JP2000338713A - Dry toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the powder fluidity, transferability, hot preservability, low temperature fixability and anti-hot-offsetting property of a dry toner by using particles formed by radical-polymerizing a condensation resin having a radical polymerizable unsaturated group in an aqueous medium. SOLUTION: The dry toner comprises particles formed by dispersing a condensation resin having a radical polymerizable unsaturated group in an aqueous medium and radical-polymerizing the resin. The radical polymerizable unsaturated group is preferably an acrylic functional group or a vinyl ester type functional group, further preferably the acrylic functional group, particularly preferably an unsaturated carboxylic acid type functional group. The condensation resin is preferably a polyester, polyurethane or epoxy resin, particularly preferably the polyester.

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 comprising a condensation resin and a colorant, wherein the dry toner radically polymerizes a condensation resin (A) having a radical polymerizable unsaturated group in an aqueous medium. Is a dry toner comprising particles formed by the following method.

The dry toner of the present invention comprises a dispersion of a condensation resin (A) having a radically polymerizable unsaturated group in an aqueous medium, and particles comprising (A) formed by radical polymerization. . In the present invention, examples of the radically polymerizable unsaturated group of the condensation resin (A) include an acrylic functional group, a [(meth) acrylate functional group, a (meth) acrylamide functional group, and an unsaturated carboxylic acid functional group. Etc.], vinyl ester type functional groups (eg, vinyl ester group, isopropenyl ester group), and vinyl ketone type functional groups (eg, vinyl ketone group, isopropenyl ketone group). Preferred of these are:
Acrylic type functional group, vinyl ester type functional group,
More preferred are acrylic functional groups, and particularly preferred are unsaturated carboxylic acid functional groups.

In the present invention, examples of the condensation resin constituting the toner binder include polyester, polyurethane, polyurea, polyamide, and epoxy resin. Preferred among these are polyester,
Polyurethanes and epoxy resins are particularly preferred are polyesters.

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 (4). As the amines (4), diamines (4-1),
Polyamine (4-2) having 3 to 6 or more valences, amino alcohol (4-3), aminomercaptan (4-
4), amino acids (4-5), and (4-1) to (4-
5) Amino group-blocked (4-6) and the like. As the diamine (4-1), a carbon number of 6 to 2 is used.
3 aromatic diamines (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, etc.). Examples of the trivalent or hexavalent or higher polyamine (4-2) include diethylenetriamine,
Triethylenetetramine and the like. Examples of the amino alcohol (4-3) include those having 2 to 12 carbon atoms, and specific examples include ethanolamine and hydroxyethylaniline. Examples of the aminomercaptan (4-4) include those having 2 to 12 carbon atoms, and specific examples thereof include aminoethylmercaptan and aminopropylmercaptan. Amino acids (4
Examples of -5) include those having 2 to 12 carbon atoms, and specific examples include aminopropionic acid and aminocaproic acid. (4-1) to (4-5) wherein the amino group is blocked (4-6) include the above-mentioned 4-1 to 4-4.
Amines of -5 and ketones having 3 to 8 carbon atoms (acetone,
Ketimine compounds and oxazoline compounds obtained from methyl ethyl ketone, methyl isobutyl ketone, etc.). Of these amines (4), preferred are (4-1) (especially 4,4 'diaminodiphenylmethane, isophoronediamine and ethylenediamine) and (4-1) and a small amount of (4-2) (especially diethylenetriamine). It is a mixture. The ratio of the mixture is (4-1)
And the molar ratio of (4-2), usually 100/0 to 100/1
0, 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 ratio of the amines (4) is determined by the molar ratio [NCO] / [NH] of the isocyanate groups [NCO] in the polyisocyanate (3) and the amino groups [NHx] in the amines (4).
x] is usually 1/2 to 2/1, preferably 1.5 /
1-1 / 1.5, more preferably 1.2 / 1-1 /
1.2. (4-3) to (4) as amines (4)
When -5) is used, the amino group and hydroxyl group in (4)
The molar ratio [NCO] / [YHx] with respect to the total [YHx] of mercapto groups or carboxyl groups 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 (4).
Examples of the polycarboxylic acid (2) include the dicarboxylic acid (2-1) and the trivalent or higher polycarboxylic acid (2-2).
Is mentioned. Examples of the amines (4) include the above-mentioned diamines (4-1), triamine or higher polyamines (4-2), amino alcohols (4-3), aminomercaptans (4-4), amino acids ( 4-5), and (4)
-1) to (4-5) in which the amino group is blocked (4
-6).

