JPH07134444A - Charge controllable resin for positively charged toner - Google Patents

Abstract

PURPOSE:To improve compatibility with a resin for fixing toners and electrostatic chargeability by copolymerizing cation monomer among a monoallylamine, diallylamine and triallylamine and another polymerizable monomer. CONSTITUTION:This resin consists of the copolymer contg. the polymerizable monomer capable of constituting a polymer having good compatibility with the resin for fixing toners or the polymerizable monomers to be the source for the resin for fixing toners and the cationic monomer of at least one kind among the monoallylamine, diallylamine and triallylamine. The ratio at which the cationic monomer occupy in the charge control resin is preferably specified to 5 to 20wt.% when expressed by the ratio of the cationic monomer occupying the total amt. of the monomers as the raw material. A monovinyl arom. monomer, acrylic monomer, etc., are usable as such polymerizable monomer. As a result, the charge controllable resin which has the excellent compatibility with the resin for fixing toners or the polymerizable monomer to be the source for the resin for fixing toners, is insoluble in water and has excellent electrostatic charge characteristics is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge control resin for positively charged toner, which is blended with a positively charged toner for electrophotography to control its charging characteristics. More specifically, it is produced by a so-called suspension polymerization method. The present invention relates to a charge control resin for positively charged toner, which is preferably used for the positively charged toner for electrophotography.

[0002]

2. Description of the Related Art Conventional toner for electrophotography is styrene-
It is manufactured by melt-kneading a fixing resin such as an acrylic copolymer and carbon black as a colorant and other additives, and then pulverizing and classifying. However, since such a pulverized toner has a wide particle size distribution, it is difficult to make charging uniform, and since the particle size is large,
It was difficult to obtain a high-resolution image. Further, since the shape of the obtained particles is irregular, the fluidity of the toner is generally low and there is a problem that blocking or the like is likely to occur.

Therefore, recently, as an alternative to the above-mentioned pulverization method, a method for producing a toner for electrophotography, a water-insoluble polymerizable monomer which is a base of a fixing resin, a polymerization initiator soluble in the monomer, and a colorant are used. A liquid monomer phase (oil phase) containing, etc. is prepared, and is suspended and dispersed in an aqueous dispersion medium such as water while being dispersed and heated to polymerize the polymerizable monomer. A method for producing a toner using the production of resin particles by the turbid polymerization method has been proposed.

The toner for electrophotography produced by the suspension polymerization method has a narrow particle size distribution and can be made smaller by changing the conditions, so that it has excellent charging characteristics and high quality. There is an advantage that an image can be obtained. It also has excellent productivity because it does not require classification.

[0005]

In the electrophotographic toner, in addition to the above-mentioned fixing resin and colorant, a charge control agent for controlling the triboelectric chargeability of the toner and an offset preventing effect for the toner are provided. Additives such as an anti-offset agent are blended. As the charge control agent, various electron-donating substances (positively charged toner) or electron-accepting substances (negatively charged toner) have been used in the case of the pulverization method, but especially in the case of the suspension polymerization method. , A charge control agent which is not dissolved or altered in an aqueous dispersion medium or aggregated without being uniformly dispersed in the monomer phase so as not to cause problems such as toner charge characteristics and particle size distribution variation. Was needed.

In order to deal with this, for example, in the case of a positively charged toner, instead of a usual charge control agent, a polymer excellent in compatibility with a polymerizable monomer which is a base of the fixing resin is used. Uses a charge control resin that is a copolymer of a polymerizable monomer that can be formed (for example, the same polymerizable monomer that is the basis of the fixing resin) and a cationic polymerizable monomer. Has been proposed (for example, Japanese Patent Laid-Open No. 58-12052).
63, etc.).

However, the conventional charge control resin is insufficient in chargeability as compared with a usual charge control agent (eg, nigrosine dye). In addition, in order to obtain sufficient chargeability, when the amount of charge control resin added is increased,
The viscosity of the monomer phase rises, making it difficult to suspend and disperse in the form of fine and uniform droplets in an aqueous dispersion medium, which causes variations in the particle size of the toner and also makes it difficult to reduce the particle size. There is a problem.

It has been attempted to add an anionic inorganic dispersant or the like to an aqueous dispersion medium to improve the suspension / dispersibility of the monomer phase containing the above charge control resin, but in this case, production Since it is difficult to completely remove the inorganic dispersant from the surface of the formed toner particles, there is a problem that the inorganic dispersant remaining on the surface of the toner particles deteriorates the charging characteristics and environmental stability of the toner ( JP-A-60-578
56, Japanese Patent Publication No. 1-51188, etc.).

The present invention has been made in view of the above circumstances, and is excellent in compatibility with a fixing resin for a toner and a polymerizable monomer which is a base of the fixing resin, and is water-insoluble. Moreover, it is an object of the present invention to provide a charge control resin for positively charged toner having excellent charging characteristics.

[0010]

Means and Actions for Solving the Problems In order to solve the above problems, the present inventors have made various studies on the polymerizable monomers constituting the charge control resin. As a result, a copolymer using a monoallylamine, a diallylamine or a triallylamine as a cationic monomer, which has not been conventionally used for a charge control resin, has excellent charging characteristics and is water-insoluble and water-soluble. It was found that the dispersion medium does not dissolve, deteriorate, or aggregate.

Therefore, as a result of further investigation of the polymerizable monomer copolymerized with the above-mentioned three kinds of cationic monomers, it was found that the polymerizable monomer was compatible with the fixing resin of the toner or the polymerizable monomer which is the base of the fixing resin. It was found that a polymerizable monomer capable of forming a good polymer should be used, and the present invention has been completed. That is, the charge control resin for positively charged toner of the present invention,
A polymerizable monomer capable of forming a polymer having good compatibility with the fixing resin of the toner or the polymerizable monomer which is the base of the fixing resin, and at least one kind of monoallylamine, diallylamine and triallylamine It is characterized by comprising a copolymer containing a cationic monomer.

The present invention will be described below. As the cationic monomer used in the present invention, as described above,
Formula (1):

[0013]

[Chemical 1]

Monoallylamine represented by the formula (2):

[0015]

[Chemical 2]

A diallylamine represented by the formula: or a formula (3)
:

[0017]

[Chemical 3]

An example is triallylamine represented by: These cationic monomers may be used alone or in combination of two or more. The proportion of the cationic monomer in the charge control resin is not particularly limited in the present invention, but is 5 to 20% by weight in terms of the proportion of the cationic monomer in the total amount of the monomer as a raw material.
Is preferred.

When the ratio of the cationic monomer is less than the above range, the charge control resin may have insufficient charging characteristics. On the contrary, when the ratio of the cationic monomer exceeds the above range, The compatibility of the charge control resin with the fixing resin of the toner and the polymerizable monomer that is the base of the fixing resin may decrease. As the polymerizable monomer to be copolymerized with the cationic monomer, various radically polymerizable polymerizable monomers can be used.

Examples of such polymerizable monomers include monovinyl aromatic monomers, acrylic monomers, vinyl ester monomers, vinyl ether monomers, diolefin monomers and monoolefin monomers. Various conventionally known compounds such as a monomer, a halogenated olefin-based monomer and a polyvinyl-based monomer can be used. As the monovinyl aromatic monomer, the following general formula (4):

[0021]

[Chemical 4]

(Wherein R ¹ is a hydrogen atom, a lower alkyl group or a halogen atom, R ² is a hydrogen atom, a lower alkyl group, a halogen atom, an alkoxy group, an amino group, a nitro group, a vinyl group, a sulfo group, or a sodium sulfo group. A monovinyl aromatic hydrocarbon represented by a nato group, a potassium sulfonato group or a carboxyl group), such as styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, o, m, p-chlorostyrene, p. -Ethyl styrene, sodium styrene sulfonate, divinyl benzene and the like.

The acrylic monomer has the following general formula
(Five) :

[0024]

[Chemical 5]

(Wherein R ³ is a hydrogen atom or a lower alkyl group, R ⁴ is a hydrogen atom, a hydrocarbon group having up to 12 carbon atoms,
It represents a hydroxyalkyl group, a vinyl ester group or an aminoalkyl group. ) An acrylic monomer represented by, for example, acrylic acid, methacrylic acid, methyl acrylate,
Ethyl acrylate, butyl acrylate, acrylic acid-2
-Ethylhexyl, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, butyl γ-hydroxyacrylate, butyl δ-hydroxyacrylate, β-hydroxy Ethyl methacrylate, γ-aminopropyl acrylate,
Examples include γ-N, N-diethylaminoacrylic acid propyl ester, ethylene glycol dimethacrylic acid ester, and tetraethylene glycol dimethacrylic acid ester.

The vinyl ester-based monomer is represented by the following general formula (6):

[0027]

[Chemical 6]

(In the formula, R ⁵ represents a hydrogen atom or a lower alkyl group.) Examples thereof include vinyl ester monomers, such as vinyl formate, vinyl acetate and vinyl propionate. The vinyl ether-based monomer has the following general formula (7):

[0029]

[Chemical 7]

(In the formula, R ⁶ represents a monovalent hydrocarbon group having up to 12 carbon atoms.) Examples thereof include vinyl ether type monomers such as vinyl methyl ether, vinyl ethyl ether and vinyl-n. -Butyl ether, vinyl phenyl ether, vinyl cyclohexyl ether and the like. As the diolefin-based monomer, the following general formula (8):

[0031]

[Chemical 8]

(Wherein R ⁷ , R ⁸ and R ⁹ are the same or different and each represents a hydrogen atom, a lower alkyl group or a halogen atom), and examples thereof include a diolefin monomer. , Isoprene, chloroprene and the like. As a mono-olefin monomer,
The following general formula (9):

[0033]

[Chemical 9]

(In the formula, R ¹⁰ and R ¹¹ are the same or different and each represents a hydrogen atom or a lower alkyl group.) A monoolefin-based monomer represented by, for example, ethylene, propylene, butene-1 , Pentene-1, 4-methylpentene-1 and the like. Examples of the halogenated olefin-based monomer include vinyl chloride and vinylidene chloride.

Further, examples of the polyvinyl monomer include divinylbenzene, diallyl phthalate and tricyanurate. These can be used alone or in combination of two or more. As described above, in the present invention, a polymerizable resin that can form a polymer having good compatibility with the fixing resin of the toner or the polymerizable monomer that is the base of the fixing resin, from the above-mentioned polymerizable monomers. Monomers are used selectively.

For example, when the charge control resin of the present invention is used in a toner containing the most common styrene-acrylic fixing resin, either styrene or acrylic is used as the polymerizable monomer. It is preferable to use a monomer or a combination of both monomers. The above cationic monomer and polymerizable monomer are preferably polymerized using a polymerization initiator.

Specific examples of the polymerization initiator for initiating the polymerization of both monomers include, for example, azobisisobutyronitrile, 2,2'-azobis- (2,4-dimethylvaleronitrile) and 2,2 '. -Azobis- (4-methoxy-2,
4-dimethylvaleronitrile), 2,2'-azobis-
(2-cyclopropylpropionitrile), 2,2'-
Azobis- (2-methylpropionitrile), 2,2 '
-Azobis- (2-methylbutyronitrile), 1,1 '
-Azo compounds such as azobis- (cyclohexane-1-carbonitrile), 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, dimethyl-2,2'-azobis (2-methylpropionate); cumene Hydroperoxide, t-butyl hydroperoxide,
Dicumyl peroxide, di-t-butyl peroxide,
In addition to peroxides such as benzoyl peroxide and lauroyl peroxide, conventionally known photopolymerization initiators can be used when the polymerization is carried out by irradiation with ultraviolet rays or visible rays. These may be used alone or in combination of two or more.

The amount of the polymerization initiator used is in the range of 0.001 to 10 parts by weight, preferably 0.01 to 0.5 parts by weight, based on 100 parts by weight of the basic monomer. Note that γ
It is also possible to initiate the polymerization using a ray, an accelerated electron beam or the like, and in this case, the polymerization initiator need not be used. Further, the polymerization may be initiated by combining ultraviolet rays and various photosensitizers.

The cationic monomer and the polymerizable monomer can be polymerized by various polymerization methods, but it is preferable to polymerize them by solution polymerization considering that the degree of polymerization is easily controlled. . As the solvent used for the solution polymerization, among the conventionally known various solvents, those capable of uniformly dissolving both monomers are preferably used. The charge control resin for positively charged toner of the present invention is used for a non-magnetic toner that constitutes a two-component developer together with a magnetic carrier, a magnetic or non-magnetic toner as a one-component developer, and the like. The amount of the charge control resin of the present invention to be blended with the toner is not particularly limited, but it is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the fixing resin constituting the toner. If the blending ratio of the charge control resin of the present invention is less than the above range, the addition effect may not be sufficiently obtained, and the chargeability of the toner may be insufficient. Further, when the blending ratio of the charge control resin of the present invention exceeds the above range, the environmental resistance stability of the toner may decrease, and particularly in the case of a toner produced by a suspension polymerization method, a monomer phase Viscosity increases, and it becomes difficult to suspend and disperse it in the form of fine and uniform droplets in the aqueous dispersion medium, which causes variations in the particle size of the toner and makes it difficult to reduce the particle size. There is a risk.

When the charge controllable resin of the present invention is used in the above toner, the toner is produced by melt-kneading the fixing resin, the charge controllable resin of the present invention, a colorant and other additives. , A pulverizing method of pulverizing and then classifying, with a water-insoluble polymerizable monomer as a base of the fixing resin,
A liquid monomer phase (oil phase) containing a polymerization initiator soluble in this, the charge control resin of the present invention, and a colorant and other additives is prepared, and is prepared in an aqueous dispersion medium such as water. A suspension polymerization method in which a polymerizable monomer is polymerized by heating while suspending and dispersing it in the form of droplets, a polymerizable monomer that is a base of a fixing resin, a polymerization initiator, and charge control of the present invention. Polymer and a colorant and other additives, the polymerizable monomer is dissolved, in a medium in which the polymer is not dissolved, dissolved with a dispersion stabilizer, a dispersion polymerization method of polymerizing under stirring, A fixing resin, the charge controllable resin of the present invention, a colorant and other additives are dissolved or dispersed in a suitable solvent, and a spray-dried liquid obtained is sprayed in a mist form using a spraying device. Meanwhile, a spray drying method of drying and removing the solvent is exemplified.

As the polymerizable monomer used as the base of the fixing resin used in the above method, various radically polymerizable polymerizable monomers exemplified above can be used. As the fixing resin used in the other method,
Polymers of the above polymerizable monomers are used. In the other method, the above-exemplified various polymerization initiators are used as the polymerization initiator for initiating the polymerization of the polymerizable monomer. As the polymerization initiator used in the suspension polymerization method, among the above-mentioned polymerization initiators, those which are insoluble in the aqueous dispersion medium and compatible with the polymerizable monomer are preferably adopted.

The amount of the polymerization initiator used is 10
The amount is 0.001 to 5 parts by weight, preferably 0.01 to 1 part by weight, relative to 0 parts by weight. It is also possible to initiate the polymerization using γ-rays, accelerated electron beams, etc. In this case, it is not necessary to use a polymerization initiator. Further, the polymerization may be initiated by combining ultraviolet rays and various photosensitizers.

In the case of the method (1), when a cross-linking agent is added to the polymerizable monomer, the fixing resin is cross-linked to improve the mechanical or thermal characteristics of the toner. Examples of the cross-linking agent include divinyl compounds such as divinylbenzene; diallyl phthalate, diallyl isophthalate, diallyl adipate, diallyl glycolate, diallyl maleate, diallyl sebacate, and the like; triallyl phosphate, triallyl aconitate, triary. Triallyl compounds such as lucyanurate, allyl ester of trimellitic acid, allyl ester of pyromellitic acid; 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol Diacrylate, butylene glycol diacrylate, pentaerythritol diacrylate, 1,4-butane Diacrylate compounds such as all-diacrylate; trimethylolpropane triacrylate, triacrylate compounds such as pentaerythritol triacrylate;
Dimethacrylate compounds such as 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, butylene glycol dimethacrylate;
Trimethacrylate compounds such as trimethylolpropane trimethacrylate; poly (meth) acrylates such as dipentaerythritol hexaacrylate, tetramethylolmethane tetraacrylate, N, N, N ′, N′-tetrakis (β-hydroxyethyl) ethylenediamine, etc. ) Acrylate compounds; allyl acrylate,
Allyl-acrylic compounds such as allyl methacrylate;
Examples thereof include acrylamide compounds such as N, N'-methylenebisacrylamide and N, N'-methylenebismethacrylamide, and prepolymers such as polyurethane acrylate, epoxy acrylate, polyether acrylate and polyester acrylate.

The crosslinking agent is used in an amount of 0 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the polymerizable monomer. To color the toner with a colorant,
When a toner is produced by each of the above methods, a predetermined amount of a colorant may be mixed in advance, or an uncolored toner may be formed first and then the colorant may be dyed later. Good.

The colorant to be preliminarily blended in the monomer phase when the toner is produced by the above-mentioned suspension polymerization method is not limited to this, and may be, for example, <black> carbon black, nigrosine dye (C.I. I.
No. 50415B), Lamp Black (C.I. No. 7)
7266), oil black, azo oil black, <red> DuPont oil red (CI. No. 2610)
5), Rose Bengal (CI. No. 45435), Orient Oil Red # 330 (CI. No. 605)
0), <yellow> chrome yellow (CI. No. 1409)
0), quinoline yellow (C.I.O. 47005), <green> malachite green oxalate (C.I.N.
o. 42000), <blue> chalco oil blue (CI No. azoec
Blue 3), aniline blue (C.I. No. 5040)
5), methylene blue chloride (C.I. No. 520)
1), phthalocyanine blue (C.I. No. 7416)
0), Ultramarine Blue (C.I. No. 7710)
3), etc. These may be used alone or in combination of two or more. The colorant is a polymerizable monomer 1
It is preferable to use 5 to 10 parts by weight per 00 parts by weight.

Among the above colorants, in the case of a black toner, carbon black, particularly carbon black which has been subjected to a surface treatment to improve the affinity with the polymerizable monomer, is most preferable. Examples of the surface treatment for improving the affinity of carbon black with the polymerizable monomer include a coupling treatment with a coupling agent and a grafting treatment with a polymerizable monomer.

As the colorant to be preliminarily added to the reaction system when the toner is produced by the above dispersion polymerization method, a dye that is more soluble in the polymerizable monomer than the medium is preferably used. Examples of the dye include oil-soluble dyes. The oil-soluble dye is transferred from the medium to the polymer when the amount of the monomer is reduced due to the progress of polymerization, so that efficient dyeing can be performed.

Specific examples of oil-soluble dyes are shown below. <Black dye> Black FS-Special A, Black S, Black # 103, Black # 107, Black #
215, Black # 141 (all are trade names manufactured by Chuo Gosei Kagaku Co., Ltd.), OPLAS Black HZ, Oplas Black # 836, and Oplas Black # 838 (all trade names manufactured by Orient Chemical Industry Co., Ltd.). <Red dye> MACROLEX red 5B,
Macrolex Red Violet R (all are trade names manufactured by Bayer), Sumiplast Red AS, Samiplast Tread B-2, Samiplast Red HLG-Z (all trade names manufactured by Sumitomo Chemical Co., Ltd.), Oprah Thread RR, Oprah Thread # 330 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.), Red 6B, Red T
R-71 (all are trade names of Chuo Gosei Kagaku KK). <Orange dye> Macrolex Orange 3G, Macrolex Orange R (all are brand names manufactured by Bayer), Orange S, Orange R, Orange # 826N (all are brand names manufactured by Chuo Synthetic Chemicals), Oplas Orange PS , Oplas Orange RR (trade name of Orient Chemical Industry Co., Ltd.), Samiplast Orange HRP (trade name of Sumitomo Chemical Industry Co., Ltd.). <Yellow dye> Macrolex Yellow 6G, Macrolex Yellow R (all are trade names manufactured by Bayer), Yellow D, Yellow GE, Yellow # 189 (all are trade names manufactured by Chuo Synthetic Chemicals), Samiplast Yellow GC ,
Samiplast Yellow R (all are trade names of Sumitomo Chemical Co., Ltd.), Oplus Yellow 3G, Oplus Yellow # 1
30 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.). <Purple dye> Macrolex Violet 3R, Macrolex Violet B (both trade names manufactured by Bayer), Violet MVB (trade name manufactured by Chuo Gosei Kagaku), Samiplast Violet RR, Samiplast Violet B (all Sumitomo) (Chemical Industry Co., Ltd.), Oplus Violet # 370, Oplus Violet #
732 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.). <Blue Dye> Macrolex Blue RR (trade name of Bayer), Blue BO, Blue # 8B (all are trade names of Chuo Gosei Kagaku), Samiplast Blue OR, Samiplast Blue GP, Samiplast Blue S (All are trade names manufactured by Sumitomo Chemical Co., Ltd.), Oplus Blue IIN, and Oplas Blue # 630 (all are trade names manufactured by Orient Chemical Co., Ltd.). <Green dye> Macrolex Green 5B, Macrolex Green G (all are trade names manufactured by Bayer), Green # 550, Green # 201 (all are trade names manufactured by Chuo Synthetic Chemicals), Samiplast Green G (Sumitomo) Chemical Industry Co., Ltd. product name), Oplus Green # 502, Oplus Green # 503 (all are product names of Orient Chemical Industry Co., Ltd.). <Brown Dye> Brown PB, Brown SG (all are trade names of Chuo Gosei Kagaku), Oplas Brown # 430,
Oplas Brown # 431 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.).

The amount of the oil-soluble dye used varies depending on the desired degree of color density, but it is usually preferable to use 1 to 15 parts by weight per 100 parts by weight of the polymerizable monomer. Any of the above-exemplified colorants can be used as the colorant to be preliminarily blended when the toner is manufactured by the pulverization method or the spray dry method.

On the other hand, in order to dye the uncolored toner later, for example, the uncolored toner may be dispersed in an aqueous medium together with a dye such as a dispersible dye and stirred at a predetermined temperature for a predetermined time. Examples of dispersible dyes used for dyeing include azo dyes, anthraquinone dyes, indigoid dyes, sulfur dyes and phthalocyanine dyes. The dispersible dye preferably has a high affinity for the polymer constituting the toner and can dye the toner firmly. The amount of the dispersible dye used varies depending on the desired degree of color density, but is usually preferably in the range of 1 to 5 parts by weight per 100 parts by weight of the fixing resin. Water is usually used as the aqueous medium, but if the dispersibility of the toner and dye is poor, a small amount of a suitable organic solvent may be added. The amount of the aqueous medium used is preferably in the range of 100 to 300 parts by weight per 100 parts by weight of the fixing resin.

Examples of additives other than the colorant include an offset preventive agent (release agent) and the like. The offset preventing agent is for preventing aggregation of the toner, and examples thereof include aliphatic hydrocarbons, aliphatic metal salts, higher fatty acids, fatty acid esters or partially saponified products thereof, silicone oil, and various waxes. Of these, aliphatic hydrocarbons having a weight average molecular weight of about 1,000 to 10,000 are preferable. Specifically, low molecular weight polypropylene, low molecular weight polyethylene, paraffin wax, and 4 carbon atoms.
It is suitable to use one or a combination of two or more kinds of low molecular weight olefin polymers composed of the above olefin units and silicone oils.

The offset preventing agent is used in an amount of 0 to 2 parts by weight, preferably 1 to 2 parts by weight, based on 100 parts by weight of the polymerizable monomer or the fixing resin. In the suspension polymerization method, the aqueous dispersion medium for dispersing the monomer phase containing each of the above components in the form of droplets includes water, or a mixed solvent containing water as a main component and incompatible with the monomer phase, Water is most preferably adopted.

A dispersion stabilizer is preferably added to the aqueous dispersion medium for the purpose of stabilizing the dispersibility of the monomer phase droplets. Examples of the dispersion stabilizer include water-soluble polymers such as polyvinyl alcohol and poorly water-soluble inorganic fine particles. The addition amount of the dispersion stabilizer may be similar to the conventional amount. Further, it is preferable to add a surfactant to the aqueous dispersion medium in order to obtain a good dispersed state of the monomer phase. The surfactant is preferably added after addition of the monomer phase in order to prevent bubbles from being caught.

As the surfactant, various conventionally known anionic, cationic or nonionic surfactants can be used. Particularly, the surfactant has excellent suspending / dispersing ability and influences the characteristics of the toner after production. In order not to give, it is desirable that it be easy to remove. The surfactant is added in an appropriate ratio according to the ratio of the monomer phase and the aqueous dispersion medium.

In the dispersion polymerization method, the medium in which the polymerizable monomer is dissolved but the polymer is not dissolved is, for example, water; lower alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; ethylene glycol, propylene. Polyhydric alcohols such as glycol, butanediol, diethylene glycol and triethylene glycol; cellosolves such as methyl cellosolve and ethyl cellosolve; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; esters such as ethyl acetate. .

These media can be used alone or in combination of two or more. Examples of the medium that is preferably used include lower alcohols such as ethanol, water, or a mixed medium of water and lower alcohol.
In the above mixed medium, the weight ratio of water to lower alcohol is 40:60 to 5:95, especially 30:70 to 10: 9.
It is preferably in the range of 0. The amount of the medium used is preferably in the range of 50 to 5000 parts by weight, particularly 500 to 2500 parts by weight, per 100 parts by weight of the polymerizable monomer.

As the dispersion stabilizer for stabilizing the dispersibility of the polymer in the medium, for example, polyacrylic acid, polyacrylic acid salt, polymethacrylic acid, polymethacrylic acid salt,
(Meth) acrylic acid- (meth) acrylic acid ester copolymer, acrylic acid-vinyl ether copolymer, methacrylic acid-styrene copolymer, carboxymethyl cellulose, poly (hydroxystearic acid-g-methyl methacrylate-co- (Methacrylic acid) copolymer, poly (ethylene oxide), polyacrylamide, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose,
Examples thereof include polyvinyl alcohol. Further, nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants and the like can also be used. The amount of the dispersion stabilizer used is 0.
It is in the range of 1 to 30% by weight, preferably 1 to 10% by weight.

In the further spray drying method, as the solvent for dissolving the above-mentioned respective components, among various conventionally known organic solvents, a solvent capable of dissolving the fixing resin is particularly preferably used. The solid content concentration of the spray-dried solution may be similar to the conventional one.

[0059]

EXAMPLES The present invention will be described below based on Examples and Comparative Examples. Example 1 90 parts by weight of styrene as a polymerizable monomer and 10 parts by weight of monoallylamine as a cationic monomer were mixed with 2,2'-azobis- (2,4) as a polymerization initiator.
-Dimethinivaleronitrile) was dissolved in toluene together with 5 parts by weight, and the solution was polymerized by stirring at 70 ° C for 6 hours under a nitrogen atmosphere.

Next, the reaction solution was added to a large amount of methanol, and the formed precipitate was filtered off, washed with methanol, purified, and dried to obtain a copolymer as a charge control resin for positively charged toner. Obtained. Examples 2 to 5 and Comparative Examples 1 and 2 Positively charged toner in the same manner as in Example 1 except that the amount of the cationic monomer shown in Table 1 was used instead of 10 parts by weight of monoallylamine. A copolymer as a charge control resin was obtained.

[0061]

[Table 1] Manufacture of Positively Charged Toner for Electrophotography A charge-controlling resin of Examples or Comparative Examples in the amounts shown in Table 2 and the following components were mixed in a high-speed stirrer (TK homomixer manufactured by Tokushu Kika Kogyo Co., Ltd.). , Rotation speed 5000r.pm 2
The monomer phase was prepared by stirring for a minute. Component Weight part-Polymerizable monomer Styrene 82 2-Ethylhexyl methacrylate 18-Coloring agent Carbon black 5-Crosslinking agent Divinylbenzene 0.2 Diethylene glycol dimethacrylate 2-Polymerization initiator Azobisisobutylvaleronitrile 0.32 2,2 ′ -Azobis- (2,4-dimethinivaleronitrile) 2.5 The above monomer phase was then mixed with 670 parts by weight of distilled water as an aqueous dispersion medium and 23 parts by weight of sodium alginate as a dispersion stabilizer. Then, using the above-mentioned high-speed stirrer, stirring was performed at a rotation speed of 10,000 rpm for 10 minutes to prepare a suspension having an average particle diameter of droplets of about 9 μm.

Next, this suspension was transferred to a 3 liter separable flask equipped with a stirrer, a nitrogen introducing tube and a condenser, and heated to 80 ° C. under a nitrogen atmosphere while stirring at a rotation speed of 120 rpm. After polymerizing for 5 hours,
The toner was cooled to room temperature, filtered, washed with ion-exchanged water, and dried to obtain toners 1 to 7 positively charged toners for electrophotography.

[0063]

[Table 2]

Practical Tests The positive charging toners for electrophotography of Examples and Comparative Examples were treated with 0.1% by weight of hydrophobic silica fine powder, and then ferrite carrier [plain paper printer manufactured by Mita Industry Co., Ltd. For LP-X1] to prepare a two-component developer having a toner concentration of 3.8% by weight. And this two-component developer
Use the plain paper printer LP-X1 to print black and white images,
The image density ID and the fog density FD of the blank area were measured using a reflection densitometer (Model No. TC-6D manufactured by Tokyo Denshoku Co., Ltd.).

Measurement of Blow-off Charge Quantity The charge quantity of the two-component developer prepared in the above practical test was measured using a blow-off charge quantity measuring device manufactured by Toshiba Chemical Co. Transfer efficiency measurement A two-component developer prepared in a practical test
It is used as a starting developer for P-X1 and
The same positive charging toner for electrophotography as that used in the component developer is filled in the toner hopper as a replenishment toner, and 1
An image was formed on ten thousand sheets, and the development amount (g) was obtained from the difference in the toner amount in the toner hopper before and after the image formation. Also above 1
The amount of toner collected by the cleaning device during the formation of 10,000 sheets of image was measured and defined as the transfer residual amount (g). Then, from the amount of development and the amount of transfer remaining, the transfer efficiency (%) of toner is calculated by the following formula.
I asked.

[0066]

[Equation 1]

The above results are shown in Table 3.

[0068]

[Table 3]

As is clear from the results shown in Table 3, all of the toners 6 and 7 using the charge control resin of Comparative Examples 1 and 2 containing a cationic monomer other than the specific cationic monomer. However, the blow-off charge amount and transfer efficiency were low, and sufficient image density could not be obtained. There was also a slight fogging. On the other hand, in all of the toners 1 to 5 using the charge controllable resin of Examples 1 to 5, good images were obtained in which the blow-off charge amount and the transfer efficiency were high, and there was no fog and the image density was high.

[0070]

As described above in detail, the charge control resin for positively charged toner of the present invention contains at least one cationic monomer selected from monoallylamine, diallylamine and triallylamine, and another polymerizable monomer. It is copolymerized with a monomer, and has excellent compatibility with the fixing resin of the toner and the polymerizable monomer which is the base of the fixing resin, is insoluble in water, and has excellent charging characteristics. Therefore, when the charge control resin of the present invention is used, uniform and sufficient charging characteristics can be obtained with a small amount of addition, so that there is no variation in the particle size distribution, and it is possible to reduce the particle size, and it is uniform and sufficient. A positively charged toner for electrophotography, which has a charging property and is excellent in environmental stability, can be manufactured by a suspension polymerization method.

Claims (1)

[Claims] 1. A polymerizable monomer capable of forming a resin having good compatibility with a fixing resin for a toner or a polymerizable monomer which is a base of the fixing resin, and monoallylamine, diallylamine and triallylamine. A charge controllable resin for positively charged toner, comprising a copolymer containing at least one cationic monomer of