JP2000298376A - Dry tuner and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the dry toner superior in powder fluidity and transferability in the case of using the toner small in its particle diameter and further. superior in each of resistance to heat storage and fixability at low temperature and offset resistance. SOLUTION: This dry toner comprising a toner binder obtained by subjecting a prepolymer (A), having a heterocyclic group capable of reacting with an active hydrogen compound (B), to extension reaction and or cross-linking reaction with the compound (B) in an aqueous medium and a colorant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dry toner used for electrophotography, electrostatic recording, electrostatic printing, and the like.

[0002]

2. Description of the Related Art Conventionally, styrene resins, dry toners used for electrophotography, electrostatic recording, electrostatic printing, and the like have been used.
A toner binder such as polyester is melt-kneaded with a coloring agent or the like, and finely pulverized. These dry toners are developed and transferred to paper or the like, and then fixed by heating and melting using a hot roll. At that time, if the temperature of the hot roll is too high, there is a problem (hot offset) that the toner is excessively melted and fused to the hot roll. On the other hand, if the temperature of the hot roll is too low, the toner does not melt sufficiently and the fixing becomes insufficient. From the viewpoint of energy saving and downsizing of apparatuses such as copying machines, toners having a higher hot offset generation temperature (hot offset resistance) and a lower fixing temperature (low temperature fixing property) are required. Further, it is necessary to have a heat-resistant storage property in which the toner does not block during storage and at ambient temperature in the apparatus. Particularly in full-color copying machines and full-color printers, since the gloss and color mixing of the image are required, the toner must have a lower melt viscosity, and a sharp-melt polyester toner binder is used. ing. Since hot offset is likely to occur in such a toner, silicone oil or the like is conventionally applied to a heat roll in a full-color device. However, the method of applying silicone oil to the heat roll requires an oil tank and an oil application device, and the device becomes complicated and large. It also causes deterioration of the heat roll and requires maintenance at regular intervals. Furthermore, copy paper, O
It is inevitable that oil adheres to films for HP (overhead projector), especially OHP
In this case, there is a problem that the color tone is deteriorated by the attached oil.
On the other hand, in recent years, there has been an increasing need for a toner having a smaller particle size for higher image quality and higher resolution. However, the conventional kneaded and ground toner has an irregular shape, so that when the particle size is small, the powder fluidity becomes insufficient, making it difficult to supply the toner to the developing device and improving the transferability. There is a problem that gets worse.

[0003] Among the above-mentioned problems, those which are compatible with heat resistance storage stability, low-temperature fixability and hot offset resistance are as follows.
Polyester partially crosslinked with a polyfunctional monomer as a toner binder
No. 109825), those using a urethane-modified polyester as a toner binder (Japanese Patent Publication No. 7-1)
01318) and the like. Further, as a method for reducing the amount of oil applied to a hot roll for full color use, a method in which polyester fine particles and wax fine particles are granulated (Japanese Patent Laid-Open No. 7-56390) has been proposed.

Further, the powder fluidity when the particle size is reduced,
To improve the transferability, a polymerizable toner prepared by dispersing a vinyl monomer composition containing a colorant, a polar resin and a releasing agent in water and then subjecting the dispersion to suspension polymerization (Japanese Patent Application Laid-Open No. 9-43909).
Japanese Patent Application Laid-Open No. 9-341), a toner obtained by spheroidizing a toner composed of a polyester resin in water using a solvent.
No. 67) has been proposed.

[0005]

However, all of the toners disclosed in (1) to (4) have insufficient powder flowability and transferability, and cannot achieve high image quality by reducing the particle size. Furthermore, the toners disclosed in and are still insufficient in compatibility between heat-resistant storage stability and low-temperature fixability, and cannot be used for full color because they do not exhibit glossiness. In addition, the toner disclosed in JP-A-2003-115122 has insufficient low-temperature fixing property and does not have satisfactory hot offset property in oil-less fixing.
Although the toners disclosed in (1) and (2) have an effect of improving powder fluidity and transferability, the toners disclosed in (2) have insufficient low-temperature fixability and require much energy for fixing. There is. In particular, this problem is remarkable in full-color toner. Although the toner disclosed in JP-A No. 5-25967 is more excellent in low-temperature fixability, it has insufficient hot offset resistance, and does not make it unnecessary to apply oil to a hot roll in full-color applications.

