HK1199465B - Non-crystalline polyester resin, and binder resin and binder resin dispersion for toner - Google Patents

Description

Amorphous polyester resin, binder resin for toner, and binder resin dispersion

Technical Field

The present invention relates to an amorphous polyester resin, and a binder resin dispersion for toner.

Background

In recent years, with the development of OA equipment and the spread of computers, high resolution color photographic printing, high resolution commercial printing such as posters and pamphlets, which have been conventionally performed in specialized printing facilities, have begun to be performed in general households, personal offices, and various office units, and higher-quality and higher-speed printing techniques have been demanded.

As such a printing technique, a printing technique using electrostatic charge image development such as an electrophotographic method, an electrostatic recording method, and an electrostatic printing method is used. In general, an electrostatic charge image is formed on a photoreceptor by various means using a photoconductive substance, and then the electrostatic charge image is developed with a toner, and the toner image is transferred onto a printing medium such as paper, and then the image is fixed by heating, pressing, or the like with a roller, and a fixed image is formed through such a plurality of steps. The toner remaining on the photoreceptor is cleaned by various methods as necessary, and printing is performed by repeating the above-described plural steps.

In recent years, in the field of electrophotography, with an increase in speed and high reliability of an apparatus, a copied matter is increasingly required to have high image quality and hue equivalent to a printed matter, and a toner having a high temperature at which a thermal offset can be generated (excellent hot offset resistance) and excellent image glossiness (glossiness) is required. Recently, energy saving has become important, and reduction of power consumption in a fixing process, which consumes the most power in an electrophotographic process, has also become a major issue. Therefore, a toner having a low fixing temperature, that is, a toner having excellent low-temperature fixability is required.

Heretofore, in order to improve low-temperature fixability of a toner and the like, a polyester resin has been used as a binder (see patent documents 1 and 2). In addition, in order to obtain excellent low-temperature fixability and the like, a binder resin containing a crystalline polyester and an amorphous polyester has been proposed (see patent document 3). Further, in order to ensure OHP light transmittance, fixability, and offset resistance, there is disclosed an image fixing method using a color toner containing, as a binder component, a resin having a number average molecular weight Mn of 1,000-4,000 and a ratio of the weight average molecular weight Mw to the number average molecular weight Mn, i.e., Mw/Mn of 45 or more as measured by gel permeation chromatography (hereinafter referred to as GPC) (see patent document 4).

On the other hand, with the progress of higher image quality, the toner has a smaller particle size, and blocking during storage of the toner has become a problem. In the case of a toner having a low fixing temperature, it becomes more disadvantageous in terms of blocking resistance. Studies have been made on toners for developing electrostatic images which are excellent in heat storability. For example, the following methods are disclosed: in the production of a so-called chemical toner having a small particle size suitable for a toner, a non-crystalline polyester resin and a crystalline polyester resin dissolved in an organic solvent are subjected to phase inversion emulsification in an aqueous medium, and the obtained resin particle dispersions are aggregated and united to produce a toner (see patent document 5).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 62-78568

Patent document 2: japanese patent laid-open publication No. 62-178278

Patent document 3: japanese unexamined patent publication No. 2003-337443

Patent document 4: japanese unexamined patent publication No. Hei 4-240660

Patent document 5: japanese laid-open patent publication No. 2008-33057

Disclosure of Invention

Problems to be solved by the invention

However, even the above conventional binder resins are still insufficient for further speeding up and saving energy of the apparatus and for improving image quality. For example, in order to improve low-temperature fixability, the glass transition temperature or melting temperature of the polyester resin must be lowered, and therefore, the average molecular weight of the polyester resin must be lowered. Conversely, in order to obtain good hot offset resistance, it is necessary to maintain a moderate melt viscosity even at high temperatures, and it is necessary to increase the average molecular weight of the polyester resin. Thus, the polyester resin is required to have the opposite properties, taking the average molecular weight of 1 as an example. Therefore, it is difficult to satisfy hot offset resistance, storability, and low-temperature fixability of the toner at a high level.

The purpose of the present invention is to provide an amorphous polyester resin that can realize a toner for developing an electrostatic charge image that has both excellent low-temperature fixing properties and hot offset resistance and storability (blocking resistance), and excellent image gloss (gloss), and to provide a binder resin for a toner and a binder resin dispersion that use the same.

Means for solving the problems

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that: the specific polyester resin satisfies the above properties, and the present invention has been completed.

That is, the present invention provides an amorphous polyester resin obtained by reacting a polyester resin (a) obtained by reacting a polyol component containing at least one component having 3 or more units (i.e., a polyol component having 3 or more units and/or a polycarboxylic acid component having 3 or more units) with a first polycarboxylic acid component under conditions satisfying the following formulae (1), (2) and (3), wherein the polyester resin (a) has a weight-average molecular weight of 6,000 to 40,000 and a hydroxyl value of 15 to 70mgKOH/g, and a second polycarboxylic acid component (a), and satisfies the following formula (4).

(1)(AV_B-AV_A)/AV_a＝0.5～0.7

(2)Mw_B/Mw_A＝1.1～2.0

(3)OHV_B/AV_B＝1.0～6.0

(4)Mw_B/Mn_B＝3.0～15.0

[ wherein, AV_B、OHV_B、Mw_BAnd Mn_BRespectively represents the acid value, hydroxyl value, weight average molecular weight and number average molecular weight of the amorphous polyester resin, AV_AAnd Mw_ARespectively represents the acid value and the weight average molecular weight, AV, of the polyester resin (A)_aThe theoretical acid value of the second polycarboxylic acid component (a) is shown.]

In the present specification, the term "polycarboxylic acid component" includes polycarboxylic acids, anhydrides of these acids, and lower alkyl (preferably, having 1 to 3 carbon atoms) esters of these acids, and contains 1 or 2 or more of these.

According to the noncrystalline polyester resin of the present invention, a toner for developing an electrostatic charge image having both excellent low-temperature fixability and hot offset resistance and storability (blocking resistance) and having excellent image glossiness (glossiness) can be realized.

The non-crystalline polyester resin of the present invention preferably has a weight average molecular weight of 8,000 to 50,000.

In the amorphous polyester resin of the present invention, the polyester resin (a) is preferably obtained by reacting the polyol component and the first polycarboxylic acid component under conditions satisfying at least one of the following conditions (5) and (6).

(5) The polyol component contains 0.3 to 15 mol% of a 3-or more-membered polyol based on the total amount of the polyol component

(6) The first polycarboxylic acid component contains 0.3 to 20 mol% of a 3-membered or higher polycarboxylic acid component based on the total amount of the first polycarboxylic acid component

The amorphous polyester resin obtained under the above conditions can have an appropriate molecular weight between crosslinking points, and when used as a binder resin for toner, the amorphous polyester resin can have opposite properties such as low-temperature fixing property and hot offset resistance at a higher level.

In the reaction of the polyester resin (a) and the second polycarboxylic acid component (a), the mass ratio of the polyester resin (a) to the second polycarboxylic acid component (a) is preferably 99.5/0.5 to 90/10. When the amorphous polyester resin obtained under these conditions is used as a binder resin for toner, a toner having excellent low-temperature fixability, image glossiness (glossiness), and excellent hot offset resistance and storability can be obtained more reliably.

The noncrystalline polyester resin of the present invention preferably has an acid value of 4 to 25mgKOH/g and a hydroxyl value of 10 to 60 mgKOH/g. If the acid value of the amorphous polyester resin is within the above range, the particle diameter can be easily controlled when the resin is emulsified and re-agglomerated to produce a chemical toner. Further, if the hydroxyl value of the amorphous polyester resin is within the above range, not only the dispersibility of the amorphous polyester resin itself but also the dispersibility of other components such as a crystalline resin, a pigment, and a wax in the granulation of toner particles in the binder resin dispersion for toner can be improved, and therefore, the storage property (blocking resistance) of the toner tends to be good. Further, by satisfying both conditions, a toner having more excellent low-temperature fixability and charging characteristics can be obtained.

The noncrystalline polyester resin of the present invention preferably has a glass transition temperature of 55 to 75 ℃ and a temperature of 95 to 125 ℃ at which the melt viscosity becomes 10,000 pas. If the glass transition temperature is within the above range, it becomes easy to obtain a toner having excellent storability, low-temperature fixability, and glossiness. Further, if the temperature at which the melt viscosity becomes 10,000Pa · s is within the above range, it becomes easy to realize a toner having good low-temperature fixability and hot offset resistance.

In the noncrystalline polyester resin of the present invention, the polyol component preferably contains an alkylene oxide adduct of bisphenol a and/or an alkylene oxide adduct of bisphenol S. When the amorphous polyester resin obtained under these conditions is used as a binder resin for a toner, it is possible to realize a toner having further improved hot offset resistance and storability.

In the amorphous polyester resin of the present invention, the first polycarboxylic acid component preferably contains a reaction product of an aromatic polycarboxylic acid component and a diol having 2 to 4 carbon atoms. Under these conditions, sublimation of the aromatic polycarboxylic acid component is suppressed and the reaction system becomes uniform during production of the amorphous polyester resin, so that the higher structure of the resin can be easily controlled and stable production becomes possible. Further, according to the amorphous polyester resin having the above-described configuration, when used as a binder resin for toner, it is possible to more highly satisfy contradictory properties such as low-temperature fixing property and hot offset resistance.

The present invention also provides a binder resin for toner comprising the above-described amorphous polyester resin of the present invention.

The present invention also provides a binder resin dispersion for toner obtained by dispersing or emulsifying the amorphous polyester resin of the present invention in an aqueous medium.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide an amorphous polyester resin capable of realizing a toner for developing an electrostatic charge image having both excellent low-temperature fixing property and hot offset resistance and storability (blocking resistance) and excellent image glossiness (glossiness), and a binder resin for toner and a binder resin dispersion using the same.

Detailed Description

In the present invention, the "amorphous" polyester resin means a polyester resin having a melting entropy of 5mJ/mg or less, which is obtained from the area of the melting endothermic peak in a DSC (differential scanning calorimetry) curve, without showing a clear melting endothermic peak of crystal. In contrast, the "crystalline" polyester resin means a polyester resin which shows a clear crystal melting endothermic peak and whose melting entropy is larger than 5 mJ/mg. The value of the melting entropy is a value obtained by using indium as a standard substance.

Since the crystalline polyester resin having a clear melting point rapidly decreases in storage modulus at a temperature equal to or lower than the melting point in the dynamic viscoelasticity measurement, if it is used alone as a binder resin of a toner for developing an electrostatic charge image, it may permeate into a printing medium, causing fixing failure and image blurring.

On the other hand, the amorphous polyester resin has a rubbery region that does not show a clear melting point in a temperature region of not less than the glass transition temperature, and therefore has a property of easily retaining the storage modulus until immediately before the start of the flow of the resin. The polyester resin of the present invention is such a noncrystalline polyester resin.

The term "low-temperature fixability" as used herein means a resistance to the occurrence of a problem (for example, the occurrence of white running and white discharge of a print, color unevenness, and poor fixing due to insufficient melting of a toner, melting unevenness, etc.) which is a main cause of the toner when the toner is heated and fixed at a low temperature, that is, at about 130 ℃. The lower the fixing lower limit temperature (also sometimes referred to as the minimum fixing temperature) of the toner, the better the low-temperature fixing property.

The "hot offset resistance" in the present invention means that the resistance to the occurrence of a problem that the toner becomes a main cause at the time of printing in a high temperature state (for example, printing overlapping and unevenness due to poor fixing, bleeding, toner contamination, fusion of the toner to the roller, and the like, which are caused by the toner itself breaking between the printing medium and the toner and the roller) is difficult. Further, as printing in a high temperature state, there is printing in a state in which heat is stored in the printer by continuous printing or high-speed printing, and thus, the temperature of a portion such as a transfer roller, a heating roller, or the like becomes high. The higher the fixing upper limit temperature of the toner is, the better the hot offset resistance is.

In the present invention, "storage stability (blocking resistance)" means storage stability of the toner. If the toner cartridge is left in a severe environment such as during transportation or during storage in summer, toner particles tend to stick together and aggregate, and in such a case, even if vibration is applied thereto, the toner may not flow and may not be used as a toner. The retention property (blocking resistance) indicates the difficulty in the occurrence of these problems.

The amorphous polyester resin of the present invention will be explained below.

The noncrystalline polyester resin (hereinafter also referred to as noncrystalline polyester resin (B)) according to the present embodiment is obtained by reacting a polyester resin (A) obtained by reacting a polyol component containing at least 3-membered component in at least one of the polyester resins (A) and a first polycarboxylic acid component with a second polycarboxylic acid component (a) under conditions satisfying the following formulas (1), (2) and (3), and satisfies the following formula (4), and is characterized in that the weight-average molecular weight of the polyester resin (A) is 6,000 to 40,000 and the hydroxyl value is 15 to 70 mgKOH/g.

(1)(AV_B-AV_A)/AV_a＝0.5～0.7

(2)Mw_B/Mw_A＝1.1～2.0

(3)OHV_B/AV_B＝1.0～6.0

(4)Mw_B/Mn_B＝3.0～15.0

Wherein, AV_B、OHV_B、Mw_BAnd Mn_BRespectively represents the acid value, hydroxyl value, weight average molecular weight and number average molecular weight of the amorphous polyester resin, AV_AAnd Mw_ARespectively represents the acid value and the weight average molecular weight, AV, of the polyester resin (A)_aThe theoretical acid value of the second polycarboxylic acid component (a) is shown.

The polyol component used for producing the polyester resin (a) is preferably a polyol containing an alkylene oxide adduct of bisphenol a, from the viewpoint of easy adjustment of the glass transition temperature and good hot offset resistance and storage properties.

In this case, the polyol component preferably contains the oxyalkylene adduct of bisphenol a in an amount of 50 mol% or more, more preferably 60 mol% or more, based on 100 mol% of the total amount of the polyol component (total amount of alcohol-derived structural units constituting the polyester resin (a)). The polyol component may be 100 mol% of an alkylene oxide adduct of bisphenol a.

The alkylene oxide in the alkylene oxide adduct of bisphenol A is preferably an alkylene oxide having 2 to 4 carbon atoms. The number of moles of alkylene oxide added is preferably 2 to 5 moles, more preferably 2 to 4.5 moles, based on 1 moles of bisphenol A. The alkylene oxide may be added in a single form of 1 type of alkylene oxide or in a combination of 2 or more types of alkylene oxides. When the number of moles added is less than 2 moles, phenolic hydroxyl groups tend to remain, which may inhibit the reaction between the polyol component and the first polycarboxylic acid component, and when it exceeds 5 moles, the glass transition temperature tends to be lowered, and the hot offset resistance and the storability tend to be lowered.

In the present embodiment, from the viewpoint of adjusting the glass transition temperature of the amorphous polyester resin, it is particularly preferable to use an ethylene oxide adduct of bisphenol a and a propylene oxide adduct in combination, and the ratio of the ethylene oxide adduct to the propylene oxide adduct is preferably (ethylene oxide adduct): (propylene oxide adduct) (molar ratio) 10: 90-50: 50, more preferably 20: 80-40: 60.

the polyol component preferably contains an alkylene oxide adduct of bisphenol S, from the viewpoint of easy adjustment of the glass transition temperature and good hot offset resistance and storage stability. Further, in order to further improve hot offset resistance and storability (blocking resistance), the polyol component more preferably contains an alkylene oxide adduct of bisphenol a and an alkylene oxide adduct of bisphenol S.

When the polyol component contains an alkylene oxide adduct of bisphenol S, the polyol component preferably contains 2 to 40 mol%, more preferably 5 to 30 mol%, of the alkylene oxide adduct of bisphenol S, based on 100 mol% of the total amount of the polyol component (the total amount of alcohol-derived structural units constituting the polyester resin (a)). The preferable ranges of the number of carbon atoms, the number of moles of addition, and the like of the alkylene oxide in the alkylene oxide adduct of bisphenol S are the same as those of the alkylene oxide adduct of bisphenol a.

Examples of the polyol component other than the above include 2-membered aliphatic alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1, 3-propanediol, butanediol, pentanediol, hexanediol, heptanediol, nonanediol, decanediol, and neopentyl glycol; hydrogenated bisphenol A, hydrogenated bisphenol S, and alkylene oxide adducts of these; 2-membered alicyclic alcohols such as cyclohexanedimethanol; and 3-or more-membered polyhydric alcohols such as glycerin, trimethylolpropane and pentaerythritol.

When the polyol component contains a 3-or more-membered polyol, the polyol component preferably contains the 3-or more-membered polyol in an amount of 0.3 to 15 mol%, more preferably 3 to 10 mol%, based on the total amount of the polyol component. As the above-mentioned 3-or more-membered polyol, trimethylolpropane is preferable from the viewpoint of ease of adjustment of the molecular weight distribution and the glass transition temperature of the amorphous polyester resin (B).

The first polycarboxylic acid component used for producing the polyester resin (a) may contain at least one compound selected from polycarboxylic acids, anhydrides of these acids, and lower alkyl (preferably, having 1 to 3 carbon atoms) esters of these acids. The first polycarboxylic acid component is preferably an aromatic polycarboxylic acid component. The aromatic polycarboxylic acid component is a component containing at least one compound selected from the group consisting of aromatic polycarboxylic acids, acid anhydrides of these acids, and lower alkyl (preferably, having 1 to 3 carbon atoms) esters of these acids. Examples of the aromatic polycarboxylic acid include aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; and aromatic polycarboxylic acids having 3 or more members such as trimellitic acid and pyromellitic acid.

The first polycarboxylic acid component may contain a reaction product of an aromatic polycarboxylic acid component and a C2-4 diol. The aromatic polycarboxylic acid component is synonymous with the above. Examples of the aromatic polycarboxylic acid include the same compounds as described above.

When the first polycarboxylic acid component contains the reactant, the aromatic polycarboxylic acid component to be reacted is preferably an aromatic dicarboxylic acid component. The aromatic dicarboxylic acid component is a component containing at least one compound selected from aromatic dicarboxylic acids, acid anhydrides of these acids, and lower alkyl (preferably, 1 to 3 carbon atoms) esters of these acids. Examples of the aromatic dicarboxylic acid include the same compounds as described above.

Examples of the diol having 2 to 4 carbon atoms include alkylene glycols such as ethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol and butylene glycol, and diols such as diethylene glycol. In order to improve the reactivity in the production of the polyester resin (A), that is, the efficiency of the transesterification reaction, it is more preferable to use an alkylene glycol having 2 to 3 carbon atoms.

The reactant of the aromatic dicarboxylic acid component and the alkylene glycol having 2 to 3 carbon atoms can be represented by the following general formula [ I ].

R¹-O(CO-R²-COO-R³-O)_n-R⁴[I]

(the above formula [ I ]]In, R¹Represents C2-3 alkylene glycol residue (i.e. a group obtained by removing 1 hydroxyl group from C2-3 alkylene glycol such as hydroxyethyl group and hydroxypropyl group), hydrogen atom or lower alkyl group (preferably C1-3), R²Denotes a residue of an aromatic dicarboxylic acid (i.e., a group obtained by removing 2 carboxyl groups from an aromatic dicarboxylic acid such as phenylene or naphthylene), R³R represents a C2-3 alkylene group⁴Represents a hydrogen atom or a monoester group formed by an aromatic dicarboxylic acid component (i.e., a group obtained by removing 1 hydroxyl group from an aromatic dicarboxylic acid or a group obtained by removing 1 alkoxy group from a lower alkyl (preferably having 1 to 3 carbon atoms) ester of an aromatic dicarboxylic acid), and n represents an integer of 1 to 12, the number of repeating units being the same as the number of repeating units. )

When the first polycarboxylic acid component is an aromatic polycarboxylic acid component, the first polycarboxylic acid component preferably contains the aromatic polycarboxylic acid component in an amount of 60 mol% or more, more preferably 70 to 98 mol%, and still more preferably 80 to 95 mol%, based on 100 mol% of the total amount of the first polycarboxylic acid component. The first polycarboxylic acid component may be 100 mol% of the aromatic polycarboxylic acid component. When the proportion is less than 60 mol%, the glass transition temperature of the resulting amorphous polyester resin tends to be 55 ℃ or lower, and as a result, the hot offset resistance and blocking resistance tend to be insufficient.

When the first polycarboxylic acid component contains a reactant of an aromatic polycarboxylic acid component and a diol having 2 to 4 carbon atoms, the content of the aromatic polycarboxylic acid component in the first polycarboxylic acid component is calculated by adding the number of moles of the aromatic polycarboxylic acid component to be supplied to the reaction for obtaining the reactant to the content of the aromatic polycarboxylic acid component in the first polycarboxylic acid component.

As other polycarboxylic acid components, linear or branched aliphatic polycarboxylic acids such as oxalic acid, malonic acid, succinic acid, maleic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, 2-ethylhexyl succinic acid, oleyl succinic acid, 2-dodecenyl succinic acid, and tetrapropenyl succinic acid; alicyclic polycarboxylic acids such as 1, 2-cyclohexanedicarboxylic acid, 1, 3-cyclohexanedicarboxylic acid, 1,2, 4-cyclohexanetricarboxylic acid, 1, 3, 5-cyclohexanetricarboxylic acid, 1,2, 4, 5-cyclohexanetetracarboxylic acid, and 1,2, 3, 4, 5, 6-cyclohexanehexacarboxylic acid; and anhydrides of these acids and lower alkyl (preferably, C1-C3) esters of these acids. However, the amount of the other polycarboxylic acid is preferably 40 mol% or less, and more preferably 30 mol% or less, based on the total number of moles of the polycarboxylic acid component used for producing the polyester resin (a). If the above-mentioned proportion exceeds 40 mol%, the glass transition temperature of the amorphous polyester resin tends to be lowered.

When the first polycarboxylic acid component contains a 3-or more-membered polycarboxylic acid component, the first polycarboxylic acid component preferably contains the 3-or more-membered polycarboxylic acid component in an amount of 0.3 to 20 mol%, more preferably 3 to 10 mol%, based on the total amount of the first polycarboxylic acid component.

From the viewpoint of hot offset resistance, the 3-membered or higher polycarboxylic acid component is preferably a 3-membered or higher aromatic polycarboxylic acid component. As the aromatic polycarboxylic acid component having 3 or more members, trimellitic acid, trimellitic anhydride and trimellitic acid alkyl ester are preferable.

As described above, in the production of the polyester resin (A), the polycarboxylic acid component having 3 or more members and/or the polyhydric alcohol having 3 or more members are used, but the content of the component having 3 or more members is less than the above rangeThe molecular weight spread in the reaction of the polyester resin (A) with the second polycarboxylic acid component (a) described later becomes small, and Mw becomes small_B/Mw_ATends to be difficult to control. On the other hand, if the content exceeds the above range, the molecular weight spread upon the reaction between the polyester resin (A) and the second polycarboxylic acid component (a) becomes large, and Mw becomes large_B/Mw_AThe viscosity of the reaction mixture increases, and the production tends to be difficult. When the content is within the above range, the obtained amorphous polyester resin (B) tends to have an appropriate molecular weight between crosslinking points and to have contradictory properties such as low-temperature fixability and hot offset resistance.

In the production of the polyester resin (a) of the present embodiment, the equivalent ratio [ OH ] of the hydroxyl group [ OH ] of the polyol component to the carboxyl group [ COOH ] of the first polycarboxylic acid component: [ COOH ] is preferably 100: 50-100: 90, more preferably 100: 60-100: 80. the carboxyl group means a moiety having an acid anhydride structure and a moiety having a lower alkyl ester structure, in addition to-COOH. The blending ratio of the polyol component to the first polycarboxylic acid component is adjusted so that the equivalent ratio of the hydroxyl group to the carboxyl group satisfies the above range.

In the production of the polyester resin (a) of the present embodiment, a solvent can be used in the reaction of the polyol component and the first polycarboxylic acid component from the viewpoint of adjustment of the reaction rate. However, in the case of carrying out the reaction using a glycol such as ethylene glycol as a solvent, from the viewpoint of easy adjustment of the hydroxyl value and the acid value, not all of them are distilled off, and 0.1 to 20 mass%, preferably 3 to 15 mass% of the amount used can be incorporated into the polyester resin (a) skeleton.

Further, in the case where a glycol such as ethylene glycol is used as a solvent or in the case where a reaction product of an aromatic polycarboxylic acid component and a glycol having 2 to 4 carbon atoms is used, the equivalent ratio [ OH ]: [ COOH ] is preferably 100: 50-100: 115, more preferably 100: 60-100: 100. wherein [ OH ] is a value calculated without considering a diol component used as a solvent, and [ COOH ] is a value calculated with considering a reaction product of an aromatic polycarboxylic acid component and a diol having 2 to 4 carbon atoms.

The polyester resin (a) is obtained by mixing the polyol component and the first polycarboxylic acid component at a predetermined ratio in the presence of a catalyst, heating, and performing a condensation reaction. The above reaction is usually carried out in the presence of a catalyst under a temperature condition of 130 to 280 ℃, preferably 150 to 270 ℃, under normal pressure, reduced pressure, or increased pressure, preferably for 5 to 15 hours.

In the production of the polyester resin (a), conventionally known catalysts such as organotin polymerization catalysts such as antimony trioxide and dibutyltin oxide, germanium catalysts, inorganic titanium catalysts, organotitanium catalysts, organocobalt catalysts, and transesterification catalysts such as zinc acetate and manganese acetate can be used as the catalyst, and germanium catalysts, inorganic titanium catalysts, and organotitanium catalysts can be particularly preferably used.

Examples of the organic titanium-based catalyst include titanium alkoxides, titanium potassium oxalate, titanium terephthalate, catalysts described in JP-A-2006-243715 (dihydroxybis (triethanolamine) titanium, monohydroxytris (triethanolamine) titanium, and intramolecular condensates thereof), and catalysts described in JP-A-2007-11307 (titanium tributoxyterephthalate, titanium triisopropoxide terephthalate, titanium diisopropoxide terephthalate, etc.).

In the present invention, an antioxidant may be added before or after the production of the polyester resin (a) in order to prevent coloration or thermal decomposition. Such an antioxidant is not particularly limited, and examples thereof include a hindered phenol-based antioxidant, a phosphite-based antioxidant, and a sulfur-containing antioxidant.

The polyester resin (A) obtained by reacting the polyol component with the first polycarboxylic acid component has a hydroxyl value (OHV) of 15 to 70mgKOH/g from the viewpoint of controlling the reaction with the second polycarboxylic acid component (a)_A) Preferably, the hydroxyl group value is 15 to 50 mgKOH/g. The hydroxyl value of the polyester resin (A) is less than 15mgKOH/g or more than 70mgKOH/gIn this case, it tends to be difficult to control the weight average molecular weight of the amorphous polyester resin (B) to a preferable range.

The polyester resin (A) preferably has an Acid Value (AV) of 5mgKOH/g or less from the viewpoint of controlling the reaction with the second polycarboxylic acid component (a)_A) More preferably, it has an acid value of 4mgKOH/g or less. If the acid value exceeds 5mgKOH/g, the polyester resin (A) is easily reacted with each other, and therefore, it tends to be difficult to control the molecular weight and acid value after the reaction with the second polycarboxylic acid component (a).

The weight average molecular weight (Mw) of the polyester resin (A)_A) Is 6,000 to 40,000, preferably 8,000 to 40,000, more preferably 9,000 to 38,000, and further preferably 10,000 to 35,000. Mw_ALess than 6,000, there is (AV)_B-AV_A)/AV_a(degree of modification) is decreased, and the hot offset resistance of the amorphous polyester resin (B) tends to be decreased, and if it exceeds 40,000, the low-temperature fixability and image gloss (gloss) tend to be decreased.

The content of the component having a weight average molecular weight of 500 or less in the polyester resin (a) is preferably 10.0% by mass or less, more preferably 8.0% by mass or less, and still more preferably 6.0% by mass or less. This makes it easy to control the reaction between the polyester resin (a) and the second polycarboxylic acid component (a), and to control the content of the component having a weight average molecular weight of 500 or less in the obtained amorphous polyester resin (B).

The polyester resin (B) of the present embodiment is obtained by the reaction of the polyester resin (a) and the second polycarboxylic acid component (a).

The second polycarboxylic acid component (a) may contain at least one compound selected from 2-or 3-membered polycarboxylic acids, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

As the second polycarboxylic acid component (a), the same components as those of the first polycarboxylic acid component used for producing the polyester resin (a) can be exemplified. From the viewpoint of ease of control of the glass transition temperature of the obtained amorphous polyester resin (B), the second polycarboxylic acid component (a) preferably contains an aromatic polycarboxylic acid component, that is, one or more compounds selected from aromatic polycarboxylic acids, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms, and more preferably contains an anhydride of an aromatic polycarboxylic acid.

The blending ratio (a) of the polyester resin (a) to the second polycarboxylic acid component (a) used for producing the amorphous polyester resin (B): (a) preferably, the ratio, expressed as a mass ratio, is 99.5: 0.5-90: 10 (reaction mass ratio [ (A)/(a)]99.5/0.5 to 90/10), more preferably 99: 1-95: 5 (reaction mass ratio [ (A)/(a)]99/1-95/5). If the reaction mass ratio is [ (A)/(a)]OHV in which more than 99.5/0.5 of amorphous polyester resin (B) is present_B/AV_BThe hot offset resistance of the toner tends to be lowered. If the reaction mass ratio is [ (A)/(a)]When the amount of the second polycarboxylic acid component (a) is smaller than 90/10, the hygroscopic property of the toner increases and the charging characteristics decrease, and the glass transition temperature decreases and the storability tends to decrease because the amount of unreacted second polycarboxylic acid component (a) increases.

The reaction for producing the amorphous polyester resin (B) is preferably carried out at a temperature of preferably 130 to 250 c, more preferably 170 to 230 c, under normal pressure, reduced pressure or increased pressure for 30 to 150 minutes. From the viewpoint of reaction control, the reaction is preferably carried out under normal pressure, and if necessary, the reaction may be carried out in the presence of a monocarboxylic acid such as benzoic acid, salicylic acid, p-hydroxybenzoic acid, toluic acid, acetic acid, propionic acid, and stearic acid, an acid anhydride thereof (e.g., benzoic anhydride), or a lower alkyl (preferably, 1 to 3 carbon atoms) ester thereof (e.g., ethyl benzoate), or in the presence of a catalyst used in the production of the polyester resin (a). The reaction product in the production of the polyester resin (a) may be heated to a predetermined reaction temperature, cooled, and reacted with the second polycarboxylic acid component (a) added thereto.

In the present embodiment, the polyester resin (a) is reacted with the second polycarboxylic acid component (a) under the conditions satisfying the following formulas (1), (2) and (3) to obtain the amorphous polyester resin (B) satisfying the following formula (4).

(1)(AV_B-AV_A)/AV_a＝0.5～0.7

(2)Mw_B/Mw_A＝1.1～2.0

(3)OHV_B/AV_B＝1.0～6.0

(4)Mw_B/Mn_B＝3.0～15.0

Wherein, AV_B、OHV_B、Mw_BAnd Mn_BRespectively represents the acid value, hydroxyl value, weight average molecular weight and number average molecular weight of the amorphous polyester resin (B), AV_AAnd Mw_ARespectively represents the acid value and the weight average molecular weight, AV, of the polyester resin (A)_aThe theoretical acid value of the second polycarboxylic acid component (a) is shown.

The above theoretical acid value AV_aThe calculation is performed by the following equation.

AV_a＝AV_a’×W_a/(W_A+W_a)

AV_a’＝W_a/Mw_a× valence (number of elements) × 56.1.1 56.1 × 1000/W_a

Wherein, AV_a' represents an acid value of the second polycarboxylic acid component (a), W_aDenotes the weight of the second polycarboxylic acid component (a) to be reacted, W_ARepresents the weight of the polyester resin (A) to be subjected to the reaction.

(AV) in the above formula (1)_B-AV_A)/AV_aThe unreacted ratio of the second polycarboxylic acid component (a) can be considered, and the formula (1) represents that 50 to 70% of the carboxyl groups of the second polycarboxylic acid component (a) are unreacted. The carboxyl group means a moiety having an acid anhydride structure and a moiety having a lower alkyl ester structure, in addition to-COOH. When the unreacted ratio of the second polycarboxylic acid component (a) is less than 50%, the unreacted ratio is determined byThe crosslinking reaction proceeds, and the viscoelasticity of the resin tends to be excessively increased, and the low-temperature fixing property and the gloss tend to be lowered. When the unreacted ratio of the second polycarboxylic acid component (a) is greater than 70%, the hot offset resistance and the storability are reduced because of the small number of crosslinked portions, and the amount of the unreacted second polycarboxylic acid component (a) is increased, so that deposition occurs on the surface of the toner particles, and as a result, the blocking resistance tends to be reduced. When the unreacted ratio of the second polycarboxylic acid component (a) is 50 to 70%, a highly crosslinked structure is not formed, but a structure in which a part is slightly crosslinked or a branched structure is formed. Therefore, tetrahydrofuran insolubility in the obtained amorphous polyester resin (B) can be made 0.5 mass% or less, and a polymer having a carboxyl group in the main chain of the polyester or a polymer having many carboxyl groups per 1 molecule of the polymer can be obtained, and thus, the emulsifying property tends to be good. (AV)_B-AV_A)/AV_aPreferably 0.55 to 0.67.

Mw in the above formula (2)_B/Mw_AThe molecular elongation before and after the reaction is considered to indicate how much the weight average molecular weight is increased by the reaction of the polyester resin (a) with the second polycarboxylic acid component (a). Mw_B/Mw_AWhen the amount is less than 1.1, hot offset resistance and storability are lowered, and when the amount exceeds 2.0, low-temperature fixability and image gloss (glossiness) tend to be lowered. Mw_B/Mw_APreferably 1.2 to 1.6.

OHV in the above formula (3)_B/AV_BAs a specific method for satisfying the condition of the formula (3) in order to obtain the ratio of the hydroxyl value to the acid value of the amorphous polyester resin (B), a method based on the weight average molecular weight (Mw) of the polyester resin (A) can be mentioned_A) And Acid Value (AV)_A) The blending ratio and the unreacted ratio of the second polycarboxylic acid component (a) are appropriately adjusted. If OHV_B/AV_BWhen the amount is less than 1.0, the fluidity of the toner is deteriorated, and the storage property (blocking resistance) is lowered, and when the amount exceeds 6.0, the dispersibility of the pigment in the toner is deteriorated, and the coloring property (color reproducibility or chroma) and the image gloss (glossiness) tend to be lowered.

By satisfying the above formulas (1), (2) and (3) in the reaction of the polyester resin (a) and the second polycarboxylic acid component (a), the noncrystalline polyester resin (B) capable of realizing a toner having excellent low-temperature fixing property, image glossiness (glossiness), hot offset resistance and storability can be obtained. Further, in the case of producing a chemical toner by an emulsion aggregation method or the like, it becomes easy to produce fine particles by satisfying the above (1) and (2).

Further, the noncrystalline polyester resin (B) satisfies the above formulae (3) and (4), and thus a toner having excellent low-temperature fixability, hot offset resistance and storability can be obtained. Mw_B/Mn_BWhen the molecular weight is less than 3.0, the viscosity of the toner at the time of high-temperature fixing is remarkably reduced, the hot offset resistance is reduced, and when the molecular weight is more than 15.0, the molecular weight distribution is too broad, and it is difficult to obtain a smooth surface of a fixed image, and the image glossiness (glossiness) tends to be reduced.

As described above, by controlling the reaction between the polyester resin (a) and the second polycarboxylic acid component (a) so as to satisfy the formulas (1) to (4) to produce the amorphous polyester (B), it is possible to realize an electrostatic charge image developing toner having both excellent low-temperature fixing property and hot offset resistance and storage property (blocking resistance) and having excellent image glossiness (glossiness).

The weight average molecular weight Mw of the amorphous polyester resin (B) of the present embodiment_BPreferably 8,000 to 50,000, more preferably 10,000 to 50,000. If the weight average molecular weight (Mw)_B) When the content is less than 8,000, the hot offset resistance and storage property tend to be insufficient, and when the content exceeds 50,000, the low-temperature fixing property and gloss property tend to be lowered.

Further, the molecular weight Mc between crosslinking points determined by the measurement of temperature dispersion in dynamic viscoelasticity of the amorphous polyester resin (B) is preferably 1.0 × 10⁵～1.0×10⁸More preferably 3.0 × 10⁵～8.0×10⁷More preferably 5.0 × 10⁵～4.0×10⁷. If the cross-linking points are separatedThe sub-amount is less than 1.0 × 10⁵The rigidity of the amorphous polyester resin (B) tends to be high, and the low-temperature fixing property or image gloss tends to be low, and if the molecular weight between crosslinking points exceeds 1.0 × 10⁸The rigidity is lowered, and the low-temperature fixing property and the image gloss are improved, but the hot offset resistance and the image strength tend to be lowered.

The content of the component having a weight average molecular weight of 500 or less in the amorphous polyester resin (B) is preferably 5.0% by mass or less. If the content of the component having a weight average molecular weight of 500 or less (so-called polyester oligomer) is large, these components tend to be easily precipitated on the surface of the toner particles, and the blocking resistance tends not to be sufficiently improved. Such components can be reduced by controlling the production conditions of the polyester resin (a), for example, by raising the reaction temperature, reducing the pressure, or extending the reaction time.

Further, 2 or more kinds of the amorphous polyester resins (B) having different weight average molecular weights may be mixed and used. When 2 or more kinds are mixed, a combination of the non-crystalline polyester resin (B-1) having a weight average molecular weight of 8,000 to 25,000 and the non-crystalline polyester resin (B-2) having a weight average molecular weight of 25,000 to 50,000 is preferable. The mixing ratio of the non-crystalline polyester resin (B-1) to the non-crystalline polyester resin (B-2) is preferably 95: 5-5: 95, more preferably 90: 10-40: 60, more preferably 80: 20-50: 50. if the mixing ratio is 95: 5-5: 95, a toner having more excellent low-temperature fixability and image glossiness (glossiness), and having good hot offset resistance and storability can be obtained.

The acid value of the amorphous polyester resin (B) is preferably 4 to 25mgKOH/g, more preferably 5 to 15mgKOH/g, and still more preferably 5 to 13 mgKOH/g. If the acid value is less than 4mgKOH/g, the ionic repulsive force between particles due to the charge on the toner surface is small, and when the toner is exposed to a high temperature state for a long period of time such as during storage, the problem of adhesion or aggregation between the toners is likely to occur, and the storage property tends to be low. On the other hand, if the acid value exceeds 25mgKOH/g, there is a possibility that hygroscopicity due to ionic functional groups increases and blocking resistance decreases, and further, environmental stability of the toner (i.e., stability of charging characteristics when temperature or humidity changes) decreases, resulting in a possibility that image quality is decreased due to image formation failure. Further, if the acid value is in the range of 4 to 25mgKOH/g, the particle diameter tends to be easily controlled in the case of a chemical toner produced by emulsifying and re-aggregating the resin.

The hydroxyl value of the amorphous polyester resin (B) is preferably 10 to 60mgKOH/g, more preferably 10 to 40 mgKOH/g. If the hydroxyl group value is less than 10mgKOH/g, the charging characteristics of the toner tend to be lowered, specifically, the accumulation of the charge of the toner tends to be deteriorated, and if it exceeds 60mgKOH/g, the hygroscopicity of the toner extremely increases, the charging characteristics of the toner decrease, specifically, the charge retention of the toner tends to be adversely affected.

The glass transition temperature of the amorphous polyester resin (B) is preferably 55 to 75 ℃. If the glass transition temperature is less than 55 ℃, the storage property becomes insufficient, and if it exceeds 75 ℃, the low-temperature fixing property and the image glossiness (glossiness) are liable to be lowered.

The temperature at which the melt viscosity of the amorphous polyester resin (B) is 10,000 pas is preferably 95 to 125 ℃. If it is in this temperature range, the low-temperature fixing property and hot offset resistance become better. More specifically, when the temperature is lower than 95 ℃, the viscosity of the binder resin is excessively reduced at the time of fixing, bleeding of an image due to excessive penetration into a printing medium is likely to occur, and the heat offset resistance tends to be reduced. On the other hand, when the temperature is higher than 125 ℃, the viscosity of the binder resin is excessively increased at the time of fixing at a low temperature, so that fixing failure is likely to occur, and the low-temperature fixing property tends to be lowered.

The amorphous polyester resin (B) preferably has a dielectric loss tangent tan of 0.0015 to 0.0060 at an applied frequency of 1kHz at a temperature of 25 ℃ and a humidity of 65% RH. When the dielectric loss tangent tan value is within this range, the charging characteristics when used as a binder resin for toner become suitable, and problems such as non-formation of an image due to insufficient charging, melting of the resin due to excessive charging, and contamination of the photoreceptor roll are less likely to occur.

The amorphous polyester resin (B) produced as described above can be used as a binder resin for toner either directly or in combination with conventionally known amorphous resins such as polystyrene, styrene butadiene polymers, styrene acrylic polymers, and polyesters, or crystalline polyester resins. These noncrystalline resins can be urethane, urea or epoxy modified. According to the present invention, a binder resin for toner containing the amorphous polyester resin (B) according to the present embodiment can be provided. The binder resin for toner is suitably used for developing an electrostatic charge image.

The crystalline polyester resin that can be used in combination with the non-crystalline polyester resin (B) includes a resin produced by the reaction of at least 1 dicarboxylic acid selected from aliphatic dicarboxylic acids having 4 to 12 carbon atoms (preferably 8 to 12 carbon atoms) and at least 1 diol selected from aliphatic diols having 2 to 12 carbon atoms (preferably 8 to 12 carbon atoms). Further, the crystalline polyester resin is preferably a crystalline polyester resin having a melting point of 65 to 75 ℃ by DSC.

The components other than the binder resin in the toner containing the binder resin for toner according to the present invention are not particularly limited, and may be appropriately selected according to the purpose, and examples thereof include conventionally known components such as a colorant such as a pigment, inorganic fine particles, organic fine particles, a charge control agent, and a release agent.

Further, the binder resin dispersion for toner can be obtained by dispersing or emulsifying the amorphous polyester resin of the present embodiment in an aqueous medium. Examples of the aqueous medium include water and a mixed solvent of a solvent miscible with water (for example, a lower alcohol or glycol having 1 to 4 carbon atoms, or a ketone such as methyl ethyl ketone or acetone) and water. Examples of the method of dispersion or emulsification include a method using a medium type dispersing machine (bead mill) or a high pressure type dispersing machine (homogenizer, アルティマイザー), and a phase inversion emulsification method in which water is added to a solution in which the amorphous polyester resin (B) is dissolved in an organic solvent, and the phase is inverted from an oil phase to an aqueous phase.

When the amorphous polyester resin of the present invention is used as a binder resin to produce a toner, conventionally known chemical toners obtained by kneading and pulverizing, spray drying, emulsion aggregation, or the like can be used, and conventionally known components can be used as components for toner production. The emulsion aggregation method is a method preferable for reducing the particle diameter of the toner and controlling the particle size distribution. The amorphous polyester resin (B) of the present invention is suitably used as the binder resin dispersion for toner as described above, and can be suitably used in the emulsion aggregation method.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

(evaluation method)

In the examples, each evaluation was performed by the following method.

(1) Hydroxyl number

The hydroxyl value of the polyester resin was measured by phthalylation (フタル) method in method B of JIS K1557-1 (2007).

(2) Acid value

Acid value of polyester resin according to the neutralization titration method of 3.1 of JISK0070(1992), as a measurement titration solution, 0.1 mol/L aqueous sodium hydroxide solution was used, and as a measurement solvent, tetrahydrofuran: water 10: 1 (volume ratio), and 3g of a sample was dissolved in 60mL of the mixed solvent and measured.

(3) Average molecular weight

The weight average molecular weight, number average molecular weight and molecular weight distribution of the polyester resin were measured in the following manner. That is, in5mL of tetrahydrofuran was added to 2mg of the polyester resin, and the weight average molecular weight Mw, the number average molecular weight Mn and the molecular weight distribution Mw/Mn of the tetrahydrofuran-soluble fraction were determined by GPC in terms of polystyrene. The calibration curve was prepared using a polystyrene standard sample (manufactured by ジーエルサイエンス K.K.). Further, the ratio (%) of the component having a weight average molecular weight Mw of 500 or less is the area Mw surrounded by the detection peak and the base line of the polyester resin having a weight average molecular weight Mw of 500 or less₅₀₀Area Mw surrounded by detection peak and base line of the entire polyester resin_totalArea ratio (Mw)₅₀₀/Mw_total× 100).

< measuring device >

HLC-8220GPC (manufactured by Toho ソー Co., Ltd.)

< detection device >

RI detector

< measurement Condition >

Mobile phase: tetrahydrofuran (THF)

Column: 2 Tsk-gelSuperHZ2000 and 1 Tsk-gelSuperHZ4000 were connected in series.

Temperature of sample injector and column: 40 deg.C

Temperature of the RI detector: 35 deg.C

Sample injection amount: 5 μ L

Flow rate: 0.25 mL/min

Measuring time: 40 minutes

(4) Glass transition temperature

The glass transition temperature of the polyester resin was measured in accordance with 9.3(3) of JIS K7121 (1987). A differential scanning calorimeter DSC-6220 (manufactured by エスアイアイ & ナノテクノロジー Co., Ltd.) was used as a measuring apparatus, and the measurement was carried out under the following conditions. In a graph having measurement data in which the vertical axis represents heat flow (HeatFlow) and the horizontal axis represents measurement temperature, the glass transition temperature is defined as the temperature at the intersection of a straight line extending from the base line on the low temperature side to the high temperature side and a tangent line at a point where the gradient of the curve of the stepwise change portion of the glass transition is maximum.

< measurement Condition >

Temperature rising and temperature lowering speed: 10 ℃/min

Temperature rising procedure: after warming from room temperature to 150 ℃ the temperature was maintained at 150 ℃ for 1 minute. Then, the temperature was lowered to 0 ℃ and maintained at 0 ℃ for 1 minute, and further, the temperature was raised to 150 ℃.

Atmosphere: in nitrogen flow (50 mL/min)

Pool: closed aluminium

The amount of the test material: 5mg of

(5) The melt viscosity of the resulting mixture was 10,000 pas

Using an elevated フローテスター CFT-500 (manufactured by Shimadzu corporation), 1.0g of an amorphous polyester resin was charged into a cylinder equipped with a die (length: 1.0mm, diameter: 0.5mm), and the mixture was held at 90 ℃ for 5 minutes, and then the melt viscosity was measured by applying a load of 25kg via a piston while heating at 3 ℃/minute, and the temperature at which the melt viscosity became 10,000 pas was measured.

(6) Particle size distribution

The volume average particle diameter (D50v) and the volume particle size distribution index (GSDv) of the resin particles in the amorphous polyester resin dispersion were measured as follows using a laser diffraction particle size distribution measuring apparatus (LA-920, manufactured by horiba, Ltd.). The sample in the state of the dispersion was put into a cell to have an appropriate concentration, and the average particle diameter was measured while the concentration in the cell was stable after about 2 minutes. The volume average particle diameter of the obtained channel (channel) was accumulated from the smaller one, and the particle diameter at 50 vol% accumulation was defined as the volume average particle diameter (D50 v). The values of D84v/D16v when the particle diameter at 16 vol% accumulation is D16v and the particle diameter at 84 vol% accumulation is D84v were used as the volume particle size distribution index (GSDv).

(7) Molecular weight between crosslinking points (Mc)

The storage modulus G' of the polyester resin at the temperature T was measured under the following measurement conditions using an ARES レオメーター (manufactured by ティー, エイ, インスツルメント, ジャパン) dynamic viscoelasticity measuring apparatus. The storage modulus G' was measured by fixing a sample between parallel plates, applying a deformation by torsional reciprocal vibration at a vibration frequency of 6.28 rad/sec to one side, and detecting a stress against the deformation on the other side. In this state, the temperature was increased in order from room temperature, and the temperature dependence of viscoelasticity was measured.

< measurement Condition >

Vibration frequency: 6.28 rad/sec

Measuring temperature: 0 to 200 DEG C

Parallel plate: phi 15mm

Determination of CAP: 1.0mm

Deformation amount: is automatically variable from 0.1%

Temperature rise rate: 3 ℃ per minute

Then, the molecular weight between crosslinking points Mc was calculated based on the following formula.

Mc＝dRT/G’

(wherein d represents the density (g/cm) of the resin³) R represents a gas constant, T represents a center temperature showing a rubbery flat region, and G' represents a storage modulus (Pa) of the center temperature T of the rubbery flat region. )

Production of the polyester resin (A)

Production example 1

A reaction vessel sufficiently dried in advance was charged with 35 parts by mole of a 2.2-mole adduct of bisphenol A with ethylene oxide, 65 parts by mole of a 2.3-mole adduct of bisphenol A with propylene oxide, 84 parts by mole of ethylene glycol, 42 parts by mole of terephthalic acid, 42 parts by mole of dimethyl terephthalate, 8 parts by mole of tetrapropenyl succinic anhydride and 4 parts by mole of trimellitic anhydride, and heated to 180 ℃ under nitrogen aeration with stirring. Wherein 0.05 molar part of n-tetrabutoxytitanium was added as a catalyst, and the temperature was raised to 250 ℃. Then, the pressure was reduced until the pressure in the final reaction vessel became 2kPa or less, and the polycondensation reaction was carried out at 250 ℃ until the weight average molecular weight became a predetermined weight average molecular weight, to obtain a polyester resin (A-1).

Production examples 2 to 9 and comparative production examples 1 to 3

Polyester resins (A-2) to (A-9) and (C-1) to (C-3) were obtained in the same manner as in production example 1, except that the raw materials and the composition (molar ratio) were changed as shown in Table 1. In Table 1, EO and PO respectively mean ethylene oxide and propylene oxide.

In addition, the DMT-EG reactant in Table 1 was prepared as follows. 100 parts by mole of dimethyl terephthalate, 220 parts by mole of ethylene glycol and 0.004 part by mole of zinc acetate as a catalyst were charged into a reaction vessel dried in advance, and the mixture was uniformly dissolved by heating under nitrogen aeration with stirring. Subsequently, the temperature of the solution was gradually raised to 170 ℃ to obtain DMT-EG reactant. The concentration (mol/g) of terephthalic acid residue in 1g of DMT-EG reactant was measured by a U-3410 type self-recording spectrophotometer (manufactured by Hitachi Ltd.), and the average molecular weight of the DMT-EG reactant was calculated to be 250. Further, the content of terephthalic acid residue contained in 1g of the DMT-EG reactant was measured by UV (absorbance), and found to be 0.004 mols. The numerical values shown in the column of DMT-EG reactant in Table 1 indicate the content (molar parts) of terephthalic acid residues in the DMT-EG reactant to be blended. In production example 5, the DMT-EG reactant was blended so that the content (molar parts) of the terephthalic acid residue shown in table 1 was obtained.

The physical properties of the polyester resin (a) obtained in each production example are shown in table 1.

[ Table 1]

(production of amorphous polyester resin (B))

[ example 1]

A reaction vessel sufficiently dried in advance was charged with 98.6 parts by mass of polyester resin (A-1), heated to 200 ℃ and further charged with 1.4 parts by mass of trimellitic anhydride, and the reaction was carried out under normal pressure until a predetermined acid value was obtained, whereby amorphous polyester resin (B-1) was obtained, and the molecular weight between crosslinking points of amorphous polyester resin (B-1) was 1.2 × 10⁷。

Examples 2 to 9 and comparative examples 1 to 6

Amorphous polyester resins (B-2) to (B-9) and (D-1) to (D-6) were obtained in the same manner as in example 1, except that the raw materials, the composition (mass ratio) and the polymerization conditions were changed as shown in tables 2 and 3.

The physical properties and the like of the amorphous polyester resins obtained in examples and comparative examples are shown in tables 2 and 3.

[ Table 2]

[ Table 3]

(production of toner)

Production of crystalline polyester resin

In a reaction vessel sufficiently dried in advance, 110 parts by mole of 1, 9-nonanediol and 100 parts by mole of 1, 10-decanedicarboxylic acid were charged and heated under nitrogen aeration with stirring until the temperature became 150 ℃. Wherein 0.05 molar part of n-tetrabutoxytitanium was added as a catalyst, and the temperature was raised to 210 ℃. Then, the pressure was reduced until the pressure in the final reaction vessel became 2kPa or less, and the polycondensation reaction was carried out at 210 ℃ for 2.5 hours to obtain a crystalline polyester resin. The weight-average molecular weight in GPC was 10,300, and the acid value was 8.6 mgKOH/g. The melting point was measured by a differential scanning calorimeter DSC-6220 (manufactured by エスアイアイ & ナノテクノロジー K.), and it was found to be 68 ℃.

Preparation of amorphous polyester resin Dispersion

56 parts by mass of an amorphous polyester resin (B-1), 35 parts by mass of methyl ethyl ketone and 9 parts by mass of 2-propanol were put into a three-necked flask, and after the resin was dissolved by stirring with スリーワンモーター, 26 parts by mass of a 5 mass% aqueous ammonia solution was added. Further, 94 parts by mass of ion-exchanged water was gradually added to perform phase inversion emulsification, and then, desolventization was performed. Then, ion-exchanged water was added thereto to adjust the solid content to 30% by mass, thereby obtaining an amorphous polyester resin dispersion (LB-1). The volume average particle diameter (D50v) of the resin particles in the dispersion was 152nm, and the volume particle size distribution index (GSDv) was 1.17.

Amorphous polyester resin dispersions (LB-2) to (LB-9), (LC-3) and (LD-1) to (LD-6) were obtained in the same manner as amorphous polyester resin dispersion (LB-1), except that amorphous polyester resins (B-2) to (B-9), (C-3) and (D-1) to (D-6) were used in place of amorphous polyester resin (B-1).

Preparation of crystalline polyester resin Dispersion

56 parts by mass of the crystalline polyester resin obtained above, 35 parts by mass of methyl ethyl ketone, and 9 parts by mass of 2-propanol were placed in a three-necked flask, and the mixture was stirred at スリーワンモーター to dissolve the resin, and then 26 parts by mass of a 5 mass% aqueous ammonia solution was added thereto. Further, 94 parts by mass of ion-exchanged water was slowly added, and after the phase inversion emulsification, the solvent removal was performed. Then, ion-exchanged water was added to adjust the solid content concentration to 30 mass%, thereby obtaining a crystalline polyester resin dispersion. The volume average particle diameter (D50v) of the resin particles in the dispersion was 213nm, and the volume particle size distribution index (GSDv) was 1.21.

Preparation of colorant dispersions

An anionic surfactant (ネオゲン RK, first Industrial pharmaceutical Co., Ltd.), ion-exchanged water and glass beads having a diameter of 1mm were mixed with 4-color colorants (carbon black, C.I. pigment blue 15: 3, C.I. pigment yellow 12, C.I. pigment Red 48: 1), and the mixture was vibrated at room temperature for 10 hours, and then the glass beads were separated with a nylon mesh to obtain a 4-color colorant dispersion.

Preparation of the mold release agent dispersion

An anionic surfactant (ネオゲン RK, manufactured by first Industrial pharmaceutical Co., Ltd.) and ion-exchanged water were mixed with a mold release agent (paraffin wax (HNP-9, manufactured by Nippon Kogyo Co., Ltd.)), and the mixture was heated and melted at 110 ℃ and then subjected to a dispersion treatment (pressure 30MPa) of the mold release agent using a homogenizer device (manufactured by ゴーリーン, trade name: ホモジナイザー) to obtain a mold release agent dispersion liquid.

Examples 10 to 19 and comparative examples 7 to 13

Preparation of toner

450 parts by mass of the amorphous polyester resin dispersion (LB-1), 50 parts by mass of the crystalline polyester resin dispersion, 20 parts by mass of the coloring agent dispersion and 70 parts by mass of the releasing agent dispersion were placed in a round stainless steel container and mixed. Then, 1.5 parts by mass of a 10 mass% aqueous solution of polyaluminum chloride as a coagulant was further added thereto, and the mixture was heated and stirred to 45 ℃ and held at 45 ℃ for 30 minutes. Then, the temperature of the obtained contents was gradually increased to 55 ℃. Adding sodium hydroxide aqueous solution, adjusting pH to 8, raising the temperature to 90 deg.C, allowing the resin particles to aggregate for about 1 hr, and cooling. The cooled contents were filtered, sufficiently washed with ion-exchanged water, and dried, thereby obtaining toner (TB-1). Further, toners were prepared for the 4-color colorant dispersions, respectively, to obtain a total of 4-color toner (TB-1).

Toners (TB-2) to (TB-10), (TD-1) to (TD-6) and (TC-3) were obtained in the same manner as toner (TB-1) except that amorphous polyester resin dispersions (LB-2) to (LB-9), (LD-1) to (LD-6) and (LC-3) were added in place of amorphous polyester resin dispersion (LB-1) in accordance with the descriptions in tables 4 and 5.

(evaluation of toner Properties)

A full color composite machine "イプシオ C-4500 IT" (manufactured by リコー K) was modified so that the temperature could be adjusted, and the performance of the toner was evaluated. The toner prepared as described above was put in a toner cartridge, and a halftone image having an image density of 0.8 to 0.85 was printed at 90g/m²A4 on copy paper (1), toner performance was evaluated. The temperature was measured by placing a film thermometer between the fixing roller and the paper.

In the following evaluation, the prepared 4-color toners were tested, and the points were given according to the following criteria for the determination of a to d with respect to the 4-color toners.

a, judging: 5 point

b, judging: 3 point

c, judging: 1 point

d, judging: point 0

Next, for each evaluation item, the total value of points given for evaluation of the 4-color toner was calculated, and the evaluation was performed again according to the following criteria, and the result was regarded as the overall evaluation of the toner. The evaluation results are summarized in tables 4 and 5.

A: the total number of points is 16-20 points

B: the total number of points is 11-15 points

C: the total number of points is 6-10 points

D: the total number of points is 0 to 5 points

< Low temperature fixability >

The minimum fixing temperature on paper when printing at a printing speed of 50 sheets/min was measured and judged according to the following criteria. The fixing was performed by repeatedly rubbing the image of the printed matter 5 times with crepe paper to which a load of 4.9kPa was applied, and the lowest temperature at which the density decrease rate before and after rubbing was 15% or less on average at 5 points was defined as the lowest fixing temperature.

a, judging: can be fixed at 130 ℃ or lower (the lowest fixing temperature is 130 ℃ or lower).

b, judging: can be fixed at 140 ℃ (the minimum fixing temperature exceeds 130 ℃ and is less than 150 ℃).

c, judging: can be fixed at 150 deg.C (the minimum fixing temperature is 150 deg.C or above and less than 160 deg.C).

d, judging: if a temperature of 160 ℃ or higher is not applied, fixing is not possible (the minimum fixing temperature is 160 ℃ or higher).

< hot offset resistance >

The contamination of the image between the fixing roller and the printed matter was visually confirmed when the image was printed at a printing speed of 50 sheets/minute, and the image was judged according to the following criteria.

a, judging: no pollution is generated above 230 ℃.

b, judging: slightly at 230 ℃ but no contamination at 220 ℃.

c, judging: slightly contaminated at 220 ℃ but not at 210 ℃.

d, judging: contamination occurred even at 210 ℃.

< gloss of image >

Using the full color composite machine, adjustment was made so that 1.0. + -. 0.1mg/cm was applied to the printed matter²The glossiness of the solid image sample was measured at an incidence angle of 75 ℃ by a gloss meter (manufactured by Nippon Denshoku industries Co., Ltd.) under a condition that the surface temperature of the fixing belt was 150 ℃ in accordance with the methodThe judgment was made according to the following criteria.

a, judging: the glossiness is more than 15 and less than 20.

b, judging: the glossiness is more than 10 and less than 15.

c, judging: the glossiness is more than 7 and less than 10.

d, judging: the glossiness is 7 or less.

< adhesion resistance >

5g of the toner was put into a glass 50mL sample bottle, and left in a drier at 50 ℃ for 24 hours, and then cooled at room temperature for 24 hours, and this cycle was repeated 2 times as 1 cycle. The toner aggregation state after 2 cycles was visually observed and judged according to the following criteria.

a, judging: the toner simply flows when the sample bottle is turned upside down.

b, judging: the sample bottle was inverted and tapped 2-3 times to flow (no coagulation).

c, judging: the sample bottle is turned upside down, and the sample bottle is beaten for 5 to 6 times to flow (partial solidification).

d, judging: the sample bottle is turned upside down and does not flow even if it is knocked.

The evaluation results obtained in examples and comparative examples are summarized in tables 4 and 5. Further, since the acid value of the amorphous polyester resin (D-2) was low, a good dispersion was not obtained, and therefore, the toner (TD-2) could not be evaluated accurately.

[ Table 4]

[ Table 5]

Claims (9)

1. An amorphous polyester resin obtained by reacting a polyester resin (A) obtained by reacting a polyol component containing at least 3-membered component in at least one thereof with a first polycarboxylic acid component under the conditions satisfying the following formulas (1), (2) and (3), wherein the polyester resin (A) has a weight-average molecular weight of 6,000 to 40,000, the polyester resin (A) has a hydroxyl value of 15 to 70mgKOH/g, and the mass ratio of the polyester resin (A) to the second polycarboxylic acid component (a) is 99.5/0.5 to 90/10,

(1)(AV_B-AV_A)/AV_a＝0.5～0.7

(2)Mw_B/Mw_A＝1.1～2.0

(3)OHV_B/AV_B＝2.18～6.0

(4)Mw_B/Mn_B＝3.0～15.0

wherein, AV_B、OHV_B、Mw_BAnd Mn_BRespectively represents the acid value, hydroxyl value, weight average molecular weight and number average molecular weight of the amorphous polyester resin, AV_AAnd Mw_ARespectively represents the acid value and the weight average molecular weight, AV, of the polyester resin (A)_aThe theoretical acid value of the second polycarboxylic acid component (a) is shown.

2. The noncrystalline polyester resin according to claim 1, wherein the noncrystalline polyester resin has a weight average molecular weight of 8,000 to 50,000.

3. The noncrystalline polyester resin according to claim 1, wherein the polyester resin (A) is obtained by reacting the polyol component and the first polycarboxylic acid component under conditions satisfying at least one of the following conditions (5) and (6),

(5) the polyol component contains 0.3 to 15 mol% of a 3-or more-membered polyol based on the total amount of the polyol component

(6) The first polycarboxylic acid component contains 0.3 to 20 mol% of a 3-membered or higher polycarboxylic acid component based on the total amount of the first polycarboxylic acid component.

4. The non-crystalline polyester resin as claimed in claim 1 or 3, which has an acid value of 4 to 25mgKOH/g, and a hydroxyl value of 10 to 60 mgKOH/g.

5. The noncrystalline polyester resin according to claim 1 or 3, which has a glass transition temperature of 55 to 75 ℃ and a temperature of 95 to 125 ℃ at which the melt viscosity becomes 10,000 Pa-s.

6. The non-crystalline polyester resin according to claim 1 or 3, wherein the polyol component comprises an alkylene oxide adduct of bisphenol A and/or an alkylene oxide adduct of bisphenol S.

7. The noncrystalline polyester resin according to claim 1 or 3, wherein the first polycarboxylic acid component comprises a reactant of an aromatic polycarboxylic acid component and a diol having 2 to 4 carbon atoms.

8. A binder resin for toner, comprising the amorphous polyester resin according to any one of claims 1 to 7.

9. A binder resin dispersion for toner, which is obtained by dispersing or emulsifying the amorphous polyester resin according to any one of claims 1 to 7 in an aqueous medium.