JPS604946A - Toner for fixing with hot roller - Google Patents

Abstract

PURPOSE:To improve the flxability at low temp. and the off-setting resistance by using polymers A, B and a cross-linking agent as starting materials for a binding resin, making the weight average mol.wt. of the polymer A lower than that of the polymer B and the amount of cross-linkable functional groups in the polymer A smaller than that in the polymer B, and specifying the melt index of the resulting toner after cross-linking. CONSTITUTION:In a toner for fixing with a hot roller contg. polymers A, B and a cross-linking agent as starting materials for a binding resin, the weight average mol.wt. of the polymer A is lower than that of the polymer B. The preferred weight average mol.wt. of the polymer A is 10<3>-5X10<5>, and that of the polymer B is 10<4>-10<6>. The amount of cross-linkable functional groups in the polymer A is smaller than that in the polymer B. The polymers A, B are mixed in 5/1-1/2 weight ratio of A/B. The melt index of the toner after cross-linking is 0.03-10g/10min. A polymer having desired melt viscosity can be easily prepd. by a mild reaction with the cross-linking agent, and a toner having desired fixing characteristics can be stably manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc., and particularly to a toner suitable for hot roller 2 fixed fixing. be.

Conventionally, as an electrophotographic method, U.S. Patent No. 2,297,69
Although many methods are known, as described in Japanese Patent Publication No. 1, Japanese Patent Publication No. 42-23910, and Japanese Patent Publication No. 43-24748, etc., they generally utilize photoconductive substances and perform various methods. forming an electrical latent image on the polyphotoreceptor by means;
The latent image is then developed using toner, and if necessary, the toner image is transferred to a transfer material such as paper, and then fixed by heat, pressure, solvent vapor, or the like to obtain a copy.

Various methods and devices have been developed for the above-mentioned final step, which is the step of fixing the toner image on a sheet such as paper. The most common method at present is the compression heating method using a heated roller.

The pressure-bonding heating method using a heating roller 2-4 is a heating roller 2- whose surface is made of a material that has releasability to the toner. This is to fix the problem. In this method, the surface of the heated roller and the toner image on the sheet to be fixed come into contact with each other under pressure, so the thermal efficiency when fusing the toner image onto the sheet to be fixed is extremely good, and the fixing can be carried out quickly. It is very effective in high-speed electrophotographic copying machines. However, in the above method, since the surface of the heat roller and the toner image contact each other under pressure in a molten state, a part of the toner image adheres to and transfers to the surface of the fixing roller, and this is transferred again to the next sheet to be fixed. This causes the so-called offset phenomenon,
It may stain the sheet to be fixed. One of the essential conditions for the heat roller fixing method is to prevent toner from adhering to the surface of the heat fixing roller.

As described in Japanese Patent Publication No. 51-23354, such an offset phenomenon tends to occur when a low molecular weight resin is used. Therefore, as described in the same publication, it may be possible to prevent the offset phenomenon by using a crosslinked resin, but even if the degree of crosslinking is simply increased, the fixing temperature will be high and the mother toner will In this case, the fixing temperature increases and the offset resistance deteriorates, causing many problems. The roller surface is formed of silicone rubber, fluorine resin, etc., and the roller surface is coated with a thin film of a liquid with good mold releasability, such as silicone oil, to prevent offset and fatigue of the roller surface. ing. However, although this method is extremely effective in preventing toner offset, the offset prevention liquid evaporates due to heating, giving the user an unpleasant odor, and the device for supplying the offset prevention liquid Since this method requires a fixing device, there are problems such as a complicated fixing device.

Therefore, it is not preferable to prevent off-set setting by supplying an offset-preventing liquid, and rather the development of a toner with high offset resistance over a wide fixing temperature range is currently desired. Naturally, in addition to fixing properties, toner also has anti-blocking properties, developing properties,
Although it is necessary to have excellent transfer properties, cleaning properties, etc., conventional toners have one or more of the following defects. That is, many toners that are easily melted at relatively low temperatures by heating tend to cake or aggregate during storage or in a copying machine. Many toners have poor triboelectric and rheological properties due to environmental humidity changes.

In addition, in many toners, toner particles are caused by collision of toner particles and carrier particles due to repeated development due to continuous use and contact between them and the surface of a photosensitive plate.

