JP3380491B2 - Dry toner - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD 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 Conventional dry toners used for electrophotography, electrostatic recording, electrostatic printing, etc. are styrene resins,
A toner binder such as polyester is melt-kneaded together with a coloring agent and finely pulverized. These dry toners are developed and transferred onto paper or the like, and then fixed by heating and melting with a heat roll. At this time, if the temperature of the hot roll is too high, the toner excessively melts and is fused to the hot roll (hot offset). Further, if the heat roll temperature is too low, the toner is not sufficiently melted and the fixing becomes insufficient. From the viewpoint of energy saving and downsizing of a device such as a copying machine, a toner having a higher hot offset generation temperature (hot offset resistance) and a lower fixing temperature (low temperature fixing property) is required. Further, it is necessary for the toner to have heat-resistant storability so that it does not block during storage and at ambient temperature in the apparatus. Particularly in full-color copying machines and full-color printers, the toner needs to have a lower melt viscosity because the glossiness and color mixing properties of the image are required, and a sharp melt polyester toner binder is used. ing. Since such a toner is likely to cause hot offset, conventionally, in a device for full color, application of silicone oil or the like to a hot roll has been performed. However, the method of applying the silicone oil to the hot roll requires an oil tank and an oil applying device, which makes the device complicated and large. It also causes deterioration of the heat roll, requiring maintenance at regular intervals. In addition, copy paper, O
It is unavoidable that oil adheres to films for HP (overhead projectors), etc.
In the above, there is a problem of deterioration of color tone due to the adhered oil.
On the other hand, in recent years, there has been an increasing need for a smaller toner particle size for higher image quality and higher resolution. However, since the conventional kneading and pulverizing toner has an irregular shape, the powder fluidity becomes insufficient when the particle size is small, and it becomes difficult to supply the toner to the developing device, and the transferability becomes poor. The problem becomes worse.

Among the above-mentioned problems, the ones that satisfy both heat-resistant storage stability, low-temperature fixability, and hot offset resistance are:
Polyester partially crosslinked with a polyfunctional monomer is used as a toner binder (JP-A-57-
No. 109825), using urethane-modified polyester as a toner binder (Japanese Patent Publication No. 7-1
No. 01318) has been proposed. Further, as a means 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 (JP-A-7-56390) is proposed.

Furthermore, powder fluidity when the particle size is reduced,
To improve the transfer property, a polymerized toner obtained by dispersing a vinyl monomer composition containing a colorant, a polar resin and a releasing agent in water and then suspension-polymerizing the same (see JP-A-9-43909).
JP-A-9-341), a toner made of a polyester-based resin is spheroidized by using a solvent in water.
No. 67) is proposed.

[0005]

However, all of the toners disclosed in (1) to (3) have insufficient powder fluidity and transferability, and cannot be made to have a small particle size and high image quality. Further, the toners disclosed in and are still unsatisfactory in both heat-resistant storage stability and low-temperature fixability, and cannot be used for full-color toner because they do not exhibit glossiness. Further, the toner disclosed in (1) has insufficient low-temperature fixability and is not satisfactory in hot offset property in oilless fixing.
Although the toners disclosed in and have the effect of improving the powder fluidity and transferability, the toner disclosed in [1] has insufficient low-temperature fixability, resulting in a large amount of energy required for fixing. There is. This problem is particularly noticeable with full-color toners. Although the toner disclosed in No. 1 is superior in low-temperature fixability, it does not have sufficient hot offset resistance, so that it is not necessary to apply oil to a heat roll for full-color use.

