JP2001034005A - Additive for electrostatic charge image developing toner and toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an additive for an electrostatic charge image developing toner capable of giving an electrostatic charge image developing toner having enhanced releasability and excellent in blocking resistance while retaining such performances as fixability, image reproducibility, filming resistance, development durability and grindability and to obtain an electrostatic charge image developing toner excellent in said various characteristics. SOLUTION: The electrostatic charge image developing toner contains an additive for an electrostatic charge image developing toner comprising a styrene oligomer (A) containing 0.5-50 wt.% aliphatic component and a polyolefin wax (B) having 100-125 deg.C melting point measured by DSC, a bonding resin (C) and a colorant. The proportion of the additive is 1-30 pts.wt. based on 100 pts.wt. bonding resin C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an additive for a toner for developing an electrostatic image and a toner for developing an electrostatic image using the additive (hereinafter also referred to as an electrostatic toner).

[0002]

2. Description of the Related Art Electrophotographic developing materials, so-called electrostatic toners, are used in electrostatic electrophotography to develop a latent image formed by charge exposure to form a visible image. This electrostatic toner is a charged fine powder obtained by dispersing a colorant such as carbon black and a pigment in a resin. The electrostatic toner is a dry two-component toner used together with carriers such as iron powder and glass particles, a wet toner dispersed using an organic solvent such as isoparaffin, and a dry toner in which magnetic fine powder is dispersed. They are roughly classified into one-component toners.

An image obtained by developing on a photoreceptor with an electrostatic toner is transferred to paper, and an image obtained by direct development on paper on which a photosensitive layer is formed is kept as it is by heat or solvent. Established by steam. Above all, fixing by a heating roller is a contact-type fixing method, and therefore has advantages such as high thermal efficiency, the ability to reliably fix an image even with a relatively low-temperature heat source, and suitability for high-speed copying. are doing.

However, when an image is fixed by contacting a heating element such as a heating roller, a phenomenon that a part of the electrostatic toner adheres to the heating element and is transferred to a subsequent image portion, that is, a so-called offset phenomenon occurs. There is. In particular, when the temperature of the heating roller is low, the electrostatic toner cannot be sufficiently softened, and the offset phenomenon is easily caused at the same time as the fixing property to the printing paper or film is lowered.

In order to improve the fixing property and prevent the offset phenomenon, a releasing agent such as a polyolefin wax is blended into the toner to improve the releasing property. In this case, the melting point of the polyolefin wax is 100 ° C.
A relatively low value is generally used to prevent the offset phenomenon at the time of low-temperature fixing, that is, to improve the releasability at the time of low-temperature fixing.

However, it is difficult to increase the amount of polyolefin wax having a low melting point because the dispersibility in the toner tends to be insufficient. Therefore, the prevention of the offset phenomenon is limited, and the softness of the wax in the wax is limited. There is also a disadvantage that the components deteriorate the blocking resistance and storage stability of the toner. On the other hand, when a polyolefin wax having a melting point exceeding 100 ° C. is used, it is possible to increase the amount of addition to some extent without deteriorating the blocking resistance or the storage stability because the soft component is small, but in this case, Since the melting point of the polyolefin wax is high, the effect of preventing the offset phenomenon at the time of low-temperature fixing is small.

Japanese Patent Application Laid-Open No. 4-257868 describes an electrophotographic powder toner containing an aromatic petroleum resin, and describes that the toner is excellent in heat resistance and pulverization performance. In addition, the above publication describes that a release agent such as a polyolefin wax can be blended. However, in the electrostatic toner disclosed in the above publication, the dispersibility of the polyolefin wax is insufficient, and therefore, the offset phenomenon cannot be prevented by increasing the blending amount of the polyolefin wax. Further, since the color of the aromatic petroleum resin is very poor, there is a problem in toner image quality.

[0008] Further, in the example of JP-A-11-72956, an electrostatic toner containing an aliphatic hydrocarbon / aromatic hydrocarbon copolymerized petroleum resin and a polyethylene wax is described. The description states that this electrostatic toner has both pulverizability and heat preservability, improves offset resistance while maintaining low-temperature fixability, and does not cause adverse effects such as occurrence of image defects and deterioration of chargeability due to filming. Have been. In addition, the above publication describes that an aliphatic hydrocarbon / aromatic hydrocarbon copolymerized petroleum resin acts as a wax dispersion aid.

In the above publication, the melting point (caloric absorption peak) is 7
Although a relatively low temperature release agent of 0 to 100 ° C. is used as a preferable release agent, when the number average molecular weight of the binder resin is 5000 or less, even if the petroleum resin acts as a dispersing aid, The wax of the mold agent greatly reduces the cohesive force of the binder resin, and the toner particles are easily hardened, and the blocking resistance and the heat storage property are poor. Further, in the above publication, polypropylene wax having a melting point of 142 ° C. is described in Examples as a release agent. In this case, the wax is not melted because the melting point is high, and it is difficult to function as a release agent. There's a problem.

In the examples of JP-A-8-278658, an electrostatic toner containing a hydrogenated aromatic petroleum resin or a hydrogenated aliphatic petroleum resin and a natural wax is described. It is described that both are good. Further, JP-A-11-65161 describes an electrostatic toner containing a copolymer resin containing a styrene-based monomer and an indene-based monomer, and describes that the toner is excellent in pulverizability and fixability. However, in these toners, the effect of preventing the offset phenomenon is small because the petroleum resin does not exhibit sufficient performance as a wax dispersing aid.

[0011] On the other hand, with the speeding up and colorization of copiers, toners are being fixed at lower temperatures, and as a result, the molecular weight of the binder resin is decreasing. Such a binder resin reduces the cohesive force of the toner in order to give priority to low-temperature fixing, and as a result, the releasability, blocking resistance, and heat storage property are reduced, and these properties are balanced. Good improvement is required.

[0012] In the case of the conventional compounding of wax alone, the dispersion is extremely poor because the polarity is too different from that of the binder resin. Further, when the molecular weight of the binder resin is further reduced, there is a problem that a shearing stress is hardly applied at the time of kneading the toner compounding material, the dispersion of the wax is further deteriorated, and the toner performance is deteriorated.

As described above, with the conventional electrostatic toner, it is difficult to realize sufficient releasability at the time of low-temperature fixing, and there is a demand for improvement in dispersibility of the release agent. In particular, in the case of a color toner using a non-crosslinked low-softening viscosity type binder resin, it is necessary to incorporate a larger amount of a release agent in order to achieve oilless toner, and therefore, the dispersibility of the release agent is improved. Is required.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner for developing an electrostatic image containing a low molecular weight binder resin intended for low-temperature fixing, and has a fixing property, an image reproducibility and a filming resistance. , While maintaining performance such as development durability and pulverizability, an additive for an electrostatic image developing toner capable of obtaining an electrostatic image developing toner having improved releasability and excellent blocking resistance. To provide.
Another object of the present invention is to provide a toner for developing an electrostatic image, which contains the above-mentioned additive for toner and is excellent in the above characteristics.

[0015]

SUMMARY OF THE INVENTION The present invention relates to the following toner additive for developing electrostatic images and toner for developing electrostatic images. (1) Styrenic oligomer (A) containing 0.5 to 50% by weight of an aliphatic component and a melting point of 100 to 1 measured by DSC.
An additive for a toner for developing an electrostatic image comprising a polyolefin wax (B) at 25 ° C. (2) An additive for a toner for developing an electrostatic charge image, wherein the styrene-based oligomer (A) has a number average molecular weight measured by GPC of 400 to 3000 and a softening point temperature of 70 to 160 ° C. (3) The polyolefin wax (B) has an intrinsic viscosity [η] measured in a decalin solvent of 0.06 to 2 dl /
g of polyethylene wax, an additive for a toner for developing an electrostatic image. (4) The content of the styrene oligomer (A) is 10 to
99% by weight of an additive for a toner for developing an electrostatic image. (5) A toner for developing an electrostatic image, comprising 1 to 30 parts by weight of the additive for a toner for developing an electrostatic image based on 100 parts by weight of the binder resin (C). (6) An electrostatic image developing toner in which the binder resin (C) is an aromatic polyester resin or a polyether polyol resin having a number average molecular weight of 5000 or less as measured by GPC.

Specific examples of the polymerizable monomer constituting the styrene oligomer (A) used in the present invention include styrene, α-methylstyrene, vinyltoluene,
Isopropenyltoluene, p-methylstyrene, p-methoxystyrene, m-methylstyrene and the like. Of these, styrene, α-methylstyrene, vinyltoluene, and isopropenyltoluene are preferred in view of price, availability, and ease of polymerization. The styrene-based oligomer (A) may be one obtained by oligomerizing one of these styrene-based monomers alone or one obtained by combining two or more kinds thereof. Further, a copolymerized oligomer of a styrene monomer and another monomer, for example, indene, methylindene, ethylindene, dimethylindene, acenaphthene, a cyclopentadiene adduct of indene, tetracyclodecene, or the like may be used.

The styrene oligomer (A) may be an aromatic petroleum resin or a hydrogenated product thereof.

The aromatic petroleum resin is a homopolymer of an aromatic hydrocarbon monomer, a copolymer of aromatic hydrocarbon monomers, or a copolymer of an aromatic hydrocarbon monomer and another monomer. It means a petroleum resin containing an aromatic hydrocarbon monomer as a main component, such as a resin containing an aromatic hydrocarbon monomer as a main component. Examples of the copolymer of an aromatic hydrocarbon monomer and another monomer include an aromatic hydrocarbon / alicyclic hydrocarbon copolymer resin, an aromatic hydrocarbon / aliphatic hydrocarbon copolymer resin, and an aromatic hydrocarbon / aliphatic copolymer resin. Alicyclic hydrocarbons
Examples thereof include aliphatic hydrocarbon copolymer resins.

The aliphatic component contained in the styrenic oligomer may be one contained by copolymerization of a polymerizable aliphatic hydrocarbon monomer and a styrene monomer, or a mixture of an aliphatic hydrocarbon oligomer and a styrene oligomer. Some are included by

As the polymerizable aliphatic hydrocarbon monomer, a C 4 carbon by-produced during petroleum refining or petroleum cracking is used.
And polymerizable petroleum fraction-based monomers contained in the fractions Nos. 5 to 5. Specific examples thereof include 1-butene, 2-butene, isobutene, butadiene and the like for the C4 fraction; pentene, methylbutene, 1,3-pentadiene (piperylene), isoprene, cyclopentene and cyclopentadiene for the C5 fraction. Is raised. Besides the petroleum fraction, hexene-1, 4-methylpentene-1, 4-methylpentene-2 as the C6 component, octene-1, diisobutylene (trimethylpentene) and the like as the C8 component. The polymerizable aliphatic hydrocarbon monomers can be used alone or in combination of two or more. The aliphatic hydrocarbon-based oligomer is obtained by polymerizing one or more kinds of the polymerizable aliphatic hydrocarbon monomer.

The content of the aliphatic component in the styrene oligomer (A) is 0.1 to 50% by weight, preferably
It is 0.5 to 20% by weight. 0.1% by weight of aliphatic component
If less, the dispersion of the polyolefin wax will worsen,
The releasability is greatly reduced. On the other hand, if it exceeds 50% by weight, the blocking resistance, storage stability and pulverizability of the toner deteriorate.

As the styrenic oligomer (A), G
Petroleum resins having a number average molecular weight in terms of polystyrene measured by PC of 400 to 3,000, preferably 800 to 2,000 are preferred. The softening point temperature measured by the ring and ball method is 70 to 160 ° C, preferably 120 to 16 ° C.
Those in the range of 0 ° C. are preferred.

The styrenic oligomer (A) in which the aliphatic hydrocarbon monomer is copolymerized is excellent in the dispersibility of the polyolefin wax (B), so that an electrostatic toner excellent in the releasability can be obtained. When contained in the above preferred range, the fixing property, image reproducibility, filming resistance, development durability, crushability, blocking resistance, etc., while maintaining excellent low-temperature release properties and high-temperature release properties. Can easily be balanced with other performances.

The content ratio of the structural unit derived from each monomer can be determined by quantifying the residual monomer in the solution after polymerization by gas chromatography. Among the aromatic petroleum resins, the number average molecular weight as a polystyrene equivalent value measured by GPC is 400 to 300.
It is desirably 0, preferably 800 to 2000. The softening point temperature measured by the ring and ball method is 70 to 160.
C, preferably in the range of 120 to 160C.

The styrenic oligomer (A) can be produced by subjecting a monomer to a polymerization reaction in the presence of a cationic polymerization catalyst. As the cationic polymerization catalyst, a catalyst generally known as a Friedel-Crafts catalyst can be used. For example, various complexes of aluminum chloride, aluminum bromide, dichloromonoethylaluminum, titanium tetrachloride, tin tetrachloride, boron trifluoride, and the like can be given. The amount of the cationic polymerization catalyst used is desirably 0.01 to 5.0% by weight, preferably 0.05 to 3.0% by weight, based on the total amount of all the monomers.

At the time of the polymerization reaction, at least one selected from aromatic hydrocarbons, aliphatic hydrocarbons and alicyclic hydrocarbons is used in order to remove heat of reaction and to suppress the increase in viscosity of the reaction mixture. It is preferable to carry out the polymerization reaction in a hydrocarbon solvent. Preferred hydrocarbon solvents include aromatic hydrocarbons such as toluene, xylene, ethylbenzene, mesitylene, cumene, cymene, or mixtures thereof, or aliphatic hydrocarbons such as pentane, hexane, heptane, octane and / or cyclohexane. Examples thereof include a mixture with an alicyclic hydrocarbon such as pentane, cyclohexane, and methylcyclohexane. In the polymerization, the amount of the hydrocarbon solvent is preferably adjusted so that the initial concentration of the monomer in the reaction mixture is in the range of 10 to 70% by weight.

The polymerization temperature depends on the type of the monomer used and the type and amount of the catalyst.
It is preferable to carry out in the range of -50 ° C. The polymerization time is generally about 0.5 to 5 hours, and usually the polymerization is almost completed in 1 to 2 hours. As the polymerization mode, either a batch type or a continuous type can be adopted. Furthermore, multi-stage polymerization can be performed.

In the present invention, as the styrene oligomer (A), a hydrogenated product obtained by hydrogenating the above petroleum resin (hereinafter, referred to as a hydrogenated product).
(Sometimes referred to as hydrogenated petroleum resin). As the styrene oligomer (A), only a hydrogenated petroleum resin can be used, or a mixture of a non-hydrogenated petroleum resin and a hydrogenated petroleum resin can be used.

The hydrogenated petroleum resin is preferably a hydrogenated aromatic petroleum resin having an aromatic monomer having 9 or more carbon atoms, preferably 9 or 10 as a main component. When a hydrogenated aromatic petroleum resin having 9 or more carbon atoms is used, grindability,
An electrostatic toner having excellent wax dispersibility, heat storage properties, and blocking resistance can be obtained. Note that the number of carbon atoms includes carbon atoms constituting the aromatic ring.

Although the hydrogenation rate of the hydrogenated petroleum resin is not limited, the hydrogenation rate is 40% or more, preferably 50-100%.
% Is preferably used. The hydrogenation rate is
The iodine value of a non-hydrogenated petroleum resin was calculated as hydrogenation rate 1
It can be determined from the iodine value of the petroleum resin by using a calibration curve prepared with the hydrogenation rate of 0% for the hydrogenated petroleum resin that is completely hydrogenated at 00%.

The hydrogenation can be carried out by a known reduction method. For example, a hydrogenated petroleum resin can be obtained by contacting hydrogen and a petroleum resin under high temperature and high pressure using a heavy metal catalyst such as nickel, palladium, and platinum.

As the polyolefin wax (B),
Polyolefin waxes composed of α-olefins having 2 to 8, preferably 2 to 6 carbon atoms are preferred. The polyolefin wax may be a homopolymer or a copolymer of α-olefin. Specific examples of the α-olefin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene,
-Heptene, 1-octene and the like.

As the polyolefin wax, polyethylene wax and polypropylene wax are preferable in terms of price and mold release performance, and polyethylene wax is particularly preferable in terms of low melting point and low molecular weight. The polyolefin wax has an intrinsic viscosity [η] of 0.03 measured in decalin (decahydronaphthalene) at 135 ° C.
6 to 2 dl / g, preferably 0.06 to 0.5 dl / g
g, more preferably 0.06 to 0.10 dl / g. The number average molecular weight is 400 to 2000,
Preferably, those having 600 to 1500 are desirable.

135 ° C. as polyethylene wax
The intrinsic viscosity [η] measured in decalin is 0.06 to 2
dl / g, preferably 0.06-0.7 dl / g, more preferably 0.06-0.10 dl / g. When the intrinsic viscosity [η] of the polyethylene wax is in the above range, the toner is excellent in dispersibility, so that an electrostatic toner excellent in low-temperature release property and high-temperature release property can be obtained, and the melt viscosity is appropriate. It is possible to obtain an electrostatic toner that does not cause aggregation of the toner or contamination of the photoconductor.

Specific examples of polyethylene wax include those obtained by pyrolysis of high-pressure polyethylene; high-pressure polymerized polyethylene wax obtained by radical polymerization of ethylene at high pressure; medium- or low-pressure polymerization of ethylene using a transition metal compound catalyst. Ethylene and propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and 1-decene
And ethylene / α-olefin copolymers obtained by medium- or low-pressure polymerization of olefin with a transition metal compound catalyst. In any case, it is a necessary condition that the crystallinity measured by X-ray is 50% or more.

The polyolefin wax (B) has a melting point of at least 100 ° C. measured by a differential scanning calorimeter (DSC),
Preferably 100 ° C to 125 ° C, more preferably 105 ° C.
It is desirable that the temperature is 120 ° C. When the melting point of the polyolefin wax (B) is in the above range, an electrostatic toner having excellent blocking resistance can be obtained. Since the additive of the present invention is excellent in dispersibility of the polyolefin wax (B), a larger amount of a release agent (polyolefin wax (B)) can be blended than in the conventional electrostatic toner. Even if the polyolefin wax (B) having a melting point exceeding 100 ° C. is used, an electrostatic toner having excellent releasability in a low temperature range can be obtained.

In the additive of the present invention, the content of the styrene oligomer (A) and the content of the polyolefin wax (B) are 10 to 99% by weight, preferably 40 to 99% by weight, based on the total of both. It is desirable that the content is 60% by weight, the polyolefin wax (B) is 90 to 1% by weight, preferably 60 to 40% by weight. When the content is within the above range, it is possible to obtain an additive capable of obtaining an electrostatic toner excellent in low-temperature releasability and high-temperature releasability.

Since the additive of the present invention contains both the styrene oligomer (A) and the polyolefin wax (B), the styrene oligomer (A) is dispersed in the electrostatic toner by the dispersion of the polyolefin wax (B). As an agent, an electrostatic toner in which the polyolefin wax (B) is uniformly finely dispersed can be obtained. For this reason, the compounding amount of the additive can be increased, whereby an electrostatic toner having excellent low-temperature releasability and high-temperature releasability can be obtained. In this case, excellent performance is maintained without deteriorating performance such as fixability, image reproducibility, filming resistance, development durability, and crushability.

The electrostatic image developing toner (electrostatic toner) of the present invention comprises the additive (X), the binder resin (C) and the colorant (Z) of the present invention, and if necessary, a charge controlling agent. And the like.

The binder resin (C) is not particularly limited as long as it is a thermoplastic resin blended in this type of electrostatic toner. For example, styrene resin, styrene-acrylic acid copolymer resin, acrylic resin,
Styrene-butadiene resin, ketone resin, maleic acid resin, polyester resin, polyvinyl acetate resin, coumarone resin, phenol resin, silicone resin, polyurethane, epoxy resin, terpene resin, polyvinyl butyral, polybutyl methacrylate, polyvinyl chloride, polyethylene, Polypropylene, polybutadiene, ethylene-vinyl acetate copolymer, polyether polyol resin,
Rosin resin, epoxy resin and the like can be mentioned. Among these, a styrene resin, an acrylic resin, a polyester resin, which has good fixability at an appropriate softening point (90 ° C. to 120 ° C.),
And polyether polyol resins are particularly preferred.

The styrene resin used as the binder resin (C) is a homopolymer of styrene or a styrene derivative such as styrene, methyl styrene, ethyl styrene, dimethyl styrene, chloro styrene, vinyl naphthalene or the like, And copolymers with other α, β-unsaturated polymerizable monomers.

The acrylic resin used as the binder resin (C) includes methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, and t-acrylate.
tert-butyl, amyl acrylate, cyclohexyl acrylate, octyl acrylate, decyl acrylate, lauryl acrylate, stearyl acrylate, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-methyl methyl acrylate, methacryl Methyl acrylate, ethyl methacrylate, propyl methacrylate,
Α such as butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, decyl methacrylate, lauryl methacrylate, stearyl methacrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, phenyl methacrylate, and dimethylaminoethyl methacrylate; Methylene aliphatic monocarboxylic acid esters or derivatives thereof, homopolymers such as acrylonitrile, methacrylonitrile, acrylamide, and copolymers containing these as main components and other α, β-unsaturated polymerizable monomers, etc. Is given as an example.

The polyester resin used as the binder resin (C) includes dicarboxylic acid, tricarboxylic acid,
Those obtained by an esterification reaction between a polycarboxylic acid such as tetracarboxylic acid and a polyhydric alcohol such as diol and triol are exemplified. Examples of the polyhydric alcohol component include propyloxylated bisphenol A, ethylene glycol, glycerin, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,4-butanediol, and 1,6-hexanediol. , 1,4-cyclohexanedimethanol,
Examples include 1,4-cyclohexanediethanol, trimethylolethane, and trimethylolpropane. Examples of the polycarboxylic acid component include fumaric acid, maleic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, octylsuccinic acid, trimellitic acid, and pyromellitic acid. Acid, 1,2,4-cyclohexanetricarboxylic acid,
2,5,7-naphthalenetricarboxylic acid, 1,2,4-
Naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid and the like can be mentioned.

The additive for an electrostatic toner of the present invention has a number average molecular weight of 5,000 as measured by GPC as a binder resin.
The following polyester resins are preferred. In this case, the color toner has good low-temperature fixability and good flowability, so that the color reproducibility and brilliancy of an image after fixing are improved, and a toner additive is also used. The improvement of the offset resistance, which is the effect of (1), is remarkably improved as compared with the case where no additive is added. On the other hand, when the number average molecular weight of the polyester resin exceeds 5,000, the offset resistance effect is at a fairly good level even when the toner additive of the present invention is not added, but the cohesive force of the toner is increased, and the above-described color toner is used. , Fixability, color reproducibility, etc. decrease.

Examples of the polyether polyol resin used as the binder resin (C) include propyloxylated bisphenol A and ethyl oxylated bisphenol A
Compounds obtained by glycidylation of such compounds with epichlorohydrin or β-methylepichlorohydrin are reacted with dihalides, diisocyanates, diamines, dithiols, polyhydric phenols or dicarboxylic acids, and the like.

As the binder resin (C), it is possible to obtain an electrostatic toner for color having excellent durability, pulverizability, image quality, storage properties and toner fluidity. Particularly preferred. The binder resin (Y) has a melt flow rate at 125 ° C. (2.14 kg load) of 1 to 100 g / 10 minutes measured according to JIS K 7210, and a glass transition temperature of 50 to 70 ° C. measured by DSC. Are preferred.
The number average molecular weight measured by GPC is desirably 5,000 or less.

The colorant (Z) may be any one as long as it is compounded in this type of electrostatic toner for color, and is not particularly limited. Examples include pigments or dyes such as carbon black, phthalocyanine blue, aniline blue, alcohol oil blue, chrome yellow, ultramarine blue, quinoline yellow, lamp black, rose bengal, diazo yellow, rhodamine B lake, carmine 6B, and quinacridone derivatives. Can be The colorant (Z) can be used alone or in combination of two or more.

The mixing ratio of each component constituting the electrostatic toner of the present invention is 1 to 10 parts by weight, preferably 1 to 6 parts by weight of the colorant (Z) with respect to 100 parts by weight of the binder resin (C). 0 to 5 parts by weight, preferably 0.5 to 2 parts by weight of a charge controlling agent;
1 to 30 parts by weight, preferably 10 parts by weight of the additive (X) of the present invention
-20 parts by weight. In this case, up to about 15 parts by weight of the polyolefin wax (B) can be blended in the electrostatic toner. If the polyolefin wax (B) is blended in a large amount in the electrostatic toner, for example, if it is blended in an amount of 30 parts by weight, the dispersibility of the wax is extremely deteriorated. Also, the image quality deteriorates, and it is impossible to use the toner as an electrostatic toner.

The electrostatic toner of the present invention may optionally contain a charge control agent, a plasticizer, a release agent other than the polyolefin wax (B), and the like. As the charge control agent to be blended in the electrostatic toner, one having an action of controlling the amount of charge generated by friction between the toner particles and the carrier can be used, and any one that is blended in this type of color electrostatic toner can be used. Any material may be used, and there is no particular limitation. For example, nigrosine dye, triphenylmethane dye,
Chromium-containing metal complex dye, molybdate chelate pigment,
Rhodamine dyes, alkoxy amines, quaternary ammonium salts, alkylamides, simple substances or compounds of phosphorus, salicylic acid metal complexes, and the like. The charge control agent contains oil-soluble dyes such as azine-based nigrosine, indulin, azo-based dyes, anthraquinone-based dyes, triphenylmethane-based dyes, xanthene-based dyes, and phthalocyanine-based dyes for complementary colors and charge control. You may.

The electrostatic toner of the present invention can be used as any one of a two-component electrostatic toner and a one-component electrostatic toner. When the electrostatic toner of the present invention is used as a two-component electrostatic toner, the two-component electrostatic toner contains a binder resin (C), a colorant (Z), an additive (X) of the present invention, and Charge control agent and other components to be blended according to
After mixing by a known method using a ball mill, an attritor, etc., kneading is performed using a heated two-roll, heating kneader, twin-screw extruder, etc., followed by cooling and solidification, and further, the obtained solidified product is hammer mill, crusher, etc. After crushing using
Jet mill, vibratory mill, or finely pulverize by adding water and using a ball mill, attritor, etc.
μm, preferably 7 to 15 μm, and a two-component electrostatic toner can be prepared by adding a carrier to the pulverized product. The finely pulverized product having a specific average particle size can be obtained by classifying the finely pulverized product with a classifier. The carrier used may be a known carrier and is not particularly limited.
Examples thereof include silica sand, glass beads, iron balls, and magnetic material powders such as iron, nickel, and cobalt having a particle size of 200 to 700 μm.

In the case of this two-component electrostatic toner, the amount of the additive (X) of the present invention is 1 to 30 parts by weight, preferably 10 to 20 parts by weight, per 100 parts by weight of the binder resin (C). Department.

When the electrostatic toner of the present invention is used as a one-component electrostatic toner, the one-component electrostatic toner is
A binder resin (C), a colorant (Z), a charge control agent and the additive (X) of the present invention, and a magnetic material powder, other additives and other thermoplastic resins blended as necessary,
It can be prepared by processing according to the same method as the preparation of the two-component electrostatic toner.

The amount of the additive (X) of the present invention in the one-component electrostatic toner is 1 to 30 parts by weight, preferably 10 to 20 parts by weight, per 100 parts by weight of the binder resin (C). It is an amount that becomes a ratio.

As the magnetic material powder to be blended with the one-component electrostatic toner, a fine powder of magnetite having a particle size of 1 μm or less is usually used, but metals such as cobalt, iron, nickel and the like, alloys thereof, Powders such as oxides, ferrites, and mixtures thereof can also be used. The compounding amount of the magnetic material powder in this one-component electrostatic toner is:
The resulting electrostatic toner does not have a low electric resistance, has a good charge retention of the electrostatic toner, has no image bleeding, and has a softening point in an appropriate range, so that the fixing can be suitably performed. Further, the amount is usually 40 to 120 parts by weight of the magnetic material powder with respect to 100 parts by weight of the binder resin (C) in that a required charge value is obtained and scattering is difficult. A known charge control agent may be added to the two-component electrostatic toner or the one-component electrostatic toner as needed.

The additive of the present invention can be easily used as a component of a so-called polymerized toner because it can be easily made into an aqueous dispersion of fine particles by itself or by adding an emulsifier such as a surfactant. It is also suitable for

[0056]

The additive for a toner for developing an electrostatic image of the present invention contains an aliphatic component-containing styrenic oligomer and a polyolefin wax.
It is possible to obtain a toner for developing an electrostatic charge image having improved low-temperature release properties and high-temperature release properties while maintaining properties such as filming resistance, development durability, and pulverizability, and also having excellent blocking resistance. . The toner for developing an electrostatic image of the present invention,
Since it contains the above additives, fixability, image reproducibility,
While maintaining performance such as filming resistance, development durability, and pulverizability, low-temperature releasability and high-temperature releasability are improved, and blocking resistance is excellent.

[0057]

Next, an embodiment of the present invention will be described. Table 1 shows the aliphatic component-containing styrenic oligomer (A), and Table 2 shows the polyolefin wax (B).
The following was used. The binder resin (C) shown in Table 3 was used (see Synthesis Example 1).

[0058]

[Table 1] * 1 Softening point: Measured by the ring and ball method according to JIS K 2207. * 2 Molecular weight: Number average molecular weight (Mn) was measured using gel permeation chromatography (GPC) under the following conditions. Solvent: Tetrahydrofuran (flow rate: 1.0 ml / min, sample concentration: 0.25% by weight) Temperature: 40 ° C. Column: TSK gel G7000HXL, manufactured by Tosoh Corporation, TSK gel G4000HXL, manufactured by Tosoh Corporation Two, manufactured by Tosoh Corporation , TSK gel G2000HXL Tosoh Corporation, TSK guard column HXL detector; SHOdex RI-71S

[0059]

[Table 2]

Synthesis Example 1 << Synthesis of Binder Resin (C) >> Polyoxypropylene (2,
2) 1,191 g of 2,2-bis (4-hydroxyphenyl) propane, 9 g of trimethylolpropane, 71 g of benzoic acid, 452 g of terephthalic acid, 50 g of adipic acid and 5 g of dibutyltin oxide were mixed with 4 liters of glass.
The flask was placed in a two-necked flask, equipped with a thermometer, a glass nitrogen introduction tube, a stainless steel stirring rod, and a dehydration tube equipped with a reflux condenser, and stirred at 240 ° C. in a heating mantle under a nitrogen stream and xylene reflux. While reacting. The reaction was followed while measuring the acid value, and when the acid value reached a predetermined value, dexylene was performed under reduced pressure of about 20 mmHg to terminate the reaction. Table 3 shows the physical properties of the obtained polyester resin.

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[Table 3] * 1 MFR: Measured under the conditions of 125 ° C. and a load of 2.14 kg according to the melt flow rate, JIS K7210. * 2 Glass transition temperature: Measured using DSC according to ASTM D3418-75. * 3 Acid value: Measured according to JIS K5902. * 4 Hydroxyl value: Measured by potentiometric titration after acetylation. * 5 Molecular weight: See Table 1 * 6 Softening start temperature: Load = 2 using a flow tester
The measurement was performed under the conditions of 0 kg and a heating rate of 6 ° C./min.

Examples 1 to 11 and Comparative Examples 1 to 6 << Preparation of Additive (X) >> The styrene oligomer (A) shown in Table 1 and the polyolefin wax (B) shown in Table 2 were used in combination as shown in Table 4. At 150 ° C,
The mixture was melted and kneaded in a stirring drum under a normal pressure of nitrogen blow and then pulverized (average particle size: 500 μm) to obtain an additive for a toner for developing an electrostatic image.

<< Preparation of Toner >> 100 parts by weight of the polyester resin synthesized in Synthesis Example 1 as the binder resin (C), 6 parts by weight of a yellow pigment (CI pigment Yellow 12) as the colorant (Z), and aromatic as the charge control agent 1.0 part by weight of a quaternary ammonium salt type, and an additive (X) for toner shown in Table 4
20 parts by weight or 10 parts by weight (corresponding to 16% by weight or 8% by weight as the content in the toner) was preliminarily mixed with a Henschel mixer, and then kneaded at 100 ° C. using a hot roll. Thereafter, the mixture was cooled, coarsely pulverized, and further classified by a classifier to obtain a toner having a particle size of 9.0 μm (50% average particle diameter).

Next, hydrophobic silica (R-972, manufactured by Aerosil Co., Ltd.) was externally added to the above toner at a ratio of 0.5% by weight, and mixed with a Henschel mixer to obtain a toner. A two-component electrostatic toner was prepared by mixing 100 parts by weight of iron powder having an average particle diameter of 50 to 80 μm as a carrier with 10 parts by weight of the toner.

<Evaluation> The fixing property of the fixed image, the offset resistance, the blocking resistance, the image reproducibility, the filming resistance, the development durability, and the pulverizability of the fixed image were evaluated by the following methods. evaluated. Table 4 shows the results.

(1) Fixability of Fixed Image A test image is copied and developed on a selenium photosensitive member by electrophotography using an electrostatic toner. The obtained image was transferred to transfer paper, and a fixing roller having a surface formed of polytetrafluoroethylene (manufactured by DuPont) and a surface formed of silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., KE-1300RTV) were used. Fixing speed is 50mm using pressure roller
/ Sec, and the temperature of the fixing roller was changed by 5 ° C. at a time to fix the image. The surface of the obtained fixed image is
The bottom with a load of 00 g was rubbed 10 times with a 15 mm × 7.5 mm sand eraser (Tonbo Pencil), and before and after that, the optical reflection density of the surface was measured with a Macbeth reflection densitometer. The fixability of the fixed image was calculated according to the following. Fixability (%) = {(image density after rubbing) / (image density before rubbing)} × 100

The lowest fixing temperature at which the rate of change of the image density at each temperature became 70% or more was defined as the lowest fixing temperature.
The evaluation criteria are as follows. The heat roller fixing device used here is a fixing device usually used in a color copier, and does not have a silicone oil supply function for preventing offset. The environmental conditions are
Normal temperature and normal pressure (temperature 22 ° C., relative temperature 55%). ：: Minimum fixing temperature = less than 90 ° C. Δ: Minimum fixing temperature = 90 ° C. or more and 120 ° C. or less X: Minimum fixing temperature = more than 120 ° C.

(2) Offset Resistance An unfixed image is formed on the same copying machine used for the fixing property of the fixed image in (1), and then the toner image is transferred to the same heat roller as in (1). The fixing process is performed by the fixing device, and then the blank transfer paper is sent to the heat roller fixing device under the same conditions, and whether or not the toner is stained on the transfer paper is visually observed. This operation is repeated while the set temperature of the heat roller of the heat roller fixing device is sequentially raised or lowered, and the highest set temperature in the low temperature range or the lowest set temperature in the high temperature range where toner contamination occurs occurs in that temperature range. At the offset occurrence temperature. The evaluation criteria are as follows. The environmental conditions were normal temperature and normal pressure (temperature 22 ° C., relative humidity 55%). [Low temperature range] ○: Offset occurrence temperature in low temperature range is less than 85 ° C △: Offset occurrence temperature in low temperature range is 85 ° C or more and 95 ° C
Less than ×: Offset occurrence temperature in low temperature range is 95 ° C. or more [High temperature range] ○: Offset occurrence temperature in high temperature is 160 ° C. or more △: Offset occurrence temperature in high temperature is 140 ° C. or more 160
Less than ° C ×: Offset occurrence temperature at high temperature is less than 140 ° C

(3) Blocking Resistance After leaving the electrostatic toner for 48 hours under environmental conditions of a temperature of 45 ° C. and a relative humidity of 50%, 5 g of the toner was placed on a 150-mesh sieve. Set the scale of the rheostat to 3, and vibrate for 1 minute. Measure the weight remaining on the 150 mesh sieve after vibration,
The residual weight ratio was determined. The evaluation criteria are as follows. ：: less than 20% △: 20% or more and 35% or less ×: more than 35%

(4) Image Reproducibility The line width before fixing on paper and the line width after fixing are measured at five points.
The average was calculated and compared. The evaluation criteria are as follows. ：: The line width after fixing is 9 times wider than the line width before fixing.
smaller than μm Δ: line width after fixing is 9 compared with line width before fixing
μm or more and 15 μm or less ×: The line width after fixing is wider than the line width before fixing by 1
Greater than 5 μm

(5) Filming Resistance After performing a continuous printing test for 100,000 sheets continuously by the above copying machine, the surface of the carrier particles, the surface of the photoreceptor, and the cleaning blade were visually observed, and the adhered substance was observed. Was determined by the presence or absence of The evaluation criteria are as follows. ：: no deposit is observed △: slight deposit is observed ×: deposit is considerably observed

(6) Development Durability After performing the same actual photographing test as the filming resistance test,
Evaluation was made based on the image density and the number of sheets at which the image quality began to deteriorate. The evaluation criteria are as follows. ：: Does not deteriorate even if it exceeds 70,000 sheets △: Deteriorates after 50 to 70,000 sheets ×: Degrades when less than 50,000 sheets

(7) Pulverizability With a jet pulverizer, the conditions such as the pulverizing pressure and the feed rate are kept constant, and the yield per fixed time to obtain a volume average particle size of 9.0 μm (yield / feed amount × 100%) ) Is styrene oligomer (A), polyolefin wax (B)
The ratio is used as an index based on the pulverization yield of the toner when not used. The evaluation criteria are as follows. ： １: 1.3 times or more △: 1.0 times or more and less than 1.3 times ×: less than 1.0 time

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[Table 4]

Claims (6)

[Claims] 1. A styrenic oligomer (A) containing 0.5 to 50% by weight of an aliphatic component and having a melting point of 1 as measured by DSC.
An additive for developing an electrostatic image, comprising a polyolefin wax (B) having a temperature of from 00 to 125 ° C. 2. The styrene oligomer (A) has a number average molecular weight of 400 to 3,000 as measured by GPC,
The additive for a toner for developing electrostatic images according to claim 1, wherein the softening point temperature is 70C to 160C. 3. The electrostatic image development according to claim 1, wherein the polyolefin wax (B) is a polyethylene wax having an intrinsic viscosity [η] of 0.06 to 2 dl / g measured in a decalin solvent. Additive for toner. 4. The additive according to claim 1, wherein the content of the styrene oligomer (A) is 10 to 99% by weight. 5. A binder resin (C) based on 100 parts by weight,
A toner for developing an electrostatic image, comprising 1 to 30 parts by weight of the toner additive for developing an electrostatic image according to any one of claims 1 to 4. 6. The electrostatic charge according to claim 5, wherein the binder resin (C) is an aromatic polyester resin or a polyether polyol resin having a number average molecular weight measured by GPC of 5,000 or less. Image developing toner.