Mutual deterioration of the carrier particles and photosensitive plate changes the density of the resulting image or increases the background density, reducing the quality of the copies. Furthermore, with many toners, when an attempt is made to increase the density of a copied image by increasing the amount of toner adhering to the surface of a photosensitive plate having a latent image, the background density usually increases, resulting in the so-called capri phenomenon. Therefore, there is a need for a toner that has excellent toner properties and is suitable for hot roller fixing.

Therefore, it is an object of the present invention to provide a toner having excellent physical and chemical properties that overcomes the above-mentioned toner deficiencies.

An object of the present invention is to provide a toner for hot roller fixing that has good low-temperature fixability and particularly good offset resistance.

A further object of the present invention is to provide a toner for hot roller fixing that has good chargeability and always has stable chargeability during use, and provides clear and fog-free images.

Furthermore, the object of the present invention is to have excellent fluidity, not cause agglomeration,
The present invention provides a toner for heat roller fixing that also has excellent impact resistance.

A further object of the present invention is to provide a toner for hot roller fixing that has less deposits on the surface of a toner holding member or photoreceptor.

A further object of the present invention is to provide a magnetic toner which, when used as a magnetic developer, exhibits good and uniform magnetism and can be fixed by a hot roller.

The present invention is characterized in that, in a toner for hot roller fixing containing at least polymers A and B as a binder resin and a crosslinking agent as starting materials, the weight average molecular weight of the polymer is k<N. Yes, the amount of functional groups capable of crosslinking in the polymer is such that Polymer A<i Coalescence B, and the MI value of the toner after crosslinking is 0.03 to 10.
11017l0 toner for thermal roller fixing.

The amount of functional groups (crosslinkable sites) that can be crosslinked is determined by the monomer (carboxylic acid) corresponding to the crosslinkable site.

Adjust the blending ratio of amines, incyanates, etc.).

Here, the weight average molecular weights of polymers A and H are each 1
0~5X10. It is preferable that it is 10-10.

Here, the weight average molecular weight of the polymer is polymer A and polymer B.
The reason why the amount of crosslinkable functional groups in the polymer is greater than that in Polymer A than in Polymer B is as follows.

That is, by using the low molecular weight polymer At, it is possible to improve the low temperature fixing property, and by using the crosslinkable high molecular weight polymer B, it is possible to improve the offset resistance.

In the present invention, the mixing weight ratio of the polymer (4) having a weight average molecular weight of 10 to 5 x 105 and the crosslinkable polymer (B) having a weight average molecular weight of 104 to 106 is preferably A = 5/1 to 1/2. Polymer B
On the other hand, if the amount of polymer A is too large, the offset to the roller during fixing will be poor, the peelability of the transfer paper will be poor, and the cohesiveness will increase. On the other hand, if the amount is too low, the minimum fixing temperature will rise, and at the same time, the flow characteristics during heating will be poor and there will be a tendency for sufficient fixing to not be achieved.Furthermore, there will be difficulties in pulverization during toner production, resulting in a particle size suitable for use as a dry developer. This tends to make it difficult to grind effectively industrially.

The toner for thermal roller fixing according to the present invention has excellent physical and chemical properties, and by using this toner, offset occurs even if the offset prevention liquid is not fully applied to the surface of the fixing roller. Since it is possible to perform good heat roller fixing without any problems, the fixing device can be simplified and lightened.Furthermore, it has stable and excellent developing characteristics, which improves the stability and reliability of the copying machine. It is possible to improve significantly.

That is, in the toner of the present invention, the binder resin reacts with the crosslinking agent to improve mechanical properties at room temperature, improve impact resistance and toughness, and improve charging characteristics. As a result, the development characteristics are improved. Further, when the toner of the present invention is fixed with a hot roller fixing device, offset resistance at high temperatures is significantly improved. However, the fixing temperature is approximately the same as when the toner is prepared with the corresponding unreacted polymer.

The above-mentioned fixing characteristics include a toner melt index of 0.03 to 101710 m1n (particularly preferably 0.03 to 101710 m1n).
6 in the range of 1 to 6#/10m1n, ). ! = (
The test conditions were a temperature of 125°C and a load of 10 to 9. Filling amount 5~
8g).

Shows especially excellent fixing properties. The melt index here is measured by a manual cut-off method using an apparatus described in the flow test method for thermoplastic plastics JIS K7210 of the Japanese Industrial Standards.

In the present invention, the crosslinkable polymer B has a true value of 104 to 106
More preferably, the weight average molecular weight (V) number average molecular weight (Mw/Mn) is as large as 4 (preferably 1).
It is preferable to use a polymer with a desired melt viscosity (larger than 0), since by using this polymer, a polymer having a desired melt viscosity can be easily produced by reaction with a crosslinking agent by a mild reaction. , it is possible to stably produce toner having desired fixing properties.

When using a polymer with an Mw of 104 to lO' + MWA x 4, it is necessary to obtain a toner having desired fixing properties through reaction with a crosslinking agent, compared to when using a polymer with an Mwkn of 4 or more. It is necessary to set the amount of crosslinking agent and reaction conditions so that the above reaction occurs actively. Under such conditions, the reaction is stopped at just the right level within the range that exhibits offset resistance. This is extremely difficult, making it impossible to stably produce toner with desired fixing characteristics with good reproducibility.

On the other hand, if a polymer with a weight of 104 to 106 and a weight of 4 is used, in order to give the toner offset resistance, the polymer must be lightly reacted with a crosslinking agent to crosslink it. The reaction can be carried out under mild conditions, the reaction can be easily controlled, and toner with excellent fixing properties can be stably produced.Furthermore, if the above polymer is lightly crosslinked by reaction with a crosslinking agent, Since the molecular weight distribution is slightly wider, it is possible to provide the toner with anti-offset properties while keeping the minimum fixing temperature low.

Polymers with a molecular weight of 10 to 10 and Mw/Mn) 4 can be synthesized using well-known polymerization methods such as solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization. A method in which resins with different numerical values are dissolved or mixed in a molten state, a method in which the reaction temperature is changed during the polymerization reaction, a method in which initiators, chain transfer agents, etc. are mixed, and a method in which resins are produced from monomers. There are methods to increase Mw/Mn and Mw by applying a certain degree of crosslinking when forming a polymer, but among these manufacturing methods, there is a method that suppresses the degree of crosslinking within a low range and increases MWA/In. The method of adjustment is the most suitable method for the present invention, and is achieved by adding a small amount of a polyfunctional compound to the polymerization reaction system.

On the other hand, a solution polymerization method is suitable as a process for synthesizing a polymer for a binder. This is because in emulsion polymerization and suspension polymerization, monomers are emulsified or dispersed using additives such as surfactants and dispersion stabilizers in water, which is a continuous phase, and then polymerized by adding salts, etc. The resulting polymer contains the hydrophilic additives mentioned above.

When such a hydrophilic additive is present in a toner, the toner absorbs moisture under high humidity conditions, resulting in a decrease in specific resistance, which often adversely affects the electrical properties of the toner. Furthermore, in the bulk polymerization method, problems such as dull effect occur when the degree of polymerization increases, making it extremely difficult to control the polymerization reaction.

On the other hand, in the solution polymerization method, the polymerization reaction is generally carried out in a hydrophobic organic solvent, so a hydrophilic additive is not required, and the presence of the solvent makes it relatively easy to control the polymerization reaction. However, the solution polymerization method has the problem that when the degree of crosslinking is increased, glue is produced that is insoluble in the solvent, making it difficult to control the polymerization reaction and to recover the polymer after polymerization. Therefore, a polymer with a degree of crosslinking within a range that does not cause the above-mentioned problems is synthesized by solution polymerization, and further, according to the present invention, a polymer with a slight degree of crosslinking made by the solution polymerization method and a degradable polymer are synthesized. By reacting with a metal compound during the manufacturing process and increasing the degree of crosslinking to the extent that it provides a melt viscosity suitable for the fixing characteristics of the toner, it is possible to easily produce polymers made by solution polymerization that have the above-mentioned excellent properties. It becomes possible to apply it to toner for heat roller fixing.

In the present invention, the MWAAllO value was calculated from the value measured by Dull Permation Chromatography. The measurement conditions were as follows: Tetrahydrofuran was used as the solvent at a flow rate of 1 mA' per minute at a temperature of 25°C, and the sample concentration was 8TV1.
Inject 0.5M of a sample solution of nl of tetrahydrofuran for measurement. In addition, as a column, 103~2X10
In order to accurately measure the molecular weight range of
μm Styragel 500,1 manufactured by Watera
0. 10. 10 combinations and 5bod manufactured by Showa Denko
A good combination is exA-802, 803, 804, and 805. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithm value and the count number of a calibration curve prepared using several types of monodisperse polystyrene standard samples. As a standard polystyrene sample for creating a calibration curve,
For example, Pre, 5sure Chemical Co.
, or manufactured by Toryo Soda Kogyo Co., Ltd. with a molecular weight of 6X102.
2. I Xi O', 4X10511.75X10
', 5.1X10', 1. lX105, 3.9X105
It is appropriate to use at least 10 standard polystyrene samples of 8.6 x 105, 2 x 10', and 4.48 x 106. Further, an RI (refractive index) detector is used as a detector.

Furthermore, among polymers crosslinked by reaction with a crosslinking agent, those with a glass transition temperature of 50°C or higher do not cause problems such as toner aggregation or adhesion to the photoreceptor surface in the developing device. Therefore, those having a glass transition temperature of 50°C to 80°C are particularly preferred. Note that the glass transition temperature of the polymer can be measured using a differential scanning calorimeter.

Polymers that react with the crosslinking agent of the present invention include general dicarboxylic groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, carboxyl groups, aqueous form, a type of type of type of type, type-carboxy type, type-carboxy type, type-like type type, type-like type type type. Nyl group, ether group.

There are thioether groups, amine groups, amide groups, etc. Among these, cal? One complex containing a xyl group shows the best reactivity. Cal for vinyl polymer synthesis? Examples of xyl group-containing monomers include acrylic acid and its α- or β-alkyl derivatives such as acrylic acid, methacrylic acid, α-ethyl acrylic acid, and crotonic acid, and unsaturated dicardines such as fumaric acid, maleic acid, and citraconic acid. Examples include acids and monoester derivatives thereof, and desired polymers can be produced by copolymerizing these monomers alone or in combination with other monomers.

As for the proportion of the Cal I xyl group-containing monomer contained in the polymer, 0.1 to 30% by weight gives good results;
．． Particularly favorable results are obtained when the amount is in the range of 5 to 20% by weight. Examples of monomers copolymerizable with the above-mentioned carboxyl group-containing monomers include styrene, α
- Methylstyrene + P-chlorostyrene vinylnaphthalene.

Methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate.

Ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile,
Substituted monocarbic acids with double bonds such as acrylamide; radicals with double bonds such as diptyl maleate, dimethyl maleate, etc. vinyl esters such as vinyl chloride, vinyl acetate, vinyl benzoate, etc.; ethylene olefins such as ethylene, propylene, butylene, etc.; vinyl methyl ketone, vinyl hexyl ketone, etc. Examples L Id, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, etc.; aromatic divinyl compounds such as vinylbenzene, divinylnaphthalene, etc.; e.g. ethylene glycol diacrylate , ethylene glycol dimethacrylate.

1. Carboxylic acid esters having two double bonds, such as 3-butanediol dimethacrylate.

Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone and 3
Compounds having two or more vinyl groups can be used alone or as a mixture.

As mentioned above, the glass transition point of the crosslinked polymer is 50°C.
In order to be above, the glass transition point of the unreacted polymer must be 4.
Preferably, the temperature is 0°C or higher.

The crosslinking agent used in the present invention is a di- or polymethylol derivative of a low molecular weight phenolic resin.

Examples include amino resins prepared by addition and condensation of formaldehyde to amine compounds such as melamine, benzoguanamine, and urea, as well as metal compounds. Metal compounds, particularly decomposable metal compounds, are preferred from the standpoint of controlling the polymerization reaction.

As the decomposable metal compound used in the present invention, those containing the following metal ions can be used.
There are metal ions with higher valences. Appropriate 1
Valent metal ions include Na, Li +Os”, Ag
+, Hg+, Cu+, etc., suitable divalent metal ions include Be, Mg", Ca", Hg,
5rPb"Fe"Co, Nl, Zn, etc.

In addition, suitable trivalent metal ions include At”, 8Q
.

Ft5+, Co3+, Ni”, Cr5+
, Y5+.

Among the metal ion compounds mentioned above, the more decomposable the compound, the better the results. This is presumably because the metal ion in the compound is more easily bonded to the carxyl group in the polymer when the compound is degradable. This decomposable metal compound has a temperature range of 100°C or higher (particularly preferably 100°C or higher).
It is preferable to have a decomposition temperature between 00°C and 400°C.

In the present invention, a metal compound having a decomposition temperature as described above is reacted at a temperature below the decomposition temperature.

If the reaction occurs above the decomposition temperature, the metal compound will rapidly decompose and react violently with the carboxylic group-containing polymer, making it difficult to control the reaction, and the degree of crosslinking formed by the reaction will be too severe, resulting in lower fixing temperatures. This is not desirable as it causes an increase in the temperature. However, when a metal compound and a polymer are reacted at a temperature below the decomposition temperature, a portion of the metal compound gradually decomposes, so the reaction proceeds slowly and the reaction can be easily controlled.
Toner having desired fixing performance can be stably produced.

Even among degradable metal compounds, organometallic compounds have excellent compatibility and dispersibility with polymers, and crosslinking by metal ions proceeds more uniformly within the polymer, giving better results. Furthermore, among the decomposable organometallic compounds mentioned above, those containing organic compounds with high vaporizability and sublimation properties as ligands and counterions are particularly useful. Examples of organic compounds that have the above-mentioned properties include salicylic acid, salicylamide, salicylamine, salicylaldehyde, salicyrosalicylic acid, ditertiarybutylsalicylic acid, and its fatty derivatives; β-diketones such as acetylacetone and propionacetone;
and so on.

In the present invention, since the temperature at which the monomer reacts with the decomposable metal compound is lower than the decomposition temperature of the decomposable metal compound (preferably 50°C or higher), most of the decomposable metal compound is Does not react with polymers. Therefore, the amount of the decomposable metal compound contained in the toner of the present invention may be necessary in excess, and although it varies depending on the type of compound, in general, it includes the unreacted metal compound. It is preferably contained in an amount of 0.01 to 20 parts by weight per 100 parts by weight of the polymer, and particularly excellent results are obtained when 0.1 to 10 parts by weight are used.

The reaction between the vinyl polymer and the metal compound in the present invention can be carried out by kneading the above-mentioned metal compound with the reactive polymer in a roll mill, or by mixing the reactive polymer in a hot xylene solution. There is a method in which a metal compound is added to and reacted with. Taking into account post-treatment steps after the reaction, the reaction by melt mixing method is most suitable for the present invention. The reaction may first produce a polymer reactant to form a binder, and then the toner may be produced together with other toner materials, or the reaction itself may be carried out during heating and mixing of the toner materials during the toner manufacturing process. Also good.

Further, the toner of the present invention has the above-mentioned polymer as a main resin component, but other polymers and resins can be mixed and used as necessary. Other resins that can be used in combination include vinyl polymers consisting of folded monomers containing caloxy groups as monomer components, and resins that do not contain vinyl monomers as monomer components, such as polystyrene and polyP-chloro. Monomer polymers of styrene and its substituted products such as styrene and polyvinyltoluene; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene/vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylate ester copolymer, styrene-α-methyl chloromethacrylate copolymer, styrene-
Acrylonitrile co-M combination, styrene-vinyl methyl ether copolymer, sf-rene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer.

Styrenic copolymers such as styrene-butadiene copolymer, styrene-isoprene copolymer, and styrene-acrylonitrile-indene copolymer; polyethylene, polypropylene, polyvinyl chloride.

Phenolic resin, natural resin modified phenolic resin.

Natural resin modified maleic acid resin, acrylic ester resin, meccrylic ester resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin,
Polyvinyl butyral.

Terpene resins, chloroindene resins, 25 oil-based resins, etc. can be used.

In particular, the melt viscosity at 140°C is 10 to 1106 cp.
The amount of ethylene olefin monopolymer or ethylene olefin copolymer in the toner is 0.1 to . 10% by weight (
By adding (preferably 0.2 to 5% by weight), the dispersibility and compatibility of pigments and magnetic particles with toner are improved, and the surface of the photoreceptor is improved.

There is less negative impact on cleaning members, etc.

Examples of the ethylene-based olefin monopolymer or ethylene-based olefin copolymer used here include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, etc. In the above copolymer, the olefin monomer is 500 mol % and 10 mol %.
(more preferably 600 mol/10 mol %) is preferred.

The Brookfleld method was used to measure the melt viscosity, and here a B-type viscometer equipped with a small sample adapter was used.

Any suitable pigment or dye can be used as a colorant in the toner of the present invention. For example, force-den black,
There are known dyes and pigments such as iron black, phthalocyanine blue, ultramarine blue, quinacridone, and benzidine yellow.

Furthermore, when the toner of the present invention is a magnetic toner, it may also serve as a coloring agent, but ferromagnetic elements and alloys and compounds containing them such as iron, cobalt, nickel, etc., such as magnetite, hematite, and ferrite, Magnetic powders conventionally known as magnetic materials, such as alloys and compounds of manganese, and other ferromagnetic alloys, may be included. Black, nigrosine, metal complex salts, colloidal silica powder, fluororesin powder, etc. may be added.

The toner of the present invention can be applied to various developing methods.

For example, a magnetic brush development method, a cascade development method, a method using a conductive magnetic toner described in U.S. Pat. , methods described in JP-A-54-42141 and JP-A-55-18656, a fur brush development method, a Yauder cloud method, an impression method, and the like.

The toner image formed on a fixing sheet such as paper using the toner according to the present invention does not cause the toner offset phenomenon even when a fixing roller that does not supply offset prevention liquid to the surface of the toner image is used. Fixing can be done with a heated roller. The surface of the fixing roller can be coated with, for example, Teflon (manufactured by DuPont), Fluon (IC), etc.
A material having a smooth surface made of fluororesin, silicone rubber, or silicone resin such as KEL-F (manufactured by 3M Company) or a material having a metal surface may be used.

An example of producing a vinyl polymer B having reactivity with decomposable metal compounds is shown below.

■ Put 4-0 parts by weight of toluene into a Mitsuro flask, and then add 75 parts by weight of styrene, 20 parts by weight of butyl acrylate, 5 parts by weight of maleic acid (monomer corresponding to crosslinking properties after polymerization), and 0.5 parts by weight of divinylbenzene. After replacing the gas phase with nitrogen gas, the mixture was kept at 80°C, and a solution of 0.3 parts by weight of benzoyl peroxide dissolved in 10 parts by weight of toluene was replaced with nitrogen gas for 30 minutes using a dropping funnel. The mixture was added dropwise and further stirred at 80°C for 8 hours. Next, 5 parts by weight of a toluene solution containing 0.3 parts by weight of benzoyl peroxide was added dropwise, the temperature was further raised to 90°C, and the temperature was maintained for 3 hours to complete the polymerization. After cooling, the polymer was precipitated in a large amount of methanol, and the precipitate was dried at 60° C. and collected. The Mw/Mn of this polymer is 22, the islands are 158,
It was 000.

■ Example I except that 70 parts by weight of styrene, 20 parts by weight of methyl methacrylate, 10 parts by weight of methacrylic acid (monomer corresponding to crosslinking sites after polymerization), and 0.6 parts by weight of divinylbenzene were used as monomers. I did the same. The channel 7Mn of this polymer is 18, and the MW is 112,0
It was 00.

■ Example 1 except that 70 parts by weight of styrene, 10 parts by weight of butyl methacrylate, 20 parts by weight of monobutyl maleate (a monomer corresponding to crosslinkable sites after polymerization) and 0.5 parts by weight of divinylbenzene were used as monomers. I did the same thing. This polymer (D Mw/Mn is 15 and Mw
was 84,000.

1 day ■ The same procedure as in Example 1 was carried out except that the monomers were 75 parts by weight of styrene, 25 parts by weight of butyl methacrylate, and 0.3 parts of methacrylic acid, a monomer corresponding to the crosslinking site after polymerization. Ta.

The MWAn of this polymer is 3.5 Te, and the Mw is 32,000.
Styrene-butyl acrylate copolymer with a weight average molecular weight of 20,000 (copolymerization ratio 70:30, does not have a functional group capable of crosslinking) 60 parts and polymer 4 synthesized in Example 2
0 parts by weight, 5 parts by weight of zinc complex salt of di-tertiary-glylsalicylic acid as a metal compound, magnetic powder (average particle size 0.
2 parts by weight of polyethylene having a melt viscosity of 4300 CPS at 140° C. was kneaded for 30 minutes at a temperature of 150° C. using a roll mill.

After cooling, the mixture was finely pulverized using an air jet type pulverizer, and then particles of 5 to 20 μm were sorted using an air classifier to obtain toner.

The MI value at this time was 1.441710 m1n.

0.5 parts by weight of hydrophobic colloidal silica was externally added to 100 parts by weight of this toner to prepare a developer.

The above developer was applied to a commercially available copying machine NP-400RE (manufactured by Canon). The fixing temperature of the above developer is 140°C, and the offset phenomenon occurs from the fixing temperature of 140°C to 210°C.
It was not recognized until then.

Furthermore, the temperature of the fixing roller was set to 160°C and the
A durability test of 10,000 sheets was conducted, and good images with high image density and no capri were obtained, even when toner was replenished. Also, even after 50,000 copies, there was no offset phenomenon to the fixing roller, and the surface of the photoreceptor drum.

There were no problems such as scratches on the cleaning blade, developing sleeve, etc., toner fusion, or aggregation within the developing device.

Comparative Example 1 The same procedure as in Example 1 was carried out except that no metal compound was used, and the MI value of the toner was 12.4! i
It was 710m1n. The fixing temperature was 140°C, which was the same as that of the developer in Example 1, but as the temperature increased, the offset phenomenon became more severe.At 9.180°C, clear image marks were observed on the surface of the fixing row 2. Became.

Furthermore, when continuous copying was carried out in the same manner as in Example 1, traces of retransfer of the offset material began to appear on the images after about 1000 copies, and the copying was discontinued after 2000 copies.

Comparative Example 2 The same procedure as in Example 1 was carried out except that 100 parts by weight of the polymer synthesized in Example 1 was used as the resin, and the MI value of the toner was 0.029/10 min. Although the image was good, the minimum fixing temperature was as high as 170° C., and the fixing performance was insufficient, making it unsatisfactory in practical terms.

Example 2 65 parts by weight of a styrene-methyl methacrylate copolymer having a weight average molecular weight of 35.00.0 (copolymerization ratio 72:25, having no functional group capable of crosslinking) and 35 parts by weight of the polymer synthesized in Example 2 A developer was prepared in the same manner as in Example 1 except that iron acetylacetonate (1) was used as the metal compound. The MI value of toner is 2.11710 mi
〇The above developer was evaluated in the same manner as in Example 1, and the result was 14.
(Fixed at 0°C, off-sera even at 140°C to 200°C or higher)
1 did not occur. It also had excellent durability.

Example 3 Styrene-butyl methacrylate copolymer with a weight average molecular weight of 50,000 (no functional group capable of crosslinking) 7
A developer was prepared in the same manner as in Example 1, except that 5 parts by weight, 35 parts by weight of the polymer synthesized in Example 3, and 2 parts by weight of chromium salt of salicylic acid were used as the metal compound. The MI value of the toner was 2.11 I/10 m1n.

The above developer was evaluated in the same manner as in Example 1 and was found to be 15
It was fixed at 0°C, and no offset occurred even at temperatures above 150°C to 210°C. It also had excellent durability.

Example 4 A developer was prepared in the same manner as in Example 1, except that 70 parts by weight of the polymer synthesized in Production Example 4 and 30 parts by weight of the polymer synthesized in Production Example 1 were used. The MI value of the toner was 4.4.

When the above toner was evaluated in the same manner as in Example 1, the same results as in Example 1 were obtained.

Claims (1)

[Claims] In a hot roller fixing toner containing at least polymers A and B as binder resins and a crosslinking agent as starting materials, the weight average molecular weight of the polymers is polymer A < polymer B
Yes, the amount of crosslinkable functional groups in the polymer is Polymer A and Polymer B, and the M of the toner after crosslinking is
A toner for thermal roller fixing, having an I value of 0.03 to 1091097l0.