JP6320749B2 - 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, there has been a strong demand for improvement in low-temperature fixability of toners from the viewpoint of energy saving, that is, reduction of energy consumption in the fixing process as well as promotion of downsizing, high speed and high image quality of electrophotographic apparatuses. In order to meet this requirement, a toner using a crystalline resin and an amorphous resin as a binder resin has been proposed. However, a toner using a crystalline resin and an amorphous resin improves the low-temperature fixability but tends to decrease the toner strength. As a result, with increasing speed and miniaturization, when more mechanical or thermal stress is applied, problems related to reduction in glossiness and durability are generated.

  In order to solve such a problem, for example, a toner production method including a melt-kneading step, a heat treatment step, a pulverization step, and a classification step of a raw material containing two or more types of polyester, The toner contains at least one amorphous polyester, and the heat treatment step is carried out at a temperature and time satisfying a specific relational expression, so that it has excellent low-temperature fixability and good pulverization. It has been proposed that a toner having excellent properties and storage stability can be produced (see Patent Document 1).

  Further, the toner includes a binder resin composed of a crystalline resin and an amorphous resin, and a colorant, wherein the crystalline resin includes an alcohol component and an aromatic component containing an aliphatic diol having 2 to 10 carbon atoms. Contains a composite resin comprising a condensation polymerization resin component obtained by condensation polymerization of a carboxylic acid component containing a dicarboxylic acid compound and a styrene resin component, and the amorphous resin contains at least 60 mol% of an aliphatic diol. A toner containing polyester obtained from an alcohol component and a carboxylic acid component is excellent in low-temperature fixability and storage stability, image density unevenness is suppressed, and the heat treatment process time is short, resulting in excellent productivity. (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 2005-308995 A JP 2012-8529 A JP 2003-323002 A JP 2002-55491 A

  However, these toners are still insufficient to satisfy all of the low-temperature fixability, glossiness and durability at the same time.

  The present invention relates to an electrophotographic toner excellent in low-temperature fixability, gloss (gloss), and durability, and a method for producing the same.

The present invention
[1] As a binder resin,
Crystalline polyester,
An electrophotographic toner containing a resin composition obtained by subjecting an amorphous polyester and polylactic acid to a transesterification reaction, and [2] Step 1: 140 ° C. or more of amorphous polyester and polylactic acid A process of mixing at 200 ° C. or lower and subjecting 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 the crystalline polyester, 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 low-temperature fixability, gloss (gloss), and durability.

  The electrophotographic toner of the present invention is an electrophotographic toner containing, as a binder resin, a resin composition obtained by transesterification between an amorphous polyester and polylactic acid, and a crystalline polyester. In addition, it has the effect of being excellent in low-temperature fixability, gloss (gloss), and durability.

  The reason for such an effect is not clear, but is considered as follows. By using a crystalline polyester and an amorphous polyester in combination with the binder resin, low-temperature fixability and gloss (gloss) can be improved. It is difficult to mix, and the crystalline polyester is localized and durability is deteriorated. On the other hand, the toner of the present invention is characterized in that it contains a resin composition obtained by carrying out a transesterification reaction between amorphous polyester and polylactic acid. Includes an unreacted amorphous polyester and polylactic acid, and a polyester-polylactic acid copolymer formed by a transesterification reaction therebetween. Amorphous polyester and polylactic acid are poorly mixed and remain separated even after melt-kneading and cannot be converted into a toner. However, when an amorphous polyester and polylactic acid are mixed in advance and partially transesterified to form a polyester-polylactic acid copolymer, the mixing of the amorphous polyester and polylactic acid in the mixture is improved. The resin composition after the reaction does not have a separation state between the amorphous polyester and the polylactic acid, and forms a high strength state in which the resin composition is densely mixed with each other. Then, when the crystalline polyester and the resin composition containing the amorphous polyester, polylactic acid, and polyester-polylactic acid copolymer are kneaded, the stirring share increases, so that the crystalline polyester maintains the crystallinity and is a binder resin. It becomes easy to disperse into the toner particles, resulting in toner particles with reduced variation in component composition among the toner particles. As a result, the low-temperature fixability and the glossiness (gloss) are improved by the crystalline polyester, and the durability by the high-strength resin composition containing the amorphous polyester, polylactic acid, and polyester-polylactic acid copolymer is improved. All of the improvement effects are considered to be exhibited.

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

  The crystalline 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.

  The alcohol component of the crystalline polyester preferably contains an aliphatic diol from the viewpoint of enhancing the crystallinity of the polyester and improving the low-temperature fixability and gloss of the toner. The number of carbon atoms of the aliphatic diol is preferably 4 or more, more preferably 6 or more, and still more preferably 9 or more, from the viewpoint of enhancing the crystallinity of the polyester. The carbon number is preferably 14 or less, more preferably 12 or less, from the viewpoint of improving the low-temperature fixability and gloss of the toner. Further, from the viewpoint of improving the durability of the toner, the aliphatic diol preferably has 10 carbon atoms.

  Examples of the aliphatic diol having 4 to 14 carbon atoms include 1,4-butanediol, 1,4-butenediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 1,7-heptane. Diol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, etc. From the viewpoint of improving low-temperature fixability and gloss of the toner, α, ω-linear alkanediol is preferable, and 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9- Nonanediol, 1,10-decanediol, and 1,12-dodecanediol are more preferable, and 1,6-hexanediol, 1,8-octanediol, and 1,10-decanediol are more preferable. Further, 1,10-decanediol is preferable from the viewpoint of improving the durability of the toner.

  The content of the aliphatic diol having 4 to 14 carbon atoms is preferably 70 mol% or more, more preferably 90 mol% or more, and still more preferably 95 mol% or more in the alcohol component from the viewpoint of enhancing the crystallinity of the polyester. More preferably, it is substantially 100 mol%, more preferably 100 mol%. Further, the proportion of one kind of the aliphatic diol having 4 to 14 carbon atoms in the alcohol component is preferably 50 mol% or more, more preferably 70 mol%, still more preferably 90 mol% or more, further preferably It is substantially 100 mol%.

  The alcohol component may contain a polyhydric alcohol component other than an aliphatic diol having 4 to 14 carbon atoms, and an aliphatic diol such as ethylene glycol, 1,2-propanediol, or 1,3-propanediol. Aromatic diols such as bisphenol A alkylene oxide adducts such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adducts; 3 such as glycerin, pentaerythritol, trimethylolpropane, sorbitol, 1,4-sorbitan Alcohols having a value higher than that are listed.

  The carboxylic acid component of the crystalline polyester preferably contains an aromatic dicarboxylic acid compound or an aliphatic dicarboxylic acid compound from the viewpoint of enhancing the crystallinity of the polyester and improving the low-temperature fixability and gloss of the toner.

  As the aromatic dicarboxylic acid compound, those having 8 to 12 carbon atoms are preferable, and at least one selected from the group consisting of phthalic acid compounds, isophthalic acid compounds and terephthalic acid compounds is more preferable, phthalic acid, isophthalic acid and More preferred is at least one selected from the group consisting of terephthalic acid.

  In the present invention, the dicarboxylic acid compound refers to dicarboxylic acid, its anhydride, and alkyl ester having 1 to 3 carbon atoms. Among these, dicarboxylic acid is preferable. Further, the preferable carbon number is the carbon number including the dicarboxylic acid part of the dicarboxylic acid compound, and does not include the carbon number (1 or more and 3 or less) of the alkyl group of the alkyl ester part.

  The number of carbon atoms of the aliphatic dicarboxylic acid compound is preferably 4 or more, more preferably 6 or more, and still more preferably 9 or more, from the viewpoint of enhancing the crystallinity of the polyester. The carbon number is preferably 14 or less, more preferably 12 or less, from the viewpoint of improving the low-temperature fixability and gloss of the toner. Further, from the viewpoint of improving the durability of the toner, the aliphatic dicarboxylic acid preferably has 10 carbon atoms.

  Examples of the aliphatic dicarboxylic acid compound having 4 to 14 carbon atoms include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, decanedioic acid, dodecanedioic acid, Examples include tetradecanedioic acid, and from the viewpoint of improving toner durability, at least one selected from the group consisting of fumaric acid, succinic acid, adipic acid, sebacic acid, decanedioic acid, and dodecanedioic acid is preferable. . Further, sebacic acid is preferable from the viewpoint of improving the durability of the toner.

  The content of the aromatic dicarboxylic acid compound having 8 to 12 carbon atoms and the aliphatic dicarboxylic acid compound having 4 to 14 carbon atoms is preferably 70 mol% or more in the carboxylic acid component from the viewpoint of enhancing the crystallinity of the polyester. More preferably, it is 90 mol% or more, more preferably 95 mol% or more, still more preferably substantially 100 mol%, still more preferably 100 mol%.

  The carboxylic acid component may contain a polyvalent carboxylic acid compound other than an aromatic dicarboxylic acid compound having 8 to 12 carbon atoms and an aliphatic dicarboxylic acid compound having 4 to 14 carbon atoms. Examples of the acid compound include oxalic acid, malonic acid, aliphatic dicarboxylic acids such as succinic acid substituted with an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms; fats such as cyclohexanedicarboxylic acid Cyclic dicarboxylic acids; trimellitic acid, 2,5,7-naphthalenetricarboxylic acid, trivalent or higher aromatic polycarboxylic acids such as pyromellitic acid, and anhydrides thereof, alkyl esters having 1 to 3 carbon atoms Etc.

  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 molecular weight.

  In the total number of moles of the carboxylic acid component and the alcohol component, an aromatic dicarboxylic acid compound having 8 to 12 carbon atoms, an aliphatic dicarboxylic acid compound having 4 to 14 carbon atoms, and an aliphatic diol having 4 to 14 carbon atoms From the viewpoint of enhancing the crystallinity of polyester, the total number of moles is preferably 80 mole% or more, more preferably 90 mole% or more, still more preferably 95 mole% or more, still more preferably substantially 100 mole%, still more preferably. Is 100 mol%.

  From the viewpoint of adjusting the softening point of the polyester, the equivalent ratio of the carboxylic acid component and the alcohol component of the crystalline polyester (COOH group / OH group) is preferably 0.70 or more, more preferably 0.75 or more, Preferably it is 1.10 or less, more preferably 1.05 or less.

  The polycondensation reaction between the carboxylic acid component and the alcohol component may be performed in an inert gas atmosphere at a temperature of 130 ° C. or higher and 250 ° C. or lower as necessary in the presence of an esterification catalyst or a polymerization inhibitor. preferable. 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. Examples of the catalyst include gallic acid, and examples of the polymerization inhibitor include tert-butylcatechol. 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. 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. 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.

  In the present invention, the term “polyester” includes polyester that has been modified to such an extent that its properties are not substantially impaired. Examples of the modified polyester include a urethane-modified polyester in which the polyester is modified with a urethane bond, an epoxy-modified polyester in which the polyester is modified with an epoxy bond, and two or more resin components including a polyester component and other resin components. And a composite resin.

  In the present invention, as the crystalline polyester, a composite resin including a polyester component composed of the crystalline polyester and a styrene resin component may be used.

  As a raw material monomer for the styrene-based resin component, at least styrene or styrene derivatives such as α-methylstyrene and vinyltoluene (hereinafter, styrene and styrene derivatives are collectively referred to as “styrene compound”) is used.

  The content of the styrene compound is preferably 70% by mass or more, more preferably 90% by mass or more, and still more preferably in the raw material monomer of the styrenic resin component, from the viewpoint of improving the durability, low-temperature fixability and gloss of the toner. It is 95 mass% or more, More preferably, it is substantially 100 mass%, More preferably, it is 100 mass%.

  The raw material monomer of the styrene resin component used in addition to the styrene compound includes: (meth) acrylic acid alkyl ester; ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; dimethyl (meth) acrylate Examples thereof include ethylenic monocarboxylic acid esters such as aminoethyl; N-vinyl compounds such as N-vinylpyrrolidone.

  The raw material monomer of the styrene resin component used in addition to the styrene compound can be used in combination of two or more. In the present specification, “(meth) acrylic acid” means acrylic acid and / or methacrylic acid.

  Among the raw material monomers for the styrene resin component used in addition to the styrene compound, (meth) acrylic acid alkyl esters are preferred from the viewpoint of improving the low-temperature fixability of the toner. From the above viewpoint, the carbon number of the alkyl group in the (meth) acrylic acid alkyl ester is preferably 1 or more, more preferably 8 or more, and preferably 22 or less, more preferably 18 or less. In addition, carbon number of this alkyl ester means carbon number derived from the alcohol component which comprises ester.

  Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, (iso) propyl (meth) acrylate, (iso or tertiary) butyl (meth) acrylate, 2- Examples include ethylhexyl (meth) acrylate, (iso) octyl (meth) acrylate, (iso) decyl (meth) acrylate, and (iso) stearyl (meth) acrylate. Here, “(iso or tertiary)” and “(iso)” mean that both of these groups are present and not present, and when these groups are not present Indicates normal. Further, “(meth) acrylate” indicates that both acrylate and methacrylate are included.

  The content of the (meth) acrylic acid alkyl ester is preferably 30% by mass or less, more preferably 20% by mass in the raw material monomer of the styrenic resin component, from the viewpoint of improving toner durability, low-temperature fixability and gloss. Hereinafter, it is more preferably 10% by mass or less.

  A resin obtained by addition polymerization of a raw material monomer containing a styrene compound and a (meth) acrylic acid alkyl ester is also referred to as a styrene- (meth) acrylic resin.

  The addition polymerization reaction of the raw material monomer of the styrene resin component can be carried out by a conventional method in the presence of a polymerization initiator such as dicumyl peroxide, a crosslinking agent, etc., in the presence of an organic solvent or in the absence of a solvent. The temperature condition for the addition polymerization reaction is appropriately selected depending on the reactivity of the raw material monomer and the polymerization initiator, but is preferably 110 ° C. or higher, more preferably 140 ° C. or higher, and preferably 200 ° C. or lower, more preferably 170 ° C. It is below ℃.

  The composite resin comprises: (a) a raw material monomer for a polyester component containing an alcohol component and a carboxylic acid component; (b) a raw material monomer for a styrene resin component; and (c) a raw material monomer for a polyester component and a raw material for a styrene resin component. A resin obtained by polymerizing a bireactive monomer capable of reacting with any of the monomers is preferred.

  As the both reactive monomers, at least one functional group selected from the group consisting of a hydroxyl group, a carboxy group, an epoxy group, a primary amino group and a secondary amino group in the molecule, preferably a hydroxyl group and / or A compound having a carboxy group, more preferably a carboxy group and an ethylenically unsaturated bond is preferred, and it is at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid and maleic anhydride. Is more preferable, but acrylic acid, methacrylic acid or fumaric acid is more preferable from the viewpoint of the reactivity of the polycondensation reaction and the addition polymerization reaction. However, when used together with a polymerization inhibitor, a polyvalent carboxylic acid compound having an ethylenically unsaturated bond such as fumaric acid functions as a raw material monomer for the polyester component. In this case, fumaric acid or the like is not a bireactive monomer but a raw material monomer for the polyester component.

  The amount of both reactive monomers used is based on the total 100 moles of the alcohol component of the polyester component from the viewpoint of enhancing the dispersibility of the styrene resin component and the polyester component and improving the durability, low-temperature fixability and gloss of the toner. The amount is preferably 1 mol or more, more preferably 2 mol or more, and preferably 30 mol or less, more preferably 25 mol or less, still more preferably 20 mol or less. Also, it is preferably 2 mol or more, more preferably 5 mol or more, and preferably 30 mol or less, more preferably 100 mol with respect to 100 mol of the raw material monomers of the styrene resin component (excluding the polymerization initiator). Is 20 mol or less, more preferably 15 mol or less.

  The composite resin is, for example, a method in which a polycondensation reaction step (A) using a raw material monomer of a polyester component and an addition polymerization reaction step (B) using a raw material monomer and an amphoteric monomer of a styrenic resin component are performed in parallel. Can be obtained.

  In this method, step (A) and step (B) are performed under reaction temperature conditions suitable for addition polymerization reaction, the reaction temperature is increased, and crosslinking is performed as necessary under temperature conditions suitable for polycondensation reaction. It is preferable to add a raw material monomer of a trivalent or higher valent polyester component as an agent to the polymerization system and further perform the polycondensation reaction in step (A). At that time, under a temperature condition suitable for the polycondensation reaction, a radical polymerization inhibitor can be added to advance only the polycondensation reaction. Both reactive monomers are involved in the polycondensation reaction as well as the addition polymerization reaction.

  When performing the step (A) and the step (B) in parallel, the mixture containing the raw material monomer of the polyester component can be dropped and reacted with the mixture containing the raw material monomer of the styrenic resin component. .

  It is preferable to perform said method in the same container.

  In the composite resin, the mass ratio of the polyester component to the styrene resin component [polyester component / styrene resin component] (in the present invention, the mass ratio of the raw material monomer of the polyester component to the raw material monomer of the styrenic resin component, that is, [ The total mass of the raw material monomers of the polyester component / the total mass of the raw material monomers of the styrene resin component]) is preferably from the viewpoint of improving the durability, low-temperature fixability and gloss of the toner by maintaining the crystallinity of the polyester. Is 55/45 to 95/5, more preferably 65/35 to 95/5, still more preferably 70/30 to 95/5. In the above calculation, the amount of both reactive monomers is included in the raw material monomer amount of the polyester component. Further, the amount of the polymerization initiator is not included in the raw material monomer amount of the styrene resin component.

  The softening point of the crystalline polyester is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and still more preferably 80 ° C. or higher, from the viewpoint of improving the heat resistant storage stability of the toner. Further, from the viewpoint of improving the low-temperature fixability and gloss of the toner, it is preferably 120 ° C. or lower, more preferably 115 ° C. or lower, and further preferably 110 ° C. or lower.

  The softening point of the crystalline polyester is preferably lower than the softening point of the amorphous polyester from the viewpoint of improving the low-temperature fixability and gloss of the toner, and the difference is preferably 20 ° C. or more, more preferably 20-60 ° C. Here, the difference from the softening point of the amorphous polyester means a difference from the weighted average softening point when the amorphous polyester is made of a plurality of resins.

  The melting point of the crystalline polyester is preferably 55 ° C. or higher, more preferably 65 ° C. or higher, and further preferably 70 ° C. or higher, from the viewpoint of improving the heat resistant storage stability of the toner. Further, from the viewpoint of improving the low-temperature fixability and gloss of the toner, it is preferably 120 ° C. or lower, more preferably 115 ° C. or lower, and further preferably 112 ° C. or lower.

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

  The amorphous polyester is 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, like the crystalline polyester.

  Examples of the alcohol component of the amorphous polyester include aliphatic diols, alicyclic diols, aromatic diols, and the like, from the viewpoint of improving high-temperature offset resistance, durability, heat-resistant storage stability and low-temperature fixability of the toner. Aliphatic diols and aromatic diols are preferred. Furthermore, an aliphatic diol is preferable from the viewpoint of improving the low-temperature fixability and gloss 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 and gloss 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 heat-resistant storage stability, low-temperature fixability and gloss of the toner. The number of carbon atoms of the aliphatic diol is preferably 3 or more from the viewpoint of improving the low-temperature fixability and gloss of the toner. Further, from the viewpoint of improving the durability and heat resistant storage stability of the toner, 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, low-temperature fixability and gloss, 1,2-propanediol and 2,3-butane Diols 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, more preferably 90 mol% or more, and still more preferably, in the alcohol component from the viewpoint of improving the low-temperature fixability and gloss of the toner. Is substantially 100 mol%. 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 in the alcohol component from the viewpoint of improving the low-temperature fixability and gloss of the toner. More preferably, it is 90 mol% or more, more preferably 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, still more preferably 90 mol% or more, and still more preferably substantially, in the alcohol component from the viewpoint of improving the heat resistant storage stability of the toner. 100 mol%.

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

  The carboxylic acid component of the amorphous 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.

  Further, the carboxylic acid component of the amorphous 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 1 mol% or more, more preferably 2 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 low-temperature fixability and gloss of the toner, it is preferably 20 mol% or less, more preferably 10 mol% or less, and still more preferably 6 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 amorphous polyester (COOH group / OH group) is preferably 0.70 or more, more preferably 0.80 or more, and preferably Is 1.15 or less, more preferably 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 cocatalyst, a polymerization inhibitor, etc. 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 amorphous polyester is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 120 ° C. or higher, from the viewpoint of improving the durability and heat-resistant storage stability of the toner. Further, from the viewpoint of improving low-temperature fixability and gloss of the toner, it is preferably 160 ° C. or lower, more preferably 140 ° C. or lower, and further preferably 130 ° C. or lower.

  The softening point of the amorphous polyester can be controlled by adjusting the kind and composition ratio 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 maximum endothermic peak temperature of the amorphous polyester is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and further preferably 65 ° C. or higher, from the viewpoint of improving the durability and heat-resistant storage stability of the toner. Further, from the viewpoint of improving low-temperature fixability and gloss of the toner, it is preferably 90 ° C. or lower, more preferably 80 ° C. or lower, and further preferably 75 ° C. or lower.

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

  The glass transition temperature of the amorphous polyester 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 low-temperature fixability and gloss of the toner, it is preferably 90 ° C. or less, more preferably 80 ° C. or less, and further preferably 70 ° C. or less.

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

  The acid value of the amorphous polyester is preferably 30 mgKOH / g or less, more preferably 20 mgKOH / g or less, and further preferably 15 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 amorphous polyester, from the viewpoint of improving low-temperature fixability and gloss of the toner, it is preferably 1 mgKOH / g or more, more preferably 2 mgKOH / g or more, and even more preferably 3 mgKOH / g or more. is there.

  The acid value of the amorphous polyester can be controlled by adjusting the type and composition ratio 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.

  In the present invention, two or more kinds of amorphous polyesters may be used.

  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, low-temperature fixability and gloss of the toner. 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, still more preferably 70% or more, and still more preferably 80, from the viewpoint of improving the durability, low-temperature fixability and gloss of the toner. % Or more, more preferably 90% or more.

  The number average molecular weight of the polylactic acid is preferably 60,000 or more, more preferably 100,000 or more, more preferably 150,000 or more, from the viewpoint of containing polylactic acid in the toner, and improving the durability, low-temperature fixability and gloss of the toner. More preferably, it is 180,000 or more. Further, from the viewpoint of being able to be melt-kneaded and obtaining a toner, and from the viewpoint of improving toner durability, low-temperature fixability and gloss, it is preferably 300,000 or less, more preferably 250,000 or less, and even more preferably 200,000 or less. is there.

  The weight average molecular weight of the polylactic acid is preferably 60,000 or more, more preferably 100,000 or more, further preferably 250,000 or more, from the viewpoint of containing the polylactic acid in the toner, and improving the durability, low-temperature fixability and gloss of the toner. More preferably, it is 400,000 or more, more preferably 450,000 or more. Further, from the viewpoint of being able to be melt kneaded and obtaining a toner, and from the viewpoint of improving the durability, low-temperature fixability and gloss of the toner, it is preferably 700,000 or less, more preferably 550,000 or less, and even more preferably 500,000 or less. is there.

  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 and gloss of the toner, it is preferably 180 ° C. or lower, more preferably 175 ° C. or lower.

  The mass ratio of amorphous polyester to polylactic acid subjected to the transesterification reaction (amorphous polyester / polylactic acid) is from the viewpoint of incorporating polylactic acid into the toner, improving the durability, low-temperature fixability and gloss of the toner. , 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 an ester exchange reaction between amorphous polyester and polylactic acid.

  The transesterification reaction between the amorphous polyester and the polylactic acid can be performed by a method of mixing the amorphous polyester and the polylactic acid at 140 ° C. or higher and 200 ° C. or lower, 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, still more preferably 3.0% or more, more preferably from the viewpoint of improving the durability, low-temperature fixability and gloss of the toner. 7.0% or more. When the transesterification rate is 0.1% or more, the mixing property of amorphous polyester and polylactic acid is improved, and a resin composition having high strength can be obtained, so that the durability of the toner is improved and the resin composition And kneading of the crystalline polyester improves the dispersion of the crystalline polyester in the binder resin, thereby reducing the variation in the component composition among the toner particles and improving the low-temperature fixability and gloss (gloss). Further, the transesterification rate based on polylactic acid is preferably 35% or less, more preferably 30% or less, further preferably 25% or less, more preferably 20% or less, from the viewpoint of improving the durability of the toner. More preferably, it is 15% or less, more 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 amorphous polyester, between components derived from polylactic acid and between components derived from amorphous polyester. This does not include the transesterification reaction.

  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 improving low-temperature fixability and gloss of the toner, it is preferably 99% by mass or less, more preferably 80% by mass or less, still more preferably 70% by mass or less, still more preferably 60% by mass or less, and further preferably 50% or less. It is below mass%.

  The content of the crystalline polyester is preferably 1% by mass or more, more preferably 7% by mass or more, further preferably 12% by mass or more, from the viewpoint of improving low-temperature fixability and gloss of the toner in the binder resin. Preferably it is 18 mass% or more. Further, from the viewpoint of improving the durability of the toner, it is preferably 40% by mass or less, more preferably 35% by mass or less, still more preferably 28% by mass or less, and further preferably 22% by mass or less.

  The toner of the present invention may further contain an amorphous polyester as a binder resin in addition to the amorphous polyester subjected to the transesterification reaction. In the case where the amorphous polyester subjected to the transesterification reaction and the amorphous polyester not subjected to the transesterification reaction are added separately, the mass ratio between the amorphous polyester subjected to the transesterification reaction and the amorphous polyester not subjected to the transesterification reaction. (Amorphous polyester subjected to transesterification reaction / amorphous polyester not subjected to transesterification reaction) is from the viewpoint of improving the mixing property of the resin composition, from the viewpoint of improving the durability, low-temperature fixability and gloss of the toner, 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 40/60 to 10/90, more preferably 35/65 to 10/90.

  The mass ratio of crystalline polyester to amorphous polyester (crystalline polyester / amorphous polyester) is preferably 1/99 to 50/50 from the viewpoint of improving toner durability, low-temperature fixability and gloss. Preferably it is 3 / 97-40 / 60, More preferably, it is 5 / 95-35 / 65, More preferably, it is 5 / 95-30 / 70, More preferably, it is 5 / 95-20 / 80. Here, the mass of the amorphous polyester refers to the mass of the amorphous polyester subjected to the transesterification reaction, or in the case of further containing an amorphous polyester, the transesterification reaction with the amorphous polyester subjected to the transesterification reaction. This is the total mass of the amorphous polyester that is not provided.

  In the present invention, when the total content of the crystalline polyester and the resin composition, or further containing the amorphous polyester, the total content of the crystalline polyester, the resin composition, and the amorphous polyester is determined in the binder resin. , Preferably 90% by mass or more, more preferably 95% by mass or more, further preferably substantially 100% by mass, and further preferably 100% by mass.

The toner of the present invention is
Step 1: A step of mixing an amorphous polyester and polylactic acid at 140 ° C. or higher and 200 ° C. or lower and subjecting them to an ester exchange reaction,
Step 2: a step of melt kneading the toner raw material mixture containing the resin composition obtained in Step 1 and the crystalline polyester, and Step 3: a step of pulverizing and classifying the melt kneaded product obtained in Step 2 Those obtained by the method are preferred.

  In Step 1, the temperature at which the amorphous 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, the temperature is preferably 200 ° C. or lower, more preferably 190 ° C. or lower, and further preferably 180 ° C. or lower.

  The mixing time in step 1 depends on the mixing temperature and cannot be determined unconditionally. However, from the viewpoint of improving the durability of the toner by adding polylactic acid to the toner, it is preferably 0.5 hours or more, more preferably 2 hours or more. It is. Also, 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 10 hours or less, and even more preferably 7 hours or less.

  The mass ratio of the amorphous polyester and polylactic acid to be mixed in Step 1 (amorphous polyester / polylactic acid) is the viewpoint of increasing the mixing property of polyester and polylactic acid so that the toner contains polylactic acid, the durability of the toner, the low temperature From the viewpoint of improving fixability and gloss, it is preferably 90/10 to 30/70, more preferably 80/20 to 35/65, still more preferably 70/30 to 40/60, and further preferably 60/40 to 45. / 55.

The mixing method is
(A) A method in which amorphous polyester and polylactic acid are mixed and heated to melt,
(B) a method in which amorphous polyester is previously heated and melted and mixed with polylactic acid, and
(C) Any method may be used in which polylactic acid is heated and melted in advance and mixed with amorphous polyester. From the viewpoint of improving the durability of the toner by adding polylactic acid to the toner, (B) This method is preferred. Therefore, it is preferable that the process 1 includes the following process 1-1 and process 1-2.
Step 1-1: Step of melting amorphous polyester Step 1-2: Step of mixing molten amorphous 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 crystalline polyester is melt-kneaded.

  In step 2, it is preferable to melt-knead the amorphous polyester from the viewpoint of improving the durability, low-temperature fixability and gloss of the toner.

  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 toner gloss and heat-resistant storage stability.

  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 and gloss 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.

  Examples of mold releasing agents include polypropylene, polyethylene, polypropylene polyethylene copolymer, α-olefin polymer, hydrocarbon wax such as microcrystalline wax, paraffin wax, Fischer-Tropsch wax and oxides thereof, carnauba wax, and montan. Examples thereof include ester waxes such as waxes, sazol waxes and their deoxidized waxes, fatty acid amides, fatty acids, higher alcohols, and fatty acid metal salts. These may be used alone or in admixture of two or more. Among these, from the viewpoint of improving the low-temperature fixability and durability of the toner, α-olefin polymers, paraffin waxes, synthetic ester waxes, and carnauba waxes are preferable, and α-olefin polymers are more preferable.

  The melting point of the release agent is preferably 60 ° C. or higher, more preferably 65 ° C. or higher, and still more preferably 70 ° C. or higher, from the viewpoint of improving the durability and heat-resistant storage stability of the toner. Further, from the viewpoint of improving low-temperature fixability and gloss of the toner, it is preferably 120 ° C. or lower, more preferably 100 ° C. or lower, and still more preferably 90 ° C. or lower.

  The content of the release agent is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, and still more preferably 1.5 parts by mass with respect to 100 parts by mass of the binder resin from the viewpoint of improving the low-temperature fixability of the toner. That's it. Further, from the viewpoint of improving the durability and heat-resistant storage stability of the toner, it is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and still more preferably 8.0 parts by mass or less.

  Among the α-olefin polymers, an α-olefin polymer obtained by polymerizing a monomer containing an α-olefin having 22 to 30 carbon atoms from the viewpoint of improving the durability and charge stability of the toner is provided. preferable.

  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 from the viewpoint of improving the durability and charge stability of the toner. It is 90 mol% or more, more preferably 95 mol% or more, and further preferably 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 is preferably 60 mol% or more, from the viewpoint of improving the durability and charge 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 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, A halogenated hydrocarbon solvent such as dichloromethane 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 melting point of the α-olefin polymer in the present invention is preferably 60 ° C. or higher, more preferably 64 ° C. or higher, and still more preferably 68 ° C. or higher, from the viewpoint of improving the low temperature fixability, durability and charging stability of the toner. Further, it is preferably 72 ° C or higher, preferably 90 ° C or lower, more preferably 85 ° C or lower, and further preferably 80 ° C or lower. The melting point of the α-olefin polymer can be determined by the method described in Examples described later.

  The melt viscosity at 100 ° C. of the α-olefin polymer is preferably 100 mPa · s or more, more preferably 120 mPa · s or more, and still more preferably, from the viewpoint of improving low-temperature fixability, durability and charging stability of the toner. It is 150 mPa · s or more, more preferably 180 mPa · s or more, further preferably 190 mPa · s or more, preferably 300 mPa · s or less, more preferably 250 mPa · s or less, and further preferably 220 mPa · s or less.

  The content of the α-olefin polymer in the release agent is preferably 50% by mass or more, more preferably 60% by mass or more, from the viewpoint of improving the low-temperature fixability, durability, and charging stability of the toner. Preferably it is 65 mass% or more, More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more.

  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, low temperature fixability and gloss of the toner, and without repeating kneading or using a dispersion aid, a colorant, a charge control agent, It is preferable to use an open roll type kneader from the viewpoint of allowing highly efficient dispersion of additives such as a release agent.

  Toner raw materials containing resin composition, crystalline polyester, amorphous polyester, and additives such as colorant, charge control agent, release agent, etc. are mixed in advance by a mixer such as a Henschel mixer or a ball mill, and then kneaded. It is preferable to supply to the machine.

  The open roll type kneader means an open kneading unit that is not sealed, and can easily dissipate the kneading heat generated during kneading. Further, the continuous open roll type kneader is preferably a kneader equipped with at least two rolls, and the continuous open roll type kneader used in the present invention comprises two rolls having different peripheral speeds, That is, the kneading machine includes two rolls, a high rotation side roll having a high peripheral speed and a low rotation side roll having a low peripheral speed. In the present invention, the viewpoint of improving the dispersibility in the toner of additives such as a colorant, a charge control agent, and a release agent, a viewpoint of reducing mechanical force during melt-kneading and suppressing heat generation, and melt-kneading. From the viewpoint of reducing the temperature at the time and improving the durability, low-temperature fixability and gloss 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 raw material charging side end temperature of the high-rotation side roll is preferably 100 ° C. from the viewpoint of reducing mechanical force during melt kneading and suppressing heat generation and improving the durability, low-temperature fixability and gloss of the toner. 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 toner durability, low-temperature fixability and gloss, it is preferably 20 ° C or higher, more preferably 30 ° C or higher, and preferably 60 ° C or lower, more preferably 50 ° C or lower. is there.

  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 reducing mechanical force during melt-kneading, suppressing heat generation, and improving the durability, low-temperature fixability and gloss of the toner, preferably 0 ° C. or higher, more preferably 10 ° C. or higher, more preferably It is preferably 20 ° C or higher and preferably 50 ° C or lower.

  Peripheral speed of the high rotation side roll is to improve the dispersibility in the toner of additives such as colorants, charge control agents, and release agents, to reduce mechanical force during melt kneading, and to suppress heat generation In addition, from the viewpoint of improving the durability, low-temperature fixability and gloss of the toner, it is preferably 2 m / min or more, more preferably 10 m / min or more, further preferably 25 m / min or more, and preferably 100 m / min. Hereinafter, it is more preferably 75 m / min or less, and further 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 the additive such as an agent in the toner, reducing the mechanical force at the time of melt kneading, suppressing heat generation, and improving the durability, low-temperature fixability and gloss of the toner, It is preferable that a plurality of spiral grooves are carved on the surface of each roll.

  The melt-kneaded product obtained in the step 2 is cooled to such an extent that it can be pulverized, and then subjected to the subsequent step 3. In the present invention, a heat treatment step may be performed after the step 2.

  In the present invention, the temperature of the heat treatment step is such that the dispersibility of additives such as a colorant, a release agent, and a charge control agent in the binder resin is improved, crystallization of the crystalline polyester is promoted, From the viewpoint of improving the low-temperature fixability and gloss, shortening the heat treatment time, and improving the productivity of the toner, it is preferably at least the glass transition temperature of the amorphous polyester. In addition, from the viewpoint of preventing deterioration of the heat-resistant storage stability of the toner due to the disorder of the arrangement accompanying the dissolution of the crystal, the temperature is preferably a temperature not higher than the melting point of the crystalline polyester, more preferably a temperature lower than the melting point by 10 ° C., more preferably the melting point. The temperature is lower than 15 ° C.

  The heat treatment time is preferably 1 hour or longer, more preferably 3 hours or longer, and further preferably 6 hours or longer from the viewpoint of promoting crystallization of the crystalline resin and improving low-temperature fixability and gloss of the toner. is there. Further, from the viewpoint of improving toner productivity, it is preferably 12 hours or shorter, more preferably 10 hours or shorter. This time is a cumulative time within the temperature range (above the glass transition temperature of the amorphous polyester and below the melting point of the crystalline polyester). Further, from the viewpoint of maintaining the dispersibility of the additive in the toner, it is preferable that the upper limit value of the temperature range is not exceeded from the start to the end of the heat treatment step.

  An oven or the like can be used for the heat treatment step. For example, when an oven is used, the heat treatment step can be performed by maintaining the kneaded material at a constant temperature in the oven.

Although the aspect which performs a heat processing process is not specifically limited, For example,
Aspect 1: An aspect in which, after Step 1, the melt-kneaded material is pulverized in Step 3, and the pulverized melt-kneaded material is maintained under the heat treatment conditions.
Aspect 2: After step 1, in the process of cooling the obtained melt-kneaded product to lower the temperature, the melt-kneaded product is kept under the heat treatment conditions, and then further cooled until reaching a pulverizable hardness, Aspect for use in the next step of 3 etc.,
Aspect 3: After Step 1, the obtained melt-kneaded product is once cooled to a pulverizable hardness, then the cooled melt-kneaded product is subjected to the heat treatment step, then the melt-kneaded product is cooled again, Step 3 etc. The aspect etc. with which it uses for the next process of this are mentioned. In the present invention, the heat treatment step may be performed in any mode, but mode 3 is preferable from the viewpoint of maintaining the dispersibility of the additive in the toner.

  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,
Crystalline polyester,
An electrophotographic toner comprising a resin composition obtained by subjecting an amorphous polyester and polylactic acid to a transesterification reaction.

<2> The electrophotographic toner according to <1>, wherein the alcohol component of the crystalline polyester preferably contains an aliphatic diol.
<3> The carbon number of the aliphatic diol is preferably 4 or more, more preferably 6 or more, still more preferably 9 or more, preferably 14 or less, more preferably 12 or less, <2> described above Toner for electrophotography.
<4> The aliphatic diol having 4 to 14 carbon atoms is preferably an α, ω-linear alkanediol, such as 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9 -At least one selected from the group consisting of nonanediol, 1,10-decanediol, and 1,12-dodecanediol is more preferable, 1,6-hexanediol, 1,8-octanediol, and 1,10 -The electrophotographic toner according to <3>, wherein at least one selected from the group consisting of decanediol is more preferable.
<5> The content of the aliphatic diol having 4 to 14 carbon atoms in the alcohol component is preferably 70 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more, and still more preferably substantially. The electrophotographic toner according to <3> or <4>, wherein the amount is 100 mol%, more preferably 100 mol%.
<6> The toner for electrophotography according to any one of <1> to <5>, wherein the carboxylic acid component of the crystalline polyester preferably contains an aromatic dicarboxylic acid compound and / or an aliphatic dicarboxylic acid compound. .
<7> The aromatic dicarboxylic acid compound preferably has 8 to 12 carbon atoms, more preferably at least one selected from the group consisting of phthalic acid compounds, isophthalic acid compounds and terephthalic acid compounds. The electrophotographic toner according to <6>, wherein at least one selected from the group consisting of acid and terephthalic acid is more preferable.
<8> The carbon number of the aliphatic dicarboxylic acid compound is preferably 4 or more, more preferably 6 or more, further preferably 9 or more, preferably 14 or less, more preferably 12 or less, <6> or <7> The toner for electrophotography as described.
<9> The aliphatic dicarboxylic acid compound having 4 to 14 carbon atoms is preferably at least one selected from the group consisting of fumaric acid, succinic acid, adipic acid, sebacic acid, decanedioic acid, and dodecanedioic acid, The toner for electrophotography according to <8>, wherein sebacic acid is more preferable.
<10> The content of the aromatic dicarboxylic acid compound having 8 to 12 carbon atoms and the aliphatic dicarboxylic acid compound having 4 to 14 carbon atoms is preferably 70 mol% or more, more preferably 90 mol in the carboxylic acid component. % Or more, more preferably 95 mol% or more, more preferably substantially 100 mol%, more preferably 100 mol%, the electrophotographic toner according to <8> or <9>.
<11> In the total number of moles of the carboxylic acid component and the alcohol component, an aromatic dicarboxylic acid compound having 8 to 12 carbon atoms, an aliphatic dicarboxylic acid compound having 4 to 14 carbon atoms, and a fat having 4 to 14 carbon atoms The total number of moles with the group diol is preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, further preferably substantially 100 mol%, further preferably 100 mol%. The toner for electrophotography according to any one of <8> to <10>.
<12> The softening point of the crystalline polyester is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, still more preferably 80 ° C. or higher, preferably 120 ° C. or lower, more preferably 115 ° C. or lower, and still more preferably 110 ° C. The toner for electrophotography according to any one of <1> to <11>, which is not higher than ° C.
<13> The melting point of the crystalline polyester is preferably 55 ° C. or higher, more preferably 65 ° C. or higher, further preferably 70 ° C. or higher, preferably 120 ° C. or lower, more preferably 115 ° C. or lower, and further preferably 112 ° C. The toner for electrophotography according to any one of <1> to <12>, which is as follows.
<14> The electrophotographic toner according to any one of <1> to <13>, wherein the alcohol component of the amorphous polyester preferably contains an aliphatic diol and / or an aromatic diol.
<15> The number of carbon atoms 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, <14> The electrophotographic toner according to <14>.
<16> The electrophotographic toner according to <14> or <15>, wherein the aliphatic diol preferably contains an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom.
<17> The electrophotographic toner according to <16>, wherein the aliphatic diol having a hydroxyl group bonded to a secondary carbon atom preferably has 3 or more carbon atoms, preferably 6 or less, and more preferably 4 or less.
<18> 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, <16 > Or <17>.
<19> The content of the aliphatic diol in the alcohol component is preferably 50 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and still more preferably substantially 100 mol%. The toner for electrophotography according to any one of <14> to <18>.
<20> 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 <16> to <19>, which is preferably substantially 100 mol%.
<21> The toner for electrophotography according to any one of <1> to <20>, wherein the carboxylic acid component of the amorphous polyester preferably contains an aromatic dicarboxylic acid compound.
<22> 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. The electrophotographic toner according to <21>.
<23> The electrophotographic toner according to any one of <1> to <22>, wherein the carboxylic acid component of the amorphous polyester preferably contains a trivalent or higher carboxylic acid compound.
<24> The trivalent or higher carboxylic acid compound is preferably 1,2,4-benzenetricarboxylic acid (trimellitic acid) and / or anhydride thereof, and 1,2,4-benzenetricarboxylic acid anhydride (anhydrous trianhydride). The electrophotographic toner according to <23>, wherein merit acid is more preferable.
<25> The content of the trivalent or higher carboxylic acid compound is preferably 1 mol% or more, more preferably 2 mol% or more, preferably 20 mol% or less, more preferably 10 mol% or less, in the carboxylic acid component. The electrophotographic toner according to <23> or <24>, more preferably 6 mol% or less.
<26> The softening point of the amorphous polyester is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, further preferably 120 ° C. or higher, preferably 160 ° C. or lower, more preferably 140 ° C. or lower, still more preferably. The electrophotographic toner according to any one of <1> to <25>, which is 130 ° C. or lower.
<27> The glass transition temperature of the amorphous polyester is preferably 50 ° C. or higher, more preferably 55 ° C. or higher, further preferably 60 ° C. or higher, preferably 90 ° C. or lower, more preferably 80 ° C. or lower, still more preferably. Is an electrophotographic toner according to any one of <1> to <26>, wherein the toner is 70 ° C. or lower.
<28> The acid value of the amorphous polyester is preferably 30 mgKOH / g or less, more preferably 20 mgKOH / g or less, still more preferably 15 mgKOH / g or less, preferably 1 mgKOH / g or more, more preferably 2 mgKOH / g. As described above, the electrophotographic toner according to any one of <1> to <27>, more preferably 3 mgKOH / g or more.
<29> 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%, <1> to <28> The toner for electrophotography according to any one of the above.
<30> The electrophotographic toner according to any one of <1> to <29>, wherein the polylactic acid is preferably a homopolymer of lactic acid.
<31> The electrophotographic toner according to any one of <1> to <30>, wherein the polylactic acid is preferably crystalline polylactic acid.
<32> The degree of crystallinity of the crystalline polylactic acid is preferably 30% or more, more preferably 50% or more, further preferably 70% or more, more preferably 80% or more, and further preferably 90% or more. <31> The toner for electrophotography described.
<33> 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 <32>, which is 200,000 or less.
<34> The weight average molecular weight of the polylactic acid is preferably 60,000 or more, more preferably 100,000 or more, further preferably 250,000 or more, more 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 <33>, which is 550,000 or less, more preferably 500,000 or less.
<35> 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>-<34> Toner for electrophotography.
<36> The mass ratio of amorphous polyester to polylactic acid used for the transesterification reaction (amorphous polyester / polylactic acid) is preferably 90/10 to 30/70, more preferably 80/20 to 35/65, The electrophotographic toner according to any one of <1> to <35>, more preferably 70/30 to 40/60, and still more preferably 60/40 to 45/55.
<37> 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 <36>, 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.
<38> 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 99% 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 <37>.
<39> The content of the crystalline polyester is preferably 1% by mass or more, more preferably 7% by mass or more, further preferably 12% by mass or more, and further preferably 18% by mass or more in the binder resin. The electrophotographic toner according to any one of <1> to <38>, wherein is 40% by mass or less, more preferably 35% by mass or less, further preferably 28% by mass or less, and further preferably 22% by mass or less.
<40> In addition to the amorphous polyester used for the transesterification, the binder resin further contains an amorphous polyester, and the amorphous polyester used for the transesterification and the amorphous polyester not used for the transesterification The mass ratio of (amorphous polyester subjected to transesterification / amorphous polyester not subjected to transesterification) is preferably 90/10 to 1/99, more preferably 70/30 to 3/97, Preferably, 60/40 to 5/95, more preferably 50/50 to 10/90, more preferably 40/60 to 10/90, more preferably 35/65 to 10/90, <1> to <39> The electrophotographic toner according to any one of the above.
<41> The mass ratio of crystalline polyester to amorphous polyester (crystalline polyester / amorphous polyester) is preferably 1/99 to 50/50, more preferably 3/97 to 40/60, and even more preferably. The toner for electrophotography according to any one of <1> to <40>, which is 5/95 to 35/65, more preferably 5/95 to 30/70, and further preferably 5/95 to 20/80.
<42> The total content of the crystalline polyester and the resin composition, or when the amorphous polyester is further contained, the total content of the crystalline polyester, the resin composition, and the amorphous polyester, The electrophotographic toner according to any one of <1> to <41>, preferably 90% by mass or more, more preferably 95% by mass or more, further preferably substantially 100% by mass, and further preferably 100% by mass. .
<43> Step 1: A step of mixing amorphous 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 the crystalline polyester, 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 <42>, comprising:
<44> In step 1, the temperature at which the amorphous 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 The method for producing a toner for electrophotography according to <43>, wherein is 190 ° C. or lower, more preferably 180 ° C. or lower.
<45> The mixing time in step 1 is preferably 0.5 hours or more, more preferably 2 hours or more, preferably 15 hours or less, more preferably 10 hours or less, and even more preferably 7 hours or less, <43 > Or <44>.
<46> Step 1
Step 1-1: A step of melting amorphous polyester, and Step 1-2: a step of mixing molten amorphous polyester and polylactic acid at 140 ° C. or higher and 200 ° C. or lower, preferably <43>-<45> The manufacturing method of the toner for electrophotography in any one of.
<47> The method for producing an electrophotographic toner according to any one of <43> to <46>, wherein in step 2, it is preferable to further melt knead amorphous polyester.
<48> In any one of the above items <43> to <47>, 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. A method for producing the electrophotographic toner according to claim.
<49> 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 an electrophotographic toner according to <48>, further preferably 5 parts by mass or less.
<50> The release agent preferably contains at least one selected from the group consisting of α-olefin polymers, paraffin waxes, synthetic ester waxes, and carnauba waxes. The method for producing an electrophotographic toner according to <48> or <49>, which is more preferably contained.
<51> The melting point of the release agent is preferably 60 ° C. or higher, more preferably 65 ° C. or higher, more preferably 70 ° C. or higher, preferably 120 ° C. or lower, more preferably 100 ° C. or lower, and still more preferably 90 ° C. The method for producing an electrophotographic toner according to <50>, wherein:
<52> The electrophotographic toner according to <51>, 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. Manufacturing method.
<53> 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 method for producing an electrophotographic toner according to <52>, further preferably substantially 100 mol%.
<54> 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 method for producing an electrophotographic toner according to the above <52> or <53>, which is more preferably 95 mol% or more, more preferably 97 mol% or more.
<55> The content of the α-olefin polymer in the release agent is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 65% by mass or more, and further preferably 80% by mass or more. The method for producing an electrophotographic toner according to any one of <50> to <54>, more preferably 90% by mass or more.
<56> The method for producing a toner for electrophotography according to any one of <43> to <55>, wherein an open roll kneader is preferably used for melt kneading.

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

[Maximum peak temperature and melting point of resin endotherm]
Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample is weighed into an aluminum pan, and the temperature drops from room temperature to 0 ° C. at a rate of 10 ° C./min. Cool and let stand for 1 minute. Then, it measured with the temperature increase rate of 50 degrees C / min. Of the endothermic peaks observed, the peak temperature appearing on the highest temperature side is defined as the highest endothermic peak temperature of the resin. If the maximum peak temperature is within 20 ° C of the softening point, the melting point is assumed.

[Glass transition temperature of resin]
Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan), 0.01 to 0.02 g of sample is weighed into an aluminum pan, heated up to 200 ° C., and the temperature drop rate from that temperature 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 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)).

[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 Place the sample solution in an NMR measurement tube (manufactured by Nippon Seimitsu Chemical Co., Ltd., inner diameter 5 mm, length 210 mm) so that the amount of the solution is 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 ).

Amorphous polyester production example 1 [APES-1, 2]
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, further reacted at 40 kPa until the desired softening point was reached, and amorphous polyester (APES -1, APES-2). Table 1 shows the physical properties of APES-1 and APES-2. The reaction rate means a value of the amount of produced reaction water / theoretical product water amount × 100.

Production Example 1 of crystalline polyester [CPES-1]
Put the raw material monomers and esterification catalyst shown in Table 2 into a 10L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer and thermocouple, and take 10 hours from 130 ° C to 200 ° C under a nitrogen atmosphere. The temperature was raised and the reaction was conducted at 200 ° C. and 8 kPa for 1 hour to obtain crystalline polyester (CPES-1). Table 2 shows the physical properties of the obtained CPES-1.

Production Example 2 of crystalline polyester [CPES-2]
Put the raw material monomers, esterification catalyst and polymerization inhibitor shown in Table 2 into a 10L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer and thermocouple, and from 130 ° C to 200 ° C under nitrogen atmosphere The temperature was raised over 10 hours, and the reaction was carried out at 200 ° C. and 8 kPa for 1 hour to obtain crystalline polyester (CPES-2). Table 2 shows the physical properties of the obtained CPES-2.

Production Example 3 of Crystalline Polyester [CPES-3]
The raw material monomer of the polyester component other than acrylic acid, which is an amphoteric monomer shown in Table 3, is placed in a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple at 160 ° C. Heat and dissolve. A premixed solution of styrene, dicumyl peroxide and acrylic acid was added dropwise with a dropping funnel over 1 hour. Stirring was continued for 1 hour while maintaining at 170 ° C. to polymerize styrene and acrylic acid, and then 13 g of tin (II) 2-ethylhexanoate was added, the temperature was raised to 210 ° C., and the reaction was carried out for 8 hours. Furthermore, reaction was performed at 8.3 kPa for 1 hour, and the composite resin (CPES-3) containing a crystalline polyester component was obtained. Table 3 shows the physical properties of the obtained CPES-3.

[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 amorphous polyester shown in Table 4 is placed in a 10-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and the temperature shown in Table 4 is reached under a nitrogen atmosphere. Heated to melt the amorphous polyester. Thereafter, a predetermined amount of polylactic acid shown in Table 4 was added and stirred for a predetermined time shown in Table 4. 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 to 14, Comparative Examples 1 and 2
A predetermined amount of the resin composition shown in Table 5, amorphous polyester, crystalline polyester, and coloring agent “ECB-301” (manufactured by Dainichi Seika Co., Ltd., phthalocyanine blue (PB15: 3)) 3.0 parts by mass, negative chargeability Charge control agent “Bontron E-84” (manufactured by Orient Chemical Co., Ltd.) 1.0 part by weight, Release agent “Release agent 1” (α-olefin polymer production example 1, α-polyolefin copolymer, melting point: 76 ° C. ) 3.0 parts by mass was mixed for 1 minute using a Henschel mixer (manufactured by Nihon Coke Kogyo Co., Ltd.) and then melt-kneaded under the following conditions.

  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 obtained coarsely pulverized product was finely pulverized by using a DS2 type airflow classifier (impact plate type, manufactured by Nippon Pneumatic Co., Ltd.) to adjust the pulverization pressure so that the volume median particle size was 8.0 μm. The resulting finely pulverized product is classified 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 15
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.

Example 16
In Example 1, after melt-kneading the toner raw material, the obtained melt-kneaded product was rolled with a cooling roll, cooled to 20 ° C. or lower, and then heated in an oven at 70 ° C. for 9 hours. It was.

  The heat-treated product after the heat treatment was cooled to 30 ° C. and pulverized and classified in the same manner as in Example 1 to obtain toner base particles. The obtained toner base particles were subjected to external addition treatment in the same manner as in Example 1 to obtain a toner.

Comparative Example 3
Predetermined amounts of amorphous polyester, crystalline polyester, and polylactic acid shown in Table 5 and a coloring agent “ECB-301” (manufactured by Dainichi Seika Co., Ltd., phthalocyanine blue (PB15: 3)) 4.0 parts by mass, negatively charged charge Control agent "Bontron E-304" (manufactured by Orient Chemical Co., Ltd.) 0.5 parts by mass and mold release agent "HNP-9" (manufactured by Nippon Seiki Co., Ltd., paraffin wax, melting point: 75 ° C) 3.0 parts by mass, Henschel mixer After mixing for 1 minute, the mixture was melted and kneaded in the same manner as in Example 1 and pulverized and classified. The resulting particles were incompatible with the amorphous polyester and polylactic acid, and separated. Was not usable as.

Comparative Example 4
A predetermined amount of amorphous polyester and polylactic acid shown in Table 5 were mixed by 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.

  90 parts by mass of the obtained kneaded composition, 10 parts by mass of crystalline polyester, 3.0 parts by mass of coloring agent “ECB-301” (manufactured by Dainichi Seika Co., Ltd., phthalocyanine blue (PB15: 3)), negative charge control Agent “Bontron E-84” (manufactured by Orient Chemical Co., Ltd.) 1.0 part by mass, and mold release agent “release agent 1” (α-olefin polymer production example 1, α-polyolefin copolymer, melting point: 76 ° C.) 3.0 parts by mass were mixed for 1 minute using a Henschel mixer and then 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.

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

[Test Example 2: gross]
Mount the toner on the non-magnetic one-component developing device `` OKI MICROLINE 5400 '' (Oki Data Co., Ltd.), adjust the toner adhesion amount to 0.40 ± 0.03 mg / cm <sup>2,</sup> and print a solid image of 4.1 cm × 4.1 cm with `` J Printed on "paper" (Fuji Xerox Office Supply). A solid image was taken out before passing through the fixing machine to obtain an unfixed image. Load the resulting paper with unfixed images into the non-magnetic one-component developer “OKI MICROLINE 5400” (Oki Data), print a 4.1cm x 4.1cm solid image again, and pass through the fixing machine. A solid image was taken out to obtain an unfixed image (two layers) of 0.80 ± 0.06 mg / cm ² . The same operation was repeated to obtain an unfixed image (3 layers) of 1.20 ± 0.09 mg / cm ² .

  Fix the obtained unfixed three-layer image to a fixing roller of 120 mm / sec by setting the temperature of the fixing roll to 100 ° C with an external fixing device that has taken out the fixing device of “OKI MICROLINE 3010” (Oki Data). Fixed at speed. Thereafter, the fixing roll temperature was set to 105 ° C., and the same operation was performed. This was performed while increasing the temperature up to 190 ° C by 5 ° C. The glossiness at each fixing temperature of the obtained three-layer fixed image was measured, and the maximum value was defined as gloss. The glossiness was measured using a gloss meter “PG-1” (manufactured by Nippon Denshoku Industries Co., Ltd.) with the light source set at 60 °. The higher the glossiness, the better the gloss. The results are shown in Table 5.

[Test Example 3: 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 5.

  From the above results, it can be seen that the toners of Examples 1 to 16 are excellent in all of low-temperature fixability, gloss and durability as compared with the toners of Comparative Examples 1 to 4.

  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 (7)

As binder resin,
Crystalline polyester,
An electrophotographic toner comprising a resin composition obtained by subjecting an amorphous polyester and a polylactic acid having a weight average molecular weight of 450,000 to 700,000 to a transesterification reaction.   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 99% 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 amorphous polyester to polylactic acid (amorphous polyester / polylactic acid) subjected to transesterification is 90/10 to 30/70.   The amorphous 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. The toner for electrophotography as described. Step 1: a step of amorphous polyester and the weight average molecular weight is subjected to mixing transesterification 200 ° C. hereinafter 140 ° C. or higher and 700,000 or less polylactic acid or 450,000,
Step 2: a step of melt-kneading the toner raw material mixture containing the resin composition obtained in Step 1 and the crystalline polyester, and Step 3: a step of pulverizing and classifying the melt-kneaded product obtained in Step 2.
A method for producing an electrophotographic toner according to claim 1, comprising: