JP2023061436A - toner - Google Patents

Abstract

To provide a toner that attains a low temperature fixation property and a resistance to degradation and can output images with less unevenness of gloss.SOLUTION: The present invention relates to a toner including a binder resin and an ester compound, the binder resin containing a styrene-acrylic resin having a unit derived from a macro-monomer and a unit with long-chain alkyl in a side chain, the SP values of the unit derived from the macro monomer, the unit with a long-chain alkyl in a side chain, and the ester compound being in a special relation.SELECTED DRAWING: None

Description

The present disclosure relates to a toner used in recording methods using electrophotography and electrostatic recording.

Electrophotographic image forming apparatuses are required to have higher image quality, longer life, and energy saving. In order to meet these demands, toners are also required to improve various performances. In recent years, there is a strong demand for high image quality even in monochromatic image forming apparatuses. This is due to the increasing number of outputting texts and photographs with high printability even in black images worldwide.
Regarding improvement in the performance of monochromatic image forming apparatuses, there is a strong demand for improvement in low-temperature fixability in order to save energy. Currently, various techniques have been proposed, and toners with improved low-temperature fixability are actually on the market. On the other hand, improvements have also been made in terms of high image quality, and there are various improvements such as sharpness of characters, density unevenness, gloss unevenness, and fine image reproducibility. In particular, when a high-quality print image is output in a single black color, uneven glossiness of the image tends to stand out, so a very high level is required. One of the causes of gloss unevenness is that light is reflected differently between portions where toner has melted and portions where agglomerates remain due to differences in the amount of local deformation of the toner during fixing.
In other words, in order to solve this gloss unevenness, it is necessary to reduce the difference in the deformation amount of the toner during fixation while improving the low-temperature fixability. From the standpoint of long life, there is a recent demand from the standpoint of ease of maintenance that the same cartridge can be used for a long period of time due to a reduction in toner consumption and an increase in toner capacity in the cartridge. When the same cartridge is used for a long period of time, the toner is subject to rubbing against members of the cartridge and the like, and deteriorates easily. As for the types of deterioration, in addition to changes in the properties of the toner surface, cracking and chipping due to high shear are often factors. These changes cause contamination of the member and deterioration of the fluidity and chargeability of the toner, and finally appear as image defects. Toner needs to solve these problems at a high level as the requirements become more sophisticated.
As a specific solution for low-temperature fixability, it is important to create a state in which the binder resin of the toner is plasticized at the time of fixation and is easily fused. In particular, there are various means for improving low-temperature fixability, and it is generally possible to improve low-temperature fixability by using a toner having a binder resin designed to be easily plasticized.
However, in this method, the resin is in a state in which a small part of the resin has fluidity even when the toner is not fixed. In Japanese Patent Application Laid-Open No. 2002-100002, a crystalline material is added to a toner to improve low-temperature fixability, and a long-chain alkyl monomer is incorporated into a binder resin (binder) to increase compatibility efficiency between the binder and the crystalline material during fixing. Enhancing toners have been proposed. From the viewpoint of prolonging the life of the toner, it is possible to make it resistant to deterioration by making the toner harder. However, simply increasing the hardness tends to deteriorate the low-temperature fixability. Patent Document 2 proposes a toner in which hot offset resistance and low-temperature fixability are improved by using a predetermined monoester compound, and crackability is improved by introducing a radical reactive polymer called a macromonomer into the binder. ing.

JP 2014-035506 A JP 2012-198569 A

As a result of investigation by the present inventors, it has been found that a toner designed to promote plasticization of a binder by using a crystalline material as a plasticizer as described in Patent Document 1 has a problem of deterioration. This is because when a printer intended for high-speed image output is used for a long period of time, the load on the toner is large and cracks are likely to occur. In addition, the toner described in Patent Document 2 achieves both low-temperature fixability and cracking suppression, but in models designed for high-speed image output and low fixation pressure during fixation, such as monochrome printers, the fixation is uneven. was confirmed. This is considered to be caused by uneven melting due to the presence of a melting promoting component called monoester and a curing component called macromonomer during fixing.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a toner capable of outputting an image with less gloss unevenness while achieving both low-temperature fixability and deterioration resistance.

The present inventors have attempted to solve the above problems by using a toner that uses an ester compound and a macromonomer that have a binder plasticizing effect and a binder that incorporates a long-chain alkyl monomer that is compatible with both the ester compound and the macromonomer. Found it.
That is, the present invention provides a toner having toner particles having a binder resin and an ester compound,
The binder resin contains a styrene-acrylic resin having a macromonomer-derived unit and a monomer unit represented by the following formula (1),

（式（１）中、Ｒ¹は水素原子またはメチル基を示し、Ｒ²は炭素数１０以上１４以下の直鎖アルキル基を示す。）
該エステル化合物が、下記式（２）で表されるエステル化合物、下記式（３）で表されるエステル化合物および下記式（４）で表されるエステル化合物からなる群より選ばれる少なくとも一種のエステル化合物であり、

(In Formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear alkyl group having 10 to 14 carbon atoms.)
The ester compound is at least one ester selected from the group consisting of an ester compound represented by the following formula (2), an ester compound represented by the following formula (3), and an ester compound represented by the following formula (4) is a compound,

（式（２）、式（３）および式（４）中、Ｒ³¹およびＲ⁴¹はそれぞれ独立して炭素数２以上８以下のアルキレン基を示し、Ｒ³²、Ｒ³³、Ｒ⁴²、Ｒ⁴³、Ｒ⁵¹およびＲ⁵²はそれぞれ独立して炭素数１４以上２４以下の直鎖アルキル基を示す。）
該マクロモノマー由来のユニットのＳＰ値をＳＰａ（Ｊ／ｃｍ³）^1/2とし、該式（１）で表されるモノマーユニットのＳＰ値をＳＰｂ（Ｊ／ｃｍ³）^1/2とし、該エステル化合物のＳＰ値をＳＰｃ（Ｊ／ｃｍ³）^1/2としたとき、
該ＳＰａが、１９．５０以上２０．５０以下であり、
該ＳＰａ、該ＳＰｂおよび該ＳＰｃが、下記関係式（ａ）、下記関係式（ｂ）および下記関係式（ｃ）を満たすことを特徴とするトナーに関する。
ＳＰａ－ＳＰｂ≦２．０ （ａ）
ＳＰｂ－ＳＰｃ≦１．５ （ｂ）
ＳＰａ－ＳＰｃ≧２．０ （ｃ）

(In formula (2), formula (3) and formula (4), R ³¹ and R ⁴¹ each independently represent an alkylene group having 2 to 8 carbon atoms, and R ³² , R ³³ , R ⁴² and R ⁴³ , R ⁵¹ and R ⁵² each independently represent a linear alkyl group having 14 to 24 carbon atoms.)
The SP value of the unit derived from the macromonomer is SPa (J/cm ³ ) ^1/2 , the SP value of the monomer unit represented by the formula (1) is SPb (J/cm ³ ) ^1/2 , and the When the SP value of the ester compound is SPc (J/cm ³ ) ^1/2 ,
The SPa is 19.50 or more and 20.50 or less,
The toner is characterized in that said SPa, said SPb and said SPc satisfy the following relational expressions (a), (b) and (c) below.
SPa-SPb≤2.0 (a)
SPb-SPc≤1.5 (b)
SPa−SPc≧2.0 (c)

According to the present invention, it is possible to provide a toner capable of outputting an image with less gloss unevenness while achieving both low-temperature fixability and deterioration resistance.

In the present disclosure, the descriptions of “XX or more and YY or less” or “XX to YY” representing numerical ranges mean numerical ranges including the lower and upper limits, which are endpoints, unless otherwise specified.

A monomeric unit refers to the reacted form of the monomeric material in the polymer. For example, one unit is defined as one segment of carbon-carbon bond in the main chain in which the vinyl-based monomer in the polymer is polymerized.

A crystalline resin or crystalline material refers to a resin or material that exhibits a distinct endothermic peak in differential scanning calorimetry.

In addition, the "unit derived from the macromonomer" according to the present invention is unit A, the "monomer unit represented by formula (1)" is unit B, and the "ester compound selected from formulas (2) to (4)" is the compound Also called C.

Modes for carrying out the present invention will be described in more detail below, but the present invention is not limited to these.

The present inventors have proposed a method for solving the above problems by using a toner that uses an ester compound and a macromonomer that have a binder plasticizing effect and a binder that incorporates a long-chain alkyl monomer that is compatible with both the ester compound and the macromonomer. Found it.

That is, the toner of the present invention is a toner having toner particles having a binder resin and an ester compound,
The binder resin contains a styrene-acrylic resin having a macromonomer-derived unit and a monomer unit represented by the following formula (1),

（式（１）中、Ｒ¹は水素原子またはメチル基を示し、Ｒ²は炭素数１０以上１４以下の直鎖アルキル基を示す。）

(In Formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear alkyl group having 10 to 14 carbon atoms.)

