JP6320750B2 - Toner for electrophotography - Google Patents

Description

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

  In recent years, with the promotion of miniaturization, higher speed and higher image quality of electrophotographic devices, and high reliability that does not impair the toner performance even in various environments, the durability of the toner and the high temperature and high humidity environment. There is a strong demand for improved developability.

In order to meet this requirement, for example, a positively chargeable toner comprising toner base particles containing at least a colorant and polyester as a binder resin and an external additive externally added to the toner base particles, The toner base particles have a BET specific surface area of 50 to 200 m ² / g whose surface is treated with a fluorine-based silane coupling agent as the external additive and a BET specific surface area of 50 A with surface modification with amino-modified silicone. It is disclosed that a positively chargeable toner containing ˜200 m ² / g of silica B provides a positively chargeable toner that provides a wide transferable region even under high temperature and high humidity. (See Patent Document 1)

  Also, a non-magnetic one-component developing toner used in a developing device in which a toner carrier is held in non-contact with an electrostatic latent image carrier, which contains a binder resin, a colorant, and an external additive. (A) Hydrophobic treatment with hydrophobic rutile titanium oxide having an average primary particle size of 5 to 30 nm, (b) Hexamethyldisilazane. And a hydrophobic silica having an average primary particle size of 6 to 14 nm and (c) a hydrophobic silica hydrophobized with silicone oil and having an average primary particle size of 20 to 100 nm. It is disclosed that the non-magnetic one-component developing toner provides a non-magnetic one-component developing toner having good transferability even in a high temperature and high humidity environment. (See Patent Document 2)

  On the other hand, the use of polylactic acid, which is a plant-derived raw material, is being studied for the purpose of reducing environmental burdens in toners that are electrophotographic developers.

  For example, an electrophotographic toner using a degradable polyester resin composed of poly α-hydroxycarboxylic acid and a resin containing other polyester resins as a binder resin has a good deinking property and whiteness. It is disclosed that it has excellent performance as an electrophotographic toner with good wax dispersibility, fixability, grindability, hot offset resistance and storage stability (see Patent Documents 3 and 4). .

JP 2010-122306 A JP 2004-258265 A JP 2003-323002 A JP 2002-55491 A

  However, the toner improved by the external additive as described in Patent Documents 1 and 2 is still insufficient to satisfy the developability and durability in a high temperature and high humidity environment at the same time. How to do it is required.

  The present invention relates to an electrophotographic toner excellent in developability (fogging suppression) and durability in a high-temperature and high-humidity environment, and a method for producing the same.

The present invention
[1] As a binder resin, a resin composition obtained by performing a transesterification reaction between polyester and polylactic acid;
A toner for electrophotography containing a hydrocarbon wax as a release agent, and [2] Step 1: a step of mixing polyester and polylactic acid at 140 ° C. or more and 200 ° C. or less and subjecting them to a transesterification reaction;
Step 2: a step of melt kneading the toner raw material mixture containing the resin composition obtained in Step 1 and a hydrocarbon wax, and Step 3: a step of pulverizing and classifying the melt kneaded product obtained in Step 2.
The method for producing an electrophotographic toner according to the above [1].

  The toner for electrophotography of the present invention is excellent in developability and durability under a high temperature and high humidity environment.

  The electrophotographic toner of the present invention is an electrophotographic toner containing, as a binder resin, a resin composition obtained by performing a transesterification reaction between polyester and polylactic acid, and a hydrocarbon wax as a release agent. It is a toner and has the effect of being excellent in developability and durability in a high temperature and high humidity environment.

The reason for such an effect is not clear, but is considered as follows.
In order to impart sufficient charge to the toner and exert its developing performance even in a high temperature and high humidity environment where the toner easily absorbs moisture in the air, it is necessary to improve the hydrophobicity of the toner particles. A wax having a high hydrophobicity such as a wax is poorly mixed with the polyester and deteriorates the durability of the toner. On the other hand, the toner of the present invention is characterized in that it contains a resin composition obtained by transesterification between polyester and polylactic acid. The polyester and polylactic acid of the reaction and the polyester-polylactic acid copolymer produced by the transesterification reaction between them are included. Polyester and polylactic acid are poorly mixed and remain separated even after melt-kneading and cannot be converted into a toner. However, when a polyester-polylactic acid copolymer is formed by mixing polyester and polylactic acid in advance and partially transesterifying between them, the mixing property of the polyester and polylactic acid in the mixture is improved, and the resin after the reaction The composition forms a high strength state in which polyester and polylactic acid are not separated and are densely mixed with each other. And, when the resin composition containing this polyester, polylactic acid and polyester-polylactic acid copolymer and a hydrocarbon wax are kneaded, the stirring share increases, so that the hydrocarbon wax may be dispersed in the binder resin. This facilitates the toner particles with reduced variation in the component composition among the toner particles. As a result, the development effect (control of fogging) in a high-temperature and high-humidity environment with a hydrocarbon wax, and durability with a high-strength resin composition containing polyester, polylactic acid, and polyester-polylactic acid copolymer It is considered that all the effects of improving the sex are exhibited.

  The resin composition is obtained by transesterification between polyester and polylactic acid.

  The polyester is preferably obtained by polycondensation of an alcohol component containing a divalent or higher alcohol and a carboxylic acid component containing a divalent or higher carboxylic acid compound.

  Examples of the alcohol component include aliphatic diols, alicyclic diols, aromatic diols, and the like. From the viewpoint of improving toner durability and suppressing fogging under high temperature and high humidity, aliphatic diols and aromatic diols. Group diols are preferred. Furthermore, an aliphatic diol is preferable from the viewpoint of improving the low-temperature fixability of the toner, and an aromatic diol is preferable from the viewpoint of improving the heat resistant storage stability of the toner.

  The carbon number of the aliphatic diol is preferably 2 or more, more preferably 3 or more, from the viewpoint of improving the low-temperature fixability of the toner. Further, from the viewpoint of improving the heat resistant storage stability of the toner, it is preferably 10 or less, more preferably 8 or less, still more preferably 6 or less, and still more preferably 4 or less.

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

  Among these, an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferable from the viewpoint of improving the heat resistant storage stability and low-temperature fixability of the toner. The carbon number of the aliphatic diol is preferably 3 or more from the viewpoint of improving the low-temperature fixability of the toner. Further, from the viewpoint of improving the heat resistant storage stability of the toner and from suppressing fogging under high temperature and high humidity, 6 or less is preferable, and 4 or less is more preferable. Specific preferred examples include 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 2,3-pentanediol, 2,4-pentanediol, and the like. From the viewpoint of improving toner durability, heat-resistant storage stability and low-temperature fixability, and suppressing fogging under high temperature and high humidity, 1 1,2-propanediol and 2,3-butanediol are preferred, and 1,2-propanediol is more preferred.

  The content of the aliphatic diol is preferably 50 mol% or more, more preferably 80 mol% or more in the alcohol component from the viewpoint of improving the low-temperature fixability of the toner and suppressing fogging under high temperature and high humidity. More preferably, it is 90 mol% or more, more preferably substantially 100 mol%. The content of the aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is from the viewpoint of improving the durability and heat-resistant storage stability of the toner, and from the viewpoint of suppressing fogging under high temperature and high humidity. Preferably it is 50 mol% or more, More preferably, it is 80 mol% or more, More preferably, it is 90 mol% or more, More preferably, it is substantially 100 mol%.

  Specific examples of the aromatic diol include the 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. The average value is preferably 1 or more and 16 or less, more preferably 1 or more and 8 or less, and still more preferably 1.5 or more and 4 or less.
An alkylene oxide adduct of bisphenol A represented by:

  The content of the aromatic diol is preferably 50 mol% or more, more preferably 80 mol% or more, more preferably 90 mol% or more, more preferably 90 mol% or more in the alcohol component from the viewpoint of improving the durability and heat-resistant storage stability of the toner. Preferably, it is substantially 100 mol%.

