JPH03197968A - Dry thermal roller fixing toner - Google Patents

Abstract

PURPOSE:To prevent hot offsetting without deteriorating flowability, aggregation property, spendability to a carrier, etc., and to improve thermal fixability by heating particles consisting of a binding resin and polypropylene having low mol. wt. and depositing the polypropylene near the surfaces of the particles. CONSTITUTION:Particles contg. polypropylene having low mol. wt. in a binding resin are heated and/or exposed to frictional heat and the polypropylene are deposited near the surfaces of the particles. Since the polypropylene are allowed to bleed out near the surfaces of the particles, the amt. of the polypropylene added to prevent hot offsetting can be reduced and the polypropylene does not bleed out again by heat generated by agitation and collision in a developing tank. Hot offsetting is prevented without deteriorating flowability, aggregation property, spendability to a carrier, etc., and thermal fixability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a dry method used for visualizing an electrostatic latent image formed by an electrophotography method, an electrostatic recording method, an electrostatic printing method, or the like. The present invention relates to a developer, and more particularly to a dry heat roller toner.

[Prior Art] Conventionally, as an electrophotographic method, US Pat.
Various methods are described in Japanese Patent Publication No. 43-24748, etc., but generally a photoconductive substance is used and an electrical latent image is formed on the photoconductive substance by various means. Then, the latent image is developed using toner, and if necessary, the toner image is transferred to paper or the like, and then fixed by heating, pressure, solvent, steam, etc. to obtain a copy.

Methods for thermally fixing toner images developed from electrical latent images include oven fixing, flash fixing, and hot roller fixing. Since thermal efficiency is high due to pressure contact with the image surface of the notice sheet, it is extremely advantageous for high-speed copying and is widely used.

However, this method has the disadvantage that because the toner contacts the roller in a molten state, the toner adheres to the roller surface, and a hot offset phenomenon in which the adhered toner adheres to the fixing sheet due to the rotation of the roller is likely to occur. are doing.

As a method for solving this problem, a method has been proposed in which low molecular weight polypropylene is added to the toner (see Japanese Patent Application Laid-Open No. 4905231).

However, toners containing low-molecular-weight polypropylene have disadvantages in that their fluidity and cohesiveness are significantly reduced and that they tend to cause the so-called spent phenomenon in which the toner is active on the surface of the carrier.

One way to improve the fluidity and cohesiveness of toner is to add fluidity improvers such as silica and titanium oxide, but these fluidity improvers reduce the amount of charge on the toner in high humidity conditions. This results in background smearing and excessive image density at high humidity, which significantly deteriorates the quality of copied images.

In addition, as a method of preventing toner from becoming spent, there is a method of coating the surface of a charge imparting member such as a carrier with a low surface energy substance. Examples of low surface energy substances include tetrafluoroethylene compounds, silicone resins, polymethyl Although methacrylate polymers and the like have been used conventionally, they are still insufficient for forming spent toners containing low molecular weight polypropylene.

[Problems to be Solved by the Invention] The present invention aims to solve the above-mentioned conventional drawbacks, and particularly improves toner quality such as fluidity, cohesiveness, and spendability with respect to carrier. To provide a dry heat roller constant wear toner that prevents hot offset and improves heat fixability without inhibiting the toner.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors have repeatedly conducted research and found that by heating particles containing at least a binder resin and low molecular weight polypropylene, It was discovered that it is effective to precipitate low molecular weight polypropylene on the particle surface, leading to the present invention.

That is, the present invention provides (1) that low molecular weight polypropylene is precipitated near the particle surface by applying heating, frictional heat, or both heat simultaneously to particles consisting of at least a binder resin and low molecular weight polypropylene; Characteristic toner for dry heat roller fixing (2) In the method for producing a toner for heat roller fixation, at least a binder resin and low molecular weight polypropylene are mixed, and then the resulting particles are subjected to heat, frictional heat, or both. A method for producing a toner for dry heat roller fixing, characterized in that the toner is added at the same time, (3) particles comprising a mixture of particles consisting of at least a binder resin and low molecular weight polypropylene, and a hard inorganic fine powder having a smaller particle size than the particles; A toner for dry heat roller fixing, characterized in that low molecular weight polypropylene is precipitated near the surface of the particles by applying heat, frictional heat, or both heat simultaneously, and hard inorganic fine powder is further solidified on the surface. 4) In the method for producing a toner for hot roller fixing, at least a binder resin and low molecular weight polypropylene are mixed, then the obtained particles are mixed with a hard inorganic fine powder having a smaller particle size than the particles, and then the A method for producing a toner for dry heat roller fixing, characterized by applying heat, frictional heat, or both heat to mixed particles simultaneously; (5) at least a binder resin;
By applying heating, frictional heat, or both heat simultaneously to particles made of a mixture of particles made of low molecular weight polypropylene and hard inorganic fine powder having a smaller particle size than the particles, low molecular weight polypropylene is precipitated near the particle surface. , a toner for dry heat roller fixing characterized in that particles formed by fixing hard inorganic fine powder on the surface and hard inorganic fine powder having the same composition as the fixed hard inorganic fine powder, and (6) ) A method for producing a toner for hot roller fixing, in which at least a binder resin and a low molecular weight polypropylene are mixed, then the obtained particles are mixed with a hard inorganic fine powder having a smaller particle size than the particles, and further the mixing is performed. heating into particles,
Dry heating characterized by mixing hard inorganic fine powder having the same composition as the inorganic fine powder into particles formed by adhering the inorganic fine powder to the surface obtained by applying frictional heat or both types of heat at the same time. This is a method for producing toner for roller fixing.

The toner of the present invention precipitates (bleeds out) the low molecular weight polypropylene near the particle surface by applying heat to the particles containing low molecular weight polypropylene in the binder resin, so the amount of polypropylene that is normally added is lower than the amount of polypropylene normally added to prevent hot offset. It is possible to minimize side effects such as deterioration of fluidity and cohesiveness caused by the addition of low molecular weight polypropylene.

Furthermore, since the polypropylene has already bled out once, it will not bleed out again due to heat generated by stirring or collision within the developing device, so polypropylene will not increase the amount spent. Moreover, since the toner particles are sphericalized by the heat treatment, the fluidity and cohesiveness are further improved.

Furthermore, adhesion of particles to each other due to surface melting during production is significantly improved by mixing hard inorganic fine powder. The range of suitable manufacturing conditions when hard inorganic fine powder was not included was quite narrow, but by mixing hard inorganic fine powder, the range of suitable manufacturing conditions became considerably wider, and the fluidity and cohesiveness of the toner were further improved. It was done.

Further, the charging characteristics of the toner can be improved by adding hard inorganic fine powder having the same composition as the fixed hard inorganic fine powder, which is another aspect of the present invention. That is, since the surface of the carrier and the surface of the toner are coated with a substance having the same composition, the chargeability does not change. The hard inorganic fine powder that adheres to the toner surface and the hard inorganic fine powder that is added later need only have the same main component composition, and may have different shapes, particle sizes, etc.

Examples of the binder resin used in the present invention include polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, and styrene-butadiene copolymer. Hinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene) -butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylate ester copolymer (styrene-methyl methacrylate copolymer, styrene-methacrylate copolymer, etc.) Styrenic compounds such as ethyl copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer), styrene-α-methyl chloroacrylate copolymer, and styrene-acrylonitrile-acrylic acid ester copolymer Resin (monoweight or copolymer containing styrene or styrene substitutes), vinyl chloride resin, styrene-vinyl acetate copolymer, rosin-modified maleic acid resin, phenolic resin, epoxy resin, polyester resin, low molecular weight polyethylene, low Molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, etc., but these resins are not limited to single use, but two or more types can be used in combination. You can also do it.

Moreover, these manufacturing methods are not particularly limited, and any of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization can be used.