[0006]

Means for Solving the Problems The present inventors have found that, when a toner having a small particle size is used, the powder fluidity and transferability are excellent, and at the same time, the heat storage stability, low-temperature fixability and hot offset resistance are all satisfactory. The present invention has been achieved as a result of intensive studies to develop an excellent dry toner, particularly a dry toner which is excellent in glossiness of an image when used in a full-color copying machine or the like and does not require oil application to a hot roll. That is, the present invention relates to a dry toner comprising a toner binder obtained by subjecting a prepolymer (A) containing a heterocyclic group capable of reacting with an active hydrogen compound to an elongation reaction and / or a crosslinking reaction, and a colorant; Is a dry toner comprising particles formed by an elongation reaction and / or a crosslinking reaction of the prepolymer (A) with a compound (B) containing active hydrogen in an aqueous medium.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The dry toner of the present invention forms a dispersion of a prepolymer (A) containing a heterocyclic group capable of reacting with an active hydrogen compound in an aqueous medium, and contains (A) and active hydrogen. It consists of particles formed by elongating and / or cross-linking (A) by reaction with compound (B).
In the present invention, as the prepolymer (A) containing a heterocyclic group capable of reacting with an active hydrogen compound, a polyester prepolymer (A1) or an epoxy resin prepolymer containing a heterocyclic group capable of reacting with an active hydrogen compound (A
2), polyurethane prepolymer (A3), polyamide prepolymer and the like. Among these, preferred are (A1), (A2) and (A3), more preferred are (A1) and (A2), and particularly preferred is (A1).

The heterocyclic group capable of reacting with an active hydrogen compound refers to a compound having a cyclic skeleton containing an element other than carbon capable of reacting with the active hydrogen compound. As elements other than carbon, oxygen, nitrogen, sulfur, phosphorus, arsenic are preferable,
More preferred are oxygen, nitrogen, and sulfur, and even more preferred is oxygen. The element other than carbon need not be one kind, and may be two or more kinds of the above elements. Further, the number of cyclic skeletons is preferably a 3- to 7-membered ring, and more preferably a 3- to 4-membered ring.
The ring is a seven-membered ring. Specific examples of the heterocyclic group capable of reacting with an active hydrogen compound include an epoxy group, an oxazoline group, an oxazolidine group, a cyclic carbonate group, a thiocarbonate group, a dithiocarbonate group, a thiirane group, a cyclic imine group, and an acid anhydride group. Can be Preferred among these are epoxy groups.

As the polyester prepolymer (A1) having an epoxy group, a polyester which is a polycondensate of a polyol (a) and a polycarboxylic acid (b) and has an active hydrogen group is reacted with a polyepoxide (c). thing;
Examples thereof include a product obtained by reacting a polyester having an active hydrogen group, which is a polycondensate of the polyol (a) and the polycarboxylic acid (b) with the polyol (a) and the polyol (a). Examples of the active hydrogen group contained in the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Of these, an alcoholic hydroxyl group is preferable.

As the polyol (a), diol (a)
-1) and a trivalent or higher polyol (a-2). (A-1) alone or (a-1) and a small amount of (a-
Mixtures of 2) are preferred. As the diol (a-1), alkylene glycol (ethylene glycol, 1,
2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycols (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetra) Alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.); alkylene oxides of the above alicyclic diols (ethylene oxide) Propylene oxide, butylene oxide, etc.) adducts (usually 1 to 10 mol added); alkylene oxides of the above bisphenols (ethylene oxide, propylene Oxides, butylene oxide, etc.) adducts (usually 2 to 10 mol addition). Among these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols, and alkylene glycols having 2 to 12 carbon atoms. Is a combination of As the trivalent or higher polyol (a-2), 3 to 6
And higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane,
Pentaerythritol, sorbitol and the like); trivalent or more phenols (such as trisphenol PA, phenol novolak, and cresol novolak); and alkylene oxide adducts of the above trivalent or more polyphenols.

The polycarboxylic acid (b) includes dicarboxylic acid (b-1) and trivalent or higher polycarboxylic acid (b-
2), and preferred is (b-1) alone or a mixture of (b-1) and a small amount of (b-2). Examples of the dicarboxylic acid (b-1) include alkylenedicarboxylic acids (succinic acid, adipic acid, sebacic acid, dodecenylsuccinic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid). , Terephthalic acid, naphthalenedicarboxylic acid, etc.). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and 8 to 15 carbon atoms.
20 aromatic dicarboxylic acids. Examples of the trivalent or higher polycarboxylic acid (b-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid).
And the like. As the polycarboxylic acid (b), the above-mentioned acid anhydride or lower alkyl ester (eg, methyl ester, ethyl ester, isopropyl ester) may be used.

Polyol (a) and polycarboxylic acid (b)
Is usually 2/1 to 1/1, as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH].
1, preferably 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

Examples of the polyepoxide (c) include polyglycidyl ethers (ethylene glycol diglycidyl ether, tetramethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, Phenol novolac glycidyl tetrates); diene oxides (such as pentadienedioxide and hexadienedioxide); Preferred among these are polyglycidyl ethers.

The ratio of the polyepoxide (c) is the equivalent ratio [BY] / [OH] of the epoxy group [BY] and the total [OH] of the hydroxyl group of the polyester having a hydroxyl group and the polyol (a).
5/1 to 1/1, preferably 4/1 to 1.
2/1, more preferably 2.5 / 1 to 1.5 / 1. Polyester prepolymer having epoxy group (A
The content of the polyepoxide (c) component in 1) is as follows:
The amount is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, more preferably 2 to 20% by weight from the viewpoints of hot offset resistance, heat storage stability and low-temperature fixability.

Examples of the epoxy resin prepolymer (A2) having an epoxy group include polyadducts of polyol (a) and polyepoxide (c) in which (c) is used in excess of (a). Can be Examples of (a) and (c) include the same as described above, and preferred examples are also the same.

Examples of the polyurethane prepolymer (A3) having an epoxy group include a polyadduct of a polyol (a) and a polyisocyanate (d). As (a), those similar to the above can be mentioned, and preferred ones are also the same. (D) includes an aromatic polyisocyanate having 6 to 20 carbon atoms (excluding carbon in the NCO group, the same applies hereinafter), an aliphatic polyisocyanate having 2 to 18 carbon atoms, and an alicyclic polyolefin having 4 to 15 carbon atoms. Isocyanate, carbon number 8-1
5 aromatic aliphatic polyisocyanates and modified products of these polyisocyanates (urethane group, carbodiimide group, allophanate group, urea group, buret group, uretdione group, uretoimine group, isocyanurate group,
Oxazolidone group-containing modified products) and mixtures of two or more thereof.

Specific examples of the aromatic polyisocyanate include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, ,
4′- and / or 4,4′-diphenylmethane diisocyanate (MDI), crude MDI [crude diaminophenylmethane [condensation product of formaldehyde and aromatic amine (aniline) or a mixture thereof; diaminodiphenylmethane and a small amount (eg, 20% by weight) of a mixture with a tri- or higher functional polyamine]: polyallyl polyisocyanate (PAPI)], 1,5-naphthylene diisocyanate, 4,4 ′, 4 ″ -triphenylmethane triisocyanate, m -And p-isocyanatophenylsulfonyl isocyanate.

Specific examples of the aliphatic polyisocyanate include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (H
DI), dodecamethylene diisocyanate, 1,6,1
1-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate And aliphatic polyisocyanates such as 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

Specific examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate,
Methylcyclohexylene diisocyanate (hydrogenated TD
I), bis (2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate, 2,5- and / or 2,6-norbornane diisocyanate.

Specific examples of the araliphatic polyisocyanate include m- and / or p-xylylene diisocyanate (XDI), α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI). Can be

The modified polyisocyanate includes modified MDI (urethane-modified MDI, carbodiimide-modified MDI, trihydrocarbylphosphate-modified MD).
I), modified products of polyisocyanates such as urethane-modified TDI, and mixtures of two or more thereof (for example, a combination of modified MDI and urethane-modified TDI (isocyanate-containing prepolymer)).

Preferred among these are aromatic polyisocyanates having 6 to 15 carbon atoms, aliphatic polyisocyanates having 4 to 12 carbon atoms, and alicyclic polyisocyanates having 4 to 15 carbon atoms, and particularly preferred are TDI ,
MDI, HDI, hydrogenated MDI, and IPDI.

The number of epoxy groups per molecule in the prepolymer (A) having an epoxy group is usually at least one, preferably 1.5 to 3 on average, and more preferably 1.8 to 2 on average. .5.

The weight average molecular weight of (A) is usually 100 from the viewpoint of the difference between the low-temperature fixing property and the hot offset occurrence temperature.
It is from 0 to 50,000, preferably from 2000 to 40000, and more preferably from 4000 to 20,000. The melt viscosity of (A) at 100 ° C. is generally 2000 poise or less, preferably 1000 poise or less.

Examples of the compound (B) containing an active hydrogen include polyamines (B-1), polyols (B-2), and polymercaptans (B- 3), polycarboxylic acid (B-
4), polyamides (B-5) and water (B-6). Of these, preferred are (B-
1), (B-2), (B-4) and (B-6), more preferably (B-1) and (B-4).
Particularly preferred is a blocked (B-
1).

The ratio of the compound (B) containing active hydrogen is determined by the equivalent ratio [B] of the epoxy group [BY] in the prepolymer (A) having an epoxy group and the active hydrogen group [H] in (B).
Y] / [H] is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, and more preferably 1.2 / 1.
１ ／ 1 / 1.2. When (B) is water (B-6), water is handled as a divalent active hydrogen compound.

In the dry toner of the present invention, the resin (i) that has been subjected to an elongation reaction and / or a cross-linking reaction in an aqueous medium by the prepolymer (A) and the compound (B) containing active hydrogen serves as a toner binder component. The weight average molecular weight of (i) is generally 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000 from the viewpoint of hot offset resistance.

Further, a polymer which does not react with (A) and (B) when the (A) and (B) are reacted in an aqueous medium together with the prepolymer (A) having a heterocyclic group [so-called dead polymer] (C) can also be contained in the system. That is, as a toner binder component when a dry toner is used, a resin (ii) that has not been subjected to an elongation reaction or a cross-linking reaction together with a resin (i) that has been subjected to an elongation reaction and / or a cross-linking reaction of the prepolymer (A) in an aqueous medium. Can also be contained. By using (C), that is, (ii) in combination, the low-temperature fixability and the glossiness when used in a full-color device are improved, and (i) is more preferable than using alone.
It is preferable that (i) and (ii) are at least partially compatible with each other in view of low-temperature fixability and hot offset resistance. Therefore, (A) forming (i) and (ii) (C)
Is preferably a similar composition. That is, when (A) is a polyester prepolymer (A1), (C) is preferably a polycondensate of a polyol (a) and a polycarboxylic acid (b). When the compound (B) containing active hydrogen is water (B-5), preferable compounds (a) and (b) are the same as those in the case of (A1). When (B) is a polyol (B-2) or a polymercaptan (B-3), (C) preferably contains substantially no hydroxyl group, and preferably has a hydroxyl value of 5 or less. Therefore,
As preferable examples of (a) and (b), (a) is the same as (A1), but (b) has 4 to 2 carbon atoms.
Lower alkyl esters of 0 alkenylene dicarboxylic acids and aromatic dicarboxylic acids having 8 to 20 carbon atoms are preferred. The peak molecular weight of (ii) is usually from 1,000 to 10,000, preferably from one to one, from the viewpoint of heat-resistant storage stability and low-temperature fixability.
500 to 10000, more preferably 2000 to 80
00.

(I) and (ii) when (ii) is contained
Is usually 5/95 to 80/20, preferably 5/95.
/ 95-30 / 70, more preferably 5 / 95-25
/ 75, particularly preferably 7/93 to 20/80.

As the aqueous medium used in the present invention, water alone may be used, or a water-miscible solvent may be used in combination. Examples of the miscible solvent include alcohols (eg, methanol, isopropanol, ethylene glycol), dimethylformamide, tetrahydrofuran, cellosolves (eg, methylcellosolve), and lower ketones (eg, acetone, methylethylketone).

As the coloring agent, known dyes, pigments and magnetic powders can be used. Specifically, carbon black, Sudan Black SM, First Yellow-G,
Benzidine Yellow, Pigment Yellow, India First Orange, Irgasin Red, Baranitoaniline Red, Toluidine Red, Carmine FB, Pigment Orange R, Lake Red 2G, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine Blue, Pigment Blue , Priliant Green, Phthalocyanine Green, Oil Yellow GG,
Kayaset YG, Orazole Brown B, Oil Pink OP, magnetite, iron black and the like. The content of the coloring agent is usually 2 to 15% by weight, preferably 3 to 10% by weight.

Further, a wax can be contained together with the toner binder and the colorant. Known waxes can be used, and examples thereof include polyolefin waxes (eg, polyethylene wax and polypropylene wax); long-chain hydrocarbons (eg, paraffin wax, sasol wax); and carbonyl group-containing waxes. Preferred among these are carbonyl group-containing waxes. Examples of the carbonyl group-containing wax include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18 Polyalkanol esters (tristearyl trimellitate, distearyl maleate, etc.); polyalkanoic amides (ethylenediamine dibehenylamide, etc.); polyalkylamides (tristearyl amide, trimellitic acid) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, preferred are polyalkanoic esters. The content of the wax in the toner is usually 0 to 40% by weight, preferably 2 to 30% by weight.
%, Particularly preferably 3 to 25% by weight.

The dry toner of the present invention further comprises:
Charge control agents and glidants can also be used. Known charge control agents include nigrosine dyes, quaternary ammonium salt compounds, quaternary ammonium base-containing polymers, metal-containing azo dyes, salicylic acid metal salts,
Examples include a sulfonic acid group-containing polymer, a fluorine-containing polymer, and a halogen-substituted aromatic ring-containing polymer. The content of the charge control agent is usually 0 to 5% by weight. Known fluidizers such as colloidal silica, alumina powder, titanium oxide powder, and calcium carbonate powder can be used.

In the present invention, the particle diameter of the particles formed by the elongation reaction and / or the crosslinking reaction of (A) is usually from 2 to 2 from the viewpoint of developability and resolution.
0 μm, preferably 3 to 15 μm, more preferably 4 μm
８8 μm.

The method for producing the dry toner of the present invention will be described. The toner particles are formed by reacting a dispersion of the prepolymer (A) having a heterocyclic group with (B) in an aqueous medium. As a method for stably forming a dispersion composed of the prepolymer (A) in an aqueous medium, a composition of a toner raw material composed of the prepolymer (A) is added to an aqueous medium.
A method of dispersing by a shear force and the like can be mentioned. The prepolymer (A) and other toner raw materials (colorant, release agent, charge control agent, etc.) may be mixed when forming a dispersion in an aqueous medium. More preferably, the mixture is added and dispersed in an aqueous medium. Further, in the present invention, other toner raw materials such as a coloring agent, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium, and after forming the particles. May be added. For example, after forming particles containing no coloring agent, a coloring agent may be added by a known dyeing method.

The method of dispersion is not particularly limited, and known equipment such as a low-speed shearing type, a high-speed shearing type, a friction type, a high-pressure jet type, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferred. When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 1000 to 30000 rpm
m, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but is usually 0.1 to 5 minutes in the case of a batch system. The temperature at the time of dispersion is usually 0
To 150 ° C (under pressure), preferably 40 to 98 ° C.
Higher temperatures are preferred because the dispersion of the prepolymer (A) has a lower viscosity and is easier to disperse.

The amount of the aqueous medium to be used per 100 parts of the prepolymer (A) is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. Further, if necessary, a dispersant can be used. The use of a dispersant is preferred in that the particle size distribution becomes sharp and the dispersion is stable. As dispersants, water-soluble polymers (polyvinyl alcohol, hydroxyethyl cellulose, etc.), inorganic powders (calcium carbonate powder, calcium phosphate powder, hydroxyapatite powder, silica fine powder, etc.) and surfactants (sodium dodecylbenzenesulfonate, Known materials such as sodium lauryl sulfate and sodium oleate can be used. When a dispersant is used, the dispersant can be left on the surface of the toner particles. However, it is preferable to remove the dispersant by washing after elongation and / or crosslinking reaction from the viewpoint of the charged surface of the toner.

Further, in order to lower the viscosity of the dispersion comprising the prepolymer (A), a solvent in which (A) is soluble can be used. The use of a solvent is preferred in that the particle size distribution becomes sharp. It is preferable that the solvent has a boiling point of less than 100 ° C. or that it can be azeotroped with water because it is easily removed. Further, as (B), polyols (B
When 1) is used, it is preferable that the hydrophilicity of the solvent is low. Examples of the solvent include ethyl acetate, acetone, methyl ethyl ketone, toluene and the like. The amount of the solvent to be used per 100 parts of the prepolymer (A) is usually from 0 to 30.
0 parts, preferably 0 to 100 parts, more preferably 25 parts
~ 70 parts. If a solvent is used, elongation and / or
Alternatively, after the crosslinking reaction, the mixture is removed by heating under normal pressure or reduced pressure.

The elongation and / or cross-linking reaction time is selected depending on the reactivity of the combination of the heterocyclic group structure of the prepolymer (A) and the compound (B) containing active hydrogen, and is usually from 10 minutes to 40 hours. , Preferably 2 to 24
Time. The reaction temperature is generally 0 to 150C, preferably 50 to 120C. In addition, a known catalyst can be used as necessary. Specific examples include dibutyltin laurate and dioctyltin laurate.

The toner particles formed by elongating and / or cross-linking the dispersion are subjected to solid-liquid separation using a centrifuge, a spacra filter, a filter press or the like, and the resulting powder is dried to obtain the dry powder of the present invention. A toner is obtained. As a method for drying the obtained powder, a known apparatus such as a fluidized bed dryer, a reduced pressure dryer, and a circulating dryer can be used. If necessary, the particles can be classified using a wind classifier or the like to obtain a predetermined particle size distribution.

The dry toner of the present invention may optionally contain iron powder,
Glass beads, nickel powder, ferrite, magnetite, and resins (acrylic resin, silicone resin, etc.)
Is mixed with carrier particles such as ferrite coated on the surface thereof and used as a developer for an electric latent image. In addition, instead of the carrier particles, friction with a member such as a charging blade can be performed to form an electric latent image.
The dry toner of the present invention is fixed on a support (paper, polyester film, or the like) by a copying machine, a printer, or the like to form a recording material. As a method for fixing to a support, a known hot roll fixing method, flash fixing method, or the like can be applied.

Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited to these examples. Hereinafter, "part" indicates "part by weight".

