JP7435094B2 - Toner for developing electrostatic images - Google Patents

Description

The present invention relates to a toner for developing electrostatic images. More specifically, the present invention relates to a toner for developing electrostatic images that can suppress tacking and prevent wax from adhering to the interior of the machine, including the conveyance member, even if the toner component has an improved low-temperature fixability.

Toners containing crystalline resins and low melting point release agents have been proposed as toners for electrostatic charge development (hereinafter also simply referred to as "toners") with improved low-temperature fixability.

However, it is known that in the image after fixing, the crystalline resin in the toner does not fully recrystallize and the elasticity of the toner is low, resulting in a tacking phenomenon in which the images stick together at the paper ejection section of the image forming device. It is being

In addition, when a toner containing a low melting point release agent comes into contact with a member such as a transport roller while the wax present on the surface layer of the image is in a molten state during image transport, the wax cools and cools down upon contact with the member. There are problems such as sticking, poor transportation, contamination inside the machine, and excessive wax being transferred to the image, causing uneven gloss.

Patent Document 1 proposes a toner in which a crystalline resin having a nucleating agent structure is dispersed while using a vinyl resin as a main binder for the purpose of suppressing performance fluctuations in a high temperature and high humidity environment.

However, the above proposal does not contain hydrocarbon wax as a release agent, and since the wax in the image surface layer comes into contact with the conveying member and other images while being molten, it is difficult to prevent tacking and prevent wax from adhering to the member. is not enough.

Patent Document 2 proposes an electrostatic charge developing toner that uses a hydrocarbon wax as a release agent and contains both a vinyl resin and a crystalline resin for the purpose of suppressing filming after high-temperature storage.

However, since the crystalline resin does not contain a nucleating agent structure, the recrystallization speed of the crystalline component in the electrostatic charge developing toner cannot keep up with the paper discharge speed, and the desired performance is also not achieved.

JP 2017-173555 Publication JP 2019-168618 Publication

The present invention has been made in view of the above-mentioned problems and situations, and the problem to be solved is to suppress tacking even with a toner component composition that improves low-temperature fixability, and to improve image forming apparatuses including conveyance members. An object of the present invention is to provide a toner for developing an electrostatic image that can suppress wax adhesion inside the toner.

In order to solve the above problems, the present inventors, in the process of studying the causes of the above problems, discovered that an amorphous resin and a crystalline resin contained at least as a binder resin in toner base particles, and a release agent. While considering the desirable functions and conditions of the matrix (corresponding to the "sea") and the domain (corresponding to the "island") in the matrix-domain structure (also referred to as the "sea-island structure") consisting of The inventors have found a specific situation that can solve the above problems and have arrived at the present invention.
That is, the above-mentioned problems related to the present invention are solved by the following means.

1. A toner for developing electrostatic images comprising toner base particles containing at least a release agent and a binder resin,
Containing at least a hydrocarbon wax as the mold release agent,
The binder resin contains at least a vinyl resin and a crystalline resin,
The content of the vinyl resin in the binder resin is 60 % by mass or more ,
the crystalline resin is a crystalline polyester,
The crystalline resin is a hybrid crystalline polyester resin formed by combining a crystalline polyester polymerized segment and a polymerized segment of another type of resin,
The content of the crystalline resin in the binder resin is 4 to 15% by mass,
The weight average molecular weight (Mw) of the crystalline resin satisfies the following formula (4),
1000≦Mw(C)≦16000…(4)
The crystalline resin has a part having a crystal structure and a crystal nucleating part,
the crystal nucleating agent moiety is stearic acid or stearyl alcohol, and
The crystal nucleating agent moiety is a moiety derived from at least one compound selected from the group consisting of aliphatic monocarboxylic acids having at least 10 to 30 carbon atoms or aliphatic monoalcohols having 10 to 30 carbon atoms,
The proportion of the crystal nucleating agent moiety in the crystalline resin is within the range of 3 to 9% by mass.
A toner for developing electrostatic images characterized by :
2 . 2. The toner for developing electrostatic images according to item 1, wherein the hydrocarbon wax used as the release agent has a melting point within a range of 80 to 92°C.
3 . 3. The toner for developing an electrostatic image according to item 1 or 2, wherein the hydrocarbon wax used as the release agent has a melting point within a range of 80 to 88°C.

By the above means of the present invention, even if the toner component has an improved low-temperature fixability, tacking can be suppressed and wax adhesion inside an image forming apparatus including a conveying member can be suppressed. can provide toner for
Although the mechanism of expression or action of the effects of the present invention is not clear, it is considered as follows.

First, the present inventor conjectures that the mechanism by which the toner of the present invention can simultaneously suppress tacking and suppress wax adhesion into the image forming apparatus is as follows.

Toner containing a crystalline resin that has excellent low-temperature fixability does not undergo recrystallization during the process of being ejected after fixing, resulting in tacking in which overlapping images stick to each other.

In addition, low melting point mold release agents are generally ester-based, which promotes tacking by becoming compatible with the binder resin, and cool and solidify when they come into contact with conveying materials in a molten state. , poor conveyance, contamination inside the machine, and excessive wax being transferred to the image, causing uneven gloss.

Generally, it is known that introducing a crystal nucleating agent moiety into a crystalline resin can speed up the crystallization rate of the crystalline resin itself and is effective in suppressing tacking. It does not change the state of existence of the crystalline domain itself.

Therefore, although it has the effect of increasing the viscosity upon contact with the member, it is not sufficient in terms of improving wax adhesion.

Using hydrocarbon wax as a mold release agent generally has a higher melting point than ester wax, so it is effective against wax adhesion, and has a fast crystallization initiation speed, which is effective in suppressing tacking. The high temperature deteriorates low-temperature fixability.

Furthermore, the compatibility with the binder resin decreases, leading to bleed-out and deterioration of heat resistance.

When these are used in combination, the hydrocarbon wax has affinity due to the nucleating agent moiety having a long-chain aliphatic structure, so bleed-out can be prevented, but there is no effect of preventing deterioration of low-temperature fixability.

At this time, if 60 % by mass or more of a vinyl resin, a crystalline resin having a nucleating agent site is used as a binder resin, and a hydrocarbon wax is used as a mold release agent, the vinyl resin becomes the sea side of the sea-island structure and the crystalline resin Since the domains can be finely dispersed, it helps the crystalline resin domains to crystallize quickly, which is effective in suppressing tacking, and also quickly melts the entire toner, which is effective in low-temperature fixing properties. .

In addition, since the vinyl resin has a seaward structure, the hydrocarbon wax domain with low compatibility can be placed closer to the inside of the toner, which is further effective in suppressing wax adhesion.

Therefore, the mold release agent contains at least a hydrocarbon wax, the binder resin contains at least a vinyl resin and a crystalline resin, and the content of the vinyl resin in the binder resin is 50% by mass or more. In a toner in which the crystalline resin has a region having a crystal structure and a crystal nucleating region, it is possible to achieve both good low-temperature fixability and suppression of tacking.

The toner for developing electrostatic latent images of the present invention is a toner for developing electrostatic latent images that includes toner base particles containing at least a release agent and a binder resin, and contains at least a hydrocarbon wax as the release agent. The binder resin contains at least a vinyl resin and a crystalline resin, the content of the vinyl resin in the binder resin is 60 % by mass or more , and the crystalline resin is a crystalline polyester. and the crystalline resin is a hybrid crystalline polyester resin formed by bonding a crystalline polyester polymerized segment and a polymerized segment of another type of resin, and the content of the crystalline resin in the binder resin is 4 to 15% by mass, the weight average molecular weight (Mw) of the crystalline resin satisfies the formula (4), the crystalline resin has a site having a crystal structure and a crystal nucleating agent site , and the crystalline resin has a crystal structure and a crystal nucleating agent site; A nucleating agent moiety is stearic acid or stearyl alcohol, and the crystal nucleating agent moiety is selected from the group consisting of an aliphatic monocarboxylic acid having at least 10 to 30 carbon atoms or an aliphatic monoalcohol having 10 to 30 carbon atoms. The crystal nucleating agent site is derived from at least one compound contained in the crystalline resin, and the proportion of the crystal nucleating agent site in the crystalline resin is within the range of 3 to 9% by mass . This feature is a technical feature common to or corresponding to each of the embodiments described below.

In an embodiment of the present invention , the crystal nucleating agent moiety is at least one member selected from the group consisting of aliphatic monocarboxylic acids having at least 10 to 30 carbon atoms or aliphatic monoalcohols having at least 10 to 30 carbon atoms. It is a part derived from a compound, and has excellent tacking suppression and low-temperature fixing properties.

The content of the vinyl resin in the binder resin is 60% by mass or more, and the low-temperature fixability is excellent .

The crystalline resin in the binder resin is a crystalline polyester, and has excellent sharp melt properties when melted and compatibility with the binder resin.

The content of the crystalline resin in the binder resin is within the range of 4 to 15% by mass, which provides excellent tacking suppression and low-temperature fixing properties.

The proportion of the crystal nucleating agent moiety in the crystalline resin is within the range of 3 to 9% by mass, and the resin has excellent low-temperature fixability.

From the viewpoint of controlling compatibility, it is preferable that the crystalline resin is a hybrid crystalline polyester resin formed by bonding a crystalline polyester polymerized segment and a polymerized segment of another type of resin.

It is even more preferable that the weight average molecular weight (Mw) of the crystalline resin satisfies the following formula (3) from the viewpoint of achieving both low-temperature fixability and tacking suppression.
1000≦Mw(C)≦15000...(3)

It is preferable that the melting point of the hydrocarbon wax used as the mold release agent is within the range of 80 to 92° C. from the viewpoint of suppressing tacking and low-temperature fixability.

It is more preferable that the melting point of the hydrocarbon wax used as the mold release agent is within the range of 80 to 88° C. from the viewpoint of suppressing tacking and low-temperature fixability.

Hereinafter, the present invention, its constituent elements, and forms and aspects for carrying out the present invention will be described in detail. In this application, "~" is used to include the numerical values described before and after it as a lower limit value and an upper limit value.

[Overview of the electrostatic image developing toner of the present invention]
The toner for developing electrostatic latent images of the present invention is a toner for developing electrostatic latent images that includes toner base particles containing at least a release agent and a binder resin, and contains at least a hydrocarbon wax as the release agent. The binder resin contains at least a vinyl resin and a crystalline resin, the content of the vinyl resin in the binder resin is 50% by mass or more, and the crystalline resin has a crystal structure. It is characterized by having a crystal nucleating agent site and a crystal nucleating agent site.

By having the above characteristics, the toner can suppress tacking and wax adhesion inside the image forming apparatus, disperse the crystalline component in a finer domain state, and have excellent low-temperature fixability.

In this specification, "toner base particles" constitute the base of "toner particles." The "toner base particles" contain at least a binder resin, and may contain other components such as a colorant, a release agent (wax), and a charge control agent, if necessary. The "toner base particles" are called "toner particles" by adding external additives. The term "toner" refers to an aggregate of "toner particles."
Hereinafter, the constituent elements of the electrostatic charge developing toner of the present invention will be explained in detail.

I. Components of toner for developing electrostatic images 1. Release Agent The toner for electrostatic charge development of the present invention contains at least a release agent, and the release agent contains at least a hydrocarbon wax.

Hydrocarbon wax generally has a high melting point and a high crystallization initiation temperature, which works to suppress tacking. In addition, lowering the affinity with the fixing member leads to the prevention of adhesion to the member, which in turn leads to suppression of internal contamination and image unevenness.

The melting point of the hydrocarbon wax used as the mold release agent according to the present invention is preferably within the range of 80 to 92°C from the viewpoint of suppressing tacking and low-temperature fixing properties, and more preferably within the range of 80 to 88°C. .

The hydrocarbon wax is not particularly limited, and any known hydrocarbon wax can be used.

Examples of the hydrocarbon wax include aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax; These block copolymers include waxes obtained by grafting aliphatic hydrocarbon wax with a vinyl monomer such as styrene or acrylic acid.

The content of the release agent can be generally in the range of 1 to 30 parts by weight, preferably in the range of 5 to 20 parts by weight, based on 100 parts by weight of the binder resin. When the content of the release agent is within the above range, sufficient fixing and separability can be obtained.
The content of the release agent in the toner particles is preferably in the range of 3 to 15% by mass.

2. Binder Resin The toner for electrostatic image development of the present invention contains at least a vinyl resin and a crystalline resin as a binder resin, and the content of the vinyl resin in the binder resin is 50% or more. be.

When the content of the vinyl resin in the binder resin is 60% by mass or more, low-temperature fixability is excellent .
The crystal nucleating agent site in the crystalline resin has the effect of accelerating the crystallization rate of the crystalline component and suppressing tacking.

It is preferable that the crystalline resin in the binder resin is a crystalline polyester from the viewpoint of sharp melt property when melted and compatibility with the binder resin.

The content of the crystalline resin in the binder resin is preferably within the range of 4 to 15% by mass from the viewpoint of suppressing tacking and low-temperature fixability.
By falling within this range, it is difficult for the domains in the matrix domain structure to form a finely dispersed state, thereby suppressing the appearance of portions that cannot be completely recrystallized, suppressing tacking, and further improving low-temperature fixability.

The "matrix domain structure" is also referred to as the "sea-island structure," and the sea-island structure refers to the continuous phase (the continuous phase corresponds to the "matrix" and the "sea") in the binder resin that constitutes the toner base particles. A structure in which island-like phases (“domains”) with closed interfaces (boundaries between phases) exist within a region (which represents a domain).

In other words, "matrix domain structure" means that when a plurality of mutually incompatible resin components (for example, two types) are mixed, one of the resin components forms a continuous phase (sea) as a higher-order structure of the mixture. A structure in which the other is scattered in the form of islands or particles.

In other words, it refers to a structure formed by one resin becoming a continuous phase (sea) corresponding to a matrix and the other becoming an island-like independent phase (dispersed phase) corresponding to domains. Incidentally, a case in which a portion of each individual domain itself is exposed on the surface of the matrix domain structure (toner base particle) is also included.

(2.1) Amorphous resin The toner for electrostatic image development of the present invention contains at least a vinyl resin and a crystalline resin as a binder resin, but the vinyl resin is an amorphous resin. It is preferable that there be.
Here, "showing amorphous" means having a glass transition point (Tg) in an endothermic curve obtained by differential scanning calorimetry (DSC), but having a melting point, that is, a clear endotherm when the temperature is increased. This means that there is no peak.

Note that the term "clear endothermic peak" refers to an endothermic peak whose half-width is within 15°C in an endothermic curve when the temperature is increased at a rate of 10°C/min.

(2.1.1) Amorphous vinyl resin Amorphous vinyl resin refers to a polymer of a monomer having a vinyl group (hereinafter referred to as vinyl monomer) that exhibits amorphous properties.

Examples of the amorphous vinyl resin that can be used include styrene-acrylic resin, styrene resin, acrylic resin, etc. Among them, styrene-acrylic resin is preferred because of its excellent heat resistance.

Vinyl monomers that can be used include the following (1) to (7), one of which can be used alone or two or more can be used in combination.

(1) Styrenic monomers styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert-butyl Monomers having a styrene structure such as styrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene and derivatives thereof

(2) (meth)acrylic acid ester monomer Methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isopropyl (meth)acrylate, isobutyl (meth)acrylate, (meth)acrylate monomer ) t-Butyl acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, phenyl (meth)acrylate, (meth)acrylate Monomers having a (meth)acrylic group such as diethylaminoethyl acid, dimethylaminoethyl (meth)acrylate, and derivatives thereof

(3) Vinyl esters Vinyl propionate, vinyl acetate, vinyl benzoate, etc.

(4) Vinyl ethers Vinyl methyl ether, vinyl ethyl ether, etc.

(5) Vinyl ketones Vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, etc.

(6) N-vinyl compounds N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidone, etc.

(7) Others Vinyl compounds such as vinylnaphthalene and vinylpyridine, acrylic acid and methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide, etc.

As the vinyl monomer, it is preferable to use a monomer having an ionic dissociative group such as a carboxy group, a sulfonic acid group, a phosphoric acid group, etc., since the affinity with the crystalline resin can be easily controlled.

Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, monoalkyl maleate, and monoalkyl itaconic acid.

Examples of the monomer having a sulfonic acid group include styrene sulfonic acid, allylsulfosuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, and the like.

Examples of the monomer having a phosphoric acid group include acid phosphooxyethyl methacrylate.

Furthermore, it is also possible to obtain a polymer having a crosslinked structure by using polyfunctional vinyls as the vinyl monomer.

Examples of polyfunctional vinyls include divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, and neopentyl glycol. Examples include diacrylate.

(2.1.2) Amorphous polyester resin Amorphous polyester resin consists of divalent or higher carboxylic acid (polyvalent carboxylic acid) monomer and divalent or higher alcohol (polyhydric alcohol) monomer. Among the polyester resins obtained by the polymerization reaction, it is a resin that exhibits amorphous properties. An amorphous polyester resin can be formed by polymerizing (esterifying) the polyhydric carboxylic acid monomer and polyhydric alcohol monomer using a known esterification catalyst.

A polyhydric carboxylic acid monomer is a compound containing two or more carboxy groups in one molecule.
Examples of polycarboxylic acid monomers that can be used to synthesize the amorphous polyester resin include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, mesaconic acid, Examples include dimethyl isophthalate, fumaric acid, dodecenylsuccinic acid, and 1,10-dodecanedicarboxylic acid.
Among these, dimethyl isophthalate, terephthalic acid, dodecenylsuccinic acid, and trimellitic acid are preferred.

A polyhydric alcohol monomer is a compound containing two or more hydroxy groups in one molecule.
Examples of polyhydric alcohol monomers that can be used to synthesize the amorphous polyester resin include ethylene glycol, propylene glycol, 1,4-butanediol, 2,3-butanediol, and dihydric or trihydric alcohols. Diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, ethylene oxide adduct of bisphenol A ( BPA-EO), propylene oxide adduct of bisphenol A (BPA-PO), glycerin, sorbitol, 1,4-sorbitan, trimethylolpropane, and the like.
Among these, ethylene oxide adducts of bisphenol A and propylene oxide adducts of bisphenol A are preferred.

Usable esterification catalysts include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; metal compounds such as aluminum, zinc, manganese, antimony, titanium, tin, zirconium, and germanium; Examples include phosphoric acid compounds; phosphoric acid compounds; amine compounds;

Although the polymerization temperature is not particularly limited, it is preferably within the range of 150 to 250°C.
Furthermore, the polymerization time is not particularly limited, but is preferably within the range of 0.5 to 10 hours. During the polymerization, the pressure inside the reaction system may be reduced if necessary.

(2.1.3) Preferable glass transition point of amorphous resin The glass transition point (Tg) of an amorphous resin is 25 to 60°C from the viewpoint of achieving both sufficient low-temperature fixability and heat-resistant storage. The temperature is preferably 35 to 55°C, more preferably 35 to 55°C.

The glass transition point (Tg) can be measured using a differential scanning calorimeter, for example, Diamond DSC (manufactured by PerkinElmer).

Specifically, 3.0 mg of a sample is sealed in an aluminum pan, and the temperature is varied in the order of heating, cooling, and heating.

The temperature was raised from room temperature (25°C) during the first heating and from 0°C during the second heating to 200°C at a heating rate of 10°C/min, and held at 150°C for 5 minutes. During cooling, the temperature was lowered from 200°C to 0°C at a cooling rate of 10°C/min, and the temperature of 0°C was maintained for 5 minutes.

Observe the shift of the baseline in the measurement curve obtained during the second heating, and determine the intersection point between the extension line of the baseline before the shift and the tangent line showing the maximum slope of the shifted portion of the baseline as the glass transition point (Tg ). An empty aluminum pan is used as a reference.

(2.1.4) Preferable weight average molecular weight of amorphous resin The weight average molecular weight (Mw) of the amorphous resin can be within the range of 10,000 to 100,000.

(2.2) Crystalline Resin The crystalline resin according to the present invention has a site having a crystal structure and a crystal nucleating agent site.
Note that the crystalline resin is not limited as long as it exhibits crystallinity, and any known crystalline resin can be used.

Here, "exhibiting crystallinity" means having a clear endothermic peak at the melting point, that is, when the temperature is increased, in an endothermic curve obtained by DSC.

A clear endothermic peak is a peak whose half-width is within 15°C in an endothermic curve when the temperature is increased at a rate of 10°C/min.

The crystal nucleating agent moiety is derived from at least one compound selected from the group consisting of aliphatic monocarboxylic acids having at least 10 to 30 carbon atoms or aliphatic monoalcohols having 10 to 30 carbon atoms. It has excellent tacking control and low-temperature fixing properties.

When the content of the crystal nucleating agent site in the crystalline resin is 3 % by mass or more, the effect of promoting crystallization is enhanced .

When the content of the crystal nucleating agent moiety in the crystalline resin is 9 % by mass or less, the crystallization start temperature does not become too high, resulting in excellent low-temperature fixability.

When the number of carbon atoms is 10 or more, it becomes easier to form incompatible domains, which is excellent in terms of suppressing tacking.

Further, when the number of carbon atoms is 30 or less, the crystallization start temperature does not become too high, which is excellent in terms of low-temperature fixability.

The content of the crystalline resin in the binder resin is within the range of 4 to 15% by mass, which provides excellent tacking suppression and low-temperature fixing properties.

If the content is 4% by mass or more, it is excellent from the viewpoint of low-temperature fixing properties, and if the content is 15% by mass or less, it is easy to create a finely dispersed state of the domains, making it difficult for parts that cannot be completely recrystallized to appear, from the viewpoint of suppressing tacking. Excellent.

From the viewpoint of controlling compatibility, it is preferable that the crystalline resin is a hybrid crystalline polyester resin formed by bonding a crystalline polyester polymerized segment and a polymerized segment of another resin.

The weight average molecular weight (Mw) of the crystalline resin satisfies the following formula ( 4 ), and low-temperature fixability and tacking suppression can be achieved at the same time.
1000≦Mw(C)≦ 16 000...( 4 )

It is even more preferable that the weight average molecular weight (Mw) of the crystalline resin satisfies the following formula (3) from the viewpoint of achieving both low-temperature fixability and tacking suppression.
1000≦Mw(C)≦15000...(3)

When the polymerization average molecular weight is 1,000 or more, melting is not too fast and is excellent from the viewpoint of suppressing tacking, and when the polymerization average molecular weight is 16,000 or less, it is easy to melt and is excellent from the viewpoint of low-temperature fixability.

(2.2.1) Melting point of crystalline resin The melting point (Tm) of the crystalline resin can be controlled by the resin composition.
Furthermore, in the present invention, the melting point of the crystalline resin is preferably within the range of 55 to 90°C, more preferably 70 to 85°C, from the viewpoint of obtaining sufficient low-temperature fixing properties and excellent hot offset resistance. be.

(2.2.2) Method for measuring melting point of crystalline resin Note that the melting point (Tm) is the temperature at the top of an endothermic peak, and can be measured by DSC.

Specifically, the sample was placed in an aluminum pan KITNO. It is sealed in B0143013 and set in the sample holder of a thermal analysis device Diamond DSC (manufactured by PerkinElmer), and the temperature is varied in the order of heating, cooling, and heating.

During the first heating, the temperature was raised from room temperature (25°C), and during the second heating from 0°C, the temperature was raised to 150°C at a heating rate of 10°C/min, and 150°C was maintained for 5 minutes. The temperature is lowered from 150°C to 0°C at a cooling rate of °C/min, and the temperature of 0°C is maintained for 5 minutes.

The temperature at the top of the endothermic peak in the endothermic curve obtained during the second heating is measured as the melting point.

(2.2.3) Site having a crystalline structure In the present invention, the term "site having a crystalline structure" refers to a site in a crystalline resin that has a structure exhibiting crystallinity.

The site having the crystal structure is present around the crystal nucleating agent site described below, so that when the crystal nucleating agent site crystallizes first, crystallization is promoted starting from this crystal nucleating agent site.

Further, as the crystalline resin, it is preferable to use a known crystalline resin (for example, a crystalline polyester resin, a crystalline polyurethane resin, etc.), and in particular, it is preferable to use a crystalline polyester resin because it has a sharp melting property when melted. It is preferable from the viewpoint of compatibility with the resin and the binder resin.
That is, it is preferable that the region having the crystal structure contains a crystalline polyester resin.

(Crystalline polyester resin)
In the present invention, the crystalline polyester resin refers to known polyester resins obtained by a polycondensation reaction between a divalent or higher carboxylic acid (polyvalent carboxylic acid) and a divalent or higher alcohol (polyhydric alcohol). Refers to a resin exhibiting the above-mentioned crystallinity.

The polyhydric carboxylic acid is a compound containing two or more carboxy groups in one molecule.

Specifically, for example, oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, n-dodecylsuccinic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid (dodecanedioic acid) , saturated aliphatic dicarboxylic acids such as tetradecanedicarboxylic acid (tetradecanedioic acid); cycloaliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; trimellitic acid, pyromellitic acid and anhydrides of these carboxylic acid compounds, or alkyl esters having 1 to 3 carbon atoms.
These may be used alone or in combination of two or more.

The polyhydric alcohol is a compound containing two or more hydroxy groups in one molecule.

Specifically, for example, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1 , 8-octanediol, 1,9-nonanediol, dodecanediol, neopentyl glycol, 1,4-butenediol, and other aliphatic diols; trivalent or higher polyhydric diols such as glycerin, pentaerythritol, trimethylolpropane, and sorbitol Examples include alcohol. These may be used alone or in combination of two or more.

The method for forming the crystalline polyester resin is not particularly limited, and it can be formed by polycondensing (esterifying) the polyhydric alcohol component and the polyhydric carboxylic acid component using a known esterification catalyst. .

The ratio of the polyhydric alcohol component to the polyhydric carboxylic acid component used is such that the equivalent ratio of the hydroxyl group of the polyhydric alcohol component to the carboxy group of the polyhydric carboxylic acid component is 1.5/1 to 1/1. It is preferably within the range of 5, and more preferably within the range of 1.2/1 to 1/1.2.

Catalysts that can be used in the production of crystalline polyester resin include alkali metal compounds such as sodium and lithium, alkaline earth metal compounds such as magnesium and calcium, aluminum, zinc, manganese, antimony, titanium, tin, zirconium, Examples include metal compounds such as germanium, phosphorous acid compounds, phosphoric acid compounds, and amine compounds.

Specifically, examples of the tin compound include dibutyltin oxide, tin octylate, tin dioctylate, salts thereof, and the like.

Examples of titanium compounds include titanium alkoxides such as tetra-n-butyl titanate, tetraisopropyl titanate, tetramethyl titanate, and tetrastearyl titanate, titanium acylates such as polyhydroxytitanium stearate, titanium tetraacetylacetonate, titanium lactate, and titanium triethanolamine. Examples include titanium chelates such as nate.

Examples of germanium compounds include germanium dioxide and the like.

Examples of the aluminum compound include oxides such as polyaluminum hydroxide, aluminum alkoxide, and tributyl aluminate.
These may be used alone or in combination of two or more.

The polymerization temperature and polymerization time are not particularly limited, and the pressure inside the reaction system may be reduced as necessary during the polymerization.

[Hybrid crystalline polyester resin]
In the present invention, by containing a hybrid crystalline polyester resin formed by chemically bonding a crystalline polyester polymerized segment and a vinyl resin polymerized segment as the crystalline resin, it can be more easily finely dispersed in the toner. , excellent low-temperature fixing properties.
That is, the site having the crystal structure contains the hybrid crystalline polyester resin.

The ratio of the aliphatic carboxylic acid monomer and aliphatic alcohol monomer derived from the crystal nucleating agent site is within the range of 0.1 to 3 mol% with respect to all units derived from the monomers constituting the crystalline polyester polymerization segment. The amount is preferably within the range of 0.5 to 1 mol%.
If the ratio is 0.1 mol% or more, the effect of suppressing fluctuations in the fixability of the crystal nucleating agent part as a crystal nucleating agent can be sufficiently achieved, and if the ratio is 3 mol% or less, the crystal nucleating agent part The melting point does not become too high, and low-temperature fixing properties can be made more suitable.

[Crystalline polyester polymerization segment]
The crystalline polyester polymerized segment is a portion derived from a crystalline polyester resin, and refers to a resin segment that has a clear endothermic peak rather than a step-like endothermic change in differential scanning calorimetry (DSC) of a toner.

The crystalline polyester polymerization segment is not particularly limited as long as it is as defined above.

For example, for resins that have a structure in which other components are copolymerized with the main chain of crystalline polyester polymerized segments, or resins that have a structure in which crystalline polyester polymerized segments are copolymerized with the main chain of other components, this resin may be used. If the toner contained therein exhibits a clear endothermic peak as described above, the resin corresponds to a hybrid crystalline polyester resin having a crystalline polyester polymerized segment as defined in the present invention.

The crystalline polyester polymerized segment is produced by polycondensing (esterifying) a polyhydric carboxylic acid monomer and a polyhydric alcohol monomer.

As the polyhydric carboxylic acid monomer and polyhydric alcohol monomer, the same monomers as the polyhydric carboxylic acid monomer and polyhydric alcohol monomer that are raw materials for the crystalline polyester resin described above can be used.

The method for forming the crystalline polyester polymerized segment is not particularly limited, and the segment may be formed by polycondensing (esterifying) a polyhydric carboxylic acid and a polyhydric alcohol using a known esterification catalyst. Can be done.

[Preferred crystalline polyester polymerization segment]
The crystalline polyester polymerized segment used in the present invention is preferably one obtained by polymerizing a polyhydric alcohol monomer having a carbon number of 4 to 14 and a polyhydric carboxylic acid monomer having a carbon number of 4 to 14. When the number of carbon atoms is 4 or more, the number of hydrogen bonds derived from ester bonds does not become too large, the melting point of the crystalline polyester resin is prevented from becoming too high, and low-temperature fixing properties can be made more suitable. Further, when the number of carbon atoms is 14 or less, the interaction between the aliphatic groups will not become too strong, the melting point of the crystalline polyester resin will be prevented from becoming too high, and the low-temperature fixability can be made more suitable.

[Polymerization segment of vinyl resin]
A polymerized segment of a vinyl resin (also referred to as a vinyl polymerized segment) is synthesized from a vinyl monomer that is a raw material for the vinyl resin.

In the present invention, the crystalline resin preferably contains vinyl polymerized segments in a range of 3 to 40% by mass, most preferably in a range of 5 to 20% by mass. Thereby, low-temperature fixability can be improved.

In particular, if the content is 3% by mass or more, the stability of the interface between the crystalline resin and the vinyl resin, which is the main binder, will not decrease too much, and it will be possible to sufficiently finely disperse the resin, resulting in better low-temperature fixing properties. can.

The content of vinyl polymerized segments in the crystalline resin is not particularly limited, but is preferably 40% by mass or less from the viewpoint of chargeability.

In addition, especially when hybridizing with a vinyl polymer segment with low heat resistance, if the above content is 40% by mass or less, the compatibility with the vinyl resin, which is the main binder of the crystalline resin, will not become too high. As a result, heat-resistant storage properties can be improved.

Examples of the synthesis method of the hybrid crystalline polyester resin include the following synthesis methods (a), (b), and (c).

(b) After reacting a bireactive monomer with a crystalline polyester polymerization segment prepared in advance, the vinyl monomer, which is a raw material for vinyl resin, is reacted to chemically convert the vinyl polymerization segment into a crystalline polyester polymerization segment. How to combine.

(b) After reacting a bireactive monomer with a vinyl resin prepared in advance, a polyhydric carboxylic acid monomer and a polyhydric alcohol monomer, which are raw materials for crystalline polyester resin, are reacted to form a vinyl polymer segment that crystallizes. A method of chemically bonding polyester polymerized segments.

(c) A method of reacting a bireactive monomer with a crystalline polyester resin prepared in advance and a vinyl resin to chemically bond the crystalline polyester polymerization segment and the vinyl polymerization segment, respectively.

A bireactive monomer is a monomer that binds the crystalline polyester resin and the vinyl resin, and contains a hydroxy group, a carboxy group, an epoxy group, a primary amino group, or a primary amino group that can react with the crystalline polyester resin in the molecule. It is a monomer that has a substituent such as a secondary amino group and an ethylenically unsaturated group that can react with an amorphous resin.

Among these, vinylcarboxylic acids having a hydroxy group or a carboxy group and an ethylenically unsaturated group are preferred.

As the bireactive monomer, for example, (meth)acrylic acid, fumaric acid, maleic acid, etc. can be used, and esters of hydroxyalkyl (having 1 to 3 carbon atoms) thereof may also be used. From the viewpoint of reactivity, acrylic acid, methacrylic acid, or fumaric acid is preferred.

From the viewpoint of improving the low-temperature fixing properties, hot offset resistance, and durability of the toner, the amount of the bireactive monomer to be used is 1 to 1 to 1 parts by mass based on 100 parts by mass of the total amount of monomers used to form the vinyl polymerized segment. It is preferably within the range of 10 parts by mass, and more preferably within the range of 4 to 8 parts by mass.

(2.2.4) Crystal nucleating agent site In the present invention, a "crystal nucleating agent site" refers to a site where the crystallization rate is faster than the site having the crystal structure, and which is a crystallization rate that is faster during cooling. The nucleating agent site quickly generates a crystal nucleus, and by using the crystal nucleus as a starting point, the crystallization of the site having a crystal structure is promoted.

The compound is not particularly limited as long as it has a faster crystallization rate than the site having the crystal structure.

Further, from the viewpoint of a high crystallization rate, it is preferable that the main component is a compound containing a hydrocarbon moiety and having one or more functional groups capable of reacting with the terminal end of the polyester moiety.

Furthermore, a compound in which the hydrocarbon moiety is linear and has one or more functional groups that react with the polyester moiety is preferred.

In addition, the crystal nucleating agent site is not particularly limited as long as it does not inhibit the low-temperature fixability of the toner of the present invention and crystallizes faster than a crystalline resin without a crystal nucleating agent site, but it can nucleate more stably. The crystal nucleating agent site is as follows in order to exhibit the effect and, in turn, to express the effect of the present invention.

That is, the crystal nucleating agent moiety for expressing the effects of the present invention consists of an aliphatic monocarboxylic acid having a carbon number of 10 to 30 or an aliphatic monoalcohol having a carbon number of 10 to 30. A site derived from at least one compound selected from the group.

The aliphatic may be unsaturated, saturated, branched, or straight-chain, but it is not limited to unsaturated, saturated, branched, or straight-chain, but from the viewpoint of both folding and fixing properties and suppression of tacking, saturated straight-chain aliphatics with carbon numbers within the range of 10 to 20 are preferred. preferable

The crystal nucleating agent moiety described above may be bonded to any location among the moieties having the crystal structure, but it is preferable that the crystal nucleating agent moiety be bonded to the molecular chain end that tends to promote crystallization of the moiety having the crystal structure. is preferred.

(Aliphatic monocarboxylic acid)
Specific examples of the aliphatic monocarboxylic acids include stearic acid, lauric acid, arachidic acid, n-behenic acid, n-tetradocosanoic acid, n-hexadocosanoic acid, n-octadocosanoic acid, and n-triacontanoic acid. can be mentioned.

(aliphatic monoalcohol)
Examples of the aliphatic monoalcohol include stearyl alcohol, lauryl alcohol, behenyl alcohol, arachidyl alcohol, 1-octadecanol, 1-icosanol, 1-docosanol, 1-tetracosanol, 1-hexacosanol, and 1-octacosanol. , 1-triacontanol.

The proportion of the crystal nucleating agent moiety in the crystalline resin is within the range of 3 to 9 % by mass, and is excellent in tacking suppressing effect and folding and fixing properties.

When the content of the above-mentioned crystalline resin in the binder resin is within the range of 4 to 7 % by mass, both low-temperature fixability and tacking suppression can be achieved .

(2.2.5) Weight average molecular weight of crystalline resin In addition, the weight average molecular weight (Mw(C)) of the crystalline resin in the present invention satisfies the following formula ( 4 ) . Preferably, the following formula (3) is satisfied.

Formula ( 4 ): 1000≦Mw(C)≦ 16 00 0
Formula (3): 1000≦Mw(C)≦15000

When 1000≦Mw(C), the crystalline resins do not become too compatible after melting, and crystallization progresses, which is excellent in suppressing tacking. Further, since Mw (C)≦ 16,000 , the crystalline resin is easily compatible with the resin when melted, and is excellent in low-temperature fixability.

The method for measuring the weight average molecular weight of a crystalline resin is as follows.

Using gel permeation chromatography (GPC), stabilize the column at 40°C, flow tetrahydrofuran (THF) as a solvent through the column at this temperature at a flow rate of 0.2 mL/min, and adjust the sample concentration to 1 mg/mL. Measurement is performed by injecting approximately 10 μL of a THF sample solution of the prepared resin.

In measuring the molecular weight of a sample, it is detected using a refractive index detector (RI detector), and the molecular weight distribution of the sample is calculated using a calibration curve created using a monodisperse polystyrene standard sample.

Standard polystyrene samples for calibration curve measurement are manufactured by Pressure Chemical and have molecular weights of 6×10 ² , 2.1×10 ³ , 4×10 ³ , 1.75×10 ⁴ , 5.1×10 ⁴ , 1 Measure 10 standard polystyrene samples using .1×10 ⁵ , 3.9×10 ⁵ , 8.6×10 ⁵ , 2×10 ⁶ , 4.48×10 ⁶ and create a calibration curve do.

Note that the weight average molecular weight of the crystalline resin can be calculated by the above-mentioned measuring method after separating the crystalline resin and the release agent in the toner as described below.

(2.2.6) Separation of Crystalline Resin In the following, a case where a crystalline polyester resin is used as the crystalline resin will be explained as an example.
First, the toner is dispersed in ethanol, which is a poor solvent for the toner, and the temperature is raised to a temperature exceeding the melting points of the crystalline polyester and wax.

At this time, pressure may be applied if necessary. At this point, the crystalline polyester and wax above the melting point have melted.

Thereafter, a mixture of crystalline polyester and wax can be collected from the toner by solid-liquid separation.

By sorting this mixture according to molecular weight, it is possible to separate the crystalline polyester and wax from the toner.

(2.2.7) Acid value of crystalline resin The acid value is the mass of potassium hydroxide (KOH) required to neutralize the acid contained in 1 g of sample, expressed in mg.

(2.2.8) Method for measuring acid value of crystalline resin The acid value of crystalline resin is measured according to the following procedures (1) to (3) in accordance with JIS K0070-1966.

(1) Preparation of reagents Dissolve 1.0 g of phenolphthalein in 90 mL of ethyl alcohol (95% by volume), add ion-exchanged water to make 100 mL, and prepare a phenolphthalein solution.

Dissolve 7 g of JIS special grade potassium hydroxide in 5 mL of ion exchange water, and add ethyl alcohol (95% by volume) to make 1 liter. After leaving it in an alkali-resistant container for 3 days to avoid contact with carbon dioxide gas, filter it to prepare a potassium hydroxide solution. Orientation follows the description of JIS K0070-1966.

(2) Main test 2.0 g of the pulverized sample is accurately weighed into a 200 mL Erlenmeyer flask, 100 mL of a mixed solution of toluene/ethanol (2:1) is added, and the sample is dissolved over 5 hours.

Then, a few drops of the prepared phenolphthalein solution as an indicator are added and titrated using the prepared potassium hydroxide solution. The end point of the titration is when the indicator remains pale red for about 30 seconds.

(3) Blank test The same operation as in the above main test is performed except that no sample is used (that is, only a mixed solution of toluene/ethanol (2:1) is used).

The acid value is calculated by substituting the titration results of the main test and the blank test into the following formula (1).

Formula (1) A=[(B-C)×f×5.6]/S

A: Acid value (mgKOH/g)
B: Addition amount (mL) of potassium hydroxide solution during blank test
C: Addition amount (mL) of potassium hydroxide solution during this test
f: Factor of 0.1 mol/L potassium hydroxide ethanol solution S: Mass of sample (g)

3. Colorant As the colorant contained in the toner base particles according to the present invention, any known inorganic or organic colorant can be used.

As the colorant, in addition to carbon black and magnetic powder, various organic and inorganic pigments and dyes can be used. The amount of the colorant added is in the range of 1 to 30% by weight, preferably 2 to 20% by weight based on the toner particles.

4. Other Internal Additives and External Additives In addition to the above, the toner particles may contain internal additives such as a charge control agent, external additives, etc., as necessary.

5. Charge Control Agent As the charge control agent, known compounds such as nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, quaternary ammonium salts, azo metal complexes, metal salicylate salts, etc. can be used. .

By using the charge control agent, a toner with excellent charging properties can be obtained.
The content of the charge control agent can be generally within the range of 0.1 to 5.0 parts by mass based on 100 parts by mass of the binder resin.

6. External Additives The toner particles can be used as toners as they are, but may be treated with external additives such as fluidizers and cleaning aids in order to improve fluidity, charging properties, cleaning properties, and the like.

Examples of external additives include inorganic oxide particles such as silica particles, alumina particles, and titanium oxide particles, inorganic stearate compound particles such as aluminum stearate particles and zinc stearate particles, strontium titanate, and zinc titanate. Examples include inorganic titanic acid compound fine particles.

These can be used alone or in combination of two or more.

These inorganic particles are preferably gloss-treated with a silane coupling agent, a titanium coupling agent, a higher fatty acid, a silicone oil, etc. from the viewpoint of improving heat-resistant storage properties and environmental stability.

The amount of external additives added (if a plurality of external additives are used, the total amount added) is preferably in the range of 0.05 to 5 parts by mass, and 0.1 to 100 parts by mass of toner. It is more preferably within the range of 3 parts by mass.

7. Structure of toner particle The toner particle can be used as a toner as it is, but toner particles with a multilayer structure such as a core-shell structure, which has the toner particle as a core particle and a shell layer covering the surface of the core particle, may also be used. It may be.

The shell layer does not need to cover the entire surface of the core particle, and the core particle may be partially exposed.

The cross section of the core-shell structure can be confirmed by a known observation means such as a transmission electron microscope (TEM) or a scanning probe microscope (SPM).

In the case of a core-shell structure, the core particles and the shell layer can have different properties such as glass transition point, melting point, hardness, etc., and it is possible to design toner particles depending on the purpose.

For example, a resin with a relatively high glass transition point (Tg) is aggregated and fused to the surface of a core particle containing a binder resin, a colorant, a mold release agent, etc. and has a relatively low glass transition point (Tg). Then, a shell layer can be formed. It is preferable that the shell layer contains an amorphous resin.

8. Particle Size of Toner Particles As for the average particle size of toner particles, the volume-based median diameter (d ₅₀ ) is preferably in the range of 3 to 10 μm, more preferably in the range of 5 to 8 μm.

Within the above range, high reproducibility can be obtained even for extremely minute dot images at the 1200 dpi level.

Note that the average particle size of the toner particles can be controlled by the concentration of the aggregating agent used during production, the amount of organic solvent added, the fusing time, the composition of the binder resin, etc.

To measure the volume-based median diameter (d ₅₀ ) of toner particles, use a measuring device that includes a Multisizer 3 (manufactured by Beckman Coulter) connected to a computer system equipped with data processing software Software V3.51. Can be done.

Specifically, the measurement sample (toner) is added to a surfactant solution (for example, a surfactant solution prepared by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing toner particles). After blending, ultrasonic dispersion is performed to prepare a toner particle dispersion.

This toner particle dispersion liquid is injected with a pipette into a beaker containing ISOTON II (manufactured by Beckman Coulter) in a sample stand until the concentration indicated by the measuring device becomes 8%.

Here, by setting this concentration, reproducible measurement values can be obtained.

Then, in the measuring device, the number of measured particles is 25,000, the aperture diameter is 100 μm, the measurement range of 2 to 60 μm is divided into 256, and the frequency value is calculated, and the frequency value is calculated by dividing the measurement range from 2 to 60 μm into 256. % particle size is obtained as the volume-based median diameter (d ₅₀ ).

9. Average Circularity of Toner Particles Toner particles preferably have an average circularity of 0.930 to 1.000, more preferably 0.950 to 0.950, from the viewpoint of improving the stability of charging characteristics and low-temperature fixability. More preferably, it is within the range of 995.

If the average circularity is within the above range, individual toner particles will be less likely to be crushed.

As a result, it is possible to suppress contamination of the triboelectric charging member, stabilize the charging property of the toner, and improve the quality of the image formed.

The average circularity of toner particles can be measured using FPIA-2100 (manufactured by Sysmex).

Specifically, a measurement sample (toner) is mixed with an aqueous solution containing a surfactant, and an ultrasonic dispersion treatment is performed for 1 minute to disperse the sample.

Thereafter, photography is performed using FPIA-2100 (manufactured by Sysmex) under the measurement condition HPF (high magnification imaging) mode at an appropriate density with the number of HPF detections of 3000 to 10000.

If the number of HPF detections is within the above range, reproducible measurement values can be obtained. The circularity of each toner particle is calculated from the photographed particle image according to the following formula (I), and the average circularity is obtained by adding up the circularity of each toner particle and dividing by the total number of toner particles.
Formula (I)
Circularity = (perimeter of a circle with the same projected area as the particle image) / (perimeter of the particle projection image)

10. Developer The toner for developing electrostatic latent images of the present invention can be used as a magnetic or non-magnetic one-component developer, or may be mixed with a carrier and used as a two-component developer.

When the toner is used as a two-component developer, magnetic particles made of conventionally known materials such as metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead are used as carriers. ferrite particles are particularly preferred.

Further, as the carrier, a coated carrier in which the surface of magnetic particles is coated with a coating agent such as a resin, a dispersed carrier in which magnetic fine powder is dispersed in a binder resin, etc. may be used.

The volume-based median diameter (d ₅₀ ) of the carrier is preferably within the range of 20 to 100 μm, more preferably within the range of 25 to 80 μm.

The volume-based median diameter (d ₅₀ ) of the carrier can be measured, for example, using a laser diffraction particle size distribution analyzer HELOS (manufactured by SYMPATEC) equipped with a wet disperser.

II. Method for producing toner for developing electrostatic images The method for producing the toner according to the present invention is not particularly limited as long as it includes at least the following steps (1) and (2), and other steps may be performed using known methods. For example, an emulsion polymerization aggregation method or an emulsion aggregation method can be suitably employed.
In addition, in the following manufacturing method, an example will be described in which a hybrid crystalline polyester resin is used as the crystalline resin.

(1) In the reaction tank, the monomer that will be the raw material for the crystalline polyester polymerization segment, the raw material monomer for the addition polymerization resin (styrene/acrylic resin) unit (the monomer that will be the raw material for the vinyl polymerization segment), and the esterification A step of mixing a catalyst and subjecting the raw material monomers to a polycondensation reaction.

(2) In step (1), after polycondensing the raw material monomers, a step of introducing a crystal nucleating agent into the reaction tank and causing the reaction to form a crystal nucleating agent site.

<Step (1)>
In step (1), a monomer serving as a raw material for the crystalline polyester polymerization segment, a raw material monomer for an addition polymerization resin (styrene/acrylic resin) unit, and an esterification catalyst are mixed in a reaction tank. The raw material monomers undergo a polycondensation reaction.

As monomers serving as raw materials for the crystalline polyester polymerization segment, known monomers such as the above-mentioned polyhydric alcohol monomers and polyhydric carboxylic acid monomers can be suitably used.

(polycondensation reaction)
The polycondensation reaction of monomers serving as raw materials, ie, the method for synthesizing the crystalline polyester polymerized segment, is not limited, but the following methods (A) to (C) are preferred.
(A) A method of polymerizing polycarboxylic acids with a valence of 3 or more or a polyhydric alcohol with a valence of 3 or more (B) A method of addition polymerizing an unsaturated dicarboxylic acid or an unsaturated dialcohol (C) A method of adding polymerization between a crystalline polyester and an amorphous polyester Method using hybrid crystalline polyester resin chemically bonded with polyester resin units

In addition, known polymerization initiators and chain transfer agents can be used in the polymerization in the methods (A) and (B) above.

(esterification catalyst)
As the esterification catalyst, known catalysts can be used, such as tin compounds such as tin dioctylate, dibutyltin oxide, tin(II) 2-ethylhexanoate, and tetrabutyl orthotitanate (hereinafter referred to as "Ti(OBu) ₄ "). ), titanium compounds such as titanium diisopropylate bistriethanolaminate, and the like. Among them, Ti(OBu) ₄ can be preferably used.

<Step (2)>
In step (2), in step (1), after polycondensing the raw material monomers, a crystal nucleating agent is introduced into the reaction tank and reacted to form a crystal nucleating agent site. .

That is, in step (1), after obtaining a crystalline polyester polymerized segment by a polycondensation reaction, a crystal nucleating agent is added to react with the crystalline polyester polymerized segment. Thereby, the crystal nucleating agent can be chemically bonded to the crystalline polyester polymerization segment, and a crystal nucleating agent site can be formed.

The reaction at this time may be any reaction that can chemically bond the crystalline polyester polymerized segment and the crystal nucleating agent, and examples include, but are not limited to, heating at 200° C. under normal pressure. .

Through steps (1) and (2), the crystalline polyester polymerized segment to which the crystal nucleating agent is chemically bonded is formed by the vinyl polymerized segment to be chemically bonded by the above-mentioned hybrid crystalline polyester resin synthesis method. , a hybrid crystalline polyester resin having a crystal nucleating agent site in the crystalline polyester polymerization segment can be synthesized.

(crystal nucleating agent)
The crystal nucleating agent may be any compound that can form a crystal nucleating agent site as described above , such as an aliphatic monocarboxylic acid having a carbon number of 10 to 30 or a fat having a carbon number of 10 to 30. It is a family of monoalcohols.

Specific examples include stearic acid, lauric acid, behenic acid, tricontanoic acid, arachidic acid, arachidic acid, stearyl alcohol, lauryl alcohol, behenyl alcohol, and arachidyl alcohol.

<Agglomeration/fusion process>
The toner for developing an electrostatic image of the present invention is the method for producing the toner for developing an electrostatic image, in which, after the step (2), the amorphous resin (vinyl resin and A method for producing a toner for developing an electrostatic latent image, comprising a step of aggregating and fusing fine particles of the crystalline resin (hybrid crystalline polyester resin), fine particles of the crystalline resin (hybrid crystalline polyester resin), and fine particles of the colorant. It can also be suitably produced.

According to these methods of producing toners for developing electrostatic latent images, the polyhydric carboxylic acid monomer and the polyhydric alcohol monomer are first reacted, and then the crystal nucleating agent moiety is introduced. A crystalline polyester resin according to the invention can be produced.
As a method for aggregating and fusing, for example, a known emulsion aggregation method can be suitably employed.

(Emulsification aggregation method)
In the emulsion aggregation method, a solution of an amorphous resin or a crystalline resin (hereinafter collectively referred to as "binder resin") dissolved in a solvent is dropped into a poor solvent to form a fine particle dispersion of the binder resin. Then, the fine particle dispersion of the binder resin, the fine particle dispersion of the colorant, and the dispersion of a release agent such as wax are mixed, and the fine particles of the amorphous resin and the crystalline resin are mixed until the desired toner particle diameter is obtained. This is a method of manufacturing toner particles by aggregating resin particles, colorant particles, and a release agent in an aqueous medium, and then controlling the shape by fusing these particles.

(aqueous medium)
In the present invention, the "aqueous medium" refers to a medium containing at least 50% by mass of water, and components other than water include organic solvents that dissolve in water, such as methanol, ethanol, and isopropanol. , butanol, acetone, methyl ethyl ketone, dimethyl formamide, methyl cellosolve, tetrahydrofuran and the like.

Among these, it is preferable to use alcohol-based organic solvents such as methanol, ethanol, isopropanol, and butanol, which are organic solvents that do not dissolve the resin. Preferably, only water, such as ion-exchanged water, is used as the aqueous medium.

Note that the embodiments to which the present invention is applicable are not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the present invention.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto. In the examples, "parts" or "%" are used, but unless otherwise specified, "parts by mass" or "% by mass" are expressed.

[Synthesis of amorphous polyester resin [a1]]
A mixture of a vinyl resin monomer, a monomer having a substituent that reacts with both the amorphous polyester resin and the vinyl resin, and a polymerization initiator was placed in a dropping funnel.

Styrene 80.0 parts by mass n-butyl acrylate 20.0 parts by mass Acrylic acid 10.0 parts by mass Di-t-butyl peroxide (polymerization initiator) 16.0 parts by mass

Further, the following monomer of the amorphous polyester resin was placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and was heated to 170° C. to dissolve it.

Bisphenol A 2 mole adduct of ethylene oxide 50.2 parts by mass Bisphenol A propylene oxide 2 mole adduct 249.8 parts by mass Terephthalic acid 120.1 parts by mass Dodecenylsuccinic acid 46.0 parts by mass

While stirring, the liquid mixture placed in the dropping funnel was dropped into a four-necked flask over 90 minutes, and after aging for 60 minutes, unreacted monomers were removed under reduced pressure (8 kPa).

Thereafter, 0.4 parts by mass of Ti(OBu) ₄ was added as an esterification catalyst, and the temperature was raised to 235°C for 5 hours under normal pressure (101.3 kPa) and further for 1 hour under reduced pressure (8 kPa). , the reaction was carried out.

Next, the mixture was cooled to 200° C., reacted under reduced pressure (20 kPa), and then the solvent was removed to obtain an amorphous polyester resin [a1].

The weight average molecular weight (Mw) of the obtained amorphous polyester resin was 24,000, and the acid value was 18.2 mgKOH/g.

[Preparation of amorphous polyester resin fine particle dispersion [A1]]
108 parts by mass of the obtained amorphous polyester resin [a1] was dissolved in 64 parts by mass of methyl ethyl ketone by stirring at 70° C. for 30 minutes.

Next, 3.4 parts by mass of a 25% by mass aqueous sodium hydroxide solution was added to this solution.

This solution was placed in a reaction vessel equipped with a stirrer, and while stirring, 210 parts by mass of water warmed to 70° C. was added dropwise and mixed over 70 minutes.

During the dropping, the liquid in the container became cloudy, and after the entire amount was dropped, a uniform emulsified state was obtained.

The particle size of the oil droplets of this emulsion was measured using a laser diffraction particle size distribution analyzer "LA-750 (manufactured by HORIBA)", and the volume average particle size was 90 nm.

Next, while keeping this emulsion at 70°C, the methyl ethyl ketone was distilled off by stirring under reduced pressure of 15 kPa (150 mbar) using a diaphragm vacuum pump "V-700" (manufactured by BUCHI) for 3 hours. Then, an amorphous polyester resin fine particle dispersion liquid [A1] in which fine particles of the amorphous polyester resin [a1] were dispersed was prepared.

As a result of measurement using the above particle size distribution analyzer, the volume average particle diameter of the amorphous polyester resin fine particles in the amorphous polyester resin fine particle dispersion [A1] was 94 nm.

[Synthesis of crystalline resin [c1]]
Raw material monomers and a radical polymerization initiator for the following addition polymerization resin (styrene acrylic resin: StAc) unit containing bireactive monomers were placed in a dropping funnel.

Styrene 40.0 parts by mass n-butyl acrylate 16 parts by mass Acrylic acid 3.5 parts by mass Polymerization initiator (di-t-butyl peroxide) 8 parts by mass

In addition, the following raw material monomers for the polycondensation resin (crystalline polyester resin: CPEs) unit were placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and heated to 170°C to dissolve them. Ta.

・Acid: 280 parts by mass of tetradecanedioic acid ・Alcohol: 105 parts by mass of 1,4-butanediol

Next, the above monomer was placed in a reaction vessel equipped with a stirrer, a thermometer, a cooling tube, and a nitrogen gas introduction tube, and the inside of the reaction vessel was replaced with dry nitrogen gas.

0.4 parts by mass of Ti(O-n-Bu) ₄ was added to the obtained mixed solution, and the temperature was raised to 235°C, under normal pressure (101.3 kPa) for 5 hours, and then under reduced pressure (8 kPa). The reaction was carried out for 1 hour.

Next, the obtained reaction solution was cooled to 200°C, and then the reaction was carried out under reduced pressure (20 kPa) so that the acid value calculated by the above measurement method was 20.0 mgKOH/g after the introduction of the nucleating agent site. Ta.

