JP6205116B2 - Method for producing toner for developing electrostatic image - Google Patents

Description

  The present invention relates to an electrostatic charge image developing toner used for developing a latent image formed in an electrostatic charge image development method, an electrostatic recording method, an electrostatic printing method, and the like, and a method for producing the same.

  In recent years, there has been a strong demand for improvement in low-temperature fixability of toners from the viewpoint of energy saving, that is, reduction of energy consumption in the fixing process as well as promotion of downsizing, high speed and high image quality of electrophotographic apparatuses.

  In order to meet this requirement, for example, Patent Document 1 discloses a toner production method including a melt-kneading step, a heat treatment step, a pulverization step, and a classification step of a raw material containing two or more kinds of polyesters. More than one kind of polyester contains at least one kind of amorphous polyester, and has excellent low-temperature fixability by a toner production method in which the heat treatment step is performed at a temperature and time satisfying a specific relational expression, and It has been proposed that toners having good pulverization and storage properties can be produced.

  In Patent Document 2, in addition to an alcohol component and a carboxylic acid component, a reaction product obtained by reacting a specific aromatic compound having a vinylene group on an aromatic ring with a carboxylic acid having a reactive unsaturated group is subjected to polycondensation. The polyester resin for toner obtained by the reaction as a binder resin for electrophotographic toner improves the charging stability under high temperature and high humidity while maintaining the low temperature fixability, storage stability and durability of the toner. It is disclosed that it can.

  Further, Patent Documents 3 and 4 disclose toners obtained by condensation polymerization of an alcohol component containing an aliphatic polyhydric alcohol and a carboxylic acid component containing a (meth) acrylic acid-modified rosin or a fumaric acid-modified rosin. It has been disclosed that a toner containing polyester is excellent in low-temperature fixability, offset resistance and storage stability, and odor generation is also reduced.

JP 2005-308995 A JP 2012-8371 A JP 2007-292816 A JP 2007-292820 A

  It is known that the use of crystalline polyester as the binder resin in addition to the amorphous resin improves the low-temperature fixability and gloss of the toner due to its melting characteristics. However, when the content of the crystalline polyester is increased, the resin strength may be reduced, and a part of the crystalline polyester becomes amorphous due to the compatibilization of the crystalline polyester and the amorphous resin during melt-kneading. As a result, there exists a subject that the heat-resistant storage stability which is stability at the time of high temperature storage falls. On the other hand, methods have been proposed in which heat treatment is performed after the melt-kneading step to reproduce the crystallinity of the polyester (Patent Document 1), and the monomer components used are changed (Patent Documents 2 to 4). There is room for improvement in terms of both low-temperature fixability, gloss and high-temperature offset resistance, and heat-resistant storage stability that can support high speed and high image quality.

  The present invention relates to an electrostatic image developing toner excellent in low-temperature fixability and heat-resistant storage stability and a method for producing the same.

The present invention
[1] A method for producing a toner for developing an electrostatic image, comprising a step of melt-kneading a mixture containing a binder resin and a wax,
The binder resin is an aliphatic diol (a) having 3 or 4 carbon atoms having a hydroxy group bonded to a secondary carbon atom and an α, ω-linear alkanediol having 2, 4, 6 or 8 carbon atoms. An amorphous polyester (A) obtained by polycondensation of an alcohol component containing an aliphatic diol (b) consisting of any one or more of the above and a carboxylic acid component,
The molar ratio of the aliphatic diol (a) and the aliphatic diol (b) (aliphatic diol (a) / aliphatic diol (b)) is 95/5 to 55/45,
The melting point of the wax is 60-120 ° C;
Obtained by the method for producing a toner for developing an electrostatic charge image, wherein the wax content is 0.2 to 13 parts by mass with respect to 100 parts by mass of the binder resin, and [2] the production method of [1]. The present invention relates to a toner for developing an electrostatic image.

  By the method of the present invention, an electrostatic image developing toner excellent in low-temperature fixability and heat-resistant storage stability can be obtained.

  The method of the present invention is a method for producing a toner for developing an electrostatic charge image, comprising a step of melt-kneading a mixture containing a binder resin and a wax, wherein the binder resin is bonded to a secondary carbon atom. An aliphatic diol (b) comprising any one or more of an aliphatic diol (a) having 3 or 4 carbon atoms and an α, ω-linear alkanediol having 2, 4, 6 or 8 carbon atoms. An electrophotographic toner having one feature in that it contains an amorphous polyester (A) obtained by condensation polymerization of an alcohol component and a carboxylic acid component. Has the effect of having good low-temperature fixability and heat-resistant storage stability.

The reason for such an effect is not clear, but is considered as follows.
The component derived from the aliphatic diol (b) comprising the α, ω-linear alkanediol in the amorphous polyester (A) is easy to take an ordered structure and easily crystallize, but is a hydroxy group bonded to a secondary carbon atom. By containing a specific amount of the component derived from the aliphatic diol (a) having 3 or 4 carbon atoms having the structure, formation of an ordered structure is moderately relaxed to such an extent that it does not show a melting point. As a result, the low-temperature fixability of the toner can be improved and a decrease in heat-resistant storage stability can be suppressed.
Furthermore, when melt-kneading the amorphous polyester (A) and a toner component such as wax, a specific amount of wax having a specific melting point is contained, so that the binder can be bound without excessive introduction of heat or shear during melt-kneading. The dispersion of components such as wax in the resin is facilitated, the ordered structure of the polyester that achieves both low-temperature fixability and heat-resistant storage stability is maintained, and the composition in the toner particles is homogenized. As a result, the low-temperature fixability is further improved, and the heat-resistant storage stability is considered to be compatible.

[Binder resin]
The binder resin used in the present invention is an aliphatic diol (a) having 3 or 4 carbon atoms having a hydroxy group bonded to a secondary carbon atom and α, ω- having 2, 4, 6 or 8 carbon atoms. It contains an amorphous polyester (A) obtained by polycondensation of an alcohol component containing an aliphatic diol (b) comprising at least one linear alkanediol and a carboxylic acid component.

  The content of the amorphous polyester (A) is preferably 80% by mass or more, more preferably 90% by mass or more, and 95% by mass in the binder resin from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. The above is more preferable, and it is more preferable to use only the amorphous polyester (A) as the binder resin. However, the amorphous polyester is used as long as the effect of improving the low-temperature fixability and heat-resistant storage stability of the toner is not impaired. Resins other than (A) may be contained. Examples of other binder resins include other polyesters, vinyl resins, epoxy resins, polycarbonates, polyurethanes, and the like.

  In the present invention, the crystallinity of the resin is determined by the ratio between the softening point and the maximum endothermic peak temperature measured by a differential scanning calorimeter, that is, the crystallinity index defined by the value of [softening point / maximum endothermic peak temperature]. Represented. The crystalline resin has a crystallinity index of 0.6 to 1.4, preferably 0.7 to 1.2, more preferably 0.9 to 1.2, and the amorphous resin is a resin having a value of 1.4 or less than 0.6. The crystallinity of the resin can be adjusted by the type and ratio of the raw material monomers, production conditions (for example, reaction temperature, reaction time, cooling rate) and the like. The highest endothermic peak temperature refers to the temperature of the peak on the highest temperature side among the observed endothermic peaks. The maximum peak temperature is the melting point if the difference from the softening point is within 20 ° C., and the peak due to the glass transition if the difference from the softening point exceeds 20 ° C.

  Examples of the aliphatic diol (a) having 3 or 4 carbon atoms having a hydroxy group bonded to a secondary carbon atom include 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, and 2, 3-butanediol is mentioned, and at least one of these is used. From the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner, 1,2-propanediol and 2,3-butanediol are preferable, and 1,2-propanediol is more preferable.

  The content of the aliphatic diol (a) is preferably 55 mol% or more, more preferably 60 mol% or more in the alcohol component of the amorphous polyester (A), from the viewpoint of improving the heat resistant storage stability of the toner. More preferably, mol% or more is more preferable, and 70 mol% or more is more preferable. In addition, the content of the aliphatic diol (a) is preferably 95 mol% or less, more preferably 93 mol% or less, still more preferably 90 mol% or less, and 85 mol% from the viewpoint of improving the low-temperature fixability of the toner. The following is more preferable.

  Taking these viewpoints together, the content of the aliphatic diol (a) is preferably 55 to 95 mol%, more preferably 60 to 93 mol%, more preferably 65 to 90 mol in the alcohol component of the amorphous polyester (A). The mol% is more preferable, 65 to 85 mol% is more preferable, and 70 to 85 mol% is more preferable.

  The content of the aliphatic diol (a) in the case where the binder resin contains a plurality of amorphous polyesters (A) is determined based on the aliphatic diol (a in the alcohol component of each amorphous polyester (A). ) Content and the product of the mass fraction of each amorphous polyester (A).

  When the binder resin contains a polyester other than the amorphous polyester (A), the content of the aliphatic diol (a) is included in the binder resin from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. 55 to 95 mol% is preferable, 60 to 93 mol% is more preferable, 65 to 90 mol% is further preferable, 65 to 85 mol% is further preferable, and 70 to 85 mol% is preferable in the alcohol component of all polyesters. Further preferred.

  The content of the aliphatic diol (a) in the alcohol component of all polyesters is determined by the sum of the product of the content of the aliphatic diol (a) in the alcohol component of each polyester and the mass fraction of each polyester. be able to.

  Examples of the aliphatic diol (b) comprising at least one of α, ω-linear alkanediols having 2, 4, 6 or 8 carbon atoms include ethanediol, 1,4-butanediol, 1,6- Examples include hexanediol and 1,8-octanediol, and at least one of these is used. From the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner, 1,4-butanediol, 1,6-hexanediol, and 1,8-octanediol are preferable, and 1,4-butanediol is more preferable.

  The content of the aliphatic diol (b) is preferably 5 mol% or more, more preferably 7 mol% or more in the alcohol component of the amorphous polyester (A), from the viewpoint of improving the low-temperature fixability of the toner. More preferably, mol% or more, and more preferably 15 mol% or more. Further, the content of the aliphatic diol (b) is preferably 45 mol% or less, more preferably 40 mol% or less, further preferably 35 mol% or less, and more preferably 30 mol% from the viewpoint of improving the heat resistant storage stability of the toner. The following is more preferable.

  Taking these viewpoints together, the content of the aliphatic diol (b) is preferably 5 to 45 mol%, more preferably 7 to 40 mol% in the alcohol component of the amorphous polyester (A), and 10 to 35 The mol% is more preferable, 15 to 35 mol% is more preferable, and 15 to 30 mol% is more preferable.

  When the binder resin contains a plurality of amorphous polyesters (A), the content of the aliphatic diol (b) is determined according to the aliphatic diol (b in the alcohol component of each amorphous polyester (A). ) Content and the product of the mass fraction of each amorphous polyester (A).

  When the binder resin contains a polyester other than the amorphous polyester (A), the content of the aliphatic diol (b) is included in the binder resin from the viewpoint of improving the low temperature fixability and heat resistant storage stability of the toner. Among all the alcohol components of polyesters, 5 to 45 mol% is preferable, 7 to 40 mol% is more preferable, 10 to 35 mol% is more preferable, 15 to 35 mol% is further preferable, and 15 to 30 mol% is more preferable. Further preferred.

  The content of the aliphatic diol (b) in the alcohol component of all polyesters is determined by the sum of the product of the content of the aliphatic diol (b) in the alcohol component of each polyester and the mass fraction of each polyester. be able to.

  The total content of the aliphatic diol (a) and the aliphatic diol (b) in the alcohol component is selected from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner in the alcohol component of the amorphous polyester (A). 80 mol% or more is preferable, 90 mol% or more is more preferable, 95 mol% or more is further preferable, and substantially 100 mol% is further more preferable.

  The molar ratio of the aliphatic diol (a) to the aliphatic diol (b) in the alcohol component of the amorphous polyester (A) (aliphatic diol (a) / aliphatic diol (b)) is the low-temperature fixability of the toner. And from the viewpoint of improving heat-resistant storage stability, it is 95/5 to 55/45, preferably 93/7 to 60/40, more preferably 90/10 to 65/35, and even more preferably 85/15 to 65/35. Preferably, 85/15 to 70/30 is more preferable.

  When the binder resin contains a polyester other than the amorphous polyester (A), the molar ratio of the aliphatic diol (a) to the aliphatic diol (b) in the alcohol component of all polyesters (aliphatic diol (a) / Aliphatic diol (b)) is from 95/5 to 55/45, preferably from 93/7 to 60/40, preferably from 90/10 to 65 from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. / 35 is more preferable, 85/15 to 65/35 is more preferable, and 85/15 to 70/30 is still more preferable.

  As alcohol components other than those described above, divalent alcohols include diols having 3 to 20 carbon atoms, preferably 3 to 15 carbon atoms, and formula (I):

(In the formula, RO and OR are oxyalkylene groups, R is an ethylene and / or propylene group, x and y indicate the number of added moles of alkylene oxide, each being a positive number, and the sum of x and y. 1 to 16 is preferable, 1 to 8 is more preferable, and 1.5 to 4 is more preferable)
An alkylene oxide adduct of bisphenol A represented by:

  Examples of the trivalent or higher alcohol include trivalent or higher alcohol having 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms. Specific examples include sorbitol, 1,4-sorbitan, pentaerythritol, glycerol, trimethylolpropane, and the like.

  In the present invention, the carboxylic acid component of the amorphous polyester (A) contains a divalent or higher carboxylic acid compound from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner.

  Examples of the divalent carboxylic acid compound include 3 to 30 carbon atoms, preferably 3 to 20 carbon atoms, more preferably 3 to 10 carbon dicarboxylic acids, and their acid anhydrides and 1 to 3 carbon atoms. Examples thereof include derivatives such as alkyl esters. Specifically, an aromatic dicarboxylic acid compound and an aliphatic dicarboxylic acid compound are preferable, and an aromatic dicarboxylic acid compound is more preferable from the viewpoint of improving low-temperature fixability and heat-resistant storage stability of the toner. Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid and the like. Among these, terephthalic acid is preferable. Examples of the aliphatic dicarboxylic acid include fumaric acid, maleic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, succinic acid substituted with an alkyl group or alkenyl group having 1 to 20 carbon atoms, and the like. From the viewpoint of improving the storage stability, fumaric acid is preferable.

  The content of the divalent carboxylic acid compound is preferably 60 to 100 mol% in the carboxylic acid component of the amorphous polyester (A) from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner, and preferably 70 to 100 mol%. More preferably, mol% is more preferable, 80-100 mol% is further more preferable, and 85-100 mol% is further more preferable.

  In the case where the binder resin contains a plurality of amorphous polyesters (A), the content of the divalent carboxylic acid compound is such that the divalent carboxylic acid in the carboxylic acid component of each amorphous polyester (A) is It can be determined by the sum of the product of the content of the acid compound and the mass fraction of each amorphous polyester (A).

  When the binder resin contains a polyester other than the amorphous polyester (A), the content of the divalent carboxylic acid compound is included in the binder resin from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. In all the carboxylic acid components of the polyester, 60 to 100 mol% is preferable, 70 to 100 mol% is more preferable, 80 to 100 mol% is further preferable, and 85 to 100 mol% is more preferable.

  The content of the divalent carboxylic acid compound in the carboxylic acid component of all polyesters is the sum of the product of the content of the divalent carboxylic acid compound in the carboxylic acid component of each polyester and the mass fraction of each polyester. Can be obtained.

  Examples of the trivalent or higher carboxylic acid compounds include, for example, carboxylic acids having 4 to 30 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and more, and acid anhydrides and carbons thereof. Examples thereof include derivatives such as alkyl esters of formulas 1 to 3. Specific examples include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid), etc. 1,2,4-benzenetricarboxylic acid (trimellitic acid) and its acid anhydride are preferable from the viewpoint of improving low-temperature fixability and heat-resistant storage stability of the toner, and 1,2,4-benzenetricarboxylic acid is anhydrous. (Trimellitic anhydride) is more preferable.

  The content of the trivalent or higher carboxylic acid compound is preferably 40 mol% or less, more preferably 30 mol% or less, and more preferably 20 mol% in the carboxylic acid component from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. The following is more preferable, and 15 mol% or less is more preferable.

  In addition, a monovalent alcohol may be appropriately contained in the alcohol component, and a monovalent carboxylic acid compound may be appropriately contained in the carboxylic acid component from the viewpoint of adjusting the softening point of the polyester.

  From the viewpoint of reducing the acid value of the polyester, the equivalent ratio of the carboxylic acid component to the alcohol component (COOH group / OH group) in the amorphous polyester (A) is preferably 0.70 to 1.15, and more preferably 0.75 to 1.10.

  The polycondensation reaction between the alcohol component and the carboxylic acid component is performed at a temperature of about 180 to 250 ° C. in an inert gas atmosphere, if necessary, in the presence of an esterification catalyst, an esterification cocatalyst, a polymerization inhibitor, etc. Can be produced by condensation polymerization. Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin (II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropylate bistriethanolamate. The amount of the esterification catalyst used is preferably 0.01 to 1.5 parts by mass, more preferably 0.1 to 1.0 part by mass with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the esterification promoter include gallic acid. The amount of the esterification cocatalyst used is preferably 0.001 to 0.5 parts by mass, more preferably 0.01 to 0.1 parts by mass with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the polymerization inhibitor include tert-butylcatechol. The amount of the polymerization inhibitor used is preferably 0.001 to 0.5 parts by mass and more preferably 0.01 to 0.1 parts by mass with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component.

  The softening point of the amorphous polyester (A) is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, further preferably 110 ° C. or higher, and further preferably 120 ° C. or higher, from the viewpoint of improving the high temperature offset resistance of the toner. . Further, from the viewpoint of improving the low-temperature fixability of the toner, 170 ° C. or lower is preferable, 160 ° C. or lower is more preferable, 150 ° C. or lower is further preferable, and 140 ° C. or lower is further preferable.

  The softening point of the amorphous polyester (A) can be controlled by adjusting the kind and composition ratio of the alcohol component and the carboxylic acid component, the amount of the catalyst, etc., and selecting the reaction conditions such as the reaction temperature, reaction time, and reaction pressure. .

  The maximum endothermic peak temperature of the amorphous polyester (A) is preferably 50 ° C. or higher from the viewpoint of improving the high temperature offset resistance and heat resistant storage stability of the toner. From the viewpoint of improving toner gloss and low-temperature fixability and suppressing fogging, 90 ° C. or lower is preferable, 85 ° C. or lower is more preferable, and 80 ° C. or lower is further preferable.

  The maximum endothermic peak temperature of the amorphous polyester (A) can be controlled by the type and composition ratio of the alcohol component and carboxylic acid component.

  The glass transition temperature of the amorphous polyester (A) is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and further preferably 65 ° C. or higher, from the viewpoint of improving the heat resistant storage stability and high temperature offset resistance of the toner. From the viewpoint of improving the low-temperature fixability of the toner, 90 ° C. or lower is preferable, 85 ° C. or lower is more preferable, and 80 ° C. or lower is further preferable. The glass transition temperature is a physical property peculiar to an amorphous resin.

  The glass transition temperature of the amorphous polyester (A) can be controlled by the type and composition ratio of the alcohol component and carboxylic acid component.

  The acid value of the amorphous polyester (A) is preferably 60 mgKOH / g or less, more preferably 50 mgKOH / g or less, from the viewpoint of improving high-temperature offset resistance and chargeability of the toner.

  The acid value of the amorphous polyester (A) can be controlled by adjusting the kind and composition ratio of the alcohol component and the carboxylic acid component, the amount of the catalyst, and the like, and selecting the reaction conditions such as the reaction temperature, reaction time, and reaction pressure. .

  In the present invention, two or more amorphous polyesters may be used as the binder resin from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner and improving the productivity.

  In the present invention, the polyester may be a polyester modified to such an extent that the characteristics are not substantially impaired. Examples of the modified polyester include grafting and blocking with phenol, urethane, epoxy and the like by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, and the like. Polyester.

[wax]
As the wax, 0.2 to 13 parts by mass of a wax having a melting point of 60 to 120 ° C. is contained with respect to 100 parts by mass of the binder resin.

  The melting point of the wax is 60 ° C. or higher, preferably 65 ° C. or higher, more preferably 68 ° C. or higher, and further preferably 70 ° C. or higher from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. From the viewpoint of reducing mechanical force during melt-kneading and suppressing heat generation, and improving the low-temperature fixability and heat-resistant storage stability of the toner, it is 120 ° C or lower, preferably 100 ° C or lower, and more preferably 90 ° C or lower. Preferably, it is 85 ° C. or lower, more preferably 80 ° C. or lower. Moreover, melting | fusing point of wax is 60-120 degreeC, 65-100 degreeC is preferable, 68-90 degreeC is more preferable, 70-85 degreeC is further more preferable, 70-80 degreeC is further more preferable.

  Any wax may be used as long as it has a melting point in the above-mentioned range. Polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax, aliphatic hydrocarbon wax such as microcrystalline wax, paraffin wax, Fischer-Tropsch wax, and the like. Oxides, synthetic ester waxes, carnauba waxes, montan waxes, sazol waxes and their deoxidized waxes, and other ester waxes, fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, etc. May be used alone or in admixture of two or more. Among these, aliphatic hydrocarbon waxes and ester waxes are preferable from the viewpoint of improving the low-temperature fixability, high-temperature offset resistance, and heat-resistant storage stability of the toner, and paraffin wax, synthetic ester wax, and carnauba wax are more preferable. Paraffin wax and synthetic ester wax are more preferable.

  The content of the wax is 0.2 parts by mass with respect to 100 parts by mass of the binder resin from the viewpoint of reducing mechanical force during melt-kneading and suppressing heat generation, and improving the low-temperature fixability and heat-resistant storage stability of the toner. It is above, 0.8 mass part or more is preferable, 1.0 mass part is more preferable, 1.5 mass part or more is further more preferable, 2.0 mass part or more is further more preferable. From the viewpoint of improving the heat resistant storage stability of the toner, it is 13 parts by mass or less, preferably 10 parts by mass or less, more preferably 8.0 parts by mass or less, further preferably 6.0 parts by mass or less, and further preferably 4.0 parts by mass or less. . Further, the content of the wax is 0.2 to 13 parts by mass, preferably 0.8 to 10 parts by mass, more preferably 1.0 to 8.0 parts by mass, and further 1.5 to 6.0 parts by mass with respect to 100 parts by mass of the binder resin. Preferably, 2.0-4.0 mass parts is more preferable.

  Two or more types of wax may be contained. When a plurality of waxes are contained, it is preferable that the melting point of the wax having the lowest melting point and the melting point based on the weighted average of all the waxes are both within the preferable range of the melting point of the wax. The melting point based on the weighted average of all the waxes can be determined by the sum of the products of the melting point and the content ratio of each wax.

  As for the content, it is preferable that the content of the wax having the lowest melting point and the total content of all the waxes are within the preferable range of the content of the wax.

[Colorant]
In the present invention, as the colorant, all of dyes and pigments used as toner colorants can be used, such as carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine. -B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, isoindoline, disazo yellow, etc. can be used, and the toner of the present invention may be either black toner or color toner . As the colorant, phthalocyanine blue 15: 3, phthalocyanine blue 15: 4, and carbon black are preferable, and phthalocyanine blue 15: 3 and carbon black are more preferable from the viewpoint of improving low-temperature fixability and heat-resistant storage stability of the toner.

  The content of the colorant is preferably 1 part by mass or more and more preferably 2 parts by mass or more with respect to 100 parts by mass of the binder resin from the viewpoint of improving the print density of the toner. Further, from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner, it is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and further preferably 5 parts by mass or less.

  The toner obtained by the method of the present invention may further contain a charge control agent and the like.

[Charge control agent]
As the charge control agent, either a negative charge control agent or a positive charge control agent can be used.

  Examples of the negatively chargeable charge control agent include metal-containing azo dyes, copper phthalocyanine dyes, metal complexes of salicylic acid alkyl derivatives, nitroimidazole derivatives, and benzyl acid boron complexes. Examples of metal-containing azo dyes include “Varifirst Black 3804”, “Bontron S-28”, “Bontron S-31”, “Bontron S-32”, “Bontron S-34”, “Bontron S-36” ( As mentioned above, “T-77”, “Eisenspiron Black TRH” (manufactured by Hodogaya Chemical Co., Ltd.) and the like can be mentioned. Examples of metal complexes of alkyl derivatives of salicylic acid include “Bontron E-81”, “Bontron E-82”, “Bontron E-84”, “Bontron E-85”, “Bontron E-304” (above, Orient Chemistry) Manufactured by Kogyo Co., Ltd.). Examples of the benzyl acid boron complex include “LR-147” (manufactured by Nippon Carlit).

  Examples of the positively chargeable charge control agent include nigrosine dyes, triphenylmethane dyes, quaternary ammonium salt compounds, polyamine resins, and imidazole derivatives. Nigrosine dyes include, for example, “Nigrosine Base EX”, “Oil Black BS”, “Oil Black SO”, “Bontron N-01”, “Bontron N-07”, “Bontron N-09”, “Bontron N-11” (Above, manufactured by Orient Chemical Industry Co., Ltd.). Examples of the triphenylmethane dye include a triphenylmethane dye containing a tertiary amine as a side chain. Examples of quaternary ammonium salt compounds include “Bontron P-51”, “Bontron P-52” (manufactured by Orient Chemical Co., Ltd.), “TP-415” (Hodogaya Chemical Co., Ltd.), cetyltrimethylammonium bromide. , "COPY CHARGE PXVP435", "COPY CHARGE PSY" (manufactured by Clariant). Examples of the polyamine resin include “AFP-B” (manufactured by Orient Chemical Industry Co., Ltd.). Examples of the imidazole derivative include “PLZ-2001”, “PLZ-8001” (manufactured by Shikoku Kasei Co., Ltd.) and the like.

  The content of the charge control agent is preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more, and more preferably 5 parts by mass or less with respect to 100 parts by mass of the binder resin from the viewpoint of improving the charging stability of the toner. Is preferable, and 3 parts by mass or less is more preferable.

  In the present invention, as a toner material, additives such as magnetic powder, fluidity improver, conductivity adjuster, reinforcing filler such as fibrous substance, antioxidant, anti-aging agent, and cleanability improver are appropriately added. May be used.

<Toner production method>
The toner of the present invention is produced by a method including a step of melt-kneading at least a mixture containing a binder resin and a wax.

  A known kneader such as a closed kneader, a single or twin screw extruder, an open roll type kneader is used for melt kneading of a mixture containing a binder resin and a wax, and if necessary, a colorant, a charge control agent and the like. Can be used. From the viewpoint of reducing the temperature during melt-kneading and improving the low-temperature fixability and heat-resistant storage stability of the toner, and without repeating kneading or using a dispersion aid, the binder resin can be treated with wax, colorant, and charge control. From the viewpoint of efficiently and highly dispersing toner components such as an agent, it is preferable to use an open roll type kneader, and the open roll type kneader includes a supply port and a kneaded material discharge along the axial direction of the roll. An outlet is preferably provided.

  It is preferable that toner components such as a binder resin, a wax, a colorant, and a charge control agent are mixed in advance with a mixer such as a Henschel mixer or a ball mill and then supplied to the kneader.

  When the mixture is supplied to an open roll type kneader, it may be supplied to the kneader from one supply port, or may be divided into a plurality of supply ports and supplied to the kneader. And from the viewpoint of simplification of the apparatus, it is preferable to supply the kneader from one supply port.

  The open roll type kneader means an open kneading unit that is not sealed, and can easily dissipate the kneading heat generated during kneading. Further, the continuous open roll type kneader is preferably a kneader equipped with at least two rolls, and the continuous open roll type kneader used in the present invention comprises two rolls having different peripheral speeds, That is, the kneading machine includes two rolls, a high rotation side roll having a high peripheral speed and a low rotation side roll having a low peripheral speed. In the present invention, the viewpoint of improving the dispersibility of toner components such as waxes, colorants, and charge control agents in the binder resin, the viewpoint of reducing the mechanical force during melt-kneading and suppressing the heat generation, and the low temperature of the toner From the viewpoint of improving fixability and heat-resistant storage stability, the high rotation side roll is preferably a heating roll, and the low rotation side roll is preferably a cooling roll.

  The temperature of the roll can be adjusted by, for example, the temperature of the heat medium passed through the inside of the roll, and each roll may be divided into two or more and the heat medium having different temperatures may be passed through each roll.

  From the viewpoint of reducing mechanical force during melt kneading, suppressing heat generation, and improving the low-temperature fixability and heat-resistant storage stability of the toner, the raw material charging side end temperature of the high-rotation side roll is 100 ° C. or higher, 160 From the same viewpoint, the raw material charging side end temperature of the low rotation side roll is preferably 30 ° C. or higher and 100 ° C. or lower.

  In the high rotation side roll, the difference in the set temperature between the raw material input side end and the kneaded product discharge side end prevents the kneaded product from detaching from the roll, reduces the mechanical force during melt kneading, and suppresses heat generation From the viewpoint of improving the low temperature fixability and heat resistant storage stability of the toner, it is preferably 20 ° C. or higher, more preferably 30 ° C. or higher. And it is preferable that it is 60 degrees C or less, and 50 degrees C or less is more preferable.

  The low rotation side roll has a difference in the set temperature between the raw material input side end and the kneaded product discharge side end to improve the dispersibility of the toner component such as wax, colorant, charge control agent, etc. in the binder resin, From the viewpoint of reducing mechanical force during melt-kneading, suppressing heat generation, and improving the low-temperature fixability and heat-resistant storage stability of the toner, it is preferably 0 ° C or higher, more preferably 10 ° C or higher, and 20 ° C. The above is more preferable. And it is preferable that it is 50 degrees C or less.

  The peripheral speed of the high-rotation side roll is from the viewpoint of improving the dispersibility of toner components such as wax, colorant, and charge control agent in the binder resin, from the viewpoint of reducing mechanical force during melt-kneading and suppressing heat generation, From the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner, it is preferably 2 m / min or more, more preferably 10 m / min or more, and even more preferably 25 m / min or more. It is preferably 100 m / min or less, more preferably 75 m / min or less, and even more preferably 50 m / min or less.

  From the same viewpoint, the peripheral speed of the low rotation side roll is preferably 1 m / min or more, more preferably 5 m / min or more, and further preferably 15 m / min or more. And 90 m / min or less is preferable, 60 m / min or less is more preferable, and 30 m / min or less is further more preferable. Further, the ratio of the peripheral speeds of the two rolls (low rotation side roll / high rotation side roll) is preferably 1/10 to 9/10, and more preferably 3/10 to 8/10.

  The structure, size, material, etc. of the roll are not particularly limited, and the roll surface may be any of smooth, corrugated, uneven, etc., but the kneading share is increased, wax, colorant, charge control agent, etc. From the viewpoint of improving the dispersibility of the toner component in the binder resin, reducing the mechanical force during melt kneading, suppressing heat generation, and improving the low-temperature fixability and heat-resistant storage stability of the toner, each roll It is preferable that a plurality of spiral grooves are carved on the surface.

  A twin-screw kneader may be used for melt-kneading the mixture. The biaxial kneader is a closed type kneader in which two kneading shafts are covered with a barrel, and a type in which the rotation directions of the shafts can rotate in the same direction is preferable. As a commercial product, from the viewpoint of improving productivity, the twin screw extruder PCM series manufactured by Ikekai Tekko Co., Ltd., which is good in high-speed two-axis meshing, is preferable.

  The melt kneading in the biaxial kneader is performed by adjusting the barrel set temperature (temperature of the inner wall surface of the extruder), the peripheral speed of biaxial shaft rotation, and the raw material supply speed. The barrel set temperature is based on the viewpoint of improving the dispersibility in the binder resin such as wax, colorant, and charge control agent, reducing the mechanical force during melt-kneading and suppressing heat generation, and fixing the toner at low temperature. Further, from the viewpoint of improving heat-resistant storage stability and from the viewpoint of improving toner productivity, 80 ° C. or higher is preferable, and 90 ° C. or higher is more preferable. And 140 degrees C or less is preferable, and 120 degrees C or less is more preferable.

  The peripheral speed of the biaxial shaft rotation is the viewpoint of improving the dispersibility in the binder resin such as wax, colorant, and charge control agent, the viewpoint of reducing the mechanical force at the time of melt kneading and suppressing the heat generation, From the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner and from the viewpoint of improving the productivity of the toner, 0.1 m / sec or more and 1 m / sec or less are preferable.

  The feed rate of the raw material to the biaxial kneader is appropriately adjusted according to the allowable capacity of the kneader to be used, the barrel set temperature and the peripheral speed of the shaft rotation.

  The obtained resin kneaded product is preferably cooled to such an extent that it can be pulverized, then pulverized and classified.

  The pulverization process may be performed in multiple stages. For example, the resin kneaded material may be coarsely pulverized to about 1 to 5 mm and further pulverized to a desired particle size.

  The pulverizer used in the pulverization step is not particularly limited, and examples of the pulverizer suitably used for coarse pulverization include a hammer mill, an atomizer, and a rotplex. Further, examples of the pulverizer suitably used for fine pulverization include a fluidized bed jet mill, a collision plate jet mill, and a rotary mechanical mill. From the viewpoint of pulverization efficiency, it is preferable to use a fluidized bed jet mill and a collision plate jet mill, and more preferably a collision plate jet mill.

  Examples of the classifier used in the classification process include an airflow classifier, an inertia classifier, and a sieve classifier. In the classification step, the pulverized product that has been removed due to insufficient pulverization may be subjected to the pulverization step again, and the pulverization step and the classification step may be repeated as necessary.

  In the toner production method of the present invention, from the viewpoint of improving the chargeability, fluidity, and transferability of the toner, the obtained toner particles (toner mother particles) are further mixed with an external additive after the pulverization and classification steps. It is preferable to include a process. Specific examples include inorganic particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as resin particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles. Two or more kinds may be used in combination. Among these, silica is preferable, and hydrophobic silica that has been subjected to a hydrophobic treatment is more preferable from the viewpoint of improving toner transferability.

  The number average particle diameter of the external additive is preferably 10 nm or more, more preferably 15 nm or more, more preferably 250 nm or less, and more preferably 200 nm or less, from the viewpoint of improving the chargeability, fluidity, and transferability of the toner. 90 nm or less is more preferable.

  The content of the external additive is preferably 0.05 parts by mass or more with respect to 100 parts by mass of the toner base particles before being treated with the external additive, from the viewpoint of improving the chargeability, fluidity, and transferability of the toner. 0.1 part by mass or more is more preferable, and 0.3 part by mass or more is more preferable. Further, it is preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and further preferably 3 parts by mass or less.

  For mixing the toner base particles and the external additive, it is preferable to use a mixer equipped with a stirring tool such as a rotary blade, a high speed mixer such as a Henschel mixer or a super mixer is preferable, and a Henschel mixer is more preferable.

The volume median particle size (D ₅₀ ) of the toner of the present invention is preferably 3 μm or more, more preferably 4 μm or more, and even more preferably 6 μm or more from the viewpoint of improving the image quality of the toner. Further, it is preferably 15 μm or less, more preferably 12 μm or less, and further preferably 9 μm or less. In the present specification, the volume-median particle size (D ₅₀ ) means a particle size at which the cumulative volume frequency calculated by the volume fraction is 50% when calculated from the smaller particle size. In addition, when the toner is treated with an external additive, the volume median particle size of the toner base particles is set as the volume median particle size of the toner.

  The toner obtained by the method of the present invention is used as it is as a one-component developing toner as it is or as a two-component developing toner used by mixing with a carrier in an image forming apparatus of a one-component developing method or a two-component developing method, respectively. Can do.

  In relation to the above-described embodiment, the present invention further discloses the following method for producing an electrostatic image developing toner and electrostatic image developing toner.

<1> A method for producing a toner for developing an electrostatic charge image, comprising a step of melt-kneading a mixture containing a binder resin and a wax,
The binder resin is an aliphatic diol (a) having 3 or 4 carbon atoms having a hydroxy group bonded to a secondary carbon atom and an α, ω-linear alkanediol having 2, 4, 6 or 8 carbon atoms. An amorphous polyester (A) obtained by polycondensation of an alcohol component containing an aliphatic diol (b) consisting of any one or more of the above and a carboxylic acid component,
The molar ratio of the aliphatic diol (a) and the aliphatic diol (b) (aliphatic diol (a) / aliphatic diol (b)) is 95/5 to 55/45,
The melting point of the wax is 60-120 ° C;
A method for producing a toner for developing an electrostatic charge image, wherein the content of the wax is 0.2 to 13 parts by mass with respect to 100 parts by mass of the binder resin.

<2> The content of the amorphous polyester (A) in the binder resin is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more. The method for producing a toner for developing an electrostatic charge image according to <1>, wherein it is more preferable to use only the high quality polyester (A).

<3> An aliphatic diol (a) having 3 or 4 carbon atoms having a hydroxy group bonded to a secondary carbon atom is selected from 1,2-propanediol, 1,2-butanediol, 1,3-butanediol and At least one selected from the group consisting of 2,3-butanediol, preferably at least one selected from the group consisting of 1,2-propanediol and 2,3-butanediol, The method for producing a toner for developing an electrostatic charge image according to <1> or <2>, wherein a diol is more preferable.

<4> The content of the aliphatic diol (a) is preferably 55 mol% or more, more preferably 60 mol% or more, still more preferably 65 mol% or more in the alcohol component of the amorphous polyester (A), 70 More preferably, mol% or more, 95 mol% or less is preferable, 93 mol% or less is more preferable, 90 mol% or less is more preferable, 85 mol% or less is further preferable, 55 to 95 mol% is preferable, and 60 to 93 mol is preferable. % Is more preferable, 65 to 90 mol% is more preferable, 65 to 85 mol% is further preferable, and 70 to 85 mol% is further preferable, for developing an electrostatic image according to any one of the above <1> to <3> Toner manufacturing method.

<5> The content of the aliphatic diol (a) is preferably 55 to 95 mol%, more preferably 60 to 93 mol%, and more preferably 65 to 90 mol% in the alcohol component of all polyesters contained in the binder resin. Is more preferable, 65 to 85 mol% is more preferable, and 70 to 85 mol% is more preferable, The manufacturing method of the electrostatic image developing toner in any one of said <1>-<4>.

<6> An aliphatic diol (b) composed of at least one of α, ω-linear alkanediols having 2, 4, 6 or 8 carbon atoms is ethanediol, 1,4-butanediol, 1, At least one selected from the group consisting of 6-hexanediol and 1,8-octanediol, selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, and 1,8-octanediol The method for producing a toner for developing an electrostatic charge image according to any one of <1> to <5>, wherein at least one selected from the above is preferable, and 1,4-butanediol is more preferable.

<7> The content of the aliphatic diol (b) is preferably 5 mol% or more, more preferably 7 mol% or more, further preferably 10 mol% or more in the alcohol component of the amorphous polyester (A), 15 More preferably mol% or more, 45 mol% or less is preferable, 40 mol% or less is more preferable, 35 mol% or less is more preferable, 30 mol% or less is more preferable, 5-45 mol% is preferable, 7-40 mol% % Is more preferable, 10 to 35 mol% is more preferable, 15 to 35 mol% is further preferable, and 15 to 30 mol% is more preferable, and for electrostatic image development according to any one of <1> to <6> above Toner manufacturing method.

<8> The content of the aliphatic diol (b) is preferably 5 to 45 mol%, more preferably 7 to 40 mol%, and more preferably 10 to 35 mol% in the alcohol component of all polyesters contained in the binder resin. Is more preferable, 15 to 35 mol% is more preferable, and 15 to 30 mol% is more preferable, The manufacturing method of the electrostatic image developing toner in any one of said <1>-<7>.

<9> The total content of the aliphatic diol (a) and the aliphatic diol (b) is preferably 80 mol% or more, more preferably 90 mol% or more in the alcohol component of the amorphous polyester (A), and 95 The method for producing a toner for developing an electrostatic charge image according to any one of <1> to <8>, wherein the amount is more preferably at least mol%, more preferably at most 100 mol%.

<10> The molar ratio of the aliphatic diol (a) to the aliphatic diol (b) in the alcohol component of the amorphous polyester (A) (aliphatic diol (a) / aliphatic diol (b)) is 93 / 7-60 / 40 are preferred, 90 / 10-65 / 35 are more preferred, 85 / 15-65 / 35 are more preferred, 85 / 15-70 / 30 are more preferred, <1> to <9> above A method for producing a toner for developing electrostatic images according to any one of the above.

<11> The molar ratio (aliphatic diol (a) / aliphatic diol (b)) of the aliphatic diol (a) and the aliphatic diol (b) in the alcohol component of all the polyesters contained in the binder resin, 95/5 to 55/45, preferably 93/7 to 60/40, more preferably 90/10 to 65/35, still more preferably 85/15 to 65/35, and 85/15 to 70/30 More preferably, the method for producing a toner for developing an electrostatic charge image according to any one of <1> to <10>.

<12> The method for producing a toner for developing an electrostatic charge image according to any one of <1> to <11>, wherein the carboxylic acid component of the amorphous polyester (A) contains a divalent or higher carboxylic acid compound.

<13> The content of the divalent carboxylic acid compound is preferably 60 to 100 mol%, more preferably 70 to 100 mol%, and more preferably 80 to 100 mol% in the carboxylic acid component of the amorphous polyester (A). The method for producing a toner for developing an electrostatic charge image according to <12>, more preferably 85 to 100 mol%.

<14> The carboxylic acid component of the amorphous polyester (A) includes a trivalent or higher carboxylic acid compound, and the trivalent or higher carboxylic acid compound is 1,2,4-benzenetricarboxylic acid (trimellitic acid). And / or an acid anhydride thereof, and an anhydride of 1,2,4-benzenetricarboxylic acid (trimellitic anhydride) is more preferable. The toner for developing an electrostatic charge image according to <12> or <13> Production method.

<15> The content of the trivalent or higher carboxylic acid compound is preferably 40 mol% or less, more preferably 30 mol% or less, still more preferably 20 mol% or less, and even more preferably 15 mol% or less in the carboxylic acid component. The method for producing a toner for developing an electrostatic charge image according to <14>.

<16> The softening point of the amorphous polyester (A) is preferably 80 ° C or higher, more preferably 100 ° C or higher, further preferably 110 ° C or higher, further preferably 120 ° C or higher, preferably 170 ° C or lower, 160 ° C. The method for producing a toner for developing an electrostatic charge image according to any one of <1> to <15>, wherein the following is more preferable, 150 ° C. or lower is further preferable, and 140 ° C. or lower is further preferable.

<17> The highest endothermic peak temperature of the amorphous polyester (A) is preferably 50 ° C. or higher, preferably 90 ° C. or lower, more preferably 85 ° C. or lower, and further preferably 80 ° C. or lower, <1> to < 16> The method for producing a toner for developing an electrostatic charge image according to any one of 16).

<18> The glass transition temperature of the amorphous polyester (A) is preferably 50 ° C or higher, more preferably 60 ° C or higher, further preferably 65 ° C or higher, preferably 90 ° C or lower, more preferably 85 ° C or lower, 80 The method for producing a toner for developing an electrostatic charge image according to any one of <1> to <17>, wherein the temperature is further preferably 0 ° C. or lower.

<19> The electrostatic charge image developing toner according to any one of <1> to <18>, wherein the acid value of the amorphous polyester (A) is preferably 60 mgKOH / g or less, more preferably 50 mgKOH / g or less. Production method.

<20> The melting point of the wax is preferably 65 ° C. or higher, more preferably 68 ° C. or higher, more preferably 70 ° C. or higher, preferably 100 ° C. or lower, more preferably 90 ° C. or lower, still more preferably 85 ° C. or lower, 80 ° C. The following is more preferable, 65 to 100 ° C is preferable, 68 to 90 ° C is more preferable, 70 to 85 ° C is more preferable, and 70 to 80 ° C is more preferable, Static according to any one of the above items <1> to <19> A method for producing a toner for developing a charge image.

<21> The wax is preferably at least one selected from the group consisting of paraffin wax, synthetic ester wax, and carnauba wax, and more preferably paraffin wax and / or synthetic ester wax. A method for producing a toner for developing electrostatic images according to any one of the above.

<22> The content of the wax is preferably 0.8 parts by mass or more, more preferably 1.0 part by mass, further preferably 1.5 parts by mass or more, further preferably 2.0 parts by mass or more, relative to 100 parts by mass of the binder resin. Mass parts or less are preferred, 8.0 parts by mass or less are more preferred, 6.0 parts by mass or less are more preferred, 4.0 parts by mass or less are more preferred, 0.8 to 10 parts by mass are preferred, 1.0 to 8.0 parts by mass are more preferred, 1.5 to 6.0 parts are preferred. The method for producing a toner for developing an electrostatic charge image according to any one of <1> to <21>, wherein the toner is more preferably part by mass, and more preferably 2.0 to 4.0 parts by mass.

<23> The method for producing a toner for developing an electrostatic charge image according to any one of <1> to <22>, wherein the melt kneading is performed with an open roll kneader.

<24> The method for producing a toner for developing an electrostatic charge image according to any one of <1> to <22>, wherein the melt kneading is performed with a biaxial kneader.

<25> An electrostatic charge image developing toner obtained by the production method according to any one of <1> to <24>.

[Softening point of resin]
Using a flow tester “CFT-500D” (manufactured by Shimadzu Corporation), a 1 g sample was heated at a heating rate of 6 ° C./min, a 1.96 MPa load was applied by a plunger, and a nozzle with a diameter of 1 mm and a length of 1 mm Extrude from. The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[Maximum peak temperature of resin endotherm]
Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample is weighed in an aluminum pan, and the temperature drops from room temperature to 0 ° C. at a rate of 10 ° C./min. Cooled and held at 0 ° C. for 1 minute. Thereafter, the measurement was carried out at a heating rate of 50 ° C./min. Among the observed endothermic peaks, the temperature of the peak on the highest temperature side is defined as the highest endothermic peak temperature.

[Glass transition temperature of amorphous resin]
Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan), 0.01 to 0.02 g of sample is weighed into an aluminum pan, heated up to 200 ° C., and the temperature drop rate from that temperature Cool to 0 ° C at 10 ° C / min. Next, the sample is heated at a heating rate of 10 ° C./min and measured. The glass transition temperature is defined as the temperature at the intersection of the base line extension below the maximum peak temperature of endotherm and the tangent line indicating the maximum slope from the peak rising portion to the peak apex.

[Acid value of the resin]
Measured according to the method of JIS K0070. However, only the measurement solvent is changed from the mixed solvent of ethanol and ether specified in JIS K0070 to the mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Melting point of wax]
Using a differential scanning calorimeter (manufactured by TA Instruments Japan, DSC Q20), 0.01 to 0.02 g of sample was weighed into an aluminum pan and heated to 200 ° C at a heating rate of 10 ° C / min. Cool from the temperature to -10 ° C at a rate of 5 ° C / min. Next, the sample is heated to 180 ° C. at a heating rate of 10 ° C./min and measured. The highest endothermic peak temperature observed from the melting endothermic curve obtained there is taken as the melting point of the wax.

[Number average particle diameter of external additives]
The particle size (average value of major axis and minor axis) of 500 particles is measured from a scanning electron microscope (SEM) photograph, and the average value is taken as the number average particle size.

[Volume-median particle size of toner]
Measuring machine: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 100μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter)
Electrolyte: Isoton II (Beckman Coulter, Inc.)
Dispersion: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB: 13.6) is dissolved in the electrolyte so as to have a concentration of 5% by mass.
Dispersion conditions: 10 mg of a measurement sample was added to 5 ml of the dispersion, and dispersed for 1 minute with an ultrasonic disperser, then 25 ml of the electrolyte was added, and further dispersed for 1 minute with an ultrasonic disperser. Prepare sample dispersion.
Measurement conditions: The sample dispersion is added to 100 ml of the electrolytic solution so that the particle size of 30,000 particles can be measured in 20 seconds, and 30,000 particles are measured. Determine the median particle size (D ₅₀ ).

Resin Production Example 1 [Resin A to H, Resin J to L, Resin N to W]
Raw material monomers other than trimellitic anhydride shown in Tables 1 to 3 and the esterification catalyst were placed in a 5 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple. The temperature was raised to ° C. and reacted for 6 hours. The temperature was further raised to 210 ° C., trimellitic anhydride was added, and the mixture was reacted at normal pressure (101.3 kPa) for 1 hour, and further reacted at 40 kPa until the desired softening point was reached. The physical properties of the obtained resin are shown in Tables 1-3.

Resin Production Example 2 [Resin I]
The raw material monomer and esterification catalyst shown in Table 1 are put into a 5 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, heated to 200 ° C. in a nitrogen atmosphere, and 6 hours. Reacted. The temperature was further raised to 210 ° C., followed by reaction at normal pressure (101.3 kPa) for 1 hour, and further at 40 kPa until the softening point reached 130 ° C. Table 1 shows the physical properties of the obtained resin.

Resin Production Example 3 [Resin M]
Raw material monomers other than trimellitic anhydride shown in Table 2, esterification catalyst, and polymerization inhibitor were placed in a 5 L four-necked flask equipped with a nitrogen inlet tube, a dehydrating tube, a stirrer, and a thermocouple. The temperature was raised to 200 ° C. and reacted for 6 hours. The temperature was further raised to 210 ° C., trimellitic anhydride was added, and the mixture was reacted at normal pressure (101.3 kPa) for 1 hour, and further reacted at 40 kPa until the softening point reached 131 ° C. Table 2 shows the physical properties of the obtained resin.

  Table 4 shows the melting points of the waxes used in Examples and Comparative Examples.

Examples 1-27, Comparative Examples 1-11 (Example 5 is a reference example)
Conditions shown below after mixing a predetermined amount of binder resin, wax and colorant shown in Tables 5 and 6 and 1.0 part by mass of charge control agent “Bontron E-304” (manufactured by Orient Chemical Co., Ltd.) with a Henschel mixer. Was melt kneaded.

  A continuous two-open roll kneader “NIDEX” (manufactured by Mitsui Mining Co., Ltd., roll outer diameter: 14 cm, effective roll length: 80 cm) was used. The operating conditions of the continuous two-open roll type kneader were high rotation side roll (front roll) peripheral speed 32.4m / min, low rotation side roll (back roll) peripheral speed 21.7m / min, and roll gap 0.1mm. It was. The heating medium temperature and cooling medium temperature in the roll are 145 ° C. on the raw material input side of the high rotation side roll and 100 ° C. on the kneaded material discharge side, 75 ° C. on the raw material input side of the low rotation side roll and 35 ° C. on the kneaded material discharge side. there were. The feed rate of the raw material mixture was 10 kg / hr, and the average residence time was about 3 minutes.

  The obtained resin kneaded product was cooled and coarsely pulverized by a pulverizer “ROTOPLEX” (manufactured by Hosokawa Micron) to obtain a coarsely pulverized product having a volume particle size of 2 mm or less using a sieve having an opening of 2 mm. The obtained coarsely pulverized product was finely pulverized by using a DS2 type airflow classifier (impact plate type, manufactured by Nippon Pneumatic Co., Ltd.) to adjust the pulverization pressure so that the volume median particle size was 8.0 μm. The resulting finely pulverized product is classified by adjusting the static pressure (internal pressure) so that the volume median particle size is 8.5 μm using a DSX2 type airflow classifier (manufactured by Nippon Pneumatic Co., Ltd.), and toner Mother particles were obtained.

  100 parts by weight of the obtained toner base particles, hydrophobic silica “R972” (manufactured by Nippon Aerosil Co., Ltd., number average particle size: 16 nm) as an external additive, 1.0 part by weight, hydrophobic silica “NAX50” (manufactured by Nippon Aerosil Co., Ltd.) A toner was obtained by mixing 1.0 part by mass of a number average particle diameter of 30 nm with a Henschel mixer (Mitsui Mining Co., Ltd.) at 2100 r / min (circumferential speed 29 m / sec) for 3 minutes.

Example 28
In Example 2, the toner raw materials were mixed with a Henschel mixer and then melt-kneaded under the following conditions.

The same direction rotating twin screw extruder PCM-30 (manufactured by Ikekai Tekko Co., Ltd., shaft diameter 2.9 cm, shaft cross section 7.06 cm ² ) was used. Operating conditions are: barrel set temperature 100 ° C, shaft rotation speed 200r / min (shaft rotation peripheral speed 0.30m / sec), mixture feed speed 10kg / hr (mixture feed rate per unit cross section of shaft 1.42kg / hr)・ Cm ² ).

  The obtained resin kneaded material was coarsely pulverized and finely pulverized in the same manner as in Example 2 and classified to obtain toner base particles.

  The obtained toner base particles were mixed with an external additive in the same manner as in Example 2 to obtain a toner.

Test Example 1 [low temperature fixability]
The printer “OKI MICROLINE 5400” (Oki Data Co., Ltd.), modified to take unfixed images, was filled with toner, and a 2cm square solid unfixed image was printed. Using an external fixing device modified from "OKI MICROLINE 3010" (made by Oki Data), increasing the fixing roll temperature from 100 ° C to 230 ° C in 5 ° C increments at a fixing roll rotation speed of 120mm / sec. The unfixed image was fixed at each temperature to obtain a fixed image. The image obtained at each fixing temperature is rubbed 5 times with a sand eraser (LION, ER-502R) applied with a load of 500 g, and the image density measuring instrument “GREGSPM50” (Gretag) before and after rubbing. The temperature at which the image density ratio before and after rubbing ([image density after rubbing / image density before rubbing] × 100) first exceeds 90% is defined as the minimum fixing temperature, and is used as an index for low-temperature fixing properties. . The smaller the value, the better the low-temperature fixability. The results are shown in Tables 5 and 6.

Test Example 2 [Heat resistant storage stability]
A metallic cylinder (inner diameter: 2.8 cm) was filled with 10 g of toner, and a weight (20 g) having a diameter of about 2.8 cm was placed on the toner and allowed to stand at a temperature of 50 ° C. and a relative humidity of 40% for 72 hours. Thereafter, the weight and the cylinder were removed, and the presence or absence of toner aggregation was confirmed. When the toner is agglomerated, a weight having a predetermined weight is placed on the toner, and the weight of the weight when the toner mass is broken and the weight falls is used as an index of heat resistant storage stability. A weight of 0 g is a case where the toner mass collapses (ie, does not aggregate) just by removing the cylinder. The smaller the value, the better the heat resistant storage stability. The results are shown in Tables 5 and 6.

  From the above results, it can be seen that, in comparison with Comparative Examples 1 to 11, the toners of Examples 1 to 28 are excellent in low-temperature fixability and excellent in heat-resistant storage stability.

  The toner for developing an electrostatic image obtained by the method of the present invention is suitably used for developing a latent image formed by an electrostatic image development method, an electrostatic recording method, an electrostatic printing method or the like.

Claims (5)

A method for producing a toner for developing an electrostatic charge image, comprising a step of melt-kneading a mixture containing a binder resin and a wax,
The binder resin is an aliphatic diol (a) having 3 or 4 carbon atoms having a hydroxy group bonded to a secondary carbon atom and an α, ω-linear alkanediol having 2, 4, 6 or 8 carbon atoms. An amorphous polyester (A) obtained by polycondensation of an alcohol component containing an aliphatic diol (b) consisting of any one or more of the above and a carboxylic acid component,
The molar ratio of the aliphatic diol (a) to the aliphatic diol (b) (aliphatic diol (a) / aliphatic diol (b)) is 93/7 to 55/45,
The melting point of the wax is 60 to 105 ° C.,
A method for producing a toner for developing an electrostatic charge image, wherein the content of the wax is 0.2 to 13 parts by mass with respect to 100 parts by mass of the binder resin.   The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the total content of the aliphatic diol (a) and the aliphatic diol (b) in the alcohol component is 80 mol% or more.   The static diol according to claim 1 or 2, wherein the aliphatic diol (b) is at least one selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, and 1,8-octanediol. A method for producing a toner for developing a charge image.   The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 3, wherein the melt kneading is performed with an open roll type kneader.   The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 4, wherein the content of the amorphous polyester (A) is 80% by mass or more in the binder resin.