TW202200666A - Toner wax - Google Patents

Abstract

The present invention provides a toner wax capable of imparting low-temperature fixability to a toner, exhibiting excellent storage stability in the toner, and contributing to the toner by improving the color developability of the toner High image quality of toner prints. The toner wax is characterized by being composed of an ester compound in which the molar percentage A mol % of the constituent components derived from (A) pentaerythritol is 19.0 to 25.0 mol %, and the ester compound is derived from (B) carbon atoms. The molar percentage B mol % of the constituents of the straight-chain saturated fatty acids whose number is 14 to 24 is 55.0 to 80.5 mol %, and the molar percentage C mol % of the constituents derived from (C) adipic acid is 0.50 to 20.0 mol %.

Description

Toner wax

The present invention relates to a toner wax suitable for use in the adjustment of a recording method for developing an electrostatic charge image, such as an electrophotographic method or an electrostatic recording method, in an image forming apparatus such as a photocopier and a laser printer. in the toner.

Toners used in image forming apparatuses such as photocopiers and printers contain a colorant (carbon black, magnetic powder, pigment, etc.), a charge modifier, and wax in a thermoplastic resin serving as a binder resin. A fluidity additive, a cleaning aid, and a transfer aid are further contained as needed.

Among them, the wax has a function of preventing the toner from remaining on the fixing roller (filming) at the time of fixing, and promoting the softening of the thermoplastic resin to improve the fixing property. In recent years, in order to reduce power consumption, low-temperature fixability has been emphasized for toners due to increased environmental awareness around the world. For waxes, which have low melting points, it has been sought to improve the toner by lowering the melting temperature of thermoplastic resins. Low temperature fixability of toner.

On the other hand, since the wax oozes out too much from the surface of the molten toner, it may adhere to fixing members such as a fixing roller or a fixing belt, which may cause poor image quality. Bleeding is a factor that causes the toner particles to stick to each other. Therefore, it has been studied to improve the storage stability of the toner by using a high molecular weight synthetic multifunctional ester wax that does not easily bleed out during storage of the toner.

Furthermore, in recent years, with the spread of digital printing of print on demand in the field of commercial printing, printed matters with high-resolution image output and metal-like printed matters, which have never been seen before, have appeared, and the color rendering properties are good. As the demand for toners increased, a material that contributes to high color development was sought.

For example, Patent Document 1 discloses a toner using a multifunctional polyester wax composed of pentaerythritol, a fatty acid having 11 to 30 carbon atoms, and a polyfunctional polyester wax having 1 to 10 carbon atoms. fatty acid obtained. It is described that these multifunctional polyester waxes are excellent in low-temperature fixability and storage stability. However, when the wax of Patent Document 1 is used, the color developability of the toner cannot be improved.

Further, Patent Document 2 describes a method for producing an ester wax for a toner, wherein a linear saturated monocarboxylic acid selected from the group consisting of 14 to 30 carbon atoms or a mixture thereof, and a method selected from the group consisting of carbon atoms Linear saturated monohydric alcohol or its mixture in 14～30, or the polyhydric alcohol of 2～6 valences or its mixture selected from carbon number 2～30 carries out condensation reaction, then use alkaline aqueous solution to carry out neutralization, by centrifugal The neutralizing salt is separated and removed, and it is also described in Patent Document 2 that by using this wax, a toner excellent in low-temperature fixability and storage stability can be provided. However, even when the wax of Patent Document 2 is used, the color developability of the toner cannot be improved.

prior art literature Patent Literature Patent Document 1: Japanese Patent Application Laid-Open No. 7-98511 Patent Document 2: Japanese Patent Laid-Open No. 2012-32479

Technical problem to be solved by the present invention

An object of the present invention is to provide a wax for a toner, which can impart low-temperature fixability to a toner, exhibit excellent storage stability in a toner, and improve the color developability of the toner. Contributes to high image quality of toner prints. technical means to solve technical problems

The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned technical problems, and as a result, have found that when the constituent components derived from (A) pentaerythritol and (B) linear saturated fatty acids having 14 to 24 carbon atoms are contained in a specific ratio When the ester compound of the constituent component and the constituent component of (C) adipic acid is used as a wax for toner, low-temperature fixability can be imparted to the toner, and excellent storage stability is exhibited in the toner, and The present invention has been completed by contributing to the improvement of the image quality of the toner printed matter by improving the color developability of the toner.

That is, the wax composition for a toner of the present invention is characterized in that it is composed of an ester compound, and in the ester compound, the molar percentage A mol % of the constituent component derived from (A) pentaerythritol is 19.0 to 25.0 mol %, and is derived from (B) The molar percentage B mol % of the constituents of straight-chain saturated fatty acids having 14 to 24 carbon atoms is 55.0 to 80.5 mol %, and the molar percentage C mol % of the constituents derived from (C) adipic acid is 0.50 to 0.50 to 20.0 mol%. Invention effect

The wax for a toner of the present invention achieves the effects of being able to impart low-temperature fixability to the toner, exhibiting excellent storage stability in the toner, and contributing to the improvement of the color developability of the toner High image quality of toner prints.

Hereinafter, embodiments of the present invention will be described. In addition, in this specification, the numerical range prescribed|regulated using the symbol "~" includes the numerical value of both ends (upper limit and lower limit) of "~". For example, "2~5" means 2 or more and 5 or less.

The toner wax of the present invention is an ester compound containing a constituent component derived from (A) pentaerythritol as an alcohol component, and a linear saturated fatty acid having 14 to 24 carbon atoms derived from (B) as a first acid component The constituents of , and the constituents derived from (C) adipic acid as the second acid component.

It is considered that an ester compound containing a constituent derived from (A) pentaerythritol, a constituent derived from (B) a straight-chain saturated fatty acid having 14 to 24 carbon atoms, and a constituent derived from (C) adipic acid in a specific ratio When used as a wax for a toner, the compatibility with the binder resin is appropriately improved, and the compatibility with the colorant is also increased.

It is considered that since the compatibility of the wax with the binder resin is appropriately increased, the low-temperature fixability of the toner can be imparted to the toner by lowering the softening temperature of the resin, and the toner is less likely to bleed out, thereby exhibiting excellent storage stability. In addition, it is considered that since the compatibility of the wax with the colorant is also high, the dispersion of the colorant is not inhibited, and the color developability of the toner is improved. In addition, it is considered that improving the color developability of the toner contributes to the improvement of the image quality of the toner printed matter while possessing the low-temperature fixability and storage stability.

As a raw material of the constituent component derived from (A) pentaerythritol as an alcohol component, pentaerythritol or a pentaerythritol derivative which can give the same structural unit as pentaerythritol in an ester synthesis reaction can be used.

Since pentaerythritol is a neopentyl polyol having a neopentyl skeleton, it is excellent in oxidation stability and heat resistance. As other neopentyl polyols, neopentyl glycol, trimethylolpropane, and dipentaerythritol are exemplified. However, when neopentyl glycol or trimethylolpropane is used as the alcohol component, the melting point of the obtained ester may be significantly lowered, and the storage stability in the toner may be deteriorated. When dipentaerythritol is used as the alcohol component When the viscosity is increased significantly, there is a possibility that the provision of low-temperature fixability may become insufficient. Therefore, the neopentyl polyol used in the present invention is preferably pentaerythritol.

As the raw material of the constituent component derived from (B) the linear saturated fatty acid having 14 to 24 carbon atoms as the first acid component, the linear saturated fatty acid having 14 to 24 carbon atoms can be used, or it can be used in the ester synthesis reaction. A fatty acid derivative having the same structural unit as a straight-chain saturated fatty acid having 14 to 24 carbon atoms.

Examples of linear saturated fatty acids having 14 to 24 carbon atoms used in the present invention include myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, and wood tar acid. In the present invention, a mixed carboxylic acid containing two or more of these monovalent linear saturated carboxylic acids can be used. Among the above-mentioned straight-chain saturated fatty acids, palmitic acid, stearic acid, arachidic acid, and behenic acid are preferable, and stearic acid, arachidic acid, and behenic acid are particularly preferable.

When the number of carbon atoms is less than 14, there is a possibility that the melting point is lowered and the storage stability in the toner is deteriorated. On the other hand, when the number of carbon atoms is more than 24, the provision of low-temperature fixability may be insufficient. possibility.

As the raw material of the constituent component derived from (C) adipic acid as the second acid component, adipic acid which is a dicarboxylic acid or adipic acid which can give the same structural unit as adipic acid in the ester synthesis reaction can be used acid derivatives.

As the divalent carboxylic acid, when succinic acid having a smaller carbon number than adipic acid or the like is used, there is a possibility that the heat resistance may be significantly deteriorated. In addition, when sebacic acid or the like having more carbon atoms than adipic acid is used, there is a possibility that the melting point is significantly lowered and the storage stability in the toner is deteriorated.

The wax for a toner of the present invention is composed of an ester compound in which the molar percentage A mol % of the constituent components derived from (A) pentaerythritol is 19.0 to 25.0 mol %, and the number of carbon atoms derived from (B) is 14 to 14 mol %. The molar percentage B mol % of the constituents of the straight-chain saturated fatty acid of 24 is 55.0 to 80.5 mol %, and the molar percentage C mol % of the constituents derived from (C) adipic acid is 0.50 to 20.0 mol %. When the respective content ratios of the component (A), the component (B) and the component (C) are outside the above ranges, the low-temperature fixability of the toner and the storage stability of the toner may become insufficient, and The effect of improving the color developability of the toner cannot be obtained.

From the above viewpoints, the molar percentage A mol % of the constituent components derived from (A) pentaerythritol is preferably 20.0 to 24.0 mol %, and more preferably 20.5 to 22.5 mol %. Further, the molar percentage B mol % of the constituents derived from the linear saturated fatty acid having 14 to 24 carbon atoms (B) is preferably 57.5 to 78.5 mol %, and more preferably 60.0 to 77.5 mol %. Moreover, it is preferable that it is 1.5-19.0 mol%, and, as for the molar percentage Cmol% of the structural component derived from (C) adipic acid, it is more preferable that it is 2.0-17.5 mol%.

The molar percentages Amol%, Bmol%, and Cmol% are values calculated by analyzing the ester compound by ¹ H-NMR and calculating the molar amount of the constituent components derived from each raw material.

The measurement conditions of ¹ H-NMR are shown below.

<Measurement conditions> ·Analysis apparatus: ¹ H-NMR (400 MHz) ·Solvent: deuterated chloroform

The molar amount can be determined by analyzing the 1H-NMR chart of the ester compound obtained under the above measurement conditions. Specifically, the following four peaks were used. Peak (I): 3.40 to 3.70 ppm = (A) α-position hydrogen of unreacted hydroxyl group of pentaerythritol Peak (II): 4.00 to 4.20 ppm = (A) α-position hydrogen of the reacted hydroxyl group of pentaerythritol {peak (I) and peak (II) total 8} Peak (III): 0.85 to 0.90 ppm = hydrogen (3) bonded to the terminal carbon of (B) straight-chain saturated fatty acid having 14 to 24 carbon atoms Peak (IV): 2.25~2.35ppm = (C) α-position hydrogen (4) of carbonyl group of adipic acid and (B) α-position hydrogen (2) of carbonyl group of straight-chain fatty acid having 14~22 carbon atoms Piece)

The integral values of the above-mentioned four peaks were calculated as the molar amounts Amol, Bmol, and Cmol of each constituent component derived from each raw material in the following manner. Amol={integrated value of peak (I)+integrated value of peak (II)}/8 Bmol=integrated value of peak (III)/3 Cmol={integrated value of peak (IV)-(Bmol×2)}/4

From the molar amounts Amol, Bmol, and Cmol obtained above, the molar percentages Amol%, Bmol%, and Cmol% were calculated in the following manner. Amol%=100×Amol/(Amol+Bmol+Cmol) Bmol%=100×Bmol/(Amol+Bmol+Cmol) Cmol%=100×Cmol/(Amol+Bmol+Cmol)

The molecular weight of the ester compound in the present invention can be measured by gel permeation chromatography (GPC). It is preferable that the molecular weight of the ester compound in this invention is the range of 2000-3500 in terms of the number average molecular weight of the monodispersed polystyrene conversion of a polyester compound. Within the range of the number average molecular weight, it is possible to achieve both the provision of low-temperature fixability and the excellent storage stability of the toner.

From the viewpoint of storage stability, the acid value of the ester compound in the present invention is preferably 5 mgKOH/g or less, more preferably 3 mgKOH/g or less, and particularly preferably 1 mgKOH/g or less.

In addition, from the viewpoint of storage stability, the hydroxyl value is preferably 20 mgKOH/g or less, more preferably 15 mgKOH/g or less, and particularly preferably 10 mgKOH/g or less.

In addition, the acid value can be measured according to JOCS (Japan Oil Chemical Society) 2.3.1-1996, and the hydroxyl value can be measured according to JOCS (Japan Oil Chemical Society) 2.3.6.2-1996.

The ester compound in the present invention can provide the toner with low-temperature fixability because it can lower the softening temperature of the resin, and can provide the toner with excellent storage stability because of its large molecular weight and high viscosity.

The melting point of the ester compound in the present invention is preferably 60 to 90°C, more preferably 65 to 85°C. When the melting point is lower than 60°C, the storage stability is deteriorated, and when the melting point is higher than 90°C, the low-temperature fixability of the toner cannot be imparted.

The melting point of the ester can be measured by differential scanning calorimetry (DSC) with a heating rate of 10°C per minute, and the temperature of the peak of the endothermic peak measured by DSC analysis can be used as the melting point.

As a method for producing the ester compound in the present invention, for example, a production method using the following reaction: pentaerythritol as an alcohol component raw material, and a straight chain saturated fatty acid having 14 to 24 carbon atoms and adipic acid as an acid component raw material can be mentioned. The dehydration condensation reaction of pentaerythritol, the reaction of pentaerythritol with the acid halide (acid halide) of each of linear saturated fatty acids having 14 to 24 carbon atoms and adipic acid, the first ester containing pentaerythritol as an alcohol component, and the first ester containing pentaerythritol as an acid component Transesterification of a linear saturated fatty acid having 14 to 24 carbon atoms and a second ester of adipic acid, etc.

A catalyst can be used during the reaction, and examples of the catalyst include acidic or basic catalysts, and examples thereof include zinc acetate, titanium compounds, p-toluenesulfonic acid, and methanesulfonic acid.

After the esterification reaction is completed, the obtained reaction product can be highly purified by a recrystallization method, a distillation method, a solvent extraction method, or the like.

The toner wax of the present invention is blended together with a binder resin, a colorant, a charge modifier, and the like, and a toner is produced by a conventional method. The blending amount of the toner wax of the present invention in the toner is preferably 0.1 to 15 parts by mass relative to 100 parts by mass of the binder resin. The toner waxes of the present invention may be blended alone or in combination of two or more kinds in the toner.

The binder resin is not particularly limited, and binder resins conventionally used as binder resins for toners can be used, for example, styrene resins, acrylate resins, styrene-acrylate copolymer resins, and polyester resins can be used , polyvinyl chloride resin, polyvinyl acetate resin, phenolic resin, epoxy resin, etc.

In addition, the colorant is not particularly limited either, and colorants conventionally used as colorants for toners can be used, for example, carbon black, magnetic powder, pigments of various colors, and the like can be used. Example

Next, the present invention will be described in further detail by showing Examples and Comparative Examples. 1. Preparation example of wax Table 1 shows the composition, acid value, hydroxyl value, number average molecular weight Mn, and melting point of the toner waxes used in Examples and Comparative Examples. The preparation methods of the various waxes shown in Table 1 are as follows.

[Preparation of wax a]

To a 3L four-necked flask equipped with a thermometer, nitrogen introduction tube, stirring blade and cooling tube, add 280g (2.06mol) of pentaerythritol, 119.9g (0.82mol) of adipic acid, 1955.2g (6.87mol) of stearin The acid, 2.36 g (0.01 mol) of p-toluenesulfonic acid, were reacted at 220°C under nitrogen flow. The obtained crude ester product was 2215.5 g, and the acid value was 7.5 mgKOH/g.

To this ester crude product, add 700 g of toluene and 150 g of 2-propanol, add 10 quality % potassium hydroxide aqueous solution containing potassium hydroxide in an amount equivalent to 2.0 times the amount of the residual acid value of the ester crude product, Stir at 70°C for 30 minutes. Then, it was left to stand for 30 minutes, and the aqueous layer part (lower layer) was separated and removed. The washing was repeated 4 times until the pH of the drained water was neutral. The solvent of the residual ester layer was distilled off under a reduced pressure of 180° C. and 1 kPa, followed by filtration to obtain 2060.4 g of wax a. The yield relative to the esterified crude product for deacidification was 93%.

[Preparation of Wax b]

To a 3L four-necked flask equipped with a thermometer, nitrogen introduction tube, stirring blade and cooling tube, add 280g (2.06mol) of pentaerythritol, 119.9g (0.82mol) of adipic acid, 1955.2g (6.87mol) of stearin The acid was reacted at 220°C under a stream of nitrogen. The obtained crude ester product was 2211.8 g, and the acid value was 11.5 mgKOH/g.

To this ester crude product, add 700 g of toluene and 150 g of 2-propanol, add 10 quality % potassium hydroxide aqueous solution containing potassium hydroxide in an amount equivalent to 2.0 times the amount of the residual acid value of the ester crude product, Stir at 70°C for 30 minutes. Then, it was left to stand for 30 minutes, and the aqueous layer part (lower layer) was separated and removed. The washing was repeated 4 times until the pH of the drained water was neutral. The solvent of the residual ester layer was distilled off under a reduced pressure condition of 180° C. and 1 kPa, followed by filtration to obtain 2057.5 g of wax b. The yield relative to the esterified crude product for deacidification was 93%.

[Preparation of wax c~g and j~l]

Waxes c to g and j to l shown in Table 1 were obtained by the same procedure except that the same raw materials were used as in the preparation of the above-mentioned wax a, and the amount of the raw materials was changed.

[Preparation of wax h]

Palmitic acid was used as the linear saturated fatty acid, and wax h was obtained in the same preparation steps as wax a.

[Preparation of wax i]

Behenic acid was used as the linear saturated fatty acid, and wax i was obtained in the same preparation steps as wax a.

[Preparation of Pentaerythritol Tetrastearate (PETS) Wax]

In a 3L four-necked flask equipped with a thermometer, a nitrogen inlet tube, a stirring blade and a cooling tube, add 280g (2.06mol) of pentaerythritol, 1955.2g (6.87mol) of stearic acid, and carry out at 220°C under nitrogen flow. reaction. The obtained crude ester product was 2640.3 g, and the acid value was 8.7 mgKOH/g.

To the crude ester product, 750 g of toluene and 200 g of 2-propanol were added, and a 10-quality % potassium hydroxide aqueous solution containing potassium hydroxide in an amount equivalent to 2.0 times the residual acid value of the crude ester product was added. Stir at 70°C for 30 minutes. Then, it was left to stand for 30 minutes, and the aqueous layer part (lower layer) was separated and removed. The washing was repeated 4 times until the pH of the drained water was neutral. Under the reduced pressure conditions of 180 degreeC and 1 kPa, the solvent of the residual ester layer was distilled off, and it filtered, and obtained 2520.7g of PETS waxes. The yield relative to the esterified crude product for deacidification was 95%.

[Table 1] Manufacturing example a b c d e f g h i Molar percentage Amol% of constituents derived from (A) 22.0 23.0 20.4 20.1 24.3 19.7 23.7 22.4 21.4 Molar percentage Bmol% of constituents derived from (B) 69.2 68.9 78.8 76.6 57.4 78.1 56.9 69.2 70.2 Molar percentage Cmol% of constituents derived from (C) 8.8 8.1 0.8 3.3 18.3 2.2 19.4 8.4 8.4 Types of straight-chain saturated fatty acids Stearic acid C18 Palmitic acid C16 Behenic acid C22 Acid value (mgKOH/g) 0.4 0.4 0.1 0.2 0.3 0.6 0.5 0.6 0.3 Hydroxyl value (mgKOH/g) 3.6 12.0 2.7 3.1 8.5 0.1 7.5 9.2 2.9 Number average molecular weight Mn 2800 2750 2160 2400 3250 2250 3600 2480 3150 DSC melting point °C 68.4 67.3 79.6 71.8 66.5 73.8 61.0 63.8 85.5 Manufacturing example PETS j k l Molar percentage Amol% of constituents derived from (A) 20.5 15.4 27.0 24.5 Molar percentage Bmol% of constituents derived from (B) 79.5 84.0 55.8 53.6 Molar percentage Cmol% of constituents derived from (C) 0.0 0.6 17.2 21.9 Types of straight-chain saturated fatty acids Stearic acid C18 Acid value (mgKOH/g) 0.1 33.5 0.8 0.2 Hydroxyl value (mgKOH/g) 4.1 1.4 42.0 4.1 Number average molecular weight Mn 1980 1985 3220 4875 DSC melting point °C 82.5 70.1 57.8 46.8

2. Evaluation method The methods of various measurements and evaluations performed in Examples and Comparative Examples are as follows.

2-1. Measurement of composition and physical properties of wax

(1) Molar percentage Amol%, Bmol%, Cmol% of each constituent in the wax About each wax, 1H-NMR analysis was performed under the following measurement conditions, the obtained 1H-NMR chart was analyzed, and the molar amount of the structural component derived from each raw material was calculated|required. From the obtained molar amount, the molar percentages Amol%, Bmol%, and Cmol% of each constituent component in the wax were calculated using the above-mentioned formula. <Measurement conditions> ·Analysis instrument: 1H-NMR (400MHz) Solvent: deuterated chloroform

(2) Acid value of wax Measured according to JOCS (Japan Oil Chemical Society) 2.3.1-1996.

(3) The hydroxyl value of wax Measured according to JOCS (Japan Oil Chemical Society) 2.3.6.2-1996.

(4) Number average molecular weight of wax "HC-8320 GPC EcoSEC (manufactured by TOSOH CORPORATION)" was used as a measuring apparatus for gel permeation chromatography (GPC). The number-average molecular weight of the wax was measured using THF as an eluent, the measurement temperature was set to 40°C, and polystyrene was used as a target substance.

(5) Melting point of wax As a differential scanning calorimeter, "DSC-7000X" manufactured by Hitachi High-Tech Science Corporation was used. About 10 mg of ester was added to a sample holder, and the measurement was performed using 10 mg of alumina as a reference material, and the temperature was increased from 30°C to 150°C at a temperature increase rate of 10°C per minute. In addition, before measurement, the sample which passed the temperature raising process from 30 degreeC to 150 degreeC and the cooling process from 150 degreeC to 30 degreeC was used as a measurement sample. The temperature of the peak of the endothermic peak measured by the above-mentioned DSC was taken as the melting point of the wax.

2-2. Performance evaluation of wax

(1) The effect of reducing the melting temperature of the resin The effect of lowering the melting temperature when the binder resin was mixed with wax was evaluated by the following method. Evaluation samples were produced for Examples 1 to 9 and Comparative Examples 1 to 4, respectively. Specifically, 95 parts by mass of a polyester resin (product name: Diacron ER-508, manufactured by MITSUBISHI RAYON CO., LTD.) and 5 parts by mass of the wax shown in Table 2 were mixed using a biaxial mixer. A kneader "LABO PLASTOMILL" (manufactured by TOYOSEKI) was used for melt-kneading to obtain a resin kneaded product. Melt-kneading was carried out at 120° C. and 80 rpm/min for about 5 minutes, and the obtained resin kneaded product was pulverized and formed into a particle size of 100 μm or less, which was used as an evaluation sample. In addition, the resin kneaded product containing polyester resin but not containing wax was pulverized and molded into a particle size of 100 μm or less to obtain a blank sample. For these evaluation samples and blank samples, 1 g of the sample was formed into a cylindrical shape having a diameter of 1 cm×a height of 1 cm, and a rheometer (CFT-500EX: manufactured by Shimadzu Corporation) was used under the conditions of a heating rate of 2°C/min and a load of 20 kg. , determine the 1/2 melting temperature. For each sample, the measurement was performed three times, the average value was calculated, and the measurement average value T of each evaluation sample and the measurement average value T blank of the blank sample were obtained. Using the measurement average value T of the evaluation sample and the measurement average value Tblank of the blank sample, the 1/2 melting temperature (1/2T) was calculated by the following calculation formula (1). The larger the value of the 1/2 melting temperature thus calculated, the more excellent the low-temperature fixability was evaluated. Calculation formula (1): 1/2T=Tblank-T

(2) Storage stability in resin The storage stability when the binder resin was mixed with wax was evaluated by the following method. In order to evaluate the storage stability in resin, the evaluation samples of Examples 1 to 9 and Comparative Examples 1 to 4 prepared in the evaluation of the effect of lowering the melting temperature of the resin were used. For these evaluation samples, 5 g of the resin kneaded product as an evaluation sample was put into a glass vial, left to stand for 2 weeks in a thermostatic bath maintained at 45°C, the glass vial was inverted, and the sample was taken out without applying force. At this time, the quality of the sample that was not deposited in the vial and flowed out and the particle size was maintained at 100 μm or less was set as X, and the anti-blocking ratio R was calculated by the following calculation formula (2). Calculation formula (2): R=X(g)/5(g) The storage stability was evaluated with reference to the following evaluation criteria for the calculated blocking resistance ratio R. The larger the value of the blocking resistance ratio R calculated in this way, the more excellent the storage stability was evaluated. In addition, the numerical values shown in parentheses in Table 2 are the calculated values of the anti-blocking ratio R. <Evaluation Criteria> 〇 (excellent): 0.85≤anti-blocking rate R △ (good): 0.75 < anti-blocking rate R < 0.85 ×(Bad): 0.75≥Anti-blocking rate R

(3) Color-development-improving effect The color-development-improving effect of wax was evaluated by the following method. Evaluation samples were produced for Examples 1 to 9 and Comparative Examples 1 to 4, respectively. Specifically, 94 parts by mass of a polyester resin (product name: Diacron ER-508, manufactured by MITSUBISHI RAYON CO., LTD.), 5 parts by mass of the wax shown in Table 2, and 1 part by mass of a coloring agent (product Name: PV-FAST BLUE BG, manufactured by Clariant Co., Ltd.) was mixed, and melt-kneaded using a twin-shaft kneader (product name "LABO PLASTOMILL", manufactured by TOYO SEKI CO., LTD.) to obtain resin kneading thing. The melt-kneading was carried out at 120° C. and 80 rpm/min for about 5 minutes, and the obtained resin kneaded product was molded into a smooth plate shape (100×100 mm) by a hot press, and used as an evaluation sample. In addition, a smooth plate-shaped molded product containing 99 parts by mass of polyester resin and 1 part by mass of a coloring agent but not containing wax was prepared as a blank sample. For these evaluation samples, using a colorimeter (colorimeter ZE6000, manufactured by Nippon Denshoku Industries Co., Ltd.), the surface of the sample was measured in the reflection mode to obtain the CIE1976 (L ^* , a ^* , b ^* ) color space (ie, Values under the colors a ^* and b ^* of each hue in the so-called CIELAB). Using the obtained measurement values, the chroma C of the evaluation sample was calculated by the following calculation formula (3). The blank sample was also measured in the same manner using a colorimeter, and the chromaticity C blank of the blank sample was obtained. Calculation formula (3): C=(a ^{* 2} +b ^{* 2} ) ^1/2 Using the value of the chroma C of the evaluation sample and the value of the chroma C blank of the blank sample, the color development was obtained by the following calculation formula (4) Sexual improvement rate Kc. The larger the value of the color rendering improvement rate Kc calculated in this way, the more excellent the color rendering effect is evaluated. Calculation formula (4): Kc=C/C blank

3. Evaluation Results

For the above Examples and Comparative Examples, the composition and physical properties of the wax itself are shown in Table 1 above, and the composition and performance evaluation results of the samples used for the performance evaluation of the wax as a toner material are shown in Table 2 .

[Table 2]

The melting points of the waxes a to i used in Examples 1 to 9 are in the range of 60°C to 90°C. By lowering the melting temperature of the resin, low-temperature fixability can be imparted to the toner, and the anti-blocking ratio R is also high, so storage The storage stability in the toner is also excellent. Furthermore, since the color developing property improvement rate Kc is Kc>1, the color developing property of the toner can be improved.

On the other hand, in Comparative Example 1 using pentaerythritol tetrastearate (PETS) monomer in which the molar percentage Cmol% of the constituents derived from adipic acid is 0 mol%, since 1 /2 The melting temperature is small, so that the low-temperature fixability of the toner cannot be sufficiently imparted. In addition, the color developing property improvement rate Kc was Kc<1, and when used as a wax for toner, the effect of improving the color developing property was not obtained.

In Comparative Example 2, in which the molar percentage B mol % of the constituents derived from the linear saturated acid was higher than that of the present invention, the wax j had a lower anti-blocking ratio R than the examples, and the storage in the toner was stable. The property deteriorated, the color rendering property improvement rate Kc was Kc<1, and the effect of improving the color rendering property was not obtained.

In Comparative Example 3 in which the molar percentage A mol % of the pentaerythritol-derived constituent was higher than the wax k in the range of the present invention, the anti-blocking ratio R was low, and the storage stability was deteriorated.

In Comparative Example 4, in which the molar percentage C mol % of the constituent components derived from adipic acid was higher than that of the wax 1 in the present invention, the anti-blocking ratio R was low, and the storage stability was deteriorated.

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Claims (1)

A toner wax, characterized in that it is composed of an ester compound, in which the molar percentage A mol % of the constituents derived from (A) pentaerythritol is 19.0 to 25.0 mol %, and the number of carbon atoms derived from (B) is 19.0 to 25.0 mol %. The molar percentage B mol % of the constituents of straight-chain saturated fatty acids of 14 to 24 is 55.0 to 80.5 mol %, and the molar percentage C mol % of the constituents derived from (C) adipic acid is 0.50 to 20.0 mol %.