Next, the pressure in the reaction tank was gradually released to return to normal pressure, and then 20.3 parts by mass of stearic acid was added as a crystal nucleating agent, and the mixture was reacted at 200°C under normal pressure for 1.5 hours.

Thereafter, the pressure of the reaction tank was reduced to 5 kPa or less at 200° C., and the reaction was carried out for 2.5 hours to obtain a crystalline resin [c1].

The crystalline resin [c1] had a weight average molecular weight (Mw) of 11,500 and an acid value of 20.0 mgKOH/g.

[Preparation of crystalline resin fine particle dispersion [C1]]
The following was added to 102 parts by mass of methyl ethyl ketone and stirred at 75° C. for 30 minutes to dissolve.

・Crystalline resin [c1] 174.3 parts by mass

Next, 3.1 parts by mass of a 25% by mass aqueous sodium hydroxide solution was added to this solution.

This solution was placed in a reaction vessel equipped with a stirrer, and while stirring, 375 parts by mass of water warmed to 70° C. was added dropwise and mixed over 70 minutes.

During the dropping, the liquid in the container became cloudy, and after the entire amount was dropped, a uniform emulsified state was obtained.

Next, while keeping this emulsion at 70°C, the methyl ethyl ketone was distilled off by stirring under reduced pressure of 15 kPa (150 mbar) using a diaphragm vacuum pump "V-700" (manufactured by BUCHI) for 3 hours. After that, the mixture was cooled at a cooling rate of 6° C./min to prepare a crystalline resin fine particle dispersion liquid [C1] in which fine particles of the crystalline resin [c1] were dispersed.

As a result of measurement using the above particle size distribution analyzer, the volume average particle diameter of the crystalline resin fine particles in the crystalline resin fine particle dispersion [C1] was 202 nm.

[Preparation of colorant fine particle dispersion [P1]]
While stirring a solution of 226 parts by mass of sodium dodecyl sulfate added to 1,600 parts by mass of ion-exchanged water, 420 parts by mass of copper phthalocyanine (C.I. Pigment Blue 15:3) was gradually added.

A colorant fine particle dispersion liquid [P1] was prepared by performing a dispersion treatment using a stirring device Clearmix (manufactured by M Technique Co., Ltd., "Clairmix" is a registered trademark of the same company).

The colorant particles in the dispersion had a volume-based median diameter of 110 nm.

[Preparation of vinyl resin fine particle dispersion [S1]]
(1st stage polymerization)
8 parts by mass of sodium dodecyl sulfate and 3,000 parts by mass of ion-exchanged water were charged into a 5 L reaction vessel equipped with a stirring device, a temperature sensor, a cooling tube, and a nitrogen introduction device, and the mixture was heated internally while stirring at a stirring speed of 230 rpm under a nitrogen stream. The temperature was raised to 80°C.

After raising the temperature, a solution prepared by dissolving 10 parts by mass of potassium persulfate in 200 parts by mass of ion-exchanged water was added, and the temperature was again raised to 80° C., and a mixed solution of the following monomers was added dropwise over 1 hour.

Styrene 480.0 parts by mass n-butyl acrylate 250.0 parts by mass Methacrylic acid 68.0 parts by mass

After the above liquid mixture was added dropwise, the monomers were polymerized by heating and stirring at 80° C. for 2 hours to prepare a vinyl resin particle dispersion liquid [s1].

(Second stage polymerization)
In a 5 L reaction vessel equipped with a stirring device, a temperature sensor, a cooling pipe, and a nitrogen introducing device, 1100 parts by mass of ion-exchanged water and the vinyl resin particle dispersion [s1] prepared by the first stage polymerization were added in terms of solid content. 55 parts by mass was charged and heated to 87°C.

Thereafter, a mixed solution in which the following monomers, chain transfer agent, and mold release agent were dissolved at 85°C was mixed and dispersed for 10 minutes using a mechanical dispersion machine CLEARMIX (manufactured by M Technique Co., Ltd.) with a circulation path. A dispersion containing emulsified particles (oil droplets) was prepared.

This dispersion was added to the above 5L reaction vessel, a polymerization initiator solution prepared by dissolving 5.4 parts by mass of potassium persulfate in 103 parts by mass of ion-exchanged water was added, and the system was heated at 87°C for 1 hour. Polymerization was carried out by heating and stirring over a period of time to prepare a vinyl resin particle dispersion liquid [s1]'.

Styrene (St) 256.5 parts by mass 2-ethylhexyl acrylate (2-EHA) 95.3 parts by mass Methacrylic acid (MAA) 38.2 parts by mass n-octyl-3-mercaptopropionate (chain transfer agent) 4. 0 parts by mass Mold release agent 1: HNP0190 (manufactured by Nippon Seirosha) 31.0 parts by mass

(Third stage polymerization)
A solution prepared by dissolving 7.3 parts by mass of potassium persulfate in 157.9 parts by mass of ion-exchanged water was further added to the vinyl resin particle dispersion [s1]' obtained by the second stage polymerization.

Furthermore, under a temperature condition of 84° C., a mixed solution of the following monomer and chain transfer agent was added dropwise over 90 minutes.

Styrene (St) 370.0 parts by mass n-butyl acrylate (BA) 165.0 parts by mass Methacrylic acid (MAA) 40.0 parts by mass Methyl methacrylate (MMA) 47.2 parts by mass n-octyl-3-mercaptopropylene Pionate 8.6 parts by mass

After the dropwise addition was completed, polymerization was carried out by heating and stirring for 2 hours, and the mixture was cooled to 28° C. to obtain a vinyl resin fine particle dispersion [S1].

[Manufacture of toner [1] and developer [1]]
480 parts by mass (in terms of solid content) of vinyl resin fine particle dispersion [S1] and 350 parts by mass of ion-exchanged water were charged into a reaction vessel equipped with a stirring device, a temperature sensor, and a cooling tube.

At room temperature (25° C.), a 5 mol/L aqueous sodium hydroxide solution was added to adjust the pH to 10.

Further, 36.4 parts by mass (in terms of solid content) of a colorant fine particle dispersion was added, and 80 parts by mass of a 50% by mass aqueous magnesium chloride solution was added at 30° C. over 10 minutes with stirring.

After the obtained dispersion was allowed to stand for 5 minutes, the temperature was raised to 80°C over 60 minutes, and after reaching 80°C, 60 parts by mass (in terms of solid content) of the crystalline polyester resin fine particle dispersion [C1] was added. The volume-based median diameter measured by Coulter Multisizer 3 (manufactured by Coulter Beckman) was 6. It was grown until it reached .0 μm.

Next, 60 parts by mass (solid content equivalent) of amorphous polyester resin dispersion [A1] was added over 30 minutes, and when the supernatant of the reaction liquid became transparent, 80 parts by mass of sodium chloride was added to 300 parts by mass of ion-exchanged water. An aqueous solution dissolved in parts by weight was added to stop the growth of particle size.

Next, the toner particles are stirred at 80°C to allow the particles to fuse together until the average circularity of the toner particles reaches 0.970, and then the liquid is cooled at a cooling rate of 0.5°C/min or higher to 30°C or lower. Lowered the temperature.

Next, solid-liquid separation was performed, and the dehydrated toner cake was redispersed in ion-exchanged water and solid-liquid separation was repeated three times for washing.

After washing, toner base particles were obtained by drying at 35° C. for 24 hours.

To 100 parts by mass of the obtained toner base particles, 0.6 parts by mass of hydrophobic silica particles (number average primary particle diameter: 12 nm, degree of hydrophobicity: 68), hydrophobic titanium oxide particles (number average primary particle diameter: 20 nm, Hydrophobicity degree: 63) 1.0 parts by mass and 1.0 parts by mass of sol-gel silica (number average primary particle diameter = 110 nm) were added, and the mixture was mixed with a Henschel mixer (manufactured by Nippon Coke Kogyo Co., Ltd.) at a rotor circumferential speed of 35 mm/ and mixed for 20 minutes at 32°C.

After mixing, coarse particles were removed using a 45 μm mesh sieve to obtain toner [1].

Toner [1] and a ferrite carrier coated with an acrylic resin and having a volume average particle diameter of 32 μm were added and mixed so that the toner particle concentration was 6% by mass.

In this way, developer [1], which is a two-component developer containing toner [1], was produced.

[Preparation of vinyl resin fine particle dispersions [S2] to [S5]]
In the preparation example [S1] of vinyl resin fine particle dispersion, except that the type of release agent in the second stage polymerization was changed as shown in Table I, vinyl resin fine particle dispersion [S2] ~ [S5] was obtained.

[Synthesis of crystalline resins [c2] to [c6], [c8] to [c9], and [c11] to [c14]]
Crystalline resins [c2] to [c6], [c8] to [ c9] and [c11] to [c14] were obtained.

The weight average molecular weights (Mw) of the crystalline resins [c2] to [c6], [c8] to [c9], and [c11] to [c14] were as shown in Table II.

[Synthesis of crystalline resin [c7]]
The following monomers were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction tube, and the inside of the reaction vessel was purged with dry nitrogen gas.

・Acid: 280 parts by mass of tetradecanedioic acid ・Alcohol: 105 parts by mass of 1,4-butanediol

0.4 parts by mass of Ti(O-n-Bu) ₄ was added to the obtained mixed solution, and the temperature was raised to 235°C, under normal pressure (101.3 kPa) for 5 hours, and then under reduced pressure (8 kPa). The reaction was carried out for 1 hour.

Next, the obtained reaction solution was cooled to 200°C, and then the reaction was carried out under reduced pressure (20 kPa) so that the acid value calculated by the above measurement method was 21.4 mgKOH/g after the introduction of the nucleating agent site. Ta.

Next, the pressure in the reaction tank was gradually released to return to normal pressure, and then 20.3 parts by mass of stearic acid was added as a crystal nucleating agent, and the mixture was reacted at 200°C under normal pressure for 1.5 hours.

Thereafter, the pressure in the reaction tank was reduced to 5 kPa or less at 200° C., and the reaction was carried out for 2.5 hours to obtain crystalline resin [c7]. The crystalline resin [c7] had a weight average molecular weight (Mw) of 10,800 and an acid value of 21.4 mgKOH/g.

[Synthesis of crystalline resin [c10]]
In a reaction apparatus equipped with a stirrer and a thermometer, 1000 parts by mass of isophorone diisocyanate, 830 parts by mass of 1,4-adipate (polyester diol consisting of 1,4-butanediol and adipic acid), and stearic acid as a crystal nucleating agent were added. 96.3 parts by mass and 250 parts by mass of methyl ethyl ketone were charged while introducing nitrogen.

Thereafter, a urethane reaction was carried out at 80° C. for 6 hours. Next, 2128 parts by mass of ion-exchanged water was added while stirring, and then the reaction system was depressurized to remove the solvent, to obtain a crystalline resin fine particle dispersion [c10].

[Synthesis of crystalline resin [c15]]
Raw material monomers and a radical polymerization initiator for the following addition polymerization resin (styrene acrylic resin: StAc) unit containing bireactive monomers were placed in a dropping funnel.

Styrene 40.0 parts by mass n-butyl acrylate 16 parts by mass Acrylic acid 3.5 parts by mass Polymerization initiator (di-t-butyl peroxide) 8 parts by mass

In addition, the following raw material monomers for the polycondensation resin (crystalline polyester resin: CPEs) unit were placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and heated to 170°C to dissolve them. Ta.

・Acid: 280 parts by mass of tetradecanedioic acid ・Alcohol: 105 parts by mass of 1,4-butanediol

Next, the above monomer was placed in a reaction vessel equipped with a stirrer, a thermometer, a cooling tube, and a nitrogen gas introduction tube, and the inside of the reaction vessel was replaced with dry nitrogen gas.

0.4 parts by mass of Ti(O-n-Bu) ₄ was added to the obtained mixed solution, and the temperature was raised to 235°C, under normal pressure (101.3 kPa) for 5 hours, and then under reduced pressure (8 kPa). The reaction was carried out for 1 hour.

Next, the obtained reaction solution was cooled to 200°C, and then reacted under reduced pressure (20 kPa) so that the acid value calculated by the above measurement method was 20.3 mgKOH/g, and the crystalline resin [ c15] was obtained.

The crystalline resin [c15] had a weight average molecular weight (Mw) of 17,500 and an acid value of 20.3 mgKOH/g.

[Preparation of crystalline resin fine particle dispersions [C2] to [C15]]
In the preparation of crystalline resin fine particle dispersion [C1], crystalline resin fine particle dispersion [C2] to [C15] was obtained.

[Production of toner [2] to [24] and production of developer [2] to [24]]
In the production of toner [1], toners [2] to [24] was obtained.

Further, developers [2] to [24] were obtained from the obtained toner particles in the same manner as toner [1].

[evaluation]
The evaluation results shown in Table III were obtained according to the following methods and evaluation criteria.
<Low temperature fixability>
The fixing device of the multifunction device "bizhub PRESS (registered trademark) C1070" (manufactured by Konica Minolta, Inc.) has been modified so that the surface temperature of the upper fixing belt and lower fixing roller can be changed, and the two-component developer is sequentially loaded. did.

The above device was modified so that the fixing temperature, toner adhesion amount, and system speed could be freely set.

At room temperature and humidity (temperature 20°C, humidity 50% RH), the adhesion amount was 11.3 g on A4 size high quality paper "NPI Fine (127.9 g/m ² )" (manufactured by Nippon Paper Industries). / ^m2 .

Thereafter, a fixing experiment in which an image of 100 mm x 100 mm size was fixed was repeated while changing the set fixing temperature from 110° C. to 180° C. in 2° C. increments.

The lowest fixing temperature at which image staining due to fixing offset was not visually confirmed was defined as the lowest fixing temperature (U.O. avoidance temperature).

(Evaluation criteria)
◎: Minimum fixing temperature is less than 135°C (excellent toner with excellent low-temperature fixing properties)
○: Minimum fixing temperature is 135°C or higher and lower than 140°C (a level that poses no practical problem)
×: Minimum fixing temperature is 140°C or higher (at the target paper feeding speed, the fixing is not sufficient and there is a practical problem)

<Tacking test>
The fixing device of the multifunction device "bizhub PRESS (registered trademark) C1070" (manufactured by Konica Minolta, Inc.) has been modified so that the surface temperature of the upper fixing belt and lower fixing roller can be changed, and the two-component developer is sequentially loaded. did.

The above device was tested on A4 size coated paper "OK Top Coat + (157.0 g/m ² )" (manufactured by Oji Paper Co., Ltd.) in an environment of normal temperature and normal humidity (temperature 20°C, humidity 50% RH). A fixing experiment was conducted in which a solid image with an adhesion amount of 10.2 g/m ² was output on 800 sheets at a fixing temperature of 180°C.

To record the paper surface temperature, a thermocouple "Mold type surface sensor: MF-OK" is attached to the 1st, 100th, 200th, 300th, 400th, 500th, 600th, and 700th image of the ejected paper. (Toa Kiki) was attached to the center of the paper.

After all 800 sheets of fixed images were loaded on the paper output tray, the paper was left for 8 hours until the paper temperature cooled. The maximum temperature reached after the paper was discharged until it cooled down was taken as the measured temperature for that paper.

After being left for 8 hours, the 1st, 100th, 200th, 300th, 400th, 500th, 600th, and 700th images were evaluated to see how well the overlapping images stuck together.

The temperature measured in the image that reached the OK level according to the following evaluation criteria was defined as the tack removal temperature.

Note that the measured temperature can be controlled by changing the air volume of the paper ejection air. The air volume was increased and the same experiment was repeated until an OK level image was obtained.

(Evaluation criteria)
OK: Can be easily removed by hand. (no peeling sound) or it can be peeled off but there is a peeling sound.
NG: The toner image surface is rough after peeling off.

The tacking release temperature is judged based on the evaluation criteria below, and ◎ and 〇 are considered to be a passing level.
It is desirable that tacking does not occur even if the paper is ejected at a higher temperature.

(Evaluation criteria)
◎: 60℃ or more ○: 56℃ or more and less than 60℃ ×: Less than 56℃

<Wax adhesion>
In the commercially available color multifunction device AccurioPress C3080 (manufactured by Konica Minolta), the surface temperature of the upper fixing belt was changed in the range of 140 to 220°C, and the surface temperature of the lower fixing roller was changed in the range of 120 to 200°C. Modified so that it can be done.

Each developer was sequentially loaded into this modified machine, and the amount of toner adhering to A4 (basis weight 157 g/m ² ) gloss-coated paper was 8.5 mm under normal temperature and normal humidity (temperature 20° C., humidity 50% RH) environment. A solid image of 0 g/m ² was formed and fixed.

The fixing speed during the fixing process was 460 mm/sec, and the fixing temperature (surface temperature of the upper fixing belt) was the under offset temperature + 35°C.

The state of wax adhesion to the conveyance roller after printing 100 sheets was visually evaluated on a 10-point scale, and ◎ and ○ were determined to be acceptable levels based on the following evaluation criteria.
(Evaluation criteria)
◎: Rank 10-9 Wax adhesion is not observed at all ○: Rank 8-7 Wax adhesion is slightly observed, but there is no problem with the quality ×: Rank 6-1 Wax adhesion is observed and it is at a level that cannot be put to practical use Table III As is clear from the results shown in Figure 2, it is clear that the toner of the present invention has overall superior performance compared to the comparative example.

Claims (3)

A toner for developing electrostatic images comprising toner base particles containing at least a release agent and a binder resin,
Containing at least a hydrocarbon wax as the mold release agent,
The binder resin contains at least a vinyl resin and a crystalline resin,
The content of the vinyl resin in the binder resin is 60 % by mass or more ,
the crystalline resin is a crystalline polyester,
The crystalline resin is a hybrid crystalline polyester resin formed by combining a crystalline polyester polymerized segment and a polymerized segment of another type of resin,
The content of the crystalline resin in the binder resin is 4 to 15% by mass,
The weight average molecular weight (Mw) of the crystalline resin satisfies the following formula (4),
1000≦Mw(C)≦16000…(4)
The crystalline resin has a part having a crystal structure and a crystal nucleating part,
the crystal nucleating agent moiety is stearic acid or stearyl alcohol, and
The crystal nucleating agent moiety is a moiety derived from at least one compound selected from the group consisting of aliphatic monocarboxylic acids having at least 10 to 30 carbon atoms or aliphatic monoalcohols having 10 to 30 carbon atoms,
The proportion of the crystal nucleating agent moiety in the crystalline resin is within the range of 3 to 9% by mass.
A toner for developing electrostatic images characterized by: The toner for developing electrostatic images according to claim 1, wherein the hydrocarbon wax used as the release agent has a melting point within a range of 80 to 92°C. The toner for developing electrostatic images according to claim 1 or 2, wherein the hydrocarbon wax used as the release agent has a melting point within a range of 80 to 88°C.