JPH0862898A - Toner resin composition and toner - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a resin composition for a toner and a toner capable of obtaining a stable image even when a copying machine is used for a long period of time or under a severe environment. [Structure] A vinyl-based copolymer polymerized by a peroxide-based initiator is used as a main component, and 0.0001 to 3
Contains wt% diethyl dimethylsuccinonitrile.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner resin composition and toner used in electrophotography and the like, and more specifically to a toner used in a so-called dry developing method among electrostatic image developing methods. The present invention relates to a resin composition for toner and a toner.

[0002]

2. Description of the Related Art In order to control triboelectric chargeability, it has been practiced to add charge control agents such as dyes and pigments to toners for developers. This charge control agent imparts a positive charge or a negative charge to the toner, and is, for example, Japanese Patent Publication No. 41-20.
No. 153, Japanese Patent Publication No. 4-6397, Japanese Patent Laid-Open No. 53-12
Such charge control agents are disclosed in Japanese Patent No. 7726, JP-A-57-141452 and the like.

The compounds disclosed in such publications are sufficient in terms of performance as a charge control agent for toner, but they are not necessarily satisfactory in terms of high image quality, high durability, and stability due to environmental changes. Was not.

In recent years, in the field of copying, personalization has progressed, and there has been an increasing demand for high durability. The charge control agent is excellent in charge control ability and environmental stability in a short period, but it does not always stabilize the charge amount sufficiently when a copying machine is used for a long period of time or in a harsh environment. . Therefore, under such conditions, there is a problem that even if the charge control agent is used, the amount of charge changes and the image becomes unstable.

In order to solve these problems, Japanese Patent Laid-Open No.
Japanese Patent No. 313412 discloses a technique of incorporating tetramethylsuccinonitrile into a toner. However, since tetramethylsuccinonitrile has a high sublimation property, it adheres to an electronic component in a copying machine and damages a circuit or the environment. There were drawbacks such as causing pollution.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above problems of the prior art and to obtain a stable image even when a copying machine is used for a long period of time or in a harsh environment. Another object of the present invention is to provide a resin composition for toner and a toner that hardly cause pollution of a copying machine or the environment.

[0007]

The toner resin composition of the present invention is a toner resin composition containing as a main component a vinyl-based copolymer polymerized by a peroxide-based initiator. It is characterized by containing diethyldimethylsuccinonitrile in an amount of 0.0001 to 4% by weight based on the resin composition.

Further, the toner of the present invention is a toner containing a toner resin composition containing a vinyl-based copolymer polymerized by a peroxide-based initiator as a main component and a colorant, and is 0% to the toner. It is characterized by containing 0.0001 to 3% by weight of diethyldimethylsuccinonitrile.

In the present invention, if the content of diethyldimethylsuccinonitrile is too low, a stable image can be obtained even when the copying machine is used for a long period of time or when the copying machine is used in a harsh environment. However, if the content of diethyldimethylsuccinonitrile is too high, the basic performance of the toner will be deteriorated and odor will be generated during fixing. Therefore, the content of diethyldimethylsuccinonitrile is 0.
0001 to 4% by weight, preferably 0.001 to 1.0
It is set to the range of wt% and is 0.0001 for the toner.
˜3% by weight, preferably 0.001 to 0.8% by weight.

It is preferable that diethyldimethylsuccinonitrile is uniformly dispersed and contained in the toner.
Further, more preferably, diethyldimethylsuccinonitrile is previously dispersed in the toner resin composition. In this case, when the toner resin composition and the colorant are kneaded into a toner, diethyl dimethylsuccinonitrile is contained in the toner resin composition so that the toner content is 0.0001 to 3% by weight based on the toner.

The resin composition for toner used in the present invention contains a vinyl copolymer as a main component. The vinyl copolymer preferably contains a styrene monomer and / or a (meth) acrylic acid ester monomer as a constitutional unit. In addition to these monomers, other vinyl-based monomers may be included as a constituent unit.

Specific examples of the styrenic monomer include styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-ter-butylstyrene, pn-hexylstyrene, pn-octylstyrene, Examples thereof include pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4 dichlorostyrene.

Specific examples of the (meth) acrylic acid ester monomer include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate. , 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate,
Isobutyl methacrylate, n-octyl methacrylate,
In addition to alkyl esters of acrylic acid or methacrylic acid such as dodecyl methacrylate and stearyl methacrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylamino methacrylate Ethyl, 2-hydroxyethyl methacrylate, glycidyl methacrylate, bisglycidyl methacrylate, polyethylene glycol dimethacrylate,
Methacryloxyethyl phosphate and the like can be mentioned, and ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate and the like are particularly preferably used.

Other vinyl monomers include acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid and other acrylic acids and their α- or β-alkyl derivatives, fumaric acid, maleic acid, citraconic acid, Examples thereof include unsaturated dicarboxylic acids such as itaconic acid and monoester derivatives and diester derivatives thereof, succinic acid monoacryloyloxyethyl ester, succinic acid monomethacryloyloxyethyl ester, acrylonitrile, methacrylonitrile, and acrylamide.

The vinyl copolymer in the present invention is not particularly limited as long as it is a resin commonly used as a toner resin, but it is a low molecular weight polymer component and a high molecular weight polymer component or a gel component. It is preferable to include. The maximum value of the molecular weight distribution of the low molecular weight polymer component is 1 × 10 ^3.
It is preferably ˜8 × 10 ⁴ , and the maximum value of the molecular weight distribution of the high molecular weight polymer component is preferably 2 × 10 ⁵ to 2 × 10 ⁶ . The maximum of these molecular weight distributions is
It can be measured by gel permeation chromatography (GPC).

Further, the vinyl copolymer in the present invention preferably has a glass transition point of 50 ° C. or higher from the viewpoint of cohesiveness. The method for adjusting the vinyl-based copolymer is not particularly limited, but an appropriate polymerization method such as suspension polymerization, emulsion polymerization, solution polymerization, or bulk polymerization can be adopted.

The vinyl-based copolymer, which is the main component of the toner resin composition in the present invention, is a vinyl-based copolymer polymerized with a peroxide-based initiator. The inclusion of diethyldimethylsuccinonitrile is particularly effective.

As the peroxide type initiator for polymerizing the vinyl type copolymer, ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, methyl acetoacetate peroxide, acetylacetone peroxide and the like; Screw (t-
Butyl peroxy) 3,3,5-trimethylcyclohexane, n-butyl 4,4, -bis (t-butyl peroxy) valerate and other peroxy ketals; t-butyl hydroperoxide, cumene hydroperoxide, diisopropyl Benzene hydroperoxide,
Hydroperoxides such as P-methane hydroperoxide; Dialkyl peroxides such as di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide; acetyl peroxide, isobutyl peroxide, octanoyl peroxide , Benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, and other diacyl peroxides; diisopropyl peroxydicarbonate, di-n
-Peroxydicarbonates such as propylperoxydicarbonate, dimethoxyisopropylperoxydicarbonate, diallylperoxydicarbonate; t
Examples include peroxyesters such as -butyl peracetate, t-butyl peroxypivalate, t-butyl peroxybenzoate and cumyl peroxy octoate.

Other peroxide type initiators include acetylcyclohexyl sulfonyl peroxide and di-t-
Butyl peroxyhexahydroterephthalate and the like. With respect to the resin composition for a toner and the toner of the present invention, vinyl acetate, vinyl chloride, ethylene and the like can be copolymerized with a vinyl-based copolymer within a range that can achieve the objects and effects of the present invention. it can. Further, polymers of these monomers and other polymers may be blended with the vinyl copolymer. Further, a polyester resin or an epoxy resin may be mixed. Furthermore, an aliphatic amide, a bis-aliphatic amide, a metal soap, paraffin, etc. may be mixed.

Further, as long as the objects and effects of the present invention can be achieved, dyes such as Nigrosine and Spiron Black (manufactured by Hodogaya Chemical Co., Ltd.) as charge control agents, and other phthalocyanine-based pigments are added. be able to. Further, as the colorant, carbon black, chrome yellow, aniline blue or the like can be used. Further, low molecular weight polyethylene, polypropylene wax or the like may be added as a release agent, or hydrophobic silica or the like may be added to improve fluidity.

Further, 10 to 80% by weight of magnetic fine particles may be contained for use as a magnetic toner.

[0022]

The present invention is directed to a toner resin composition containing a vinyl copolymer polymerized by a peroxide initiator as a main component, and a toner containing the resin composition for toner and a colorant. Although various initiators other than peroxide-based initiators may be used, vinyls using peroxide-based initiators are generally used because they cannot give sufficient charging performance to the toner. The system copolymer is used as a resin for toner. Thus, as the polymerization initiator of the vinyl-based copolymer, a peroxide-based initiator is often used, but if a vinyl-based copolymer polymerized with the peroxide-based initiator is used, There is a problem that an image becomes unstable when a copying machine is used or in a harsh environment. As a result of various studies on this cause, the present inventors have found that the main factor thereof is the residue of the peroxide type initiator. In particular, it was found that benzoic acid, which is a decomposition product of benzoyl peroxide, has a great influence.

As a result of various studies on the method for removing the residues of these peroxide-based initiators, the present inventors have found that it is not necessary to completely remove these residues from the vinyl-based copolymer, and diethyl dimethylsuccinonitrile It has been found that the addition of a small amount of can stabilize the image even when the copying machine is used for a long period of time or in a severe environment. Thus, diethyl dimethylsuccinotitril is effective against the residue of the peroxide-based initiator,
It is considered that diethyldimethylsuccinotolyl has a function of trapping the residue of the peroxide-based initiator and suppressing the residual of the peroxide-based initiator from adversely affecting the stability of the image.

[0024]

Description of Examples Example 1 2 liters of toluene was placed in a 5 liter separable flask, the gas phase was replaced with nitrogen gas, and the system was heated to the boiling point of toluene.

800 g of styrene, 200 g of n-butyl acrylate and 200 g of toluene under reflux with stirring.
g and 30 g of t-butylperoxy 2-ethylhexanoate as a polymerization initiator were dissolved in 2.5 parts.
Solution polymerization was carried out while dropping the solution over time. After completion of dropping, while stirring at the boiling temperature of toluene,
After aging for 6 hours, a resin having a maximum molecular weight distribution of 20,000 was obtained.

A maximum value of 2 g was obtained by polymerizing 60 parts by weight of styrene and 40 parts by weight of n-butyl methacrylic acid, 400 g of a resin having a maximum molecular weight distribution of 600,000, and 0.2 g of diethyldimethylsuccinonitrile. Thousands of resins were put into a separable flask and mixed with stirring under reflux of toluene for 3 hours.

Then, while gradually raising the temperature of the system to 180 ° C., toluene was removed under reduced pressure to obtain a resin A having a glass transition point of 63 ° C. Resin A 100 parts by weight and carbon black (manufactured by Mitsubishi Kasei Co., Ltd., trade name: MA-100) 5
Parts by weight, 1 part by weight of Spiron Black TRH, and 3 parts by weight of PP wax (manufactured by Sanyo Kasei Co., Ltd .: Viscor 660P) are melt blended, coarsely pulverized after cooling, and further finely pulverized by a jet mill to obtain about 12 to 15 microns. A toner powder having an average particle size of

To the toner powder, 0.3 part by weight of hydrophobic silica powder (trade name: R-972, manufactured by Nippon Aerosil Co., Ltd.) was added to prepare a toner. This toner contains 0.013% by weight of diethyldimethylsuccinonitrile.

10 g of this toner was placed in a 100 ml sample bottle and left in a constant temperature bath at 50 ° C. for 16 hours.
When the degree of coagulation was measured with a powder tester (manufactured by Hosokawa Micron), no cohesiveness was observed.

4 parts by weight of this toner was mixed with 96 parts by weight of an iron powder carrier having an average particle size of about 50 to 80 microns to prepare a developer, and this developer was used to obtain a copy.
No offset was observed in the obtained image, and the image was sufficiently fixed even by rubbing with a finger. The electrophotographic copying machine used for this copying is a modification of DC-5055 manufactured by Mita.

A running test was conducted in a room at 25 ° C. and a humidity of 50%. As a result, even if 200,000 images were printed, the images were uniform and the density was sufficiently maintained. Furthermore, 40
When the same test was conducted on 100,000 sheets in a room at a temperature of 85 ° C. and a humidity of 85%, the image was uniform and a sufficient density was maintained.
In addition, we performed a long-term running test of 500,000 sheets,
No adhesion to electronic parts or environmental pollution was observed.

Example 2 2 liters of xylene was placed in a 5 liter separable flask, the gas phase was replaced with nitrogen gas, and the system was heated to the boiling point of xylene.

While refluxing xylene, while stirring, a solution of 830 g of styrene, 170 g of 2-ethylhexyl acrylate, 10 g of divinylbenzene and 30 g of benzoyl peroxide was added dropwise over 4 hours to carry out solution polymerization. I did. After completion of the dropping, the mixture was aged for 6 hours while stirring at the boiling temperature of xylene,
Then, add 5 g of diethyl dimethyl succinonitol,
The mixture was mixed while stirring under reflux of xylene for 3 hours.

Thereafter, while gradually raising the temperature of the system to 180 ° C., the solvent for xylene was removed under reduced pressure to obtain a glass transition point of 65 ° C., the maximum value of the molecular weight distribution was 20,000, and the gel content was 2%.
0% resin B was obtained.

100 parts by weight of the resin B obtained as described above and carbon black (trade name; M, manufactured by Mitsubishi Kasei Co., Ltd.)
A-100) 5 parts by weight, spirone black TRH 1 part by weight, and PP wax (manufactured by Sanyo Chemical Co., Ltd., trade name: VISCOL 660P) 3 parts by weight are melt-blended, coarsely pulverized after cooling, and further finely divided by a jet mill. About 12 to 15 after crushing
A toner powder having an average particle size of micron was made. To the toner powder, 0.3 part by weight of hydrophobic silica powder (trade name: R-972 manufactured by Nippon Aerosil Co., Ltd.) was added to prepare a toner. This toner contains 0.45% by weight of diethyldimethylsuccinonitrile.

10 g of this toner was placed in a 100 ml sample bottle and left in a constant temperature bath at 50 ° C. for 16 hours.
When the degree of coagulation was measured with a powder tester (manufactured by Hosokawa Micron), no cohesiveness was observed.

Further, when a developer was prepared in the same manner as in Example 1 and tested by a copying machine, no offset was found in the obtained image, and the image was sufficiently fixed even by rubbing with a finger.
In a running test at 25 ° C and 50% humidity, 4
Even in the running test at 0 ° C. and 85% humidity, the image was uniform and the density was sufficiently maintained.

Furthermore, a long-term running test was conducted on 500,000 sheets, but no adhesion to electronic parts or environmental pollution was observed.

Example 3 0.8 g of partially saponified polyvinyl alcohol was placed in a 5 liter separable flask, and 1200 ml of distilled water was added.
Dissolved in 300 g of styrene, acrylic acid n-
Butyl 80g, and benzoyl peroxide 0.4g
Was suspended and dispersed, and the gas phase was replaced with nitrogen gas, and then the temperature of this system was raised to 80 ° C. and maintained at 80 ° C. for 24 hours for polymerization. Then, the mixture was cooled to 40 ° C., a mixture of 700 g of styrene, 180 g of n-butyl acrylate and 30 g of benzoyl peroxide was dispersed therein, stirred for 3 hours at 40 ° C., and the temperature of the system was gradually raised to 80 ° C. . 8 more
After the temperature was maintained at 80 ° C. for polymerization, the system temperature was raised to 95 ° C. and maintained for 3 hours to complete the polymerization. Then cooling, dehydration,
After washing and drying, Resin C having maximum molecular weight distributions of 20,000 and 300,000 was obtained. The glass transition point of this resin C was 55 ° C.

100 parts by weight of the resin C obtained as described above and carbon black (trade name: M, manufactured by Mitsubishi Kasei Co., Ltd.)
A-100) 5 parts by weight, spirone black TRH 1 part by weight, PP wax (manufactured by Sanyo Kasei Co., trade name: Viscole 660P) 3 parts by weight, and diethyl dimethylsuccinonitol 0.05 parts by weight melt blended. After cooling, coarse pulverization is performed, and then fine pulverization is performed with a jet mill to obtain about 12 to 15
A toner powder having an average particle size of micron was made. To the toner powder, 0.3 part by weight of hydrophobic silica powder (trade name: R-972 manufactured by Nippon Aerosil Co., Ltd.) was added to prepare a toner. This toner contains 0.045% by weight of diethyldimethylsuccinonitrile.

10 g of this toner was placed in a 100 ml sample bottle and left in a constant temperature bath at 50 ° C. for 16 hours.
When the cohesion degree was measured with a Bowder tester (manufactured by Hosokawa Micron), no cohesiveness was observed.

Further, a developer was prepared in the same manner as in Example 1 and a copy test was conducted. No offset was observed in the obtained image, and the image was sufficiently fixed even if it was rubbed with a finger. In a running test at 25 degrees and 50% humidity, 40
Even in a running test at a temperature of 85 ° C and a humidity of 85%, the image was uniform and had a sufficient density.

Further, a long-term running test of 500,000 sheets was conducted, but no adhesion to electronic parts or environmental pollution was observed.

Comparative Example 1 A developer was prepared and tested in the same manner as in Example 1 except that diethyldimethylsuccinonitrile was not used in Example 1. As a result, neither cohesiveness nor offset was observed, and the image was sufficiently fixed even by rubbing with a finger. However, when a running test was performed in a room at 25 ° C. and a humidity of 50%, the image became non-uniform at 50,000 sheets and the image density became thin at 100,000 sheets. Furthermore, 40
When the same test was conducted in a room at a temperature of 85% and a humidity of 85%, the image became non-uniform after 40,000 sheets.

Comparative Example 2 A developer was prepared and tested in the same manner as in Example 2 except that diethyldimethylsuccinonitrile was not used in Example 2. As a result, neither cohesiveness nor offset was observed, and the image was sufficiently fixed even by rubbing with a finger. However, when a running test was carried out in a room at 25 ° C. and a humidity of 50%, the image density was reduced at 70,000 sheets. Further, when the same test was conducted in a room at 40 ° C. and a humidity of 85%, the image density became low after 50,000 sheets.

COMPARATIVE EXAMPLE 3 100 parts by weight of the resin prepared in Example 2 without using diethyldimethylsuccinonitrile was dissolved in 400 parts by weight of toluene, mixed well with 400 parts by weight of a 1N hydrochloric acid aqueous solution, and then separated to form an aqueous solution. I removed it. Similarly, the mixture was thoroughly mixed with a 1N sodium hydroxide aqueous solution and then separated to remove the aqueous solution. Further, the initiator residue was removed by washing with 400 parts by weight of distilled water three times. After that, toluene was further removed to obtain a resin. Using this resin, a developer was prepared and tested in the same manner as in Example 2. As a result, neither cohesiveness nor offset was observed, and the image was sufficiently fixed even by rubbing with a finger. However, when a running test was carried out in a room at 25 ° C. and a humidity of 50%, the image density became low at 100,000 sheets. Further, when the same test was conducted in a room at 40 ° C. and a humidity of 85%, the image density was reduced at 80,000 sheets.

Comparative Example 4 A developer was prepared and tested in the same manner as in Example 3 except that diethyldimethylsuccinonitrile was not used in Example 3. As a result, neither cohesiveness nor offset was observed, and the image was sufficiently fixed even by rubbing with a finger. However, when a running test was carried out in a room at 25 ° C. and a humidity of 50%, the image density was reduced at 60,000 sheets. When the same test was conducted in a room at 40 ° C. and a humidity of 85%, the image density became low after 40,000 sheets.

Comparative Example 5 A developer was prepared and tested in the same manner as in Example 3 except that 5 parts by weight was used instead of 0.05 parts by weight of diethyldimethylsuccinonitrile in Example 3. The obtained toner contains 4.4% by weight of diethyldimethylsuccinonitrile. As a result, no offset was recognized, and the image was sufficiently fixed even if it was rubbed with a finger. However, cohesiveness was observed and 25
When a running test was carried out in a room at a temperature of 50 ° C. and a humidity of 50%, the image was not uniform from the beginning. 40 ° C,
When the same test was performed in a room with a humidity of 85%, the image was not uniform from the beginning.

Comparative Example 6 A developer was prepared and tested in the same manner as in Example 2 except that tetramethylsuccinonitrile was used instead of diethyldimethylsuccinonitrile. In the obtained toner, tetramethylsuccinonitrile is
The content is 0.45% by weight. As a result, no offset was recognized, and the image was sufficiently fixed even if it was rubbed with a finger.
No toner cohesiveness was observed, and the temperature was 25 ° C and the humidity was 50%.
% Running test, humidity of 40%, 85%
The image was uniform and the density was sufficient in the test.

However, when a long-term running test was performed on 500,000 sheets, adhesion to electronic parts was observed and odor was accumulated in the copying machine.

[0051]

The resin composition for toner and the toner of the present invention have the constitution as described above, and the resin composition for toner contains a vinyl copolymer polymerized by a peroxide initiator as a main component. Since diethyl dimethylsuccinonitrile is contained in the toner or toner in an amount of 0.0001 to 4% by weight or 0.0001 to 3% by weight, respectively, even when a copying machine is used for a long period of time or in a harsh environment, It is possible to obtain a stable image. Moreover, contamination of the copying machine and the environment is unlikely to occur.

Claims (2)

[Claims] 1. A resin composition for a toner, comprising a vinyl-based copolymer polymerized by a peroxide-based initiator as a main component, which is 0.0001 to 4% by weight based on the resin composition for a toner. Thus, a resin composition for a toner, which contains diethyldimethylsuccinonitrile. 2. A toner containing a resin composition for a toner comprising a vinyl copolymer polymerized by a peroxide initiator as a main component and a colorant, wherein the toner is 0.0001 to 3% by weight with respect to the toner. A toner containing the above-mentioned diethyldimethylsuccinonitrile.