JP2017207679A - toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner that suppresses unevenness in image density in a high-printing ratio image and is excellent in storage property in an environment where the temperature largely changes.SOLUTION: There is provided a toner including toner particles each containing a binder resin, colorant, mold release agent, and crystalline polyester. The ratio of the content of the crystalline polyester to the content of the mold release agent is 0.20 or more and 0.95 or less; when the maximum exothermic peak temperature of a DSC curve obtained, using a differential scanning calorimeter (DSC), in a process of increasing the temperature of the mold release agent to 180°C and subsequently decreasing the temperature is Tcw, the maximum exothermic peak temperature of a DSC curve obtained, using the differential scanning calorimeter (DSC), in a process of increasing the temperature of the crystalline polyester to 180°C and subsequently decreasing the temperature is Tcp, and the softening temperature of the toner is Ts, the Tcw, the Tcp, and the Ts satisfy the following formula (1); when the maximum exothermic peak temperature of a DSC curve obtained, using the differential scanning calorimeter (DSC), in a process of increasing the temperature of the toner to 180°C and subsequently decreasing the temperature is Tc(max), the Ts and the Tc(max) satisfy the following formula (2). Formula (1) Tcp<Ts<Tcw; formula (2) Tc(max)<Ts.SELECTED DRAWING: None

Description

  The present invention relates to a toner used in a recording method using electrophotography or the like.

Many methods are known as electrophotographic methods. In general, an electrostatic latent image is formed on an electrostatic charge image carrier (hereinafter also referred to as “photoconductor”) by using a photoconductive substance by various means. Next, the latent image is developed with toner to form a visible image, and if necessary, the toner image is transferred to a recording medium such as paper, and then the toner image is fixed on the recording medium by heat or pressure, etc. Is what you get. Examples of such an image forming apparatus using electrophotography include a copying machine and a printer.
These printers and copiers are moving from analog to digital, and have excellent reproducibility of latent images and high resolution, and at the same time, stable image quality is required even when used for a long period of time. In recent years, various images are output, and it is required to stably obtain an image with a very high printing rate (hereinafter, a solid image) in which the entire surface of the medium is covered with toner. In addition, it is necessary that there is no change in performance even in an environment where there is excellent storage stability to withstand long-term specifications, especially in a large temperature change. Further, as a measure for energy saving, a toner having a good fixability is demanded, and an improvement focusing on a crystalline material having a characteristic of plasticizing a binder resin, particularly a crystalline polyester, has been made to improve the fixability.
Since the crystalline polyester is excellent in compatibility with the resin, it can be expected to have fixing properties accompanying a decrease in the melt viscosity of the binder resin. However, when the amount of the compatible crystalline polyester increases, the storage stability under a high temperature environment tends to deteriorate.
In order to solve these problems, studies have been made to promote the crystallization of the crystalline polyester by using the crystalline polyester in combination with a crystal nucleating agent to achieve both fixability and storage stability (for example, see Patent Document 1). Furthermore, studies have been made to promote crystallization of both the release agent and the crystalline polyester by controlling the melting points thereof (see, for example, Patent Document 1 and Patent Document 2).
However, even if the toner has both the fixing property and the storage property, when a so-called solid image with a large amount of applied toner is output, an image having a non-uniform density is obtained (hereinafter referred to as image density unevenness). ) There are cases. Even if the storage stability in a high temperature environment is sufficient, the state of the crystalline polyester in the toner may change depending on the width and period of the temperature change, for example, and an aggregate may be generated.
Many techniques have been disclosed in the past with respect to the above fixing problem (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3). However, even with these proposed toners, there remains room for improvement in image density unevenness and resistance to temperature changes when a large amount of solid image with a large amount of applied toner is output.

JP 2012-168505 A Japanese Patent No. 4962377 JP 2013-137420 A

  An object of the present invention is to solve the above problems. Specifically, an object of the present invention is to provide a toner that suppresses image density unevenness in a high-printed image and has excellent storage stability in an environment with a large temperature change.

The present invention is a toner having toner particles containing a binder resin, a colorant, a release agent and a crystalline polyester,
The ratio of the content of the crystalline polyester to the content of the release agent is 0.20 or more and 0.95 or less,
The mold release agent is heated to 180 ° C. using a differential scanning calorimeter (DSC) and then the maximum exothermic peak temperature of the DSC curve obtained in the process of lowering the temperature is Tcw, and the crystalline polyester is subjected to differential scanning calorimeter (DSC). ), When the maximum exothermic peak temperature of the DSC curve obtained in the process of lowering the temperature is Tcp and the softening temperature of the toner is Ts, the Tcw, Tcp and Ts Satisfy (1)
When the maximum exothermic peak temperature of the DSC curve obtained in the process of raising the temperature of the toner to 180 ° C. using a differential scanning calorimeter (DSC) and then lowering the temperature is Tc (max), the Ts and the Tc (max And a toner satisfying the following formula (2).
Tcp <Ts <Tcw Formula (1)
Tc (max) <Ts Formula (2)

  According to the present invention, it is possible to provide a toner that suppresses image density unevenness in a high-printed image, which is a subject of the present invention, and is excellent in storage stability in an environment where the temperature change is large.

FIG. 2 is a schematic cross-sectional view illustrating an example of an image forming apparatus that can suitably use the toner of the present invention. It is a figure which shows an example of the analysis method at the time of performing DSC measurement of the toner of this invention. It is a figure which shows the temperature transition of harsh environment leaving.

The toner of the present invention having toner particles containing a binder resin, a colorant, a release agent and a crystalline polyester,
i) The ratio of the content of the crystalline polyester to the content of the release agent is 0.20 or more and 0.95 or less;
ii) After the temperature of the release agent is raised to 180 ° C. using a differential scanning calorimeter (DSC), the maximum exothermic peak temperature of the DSC curve obtained in the process of lowering the temperature is Tcw, and the crystalline polyester is subjected to the differential scanning calorimeter. (DSC) is used to raise the maximum exothermic peak temperature of the DSC curve obtained in the process of raising the temperature to 180 ° C. and then lowering the temperature Tcp,
When the softening temperature of the toner is Ts, the Tcw, the Tcp, and the Ts satisfy the following formula (1);
Tcp <Ts <Tcw Formula (1)
iii) When the maximum exothermic peak temperature of the DSC curve obtained in the process of lowering the temperature after the temperature of the toner is raised to 180 ° C. using a differential scanning calorimeter (DSC) is Tc (max), Ts and Tc (Max) satisfies the following formula (2).
Tc (max) <Ts Formula (2)

  As a result of intensive studies by the present inventors, when the toner material and the internal structure are controlled so that the maximum exothermic peak temperature of the release agent moves around the toner softening temperature before and after the toner conversion, a remarkable effect on image density unevenness is obtained. Found that there is. Furthermore, the inventors have found that the storability is excellent in an environment with a large temperature change, and have reached the present invention.

  Image density unevenness, which is a problem in the present invention, is density unevenness in a solid image that occurs when an image having a high printing rate such as a solid image is continuously fed at a particularly high process speed. This occurs because the amount of heat received by the toner fluctuates due to fluctuations in the temperature of the fixing device and the thickness of the paper when the paper is passed, and the degree of melting varies. The cause of such variation may be resin physical properties and toner shape fluctuations, but the present inventors have paid attention to plasticization speed and plastic ability fluctuations. Plasticity generally occurs when a material having a plastic ability such as a release agent or crystalline polyester (hereinafter also referred to as a plasticizer) is compatible with the resin. As a result of detailed examination of the relationship between the state of plasticizer and image density unevenness, it was very effective to form a domain (hereinafter also referred to as a compatible domain) in which the release agent and crystalline polyester were compatible. . This is because the release agent and the crystalline polyester existed independently in the past, and the presence state and content of the particles varied among the particles, which affected the plasticization speed and plastic ability. .

  As a result of examining these compatible domains in more detail, it was found that the behavior on the exothermic side of DSC takes a characteristic behavior. First, with regard to the maximum exothermic peak of the release agent (hereinafter also referred to as crystallization temperature), the maximum exothermic peak moves greatly to the low temperature side before and after the toner conversion and shifts to almost the same position as the maximum exothermic peak of crystalline polyester. The maximum exothermic peak Tc (max) is formed. This indicates that the release agent is fully compatible with the crystalline polyester.

  At this time, regarding the maximum exothermic peak temperature as the material of the release agent and the crystalline polyester, the release agent needs to be higher in temperature than the crystalline polyester. As will be described later, the maximum exothermic peak temperature of the release agent needs to be higher than at least the maximum exothermic peak temperature of the crystalline polyester and the softening temperature of the toner. In general, the melting point and the crystallization temperature of the crystalline polyester have a large temperature difference and often have a difference of 10 ° C. or more, but the release agent has a small difference. The softening temperature of the toner often correlates with the glass transition temperature of the toner, and is a physical property value that greatly affects the storage stability. Therefore, if the crystallization temperature of the release agent is lower than the softening temperature, the melting point of the release agent is at least near the glass transition temperature of the toner. For this reason, the storage stability is remarkably deteriorated, which is not preferable.

  In addition, when the crystallization temperature of the release agent is set higher than that of the crystalline polyester, a compatible domain is formed in the toner production, and when the crystallization of the domain is advanced, if the release agent is crystallized first, the crystalline polyester Crystallization proceeds rapidly and tends to be highly crystalline. Further, when the crystallization temperature of both is lower than the softening temperature, the binder resin component substantially does not move below the softening temperature in the toner production, so that the release agent and the crystalline polyester can gather together to grow crystals. , Easy to form domains with higher crystallinity.

  For the above reasons, it is important to satisfy the above formula (1). Further, the fact that the maximum exothermic peak of the release agent is shifted to the maximum exothermic peak position of the crystalline polyester to form the maximum exothermic peak Tc (max) as the toner is expressed by the formulas (1) and (2). It is necessary to satisfy the two equations at the same time.

  Ts related to the above two formulas can be controlled by the structure of the resin component of the toner, particularly when the styrene acrylic resin is used, by the ratio of styrene and acrylic component. Tcw and Tcp can be controlled by the type of release agent and crystalline polyester used. Whether or not the maximum exothermic peak of the release agent shifts depends on the content ratio of the release agent and crystalline polyester, the type of release agent and crystalline polyester, the structure of the binder resin, and the toner production conditions. (Especially by the cooling method).

  Further, in order for the release agent to be sufficiently compatible with the crystalline polyester, it is necessary to adjust the content ratio between them. Specifically, the ratio of the content of the crystalline polyester to the content of the release agent is 0.20 or more and 0.95 or less. This indicates that the release agent is contained in a larger amount than the crystalline polyester, and when the ratio is the above ratio, a compatible domain tends to be formed. This is because the release agent is a relatively low molecular weight component, so that it easily enters between the molecular chains of the crystalline polyester, and the compatibility of both tends to proceed only when the release agent is large.

  Hereinafter, preferred embodiments of the toner of the present invention will be described.

  In the toner of the present invention, the maximum heat generation peak derived from the release agent is largely shifted before and after the toner formation. At this time, it is preferable that the peak derived from the release agent is almost eliminated in the DSC curve of the toner. Specifically, in the DSC curve of the toner, the calorific value (J / g) derived from the releasing agent is 20% or less with respect to the theoretical calorific value (J / g) calculated from the content of the releasing agent. It is. This indicates that there are few domains of the release agent alone, and since the crystallization of the compatible domain tends to be stable, the image density uniformity is also excellent, which is preferable.

  Further, as described above, it is important to obtain compatible domains with high crystallinity. Specifically, in the DSC curve of the toner, the degree of crystallinity is calculated by calculating the total calorific value (J / g) in the region of 20 ° C. to 100 ° C. from the contents of the release agent and the crystalline polyester. It is 60% or more with respect to the theoretical total calorific value (J / g). This indicates that the combined crystallinity of the release agent and the crystalline polyester is 60% or more, and a high crystallinity is preferable because the storage stability tends to be improved. More preferably, it is 65% or more.

  Next, a preferred range for the maximum heat generation peak of the toner of the present invention will be described. Tc (max) is a peak derived from the compatible domain, and preferably accounts for most of the heat generation amount of the toner. Specifically, the ratio of the calorific value (J / g) of the exothermic peak having the Tc (max) to the total calorific value (J / g) in the region of 20 ° C. to 100 ° C. is 0.50 or more and 1 0.000 or less, more preferably 0.65 or more and 1.00 or less. Within this range, the amount of compatible domains is sufficiently secured, and the image density uniformity is increased, which is preferable.

  The softening temperature of the toner in the present invention is preferably 60 ° C. or higher and 72 ° C. or lower, more preferably 63 ° C. or higher and 68 ° C. or lower. Within this range, it is easy to balance image density uniformity and storage stability.

  Further, if the difference between the softening temperature and Tc (max) exceeds 5 ° C., it tends to be excellent in image density uniformity, which is preferable. This is considered to be because, in the toner manufacturing process, if the crystallization of the compatible domain is started after the binder resin is sufficiently hardened, the amount of the compatible domain can be sufficiently crystal-grown.

  On the other hand, if the difference between the maximum exothermic peak temperature Tcw and Tc (max) of the crystalline polyester exceeds 15 ° C., it tends to be excellent in storage stability, which is preferable. This is presumably because the higher the crystallization temperature, the easier it is to crystallize, and the release agent tends to promote the crystallization of the crystalline polyester.

  Regarding the binder resin, it is preferable to use a styrene acrylic resin as a main component because a release agent and a crystalline polyester domain can be easily formed stably. Here, the main component refers to a component of 70% or more. From the viewpoint of image stability, it is more preferably 80% or more, still more preferably 90% or more.

  The crystalline polyester that can be used in the present invention will be described.

  The crystalline polyester of the present invention can be a known one, but is preferably a saturated polyester. Furthermore, it is preferable that it is a condensate of aliphatic dicarboxylic acid, aliphatic diol, and aliphatic monocarboxylic acid. An aliphatic monocarboxylic acid is a preferred form because it can easily adjust the molecular weight and hydroxyl value, and can control the affinity with a release agent. The following are examples of monomers that can be used when the crystalline polyester is a condensate of an aliphatic dicarboxylic acid, an aliphatic diol, and an aliphatic monocarboxylic acid, and is a saturated polyester.

  Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, hexadecanedicarboxylic acid, and octadecanedicarboxylic acid.

  Specific examples of the aliphatic diol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, trimethylene glycol, neopentyl glycol, 1, 4-butanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12 -Dodecanediol, 1,16-hexadecanediol, 1,18-octadecanediol and the like.

  Aliphatic monocarboxylic acids include decanoic acid (capric acid), dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), eicosanoic acid (arachidic acid), Examples include docosanoic acid (behenic acid) and tetracosanoic acid (lignoceric acid).

  When the crystalline polyester used in the present invention is a polyester having a structure derived from an acid monomer selected from lauric acid, stearic acid, and behenic acid at the terminal, the domain of the crystalline polyester covering the release agent and the release agent is This is preferable because it tends to be thermally stabilized.

  The melting point of the crystalline polyester used in the present invention is 55 ° C. or higher and 90 ° C. or lower. However, it is necessary that the maximum exothermic peak temperature does not exceed the toner softening temperature. Since the melting point is determined by the combination of the carboxylic acid component and alcohol component to be used, it is appropriately selected so as to fall within the above range.

  The crystalline polyester used in the present invention can be produced by an ordinary polyester synthesis method. For example, it can be obtained by subjecting a dicarboxylic acid component and a dial alcohol component to an esterification reaction or a transesterification reaction, and then performing a polycondensation reaction under reduced pressure or by introducing nitrogen gas according to a conventional method.

  In the esterification or transesterification reaction, a normal esterification catalyst or a transesterification catalyst such as sulfuric acid, tertiary butyl titanium butoxide, dibutyl tin oxide, manganese acetate, magnesium acetate can be used as necessary. For polymerization, it is possible to use conventional polymerization catalysts such as tertiary butyl titanium butoxide, dibutyl tin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, germanium dioxide and the like. it can. The polymerization temperature and the amount of catalyst are not particularly limited, and may be arbitrarily selected as necessary.

  As the catalyst, a titanium catalyst is preferably used, and a chelate type titanium catalyst is more preferable. This is because the reactivity of the titanium catalyst is appropriate, and a polyester having a desirable molecular weight distribution can be obtained in the present invention.

  The crystalline polyester preferably has a weight average molecular weight (Mw) of 10,000 to 55000, more preferably 25,000 to 50,000. This is because, in the toner production process, the crystalline polyester tends to be phase-separated from the binder resin and tends to have excellent developability.

  The weight average molecular weight (Mw) of the crystalline polyester can be controlled by various production conditions of the crystalline polyester.

  In addition, the acid value (mgKOH / g) of the crystalline polyester is preferably controlled to be low in consideration of dispersibility in the toner, and specifically 8.0 or less. More preferably, it is 5.0 or less, More preferably, it is 3.5 or less, Most preferably, it is 3.0 or less.

  Next, the release agent will be described.

  The peak temperature for crystallization of the release agent used in the present invention is preferably 50 ° C. or higher and 90 ° C. or lower, more preferably 60 ° C. or higher and 90 ° C. or lower, and further preferably 65 ° C. or higher and 85 ° C. or lower. .

  Examples of the release agent include the following. Aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, Fischer-Tropsch wax, paraffin wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax, or block copolymers thereof ; Waxes mainly composed of fatty acid esters such as carnauba wax and montanic acid ester wax, and deoxidized part or all of fatty acid esters such as deoxidized carnauba wax; palmitic acid, stearic acid, montanic acid, etc. Saturated linear fatty acids; unsaturated fatty acids such as brassic acid, eleostearic acid, parinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, seryl alcohol, Saturated alcohols such as alcohols; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; methylene bis stearic acid amide, ethylene biscapric acid amide, ethylene bis lauric acid amide , Saturated fatty acid bisamides such as hexamethylenebisstearic acid amide; unsaturated bisamides such as ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N, N ′ dioleyl adipic acid amide, N, N ′ dioleyl sebacic acid amide Fatty acid amides; aromatic bisamides such as m-xylene bis-stearic acid amide and N, N ′ distearyl isophthalic acid amide; calcium stearate, calcium laurate, zinc stearate, magnesium stearate, etc. Aliphatic metal salts (generally called metal soaps); waxes grafted with aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid; fatty acids such as behenic acid monoglycerides and polyvalent Examples include partially esterified alcohols; methyl ester compounds having a hydroxyl group obtained by hydrogenation of vegetable oils and the like.

  In the present invention, it is preferable to use a hydrocarbon wax and a wax having a fatty acid ester as a main component (hereinafter referred to as an ester wax) because the affinity with the crystalline polyester can be easily controlled.

  Below, the ester wax which can be used conveniently for this invention is mentioned. The functional number described below indicates the number of ester groups contained in one molecule. For example, behenyl behenate is a monofunctional ester wax, and dipentaerythritol hexabehenate is a hexafunctional ester wax.

  As the monofunctional ester wax, a condensate of an aliphatic alcohol having 6 to 12 carbon atoms and a long chain carboxylic acid, or a condensate of an aliphatic carboxylic acid having 4 to 10 carbon atoms and a long chain alcohol can be used. Here, any long-chain carboxylic acid or long-chain alcohol can be used, but it is necessary to combine monomers that can satisfy the melting point of the present invention.

  Examples of the aliphatic alcohol include 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, undecyl alcohol, and lauryl alcohol. Examples of the aliphatic carboxylic acid include pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, and decanoic acid.

  As the bifunctional ester wax, a combination of dicarboxylic acid and monoalcohol, or diol and monocarboxylic acid can be used.

  Examples of the dicarboxylic acid include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid.

  Examples of the diol include 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12- Dodecanediol is mentioned.

  As alcohol to be condensed with dicarboxylic acid, aliphatic alcohol is preferable. Specific examples include tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, octacosanol and the like. . Among these, docosanol is preferable from the viewpoints of fixability and developability.

  As the carboxylic acid condensed with the diol, an aliphatic carboxylic acid is preferable. Specific examples of fatty acids include lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, tuberculostearic acid, arachidic acid, behenic acid, lignoceric acid, and serotic acid. Among these, behenic acid is preferable from the viewpoints of fixability and developability.

  In addition, although linear fatty acid and linear alcohol were illustrated here, you may have a branched structure.

  Trifunctional or higher ester waxes can also be used. Here, the example in the case of obtaining trifunctional or more functional ester wax is given.

  Examples of the trifunctional SL wax include a condensate of a glycerin compound and a monofunctional aliphatic carboxylic acid. Examples of the tetrafunctional ester wax include a condensate of pentaerythritol and a monofunctional aliphatic carboxylic acid, and a condensate of diglycerin and a carboxylic acid. Examples of pentafunctional ester waxes include condensates of triglycerin and monofunctional aliphatic carboxylic acids. Examples of the hexafunctional ester wax include a condensate of dipentaerythritol and a monofunctional aliphatic carboxylic acid, and a condensate of tetraglycerin and a monofunctional aliphatic carboxylic acid.

  As a mold release agent applied to this invention, it is preferable to contain the ester wax obtained as a condensate of 2-6 valent alcohol and monocarboxylic acid or a condensate of monoalcohol and 2-6 carboxylic acid.

The structure and content of the crystalline polyester used in the present invention and the content of the release agent are described as examples because there are the following analytical methods. First, the toner is extracted with tetrahydrofuran to remove most of the resin components. Here, external additives and the like other than the resin are removed by centrifugation using the difference in specific gravity. Since the remaining resin is a mixture of crystalline polyester and release agent, the crystalline polyester and release agent are isolated by preparative LC, and the structure such as nuclear magnetic resonance spectroscopy ( ¹ H-NMR) is obtained. The structure is identified by analysis. Further, the total amount of the release agent and the crystalline polyester can be known by measuring the weight.

  To obtain the crystalline polyester content, compare the nuclear magnetic resonance spectroscopic analysis results of the toner and the crystalline polyester after separation, and take the area ratio between the peak specific to the crystalline polyester and the peak derived from the binder resin. It is obtained by.

  The crystalline polyester can be used in an appropriate amount, but in the present invention, the amount ratio to the binder resin component is preferably 3.0% by mass or more and 20.0% by mass or less, more preferably It is 5.0 mass% or more and 15 mass% or less. Within this range, developability, image density uniformity, and storage stability can be easily improved in a well-balanced manner.

  Examples of the binder resin used in the toner of the present invention include styrene such as polystyrene and polyvinyltoluene, and homopolymers of substitution products thereof; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer. Polymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene -Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene -Vinyl ethyl ether copolymer, Styrene copolymers such as lene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate , Polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin can be used, and these can be used alone or in combination. Can do. Of these, styrene copolymers represented by styrene-butyl acrylate are particularly preferred in terms of development characteristics, fixing properties, and the like.

  The following can be illustrated as a polymerizable monomer which forms the said styrene-type copolymer.

  Examples of the styrene polymerizable monomer include styrene; styrene polymerizable monomers such as α-methyl styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, and p-methoxy styrene.

  Acrylic polymerizable monomers include methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate And acrylic polymerizable monomers such as n-octyl acrylate and cyclohexyl acrylate.

  Methacrylic polymerizable monomers include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate. And methacrylic polymerizable monomers such as n-octyl methacrylate.

  In addition, the manufacturing method of a styrene-type copolymer is not specifically limited, A well-known method can be used. The content of the styrene copolymer relative to the total amount of the binder resin is preferably 70% by mass or more, and more preferably 80% by mass or more. The binder resin may be used in combination with a known resin such as amorphous polyester.

  Examples of the colorant used in the present invention include the following organic pigments, organic dyes, and inorganic pigments.

  Examples of cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds.

  Examples of the magenta colorant include the following. Condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

  Examples of the black colorant include carbon black, and those that are toned in black using the yellow colorant, magenta colorant, cyan colorant, and magnetic powder.

  These colorants can be used alone or in combination and further in the form of a solid solution. The colorant used in the present invention is selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in toner particles.

  Regarding the toner of the present invention, among the above, magnetic powder is preferred from the viewpoint of ease of application to the toner production method. The toner of the present invention can be produced by any known method, but is preferably produced in an aqueous medium.

When magnetic powder is used in the toner of the present invention, the magnetic powder is mainly composed of magnetic iron oxide such as triiron tetroxide and γ-iron oxide, and phosphorus, cobalt, nickel, copper, magnesium, Elements such as manganese, aluminum, and silicon may be included. These magnetic powders preferably have a BET specific surface area of 2 m ² / g or more and 30 m ² / g or less, more preferably 3 m ² / g or more and 28 m ² / g or less by a nitrogen adsorption method. Further, those having a Mohs hardness of 5 or more and 7 or less are preferable. The shape of the magnetic powder includes polyhedron, octahedron, hexahedron, spherical shape, needle shape, scale shape, etc., but those having low anisotropy such as polyhedron, octahedron, hexahedron, spherical shape, etc. It is preferable in terms of enhancement.

  The magnetic powder preferably has a number average particle diameter of 0.10 μm or more and 0.40 μm or less. In general, the smaller the particle size of the magnetic powder, the higher the coloring power, but the magnetic powder tends to aggregate. Therefore, the above range is preferable from the viewpoint of the balance between the coloring power and the cohesiveness.

  The number average particle diameter of the magnetic powder can be measured using a transmission electron microscope. Specifically, after sufficiently dispersing the toner particles to be observed in the epoxy resin, a cured product obtained by curing in an atmosphere at a temperature of 40 ° C. for 2 days is obtained. The obtained cured product is used as a flaky sample by a microtome, and the diameter of 100 magnetic powder particles in the field of view is measured with a transmission electron microscope (TEM) at a magnification of 10,000 to 40,000 times. Then, the number average particle diameter is calculated based on the equivalent diameter of a circle equal to the projected area of the magnetic powder. It is also possible to measure the particle size with an image analyzer.

  The magnetic powder used for the toner of the present invention can be produced, for example, by the following method. An aqueous solution containing ferrous hydroxide is prepared by adding an alkali such as sodium hydroxide in an amount equivalent to or greater than the iron component to the ferrous salt aqueous solution. Air was blown in while maintaining the pH of the prepared aqueous solution at pH 7 or higher, and ferrous hydroxide was oxidized while heating the aqueous solution to 70 ° C. or higher. First, seed crystals serving as the core of the magnetic iron oxide powder were formed. Generate.

  Next, an aqueous solution containing about 1 equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals based on the amount of alkali added previously. While maintaining the pH of the solution at 5 or more and 10 or less, the reaction of ferrous hydroxide proceeds while blowing air to grow magnetic iron oxide powder with the seed crystal as the core. At this time, it is possible to control the shape and magnetic properties of the magnetic powder by selecting an arbitrary pH, reaction temperature, and stirring conditions. As the oxidation reaction proceeds, the pH of the liquid shifts to the acidic side, but the pH of the liquid is preferably not less than 5. A magnetic powder can be obtained by filtering, washing, and drying the magnetic material thus obtained by a conventional method.

  In the present invention, when the toner is produced in an aqueous medium, it is very preferable to subject the surface of the magnetic powder to a hydrophobic treatment. When the surface treatment is performed by a dry method, the coupling agent treatment is performed on the magnetic powder that has been washed, filtered, and dried. When wet surface treatment is performed, after the oxidation reaction is completed, the dried product is redispersed, or after completion of the oxidation reaction, the iron oxide body obtained by washing and filtering is not dried but in another aqueous medium. The dispersion is redispersed and a coupling treatment is performed. In the present invention, both a dry method and a wet method can be selected as appropriate.

Examples of the coupling agent that can be used in the surface treatment of the magnetic powder in the present invention include a silane coupling agent and a titanium coupling agent. More preferably used is a silane coupling agent, which is represented by the general formula (I).
R _m SiY _n (I)
[Wherein, R represents an alkoxy group, m represents an integer of 1 to 3, Y represents a functional group such as an alkyl group, a vinyl group, an epoxy group, or a (meth) acryl group, and n represents 1 to 3] Indicates an integer. However, m + n = 4. ]

  In the present invention, those in which Y in formula (I) is an alkyl group can be preferably used. Among them, an alkyl group having 3 to 6 carbon atoms is preferable, and 3 or 4 is particularly preferable.

  When using the said silane coupling agent, it is possible to process independently or to process in combination of several types. When using several types together, you may process separately with each coupling agent, and may process simultaneously.

  The total amount of the coupling agent used is preferably 0.9 to 3.0 parts by mass with respect to 100 parts by mass of the magnetic powder, and the surface area of the magnetic powder, the reactivity of the coupling agent, etc. It is important to adjust the amount of the treatment agent accordingly.

  In the present invention, other colorants may be used in combination with the magnetic powder. Examples of the colorant that can be used in combination include magnetic or nonmagnetic inorganic compounds in addition to the above-described known dyes and pigments. Specifically, ferromagnetic metal particles such as cobalt and nickel, or alloys obtained by adding chromium, manganese, copper, zinc, aluminum, rare earth elements and the like to these. Examples thereof include particles such as hematite, titanium black, nigrosine dye / pigment, carbon black, and phthalocyanine. These are also preferably used by treating the surface.

  Note that the content of the magnetic powder in the toner can be measured using a thermal analyzer manufactured by PerkinElmer, TGA7. The measuring method is as follows. The toner is heated from room temperature to 900 ° C. at a temperature rising rate of 25 ° C./min in a nitrogen atmosphere. The weight loss mass% between 100 ° C. and 750 ° C. is defined as the binder resin amount, and the remaining mass is approximately defined as the magnetic powder amount.

  The toner of the present invention and a charge control agent can be used as necessary. As the charge control agent, known ones can be used, but a charge control agent that has a high tribocharging speed and can stably maintain a constant triboelectric charge amount is preferable. Further, when the toner particles are produced by a suspension polymerization method, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous medium is required.

  As the charge control agent, there are one that controls the toner to negative charge and one that controls the toner to positive charge. Examples of controlling the toner to be negatively charged include the following. Monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acid and dicarboxylic acid-based metal compounds, aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, Examples include anhydrides, esters, phenol derivatives such as bisphenol, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarenes, and charge control resins.

  Examples of the charge control agent that controls the toner to be positively charged include the following. Guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts that are analogs thereof And these lake pigments; triphenylmethane dyes and lake pigments (including phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, and Ferrocyanide); metal salt of higher fatty acid; charge control resin.

  Said charge control agent can be used individually or in combination of 2 or more types.

  Among these charge control agents, metal-containing salicylic acid compounds are preferable, and those in which the metal is aluminum or zirconium are particularly preferable.

  The addition amount of the charge control agent is preferably 0.01 parts by mass or more and 20.0 parts by mass or less, more preferably 0.5 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the binder resin. It is.

  As the charge control resin, it is preferable to use a polymer or copolymer having a sulfonic acid group, a sulfonic acid group, or a sulfonic acid ester group. The polymer having a sulfonic acid group, a sulfonic acid group or a sulfonic acid ester group preferably contains a sulfonic acid group-containing acrylamide monomer or a sulfonic acid group-containing methacrylamide monomer in a copolymerization ratio of 2% by mass or more. . More preferably, it is 5% by mass or more in terms of copolymerization ratio. The charge control resin has a glass transition temperature (Tg) of 35 ° C. or more and 90 ° C. or less, a peak molecular weight (Mp) of 10,000 or more and 30,000 or less, and a weight average molecular weight (Mn) of 25,000 or more and 50,000 or less. Some are preferred. When this charge control resin is used, preferable triboelectric charging characteristics can be imparted without affecting the thermal characteristics required of the toner particles. Furthermore, since the charge control resin contains a sulfonic acid group, the dispersibility of the charge control resin itself in the dispersion of the colorant, and the dispersibility of the colorant are improved, and the coloring power, transparency, and The triboelectric charging characteristics can be further improved.

  The weight average particle diameter (D4) of the toner produced according to the present invention is preferably 3.0 μm or more and 12.0 μm or less, and more preferably 4.0 μm or more and 10.0 μm or less. When the weight average particle diameter (D4) is 3.0 μm or more and 12.0 μm or less, good fluidity can be obtained and development can be performed faithfully to the latent image.

  The toner of the present invention can be produced by any known method. First, when manufacturing by a pulverization method, for example, a binder resin, a colorant, an ester wax, a low melting point material, a charge control agent and other necessary components and other additives are mixed in a Henschel mixer, a ball mill, etc. Mix thoroughly with a vessel. Thereafter, the toner material is dispersed or dissolved by using a heat kneader such as a heating roll, a kneader, or an extruder to disperse or dissolve the toner material, and after cooling and solidification, pulverization, and surface treatment as necessary to obtain toner particles. be able to. Either the classification or the surface treatment may be performed first. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency.

  The pulverization step can be performed by a method using a known pulverizer such as a mechanical impact type or a jet type. Further, it is preferable to further pulverize by applying heat or to add a mechanical impact to the auxiliary. Further, a hot water bath method in which finely pulverized (classified as necessary) toner particles are dispersed in hot water, a method of passing in a hot air stream, or the like may be used.

  Examples of means for applying a mechanical impact force include a method using a mechanical impact pulverizer such as a kryptron system manufactured by Kawasaki Heavy Industries, Ltd. or a turbo mill manufactured by Turbo Industry. In addition, like the Hosokawa Micron Mechano-Fusion System and the Nara Machinery Co., Ltd. Hybridization System, the toner is pressed against the inside of the casing by centrifugal force using high-speed rotating blades. There is a method of applying a mechanical impact force to the toner.

  The toner of the present invention can also be produced by a pulverization method as described above. Further, it can also be produced by an emulsion aggregation method. The toner of the present invention is preferably produced in an aqueous medium in order to control the presence state of the crystalline polyester and the release agent. However, in the case of producing by the pulverization method, the crystalline polyester and the release agent are uniformly dispersed in the resin, so that the contact opportunity tends to be reduced. Therefore, it is necessary to devise a manufacturing method for forming a compatible domain. Also in the case of the emulsion aggregation method, it is necessary to create an emulsion particle in which the crystalline polyester and the release agent are compatible, and further to devise a toner without applying heat as much as possible after the aggregation. On the other hand, the suspension polymerization method is preferable because a compatible domain can be obtained by heating to a temperature equal to or higher than the melting points of the crystalline polyester and the release agent and carefully cooling.

  The suspension polymerization method will be described below.

  The suspension polymerization method is a polymerizable monomer in which a polymerizable monomer and a colorant (in addition, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives as necessary) are uniformly dissolved or dispersed. A composition is obtained. Thereafter, this polymerizable monomer composition is dispersed in a continuous layer containing a dispersant (for example, an aqueous phase) using a suitable stirrer and simultaneously subjected to a polymerization reaction to obtain a toner having a desired particle size. Is. The toner obtained by this suspension polymerization method (hereinafter also referred to as “polymerized toner”) has an almost uniform spherical toner particle shape, and the charge amount distribution is relatively uniform, improving the image quality. I can expect.

  In the production of the polymerized toner according to the present invention, examples of the polymerizable monomer constituting the polymerizable monomer composition include the following.

  Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; methyl acrylate, ethyl acrylate, Acrylate esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate , Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, Methacrylic acid dimethyl aminoethyl, methacrylic acid esters such as diethylaminoethyl methacrylate; and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide. These monomers can be used alone or in combination. Among the above-mentioned monomers, styrene is preferably used alone or mixed with other monomers from the viewpoint of toner development characteristics and durability.

  The polymerization initiator used in the production of the toner according to the present invention by polymerization is preferably one having a half-life of 0.5 hours or more and 30 hours or less during the polymerization reaction. In addition, when the polymerization reaction is carried out using an addition amount of 0.5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer, a weight having a maximum between 5,000 and 50,000 in molecular weight is obtained. The coalescence can be obtained and the toner can be given the desired strength and suitable melting properties.

  Specific examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1- Carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and other azo or diazo polymerization initiators; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxide Peroxide polymerization initiators such as oxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy 2-ethylhexanoate, t-butylperoxypivalate, etc. Can be mentioned.

  When the toner of the present invention is produced by a polymerization method, a crosslinking agent may be added, and a preferable addition amount is 0.001 part by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. is there.

  Here, as the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; for example, ethylene glycol diacrylate, ethylene glycol diester Carboxylic acid ester having two double bonds such as methacrylate, 1,3-butanediol dimethacrylate, etc .; Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, etc .; and having three or more vinyl groups Are used alone or as a mixture of two or more.

  In the method for producing the toner of the present invention by a polymerization method, generally, the above-described toner composition or the like is added as appropriate, and the polymerizable single particle is uniformly dissolved or dispersed by a disperser such as a homogenizer, a ball mill, or an ultrasonic disperser. The meter composition is suspended in an aqueous medium containing a dispersant. At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to obtain a desired toner particle size at a stretch. The polymerization initiator may be added at the same time when other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Also, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction.

  After granulation, stirring may be performed using a normal stirrer to such an extent that the particle state is maintained and particle floating and sedimentation are prevented.

  When the toner of the present invention is produced, known surfactants, organic dispersants and inorganic dispersants can be used as the dispersant. In particular, inorganic dispersants are less likely to produce harmful ultrafine powders, and because of their steric hindrance, dispersion stability is obtained, so even if the reaction temperature is changed, stability is not easily lost, and washing is easy and does not adversely affect the toner. Therefore, it can be preferably used. Examples of such inorganic dispersants include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, phosphate polyvalent metal salts such as hydroxyapatite, carbonates such as calcium carbonate and magnesium carbonate, calcium metasuccinate, calcium sulfate, Examples thereof include inorganic salts such as barium sulfate and inorganic compounds such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide.

  These inorganic dispersants are preferably used in an amount of 0.2 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. Moreover, the said dispersing agent may be used independently and may use multiple types together. Furthermore, you may use together 0.001 mass part or more and 0.1 mass part or less surfactant.

  When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated and used in an aqueous medium. For example, in the case of tricalcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution can be mixed under high-speed stirring to produce water-insoluble calcium phosphate, which enables more uniform and fine dispersion. At the same time, water-soluble sodium chloride salt is produced as a by-product. However, if water-soluble salt is present in the aqueous medium, dissolution of the polymerizable monomer in water is suppressed, and ultrafine toner is generated by emulsion polymerization. This is more convenient.

  Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

  In the step of polymerizing the polymerizable monomer, the polymerization temperature is set to 40 ° C. or higher, generally 50 to 90 ° C. When the polymerization is carried out in this temperature range, the ester wax to be sealed inside precipitates by phase separation, and the encapsulation becomes more complete.

  After the polymerization of the polymerizable monomer is completed to obtain colored particles, the temperature is raised to a temperature exceeding the melting points of the crystalline polyester and the release agent in a state where the colored particles are dispersed in the aqueous medium. This operation is not necessary when the polymerization temperature exceeds the melting point described above.

  Regarding the subsequent cooling rate, the preferable range in the present invention is described not only for the polymerization method but also for the entire toner production method.

  Focusing on the toner production method for the purpose of crystallizing the crystalline polyester, for example, when the toner is produced by a pulverization method, suspension polymerization or emulsion polymerization, the temperature is raised to a temperature at which the crystalline polyester or ester wax is once melted. In many cases, the method includes a step of cooling to room temperature. Considering the cooling process, the crystalline polyester liquefied by the temperature rise becomes dull as the temperature decreases, and crystallization starts when it reaches the vicinity of the crystallization temperature. When it is further cooled, crystallization proceeds and it is completely solidified at room temperature. According to the study by the present inventors, it was found that the amount of the crystalline polyester finally crystallized varies depending on the cooling rate. Specifically, cooling is performed at a rate of 5.0 ° C./min or more from a temperature equal to or higher than the melting point of the crystalline polyester to 50 ° C. ± 5 ° C., and 30 in a range of ± 10 ° C. with respect to the glass transition temperature Tg of the toner. Holding for more than a minute tended to increase the amount of crystals while maintaining the compatible domain. According to the study by the present inventors, a toner having the effect of the present invention having a compatible domain can be obtained when such cooling conditions are combined with the types and amounts of the above-described crystalline polyester and release agent. The cooling rate is more preferably 10.0 ° C./min or more, and the holding time is more preferably 60 minutes or more, and still more preferably 90 minutes or more.

  Toner particles are obtained by filtering, washing and drying the obtained polymer particles by a known method. The toner of the present invention can be obtained by mixing the toner particles with inorganic fine powder as will be described later, if necessary, and adhering them to the surface of the toner particles. It is also possible to insert a classification step in the manufacturing process (before mixing the inorganic fine powder) to cut coarse powder and fine powder contained in the toner particles.

  In the toner of the present invention, an additive such as a fluidizing agent is mixed with the toner particles obtained by the above-described manufacturing method, if necessary, to obtain a toner. As for the mixing method, a known method can be used. For example, a Henschel mixer is a device that can be suitably used.

  In the toner of the present invention, an inorganic fine powder having a number average primary particle size of 4 nm to 80 nm, more preferably 6 nm to 40 nm, is preferably added to the toner particles as a fluidizing agent. The inorganic fine powder is added to improve the fluidity of the toner and to make the charge of the toner particles uniform. However, adjustment of the charge amount of the toner, improvement of environmental stability, etc. by treatment such as hydrophobizing the inorganic fine powder. It is also a preferable form to provide the function. The method for measuring the number average primary particle size of the inorganic fine powder is performed using a photograph of the toner magnified by a scanning electron microscope.

Silica, titanium oxide, alumina, etc. can be used as the inorganic fine powder used in the present invention. As the fine silica powder, for example, both a so-called dry method produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and so-called wet silica produced from water glass or the like can be used. is there. However, dry silica having fewer silanol groups on the surface and in the silica fine powder and less production residue such as Na ₂ O and SO ₃ ²⁻ is more preferable. In dry silica, it is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process, They are also included.

  The addition amount of the inorganic fine powder having a number average primary particle size of 4 nm or more and 80 nm or less is preferably 0.1% by mass or more and 3.0% by mass or less with respect to the toner particles, and the addition amount is 0.1% by mass. If it is less than%, the effect is not sufficient, and if it exceeds 3.0% by mass, the fixing property is deteriorated. The content of the inorganic fine powder can be quantified using a calibration curve prepared from a standard sample using fluorescent X-ray analysis.

  In the present invention, the inorganic fine powder is preferably a hydrophobized product because the environmental stability of the toner can be improved. When the inorganic fine powder added to the toner absorbs moisture, the charge amount of the toner particles is remarkably reduced, the charge amount is likely to be non-uniform, and toner scattering is likely to occur. Treatment agents used for hydrophobizing inorganic fine powders include silicone varnishes, various modified silicone varnishes, silicone oils, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, and organic titanium compounds. May be used alone or in combination of two or more.

  In the toner of the present invention, other additives within a range that does not have a substantial adverse effect, for example, a lubricant powder such as fluororesin powder, zinc stearate powder, polyvinylidene fluoride powder; cerium oxide powder, silicon carbide powder, A small amount of an abrasive such as strontium titanate powder; a fluidity-imparting agent such as titanium oxide powder or aluminum oxide powder; an anti-caking agent; or organic fine particles and inorganic fine particles having opposite polarity can be used in small amounts. It is also possible to use the surface of these additives after hydrophobizing them.

  Next, an example of an image forming apparatus that can suitably use the toner of the present invention will be specifically described with reference to FIG. In FIG. 1, reference numeral 100 denotes a photosensitive drum, which is provided with a primary charging roller 117, a developing device 140 having a developing sleeve 102, a transfer charging roller 114, a cleaner 116, a register roller 124, and the like. The photosensitive drum 100 is charged to, for example, −600 V by the primary charging roller 117 (applied voltages are, for example, an AC voltage of 1.85 kVpp and a DC voltage of −620 Vdc). Then, exposure is performed by irradiating the photoreceptor 100 with the laser beam 123 by the laser generator 121, and an electrostatic latent image corresponding to the target image is formed. The electrostatic latent image on the photosensitive drum 100 is developed with a one-component toner by the developing device 140 to obtain a toner image, and the toner image is transferred onto the transfer material by the transfer roller 114 in contact with the photoreceptor via the transfer material. Is done. The transfer material on which the toner image is placed is conveyed to the fixing device 126 by the conveying belt 125 or the like and fixed on the transfer material. In addition, toner remaining on a part of the photoconductor is cleaned by a cleaner 116.

  Although an image forming apparatus for magnetic one-component jumping development is shown here, it may be used for any method of jumping development or contact development.

  Next, a method for measuring each physical property related to the toner of the present invention will be described.

[1] Maximum exothermic peak temperature of crystalline polyester, release agent and toner The maximum exothermic peak temperature of crystalline polyester, release agent and toner is as follows using DSC Q1000 (manufactured by TA Instruments). Measurements were made. The measurement conditions were a heating rate: 10 ° C./min, a measurement temperature range of 20 ° C. to 180 ° C., and measurement was performed in the standard mode. About 2 mg of the sample was precisely weighed and placed in a silver pan, and an empty silver pan was used as a reference, and differential scanning calorimetry was performed. The maximum exothermic peak of the present invention refers to a peak having the largest calorific value when there are a plurality of peaks. After the measurement, the peak top temperature of the maximum exothermic peak was analyzed from the obtained DSC curve to obtain the maximum exothermic peak temperature. For example, when a plurality of release agents are included, a single substance is obtained, and the release agent is pulverized and uniformly mixed at the same ratio as the content in the toner. The same process is performed when a plurality of crystalline polyesters are contained.