The molecular weight of the low molecular weight polypropylene used in the present invention is a number average molecular weight of 20,000 or less, preferably 1.500.
~10,000 are used.

The amount of low molecular weight polypropylene added to the binder resin is 1
~50 parts by weight, preferably 3 to 15 parts by weight.

Various colorants can be used in the toner of the present invention as required. Specifically, carbon black, nigrosine dye, aniline blue ultramarine blue, phthalocyanine blue chrome yellow, malachite green,
Rose Bengal etc. can be used alone or in combination. The amount of the coloring agent added is 1 to 30 parts by weight, preferably 5 to 15 parts by weight, per 100 parts by weight of the resin component.

Further, magnetic substances such as triiron tetroxide and ferrite powder can also be added. The toner base of the present invention can be obtained by a known method, for example, by thoroughly mixing a binder resin, low molecular weight polypropylene, a coloring agent, etc., and then kneading with a pressurized kneader, heated twin rolls, or the like. Thereafter, the particles are cooled, solidified, pulverized, and classified to produce the base particles of the toner used in the present invention. The toner of the present invention can be obtained by bleeding out the low molecular weight polypropylene by placing the base particles in a closed container and subjecting them to frictional heat or heating by high-speed rotation, or by instantaneously contacting them with a high-temperature air stream.

In another aspect of the present invention, in order to prevent adhesion between particles due to surface melting of the particles when the toner is heated, a hard inorganic fine powder is further used for the above base particles,
The fine powder can be fixed to the particle surface.

As such hard inorganic fine powder, known materials that have been widely used can be used.

Examples include silicon oxide, titanium oxide, silicon carbide, barium titanate, aluminum oxide, and silicon nitride.

The amount of the hard inorganic fine powder added to the base particles is 0.1 to 10.0 parts by weight, preferably 0.3 to 3.0 parts by weight, based on 100 parts by weight of the base particles.

In addition, the above-mentioned adhesion mentioned in the present invention refers to a state in which small particle size particles (hard inorganic fine powder) adhere to large particle size particles (base particles) with a certain degree of strong physical force. It does not matter whether the particles are buried in large particles or not.

Further, in the present invention, 0.1 to 5.0 parts by weight of hard inorganic fine powder having the same composition as the above-mentioned hard inorganic fine powder is further added to 100 parts by weight of the base particles. This embodiment also includes toners such as: In this case, among other aspects of the present invention, the amount of charge can be particularly stabilized.

Example 1 Polystyrene (D-125: Esso Petrochemical) 90.
0 parts by weight polypropylene (number average molecule, i 3,500) 3.0
A matrix toner having a volume average particle diameter of 10 μm was obtained by mixing with a formulation of 7.0 parts by weight or more of carbon black ($44, manufactured by Mitsubishi Kasei) using two heated rollers.

200 g of this base toner is placed in a sealed container with a diameter of 50 cm and a rotating blade installed inside. The number of rotations of the rotating blade is 5.
00 Or, p, 1 m, the temperature of the container was kept at 40'C, and after operating for 5 minutes, the toner of the present invention was obtained.

Comparative Example 1 For comparison, the base toner prepared in Example 1 was used as a comparative example.

An unfixed image was created using the above toner using a PT4420 (copying machine manufactured by Ricoh). Note that the toner adhesion amount at this time is 1. It was controlled to be Omg/cn2.

The hot offset performance of the unfixed image was evaluated using the apparatus shown in FIG.

Gradually increase the temperature of the Teflon roller and find the temperature at which hot offset occurs (the higher the temperature at which hot offset occurs, the better).

In addition, in order to examine fluidity and cohesiveness, a powder tester (manufactured by Koyo Micron) was used to measure the fluidity index (angle of repose, degree of compaction,
Spatula angle, degree of agglomeration) were determined. Note that the larger the fluidity index, the better the fluidity and cohesiveness.

From the results in the table, the toner of Example 1 has hot offset properties.
It is great that it has excellent liquidity.

