roller pair is 20 kg / cm ² or more and 150 kg / cm ² or less,
Further, a polymerized toner in which the toner forming the toner image contains 50 to 3000 parts by weight of a low softening point compound having a softening point of 40 to 130 ° C. with respect to 100 parts by weight of a polymer formed from a polymerizable monomer. The heat roller fixing method is characterized in that 2. A final transfer material having a toner image is sandwiched and conveyed between a pair of heat rollers having a heat source inside and at least one roller heated and heated by the heat source, and the toner image is fixed. In the heat roller fixing device, the softening point is 40 to 130 with respect to 100 parts by weight of the polymer formed from the polymerizable monomer.
A heat roller pair for fixing a toner image formed from a polymerized toner containing 50 to 3000 parts by weight of a low-softening point compound at a temperature of 20 kg.
A heat roller fixing device comprising a heat roller pair adjusted to be not less than / cm ^{2 and not} more than 150 kg / cm ² .