[2] The calorific value of the exothermic peak having Tc (max), the calorific value derived from the release agent, the theoretical calorific value of the release agent, the theoretical total calorific value In the DSC curve obtained in [1] above, Tc (max ) Is described. If there is a valley (local minimum), the peak is divided there. When there is no clear valley, for example, there is a valley on the high temperature side of Tc (max), but when there is no valley on the low temperature side, the low temperature side is divided by a portion of Tc (max) −5 ° C. FIG. 2 shows an example of the DSC curve analysis method. Here, a chart in the case of using a release agent having Tc (max) at 50 ° C. and a crystallization temperature of 70 ° C. is shown. In this case, each calorific value is calculated by dividing with a dotted line. In addition, since there is no clear trough about a mold release agent, it has divided | segmented in the area | region of +/- 5 degreeC.

  Regarding the calorific value derived from the release agent, first, the maximum exothermic peak temperature as a single material of the release agent is measured. The method for isolating and identifying the release agent present in the toner is the same as the measurement example described above. Next, a peak centering on the maximum exothermic peak temperature of the release agent is searched, and if there is a peak, the calorific value is calculated by dividing the peak at a valley portion. If there is no clear valley, the calorific value in the region of the maximum exothermic peak temperature ± 5 ° C. of the release agent is taken as the calorific value derived from the release agent.

  Further, the theoretical heat generation amount when all the release agents are crystallized is calculated from the heat generation amount of the release agent and the content in the toner. Similarly, it is performed on the crystalline polyester, and the theoretical total calorific value when the crystalline polyester and the release agent are all crystallized is calculated.

  By using the numerical values of the calorific value derived from Tc (max), the calorific value derived from the release agent, the theoretical calorific value of the release agent, and the theoretical total calorific value, the ratio of the calorific values is obtained. I can do it.

[3] (Measurement of weight average particle diameter (D4) and number average particle diameter (D1) of toner (particles))
The weight average particle diameter (D4) and the number average particle diameter (D1) of the toner (particles) are determined by a fine particle size distribution measuring apparatus “Coulter Counter Multisizer 3” (registered trademark) using a pore electrical resistance method equipped with an aperture tube of 100 μm. Using Beckman Coulter Multisizer 3 Version 3.51 (manufactured by Beckman Coulter, Inc.) and the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.). Measure with 55,000 channels, analyze the measured data, and calculate.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software is set as follows.

  In the “Standard measurement method (SOM) change screen” of the dedicated software, set the total count in the control mode to 50000 particles, the number of measurements is 1 and the Kd value is “standard particles 10.0 μm” (Beckman Coulter Set the value obtained using The threshold and noise level are automatically set by pressing the threshold / noise level measurement button. Also, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the aperture tube flash after measurement is checked.

  In the “pulse to particle size conversion setting screen” of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm or more and 60 μm or less.

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic solution is placed in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the analysis software.
(2) About 30 ml of the electrolytic aqueous solution is put in a glass 100 ml flat bottom beaker, and "Contaminone N" (nonionic surfactant, anionic surfactant, organic builder pH 7 precision measurement is used as a dispersant therein. About 0.3 ml of a diluted solution obtained by diluting a 10% by weight aqueous solution of a neutral detergent for washing a vessel (made by Wako Pure Chemical Industries, Ltd.) 3 times with ion exchange water is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated in a state where the phase is shifted by 180 degrees, and is placed in a water tank of an ultrasonic disperser “Ultrasonic Dispersion System Tetora 150” (manufactured by Nikka Ki Bios) with an electrical output of 120 W. A predetermined amount of ion-exchanged water is put, and about 2 ml of the above-mentioned Contaminone N is added to this water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
(5) About 10 mg of toner (particles) is added to the electrolytic aqueous solution little by little in a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) The electrolytic solution (5) in which the toner (particles) is dispersed with a pipette is dropped into the round bottom beaker (1) installed in the sample stand so that the measured concentration becomes about 5%. Adjust to. Measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) is calculated. When the graph / volume% is set with the dedicated software, the “average diameter” on the analysis / volume statistics (arithmetic average) screen is the weight average particle size (D4), and the graph / number% is set with the dedicated software. The “average diameter” on the “analysis / number statistics (arithmetic average)” screen is the number average particle diameter (D1).

[4] Method for measuring molecular weight of crystalline polyester The molecular weight of the crystalline polyester, the amorphous saturated polyester resin and the toner is measured by gel permeation chromatography (GPC) as follows.

First, crystalline polyester or toner is dissolved in tetrahydrofuran (THF) at room temperature. The obtained solution is filtered through a solvent-resistant membrane filter “Maescho Disc” (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of the component soluble in THF is 0.8% by mass. Using this sample solution, measurement is performed under the following conditions.
Equipment: High-speed GPC equipment “HLC-8220GPC” [manufactured by Tosoh Corporation]
Column: LF-604 double eluent: THF
Flow rate: 0.6 ml / min
Oven temperature: 40 ° C
Sample injection amount: 0.020 ml
In calculating the molecular weight of the sample, standard polystyrene resin (for example, trade name “TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F— 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500 ", manufactured by Tosoh Corporation) are used.

[5] Method for Measuring Acid Value of Crystalline Polyester The acid value of the crystalline polyester in the present invention is determined by the following operation. The basic operation is JIS K0070. The acid value of the genus polar resin was measured by the following method.

  The acid value is the number of mg of potassium hydroxide necessary for neutralizing the acid contained in 1 g of the sample. The acid value of the polar resin was measured according to JIS K 0070-1992. Specifically, it measured according to the following procedures.

(1) Preparation of Reagent 1.0 g of phenolphthalein was dissolved in 90 ml of ethyl alcohol (95 vol%), and ion exchanged water was added to make 100 ml to obtain a phenolphthalein solution.

  7 g of special grade potassium hydroxide was dissolved in 5 ml of water, and ethyl alcohol (95 vol%) was added to make 1 l. In order to avoid contact with carbon dioxide, etc., it was placed in an alkali-resistant container and allowed to stand for 3 days, followed by filtration to obtain a potassium hydroxide solution. The obtained potassium hydroxide solution was stored in an alkali-resistant container. The factor of the potassium hydroxide solution was as follows: 25 ml of 0.1 mol / l hydrochloric acid was placed in an Erlenmeyer flask, a few drops of the phenolphthalein solution were added, titrated with the potassium hydroxide solution, and the hydroxide required for neutralization. It calculated | required from the quantity of the potassium solution. The 0.1 mol / l hydrochloric acid was prepared according to JIS K 8001-1998.

(2) Operation (A) Main test 2.0 g of the pulverized crystalline polyester was precisely weighed into a 200 ml Erlenmeyer flask, and 100 ml of a mixed solution of toluene: ethanol (2: 1) was added and dissolved over 5 hours. . Next, several drops of the phenolphthalein solution were added as indicators and titrated with the potassium hydroxide solution. The end point of the titration was when the indicator was light red for about 30 seconds.
(B) Blank test Titration was performed in the same manner as described above, except that no sample was used (that is, only a mixed solution of toluene: ethanol (2: 1) was used).

(3) The acid value was calculated by substituting the obtained result into the following formula.
A = [(C−B) × f × 5.61] / S

  Here, A: acid value (mgKOH / g), B: addition amount (ml) of a potassium hydroxide solution in a blank test, C: addition amount (ml) of a potassium hydroxide solution in this test, f: potassium hydroxide Solution factor, S: sample (g).

[6] Method for Measuring Hydroxyl Value of Crystalline Polyester In the present invention, the hydroxyl value OHv (JIS hydroxyl value) of the crystalline polyester is determined by the following method. The hydroxyl value is the number of mg of potassium hydroxide required to neutralize acetic acid bonded to a hydroxyl group when 1 g of a sample is acetylated. The hydroxyl value of the crystalline polyester is measured according to JIS K 0070-1992.

[7] Identification of terminal structure of crystalline polyester 2 mg of a resin sample is precisely weighed, and 2 ml of chloroform is added and dissolved to prepare a sample solution. Crystalline polyester resin A is used as the resin sample, but a toner containing resin A can be used as a sample. Next, 20 mg of 2,5-dihydroxybenzoic acid (DHBA) is precisely weighed, and 1 ml of chloroform is added and dissolved to prepare a matrix solution. In addition, after accurately weighing 3 mg of sodium trifluoroacetate (NaTFA), 1 ml of acetone is added and dissolved to prepare an ionization aid solution.

  25 μl of the sample solution thus prepared, 50 μl of the matrix solution and 5 μl of the ionization aid solution are mixed, dropped onto a sample plate for MALDI analysis, and dried to obtain a measurement sample. As an analytical instrument, MALDI-TOFMS (Reflex III manufactured by Bruker Daltonics) is used to obtain a mass spectrum. In the obtained mass spectrum, assignment of each peak in the oligomer region (m / Z is 2000 or less) is performed, and it is confirmed whether or not a peak corresponding to a structure in which a monocarboxylic acid is bonded to the molecular end exists.