Next, 97.0 parts by weight of a spherical iron oxide carrier having an average particle size of 100 μm and 3.0 parts by weight of the toner were placed in a 100 ml stainless steel pot, and the mixture was continuously stirred for 24 hours to conduct a spent property test.

The spent amount is determined by blowing off the developer (a mixture of toner and carrier) after stirring for 24 hours, expelling the adhering toner by electrostatic force, and measuring the weight (Wl). Next, dissolve the fused material in toluene and measure the weight (w
2).

Calculate the spent amount using the following formula.

From the above results, it can be seen that the toner of Example 1 has excellent spent properties.

Example 2 Styrene-n-butyl methacrylate copolymer 82.0 parts by weight Polypropylene (number average molecular weight 12,000) 7.0 parts by weight Metal complex dye 1.0 parts by weight Carbon black (#44) 10.0 parts by weight A base toner having a volume average particle diameter of 10 μm was obtained in the same manner as in Example 1 using a formulation of 10 parts or more.

200 g of this base toner was heat-treated in the same manner as in Example 1. However, the rotation speed of the rotating blade is 5500r,
p, m, and the temperature of the container were set at 50° C. to obtain the toner of the present invention.

Comparative Example 2 For comparison, the base toner prepared in Example 2 was used as a comparative example.

Using the above toner, the hot offset generation temperature, fluidity index, and spent amount were determined in the same manner as in Example 1.

From the results in the table, the toner of Example 2 has hot offset properties.
It can be seen that it has excellent fluidity and spent properties.

Example 3 Unsaturated polyester 90.0 parts by weight Polypropylene (number average molecular weight 5,300) 5.0 parts by weight Lionol Blue PG-7351 (manufactured by Toyo Ink)5.
A base toner having a volume average particle diameter of 10 μm was obtained in the same manner as in Example 1 using a formulation of 0 parts by weight or more.

200 g of this base toner was heat-treated in the same manner as in Example 1. However, the rotation speed of the rotating blade is 400Or,
p, m, and the temperature of the container were set at 35° C. to obtain the toner of the present invention.

Comparative Example 3 For comparison, the base toner prepared in Example 3 was used as a comparative example.

Using the above toner, the results of the hot offset generation temperature, fluidity index, and spent melon table as in Example 1 show that the toner of Example 3 is superior in hot offset properties, fluidity, and spent properties. .

Example 4 Styrene-n-butyl methacrylate copolymer 50.0 parts by weight Polypropylene (number average molecular weight 3,500) 5.0 parts by weight Magnetic powder (EPT-1000: manufactured by Toda Kogyo) 40.0 parts by weight Nigrosine dye 3 0 parts by weight of carbon black (#44) 2.0 parts by weight or more was mixed using two heated rollers to obtain a base toner having a volume average particle diameter of 13 μm.

300 g of this base toner was heat-treated in the same manner as in Example 1. However, the rotation speed of the rotating blade is 6500r,
The temperature of the Lrl-1 container was set at 45° C. to obtain the toner of the present invention.

Comparative Example 4 For comparison, the base toner prepared in Example 4 was used as a comparative example.

An unfixed image was created using the above toner using a TO20 (copying machine manufactured by Ricoh). Note that the toner adhesion amount at this time is 1.
It was controlled to be 7B/cm2.

Using the above toner, the hot offset generation temperature, fluidity index, and amount of spent were determined in the same manner as in Example 1. From the results shown in the table, it can be seen that the toner of Example 4 has excellent hot offset properties and fluidity.

Example 5 Polystyrene (D-125: Esso Petrochemical) 90.
0 parts by weight polypropylene (number average molecular Ja3.500) 3.0 parts by weight carbon black (#44: manufactured by Mitsubishi Kasei) 7.0 parts by weight or more was cross-wired using two heated rollers to obtain a volume average particle diameter Iθμ The parent toner was obtained.

200 g of this base toner and 2.0 g of silicon oxide (R972, manufactured by Nippon Aerosil Co., Ltd.) were mixed in a mixer and placed in a sealed container having a diameter of 50 cm + 5 and equipped with a rotating blade inside. The rotation speed of the rotating blade is 5.500r,
After operating for 5 minutes while keeping the temperature of the container at 45° C., the toner of the present invention was obtained.

Example 6 and Comparative Example 5.6 In order to explain the effect of fixing the hard inorganic fine powder shown in Example 5 above, Example 6 is shown below in comparison with Example 5 above.
and Comparative Example 5.6. That is, the base toner prepared in Example 5 (Comparative Example 5), the base toner and silicon oxide simply mixed in a mixer (Comparative Example 6), and the one heat-treated without adding silicon oxide (Example 6) was evaluated using the method described below.

That is, an unfixed image was created using the above toner using an FT-4420 (copying machine manufactured by Ricoh). Note that the toner adhesion amount at this time is 1. Omg/c++”.

The hot offset performance of the five undetermined images was evaluated using the apparatus shown in FIG.

Gradually increase the temperature of the Teflon roller and find the temperature at which hot offset occurs (the higher the temperature at which hot offset occurs, the better).

In addition, in order to examine fluidity and cohesiveness, a powder tester (manufactured by Koyo Micron) was used to measure the fluidity index (angle of repose, degree of compaction,
The spatula angle and degree of cohesion were measured. Note that the larger the fluidity index, the better the fluidity and cohesiveness.

Melt the melt and measure the weight (w2).

Calculate the spent amount using the following formula.

Spent m (wt%) -”-W2x1001 From the results in the table, the toner of Example 5 has hot offset properties,
It can be seen that both fluidity is excellent.

Next, 97.0 parts by weight of a spherical iron oxide carrier having an average particle diameter of 100 μm and 3.0 parts by weight of the above toner were placed in a 100 ml stainless steel pot and continuously stirred for 24 hours to evaluate spent properties.

The spent amount is determined by blowing off the developer (a mixture of toner and carrier) after stirring for 24 hours, expelling the adhering toner by electrostatic force, and measuring the weight (Wl). Next, the toner of Example 5 was poured into toluene, and from the results shown in the table, it can be seen that the toner of Example 5 was excellent in terms of spent properties.

Example 7 Styrene-n-butyl methacrylate copolymer 82.0 parts by weight Polypropylene (number average molecular weight 12,000) 7.0 parts by weight Metal complex dye 1.0 parts by weight Carbon black (#44) 10.0 parts by weight A base toner having a volume average particle diameter of lOμ was obtained in the same manner as in Example 5 using the above recipe.

A mixture of 200 g of this base toner and 2.4 g of titanium oxide (P-25, manufactured by Nippon Aerosil Co., Ltd.) using a mixer was heat-treated in the same manner as in Example 1. However, the rotation speed of the rotating blade is 8000r.

p, m, and the temperature of the container were set at 55° C. to obtain the toner of the present invention.

Example 8 and Comparative Example 7.8 In order to explain the effect of the hard inorganic fine powder adhering to the toner particle surface, Example 8 and Comparative Example 7.8 are listed below in comparison with Example 6 above.

That is, the base toner prepared in Example 7 (Comparative Example 7),
Similar to Example 5, hot offset generation temperature, fluidity index, The amount of spent was determined.

It can be seen that it is particularly excellent in setting properties, fluidity, and spending properties.

Example 9 Unsaturated polyester 90.0 parts polypropylene (number average molecule H5,300) 5.0 parts by weight Lionol Blue 1'G-7351 (manufactured by Toyo Ink) Example with a formulation of 5.0 parts by weight or more A base toner having a volume average particle diameter of lOμ was obtained in the same manner as in Example 5.

A mixture of 200 g of this base toner and 3.0 g of aluminum oxide (Mechanox UB-10 manufactured by Uezai Kogyo Co., Ltd.) using a mixer was heat-treated in the same manner as in Example 1. However, the number of rotations of the rotating blade was 450Or, p, +n
The temperature of the container was set at 40° C. to obtain the toner of the present invention.