[0044]

EXAMPLES The methods for measuring the properties of the toner and toner binder obtained in the examples and comparative examples are described below. 1. Glass transition point (Tg) The method (DSC) specified in ASTM D3418-82
Law). Apparatus: DSC20, SSC manufactured by Seiko Electronic Industry Co., Ltd.
/ 580 2. Molecular weight The soluble matter in THF was measured by gel permeation chromatography (GPC). The conditions for molecular weight measurement by GPC are as follows. Apparatus: HLC-802A manufactured by Toyo Soda Column: 2 TSK GEL GMH6 (manufactured by Toyo Soda) Measurement temperature: 25 ° C. Sample solution: 0.25 wt% tetrahydrofuran solution Solution injection amount: 200 μl Detector: Refractive index detector The molecular weight calibration curve was created using standard polystyrene.

Example 1 (Preparation example of prepolymer) In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe, 724 parts of a 2-mol adduct of bisphenol A ethylene oxide, 276 parts of isophthalic acid and 276 parts of dibutyltin oxide 2 Put the part, 23 at normal pressure
The reaction was carried out at 0 ° C. for 8 hours, followed by a reaction for 5 hours while dehydrating at a reduced pressure of 10 to 15 mmHg, then cooled to 160 ° C., and 74 parts of phthalic anhydride was added thereto, followed by a reaction for 2 hours. Next, the mixture was cooled to 80 ° C. and reacted with 174 parts of ethylene glycol diglycidyl ether in toluene for 2 hours to obtain an epoxy group-containing prepolymer (1) having a weight average molecular weight of 13,000. (Production Example of Ketimine Compound) 30 parts of isophoronediamine and 70 parts of methyl ethyl ketone were charged into a reaction vessel equipped with a stirring rod and a thermometer, and reacted at 50 ° C. for 5 hours to obtain a ketimine compound (1). (Production Example of Dead Polymer) In the same manner as described above, 654 parts of bisphenol A ethylene oxide 2 mol adduct and 516 parts of terephthalic acid dimethyl ester were polycondensed at 230 ° C. for 6 hours under normal pressure, and then dehydrated under reduced pressure of 10 to 15 mmHg. While reacting for 5 hours, a dead polymer (1) having a peak molecular weight of 2400 and a hydroxyl value of 2 was obtained. (Production Example of Toner) In a beaker, 15.4 parts of the prepolymer (1), 64 parts of the dead polymer (1), and 78.6 parts of ethyl acetate were added and stirred to dissolve. Next, 20 parts of pentaerythritol tetrabehenate and 4 parts of cyanine blue KRO (manufactured by Sanyo Dye) were added, and TK was performed at 60 ° C.
The mixture was stirred at 12,000 rpm with a homomixer and uniformly dissolved and dispersed. Finally, ketimine compound (1) 2.7
Was added and dissolved. This is designated as a toner material solution (1). In a beaker, 706 parts of ion-exchanged water, 294 parts of a hydroxyapatite 10% suspension (Supatite 10 manufactured by Nippon Chemical Industry Co., Ltd.), and 0.2 part of sodium dodecylbenzenesulfonate were put and uniformly dissolved. Then, the temperature was raised to 60 ° C., and the toner material solution (1) was charged and stirred for 10 minutes while stirring at 12,000 rpm with a TK homomixer. Then, the mixed solution was transferred to a kolben equipped with a stir bar and a thermometer, heated to 98 ° C., and the solvent was removed while the urea reaction was being performed. Toner particles having a d50 of 6 μm were obtained. Next, 0.5 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil) was mixed with 100 parts of the toner particles using a sample mill to obtain the toner (1) of the present invention. The weight average molecular weight of the toner binder component in the toner (1) was 14,000, the number average molecular weight was 2,000, and the glass transition point (Tg) was 52 ° C. Table 1 shows the evaluation results.

Example 2 (Preparation example of prepolymer) In the same manner as in Example 1, bisphenol A ethylene oxide 2 mol adduct 669
Parts, 274 parts of isophthalic acid and trimellitic anhydride 2
After polycondensation of 0 parts, 121 parts of ethylene glycol diglycidyl ether was reacted to obtain a weight average molecular weight of 1500.
0 of prepolymer (2) was obtained. (Production Example of Toner) 15.5 parts of the prepolymer (2), 64 parts of the dead polymer (1), and 78.8 parts of ethyl acetate were placed in a beaker, and stirred and dissolved. Next, 20 parts of trimethylolpropane tribehenate and 4 parts of cyanine blue KRO (manufactured by Sanyo Pigment Co., Ltd.) were added.
The mixture was stirred at 12,000 rpm with a homomixer and uniformly dissolved and dispersed. Finally, ketimine compound (1) 2.4
And 0.036 part of dibutylamine were added and dissolved. This is designated as a toner material solution (2). Using the toner material solution (2) and changing the dispersion temperature to 50 ° C., a toner was prepared in the same manner as in Example 1 to obtain a toner (2) of the present invention having a particle diameter d50 of 6 μm. The weight average molecular weight of the toner binder component in the toner (2) was 18,000, the number average molecular weight was 2,000, and the glass transition point (Tg) was 52 ° C. Table 1 shows the evaluation results.

Comparative Example 1 (Synthesis of Toner Binder) 354 parts of bisphenol A ethylene oxide 2 mol adduct and isophthalic acid 1
66 parts were subjected to polycondensation using 2 parts of dibutyltin oxide as a catalyst to obtain a comparative toner binder (1) having a weight average molecular weight of 8,000. (Production Example of Toner) 100 parts of the above comparative toner binder (1), 200 parts of ethyl acetate, and 4 parts of cyanine blue KRO (manufactured by Sanyo Pigment Co., Ltd.) were placed in a beaker.
The mixture was stirred at 12000 rpm with a formula homomixer and uniformly dissolved and dispersed to obtain a comparative toner material solution (1). Next, a toner was prepared in the same manner as in Example 1 to obtain a comparative toner (1) having a particle diameter d50 of 6 μm. Table 1 shows the evaluation results.

[0048]

[Table 1]

[Evaluation Method] Powder Fluidity The calm density was measured using a powder tester manufactured by Hosokawa Micron. The quieter the toner, the better the fluidity. Heat Storage Stability After storing the toner at 50 ° C. for 8 hours, the toner was sieved with a 42 mesh sieve for 2 minutes. The residual ratio of toner having better heat resistance storage stability is smaller. Gloss development temperature (GLOSS) Fixing was evaluated using a modified machine in which the oil supply device was removed from the fixing device of a commercially available color copying machine (CLC-1; manufactured by Canon) and the oil on the fixing roll was removed. The gloss development temperature was defined as the fixing roll temperature at which the 60 ° gloss of the fixed image became 10% or more. Hot Offset Occurrence Temperature (HOT) The fixing was evaluated in the same manner as in the above GLOSS, and the presence or absence of hot offset to the fixed image was visually evaluated. The temperature of the fixing roll at which the hot offset occurred was defined as the hot offset occurrence temperature.

Example 3 (Example of toner production) A toner was prepared in the same manner as in Example 2 except that the colorant was changed to 8 parts of carbon black (MA100 manufactured by Mitsubishi Kasei Co., Ltd.). The toner (3) was obtained. Table 2 shows the evaluation results.

Example 4 (Production example of dead polymer) Bisphenol A ethylene oxide 2 mol adduct 363 parts, isophthalic acid 166
Was subjected to polycondensation in the same manner as in Example 1 to obtain a peak molecular weight of 430.
A dead polymer (2) having 0, a hydroxyl value of 25 and an acid value of 7 was obtained. (Production Example of Toner) In a beaker, 28.8 parts of the prepolymer (2), 69.2 parts of the dead polymer (2),
99 parts of ethyl acetate was added and dissolved by stirring. Then, 5 parts of montan wax WE-40 (manufactured by Hoechst Japan) and carbon black (MA10 manufactured by Mitsubishi Kasei Co., Ltd.)
0) Add 8 parts and add 12 parts at 50 ° C with TK homomixer.
The mixture was stirred at 000 rpm and uniformly dissolved and dispersed. Finally, 4.4 parts of ketimine compound (1) and 0.068 parts of dibutylamine were added and dissolved. This is designated as a toner material solution (3). A toner was prepared in the same manner as in Example 1 except that the toner material solution (3) was used, and the particle size d50 was 6 μm.
Of the present invention (4) was obtained. The weight average molecular weight of the toner binder component in the toner (4) is 28,000, the number average molecular weight is 4300, and the glass transition point (Tg) is 57 ° C.
Met. Table 2 shows the evaluation results.

Comparative Example 2 (Synthesis of Toner Binder) In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 343 parts of a 2-mol adduct of bisphenol A ethylene oxide and 166 parts of isophthalic acid were added.
Parts and 2 parts of dibutyltin oxide, and
After reacting at 30 ° C. for 8 hours and further reacting under reduced pressure of 10 to 15 mmHg for 5 hours, the mixture was cooled to 80 ° C., and 14 parts of toluene diisocyanate was added in toluene, and the reaction was carried out at 110 ° C. for 5 hours. , Weight average molecular weight 9
8000 modified polyesters were obtained. Bisphenol A
363 parts of ethylene oxide 2 mol adduct and 166 parts of isophthalic acid were polycondensed in the same manner as in Example 1 to obtain a dead polymer having a peak molecular weight of 3,800, a hydroxyl value of 25 and an acid value of 7. 350 parts of the modified polyester and dead polymer 6
After dissolving 50 parts in toluene and mixing, the solvent was removed to obtain a comparative toner binder (2). (Preparation of toner) Comparative toner binder (2) 100
Part, Montan wax WE-40 (manufactured by Hoechst Japan) and 5 parts carbon black (M, manufactured by Mitsubishi Kasei Corporation)
A100) 8 parts were formed into a toner by the following method. First, Henschel mixer (FM10B, manufactured by Mitsui Miike Kakoki Co., Ltd.)
After pre-mixing using a mixer, a twin-screw kneader (Ikegai Co., Ltd.
CM-30). Then, after crushing finely using a supersonic jet crusher LabJet (manufactured by Nippon Pneumatic Industries, Ltd.), an airflow classifier (Nippon Pneumatic Industries, Ltd.)
The particles were classified by MDS-I) to obtain toner particles having a particle diameter d50 of 6 μm. Then, 0.5 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil) was mixed with 100 parts of the toner particles using a sample mill to obtain Comparative Toner (2). Table 2 shows the evaluation results.

[0053]

[Table 2]

[Evaluation Method] Powder Fluidity The calm density was measured using a powder tester made by Hosokawa Micron. The quieter the toner, the better the fluidity. Heat Storage Stability After storing the toner at 50 ° C. for 8 hours, the toner was sieved with a 42 mesh sieve for 2 minutes. The residual ratio of toner having better heat resistance storage stability is smaller. Minimum Fixing Temperature (MFT) The fixing was evaluated using a commercially available black-and-white copying machine (SF8400A; manufactured by Sharp). The minimum fixing temperature was the fixing roll temperature at which the residual ratio of the image density after rubbing the fixed image with a pad was 70% or more. Hot offset occurrence temperature (HOT) The fixing was evaluated in the same manner as in the above MFT, and the presence or absence of hot offset to the fixed image was visually evaluated. The fixing roll temperature at which hot offset occurred was taken as the hot offset occurrence temperature.

[0055]

The dry toner of the present invention and the method for producing the same have the following effects. 1. Excellent powder fluidity, excellent developability and transferability. 2. A toner having a small particle size can be easily obtained, and the sharpness is excellent. 3. Excellent heat-resistant storage stability, and excellent both low-temperature fixability and hot offset resistance. 4. Since the color toner is excellent in glossiness and hot offset resistance, it is not necessary to apply oil to the fixing roll. 5. High transparency and excellent color tone when used as a color toner. 6. It is economical because kneading and pulverization are unnecessary and a large amount of solvent is not required.

Claims (9)

[Claims] 1. A dry toner comprising a toner binder obtained by subjecting a prepolymer (A) containing a heterocyclic group capable of reacting with an active hydrogen compound to an elongation reaction and / or a crosslinking reaction, and a colorant, wherein the dry toner is A dry toner comprising particles formed by an elongation reaction and / or a crosslinking reaction of the prepolymer (A) with a compound (B) containing active hydrogen in an aqueous medium. 2. The compound according to claim 1, wherein the heterocyclic group contained in (A) contains at least one element selected from oxygen, nitrogen and sulfur in the ring.
The dry toner according to claim 1, which has a seven-membered ring. 3. The dry toner according to claim 2, wherein the heterocyclic group of (A) is an epoxy group. 4. The dry toner according to claim 1, wherein the component of the prepolymer (A) is a polyester (A1), an epoxy resin (A2) or a polyurethane (A3). 5. The dry toner according to claim 4, wherein (A1) is a polycondensate of a polyol (a) comprising an alkylene oxide adduct of a bisphenol and a polycarboxylic acid (b). 6. The dry toner according to claim 1, wherein said (A) has a melt viscosity at 100 ° C. of 2,000 poise or less. 7. The toner binder comprises a resin (i) obtained by subjecting the prepolymer (A) to an extension reaction and / or a crosslinking reaction in an aqueous medium, and a resin (ii) not subjected to an extension reaction or a crosslinking reaction. , (I) and (ii) have a weight ratio of 5
The dry toner according to any one of claims 1 to 6, wherein the ratio is in the range of / 95 to 80/20. 8. The dry toner according to claim 1, which is used as a dry toner for heat fixing. 9. A method for producing a dry toner in which a composition comprising a thermoplastic resin is dispersed in an aqueous medium to form toner particles, the method comprising a heterocyclic group capable of reacting with an active hydrogen compound dispersed in the aqueous medium. A method for producing a dry toner, comprising subjecting a prepolymer (A) to an elongation reaction and / or a crosslinking reaction with a compound (B) containing active hydrogen.