[0006]

The inventors of the present invention have excellent powder fluidity and transferability in the case of using a toner having a small particle diameter, and have excellent heat resistance storage stability, low temperature fixing property and hot offset resistance. The present invention has been accomplished as a result of earnest studies to develop an excellent dry toner, particularly a dry toner which has excellent image glossiness when used in a full-color copying machine and the like and does not require oil coating on a heat roll. That is, the present invention is a Wad comprising a toner binder and a colorant.
In a dry toner having a practical sphericity of 0.90 to 1.00, the toner binder is composed of a condensation resin (i) containing 5 wt% or more of tetrahydrofuran (THF) insoluble matter, and the measurement frequency of the toner binder is 20
Storage elastic modulus at 10000 dyne / cm2
The dry toner is characterized in that the difference (TG′−Tη) between the temperature (TG ′) at which the viscosity becomes 1000 poise and the temperature (Tη) at which the viscosity reaches 1000 poise is 0 ° C. or more.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. In the present invention, the Wadell's practical sphericity is a value represented by (diameter of a circle equal to the projected area of a particle) ÷ (diameter of the smallest circle circumscribing the projected image of the particle), and toner particles are measured by an electron microscope. It can be measured by observing. The practical sphericity of Wadell is usually 0.90 to 1.00, preferably 0.9.
It is 5 to 1.00, and more preferably 0.98 to 1.00. In the present invention, the practical sphericity of all the toner particles does not have to be in the above range, and may be an average value in the above range. The particle size of the toner is the median size (d
50) is usually 2 to 20 μm, preferably 3 to 10 μm.

Examples of the condensed resin (i) which constitutes the toner binder include polyester, polyurethane, polyurea, polyamide and epoxy resin. Among these, preferred are polyester, polyurethane and epoxy resin, and particularly preferred is polyester.

As polyester, polyol (1)
And a polycondensation product of polycarboxylic acid (2).
Examples of the polyol (1) include a diol (1-1) and a trivalent or higher valent polyol (1-2).
1) A single compound or a mixture of (1-1) and a small amount of (1-2) is preferable. The diol (1-1) has 2 carbon atoms.
~ 18 alkylene glycol (ethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, dodecanediol, etc .; alkylene ether glycols having 4 to 1000 carbon atoms (diethylene glycol, triethylene glycol, tridecane). Ethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diol having 5 to 18 carbon atoms (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); 12 carbon atoms ~ 23 bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.); C2-C18 alkylene oxides (ethylene oxide, propylene oxide) Pyrene oxide, butylene oxide, α-olefin oxide, etc.) adduct (the number of added moles is 2 to 20). Of these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts having 2 to 18 carbon atoms of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols (particularly bisphenol A) (particularly Ethylene oxide or propylene oxide (2 to 3 mol addition product), and an alkylene glycol having 2 to 12 carbon atoms (especially ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, neopentyl glycol) It is a combination.
When used in combination, the ratio of the alkylene oxide adduct of bisphenols is usually 30 mol% or more, preferably 5
It is 0 mol% or more, particularly preferably 70 mol% or more.
Examples of the trihydric or higher polyol (1-2) include trihydric or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); Phenols higher than that (trisphenol PA, phenol novolac, cresol novolac, etc.); and alkylene oxide adducts having 2 to 18 carbon atoms (the number of added moles is 2 to 20) of the above trivalent or higher polyphenols.

As the polycarboxylic acid (2), a dicarboxylic acid (2-1) and a polycarboxylic acid having a valence of 3 or more (2-
2), and (2-1) alone or a mixture of (2-1) and a small amount of (2-2) is preferable. As the dicarboxylic acid (2-1), an alkylenedicarboxylic acid having 2 to 20 carbon atoms (succinic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, dodecenylsuccinic acid, dodecylsuccinic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumar) Acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, etc.) and the like. Of these, the preferred one is
Alkenylene dicarboxylic acid having 4 to 20 carbon atoms (especially adipic acid and dodecenyl succinic acid) and 8 to 2 carbon atoms
0 aromatic dicarboxylic acids, especially isophthalic acid and terephthalic acid. Tricarboxylic or higher polycarboxylic acid (2-
Examples of 2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). As the polycarboxylic acid (2), an acid anhydride or a lower alkyl ester (such as methyl ester, ethyl ester or isopropyl ester) of the above may be used to react with the polyol (1).

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

Polyurethanes include polyol (1)
And a polyaddition product of polyisocyanate (3). As the polyol (1), the diol (1-
1) and polyols (1-2) having 3 or more valences. As the polyisocyanate (3), an aromatic polyisocyanate having 6 to 20 carbon atoms (excluding carbons in the NCO group, the same applies hereinafter), an aliphatic polyisocyanate having 2 to 18 carbon atoms, and an alicyclic ring having 4 to 15 carbon atoms Formula polyisocyanate, araliphatic polyisocyanate having 8 to 15 carbon atoms and modified products of these polyisocyanates (urethane group, carbodiimide group, allophanate group, urea group,
(Bullet group, uretdione group, uretoimine group, isocyanurate group, modified product containing oxazolidone group, etc.)
And mixtures of two or more thereof.

Specific examples of the above aromatic polyisocyanate include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, 2 ，
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 (for example, 5 to 5). 20% by weight) and a mixture with a trifunctional or higher polyamine] phosgene: 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-diisocyanatomethylcaproate, 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 and the like.

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

The modified polyisocyanate may be modified MDI (urethane modified MDI, carbodiimide modified MDI, trihydrocarbyl phosphate modified MD).
I, etc.), modified products of polyisocyanates such as urethane-modified TDI, and mixtures of two or more thereof (for example, combined use of modified MDI and urethane-modified TDI (isocyanate-containing prepolymer)).

Of these, preferred 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. ,
These are MDI, HDI, hydrogenated MDI, and IPDI.

Examples of the polyurea include the reaction products of the above polyisocyanate (3) and amines (b). As amines (b), diamines (b1), 3
To hexavalent or higher polyamines (b2), amino alcohols (b3), amino mercaptans (b4), amino acids (b5), and blocked amino groups of b1 to b5 (b6). Diamine (b1)
Examples include aromatic diamines having 6 to 23 carbon atoms (phenylenediamine, diethyltoluenediamine, 4,4'diaminodiphenylmethane, etc.); alicyclic diamines having 5 to 20 carbon atoms (4,4'-diamino-3,3). 'Dimethyldicyclohexylmethane, diaminocyclohexane, isophoronediamine, etc.); and aliphatic diamines having 2 to 18 carbon atoms (ethylenediamine, tetramethylenediamine,
Hexamethylenediamine) and the like. 3-
Examples of the hexavalent or higher polyamine (b2) include diethylenetriamine and triethylenetetramine. Examples of the amino alcohol (b3) include those having 2 to 12 carbon atoms, and specific examples thereof include ethanolamine and hydroxyethylaniline.
The amino mercaptan (b4) has 2 to 12 carbon atoms.
Examples thereof include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (b5) include those having 2 to 12 carbon atoms, and specific examples thereof include aminopropionic acid and aminocaproic acid. The blocked amino group of b1 to b5 (b6) includes the above b1 to b5.
Examples thereof include ketimine compounds and oxazoline compounds obtained from the amines and ketones having 3 to 8 carbon atoms (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Preferred of these amines (b) are
b1 (especially 4,4'diaminodiphenylmethane, isophoronediamine and ethylenediamine) and a mixture of b1 and a small amount of b2 (especially diethylenetriamine). The ratio of the mixture is a molar ratio of b1 and b2, usually 10
0/0 to 100/10, preferably 100/0 to 100
/ 5.

Further, if necessary, a reaction terminator may be used to adjust the molecular weight of polyurea. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and blocked products thereof (ketimine compounds).

The ratio of the amines (b) is the molar ratio [NCO] / [NH] of the isocyanate group [NCO] in the polyisocyanate (3) and the amino group [NHx] in the amines (b).
x] is usually 1/2 to 2/1, preferably 1.5 /
1-1 / 1.5, more preferably 1.2 / 1/1 /
1.2. When b3 to b5 are used as the amines (b), the molar ratio [NC] of the amino groups in (b) to the total of hydroxyl groups, mercapto groups or carboxyl groups [YHx]
O] / [YHx] is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 /.
It is 1 to 1 / 1.2. When the molar ratio is within the above range, the molecular weight of polyurea is increased and the hot offset resistance is improved.

Examples of polyamides include polycondensates of polycarboxylic acids (2) and amines (b).
As the polycarboxylic acid (2), the above-mentioned dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2)
Is mentioned. Examples of the amines (b) include the above-mentioned diamine (b1), polyamine having a valence of 3 to 6 or more (b).
2), amino alcohol (b3), amino mercaptan (b4), amino acid (b5), and those in which amino groups of b1 to b5 are blocked (b6).

Examples of the epoxy resin include addition condensation products of bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.) and epichlorohydrin.

Further, in the present invention, the condensation resin (i)
May be modified with a small amount of other condensed bonds together with its main condensed bond. For example, in the case of polyester, it may be modified with a small amount of urethane bond, urea bond or amide bond.

The condensation resin (i) preferably has a wide molecular weight distribution in order to achieve both low temperature fixability and hot offset resistance. That is, in gel permeation chromatography (GPC), a molecular weight of 10
By having the maximum value in the range of 00 to 15000, the low temperature fixability becomes good. Further, by containing a THF insoluble component (crosslinkable gel component), the hot offset resistance becomes good. In order to obtain such a molecular weight distribution, a molecular weight of 1000-1
It is preferable to comprise a component (i-1) having a maximum value of 5,000 and a molecular weight of less than 20,000 and a component (i-2) having a molecular weight of 20,000 or more containing a THF-insoluble component. The THF-insoluble component can be contained by using a small amount of trivalent or higher valent monomer as the constituent monomer of (i-2) and partially crosslinking it. The content of the THF insoluble component in the condensed resin (i) is usually 5% by weight or more, preferably 5 to 90% by weight, more preferably 7 to 80% by weight. 5% by weight
If it is less than this, the hot offset resistance is not sufficient.

In the present invention, the glass transition point (Tg) of the toner binder is usually 35 to 85 ° C., preferably 45.
~ 70 ° C. The storage elastic modulus of the toner binder is 10,000 dyne / at a measurement frequency of 20 Hz.
The temperature (TG ′) at which cm 2 is obtained is usually 100 ° C. or higher, preferably 110 to 200 ° C. As the viscosity of the toner binder, the temperature (Tη) at which the porosity is 1000 poise at the measurement frequency of 20 Hz is usually 180 ° C or lower, preferably 90 to 160 ° C. That is, TG ′ needs to be higher than Tη from the viewpoint of achieving both low temperature fixability and hot offset resistance. In other words, the difference between TG ′ and Tη (TG′−Tη) is 0 ° C. or higher. Preferably 10
C. or higher, and particularly preferably 20.degree. C. or higher. From the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 100 ° C or less. The temperature is more preferably 90 ° C or lower, and particularly preferably 80 ° C or lower.

As the colorant of the present invention, 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, Balanitoaniline Red, Toluidine Red, Carmine FB, Pigment Orange R, Lake Red 2G, Rhodamine F
B, Rhodamine B lake, Methyl violet B lake, Phthalocyanine blue, Pigment blue, Priliant green, Phthalocyanine green, Oil yellow GG, Kayaset YG, Orazol brown B, Oil pink OP, magnetite, iron black and the like. The content of the colorant is usually 2 to 15% by weight, preferably 3 to 10% by weight.

A wax may be contained together with the toner binder and the colorant. Known waxes can be used as the wax of the present invention, for example, polyolefin waxes (polyethylene wax, polypropylene wax, etc.); long-chain hydrocarbons (paraffin wax,
Sazol wax and the like); carbonyl group-containing wax and the like. Of these, preferred is a carbonyl group-containing wax. 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 -Octadecanediol-
Bis-stearate, etc.); polyalkanol ester (tristearyl trimellitate, distearyl maleate, etc.); polyalkanoic acid amide (ethylenediamine dibehenylamide, etc.); polyalkylamide (trimellitic acid tristearylamide, etc.); and Dialkyl ketone (distearyl ketone etc.) etc. are mentioned. Of these carbonyl group-containing waxes, polyalkanoic acid esters are preferable. The melting point of the wax of the present invention is usually 40 to 160 ° C., preferably 5
The temperature is 0 to 120 ° C, more preferably 60 to 90 ° C.
The melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps, as a measured value at a temperature 20 ° C. higher than the melting point. The content of wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight, particularly preferably 10 to 25% by weight.
Is.

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

A method for producing the dry toner of the present invention will be exemplified. The polyester can be obtained by heating polycarboxylic acid and polyol at 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, and dehydration condensation. It is also effective to reduce the pressure in order to improve the reaction rate in the final stage of the reaction. The polyester modified with a urea bond can be produced by the following method. Polyol (1) and polycarboxylic acid (2)
In the presence of a known esterification catalyst such as tetrabutoxy titanate and dibutyltin oxide, 150 to 280
The resulting water is distilled off by heating to ℃ and reducing the pressure if necessary to obtain a hydroxyl group-containing polyester. Then 4
This is reacted with polyisocyanate (3) at 0 to 140 ° C. to obtain a prepolymer (A) having an isocyanate group. Further, 0 to 1 of the amines (B) is added to (A).
The reaction is carried out at 40 ° C. to obtain a urea bond-modified polyester. When reacting (3) and reacting (A) and (B), a solvent can be used if necessary. As usable solvents, aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers Examples thereof include those inert to isocyanate (3) such as the class (tetrahydrofuran etc.). When reacting (B), a ketone (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) or the like is added in an amount of 20 to 10
After reacting at 0 ° C. to block the amino group, (A)
May be reacted. When the polyester (ii) not modified with a urea bond is used in combination, (ii) is produced in the same manner as the polyester having a hydroxyl group, and this is dissolved in the solution after completion of the reaction of (i) and mixed. To do. The polyester modified with a urethane bond can be produced by the following method. Polyol (1) and polycarboxylic acid (2)
In the presence of a known esterification catalyst such as tetrabutoxy titanate and dibutyltin oxide, 150 to 280
The resulting water is distilled off by heating to ℃ and reducing the pressure if necessary to obtain a hydroxyl group-containing polyester. Then 5
This is reacted with polyisocyanate (3) and optionally a polyol at 0 to 140 ° C. to obtain a urethane bond-modified polyester. When reacting (3), a solvent can be used if necessary. As usable solvents, aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers Examples thereof include those inert to isocyanate (3) such as the class (tetrahydrofuran etc.). When the polyester (ii) not modified with a urethane bond is used together, (ii) is produced by the same method as the polyester having a hydroxyl group, and this is dissolved in the solution after completion of the reaction of (i) and mixed. To do.

The dry toner can be manufactured by the following method (1). Sphericalization of pulverized toner A method in which a toner material composed of a toner binder and a colorant is melt-kneaded, and then finely pulverized and mechanically spheroidized using a hybridizer, mechanofusion or the like. Spray dry method A method in which a toner material is dissolved and dispersed in a solvent in which a toner binder is soluble, and then a solvent is removed using a spray dry device to obtain a spherical toner. Dispersion granulation method (for example, the method described in JP-A-9-15902) After dissolving and dispersing the toner material in a solvent in which the toner binder is soluble, the toner material is dispersed in a poor solvent (for example, water) of the toner binder with stirring, and then the solvent Is removed to form toner particles, and after cooling, solid-liquid separation and drying are performed to obtain spherical toner. And so on. Among these, the preferred method is the dispersion granulation method, and particularly the dispersion granulation method in which the poor solvent serving as the disperse phase is an aqueous medium. Examples of the solvent used in the dispersion granulation method in an aqueous medium, which dissolves the toner binder in advance, include ethyl acetate, acetone, and methyl ethyl ketone. In addition, a dispersant can be used if necessary. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable. As the dispersant, a water-soluble polymer (polyvinyl alcohol,
Known substances such as hydroxyethyl cellulose), inorganic powders (calcium carbonate powder, calcium phosphate powder, silica fine powder, etc.) and surfactants (sodium lauryl sulfate, sodium oleate, etc.) can be used.
When a dispersant is used, the dispersant can be left as it is on the surface of the toner particles, but it is preferable to remove it by washing after the curing reaction from the viewpoint of toner charging.

The dry toner of the present invention contains iron powder, if necessary.
Glass beads, nickel powder, ferrite, magnetite, and resin (acrylic resin, silicone resin, etc.)
It is mixed with carrier particles such as ferrite whose surface is coated with, and used as a developer for an electric latent image. Further, instead of the carrier particles, it is possible to rub against a member such as a charging blade to form an electric latent image.
Then, the recording material is fixed on a support (paper, polyester film, etc.) by a known heat roll fixing method, flash fixing method or the like.

The present invention will be further described below with reference to examples, but the present invention is not limited thereto. Hereinafter, parts are parts by weight.

[0034]

EXAMPLES The methods for measuring the properties of the toners and toner binders obtained in the examples and comparative examples are shown below. 1. Glass transition point (Tg) Method specified in ASTM D3418-82 (DSC
Law). Equipment: Seiko Electronics Co., Ltd. DSC20, SSC
/ 580 2. Molecular weight THF-soluble matter was measured by gel permeation chromatography (GPC). The conditions for measuring the molecular weight by GPC are as follows. Device: Toyo Soda HLC-802A column: TSK GEL GMH6 2 (Toyo Soda) Measurement temperature: 25 ° C. Sample solution: 0.25 wt% tetrahydrofuran solution Injection amount: 200 μl Detector: Refractive index detector The molecular weight calibration curve was prepared using standard polystyrene. 3. 50 ml of THF is added to 0.5 g of a sample insoluble in tetrahydrofuran (THF), and the mixture is stirred and refluxed for 3 hours. After cooling, the insoluble matter is filtered off with a glass filter and dried under reduced pressure at 80 ° C. for 3 hours. The insoluble matter is calculated from the weight ratio of the resin component on the glass filter to the sample weight. 4. Storage elastic modulus (G '), viscosity (η) measurement device: Rheometrics RDS-7700II dynamics spectrometer test fixture: 25 mmφ cone plate Measurement frequency: 20 Hz (125.6 rad / sec) Strain rate: 5% Fixed

Example 1 (Preparation Example of Prepolymer) In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 669 parts of a 2 mol adduct of ethylene oxide of bisphenol A and 274 parts of isophthalic acid.
Part, 20 parts of trimellitic anhydride and 2 parts of dibutyltin oxide were added, reacted at 230 ° C. for 8 hours under normal pressure, further reacted for 5 hours while dehydrating under reduced pressure of 10 to 15 mmHg, and then cooled to 80 ° C., By reacting with 154 parts of isophorone diisocyanate in ethyl acetate for 2 hours, an isocyanate group-containing prepolymer (1) having a weight average molecular weight of 20,000 was obtained. (Production Example of Ketimine Compound) 30 parts of isophoronediamine, 8 parts of diethylenetriamine and 70 parts of methyl ethyl ketone were charged into a reaction tank equipped with a stir bar and a thermometer, and reacted at 50 ° C. for 5 hours to obtain a ketimine compound (1). . (Production Example of Polyester) In the same manner as above, 770 parts of bisphenol A propylene oxide 2 mol adduct, 138 parts of terephthalic acid and 138 parts of isophthalic acid were added under normal pressure.
Polycondensation at 230 ° C. for 6 hours, then 10-15 mmHg
Number average molecular weight 1 while reacting for 5 hours while dehydrating under reduced pressure
900, weight average molecular weight 4000 polyester (1)
Got (Production Example of Toner) 15.4 parts of the above prepolymer (1), 64 parts of polyester (1) and 78.6 parts of ethyl acetate were placed in a beaker and stirred to dissolve. Then, 20 parts of pentaerythritol tetrabehenate and 4 parts of cyanine blue KRO (manufactured by Sanyo Dye Co., Ltd.) were added and stirred at 60 ° C. with a TK homomixer at 12000 rpm to uniformly dissolve and disperse. Finally, the ketimine compound (1) 2.7
Parts were added and dissolved. This is designated as toner material solution (1). In a beaker, 706 parts of ion-exchanged water, 294 parts of a 10% suspension of hydroxyapatite (Supatite 10 manufactured by Nippon Kagaku Kogyo Co., Ltd.) and 0.2 part of sodium dodecylbenzenesulfonate were uniformly dissolved. Then, the temperature was raised to 60 ° C., and the above toner material solution (1) was charged and stirred for 10 minutes while stirring at 12000 rpm with a TK homomixer. Then, this mixed solution was transferred to a Korben equipped with a stir bar and a thermometer, heated to 98 ° C., the solvent was removed while the urea formation reaction was carried out, and after filtration, washing and drying, air classification was performed to obtain a particle size. Toner particles having a d50 of 6 μm were obtained. Then, 100 parts of the toner particles and 0.5 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil) were mixed in a sample mill to obtain a toner (1) of the present invention. The practical sphericity of the toner particles was 0.98. The toner binder component in the toner (1) has a weight average molecular weight of 40,000, a number average molecular weight of 2,000, and a Tg of 55 ° C.
T η is 131 ° C., TG ′ is 155 ° C., THF insoluble matter is 1
It was 2% by weight. The evaluation results are shown in Table 1.

Example 2 (Synthesis of Toner Binder) 343 parts of bisphenol A ethylene oxide 2 mol adduct and 166 parts of isophthalic acid were placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube.
And 2 parts of dibutyltin oxide are added, and 2 at normal pressure
After reacting at 30 ° C. for 8 hours and further at a reduced pressure of 10 to 15 mmHg for 5 hours, the mixture was cooled to 110 ° C., and 20 parts of isophorone diisocyanate was added in toluene.
The reaction was carried out at 0 ° C. for 5 hours, and then the solvent was removed to obtain a urethane-modified polyester (2) having a weight average molecular weight of 200,000. In the same manner as above, 607 parts of bisphenol A propylene oxide 2 mol adduct and 217 parts of isophthalic acid were subjected to polycondensation at 230 ° C. for 6 hours to give a number average molecular weight of 200.
A polyester (2) having a weight average molecular weight of 4,200 was obtained. 200 parts of urethane modified polyester (2) and 800 parts of polyester (2) are dissolved in 2000 parts of ethyl acetate,
By mixing, an ethyl acetate solution of toner binder (2) was obtained. Partially dried under reduced pressure to isolate the toner binder (2). Tg is 57 ° C, Tη is 140 ° C, TG 'is 155
℃, weight average molecular weight 42,000, number average molecular weight 23
00, THF insoluble content was 14% by weight. (Preparation of Toner) 240 parts of ethyl acetate solution of the above-mentioned toner binder (2), pentaerythritol tetrabehenate (melting point: 81 ° C., melt viscosity: 25 cp) were placed in a beaker.
s) 20 parts and 4 parts of cyanine blue KRO (manufactured by Sanyo dye) are put, and 12,000 rp at 60 ° C. with a TK homomixer.
It was stirred at m to uniformly dissolve and disperse. 706 parts of ion-exchanged water and 10% suspension of hydroxyapatite (Super Chemical 10 manufactured by Nippon Kagaku Kogyo Co., Ltd.) 294 in a beaker
And 0.2 part of sodium dodecylbenzenesulfonate were added and uniformly dissolved. Then, the temperature was raised to 60 ° C., and the above toner material solution was charged while stirring at 12000 rpm with a TK homomixer and stirred for 10 minutes. The mixture was then transferred to a Kolben with stir bar and thermometer, 98 ° C
The temperature is raised to remove the solvent, and after filtering, washing and drying,
By air classification, toner particles having a particle size d50 of 6 μm were obtained.
Then, 100 parts of the toner particles and 0.5 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil) were mixed in a sample mill to obtain a toner (2) of the invention. The practical sphericity of the toner particles was 0.96. The evaluation results are shown in Table 1.

Comparative Example 1 (Synthesis of Toner Binder) 354 parts of bisphenol A ethylene oxide 2 mol adduct and isophthalic acid 1
Polycondensation of 66 parts with 2 parts of dibutyltin oxide as a catalyst, number average molecular weight 3700, weight average molecular weight 8000
Comparative toner binder (1) was obtained. Comparative toner binder (1) has Tg of 57 ° C., Tη of 136 ° C., and TG ′
Was 133 ° C., and the THF-insoluble matter was 0%. (Preparation of Toner) 100 parts of the comparative toner binder (1), 200 parts of ethyl acetate solution, and 4 parts of Cyanine Blue KRO (manufactured by Sanyo Dye Co., Ltd.) were placed in a beaker, and T
The mixture was stirred at 12000 rpm with a K type homomixer to uniformly dissolve and disperse. Then, a toner was obtained in the same manner as in Example 1 to obtain a comparative toner (1) having a particle diameter d50 of 6 μm. The practical sphericity of the toner particles was 0.98. The evaluation results are shown in Table 1.

[0038]

[Table 1]

[Evaluation Method] Powder Flowability The quietness density was measured using a Hosokawa Micron powder tester. A toner having a better fluidity has a higher quietness density. The heat-resistant storage toner was stored at 50 ° C. for 8 hours, and then sieved through a 42-mesh sieve for 2 minutes. A toner having a better heat resistant storage stability has a smaller residual rate. Gloss development temperature (GLOSS) The fixing device of a commercial color copying machine (CLC-1; manufactured by Canon Inc.) was removed from the fixing device, and the fixing evaluation was performed using a modified machine in which the oil on the fixing roll was removed. The fixing roll temperature at which the 60 ° gloss of the fixed image was 10% or more was defined as the gloss development temperature. Hot Offset Occurrence Temperature (HOT) The fixation 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 fixing roll temperature at which hot offset occurred was defined as the hot offset occurrence temperature.

[0040]

The dry toner of the present invention has the following effects. 1. Excellent powder flowability, developability and transferability. 2. It excels in heat-resistant storage stability and in both low-temperature fixability and hot offset resistance. 3. When used as a color toner, it is excellent in glossiness and hot offset resistance, so that it is not necessary to apply oil to the fixing roll. 4. When used as a color toner, it has high transparency and excellent color tone.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI G03G 9/08 361 (56) References JP-A-11-65172 (JP, A) JP-A-11-52619 (JP, A) JP-A-9-304965 (JP, A) JP-A-9-292737 (JP, A) JP-A-9-146300 (JP, A) JP-A-8-129269 (JP, A) JP-A-7-64327 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (6)

(57) [Claims] 1. A dry toner having a practical sphericity of Wadell comprising a toner binder and a colorant of 0.90 to 1.00, wherein the toner binder contains a tetrahydrofuran (THF) insoluble content of 5% by weight or more. (I), and the measurement frequency of the toner binder is 2
Storage modulus at 0 Hz is 10000 dyne / cm
A dry toner characterized in that a difference (TG'-Tη) between a temperature (TG ') of 2 and a temperature (Tη) of which viscosity is 1000 poise is 0 ° C or more. 2. The dry toner according to claim 1, wherein the condensed resin (i) is at least one resin selected from the group consisting of polyester, polyamide, polyurethane, polyurea and epoxy resin. 3. The glass transition point (T
The dry toner according to claim 1 or 2, wherein g) is 35 to 85 ° C. 4. The dry toner according to claim 1, wherein the toner particles are particles formed in an aqueous medium. 5. The dry toner according to claim 1, wherein the colorant is a colorant selected from the group consisting of cyan, magenta and yellow dyes and / or pigments. 6. The dry toner according to claim 1, which is used as a heat fixing dry toner.