The ester compound is at least one ester selected from the group consisting of an ester compound represented by the following formula (2), an ester compound represented by the following formula (3), and an ester compound represented by the following formula (4) is a compound,

（式（２）、式（３）および式（４）中、Ｒ³¹およびＲ⁴¹はそれぞれ独立して炭素数２以上８以下のアルキレン基を示し、Ｒ³²、Ｒ³³、Ｒ⁴²、Ｒ⁴³、Ｒ⁵¹およびＲ⁵²はそれぞれ独立して炭素数１４以上２４以下の直鎖アルキル基を示す。）

(In formula (2), formula (3) and formula (4), R ³¹ and R ⁴¹ each independently represent an alkylene group having 2 to 8 carbon atoms, and R ³² , R ³³ , R ⁴² and R ⁴³ , R ⁵¹ and R ⁵² each independently represent a linear alkyl group having 14 to 24 carbon atoms.)

The SP value of the unit derived from the macromonomer is SPa (J/cm ³ ) ^1/2 , the SP value of the monomer unit represented by the formula (1) is SPb (J/cm ³ ) ^1/2 , and the When the SP value of the ester compound is SPc (J/cm ³ ) ^1/2 ,
The SPa is 19.50 or more and 20.50 or less,
Said SPa, said SPb and said SPc are characterized by satisfying the following relational expressions (a), (b) and (c) below.
SPa-SPb≤2.0 (a)
SPb-SPc≤1.5 (b)
SPa−SPc≧2.0 (c)

The binder resin in the toner of the present invention must contain a styrene-acrylic resin having a macromonomer-derived unit and a monomer unit represented by the formula (1).

A macromonomer in the present invention refers to a monomer having a high molecular weight having a reactive functional group, and is a monomer having a unit obtained by polymerizing a polymerizable monomer.

A styrene-acrylic resin having a unit derived from a macromonomer has a branched structure and has a high impact stress. As a result, the toner has properties that are resistant to cracking. Furthermore, the toner of the present invention must contain the ester compound (compound C) represented by the above formulas (2) to (4). Containing an ester compound having a specific structure promotes plasticization of the toner during fixation, thereby improving low-temperature fixability.

The monomer unit (unit B) represented by formula (1) has an alkyl group. Since the styrene-acrylic resin has an alkyl group in the side chain, the styrene-acrylic resin has a structure similar to the above formulas (2) to (4), and when the compound C melts during fixing, styrene - Promotes the plasticizing effect of acrylic resins.

In the toner of the present invention, the unit B has a structure represented by formula (1) below.

（式（１）中、Ｒ¹は水素原子またはメチル基を示し、Ｒ²は炭素数１０以上１４以下の直鎖アルキル基を示す。）

(In Formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear alkyl group having 10 to 14 carbon atoms.)

More preferably, R ² has 12 carbon atoms (lauryl acrylate). If the number of carbon atoms is less than 10, the affinity with the unit A is impaired, causing uneven melting and uneven gloss during fixing. If the number of carbon atoms exceeds 14, the affinity with the ester compound is impaired, making it difficult for the resin to be plasticized during fixing. In addition, since the mobility of the unit A during fixing is impaired, gloss unevenness also occurs.

The styrene-acrylic resin is preferably a styrene-acrylic resin containing the unit B in an amount of 1% by mass or more and 15% by mass or less. Within this range, the plasticizing effect of the compound C and the associated molecular motion of the unit A are induced, the low-temperature fixability is improved, and an image with suppressed gloss unevenness can be obtained. Further, it is more preferable that the unit B is a styrene-acrylic resin containing 2% by mass or more and 10% by mass or less.

The content of the unit B in the styrene-acrylic resin can be adjusted by adjusting the amount of the precursor monomer having an unsaturated bond added during polymerization.

Styrene-acrylic resin contains unit A.

Specific examples of macromonomers serving as precursors of unit A include polymers obtained by polymerizing styrene, styrene derivatives, methacrylic acid esters, acrylic acid esters, acrylonitrile, methacrylonitrile, etc. alone or in combination of two or more; Examples include macromonomers having a polysiloxane skeleton. Among them, a polymer having a glass transition temperature higher than that of the binder resin is preferable, and a copolymer macromonomer of styrene and a methacrylic ester and/or an acrylic ester and a polymethacrylic ester macromonomer are preferable. A macromonomer having a unit represented by formula (3) in the main chain portion of the macromonomer is particularly preferred.

（式（３）はＲ¹およびＲ²はメチル基を示す。）

(In formula (3), R ¹ and R ² represent methyl groups.)

The macromonomer is preferably a monomer having a number average molecular weight of 1,000 or more and 30,000 or less from the viewpoint of imparting elasticity and polymerizability. Furthermore, 2000 or more and 10000 or less are more preferable, and 5000 or more and 10000 or less are especially preferable. The glass transition temperature of the macromonomer is preferably 60° C. or higher and 110° C. or lower, more preferably 70° C. or higher and 105° C. or lower.

The styrene-acrylic resin is preferably a styrene-acrylic resin containing 0.01% by mass or more and 10.00% by mass or less of the unit A. More preferably, it is 0.05% by mass or more and 1.00% by mass or less.

In the toner of the present invention, the compound C is selected from the group consisting of an ester compound represented by the following formula (2), an ester compound represented by the following formula (3), and an ester compound represented by the following formula (4). At least one kind of ester compound.

（式（２）、式（３）および式（４）中、Ｒ³¹およびＲ⁴¹はそれぞれ独立して炭素数２以上８以下のアルキレン基を示し、Ｒ³²、Ｒ³³、Ｒ⁴²、Ｒ⁴³、Ｒ⁵¹およびＲ⁵²はそれぞれ独立して炭素数１４以上２４以下の直鎖アルキル基を示す。）

(In formula (2), formula (3) and formula (4), R ³¹ and R ⁴¹ each independently represent an alkylene group having 2 to 8 carbon atoms, and R ³² , R ³³ , R ⁴² and R ⁴³ , R ⁵¹ and R ⁵² each independently represent a linear alkyl group having 14 to 24 carbon atoms.)

Among the above formulas (2), (3) and (4), ethylene glycol distearate (R ³¹ =-C ₂ H ₄ -, R ³² =R ³³ =-C ₁₇ H ₃₅ ), ethylene glycol dipalmi tate (R ³¹ = -C ₂ H ₄ -, R ³² = R ³³ = -C ₁₅ H ₃₁ ), ethylene glycol dibehenate (R ³¹ = -C ₂ H ₄ -, R ³² = R ³³ = -C ₂₁ H ₄₃ ), dibehenyl sebacate (R ⁴¹ = -C ₈ H ₁₆ -, R ⁴² = R ⁴³ = -C ₂₁ H ₄₃ ), behenyl stearate (R ⁵¹ = C ₁₇ H ₃₅ , R ⁵² = C ₂₂ H ₄₅ ), _stearyl behenate ( ^R51 = _{C21H43 ,} ^R52 = _C18H37 ), _{and behenyl behenate (R51=C21H43 ,} ^R52 ₌ ^C22H45 ₎ .

The content of compound C contained in the ester compound in the toner of the present invention is preferably 50% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less.

The content of the ester compound in the toner of the present invention is preferably 5 parts by mass or more and 30 parts by mass or less, more preferably 10 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the binder resin. preferable. By containing 5 parts by mass or more, the effects of the present invention can be stably obtained. On the other hand, when the content is 30 parts by mass or less, compatibility with storage stability becomes easier.

The acid value of compound C is preferably 0.01 mgKOH/g or more and 2.0 mgKOH/g or less, more preferably 0.03 mgKOH/g or more and 1.0 mgKOH/g or less, and 0.05 mgKOH/g or more. It is more preferably 0.5 mgKOH/g or less. The acid value of compound C is a value measured according to JIS K 0070 using the test method for acid value of chemical products established by Japanese Industrial Standards. Details of the measurement method will be described later.

When the acid value of compound C is 0.01 mgKOH/g or more and 2.0 mgKOH/g or less, an unreacted fatty acid-derived carboxylic acid group is present in the compound in an appropriate amount. It tends to be easier to stably form droplets of the monomer composition. As a result, the particle size of the toner particles tends to be uniform.

The hydroxyl value of Compound C is preferably 0.1 mgKOH/g or more and 15 mgKOH/g or less, more preferably 0.3 mgKOH/g or more and 10 mgKOH/g or less. It is more preferably 0.5 mgKOH/g or more and 5.0 mgKOH/g or less, and particularly preferably 1.0 mgKOH/g or more and 4.0 mgKOH/g or less. The hydroxyl value of compound C is a value measured according to JIS K 0070 using the testing method for hydroxyl value of chemical products established by Japanese Industrial Standards.

When the hydroxyl value of compound C is 0.1 mgKOH/g or more and 15 mgKOH/g or less, the hydroxyl groups derived from unreacted raw materials are present in the wax in an appropriate amount. It tends to be easier to stably form droplets of the material. As a result, the particle size of the toner particles tends to be uniform.

The method for producing compound C is not particularly limited, but it is a synthesis method by oxidation reaction, synthesis from carboxylic acid and its derivatives, ester group introduction reaction represented by Michael addition reaction, dehydration condensation from a carboxylic acid compound and an alcohol compound. A method using a reaction, a reaction from an acid halide and an alcohol compound, a transesterification reaction, and the like can be mentioned.

A catalyst can also be appropriately used for the production of compound C. The catalyst is preferably an acidic or alkaline catalyst commonly used in esterification reactions, such as zinc acetate and titanium compounds. After the esterification reaction, the target product may be purified by recrystallization, distillation, or the like.

Specific production examples of compound C are shown below, but are not limited to the following production examples.

First, an alcohol monomer and a carboxylic acid monomer, which are raw materials, are added to a reaction vessel. The molar ratio of the alcohol monomer and the carboxylic acid monomer is appropriately adjusted according to the chemical structure of the desired monoester compound. That is, the alcohol monomer and the carboxylic acid monomer are mixed so that the molar ratio of the alcohol monomer to the carboxylic acid monomer is 1:1. Considering the reactivity in the dehydration condensation reaction, either one of the alcohol monomer and the carboxylic acid monomer may be added in a slightly excess amount from the above ratio.

Next, the mixture of the alcohol monomer and the carboxylic acid monomer is appropriately heated to carry out a dehydration condensation reaction. A basic aqueous solution and an appropriate organic solvent are added to the esterified crude product obtained by the dehydration condensation reaction to deprotonate unreacted alcohol monomers and carboxylic acid monomers, thereby separating the aqueous phase. Thereafter, compound C can be obtained by appropriately washing with water, distilling off the solvent, and filtering.

The toner of the present invention may contain a hydrocarbon wax. Specifically, the following are exemplified.

Aliphatic hydrocarbons such as low-molecular-weight polyethylene, low-molecular-weight polypropylene, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax are included.

The wax preferably has a melting point of 60° C. or higher and 85° C. or lower, more preferably 65° C. or higher and 80° C. or lower. By setting the amount within the above range, it becomes easy to achieve both storage stability and low-temperature fixability of the toner.

The SP value of the toner of the present invention was obtained as follows according to the calculation method proposed by Fedors.

Eng. Sci., 14(2), 147-154 (1974), evaporation energy (Δei) (J/mol) and molar volume (Δvi) (cm ³ /mol) of low-molecular-weight compounds. ) and calculated from the following formula (5).
Equation (5): _σm = (ΣΔei/ΣΔvi) ^1/2

Next, the SP value of the repeating unit that constitutes the binder resin or resin (hereinafter also referred to as "resin etc.") is obtained as follows. Here, the repeating unit constituting the resin means that, when the binder resin or the resin is a vinyl-based resin (when a polymer constituting the resin is produced by a polymerization reaction of a vinyl-based monomer), the vinyl-based monomer means a molecular structure in which the double bond of is cleaved by polymerization.

For example, when calculating the SP value (σ _m ) (J/cm ³ ) ^1/2 of the repeating unit, for the atom or atomic group in the molecular structure of the repeating unit, "Polym. Eng. Sci., 14 (2), 147-154 (1974)”, the vaporization energy (Δei) (J/mol) and molar volume (Δvi) (cm ³ /mol) are obtained from the table described in the following formula (6).
Equation (6): _σm = (ΣΔei/ΣΔvi) ^1/2

In the toner of the present invention, the SP value of the unit derived from the macromonomer is SPa (J/cm ³ ) ^1/2 , and the SP value of the monomer unit represented by the formula (1) is SPb (J/cm ³ ) ^{1 . /2} , when the SP value of the ester compound is SPc (J/cm ³ ) ^1/2 , the SPa is 19.50 or more and 20.50 or less, and the SPa, the SPb and the SPc are represented by the following relational expression: (a), relational expression (b) and relational expression (c) are satisfied.
SPa-SPb≤2.0 (a)
SPb-SPc≤1.5 (b)
SPa−SPc≧2.0 (c)

A conventional toner containing a macromonomer and an ester compound has a difference in SP values of 2.0 (J/cm ³ ) ^1/2 or more, and tends to be less compatible. Therefore, the phase separation between the ester compound domain and the macromonomer unit tends to occur during toner production. As a result, when the ester compound domain melts during fixing, the plasticization of the binder resin is facilitated to proceed partially. On the other hand, in the vicinity of the macromonomer unit, the ester compound is deficient, and the plasticizing effect cannot be obtained at the time of fixing. As a result, the toner melts unevenly, resulting in gloss unevenness.

On the other hand, by introducing the unit B of the present invention together with the unit A into the resin, the performance can be greatly changed. Specifically, a unit B having an SP value intermediate between that of the unit A and the ester compound is introduced. First, the plasticizing effect of the ester compound effectively acts on the unit B by setting the difference in SP value from the ester compound to 1.5 (J/cm ³ ) ^1/2 or less. Furthermore, when the SP value difference between Unit A and Unit B is 2.0 (J/cm ³ ) ^1/2 or less, Unit A and Unit B are likely to exist close to each other in the resin. As a result, the ester compound can be present near the unit A in the toner during toner production due to the effect of the unit B. As a result, the entire toner is uniformly plasticized by the ester compound, and gloss unevenness can be suppressed.

When the SP value of unit B is SPb (J/cm ³ ) ^1/2 and the SP value of compound C is SPc (J/cm ³ ) ^1/2 , compatibility is achieved when SPb−SPc≦1.5. It has an easy structure.

In addition, the SP value SPa (J/cm ³ ) ^1/2 of the macromonomer-derived unit (unit A) is 19.50 or more and 20.50 or less, SPa−SPb≦2.0, and SPa−SPc≧ It should be 2.0. When the SP value of the unit A and the compound C is 2.0 or more, the effect of the plasticizing effect of the compound C on the unit A can be suppressed except during fixing. As a result, the elasticity of the toner is maintained during long-term use, and cracking can be suppressed. On the other hand, since the unit A and the unit B have similar SP values, they can be present at positions close to each other in the resin or molecule. The unit B is also easily plasticized by the plasticizing effect of the compound C at the time of fixing due to the presence of the unit B at a close position. As a result, the unit A existing in the vicinity thereof is also induced to move, and the unit A also becomes easy to move only when it is fixed. Therefore, uneven melting is less likely to occur on the image during fixing, and uneven gloss can be improved.

SPa-SPb is preferably 1.7 (J/cm ³ ) ^1/2 or less, more preferably 1.5 (J/cm ³ ) ^1/2 or less. The smaller the difference, the higher the affinity between unit A and unit B, which leads to suppression of uneven gloss. SPb-SPc is preferably 1.3 (J/cm ³ ) ^1/2 or less, more preferably 1.1 (J/cm ³ ) ^1/2 or less. The smaller the difference, the higher the affinity between the unit B and the compound C, leading to improved low-temperature fixability and suppression of uneven gloss. SPa-SPc is preferably 2.5 (J/cm ³ ) ^1/2 or more, more preferably 2.7 (J/cm ³ ) ^1/2 or more. The greater the difference, the lower the affinity between the unit A and the compound C, making it possible to suppress cracking of the toner during long-term use.

SPa, SPb, and SPc can be adjusted by molecular structure. Specifically, it can be controlled by selecting the macromonomer that is the precursor of the unit A, the precursor of the unit B, and the compound C.

The toner is not particularly limited as long as the toner particles contain a styrene-acrylic resin and an ester compound, and the manufacturing method thereof is not particularly limited.

The toner particles can be produced by a pulverization method, or by a method of producing toner particles in an aqueous medium such as a dispersion polymerization method, an association aggregation method, a dissolution suspension method, a suspension polymerization method, and an emulsion aggregation method. It is possible to manufacture

However, from the viewpoint of controlling the existence state of the ester compound, a method of producing toner particles in an aqueous medium is preferred, and from the viewpoint of toner shape control, it is more preferred to produce toner particles by a suspension polymerization method.

The suspension polymerization method will be described below.

Suspension polymerization is a process in which polymerizable monomers and wax (and, if necessary, colorants, polymerization initiators, cross-linking agents, charge control agents, and other additives) are uniformly dissolved or dispersed to form polymerizable monomers. A polymer composition is obtained. Thereafter, this polymerizable monomer composition is dispersed in a continuous layer (for example, an aqueous phase) containing a dispersant using a suitable stirrer, and a polymerization reaction is simultaneously carried out to obtain toner particles having a desired particle size. is obtained. Toner particles obtained by this suspension polymerization method (hereinafter also referred to as "polymerized toner particles") have a substantially spherical shape, so that the distribution of charge amount is relatively uniform, resulting in good image quality. Improvement can be expected.

Polymerizable monomers constituting the polymerizable monomer composition in the production of polymerized toner particles include the following.

A monovinyl monomer is preferably used as the polymerizable monomer. Examples of monovinyl monomers include styrene; styrene derivatives such as vinyl toluene and α-methylstyrene; acrylic acid and methacrylic acid; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, acrylic acid 2; - acrylic acid esters such as ethylhexyl and dimethylaminoethyl acrylate; methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and dimethylaminoethyl methacrylate; acrylonitrile , and nitrile compounds such as methacrylonitrile; amide compounds such as acrylamide and methacrylamide; olefins such as ethylene, propylene, and butylene;

Among these, it is preferable that at least one selected from the group consisting of styrene, styrene derivatives, acrylic acid esters and methacrylic acid esters is included as a monovinyl monomer. More preferably, at least one selected from the group consisting of styrene and styrene derivatives and at least one selected from the group consisting of acrylic acid esters and methacrylic acid esters are included as monovinyl monomers.

These monovinyl monomers may be used alone or in combination of two or more.

The polymerizable monomer preferably contains the monovinyl monomer as a main component. Specifically, the content of the monovinyl monomer in the polymerizable monomer is preferably 50% by mass or more and 100% by mass or less.

Polymerization initiators used in the production of toner particles by a polymerization method include persulfates such as potassium persulfate and ammonium persulfate; (2-methyl-N-(2-hydroxyethyl)propionamide), 2,2′-azobis(2-amidinopropane) dihydrochloride, 2,2′-azobis(2,4-dimethylvaleronitrile) and 2, Azo compounds such as 2′-azobisisobutyronitrile; di-t-butyl peroxide, benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, t-butylperoxydiethylacetate, t-hexyl organic peroxides such as peroxy-2-ethylbutanoate, diisopropylperoxydicarbonate, di-t-butylperoxyisophthalate and t-butylperoxyisobutyrate; These can be used alone or in combination of two or more. Among these, organic peroxides are preferred because they can reduce the amount of residual polymerizable monomers and are excellent in printing durability.

Among organic peroxides, peroxyesters are preferred because they have good initiator efficiency and can reduce residual polymerizable monomers, and non-aromatic peroxyesters, that is, peroxyesters having no aromatic ring. more preferred.

As described above, the polymerization initiator may be added after the polymerizable monomer composition is dispersed in the aqueous medium and before droplet formation. It may be added to the monomer composition.

The amount of the polymerization initiator used for polymerization of the polymerizable monomer composition is preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 100 parts by mass of the polymerizable monomer. is 0.3 parts by mass or more and 15 parts by mass or less, and particularly preferably 1 part by mass or more and 10 parts by mass or less.

A cross-linking agent may be added when the toner particles are produced by a polymerization method. A preferable addition amount of the cross-linking agent is 0.001 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer.

A compound having two or more polymerizable double bonds is mainly used as the cross-linking agent. Specifically, for example, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene and derivatives thereof; alcohols having two or more hydroxyl groups such as ethylene glycol dimethacrylate and diethylene glycol dimethacrylate having a carbon-carbon double bond ester compounds in which two or more carboxylic acids are ester-bonded; other divinyl compounds such as N,N-divinylaniline and divinyl ether; compounds having three or more vinyl groups;

These cross-linking agents may be used alone or in combination of two or more.

The toner particles may also contain a colorant. When making colored toners, black, cyan, yellow, and magenta colorants can be used.

Examples of black colorants that can be used include carbon black, titanium black, and magnetic powders such as zinc iron oxide and nickel iron oxide.

As the cyan colorant, for example, copper phthalocyanine compounds, derivatives thereof, anthraquinone compounds, and the like can be used. Specifically, C.I. I. Pigment Blue 2, 3, 6, 15, 15:1, 15:2, 15:3, 15:4, 16, 17:1, and 60.

As the yellow colorant, for example, compounds such as monoazo pigments, azo pigments such as disazo pigments, and condensed polycyclic pigments are used. Specifically, C.I. I. pigment yellow 3, 12, 13, 14, 15, 17, 62, 65, 73, 74, 83, 93, 97, 120, 138, 155, 180, 181, 185, 186, and 213;

Examples of magenta colorants include compounds such as azo pigments such as monoazo pigments and disazo pigments, and condensed polycyclic pigments. Specifically, C.I. I. Pigment Red 31, 48, 57: 1, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 149, 150, 163, 170, 184, 185, 187, 202, 206, 207, 209, 237, 238, 251, 254, 255, 269 and C.I. I. Pigment Violet 19 and the like.

Each colorant can be used alone or in combination of two or more. The amount of the coloring agent is preferably 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer.

As other additives, a positively or negatively chargeable charge control agent can be used in order to improve the chargeability of the toner.

The charge control agent is not particularly limited as long as it is generally used as a charge control agent for toner. Among charge control agents, positively or negatively chargeable charge control resins have high compatibility with polymerizable monomers and can impart stable chargeability (charge stability) to toner particles. preferable. Furthermore, from the viewpoint of obtaining a positively chargeable toner, a positively chargeable charge control resin is more preferably used.

Examples of positive charge control agents include nigrosine dyes, quaternary ammonium salts, triaminotriphenylmethane compounds and imidazole compounds, polyamine resins as charge control resins preferably used, and copolymers containing quaternary ammonium groups. , and quaternary ammonium base-containing copolymers. Commercially available charge control resins include FCA-592P manufactured by Fujikura Kasei Co., Ltd., for example.

Examples of negative charge control agents include azo dyes containing metals such as Cr, Co, Al and Fe, metal salicylate compounds and metal alkylsalicylate compounds, and sulfonic acid group-containing co-agents as charge control resins that are preferably used. Examples thereof include polymers, sulfonic acid group-containing copolymers, carboxylic acid group-containing copolymers, and carboxylic acid group-containing copolymers.

The charge control agent is used in a proportion of preferably 0.01 to 10 parts by mass, more preferably 0.03 to 8 parts by mass, per 100 parts by mass of the polymerizable monomer. When the amount of charge control agent added is 0.01 parts by mass or more, fogging is less likely to occur. On the other hand, when the amount of the charge control agent added is 10 parts by mass or less, printing stains are less likely to occur.

Further, as another additive, it is preferable to use a molecular weight modifier when polymerizing a polymerizable monomer that is polymerized to form a binder resin.

The molecular weight modifier is not particularly limited as long as it is generally used as a molecular weight modifier for toner, but a molecular weight modifier having a sulfide group is preferred. Mercaptans such as, for example, t-dodecylmercaptan, n-dodecylmercaptan, n-octylmercaptan, and 2,2,4,6,6-pentamethylheptane-4-thiol; thiuram disulfides such as butyl thiuram disulfide, N,N'-dimethyl-N,N'-diphenylthiuram disulfide, N,N'-dioctadecyl-N,N'-diisopropylthiuram disulfide; These molecular weight modifiers may be used alone or in combination of two or more.

The molecular weight modifier is preferably used in a proportion of 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the polymerizable monomer.

In the method of producing toner particles by a polymerization method, generally, the raw materials for the toner particles described above are added as appropriate and uniformly dissolved or dispersed using a dispersing machine such as a homogenizer, a ball mill, and an ultrasonic dispersing machine to form a polymerizable monomer composition. is suspended in an aqueous medium containing a dispersing agent. At this time, if a high-speed dispersing machine such as a high-speed agitator or an ultrasonic dispersing machine is used to obtain a desired toner particle size at once, the resulting toner particles have a sharper particle size.

As for the timing of adding the polymerization initiator, it may be added at the same time as other additives are added to the polymerizable monomer, or it may be mixed immediately before suspending in the aqueous medium. Further, a polymerization initiator dissolved in a polymerizable monomer or a solvent may be added immediately after granulation and before starting the polymerization reaction.

After the granulation, the particles may be stirred using an ordinary stirrer to such an extent that the particle state is maintained and the particles are prevented from floating and sedimentation.

When producing toner particles, a known surfactant, organic dispersant or inorganic dispersant can be used as a dispersant. Among them, the inorganic dispersant is preferably used because it obtains dispersion stability due to its steric hindrance, so that the stability does not easily deteriorate even when the reaction temperature is changed, it is easy to wash, and it does not adversely affect the toner. Examples of such inorganic dispersants include sulfates such as barium sulfate and calcium sulfate; carbonates such as barium carbonate, calcium carbonate and magnesium carbonate; phosphates such as calcium phosphate; metal oxides such as aluminum oxide and titanium oxide; metal hydroxides such as aluminum hydroxide, magnesium hydroxide, sodium hydroxide and ferric hydroxide;

It is desirable to use 0.2 parts by mass or more and 20 parts by mass or less of these inorganic dispersants with respect to 100 parts by mass of the polymerizable monomer. Moreover, the said dispersing agent may be used individually, and may use multiple types together. Furthermore, 0.001 parts by mass or more and 0.1 parts by mass or less of a surfactant may be used in combination.

In the step of polymerizing the polymerizable monomer, the polymerization temperature is preferably 50°C or higher, more preferably 60°C to 95°C. The polymerization reaction time is preferably 1 hour to 20 hours, more preferably 2 hours to 15 hours.

The toner particles are so-called core-shell type (or “capsule type”) polymer particles obtained by forming a core layer of polymer particles and forming a shell layer different from the core layer on the outer side of the core layer. The core-shell type polymer particles have a core layer made of a substance with a low softening point and coated with a substance with a higher softening point to achieve a balance between lowering the fixing temperature and preventing aggregation during storage. be able to.

The method for producing core-shell type polymer particles using the polymer particles described above is not particularly limited, and can be produced by a conventionally known method. Among them, the in situ polymerization method and the phase separation method are preferable from the viewpoint of production efficiency.

A method for producing core-shell type polymer particles by an in situ polymerization method will be described below.

A polymerizable monomer for forming the shell layer (polymerizable monomer for shell) and a polymerization initiator are added to the aqueous medium in which the polymer particles are dispersed, and polymerized to form a core-shell type polymer. Coalesced particles can be obtained.

As the polymerizable monomer for the shell, the same polymerizable monomers as described above can be used. Among them, it is preferable to use monomers such as styrene, acrylonitrile and methyl methacrylate, which give polymers having a glass transition temperature (Tg) of over 80°C, singly or in combination of two or more. Among them, it is preferable to use at least methyl methacrylate as the polymerizable monomer for the shell.

Polymerization initiators used for polymerization of the polymerizable monomer for the shell include metal persulfates such as potassium persulfate and ammonium persulfate; ) propionamide), and 2,2′-azobis-(2-methyl-N-(1,1-bis(hydroxymethyl)2-hydroxyethyl)propionamide), 2,2′-azobis[N-(2 -carboxyethyl)-2-methylpropionamidine] or a hydrate thereof; These can be used alone or in combination of two or more. The amount of the polymerization initiator is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer for the shell.

When a phase separation method is used, it is preferable to add the polymer, which has been polymerized in advance with the substance forming the shell, to the polymerizable monomers for forming the core. When a prepolymerized polymer is used, it is more preferably a reactive polymer having an unsaturated bond.

The polymerization temperature of the shell layer is preferably 50°C or higher, more preferably 60°C to 95°C. The polymerization reaction time is preferably 1 hour to 20 hours, more preferably 2 hours to 15 hours.

Toner particles can also be obtained by filtering, washing and drying the obtained polymer particles by a known method, if necessary. Further, it is also possible to insert a classification step as necessary to cut coarse powder and fine powder contained in the toner particles.

The obtained toner particles can be used as a toner as they are. Further, the toner can be obtained by mixing the toner particles with an external additive, if necessary, and adhering it to the surface of the toner particles.

The stirrer for performing the mixing process is not particularly limited as long as it is a stirrer capable of adhering the external additive to the surface of the toner particles. (trade name, manufactured by Kawada Seisakusho), Q Mixer (trade name, manufactured by Nippon Coke Kogyo Co., Ltd.), Mechanofusion System (trade name, manufactured by Hosokawa Micron Corporation), and Mechanomill (trade name, manufactured by Okada Seiko Co., Ltd.). External addition treatment can be carried out using a possible stirrer.

Examples of external additives include inorganic fine particles such as silica, titanium oxide, aluminum oxide, zinc oxide, tin oxide, calcium carbonate, calcium phosphate, and cerium oxide; organic fine particles such as polymethyl methacrylate resin, silicone resin, and melamine resin; mentioned. Among these, inorganic fine particles are preferred. Among inorganic fine particles, silica and titanium oxide are preferred, and silica is more preferred.

These external additives may be used alone, but may be used in combination of two or more.

The content of the external additive is preferably 0.05 parts by mass or more and 6 parts by mass or less, more preferably 0.2 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the toner particles.

The glass transition temperature (Tg) of the toner is preferably 45.0°C to 65.0°C, more preferably 50.0°C to 65.0°C.

When the glass transition temperature of the toner is within the above range, both storage stability and low-temperature fixability can be highly achieved. The glass transition temperature can be controlled by the composition of the binder resin, the type of crystalline polyester, the molecular weight of the binder resin, and the like.

The volume average particle diameter (Dv) of the toner is preferably 3.00 μm or more and 9.00 μm or less, more preferably 5.00 μm or more and 8.00 μm or less.

By setting the volume average particle diameter (Dv) of the toner within the above range, it is possible to sufficiently satisfy the reproducibility of dots while improving the handleability of the toner.

The ratio (Dv/Dn) of the volume average particle size (Dv) to the number average particle size (Dn) of the toner is preferably 1.25 or less, more preferably less than 1.25.

Dv and Dv/Dn of the toner can be controlled by the amount of dispersant, the type of stirrer, the number of revolutions, and the like.

The average circularity of the toner is preferably 0.970 or more, more preferably 0.975 or more. Although the upper limit of the average circularity is not particularly limited, it is, for example, 0.995 or less.

By setting the average circularity within the above range, the fluidity of the toner is improved, and deterioration of the toner can be reduced during long-term printing. The average circularity can be controlled by the amount of the material forming the shell layer added, the amount of the dispersant used, and the like.

The weight average molecular weight (Mw) of the binder resin is preferably 10,000 to 300,000, more preferably 15,000 to 260,000, even more preferably 20,000 to 230,000. When the weight-average molecular weight of the binder resin is 300,000 or less, the low-temperature fixability tends to be improved. When the weight-average molecular weight of the binder resin (B) is 10,000 or more, the heat-resistant storage stability tends to be improved.

The molecular weight distribution (Mw/Mn) of the binder resin is preferably 2-40, more preferably 3-35, even more preferably 3-23. When the molecular weight distribution is 40 or less, there is a tendency that low-temperature fixability and storage stability are improved. When the molecular weight distribution is 2 or more, hot offset resistance tends to be improved.

As for the loss elastic modulus of the toner, the loss elastic modulus G″ at 100° C. in dynamic viscoelasticity measurement is preferably 3.0×10 ⁵ (dyn/cm ² ) or less. When it is 0×10 ⁵ (dyn/cm ² ) or less, the low-temperature fixability is further improved, and it is more preferably 1.0×10 ⁵ (dyn/cm ² ) or less.

Control of the loss modulus is roughly divided into control of the binder resin and control of the ester compound. As for the binder resin, it can be controlled by adjusting the molecular weight, and by changing the type of monomer constituting the binder resin, such as the amount of unit A and unit B introduced. The ester compound can be controlled by the content in the toner and the type of the ester compound.

The toner has domains of the compound C in the cross section of the toner particles observed with a scanning transmission electron microscope, the average number of the domains in the cross section is 100 or more, and the average major axis of the domains is r1 (μm ), the r1 is preferably 1.0 μm or less. More preferably, the average number of domains is 150 or more. Further, it is more preferable that the average length of the domain is 0.5 μm or less.

When the average number of the domains in the cross section is 100 or more, the contact area of the compound C with the binder resin is increased, and the low-temperature fixability is improved. When r1 is also 1.0 μm or less, the contact area with the binder resin is increased, and the low-temperature fixability is improved.

The method for measuring each physical property value according to the present disclosure is described below.

<Volume Average Particle Size Dv and Particle Size Distribution Dv/Dn of Toner>
The volume average particle size Dv, the number average particle size Dn, and the particle size distribution Dv/Dn of the toner are measured by a particle size measuring machine (manufactured by Beckman Coulter, trade name: Multisizer). The measurement with this Multisizer is performed under the conditions of aperture diameter: 100 μm, dispersion medium: Isoton II (trade name), concentration: 10%, and number of measured particles: 100,000.

Specifically, 0.2 g of toner is placed in a beaker, and an aqueous alkylbenzenesulfonic acid solution (manufactured by Fuji Film Co., Ltd., trade name: Drywell) is added therein as a dispersant. 2 mL of a dispersing medium is further added to the toner to moisten the toner, and then 10 mL of a dispersing medium is added, dispersed for 1 minute with an ultrasonic disperser, and then measured by the above particle size measuring device.

<Method for measuring melting point of wax>
Weigh 6 mg to 8 mg of wax in a sample holder and use a differential scanning calorimeter (manufactured by Seiko Instruments Inc., trade name: RDC-220) to raise the temperature from -200 ° C. to 1,000 ° C. at 100 ° C./min. A DSC curve is obtained by performing measurement under warm conditions. Let the peak temperature of the endothermic peak of the DSC curve be the melting point.

<Method for Measuring Glass Transition Temperature of Toner or Macromonomer>
Glass transition temperatures of toners or macromonomers are measured according to ASTM D3418-97.

Specifically, 10 mg of toner obtained by drying is precisely weighed and placed in an aluminum pan. An empty aluminum pan is used as a reference. Using a differential scanning calorimeter (manufactured by SII Nano Technology Co., Ltd., trade name: DSC6220), the glass transition temperature of the accurately weighed toner or macromonomer was measured according to ASTM D 3418-97 in the measurement temperature range of 0°C to 150°C. Measured under the condition of a temperature increase rate of 10°C/min.

<Measurement method of weight average molecular weight (Mw) and peak molecular weight (Mp) of resin>
The weight average molecular weight (Mw) and peak molecular weight (Mp) of the resin are measured using gel permeation chromatography (GPC) as follows.

(1) Preparation of measurement sample A sample and tetrahydrofuran (THF) are mixed at a concentration of 5.0 mg/mL, left at room temperature for 5 to 6 hours, and then shaken sufficiently to combine THF and the sample. Mix well until there are no coalescences. Furthermore, it is allowed to stand at room temperature for 12 hours or more. At this time, the tetrahydrofuran (THF)-soluble portion of the sample is obtained by setting the time from the start of mixing of the sample and THF to the end of standing to be 72 hours or longer.

Then, it is filtered through a solvent-resistant membrane filter (pore size 0.45 μm to 0.50 μm, Myshoridisc H-25-2 [manufactured by Tosoh Corporation]) to obtain a sample solution.

(2) Measurement of sample Using the obtained sample solution, measure under the following conditions.
Apparatus: High-speed GPC apparatus LC-GPC 150C (manufactured by Waters)
Column: 7 series of Shodex GPC KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko) Mobile phase: THF
Flow rate: 1.0 mL/min
Column temperature: 40°C
Sample injection volume: 100 μL
Detector: RI (refractive index) detector

In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts.

As a standard polystyrene sample for preparing a calibration curve, Pressure Chemical Co. or Toyo Soda Kogyo Co., Ltd., having molecular weights of 6.0×10 ² , 2.1×10 ³ , 4.0×10 ³ , 1.75×10 ⁴ , 5.1×10 ⁴ , 1.1× 10 ⁵ , 3.9×10 ⁵ , 8.6×10 ⁵ , 2.0×10 ⁶ and 4.48×10 ⁶ are used.

<Method of measuring the area occupied by the wax domain in the cross section of the toner using a transmission electron microscope>
Cross-sectional observation of the toner by a transmission electron microscope (TEM) and evaluation of wax domains are performed as follows.

Ruthenium staining of the toner cross-section results in a clear contrast of crystalline material. Crystalline materials are less dyed than amorphous materials. This is probably because the dyeing material permeates into the crystalline material more weakly than the amorphous material due to differences in density and the like.

Since the amount of ruthenium atoms varies depending on the intensity of staining, a large amount of ruthenium atoms are present in strongly stained portions, making it difficult for electron beams to pass through them, resulting in a black image. On the other hand, weakly dyed portions have few ruthenium atoms, are easily transmitted by electron beams, and appear white on the observation image.

An osmium film (5 nm) and a naphthalene film (20 nm) were applied to the toner as a protective film using an osmium plasma coater (OPC80T, manufactured by Filgen), embedded in a photocurable resin D800 (JEOL Ltd.), and then superimposed. A toner cross section with a film thickness of 60 nm is produced at a cutting speed of 1 mm/s using a sonic ultramicrotome (UC7, Leica).

The resulting cross section is stained with a vacuum electron dyeing apparatus (VSC4R1H, Filgen) for 15 minutes in a RuO ₄ gas atmosphere of 500 Pa, and is observed using a STEM mode of a TEM (JEM2800, JEOL).

The STEM probe size is 1 nm, and the image size is 1024 pixels×1024 pixels.

The obtained image is binarized (threshold value 120/255 steps) using image processing software “Image-Pro Plus (manufactured by Media Cybernetics)”. Crystal domains can be extracted by binarization.

<Method for Calculating the Average Number of Domains of the Ester Compound and the Average Length r1 (μm) of the Domain of the Ester Compound>
Observation is performed by the above-described toner section observation method, and 50 toner particles within ±2.0 μm from the weight-average particle diameter of the toner are randomly selected and photographed to obtain a section image. It should be noted that crystalline materials are more difficult to stain with Ru than amorphous resins and magnetic materials, and appear white to gray in the cross-sectional image.

The average number of domains of the ester compound is obtained by counting the number of domains having a major axis of 20 nm or more in the above 50 toner cross-sectional images, and taking the average value among the 50 toner particles as the average number of the domains of the ester compound.

Furthermore, the average major axis r1 (μm) of the domains of the ester compound is determined by randomly selecting 10 cross sections from the above toner cross-sectional images, further selecting 100 domains of the ester compound at random from the 10 cross sections, Measure the length. The average value thereof is defined as the average length r1 (μm) of the domain of the ester compound in the cross section of the toner.

<Method for Measuring Average Circularity of Toner>
The average circularity of the toner is measured using a flow type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) under measurement and analysis conditions during calibration work.

A specific measuring method is as follows.

First, about 20 mL of ion-exchanged water, from which solid impurities have been removed in advance, is placed in a glass container. As a dispersant, "Contaminon N" (a 10% by mass aqueous solution of a neutral detergent for cleaning precision measuring instruments at pH 7 consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) was used as a dispersant. ) is diluted with ion-exchanged water to about 3 times the mass, and about 0.2 mL of the diluted solution is added.

Further, about 0.02 g of a measurement sample is added, and dispersion treatment is performed for 2 minutes using an ultrasonic disperser to obtain a dispersion liquid for measurement. At that time, the temperature of the dispersion liquid is appropriately cooled to 10° C. or higher and 40° C. or lower. As the ultrasonic disperser, a desktop ultrasonic cleaner disperser "VS-150" (manufactured by Vervoclea) with an oscillation frequency of 50 kHz and an electrical output of 150 W was used. and about 2 mL of the contaminon N is added to the water bath.

For the measurement, the flow-type particle image analyzer equipped with "LUCPLFLN" (magnification 20 times, numerical aperture 0.40) as the objective lens was used, and the sheath liquid was the particle sheath "PSE-900A" (manufactured by Sysmex Corporation). to use. The dispersion liquid prepared according to the above procedure is introduced into the flow type particle image analyzer, and 2000 magnetic toner particles are counted in the HPF measurement mode and the total count mode. The average circularity of the toner is calculated from the result.

The secondary ion intensity at the outermost surface of the toner (that is, at t=0) is the value of secondary ion mass/secondary ion charge number (m/z) measured without sputtering the toner.

<Dynamic Viscoelasticity Measurement of Toner>
As a measuring device, a rotating plate type rheometer "ARES" (manufactured by TA INSTRUMENTS) is used.

As a measurement sample, a sample obtained by pressure-molding the toner into a disc having a diameter of 7.9 mm and a thickness of 2.0±0.3 mm using a tablet molding machine under an environment of 25° C. is used.

The sample is mounted on a parallel plate, the temperature is raised from room temperature (25° C.) to the viscoelasticity measurement starting temperature (50° C.), and measurement is started under the following conditions.

As the measurement conditions,
(1) Set the sample so that the initial normal force is zero.
(2) A parallel plate with a diameter of 7.9 mm is used.
(3) Frequency shall be 1.0 Hz.
(4) Set the applied strain initial value (Strain) to 0.1%.
(5) Measurement is performed between 50°C and 160°C at a temperature increase rate (Ramp Rate) of 2.0°C/min and a sampling frequency of 1 time/°C.

The measurement is performed under the following setting conditions of the automatic adjustment mode.

Measurements are taken in the automatic strain adjustment mode (Auto Strain).
(6) Set the Max Applied Strain to 20.0%.
(7) Set the maximum torque (Max Allowed Torque) to 200.0 g·cm and the minimum torque (Min Allowed Torque) to 0.2 g·cm.
(8) Set Strain Adjustment to 20.0% of Current Strain. In the measurement, an automatic tension adjustment mode (Auto Tension) is adopted.
(9) Set Auto Tension Direction to Compression.
(10) Set Initial Static Force to 10.0 g and Auto Tension Sensitivity to 40.0 g.
(11) The operating conditions for automatic tension are that the sample modulus is 1.0×10 3 (Pa) or more.

From the value of the loss elastic modulus G″ at 100° C. in this measurement, the loss elastic modulus G″ (dyn/cm ² ) at 100° C. in the dynamic viscoelasticity measurement is obtained.

EXAMPLES The present disclosure will be specifically described below with reference to Examples, but the present disclosure is not limited to these Examples. The number of parts in the examples is based on mass unless otherwise specified.

<Method for producing ester compound C1>
100 parts of behenyl alcohol as an alcohol monomer and 80 parts of stearic acid as a carboxylic acid monomer are added to a reaction vessel equipped with a thermometer, a nitrogen inlet tube, a stirrer, a Dean-Stark trap and a Dimroth condenser, and esterified at 200° C. for 15 hours. reacted.

20 parts of toluene and 25 parts of isopropanol were added to the obtained ester compound, 190 parts of 10% potassium hydroxide aqueous solution was added in an amount corresponding to 1.5 times the acid value of the ester compound, and the mixture was stirred at 70° C. for 4 hours. After that, the water tank part was removed. After adding 20 parts of ion-exchanged water and stirring at 70° C. for 1 hour, the water tank was removed and washed. The above washing steps were repeated until the pH of the removed water bath was neutral.

Thereafter, the solvent was removed under reduced pressure at 200° C. and 1 kPa to obtain the final product, behenyl stearate (ester compound C1), which is an ester compound of behenyl alcohol and stearic acid. Table 1 shows the physical properties of the obtained ester compound C1.

<Method for producing ester compounds C2 to C4>
Ester compounds C2 to C5 were obtained in the same manner as in the method for producing ester compound C1, except that the monomers were changed as shown in Table 1. Table 1 shows the physical properties of the obtained ester compounds C2 to C5.

<Macromonomer>
Monomers shown in Table 2 were prepared as macromonomers that were precursors of macromonomer-derived units to be contained in the styrene-acrylic resin in the binder resin.

<Method for producing decyl acrylate>
288 g of acrylic acid, 160 g of decanol, 0.2 g of copper chloride, 0.14 g of hydroquinone monomethyl ether as a polymerization inhibitor, and toluene were added to a reaction vessel equipped with a thermometer, nitrogen inlet tube, stirrer, Dean-Stark trap and Dimroth condenser. 300 g of the mixture was mixed, and an esterification reaction was carried out at a reaction temperature of about 80° C. for 10 hours while removing condensed water.

100 parts of isopropanol was added, 190 parts of 10% potassium hydroxide aqueous solution was added, and the mixture was stirred at 70° C. for 4 hours. After that, the aqueous layer was removed. After adding 20 parts of ion-exchanged water and stirring at 70° C. for 1 hour, the aqueous layer was removed and washed. The above washing steps were repeated until the pH of the removed aqueous layer was neutral.

Thereafter, the pressure was reduced under conditions of 70° C. and 1 kPa to remove the solvent to obtain the final target decyl acrylate (b3).

<Long-chain alkyl monomer>
Monomers shown in Table 3 were prepared as precursors of units derived from long-chain alkyl monomers to be contained in the styrene-acrylic resin in the binder resin.

<Method for producing styrene-acrylic resin 1>
- 74 parts of styrene - 26 parts of n-butyl acrylate - 8 parts of lauryl acrylate (b1) - Macromonomer a1: Polymethacrylate macromonomer (manufactured by Toagosei Kagaku Kogyo Co., Ltd., trade name: AA6, Tg = 94°C)0. 25 parts, 200.0 parts of toluene, 0.16 parts of polymerization initiator: azobisisobutyronitrile (AIBN) The above ingredients were introduced into a reaction vessel equipped with a stirrer and a thermometer while replacing with nitrogen. After heating to 65° C., polymerization was carried out over 5 hours. After cooling to room temperature, the solvent toluene was distilled off to obtain styrene-acrylic resin 1 (binder resin for toner 13).

<Manufacturing Method of Toner 1>
・Polymerizable monomer: 74 parts of styrene, 26 parts of n-butyl acrylate ・8 parts of lauryl acrylate (b1) ・Coloring agent: 7 parts of carbon black (manufactured by Mitsubishi Chemical, trade name: #25B) ・Cross-linking agent: divinylbenzene 0.74 parts Charge control agent: 0.37 parts of styrene/acrylic resin (manufactured by Fujikura Kasei Co., Ltd., trade name: FCA-592P) Molecular weight modifier: 1 part of tetraethylthiuram disulfide Macromonomer a1: polymethacrylic acid ester Macromonomer (manufactured by Toagosei Chemical Industry Co., Ltd., trade name: AA6, Tg = 94 ° C.) 0.25 parts After stirring and mixing the above materials with a normal stirring device, a media type disperser is used to uniformly disperse and heat to 63 ° C. warmed up.

20 parts of the ester compound C1 was added, mixed and dissolved to obtain a polymerizable monomer composition.

On the other hand, in a stirring tank, an aqueous solution of 7.4 parts of magnesium chloride dissolved in 250 parts of ion-exchanged water and an aqueous solution of 4.1 parts of sodium hydroxide dissolved in 50 parts of ion-exchanged water were stirred at room temperature. It was gradually added to prepare a magnesium hydroxide colloidal dispersion (3.0 parts of magnesium hydroxide).

The polymerizable monomer composition was added to the magnesium hydroxide colloidal dispersion obtained above at room temperature, the temperature was raised to 60°C, and the mixture was stirred until the droplets were stabilized. After adding 5 parts of t-butyl peroxy-2-ethylhexanoate (manufactured by NOF Corporation, trade name: Perbutyl O), an in-line emulsifying disperser (manufactured by Taiheiyo Kiko Co., Ltd., trade name: Milder) was used. , 15,000 rpm for high shear stirring to form droplets of the polymerizable monomer composition.

The magnesium hydroxide colloidal dispersion in which the droplets of the polymerizable monomer composition were dispersed was charged into a reactor equipped with a stirring blade, and the temperature was raised to 89°C and controlled to be constant. , the polymerization reaction was carried out. Next, when the polymerization conversion rate reached 98%, the temperature in the system was cooled to 75°C, and 15 minutes after reaching 75°C, 3 parts of methyl methacrylate as a polymerizable monomer for the shell and ion exchange 2,2′-azobis[2-methyl-N-(1,1-bis(hydroxymethyl)2-hydroxyethyl)propionamide]tetrahydrate dissolved in 10 parts of water (manufactured by Wako Pure Chemical Industries, trade name: VA086) was added at 0.36 parts. After further continuing the polymerization for 3 hours, the reaction was terminated to obtain an aqueous dispersion of colored resin particles having a pH of 9.5.

Thereafter, the aqueous dispersion of the colored resin particles was heated to 90° C. and subjected to stripping treatment at a nitrogen gas flow rate of 0.6 m ³ /(hr·kg) for 5 hours. Thereafter, as a cooling step, water of 0° C. was added to the suspension, and the suspension was cooled from 98.0° C. to 30° C. at a rate of 100° C./min, and then heated to 50° C. for 6 hours. held. After that, it was cooled down to 25°C by natural cooling at room temperature. The cooling rate at that time was 1° C./min. Next, while stirring the resulting aqueous dispersion, the pH of the system is adjusted to 6.5 or less with sulfuric acid for acid washing. After separating the water by filtration, 500 parts of ion-exchanged water is newly added to re-slurry. It was then washed with quenched water. Thereafter, dehydration and washing with water were repeated several times, and the solid content was separated by filtration.

To the toner particles 1 (100 parts) obtained above, 0.7 parts of hydrophobized silica fine particles having a number average primary particle size of 7 nm and 1 part of hydrophobized silica fine particles having a number average primary particle size of 50 nm were added. and mixed using a high-speed stirrer (manufactured by Nippon Coke Kogyo Co., Ltd., trade name: FM Mixer) to produce Toner 1. Tables 5 and 6 show the physical properties of Toner 1 thus obtained.

<Manufacturing Method of Toners 2 to 12 and 14 to 21>
Toners 2 to 12 and 14 to 21 were produced in the same manner as in the production method of toner 1, except that the toner composition and toner production method were changed as shown in Table 4. Tables 5 and 6 show the physical properties of toners 2-12 and 14-21.

<Manufacturing Method of Toner 13>
The following materials were mixed for 4 minutes using an FM mixer (“FM-20” manufactured by Nippon Coke Kogyo Co., Ltd.) at a rotation speed of 2000 rpm.
Binder resin: Styrene-acrylic resin 1 90 parts Charge control agent: Styrene/acrylic resin ("FCA-207P" manufactured by Fujikura Kasei Co., Ltd.) 3 parts Coloring agent: Carbon black (manufactured by Mitsubishi Chemical, trade name: #25B) 4 Partial ester compound C1 3 parts The obtained mixture was melt-kneaded with a twin-screw extruder ("PCM-30" manufactured by Ikegai Co., Ltd.) at a melt-kneading temperature (cylinder temperature) of 120 ° C., a rotation speed of 150 rpm, and a processing speed of 100 g / min. was melt-kneaded. The resulting melt-kneaded product was coarsely pulverized to about 2 mm by a Rotoplex pulverizer (manufactured by Alpine), and then pulverized by a mechanical pulverizer ("Turbo Mill T250" manufactured by Freund Turbo Co., Ltd.). The resulting pulverized material was classified by an air classifier (“EJ-L3 type” manufactured by Nittetsu Mining Co., Ltd.) to obtain toner particles 13 having an average particle size of 8.5 μm.

The obtained toner particles 13 (100 parts), 0.8 parts of fine silica particles (“RA200” manufactured by Nippon Aerosil Co., Ltd.), and 0.8 parts of titanium oxide (“EC100” manufactured by Titan Kogyo Co., Ltd.) were mixed in an FM mixer ( Toner 13 was obtained by mixing for 5 minutes at a rotation speed of 2000 rpm using "FM-20" manufactured by Nippon Coke Kogyo Co., Ltd.

Tables 5 and 6 show the physical properties of Toner 13.

[Example 1]
Toner 1 was evaluated as follows. Table 7 shows the evaluation results.

[Evaluation 1: Evaluation of gloss unevenness]
Evaluation of gloss unevenness was performed using HL-5470DW (Monochrome laser printer manufactured by Brother Industries) and a cartridge from which the paper dust collection roller was removed, under a low temperature and low humidity environment (temperature 15 ° C., humidity 5% RH), and the paper was rough paper. FOX RIVER BOND paper (110 g/m ² ) was used to output a solid black image with a print ratio of 100%.

Gloss was measured using a handy type gloss meter PG-1 (manufactured by Nippon Denshoku Industries Co., Ltd.). For the measurement, the light projection angle and the light reception angle were adjusted to 75°. The image glossiness was determined by measuring the glossiness (gloss) of 10 points randomly selected from the output image, and the difference between the highest glossiness and the lowest glossiness was evaluated for glossiness unevenness. The evaluation criteria were as follows.
A: The gloss difference is less than 2.00%.
B: The gloss difference is 2.00% or more and less than 3.00%.
C: The gloss difference is 3.00% or more and less than 5.00%.
D: The gloss difference is 5.00% or more.

[Evaluation 2: Evaluation of toner deterioration]
As the evaluation procedure, HL-5470DW (Monochrome laser printer manufactured by Brother Industries, Ltd.) and a cartridge from which the paper dust collection roller was removed were used, and the toner was imaged in a high-temperature and high-humidity environment (temperature 32.5°C, humidity 80% RH). After being left alone with the apparatus for one day, 15,000 sheets of horizontal line images with a printing ratio of 1% were output in the intermittent mode, and 3 sheets of solid images were output under the above environment. For evaluation of image quality, densities of the last three solid images were measured at four corners with a Macbeth reflection densitometer, and these 12 numerical values were evaluated according to the following criteria.
A: Difference between maximum and minimum image density is less than 0.10 B: Difference between maximum and minimum image density is 0.10 or more and less than 0.20 C: Difference between maximum and minimum image density is 0.20 or more and less than 0.25 D: The difference between the maximum value and the minimum value of image density is 0.25 or more

[Evaluation 3: Evaluation of low temperature fixability]
Low-temperature fixability was evaluated using HL-5470DW (Monochrome laser printer manufactured by Brother Industries, Ltd.) and a cartridge from which the paper dust collecting roller was removed, under a low-temperature and low-humidity environment (temperature 15°C, humidity 5% RH). . The fixing temperature of the fixing device in the image forming apparatus was modified so that it could be set arbitrarily.

Using this device, the fixing temperature of the fixing device was adjusted in the range of 180° C. to 230° C. at intervals of 5° C., and rough paper FOX RIVER BOND paper (110 g/m ² ) was used, and the printing ratio was 100%. A solid black image was output. At this time, it was visually evaluated whether or not there was a white spot portion in the image of the solid image portion, and the lowest temperature at which the white spot portion was generated was used as the evaluation of the low-temperature fixability.
A: White spots occurred below 200°C.
B: White spots occurred at 200°C or higher and lower than 210°C.
C: White spots occurred at 210°C or higher and lower than 220°C.
D: White spots occurred at 220°C or higher.

[Evaluation 4: Evaluation of storage stability]
Storage stability was evaluated by the following procedure.

Using HL-5470DW (Monochrome laser printer manufactured by Brother Industries) and a cartridge with the paper dust collection roller removed, print out one solid image in a normal temperature and humidity environment (temperature 25.0 ° C, relative humidity 60%). After that, the developing device was stored for 40 days under a severe environment (temperature of 40.0° C., relative humidity of 95%). After storage, one solid image was printed out in a normal temperature and normal humidity environment (temperature: 25.0° C., relative humidity: 60%), and the image density before and after storage was compared and evaluated. The density of the solid image was measured with a Macbeth reflection densitometer (manufactured by Macbeth).
A: Density difference less than 0.05 B: Density difference 0.05 to less than 0.10 C: Density difference 0.10 to less than 0.20 D: Density difference 0.20 or more

[Examples 2 to 15, Comparative Examples 1 to 5]
Examples 2 to 15 and Comparative Examples 1 to 5 were evaluated in the same manner as in Example 1, except that the combination of the toner and photoreceptor was changed as shown in Table 5. Table 7 shows the evaluation results.

Claims (10)

A toner having toner particles having a binder resin and an ester compound,
The binder resin contains a styrene-acrylic resin having a macromonomer-derived unit and a monomer unit represented by the following formula (1),

(In Formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear alkyl group having 10 to 14 carbon atoms.)
The ester compound is at least one ester selected from the group consisting of an ester compound represented by the following formula (2), an ester compound represented by the following formula (3), and an ester compound represented by the following formula (4) is a compound,

(In formula (2), formula (3) and formula (4), R ³¹ and R ⁴¹ each independently represent an alkylene group having 2 to 8 carbon atoms, and R ³² , R ³³ , R ⁴² and R ⁴³ , R ⁵¹ and R ⁵² each independently represent a linear alkyl group having 14 to 24 carbon atoms.)
The SP value of the unit derived from the macromonomer is SPa (J/cm ³ ) ^1/2 , the SP value of the monomer unit represented by the formula (1) is SPb (J/cm ³ ) ^1/2 , and the When the SP value of the ester compound is SPc (J/cm ³ ) ^1/2 ,
The SPa is 19.50 or more and 20.50 or less,
A toner in which said SPa, said SPb and said SPc satisfy the following relational expressions (a), (b) and (c) below.
SPa-SPb≤2.0 (a)
SPb-SPc≤1.5 (b)
SPa−SPc≧2.0 (c) 2. The toner according to claim 1, wherein the styrene-acrylic resin contains 1% by mass or more and 15% by mass or less of the unit represented by the formula (1). 3. The toner according to claim 1, wherein the unit represented by formula (1) is a unit represented by formula (1') below.

(In formula (1′), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear alkyl group having 12 carbon atoms.) The toner according to any one of claims 1 to 3, wherein the styrene-acrylic resin has a sulfide group. 5. The toner according to claim 1, wherein the loss elastic modulus G″ at 100° C. in dynamic viscoelasticity measurement of the toner is 3.0×10 ⁵ (dyn/cm ² ) or less. The toner according to any one of claims 1 to 5, wherein the macromonomer is a macromonomer having a unit represented by the following formula (3) in the main chain portion of the macromonomer.

(In formula (3), R ¹ and R ² represent methyl groups.) The toner according to any one of claims 1 to 6, wherein the toner has an average circularity of 0.975 or more and 0.995 or less. domains of the ester compound are present in cross sections of the toner particles observed with a scanning transmission electron microscope;
The average number of domains in the cross section is 100 or more,
8. The toner according to any one of claims 1 to 7, wherein r1 (μm) is 1.0 μm or less, where r1 (μm) is the average length of the domain. The toner according to any one of claims 1 to 8, wherein the glass transition temperature of the macromonomer that is a precursor of the unit derived from the macromonomer is 60°C or higher. 10. The toner according to any one of claims 1 to 9, wherein the macromonomer, which is a precursor of the unit derived from the macromonomer, has a number average molecular weight of 5000 or more.