JP2023176546A - Binder resin for toner - Google Patents

Abstract

To provide a binder resin for toner, or the like, that has a wide fixation temperature range while maintaining excellent low-temperature fixability, and has excellent heat-resistance storage stability and productivity.SOLUTION: A binder resin for toner includes a composite resin in which an addition polymerization resin unit and a polyester resin unit are covalently bonded. The addition polymerization resin (A) comprising the addition polymerization resin unit contains 60 mass% or more of a constituent unit derived from (meth) acrylic monomer. The addition polymerization resin (A) has an acid value of is 40 mgKOH/g or more.SELECTED DRAWING: None

Description

The present invention relates to a binder resin used in a toner used for developing a latent image formed in electrophotography, electrostatic recording, electrostatic printing, or the like.

In recent years, in the field of electrophotography, with the development of electrophotographic systems, there has been a demand for the development of toners for developing electrostatic images that are compatible with higher image quality and faster printing speeds. In response to such demands, a composite resin in which a polyester resin having excellent low-temperature fixability is bonded to an addition polymerization resin through a covalent bond has been proposed as a binder resin for toner.
In Patent Document 1, a polyester resin obtained by polycondensing a polycondensable monomer containing a carboxylic acid component and an alcohol component with polyethylene terephthalate, and a vinyl resin obtained by addition polymerizing an addition polymerizable monomer are used. The polyethylene terephthalate contains an amorphous composite resin chemically bonded via a bireactive monomer capable of reacting with both the condensation monomer and the addition polymerizable monomer, and the polyethylene terephthalate has an IV value of 0.40 or more. It is disclosed that a toner having excellent low-temperature fixability can be obtained by using a binder resin composition for a toner containing polyethylene terephthalate having a molecular weight of 75 or less.
Further, Patent Document 2 discloses a toner having toner particles containing a binder resin and a colorant, wherein the binder resin is obtained by polymerizing a vinyl monomer in the absence of a polyester unit and its raw material. It is disclosed that by using a hybrid resin in which a vinyl polymer unit and a polyester unit are chemically bonded, a toner with excellent low-temperature fixing properties, storage stability, and control of toner fusion to a photosensitive drum can be obtained. ing.

JP 2018-13523 Publication JP 2018-10124 Publication

Generally, by lowering the minimum fixing temperature and increasing the temperature at which high-temperature offset occurs, the fixing temperature range is widened, and demands for energy saving and high-speed fixing can be met. Therefore, there is a high demand for toner binder resins and toners that have a wide fixing temperature range.
In addition, toners are generally required to have heat-resistant storage properties such that toner particles do not aggregate even when stored for long periods of time under high temperature and high humidity conditions.
However, in the toner disclosed in Patent Document 1, the vinyl resin constituting the composite resin is obtained by addition polymerizing a vinyl monomer in the presence of a polycondensable monomer containing a carboxylic acid component and an alcohol component, and polyethylene terephthalate. Therefore, there are problems in controlling the molecular weight and molecular weight distribution and monomer copolymerizability. Therefore, it was subsequently found that the composite resin obtained by polycondensing the polycondensable monomer and polyethylene terephthalate did not have sufficient high-temperature offset resistance.
Further, in the toner disclosed in Patent Document 2, since the acid value of the vinyl polymer constituting the hybrid resin is low, the composite of the resin is insufficient, and the high temperature offset resistance and heat storage stability are insufficient.
Furthermore, since the crushability of the resin decreases due to the increase in molecular weight due to the compounding of the resin, improvements in productivity such as crushability are also required.
The present invention provides a binder resin for a toner, a toner for developing an electrostatic image, and a binder resin for a toner, which has a wide fixing temperature range while maintaining excellent low-temperature fixability, and has excellent heat-resistant storage stability and productivity. Relating to a manufacturing method.

The present inventors have proposed a toner binder resin containing a composite resin in which a polyester resin unit with excellent low-temperature fixing properties and an addition polymer resin unit with excellent high-temperature offset resistance are bonded via a covalent bond. The addition polymerization resin constituting the addition polymerization resin unit of the composite resin contains 60% by mass or more of a structural unit derived from a (meth)acrylic monomer, and the acid value of the addition polymerization resin is a predetermined value or more. It has been found that the above problems can be solved by doing so.
That is, the present invention relates to the following embodiments [1] to [3].
[1] A toner binder resin containing a composite resin in which an addition polymerization resin unit and a polyester resin unit are bonded via a covalent bond,
The addition polymerization resin (A) constituting the addition polymerization resin unit contains 60% by mass or more of structural units derived from (meth)acrylic monomers,
A binder resin for toner, wherein the addition polymerization resin (A) has an acid value of 40 mgKOH/g or more.
[2] A toner for developing an electrostatic image, containing the toner binder resin described in [1] above.
[3] A method for producing a binder resin for toner containing a composite resin in which an addition polymerization resin unit and a polyester resin unit are bonded via a covalent bond,
Step I: A step of polymerizing the raw material monomer (a) to obtain an addition polymerized resin (A), and Step II: After reacting the alcohol component (b-al) and the carboxylic acid component (b-ac), A step of adding the addition polymerization resin (A) obtained in Step I to perform a reaction to obtain the composite resin,
The raw material monomer (a) contains 60% by mass or more of a (meth)acrylic monomer,
A method for producing a binder resin for toner, wherein the addition polymerization resin (A) has an acid value of 40 mgKOH/g or more.

According to the present invention, there is provided a binder resin for toner, a toner for developing an electrostatic image, and a binder resin for toner that has a wide fixing temperature range while maintaining excellent low-temperature fixability, and has excellent heat-resistant storage stability and productivity. A method for producing a bonded resin can be provided.

[Binder resin for toner]
The binder resin for toner of the present invention (hereinafter also referred to as "the binder resin of the present invention") contains a composite resin in which an addition polymerization resin unit and a polyester resin unit are bonded via a covalent bond. do.
The addition polymerization resin (A) constituting the addition polymerization resin unit contains 60% by mass or more of structural units derived from (meth)acrylic monomers, and the acid value of the addition polymerization resin (A) is 40 mgKOH. /g or more.
The toner of the present invention has a wide fixing temperature range while maintaining excellent low-temperature fixability, and exhibits excellent heat-resistant storage stability and productivity.

The reason why the effects of the present invention can be obtained is not clear, but it is thought to be as follows.
The addition polymerization resin unit of the composite resin contained in the binder resin of the present invention is such that the constituting addition polymerization resin contains 60% by mass or more of structural units derived from a (meth)acrylic monomer, and the addition polymerization resin unit contains an acid of the addition polymerization resin. By setting the value to 40 mgKOH/g or more, it becomes easier to control the molecular motion of the composite resin at low temperatures and the entanglement of polymer chains at high temperatures, and the resin has low viscosity at low temperatures and high elasticity at high temperatures, improving low-temperature fixing properties. In addition to improving high-temperature offset resistance and widening the fixing temperature range, it also improves heat-resistant storage stability and maintains high viscosity during toner production, so shearing force is efficiently applied. It is thought that the mixability with other components such as colorants contained in the toner is improved, and productivity can be improved.

Definitions of various terms used in this specification are shown below.
The crystallinity of the resin is expressed by the crystallinity index defined as the ratio of the softening point to the maximum endothermic peak temperature measured by differential scanning calorimetry (DSC), ie, "softening point/maximum endothermic peak temperature." Generally, when this crystallinity index exceeds 1.4, the resin is amorphous, and when it is less than 0.6, crystallinity is low and there are many amorphous parts. In the present invention, "amorphous resin" refers to a resin with a crystallinity index of more than 1.4 or less than 0.6, and "crystalline resin" refers to a resin with a crystallinity index of 0.6 or more, It is preferably 0.7 or more, more preferably 0.9 or more, and 1.4 or less, preferably 1.2 or less.
The above-mentioned "maximum endothermic peak temperature" refers to the temperature of the peak with the largest peak area among the endothermic peaks observed under the conditions of the measurement method described in the Examples.
The crystallinity of the resin can be adjusted by the types and ratios of raw material monomers, manufacturing conditions (for example, reaction temperature, reaction time, cooling rate), and the like.
The "polyester resin" may include a polyester resin modified to the extent that its properties are not substantially impaired. Examples of modified polyester resins include urethane-modified polyester resins in which polyester resins are modified with urethane bonds, and epoxy-modified polyester resins in which polyester resins are modified with epoxy bonds.
"Bisphenol A" means 2,2-bis(4-hydroxyphenyl)propane.
Examples of the "carboxylic acid compound" include carboxylic acids, their anhydrides, and alkyl esters having 1 to 3 carbon atoms. Note that the number of carbon atoms in the alkyl group of the alkyl ester is not included in the number of carbon atoms in the carboxylic acid compound.
"Binder resin" means a resin component containing a composite resin in the toner.

<Composite resin>
A composite resin is a resin in which an addition polymerization resin unit and a polyester resin unit are bonded via a covalent bond.
The addition polymerization resin (A) constituting the addition polymerization resin unit (hereinafter also referred to as "addition polymerization resin (A)") contains 60% by mass or more of structural units derived from (meth)acrylic monomers. The addition polymerization resin (A) has an acid value of 40 mgKOH/g or more.

[Addition polymerization resin (A)]
(Raw material monomer (a))
The addition polymerization resin (A) constitutes the addition polymerization resin unit of the composite resin, from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixability, and from the viewpoint of improving heat-resistant storage stability and productivity. It is an addition polymer of addition polymerizable raw material monomer (a).
From the same viewpoint as above, the raw material monomer (a) contains 60% by mass or more of a (meth)acrylic monomer. One type or two or more types of raw material monomers (a) may be used. That is, the addition polymerization resin (A) may be a homopolymer using only one type of raw material monomer (a), or a copolymer using two or more types of raw material monomer (a). However, a copolymer is preferable.

Examples of the (meth)acrylic monomer include acrylic acid, methacrylic acid, and (meth)acrylic acid derivatives.
Examples of (meth)acrylic acid derivatives include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, Isobutyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, (meth)acrylate Decyl acid, lauryl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, methoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate , 2-chloroethyl (meth)acrylate, phenyl (meth)acrylate, 2-(dimethylamino)ethyl (meth)acrylate, 2-(diethylamino)ethyl (meth)acrylate, methyl α-chloroacrylate, etc. Examples include (meth)acrylic acid esters. Note that the (meth)acrylic ester may have a hydroxyl group, such as 2-hydroxyethyl methacrylate.
Here, "(meth)acrylic acid" includes both acrylic acid and methacrylic acid. Furthermore, "(meth)acrylic ester" includes both acrylic ester and methacrylic ester.
Among these, the (meth)acrylic monomer preferably contains one or more selected from acrylic acid and methacrylic acid from the viewpoint of giving the addition polymerization resin (A) a desired acid value.

The raw material monomer (a) may contain a styrene compound as a monomer other than the (meth)acrylic monomer.
Examples of styrene compounds include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-chlorostyrene, vinylnaphthalene, etc. Examples include styrene and styrene derivatives, with styrene and α-methylstyrene being preferred.

Furthermore, the raw material monomer (a) may contain other monomers than the (meth)acrylic monomer and the styrene compound.
Other monomers include, for example, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene; diolefins such as butadiene; halobinyls such as vinyl chloride, vinyl bromide, and vinyl fluoride; vinyl acetate; Examples include vinyl esters such as vinyl propionate, vinyl formate, and vinyl caproate; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride; and N-vinyl compounds such as N-vinylpyrrole and N-vinylpyrrolidone. It will be done.

The raw material monomer (a) preferably contains one or more types selected from acrylic acid and methacrylic acid as a (meth)acrylic monomer, more preferably selected from acrylic acid and methacrylic acid as a (meth)acrylic monomer. Contains one or more types and a (meth)acrylic acid alkyl ester.
The number of carbon atoms in the alkyl group in the (meth)acrylic acid alkyl ester is preferably 1 or more, and preferably 22 or less, more preferably 18 or less, still more preferably 12 or less, still more preferably 8 or less.
Note that the number of carbon atoms in the alkyl group of the (meth)acrylic acid alkyl ester means the carbon number derived from the alcohol component constituting the (meth)acrylic acid alkyl ester.
(Meth)acrylic acid alkyl esters include methyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, n-butyl methacrylate, and 2-ethyl acrylate. Preferred examples include one or more selected from hydroxyethyl.

The content of the (meth)acrylic monomer in the raw material monomer (a) constituting the addition polymerization resin (A) or the content of structural units derived from the (meth)acrylic monomer in the addition polymerization resin (A) is , from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixability, and from the viewpoint of further improving heat-resistant storage stability and productivity, the content is 60% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass. % or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and preferably 100% by mass or less.
When the raw material monomer (a) constituting the addition polymerization resin (A) contains one or more selected from acrylic acid and methacrylic acid, the total content of acrylic acid and methacrylic acid in the raw material monomer (a) or addition polymerization The total content of structural units derived from acrylic acid and structural units derived from methacrylic acid in the system resin (A) is determined from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixing properties, as well as improving heat-resistant storage stability and productivity. From the viewpoint of further improvement, the content is preferably 0.5% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, even more preferably 8% by mass or more, and even more preferably 10% by mass or more. , preferably 40% by mass or less, more preferably 30% by mass or less, still more preferably 20% by mass or less, still more preferably 15% by mass or less.
When the raw material monomer (a) constituting the addition polymerization resin (A) contains a styrene compound, the content of the styrene compound in the raw material monomer (a) constituting the addition polymerization resin (A) or the addition polymerization system The content of the structural unit derived from the styrene compound in the resin (A) is preferably from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and from the viewpoint of further improving heat-resistant storage stability and productivity. 0% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 15% by mass or more, even more preferably 20% by mass or more, and preferably 40% by mass or less, more preferably is 30% by mass or less, more preferably 25% by mass or less.

The total content of the (meth)acrylic monomer and styrene compound in the raw material monomer (a) constituting the addition polymerization resin (A) or the composition derived from the (meth)acrylic monomer in the addition polymerization resin (A) The total content of units and structural units derived from styrene compounds is preferably 90% by mass from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and from the viewpoint of further improving heat-resistant storage stability and productivity. The content is more preferably 95% by mass or more, still more preferably 99% by mass or more, and 100% by mass or less, still more preferably 100% by mass.

In the present invention, the addition polymerization resin (A) constituting the addition polymerization resin unit may be formed by a bulk polymerization method, a solution polymerization method, a suspension polymerization method, or an emulsion polymerization method. Among these, addition polymerization resin (A) controls molecular weight, molecular weight distribution, and copolymerizability of monomers, maintains excellent low-temperature fixing properties, widens the fixing temperature range, and improves heat-resistant storage stability and productivity. In view of this, it is preferable that the polyester resin be formed by bulk polymerization in the absence of the polyester resin constituting the polyester resin unit or the polycondensation monomer constituting the polyester resin.
In the present invention, "bulk polymerization" refers to addition polymerization carried out under conditions in which a solvent is substantially absent in the reaction system, ie, under solvent-free conditions.

A radical generator may be used for bulk polymerization.
Examples of the radical generator include peroxides such as di-tert-butyl peroxide, persulfates such as sodium persulfate, and azo compounds such as 2,2'-azobis(2,4-dimethylvaleronitrile). can be mentioned.
The concentration of the radical generator in bulk polymerization is determined from the viewpoints of controlling the molecular weight, molecular weight distribution, and copolymerizability, widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and further improving heat-resistant storage stability and productivity. , preferably 10 parts by mass or less, more preferably 7 parts by mass or less, still more preferably 5 parts by mass or less, and even more preferably 3 parts by mass, per 100 parts by mass of the raw material monomer (a) of the addition polymerization resin (A). parts by weight or less, more preferably 2 parts by weight or less, still more preferably 1 part by weight or less, still more preferably 0.5 parts by weight or less, and even more preferably 0 parts by weight or less, that is, it is preferable to carry out under catalyst-free conditions.

The bulk polymerization is preferably carried out at high temperature under pressure equal to or higher than normal pressure, and more preferably continuous bulk polymerization under high temperature and high pressure.
In the present invention, the pressurized state refers to a state in which the contents are heated to a temperature higher than the boiling point under normal pressure in a closed container such as an autoclave.
The radicals generated by the thermal initiation reaction of the raw material monomer (a) at high temperatures under pressure above normal pressure function as a polymerization initiator, allowing addition polymerization to proceed even under conditions where there is a relatively small amount of radical generator. It is possible to obtain an addition polymerization resin (A) having a narrow molecular weight distribution.
Furthermore, in the case of continuous bulk polymerization under high temperature and high pressure, the monomer composition distribution can be controlled in addition to the molecular weight distribution, and a more uniform addition polymerization resin (A) with a narrow monomer composition distribution can be obtained. As a result, the fixing temperature range can be widened while maintaining excellent low-temperature fixing properties, and heat-resistant storage stability and pulverizability can be further improved.
From the above point of view, the temperature of bulk polymerization is preferably 140°C or higher, more preferably 180°C or higher, even more preferably 220°C or higher, even more preferably 260°C or higher, even more preferably 280°C or higher, and is 350°C or less, more preferably 320°C or less.

The acid value of the addition polymerization resin (A) is such that it can be sufficiently composited with the polyester resin (B) constituting the polyester resin unit, and from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixability, And from the viewpoint of further improving heat-resistant storage stability and productivity, it is 40 mgKOH/g or more, preferably 43 mgKOH/g or more, more preferably 46 mgKOH/g or more, still more preferably 48 mgKOH/g or more, and still more preferably 50 mgKOH/g. Above, more preferably 60 mgKOH/g or more, still more preferably 70 mgKOH/g or more, still more preferably 80 mgKOH/g or more, and preferably 300 mgKOH/g or less, more preferably 200 mgKOH/g or less, still more preferably 150 mgKOH/g. g or less, more preferably 100 mgKOH/g or less.

The weight average molecular weight of the addition polymerization resin (A) is preferably 5,000 or more, from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixability, and from the viewpoint of improving heat-resistant storage stability and productivity. Preferably 6,000 or more, more preferably 7,000 or more, still more preferably 8,000 or more, even more preferably 9,000 or more, and preferably 200,000 or less, more preferably 100,000 or less, More preferably 50,000 or less, still more preferably 30,000 or less, even more preferably 20,000 or less, still more preferably 15,000 or less, still more preferably 13,000 or less.
The weight average molecular weight of the addition polymerization resin (A) can be adjusted by adjusting the polymerization temperature and polymerization time.

The glass transition temperature of the addition polymerization resin (A) is preferably 45°C or higher, from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and from the viewpoint of further improving heat-resistant storage stability and productivity. The temperature is preferably 50°C or higher, more preferably 55°C or higher, even more preferably 60°C or higher, and preferably 120°C or lower, more preferably 90°C or lower, even more preferably 80°C or lower, and even more preferably 70°C or lower. It is.
The softening point of the addition polymerization resin (A) is preferably 90° C. or higher, more preferably 90° C. or higher, from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and from the viewpoint of further improving heat-resistant storage stability and crushability. is 100°C or higher, more preferably 105°C or higher, even more preferably 110°C or higher, and is preferably 160°C or lower, more preferably 140°C or lower, even more preferably 130°C or lower. Among these, the addition polymerization resin (A) constituting the addition polymerization resin unit is suitable for use with glass, from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and from the viewpoint of further improving heat-resistant storage stability and productivity. More preferably, the transition temperature is 50°C or higher and the softening point is 105°C or higher.
The acid value, weight average molecular weight, glass transition temperature, and softening point of the addition polymerization resin (A) can be measured by the methods described in Examples.

[Polyester resin (B)]
The polyester resin (B) constitutes the polyester resin unit of the composite resin, and is preferably This is a polyester resin containing a polycondensate of an alcohol component (b-al) and a carboxylic acid component (b-ac) as a raw material monomer (b).

(Raw material monomer (b))
The raw material monomer (b) is a constituent component of the polyester resin (B), and preferably contains an alcohol component (b-al) and a carboxylic acid component (b-ac).

[Alcohol component (b-al)]
Examples of the alcohol component (b-al) include diols such as aromatic diols, aliphatic diols, and alicyclic diols, and polyhydric alcohols having a valence of 3 or more.
Examples of aromatic diols include alkylene oxide adducts of bisphenol A [2,2-bis(4-hydroxyphenyl)propane] (hereinafter also referred to as "BPA-AO"). BPA-AO preferably has the formula (I):

[In the formula, OR ¹¹ and R ¹² O are alkyleneoxy groups, R ¹¹ and R ¹² are each independently an alkylene group having 1 to 4 carbon atoms (preferably an ethylene group or a propylene group), and x and y are the average number of added moles of alkylene oxide, each independently a positive number, and the average value of the sum of x and y is preferably 1 or more, more preferably 1.5 or more, even more preferably The number is 2 or more, and preferably 16 or less, more preferably 8 or less, and even more preferably 4 or less. ] BPA-AO is exemplified.

BPA-AO specifically includes polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene (3.3)-2,2-bis(4- hydroxyphenyl)propane, polyoxyethylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene(2.0)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene(2.2)-2,2-bis(4-hydroxyphenyl)propane, Oxypropylene (2.0)-polyoxyethylene (2.0)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene (6)-2,2-bis(4-hydroxyphenyl)propane, etc. can be mentioned.
The numerical value in parentheses above corresponds to the average value of the sum of x and y in the above formula (I).

BPA-AO is preferably selected from propylene oxide adducts of bisphenol A (hereinafter also referred to as "BPA-PO") and ethylene oxide adducts of bisphenol A (hereinafter also referred to as "BPA-EO"). One or more types. These BPA-AO may be used alone or in combination of two or more.
Furthermore, BPA-AO may be used in combination with BPA-PO and BPA-EO.

The number of carbon atoms in the aliphatic diol is preferably 2 or more, and preferably 18 or less, more preferably 14 or less, still more preferably 10 or less, and still more preferably 6 or less.
Examples of aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, Examples include 1,6-hexanediol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, and polytetramethylene glycol.

Examples of the alicyclic diol include 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, and alkylene oxide adducts having 2 to 4 carbon atoms (average number of added moles of 2 to 12) of hydrogenated bisphenol A. It will be done.

Examples of trivalent or higher polyhydric alcohols include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, and 1,2,4-butane. Triol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene can be mentioned.
Note that from the viewpoint of adjusting the molecular weight and softening point of the resin, the alcohol component (b-al) may include a monohydric alcohol.
These alcohol components may be used alone or in combination of two or more.

Among these, the alcohol component (b-al) is preferably one or more selected from alkylene oxide adducts of bisphenol A, ethylene glycol, 1,2-propanediol, 1,3-propanediol, and neopentyl glycol. , more preferably an alkylene oxide adduct of bisphenol A (BPA-AO).
The amount of BPA-AO is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, even more preferably 98 mol% or more in the alcohol component (b-al), and , 100 mol% or less, more preferably 100 mol%.
When BPA-PO and BPA-EO are used together as BPA-AO, the amount of BPA-PO in the total amount of BPA-PO and BPA-EO is preferably 20 mol% or more, more preferably 30 mol% or more. , more preferably 40 mol% or more, still more preferably 50 mol% or more, and 100 mol% or less.

[Carboxylic acid component (b-ac)]
Examples of the carboxylic acid component (b-ac) include dicarboxylic acid compounds and trivalent or higher polyvalent carboxylic acid compounds.

Examples of dicarboxylic acid compounds include aromatic dicarboxylic acid compounds, aliphatic dicarboxylic acid compounds, and alicyclic dicarboxylic acid compounds.
The number of carbon atoms in the dicarboxylic acid compound is preferably 2 or more, more preferably 3 or more, and preferably 30 or less, more preferably 20 or less.
Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid and terephthalic acid are preferred, and terephthalic acid is more preferred.
Examples of aliphatic dicarboxylic acid compounds include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, pentanedioic acid, adipic acid, sebacic acid, dodecanedioic acid, and azelaic acid. , succinic acid substituted with an aliphatic hydrocarbon group having 1 or more and 20 or less carbon atoms.
Examples of the succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms include n-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octenylsuccinic acid, n-dodecenylsuccinic acid, -Octylsuccinic acid, isooctenylsuccinic acid, isooctylsuccinic acid, etc.
Examples of the alicyclic dicarboxylic acid include cyclohexanedicarboxylic acid and the like.

Examples of trivalent or higher polycarboxylic acid compounds include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, and pyromellitic acid.

Among these, the carboxylic acid component (b-ac) preferably contains one or more selected from terephthalic acid, isophthalic acid, maleic acid, fumaric acid, alkenylsuccinic acid, and trimellitic acid, and more preferably, It contains one or more selected from terephthalic acid, isophthalic acid, fumaric acid, and trimellitic acid, and more preferably one or more aromatic dicarboxylic acid compounds selected from terephthalic acid and isophthalic acid.
The amount of the aromatic dicarboxylic acid compound in the carboxylic acid component (b-ac) is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more. The content is 100 mol% or less, more preferably 100 mol%.

Note that the carboxylic acid component (b-ac) may contain a trivalent or higher polyvalent carboxylic acid compound as appropriate from the viewpoint of controlling the degree of polymerization of the resin.

The equivalent ratio [COOH group/OH group] of the carboxy group (COOH group) of the carboxylic acid component (b-ac) to the hydroxy group (OH group) of the alcohol component (b-al) is preferably 0.5 or more, and more It is preferably 0.6 or more, more preferably 0.7 or more, and preferably 1.2 or less, more preferably 1.0 or less, and even more preferably 0.9 or less.

(polyethylene terephthalate)
The polyester resin (B) is preferably polyethylene terephthalate (hereinafter also referred to as "PET") from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and improving heat-resistant storage stability and crushability. and the raw material monomer (b).
PET is a polycondensate of ethylene glycol, terephthalic acid, dimethyl terephthalate, etc., and the terminal functional group of PET and the raw material monomer (b) are condensed, and the component is incorporated into the polyester resin (B). It is. PET may depolymerize during condensation with the raw material monomer (b), producing ethylene glycol, terephthalic acid, or decomposed polymer chains, which can become constituent components of the polyester resin (B). .

The intrinsic viscosity (hereinafter also referred to as "IV value") of PET is preferably 0.4 or more, more preferably 0.45 or more, still more preferably 0.5 or more, and even more preferably It is 0.55 or more, more preferably 0.6 or more, and preferably 0.8 or less, more preferably 0.75 or less, and still more preferably 0.7 or less. The IV value is an indicator of molecular weight. The IV value of PET can be adjusted by adjusting the molar ratio of raw material monomers, polycondensation time, etc.
To measure the IV value, for example, dissolve the sample in a mixed solvent of phenol/tetrachloroethane = 60/40 (mass ratio) at a concentration of 0.4 g/dL, measure with an Ubbelohde viscometer, and use the following formula: It can be calculated according to

[In the formula, k is Huggins' constant, C is the concentration of the sample solution (g/dL), η = (t ₁ /t ₀ )-1, and t ₀ is the number of seconds in which the solvent only falls. t ₁ is the number of seconds the sample solution falls. Let k be 0.33. ]

PET manufactured according to a conventional method or a commercially available product can be used.
Commercially available PET products include, for example, "RAMAPET BF3067" (IV value: 0.64), "RAMAPET L1" (IV value: 0.60), and "RAMAPET N2G" (IV value: 0.64) manufactured by Indorama Ventures. 75); Examples include "TRN-NTJ" (IV value: 0.53) and "TRN-RTJC" (IV value: 0.64) manufactured by Teijin Ltd.

The amount of the PET component in the polyester resin (B) is determined from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and from the viewpoint of further improving heat-resistant storage stability and crushability. b-al) is preferably 5 mol parts or more, more preferably 7 mol parts or more, even more preferably 10 mol parts or more, and preferably 50 mol parts or less, more preferably is 40 mol parts or less, more preferably 30 mol parts or less.
The number of moles of the PET component is calculated as the number of moles of condensed units of ethylene glycol and terephthalic acid.

The amount of addition polymerization resin (A) in the composite resin according to the present invention is determined from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixability, and from the viewpoint of further improving heat-resistant storage stability and productivity. Based on 100 parts by mass of resin (B), preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 3 parts by mass or more, still more preferably 4 parts by mass or more, and preferably 50 parts by mass. parts by weight or less, more preferably 30 parts by weight or less, still more preferably 20 parts by weight or less, still more preferably 10 parts by weight or less, still more preferably 7 parts by weight or less, still more preferably 5 parts by weight or less.

The softening point of the composite resin according to the present invention is preferably 70°C or higher, more preferably 80°C or higher, even more preferably 90°C or higher, even more preferably 100°C or higher, and preferably 170°C or lower, more preferably is 150°C or lower, more preferably 140°C or lower, even more preferably 135°C or lower, even more preferably 130°C or lower, even more preferably 120°C or lower, even more preferably 115°C or lower.
The glass transition temperature of the composite resin according to the present invention is preferably 50°C or higher, more preferably 53°C or higher, and preferably 80°C or lower, more preferably 70°C or lower, and still more preferably 60°C or lower. .
The acid value of the composite resin according to the present invention is preferably 50 mgKOH/g or less, more preferably 40 mgKOH/g or less, even more preferably 30 mgKOH/g or less, even more preferably 20 mgKOH/g or less, even more preferably 15 mgKOH/g or less. It is preferably 2 mgKOH/g or more, more preferably 3 mgKOH/g or more.
The hydroxyl value of the composite resin according to the present invention is preferably 10 mgKOH/g or more, more preferably 20 mgKOH/g or more, still more preferably 30 mgKOH/g or more, still more preferably 40 mgKOH/g, and preferably 80 mgKOH/g. g or less, more preferably 70 mgKOH/g or less, even more preferably 60 mgKOH/g or less, still more preferably 55 mgKOH/g or less.
In order to bring the softening point, glass transition temperature, acid value, and hydroxyl value of the composite resin according to the present invention into these ranges, adjustment of the type and amount of raw material monomers, amount of radical generator, amount of catalyst, etc., or selection of reaction conditions is required. This can be easily done by
The softening point, glass transition temperature, acid value, and hydroxyl value of the composite resin according to the present invention can be measured by the methods described in Examples.

The binder resin of the present invention contains the composite resin as an amorphous polyester resin from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixability, and from the viewpoint of further improving heat-resistant storage stability and productivity. It is preferable to do so.

The binder resin of the present invention preferably has a softening point of 5° C. or higher, more preferably It is preferable to contain two or more types of amorphous polyester resins that differ from each other by 10° C. or more, and it is more preferable to contain the composite resin as an amorphous polyester resin having a low softening point.
Among the two or more types of amorphous polyester resins, the softening point of the polyester resin having the lowest softening point is preferably 70°C or higher, more preferably 80°C or higher, from the viewpoint of improving heat-resistant storage stability. The temperature is more preferably 90°C or higher, even more preferably 100°C or higher, and from the viewpoint of improving low-temperature fixability, the temperature is preferably 135°C or lower, more preferably 120°C or lower, and even more preferably 115°C or lower.
Among the two or more types of amorphous polyester resins, the softening point of the polyester resin having the highest softening point is preferably 110°C or higher, more preferably 120°C or higher, from the viewpoint of improving high temperature offset resistance. From the viewpoint of improving low-temperature fixability, the temperature is preferably 170°C or lower, more preferably 150°C or lower, and even more preferably 140°C or lower.
As the binder resin of the present invention, from the viewpoint of improving toner productivity, it is preferable to use two kinds of binder resins, a high softening point amorphous polyester resin and a low softening point amorphous polyester resin.
The difference in softening point between a polyester resin with a high softening point and a polyester resin with a low softening point is preferably 5°C or higher, more preferably 7°C or higher, and even more preferably 10°C or higher, from the viewpoint of high temperature offset resistance. And, from the viewpoint of low-temperature fixability and heat-resistant storage stability, the temperature is preferably 60°C or lower, more preferably 50°C or lower, even more preferably 40°C or lower, even more preferably 30°C or lower, and still more preferably 25°C or lower. .

The content of the composite resin in the binder resin of the present invention is preferably 50% by mass from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and from the viewpoint of further improving heat-resistant storage stability and productivity. The above is more preferably 55% by mass or more, still more preferably 60% by mass or more, and 100% by mass or less, preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less. be.

<Amorphous polyester resin>
The binder resin of the present invention may further contain an amorphous polyester resin from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixability, and from the viewpoint of further improving heat-resistant storage stability and productivity. preferable.
The amorphous polyester resin preferably has a softening point different from that of the composite resin, and more preferably has a softening point higher than the softening point of the composite resin. That is, the binder resin of the present invention preferably contains the composite resin as an amorphous polyester resin with a low softening point and the amorphous polyester resin as an amorphous polyester resin with a high softening point. . In this case, the difference between the softening points of the composite resin and the amorphous polyester resin is in the same range as the difference in softening points between the high softening point polyester resin and the low softening point polyester resin described above. It is preferable.

The amorphous polyester resin is preferably an amorphous polyester resin that is a condensate of an alcohol component and a carboxylic acid component.
Examples of the alcohol component and carboxylic acid component of the amorphous polyester resin are the same as those of the alcohol component (b-al) and carboxylic acid component (b-ac) of the polyester resin (B) described above.
As the alcohol component of the amorphous polyester resin, BPA-AO is preferable.
BPA-AO is preferably one or more selected from BPA-PO and BPA-EO.
As the carboxylic acid component of the amorphous polyester resin, aromatic dicarboxylic acid compounds, aliphatic dicarboxylic acid compounds, and trivalent or higher polyvalent carboxylic acid compounds are preferable.
As the aromatic dicarboxylic acid compound, terephthalic acid and isophthalic acid are preferred, and terephthalic acid is more preferred.
The amount of the aromatic dicarboxylic acid compound in the carboxylic acid component is preferably 20 mol% or more, more preferably 40 mol% or more, even more preferably 60 mol% or more, and preferably 90 mol% or less, more preferably is 80 mol% or less, more preferably 70 mol% or less.
As the aliphatic dicarboxylic acid compound, maleic acid, fumaric acid, and alkenylsuccinic acid are preferred, and alkenylsuccinic acid is more preferred.
The amount of the aliphatic dicarboxylic acid compound in the carboxylic acid component is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, and preferably 20 mol% or less, more preferably is 15 mol% or less, more preferably 10 mol% or less.
As the trivalent or higher polyvalent carboxylic acid compound, trimellitic acid or its anhydride is preferred.
The amount of the trivalent or higher polycarboxylic acid compound is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and preferably 40 mol% in the carboxylic acid component. The content is more preferably 35 mol% or less, still more preferably 30 mol% or less.

(Physical properties of amorphous polyester resin)
The softening point of the amorphous polyester resin is preferably 90°C or higher, more preferably 100°C or higher, even more preferably 110°C or higher, even more preferably 120°C or higher, even more preferably higher than 120°C, and preferably is 170°C or lower, more preferably 150°C or lower, even more preferably 130°C or lower.
When the softening point of the composite resin is 80°C or higher and 120°C or lower, the softening point of the amorphous polyester resin is preferably higher than 120°C, more preferably 123°C or higher, and preferably 170°C or lower. , more preferably 150°C or lower, still more preferably 130°C or lower.

The glass transition temperature of the amorphous polyester resin is preferably 40°C or higher, more preferably 45°C or higher, even more preferably 50°C or higher, and preferably 90°C or lower, more preferably 80°C or lower, and Preferably it is 70°C or lower.

The acid value of the amorphous polyester resin is preferably 2 mgKOH/g or more, more preferably 5 mgKOH/g or more, even more preferably 10 mgKOH/g or more, and preferably 40 mgKOH/g or less, more preferably 30 mgKOH/g. g or less, more preferably 20 mgKOH/g or less.
The hydroxyl value of the amorphous polyester resin is preferably 10 mgKOH/g or more, more preferably 20 mgKOH/g or more, even more preferably 30 mgKOH/g or more, and preferably 50 mgKOH/g or less, more preferably 45 mgKOH/g. g or less, more preferably 40 mgKOH/g or less.

The softening point, glass transition temperature, acid value, and hydroxyl value of the amorphous polyester resin should be adjusted as appropriate depending on the type of raw material monomer and its charging molar ratio, as well as manufacturing conditions such as reaction temperature, reaction time, and cooling rate. I can do it. These values are determined by the method described in Examples below. In addition, when using a combination of two or more kinds of amorphous polyester resins, it is preferable that the values of the physical properties obtained as the mixture are each within the above range.

The content of the amorphous polyester resin in the binder resin of the present invention is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and preferably 50% by mass or more. % or less, more preferably 45% by mass or less, still more preferably 40% by mass or less.
The mass ratio [composite resin/amorphous polyester resin] of the composite resin and the amorphous polyester resin contained in the binder resin of the present invention is preferably 0.5 or more, more preferably 1.0 or more, It is more preferably 1.5 or more, still more preferably 1.7 or more, and is preferably 4.0 or less, more preferably 3.0 or less, still more preferably 2.0 or less.

<Crystalline polyester resin>
The binder resin of the present invention preferably further contains a crystalline polyester resin, from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixability, and from the viewpoint of further improving heat-resistant storage stability and productivity. .
Examples of the crystalline polyester resin include a crystalline polyester resin and a crystalline composite resin having a polyester resin segment and a vinyl resin segment. As the crystalline polyester resin, for example, a polycondensate of an alcohol component containing an α,ω-aliphatic diol having 2 to 16 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 2 to 14 carbon atoms; can be mentioned. Specifically, examples of the crystalline polyester resin include those described in JP-A No. 2016-45358.

The content of the crystalline polyester resin in the binder resin of the present invention is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and even more preferably 3% by mass. % or more, and preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 7% by mass or less.

The total content of the composite resin, amorphous polyester resin, and crystalline polyester resin in the binder resin of the present invention is determined from the viewpoint of widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and heat-resistant storage stability. From the viewpoint of further improving the pulverizability, the content is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 98% by mass or more, and 100% by mass or less.
Mass ratio of the total content of the composite resin and amorphous polyester resin contained in the binder resin of the present invention to the content of the crystalline polyester resin [(total content of the composite resin and amorphous polyester resin) amount)/(content of crystalline polyester resin)] is preferably 70/30 or more, more preferably 80/20 or more, even more preferably 90/10 or more, and from the viewpoint of low temperature fixability, Preferably it is 98/2 or less, more preferably 97/3 or less, still more preferably 96/4 or less.

[Method for producing binder resin for toner]
The binder resin of the present invention is made by combining an addition polymerization resin (A) constituting an addition polymerization resin unit and a polyester resin (B) constituting a polyester resin unit through a covalent bond to form a composite. It can be manufactured by a method including a step of obtaining the composite resin.

<Manufacture of composite resin>
Compositeization of addition polymerization resin (A) and polyester resin (B) is effective from the viewpoint of achieving sufficient compositeness and widening the fixing temperature range while maintaining excellent low-temperature fixability, as well as improving heat-resistant storage stability and productivity. From the viewpoint of further improving properties, it is preferable to form a covalent bond via a compound that can react with either of these resins (A) and resin (B) (hereinafter also referred to as "bi-reactive compound"). The bireactive compound is preferably a compound that can react with either of the raw material monomers constituting the addition polymerization resin (A) and the polyester resin (B), for example, the following general formulas (II-1) and (II-2). ).

[In the formula, R ²¹ , R ²² and R ²³ are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group which may have a substituent, an alkoxy group, an aryl group, a vinyl group, or a halogen atom; may be bonded to each other to form a ring. A and B are the same or different and represent a group represented by the following general formula (III-1), general formula (III-2) or general formula (III-3). X and Y are the same or different and represent -COOR ⁴ (R ⁴ represents a hydrogen atom or a lower alkyl group which may have a substituent). ]

[In the formula, R ³¹ , R ³² and R ³³ are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group which may have a substituent, an alkoxy group, an aryl group, a vinyl group, or a halogen atom; may be bonded to each other to form a ring. m represents a number of 0 or more and 5 or less, and n represents a number of 0 or more and 2 or less. ]

Here, these bireactive compounds are preferably capable of reacting with either of the raw material monomers of the addition polymerization resin (A) and the polyester resin (B); When there are two or more types of raw material monomers in B), it is sufficient that they can react with at least one of them.

In general formulas (II-1), (II-2), and (III-1) to (III-3), among those represented by R ²¹ to R ²³ and R ³¹ to R ³³ , an alkyl group, an alkoxy group , aryl group, vinyl group, and halogen atom are as follows.
The alkyl group is linear or branched and has 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, such as methyl group, ethyl group, n-propyl group, i-propyl group, n -butyl group and tert-butyl group. These alkyl groups may be substituted with a phenyl group, a naphthyl group, a hydroxyl group, or the like.
Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and a t-butoxy group, and these groups may be substituted with a hydroxyl group, a carboxyl group, or the like.
Examples of the aryl group include a phenyl group, a benzyl group, and a naphthyl group, and these groups may be substituted with a methyl group, an ethyl group, a methoxy group, an ethoxy group, a carboxyl group, a hydroxyl group, and the like.
The vinyl group may be substituted with, for example, a hydroxyl group, a phenyl group, an alkyl group, an alkoxy group, or a carboxyl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a chlorine atom and a bromine atom being preferred.
The lower alkyl group represented by R ⁴ preferably has 1 or more and 4 or less carbon atoms, and includes methyl, ethyl, and the like, and these groups may be substituted with a hydroxyl group or the like.

When X is a carboxy group in general formula (II-2), the compounds represented by general formula (II-2) are represented by the following general formulas (IV-1) to (IV-3). Examples include ethylenically unsaturated monocarboxylic acid compounds.

[In the formula, R ⁴¹ and R ⁴² represent a hydrogen atom, an alkyl group which may have a substituent, an aryl group, a vinyl group, or a halogen atom, as in R ²¹ to R ²³ . R ⁴³ and R ⁴⁴ are the same or different and represent an alkyl group, an aryl group, a vinyl group, or a halogen atom, which may have a substituent, similar to R ²¹ to R ²³ . A is the same as above. ]

Specific examples of ethylenically unsaturated monocarboxylic acid compounds represented by general formulas (IV-1) to (IV-3) include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, and lower alkyl esters and esters thereof. Examples include anhydrides.

When X and Y are carboxyl groups in general formula (II-1), the compounds represented by general formula (II-1) are represented by the following general formulas (V-1) and (V-2). Examples include ethylenically unsaturated dicarboxylic acid compounds.

[In the formula, R ⁵¹ and R ⁵² represent a hydrogen atom, an alkyl group that may have a substituent, an aryl group, a vinyl group, or a halogen atom, as in R ²¹ to R ²³ . A and B are the same as above. ]

Specific examples of ethylenically unsaturated dicarboxylic acid compounds represented by general formulas (V-1) and (V-2) include maleic acid, fumaric acid, itaconic acid, mesaconic acid, citraconic acid, and lower alkyls thereof. Mention may be made of esters and anhydrides.

The dual-reactive compound is preferably an ethylenic compound, from the viewpoint of achieving sufficient compositing, widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and further improving heat-resistant storage stability and productivity. It is a saturated monocarboxylic acid compound, more preferably one or more selected from acrylic acid and methacrylic acid.
The bireactive compound is introduced into the polymer skeleton as a raw material monomer for either the addition polymerization resin (A) or the polyester resin (B) before compounding, and then introduced into the other resin via the bireactive compound. It is preferable to composite with the compound, and from the viewpoint of making the composite sufficient, the bireactive compound is introduced into the polymer skeleton as the raw material monomer (a) of the addition polymerization resin (A) before composite. It is more preferable to form a composite with the polyester resin (B) via the polyester resin (B).

The amount of the bireactive compound capable of reacting with both the addition polymerization resin (A) and the polyester resin (B) is determined in the raw material monomer (a) of the addition polymerization resin (A) constituting the addition polymerization resin unit. , preferably 0.5% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass. % or less, more preferably 15% by mass or less.

Methods for compounding addition polymerization resin (A) and polyester resin (B) include (i) polymer reaction between addition polymerization resin (A) and polyester resin (B), (ii) addition A method of reacting the constituent components of the polyester resin (B) in the presence of the polymeric resin (A), (iii) a method of reacting a part of the constituent components of the polyester resin (B), and then reacting the addition polymerized resin ( Examples include a method in which A) and the remainder of the constituent components of the polyester resin (B) are added to carry out the reaction.

In the case of method (i), the addition polymerization resin (A) and the polyester resin (B) are preferably polymerized in independent reaction systems. The polymerization system of the addition polymerization resin (A) is preferably an addition polymerization type, and the polymerization system of the polyester resin (B) is preferably a polycondensation type. As long as the polymerization reactions of the addition polymerization resin (A) and the polyester resin (B) are independent reaction systems, the progress and completion of the two polymerization reactions do not need to be simultaneous in time, and each reaction The reaction may proceed and be completed by appropriately selecting the reaction temperature and time depending on the mechanism.
In addition, in the polymer reaction of method (i), there is no particular restriction on the method of mixing the addition polymerization resin (A) and the polyester resin (B). A method of isolating the polyester resin (B) obtained by condensation and then mixing the polyester resin (B) with addition polymerization resin (A), condensing the raw material monomer (b) and PET as necessary. An example of this method is to add and mix the addition polymerized resin (A) without isolating the resulting polyester resin (B). In method (i), PET may be produced by polycondensation of ethylene glycol with terephthalic acid, dimethyl terephthalate, etc. in a reaction system, or the above-mentioned commercial products may be used.

In the case of method (ii), the constituent component of the polyester resin (B) reacted in the presence of the addition polymerization resin (A) may be the raw material monomer (b), and the raw material monomer (b) and PET may be There may be.

In the case of method (iii), after the alcohol component (b-al) and a part of the carboxylic acid component (b-ac) are reacted, the addition polymerization resin (A) and the carboxylic acid component (b-ac) are reacted. A method of carrying out the reaction by adding the remaining components can be mentioned. When the polyester resin (B) is a condensate of PET and the raw material monomer (b), reaction of the alcohol component (b-al) with a part of the carboxylic acid component (b-ac), and addition It is preferable to add PET to one of the reactions of the polymeric resin (A) and the remainder of the carboxylic acid component (b-ac). In method (iii), PET may be produced by polycondensation of ethylene glycol with terephthalic acid, dimethyl terephthalate, etc. in the reaction system, and the above-mentioned commercial products may be used.

Among these methods, from the viewpoint of controlling the molecular weight, molecular weight distribution, and copolymerizability of monomers, widening the fixing temperature range while maintaining excellent low-temperature fixing properties, and improving heat-resistant storage stability and crushability, Method (i) as described above is preferred. That is, the binder resin of the present invention is preferably produced by a method including the following steps I and II.
Step I: Step of polymerizing the raw material monomer (a) to obtain addition polymerized resin (A) Step II: After reacting the alcohol component (b-al) and the carboxylic acid component (b-ac), Step I A step of adding the addition polymerized resin (A) obtained in step 1 and performing a reaction to obtain the composite resin.

Step I is as explained in the above-mentioned addition polymerization resin (A).
In Step II, the reaction between the alcohol component (b-al) and the carboxylic acid component (b-ac) is preferably a transesterification reaction and a condensation reaction.
In addition, when the polyester resin (B) is a condensate of PET and the raw material monomer (b), Step II includes PET, an alcohol component (b-al), and a carboxylic acid component (b-ac). After reacting, the addition polymerization resin (A) obtained in Step I is added and reacted to obtain the composite resin (hereinafter also referred to as "Step II'").
In the case of step II', a transesterification reaction occurs between ethylene glycol and terephthalic acid, which are the raw material monomers of PET, and an alcohol component (b-al) and a carboxylic acid component (b-ac), forming the polyester resin (B). The compatibility between the PET chain and the polymer chain formed by polycondensation of the alcohol component (b-al) and the carboxylic acid component (b-ac) can be improved.

In Step II or Step II', the reaction of the alcohol component (b-al), the carboxylic acid component (b-ac), and PET used as necessary, and the reaction after adding the addition polymerization resin (A) are , If necessary, an esterification catalyst such as tin (II) 2-ethylhexanoate, dibutyltin oxide, titanium diisopropylate bistriethanolaminate, etc. is added to 100 parts by mass of the total amount of the constituent components of the polyester resin (B). 0.01 parts by mass or more and 5 parts by mass or less; Add an esterification promoter such as gallic acid (same as 3,4,5-trihydroxybenzoic acid) to the total amount of 100 parts by mass of the constituent components of the polyester resin (B). 0.001 parts by mass or more and 0.5 parts by mass or less may be used.
In addition, when using a monomer having an unsaturated bond such as fumaric acid as the raw material monomer (b), preferably 0 A radical polymerization inhibitor of 0.001 parts by mass or more and 0.5 parts by mass or less may be used. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol.
The reaction temperature in Step II or Step II' is preferably 120°C or higher, more preferably 160°C or higher, even more preferably 180°C or higher, and preferably 260°C or lower, more preferably 240°C or lower. . Note that the reaction in step II or step II' may be performed in an inert gas atmosphere.

When the binder resin of the present invention further contains the amorphous polyester resin and the crystalline polyester resin in addition to the composite resin, these resins are added to the composite resin obtained in Step II. It is preferable to include a step of mixing.

[Toner for developing electrostatic images]
The electrostatic image developing toner of the present invention (hereinafter also referred to as "toner of the present invention") contains the binder resin, and preferably contains a colorant and the binder resin.
The toner of the present invention contains, for example, toner particles and external additives.
The toner particles contain the binder resin, preferably a colorant and the binder resin.
The toner particles may contain, for example, a colorant derivative, a charge control agent, a release agent such as wax, and other additives.
The content of the binder resin in the toner is preferably 80% by mass or more, more preferably 85% by mass or more, still more preferably 87% by mass or more, and 100% by mass or less.
The content of the composite resin in the toner is preferably 40% by mass or more, more preferably 45% by mass or more, even more preferably 50% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass. % or less, more preferably 60% by mass or less.

<Colorant>
The colorant may be either a pigment or a dye.
Colorants include various carbon blacks produced by thermal black method, acetylene black method, channel black method, lamp black method, etc.; grafted carbon black in which the surface of carbon black is coated with resin; nigrosine dye; phthalocyanine. Examples include blue, permanent brown FG, brilliant first scarlet, pigment green B, pigment blue 15:3, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, and mixtures thereof.
From the viewpoint of improving the image density of the toner, the content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 20 parts by mass or less, based on 100 parts by mass of the binder resin. , more preferably 17 parts by mass or less.

<Charge control agent>
The toner of the present invention may contain a charge control agent. The charge control agent may contain either a positively chargeable charge control agent or a negatively chargeable charge control agent.
These charge control agents may be used alone or in combination of two or more.

Examples of the positively chargeable charge control agent include nigrosine dyes, triphenylmethane dyes containing a tertiary amine as a side chain, quaternary ammonium salt compounds, polyamine resins, imidazole derivatives, and styrene-acrylic resins.
Nigrosine dyes include "Nigrosine Base EX", "Oil Black BS", "Oil Black SO", "Bontron N-01", "Bontron N-07", and "Bontron N-11" (manufactured by Orient Chemical Industry Co., Ltd.) ). Examples of the quaternary ammonium salt compound include "Bontron P-51" (manufactured by Orient Chemical Industry Co., Ltd.), cetyltrimethylammonium bromide, and "COPY CHARGE PX VP435" (manufactured by Hoechst). Examples of the polyamine resin include "AFP-B" (manufactured by Orient Chemical Industry Co., Ltd.). Examples of imidazole derivatives include "PLZ-2001" and "PLZ-8001" (manufactured by Shikoku Kasei Kogyo Co., Ltd.). Examples of the styrene-acrylic resin include "FCA-701PT" (manufactured by Fujikura Kasei Co., Ltd.).

Specific examples of negatively chargeable charge control agents include metal-containing azo dyes, metal compounds of benzylic acid compounds, metal compounds of salicylic acid compounds, copper phthalocyanine dyes, quaternary ammonium salts, nitroimidazole derivatives, and organometallic compounds. It will be done.
Examples of metal-containing azo dyes include "Varifast Black 3804", "Bontron S-31" (manufactured by Orient Chemical Industry Co., Ltd.), "T-77" (manufactured by Hodogaya Chemical Industry Co., Ltd.), and "Bontron S". -32'', ``Bontron S-34'', ``Bontron S-36'' (manufactured by Orient Chemical Industry Co., Ltd.), and ``Eisenspiron Black TRH'' (manufactured by Hodogaya Chemical Industry Co., Ltd.). Examples of the metal compound of the salicylic acid compound include "Bontron E-81", "Bontron E-82", "Bontron E-84", and "Bontron E-85" (manufactured by Orient Chemical Industry Co., Ltd.). Examples of quaternary ammonium salts include "COPY CHARGE NX VP434" (manufactured by Hoechst). Examples of the organometallic compound include "TN105" (manufactured by Hodogaya Chemical Industry Co., Ltd.).

The content of the charge control agent is preferably 0.1 parts by mass or more and 8 parts by mass or less, more preferably 0.2 parts by mass or more and 5 parts by mass or less, based on 100 parts by mass of the binder resin.

<Wax>
The toner of the present invention preferably contains wax such as polyolefin or paraffin wax as an anti-offset agent.
The content of wax is preferably 0.5 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the binder resin.
Examples of the polyolefin include polyethylene, polypropylene, etc., and those having a relatively low molecular weight, particularly those having a molecular weight of 3,000 to 15,000 as measured by the vapor permeation method, are preferable. Moreover, those having a softening point measured by the ring and ball method of 70° C. or more and 150° C. or less, particularly 120° C. or more and 150° C. or less are preferable.

<Other additives>
The toner particles may also contain other additives such as magnetic powder, fluidity improvers, conductivity modifiers, reinforcing fillers such as fibrous substances, antioxidants, anti-aging agents, and cleanability improvers. It may be contained as appropriate.

In the toner of the present invention, the content of toner particles is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and 100% by mass or less, preferably 99% by mass. It is as follows.

The volume median particle diameter (D ₅₀ ) of the toner particles is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more, and preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm. It is as follows. In this specification, the volume median particle size (D ₅₀ ) means a particle size at which the cumulative volume frequency calculated by volume fraction is 50% from the smallest particle size.

<External additives>
The toner of the present invention may contain, for example, toner particles and external additives by treating the surface of the toner particles with a property improving agent such as an external additive in order to improve fluidity. . Examples of external additives include fine particles of inorganic materials 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. It will be done. These may be used alone or in combination of two or more. Among these external additives, silica is preferred, and hydrophobic silica treated with a hydrophobizing agent is more preferred.

Examples of the hydrophobizing agent include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), silicone oil, octyltriethoxysilane (OTES), and methyltriethoxysilane. Among these, hexamethyldisilazane is preferred.

When surface-treating toner particles using an external additive, the content of the external additive is preferably 0.05 parts by mass per 100 parts by mass of toner particles from the viewpoint of toner chargeability and fluidity. At least 0.08 parts by mass, more preferably at least 0.1 parts by mass, and preferably at most 5 parts by mass, more preferably at most 3 parts by mass, even more preferably at most 2 parts by mass. It is.

[Toner manufacturing method]
The toner of the present invention may be a toner obtained by any known method such as a melt-kneading method, an emulsion phase inversion method, a suspension polymerization method, an emulsion aggregation method, etc.; From this point of view, toner pulverized by the melt-kneading method is preferable.
In the melt-kneading method, after uniformly dispersing the binder resin, colorant, and optionally a property improver, the volume median particle size ( D ₅₀ ) A toner with a diameter of 5 μm or more and 15 μm or less can be obtained.

The toner of the present invention is used for developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, and the like. The toner can be used as a non-magnetic one-component developer or as a dry two-component developer by mixing a carrier such as an iron oxide carrier, a true spherical iron oxide carrier, or a ferrite carrier as it is or with a carrier coated with a resin or the like. It can be used as a system developer.

[measurement]
[Acid value and hydroxyl value of resin]
The acid value and hydroxyl value of the resin were measured based on the method of JIS K0070:1992. However, the measurement solvent should be a mixed solvent of ethanol and ether specified in JIS K0070:1992, and for amorphous resin, a mixed solvent of acetone and toluene [acetone:toluene = 1:1 (volume ratio)], crystalline polyester. If using resin, change to chloroform.

[Weight average molecular weight of resin]
The molecular weight distribution was measured by gel permeation chromatography (GPC) method obtained by the following method, and the weight average molecular weight was determined.
(1) Preparation of sample solution A sample was dissolved in tetrahydrofuran (in the case of an amorphous resin) or chloroform (in the case of a crystalline polyester resin) at 25°C so that the concentration was 0.5 g/100 mL. Next, this solution was filtered using a fluororesin filter "DISMIC-25JP" (manufactured by ADVANTEC) with a pore size of 0.2 μm to remove insoluble matter, and a sample solution was obtained.
(2) Molecular weight measurement Using the measuring device and analytical column below, run tetrahydrofuran (amorphous resin) or chloroform (crystalline polyester resin) as an eluent at a flow rate of 1 mL/min, and place in a constant temperature bath at 40°C. The column was stabilized. 100 μL of the sample solution was injected thereto for measurement. The molecular weight of the sample was calculated based on a calibration curve prepared in advance. The calibration curve at this time includes several types of monodisperse polystyrene "A-500" (5.0 x 10 ² ), "A-1000" (1.01 x 10 ³ ), and "A-2500" (2.63 ×10 ³ ), “A-5000” (5.97×10 ³ ), “F-1” (1.02×10 ⁴ ), “F-2” (1.81×10 ⁴ ), “F- 4” (3.97×10 ⁴ ), “F-10” (9.64×10 ⁴ ), “F-20” (1.90×10 ⁵ ), “F-40” (4.27×10 ⁵ ), "F-80" (7.06×10 ⁵ ), and "F-128" (1.09×10 ⁶ ) (manufactured by Tosoh Corporation) were used as standard samples. The molecular weight is shown in parentheses.
Measuring device: “HLC-8220CPC” (manufactured by Tosoh Corporation)
Analysis column: “GMHXL” + “G3000HXL” (manufactured by Tosoh Corporation)

[Softening point of resin]
Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), 1 g of sample was heated at a heating rate of 6°C/min while applying a load of 1.96 MPa with a plunger to a diameter of 1 mm and a length of 1 mm. It was extruded from the nozzle. The fall of the plunger of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was defined as the softening point.

[Maximum peak temperature of endotherm]
Using a differential scanning calorimeter "Q-20" (manufactured by TA Instruments Japan Co., Ltd.), a sample was cooled from room temperature (20°C) to 0°C at a cooling rate of 10°C/min, and then the temperature was measured as it was. The temperature was maintained at 180° C. for 1 minute, and then the temperature was increased to 180° C. at a rate of 10° C./min. Among the endothermic peaks observed, the temperature of the largest peak was defined as the maximum endothermic peak temperature.

[Glass transition temperature of amorphous resin]
Using a differential scanning calorimeter "Q-20" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.01 to 0.02 g of the sample was weighed into an aluminum pan, heated to 200°C, and then The temperature was cooled down to 0°C at a cooling rate of 10°C/min. Next, the sample was heated at a heating rate of 10°C/min, and the temperature at the intersection of the extension line of the baseline below the highest endothermic peak temperature and the tangent line showing the maximum slope from the rising part of the peak to the top of the peak was determined. It was taken as the glass transition temperature.

[Melting point of crystalline polyester resin]
Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.01 to 0.02 g of the sample was weighed into an aluminum pan, and the temperature was lowered from room temperature at a rate of 10°C/min. The mixture was cooled to −10° C. and the temperature was maintained for 1 minute. Next, the sample was heated to 200°C at a heating rate of 10°C/min, and then cooled from that temperature to -30°C at a cooling rate of 10°C/min. Next, the temperature of the sample was raised at a heating rate of 10° C./min, and among the endothermic peaks observed, the peak temperature on the highest temperature side was taken as the melting point.

[Melting point of mold release agent]
Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan, heated to 200°C, and then lowered from 200°C. It was cooled down to 0°C at a rate of 10°C/min. Next, the sample was heated at a heating rate of 10° C./min, and the amount of heat was measured. The maximum peak temperature of the endotherm obtained was taken as the melting point.

[Volume median particle diameter (D ₅₀ ) of toner particles]
The volume median particle diameter (D ₅₀ ) of the toner particles was measured as follows.
・Measuring device: “Coulter Multisizer (registered trademark) III” (manufactured by Beckman Coulter, Inc.)
・Aperture diameter: 50μm
・Analysis software: “Coulter Multisizer (registered trademark) III version 3.51” (manufactured by Beckman Coulter, Inc.)
・Electrolyte: “Isoton (registered trademark) II” (manufactured by Beckman Coulter, Inc.)
・Dispersion liquid: "Emulgen (registered trademark) 109P" [polyoxyethylene lauryl ether, manufactured by Kao Corporation, HLB (Hydrophile-Lipophile Balance, Griffin method) = 13.6] was dissolved in the electrolyte, and the concentration was 5 mass. % dispersion was obtained.
・Dispersion conditions: Add 10 mg of the measurement sample to 5 mL of the dispersion liquid, disperse for 1 minute with an ultrasonic disperser, then add 25 mL of electrolyte, and further disperse for 1 minute with an ultrasonic disperser, A sample dispersion was prepared.
・Measurement conditions: Add the sample dispersion to 100 mL of the electrolyte in a beaker to adjust the particle size of 30,000 particles to a concentration that can be measured in 20 seconds, and then measure 30,000 particles. Then, the volume median particle diameter (D ₅₀ ) was determined from the obtained particle size distribution.

[Production of addition polymerization resin (A) and addition polymerization resin (A')]

Production examples A1 to A3, and A5 (manufacture of resins A-1, A-2, A'-3, and A'-5)
The raw material monomer (a) for addition polymerization resin containing acrylic acid or methacrylic acid as a bireactive compound shown in Table 1 was placed in an autoclave equipped with a stainless steel stirring rod, and heated under pressure and heating conditions (300°C) for 2 hours. The raw material monomer (a) was polymerized. Addition polymerization resins A-1, A-2, A'-3, and A'-5 were obtained by recovering the precipitated addition polymerization resins by returning the mixture to normal pressure and room temperature. Various physical properties are shown in Table 1.

Production example A4 (manufacture of resin A'-4)
The raw material monomer (a) of the addition polymerization resin containing acrylic acid as a bireactive compound shown in Table 1, and the radical generator were made using a stainless steel tube equipped with a thermometer, a stainless steel stirring bar, a flowing condenser, and a nitrogen introduction tube. The raw material monomer (a) was placed in a reaction vessel and polymerized at 150°C for 2 hours. Addition polymerization resin A'-4 was obtained by recovering the precipitated addition polymerization resin by returning the temperature to room temperature. Various physical properties are shown in Table 1.

[Manufacture of amorphous polyester resin]
Production example AH1 (manufacture of resin AH-1)
Equipped with the alcohol components, terephthalic acid, dodecenyl succinic anhydride, esterification catalyst, and esterification cocatalyst shown in Table 2, a thermometer, stainless steel stirring rod, fractionator, dehydration tube, cooling tube, and nitrogen introduction tube. The mixture was placed in a 10-liter four-necked flask, heated to 235°C in a mantle heater in a nitrogen atmosphere, and reacted at normal pressure for 2.5 hours, then at 8 kPa and reduced pressure for 1 hour. Ta. Thereafter, the mixture was cooled to 190° C. under normal pressure, trimellitic acid anhydride shown in Table 2 was added, and then the temperature was raised to 210° C. at a rate of 10° C./h. Thereafter, the reaction was carried out at 8 kPa to a desired softening point to obtain amorphous polyester resin AH-1. Various physical properties are shown in Table 2.

[Manufacture of crystalline polyester resin]
Production example C1 (manufacture of resin C-1)
The alcohol components, carboxylic acid components, esterification catalysts, and polymerization inhibitors shown in Table 3 were prepared in a 10-liter cell equipped with a thermometer, a stainless steel stirring rod, a fractionating column, a dehydration tube, a cooling tube, and a nitrogen introduction tube. The mixture was placed in a neck flask, heated to 140°C in a mantle heater under a nitrogen atmosphere, and reacted for 5 hours, and then heated to 200°C at a rate of 10°C/h. Thereafter, the reaction was carried out at 8 kPa to a desired softening point to obtain crystalline polyester resin C-1. Various physical properties were measured and shown in Table 3. Note that since Resin C-1 was insoluble in the measurement solvent, the acid value and weight average molecular weight were not measured.

[Manufacture of composite resin]
Production Examples 1 and 2 (Production of composite resins AL-1 and AL-2)
The alcohol component (b-al), carboxylic acid component (b-ac), esterification catalyst, and esterification cocatalyst shown in Table 4 were combined with a thermometer, stainless steel stirring bar, fractionator, dehydration tube, cooling tube, The mixture was placed in a 10-liter four-necked flask equipped with a nitrogen introduction tube, heated to 235° C. in a mantle heater in a nitrogen atmosphere, and reacted at normal pressure for 3 hours. Thereafter, the mixture was cooled to 180°C, added with the addition polymerization resin (A) shown in Table 4, and then heated to 230°C at a rate of 10°C/h. Thereafter, the reaction was carried out at 67 kPa to a desired softening point to obtain composite resins AL-1 and AL-2. Table 4 shows various physical properties.

Production Examples 3 to 7 (Production of composite resins AL-3 to AL-7)
The PET, alcohol component (b-al), carboxylic acid component (b-ac), esterification catalyst, and esterification cocatalyst shown in Table 4 were combined with a thermometer, stainless steel stirring bar, fractionator, dehydration tube, and cooling. The mixture was placed in a 10 liter four-necked flask equipped with a tube and a nitrogen introduction tube, heated to 235° C. in a mantle heater in a nitrogen atmosphere, and reacted at normal pressure for 3 hours. Thereafter, the mixture was cooled to 180°C, added with the addition polymerization resin (A) shown in Table 4, and then heated to 230°C at a rate of 10°C/h. Thereafter, the reaction was carried out at 67 kPa to a desired softening point to obtain composite resins AL-3 to AL-7. Table 4 shows various physical properties.

Comparative Production Examples 1, 2, and 4 (Production of composite resins AX-1, AX-2, and AX-4)
The alcohol components and carboxylic acid components, esterification catalyst, and esterification promoter shown in Table 5 were mixed into a 10-liter tube equipped with a thermometer, a stainless steel stirring rod, a fractionating column, a dehydration tube, a cooling tube, and a nitrogen introduction tube. The mixture was placed in a four-necked flask, heated to 235° C. in a mantle heater in a nitrogen atmosphere, and reacted at normal pressure for 2.5 hours, and then at reduced pressure of 8 kPa for 1 hour. Thereafter, the mixture was cooled to 190°C under normal pressure, added with the addition polymerization resin (A') shown in Table 5, and then heated to 235°C. Thereafter, the reaction was carried out to a desired softening point to obtain composite resins AX-1, AX-2, and AX-4. Various physical properties are shown in Table 5.

Comparative Production Examples 3 and 5 (Production of composite resins AX-3 and AX-5)
The alcohol component and carboxylic acid component, addition polymerization resin (A'), esterification catalyst, and esterification cocatalyst shown in Table 5 were prepared using a thermometer, stainless steel stirring rod, fractionator, dehydration tube, cooling tube, and It was placed in a 10 liter four-necked flask equipped with a nitrogen inlet tube, heated to 190°C in a mantle heater in a nitrogen atmosphere, reacted for 2.0 hours at normal pressure, and then heated at 10°C to 235°C. The temperature was raised at a rate of /h. Thereafter, the reaction was carried out to a desired softening point to obtain composite resins AX-3 and AX-5. Various physical properties are shown in Table 5.

Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-5
Each of the composite resins obtained in Production Examples 1 to 7 and Comparative Production Examples 1 to 5 was evaluated as a binder resin by the following method.
[Solution viscosity]
1.5 g of the binder resin shown in Table 6 was dissolved in 8.5 g of chloroform to give a concentration of 15%. Using an E-type viscometer "TVE-25L" (manufactured by Toki Sangyo Co., Ltd.), after stabilizing the temperature of the cone plate at 20° C., 1030 μL of the above solution was sampled with a chemical pipette and measured. The results are shown in Table 6.
The higher the solution viscosity, the more efficiently shearing force can be applied to the resin during toner production, which improves the mixability with other components such as colorants contained in the toner, and improves toner productivity. be able to. When the solution viscosity is 4.0 mPa·s or more, toner productivity is excellent.

[Crushability index]
A volume of approximately 1000 mL of the binder resin shown in Table 6 was prepared. Using a sieve shaker (manufactured by Verder Scientific Co., Ltd.), the sample was sieved with 16 mesh and 22 mesh, and 20 g of the sample remaining between 16 mesh and 22 mesh was accurately weighed.
Next, 20 g of the accurately weighed sample was ground in a coffee mill for 10 seconds, and further sieved through a 30 mesh screen until no sample fell through, and the sample remaining on the 30 mesh screen was accurately weighed.
The crushability index was determined from the formula below and was taken as the average value of three measurements. The results are shown in Table 6.
The higher the pulverizability index is, the better the pulverizability of the resin is, and the productivity of toner can be improved. If the crushability index is 95.0% or more, toner productivity is excellent.
Grindability index (%) = [[20 (g) - mass of sample remaining on 30 mesh (g)] / 20 (g)] × 100

As shown in Table 6, it can be seen that the examples using specific binder resins have higher solution viscosity and higher crushability index than the comparative examples, and are excellent in toner productivity.

[Manufacture of toner]
Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-5
105 parts by mass of the binder resin having the compounding ratio shown in Table 7, 1 part by mass of the negatively chargeable charge control agent "Bontron E-81" (manufactured by Orient Chemical Industry Co., Ltd.), and the colorant "Cyanine Blue 4927" (Dainichiseika Chemical Co., Ltd.) 10 parts by mass of C.I. Pigment Blue 15:3 (manufactured by Kogyo Co., Ltd.) and 1 part by mass of mold release agent "HNP-9" (manufactured by Nippon Seiro Co., Ltd., paraffin wax, melting point: 80°C) were added to a Henschel mixer. After thorough mixing, the mixture was melt-kneaded using a co-rotating twin-screw extruder with a kneading portion having a total length of 1560 mm, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm at a roll rotation speed of 200 r/min and a heating temperature in the rolls of 100°C. The feed rate of the mixture was 20 kg/h, and the average residence time was about 18 seconds. The obtained melt-kneaded product was cooled and coarsely pulverized, then pulverized with a jet mill and classified to obtain toner particles having a volume median particle diameter (D ₅₀ ) of 8 μm.
To 100 parts by mass of the obtained toner particles, 1 part by mass of external additive "AEROSIL NAX 50" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic silica, hydrophobic treatment agent: HMDS, number average particle diameter: about 30 nm) was added. By mixing with a Henschel mixer at 3,600 r/min for 5 minutes, external additive treatment was performed to obtain toners 1 to 7 and 51 to 55.

[Toner evaluation]
[Heat-resistant storage stability]
4 g of toner was placed in a 20 mL container (about 3 cm in diameter) and left for 48 hours under an environment of a temperature of 55° C. and a relative humidity of 60%. Thereafter, the degree of toner aggregation was visually observed every 6 hours until 72 hours. The larger the value of time at which aggregation is observed, the better the heat-resistant storage stability under high temperature and high humidity conditions. The results are shown in Table 7. In Table 7, ">72" indicates that no aggregation was observed even after 72 hours.

[Minimum fusing temperature and hot offset temperature]
Each toner was mounted on a fixing device of a copying machine "AR-505" (manufactured by Sharp Corporation) that had been modified to enable fixing outside the device, and printed matter was obtained in an unfixed state (print area: 2 cm x 12 cm, adhesion amount: 0.5 mg/cm ² ). After that, using a fixing machine (fixing speed 300 mm/sec) adjusted so that the total fixing pressure is 40 kgf, the temperature of the fixing roll was increased sequentially by 5 degrees Celsius from 80 degrees Celsius to 240 degrees Celsius, and at each temperature, no fixation occurred. A fixation test was conducted on the printed matter. A cellophane adhesive tape "Unicellophane Tape" (manufactured by Mitsubishi Pencil Co., Ltd., width: 18 mm, JIS Z1522) was applied to the image area of the obtained printed matter, passed through a fixing roller set at 30 ° C., and then the tape was peeled off. Ta. The optical reflection density before applying the tape and after peeling it off was measured using a reflection densitometer "RD-915" (manufactured by Gretag Macbeth), and the ratio of both (after peeling/before pasting x 100) was 90% at first. The temperature of the fixing roller exceeding the above was defined as the minimum fixing temperature. The lower the minimum fixing temperature, the better the low-temperature fixing properties.
Further, the fixed image obtained above was visually judged, and the lowest temperature of the fixing roll at which hot offset was observed was defined as the hot offset temperature. The higher the hot offset temperature, the better the high temperature offset resistance.
Further, the difference between the lowest fixing temperature and the hot offset temperature was defined as the fixing temperature width. The wider the fixing temperature range, the wider the usable temperature range, and the more energy-saving and high-speed fixing requirements can be met.
As the fixing paper, "CopyBond SF-70NA" (manufactured by Sharp Corporation, 75 g/m ² ) was used.
These results are shown in Table 7.

As shown in Table 7, the toner of the example using the binder resin containing a specific composite resin has excellent heat-resistant storage stability, has a low minimum fixing temperature and high hot offset temperature, and has a wide fixing temperature range. It can be seen that it is possible to achieve both heat-resistant storage stability and a wide usable temperature range.
On the other hand, compared to the toners of Examples, the toners of Comparative Examples either have poor heat-resistant storage stability, have a higher minimum fixing temperature, or have a narrower fixing temperature range. It can be seen that a balance between the two has not been achieved.

Claims (11)

A toner binder resin containing a composite resin in which an addition polymerization resin unit and a polyester resin unit are bonded via a covalent bond,
The addition polymerization resin (A) constituting the addition polymerization resin unit contains 60% by mass or more of structural units derived from (meth)acrylic monomers,
A binder resin for toner, wherein the addition polymerization resin (A) has an acid value of 40 mgKOH/g or more. The binder resin for toner according to claim 1, wherein the addition polymerization resin (A) is formed by bulk polymerization. The binder resin for a toner according to claim 2, wherein the bulk polymerization of the addition polymerization resin (A) is performed at a temperature of 140° C. or higher. The binder resin for toner according to claim 2 or 3, wherein the bulk polymerization of the addition polymerization resin (A) is carried out under solvent-free conditions. Claims 2 to 4, wherein the concentration of the radical generator in the bulk polymerization of the addition polymerization resin (A) is 10 parts by mass or less based on 100 parts by mass of the raw material monomer (a) of the addition polymerization resin (A). The binder resin for toner according to any one of the above. The binder resin for toner according to any one of claims 2 to 5, wherein the bulk polymerization of the addition polymerization resin (A) is carried out under non-catalytic conditions. The binder resin for a toner according to any one of claims 1 to 6, wherein the addition polymerization resin (A) has a weight average molecular weight of 5,000 or more. The binder resin for a toner according to claim 1, wherein the polyester resin (B) constituting the polyester resin unit is a condensate of polyethylene terephthalate and a raw material monomer (b). A toner for developing an electrostatic image, comprising the toner binder resin according to any one of claims 1 to 8. A method for producing a toner binder resin containing a composite resin in which an addition polymerization resin unit and a polyester resin unit are bonded via a covalent bond, the method comprising:
Step I: A step of polymerizing the raw material monomer (a) to obtain an addition polymerized resin (A), and Step II: After reacting the alcohol component (b-al) and the carboxylic acid component (b-ac), A step of adding the addition polymerization resin (A) obtained in Step I to perform a reaction to obtain the composite resin,
The raw material monomer (a) contains 60% by mass or more of a (meth)acrylic monomer,
A method for producing a binder resin for toner, wherein the addition polymerization resin (A) has an acid value of 40 mgKOH/g or more. In step II, after reacting polyethylene terephthalate, an alcohol component (b-al), and a carboxylic acid component (b-ac), the addition polymerization resin (A) obtained in step I is added to carry out the reaction. 11. The method for producing a binder resin for toner according to claim 10, which is a step of obtaining the composite resin.