JPH07120976A - Toner binder resin and positively chargeable toner containing the same - Google Patents

Abstract

PURPOSE:To improve low temp. fixation properties, offset resistance and environmental stability of a pasitively chargeable toner by using a combination of specific resins as the toner binder resin. CONSTITUTION:This toner binder resin consists of a resin A, out of which a continuous phase can be formed in the toner and another resin B that can be dispersed into the continuous phase to form a dispersed phase in the toner. The resin A is a hybrid resin comprising a polyester resin and a vinylic resin and the resin B is a vinylic resin having positively chargeable, functional groups. The resin A is obtained by parallelly subjecting a monomer of a vinylic resin, a monomer of a polyester resin and a compound reactive with both of these monomers to condensation polymerization and addition polymerization in the same reaction vessel. This vinylic resin in the resin A is obtained by polymerizing one or more styrenic monomer(s). The vinylic resin of the resin B having positively chargeable, functional groups is obtained by polymerizing the monomer(s) of polystyrene or styrene acrylic copolymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binder resin for toner and a positively chargeable toner containing the binder resin, and more specifically, an electrostatic latent image in electrophotography, electrostatic recording, electrostatic printing and the like. The present invention relates to a positively chargeable toner used for developing a toner.

[0002]

2. Description of the Related Art Conventional electrophotographic methods include US Pat. Nos. 2,297,691 and 235780.
As described in, for example, No. 9, the photoconductive insulating layer is uniformly charged, and then the layer is exposed to light to dissipate the charge on the exposed portion to form an electrical latent image. After being formed, and further visualized by adhering a fine powder having a colored charge called a toner to the latent image (developing step), after transferring the obtained visible image to a transfer material such as transfer paper (Transfer step), permanent fixing by heating, pressure or other suitable fixing method (fixing step).

As described above, the toner must have the functions required not only in the developing process but also in the transferring process and the fixing process.

Generally, in order to obtain a positively chargeable toner, a styrene / acrylic resin which is easily obtained in a positive charge is used as a binder resin. However, the styrene / acrylic resin has a low mechanical strength and cannot withstand continuous printing. If a resin having a relatively high molecular weight is used for the purpose of improvement, there is a problem that the fixability becomes extremely poor. Further, a polyester resin having excellent mechanical strength can achieve both fixability and stability during continuous printing, but it is difficult to obtain positive chargeability because of its strong negative chargeability.

Therefore, in order to solve these problems,
Studies have been conducted on the use of a mixture of a polyester resin having excellent fixability and a styrene-acrylic resin, which has a smaller fluctuation rate of charge amount under high temperature and high humidity than under normal temperature and normal humidity. For example, the following method may be mentioned. A method of mixing a polyester resin and a styrene acrylic resin (JP-A-49-6931 and JP-A-54-1142).
45, JP-A-57-70523, JP-A-2-161.
464); a method of chemically bonding a polyester resin and a styrene-acrylic resin (JP-A-56-116043); a method of copolymerizing a vinyl-based monomer with an unsaturated polyester (JP-A-57-60339, Kaisho 63-
279265, JP-A-1-156759, JP-A-2
No. 5073); a method of copolymerizing a vinyl monomer with a polyester resin having a (meth) acryloyl group (JP-A-59-4).
No. 5453); A method of copolymerizing a reactive polyester and a vinyl monomer in the presence of a polyester resin (JP-A-2-2966).
No. 4); and a method of blocking a polyester resin and a vinyl resin with an ester bond (JP-A-2-881).

However, the polyester resin and the styrene-acrylic resin are originally poor in compatibility, and when they are simply mechanically mixed, depending on the mixing ratio, the resin and the internal additive such as carbon black may be used depending on the mixing ratio. And the chargeability becomes non-uniform, which may cause problems such as scumming in image evaluation. Further, when the two types of resins have different molecular weights, the melt viscosities of the two types may differ. Then, it becomes difficult to make the dispersed particle diameter of the resin in the dispersed phase fine, and when toner is formed, the dispersion of the internal additive such as carbon black is very poor, and the image stability is largely lost. Furthermore, when polymerizing a vinyl-based monomer with a reactive polyester, the composition is limited in order to prevent gelation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a binder resin for a toner for obtaining a toner which is uniformly charged satisfactorily and has a rapid rise in charging, in order to solve the above problems. Another object of the present invention is to satisfactorily and uniformly charge by using such a binder resin,
It is intended to provide a positively chargeable toner that has a quick rise in charging and little reverse charging.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, by using a combination of specific resins as a binder resin, excellent low-temperature fixability and anti-offset property, and electrostatic charging can be obtained. The inventors have found that a positively chargeable toner having good environmental stability in terms of amount and image quality and excellent developer durability can be obtained, and thus completed the present invention.

That is, the gist of the present invention consists of (1) a resin (1) capable of forming a continuous phase in a toner and a resin (2) capable of being dispersed in the continuous phase in a toner to form a dispersed phase. The toner binder resin, wherein the resin (1) is a hybrid resin of a polyester resin and a vinyl resin, and the resin (2) is a vinyl resin having a regular functional group. Resin (2) Resin (1) is a polyester resin monomer, vinyl resin monomer, or a compound capable of reacting with any of these monomers, and polycondensation polymerization and addition polymerization are carried out in parallel in the same reaction vessel. And (3) the vinyl resin of the resin (1), which is obtained by a polymerization using one or more styrene monomers. The above (1) Is (2), wherein the binder resin,
(4) Any of the above (1) to (3), wherein the vinyl resin having a positively chargeable functional group of the resin (2) is obtained by polymerization using a monomer of polystyrene or a styrene-acrylic copolymer. Binder resin described in (5)
The binder resin according to any one of (1) to (4) above, wherein the positively chargeable functional group is a functional group containing nitrogen and / or phosphorus, (6) at least containing a binder resin and a colorant. In the positively chargeable toner, the binder resin is the above (1).
To (5) a positively chargeable toner characterized by being a binder resin according to any one of (5) to (7), and (7) a compound represented by the following general formula (I) and / or general formula (II): The positively chargeable toner according to claim 6, which further comprises:

[0010]

[Chemical 2]

(Wherein R ₁ , R ₂ , R ₃ and R ₄ are the same or different and each represents an alkyl group, an alkoxy group, an aryl group or an allyl group, which may form a ring. , A ⁻ represents an anion.)

The binder resin of the present invention is a resin (1) capable of forming a continuous phase in a toner and a resin (2) capable of forming a dispersed phase dispersed in the continuous phase formed by the resin (1). It contains and. The resin (1) is a hybrid resin of a polyester resin and a vinyl resin, and the resin (2) is a vinyl resin having a regular functional group. First, a preferable aspect of the resin (1) will be described in detail.

The resin (1) is a hybrid resin of polyester resin and vinyl resin, in which polyester resin and vinyl resin are partially chemically bonded.
It is produced using a polyester resin monomer, a vinyl resin monomer, a compound capable of reacting with any of them, and the like. As the monomer of the polyester resin, a divalent or trivalent or more alcohol and a carboxylic acid, or a divalent or trivalent or more carboxylic acid component such as a carboxylic acid anhydride or a carboxylic acid ester is used.

Examples of the dihydric alcohol include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (3.3) -2,2-
Bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl)
Propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis
(4-Hydroxyphenyl) alkylene oxide adduct of bisphenol A such as propane, ethylene glycol, diethylene glycol, triethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol,
1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, bisphenol A propylene adduct, bisphenol A ethylene adduct,
Hydrogenated bisphenol A and the like can be mentioned.

Examples of trihydric or higher alcohols include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol and 1,2,4-butane. Triol, 1,2,5-pentanetriol, glycerol,
2-methylpropanetriol, 2-methyl-1,2,4-
Examples include butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene. Of these alcohols, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2.0) -2,2-
Bis (4-hydroxyphenyl) propane is preferably used. In the present invention, these dihydric alcohol monomers and trihydric or higher polyhydric alcohol monomers can be used alone or in combination.

The acid component is a carboxylic acid component and is a divalent monomer such as maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, Adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octenylsuccinic acid,
Examples thereof include n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, and anhydrides or lower alkyl esters of these acids. Of these divalent carboxylic acid components, maleic acid, fumaric acid, terephthalic acid, isododecenyl succinic acid, and anhydrides or lower alkyl esters of these acids are preferably used.

Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid and 1,2,4- Butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-
2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl)
Methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empol trimer acid and their acid anhydrides,
Lower alkyl ester and the like can be mentioned. Of these,
In particular, 1,2,4-benzenetricarboxylic acid, that is, trimellitic acid or its derivative is inexpensive and easy to control the reaction, and thus is preferably used. In the present invention, these divalent carboxylic acid monomers and trivalent or higher polyvalent carboxylic acid monomers may be used alone or in combination.

On the other hand, examples of the vinyl resin monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene and p-methylstyrene.
Styrene or styrene derivatives such as ethylstyrene, 2,4-dimethylstyrene, p-chlorostyrene, vinylnaphthalene; for example, ethylene, propylene, butylene,
Ethylenically unsaturated monoolefins such as isobutylene;
Vinyl esters such as vinyl chloride, vinyl bromide, vinyl iodide, vinyl acetate, vinyl propionate, vinyl formate, vinyl caproate; for example, acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic. Isopropyl acid, n-butyl acrylate,
Isobutyl acrylate, tert-butyl acrylate,
Amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methoxyethyl acrylate, 2-hydroxyethyl acrylate, acrylic acid Glycidyl, 2-chloroethyl acrylate, phenyl acrylate, α-chloromethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, Tert-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, decyl methacrylate, lauryl methacrylate, meth Acrylic acid 2-ethylhexyl, stearyl methacrylate, methoxyethyl methacrylate,
Ethylenic monocarboxylic acids such as 2-hydroxyethyl methacrylate, glycidyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and the like; and ethylenic monocarboxylic acids such as acrylonitrile, methacrylonitrile and acrylamide. Examples thereof include acid-substituted compounds; ethylenic dicarboxylic acids such as dimethyl maleate and substituted compounds thereof; vinyl ketones such as vinyl methyl ketone; vinyl ethers such as vinyl ethyl ether; and vinylidene halides such as vinylidene chloride. Among these, a combination of styrene and acrylic acid or an ester thereof and a combination of styrene and methacrylic acid or an ester thereof are preferably used in the present invention because of good dispersibility of a colorant, a wax and the like.

Further, a cross-linking agent can be used if necessary, and for example, divinylbenzene, divinylnaphthalene, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexylene glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4-methacryloxydiethoxyphenyl) propane, 2,2'-bis (4
-Acryloxydiethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, dibromoneopentyl glycol dimethacrylate, diallyl phthalate, etc. And a combination of two or more thereof can be used. Divinylbenzene and polyethylene glycol dimethacrylate are preferably used.

The amount of these crosslinking agents used is 0.001 to 15% by weight, preferably 0.1 to 15% by weight, based on the vinyl polymerizable monomer.
It is recommended to use ~ 10% by weight. When the amount of these cross-linking agents used is more than 15% by weight, the toner obtained is less likely to be melted by heat, resulting in poor heat fixing property or heat pressure fixing property. When the amount used is less than 0.001% by weight, it is difficult to prevent the offset phenomenon in which a part of the toner adheres to the roller surface without being completely fixed to the paper and is transferred to the next paper during thermal pressure fixing.

Examples of the polymerization initiator used for the polymerization of the vinyl resin monomer include, for example, 2,2'-azobis (2,4-dimethylvaleronitrile) and 2,2'-azobisisobutyronitrile. , 1,1'-azobis (cyclohexane-
1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, other azo or diazo polymerization initiator, or benzoyl peroxide,
Methyl ethyl ketone peroxide, isopropyl peroxycarbonate, cumene hydroperoxide,
Examples thereof include peroxide-based polymerization initiators such as 2,4-dichlorobenzoyl peroxide, lauroyl peroxide and dicumyl peroxide.

Two or more kinds of polymerization initiators may be mixed and used for the purpose of controlling the molecular weight and the molecular weight distribution of the polymer or the reaction time.

The amount of the polymerization initiator used is 0.1 to 20 parts by weight, preferably 1 to 100 parts by weight of the vinyl resin monomer.
~ 10 parts by weight.

In the present invention, in order to obtain a resin in which a polyester resin and a vinyl resin are chemically bonded, polymerization is carried out using a compound capable of reacting with any of the monomers of both resins (hereinafter referred to as "both reactive compound"). To do. Such bireactive compounds include compounds such as fumaric acid, acrylic acid, methacrylic acid, citraconic acid, maleic acid, and dimethyl fumarate in the above-mentioned polyester resin monomer and vinyl resin monomer. . Of these, fumaric acid, acrylic acid, and methacrylic acid are preferably used. The amount of both reactive compounds used is 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the total raw material monomers.

The polymerization reaction is carried out, for example, by adding the vinyl monomer raw material monomer mixture dropwise to the polyester raw material monomer mixture under the temperature conditions suitable for the addition polymerization reaction in the presence of the bireactive compound. In parallel with this, a step of partially carrying out the polycondensation reaction, a step of maintaining the temperature of the obtained mixture under the above conditions to complete only the addition polymerization reaction, and then raising the reaction temperature to carry out the polycondensation reaction. And a step of increasing the degree of polymerization.

Here, the temperature condition suitable for the addition polymerization reaction depends on the kind of the polymerization initiator used, but it is 50 to 1
It is usually carried out in the temperature range of 80 ° C. The optimum temperature range for increasing the polymerization degree of the polycondensation reaction is usually 190 to
270 ° C. In this way, a hybrid resin is obtained by the method of allowing two independent reactions to proceed in parallel in the reaction vessel. Here, the hybrid resin means a resin obtained by partially bonding a polyester resin and a vinyl resin by a chemical bond. Such hybrid resin has two aspects. In one aspect,
The polyester resin is uniformly mixed with the vinyl resin. In another embodiment, a vinyl resin is dispersed in a polyester resin to form a sea / island structure together with the vinyl resin.

The proportion of the polyester resin in the resin (1) is not particularly limited, but is preferably 51 to 95% by weight, more preferably 60 to 80% by weight.

