KR20140097018A - Electrostatic charge image developing toner, developer and image forming apparatus - Google Patents

Abstract

Provided in the present invention is a toner with excellent storage stability and with fixing properties at low temperature, while having an excellent image quality like less blur of the image. An electrostatic developing toner of the present invention can be easily produced at a low cost and the toner is manufactured with a toner material including at least a coupling resin, a colorant, and one or more kind of inorganic filler selected from a group composed of calcium carbonate, kaolin clay, talc, and barium sulfate, and the toner has a glass transition temperature in a range of 50-58 °C. In addition, the ″parts by weight″ of the inorganic filer is 1~10 for 100 ″parts by weight″ of the toner. The inorganic filer existed on the surface of the toner base particles is within 5-40% range against the content of the inorganic filer.

Description

TECHNICAL FIELD [0001] The present invention relates to an electrostatic latent image developing toner, a developer for electrostatic latent image development, and an image forming apparatus using the electrostatic latent image developing toner,

The present invention relates to an electrostatic latent image developing toner, an electrostatic latent image developing developer, and an image forming apparatus which are excellent in storage stability, low temperature fixability, and are excellent in image quality with less image fogging.

Generally, a toner used in an electrophotographic copying machine, a printer, or the like is a mixture composed of a plurality of materials such as a colorant, a releasing agent, and a charge control agent with a binder resin as a main component. With respect to the pulverized toner, such a raw material is usually melt-kneaded, and this melt-kneaded product is pulverized and classified to obtain a toner of desired particle diameter.

Among the raw materials constituting the toner, the proportion of the binder resin usually accounts for 80 to 90% by weight, and most of the components in the toner are made of plastic. In recent years, measures have been taken to reduce the content of plastics and the use amount of plastics as much as possible in order to reduce the environmental load and the waste, and further reduce the burden of incineration disposal of local governments and the like. As a method of reducing the content of the plastic, for example, a method of adding a filler such as calcium carbonate to a plastic bag or the like. This method is used in many plastic products because it can reduce the content of plastics and considerably reduce the cost of the product.

Likewise, with regard to toner, if the amount of binder resin or other toner raw materials used can be reduced by using a filler or the like, there is a possibility that environmental load reduction or drastic cost reduction can be realized.

Patent Document 1 (Japanese Patent Application Laid-Open No. 63-139364) discloses a lithium secondary battery which contains calcium carbonate, magnesium oxide and magnesium hydroxide particles for positive charging and contains silicon dioxide, aluminum silicate, JP-A No. 2004-361663) discloses a toner for electrostatic charge development comprising at least a binder resin and a black metal oxide as a colorant, And a powder obtained by pulverizing and classifying a kneaded product obtained by adding calcium carbonate to the toner particles. In this patent publication, it is disclosed that it is preferable to add calcium carbonate to the toner in an amount of 0.01 to 10 wt%. However, when an inorganic filler such as calcium carbonate is added to the toner, since the melt viscosity of the toner increases, there is a fear that the low temperature fixability is deteriorated or the pulverization property of the toner is deteriorated. Lowering the toner pulverization property and lowering the low temperature fixing property are also not preferable from the viewpoint of environmental load reduction.

In order to improve the low-temperature fixing property and the pulverizing property of the toner, a method of lowering the thermal property such as the glass transition temperature and the flow softening temperature of the binder resin is generally cited. However, since the preservability of the toner deteriorates in this method, There is a possibility that a pressure piece or agglomerate of the toner is generated and the image quality is deteriorated. In addition, there is a fear that the charging performance of the toner significantly decreases due to the dispersion failure of the calcium carbonate or the exposure of the surface of the toner of the calcium carbonate.

Patent Document 3 (Japanese Patent Application Laid-Open No. 2007-011347) discloses a toner including a binder, at least one colorant, and toner particles containing silicate particles distributed in the binder. Also disclosed in this document is a method of improving the relative humidity dependence of a toner by including silicate particles in the binder.

However, when the silicate clay particles are added to the toner, since the melt viscosity of the toner is increased as in the case of calcium carbonate, the low temperature fixability may be deteriorated or the pulverization property of the toner may be deteriorated. In addition, there is a fear that the chargeability of the toner may deteriorate due to the dispersion failure of the silicate particles, the exposure of the toner surface, and the like. With respect to the emulsion aggregated toner, silicate clay particles tend to be contained in the toner. However, since the silicate clay particles tend to be exposed on the surface in the process of pulverizing the melt-kneaded product of the toner raw materials with respect to the pulverization toner, This may lead to deterioration in quality.

An object of the present invention is to provide a toner which is excellent in preservability, low temperature fixability and the like, and has excellent image quality with little image fogging. Another object of the present invention is to provide a toner which is inexpensive and excellent in productivity.

As a result of intensive investigation to achieve the above object, the present inventors have found that a toner for developing an electrostatic latent image, which is obtained from a toner material containing at least one kind of an inorganic filler selected from a binder resin, a colorant and calcium carbonate, kaolin clay, talc and barium sulfate , The glass transition temperature of the toner is in the range of 50 to 58 占 폚, and the content of the inorganic filler is 1 to 10 parts by weight with respect to 100 parts by weight of the toner. Part of the inorganic filler exists on the toner surface, Characterized in that the ratio of the inorganic filler present on the surface of the mother particle is in the range of 5 to 40% with respect to the content of the inorganic filler. The toner is excellent in storage stability, low temperature fixability, And also has excellent productivity, and has completed the present invention.

That is, the present invention includes the following [toner for developing electrostatic latent images], [developer for electrostatic latent image development], and [image forming apparatus].

(1) A toner for electrostatic charge image developing comprising at least a binder resin, a colorant and at least one inorganic filler selected from calcium carbonate, kaolin clay, talc, and barium sulfate, wherein the toner has a glass transition temperature of 50 And the inorganic filler is contained in an amount of 1 to 10 parts by weight based on 100 parts by weight of the toner, wherein a part of the inorganic filler is present on the surface of the toner base particles, Wherein the ratio of the inorganic filler to the content of the inorganic filler is in the range of 5 to 40%.

(2) The toner for electrostatic charge image developing described in (1) above, wherein the inorganic filler has an average particle diameter of 0.1 to 10 占 퐉.

(3) The toner for electrostatic charge image developing described in (1) or (2) above, wherein the inorganic filler is surface-treated with at least one treating agent selected from a silane coupling agent, a surfactant and a metallic soap. ]

(4) The toner for electrostatic charge image developing described in any one of (1) to (3) above, wherein the binder resin comprises a binder resin having a glass transition temperature of 48 to 55 ° C.

(5) Toner for electrostatic charge image developing described in any one of (1) to (4) above, wherein the binder resin comprises a polyester resin.

(6) (Toner for electrostatic charge image developing described in any one of (1) to (5), which is obtained by pulverizing and classifying a melt-kneaded product obtained by melt-kneading the toner material.

(7) The electrostatic charge image developer according to any one of (1) to (5) above, wherein the binder resin comprises a binder resin contained in toner base particles assembled in an aqueous medium Toner for.]

(8) A one-component developer for electrostatic charge image, comprising toner base particles of an electrostatic latent image developing toner according to any one of (1) to (5) and an external additive agent.

(9) A two-component developer for electrostatic charge image, comprising toner base particles and carrier particles of the electrostatic latent image developing toner according to any one of (1) to (5).

(10) An image forming apparatus characterized by comprising a developing means on which the developer described in (8) or (9) is mounted.

The toner of the present invention is a toner for developing an electrostatic latent image which is made of a toner material containing at least one kind of inorganic filler selected from a binder resin, a colorant and calcium carbonate, kaolin clay, talc and barium sulfate , The glass transition temperature of the toner is in the range of 50 to 58 캜, the content of the inorganic filler is 1 to 10 parts by weight with respect to 100 parts by weight of the toner, a part of the inorganic filler is present on the surface of the toner base particles , The ratio of the inorganic filler present on the surface of the toner base particles is in the range of 5 to 40% with respect to the content of the inorganic filler. Thus, the toner having excellent low-temperature fixability, storage stability, . Further, since the toner of the present invention can be produced at low cost and is excellent in productivity, it is possible to reduce environmental burdens such as waste reduction, energy use load reduction, and carbon dioxide emission reduction.

As described above, the toner of the present invention is an electrostatic latent image developing toner obtained from a toner material containing at least one kind of inorganic filler selected from a binder resin, a colorant, calcium carbonate, kaolin clay, talc and barium sulfate, And the inorganic filler is contained in an amount of 1 to 10 parts by weight based on 100 parts by weight of the toner, wherein a part of the inorganic filler is present on the surface of the toner base particles and is present on the surface of the toner base particles The content of the inorganic filler is within a range of 5 to 40% with respect to the content of the inorganic filler. Such a toner may be a [pulverized toner] or a so-called [chemical toner]. However, in the case of a pulverized toner, it is preferable that the amount of the inorganic filler present on the surface of the toner base particles is in the range of 5 to 40% Is relatively easy to manufacture. Therefore, mainly [pulverizing toner] will be mainly described below, but it goes without saying that the present invention can be applied to the case of chemical toner as well as the case of [pulverizing toner]. A variety of inorganic fillers such as silica, alumina, titanium oxide, cryolite, zinc oxide, bentonite, (a) iron oxide, molybdenum disulfide, and magnesium hydroxide are known as inorganic fillers for use in toners. However, in the present invention, it is important that the above-mentioned inorganic filler is not suitable, and only a limited selection from calcium carbonate, kaolin clay, talc, and barium sulfate is very preferably used. The toner according to the present invention has a relatively low melt-bonding property within a glass transition temperature of 50 to 58 占 폚 and is excellent in preservability.

As a more remarkable feature point, a high-quality image with less image blur can be obtained.

Hereinafter, the present invention will be described in detail.

First, at least one kind of inorganic filler selected from a binder resin, a coloring agent, calcium carbonate, kaolin clay, talc, and barium sulfate is mixed and mixed at a predetermined ratio.

Then, after the mixture is melt-kneaded, the resulting melt-kneaded product is pulverized and classified to obtain the toner of the present invention. The toner raw material in the present invention can be any known one without particular limitation.

The binder resin is not particularly limited as long as it is a resin that can be fixed on a medium such as paper. Examples of the binder resin include homopolymers of styrene and its substituents such as polystyrene, poly (p-chlorostyrene) and polyvinyltoluene; styrene- Styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethacrylic acid methyl copolymer, styrene-acrylonitrile copolymer, Styrene copolymers such as styrene-vinylmethyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer and styrene- acrylonitrile- Polyvinyl chloride, phenol resin, natural modified phenolic resin, natural resin-modified maleic acid resin, acrylic resin, A polyurethane resin, a polyamide resin, a furan resin, an epoxy resin, a xylene resin, a polyvinyl butyral, a terpene resin, a coumarone indene resin, a petroleum resin and the like, . These resins may be used alone or in combination of two or more. Of these, polyester resins and styrene copolymers are preferable, and polyester resins are particularly preferably used from the viewpoints of low-temperature fixability and dispersibility of inorganic fillers.

Examples of the alcohol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1, 2-propylene glycol, (Hydroxymethyl) cyclohexane, and bisphenol A, hydrogenated bisphenol A, polyoxyethylene (meth) acrylates such as diethylene glycol, 1,4-butylene glycol, Etherified bisphenols such as ethylenated bisphenol A and polyoxypropylenated bisphenol A, and other divalent alcohol monomers. These alcohols may be used alone or in combination of two or more.

Examples of the carboxylic acid include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, Lactic acid, anhydrides of these acids, dimers of lower alkyl esters and linoleic acid, and other divalent organic acid monomers. These carboxylic acids may be used alone or in combination of two or more.

The polyester resin may be a polymer containing not only a bifunctional monomer but also a component containing three or more functional polyfunctional monomers. Examples of the trivalent or higher polyhydric alcohol monomer as the polyfunctional monomer include monovalent alcohols such as sorbitol, 1,2,3,6-hexanetetrole, 1,4-sorbitan, pentaerythritol, dipentaerythritol, , Sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, Trimethylolpropane, 1,3,5-trihydroxymethylbenzene, and other trihydric or higher polyhydric alcohol monomers.

The glass transition temperature (Tg) of the binder resin is usually in the range of 45 to 75 占 폚, preferably 45 to 60 占 폚, more preferably 48 to 60 占 폚, and most preferably 48 to 55 占 폚. Since the toner of the present invention contains an inorganic filler, even when the glass transition temperature of the binder resin is within the above range, the toner is excellent in storage stability and excellent in low temperature fixability. When the glass transition temperature of the binder resin is lower than 45 캜, the preservability of the toner deteriorates. When the glass transition temperature of the binder resin is higher than 75 캜, the low temperature fixability deteriorates and the grindability also deteriorates.

The binder resin of the present invention may contain a binder resin contained in the assembled toner particles in an aqueous medium. The method for preparing the assembled toner particles in the aqueous medium can be selected from suspension polymerization, emulsion polymerization, agglomeration, melt suspension, ester elongation polymerization and the like. The toner produced by the above-described production method is excellent in low-temperature fixability, and a toner excellent in low temperature fixability can be obtained by including a binder resin contained in the toner particles in the inorganic filler-containing toner of the present invention.

The inorganic filler in the present invention may be added at least one kind selected from at least calcium carbonate, kaolin clay, talc, and barium sulfate, alone or in combination. Such an inorganic filler may be surface-treated with a silane coupling agent, a surfactant, a metallic soap, or the like and adjusted to a desired particle size distribution by classification or the like.

Kaolin clay is mainly composed of aluminum silicate, and usually contains aluminum hydroxide, magnesium hydroxide, water and the like. Kaolin clay is a functional kaolin, a fired kaolin, a surface treated kaolin surface-treated with stearic acid, a silane coupling agent, a surfactant, or the like. From the viewpoint of economy, the use of functional kaolin is preferable, and from the viewpoints of image quality and toner environmental stability, use of fired kaolin or surface treated kaolin is preferable. The particle diameter of kaolin is usually 0.1 to 10 mu m, preferably 0.3 to 3 mu m, more preferably 0.3 to 1 mu m. If the particle diameter is 10 mu m or more, it is difficult to be contained in the toner because it is larger than the toner particle diameter, and if the particle diameter is 0.1 mu m or less, it is difficult to uniformly disperse the toner in the toner particles. If the particle diameter is 0.1 mu m or less, the cost becomes high and it is not economically preferable.

Examples of the calcium carbonate include heavy calcium carbonate, light calcium carbonate, and surface-treated calcium carbonate surface-treated with stearic acid, silane coupling agent, surfactant, and the like. The heavy calcium carbonate can be divided into dry heavy calcium carbonate and wet heavy calcium carbonate according to the pulverization method, and the particle diameter is usually 0.5 to 10 탆, preferably 0.5 to 3 탆, more preferably 0.5 to 1 탆. If the particle diameter is 10 mu m or more, it is difficult to be contained in the toner because it is larger than the toner particle diameter, and if the particle diameter is 0.5 mu m or less, it is difficult to uniformly disperse the toner particles in the toner particles. If the particle diameter is 0.5 mu m or less, the cost is increased, which is not economically advantageous. The hard calcium carbonate is manufactured through a chemical process, and the particle shape is usually a spindle shape or a column shape, and can be used without particular limitation. The particle size of the hard calcium carbonate is usually 0.05 to 5 占 퐉, preferably 0.1 to 3 占 퐉, and more preferably 0.1 to 1 占 퐉. If the particle diameter is 5 占 퐉 or more, it is difficult to encapsulate the toner particles, and if the particle diameter is 0.05 占 퐉 or less, it is difficult to uniformly disperse the toner particles in the toner particles, which may result in deterioration of toner quality.

The talc is composed of a composite salt of magnesium oxide and silicic acid and has a particle diameter of usually 0.1 to 10 탆, preferably 0.3 to 3 탆, more preferably 0.3 to 1 탆.