  Examples of other alcohol components include trivalent or higher alcohols such as glycerin.

  The carboxylic acid component of the polyester preferably contains an aromatic dicarboxylic acid compound from the viewpoint of improving the durability and heat-resistant storage stability of the toner.

  Examples of the aromatic dicarboxylic acid compound include phthalic acid, isophthalic acid, terephthalic acid, their anhydrides, and alkyl esters having 1 to 3 carbon atoms.

  The content of the aromatic dicarboxylic acid compound is preferably 50 mol% or more, more preferably 70 mol% or more, and even more preferably 85 mol%, from the viewpoint of improving the durability and heat-resistant storage stability of the toner in the carboxylic acid component. More preferably, it is 90 mol% or more.

  The carboxylic acid component of the polyester preferably contains a trivalent or higher carboxylic acid compound from the viewpoint of improving the durability and heat-resistant storage stability of the toner.

  Examples of the trivalent or higher carboxylic acid compound include, for example, a carboxylic acid having 4 or more and 30 or less carbon atoms, preferably 4 or more and 20 or less carbon atoms, more preferably 4 or more and 10 or less carbon atoms, and anhydrides thereof. And alkyl esters having 1 to 3 carbon atoms. The carbon number of the carboxylic acid compound does not include the carbon number of the alkyl group of the alkyl ester.

  Specific examples include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid), etc. From the viewpoint of improving the durability and heat-resistant storage stability of the toner, 1,2,4-benzenetricarboxylic acid (trimellitic acid) and its anhydride are preferable, and 1,2,4-benzenetricarboxylic acid anhydride ( Trimellitic anhydride) is more preferred.

  The content of the trivalent or higher carboxylic acid compound is preferably 5 mol% or more, more preferably 10 mol% or more, from the viewpoint of improving the durability and heat-resistant storage stability of the toner in the carboxylic acid component. Further, from the viewpoint of improving the low-temperature fixability of the toner, it is preferably 20 mol% or less, more preferably 15 mol% or less.

  Other carboxylic acid components include oxalic acid, malonic acid, maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, azelaic acid, an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms Aliphatic dicarboxylic acids such as succinic acid substituted with a group, cycloaliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid; rosins such as unpurified rosin and purified rosin; rosin modified with fumaric acid, maleic acid, acrylic acid or the like, These anhydrides, alkyl esters having 1 to 3 carbon atoms and the like can be mentioned.

  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 and the alcohol component in the polyester (COOH group / OH group) is preferably 0.70 or more, more preferably 0.80 or more, and preferably 1.15 or less. More preferably, it is 1.05 or less.

  The polycondensation reaction between the alcohol component and the carboxylic acid component is carried out in an inert gas atmosphere, if necessary, in the presence of an esterification catalyst, an esterification co-catalyst, a polymerization inhibitor, etc. at 130 ° C to 250 ° C. Can be done at temperature. 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 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, more preferably 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Preferably it is 1.0 mass part or less. Examples of the esterification promoter include gallic acid. The amount of the esterification promoter used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. More preferably, it is 0.1 parts by mass or less. Examples of the polymerization inhibitor include tert-butylcatechol. The amount of the polymerization inhibitor used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, more preferably 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Preferably it is 0.1 mass part or less.

  The softening point of the polyester is preferably 80 ° C. or higher, more preferably 90 ° C. or higher, and further preferably 100 ° C. or higher, from the viewpoint of improving the durability and heat-resistant storage stability of the toner. Further, from the viewpoint of improving the low-temperature fixability of the toner, it is preferably 160 ° C. or lower, more preferably 140 ° C. or lower.

  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 glass transition temperature of the polyester is preferably 50 ° C. or higher, more preferably 55 ° C. or higher, and further preferably 60 ° C. or higher from the viewpoint of improving the durability and heat-resistant storage stability of the toner. Further, from the viewpoint of improving the low-temperature fixability of the toner, it is preferably 90 ° C. or lower, more preferably 80 ° C. or lower, and further preferably 75 ° C. or lower.

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

  The acid value of the polyester is preferably 30 mgKOH / g or less, more preferably 20 mgKOH / g or less, from the viewpoint of improving the heat resistant storage stability and durability of the toner. Further, from the viewpoint of improving the productivity of polyester and improving the low-temperature fixability of the toner, it is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more, and further preferably 5 mgKOH / g or more.

  The acid value of the polyester can be controlled by adjusting the types and composition ratios 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.

  In the present invention, the polyester contains two or more kinds of polyesters having a softening point of preferably 5 ° C. or more, more preferably 10 ° C. or more, from the viewpoint of achieving both durability and heat-resistant storage stability of the toner and low-temperature fixability. It may be. Among the two or more kinds of polyesters, the softening point of the resin having the lowest softening point is preferably 80 ° C. or higher, more preferably 95 ° C. or higher, more preferably, from the viewpoint of improving the durability and heat-resistant storage stability of the toner. From the viewpoint of improving the low-temperature fixability of the toner, it is preferably 135 ° C. or lower, more preferably 120 ° C. or lower, and still more preferably 115 ° C. or lower. The softening point of the resin having the highest softening point is preferably 110 ° C. or higher, more preferably 120 ° C. or higher, more preferably 130 ° C. or higher, from the viewpoint of improving the durability and heat-resistant storage stability of the toner. From the viewpoint of improving the low-temperature fixability of the toner, the temperature is preferably 160 ° C. or lower, more preferably 150 ° C. or lower, and further preferably 140 ° C. or lower. When two or more types of polyester are contained, two types are preferable from the viewpoint of improving toner productivity.

  When two types of polyesters are used, the mass ratio of the high softening point polyester to the low softening point polyester (high softening point polyester / low softening point polyester) is preferably 1/9 to 9/1, more preferably 2 / It is 8 to 8/2, more preferably 5/5 to 8/2.

  The polylactic acid may be a homopolymer of lactic acid or a copolymer of lactic acid and another hydroxycarboxylic acid.

  Lactic acid that is a monomer of polylactic acid may be either L-lactic acid or D-lactic acid.

  Examples of other hydroxycarboxylic acids include hydroxycarboxylic acids having 3 to 8 carbon atoms, specifically, glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid, and the like. Can be mentioned.

  In the present invention, from the viewpoint of improving the durability of the toner, the content of lactic acid in the monomer constituting the polylactic acid is preferably 80 mol% or more, more preferably 90 mol% or more, and still more preferably substantially 100 mol%. Mol%. Therefore, polylactic acid is preferably a homopolymer of lactic acid rather than a copolymer of lactic acid and other hydroxycarboxylic acids.

  Polylactic acid can be produced according to a conventional method by polycondensation of lactic acid or polycondensation of lactic acid with another hydroxycarboxylic acid. In the present invention, polylactic acid that is commercially available, for example, “N-3000” is used. (Glass transition temperature: 63 ° C.), “N-4000” (glass transition temperature: 61 ° C.) (above, lactic acid homopolymer, manufactured by Nature Works) can also be used.

  In the present invention, the polylactic acid is preferably crystalline polylactic acid from the viewpoint of improving the durability of the toner and suppressing fogging under high temperature and high humidity. The crystallinity of polylactic acid is expressed by crystallinity. The crystallinity can be determined by the method described in the examples.

  The crystallinity of the crystalline polylactic acid is preferably 30% or more, more preferably 50% or more, and still more preferably 70, from the viewpoint of improving the durability of the toner and suppressing fogging at high temperature and high humidity. % Or more, more preferably 80% or more, and further preferably 90% or more.

  The number average molecular weight of the polylactic acid is preferably 60,000 or more, from the viewpoint of containing polylactic acid in the toner, improving the durability and heat-resistant storage stability of the toner, and suppressing fogging at high temperature and high humidity. Preferably it is 100,000 or more, More preferably, it is 150,000 or more, More preferably, it is 180,000 or more. Further, from the viewpoint of being able to be melt kneaded and obtaining a toner, from the viewpoint of improving the durability of the toner, and from the viewpoint of suppressing fogging under high temperature and high humidity, preferably 300,000 or less, more preferably 250,000 or less. More preferably, it is 200,000 or less.

  The weight average molecular weight of polylactic acid is preferably 60,000 or more from the viewpoint of containing polylactic acid in the toner, improving the durability and heat-resistant storage stability of the toner, and suppressing fogging at high temperature and high humidity. Preferably they are 100,000 or more, More preferably, it is 250,000 or more, More preferably, it is 400,000 or more, More preferably, it is 450,000 or more. Further, from the viewpoint of being able to be melt-kneaded and obtaining a toner, from the viewpoint of improving the durability of the toner, and from the viewpoint of suppressing fogging under high temperature and high humidity, preferably 700,000 or less, more preferably 550,000 or less. More preferably, it is 500,000 or less.

  The melting point of polylactic acid is preferably 155 ° C. or higher, more preferably 160 ° C. or higher, from the viewpoint of improving the durability and heat-resistant storage stability of the toner. Further, from the viewpoint of improving the low-temperature fixability of the toner, it is preferably 180 ° C. or lower, more preferably 175 ° C. or lower.

  When using two or more kinds of polyesters having different softening points as the binder resin, the polyester used for the transesterification reaction with polylactic acid is from the viewpoint of increasing the mixing property of the resin composition while avoiding an increase in viscosity during the transesterification reaction. Polyester having a low softening point is preferred.

  The weight ratio of polyester to polylactic acid (polyester / polylactic acid) used for the transesterification reaction is a viewpoint that causes the toner to contain polylactic acid, a viewpoint that improves the durability of the toner, and a viewpoint that suppresses fogging under high temperature and high humidity. Therefore, it is preferably 90/10 to 30/70, more preferably 80/20 to 35/65, still more preferably 70/30 to 40/60, still more preferably 60/40 to 45/55.

  As described above, the resin composition includes a polyester-polylactic acid copolymer in which a part of polylactic acid is converted by a transesterification reaction between polyester and polylactic acid.

  The transesterification reaction between polyester and polylactic acid can be performed by a method of mixing polyester and polylactic acid at 140 ° C. or more and 200 ° C. or less, which corresponds to Step 1 described later.

  The transesterification rate based on polylactic acid is preferably 0.1% or more, more preferably 1.0% or more, and still more preferably from the viewpoint of improving the durability of the toner and suppressing fogging under high temperature and high humidity. It is 3.0% or more, more preferably 7.0% or more. When the transesterification rate is 0.1% or more, the mixing property of polyester and polylactic acid is improved, and a resin composition having high strength can be obtained. Thus, the durability of the toner is improved, and the resin composition and hydrocarbon are improved. Since the dispersion of the hydrocarbon wax into the binder resin is improved by kneading the wax, the variation in the component composition among the toner particles is reduced, and the developability (suppression of fogging) in a high temperature and high humidity environment is reduced. improves. Further, from the viewpoint of improving the durability of the toner, it is preferably 35% or less, more preferably 30% or less, further preferably 25% or less, more preferably 20% or less, further preferably 15% or less, and further preferably 10%. % Or less. When the transesterification rate is 35% or less, in the resin composition, the component derived from polylactic acid is kept at a sufficient lactic acid chain length to exhibit the properties of polylactic acid, so that a high strength state is obtained, The durability of the toner is improved.

The transesterification rate based on polylactic acid can be estimated from the amount of change in integrated intensity between the carbonyl carbon-derived peak of the ester bond of polylactic acid and the carbonyl carbon-derived peak that appears after transesterification by the ¹³ C-NMR method. It can be obtained by the method described in the examples. The transesterification reaction in the present invention refers to a transesterification reaction that occurs between a component derived from polylactic acid and a component derived from polyester, and the transesterification reaction between components derived from polylactic acid and between components derived from polyester is Not included.

  The content of the resin composition is preferably 2% by mass or more, more preferably 5% by mass or more, still more preferably 8% by mass or more, and more preferably 10% from the viewpoint of improving the durability of the toner in the binder resin. It is at least 15% by mass, more preferably at least 15% by mass. Further, from the viewpoint of suppressing fogging under high temperature and high humidity, it is preferably 100% by mass or less, more preferably 80% by mass or less, further preferably 70% by mass or less, further preferably 60% by mass or less, and further preferably 50% or less. It is below mass%.

  The toner of the present invention may further contain a polyester as a binder resin in addition to the polyester used for the transesterification reaction. From the viewpoint of improving the mixing property of the resin composition while avoiding an increase in viscosity during the transesterification reaction, it is preferable to add the polyester having a high softening point separately from the transesterification reaction. When adding separately to the polyester used for the transesterification reaction and the polyester not used for the transesterification reaction, the mass ratio between the polyester used for the transesterification reaction and the polyester not used for the transesterification reaction (for the polyester / transesterification reaction used for the transesterification reaction) (Polyester not provided) is from the viewpoint of increasing the mixing property of the resin composition while avoiding the increase in viscosity during the transesterification reaction, from the viewpoint of improving the durability of the toner, and from the viewpoint of suppressing fogging at high temperature and high humidity. Preferably 90/10 to 1/99, more preferably 70/30 to 3/97, more preferably 60/40 to 5/95, still more preferably 50/50 to 10/90, still more preferably 45/55 to 10/90.

  In the present invention, the content of the resin composition, or when the polyester further contains, the total content of the resin composition and the polyester is preferably 90% by mass or more, more preferably 95% by mass or more in the binder resin. More preferably, it is substantially 100% by mass, and more preferably 100% by mass.

  The present invention contains a hydrocarbon wax as a release agent.

  Examples of the hydrocarbon wax in the present invention include polypropylene, polyethylene, polypropylene polyethylene copolymer, α-olefin polymer, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax. Among these, from the viewpoint of suppressing fogging under high temperature and high humidity, preferably polypropylene, α-olefin polymer, paraffin wax and Fischer-Tropsch wax, more preferably polypropylene, α-olefin polymer and paraffin. Wax, more preferably an α-olefin polymer.

  Among α-olefin polymers, a monomer containing an α-olefin having 22 to 30 carbon atoms is polymerized from the viewpoint of improving toner durability and charging stability and suppressing fogging at high temperature and high humidity. The α-olefin polymer obtained in this manner is preferable.

  The content of the α-olefin having 22 to 30 carbon atoms in the raw material monomer of the α-olefin polymer is from the viewpoint of suppressing the fogging under high temperature and high humidity by improving the durability and charging stability of the toner. Preferably it is 80 mol% or more, More preferably, it is 90 mol% or more, More preferably, it is 95 mol% or more, More preferably, it is substantially 100 mol%.

  Furthermore, the content of the α-olefin having 26 to 28 carbon atoms in the raw material monomer of the α-olefin polymer improves the durability and charge stability of the toner and suppresses fogging under high temperature and high humidity. Therefore, it is preferably 60 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more, still more preferably 97 mol% or more.

  Examples of the monomer containing an α-olefin having 22 to 30 carbon atoms in an amount of 80 mol% or more include a mixture of α-olefins having 18 or more carbon atoms, such as “Linearene 26+” (manufactured by Idemitsu Kosan Co., Ltd., mainly 26 or more carbon atoms). A mixture of α-olefins), “Linearene 2024” (manufactured by Idemitsu Kosan Co., Ltd., mainly a mixture of α-olefins having 18 to 26 carbon atoms), and the like, preferably in a hydrocarbon solvent at 50 ° C. or less. The monomer obtained by dissolving at a temperature of 15 to 50 ° C. and then extracting the uniform supernatant solution can be used.

  Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene and xylene, alicyclic hydrocarbon solvents such as cyclopentane and cyclohexane, aliphatic hydrocarbon solvents such as pentane and hexane, chloroform, and dichloromethane. Halogenated hydrocarbon solvents such as can be used. These solvents may be used alone or in combination of two or more.

  The α-olefin polymer can be synthesized by the method described in International Publication No. 2007/063885. Specifically, it is obtained by dissolving an α-olefin monomer in an aromatic hydrocarbon solvent such as toluene, adding a metallocene catalyst and hydrogen, and polymerizing at 0 to 180 ° C. under normal pressure to 10 MPa. It is done.

  The melt viscosity at 100 ° C. of the α-olefin polymer is preferably 100 mPa · s or more from the viewpoint of improving low-temperature fixability, durability and charge stability of the toner and suppressing fogging under high temperature and high humidity. Preferably 120 mPa · s or more, more preferably 150 mPa · s or more, more preferably 180 mPa · s or more, more preferably 190 mPa · s or more, and preferably 300 mPa · s or less, more preferably 250 mPa · s or less, More preferably, it is 220 mPa · s or less.

  The melting point of the hydrocarbon wax in the present invention is preferably 60 ° C. or more, more preferably 64 ° C., from the viewpoint of improving the heat-resistant storage stability, durability and charge stability of the toner and suppressing fogging under high temperature and high humidity. Above, more preferably 68 ° C. or more, more preferably 72 ° C. or more, and from the viewpoint of improving the low-temperature fixability of the toner, preferably 140 ° C. or less, more preferably 130 ° C. or less, more preferably 120 ° C. or less. More preferably, it is 100 ° C. or lower. The melting point of the hydrocarbon wax can be determined by the method described in Examples described later.

  The content of the hydrocarbon wax in the toner is based on 100 parts by weight of the binder resin from the viewpoint of improving the charging stability of the toner and suppressing fogging under high temperature and high humidity, and improving the low temperature fixability. The amount is preferably 0.5 parts by mass or more, more preferably 1.5 parts by mass or more, further preferably 2.5 parts by mass or more, and further preferably 4.0 parts by mass or more. Further, from the viewpoint of improving the durability of the toner, the amount is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and further preferably 8.0 parts by mass or less with respect to 100 parts by mass of the binder resin.

  The content of the hydrocarbon wax in the release agent is preferably 50% by mass or more, more preferably 60% by mass or more, from the viewpoint of improving the charging stability of the toner and suppressing fogging at high temperature and high humidity. More preferably, it is 70 mass% or more, More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more.

  Examples of release agents other than hydrocarbon waxes include carnauba wax, montan wax, sazol wax and ester waxes such as deoxidized wax thereof, fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, and the like. Can be mentioned.

The toner of the present invention is
Step 1: A step of mixing polyester and polylactic acid at 140 ° C. or higher and 200 ° C. or lower and subjecting them to a transesterification reaction,
Step 2: A step of melt kneading the toner raw material mixture containing the resin composition obtained in Step 1 and a hydrocarbon wax, and Step 3: a step of pulverizing and classifying the melt kneaded product obtained in Step 2 What is obtained by the method of including is preferable.

  In step 1, the temperature at which the polyester and polylactic acid are mixed is preferably 140 ° C. or higher, more preferably 150 ° C. or higher, and further preferably 160 ° C. or higher, from the viewpoint of causing transesterification. Further, from the viewpoint of improving the durability of the toner by adding polylactic acid to the toner and suppressing fogging under high temperature and high humidity, it is preferably 200 ° C. or less, more preferably 190 ° C. or less, and still more preferably 180 ° C. It is as follows.

  The mixing time in Step 1 depends on the mixing temperature and cannot be determined unconditionally. However, from the viewpoint of suppressing fogging under high temperature and high humidity, it is preferably 0.5 hours or more, more preferably 2 hours or more, and still more preferably. 4 hours or more. Further, from the viewpoint of improving the durability of the toner by adding polylactic acid to the toner and improving the productivity of the toner, it is preferably 15 hours or less, more preferably 13 hours or less, still more preferably 11 hours or less, and still more preferably Is 9 hours or less, more preferably 6 hours or less.

  The mass ratio of polyester and polylactic acid (polyester / polylactic acid) to be mixed in step 1 is a viewpoint that causes the toner to contain polylactic acid, a viewpoint that improves the durability of the toner, and a viewpoint that suppresses fogging under high temperature and high humidity. Therefore, it is preferably 90/10 to 30/70, more preferably 80/20 to 35/65, still more preferably 70/30 to 40/60, still more preferably 60/40 to 45/55.

The mixing method is
(A) A method in which polyester and polylactic acid are mixed and heated to melt,
(B) a method in which polyester is heated and melted in advance and mixed with polylactic acid, and
(C) Any of the methods in which polylactic acid is heated and melted in advance and mixed with the polyester may be used. From the viewpoint of improving the durability of the toner by adding polylactic acid to the toner, the method (B) is preferable. Therefore, it is preferable that the process 1 includes the following process 1-1 and process 1-2.
Step 1-1: Step of melting polyester Step 1-2: Step of mixing molten polyester and polylactic acid at 140 ° C. or higher and 200 ° C. or lower

  The resin composition obtained in step 1 is preferably cooled and pulverized to a particle size of about 0.01 to 2 mm, and then subjected to subsequent step 2.

  In step 2, the toner raw material mixture containing the resin composition obtained in step 1 and a hydrocarbon wax is melt-kneaded.

  In step 2, it is preferable to further melt and knead the polyester from the viewpoint of improving the durability of the toner and suppressing fogging under high temperature and high humidity.

  In step 2, it is preferable to melt and knead together additives such as a colorant, a charge control agent, and a release agent.

  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 and the like 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 is preferable from the viewpoint of improving the heat-resistant storage stability of the toner.

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

  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, 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, “Orient Chemical Co., Ltd.”, “T-77”, “Eisenspiron Black TRH” (above, 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.

  From the viewpoint of improving the charging stability of the toner, 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 with respect to 100 parts by mass of the binder resin, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less.

  In the present invention, additives such as magnetic powders, fluidity improvers, conductivity modifiers, reinforcing fillers such as fibrous substances, antioxidants, anti-aging agents, and cleanability improvers may be used as appropriate. Good.

  The melt-kneading can be performed using a known kneader such as a closed kneader, a single-screw or twin-screw extruder, and an open roll kneader. From the viewpoint of reducing the temperature at the time of melt kneading and improving the durability of the toner, and adding a colorant, a charge control agent, a release agent, etc. to the toner without repeating kneading or using a dispersion aid From the viewpoint of efficiently dispersing the agent and suppressing fogging under high temperature and high humidity, it is preferable to use an open roll type kneader.

  The toner raw material containing the resin composition, polyester, hydrocarbon wax, and additives such as a colorant and a charge control agent is mixed in advance with a mixer such as a Henschel mixer or a ball mill, and then supplied to the kneader. preferable.

  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, it is possible to improve the dispersibility in the toner of additives such as a colorant, a charge control agent, and a release agent and to suppress fogging under high temperature and high humidity, and to reduce mechanical force during melt kneading. From the viewpoint of suppressing heat generation and reducing the temperature during melt kneading and improving the durability of the toner, 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 locations through the heat medium having different temperatures.

  The temperature at the raw material input side of the high-rotation side roll reduces the mechanical force during melt-kneading, suppresses heat generation, improves the durability of the toner, and suppresses fogging under high temperature and high humidity. Therefore, the temperature is preferably 100 ° C. or higher and 160 ° C. or lower, and 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 durability of the toner, and from the viewpoint of suppressing fogging under high temperature and high humidity, it is preferably 20 ° C or higher, more preferably 30 ° C or higher, and preferably 60 ° C or lower, more Preferably it is 50 degrees C or less.

  In the low rotation side roll, the difference in the set temperature between the raw material input side end and the kneaded product discharge side end improves the dispersibility of the colorant, charge control agent, release agent and other additives in the toner. From the viewpoint of suppressing fogging under high humidity, reducing the mechanical force during melt kneading, suppressing heat generation, and improving the durability of the toner, it is preferably 0 ° C or higher, more preferably 10 ° C or higher. More preferably, it is 20 ° C. or higher, and preferably 50 ° C. or lower.

  The peripheral speed of the high-rotation side roll is the machine that improves the dispersibility of additives such as colorants, charge control agents, release agents, etc. in the toner and suppresses fogging under high temperature and high humidity. From the viewpoint of reducing force, suppressing heat generation, and improving the durability 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. Is 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, still more preferably 15 m / min or more, and preferably 90 m / min or less, more preferably Is 60 m / min or less, more preferably 30 m / min or less. 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, and the colorant, charge control agent, mold release From the viewpoint of improving the dispersibility of additives such as additives in the toner and suppressing fogging under high temperature and high humidity, reducing the mechanical force during melt kneading, suppressing heat generation, and improving the durability of the toner In view of the above, it is preferable that a plurality of spiral grooves are carved on the surface of each roll.

  The melt-kneaded product obtained in step 2 is cooled to such an extent that it can be crushed, and then subjected to the subsequent step 3.

  In step 3, the melt-kneaded product obtained in step 2 is 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.

  Examples of the classifier used in the classification process include a rotor classifier, 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 electrophotographic toner of the present invention, the toner particles (toner mother particles) obtained are further mixed with an external additive after the pulverization and classification steps from the viewpoint of improving the chargeability, fluidity, and transferability of the toner. It may be obtained by a method including steps. 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 volume average particle diameter of the external additive is preferably 10 nm or more, more preferably 15 nm or more, and preferably 250 nm or less, more preferably, from the viewpoint of improving the chargeability, fluidity, and transferability of the toner. 200 nm or less, more preferably 90 nm or less.

  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 processed with the external additive, from the viewpoint of improving the chargeability, fluidity, and transferability of the toner. More preferably, it is 0.1 parts by mass or more, further preferably 0.3 parts by mass or more, 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 electrophotographic 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. The thickness is preferably 15 μm or less, more preferably 12 μm or less, and still more 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. 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 electrophotographic toner of the present invention can be used as it is in a one-component development type or two-component development type image forming apparatus as a one-component development toner as it is or as a two-component development toner mixed with a carrier. it can.

  In relation to the above-described embodiment, the present invention further discloses the following electrophotographic toner and a method for producing the same.

<1> As a binder resin, a resin composition obtained by performing a transesterification reaction between polyester and polylactic acid;
An electrophotographic toner containing a hydrocarbon wax as a release agent.

<2> The electrophotographic toner according to <1>, wherein the alcohol component of the polyester preferably contains an aliphatic diol and / or an aromatic diol.
<3> The carbon number of the aliphatic diol is preferably 2 or more, more preferably 3 or more, preferably 10 or less, more preferably 8 or less, still more preferably 6 or less, still more preferably 4 or less, <2> The electrophotographic toner according to <2>.
<4> The electrophotographic toner according to <2> or <3>, wherein the aliphatic diol preferably contains an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom.
<5> The electrophotographic toner according to <4>, wherein the aliphatic diol having a hydroxyl group bonded to a secondary carbon atom has preferably 3 or more, preferably 6 or less, and more preferably 4 or less.
<6> The aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferably 1,2-propanediol and / or 2,3-butanediol, more preferably 1,2-propanediol, <4 > Or <5>.
<7> The content of the aliphatic diol in the alcohol component is preferably 50 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, and further preferably substantially 100 mol%. The toner for electrophotography according to any one of <2> to <6>.
<8> The content of the aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferably 50 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, in the alcohol component. The electrophotographic toner according to any one of <4> to <7>, which is preferably substantially 100 mol%.
<9> The electrophotographic toner according to any one of <1> to <8>, wherein the carboxylic acid component of the polyester preferably contains an aromatic dicarboxylic acid compound.
<10> The content of the aromatic dicarboxylic acid compound is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 85 mol% or more, further preferably 90 mol% or more in the carboxylic acid component. <9> The electrophotographic toner according to <9>.
<11> The electrophotographic toner according to any one of <1> to <10>, wherein the carboxylic acid component of the polyester preferably contains a trivalent or higher carboxylic acid compound.
<12> The trivalent or higher carboxylic acid compound is preferably 1,2,4-benzenetricarboxylic acid (trimellitic acid) and / or an anhydride thereof, and 1,2,4-benzenetricarboxylic acid anhydride (anhydrous trianhydride). The electrophotographic toner according to <11>, wherein merit acid is more preferable.
<13> The content of the trivalent or higher carboxylic acid compound is preferably 5 mol% or more, more preferably 10 mol% or more, preferably 20 mol% or less, more preferably 15 mol% in the carboxylic acid component. The toner for electrophotography according to <11> or <12>, which is the following.
<14> The softening point of the polyester is preferably 80 ° C. or higher, more preferably 90 ° C. or higher, further preferably 100 ° C. or higher, preferably 160 ° C. or lower, more preferably 140 ° C. or lower, <1> ~ <13> The electrophotographic toner according to any one of the above.
<15> The glass transition temperature of the polyester is preferably 50 ° C. or higher, more preferably 55 ° C. or higher, more preferably 60 ° C. or higher, preferably 90 ° C. or lower, more preferably 80 ° C. or lower, more preferably 75 ° C. The toner for electrophotography according to any one of <1> to <14>, which is as follows.
<16> The acid value of the polyester is preferably 30 mgKOH / g or less, more preferably 20 mgKOH / g or less, preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more, and even more preferably 5 mgKOH / g or more. The toner for electrophotography according to any one of <1> to <15>.
<17> The electrophotographic toner according to any one of <1> to <16>, wherein the polyester contains two or more kinds of polyesters having a softening point of preferably 5 ° C or higher, more preferably 10 ° C or higher.
<18> Among two or more kinds of polyesters, the softening point of the resin having the lowest softening point is preferably 80 ° C or higher, more preferably 95 ° C or higher, further preferably 105 ° C or higher, preferably 135 ° C or lower. More preferably, the softening point of the resin having the highest softening point is preferably 110 ° C. or higher, more preferably 120 ° C. or higher, and further preferably 130 ° C. or higher. The electrophotographic toner according to <17>, preferably 160 ° C. or lower, more preferably 150 ° C. or lower, and still more preferably 140 ° C. or lower.
<19> The polyester contains two types of polyester, and the mass ratio of the high softening point polyester to the low softening point polyester (high softening point polyester / low softening point polyester) is preferably 1/9 to 9/1. The electrophotographic toner according to <17> or <18>, preferably 2/8 to 8/2, more preferably 5/5 to 8/2.
<20> The content of lactic acid in the monomer constituting the polylactic acid is preferably 80 mol% or more, more preferably 90 mol% or more, and further preferably substantially 100 mol%, <1> to <19> The toner for electrophotography according to any one of the above.
<21> The electrophotographic toner according to any one of <1> to <20>, wherein the polylactic acid is preferably a homopolymer of lactic acid.
<22> The electrophotographic toner according to any one of <1> to <21>, wherein the polylactic acid is preferably crystalline polylactic acid.
<23> The crystallinity of the crystalline polylactic acid is preferably 30% or more, more preferably 50% or more, still more preferably 70% or more, still more preferably 80% or more, and further preferably 90% or more. <22> The toner for electrophotography described.
<24> The number average molecular weight of the polylactic acid is preferably 60,000 or more, more preferably 100,000 or more, further preferably 150,000 or more, more preferably 180,000 or more, preferably 300,000 or less, more preferably 250,000 or less, more preferably The electrophotographic toner according to any one of <1> to <23>, which is 200,000 or less.
<25> The polylactic acid has a weight average molecular weight of preferably 60,000 or more, more preferably 100,000 or more, further preferably 250,000 or more, further preferably 400,000 or more, further preferably 450,000 or more, preferably 700,000 or less, more preferably The electrophotographic toner according to any one of <1> to <24>, which is 550,000 or less, more preferably 500,000 or less.
<26> Melting | fusing point of polylactic acid becomes like this. Preferably it is 155 degreeC or more, More preferably, it is 160 degreeC or more, Preferably it is 180 degrees C or less, More preferably, it is 175 degrees C or less, Any one of said <1>-<25> Toner for electrophotography.
<27> The mass ratio of polyester to polylactic acid (polyester / polylactic acid) to be used for the transesterification reaction is preferably 90/10 to 30/70, more preferably 80/20 to 35/65, and still more preferably 70/30. The electrophotographic toner according to any one of <1> to <26>, which is ˜40 / 60, more preferably 60/40 to 45/55.
<28> The transesterification rate based on polylactic acid is preferably 0.1% or more, more preferably 1.0% or more, further preferably 3.0% or more, further preferably 7.0% or more, preferably 35% or less, more The electrophotography according to any one of <1> to <27>, preferably 30% or less, more preferably 25% or less, more preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less. Toner.
<29> The content of the resin composition in the binder resin is preferably 2% by mass or more, more preferably 5% by mass or more, further preferably 8% by mass or more, further preferably 10% by mass or more, and further preferably. 15% by mass or more, preferably 100% by mass or less, more preferably 80% by mass or less, further preferably 70% by mass or less, further preferably 60% by mass or less, and further preferably 50% by mass or less. The toner for electrophotography according to any one of 1> to <28>.
<30> In addition to the polyester used for the transesterification, the binder resin further contains a polyester, and the mass ratio of the polyester used for the transesterification and the polyester not used for the transesterification (polyester / used for the transesterification) The polyester not subjected to transesterification is preferably 90/10 to 1/99, more preferably 70/30 to 3/97, still more preferably 60/40 to 5/95, and still more preferably 50/5 to 10 The electrophotographic toner according to any one of <1> to <29>, which is / 90, more preferably 45/55 to 10/90.
<31> The content of the resin composition, or when the polyester is further contained, the total content of the resin composition and the polyester is preferably 90% by mass or more, more preferably 95% by mass or more, in the binder resin. The toner for electrophotography according to any one of <1> to <30>, further preferably substantially 100% by mass, and more preferably 100% by mass.
<32> The hydrocarbon wax preferably contains at least one selected from the group consisting of polypropylene, α-olefin polymer, paraffin wax and Fischer-Tropsch wax, more preferably polypropylene, α-olefin heavy. The electrophotographic toner according to any one of <1> to <31>, which contains at least one selected from the group consisting of a coalescence and a paraffin wax, and more preferably an α-olefin polymer.
<33> The electrophotographic toner according to <32>, wherein the α-olefin polymer is preferably an α-olefin polymer obtained by polymerizing a monomer containing an α-olefin having 22 to 30 carbon atoms. .
<34> The content of the α-olefin having 22 to 30 carbon atoms in the raw material monomer of the α-olefin polymer is preferably 80 mol% or more, more preferably 90 mol% or more, and still more preferably 95 mol%. As described above, the toner for electrophotography according to <33>, further preferably substantially 100 mol%.
<35> The content of the α-olefin having 26 to 28 carbon atoms in the raw material monomer of the α-olefin polymer is preferably 60 mol% or more, more preferably 80 mol% or more, and still more preferably 90 mol%. The toner for electrophotography according to the above <33> or <34>, which is more preferably 95 mol% or more, more preferably 97 mol% or more.
<36> The melting point of the hydrocarbon wax is preferably 60 ° C. or higher, more preferably 64 ° C. or higher, further preferably 68 ° C. or higher, more preferably 72 ° C. or higher, preferably 140 ° C. or lower, more preferably 130 ° C. The toner for electrophotography according to any one of <1> to <35>, wherein the toner is at most 0 ° C, more preferably at most 120 ° C, still more preferably at most 100 ° C.
<37> The content of the hydrocarbon wax in the toner is preferably 0.5 parts by mass or more, more preferably 1.5 parts by mass or more, further preferably 2.5 parts by mass or more, further preferably 100 parts by mass of the binder resin. Is at least 4.0 parts by mass, preferably at most 15 parts by mass, more preferably at most 10 parts by mass, even more preferably at most 8.0 parts by mass, according to any one of <1> to <36>.
<38> The content of the hydrocarbon wax in the release agent is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, and further preferably 80% by mass or more, and further preferably. The electrophotographic toner according to any one of <1> to <37>, wherein is 90% by mass or more.
<39> Step 1: A step in which polyester and polylactic acid are mixed at 140 ° C. or higher and 200 ° C. or lower and subjected to a transesterification reaction,
Step 2: a step of melt kneading the toner raw material mixture containing the resin composition obtained in Step 1 and a hydrocarbon wax, and Step 3: a step of pulverizing and classifying the melt kneaded product obtained in Step 2.
The method for producing an electrophotographic toner according to any one of <1> to <38>, comprising:
<40> In step 1, the temperature at which the polyester and polylactic acid are mixed is preferably 140 ° C. or higher, more preferably 150 ° C. or higher, still more preferably 160 ° C. or higher, preferably 200 ° C. or lower, more preferably 190 ° C. The method for producing an electrophotographic toner according to <39>, wherein the toner is more preferably 180 ° C. or lower.
<41> The mixing time in step 1 is preferably 0.5 hours or more, more preferably 2 hours or more, further preferably 4 hours or more, preferably 15 hours or less, more preferably 13 hours or less, and even more preferably 11 hours. The method for producing a toner for electrophotography according to <39> or <40>, further preferably 9 hours or less, more preferably 6 hours or less.
<42> The mass ratio of polyester and polylactic acid mixed in step 1 (polyester / polylactic acid) is preferably 90/10 to 30/70, more preferably 80/20 to 35/65, and still more preferably 70/30. The method for producing an electrophotographic toner according to any one of <39> to <41>, wherein the toner is 40/60, more preferably 60/40 to 45/55.
<43> Step 1
Any one of the above <39> to <42>, which preferably includes a step 1-1 of melting the polyester, and a step 1-2: mixing the melted polyester and polylactic acid at 140 ° C. or higher and 200 ° C. or lower. A method for producing the electrophotographic toner according to claim.
<44> The method for producing an electrophotographic toner according to any one of <39> to <43>, wherein in step 2, it is also preferable to melt knead polyester.
<45> In any one of the above items <39> to <44>, in Step 2, it is preferable to melt and knead together at least one additive selected from the group consisting of a colorant, a charge control agent, and a release agent. Manufacturing method of electrophotographic toner.
<46> The content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, preferably 20 parts by mass or less, more preferably 10 parts by mass with respect to 100 parts by mass of the binder resin. The method for producing a toner for electrophotography according to <45>, further preferably 5 parts by mass or less.
<47> The method for producing an electrophotographic toner according to any one of <39> to <46>, wherein an open roll kneader is preferably used for melt kneading.

[Polyester softening point]
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, 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.

[Glass transition temperature of polyester]
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 Cooled to 0 ° C at 10 ° C / min. Next, the sample is heated and measured at a heating rate of 10 ° C./min. 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 polyester]
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)).

[Polylactic acid crystallinity]
Using a powder X-ray diffraction (XRD) measuring device “Rigaku RINT 2500VC X-RAY diffractometer” (manufactured by Rigaku Corporation), X-ray source: Cu / Kα-radiation, tube voltage: 40 kV, tube current: 120 mA, measurement range: The peak intensity is measured by a continuous scanning method at a diffraction angle (2θ) of 5 to 40 ° and a scanning speed of 5.0 ° / min. The sample is crushed and then packed into a glass plate for measurement. From the obtained X-ray diffraction, the value calculated from the following formula is defined as the crystallinity of polylactic acid.

[Melting point of polylactic acid]
Using a differential scanning calorimeter “DSC Q20” (manufactured by TA Instruments Japan), 0.01-0.02 g of polylactic acid is weighed into an aluminum pan and heated from 20 ° C. to 200 ° C. at a heating rate of 10 ° C./min. The temperature is raised to ° C. The highest endothermic peak temperature observed from the obtained melting endothermic curve is defined as the melting point of polylactic acid.

[Average molecular weight of polylactic acid]
The molecular weight distribution is measured by gel permeation chromatography (GPC) method to determine the number average molecular weight (Mn) and the weight average molecular weight (Mw).
(1) Preparation of sample solution Dissolve the sample in chloroform at 25 ° C so that the concentration is 0.5 g / 100 ml. Next, this solution is filtered using a fluororesin filter “DISMIC-25JP” (manufactured by ADVANTEC) having a pore size of 0.2 μm to remove insoluble components to obtain a sample solution.
(2) Molecular weight measurement Using the following measuring device and analytical column, flow chloroform at 1 ml / min as the eluent and stabilize the column in a constant temperature bath at 40 ° C. Measurement is performed by injecting 100 μl of the sample solution. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. There are several types of monodisperse polystyrene (A-500 (Mw 5.0 × 10 ² ), A-1000 (Mw 1.01 × 10 ³ ), A-2500 (Mw 2.63 × 10 ³ ) manufactured by Tosoh Corporation) , A-5000 (Mw 5.97 × 10 ³ ), F-1 (Mw 1.02 × 10 ⁴ ), F-2 (Mw 1.81 × 10 ⁴ ), F-4 (Mw 3.97 × 10 ⁴ ), F-10 (Mw 9.64 × 10 ⁴ ), F-20 (Mw 1.90 × 10 ⁵ ), F-40 (Mw 4.27 × 10 ⁵ ), F-80 (Mw 7.06 × 10 ⁵ ), F-128 (Mw 1.09 × 10 ⁶ )) Is used as a standard sample.
Measuring device: HLC-8220GPC (manufactured by Tosoh Corporation)
Analytical column: GMHXL + G3000HXL (manufactured by Tosoh Corporation)

[Transesterification rate based on polylactic acid]
According to the following method, the amount of change in the carbonyl carbon of the ester bond of polylactic acid is quantified by ¹³ C-NMR method, and the transesterification rate based on polylactic acid is determined.
(1) Preparation of sample solution 0.15 g of the resin composition was dissolved in 1 g of chloroform-D (manufactured by Wako Pure Chemical Industries, Ltd., containing D, 99.8%, 0.05v / v% TMS) to obtain a sample solution (sample concentration) : 12% by mass).
(2) ¹³ C-NMR spectrum measurement The sample solution was placed in an NMR measurement tube (Nippon Seimitsu Chemical Co., Ltd., inner diameter 5 mm, length 210 mm) so that the amount of the solution was 5 cm from the bottom of the tube. A ¹³ C-NMR spectrum is measured under the conditions.
<Measurement conditions>
Equipment: 400MR (Agilent Technologies)
Magnetic field: 400MHz
Pulse program ： CARBON (s2pul)
Integration count: 20000
45 ° pulse: 4.35μs
Relaxation delay: 1s
Receiver gain: 60
TEMP: 25 ° C
(3) Calculation of transesterification rate
The integrated intensity of the peak (a) derived from the carbonyl carbon of the ester bond of polylactic acid observed at 169.5 ppm to 169.6 ppm and between the newly produced polyester and polylactic acid by the transesterification reaction observed at 168 ppm to 176 ppm The value calculated from the following formula from the integrated intensity of the peak (b) derived from the carbonyl carbon of the ester bond is defined as a transesterification rate based on polylactic acid.

[Melting point of release agent]
Using a differential scanning calorimeter “DSC Q20” (manufactured by TA Instruments Japan), 0.01 to 0.02 g of sample is weighed into an aluminum pan and heated to 200 ° C. at a heating rate of 10 ° C./min. Then, the temperature is cooled to −10 ° C. at a temperature lowering rate of 5 ° C./min. Next, the sample is heated to 180 ° C. at a heating rate of 10 ° C./min and measured. The maximum peak temperature of the endotherm observed from the melting endotherm curve thus obtained is taken as the melting point of the release agent.

[Melting viscosity of release agent]
Using a B-type viscometer (LVT manufactured by Japan ST Johnson) according to the Brookfield method, the measurement sample is heated and measured at 100 ° C., which is equal to or higher than the melting temperature of the release agent.

[Volume average particle diameter of external additive]
The volume 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. For example, 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. The above formula is assumed to be a sphere having a particle size 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

[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 ).

Polyester resin production example 1 [H-1, H-2, L-1]
Raw material monomers and esterification catalyst other than trimellitic anhydride shown in Table 1 were put into a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple. The temperature was raised and reacted for 6 hours. The temperature was further raised to 210 ° C., trimellitic anhydride was added, 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 to obtain a polyester. Table 1 shows the physical properties of the obtained polyester. The reaction rate means a value of the amount of produced reaction water / theoretical product water amount × 100.

Polyester resin production example 2 [L-2]
The raw material monomer and esterification catalyst shown in Table 1 were put into a 10 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 108 ° C. to obtain a polyester. Table 1 shows the physical properties of the obtained polyester.

[Α-Olefin Copolymer Production Example 1 (Releasing Agent 1)]
“Linearene 26+” (manufactured by Idemitsu Kosan Co., Ltd., mainly a mixture of α-olefins having 26 or more carbon atoms) is distilled under reduced pressure (0.1 kPa) to obtain monomer A which is a fraction having a distillation temperature of 200 to 300 ° C. It was. The composition ratio of this fraction was C (carbon number, the same applies hereinafter) 24: 1 mol%, C26: 59 mol%, C28: 38 mol%, C30: 2 mol%.
Next, after dehydrating the monomer A and toluene with dry nitrogen and activated alumina in a nitrogen atmosphere, a uniform supernatant solution was extracted at room temperature (25 ° C.), and the monomer A toluene solution (concentration 23) Mass%).
Into a Schlenk bottle with an internal volume of 200 ml that has been dried by heating, 50 ml of the resulting toluene solution of monomer A is added, 0.5 mmol of triisobutylaluminum, (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (3 -Trimethylsilylmethylindenyl) zirconium dichloride (2 μmol) and dimethylanilinium tetrakispentafluorophenylborate (8 μmol) were added, and 0.15 MPa of hydrogen was added at 85 ° C. for polymerization for 60 minutes. After the completion of the polymerization reaction, the precipitated reaction product is separated at room temperature (25 ° C.), washed with toluene and acetone, and then dried under heating and reduced pressure to produce an α-olefin copolymer (release agent). 1) was obtained. The release agent 1 obtained had a melting point of 76 ° C. and a melt viscosity at 100 ° C. of 200 mPa · s.

[Production Example of Resin Composition]
A predetermined amount of polyester shown in Table 2 is put into a 10-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, and heated to the temperature shown in Table 2 under a nitrogen atmosphere. The polyester was melted. Thereafter, a predetermined amount of polylactic acid shown in Table 2 was added and stirred for a predetermined time shown in Table 2. After cooling the obtained resin composition to 40 ° C. or less, it is coarsely pulverized by a Rotoplex (manufactured by Hosokawa Micron), and a polyester-polylactic acid copolymer having a particle size of 2 mm or less using a sieve having an opening of 2 mm. Resin compositions (RC-1 to RC-6) were obtained.

[Example of toner production]
Examples 1-15, Comparative Examples 1-3
Predetermined amounts of resin composition, polyester and mold release agent shown in Table 4, 3.0 parts by weight of a coloring agent “ECB-301” (manufactured by Dainichi Seika Co., Ltd., phthalocyanine blue (PB15: 3)) and a negatively chargeable charge control agent 1.0 part by mass of “Bontron E-84” (manufactured by Orient Chemical Co., Ltd.) was mixed for 1 minute using a Henschel mixer (manufactured by Nippon Coke Kogyo Co., Ltd.), and then melt-kneaded under the conditions shown below.

  A continuous two-open roll kneader “NIDEX” (manufactured by Nippon Coke Industries, 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, 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.

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

  100 parts by mass of the obtained toner base particles, 1.0 part by mass of hydrophobic silica “R972” (manufactured by Nippon Aerosil Co., Ltd., volume average particle size: 16 nm), hydrophobic silica “NAX50” (manufactured by Nippon Aerosil Co., Ltd., volume average particle size) : 30 nm) 1.0 part by mass was mixed for 3 minutes at 2100 r / min (circumferential speed 29 m / sec) with a Henschel mixer (Nihon Coke Kogyo Co., Ltd.) to obtain a toner.

Example 16
In Example 1, the toner raw materials were mixed with a Henschel mixer and then melt-kneaded under the following conditions.

A co-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 supply speed 10kg / hr (mixture supply rate per unit cross section of shaft 1.42kg / hr)・ Cm ² ).
The obtained melt-kneaded product was coarsely pulverized and finely pulverized in the same manner as in Example 1 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 1 to obtain a toner.

Comparative Example 4
Predetermined amounts of polyester, polylactic acid and a release agent shown in Table 4 and a coloring agent “ECB-301” (manufactured by Dainichi Seika Co., Ltd., phthalocyanine blue (PB15: 3)) 4.0 parts by mass and a negatively chargeable charge control agent “ After mixing 0.5 part by weight of “Bontron E-304” (manufactured by Orient Chemical Co., Ltd.) for 1 minute using a Henschel mixer, the mixture was melt-kneaded in the same manner as in Example 1 and pulverized and classified. The polyester and polylactic acid were not compatible with each other and separated, and were not usable as a toner.

Comparative Example 5
A predetermined amount of polyester and polylactic acid shown in Table 4 were mixed with a Henschel mixer, and then melt-kneaded under the following conditions.

A co-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 160 ° C, shaft rotation speed 200r / min (shaft rotation peripheral speed 0.30m / sec), mixture supply speed 10kg / hr (mixture supply rate per unit cross section of shaft 1.42kg / hr)・ Cm ² ). The obtained kneaded product was cooled to 40 ° C. or lower and then coarsely pulverized with a Rotoplex (manufactured by Hosokawa Micron) to obtain a kneaded composition having a particle size of 2 mm or less using a sieve having an opening of 2 mm.

  100 parts by mass of the obtained kneaded composition, 6 parts by mass of release agent W-16, 3.0 parts by mass of colorant “ECB-301” (manufactured by Dainichi Seika Co., Ltd., phthalocyanine blue (PB15: 3)), and negative After charging 1.0 part by mass of a chargeable charge control agent “Bontron E-84” (manufactured by Orient Chemical Co., Ltd.) for 1 minute using a Henschel mixer, the mixture was melt-kneaded in the same manner as in Example 1.

  The obtained melt-kneaded product was coarsely pulverized and finely pulverized in the same manner as in Example 1 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 1 to obtain a toner.

  Table 3 shows release agents used in Examples and Comparative Examples.

[Test Example 1: High-temperature and high-humidity fogging]
After mounting the toner on the non-magnetic one-component developing device “OKI MICROLINE 5400” (Oki Data) and leaving it in a 30 ° C / 80% RH environment for 6 hours, the image with a standard development bias of 1% printing 10 sheets were printed. The whiteness before and after printing was measured using an image density measuring device “GRETAG SPM50” (manufactured by GRETAG), and the average value of the difference in whiteness (ΔE) before and after printing was used as an index of fog on the paper. The smaller the value, the lower the occurrence of fog. The results are shown in Table 4.

[Test Example 2: Durability]
Toner can be mounted on an ID cartridge “ML-5400, Image Drum” (Oki Data Co., Ltd.) modified so that the developing roller can be seen visually, at a temperature of 30 ° C and a humidity of 50%. An idling operation was performed at (equivalent to 36 ppm), and developing roller filming was visually observed. The time until filming occurred was used as an index of durability. It shows that it is excellent in durability, so that the time until development roller filming occurs is long. The results are shown in Table 4.

  From the above results, the toners of Examples 1 to 16 are superior to the toners of Comparative Examples 1 to 5 in both developability (fogging suppression) and durability in a high temperature and high humidity environment. I understand.

  The toner for electrophotography 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 (8)

As a binder resin, a resin composition obtained by performing a transesterification reaction between polyester and polylactic acid having a weight average molecular weight of 450,000 or more and 700,000 or less ,
An electrophotographic toner containing a hydrocarbon wax as a release agent.   2. The electrophotographic toner according to claim 1, wherein the transesterification rate based on polylactic acid is 0.1% or more and 35% or less.   The electrophotographic toner according to claim 1, wherein the polylactic acid is crystalline polylactic acid.   The electrophotographic toner according to claim 1, wherein the content of the resin composition is 2% by mass or more and 100% by mass or less in the binder resin.   The toner for electrophotography according to any one of claims 1 to 4, wherein a mass ratio of polyester to polylactic acid (polyester / polylactic acid) subjected to transesterification is 90/10 to 30/70.   6. The electron according to claim 1, wherein the polyester is obtained by polycondensation of an alcohol component and a carboxylic acid component, and the alcohol component contains an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom. Toner for photography.   The electrophotography according to any one of claims 1 to 6, wherein the hydrocarbon wax is an α-olefin polymer obtained by polymerizing a monomer containing 80 mol% or more of an α-olefin having 22 to 30 carbon atoms. Toner. Step 1: A step of mixing a polyester and a polylactic acid having a weight average molecular weight of 450,000 or more and 700,000 or less at 140 ° C. or more and 200 ° C. or less to be subjected to a transesterification reaction,
Step 2: a step of melt kneading the toner raw material mixture containing the resin composition obtained in Step 1 and a hydrocarbon wax, and Step 3: a step of pulverizing and classifying the melt kneaded product obtained in Step 2.
The method for producing an electrophotographic toner according to claim 1, comprising: