JP2000292981A - Dry toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dry toner excellent in thermal preservation resistance, low temperature fixability and anti-hot offsetting property as well as in powder flowability and transferability in the case of a small particle diameter. SOLUTION: This dry toner comprises a toner binder and a colorant and has a Wadell's practical sphericity of 0.90-1.00. The toner binder comprises a high molecular weight resin (A) and a low molecular weight resin (B). The difference (SPA-SPB) between the SP value (SPA) of the resin A and the SP value (SPB) of the resin B is >=0.1 and the ratio (MwA/MwB) of the weight average molecular weight (MwA) of the resin A to the weight average molecular weight (MwB) of the resin B is >=2.

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 provides 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 comprises a high molecular weight resin (A) and a low molecular weight resin (B), and the SP value (SP) of (A)
The difference (SPA-SPB) between A) and the SP value (SPB) of (B) is 0.1 or more, and the weight average molecular weight (Mw) of (A)
A) The ratio (MwA / M) of the weight average molecular weight (MwB) of (B)
wB) is 2 or more.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. In the present invention, Wadell's practical sphericity is a value represented by (diameter of a circle equal to the projected area of a particle) ÷ (diameter of a minimum circle circumscribing a projected image of the particle). It can be measured by observation. Wadell's practical sphericity is usually 0.90 to 1.00, preferably 0.9 to 1.00.
5 to 1.00, more preferably 0.98 to 1.00. In the present invention, the practical sphericity of all the toner particles need not be in the above range, but may be in the above range as an average value. The particle diameter of the toner is a medium diameter (d
50) is usually 2 to 20 μm, preferably 3 to 10 μm.

The high molecular weight condensation resin (A) and the low molecular weight condensation resin (B) constituting the toner binder include polyester, polyurethane, polyurea, polyamide and epoxy resin. Of these, polyesters, polyurethanes and epoxy resins are preferred, and polyesters are particularly preferred.

As the polyester, polyol (1)
And polycarboxylic acids (2).
Examples of the polyol (1) include a diol (1-1) and a polyol having a valency of 3 or more (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.
To 18 alkylene glycols (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, etc.) Ethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); an alicyclic diol having 5 to 18 carbon atoms (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); To 23 bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.); alkylene oxides having 2 to 18 carbon atoms of the alicyclic diols or bisphenols (ethylene oxide, Pyrene oxide, butylene oxide, α-olefin oxide, etc.) adducts (the number of moles to be added is 2 to 20). Preferred among these are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols having 2 to 18 carbon atoms, and particularly preferred are alkylene oxide adducts of bisphenols (particularly bisphenol A) (particularly, Of ethylene oxide or propylene oxide (2 to 3 mol adduct) and 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 mol% or more.
It is at least 0 mol%, particularly preferably at least 70 mol%.
Examples of the trivalent or higher polyol (1-2) include trihydric or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); Higher phenols (trisphenol PA, phenol novolak, cresol novolak, etc.); alkylene oxide adducts of the above trivalent or higher polyphenols having 2 to 18 carbon atoms (addition moles: 2 to 20);

As the polycarboxylic acid (2), dicarboxylic acid (2-1) and tricarboxylic or higher polycarboxylic acid (2-
2), and (2-1) alone or a mixture of (2-1) and a small amount of (2-2) is preferable. Examples of the dicarboxylic acid (2-1) include alkylene dicarboxylic acids having 2 to 20 carbon atoms (succinic acid, adipic acid, sebacic acid, dodecane dicarboxylic acid, dodecenyl succinic acid, dodecyl succinic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaral Acids); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.); Preferred of these are:
C4-20 alkenylenedicarboxylic acids (especially adipic acid and dodecenylsuccinic acid) and C8-2
0 aromatic dicarboxylic acids (especially isophthalic acid and terephthalic acid). Trivalent 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). The polycarboxylic acid (2) may be reacted with the polyol (1) using the above-mentioned acid anhydride or lower alkyl ester (eg, methyl ester, ethyl ester, isopropyl ester).

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

As the polyurethane, polyol (1)
And polyaddition products of polyisocyanate (3). As the polyol (1), the diol (1-
1) and tri- or higher valent polyol (1-2). Examples of the polyisocyanate (3) include 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 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,
Buret group, uretdione group, uretimine group, isocyanurate group, modified product containing oxazolidone group, etc.)
And mixtures of two or more of these.

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 above 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, trihydrocarbyl phosphate-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 is TDI. ,
MDI, HDI, hydrogenated MDI, and IPDI.