[8] Method for Measuring Toner Softening Temperature (Ts) To measure the toner softening temperature (Ts), a constant load extrusion type capillary rheometer “Flow Characteristic Evaluation Device Flow Tester CFT-500D” (manufactured by Shimadzu Corporation) is used. Use according to the manual supplied with the device. In this apparatus, while applying a constant load from the top of the measurement sample by the piston, the measurement sample filled in the cylinder is heated and melted, and the molten measurement sample is pushed out from the die at the bottom of the cylinder. At this time, a flow curve indicating the relationship between the piston lowering amount and the temperature can be obtained.

  In the present invention, the softening temperature (Ts) is the first maximum point in the flow curve.

The measurement sample was about 1.5 g of toner in a tablet molding compressor (NT-10) at 25 ° C.
0H, manufactured by NP System Co., Ltd.) and compression molded at about 10 MPa for about 60 seconds to use a cylindrical shape having a diameter of about 8 mm.
The measurement conditions of the flow tester CFT-500D are as follows.
Test mode: Temperature rising start temperature: 35 ° C
Achieving temperature: 200 ° C
Measurement interval: 1.0 ° C
Temperature increase rate: 4.0 ° C./min
Piston cross-sectional area: 1.000cm2
Test load (piston load): 10.0 kgf (0.9807 MPa)
Preheating time: 300 seconds Die hole diameter: 1.0 mm
Die length: 1.0mm

  Hereinafter, the present invention will be described more specifically with reference to production examples and examples, but these do not limit the present invention in any way. In addition, all the parts in the following mixing | blending show a mass part.

<Production of crystalline polyester 1>
In a reaction vessel equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, sebacic acid (decanedioic acid) as carboxylic acid monomer 1, stearic acid as carboxylic acid monomer 2, and 1,9-nonanediol as alcohol monomer The crystalline polyester 1 was obtained by adjusting the amount of each monomer added and the reaction conditions so that the desired physical properties were obtained using tin dioctylate as a catalyst. Table 1 shows the physical properties of the obtained crystalline polyester 1.

<Production of crystalline polyester 2-10>
In the production of the crystalline polyester 1, the alcohol monomer and the carboxylic acid monomers 1 and 2 are changed as shown in Table 1, and the reaction conditions and the addition amount are adjusted so as to obtain the desired physical properties. Polyesters 2 to 10 were obtained. The physical properties of the obtained crystalline polyester are shown in Table 1.

<Production of crystalline polyester 11>
In the production of the crystalline polyester 1, the carboxylic acid monomer was changed to a dodecanedioic acid and fumaric acid 95: 3 mixture, and the reaction conditions and the addition amount were adjusted so as to obtain the desired physical properties. Polyester 11 was obtained. The obtained crystalline polyester 11 had a weight average molecular weight (Mw) of 35,000, a maximum exothermic peak temperature of 60 ° C., and an acid value of 5.3.

<Production of crystalline polyester 12>
In the production of the crystalline polyester 1, except that the alcohol monomer was changed to a mixture of 1,8-octanediol and 1,6-hexanediol 56:44, and the reaction conditions, addition amount, etc. were adjusted so as to obtain desired physical properties. In the same manner, crystalline polyester 12 was obtained. The obtained crystalline polyester 12 had a weight average molecular weight (Mw) of 15000, a maximum exothermic peak temperature of 55 ° C., and an acid value of 5.4.

<Production of crystalline polyester 13>
In the production of crystalline polyester 1, in the same manner, except that the alcohol monomer is ethylene glycol, the carboxylic acid monomer is changed to dodecanedioic acid, and the reaction conditions, addition amount, etc. are adjusted to achieve the desired physical properties. Polyester 13 was obtained. The obtained crystalline polyester 13 had a weight average molecular weight (Mw) of 11000, a maximum exothermic peak temperature of 51 ° C., and an acid value of 5.0.

<Examples of magnetic iron oxide production>
Ferrous salt aqueous solution containing ferrous hydroxide colloid by mixing and stirring 50 liters of 4.0 mol / L sodium hydroxide aqueous solution with 50 liters of ferrous sulfate first aqueous solution containing 2.0 mol / L of Fe ²⁺ Got. This aqueous solution was kept at 85 ° C., and an oxidation reaction was performed while blowing air at 20 L / min to obtain a slurry containing core particles.

  The obtained slurry was filtered and washed with a filter press, and then the core particles were dispersed again in water and reslurried. To this reslurry liquid, sodium silicate that is 0.20% by mass in terms of silicon per 100 parts of the core particles is added, the pH of the slurry liquid is adjusted to 6.0, and the magnetic oxidation having a silicon-rich surface is performed by stirring. Iron particles were obtained. The obtained slurry was filtered and washed with a filter press, and further reslurried with ion-exchanged water. To this reslurry liquid (solid content 50 g / L), 500 g (10% by mass with respect to magnetic iron oxide) of ion exchange resin SK110 (manufactured by Mitsubishi Chemical) was added, and ion exchange was performed by stirring for 2 hours. Thereafter, the ion exchange resin was removed by filtration through a mesh, filtered and washed with a filter press, dried and crushed to obtain magnetic iron oxide having a number average diameter of 0.23 μm.

<Manufacture of silane compounds>
30 parts of iso-butyltrimethoxysilane was added dropwise to 70 parts of ion exchange water with stirring. Then, this aqueous solution was kept at pH 5.5 and a temperature of 55 ° C., and hydrolyzed by dispersing for 120 minutes at a peripheral speed of 0.46 m / s using a disper blade. Thereafter, the pH of the aqueous solution was adjusted to 7.0 and cooled to 10 ° C. to stop the hydrolysis reaction. Thus, an aqueous solution containing a silane compound was obtained.

<Manufacture of magnetic material>
100 parts of magnetic iron oxide was put in a high speed mixer (LFS-2 type, manufactured by Fukae Pautech Co., Ltd.), and 8.0 parts of an aqueous solution containing a silane compound was dropped over 2 minutes while stirring at a rotational speed of 2000 rpm. Thereafter, the mixture was mixed and stirred for 5 minutes. Next, in order to enhance the fixing property of the silane compound, after drying at 40 ° C. for 1 hour to reduce moisture, the mixture was dried at 110 ° C. for 3 hours to proceed the condensation reaction of the silane compound. Thereafter, it was crushed and a magnetic material was obtained through a sieve having an opening of 100 μm.

<Manufacture of toner particles 1>
After adding 450 parts of 0.1 mol / L-Na ₃ PO ₄ aqueous solution to 720 parts of ion-exchanged water and heating to 60 ° C., 67.7 parts of 1.0 mol / L-CaCl ₂ aqueous solution was added. An aqueous medium containing a dispersion stabilizer was obtained.

・ Styrene 73.0 parts ・ N-butyl acrylate 22.0 parts ・ Divinylbenzene 0.6 parts ・ Monoazo dye iron complex (T-77: Hodogaya Chemical Co., Ltd.) 1.5 parts ・ Magnetic substance 1 95.0 parts Amorphous saturated polyester resin 5.0 parts (Amorphous saturated polyester resin obtained by condensation reaction of bisphenol A ethylene oxide and propylene oxide adducts with terephthalic acid; Mw = 9500, acid value = 2.2 mgKOH / g, glass transition temperature = 68 ° C.)
The above formulation was uniformly dispersed and mixed using an attritor (manufactured by Mitsui Miike Chemical Co., Ltd.) to obtain a monomer composition. This monomer composition was heated to 63 ° C., and 10 parts of the crystalline polyester 1 listed in Table 1 was used, 15.0 parts of dibehenyl sebacate as a release agent, and HNP-51 (manufactured by Nippon Seiwa Co., Ltd.). ) 5.0 parts were mixed and dissolved.

The aqueous medium of the above monomer composition was charged in, 60 ° C., T. under N ₂ atmosphere K. The mixture was stirred at 12000 rpm for 10 minutes with a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) and granulated. Thereafter, 5.0 parts of a polymerization initiator t-butyl peroxypivalate was added while stirring with a paddle stirring blade, and the temperature was raised to 70 ° C. and reacted for 4 hours. After completion of the reaction, the suspension was heated to 100 ° C. and held for 2 hours. Thereafter, as a cooling step, normal temperature water was added to the suspension, and the suspension was cooled from 100 ° C. to 50 ° C. at a rate of 10 ° C./min, and then kept for 2 hours. Thereafter, the mixture was cooled to room temperature, hydrochloric acid was added to the suspension and thoroughly washed to dissolve the dispersion stabilizer, filtered and dried to obtain toner particles 1. Table 2-1 shows the production method and prescription, and Table 2-2 shows the relationship between formula (1) and formula (2).

<Production of toner particles 2 to 7>
Toner particles 2 to 7 were produced in the same manner as in the production of toner particles 1 except that the types and number of crystalline polyesters and release agents and the cooling process were changed as shown in Table 2-1. Further, Table 2-2 shows the relationship between Expression (1) and Expression (2).

<Manufacture of toner particles 8>
In the production of the toner particles 1, the amorphous polyester is changed to 10.0 parts, the styrene is 69.0 parts, the n-butyl acrylate is 21.0 parts, and the types and parts of the crystalline polyester and the release agent; Toner particles 8 were produced in the same manner except that the cooling process was changed as shown in Table 2-1.