Example 10 and Comparative Example 9.10 In order to explain the effect of hard inorganic fine powder adhering to the toner particle surface, the results of Example 10 and Comparative Example 9.10 are shown below in comparison with Example 9 above. From Example 7, the toner is hot-off. That is, the base toner prepared in Example 9 (Comparative Example 9), the base toner and aluminum oxide simply mixed in a mixer (Comparative Example 10), and the one heat-treated without adding aluminum oxide (Example 10) Similarly to Example 5, the hot offset occurrence temperature, fluidity index, and spent value were determined.

From the results in the table, the toner of Example 9 has hot offset properties.
It can be seen that the fluidity and spent properties are particularly excellent.

Example 11 85 parts by weight of polystyrene (D-125: manufactured by Esso Petrochemical) 5 parts by weight of polypropylene (number average molecule m3,500) Carbon black (#44: manufactured by Mitsubishi Chemical) 10 parts by weight or more of heated two rollers Kneading was carried out using a machine to obtain base particles having a volume average particle diameter of 10 μm.

A mixture of 200 g of the base particles and 2.0 g of silicon oxide (R-972, manufactured by Nippon Aerosil Co., Ltd.) using a mixer is placed in a sealed container having a diameter of 50 cm and equipped with a rotating blade.

The rotation speed of the rotary blade was maintained at 5,000 rpm, the temperature of the container was maintained at 40° C., and after operation for 5 minutes, a base toner was obtained.

150 g of this base toner and 3 g of R-9720 were mixed in a mixer to obtain the toner of the present invention.

Next, in order to show that the aspect of the present invention shown in Example 11 is particularly superior, Examples 12.13 and Comparative Examples 11.12 are listed below in comparison with Example 11. That is, only the base particles prepared in Example 11 (Comparative Example 11),
About the one in which base particles and R-972 were simply mixed in a mixer (Comparative Example 12), the one heat-treated without R-972 (Example 12), and the one without R-972 added afterward (Example 13) Similarly to Example 5, the hot offset generation temperature, fluidity index, and spent properties were evaluated. Furthermore, charging stability was evaluated as follows.

A developer (97 parts by weight of spherical iron oxide with an average particle size of 100μ, part of toner affim) was prepared, and copies were made 100,000 times using an experimental machine (charging, exposure, development, transfer, and charge removal were repeated 30 times per minute). Do, start, 10,000, 20,000, 30,000, 50,000, 1
The amount of charge at 00,000 hours was determined by the blow-off method. The more constant this value is, the more stable it is with respect to mechanical conditions, environment, etc.

The evaluation results for each characteristic are shown below.

From the above results, it is clear that the toner of Example 11 is particularly excellent in hot offset properties, fluidity, spent properties, and charging stability.

Example 14 Styrene-n-butyl methacrylate copolymer 80 parts by weight Polypropylene (number average molecule ffi 12,000) 10 parts by weight Metal complex dye 2 parts by weight Carbon black (#44) 8 parts by weight or more Mixing was performed using this roller to obtain base particles having a volume average particle diameter of 10 μm.

A mixture of 200 g of the base particles and 2.4 g of titanium oxide (P-25, manufactured by Nippon Aerosil Co., Ltd.) using a mixer was heat-treated in the same manner as in Example 11. however,
The rotation speed of the rotary vane is 8000 rpIIs The temperature of the container is 5
A mother toner was obtained which was kept at 5°C.

150 g of this base toner and 75 g of P-250 were mixed in a mixer to obtain the toner of the present invention.

In order to explain that the aspect shown in Example 14 is particularly excellent, Example 15.
16 and Comparative Examples 13 and 14. That is, Example 1
Only the base particles prepared in step 4 (Comparative Example 13) Only the base particles and p-25 were mixed in a mixer (Comparative Example 14)
), heat treated without P-25 (Example 15)
The same evaluation as in Example 11 was also carried out for the sample without post-addition of P-25 and P-25 (Example 16).

