JPH11338195A - Positive charge type toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a positive charge type toner excellent in initial build-up property of electrostatic charge and stability of a charged state by incorporating specified amts. of a polymer prepd. by copolymerizing a vinyl monomer with a monomer having an amino group converted into a quat. salt or a polymer prepd. by copolymerizing a vinyl monomer with an amino monomer and a specified quat. ammonium salt. SOLUTION: The toner contains a styrene-acrylic copolymer resin (A) contg. no positive charge factor, a polymer (B) prepd. by copolymerizing a vinyl monomer with a monomer having an amino group converted into a quat. salt in a weight ratio of 7:3 to 9:1 or a polymer (B') prepd. by copolymerizing a vinyl monomer with an amino monomer in a weight ratio of 5:5 to 7.5:2.5 and a quat. ammonium salt (C) represented by the formula. The content of the component B or B' is 0.5-4.5 pts.wt. per 100 pts.wt. of the component A, the content of the component C is 0.1-2 pts.wt. and the content of the component B or B' is higher than that of the component C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positively chargeable toner used in the field of electrophotography and the like.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus such as an electrophotographic apparatus, an electrostatic latent image formed on an electrostatic latent image carrier such as a photoreceptor is developed with a toner charged to a predetermined polarity.
After the toner image is transferred to a transfer sheet, the image is formed by fixing by contact heating fixing such as hot roll fixing or surf fixing. In the development of the electrostatic latent image, the electrostatic latent image having a positive or negative charge formed on the electrostatic latent image carrier by various methods is charged with a negative or positive charge, respectively, in the case of regular development. The reversal development is performed by electrostatically adsorbing toner having positive or negative charge, respectively. The present invention relates to a positively chargeable toner that is used by being positively charged by friction charging among such toners.

Conventionally, as a positively chargeable toner, for example, a toner obtained by adding a positive charge control agent such as a nigrosine dye, a quaternary ammonium salt or triphenylmethane to a styrene-acrylic resin is known. However, when such a positively chargeable toner is used in a two-component developer used with a magnetic carrier, the positive charge control agent, which is a toner component, is spent on the surface of the magnetic carrier during repeated use for a long period of time, and the carrier of the carrier is used. There has been a problem that the frictional charging ability with respect to the toner is reduced and toner fog is generated in a non-image portion of an image.

In order to solve such a problem, there have been known toners using a chargeable resin as a binder resin or using a chargeable resin as a charge control agent. For example, Japanese Patent Application Laid-Open No. 62-291667 reports a toner using a resin having an amino group as a binder resin without containing a conventional charge control agent.

In Japanese Patent Application Laid-Open No. 62-21169, amino (meth) acrylic monomers 1 to 1 are used as charge control agents.
A toner using a quaternary ammonium salt in combination with a copolymer or polymer of 00% by weight and 99 to 0% by weight of styrene has been reported.

JP-A-3-15079 discloses, as a charge controlling agent, a block and / or graft copolymer of a polymer composed of a monomer having a quaternary salt of an amino group and a styrene-based polymer, and optionally a quaternary ammonium. A toner using a salt or the like has been reported.

In Japanese Patent Application Laid-Open No. 8-220809, 1 to 30% by weight of methacryloyloxytrimethylammonium sulfate and a vinyl monomer 9 are used as charge control agents.
A toner using a copolymer of 9 to 70% by weight is disclosed.

However, in any of the toners, the problem of fogging or the like caused by the deterioration of the charging stability as described above is not completely solved, or the initial charge rising property is reduced, and the desired charge amount at the time of startup is reduced. Is not obtained, and a new problem arises in that fogging occurs on the copied image at the initial stage, and it is difficult at present to achieve both excellent charging stability and initial charging startability.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a positively chargeable toner which is excellent in initial charge rising property and charge stability.

[0010]

According to the present invention, there is provided (A) a styrene-acrylic copolymer resin containing no positive charge factor,
(B) a polymer obtained by copolymerizing a vinyl monomer and a monomer in which an amino group is quaternary salified in a polymerization weight ratio of 7: 3 to 9: 1, or (B ′) a polymerization weight of a vinyl monomer and an amino monomer A polymer copolymerized in a ratio of 5: 5 to 7.5: 2.5; and (C) a general formula (I);

Embedded image (In the formula, R ₁ is an alkyl group having 1 to 8 carbon atoms or a benzyl group, R ₂ and R ₃ are each independently an alkyl group having 1 to 18 carbon atoms, and R ₄ is a carbon atom. A positively charged quaternary ammonium salt represented by 1 to 18 alkyl groups or benzyl groups, and X and Y each independently represent hydrogen or a hydroxyl group (but not simultaneously hydrogen). Toner having a content of the polymer (B) or the polymer (B ′) of the resin (A) 10
0.5 to 4.5 parts by weight with respect to 0 parts by weight, and the content of the quaternary ammonium salt (C) is 0.1 to 2 parts by weight with respect to 100 parts by weight of the resin (A). The copolymer (B) or the polymer (B ') is contained more than the quaternary ammonium salt (C), and the total content of the polymer (B) or the polymer (B') and the quaternary ammonium salt (C) is contained. Resin (A) 1
The present invention relates to a positively chargeable toner, wherein the amount is 5 parts by weight or less based on 00 parts by weight.

In the present invention, as a charge controlling agent, a polymer obtained by copolymerizing a vinyl monomer and a monomer whose amino group has been quaternized at a specific polymerization ratio or a vinyl monomer and an amino monomer having a specific polymerization ratio are used. By controlling the content of a polymer obtained by copolymerization and a specific quaternary ammonium salt, it is possible to achieve both the initial charge rising property and charge stability of a positively chargeable toner. It became. In the present invention, it is possible to further improve the initial charge rising property and charge stability by controlling the dispersion particle size of the charge control agent in the toner.

The positively chargeable toner of the present invention is a polymer obtained by copolymerizing at least a vinyl monomer and a monomer whose amino group has been quaternized into a styrene / acrylic copolymer resin containing no positive charge factor. It contains a polymer obtained by copolymerizing a vinyl monomer and an amino monomer and a specific quaternary ammonium salt.

The styrene-acrylic copolymer resin used in the toner of the present invention (the resin (A) in the present specification)
Does not include a positive charge factor, that is, does not have a substituent capable of imparting a positive charge such as an amino group. Styrene / acrylic copolymer resin is composed of styrene monomer and (meth)
It is a copolymer with an acrylic acid monomer. Examples of styrene monomers include styrene, α-methylstyrene,
α-ethylstyrene, α-chlorostyrene, α-bromostyrene, 2,5-dichlorostyrene and the like can be mentioned, and one or more of these can be selected and used. Examples of (meth) acrylic acid-based monomers include (meth) acrylic acid and derivatives thereof, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, amyl (meth) acrylate, and the like. One or more of these can be selected and used. Further, as the resin (A), two or more different resins composed of the above-mentioned monomers can be mixed and used.

Preferred combinations of the above-mentioned styrene monomer and (meth) acrylic acid monomer constituting the resin (A) include styrene, butyl acrylate and butyl methacrylate, styrene and butyl acrylate,
Styrene and butyl methacrylate can be exemplified.

The number average molecular weight (Mn) of the resin (A) is 20
00 to 10,000, preferably 2500 to 7000, and the weight average molecular weight / number average molecular weight (Mw / Mn) is 2
It is desirably 0 to 90, preferably 20 to 50. In the present specification, this measurement condition is defined as JPC as a GPC device.
ASCO TWINCLE HPLC, SHOdex RI SE-31 as a detector, and SHO as a column
DEX GPCA-80M × 2 and KF-802 were performed using tetrahydrofuran as a solvent at a flow rate of 1.2 ml / min.

The peak value of the molecular weight distribution of the weight average molecular weight of the resin (A) measured by the GPC apparatus is 5,0.
00 to 200,000, preferably 10,000 to 16
Desirably, it is in the range of 000. If the peak value is less than 5,000, the initial charge rising property is deteriorated, and the charge distribution becomes broad. On the other hand, 200,0
If it exceeds 00, the Tg of the resin increases, and the fixability decreases. The measurement conditions of the peak value are the same as the above conditions.

The softening point (Tm) of the resin (A) is 110 to 1
30 ° C, preferably 115 to 125 ° C, and a glass transition point (Tg) of 50 to 75 ° C, preferably 55 to 70 ° C.
Is desirably within the range. Softening point of resin (A) is 1
If the temperature is lower than 10 ° C., the offset resistance decreases, and
This is because if the temperature is higher than ℃, the fixing strength of the image decreases. When the glass transition point is lower than 50 ° C., the heat resistance of the toner decreases, and when it exceeds 75 ° C., the fixability decreases.

In the present specification, the softening point is determined by using a flow tester (CFT-500: manufactured by Shimadzu Corporation) as a measuring device, the nozzle pore diameter is 1 mm, the load is 30 kg / cm ² ,
This is the temperature at which 1.0 g of the sample flows out at a rate of 3 ° C./min. For the glass transition point, a differential scanning calorimeter (DSC-200:
(Seiko Electronics Co., Ltd.) and using alumina as a reference. 10 mg of the weighed sample was heated from normal temperature to 200 ° C. at a heating rate of 30 ° C./min, then cooled, measured at a heating rate of 10 ° C./min between 20 ° C. and 120 ° C., and the shoulder value of the main absorption peak was measured. Was taken as the glass transition point.

In the toner of the present invention, as the resin (A), of the styrene-acrylic copolymer resin, the peak value of the molecular weight distribution measured by the GPC apparatus is in the range of 150,000 to 350,000. Resin and 4
It is preferable to use a resin in the range of 000 to 6000 as a mixture. The resin having the peak value in the range of 150,000 to 350,000 has Mn of 100,000 to 500,000 and Mw of 50,000.
10,000 to 1.5 million, Tg of 55 to 75 ° C, Tm of 120 to 1
More preferably, the temperature is 30 ° C. On the other hand, the resin having the peak value in the range of 4000 to 6000 has Mn of 200.
0-5000, Mw is 5000-8000, Tg is 50
More preferably, the Tm is 115 to 125 ° C. By using such a resin, it is possible to achieve both fixability and offset resistance.

A polymer contained in the toner of the present invention, which is obtained by copolymerizing a vinyl monomer and a monomer whose amino group has been quaternized (hereinafter referred to as a quaternary chlorinated amino monomer). Medium, referred to as polymer (B))
The monomer whose amino group has been quaternized is not particularly limited as long as it is a monomer having a quaternized amino group that can be copolymerized with a vinyl monomer described below. Formula (II);

Embedded image And methacryloyloxytrimethylammonium sulfate (MTAS).

The vinyl monomer constituting the polymer (B) is not particularly limited as long as it has a polymerizable unsaturated bond, and examples thereof include an acrylic monomer, a styrene monomer, and a vinyl monomer. Can be Specifically, acrylic monomers include (meth) acrylic acid, maleic acid, itaconic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, amyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate,
Behenyl (meth) acrylate, acrylamide, etc., and styrene monomers such as styrene, o, m, p
-Chlorostyrene, α-methylstyrene, vinyltoluene and the like, and as the vinyl monomer, vinyl chloride,
Vinyl acetate and the like. One or more of these are selected and used. Among these, it is preferable to use an acrylic monomer and a styrene monomer, and it is more preferable to use styrene and an alkyl (meth) acrylate. Examples of the alkyl (meth) acrylate include those having 1 to 1 carbon atoms.
8, preferably having 3 to 15 alkyl groups (meth)
It is preferred to use alkyl acrylates.

The polymerization weight ratio of the vinyl monomer constituting the polymer (B) to the quaternary amino chloride monomer is 7:
3-9: 1, preferably 7.2: 2.8-8.8: 1.
2. If the quaternary amino chloride monomer is less than the above ratio, it is difficult for the obtained toner to maintain a sufficient charge amount, and problems such as toner scattering occur. On the other hand, if the quaternary amino chloride monomer is more than the above ratio, the dispersibility of the quaternary amino chloride monomer in the toner decreases, and the toner charge increases due to repeated use. Rises, and toner fog occurs in a non-image portion of the image. Further, the compatibility with the resin (A) is deteriorated, which causes a decrease in the transparency of the resin. Furthermore, when the quaternary amino chloride monomer is more than the above ratio,
Dispersibility decreases, and blocking properties deteriorate.

The method of polymerizing the vinyl monomer and the quaternary amino chloride monomer is not particularly limited, and a known radical polymerization method can be employed. Specifically, these monomers can be copolymerized by a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, or the like. Among these polymerization methods, a solution polymerization method in which a polymerization reaction is performed in an organic solvent in the presence of an appropriate polymerization initiator is suitable. As the polymerization initiator at this time, a known initiator usually used in a radical polymerization reaction can be used, for example, azobisisobutyronitrile, benzoyl peroxide, tert-butyl perbenzoate, dicyclohexyl peroxide, Dicumyl peroxide, azobismethylbutyronitrile, azobisdimethylvaleronitrile and the like can be mentioned. At this time, the solvent to be used is not particularly limited as long as it is inert to various monomers to be used, and examples thereof include benzene, toluene, and xylene. In the method for polymerizing the polymer (B) of the present invention, since the monomers are simultaneously mixed and used as described above, the polymer (B) is considered to be a random copolymer.

The toner of the present invention contains a polymer obtained by copolymerizing a vinyl monomer and an amino monomer instead of the polymer (B) (herein, referred to as polymer (B ')). You may. The amino monomer constituting the polymer (B ′) is a monomer having an amino group that is not quaternized and is not particularly limited as long as it can be copolymerized with a vinyl monomer described below. For example, the following general formula (III):

Embedded image (Wherein, R ₁ represents hydrogen or a methyl group, R ₂ and R ₃ each independently represent hydrogen or an alkyl group having 1 to 20 carbon atoms, X represents an oxygen atom or a nitrogen atom, and Q represents an alkylene group or an arylene group. )).

Typical examples of amino monomers include N, N
-Dimethylaminomethyl (meth) acrylate, N, N-
Diethylaminomethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminobutyl ( (Meth) acrylate, p-N, N-dimethylaminophenyl (meth) acrylate, p-N, N-diethylaminophenyl (meth) acrylate, p-N, N-dipropylaminophenyl (meth) acrylate, p-N, N
-Dibutylaminophenyl (meth) acrylate, p-N
-Laurylaminophenyl (meth) acrylate, p-N
-Stearylaminophenyl (meth) acrylate, p-
N, N-dimethylaminobenzyl (meth) acrylate, p
-N, N-diethylaminobenzyl (meth) acrylate, pN, N-dipropylaminobenzyl (meth) acrylate, pN, N-dibutylaminobenzyl (meth) acrylate, pN-laurylaminobenzyl (meth) ) Acrylate, p-N-stearylaminobenzyl (meth) acrylate and the like. Further, N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, p- N, N-dimethylaminophenyl (meth) acrylamide, p-N, N
-Diethylaminophenyl (meth) acrylamide, p-
N, N-dipropylaminophenyl (meth) acrylamide, pN, N-dibutylaminophenyl (meth) acrylamide, pN-laurylaminophenyl (meth) acrylamide, pN-stearylaminophenyl (meth) acrylamide , PN, N-dimethylaminobenzyl (meth) acrylamide, pN, N-diethylaminobenzyl (meth) acrylamide, pN, N-dipropylaminobenzyl (meth) acrylamide, pN, N-dibutyl Examples include aminobenzyl (meth) acrylamide, pN-laurylaminobenzyl (meth) acrylamide, and pN-stearylaminobenzyl (meth) acrylamide.

The vinyl monomer constituting the polymer (B ') is not particularly limited as long as it is a monomer having a polymerizable unsaturated bond, and examples thereof include an acrylic monomer, a styrene monomer, and a vinyl monomer. No. Specifically, the same monomers as the vinyl monomers constituting the polymer (B) can be exemplified.

Preferred combinations of the above amino monomers and vinyl monomers include N, N-dimethylaminoethyl (meth) acrylate and styrene, N, N
-Dimethylaminoethyl (meth) acrylate and methyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate and butyl (meth) acrylate,
N, N-dimethylaminoethyl (meth) acrylate and butyl acrylate, N, N-dimethylaminoethyl (meth) acrylate and styrene and methyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate and styrene and butyl (Meth) acrylate,
N, N-dimethylaminoethyl (meth) acrylate, styrene, butyl acrylate, and the like.

The method for polymerizing the vinyl monomer and the amino monomer is not particularly limited, and a known radical polymerization method may be employed in the same manner as the polymerization method for the polymer (B). it can. In the method for polymerizing the polymer (B ′), the monomers are simultaneously mixed and used, so that the polymer (B ′) is considered to be a random copolymer.

The polymerization weight ratio of the vinyl monomer to the amino monomer in the polymer (B ') is 5: 5 to 7.5:
2.5, preferably 5.5: 4.5 to 7.2: 2.8. If the amino monomer is less than the above ratio, it is difficult for the obtained toner to maintain a sufficient charge amount,
Problems such as toner scattering occur. On the other hand, when the amino monomer is more than the above ratio, the polymer (B ′) in the resin (A)
When the obtained toner is used in a two-component developer, the carrier is frictionally charged with the toner. As a result, toner fog occurs in a non-image portion of an image. In addition, it causes the blocking resistance to decrease as the resin Tg decreases.

The weight average molecular weight (Mw) of the polymer (B) or the polymer (B ') as described above, which can be contained in the toner of the present invention, measured by gel permeation chromatography (GPC) is from 5,000 to 5,000. 200,00
0, preferably in the range of 10,000 to 150,000. The weight average molecular weight is 5,000
If it is less than 200, the charge distribution is poor and the charge distribution becomes broad, and image noise occurs. On the other hand, if it exceeds 200,000, the fixing property is lowered due to an increase in the resin Tg.

In the toner of the present invention, the polymer (B) or the polymer (B ′) has a dispersed particle size of 0.05 to 0.4 μm.
m, preferably 0.05 to 0.35 μm, more preferably 0.1 to 0.2 μm.
If the dispersed particle size is less than 0.05 μm, the dispersed particle size is too small to achieve a sufficient surface charging function. 0.4 μm
If it is larger, the dispersion diameter is too large and detachment from the toner surface occurs. The dispersed particle size can be determined by visual confirmation of a photograph by TEM morphological observation.

The content of the polymer (B) or the polymer (B ′) is 0.5 to 100 parts by weight of the resin (A).
It is desirably 4.5 parts by weight, preferably 1 to 4 parts by weight. If the amount is less than 0.5 parts by weight, the obtained toner does not reach a predetermined charge level. If the amount exceeds 4.5 parts by weight, the initial charge rising property and the charging stability deteriorate.

In the positively chargeable toner of the present invention, the polymer (B) or the polymer (B ') is contained in the resin (A).
And a quaternary ammonium salt. The quaternary ammonium salt contained in the present invention has a general formula (I);

Embedded image (In the formula, R ₁ is an alkyl group having 1 to 8 carbon atoms or a benzyl group, R ₂ and R ₃ are each independently an alkyl group having 1 to 18 carbon atoms, and R ₄ is a carbon atom. 1 to 18 alkyl groups or benzyl groups, and X and Y are each independently hydrogen or a hydroxyl group (but not simultaneously hydrogen). By using such a quaternary ammonium salt (herein, referred to as a quaternary ammonium salt (C)) together with the above-mentioned polymer (B) or polymer (B ′), initial charge rising property and charge stability can be improved. It is thought that it is possible to achieve sexual compatibility.

Among the above quaternary ammonium salts (C),
In formula (I), a quaternary ammonium salt in which R _{1 to} R ₄ are an alkyl group having 1 to 4 carbon atoms is preferable.

In the toner of the present invention, the quaternary ammonium salt (C) has a dispersed particle size of 0.05 to 0.4 μm, preferably 0.05 to 0.35 μm, more preferably 0.1 to 0.1 μm.
More preferably, it is dispersed at 2 μm. When the dispersion particle size is less than 0.05 μm, the dispersion particle size is too small, and there is a strong tendency that a sufficient surface charging function cannot be achieved.
If it is larger, the dispersion diameter is too large and detachment from the toner surface tends to occur. The dispersed particle size can also be determined by visual confirmation of a photograph by TEM observation, similarly to the dispersed particle size of the polymer (B) or the polymer (B ′).

The content of the quaternary ammonium salt (C) is desirably 0.1 to 2 parts by weight, preferably 0.5 to 1.5 parts by weight, per 100 parts by weight of the resin (A). 0.
If the amount is less than 1 part by weight, the initial charge rising property and charge stability are deteriorated, causing not only fog but also a decrease in blocking property. If the amount exceeds 2 parts by weight, the initial charge rising property and charge stability, especially the charge stability, are deteriorated, and it becomes impossible to withstand repeated use.

As described above, the polymer (B) or the polymer (B ′) and the quaternary ammonium salt (C) are contained in the resin (A) in specific amounts, respectively. The polymer (B) or the polymer (B ′) contains more than the quaternary ammonium salt (C). When the content of the polymer (B) or the polymer (B ′) is lower than that of the quaternary ammonium salt (C), the charging stability is significantly reduced.

In the present invention, the total content of the polymer (B) or the polymer (B ′) and the quaternary ammonium salt (C) is 5 parts by weight or less based on 100 parts by weight of the resin (A). Preferably, it is 1 to 4 parts by weight. If the total content exceeds 5 parts by weight, fogging occurs due to deterioration of the charging property, and a problem occurs. If the total content is less than 1 part by weight, it is difficult to reach a predetermined charging level.

The toner of the present invention contains a colorant, an anti-offset agent, a magnetic powder, a fluidizing agent, a cleaning agent and the like which are usually used in the toner within a range that does not impair the initial charge rising property and the charging stability that characterize the present invention. Can be appropriately blended.

The colorant used in the toner of the present invention is not particularly limited, and a colorant conventionally used in electrophotography can be used, and examples thereof include the following. Black pigments include carbon black, copper oxide,
Manganese dioxide, aniline black, activated carbon, ferrite, magnetite and the like can be used. As a yellow pigment, graphite, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navels yellow, naphthol yellow S,
Bunzer Yellow G, Bunzer Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, and the like can be used.

Examples of the red pigment include red lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indaslen brilliant orange RK, benzidine orange G, indaslen brilliant orange GK, bengala, cadmium red, lead red, permanent Red 4R, Risor Red,
Pyrazolone red, watching red, lake red C, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, alizarin lake,
Brilliant Carmine 3B, permanent orange GT
R, Vulcan Fast Orange GG, Permanent Red F4RH, Permanent Carmine FB and the like can be used. Blue pigments include navy blue, cobalt blue, alkaline blue lake, Victoria blue lake,
Phthalocyanine blue or the like can be used. The content of these coloring agents is not particularly limited, either,
Usually, the amount is 1 to 20 parts by weight, preferably 3 to 15 parts by weight based on 100 parts by weight of the resin (A).

As the anti-offset agent, polyethylene wax, polypropylene wax, oxidized polyethylene wax, oxidized polypropylene wax, carnauba wax, sasol wax, rice wax, candelilla wax, jojoba oil wax, beeswax wax and the like can be used. . The content of the offset preventing agent is set to 1 to 7 parts by weight, preferably 2 to 5 parts by weight based on 100 parts by weight of the resin (A).

As the magnetic powder, iron powder, iron oxide powder, ferrite, nickel and the like can be used.

When a fluidizing agent is used, silica fine particles, titanium dioxide fine particles, amylna fine particles, magnesium fluoride fine particles, silicon carbide fine particles, boron carbide fine particles, titanium carbide fine particles, zirconium carbide fine particles, boron nitride fine particles, titanium nitride fine particles. , Zirconium nitride fine particles, magnetite fine particles, molybdenum disulfide fine particles,
Fine particles of aluminum stearate, fine particles of magnesium stearate, fine particles of zinc stearate and the like can be used. It is desirable that these fine particles are used after being subjected to a hydrophobic treatment with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil, or the like. The amount of the fluidizing agent is 0.05 to 100 parts by weight of the toner.
It is desirable to use 5 parts by weight, preferably 0.1 to 3 parts by weight.

As a cleaning agent, styrene, acrylic, methacrylic, benzoguanamine, silicone, Teflon, polyethylene, etc. granulated by a wet polymerization method such as emulsion polymerization, soap-free emulsion polymerization, non-aqueous dispersion polymerization or a gas phase method. And various organic fine particles such as polypropylene can be used alone or in combination.

The toner of the present invention can be prepared by a conventionally known method, for example, in addition to the above resin (A), polymer (B) or polymer (B ′), and quaternary ammonium salt (C),
After adding a predetermined amount of the above coloring agent, anti-offset agent and other desired additives and mixing, melting and kneading,
It is obtained by crushing and classifying.

In producing the toner of the present invention, the quaternary ammonium salt (C) used has a volume average particle diameter of 1 to 3.
It is desirably 20 μm, preferably 2 to 10 μm. If the particle size is less than 1 μm, the dispersed particle size of the quaternary ammonium salt in the resulting toner tends to be too small to achieve a sufficient surface charging function.
If the ratio exceeds the above range, the dispersed particle size of the quaternary ammonium salt (C) in the obtained toner will be too large, and the toner will be easily separated from the toner surface.

In the present invention, a quaternary ammonium salt (C)
Is preferably used as a quaternary ammonium salt (C) -dispersed resin obtained by a masterbatch treatment with a styrene-acrylic resin or a polyester resin. That is, the toner of the present invention is preferably obtained by adding a quaternary ammonium salt-dispersed resin obtained by subjecting a quaternary ammonium salt (C) to a masterbatch treatment with a styrene-acrylic resin or a polyester resin. This is because the dispersibility of the quaternary ammonium salt (C) in the toner is further improved.

[0049] In the present specification, the master batch treatment refers to a treatment of melting and kneading a quaternary ammonium salt and a resin in order to uniformly disperse the quaternary ammonium salt in the resin. Specifically, a mixture of the quaternary ammonium salt (C) and a styrene-acrylic resin or a polyester resin is charged into an extrusion kneader such as a pressure kneader and kneaded. In the present invention, in order to further promote the uniform dispersion of the quaternary ammonium salt in the toner, the obtained kneaded product is cooled, and then has a volume average particle size of 1 to 20 μm, preferably by a pulverizer such as a feather mill. 5-20 μm
It is preferable to pulverize to a degree.

The resin used in the masterbatch treatment is not limited to the above-mentioned styrene-acrylic resin or polyester resin as long as it is compatible with the resin (A). For example, styrene-butadiene It may be a resin or an epoxy resin. The peak value of the molecular weight distribution of the weight average molecular weight of the resin measured by gel permeation chromatography (GPC) was 5,
000-200,000, preferably 10,000-1
Desirably, it is in the range of 50,000. If the peak value is less than 5,000, the initial charge rising property is deteriorated, and the charge distribution becomes broad. On the other hand, 200,
If it exceeds 000, the Tg of the resin increases, and the fixability decreases. The resin has a number average molecular weight (Mn) of 2,000 to 10,000, preferably 2,000.
７ 7000, weight average molecular weight / number average molecular weight (Mw / M
n) is 5 to 90, preferably 5 to 50, and the softening point (Tm)
Is from 110 to 130 ° C, preferably from 115 to 125 ° C, and the glass transition point (Tg) is from 50 to 75 ° C, preferably from 55 to 75 ° C.
It is desirable to be in the range of 70 ° C. In addition, when the resin used for the masterbatch treatment is hardly compatible with the resin (A), it is preferable to use the obtained quaternary ammonium salt-dispersed resin by pulverizing it to a volume average particle size of about 1 to 3 μm. .

When the quaternary ammonium salt (C) is used after being subjected to a master batch treatment, the weight ratio of the resin to the quaternary ammonium salt (C) is from 6: 4 to 8: 2, preferably 6.5: 3.5 to 7.5: 2.5. If the quaternary ammonium salt (C) is less than the above ratio, it is difficult for the obtained toner to maintain a sufficient charge amount, and problems such as toner scattering are likely to occur. On the other hand, when the quaternary ammonium salt is more than the above ratio, the dispersibility of the quaternary ammonium salt in the toner is reduced, so that the dispersed particle size of the salt becomes too large and detachment from the toner surface easily occurs. . For this reason, the initial charge rising property of the toner is deteriorated, and the charge amount of the toner is increased due to repeated use. When the toner is used in the two-component developing method, the frictional charging ability of the carrier with respect to the toner is reduced, and the image is formed. Fog occurs in the non-image area of the image.

The amount of the quaternary ammonium salt (C) -dispersed resin is not particularly limited as long as the amount of the quaternary ammonium salt contained in the toner is within the above-mentioned range. The amount is preferably 0.5 to 4 parts by weight, more preferably 1 to 3 parts by weight, based on 100 parts by weight of the resin (A). If the addition amount is less than 0.5 parts by weight, the initial charge rising property and charge stability are deteriorated, and fog is likely to occur. On the other hand, if the amount exceeds 4 parts by weight, the initial charge rising property and charge stability, particularly the charge stability, deteriorate, and it becomes difficult to withstand repeated use.

In producing the toner of the present invention, the quaternary ammonium salt (C) is added at the time of synthesizing the resin (A) regardless of whether the quaternary ammonium salt (C) is added as it is or is added after being subjected to a master batch treatment. Is particularly preferred. That is, the toner of the present invention is particularly preferably obtained by adding the quaternary ammonium salt (C) during the synthesis of the resin (A).

More specifically, in a preferred embodiment of the present invention, the toner of the present invention is obtained by preparing (i) a styrene-acrylic copolymer resin (A) containing no positive charge factor when the above-mentioned general formula (I) is synthesized. Adding a quaternary ammonium salt (C) represented by the following formula to obtain a resin (A) in which the quaternary ammonium salt (C) is dispersed; and (ii) at least the resin obtained in the step (i). A process of melting and kneading the above-mentioned polymer (B) or polymer (B ′) and the above-mentioned desired additive, and pulverizing and classifying the obtained kneaded product. can get.

In the step (i), when the quaternary ammonium salt (C) is synthesized at the time of the synthesis of the resin (A), specifically, the resin (A)
After the polymerization is completed, the resin (A) in which the quaternary ammonium salt (C) is dispersed is obtained before the post-treatment such as solvent evaporation and drying.

The polymerization method for the resin (A) is not particularly limited, and is the same as the polymerization method for the polymer (B), and a known radical polymerization method can be employed. In this embodiment, the quaternary ammonium salt (C) is added after the resin (A) is obtained by the above method. For example, when a solution polymerization method is adopted as the polymerization method of the resin (A), a quaternary ammonium salt (C) is added to the resin solution after the polymerization of the resin (A) is completed and before the solvent is distilled off. Mix well and evaporate the resulting mixture,
The resin (A) in which the quaternary ammonium salt (C) is uniformly dispersed is obtained. When an emulsion polymerization method is employed as the polymerization method for the resin (A), a quaternary ammonium salt is used after the polymerization of the resin (A) and before drying the filtered resin particles (the smaller the particle size, the better). (C) is added, mixed well, and the obtained mixture is dried to obtain a resin (A) in which the quaternary ammonium salt (C) is uniformly dispersed. In the case where the resin (A) is synthesized by another polymerization method, the addition of the quaternary ammonium salt (C) is performed according to the above-described example, but the resin (A) obtained by the above-described known polymerization method is used. ) Is once dissolved in an organic solvent, and then a quaternary ammonium salt (C) is added to the obtained resin solution, mixed well, and the mixture is evaporated to remove the quaternary ammonium salt (C). May be obtained uniformly dispersed resin (A).

In this embodiment, the quaternary ammonium salt (C) may be used as it is, but is preferably used as a quaternary ammonium salt dispersed resin obtained by a master batch treatment as described above.

In step (ii), at least the resin, polymer (B) or polymer (B ′) obtained in step (i), and other desired additives are melted and kneaded,
The obtained kneaded material is pulverized and classified. For the melting and kneading means, the pulverizing means and the classifying means, known means employed in a conventional pulverizing method can be employed.For example, after kneading with a twin-screw extruder and cooling, the kneaded material is cooled. A method of coarse pulverization, further fine pulverization by a jet pulverizer, and classification by an air classifier can be employed.

When the solution polymerization method is used as the polymerization method for the resin (A) in the step (i), the step (ii) is performed after the solvent obtained in the step (i) is distilled off as described above. After melting and kneading the resin, the polymer (B) or the polymer (B ′), and other desired additives, the kneaded material may be pulverized and classified for granulation, or may be used in the step (i). The polymer solution (B) or the polymer (B ′) and other desired components are added to the resin solution obtained in the process, without distilling off the solvent, in which the quaternary ammonium salt (C) is mixed and dispersed. Additives are added and mixed, and the obtained mixture is emulsified and dispersed in water to obtain an O / W emulsion. The emulsion is heated to evaporate the organic solvent, and the obtained resin particles are filtered and dried. You may make it granulate.

In this embodiment, the quaternary ammonium salt (C) is added during the synthesis of the resin (A) as described above, but when two or more resins are used as the resin (A), May be added at the time of synthesizing the resin. In this case, the resin to which the quaternary ammonium salt (C) is added preferably accounts for at least 50% by weight of the mixed binder resin of the resin (A).

The toner of the present invention obtained as described above has a volume average particle diameter of 6 to 10 μm, preferably 7 to 9 μm.
Is controlled.

The thus obtained positively chargeable toner of the present invention is excellent not only in initial charge rising property and charge stability but also in blocking property, and is evaluated by fixing strength and offset property. Excellent fixability. Further, when the toner of the present invention is used, noise such as fogging and filming hardly occurs on a copied image.

The toner of the present invention can be used in either a one-component developer using no carrier or a two-component developer used with a carrier, but is preferably used as a two-component developer. As the carrier used with the toner of the present invention, known carriers can be used, for example, iron powder, a carrier composed of magnetic particles such as ferrite, a coated carrier in which the surface of the magnetic particles is coated with a coating agent such as a resin, Alternatively, any of a dispersion type carrier obtained by dispersing a magnetic fine powder in a binder resin can be used. As such a carrier, those having a volume average particle size of 15 to 100 μm, preferably 20 to 80 μm are suitable. A preferred carrier in the present invention is a carrier having a charge point for the toner, that is, a negatively chargeable resin present on the surface. Such resins include polyester resins, polyolefin resins such as polyethylene,
Examples include a fluoropolymer resin such as a homopolymer of a fluorovinyl monomer such as tetrafluoroethylene and vinylidene fluoride or a copolymer with another vinyl monomer.
In particular, a carrier in which a polyolefin-based resin coating layer is formed by directly polymerizing an olefin monomer on the surface of a magnetic particle, or a carrier obtained by dispersing a magnetic substance fine powder in a polyester resin is used in combination with the toner of the present invention. It is preferable from the viewpoint of chargeability. The following examples illustrate the invention in more detail.

[0064]

EXAMPLES (Production of polymers B1 to B5) 1 liter of 4
In a mouth opening corben, 85 parts by weight of styrene (ST), 10 parts by weight of butyl methacrylate (BMA),
5 parts by weight of methacryloyloxytrimethylammonium sulfate (MTAS) represented by I)
0 parts by weight and azobisisobutyronitrile (AIB
N) After adding and dissolving 0.5 part by weight, under a nitrogen stream,
Reaction was carried out at 80 ° C. for 6 hours to carry out polymerization. Next, after distilling off the toluene, at 40 to 50 mmH at 180 to 190 ° C.
g and the volatile components were completely removed. The obtained polymer is a colorless and transparent solid, having a glass transition point (Tg) of 67 ° C.
The weight average molecular weight (Mw) was 45,000, and this polymer was designated as polymer B1. Also, polymers B2 to B5 were obtained in the same manner as in the method for producing polymer B1, except that the compounds shown in Table 1 were used in the amounts indicated. These Tg and Mw are summarized in Table 1. In addition, Mw was measured by gel permeation chromatography (GPC).

[0065]

[Table 1]

Example 1 parts by weight styrene-butyl acrylate-butyl methacrylate copolymer resin 55 (polymerization weight ratio 65:10:25, peak molecular weight distribution = 4500) styrene-butyl acrylate-butyl methacrylate Copolymer resin 45 (polymerization weight ratio 60:10:30, molecular weight distribution peak value = 150,000) ・ Carbon black (REGAL330; manufactured by Cabot) 6 ・ Polypropylene wax (Viscol 550P; manufactured by Sanyo Chemical) 3 ・ The above polymer B3 3.5-Quaternary ammonium salt 0.5 (Bontron P-51; manufactured by Orient Chemical Co., Ltd.)-Magnetic powder (magnetite BR-605; manufactured by Titanium Industry Co., Ltd.) 2 After sufficiently mixing the above raw materials with a Henschel mixer, 2
The mixture was kneaded with a screw extruder and cooled. Next, the kneaded material was coarsely pulverized, further finely pulverized by a jet pulverizer, and classified by an air classifier to obtain toner particles having a volume average particle diameter of 8 μm. To 100 parts by weight of the obtained toner particles, 0.2 part by weight of hydrophobic silica (R974; manufactured by Nippon Aerosil Co., Ltd.) was externally added and mixed to obtain a toner.

Example 2 A toner was obtained in the same manner as in Example 1, except that 4.0 parts by weight of the polymer B2 was used instead of the polymer B3. Example 3 A toner was obtained in the same manner as in Example 1, except that the polymer B4 was used instead of the polymer B3. Example 4 A toner was obtained in the same manner as in Example 1, except that 2.5 parts by weight of the polymer B3 and 1.5 parts by weight of the quaternary ammonium salt were used.

Example 5 A toner was prepared in the same manner as in Example 1, except that 3.0 parts by weight of the polymer B2 was used instead of the polymer B3, and 1.0 part by weight of the quaternary ammonium salt was used. I got Implementation
Example 6 A toner was obtained in the same manner as in Example 1, except that 2.5 parts by weight of the polymer B4 was used instead of the polymer B3 and 1.5 parts by weight of the quaternary ammonium salt was used.

Comparative Example 1 A toner was obtained in the same manner as in Example 1, except that 3.0 parts by weight of the polymer B1 was used instead of the polymer B3. Comparative Example 2 A toner was obtained in the same manner as in Example 1, except that 3.0 parts by weight of the polymer B5 was used instead of the polymer B3. Comparative Example 3 A toner was obtained in the same manner as in Example 1, except that 2.0 parts by weight of the polymer B3 was used and 3.0 parts by weight of the quaternary ammonium salt was used.

Comparative Example 4 A toner was obtained in the same manner as in Example 1, except that 7.0 parts by weight of the polymer B3 was used and 1.0 part by weight of the quaternary ammonium salt was used. Comparative Example 5 A toner was obtained in the same manner as in Example 1, except that 3.0 parts by weight of the polymer B3 was used and 5.0 parts by weight of the quaternary ammonium salt was used. Comparative Example 6 A toner was obtained in the same manner as in Example 1, except that 3.0 parts by weight of the polymer B3 was used and the quaternary ammonium salt was not used.

Comparative Example 7 A toner was obtained in the same manner as in Example 1, except that 0.5 parts by weight of the polymer B3 was used and 3.5 parts by weight of the quaternary ammonium salt was used. Comparative Example 8 A toner was obtained in the same manner as in Example 1, except that Polymer B was not used and that the above quaternary ammonium salt was used in an amount of 3.0 parts by weight.

Further, the following Examples and Comparative Examples were carried out using the following charge control agents C1 to C3, resins A1 to A3 and polymers B'1 to B'5.

(Production of Charge Control Agents C1 to C3) Parts by Weight Styrene-acrylic resin (Tg; 62 ° C., Tm; 130 ° C.) 70 Quaternary ammonium salt represented by the general formula (I) 30 (Bontron (P-51; manufactured by Orient Chemical Co., Ltd.) The mixture having the above composition was charged into a pressure kneader and kneaded. After cooling the obtained kneaded product, it was pulverized with a feather mill to obtain a quaternary ammonium salt-dispersed resin having a volume average particle size of 20 μm. The obtained dispersion resin is referred to as a charge control agent C1.

Also, a styrene-acrylic resin was replaced by a polyester resin (Tg; 58 ° C., Tm; 125 ° C.) except that a volume average particle size of 20 μm was used in the same manner as in the production method of the charge control agent C1. A quaternary ammonium salt dispersion resin was obtained. The obtained dispersion resin is referred to as a charge control agent C2.
As the charge control agent C3, the quaternary ammonium salt used in the production of the charge control agent B1 was used as it was (volume average particle size: 6 μm).

(Production of Resin A1) Into a 1-liter four-necked corben, 60 parts by weight of styrene (ST), 10 parts by weight of butyl acrylate (BA), and butyl methacrylate (BM)
A) 30 parts by weight, 50 parts by weight of toluene and 0.5 parts by weight of azobisisobutyronitrile (AIBN) were added and dissolved, and the mixture was reacted at 80 ° C. for 6 hours under a nitrogen stream to carry out polymerization. A solution was obtained. Next, after the toluene was distilled off, the pressure was reduced to 40 to 50 mmHg at 180 to 190 ° C,
Volatile components were completely removed. The glass transition point (Tg) of the obtained resin was 62 ° C., and the peak value of the molecular weight distribution measured by GPC was 150,000. The obtained resin was designated as resin A1.

(Production of Resin A2) To the resin solution obtained after the polymerization, 2.5 parts by weight of a charge controlling agent C1 was added and mixed for 3 minutes with a Henschel mixer, except that the mixture was subjected to solvent distillation. Resin A2 is produced in the same manner as in the method for producing A1.
I got The Tg and peak value of the resin before the addition of the charge control agent were the same as those of the resin A1. The amount of the charge control agent C1 is a value when the resin solution contains 55 parts by weight of the resin.

(Preparation of Resin A3) To the resin solution obtained after the polymerization, 0.75 parts by weight of a charge controlling agent C3 was added and mixed with a Henschel mixer for 3 minutes. Resin A in the same manner as in the production method of A1
3 was obtained. The Tg and peak value of the resin before the addition of the charge control agent were the same as those of the resin A1. The amount of the charge control agent C3 is a value when 55 parts by weight of the resin is contained in the resin solution.

(Production of Polymers B'1 to B'5) Into a 1-liter four-necked corbene, 90 parts by weight of styrene (ST), 10 parts by weight of dimethylaminoethyl methacrylate (DDMA), 50 parts by weight of toluene and 50 parts by weight of azo After adding and dissolving 0.5 parts by weight of bisisobutyronitrile (AIBN), the mixture was reacted at 80 ° C. for 6 hours in a nitrogen stream to carry out polymerization. Next, after distilling off toluene, the pressure was reduced to 40 to 50 mmHg at 180 to 190 ° C to completely remove volatile components. The obtained polymer is a colorless and transparent solid, having a glass transition point (Tg) of 72 ° C. and a weight average molecular weight (Mw) of 60,000.
This polymer was designated as polymer B′1. Table 2
Polymers B′2 to B′5 were obtained in the same manner as in the production method of the polymer B′1, except that the indicated amount of the compound was used. Table 2 summarizes these Tg and Mw.

[0079]

[Table 2]

Example 7 parts by weight Resin A1 55 Styrene-butyl acrylate-butyl methacrylate copolymer resin 45 (polymerization weight ratio 65:10:25, molecular weight distribution peak value = 4500, Tg = 58 ° C.) Carbon black (REGAL330; manufactured by Cabot Corporation) 7 ・ Polypropylene wax (Viscol 550P; manufactured by Sanyo Chemical Co., Ltd.) 3 ・ Charge control agent C1 2.5 ・ Polymer B′2 2 After sufficiently mixing the above raw materials with a Henschel mixer, 2
The mixture was kneaded with a screw extruder and cooled. Next, the kneaded material was coarsely pulverized, further finely pulverized by a jet pulverizer, and classified by an air classifier to obtain toner particles having a volume average particle diameter of 8 μm. To 100 parts by weight of the obtained toner particles, 0.2 part by weight of hydrophobic silica (R974; manufactured by Nippon Aerosil Co., Ltd.) was externally added and mixed.

Example 8 A toner was obtained in the same manner as in Example 7, except that polymer B′3 was used instead of polymer B′2. Example 9 A toner was obtained in the same manner as in Example 7, except that Polymer B'4 was used instead of Polymer B'2. Example 10 A toner was obtained in the same manner as in Example 7, except that Polymer B2 was used instead of Polymer B'2.

Example 11 A toner was obtained in the same manner as in Example 7, except that Polymer B3 was used instead of Polymer B'2. Example 12 A toner was obtained in the same manner as in Example 7, except that Polymer B4 was used instead of Polymer B'2. Example 13 using a charge control agent C2 instead of the charge control agent C1,
A toner was obtained in the same manner as in Example 7, except that polymer B′3 was used instead of polymer B′2.

Example 14 A toner was obtained in the same manner as in Example 13, except that Polymer B3 was used instead of Polymer B'3. Example 15 57.5 parts by weight of resin A2 was used instead of resin A1, no charge control agent C1 was added during the production of toner particles, and polymer B'3 was used instead of polymer B'2 A toner was obtained in the same manner as in Example 7, except for using. Example 16 A toner was obtained in the same manner as in Example 15, except that Polymer B3 was used instead of Polymer B'3.

Example 17 55.75 parts by weight of resin A3 was used instead of resin A1, no charge control agent C1 was added during the production of toner particles, and polymer was used instead of polymer B'2. A toner was obtained in the same manner as in Example 7, except that B′3 was used. Example 18 A toner was obtained in the same manner as in Example 17, except that Polymer B3 was used instead of Polymer B'3.

Comparative Example 9 A toner was obtained in the same manner as in Example 8, except that the amount of the polymer B'3 was changed to 4.5 parts by weight. Comparative Example 10 A toner was obtained in the same manner as in Comparative Example 9, except that 57.5 parts by weight of the resin A2 was used instead of the resin A1 and that the charge control agent C1 was not added during the production of the toner particles. Comparative Example 11 A toner was obtained in the same manner as in Example 7, except that Polymer B′1 was used instead of Polymer B′2.

Comparative Example 12 A toner was obtained in the same manner as in Example 7, except that polymer B′5 was used instead of polymer B′2. Comparative Example 13 A toner was obtained in the same manner as in Example 7, except that Polymer B1 was used instead of Polymer B'2. Comparative Example 14 A toner was obtained in the same manner as in Example 7, except that Polymer B5 was used instead of Polymer B'2.

Comparative Example 15 A toner was obtained in the same manner as in Example 11, except that the amount of the polymer B3 was changed to 4.5 parts by weight. Comparative Example 16 A toner was obtained in the same manner as in Comparative Example 15, except that 57.5 parts by weight of the resin A2 was used instead of the resin A1 and that the charge control agent C1 was not added during the production of the toner particles. Comparative Example 17 A toner was obtained in the same manner as in Example 8, except that the addition amount of the charge control agent C1 was changed to 7.0 parts by weight.

Comparative Example 18 A toner was obtained in the same manner as in Comparative Example 17 except that Polymer B3 was used instead of Polymer B'3. Comparative Example 19 55.75 parts by weight of resin A3 was used instead of resin A1, no charge control agent C1 was added during the production of toner particles, and polymer B′1 was used instead of polymer B′2. 3
A toner was obtained in the same manner as in Example 7, except that parts by weight were used. Comparative Example 20 A toner was obtained in the same manner as in Comparative Example 19, except that Polymer B′5 was used instead of Polymer B′1.

The toners obtained in Examples and Comparative Examples were
According to the following evaluation method, the initial charge rising property,
Each property of charging stability, fog, high-temperature offset property, fixing strength, and blocking property was evaluated. Table 3 ~
5 is shown. In addition, various manufacturing conditions are shown together. Further, the dispersed particle size of the polymer B or the quaternary ammonium salt in each toner was measured according to a measuring method described later, and is shown together.

[0090]

[Table 3]

[0091]

[Table 4]

[0092]

[Table 5]

[Evaluation Method] A developer was obtained by adjusting the amounts of the toner and the magnetic carrier so that the initial charge rising toner concentration was 5% by weight. 30 g of this developer was placed in a 50 cc plastic bottle. 120 rpm per minute
The charge amount (μC / g) of the toner after 3 minutes, 10 minutes, and 30 minutes after being put on a rotating base was measured, and ranked as follows. ：: The charge amount reached the saturation region in 3 minutes. Δ: The charge amount reached the saturation region in 10 minutes. X: Even after 30 minutes, the charge amount was not saturated and still increased and was not stable.

In measuring the charge amount, 1 g of the developer measured by a precision balance was placed on the entire surface of the conductive sleeve (1) of the charge amount measuring device shown in FIG. The rotation speed of the magnet roll (2) provided in the conductive sleeve (1) was set to 100 rpm. Then, a bias voltage of 2 KV was applied from the bias power source (3) with the same polarity as the charging potential of the toner, and the potential Vm at the cylindrical electrode (4) was read, and the potential Vm was attached to the cylindrical electrode (4) from the conductive sleeve (1). The weight of the toner was measured with a precision balance, and the average charge amount (μC / g) of each toner was determined.

Charge Stability The developer prepared at the time of the evaluation of the initial charge rise property was loaded into a copying machine (EP 9765: manufactured by Minolta Co., Ltd.).
The amount of charge of the toner after copying and after 10,000 copies was measured. The change in charge amount was ranked as follows. ：: The fluctuation width of the charge amount is less than 3 μC / g. Δ: The fluctuation of the charge amount is 3 μC / g or more and less than 5 μC / g. ×: The fluctuation width of the charge amount is 5 μC / g or more.

Fog The above developer was loaded into a copying machine (EP 9765, manufactured by Minolta Co., Ltd.) as a replenishing toner, and toner fog after copying 10,000 sheets was visually observed and ranked as follows. ：: Fog was hardly observed. Δ: Fog was slightly observed, but there was no actual use problem. ×: Fog was large and not suitable for actual use.

The high-temperature offset fixing roller was raised to about 240 ° C., and was ranked as follows according to the temperature at which the offset occurred. ：: no offset occurs at 240 ° C. Δ: No offset occurs below 220 ° C. X: Offset occurred below 220 ° C. The presence or absence of the offset was determined by visually observing the obtained image.

Fixing strength A black solid portion having an image density of 1.2 was rubbed with a Gakushin-type fastness tester (paper on the friction portion) three times, and the image density of the solid portion after the friction was measured. The following ranking was performed. However, fixing was performed at a roller temperature of 150 ° C. ：: Image density residual rate of 80% or more Δ: Image density residual rate of 70% or more and less than 80% ×: Image density residual rate of less than 70% The image density was measured by a Macbeth reflection densitometer RD-900.

After 10 g of the blocking toner was left in a high-temperature bath at 50 ° C. for 24 hours, the toner was visually checked. ：: 0 to less than 5 aggregates were observed. Δ: 5 to less than 10 aggregates were observed. X: Many aggregates were found (10 or more).

(Method of Measuring Dispersion Particle Size of Polymer B or B 'and Quaternary Ammonium Salt) The toner particles obtained in each of the Examples and Comparative Examples are mixed with an epoxy resin to cure the epoxy resin. The cured product was dyed in ruthenium vapor. The dyed cured product is cut with an ultramicrotome to prepare an ultrathin section, which is immersed in alcohol and then TEM (measurement apparatus; Hitachi H-800)
By analyzing the photograph by observation, the dispersed particle size of the polymer B or B 'and the quaternary ammonium salt was measured as an average value of about 20 particles. In addition, in the photograph by the TEM observation, the dispersed particles of the polymer B or B ′ are stained,
Also, the quaternary ammonium salt is dissolved in alcohol,
Where the salt was present, pores can be observed. Therefore, the dispersed particle size of the polymer B or B 'can be measured by measuring the particle size of the dyed particles, and the dispersed particle size of the quaternary ammonium salt can be measured by measuring the particle size of the pores. . (Method of measuring weight average molecular weight (Mw)) In the present specification, M
w is gel permeation chromatography (GPC)
Was measured by

(Manufacture of Carrier) Carriers used for evaluating the toners of Examples and Comparative Examples were manufactured as follows. Carrier compounding component: 100 parts by weight of polyester resin (number average molecular weight: 5000, weight average molecular weight: 115000, glass transition point: 67 ° C., softening point: 123 ° C.) 500 parts by weight of ferrite fine particles (MFP-2, manufactured by TDK Corporation) dispersion 3 parts by weight of colloidal silica (Aerosil # 200, manufactured by Nippon Aerosil Co., Ltd.) After thoroughly mixing the above ingredients with a Henschel mixer,
After melt-kneading with a twin-screw extruder, cooling, coarse pulverization, fine pulverization with a jet mill, and classification using an air classifier, a volume average particle size of 60 μm, and an electric resistance value of 5.
A dispersion type carrier of 8 × 10 ¹³ Ω · cm was obtained.

[0102]

As can be seen from the examples and comparative examples,
The positively chargeable toner of the present invention exhibits excellent initial charge rising property, charge stability and blocking property, hardly causes fogging or filming even after printing a large number of sheets, and is evaluated for fixing strength and high-temperature offset property. Excellent fixability. Further, by using the quaternary ammonium salt (C) in a masterbatch treatment, it is easier to achieve both the initial charge rising property and the charge stability, and furthermore, the quaternary ammonium salt (C) is synthesized with the resin (A). By adding the compound sometimes, the initial charge rising property and the charge stability are further improved.

[Brief description of the drawings]

FIG. 1 is a charge amount measuring device.

[Explanation of symbols]

1: conductive sleeve, 2: magnet roll, 3: bias power supply, 4: cylindrical electrode.

Claims (7)

[Claims] (A) Styrene containing no positive charge factor
Acrylic copolymer resin, (B) a polymer obtained by copolymerizing a vinyl monomer and a monomer having a quaternary amino group at a polymerization weight ratio of 7: 3 to 9: 1, or (B ′) a vinyl resin A polymer obtained by copolymerizing a monomer and an amino monomer at a polymerization weight ratio of 5: 5 to 7.5: 2.5; and (C) a general formula (I); (In the formula, R ₁ is an alkyl group having 1 to 8 carbon atoms or a benzyl group, R ₂ and R ₃ are each independently an alkyl group having 1 to 18 carbon atoms, and R ₄ is a carbon atom. A positively charged quaternary ammonium salt represented by 1 to 18 alkyl groups or benzyl groups, and X and Y each independently represent hydrogen or a hydroxyl group (but not simultaneously hydrogen). Toner having a content of the polymer (B) or the polymer (B ′) of the resin (A) 10
0.5 to 4.5 parts by weight with respect to 0 parts by weight, and the content of the quaternary ammonium salt (C) is 0.1 to 2 parts by weight with respect to 100 parts by weight of the resin (A). The copolymer (B) or the polymer (B ′) is contained more than the quaternary ammonium salt (C), and the total content of the polymer (B) or the polymer (B ′) and the quaternary ammonium salt (C) is contained. Resin (A) 1
A positively chargeable toner, wherein the amount is 5 parts by weight or less based on 00 parts by weight. 2. The positively chargeable toner according to claim 1, wherein the vinyl monomer in the polymer (B) or the polymer (B ′) is an acrylic monomer, a styrene monomer, or a mixture thereof. 3. The weight average molecular weight (Mw) of the polymer (B) or the polymer (B ′) measured by gel permeation chromatography is from 5,000 to 200,000.
The positively chargeable toner according to claim 1, wherein the toner is in a range of 0. 4. 4. The positively chargeable toner according to claim 1, wherein the dispersed particle size of the polymer (B) or the polymer (B ′) is 0.05 to 0.4 μm. . 5. The quaternary ammonium salt (C) having a dispersed particle size of 0.05 to 0.4 μm.
5. The positively chargeable toner according to any one of items 1 to 4. 6. The quaternary ammonium salt (C) is styrene-
The positively chargeable toner according to any one of claims 1 to 5, wherein the toner is obtained by adding a quaternary ammonium salt dispersed resin obtained by performing a masterbatch treatment with an acrylic resin or a polyester resin. 7. The quaternary ammonium salt (C) is converted to a resin (A).
2. A compound obtained by adding at the time of synthesizing.
A positively chargeable toner according to any one of claims 1 to 6.