Next, a preferred embodiment of the resin (2) will be described in detail. In the present invention, a vinyl resin having a positively chargeable functional group is used as the resin (2). In particular, a functional group containing nitrogen and / or phosphorus is preferable as the positively chargeable functional group. The vinyl resin having a positively chargeable functional group contains, for example, one or more monomers selected from the monomers of the vinyl resin used for the resin (1) and one or more nitrogen. It is obtained by copolymerizing the above-mentioned monomer and / or a monomer containing at least one phosphorus. Here, it is preferable to use polystyrene or a monomer of styrene-acrylic copolymer as the monomer of the vinyl resin from the viewpoint of easy adjustment of the glass transition point of the resin and economical efficiency.
Examples of nitrogen-containing monomers include N, N-dialkylamino such as N, N-dimethylaminomethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate. Alkyl (meth) acrylates; N, N-
Dimethylaminoethyl (meth) acrylamide, N, N
-N, N-dialkylaminoalkyl (meth) acrylamides such as dimethylaminopropyl (meth) acrylamide; N-vinylpyrrole, N-vinylpyrrolidone,
N-vinyl compounds such as N-vinylcarbazole; vinylpyridine; morpholine ethyl (meth) acrylate;
Examples thereof include quaternized monomers such as trimethylaminoethyl chloride (meth) acrylate and trimethylaminopropyl (meth) acrylamide chloride. Examples of the phosphorus-containing monomer include allyltriphenylphosphonium bromide and allyltriphenylphosphonium chloride. Of these, N, N-dialkylaminoalkyl (meth) acrylates, N, N-dialkylaminoalkyl (meth) acrylamides, and N-
Vinylpyrrolidone is preferably used.

By using a compound having a nitrogen atom in the molecule as a polymerization initiator in the production of the resin (2), a functional group may be introduced at the terminal of the molecule of the resin (2). A stable positive charging property can be imparted therein. Examples of the compound having a nitrogen atom in the molecule include 2,2'-azobis (2-methyl-N-phenylpropionamidine) and 2,2'-azobis [N-
(4-chlorophenyl) -2-methylpropionamidine], 2,2'-azobis [N- (4-hydroxyphenyl) -2-methylpropionamidine], 2,2'-azobis [N- (4-aminophenyl] ) -2-Methylpropionamidine], 2,2′-azobis [2-methyl-N- (phenylmethyl) propionamidine], 2,2′-azobis (2-methyl-N-2-propenylpropionamidine), Azoamidine compounds such as 2,2′-azobis (2-methyl-N-propionamidine) and 2,2′-azobis [N- (2-hydroxyethyl) -2-methyl-propionamidine] and their hydrochlorides, methane Sulfonate, p-
Toluenesulfonate: 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane], 2,2 '
-Azobis [2- (2-imidazolin-2-yl) propane], 2,2'-azobis [2- (4,5,6,7-tetrahydro-1H-1,3-diazepin-2-yl) propane ], 2,
2'-azobis [2- (3,4,5,6-tetrahydropyrimidin-2-yl) propane], 2,2'-azobis [2- (5-
Hydroxy-3,4,5,6-tetrahydropyrimidine-2-
Yl) propane], 2,2'-azobis [2- {1- (2-
Hydroxyethyl) -2-imidazolin-2-yl} propane] and other cyclic azoamidine compounds and their hydrochlorides, methanesulfonates, p-trisulfonates and the like.

The resin (2) can be obtained by the usual solution polymerization method, emulsion polymerization method, suspension polymerization method, bulk polymerization method or dispersion polymerization method using the above-mentioned monomers.

In the present invention, the mixing ratio (parts by weight) of the resin (1) and the resin (2) is (1) / (2) = 99/1 to 50/50,
It is preferably 95/5 to 70/30.

The average particle size of the dispersed phase of the resin (2) can be controlled by
The following method is used. Examples include (a) a method in which the compatibility between the vinyl resin component of the resin (1) and the resin (2) is changed, and (b) a method in which the mixing ratio of the resin (1) and the resin (2) is changed. . In the case of the method of changing the mixing ratio of the resin (1) and the resin (2) of (a), since the toner may deviate from the proper charge amount, 55 to 98 parts by weight of the resin (1), 2) is preferably 45 to 2 parts by weight.

The particle size of the dispersed phase composed of the resin (2) is
0.05 to 1.0 μm is preferable. If the particle size of the dispersed phase becomes too fine, the rise of charging will be delayed and the distribution of the amount of charge will be broad. Further, when the particle size of the dispersed phase becomes too large, the rise of charging becomes faster, but the distribution of the amount of charge becomes wider, and in some cases, reverse charging occurs. Further, when the dispersed phase becomes large, the mechanical strength of the toner becomes too weak, and when printing is continued, the binder resin cracks and fine powder increases, and the stability over time deteriorates. Here, the diameter of the dispersed phase is about 0.
A 2 mm resin was cut with a microtome to a thickness of 100 to 300 nm, and the obtained thin piece was subjected to a transmission scanning electron microscope (for example, JEOL (JEOL Ltd.), "JEM-").
2000 ") and perform image analysis by a well-known method.

In the present invention, the binder resin of the present invention contains the resin (1) and the resin (2), and other resins such as polyamide resin, polyester resin, styrene-acrylic resin, epoxy resin. You may further contain resin etc. to 30 weight% with respect to binder resin.

The toner of the present invention is a positively chargeable toner comprising at least the binder resin containing the resins (1) and (2) and a colorant. Further, from the viewpoint of charge stability, the positively charged toner of the present invention may further contain the following general formula (I) and / or (II).

[0036]

[Chemical 3]

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ are the same or different and each represents an alkyl group, an alkoxy group, an aryl group or an allyl group, which may form a ring. , A ⁻ represents an anion.)

In the compound having the general formula (I) or the general formula (II) used in the present invention, R ₁ , R
₂ , R ₃ and R ₄ are the same or different and each has 12 carbon atoms.
Each of the above is an alkyl group, an alkoxy group, an aryl group, and an allyl group, which may form a ring.
A ⁻ is an anion, and typical examples thereof include halogen, naphthol sulfonate, heteropolyacid anion,
Methyl sulfonate, p-toluene sulfonate, tetrafluoroborate, tetraphenyl borate and the like can be mentioned.

Examples of the compound represented by the general formula (I) or (II) include a quaternary ammonium salt compound such as "Bontron P-51" (manufactured by Orient Chemical Co.),
Cetyl trimethyl ammonium bromide, "COPY CHARG
E PX VP435 "(made by Hoechst)," TP-415 ",
"TP-302" (above, Hodogaya Chemical Co., Ltd.), cetylpyridinium chloride, cetylpyridinium bromide, benzylcetyldimethylammonium chloride,
Benzyl cetyl dimethyl ammonium bromide and the like, and preferably Bontron P-51 and TP-4.
15 is used.

The compound having the structural formula of the general formula (I) or the general formula (II) used in the present invention is added to the binder resin.
By adding 0.1 to 8.0% by weight, preferably 0.2 to 5.0% by weight, a more uniform charge amount distribution can be given and the rising property of charge can be improved.

In the present invention, a positively chargeable toner is obtained by using the above-mentioned binder resin. When the toner is prepared, for example, the resins (1) and (2), a colorant, and a charge control agent as necessary, A magnetic substance or the like is added.

As the colorant used in the present invention, various carbon blacks produced by thermal black method, acetylene black method, channel black method, lamp black method, etc., nigrosine dye, phthalocyanine blue, permanent brown FG, brilliant first Scarlet, Pigment Green B, Rhodamine-
B base, Solvent Red 49, Solvent Red 146
, Solvent Blue 35, etc., and mixtures thereof, etc., usually 1 to 15 parts by weight with respect to 100 parts by weight of the binder resin.
It is preferable to use about parts by weight.

The following charge control agents used in the present invention may be used in combination. As a concrete example,
For example, as a nigrosine dye, "Nigrosine base E
"X", "Oil Black BS", "Oil Black S"
O "," Bontron N-01 "," Bontron N-0 "
4 "," Bontron N-07 "," Bontron N-1 "
1 "," Bontron N-13 "(above, manufactured by Orient Chemical Co., Ltd.) and the like;" COPY BLUE PR "(manufactured by Hoechst Co.) and the like, triphenylmethane dyes containing a tertiary amine as a side chain;
Polyamine resin such as "AFP-B" (manufactured by Orient Chemical Co.), imidazole derivative such as "PLZ-20".
01 "," PLZ-8001 "(above, manufactured by Shikoku Kasei)
Etc. can be mentioned. The above charge control agent is used in an amount of 0.1 to 8.0% by weight, preferably 0.2 to 5.0% by weight, based on the binder resin.

When manufacturing the toner, it is possible to add wax such as polyolefin as the offset preventing agent, inorganic fine particles such as hydrophobic silica, titanium oxide and alumina as the fluidity improving agent, and a property improving agent.

The binder resin in the present invention is used as an essential component, a colorant and, in some cases, a property improving agent are uniformly dispersed, and then melt-kneaded, cooled, pulverized and classified by a known method to obtain an average particle diameter of 5 A toner having a particle size of up to 15 μm can be obtained, and the toner is a magnetic powder, that is, an iron oxide-based carrier, a spherical iron oxide-based carrier or a ferrite-based carrier as it is or by mixing with a resin or the like, It can be a dry two-component developer.

Further, it is used as a one-component developer characterized by being charged by being pressed by a pressing member.

In order to generate the magnetic toner, magnetic particles may be added to the binder resin. As the magnetic particles, for example, ferrite, magnetite and other iron, cobalt, nickel and other ferromagnets or alloys showing ferromagnetism, compounds containing these elements, or containing no ferromagnetism elements, an appropriate heat treatment is applied. Examples thereof include alloys that exhibit ferromagnetism, such as manganese-copper-aluminum, manganese-copper-tin, and other types of alloys called Heusler alloys containing manganese and copper, or chromium dioxide. A compound containing a metal exhibiting ferromagnetism is preferably used, and magnetite is particularly preferably used. These magnetic materials are uniformly dispersed in the core material in the form of fine powder having an average particle size of 0.1 to 1 μm. The content thereof is 20 to 70 parts by weight, preferably 30 to 70 parts by weight, based on 100 parts by weight of the binder resin.

[0048]

EXAMPLES The present invention will be described in more detail with reference to production examples, examples, comparative examples and test examples, but the present invention is not limited to these examples.
The composition ratios shown in Examples and the like are parts by weight unless otherwise specified.

In the present invention, the glass transition temperature (Tg) and the molecular weight of the obtained resin and toner by gel permeation chromatography (hereinafter abbreviated as "GPC") were measured, and the conditions were as follows.

Glass transition temperature (Tg) Using a differential scanning calorimeter ("DSC 200", manufactured by Seiko Instruments Inc.), the temperature was raised to 100 ° C., and the temperature was raised to 3
When the sample cooled to room temperature at a temperature decrease rate of 10 ° C / min. After being left for a minute was measured at a temperature increase rate of 10 ° C / min., From the extension line of the baseline below the glass transition temperature and the rising portion of the peak. The temperature at the intersection with the tangent line showing the maximum slope up to the apex of the peak is the glass transition temperature (T
g).

Molecular weight measurement by GPC Stabilize the column in a constant temperature bath at 40 ° C., and use chloroform as an eluent at a flow rate of 1 ml / min to give a sample concentration of 0.05.
Approximately 0.5% by weight of the sample chloroform solution adjusted to 1
The measurement was performed by injecting 00 μl. The molecular weight of the sample was calculated from the molecular weight distribution determined from the retention time based on the calibration curve prepared in advance. The calibration curve at this time was prepared by using several kinds of monodisperse polystyrene as standard samples. Analytical column: GMHLX + G3000HXL (manufactured by Tosoh Corporation)

Resin Production Example 1 [Resin (1)] 410 g of styrene as a monomer of vinyl resin, 2-
90 g of ethylhexyl acrylate and 20 g of azobisisobutyronitrile as a polymerization initiator are placed in a dropping funnel. Polyoxypropylene (2.2) -2,2-bis (4-
Hydroxyphenyl) propane 780 g, fumaric acid 24
g, isododecenyl succinic anhydride 76 g, terephthalic acid 250 g and dibutyltin oxide 2 g were placed in a glass 5 liter 4-neck flask, and a thermometer, a stainless stir bar, a downflow condenser and a nitrogen inlet pipe were attached,
While stirring in a nitrogen atmosphere in a mantle heater at a temperature of 135 ° C., the vinyl resin monomer and the polymerization initiator were dropped from the dropping funnel over 1 hour. While maintaining the temperature at 135 ° C, the mixture was aged for 2 hours, heated to 230 ° C and reacted.

The degree of polymerization was traced from the softening point according to ASTM E28-67, and the reaction was terminated when the softening point reached 120 ° C. The glass transition temperature (Tg) of the obtained resin was 60 ° C. with one peak. The vinyl resin had an average dispersed particle diameter of 0.5 μm, which was in a good dispersed state. Here, the dispersed particle size is obtained by cutting a resin having a diameter of 0.2 mm to a thickness of 150 nm with a microtome, and the obtained thin piece is manufactured by a transmission scanning electron microscope (JEOL (JEOL Ltd.), “JEM-2000”). )). Moreover, the polymerization of the vinyl resin was completed before the reaction temperature was raised to 230 ° C., but the vinyl resin at that time had a number average molecular weight of 10 according to GPC measurement.
It was 000. The resin thus obtained is called resin 1a.

Resin Production Example 2 [Resin (1)] 350 g of styrene and 150 g of butyl methacrylate as monomers of vinyl resin and 25 g of dicumyl peroxide as a polymerization initiator are placed in a dropping funnel. Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 780 g, isophthalic acid 240 g, 1,
76 g of 2,4-benzenetricarboxylic acid, 22 g of fumaric acid
And 2 g of dibutyltin oxide were placed in a glass 5-liter four-necked flask, and a thermometer, a stainless stir bar, a downflow condenser and a nitrogen inlet tube were attached. The following operations and polymerization conditions are the same as in Resin Production Example 1.

The obtained resin was evaluated in the same manner as in Resin Production Example 1, and the glass transition temperature was 62 at a peak.
The dispersion particle diameter of the vinyl resin was 2.0 μm. The number average molecular weight of the vinyl resin before raising the reaction temperature to 230 ° C. was 17,000. The resin is referred to as resin 1b.

Resin Production Example 3 550 g of xylene was placed in a 2-liter glass four-necked flask equipped with a thermometer, a stainless stir bar, a downflow condenser and a nitrogen introducing tube, and the temperature was raised to 135 ° C. after purging with nitrogen. Styrene 700 as a monomer of vinyl resin
g, 300 g of butyl methacrylate, and 30 g of dicumyl peroxide as a polymerization initiator were placed in a dropping funnel, added dropwise over 1 hour, and aged at 135 ° C. for 2 hours. Then, the temperature was raised to 200 ° C., xylene was distilled off under reduced pressure, the mixture was extracted into a vat, cooled, and then pulverized.

When the obtained resin was evaluated in the same manner as in Resin Production Example 1, the softening point according to ASTM E28-67 was 110 ° C and the glass transition temperature was 66 ° C. The number average molecular weight of the resin measured by GPC was 28,000. The resin is referred to as resin c.

Resin Production Example 4 Polyoxypropylene (2.2) -2 used in Resin Production Example 2
2-bis (4-hydroxyphenyl) propane 780
g, 240 g of isophthalic acid, 76 g of 1,2,4-benzenetricarboxylic acid and 2 g of dibutyltin oxide were placed in a glass 5 liter 4-neck flask, and a thermometer, a stainless stir bar, a downflow condenser and a nitrogen inlet tube were added. Homopolymerization was carried out at 230 ° C. by the same method as in Resin Production Example 2. When the obtained resin was evaluated in the same manner as in Resin Production Example 1, its softening point was 130 ° C. and its glass transition temperature was 60.3.
It was ℃. This is designated as resin d.

Resin Production Example 5 [Resin (2)] 900 g of xylene was added to a 2-liter four-necked flask equipped with a stirrer, a flow-down condenser, a thermometer, and a nitrogen introducing tube. While maintaining at 80 ℃, as a vinyl resin monomer,
Styrene 765 g, 2-ethylhexyl acrylate 18
0 g and 27 g of dimethylaminomethyl methacrylate,
And azobisisobutyronitrile 1 as a polymerization initiator
8 g of the mixed solution was placed in a dropping funnel and added dropwise to the mixture in the glass flask through the dropping funnel over 2 hours. After completion of dropping, aging at 80 ° C. for 4 hours, distilling out xylene under reduced pressure at 200 ° C., extracting into a vat, cooling and crushing,
A transparent resin was obtained. When the obtained resin was evaluated in the same manner as in Resin Production Example 1, the softening point was 128 ° C. and the glass transition point was 66 ° C. This is referred to as resin 2a.

Resin Production Example 6 [Resin (2)] Ion-exchanged water 1400 was placed in a 2-liter four-necked flask equipped with a stirrer, a flow-down condenser, a thermometer, and a nitrogen inlet tube.
g, and 7 g of cetyltrimethylammonium chloride were added and the temperature was raised to 70 ° C.
7 g of 2,2'-azobis (2-methyl-N-propionamidine) dihydrochloride was dissolved and added, and styrene 1 was added after the addition.
A mixture of 75 g, 52.5 g of methyl methacrylate, and 122.5 g of n-butyl methacrylate is placed in a dropping funnel and added dropwise to the mixture in the glass flask from the dropping funnel over 1 hour. After dropping, the mixture was aged at 70 ° C. for 1.5 hours, then salted out, washed and dried to obtain a resin. When the obtained resin was evaluated in the same manner as in Resin Production Example 1, the softening point was 1
The glass transition point was 53 ° C and the glass transition point was 65 ° C. This is resin 2
b.

Examples 1 to 4 and Comparative Examples 1 to 2 Materials having the following compositions were premixed with a Henschel mixer (manufactured by Mitsui Miike Kakoki Co., Ltd.), melt-kneaded with a twin-screw extruder, cooled, and then subjected to normal pulverization. , A mean particle size of 10.
A 5 μm untreated toner was prepared.

Composition Example 1 Resin 1a 70 parts by weight Resin 2a 30 parts by weight Carbon black "Regal 330R" (manufactured by Cabot) 6 parts by weight Low molecular weight polypropylene "NP-055" (manufactured by Mitsui Petrochemical Co., Ltd.) 2 parts by weight

Example 2 Resin 1b 70 parts by weight Resin 2a 30 parts by weight Carbon black "Regal 330R" (manufactured by Cabot) 6 parts by weight Low molecular weight polypropylene "NP-055" (manufactured by Mitsui Petrochemical Co., Ltd.) 2 parts by weight

Example 3 Resin 1a 70 parts by weight Resin 2b 30 parts by weight Carbon black "Regal 330R" (manufactured by Cabot) 6 parts by weight Low molecular weight polypropylene "NP-055" (manufactured by Mitsui Petrochemical Co., Ltd.) 2 parts by weight

Example 4 70 parts by weight of resin 1a 30 parts by weight of resin 2a 30 parts by weight of quaternary ammonium salt "P-51" (manufactured by Orient Chemical Co.) 0.5 part by weight 6 parts by weight of carbon black "Regal 330R" (manufactured by Cabot) Low molecular weight polypropylene "NP-055" (Mitsui Petrochemical Co., Ltd.) 2 parts by weight

Comparative Example 1 Resin c 70 parts by weight Resin 2a 30 parts by weight Carbon black “Regal 330R” (manufactured by Cabot) 6 parts by weight Low molecular weight polypropylene “NP-055” (manufactured by Mitsui Petrochemical Co., Ltd.) 2 parts by weight

Comparative Example 2 Resin d 70 parts by weight Resin 2a 30 parts by weight Carbon black "Regal 330R" (manufactured by Cabot) 6 parts by weight Low molecular weight polypropylene "NP-055" (manufactured by Mitsui Petrochemical Co., Ltd.) 2 parts by weight

To 100 parts by weight of the untreated toners obtained in each of Examples 1 to 4 and Comparative Examples 1 and 2 described above, 0.3 part by weight of alumina fine particles hydrophobically treated with hexamethyldisilazane was added. The toner was mixed and adhered using a Henschel mixer to complete the toner. A developer was prepared by mixing 39 parts by weight of each of the above toners and 1261 parts by weight of silicone resin-coated ferrite powder (average particle size 100 μm). The charge amount of each of these developers was measured by the following method.

The charge amount during 30 seconds and 10 minutes was measured by a ball mill (manufactured by Kao Corporation, container: 35 mmφ, depth 4).
0 mm, rotation speed 250 rpm) for 30 seconds and 1
It was measured by mixing for 0 minutes.

The charge amount was measured by a blow-off type charge amount measuring device described below, that is, a specific charge measuring device equipped with a Faraday cage, a condenser and an electrometer. The measuring method is as follows. First, the developer prepared with brass (W (g) (0.15 to 0.20 g)) equipped with a 500 mesh stainless steel mesh (which can be changed to a size that does not allow carrier particles to pass) is used. Put in the measuring cell of. Next, after suctioning for 5 seconds from the suction port, the air pressure is blown for 5 seconds at an air pressure of 0.6 kg / cm ² to remove only the toner from the cell. The voltage of the electrometer 2 seconds after the start of the blow at this time is V (volt). Here, if the electric capacity of the condenser is C (μF), the specific charge Q / m of this toner is obtained by the following equation. Q / m (μC / g) = C × V / m Here, m is the weight of the toner contained in the developer in W (g), and the weight of the toner in the developer is T (g). When the weight of the developer is D (g), the toner concentration of the sample is expressed as T / D × 100 (%), and m is calculated by the following formula. m (g) = W × (T / D) Table 1 shows the result of the charge amount in 10 minutes.

The rising property of the charge of the developer was also measured from the ratio of the value of 30 seconds to the value of 10 minutes of the charge amount. That is, the rising value of the charge amount is a value calculated by the following formula. Rise of charge amount = charge amount after 30 seconds / 10 charge amount after 10 minutes

Further, the charge amount distribution was measured using an Espert Analyzer (manufactured by Hosokawa Micron Co., Ltd.) to evaluate the amount of reversely charged toner. Furthermore, the dispersibility of the resin (1) and the resin (2) was evaluated as follows. That is, the dispersed particle size is obtained by cutting a resin having a diameter of 0.2 mm with a microtome to a thickness of 150 nm, and the obtained thin piece is manufactured by a transmission scanning electron microscope (JEOL (JEOL Ltd.), "J
EM-2000 ").
The results are shown in Table 1.

[0073]

[Table 1]

As shown in Table 1, the toners of the present invention (Examples 1 to 4) were able to obtain the toners that were well charged, had a rapid rise in charging, and had little reverse charging.
Especially when a quaternary ammonium salt is used (Example 4)
The charge rise was significantly faster than in other cases. On the other hand, when a styrene-acrylic resin was used instead of the resin (1) in the binder resin (Comparative Example 1), the binder was uniformly dispersed and the rise of charging was delayed. When a polyester resin was used in place of the resin (2) (Comparative Example 2), the charge amount was not increased but the amount of the reversely charged toner was increased, although the charge started up quickly.

Printing test An image was printed on the toner of Example 1 of the present invention using a commercially available electrophotographic copying machine, a modified SF-8350 manufactured by Sharp Corporation, and printing durability was evaluated. , 00
When 0 sheets were continuously copied, a stable image with little image fog was provided.

The fixing property was also evaluated while changing the fixing temperature of the copying machine and the toner used in the printing durability test. The toner of the present invention was excellent in low-temperature fixability and offset resistance.

[0077]

The positively chargeable toner containing the binder resin according to the present invention makes it possible to obtain a toner which is well uniformly charged, has a rapid rise in charging, and has little reverse charging. Further, in the heat roller fixing method, it is possible to obtain a toner that can be fixed at a low temperature without using an offset preventing liquid.

Claims (7)

[Claims] 1. A binder resin for a toner comprising a resin (1) capable of forming a continuous phase in a toner and a resin (2) capable of being dispersed in the continuous phase in a toner to form a dispersed phase. A binder resin for toner, wherein the resin (1) is a hybrid resin of a polyester resin and a vinyl resin, and the resin (2) is a vinyl resin having a regular functional group. 2. A resin (1) comprising a monomer of polyester resin, a monomer of vinyl resin, and a compound capable of reacting with any of these monomers, and polycondensation and addition polymerization in parallel in the same reaction vessel. The binder resin according to claim 1, which is obtained by the method. 3. The vinyl resin of the resin (1) is one kind or two kinds.
The binder resin according to claim 1 or 2, which is obtained by polymerization using at least one styrene-based monomer. 4. The resin (2), which is a vinyl-based resin having a positively chargeable functional group, is obtained by polymerization using a monomer of polystyrene or a styrene-acryl copolymer. The binder resin described. 5. The binder resin according to claim 1, wherein the positively chargeable functional group is a functional group containing nitrogen and / or phosphorus. 6. A positively chargeable toner containing at least a binder resin and a colorant, wherein the binder resin is
<5> A positively chargeable toner, which is the binder resin according to any one of <5> to <5>. 7. The general formula (I) and / or
The positively chargeable toner according to claim 6, further comprising a compound represented by the general formula (II). [Chemical 1] (In the formula, R ₁ , R ₂ , R ₃ , and R ₄ are the same or different and each represents an alkyl group, an alkoxy group, an aryl group, or an allyl group, which may form a ring,
A ⁻ represents an anion. )