Examples of the polyurea include a reaction product of the above-mentioned polyisocyanate (3) and amines (b). As the amines (b), diamines (b1), 3
Examples thereof include a polyamine (b2) having a valence of 6 or more, an amino alcohol (b3), an aminomercaptan (b4), an amino acid (b5), and a product obtained by blocking an amino group of b1 to b5 (b6). Diamine (b1)
As aromatic diamines having 6 to 23 carbon atoms (such as phenylenediamine, diethyltoluenediamine and 4,4′-diaminodiphenylmethane); and alicyclic diamines having 5 to 20 carbon atoms (eg, 4,4′-diamino-3,3). 'Dimethyldicyclohexylmethane, diaminocyclohexane, isophoronediamine, etc.); and aliphatic diamines having 2 to 18 carbon atoms (ethylenediamine, tetramethylenediamine,
Hexamethylenediamine, etc.). 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 include ethanolamine and hydroxyethylaniline.
As aminomercaptan (b4), it has 2 to 12 carbon atoms.
And specific examples thereof include aminoethyl mercaptan and aminopropyl mercaptan. The amino acid (b5) includes one having 2 to 12 carbon atoms, and specific examples include aminopropionic acid and aminocaproic acid. Examples of the product obtained by blocking the amino group of b1 to b5 (b6) include the aforementioned b1 to b5
And oxazoline compounds obtained from amines of the formula (I) and ketones having 3 to 8 carbon atoms (such as acetone, methyl ethyl ketone and methyl isobutyl ketone). Preferred of these amines (b) are
a mixture of b1 (especially 4,4 ′ diaminodiphenylmethane, isophoronediamine and ethylenediamine) and b1 with a small amount of b2 (especially diethylenetriamine). The mixture ratio is a molar ratio between b1 and b2, usually 10
0/0 to 100/10, preferably 100/0 to 100
/ 5.

Further, if necessary, the molecular weight of the polyurea can be adjusted by using a reaction terminator. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine and the like), and those obtained by blocking them (ketimine compounds).

The molar ratio of the isocyanate group [NCO] in the polyisocyanate (3) to the amino group [NHx] in the amine (b) is [NCO] / [NH].
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 total [YHx] of amino groups and hydroxyl groups, mercapto groups or carboxyl groups in (b) is used.
O] / [YHx] is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 /
1 to 1 / 1.2. By setting the molar ratio in the above range, the molecular weight of the polyurea is increased, and the hot offset resistance is improved.

Examples of the polyamide include polycondensates of polycarboxylic acid (2) and amines (b).
Examples of the polycarboxylic acid (2) include the dicarboxylic acid (2-1) and the trivalent or higher polycarboxylic acid (2-2).
Is mentioned. As the amines (b), the above-mentioned diamine (b1), a polyamine having 3 to 6 or more valences (b)
2), an amino alcohol (b3), an aminomercaptan (b4), an amino acid (b5), and those obtained by blocking amino groups b1 to b5 (b6).

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

In the present invention, the condensation resin (A) or (B) may be modified with a small amount of another condensation bond together with its main condensation 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 SP value (SPA) of (A) and the SP value of (B)
The difference (SPA-SPB) from the value (SPB) is usually 0.1 or more, preferably 0.2 or more, and more preferably 0.3 or more. If it is less than 0.1, the compatibility becomes insufficient,
Insufficient hot offset resistance. Note that the SP value can be calculated by a known Fedors method. The weight average molecular weight (MwA) of (A) is generally from 1,000 to 50,000, preferably from 1,500 to 20,000, more preferably from 200 to 50,000.
0 to 20,000. (B) weight average molecular weight (Mw
B) is usually 5000 or more, preferably 6000
It is more preferably 8000 or more. The ratio (MwA / MwB) of the weight average molecular weight of (A) and (B) is usually 2.
0 or more, preferably 2.5 or more, more preferably 5.
00 or more, particularly preferably 8.0 or more. If it is less than 2.0, the hot offset resistance is not sufficient.

(A) preferably contains an alkylene glycol as a constituent, and the content of alkylene glycol (AGA) in the polyol component of (A) is 10 mol%.
The difference (AGA-AGB) between the alkylene glycol content (AGB) in the polyol components (AGA) and (B) is preferably 10 mol% or more.

The weight ratio of (A) to (B) is usually 5/95 to
60/40, preferably 8/92 to 55/45, more preferably 10/90 to 50/50, particularly preferably 1.
5/85 to 40/60.

In the present invention, the glass transition point (Tg) of the toner binder is usually from 35 to 85 ° C., preferably from 45 to 85 ° C.
７０70 ° C. The storage elastic modulus of the toner binder was 10,000 dyne /
The temperature (TG ′) at which cm 2 is reached is usually 100 ° C. or higher, preferably 110 to 200 ° C. If the temperature is lower than 100 ° C., the hot offset resistance deteriorates. As for the viscosity of the toner binder, the temperature (Tη) at which the polish is 1000 poise at a measurement frequency of 20 Hz is usually 180 ° C. or less, preferably 90 to 160 ° C. If it exceeds 180 ° C., the low-temperature fixability deteriorates. That is, TG ′ is preferably 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′−T
η) is preferably 0 ° C or higher. It is more preferably at least 10 ° C, particularly preferably at least 20 ° C. 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. More preferably 90 ° C
Or less, particularly preferably 80 ° C. or less.

As the colorant of the present invention, known dyes, pigments and magnetic powders can be used. Specifically, carbon black, Sudan Black SM, Fast Yellow-G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgasin Red, Baranitoaniline 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 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 as the wax of the present invention, for example, polyolefin waxes (polyethylene wax, polypropylene wax, etc.); long-chain hydrocarbons (paraffin wax,
And carbonyl group-containing wax. 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 -Octadecanediol-
Polyalkanol esters (such as tristearyl trimellitate and distearyl maleate); polyalkanoic acid amides (such as ethylenediamine dibehenylamide); polyalkylamides (such as trimellitic acid tristearyl amide); and And dialkyl ketones (such as distearyl ketone). Preferred among these carbonyl group-containing waxes are polyalkanoic esters. The wax of the present invention has a melting point of usually 40 to 160 ° C, preferably 5 to 160 ° C.
It is 0-120 ° C, more preferably 60-90 ° C.
The melt viscosity of the wax is preferably from 5 to 1000 cps, more preferably from 10 to 100 cps, as a value measured at a temperature 20 ° C. higher than the melting point. The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight, and particularly preferably 10 to 25% by weight.
It is.

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, sulfonic acid group-containing polymers, fluorinated polymers, and halogen-substituted aromatics. Ring-containing polymers and the like. 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.

The method for producing the dry toner of the present invention will be exemplified. The polyester is obtained by heating and dehydrating and condensing a polycarboxylic acid and a polyol at 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide. It is also effective to reduce the pressure in order to improve the reaction rate at the end 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 tetrabutoxytitanate, dibutyltin oxide,
The resulting water is distilled off by heating to ° C. and, if necessary, while reducing the pressure, to obtain a polyester having a hydroxyl group. Then 4
The polyisocyanate (3) is reacted therewith at 0 to 140 ° C. to obtain a prepolymer (A) having an isocyanate group. Furthermore, amines (B) are added to (A) in an amount of 0 to 1;
The reaction is performed at 40 ° C. to obtain a urea-modified polyester. When reacting (3) and when reacting (A) and (B), a solvent can be used if necessary. Solvents that can be used include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And the like (e.g., tetrahydrofuran), which are inert to isocyanate (3). In the case of reacting (B), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) and the like are used in 20 to 10 times.
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 the completion of the reaction (i) and mixed. I 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 tetrabutoxytitanate, dibutyltin oxide,
The resulting water is distilled off by heating to ° C. and, if necessary, while reducing the pressure, to obtain a polyester having a hydroxyl group. Then 5
At 0 to 140 ° C., this is reacted with the polyisocyanate (3) and, if necessary, a polyol to obtain a polyester modified with a urethane bond. When reacting (3), a solvent can be used if necessary. Solvents that can be used include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And the like (e.g., tetrahydrofuran), which are inert to isocyanate (3). When a polyester (ii) not modified with a urethane 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 the completion of the reaction (i) and mixed. I do.

The dry toner can be manufactured by the following methods (1) to (4). Spherification of pulverized toner A method in which a toner material comprising a toner binder and a colorant is melt-kneaded, and then finely pulverized is 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 the solvent is removed using a spray dry device to obtain a spherical toner. Dispersion granulation method (for example, a method described in JP-A-9-15902) After dissolving and dispersing a toner material in a solvent in which a toner binder is soluble, dispersing in a poor solvent (for example, water) of the toner binder with stirring, Is removed to form toner particles, and after cooling, solid-liquid separation and drying are performed to obtain spherical toner.
And the like. Of these, preferred is the dispersion granulation method, and particularly preferred is the dispersion granulation method in which the poor solvent serving as the dispersed phase is an aqueous medium. Examples of the solvent for dissolving the toner binder in advance used in the dispersion granulation method in an aqueous medium include ethyl acetate, acetone, and methyl ethyl ketone. 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 a dispersant, a water-soluble polymer (polyvinyl alcohol,
Known materials 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 remain on the surface of the toner particles. However, after the curing reaction, it is preferable to wash and remove the dispersant from the charged surface of the toner.

The dry toner of the present invention may 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.
Next, the recording material is fixed on a support (paper, polyester film, or the like) by a known hot roll fixing method, flash fixing method, or the like.

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".

[0036]

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) A method specified by ASTM D3418-82 (DSC method). Apparatus: DSC20, SSC / 580 manufactured by Seiko Electronic Industry Co., Ltd. 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. 3. Measurement of storage elastic modulus (G ′) and viscosity (η) Apparatus: RDS-7700II Dynamic Spectrometer Test Fixture, manufactured by Rheometrics Co., Ltd. Test Fixture: 25 mmφ cone plate Measurement Frequency: 20 Hz (125.6 rad / sec) Strain Rate: 5% Fixed

Example 1 (Prepolymer Production Example) 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
After reacting at 0 ° C. for 8 hours and further dehydrating at a reduced pressure of 10 to 15 mmHg for 5 hours, the mixture was cooled to 80 ° C.
The mixture was reacted with 188 parts of isophorone diisocyanate in ethyl acetate for 2 hours to obtain an isocyanate group-containing prepolymer (1) having a weight average molecular weight of 12,000. (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 Condensation Resin (B)) In the same manner as described above, 770 parts of bisphenol A propylene oxide 2 mol adduct, 138 parts of terephthalic acid and 138 parts of isophthalic acid are polycondensed at 230 ° C. for 6 hours under normal pressure, and ~ 15mm
The reaction was carried out for 5 hours while dehydrating under reduced pressure of Hg, and a condensation resin (B) having a number average molecular weight of 1900 and a weight average molecular weight of 4000
-1) was obtained. The SP value of (B-1) was 11.0. (Production Example of Toner) In a beaker, 15.4 parts of the above prepolymer (1), 64 parts of the condensed resin (B-1), and 78.6 parts of ethyl acetate were placed, stirred and dissolved. 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 practical sphericity of the toner particles was 0.98. Tg of the toner binder component in the toner (1) is 55 ° C., Tη
Was 126 ° C. and TG ′ was 132 ° C. The number average molecular weight of the high molecular weight condensation resin (A-1) in the toner binder was 6000, the weight average molecular weight was 64000, and the SP value was 11.3. MwA / MwB was 16. (A-
Difference between SP value of 1) and SP value of (B-1) (SPA-SPB)
Was 0.3. Table 1 shows the evaluation results.

Example 2 (Synthesis of Toner Binder) In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introducing 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 110 ° C., and 17 parts of isophorone diisocyanate was added in toluene to obtain 11 parts.
The reaction was performed at 0 ° C. for 5 hours, and then the solvent was removed to obtain a high molecular weight condensation resin (A-2) having a number average molecular weight of 6,500 and a weight average molecular weight of 72,000. The SP value of (A-2) is 1
1.4. 607 parts of bisphenol A propylene oxide 2 mol adduct, isophthalic acid 2
17 parts were polycondensed at 230 ° C. for 6 hours under normal pressure to obtain a low molecular weight condensation resin (B-2) having a number average molecular weight of 2,000 and a weight average molecular weight of 4,200. The SP value of (B-2) is 1
1.0. (A-2) 200 parts and (B-2) 80
0 parts were dissolved and mixed in 2000 parts of ethyl acetate to obtain a solution of the toner binder (2) in ethyl acetate. The toner binder (2) was partially isolated by drying under reduced pressure. Tg is 55
° C, Tη was 128 ° C, and TG 'was 140 ° C. (A
(SPA-SP) between the SP value of (-2) and the SP value of (B-2)
B) was 0.4. MwA / MwB was 17. (Preparation of toner) In a beaker, 240 parts of an ethyl acetate / MEK solution of the toner binder (2) and pentaerythritol tetrabehenate (melting point: 81 ° C., melt viscosity: 2)
5 cps) 20 parts, cyanine blue KRO (manufactured by Sanyo Dyestuff)
Add 4 parts, and use TK homomixer at 60 ° C for 1200
The mixture was stirred at 0 rpm and uniformly dissolved and dispersed. 706 parts of ion-exchanged water and hydroxyapatite 1 in a beaker
0% suspension (Superite 10 manufactured by Nippon Chemical Industry Co., Ltd.) 2
94 parts, sodium dodecylbenzenesulfonate 0.2
And the mixture was uniformly dissolved. Then, the temperature was raised to 60 ° C and TK
The toner material solution was charged while stirring at 12,000 rpm with a formula homomixer and stirred for 10 minutes. The mixture was then transferred to a Kolben equipped with a stir bar and a thermometer.
The temperature was raised to 8 ° C. to remove the solvent, followed by filtration, washing and drying, followed by air classification to obtain toner particles having a particle size d50 of 6 μm. 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 a toner (2) of the present invention. The practical sphericity of the toner particles was 0.96. Table 1 shows the evaluation results.

Example 3 (Synthesis of Toner Binder) 42 parts of terephthalic acid and 34 parts of ethylene glycol were placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe, and reacted at 240 ° C. for 5 hours under pressure. did. Then, 276 parts of bisphenol A ethylene oxide 2 mol adduct, 79 parts of bisphenol A ethylene oxide 4 mol adduct, 173 parts of terephthalic acid and 2 parts of dibutyltin oxide were added, and the mixture was heated at normal pressure to 230 parts.
C. for 8 hours, and further under reduced pressure of 10 to 15 mmHg for 5 hours to obtain a high molecular weight condensation resin (A-3) having a number average molecular weight of 8,000 and a weight average molecular weight of 350,000. The SP value of (A-3) was 11.8. (A-
3) 200 parts of (B-2) and 800 parts of ethyl acetate 200
The resulting mixture was dissolved and mixed in 0 parts to obtain a solution of the toner binder (2) in ethyl acetate. A portion was dried under reduced pressure to isolate the toner binder (3). Tg is 53 ° C, Tη is 123 ° C, T
G ′ was 136 ° C. The SP value of (A-3) and (B-
The difference (SPA-SPB) from the SP value of 2) was 0.8. MwA
/ MwB was 8.3. (Preparation of Toner) A toner (2) of the present invention was obtained in the same manner as in Example 1 except that the toner binder (2) was used. The practical sphericity of the toner particles was 0.97. 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 give a number average molecular weight of 3,700 and a weight average molecular weight of 8,000.
Comparative toner binder (1) was obtained. Tg of the comparative toner binder (1) was 57 ° C., Tη was 136 ° C., and TG ′
Was 133 ° C. (Preparation of Toner) In a beaker, 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) were put into a beaker.
The mixture was stirred at 12000 rpm with a K-type homomixer and uniformly dissolved and dispersed. 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. The practical sphericity of the toner particles was 0.98. Table 1 shows the evaluation results.

[0041]

[Table 1]

[Evaluation Method] Powder Fluidity The quietness 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. 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.

[0043]

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

Claims (10)

[Claims] 1. A dry toner comprising a toner binder and a colorant and having a practical sphericity of 0.90 to 1.00, wherein the toner binder comprises a high molecular weight resin (A) and a low molecular weight resin (B). And the S of (A)
The difference (SPA-S) between the P value (SPA) and the SP value (SPB) of (B)
PB) is 0.1 or more, and a ratio (MwA / MwB) of the weight average molecular weight (MwA) of (A) to the weight average molecular weight (MwB) of (B) is 2 or more. Dry toner. 2. The dry toner according to claim 1, wherein said resins (A) and (B) are condensation resins. 3. The dry toner according to claim 2, wherein said resins (A) and (B) are polyesters comprising a polycondensate of a polyol and a polycarboxylic acid. 4. The (A) contains an alkylene glycol as a constituent, and the alkylene glycol content (AGA) in the polyol component (A) is 10 mol% or more.
4. The dry toner according to claim 3, wherein the difference (AGA-AGB) between the alkylene glycol content (AGB) in the polyol component (AGA) and (B) is 10 mol% or more. 5. The weight ratio of (A) to (B) is from 5/95.
The dry toner according to any one of claims 1 to 4, wherein the ratio is 60/40. 6. The glass transition point (T) of the toner binder.
The dry toner according to any one of claims 1 to 5, wherein g) is 35 to 85 ° C. 7. The measurement frequency of the toner binder is 20H.
7. The difference (TG'-T [eta]) between the temperature (TG ') at which the storage elastic modulus at z is 10,000 dyne / cm <2> and the temperature (T [eta]) at which the viscosity becomes 1000 poise is 0 [deg.] C. or more. Dry toner. 8. The dry toner according to claim 1, wherein the toner particles are particles formed in an aqueous medium. 9. 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. 10. The dry toner according to claim 1, which is used as a dry toner for heat fixing.