<Manufacture of toner particles 9>
In the production of toner particles 1, the amorphous polyester was changed to 20.0 parts, the styrene was changed to 62.0 parts, the n-butyl acrylate was changed to 18.0 parts, the types and the number of parts of the crystalline polyester and the release agent, Toner particles 9 were produced in the same manner except that the cooling process was changed as shown in Table 2-1. Further, Table 2-2 shows the relationship between Expression (1) and Expression (2).

<Manufacture of toner particles 10-11>
In the production of the toner particles 1, the amorphous polyester is changed to 25.0 parts, the styrene is 58.0 parts, the n-butyl acrylate is 17.0 parts, the types and parts of the crystalline polyester and the release agent, Toner particles 10 to 11 were produced in the same manner except that the cooling step was changed as shown in Table 2-1. Further, Table 2-2 shows the relationship between Expression (1) and Expression (2).

<Production of toner particles 12 to 14>
In the production of toner particles 1, the amorphous polyester was changed to 25.0 parts, styrene was changed to 60.0 parts, n-butyl acrylate was changed to 15.0 parts, the kind and the number of parts of the crystalline polyester and the release agent, Toner particles 10 to 14 were produced in the same manner except that the cooling step was changed as shown in Table 2-1. Further, Table 2-2 shows the relationship between Expression (1) and Expression (2).

<Production of Comparative Toner Particles 1 to 11>
In the production of the toner particles 1, the addition amount of styrene and n-butyl acrylate is appropriately adjusted so as to obtain a desired softening temperature, and the types and number of crystalline polyesters and release agents, and the cooling step are described in Table 2-1. Comparative toner particles 1 to 11 were produced in the same manner except for the above. Further, Table 2-2 shows the relationship between Expression (1) and Expression (2).

<Production of Toners 1 to 21 and Comparative Toners 1 to 11>
Mitsui Henschel mixer (100 parts of toner particles 1) and 0.8 parts of hydrophobic silica fine powder obtained by subjecting dry silica fine particles having a BET value of 300 m ² / g (primary particle size 8 nm) to hexamethyldisilazane treatment ( Toner 1 was obtained by mixing with Mitsui Miike Chemical Industries, Ltd.

  Further, toners 2 to 14 and comparative toners 1 to 11 were obtained in the same manner except that toner particles 1 were changed to toner particles 2 to 14 and comparative toner particles 1 to 11. Each toner had a weight average particle diameter (D4) of 6.0 to 9.0 μm.

<Example 1>
(Initial developability)
An LBP3410 (a monochrome laser beam printer manufactured by Canon Inc.) was used as an image forming apparatus, and the toner 1 was used and left for 1 day in a normal temperature and humidity environment (23 ° C./60% RH). A4 color laser copy paper (manufactured by Canon, 80 g / m ² ) was used as the paper type. Five solid images were output continuously in a room temperature and humidity environment, and the resulting 5 solid images were measured using a printed image density (Macbeth reflection densitometer (Macbeth Co., Ltd.)). As the solid density was higher, the evaluation was made with the development property being better.

(Image density uniformity)
Using the toner 1, the following evaluation was performed.

FOX RIVER BOND paper (110 g / m ² ) is used as the fixing medium, and as the image forming apparatus, the image forming apparatus used for the evaluation of developability is set to a process speed of 400 mm / s, and the developing bias can be changed. Also modified. The evaluation image is a solid image, the development bias is set to increase the reflection density of the solid portion to increase the amount of toner on the image, and by using thick paper with relatively large surface irregularities, the concave portion of the paper is used in the fixing process. Further, since the toner in the lower layer portion of the toner layer is difficult to melt, the uniformity becomes severe. Even in the evaluation environment, if the temperature is low, the fixing device is difficult to warm up, and the evaluation is severe.

The evaluation procedure is shown below. First, the image forming apparatus was left overnight in a low-temperature and low-humidity environment (temperature: 15 ° C., humidity: 10%). Thereafter, when a solid image is printed using FOX RIVE BOND paper, development is performed so that the image density (measured using a Macbeth reflection densitometer (manufactured by Macbeth)) is 1.5 or more and 1.55 or less. The bias was adjusted. After leaving for 1 hour in a low-temperature, low-humidity environment, 50 solid images are output with the adjusted bias setting, and the density of the 1st, 10th, 25th, and 50th images is equally spaced from the top to the bottom. The density of the region divided into 5 parts and further divided into 4 parts at equal intervals was measured. The image density uniformity was evaluated by observing the fluctuation of a total of 80 density measurement values.
A; Concentration difference is 0.1 or less B; Concentration difference is 0.25 or less C; Concentration difference is 0.5 or less D; Concentration difference is 0.8 or less E; Concentration difference is 0.9 or more

(Procedure for leaving a harsh environment)
The toner 1 is placed in a thermostat adjusted to 22 ° C. and 90% RH, and an aging treatment is performed for 24 hours. Thereafter, the temperature is raised at a rate of 17.5 ° C. per hour and adjusted to 57 ° C. and 90% RH over 2 hours. In this state, after holding for 2 hours, the temperature is lowered at a rate of 17.5 ° C. per hour and returned to 22 ° C. and 90% RH. And after hold | maintaining for 2 hours, it heats up again. In this way, the temperature was increased and decreased 10 times as shown in FIG. 3 at the temperatures and humidity of 22 ° C., 90% RH, 57 ° C., 90% RH.

  By using this mode, abrupt thermal fluctuations are imparted to the toner and repeated high and low temperatures to promote mass transfer inside the toner and make it easier for the crystalline substance to ooze out on the toner surface. Among the evaluations related to leaving the environment, it is severe for toner.

Before and after leaving such a harsh environment, the presence / absence of visible toner aggregation and initial developability were evaluated to evaluate the storage stability.
A: There is no change in appearance and developability before and after leaving in a severe environment. Initial density change is 0.09 or less.
B: Although there is no change in appearance before and after leaving the harsh environment, the initial concentration fluctuates between 0.10 and 0.20. C: There is no change in appearance before and after leaving the harsh environment, but the initial concentration is 0.21 or more and 0. .50 or less Fluctuation D: Some agglomerates are seen before and after leaving in a severe environment.
E: Agglomerates are clearly seen before and after standing in a severe environment.

<Examples 2 to 14>
In Example 1, an image forming test was performed in the same manner as in Example 1 except that the toner 1 was changed to the toners 2 to 14. The evaluation results are shown in Table 3.

<Comparative Examples 1-11>
In Example 1, an image output test was performed in the same manner as in Example 1 except that the toner 1 was changed to the comparative toners 1 to 11. The evaluation results are shown in Table 3.

  DESCRIPTION OF SYMBOLS 100 Photosensitive drum (image carrier, to-be-charged body), 102 Developing sleeve (toner carrier), 114 Transfer charging roller (transfer member), 116 Cleaner, 117 Primary charging roller (contact charging member), 121 Laser generator (latent (Image forming means, exposure apparatus), 124 register roller, 125 transport belt, 126 fixing device, 140 developing device, 141 stirring member

Claims (6)

A toner having toner particles containing a binder resin, a colorant, a release agent and a crystalline polyester,
The ratio of the content of the crystalline polyester to the content of the release agent is 0.20 or more and 0.95 or less,
The mold release agent is heated to 180 ° C. using a differential scanning calorimeter (DSC) and then the maximum exothermic peak temperature of the DSC curve obtained in the process of lowering the temperature is Tcw, and the crystalline polyester is subjected to differential scanning calorimeter (DSC). ), When the maximum exothermic peak temperature of the DSC curve obtained in the process of lowering the temperature is Tcp and the softening temperature of the toner is Ts, the Tcw, Tcp and Ts Satisfy (1)
When the maximum exothermic peak temperature of the DSC curve obtained in the process of raising the temperature of the toner to 180 ° C. using a differential scanning calorimeter (DSC) and then lowering the temperature is Tc (max), the Ts and the Tc (max And a toner satisfying the following formula (2).
Tcp <Ts <Tcw Formula (1)
Tc (max) <Ts Formula (2)   In the DSC curve obtained in the process of raising the temperature of the toner to 180 ° C. using a differential scanning calorimeter (DSC) and then lowering the temperature, the calorific value (J / g) derived from the release agent is the release agent. The toner according to claim 1, wherein the toner is 20% or less with respect to a theoretical calorific value (J / g) calculated from the content of.   In the DSC curve obtained in the process of raising the temperature of the toner to 180 ° C. using a differential scanning calorimeter (DSC) and then lowering the temperature, the total calorific value (J / g) in the region of 20 ° C. to 100 ° C. is The toner according to claim 1, wherein the toner is 60% or more with respect to a theoretical total calorific value (J / g) calculated from the contents of the release agent and the crystalline polyester.   The toner is heated to 180 ° C. using a differential scanning calorimeter (DSC), and then the total calorific value (J / g) in the region of 20 ° C. to 100 ° C. is obtained in the DSC curve obtained in the process of lowering the temperature. 4. The toner according to claim 1, wherein a ratio of a calorific value (J / g) of an exothermic peak having the Tc (max) is 0.50 or more and 1.00. 5.   The toner according to claim 1, wherein the binder resin contains a styrene acrylic resin as a main component.   The release agent according to any one of claims 1 to 5, comprising a condensate of a divalent to hexavalent alcohol and a monocarboxylic acid, or a condensate of a monoalcohol and a divalent to hexavalent carboxylic acid. toner.

Images