From the results of the hot offset occurrence temperature, fluidity index, and spent properties, it can be seen that the toner of Example 14 is particularly excellent in hot offset properties, fluidity, spent properties, and charging stability.

Example 17 Unsaturated polyester 85! Iiu N polypropylene (number average molecular weight 5,300) 10 parts by weight Lionol Blue PG-7351 (manufactured by Toyo Ink) A formulation of 5 parts by weight or more was kneaded using two heated rollers to form base particles with a volume average particle diameter of lOμ. I got it.

A mixture of 200 g of these base particles and 3.0 g of aluminum oxide (Mechanox UB-10 manufactured by Uezai Kogyo Co., Ltd.) in a mixer was heat-treated in the same manner as in Example 1. However, the number of rotations of the rotating blade was A base toner was obtained at a speed of 4000 rpm and a container temperature of 35°C.

150 g of this base toner and 3.0 g of 013-10 were mixed in a mixer to obtain the toner of the present invention.

In order to explain that the aspect shown in Example 17 is particularly excellent, Example 18.
19 and Comparative Examples 15 and 16. That is, Example 1
Only the base particles prepared in step 7 (Comparative Example 15) and the base particles UB-1O prepared by mixing them in a mixer (Comparative Example 1)
6) and heat treated without UB-10 (Example 1)
8) and one in which UB-10 was not post-added (Example 19), each characteristic was evaluated in the same manner as in Example 1.

From the results of the hot offset occurrence temperature, fluidity index, and spent properties, it can be seen that the toner of Example 17 is particularly excellent in hot offset properties, fluidity, spent properties, and charging stability.

[Effects of the Invention] As explained above, the present invention provides a dry heat roller fixing system that prevents hot offset and improves heat fixing properties without impairing properties such as fluidity, cohesiveness, and spent properties against carriers. You can get toner for.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating a hot offset performance evaluation device.

Claims (6)

[Claims] (1) A dry heated roller characterized in that low molecular weight polypropylene is precipitated near the particle surface by applying heat, frictional heat, or both heat simultaneously to particles consisting of at least a binder resin and low molecular weight polypropylene. Fixing toner. (2) A method for producing a toner for thermal roller fixation, which includes mixing at least a binder resin and low molecular weight polypropylene, and then applying heating, frictional heat, or both heat simultaneously to the resulting particles. A method for producing toner for roller fixing. (3) By applying heating, frictional heat, or both heat simultaneously to particles made of a mixture of particles made of at least a binder resin and low molecular weight polypropylene, and a hard inorganic fine powder having a smaller particle size than the particles, the particles are A toner for dry heat roller fixing, characterized in that low molecular weight polypropylene is precipitated near the surface, and hard inorganic fine powder is further fixed on the surface. (4) In a method for producing a toner for hot roller fixing, at least a binder resin and a low molecular weight polypropylene are mixed, then the obtained particles are mixed with a hard inorganic fine powder having a particle size smaller than the particles, and then A method for producing a toner for dry heat roller fixing, which comprises applying heat, frictional heat, or both heat simultaneously to the mixed particles. (5) By applying heating, frictional heat, or both heat simultaneously to particles made of a mixture of particles made of at least a binder resin and low molecular weight polypropylene and a hard inorganic fine powder having a smaller particle size than the particles, the particles are A dry method characterized by a mixture of particles in which low molecular weight polypropylene is precipitated near the surface and hard inorganic fine powder is fixed to the surface, and hard inorganic fine powder having the same composition as the fixed hard inorganic fine powder. Toner for heat roller fixing. (6) In the method for producing a toner for hot roller fixing, at least a binder resin and low molecular weight polypropylene are mixed, then the obtained particles are mixed with a hard inorganic fine powder having a smaller particle size than the particles, and Mixing hard inorganic fine powder having the same composition as the inorganic fine powder into particles obtained by applying heating, frictional heat, or both heat to the mixed particles and fixing the inorganic fine powder on the surface. A method for producing toner for dry heat roller fixing, characterized by: