Wax composition for toner

Abstract

To provide a toner wax composition capable of applying blocking resistance and storage stability to a toner, having small difference between a melting temperature and a coagulation temperature during high-speed rising and falling temperatures, adapted for high-speed printing and capable of applying high glossiness and gloss uniformity.SOLUTION: A toner wax composition includes 100 pts.mass of an aliphatic ketone compound (a) represented by the following formula (1) and 0.001-5 pts.mass of a 14-24C linear alkane compound (b), [the formula (1):R1-CO-R2] (where in the formula (1), R1 and R2 independently represent a straight chain saturated hydrocarbon chain, and the total carbon atoms of R1 and R2 is 30-48.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a toner wax that is suitably added to a toner used for developing electrostatic charges formed by electrophotography, electrostatic recording, etc. in a multifunction machine, printer, commercial printing machine, etc. [Background technology]

[0002] Toners used in electrophotographic devices such as electrophotographic printers, facsimiles, and copying machines having these functions contain, in addition to the thermoplastic resin (styrene-acrylic binder resin, polyester binder resin, etc.) that is the main component, colorants (carbon black, magnetic powder, pigment, etc.), charge control agents, waxes, and, if necessary, fluidity additives, cleaning aids, and transfer aids. In the fixing process, the toner is heated by the fixing roll and softened, and is fixed to the surface of the printing medium by the pressure of the fixing roll, forming an image. The wax contained in the toner exudes onto the toner surface during fixing, providing release properties that prevent the phenomenon of toner remaining on the fixing roll, i.e., filming, and also contributes to the gloss of the printed matter by exuding and crystallizing onto the surface of the toner fixed to the printing medium.

[0003] In recent years, the performance and functionality required of copying machines such as multifunction copiers and commercial printers have become increasingly sophisticated, and in addition to improvements to the machines themselves, the toners used in these machines are also required to have high performance. For example, the production of solid prints such as photographs and posters requires uniform, high gloss that is at least as good as the image quality obtained by silver halide photography or gravure printing. Furthermore, in these commercial printing fields, toners that can be adapted to ultra-high-speed printing are required to improve production efficiency and save energy. As such, there are many needs for toners, and a toner that can meet all of these challenges simultaneously is needed.

[0004] To achieve ultra-high-speed printing, the toner must quickly develop adhesive strength during the fixing process and quickly lose adhesive strength after fixing in order to prevent blocking between printed objects. To achieve this, the wax used in the toner must also have excellent thermal responsiveness, and a wax with a very narrow melting and solidifying temperature range is required, which shows sharp melting properties when heated and solidifies quickly when cooled. Furthermore, in order to achieve high gloss and uniform gloss without unevenness, it is necessary to reduce the irregularities of the wax that has exuded onto the surface of the toner fixed on the print medium. Patent Document 1 discloses a method of using a combination of two monoester waxes in which the two types of hydrocarbon chains in each monoester molecule are different from each other. However, because the solidification temperature of monoester wax is significantly lower than the melting temperature, when printing at ultra-high speeds, the monoester wax that seeps out onto the surface of the toner fixed on the print medium does not solidify quickly, easily causing blocking, in which printed items stick together. Furthermore, it is not possible to achieve high gloss with uniformity equivalent to or better than the image quality obtained by silver halide photography or gravure printing. Therefore, Patent Document 2 describes a toner release agent made of a ketone compound, which is used in heat-fixing copiers or printers and has excellent low-temperature fixability, hot offset resistance, and fluidity. However, the ketone compound in Patent Document 2 cannot impart uniform, high gloss that is equivalent to or better than the image quality obtained by silver halide photography or gravure printing. Furthermore, compared to paraffin wax, ester wax, and other waxes used as toner waxes, ketone compounds have high molecular symmetry, which narrows the melting and solidifying temperature range, but this is insufficient for ultra-high-speed printing.

[0005] In order to simultaneously suppress adhesion (blocking) between printed objects during ultra-high-speed printing on commercial printing machines and impart uniform, high gloss to solid prints such as photographs and posters, the wax must melt quickly at a specified temperature during fixation during high-speed printing, thereby exhibiting its wax function, and also solidify quickly after printing to prevent printed objects from sticking together. This requires a wax with an unprecedented narrow range of melting and solidifying temperatures, and a wax composition for toners that allows the wax to seep out onto the surface of the printed object during fixation, imparting a high level of smoothness and gloss to the surface. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2019-120861 [Patent Document 2] Patent Publication No. 10-232505 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a wax composition for a toner, which narrows the temperature difference between the melting temperature and the solidification temperature during rapid temperature increase and decrease, making it suitable for high-speed printing, can impart blocking resistance to the toner, and can impart high gloss to images printed on a printing medium. [Means for solving the problem]

[0008] As a result of intensive research into the above-mentioned problems, the present inventors have found that a wax-based mixture containing 100 parts by mass of an aliphatic ketone compound (a) represented by the following formula (1) and 0.001 to 5 parts by mass of a linear alkane compound (b) having 12 to 24 carbon atoms melts and solidifies quickly even at a high temperature increase / decrease rate compared to the aliphatic ketone compound (a), has an extremely narrow range of melting and solidifying temperatures, and the wax that seeps out onto the surface after the wax-based mixture is heated, melted, and solidified again becomes smooth and can impart high gloss, thereby completing the present invention. Formula (1): R 1 -CO-R 2 (In formula (1), R 1 and R 2 each independently represents a linear saturated hydrocarbon chain, and R 1 and R 2 The total number of carbon atoms is 30 to 48.

[0009] That is, the toner wax composition of the present invention is characterized by containing an aliphatic ketone compound (a) represented by the following formula (1) and a linear alkane compound (b) having 14 to 24 carbon atoms, and the content of the linear alkane compound (b) is 0.001 to 5 parts by mass per 100 parts by mass of the aliphatic ketone compound (a). Formula (1): R 1 -CO-R 2 (In formula (1), R 1 and R 2 each independently represents a linear saturated hydrocarbon chain, and R 1 and R 2 The total number of carbon atoms is 30 to 48. [Effects of the Invention]

[0010] The toner wax composition of the present invention melts and solidifies quickly even when the temperature is increased or decreased at a high rate, and the temperature difference between the melting temperature and the solidification temperature is extremely narrow, making it suitable for ultra-high speed printing, and can impart blocking resistance to the toner and high gloss to images printed on a printing medium such as paper. DETAILED DESCRIPTION OF THE INVENTION

[0011] The toner wax composition of the present invention contains an aliphatic ketone compound (a) and a linear alkane compound (b) having 14 to 24 carbon atoms, as described below, in a ratio of 0.001 to 5 parts by mass of the linear alkane compound (b) to 100 parts by mass of the aliphatic ketone compound (a). In the present invention, the aliphatic ketone compound refers to a compound containing the target aliphatic ketone and compounds such as fatty acids and fatty acid metal salts derived from raw materials that accompany the compound during production. Furthermore, in this specification, numerical ranges defined using the symbol "to" are intended to include the numerical values ​​at both ends (upper and lower limits) of the symbol "to." For example, "2 to 5" means "2 or more and 5 or less."

[0012] A wax-based mixture containing an aliphatic ketone compound (a) and a linear alkane compound (b) in a ratio of 0.001 to 5 parts by mass of the linear alkane compound (b) to 100 parts by mass of the aliphatic ketone compound (a) melts and solidifies quickly even at high temperature rise and fall rates, and the melting and solidification temperatures are within an extremely narrow range. Furthermore, the wax-based mixture is heated, melted, and then solidified again, and the wax that seeps out onto the surface becomes smooth and can impart high gloss. Therefore, by using this wax-based mixture as a wax composition for toner, it can be quickly solidified in the toner during the fixing process of ultra-high speed printing, thereby suppressing adhesion (blocking) between printed objects, and the wax that seeps out and solidifies onto the surface of an image printed on a printing medium such as paper makes the surface smooth, thereby imparting high gloss and gloss uniformity to the image. In particular, by using the wax base mixture as a wax composition for toner, it can be applied to ultra-high speed printing, and when producing solid printed matter such as photographs and posters, it is possible to produce high-quality images with uniform, high gloss that are equivalent to or better than the image quality obtained by silver halide photography or gravure printing.

[0013] [Aliphatic ketone compound (a)] The aliphatic ketone compound (a) as a wax is a compound represented by the following formula (1). Formula (1): R 1 -CO-R 2 In formula (1), R 1 and R 2 each independently represents a linear saturated hydrocarbon chain, and R 1 and R 2 The total number of carbon atoms is 30 to 48.

[0014] In the above formula (1), the linear saturated hydrocarbon chain R 1 and R 2 From the viewpoints of storage stability, releasability, and compatibility with the toner binder resin, R preferably each independently has 15 or more and 23 or less carbon atoms. 1 and R 2 Each of these groups preferably has 16 or more and 23 or less carbon atoms, and more preferably has 17 or more and 20 or less carbon atoms. If the carbon number of the straight-chain saturated aliphatic hydrocarbon group is less than 15, the heat resistance will be poor, which may cause contamination of the fixing device, or the toner may bleed out during storage, which may lead to blocking of toner particles. On the other hand, if the carbon number of the straight-chain saturated aliphatic hydrocarbon group is more than 23, the melting point will be too high, which will make fixing failure (cold offset) more likely to occur when fixing the toner to the print medium. In addition, the compatibility with the toner binder resin will be poor, which will make the toner more likely to bleed out during storage, causing blocking.

[0015] Specific examples of the aliphatic ketone compound represented by formula (1) include dipentadecyl ketone, dihexadecyl ketone, diheptadecyl ketone, dioctadecyl ketone, dinonanedecyl ketone, dieicosyl ketone, diheneicosyl ketone, didocosyl ketone, ditricosyl ketone, and ditetracosyl ketone.

[0016] The aliphatic ketone compounds can be obtained by decarboxylating the aforementioned carboxylic acid having a linear saturated aliphatic hydrocarbon group in the presence of a metal oxide catalyst at high temperatures, preferably 300 to 350°C, and high pressures, preferably 0.1 to 5 MPa. Examples of the metal oxide catalyst include magnesium oxide, calcium oxide, and zinc oxide. Examples of the carboxylic acid include palmitic acid, margaric acid, stearic acid, arachidic acid, behenic acid, and lignoceric acid. Alternatively, metal salts of carboxylic acids, such as magnesium carboxylate, calcium carboxylate, and zinc carboxylate, may be used in place of the aforementioned carboxylic acid having a linear saturated aliphatic hydrocarbon group and the metal oxide catalyst. Typical examples include magnesium stearate, calcium stearate, zinc stearate, magnesium behenate, calcium behenate, and zinc behenate.

[0017] From the viewpoint of toner storage stability, the aliphatic ketone compound (a) represented by formula (1) constituting the toner wax composition of the present invention preferably has an upper limit of acid value of 1.0 mgKOH / g, more preferably 0.7 mgKOH / g, and even more preferably 0.5 mgKOH / g. From the viewpoint of the above, the lower the acid value, the better. However, from the viewpoints of productivity and compatibility with the toner binder, the lower limit is preferably 0.01 mgKOH / g, and even more preferably 0.03 mgKOH / g. In the present invention, the acid value of the aliphatic ketone compound refers to the amount of carboxylic acid having an unreacted linear saturated aliphatic hydrocarbon group in the synthesis of the aliphatic ketone compound, and examples thereof include the carboxylic acid used in the reaction and the carboxylic acid contained in the carboxylic acid metal salt.

[0018] The transparent melting point of the aliphatic ketone compound is preferably 70 to 100°C, more preferably 80 to 95°C. The solidification temperature of the aliphatic ketone compound in the present invention is preferably 45 to 75°C, more preferably 55 to 70°C. The melting temperature is preferably 80 to 110°C, more preferably 90 to 100°C. The temperature difference between the melting temperature and solidification temperature of the aliphatic ketone compound is preferably as small as possible, but is preferably 45°C or less, more preferably 40°C or less. The transparent melting point of the aliphatic ketone compound can be measured in accordance with JOCS (Chemical Society of Japan) 2.2.4.1-2003, and the melting temperature and solidification temperature can be measured using a differential scanning calorimeter (DSC).

[0019] [Linear alkane compounds (b)] The linear alkane compound (b) is a linear alkane having 14 to 24 carbon atoms, specifically tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, icosane, henicosane, docosane, tricosane, and tetracosane. From the viewpoints of toner storage stability and gloss of printed matter, the number of carbon atoms in the linear alkane compound (b) is preferably 15 to 23, and more preferably 15 to 21.

[0020] If the carbon number of the linear alkane compound (b) is less than 14, the heat resistance will be poor and the compound will volatilize, contaminating the fixing device, or the compound will bleed out during toner storage, causing blocking of toner particles. On the other hand, if the carbon number of the linear alkane compound (b) is more than 24, the compound will not bleed out of the toner when fixed to the print medium, and high gloss will not be obtained.

[0021] The linear alkane compound (b) preferably has an ascending melting point of 15 to 50° C., more preferably 20 to 45° C. The ascending melting point can be measured in accordance with JOCS (Chemical Society of Japan) 2.2.4.2-2003.

[0022] [Wax composition for toner] The toner wax composition of the present invention contains the aliphatic ketone compound (a) and the linear alkane compound (b), and the content of the linear alkane compound (b) relative to 100 parts by mass of the aliphatic ketone compound (a) is 0.001 to 5 parts by mass, preferably 0.005 to 4 parts by mass, and more preferably 0.01 to 3 parts by mass. If the content of the linear alkane compound (b) is less than 0.001 parts by mass, when used as a toner wax composition, high gloss may not be obtained in printed matter. Furthermore, if the content of the linear alkane compound (b) exceeds 5 parts by mass, high gloss may be obtained, but the linear alkane compound (b) may bleed out of the toner during storage, causing blocking. Furthermore, the solidification temperature of the wax composition may be significantly lowered, widening the temperature difference between the melting temperature and solidification temperature, making it unsuitable for ultra-high-speed printing.

[0023] The toner wax composition of the present invention can be produced by a known method. For example, the aliphatic ketone compound and the linear alkane compound may be produced separately and then blended to a specified mass ratio, or they may be produced all at once by adjusting the amounts of the raw carboxylic acid, metal oxide catalyst, and linear alkane compound, or the amounts of the carboxylic acid metal salt and linear alkane compound, to a specified mass ratio. Regarding the method of producing a toner wax composition by blending the aliphatic ketone compound and the linear alkane compound separately, it is preferable to heat them to a temperature equal to or higher than the melting point of the aliphatic ketone compound, melt and mix them uniformly in an environment that does not cause oxidative degradation, and then cool and pulverize them, from the viewpoint of preventing variation in quality.

[0024] The toner wax composition of the present invention is blended with binder resins such as polyesters and styrene acrylics that are commonly used as toner materials, colorants, external additives, charge control agents, etc., and toner is produced by a conventional manufacturing method. The blending amount of the toner wax composition of the present invention in the toner is usually 0.1 to 40 parts by mass per 100 parts by mass of the binder resin. [Example]

[0025] The present invention will be explained in more detail below by showing examples of the production of the toner wax composition of the present invention and the evaluation method thereof. In the following examples and comparative examples, "%" means a percentage by mass.

[0026] [Preparation of Aliphatic Ketone Compounds and Measurement of Their Physical Properties] [Production of Aliphatic Ketone Compound A-1] 700.0 g of magnesium stearate (product name: Nissan Electol MM-2, manufactured by NOF Corporation, magnesium stearate, stearic acid content: 98%) was weighed into a 1 L stainless steel separable flask and heated to 250°C by blowing in nitrogen. At this time, the water contained in the material was distilled out of the system. Nitrogen was then injected at 2 MPa, and the temperature was raised to 340-350°C. The reaction was continued for 8 hours, and then cooled to 100°C to obtain a crude aliphatic ketone compound. The aliphatic ketone compound was filtered at 100°C with nitrogen blowing in using a 100-mesh metal strainer to remove the magnesium oxide produced as a by-product. The wax obtained by filtration was poured into a stainless steel tray, solidified at room temperature, and pulverized in a mixer. 1 and R 2 The total carbon number of the compound (=34) was 0.28 mg KOH / g, and the clear melting point was 88.7°C.

[0027] [Production of Aliphatic Ketone Compound A-2] 600.0 g (1.8 mol) of behenic acid [behenic acid manufactured by NOF Corporation, behenic acid content: 97%, acid value = 164.9 mg KOH / g] and 35.6 g (0.9 mol) of magnesium oxide were weighed into a 1 L stainless steel separable flask and heated to 250 °C by blowing in nitrogen. At this time, the water contained in the material was distilled out of the system. Then, nitrogen was blown in at 2 MPa, and the temperature was raised to 340-350 °C. The reaction was continued for 8 hours, and then cooled to 100 °C to obtain a crude aliphatic ketone compound. The aliphatic ketone compound was filtered at 100 °C under nitrogen blowing using a 100-mesh metal strainer to remove excess magnesium oxide. The wax obtained by filtration was discharged into a stainless steel tray, solidified at room temperature, and pulverized in a mixer. The resulting aliphatic ketone compound (diheneicosyl ketone; R 1 and R 2 The total carbon number of the compound (=42) was 0.33 mg KOH / g, and the clear melting point was 92.6°C.

[0028] [Production of Aliphatic Ketone Compound A-3] 600.0 g (2.2 mol) of stearic acid (NOF Corporation, Sakura Stearic Acid Beads, stearic acid / palmitic acid mixture (mass ratio 65 / 35), acid value = 207.8 mgKOH / g) and 44.4 g (1.01 mol) of magnesium oxide were weighed into a 1 L stainless steel separable flask and heated to 250 °C with nitrogen blowing. During this time, moisture contained in the material was distilled out of the system. Nitrogen was then blown in under 2 MPa, and the temperature was further raised to 340-350 °C. The reaction was continued for 8 hours, and then cooled to 100 °C to obtain a crude aliphatic ketone compound. The aliphatic ketone compound was filtered at 100 °C with nitrogen blowing through a 100-mesh metal strainer to remove excess magnesium oxide. The filtered wax was then discharged into a stainless steel tray, solidified at room temperature, and pulverized in a mixer. The resulting aliphatic ketone compound (a mixture of diheptadecyl ketone, dipentadecyl ketone, and pentadecyl heptadecyl ketone; R 1 and R 2The total number of carbon atoms (30-34) had an acid value of 0.15 mg KOH / g and a clear melting point of 78.4°C. GC analysis revealed that the mass ratio of the aliphatic ketone mixture was diheptadecyl ketone / dipentadecyl ketone / pentadecyl heptadecyl ketone = 42 / 13 / 45.

[0029] [Method for measuring physical properties of aliphatic ketone compounds] (1) Acid value: Measured in accordance with JOCS (Chemical Society of Japan) 2.4.2.2-2003. (2) Transparent melting point: Measured in accordance with JOCS (Chemical Society of Japan) 2.2.4.1-2003. (3) Melting temperature (Tpm), solidification temperature (Tec): Differential scanning calorimetry (DSC) was performed using a Hitachi High-Tech Science DSC7000X. The DSC was performed in accordance with JIS K 7121 (international standard ASTM D3418-82). The melting points of indium and zinc were used for temperature correction of the detector, and the heat of fusion of indium was used for heat correction. The melting temperature of the aliphatic ketone compound was read from the melting peak temperature (Tpm), and the solidification temperature was read from the extrapolated crystallization end temperature (Tec). The extrapolated crystallization end temperature was determined as the temperature at the intersection of a straight line extending the low-temperature baseline toward the high-temperature side and a tangent drawn at the point where the slope of the curve on the low-temperature side of the crystallization peak is maximum. The measurement was performed by placing approximately 10 mg of an aliphatic ketone compound in a sample holder and using an empty sample holder as a reference material.The temperature was raised to 150°C, then lowered from 150°C to 30°C at a rate of 30°C / min, and then raised from 30°C to 150°C. The temperature difference ΔT was calculated by dividing the solidification temperature (Tec) from the melting temperature (Tpm) using the following formula (1). Calculation formula (1) Melting temperature (Tpm) - Freezing temperature (Tec) = ΔT

[0030] [Preparation of linear alkane compounds and measurement of their properties] [Linear alkane compound B-1] As the linear alkane compound B-1, heptadecane [Heptadecane (>99.5% (gas chromatography purity)) manufactured by Tokyo Chemical Industry Co., Ltd.] was used. [Linear alkane compound B-2] Octadecane [Octadecane (>99.5% (gas chromatography purity)) manufactured by Tokyo Chemical Industry Co., Ltd.] was used as the linear alkane compound B-2. [Linear alkane compound B-3] As the linear alkane compound B-3, heneicosane [Heneicosane (>99.0% (gas chromatography purity)) manufactured by Tokyo Chemical Industry Co., Ltd.] was used.

[0031] [Method for measuring the slip melting point of linear alkane compounds] Slip melting point: Measured in accordance with JOCS (Chemical Society of Japan) 2.2.4.2-2003.

[0032] Table 1 shows the results of measuring the physical properties of the aliphatic ketone compounds A-1 to A-3.

[0033] [Table 1]

[0034] Table 2 shows the results of measuring the slip melting points of the linear alkane compounds B-1 to B-3.

[0035] [Table 2]

[0036] [Preparation and Evaluation of Toner Wax Compositions] Toner wax compositions (C-1) to (C-12) were prepared according to the formulations shown in Table 3, and the resulting toner wax compositions were evaluated for ΔT [melting temperature (Tpm) - solidification temperature (Tec)], gloss, uniform gloss, and colorant dispersibility. The evaluation results are also shown in Table 3.

[0037] [Preparation of Toner Wax Composition (C-1)] 1000 g of aliphatic ketone compound (A-1) and 0.03 g of linear alkane compound (B-1) (0.003 parts by mass per 100 parts by mass of aliphatic ketone compound (A-1)) were placed in a four-neck flask equipped with a thermometer, nitrogen inlet tube, stirring blade, and condenser, and melted under nitrogen at 100°C. The contents were heated and stirred for 30 minutes to homogenize. 10 g of this mixture was poured into an aluminum case (No. 3) with a handle manufactured by AS ONE Corporation, and allowed to cool at room temperature to solidify the wax, yielding wax composition (C-1).

[0038] [Preparation of Toner Wax Compositions (C-2) to (C-12)] Toner wax compositions (C-2) to (C-12) were prepared according to the formulations shown in Table 3 in the same manner as in the preparation of the toner wax composition (C-1).

[0039] [Method for evaluating wax compositions for toner] (1) Deviation from blank The melting temperature (Tpm) and solidification temperature (Tec) of the obtained toner wax composition were measured in the same manner as for the aliphatic ketone compound. Furthermore, ΔT [melting temperature (Tpm) - solidification temperature (Tec)] of the aliphatic ketone compound (a) alone was used as a blank, and the deviation (unit: °C) of ΔT [melting temperature (Tpm) - solidification temperature (Tec)] of the toner wax composition from the blank ΔT was calculated using the following calculation formula (2). The larger the deviation, the narrower the temperature difference between the melting temperature and solidification temperature compared to the blank. Calculation formula (2) Temperature difference from blank (°C) = (ΔT of aliphatic ketone compound (a)) - (ΔT of toner wax composition) Specifically, for wax compositions C-1 to C-4 (Examples 1 to 4) based on aliphatic ketone compound A-1, sample C-8 (Comparative Example 1) containing aliphatic ketone compound A-1 alone was used as a blank sample; for wax compositions C-5 and C-6 (Examples 5 and 6) based on aliphatic ketone compound A-2, sample C-9 (Comparative Example 2) containing aliphatic ketone compound A-2 alone was used as a blank sample; and for wax composition C-7 (Example 7) based on aliphatic ketone compound A-3, sample C-10 (Comparative Example 3) containing aliphatic ketone compound A-3 alone was used as a blank sample. The evaluation criteria are as follows: ◎: Deviation from blank (℃) is 3.0 or more 〇: Temperature difference with blank (℃) is more than 0.0 and less than 3.0 ×: Temperature difference with blank (℃) is 0.0 or less

[0040] (2) Glossiness 10.0 g of the toner wax composition was melted at a temperature above the melting point, a 2 mm thick frame was sandwiched between mirror-finished metal plates with a diameter of 20 cm, the molten liquid was poured into the frame, and the plate was cooled by sandwiching it between the metal plates from above and below to prepare a wax plate of the toner wax composition. The resulting wax plate was measured (evaluated at 10 measurement areas) using a gloss checker IG-320 manufactured by Horiba, Ltd., at an incident angle of 60 degrees, and the average value was taken as the gloss. The evaluation criteria are as follows: ◎: 20.0 or higher 〇: 17.0 or more, less than 20.0 ×: Less than 17.0

[0041] (3) Uniform gloss In the evaluation (2) (glossiness) above, the image of 10 places on the plate of the toner wax composition was evaluated, and the maximum gloss value and the minimum gloss value were used to calculate the glossiness using the following formula (3). Calculation formula (3) (Maximum gloss value) - (Minimum gloss value) = (Uniform gloss) The evaluation criteria are as follows: ◎: 2.0 or less 〇: Over 2.0 and under 3.0 ×: 3.0 or higher

[0042] (4) Colorant dispersibility using toner wax composition 5 g of the toner wax composition, 80 g of the toner polyester resin, a colorant (pigment red; product name Permanent Rubin L6B05 manufactured by Clariant), and 1 g of aluminum salicylate were taken and thoroughly mixed in a Henschel mixer, and then heated and kneaded in a Labo Plastomill (Toyo Seiki Co., Ltd.) at a temperature of 130 to 140° C. The resulting kneaded product was placed on a glass slide and observed under an optical microscope (magnification x200). The evaluation criteria are as follows: ◯: Pigment particles are uniformly dispersed without aggregation. ×: Aggregation occurs and voids are observed.

[0043] Table 3 shows the evaluation results (ΔT (° C.), gloss, uniform gloss, colorant dispersibility) of the toner wax compositions obtained in the examples and comparative examples.

[0044] [Table 3]

[0045] As shown in Table 3, the toner wax compositions (C-1) to (C-7) of Examples 1 to 7 each have a narrower difference between the melting and solidifying temperatures than the corresponding aliphatic ketone compounds alone (Comparative Examples 1 to 3). When these compositions are used as toner wax compositions, they exhibit high temperature responsiveness even in ultra-high-speed printing, thereby suppressing blocking between printed objects and improving storage stability. Furthermore, these wax compositions contain a certain amount of a specific linear alkane compound, which can improve gloss and uniform gloss. Furthermore, when used in a composition with a toner resin, they can improve the color development of the pigment, contributing to higher image quality.

[0046] On the other hand, since the straight-chain alkane compound was not contained in Comparative Examples 1 to 3, the difference between the melting temperature and the solidification temperature did not narrow, and the gloss and uniform gloss did not improve. Moreover, since the straight-chain alkane content was too high in Comparative Examples 4 and 5, the gloss increased, but the difference between the melting temperature and the solidification temperature became large.

Claims

[Claim 1] A toner wax composition comprising an aliphatic ketone compound (a) represented by the following formula (1) and a linear alkane compound (b) having 14 to 24 carbon atoms, wherein the content of the linear alkane compound (b) is 0.001 to 5 parts by mass per 100 parts by mass of the aliphatic ketone compound (a): Formula (1): R １ -CO-R ２ (In formula (1), R １ and R ２ each independently represents a linear saturated hydrocarbon chain, R １ and R ２ The total number of carbon atoms is 30 to 48.

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