JP5840053B2 - Toner for electrostatic image development - Google Patents

Description

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

  As the print-on-demand market has grown in recent years, there has been an increasing demand for high-quality electrophotographic technology and stability of printed images. In particular, suppression of toner fog and photoconductor scratches that adversely affect a printed image is desired.

  For example, by using hydrophobic silica surface-treated with dimethyl silicone oil, having a specific carbon content attributable to the surface treatment agent, and having specific primary particles as an external additive, the background image can be obtained at an appropriate image density. It is disclosed that a high-quality copy image can be obtained stably over a long period of time (see Patent Document 1).

  On the other hand, in recent years, the use of biomass raw materials has been desired from the viewpoint of reducing environmental impact.

  For example, a thermoplastic resin having a furan structure, a reduced viscosity (ηsp / C) of 0.48 dL / g or more, and a terminal acid value of less than 200 μeq / g has excellent heat resistance, mechanical properties, and weather resistance. It is disclosed that it is excellent (see Patent Document 2).

  Further, it is disclosed that a polyester resin having a specific furan ring structural unit is excellent in impact resistance and suitable for a material for producing a molded product (see Patent Document 3).

JP-A-8-292598 JP 2008-291243 A JP 2009-197110 A

  However, since the resin described in Patent Document 2 is mainly used for film applications and injection molded products, it has high crystallinity, is not suitable as a binder resin for toner, and liberates hydrophobic silica. It is easy to occur and a photoreceptor damage is easy to occur. In addition, the resin described in Patent Document 3 is also a molded product composition, so it has high crystallinity and is not suitable as a binder resin for toner, and the release of hydrophobic silica is likely to occur, causing damage to the photoreceptor. Easy to do.

  Further, in the toner described in Patent Document 1, fog suppression is insufficient, hydrophobic silica is easily liberated, and photoconductor scratches are likely to occur.

  An object of the present invention is to provide a toner for developing an electrostatic image that suppresses fogging and scratches on a photoreceptor, and a method for producing the same.

The present invention
[1] An electrostatic charge image developing toner comprising toner base particles containing at least a binder resin and an external additive, wherein the binder resin contains polyester A having a furan ring, and the external additive is An electrostatic charge image developing toner containing hydrophobic silica particles (external additive A) having an average particle size of 20 to 80 nm and a carbon content of 2.6 to 6.0% by weight calculated by the following formula (1), and an average particle size (nm) = 6 / (ρ x specific surface area (m ² / g)) x 1000 (1)
(In the formula, ρ is the true specific gravity of silica 2.2. The specific surface area is the BET specific surface area determined by the nitrogen adsorption method.)
[2] A method for producing a toner for developing an electrostatic image comprising toner base particles containing at least a binder resin and an external additive,
Step 1: a step of mixing toner base particles and external additive A, and step 2: a step of further mixing with external additive B,
The binder resin contains polyester A having a furan ring, the external additive A is hydrophobic silica particles having an average particle diameter of 20 to 80 nm and a carbon content of 2.6 to 6.0% by weight, and the external additive B is an average. The present invention relates to a method for producing a toner for developing an electrostatic charge image, which is a hydrophobic silica particle having a particle size of 6 nm or more and less than 20 nm, wherein the difference in average particle size between external additive A and external additive B is 10 nm or more.

  The toner for developing an electrostatic charge image of the present invention has an effect of suppressing fogging and photoconductor scratches.

  The toner of the present invention is an electrostatic charge image developing toner containing toner base particles containing at least a binder resin and an external additive, wherein the binder resin contains a polyester having a furan ring, and a specific external additive. It is characterized by containing an agent.

The reason why the toner of the present invention is excellent in suppressing fog and photoconductor scratches is not clear, but is considered as follows.
A resin having a furan ring has a high glass transition temperature, is a hard resin, and suppresses embedding of an external additive. In addition, by using hydrophobic silica having a specific average particle size and a specific carbon amount as an external additive, the intermolecular force with the resin having a furan ring is improved, and the adhesion between the resin and the external additive is improved. And the release of the external additive is suppressed. As a result, it is considered that charging stability is improved, fogging is suppressed, and occurrence of photoconductor scratches is also suppressed.

<Binder resin>
The binder resin used in the toner of the present invention contains polyester A having a furan ring.
Polyester A is a polyester obtained by condensation polymerization of a carboxylic acid component and an alcohol component using a carboxylic acid component containing at least a carboxylic acid compound having a furan ring and / or an alcohol component containing an alcohol having a furan ring as a raw material monomer. Preferably, the furan ring has the formula (Ia) or (Ib):

The structure represented by these is preferable.

  Examples of the carboxylic acid compound having a furan ring include furan carboxylic acid compounds such as 2,5-furandicarboxylic acid, 2,4-furandicarboxylic acid, 2,3-furandicarboxylic acid, and 3,4-furandicarboxylic acid (this specification) In the description, the carboxylic acid compound includes a carboxylic acid, an ester of a carboxylic acid and an alcohol having 1 to 6 carbon atoms, preferably an alcohol having 1 to 3 carbon atoms, and an acid anhydride); 2-furancarboxylic acid, 3-furancarboxylic acid Such as 5-hydroxymethyl-furan-2-carboxylic acid; furfuryl acetic acid compound, 3-carboxy-4-methyl-5-propyl-2-furanpropionate, etc. Carboxylic acid compounds (in this specification, hydroxycarboxylic acid compounds are included in the carboxylic acid compounds) and the like.

  Among these, from the viewpoint of reducing the amount of free external additives and suppressing scratches on the photoreceptor, improving the charging stability of the toner, suppressing fogging, and improving the low-temperature fixability and heat-resistant storage stability of the toner. Therefore, at least one selected from the group consisting of furandicarboxylic acid compounds, furancarboxylic acid compounds and hydroxyfurancarboxylic acid compounds is preferable, furancarboxylic acid compounds are more preferable, and 2,5-furandicarboxylic acid is more preferable.

  Examples of the alcohol having a furan ring include furan alcohol such as dihydroxyfuran; hydroxymethylfurfuryl alcohol such as 5-hydroxymethylfurfuryl alcohol; furfuryl alcohol; 5-hydroxymethylfurfural.

  Examples of the carboxylic acid compound having a furan ring represented by the formula (Ia) include 2,5-furandicarboxylic acid, 2,4-furandicarboxylic acid, 2,3-furandicarboxylic acid, and 3,4-furandicarboxylic acid. Flanged carboxylic acid compounds; carboxylic acid compounds such as hydroxyfuran carboxylic acid compounds such as 5-hydroxymethyl-furan-2-carboxylic acid.

  Examples of the alcohol having a furan ring represented by the formula (Ia) include hydroxymethylfurfuryl alcohol such as 5-hydroxymethylfurfuryl alcohol; flanged alcohol such as dihydroxyfuran; 5-hydroxymethylfurfural.

  Examples of the carboxylic acid compound having a furan ring represented by the formula (Ib) include furan carboxylic acid compounds such as 2-furan carboxylic acid and 3-furan carboxylic acid; and furfuryl acetic acid compounds.

  Examples of the alcohol having a furan ring represented by the formula (Ib) include furfuryl alcohol.

  Among the carboxylic acid compounds and alcohols described above, the amount of free external additives is reduced, the photoreceptor scratches are suppressed, the charging stability of the toner is improved, the fog is suppressed, and the low temperature fixability and heat resistance of the toner. From the viewpoint of improving the storage stability, a carboxylic acid compound having a furan ring represented by the formula (Ia) and an alcohol are preferable, a furan carboxylic acid compound and a furan alcohol are more preferable, and a furan dicarboxylic acid compound is more preferable.

  The total amount of the carboxylic acid compound having a furan ring and the alcohol having a furan ring reduces the amount of free external additive, suppresses scratches on the photoreceptor, improves the charging stability of the toner, and suppresses fogging. From the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner, the total amount of the carboxylic acid component and the alcohol component of polyester A is preferably 10 to 100 mol%, more preferably 20 to 90 mol%, still more preferably Is 20 to 80 mol%, more preferably 30 to 70 mol%, still more preferably 40 to 50 mol%.

  Furthermore, the content of the carboxylic acid compound having a furan ring reduces the amount of the free external additive, suppresses the photoreceptor scratches, improves the charging stability of the toner, suppresses fogging, and fixes the toner at a low temperature. From the viewpoint of improving the stability and heat-resistant storage stability, it is preferably 10 to 100 mol%, more preferably 20 to 100 mol%, still more preferably 30 to 100 mol%, and still more preferably 60 in the carboxylic acid component of polyester A. -100 mol%, more preferably 90-100 mol%, substantially more preferably 100 mol%.

  From the same viewpoint, the content of the furandicarboxylic acid compound is preferably 10 to 100 mol%, more preferably 20 to 100 mol%, still more preferably 30 to 100 mol%, and even more preferably in the carboxylic acid component of the polyester A. Preferably it is 60-100 mol%, More preferably, it is 90-100 mol%, and substantially 100 mol% is still more preferable.

  When using a carboxylic acid compound having a furan ring, an alcohol having a furan ring may not be used. In the case of using an alcohol having a furan ring, the content of the alcohol having a furan ring reduces the amount of free external additive, suppresses scratches on the photoreceptor, improves the charging stability of the toner, and suppresses fogging. From the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner, the alcohol component of polyester A is preferably 10 to 100 mol%, more preferably 20 to 90 mol%, still more preferably 20 to 80 mol%, and more. More preferably, it is 20-60 mol%.

  In addition, when the binder resin contains a plurality of polyesters A, the total amount of the carboxylic acid compound having a furan ring and the alcohol having a furan ring, the content of the carboxylic acid compound having a furan ring, the flange carboxylic acid compound The content of the alcohol and the content of the alcohol having a furan ring are determined by the sum of the product of the content of each compound in each polyester A and the weight fraction of each polyester A.

  As the alcohol component other than the alcohol having a furan ring, an aliphatic diol is preferable from the viewpoint of improving the low-temperature fixability of the toner. The carbon number of the aliphatic diol is preferably 2 to 10, more preferably 3 to 8, and further preferably 3 to 4 from the viewpoint of improving the low-temperature fixability of the toner.

  Aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 1,4-butenediol, neopentyl glycol, 2,3-butanediol, 2,3-pentanediol, 2,4-pentanediol, 2,3-hexanediol, 3,4- Examples include hexanediol, 2,4-hexanediol, and 2,5-hexanediol.

  Among these, together with the furan ring, an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferred from the viewpoint of further improving the heat resistant storage stability of the toner by further reducing the mobility of the resin. From the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner, the aliphatic diol preferably has 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 to 4 carbon atoms, and a specific preferred example. 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 2,3-pentane Examples include diol and 2,4-pentanediol, and 1,2-propanediol and 2,3-butanediol are preferable from the viewpoint of improving the heat-resistant storage stability of the toner.

  The content of the aliphatic diol is preferably 20 to 100 mol%, more preferably 50 to 100 mol% in the alcohol component other than the alcohol having a furan ring, from the viewpoint of improving the low-temperature fixability of the toner. Preferably it is 70-100 mol%, and 100 mol% is still more preferable substantially.

  The content of the aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferably 20 to 100 in an alcohol component other than an alcohol having a furan ring from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. The mol%, more preferably 50 to 100 mol%, still more preferably 70 to 100 mol%, and substantially 100 mol% is even more preferable.

  The content of the aliphatic diol is preferably 20 to 100 mol%, more preferably 50 to 100 mol%, and further preferably 70 to 100 mol% in the alcohol component from the viewpoint of improving the low-temperature fixability of the toner. And substantially 100 mol% is even more preferable.

  The content of the aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferably 20 to 100 mol%, more preferably 50% in the alcohol component from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. It is -100 mol%, More preferably, it is 70-100 mol%, and substantially 100 mol% is still more preferable.

  Examples of alcohol components other than these include aromatic alcohols from the viewpoint of improving the heat resistant storage stability of the toner.

  As the aromatic alcohol, from the viewpoint of improving the heat resistant storage stability of the toner, the formula (II):

(In the formula, R ¹ O and OR ¹ are oxyalkylene groups, R ¹ is an ethylene and / or propylene group, x and y indicate the number of added moles of alkylene oxide, and each is a positive number; The average value of the sum of y and y is preferably 1 to 16, more preferably 1 to 8, and even more preferably 1.5 to 4)
The alkylene oxide addition product of bisphenol A represented by these is mentioned.

  Specific examples of the alkylene oxide adduct of bisphenol A represented by the formula (II) include 2,2-bis (4-hydroxyphenyl) propane polyoxypropylene adduct and 2,2-bis (4-hydroxy). And an alkylene oxide adduct of bisphenol A such as a polyoxyethylene adduct of phenyl) propane.

  In the present invention, the alcohol component contains a trihydric or higher polyhydric alcohol, preferably glycerin, pentaerythritol, trimethylolpropane, more preferably glycerin, from the viewpoint of improving the printing durability and high temperature offset resistance of the toner. It is preferable. The content of the trihydric or higher polyhydric alcohol is preferably 1 to 35 mol%, more preferably 10 to 30 mol% in the alcohol component from the viewpoint of improving the printing durability and high temperature offset resistance of the toner. More preferred is ˜25 mol%.

  As a carboxylic acid component other than the carboxylic acid compound having a furan ring, an aromatic dicarboxylic acid compound, an aliphatic dicarboxylic acid compound, and a trivalent or higher polyvalent carboxylic acid compound may be contained. In the present invention, the term “carboxylic acid compound” is used generically, including derivatives such as carboxylic acid, acid anhydride, and alkyl (carbon number 1 to 6) ester.

  Examples of the aromatic dicarboxylic acid compound include phthalic acid, isophthalic acid, terephthalic acid, acid anhydrides thereof, and alkyl (carbon number 1 to 6) esters.

  Aliphatic dicarboxylic acid compounds include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, their acid anhydrides, alkyl (carbon Formula 1-6) ester etc. are mentioned.

  Examples of the trivalent or higher polyvalent carboxylic acid compounds include trimellitic acid, pyromellitic acid, acid anhydrides thereof, and alkyl (C1-6) esters.

  A monovalent alcohol having no furan ring in the alcohol component and a monovalent carboxylic acid compound having no furan ring in the carboxylic acid component are appropriately contained from the viewpoint of adjusting the softening point of the polyester. Also good.

  From the viewpoint of reducing the acid value of the polyester A, the equivalent ratio of the carboxylic acid component to the alcohol component (COOH group / OH group) in the polyester A is preferably 0.70 to 1.10, and more preferably 0.75 to 1.00.

  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, titanium compounds such as titanium diisopropylate bistriethanolamate, and the esterification cocatalyst includes gallic acid. Etc. The amount of the esterification catalyst used is preferably 0.01 to 1.5 parts by weight, more preferably 0.1 to 1.0 part by weight, based on 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component. The amount of esterification promoter used is preferably 0.001 to 0.5 parts by weight, more preferably 0.01 to 0.1 parts by weight, based on 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.

  The softening point of polyester A is preferably 90 to 155 ° C. from the viewpoint of improving the low-temperature fixability, high-temperature offset resistance and printing durability of the toner.

  When the binder resin contains a plurality of polyesters A, the sum of the products of the softening points of the polyesters A and the weight fractions of the polyesters A is preferably within the above range.

  The softening point of the 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.

  The glass transition temperature of the polyester A is preferably 50 to 85 ° C., and preferably 60 to 75 ° C., from the viewpoint of improving the low temperature fixability, heat resistant storage stability and printing durability of the toner.

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

  When the binder resin contains a plurality of polyesters A, the sum of the products of the glass transition temperatures of the polyesters A and the weight fractions of the polyesters A is preferably within the above range.

  The acid value of polyester A is preferably 30 mgKOH / g or less, from the viewpoint of improving the charging stability of the toner and suppressing fogging, and improving the heat resistant storage stability, high temperature offset resistance and printing durability of the toner, and 25 mgKOH / g or less is more preferable.

  The acid value of the 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.

  The binder resin used in the present invention preferably contains two or more polyesters having different softening points from the viewpoint of improving the low-temperature fixability and high-temperature offset resistance of the toner.

  The difference in softening point between polyester H having a higher softening point and polyester L having a lower softening point is preferably 10 ° C. or more, and 20 to 60 ° C. from the viewpoint of improving the low temperature fixability and high temperature offset resistance of the toner. Is more preferable, and 30 to 50 ° C. is more preferable.

  The softening point of the polyester H is preferably from 125 to 160 ° C, more preferably from 135 to 155 ° C, from the viewpoint of improving the low temperature fixability, high temperature offset resistance and printing durability of the toner.

  The softening point of the polyester L is preferably 90 to 125 ° C, more preferably 90 to 110 ° C, from the viewpoint of improving the low temperature fixability, high temperature offset resistance and heat resistant storage stability of the toner.

  The binder resin may contain a plurality of polyesters L and a plurality of polyesters H. When the binder resin contains a plurality of polyesters L and a plurality of polyesters H, the softening point of polyester L and the softening point of polyester H are the sum of products of the softening point of each polyester and the weight fraction of each polyester in the above range. It is preferable that

  The softening point of the polyester can be controlled by adjusting the types and composition ratios of the alcohol component and carboxylic acid component, the amount of catalyst, and the like, and selecting reaction conditions such as reaction temperature, reaction time, and reaction pressure.

  The total content of polyester H and polyester L is preferably 80% by weight or more, more preferably 90% by weight or more, and 95% by weight in the binder resin from the viewpoint of improving the low-temperature fixability and high-temperature offset resistance of the toner. % Or more is more preferable, and it is still more preferable that it is substantially 100% by weight.

  In the binder resin used in the present invention, at least one of polyester H and polyester L from the viewpoint of reducing the amount of free external additive and suppressing scratches on the photoreceptor, improving the charging stability of the toner, and suppressing fogging. Either one is preferably polyester A, and polyester L and polyester H are more preferably polyester A.

  The polyester other than polyester A is not particularly limited.

  The preferred embodiment of the alcohol component of the polyester other than polyester A is the same as the alcohol component other than the alcohol having a furan ring of polyester A, preferably an aliphatic diol, and an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom. Is more preferable.

  Further, from the viewpoint of improving the low-temperature fixability, high-temperature offset resistance and printing durability of the toner, it preferably contains a trihydric or higher polyhydric alcohol, and more preferably contains glycerin.

  Preferable contents in the alcohol component of the aliphatic diol, the aliphatic diol having a hydroxyl group bonded to a secondary carbon atom, and a trihydric or higher polyhydric alcohol are the same as those described in the polyester A.

  Further, as the carboxylic acid component of the polyester other than polyester A, an aromatic carboxylic acid compound is used from the viewpoint of improving the charging stability of the toner and suppressing fogging, and improving the heat resistant storage stability and printing durability of the toner. Specific examples include phthalic acid, isophthalic acid, terephthalic acid, acid anhydrides thereof, and alkyl (carbon number 1 to 6) esters.

  The content of the aromatic carboxylic acid compound in the carboxylic acid component is 20 to 100 mol% from the viewpoint of improving the charging stability of the toner and suppressing fogging, and improving the heat resistant storage stability and printing durability of the toner. More preferably, it is 50-100 mol%, More preferably, it is 80-100 mol%, and substantially 100 mol% is still more preferable.

  From the viewpoint of reducing the amount of free external additive and suppressing scratches on the photoreceptor, improving the charging stability of the toner, suppressing fogging, and improving the printing durability of the toner, the content of polyester A is reduced. In the binder resin, 30% by weight or more is preferable, 50% by weight or more is more preferable, 80% by weight or more is further preferable, and substantially 100% by weight is further more preferable.

  In addition, the total amount of carboxylic acid component and alcohol component having a furan ring in the total amount of carboxylic acid component and alcohol component of all polyesters in the binder resin reduces the amount of free external additives and damages on the photoreceptor. From the viewpoint of suppressing toner, improving the charging stability of the toner, suppressing fog and improving the printing durability of the toner, it is preferably 15 mol% or more, more preferably 20 mol% or more, more preferably 30 mol% or more. Is more preferable, and 40 mol% or more is more preferable. Further, from the viewpoint of improving the high temperature offset resistance of the toner, 80 mol% or less is preferable, 70 mol% or less is more preferable, 60 mol% or less is more preferable, and 50 mol% or less is even more preferable. When these viewpoints are put together, 15 to 80 mol% is preferable, 20 to 70 mol% is more preferable, 30 to 60 mol% is more preferable, and 40 to 50 mol% is still more preferable.

  The binder resin may contain other resins in addition to the polyesters other than the polyester A and the polyester A within the range in which the effects of the present invention are not impaired, but the total of the polyesters other than the polyester A and the polyester A The content reduces the amount of free external additives, suppresses photoconductor scratches, improves toner charging stability, suppresses fogging, toner low temperature fixability, heat resistant storage stability and printing durability. From the viewpoint of improvement, the binder resin content is preferably 80% by weight or more, more preferably 90% by weight or more, still more preferably 95% by weight or more, and still more preferably 100% by weight. Examples of other binder resins include vinyl resins, epoxy resins, polycarbonates, polyurethanes, and the like.

  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.

  The toner of the present invention may contain a colorant, a release agent, a charge control agent and the like in addition to the binder resin.

<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 . The content of the colorant in the toner is preferably 1 to 20 parts by weight, more preferably 2 to 10 parts by weight with respect to 100 parts by weight of the binder resin, from the viewpoint of improving the print density and fixability of the toner. More preferably, 3 to 8 parts by weight.

<Release agent>
As the release agent, low molecular weight polypropylene, low molecular weight polyethylene, low molecular weight polypropylene polyethylene copolymer, aliphatic hydrocarbon waxes such as microcrystalline wax, paraffin wax, and Fischer-Tropsch wax and their oxides, carnauba wax, Examples thereof include montan wax, sazol wax and their deoxidized wax, ester waxes such as fatty acid ester wax, fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts and the like. These may be used alone or in admixture of two or more.

  The melting point of the release agent is preferably 60 to 160 ° C., more preferably 60 to 150 ° C., from the viewpoint of improving the low-temperature fixability and high-temperature offset resistance of the toner.

  The content of the release agent is preferably 10 parts by weight or less, more preferably 8 parts by weight or less, and even more preferably 7 parts by weight or less from the viewpoint of improving the heat resistant storage stability of the toner with respect to 100 parts by weight of the binder resin. preferable. Further, from the viewpoint of improving the low-temperature fixability and high-temperature offset resistance of the toner, 0.5 part by weight or more is preferable, 1.0 part by weight or more is more preferable, and 1.5 part by weight or more is further preferable. Therefore, taking these viewpoints together, the content of the release agent is preferably 0.5 to 10 parts by weight, more preferably 1.0 to 8 parts by weight, and even more preferably 1.5 to 7 parts by weight. Further, from the viewpoint of oilless fixing of the toner, 2.0 parts by weight or more is preferable, 2.5 parts by weight or more is more preferable, and 3.0 parts by weight or more is more preferable. Therefore, taking these viewpoints together, the content of the release agent is preferably 2.0 to 10 parts by weight, more preferably 2.5 to 8 parts by weight, and even more preferably 3.0 to 7 parts by weight.

<Charge control agent>
As the charge control agent, either a negatively chargeable charge control agent or a positively chargeable charge control agent can be used.

  Examples of the negatively chargeable charge control agent include metal-containing azo dyes such as `` Bontron S-28 '' (manufactured by Orient Chemical Co., Ltd.), `` T-77 '' (manufactured by Hodogaya Chemical Co., Ltd.), `` Bontron S-34 '' ( (Orient Chemical Co., Ltd.), “Eisenspiron Black TRH” (Hodogaya Chemical Co., Ltd.), etc .; copper phthalocyanine dyes; metal complexes of alkyl derivatives of salicylic acid, such as “Bontron E-81”, “Bontron E-84” , “Bontron E-304” (manufactured by Orient Chemical Co., Ltd.), etc .; nitroimidazole derivatives; boron benzylate complexes, such as “LR-147” (manufactured by Nippon Carlit), etc .; Bontron F-21, Bontron E-89 (above, Orient Chemical Co., Ltd.), T-8 (Hodogaya Chemical Co., Ltd.), FCA-2521NJ, FCA-2508N (above, Fujikura Kasei Co., Ltd.).

  Examples of positively chargeable charge control agents include nigrosine dyes such as `` Bontron N-01 '', `` Bontron N-04 '', `` Bontron N-07 '' (above, manufactured by Orient Chemical Industries), `` CHUO CCA-3 '' ( Chuo Gosei Co., Ltd.), etc .; Triphenylmethane dyes containing tertiary amines as side chains; Quaternary ammonium salt compounds such as “Bontron P-51” (Orient Chemical Industries), “TP-415” And Tetsuya Chemical Industry Co., Ltd.), cetyltrimethylammonium bromide, “COPY CHARGE PXVP435” (manufactured by Clariant), and the like.

  The content of the charge control agent in the toner is preferably 0.5 to 5 parts by weight, and 1 to 3 parts by weight with respect to 100 parts by weight of the binder resin, from the viewpoint of improving the charging stability of the toner and suppressing fogging. Is more preferable.

<Other ingredients>
The toner obtained by the production method of the present invention further includes a magnetic powder, a fluidity improver, a conductivity modifier, an extender pigment, a reinforcing filler such as a fibrous substance, an antioxidant, and a cleaning property improver. And the like may be added as appropriate.

<Toner production method>
The toner of the present invention may be a toner obtained by any conventionally known method such as a melt-kneading method, an emulsion aggregation method, or a polymerization method. However, from the viewpoint of productivity, a pulverized toner by the melt-kneading method is used. preferable. Specifically, the components such as a binder resin, a colorant, a charge control agent, and a release agent are uniformly mixed with a mixer such as a Henschel mixer, then melt-kneaded, cooled, pulverized, and classified to give a toner. The mother particles can be produced and further mixed with an external additive to produce a toner. On the other hand, from the viewpoint of reducing the particle size of the toner, a toner by a polymerization method, an emulsion aggregation method or the like is preferable.

  Melting and kneading of the toner component can be performed using a known kneader such as a closed kneader, a single or twin screw extruder, and an open roll type kneader. From the viewpoint that the toner components such as the colorant and the charge control agent can be efficiently and highly dispersed in the binder resin without repeating kneading or using a dispersion aid, it is provided along the axial direction of the roll. It is preferable to use an open roll kneader equipped with a supply port and a kneaded product discharge port.

  The toner component is preferably mixed in advance using a Henschel mixer, a super mixer, etc., and then supplied to an open roll kneader. The toner component may be supplied from one supply port to the kneader, and a plurality of supply ports However, from the viewpoint of ease of operation and 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. The open roll type kneader is preferably a kneader having at least two rolls, and the open roll type kneader used in the present invention has two rolls having different peripheral speeds, that is, a peripheral speed. A kneading machine provided with two rolls, a high rotation side roll having a high speed and a low rotation side roll having a low peripheral speed. In the present invention, from the viewpoint of improving the dispersibility of toner components such as a colorant and a charge control agent in the binder resin, it is desirable that the high rotation side roll is a heating roll and the low rotation side roll is 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.

  The raw material charging side end temperature of the high rotation side roll is preferably 100 to 160 ° C, and the raw material charging side end temperature of the low rotation side roll is preferably 30 to 100 ° C.

  The high rotation side roll preferably has a set temperature difference between the raw material charging side end and the kneaded product discharge side end of 20 to 60 ° C. from the viewpoint of preventing detachment of the kneaded product from the roll. More preferably, it is 50 degreeC, and it is further more preferable that it is 30-50 degreeC. From the viewpoint of improving the dispersibility of the toner components such as the colorant and the charge control agent in the binder resin, the difference in the set temperature between the raw material input side end and the kneaded product discharge side end is 0. It is preferably ˜50 ° C., more preferably 0 to 40 ° C., and further preferably 0 to 20 ° C.

  The peripheral speed of the high rotation side roll is preferably 2 to 100 m / min, more preferably 10 to 75 m / min, and further preferably 25 to 50 m / min. The peripheral speed of the low-rotation side roll is preferably 1 to 90 m / min, more preferably 5 to 60 m / min, and even more preferably 15 to 30 m / min. 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, 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 in order to increase the kneading share, a plurality of roll surfaces are provided on the surface of each roll. It is preferable that the spiral groove is cut.

  The pulverization process may be performed in multiple stages. For example, the melt-kneaded product 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 collision plate jet mill, a fluidized bed jet mill, and a rotary mechanical mill. From the viewpoint of grinding efficiency, it is desirable to use a fluidized bed jet mill.

  Examples of the classifier used in the classification process include an air 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.

<External additive A>
In the present invention, the external additive A used as the external additive is hydrophobized from the viewpoint of reducing the amount of free external additive and suppressing damage to the photoreceptor, improving the charging stability of the toner, and suppressing fogging. Hydrophobic silica particles.

  The amount of carbon in external additive A reduces the amount of free external additive, suppresses photoconductor scratches, improves toner charging stability, suppresses fogging, and improves heat resistant storage stability of toner. From the viewpoint of achieving the above, it is 2.6% by weight or more, preferably 2.7% by weight or more, and more preferably 2.8% by weight or more. Also, from the viewpoint of reducing the amount of free external additives and suppressing scratches on the photoreceptor, improving the charging stability of the toner, suppressing fogging, and improving the printing durability of the toner, 6.0% by weight or less It is preferably 5.8% by weight or less, and more preferably 5.6% by weight or less. Taking these viewpoints together, the amount of carbon in the external additive A is 2.6 to 6.0% by weight, preferably 2.7 to 5.8% by weight, and more preferably 2.8 to 5.6% by weight. In addition, the amount of carbon in the external additive A can be obtained by a method described in Examples described later.

  The amount of carbon in the external additive A is derived from the hydrophobizing agent. As the hydrophobizing agent, organopolysiloxane is preferable from the viewpoint of increasing the carbon content, and among these, silicone oil is more preferable.

  The kinematic viscosity at 25 ° C. of the silicone oil is preferably 50 cSt or more from the viewpoint of suppressing the volatility and flammability of the silicone oil in the hydrophobizing treatment step, and preferably 10,000 cSt or less, and 500 cSt from the viewpoint of uniformly adhering to the silica surface. The following is more preferable.

  The average particle diameter of the external additive A is 20 nm or more, preferably 25 nm or more, and preferably 28 nm or more from the viewpoint of improving the charging stability of the toner, suppressing fogging, and improving the printing durability of the toner. More preferred. In addition, from the viewpoint of reducing the amount of free external additive and suppressing scratches on the photoreceptor, improving the charging stability of the toner, suppressing fogging, and improving the printing durability of the toner, it is 80 nm or less. 60 nm or less is preferable, and 50 nm or less is more preferable. Taking these viewpoints together, the average particle diameter of the external additive A is 20 to 80 nm, preferably 25 to 60 nm, and more preferably 28 to 50 nm. An average particle diameter can be calculated | required by the method described in the Example mentioned later.

  The content of the external additive A is 0.1 parts by weight or more with respect to 100 parts by weight of the toner base particles from the viewpoint of improving the charging stability of the toner, suppressing fogging, and improving the printing durability of the toner. Is preferably 0.2 parts by weight or more, more preferably 0.3 parts by weight or more. Further, from the viewpoint of reducing the amount of free external additive, suppressing damage to the photoreceptor, and not impairing the low temperature fixability of the toner, 4.0 parts by weight or less is preferable, 3.0 parts by weight or less is more preferable, and 1.5 parts by weight or less is preferable. More preferred is 1.0 part by weight or less. From these viewpoints, the content of the external additive A is preferably 0.1 to 4.0 parts by weight, more preferably 0.2 to 3.0 parts by weight, and further 0.2 to 1.5 parts by weight with respect to 100 parts by weight of the toner base particles. Preferably, 0.3 to 1.0 part by weight is even more preferable.

  The external additive A is obtained as follows, for example. The silica particles are put in a mixing tank, and a solution obtained by diluting a necessary amount of the hydrophobizing agent with a solvent in advance is sprayed while stirring at room temperature. After spraying, the inside of the tank is heated while stirring the silica particles, and further stirred. Then, it cools and external additive A is obtained.

<External additive B>
As the external additive, it is preferable to further contain hydrophobic silica particles (external additive B) having an average particle diameter of 6 nm or more and less than 20 nm.

  The average particle diameter of the external additive B is preferably 6 nm or more from the viewpoints of improving the charging stability of the toner and suppressing fogging, improving the printing durability of the toner, and improving the heat resistant storage stability of the toner. 7 nm or more is more preferable, and 8 nm or more is more preferable. In addition, from the viewpoint of reducing the amount of free external additive, suppressing damage to the photoreceptor and improving the charging stability of the toner, and suppressing fogging, it is preferably less than 20 nm, more preferably 18 nm or less, and further 17 nm or less. preferable. Taking these viewpoints together, the average particle diameter of the external additive B is preferably 6 nm or more and less than 20 nm, more preferably 7 to 18 nm, and even more preferably 8 to 17 nm. An average particle diameter can be calculated | required by the method described in the Example mentioned later.

<Difference in particle size between external additive A and external additive B>
The difference in the average particle size between the external additive A and the external additive B is that the amount of the free external additive is reduced, the photoreceptor scratches are suppressed, the charging stability of the toner is improved, and the fog is suppressed. From the viewpoint of improving printing durability and improving heat-resistant storage stability, the average particle size difference is preferably 10 nm or more, more preferably 10 to 70 nm, still more preferably 10 to 40 nm, and even more preferably 10 to 30 nm.

  The amount of carbon in the external additive B reduces the amount of free external additive, reduces the photoreceptor scratches, improves the charging stability of the toner, and suppresses fogging, and improves the printing durability of the toner. From the viewpoint of improving the heat-resistant storage stability of the toner, 0.3% by weight or more is preferable, 0.5% by weight or more is more preferable, and 0.7% by weight or more is more preferable. Further, from the viewpoint of improving the charging stability of the toner and suppressing fogging, from the viewpoint of improving the printing durability of the toner and from the viewpoint of improving the heat resistant storage stability, 6.0% by weight or less is preferable, and 5.0% by weight or less is more preferable. 4.0% by weight or less is more preferable. Taking these viewpoints together, the amount of carbon in the external additive B is preferably 0.3 to 6.0% by weight, more preferably 0.5 to 5.0% by weight, and even more preferably 0.7 to 4.0% by weight. The amount of carbon in the external additive B can be determined by the method described in the examples described later.

  The content of the external additive B is 100% by weight of the toner base particles from the viewpoint of improving the charging stability of the toner and suppressing fogging, improving the printing durability of the toner, and improving the heat resistant storage stability of the toner. Is preferably 0.2 parts by weight or more, more preferably 0.4 parts by weight or more, and still more preferably 0.6 parts by weight or more. In addition, from the viewpoint of reducing the amount of free external additives and suppressing scratches on the photoreceptor, improving the charging stability of the toner, suppressing fogging, and not impairing the low-temperature fixability of the toner, 4.0 weight or less is preferable. 3.0 parts by weight or less is more preferable, and 2.0 parts by weight or less is more preferable. Taking these viewpoints together, the content of the external additive B is preferably 0.2 to 4.0 parts by weight, more preferably 0.4 to 3.0 parts by weight, and further 0.6 to 2.0 parts by weight with respect to 100 parts by weight of the toner base particles. preferable.

<Contents of external additive A and external additive B>
The total content of the external additive A and the external additive B improves the charging stability of the toner, suppresses fogging, improves the printing durability of the toner, and improves the heat resistant storage stability of the toner. Therefore, the amount is preferably 0.3 parts by weight or more, more preferably 0.6 parts by weight or more, still more preferably 0.8 parts by weight or more, and still more preferably 1.0 parts by weight or more with respect to 100 parts by weight of the toner base particles. Also, from the viewpoint of reducing the amount of free external additives and suppressing scratches on the photoreceptor, improving the charging stability of the toner, suppressing fogging, and not impairing the low-temperature fixability of the toner, 6.0 wt. Preferably, 5.0 parts by weight or less is more preferable, 4.0 parts by weight or less is more preferable, and 3.5 parts by weight or less is more preferable. Taking these viewpoints together, the total content of the external additive A and the external additive B is preferably 0.3 to 6.0 parts by weight, more preferably 0.6 to 5.0 parts by weight with respect to 100 parts by weight of the toner base particles. 0.8-4.0 weight part is further more preferable, and 1.0-3.5 weight part is still more preferable.

<Ratio of external additive A / external additive B>
The weight ratio of the external additive A and the external additive B [external additive A / external additive B] improves the charging stability of the toner from the viewpoint of reducing the amount of free external additive and suppressing photoconductor scratches. From the viewpoint of suppressing fogging, 90/10 to 10/90 is preferable, 70/30 to 15/85 is more preferable, 60/40 to 20/80 is more preferable, and 40/60 to 20/80 is still more preferable preferable.

<Other external additives>
The toner of the present invention may appropriately contain external additives other than the external additive A and the external additive B to the extent that the effects of the present invention are not impaired. Examples of external additives other than external additive A and external additive B include inorganic fine particles such as alumina, titania, zirconia, tin oxide and zinc oxide, and organic fine particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles. Can be mentioned.

  The total content of external additive A and external additive B in the external additive is preferably 80% by weight or more, more preferably 90% by weight or more from the viewpoint of improving the charging stability of the toner and suppressing fogging. Preferably, 95% by weight or more is further preferable, and substantially 100% by weight is even more preferable.

<External treatment process>
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.

<Two-stage processing>
The external addition process can be performed in two stages. For example, the toner base particles and the external additive A are externally added by a high speed mixer such as a Henschel mixer or a super mixer, and after the external addition process, other external additives are put into the high speed mixer, and the external additive is removed again. Perform attachment processing. From the viewpoint of reducing the amount of free external additive and suppressing scratches on the photoreceptor, improving the charging stability of the toner, and suppressing fogging, a two-step process is preferred, and the amount of free external additive is reduced. From the viewpoint of reducing and suppressing photoconductor scratches, the external additive A is preferably used for the first stage treatment. Therefore, when using external additive A and external additive B as external additives,
Step 1: It is preferable to perform a step of mixing the toner base particles and the external additive A, and a step 2: a step of further mixing with the external additive B.

<Volume Median Particle Size of Toner Base Particle>
The volume median particle size (D ₅₀ ) of the toner base particles is preferably 3 to 15 μm, more preferably 4 to 12 μm, and even more preferably 6 to 9 μm, from the viewpoint of improving the image quality of the toner. 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. The volume median particle size of the toner is the same as the volume median particle size of the toner base particles.

  The toner of the present invention can be used in an image forming apparatus of a one-component development system or a two-component development system as a one-component development toner as it is or as a two-component development toner mixed with a carrier.

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

[Glass transition temperature of resin]
Using a differential scanning calorimeter (Q-100 Japan, Q-100), 0.01 to 0.02 g of sample was weighed into an aluminum pan, heated to 200 ° C, and the temperature drop rate was 10 Cooled to 0 ° C at 0 ° C / min. Next, the sample was 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 by 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 release agent]
Using a differential scanning calorimeter (DS Instruments Q20, manufactured by T.A. Instruments Japan Co., Ltd.), the temperature was increased to 200 ° C. at a temperature increase rate of 10 ° C./min, and from that temperature, the temperature decrease rate was 5 ° C./min. The sample cooled to 0 ° C. is heated to 180 ° C. at a heating rate of 10 ° C./min, and the highest endothermic peak temperature observed from the melting endothermic curve obtained there is taken as the melting point of the release agent.

[Average particle diameter of external additive]
The average particle diameter of the primary particles is obtained from the following formula.
Average particle diameter (nm) = 6 / (ρ × specific surface area (m ² / g)) × 1000
In the formula, ρ is the true specific gravity of the external additive, and the true specific gravity of silica is 2.2. The specific surface area is a BET specific surface area determined by a nitrogen adsorption method. In the case of a hydrophobized external additive, the specific surface area of the raw material before the hydrophobizing treatment is used. The above formula is assumed to be a sphere having a particle diameter R,
Specific surface area = S x (1 / m)
m (weight of particle) = 4/3 x π x (R / 2) ³ x true specific gravity
S (surface area) = 4π (R / 2) ²
Is an expression obtained from

[Carbon content of external additives]
Put 0.05g of external additive on a 12x9x60mm combustion boat, and cover it with 0.5g of tin powder as a combustion aid. Using a solid carbon analyzer (Horiba Seisakusho Co., Ltd .: Model EIA-110), set the measurement to AUTO, and set the combustion boat with external additives and combustion aids to a furnace temperature of 1200 ° C and a furnace pressure. Burn in an oxygen atmosphere for 120 seconds under the condition of 0.08Mpa and measure the carbon content.

[Kinematic viscosity of silicone oil at 25 ° C]
Put silicone oil in Ostwald viscometer and adjust the temperature in the system to 25 ℃ in a high temperature bath at 25 ℃. Thereafter, the falling speed of the silicone oil is measured to determine the kinematic viscosity.

[Volume-median particle diameter of toner (D ₅₀ )]
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 weight.
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 ).

[Examples of resin production]
The raw material monomer and esterification catalyst / co-catalyst shown in Table 1 are put into a 5-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser and a nitrogen introduction tube, and in a mantle heater in a nitrogen atmosphere. Then, the temperature was raised to 180 ° C. and then raised to 210 ° C. over 5 hours. Thereafter, it was confirmed that the reaction rate reached 95% or higher at 210 ° C., and the reaction was conducted at 40 kPa until the softening point shown in Table 1 was reached. Resins L-1, L-2, H-1, H-2 was obtained. The reaction rate means a value of the amount of produced reaction water / theoretical product water amount × 100.

[External additive production example]
External additive production example 1 [External additive A1]
100 parts by weight of silica stock with an average primary particle size of 40 nm is stirred in a mixing tank at 20 ° C, and under a nitrogen atmosphere, silicone oil (KF-96-100cs manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity at 25 ° C: 99cst) A solution obtained by diluting 8 parts by weight in 20 parts by weight of n-hexane solvent was sprayed. While stirring, the temperature in the tank was raised to 105 ° C. and maintained for 2 hours, and then cooled to 20 ° C. to obtain an external additive A1 shown in Table 2.

External additive production example 2 [External additive A2]
External additive A2 shown in Table 2 was obtained in the same manner as in External additive production example 1, except that the amount of silicone oil added was changed to 10 parts by weight.

External additive production example 3 [External additive A3]
External additive A3 shown in Table 2 was obtained in the same manner as in External additive production example 1, except that the amount of silicone oil added was changed to 20 parts by weight.

External additive production example 4 [External additive a6]
External additive a6 shown in Table 2 was obtained in the same manner as in External additive production example 1, except that the amount of silicone oil added was changed to 7 parts by weight.

External additive production example 5 [External additive a7]
External additive a7 shown in Table 2 was obtained in the same manner as in External additive production example 1 except that the amount of silicone oil added was changed to 23 parts by weight.

  Table 2 shows the physical properties of the external additives used in Examples and Comparative Examples.

[Example of toner production]
Examples 1-9 and Comparative Examples 1-4
The specified amount of binder resin shown in Table 3, the coloring agent “Mogul-L” (Cabot, carbon black) 4.0 parts by weight, the charge control agent “T-77” (Hodogaya Chemical Co., metal-containing azo dye) 2.0 parts by weight and 3.0 parts by weight of release agent “HNP-9” (manufactured by Nippon Seiki Co., Ltd., paraffin wax, melting point: 75 ° C.) were mixed for 1 minute using a Henschel mixer and then melt-kneaded under the conditions shown below. .

  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 135 ° C. on the raw material input side of the high rotation side roll and 90 ° C. on the kneaded material discharge side, 35 ° 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 4 kg / hour, and the average residence time was about 6 minutes.

After the kneaded product was cooled, it was coarsely pulverized to an average particle size of 1 mm using Rotoplex (manufactured by Toa Machinery Co., Ltd.). The resulting coarsely pulverized product is finely pulverized with a fluidized bed jet mill pulverizer AFG-200 (Alpine) and classified with a rotor classifier TTSP-100 (Alpine). Toner mother particles having a diameter (D ₅₀ ) of 7.0 μm were obtained.

  100 parts by weight of the obtained toner base particles and a predetermined amount of external additives shown in Table 3 are mixed for 3 minutes at 2100 r / min (circumferential speed 29 m / sec) with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). Got.

Example 10
A toner was obtained in the same manner as in Example 2 except that the external addition process was changed as follows.

  100 parts by weight of the obtained toner base particles and 1.0 part by weight of external additive A2 were mixed for 1 minute at 2100 r / min (circumferential speed 29 m / sec) with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). Next, 1.0 part by weight of external additive B1 was added and mixed for 2 minutes at 2100 r / min (circumferential speed 29 m / sec) with a Henschel mixer (manufactured by Mitsui Mining) to obtain a toner.

Comparative Examples 5 and 6
A toner was obtained in the same manner as in Example 10 except that the external additive A2 was changed to the external additive a5 in Comparative Example 5 and the external additive a7 in Comparative Example 6.

[Test Example 1: fogging]
The non-magnetic one-component developing device “MicroLine 5400” (manufactured by Oki Data Co., Ltd.) equipped with an organic photoreceptor (OPC) was mounted with the toner of each example and each comparative example, and 2,000 sheets were printed at a printing rate of 10% . After printing, the toner cartridge was replaced with a new one, and 100 sheets were printed at a printing rate of 10%. Next, 5 sheets of blank paper (printing rate 0%) are printed with the old and new toners mixed well. After that, the toner on the surface of the photoconductor is "Scotch (registered trademark) Mending Tape 810" (Sumitomo 3M). Manufactured, width: 18 mm), and the difference from the image density of the tape itself before the toner was adhered was measured. A color difference meter “X-Rite” (manufactured by X-Rite) was used for the measurement. As the value is smaller, the fog is suppressed.

[Test Example 2: Photoconductor scratches]
The toner of each example and each comparative example was mounted on the same apparatus as in Test Example 1, and 5000 sheets were printed at a printing rate of 5%. Thereafter, a new toner cartridge filled with each toner was replaced three times in the same manner, and 20,000 sheets were printed in total. After printing, the photoconductor unit was removed from the image drum, the photoconductor scratches on the photoconductor unit were observed, and the number of photoconductor scratches was counted.

  As is apparent from the results in Table 3, the toners of Examples 1 to 9 are less subject to fog and photoconductor damage than the toners of Comparative Examples 1 to 4.

  From the results shown in Table 4, it is found that the toner obtained by the two-stage treatment method in which the toner base particles are treated with the external additive A and subsequently treated with the external additive B has less fog and photoreceptor damage. Recognize.

  The electrostatic image developing toner of the present invention is suitably used for developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method and the like.

Claims (7)

An electrostatic charge image developing toner comprising toner base particles containing at least a binder resin and an external additive, wherein the binder resin contains polyester A having a furan ring, and the external additive is represented by the following formula ( A toner for developing an electrostatic charge image, comprising hydrophobic silica particles (external additive A) having an average particle size of 20 to 80 nm and a carbon content of 2.6 to 6.0% by weight obtained in 1).
Average particle diameter (nm) = 6 / (ρ × specific surface area (m ² / g)) × 1000 (1)
(In the formula, ρ is the true specific gravity of silica 2.2. The specific surface area is the BET specific surface area determined by the nitrogen adsorption method.) Polycondensation of the polyester A having a furan ring, an alcohol component containing an alcohol having a carboxylic acid component and / or a furan ring containing a carboxylic acid compound having at least furan ring as a raw material monomer used, the carboxylic acid component and alcohol component a Karadadea Ru polyester, claim 1 toner according.   The total amount of the carboxylic acid compound having a furan ring and the alcohol having a furan ring is 15 to 80 mol% in the total amount of the carboxylic acid component and the alcohol component of all the polyesters in the binder resin. 2. The toner for developing an electrostatic charge image according to 2.   The binder resin contains polyester H having a softening point of 125 to 160 ° C. and polyester L having a softening point of 90 to 125 ° C., and the difference in softening point between polyester H and polyester L is 10 ° C. or more. The toner for developing electrostatic images according to claim 1, wherein at least one of polyester H and polyester L is polyester A having a furan ring.   The electrostatic image developing toner according to claim 1, wherein the content of the polyester A having a furan ring is 30% by weight or more in the binder resin.   The external additive further contains hydrophobic silica particles (external additive B) having an average particle diameter of 6 nm or more and less than 20 nm, and the difference in average particle diameter between the external additive A and the external additive B is 10 nm or more. Item 6. The electrostatic image developing toner according to any one of Items 1 to 5. A method for producing an electrostatic charge image developing toner comprising toner base particles containing at least a binder resin and an external additive,
Step 1: a step of mixing toner base particles and external additive A, and step 2: a step of further mixing with external additive B,
The binder resin contains polyester A having a furan ring, and the external additive A is hydrophobic silica particles having an average particle size of 20 to 80 nm and a carbon content of 2.6 to 6.0% by weight obtained by the following formula (1). The external additive B is a hydrophobic silica particle having an average particle diameter of 6 nm or more and less than 20 nm obtained by the following formula (1), and the difference in average particle diameter between the external additive A and the external additive B is 10 nm or more. And a method for producing a toner for developing an electrostatic image.
Average particle diameter (nm) = 6 / (ρ × specific surface area (m ² / g)) × 1000 (1)
(In the formula, ρ is the true specific gravity of silica 2.2. The specific surface area is the BET specific surface area determined by the nitrogen adsorption method.)