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 may be modified with a small amount of another condensation bond together with the 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.

In the present invention, as a method of introducing a radical polymerizable unsaturated group into the condensation resin, the polymerization of the condensation resin may be carried out by adding a functional group copolymerizable with a monomer of the condensation resin to a radical polymerizable unsaturated monomer. A method of copolymerizing a monomer containing an unsaturated group. A method in which a monomer having a radical polymerizable unsaturated group and a functional group capable of undergoing an exchange reaction with a condensation resin are exchanged. A method of reacting a condensation-based resin having a reactive group with a radical polymerizable unsaturated group and a compound having a reactive group is exemplified. In the case of polyester as the condensation resin, unsaturated group-containing carboxylic acids (such as maleic acid (anhydride), fumaric acid, dodecenyl succinic acid (anhydride), (meth) acrylic acid, etc.), unsaturated group-containing polyol (hydroxy Radical polymerizable unsaturated groups can be introduced by copolymerizing ethyl (meth) acrylate or the like. As for the method, a radical polymerizable unsaturated group can be introduced by performing an exchange reaction using the same method as described above. Examples of the combination of the reactive group of the condensation resin and the reactive group of the radical polymerizable unsaturated group-containing compound used in the method include an isocyanate group and an active hydrogen group (amino group, alcoholic hydroxyl group, phenolic hydroxyl group). , Mercapto groups, carboxyl groups, etc.); epoxy groups (glycidyl groups, etc.) and active hydrogen groups (amino groups, alcoholic hydroxyl groups, phenolic hydroxyl groups, mercapto groups, carboxyl groups, etc.); acid anhydride groups and active hydrogen groups (amino Group, alcoholic hydroxyl group, phenolic hydroxyl group, mercapto group, carboxyl group, etc.). That is, for example, radical polymerization is performed on a condensation resin by reacting a condensation resin having an isocyanate group (such as an isocyanate-terminated polyester prepolymer) with a compound having an alcoholic hydroxyl group and a radical polymerizable unsaturated group (such as hydroxyethyl acrylate). Sexually unsaturated groups can be introduced.

The number of radically polymerizable unsaturated groups introduced into one molecule of the condensation resin is usually at least one, preferably 1 to 5,
More preferably, it is 1-2.

The number average molecular weight of the condensation resin (A) having a radical polymerizable unsaturated group is usually from 500 to 20,000,
Preferably it is 1000-10000, More preferably, it is 1500-8000.

The number average molecular weight of the condensation resin (A) after radical polymerization is usually 1,000 to 200,000, preferably 1500 to 10,000, more preferably 2,000.
~ 80000. It is preferably from 1000 or more from the viewpoint of heat-resistant storage stability, and from 20000 or less from the viewpoint of low-temperature fixability. Further, in GPC, it has a low molecular weight of 2000 to 20000 and has a subpeak or shoulder at a molecular weight of 30,000 or more, or contains tetrahydrofuran (THF) -insoluble matter, so that it has low-temperature fixability. It is preferable from the viewpoint of compatibility of hot offset resistance. In order to obtain the above-mentioned molecular weight, the condensation resin is preferably a mixture of two or more kinds having different molecular weights. That is, molecular weight 3
It is preferably a mixture of a high molecular weight substance having a main peak at 0000 or more and a low molecular weight substance having a main peak at a molecular weight of 2000 to 20,000. To form such a mixture, together with the condensation resin (A) having a radical polymerizable unsaturated group as a high molecular weight substance, the condensation resin (B) having no radical polymerizable unsaturated group as a low molecular weight substance
Is preferable. By making the number of radically polymerizable unsaturated groups introduced into one molecule (A) less than one, a molecule having no radically polymerizable unsaturated group can be regarded as (B).

The weight ratio of (A) and (B) is usually 100 /
0/1/99, preferably 70 / 30-5 / 9
5, more preferably 50/50 to 10/90.

In the present invention, toner particles are formed by radical polymerization of a condensation resin (A) having a radically polymerizable unsaturated group. In this case, a vinyl monomer (C) is used in combination. May be copolymerized.

Examples of the vinyl monomer (C) include styrenes (C1), alkyl (meth) acrylates (C2),
Nitrile monomer (C3), substituted alkyl (meth) acrylate (C4), unsaturated carboxylic acids and their anhydrides (C5), unsaturated dicarboxylic acid alkyl esters (C6), vinyl esters (C7), vinyl ether (C8), α-olefin (C9), diene (C1
0) and the like. As styrenes (C1),
Styrene, α-methylstyrene, p-methylstyrene,
Examples include m-methylstyrene, p-methoxystyrene, p-hydroxystyrene, p-acetoxystyrene, and the like. Of these, styrene and a combination of styrene and other styrenes are preferred, and styrene is particularly preferred. As the alkyl (meth) acrylate (C2), methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate,
2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, tetradecyl (meth) acrylate, hexadecyl (meth) acrylate, stearyl (meth) acrylate,
Behenyl (meth) acrylate; Of these, preferred are long-chain alkyl (meth) acrylates having a C8-C24 alkyl group, and more preferred are long-chain alkyl (meth) acrylates having a C12-C22 alkyl group, and particularly preferred. Those are lauryl (meth) acrylate and stearyl (meth) acrylate. Examples of the nitrile monomer (C3) include (meth) acrylonitrile and cyanostyrene. Preferred among these is (meth) acrylonitrile. Examples of the substituted alkyl (meth) acrylate (C4) include hydroxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and the like. Examples of the unsaturated carboxylic acids and their anhydrides (C5) include meth) acrylic acid, maleic acid, fumaric acid, itaconic acid and anhydrides thereof. Examples of the unsaturated dicarboxylic acid alkyl esters (C6) include monomethyl maleate, monobutyl maleate, dibutyl maleate, and monomethyl itaconate. Vinyl esters (C7)
Examples include vinyl acetate. Examples of the vinyl ethers (C8) include butyl vinyl ether. Examples of the α-olefin (C9) include hexene, octene, and dodecene. Examples of dienes (C10) include butadiene, isoprene, chloroprene, hexadiene, octadiene and the like. These may be used alone or in combination of two or more. Of these, preferred are (C1),
(C2), (C3) and combinations thereof.
More preferred is a combination of (C1) and (C3).

In the present invention, the content of the condensation resin in the toner binder is usually 50% by weight or more, preferably 55 to 95% by weight, more preferably 60 to 90% by weight.

In the present invention, the polymer of the vinyl monomer (C) and the condensed resin (A) having a radically polymerizable unsaturated group are preferably at least partially compatible with each other to obtain a hot offset resistance. Is improved. To increase compatibility,
The closer each SP value is, the better the vinyl monomer (C)
The absolute value of the difference (SPc-SPa) between the SP value (SPc) of the polymer (A) and the SP value (SPa) of the condensation resin (A) having a radical polymerizable unsaturated group is usually 2.0 or less. . Preferably it is 1.0 or less. More preferably, it is 0.5 or less. Note that the SP value is a known Fedors
It can be calculated by the method.

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. When the temperature is 35 ° C. or higher, the heat-resistant storage stability of the toner is improved, and when the temperature is 85 ° C. or lower, the low-temperature fixability is improved. For unknown reasons, the toner of the present invention tends to have good heat-resistant storage stability even at a low glass transition point, as compared with known polyester-based toners.

The storage elastic modulus (G ') of the toner binder was 10,000 dyn at a measurement frequency of 20 Hz.
The temperature (TG ′) at which e / cm 2 is reached is usually 100 ° C. or higher, preferably 110 to 200 ° C. By setting the temperature to 100 ° C. or higher, hot offset resistance is improved. As for the viscosity of the toner binder, the temperature (Tη) at which the measurement frequency becomes 20 poise at 1000 poise is usually 180 ° C.
Hereinafter, the temperature is preferably 90 to 160 ° C. By setting the temperature to 180 ° C. or lower, the low-temperature fixability is improved. That is, from the viewpoint of achieving both low-temperature fixing property and hot offset resistance, TG ′
Is preferably higher than Tη. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or more. It is more preferably at least 10 ° C, particularly preferably at least 20 ° C.
That is all. The upper limit of the difference is not particularly limited. In addition, the difference between Tη and Tg (Tη−Tg) is preferably from 0 to 100 ° C. from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability. The temperature is more preferably 10 to 90 ° C, particularly preferably 20 to 80 ° C.
° C.

In the present invention, known dyes, pigments and magnetic powders can be used as the colorant. Specifically, carbon black, Sudan Black SM, Fast Yellow-G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgasin Red,
Balanitoaniline red, toluidine red, carmine FB, pigment orange R, lake red 2G, rhodamine FB, rhodamine B lake, methyl violet B lake, phthalocyanine blue, pigment blue,
Examples include Priliant Green, Phthalocyanine Green, Oil Yellow GG, Kayaset YG, Orazol Brown B, Oil Pink OP, magnetite, and iron black. 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. The content of the fluidizing agent is usually 0 to 10% by weight.

In the present invention, the particle diameter of the particles formed by radical polymerization of (A) is usually from 2 to 20 μm, preferably from 3 to 15 μm, from the viewpoint of developability and resolution. And more preferably 4 to 8 μm. The shape is preferably spherical from the viewpoint of fluidity.

An example of the method for producing the dry toner of the present invention will be described. The polyester is prepared by converting a polycarboxylic acid and a polyol to 150 to 280 in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide.
It is obtained by heating to ° C. and performing dehydration condensation. It is also effective to reduce the pressure in order to improve the reaction rate at the end of the reaction. The polyester having a radical polymerizable unsaturated group is produced by copolymerizing a functional group copolymerizable with the constituent monomer of the condensation resin and a monomer containing a radical polymerizable unsaturated group in the same manner as the polyester described above. it can. It is also effective to add a small amount of a polymerization inhibitor (hydroquinone, t-butylcatechol, etc.) in order to suppress radical polymerization during the condensation reaction. The toner particles are formed by radically polymerizing a dispersion comprising a condensation resin (A) having a radically polymerizable unsaturated group in an aqueous medium. As a method for stably forming a dispersion composed of the condensation resin (A) having a radically polymerizable unsaturated group in an aqueous medium, the condensation resin (A) having a radically polymerizable unsaturated group in an aqueous medium can be used. And dispersing the composition by shearing force.
It is possible to polymerize (A) in the presence of (B) by mixing or dispersing the condensation resins (B) and (A) having no radically polymerizable unsaturated group in advance. it can. Similarly, copolymerization can be performed by mixing (A) with vinyl monomer (C) and then polymerizing. Condensation resin having radically polymerizable unsaturated group (A)
And other toner raw materials (colorant, release agent, charge control agent, etc.)
May be mixed when forming a dispersion in an aqueous medium, but it is more preferable to mix the toner raw materials in advance and then add and disperse the mixture in the 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, but 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 dispersion resin (A) having a radically polymerizable unsaturated group has a lower viscosity and is easier to disperse.

The radical polymerization can be carried out by a known method, but is usually carried out by using a known polymerization initiator. Examples of the polymerization initiator include azo initiators (azobisisobutyronitrile, azobisvaleronitrile, etc.) and peroxide initiators (benzoyl peroxide, t-butyl perbenzoate, di-t-butyl peroxide, di-
t-butyl peroxyhexahydroterephthalate) and the like. The polymerization temperature is selected depending on the polymerization initiator used and the molecular weight of the toner binder, but is usually 5 to 200 ° C, preferably 50 to 100 ° C. The polymerization time is usually 1 to 48 hours, preferably 2 to 2 hours.
4 hours. The polymerization is usually carried out by heating after dispersion,
Partial advance may be made before dispersion.

The amount of the aqueous medium used is usually 5 parts per 100 parts of the condensation resin (A) having a radical polymerizable unsaturated group.
It is 0 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of (A) is poor and toner particles having a predetermined particle size cannot be obtained. 20,000
It is not economical to exceed the weight part. Also, if necessary,
Dispersants can also be used. It is better to use a dispersant
This is preferred because 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,
Known materials such as hydroxyapatite powder, silica fine powder, and surfactants (such as sodium dodecylbenzenesulfonate, sodium lauryl sulfate, and sodium oleate) can be used. When a dispersant is used, the dispersant may remain on the surface of the toner particles. However, it is preferable to remove the dispersant by washing after the radical polymerization reaction from the viewpoint of charging the toner.

Further, in order to lower the viscosity of the dispersion comprising the condensation resin (A) having a radically polymerizable unsaturated group, 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 is volatile having a boiling point of less than 100 ° C. from the viewpoint of easy removal. Examples of the solvent include ethyl acetate, acetone, methyl ethyl ketone and the like. The amount of the solvent used is usually from 0 to 30 based on 100 parts of the condensation resin (A) having a radical polymerizable unsaturated group.
0 parts, preferably 0 to 100 parts, more preferably 25 parts
~ 70 parts. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after the radical polymerization reaction.

The toner particles formed by radical polymerization of this dispersion are separated into solid and liquid by a centrifuge, a spacra filter, a filter press or the like, and the obtained powder is dried to obtain the dry toner of the present invention. . As a method of drying the obtained powder, fluidized bed dryer,
It can be carried out using known equipment such as a reduced pressure dryer and a circulation dryer. 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".

[0048]

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. 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 (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, 12 parts of maleic acid, 0.5 part of hydroquinone and 2 parts of dibutyltin oxide, and reacted at 230 ° C. for 8 hours under normal pressure and further for 5 hours under reduced pressure of 10 to 15 mmHg to obtain a number average molecular weight of 6,500. Weight average molecular weight 2
A condensation resin (A-1) having 3000 radically polymerizable unsaturated groups was obtained. In the same manner as above, 607 parts of a 2-mol adduct of bisphenol A propylene oxide and 217 parts of isophthalic acid are polycondensed at 230 ° C. for 6 hours under normal pressure, and then reacted at a reduced pressure of 10 to 15 mmHg for 5 hours to obtain a number average molecular weight of 2,000 and weight. A low molecular weight condensation resin (B-1) having an average molecular weight of 4,200 was obtained. (A-1) 200 parts and (B-
1) 800 parts are dissolved and mixed in 2000 parts of ethyl acetate,
An ethyl acetate solution (1) of the condensation resin was obtained. (Preparation of Toner) In a beaker, 240 parts of the above-mentioned condensation resin in ethyl acetate (1), pentaerythritol tetrabehenate (melting point: 81 ° C., melt viscosity: 25 cps) 20
Parts, 4 parts of cyanine blue KRO (manufactured by Sanyo Dye) and 0.8 parts of azobisisobutyronitrile were added, and the mixture was stirred at 60 ° C. with a TK homomixer at 12000 rpm to be uniformly dissolved and dispersed. 706 parts of ion-exchanged water in a beaker,
Hydroxyapatite 10% suspension (Nippon Chemical Industry
294 parts of Superite 10) and 0.2 part of sodium dodecylbenzenesulfonate were added and uniformly dissolved.
Then, the temperature was raised to 60 ° C., and 1200
While stirring at 0 rpm, the toner material solution was charged and stirred for 10 minutes. Then, the mixture was transferred to a kolben equipped with a stirring rod and a thermometer, and the temperature was raised to 98 ° C. over 4 hours.
Further, the temperature was kept at 98 ° C. for 4 hours to carry out a polymerization reaction and solvent removal. Then, the resultant was filtered, washed, and dried, and then subjected to air classification to obtain toner particles having a particle diameter d50 of 6 μm. Then
Colloidal silica (Aerosil R) is used in 100 parts of toner particles.
972: manufactured by Nippon Aerosil Co., Ltd.) was mixed in a sample mill to obtain Toner (1) of the present invention. Tg of the toner binder component in the toner (1) is 55 ° C., Tη
Was 128 ° C. and TG ′ was 140 ° C. The weight average molecular weight was 45,000 and the number average molecular weight was 2,600. Table 1 shows the evaluation results.

Example 2 (Synthesis of Toner Binder) In the same manner as described above, 343 parts of bisphenol A ethylene oxide 2 mol adduct, 166 parts of isophthalic acid, and 8 parts of fumaric acid were added under normal pressure at 230 ° C. for 6 hours.
And then reacted under reduced pressure of 10 to 15 mmHg for 5 hours to obtain a number average molecular weight of 6,500 and a weight average molecular weight of 21.
A condensation resin (A-2) having 000 radically polymerizable unsaturated groups was obtained. (A-2) 200 parts and (B-1) 8
00 parts were dissolved and mixed in 2000 parts of ethyl acetate to obtain an ethyl acetate solution (2) of the condensation resin. (Preparation of monomer solution) 80 parts of styrene in a beaker,
15 parts of acrylonitrile and 5 parts of butyl acrylate were mixed and dissolved to obtain a monomer solution (2). (Preparation of toner) In a beaker, 240 parts of an ethyl acetate solution (2) of the above-mentioned condensation resin and a monomer solution (2) 20
Part, azoisobutyronitrile 1.0 part, pentaerythritol tetrabehenate (melting point 81 ° C, melt viscosity 25c
ps) 20 parts and 4 parts of cyanine blue KRO (manufactured by Sanyo Pigment Co., Ltd.) are added, and the mixture is subjected to 12000 r with a TK homomixer at 60 ° C.
The mixture was stirred at pm and uniformly dissolved and dispersed. 706 parts of ion-exchanged water and 10% of hydroxyapatite in a beaker
Suspension (Superite 10 manufactured by Nippon Chemical Industry Co., Ltd.) 294
And 0.2 part of sodium dodecylbenzenesulfonate were added and uniformly dissolved. Then, the temperature was raised to 60 ° C., and the above-mentioned toner material solution was charged while stirring at 12,000 rpm with a TK homomixer, followed by stirring for 10 minutes. Then, the mixture was transferred to a kolben equipped with a stir bar and a thermometer.
The temperature was raised over 4 hours, and the temperature was further maintained at 98 ° C. for 4 hours to carry out the polymerization reaction and the solvent removal. Then, filtration, washing,
After drying, the particles were classified by air to obtain toner particles having a particle diameter d50 of 6 μm. Next, colloidal silica (Aerosil R972: manufactured by Nippon Aerosil) was added to 100 parts of the toner particles.
Five parts were mixed by a sample mill to obtain a toner (1) of the present invention. Tg of the toner binder component in the toner (1) was 56 ° C., Tη was 135 ° C., and TG ′ was 155 ° C. The weight average molecular weight was 78,000 and the number average molecular weight was 3,600. SP of polymer in monomer solution (2)
Value (SPc) is 11.0, and the SP value (SPa) of the condensation resin (A-2) having a radically polymerizable unsaturated group is 11.
4. The absolute value of the difference (SPc-SPa) between the SP value (SPc) of the polymer of (2) and the SP value (SPa) of (A-2) was 0.4. 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. Then, 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.

[0052]

[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.

[0054]

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 it has excellent gloss and hot offset resistance when used as a color toner, there is no need to apply oil to the fixing roll. 4. High transparency and excellent color tone when used as a color toner.

Claims (9)

[Claims] 1. A dry toner comprising a toner binder comprising a condensation resin and a colorant, wherein the dry toner comprises a condensation resin having a radical polymerizable unsaturated group (A).
A dry toner comprising particles formed by radical polymerization of a polymer in an aqueous medium. 2. The dry toner according to claim 1, wherein the content of the condensation resin in the toner binder is 50% by weight or more. 3. The dry toner according to claim 1, wherein the main skeleton of (A) is at least one resin selected from the group consisting of polyester, polyamide, polyurethane, polyurea, and epoxy resin. 4. Particles formed by polymerizing a condensation resin (A) having a radically polymerizable unsaturated group in the presence of a condensation resin (B) having no radically polymerizable unsaturated group. The dry toner according to any one of claims 1 to 3, comprising: 5. The method according to claim 1, comprising particles formed by copolymerizing the condensation resin (A) having a radical polymerizable unsaturated group and a vinyl monomer (C). Dry toner. 6. The difference (SPc-SPa) between the SP value (SPc) of the polymer (C) and the SP value (SPa) of the polymer (A).
6. The dry toner according to claim 5, wherein the absolute value of is less than or equal to 2.0. 7. The dry toner according to claim 5, wherein (C) is a mixture of styrenes and a nitrile monomer. 8. The glass transition point (T) of the toner binder.
The dry toner according to any one of claims 1 to 7, wherein g) is 35 to 85 ° C. 9. The measurement frequency of the toner binder is 20H.
9. 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.