If the particle diameter is 10 mu m or more, it is difficult to be contained in the toner because it is larger than the toner particle diameter, and if the particle diameter is 0.1 mu m or less, it is difficult to uniformly disperse the toner in the toner particles. Further, if the particle diameter is 0.1 m or less, the cost becomes high, which is economically undesirable. Barium sulphate is generally obtained by pulverizing barite mineral (barite powder), which is generally called natural barite, and precipitated barium sulfate by chemical process, and can be used without limitation. The particle diameter is usually 0.1 to 10 mu m, preferably 0.3 to 3 mu m, more preferably 0.3 to 1 mu m.

Taken together, it can be said that the inorganic filler of the present invention preferably has a number average particle diameter of 0.1 to 10 mu m.

The addition amount of the inorganic filler is 1 to 10 parts by weight, preferably 3 to 10 parts by weight, and particularly preferably 5 to 8 parts by weight, based on 100 parts by weight of the toner. If the addition amount of the inorganic filler exceeds 10 parts by weight, the melt viscosity of the toner increases and the low-temperature fixability deteriorates.

In addition, since the amount of the inorganic filler to be exposed on the toner surface increases, the toner charge amount may be lowered and the image quality may be deteriorated. In addition, it is difficult to uniformly disperse the toner in the binder resin, which may cause deterioration of toner quality. When the addition amount of the inorganic filler is less than 1 part by weight, the toner storage property is deteriorated and it becomes difficult to achieve both low temperature fixability and storage stability.

In addition, the inorganic filler needs to have a part on the surface in the process of pulverizing and classifying the toner. When the inorganic filler is present on the surface, a toner excellent in preservability can be obtained.

The ratio (surface presence ratio) of the inorganic filler present on the toner surface is preferably 5 to 40%, more preferably 5 to 35%, and particularly preferably 10 to 30% based on the content of the inorganic filler.

The surface abundance ratio of the inorganic filler in the surface of the toner base particles not only means the compatibility or dispersion degree of the inorganic filler content in the present invention but also reflects the appropriate particle size of the inorganic filler to the toner base particles. That is, the surface area S of one toner base particle with an average radius r and the volume V of one of the base particles are of course S = 4πr2, V = (4/3) πr3. Assuming that 100 inorganic fillers are completely dispersed in one of the matrix particles having an average volume (V), the average distance L between the inorganic filler particles dispersed in the arbitrary direction in the longitudinal direction, the transverse direction, (N) of the dispersed inorganic filler microparticles and the volume (v) of each inorganic filler microparticle. v = V / N, and L = v1 / 3. This idea is basically the same, even if L >> v, the space in which v does not exist increases.

The average distance L between the 100 inorganic filler particles dispersed in the volume V is approximately 1,6117r calculated from the above formula (the same is true even if the influence of v is neglected). The number of the 100 inorganic fillers on the surface of the mother globes is 100 x 1/3 r. That is, [the number of the inorganic filler particles shown on the surface is decreased as the parent particle radius (r) becomes larger as the particle size r becomes larger) and is in proportion to the radius r compared with the inorganic filler particle volume (v) The integer is 1/3. Assuming that r = 5 (therefore, V = 523, S = 314), N = 100, v = 52.3 (total radius of inorganic filler particles is 1.612) The number% of inorganic filler particles observed on the particle surface is 100 x 1/3 x (5 / 1.612) = 7.2%. L '= (L1 / 2 / Lr1 / 3) = 0.899L × (1/2) L / (3) 2)? 0.45. These are, of course, examples for facilitating understanding of the present invention. In comparison with the above-mentioned exemplary values of the surface abundance of the surface of the toner base particles of the inorganic filler in the specific examples to be described later, the inorganic filler content, the degree of dispersion and the particle size of the inorganic filler of the present invention Can be understood.

When the inorganic filler surface presence ratio is larger than 40%, the charge amount of the toner is lowered, and the image quality such as image blur is likely to deteriorate. When the amount of the inorganic filler present on the surface is less than 5%, the amount of the inorganic filler present on the surface of the toner is small, so that the storage stability tends to deteriorate. Since the inorganic filler is present on the surface of the toner, both the preservability and the low-temperature fixability can be achieved.

The state in which the inorganic filler is present on the surface of the toner may be a state in which particles of the inorganic filler adhere to the surface of the toner, and the inorganic filler is buried in the toner base. Part of the buried inorganic filler Or may be exposed to the surface of the toner.

The presence of the surface of the inorganic filler can be confirmed, for example, by confirming the toner surface with an electron microscope image. The surface existing ratio (surface existing ratio) of the inorganic filler can be obtained from the Fourier transform infrared spectrophotometer (FT-IR), and the surface existing ratio of the inorganic filler can be calculated from the intensity of the infrared absorption spectrum attributable to the inorganic filler . In this case, a predetermined amount of the inorganic filler is attached to the surface of the toner to measure the infrared absorption spectrum intensity, and the relationship between the inorganic filler surface existing amount and the infrared absorption spectrum intensity is confirmed.

As the colorant for use in the toner of the present invention, a black pigment may be used for the black toner, a magenta pigment, a cyan pigment, a yellow pigment and the like may be used for the color toner.

As the pigment for black, carbon black can be usually used. The carbon black can be used without being limited to the number average particle diameter, oil absorption amount, and PH, and the following may be mentioned as commercially available products. For example, REVAL 400, 660, 330, 300, SRF-S, STERLING SO, V, NS, R, manufactured by Colombia Carbon Japan under the trade name of RAVEN H20, MT- 430, 450, 500, 760, 780, 1000, 1035, 1060, 1080 and # 5B, # 10B, # 40, # 2400B and MA-100 available from Mitsubishi Chemical Corporation. These carbon blacks may be used alone or in combination of two or more. The ratio of the carbon black to the weight of the toner is usually 1 to 20 parts by weight, preferably 1 to 10 parts by weight, more preferably 3 to 10 parts by weight. If the ratio of the carbon black is too small, the image density is deteriorated. If the ratio is too large, the image quality is likely to be deteriorated, and the toner formability also deteriorates. In addition to carbon black, black magnetic powder such as iron oxide and ferrite may be used as the black pigment.

 As magenta pigments, CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22 , 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83 , 87, 88, 89, 90, 112, 114, 122, 123, 163, 202, 206, 207, 209; I. Pigment Violet 19; I. vat red 1, 2, 10, 13, 15, 23, 29, 35 and the like can be used. These magenta pigments may be used singly or in combination of two or more kinds.

Cyan pigments include C. I. Pigment Blue 2, 3, 15, 16, 17; I. Bat Blue 6; I. Acid Blue 45, and the like. These cyan pigments may be used alone or in combination of two or more.

As yellow pigments, CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 74, 83, 94, 97, 155, 180, and the like can be used. These yellow pigments may be used alone or in combination of two or more.

From the viewpoint of color mixing property and color reproducibility, CI Pigment Red 57 and CI Pigment Red 122 are preferably used as the magenta pigment, CI Pigment Blue 15 is preferably used as the cyan pigment, CI Pigment Yellow 17, 83, 155 and 180 are preferably used as the pigment. The ratio of the pigment for color can be selected from the range of usually 1 to 20 parts by weight, preferably 3 to 10 parts by weight, more preferably 4 to 9 parts by weight, based on 100 parts by weight of the toner. If the ratio of these pigments is less than the above range, the image density is deteriorated. If the ratio is too large, the dispersibility of the pigment becomes worse to deteriorate the color reproducibility, and the stability of the toner charge amount also deteriorates and the image quality tends to deteriorate. It is also disadvantageous in cost.

In the toner of the present invention, a charge control agent may be used if necessary. The charge control agent may be a negative charge control agent, a positive charge control agent, or a combination thereof depending on the charging property of the toner.

Examples of the positive charge control agent include quaternary ammonium salts such as modified products of nigrosine and fatty acid metal salts, tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, Diorganotin borates such as dibutyltin oxide, dibutyltin oxide, dioctyltin oxide and dicyclopentyltin oxide, diorganotin oxide, dibutyltin borate, dioctyltin borate and dicyclohexyltin borate, pyridinium salts, azine, triphenyl Methane-based compounds and low molecular weight polymers having cationic functional groups. These positive charge control agents may be used alone or in combination of two or more. As such positive charge control agents, nigrosine compounds and quaternary ammonium salts are preferably used.

Examples of the negative charge control agent include organic metal compounds such as acetylacetone metal complex, monoazo metal complex, naphthoic acid or salicylic acid metal complex or salt, chelate compounds, and low molecular weight polymers having anionic functional groups. . These negative charge control agents may be used alone or in combination of two or more. Such charge control agents having a negative charge tendency are preferably salicylic acid metal complexes or monoazo metal complexes. The amount of the charge control agent to be added is usually in the range of 0.1 to 5% by weight, preferably 0.3 to 4% by weight, and more preferably 0.5 to 4% by weight based on 100 parts by weight of the toner. It is preferable that the charge control agent is colorless or pale in color toners.

A release agent (wax) may be added to the toner of the present invention if necessary. Examples of the release agent include petroleum waxes such as polyolefin waxes such as polyethylene wax, polypropylene wax and modified polyethylene wax, synthetic waxes such as Fischer-Tropsch wax, ester synthetic wax, paraffin wax and microcrystalline wax, carnauba wax, Vegetable waxes such as candy lira wax, rice wax, hardened castor oil, and the like. These waxes may be used alone or in combination of two or more. The amount of the wax to be added may be selected in the range of usually 0.1 to 10% by weight, preferably 0.5 to 7% by weight, and more preferably 1 to 5% by weight based on 100 parts by weight of the toner. If the addition amount of the wax is more than the above range, the dispersibility of the releasing agent deteriorates, and the toner charging member and the surface of the carrier become contaminated and the image quality is liable to be deteriorated. If the amount is too small, the releasability of the toner becomes insufficient and the fixing property deteriorates. The melting point of the releasing agent is usually 40 to 160 캜, preferably 50 to 120 캜, and more preferably 60 to 90 캜. If the melting point of the releasing agent is less than 40 占 폚, the storage stability of the toner deteriorates, and if it exceeds 160 占 폚, the fixing property of the toner may be deteriorated.

The toner of the present invention may contain a magnetic powder such as a metal powder such as cobalt, iron or nickel, aluminum, copper, iron, nickel, magnesium, tin, zinc, gold, silver, selenium, titanium, tungsten, zirconium , Alloys of other metals, metal oxides such as aluminum oxide, iron oxide, and nickel oxide, ferrite, magnetite, and the like. The amount of the magnetic powder to be added is usually 1 to 70% by weight, preferably 5 to 50% by weight, and more preferably 10 to 40% by weight based on 100% by weight of the resin composition. The magnetic powder preferably has an average particle diameter of 0.01 to 3 mu m.

In the toner of the present invention, various additives such as a stabilizer (for example, ultraviolet absorber, antioxidant, heat stabilizer, etc.), a flame retardant, an antifogging agent, a dispersant, a nucleating agent, a plasticizer (phthalate ester plasticizer, Based plasticizer, a polymeric antistatic agent, a low molecular weight antistatic agent, a compatibilizer, a conductive agent, a filler, a fluidity improver, and the like may be added.

It is preferable that the toner of the present invention has the inorganic fine particles attached to the surface thereof. Examples of the inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, Inorganic compounds such as antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, valium carbonate, calcium carbonate, silicon carbide, silicon nitride, magnetic powder and the like. These inorganic fine particles may be used singly or in combination of two or more kinds. Among these inorganic fine particles, silica and titanium oxide are particularly preferably used. The BET specific surface area of the inorganic fine particles is preferably in the range of 50 to 400 m < 2 > / g, and the inorganic fine particles are subjected to surface treatment to be hydrophobic . In addition to the inorganic fine particles, resin fine particles or the like may be used instead of the inorganic fine particles.

The ratio of the inorganic fine particles and the resin fine particles to the toner may be appropriately selected in the range of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, You can choose. If the addition ratio is out of the above range, the fluidity and chargeability of the toner are lowered, and uniform image formation is difficult and the image quality is deteriorated.

The toner of the present invention can be obtained by mixing the respective raw materials at a predetermined ratio and then melt-kneading, and then pulverizing and classifying the melt-kneaded product. As the apparatus for mixing the toner raw materials, there can be used an existing apparatus and is not particularly limited as long as it is an apparatus capable of dry mixing the raw material of the toner. However, a gravity falling mixer such as a V blender or a ball mill, a super mixer A high-fluid bed mixer such as a Henschel mixer (manufactured by Mitsui Mining Co.), a Q mixer (manufactured by Mitsui Mining Co.), and a NOVITER (manufactured by Hosokawa Micron Corporation). From the viewpoint of productivity, a high-speed fluidized-bed mixer such as a super mixer is preferable. Then, the mixed raw material mixture is melt-kneaded.

The apparatus used in melt kneading is not particularly limited as long as the apparatus can be used as long as it can use an existing apparatus and can melt and knead the raw material mixture. However, a roll kneader such as two rolls or three rolls, a Banbury mixer or a pressurized kneader A batch-type closed kneader, a continuous-type closed kneader such as a single screw extruder or a twin screw extruder, and a continuous roll kneader. From the viewpoint of productivity, a continuous type closed kneader such as a single screw extruder or a twin screw extruder, or a continuous roll kneader is preferable.

Next, after the melt-kneaded product is cooled and solidified, toner is produced through each of the steps of a coarse grinding step, a fine grinding step and a classifying step. For example, a hammer mill, a cutter mill, and the like are used for the coarse grinding process, and a high-speed rotary fine grinder, an airflow impingement grinder, a fluidized bed grinder, or the like can be used for the fine grinding process have. For example, in the classification step, a forced whirl centrifuge or inertial classifier is used. The volume average particle size of the toner thus obtained is usually about 5 to 10 mu m, preferably 6 to 9 mu m, and more preferably 6 to 8 mu m. The volume average particle diameter is a 50% particle diameter measured using a particle size distribution measuring apparatus such as Multisizer III (manufactured by Beckman, Korte). By obtaining each of the above steps, a toner having a desired particle diameter can be obtained. However, in the classifying step, toner fine particles smaller than a predetermined particle diameter are generated. The toner fine particles are usually returned to the mixing process from the viewpoint of productivity and the toner fine particles are reused. When the toner fine powder is reused in the mixing process, the toner fine powder and each of the toner raw materials are mixed in a mixing process, and the mixture is subjected to a kneading process, a pulverizing process and a classification process to produce a toner.

The toner of the present invention thus obtained has a glass transition temperature of 50 to 58 캜, preferably 52 to 58 캜, more preferably 54 to 58 캜. When the glass transition temperature is higher than 58 deg. C, the low temperature fixing property is deteriorated. When the glass transition temperature is lower than 50 deg. C, the storage stability is deteriorated. The glass transition temperature is within the above range and the presence of the inorganic filler on the toner surface makes it possible to achieve both the preservability and the low-temperature fixability.

In addition, the toner of the present invention is not limited particularly in terms of the developing method, and can be used for a non-magnetic one-component developing method, a magnetic one-component developing method, a two-component developing method and other developing methods. The toner for the magnetic one-component developing system is obtained by mixing the above-mentioned magnetic powder with the binder resin and using the toner as the magnetic toner and the toner for the two-component developing system using the carrier mixed.

As the carrier in the two-component developing system, nickel, cobalt, iron oxide, ferrite, iron, glass beads, or the like can be used. These carriers may be used singly or in combination of two or more. The average particle diameter of the carrier is preferably 20 to 150 mu m.

The surface of the carrier may be covered with a coating agent such as a fluorine resin, an acrylic resin, a silicone resin, or the like.

The toner of the present invention may be a black toner or a full color toner. In the toners for black and white, carbon black described above may be used as the colorant, and those described above as the colorant in the toner for full color can be preferably used. The toner of the present invention can be preferably used in a black and white toner from the viewpoint of color reproducibility and economical efficiency.

The method for producing the mother particles is not particularly limited, and examples thereof include a pulverization method and a polymerization method.

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. The raw materials used in Examples and Comparative Examples, the evaluation method of toner physical properties, and the evaluation method of image characteristics are shown below.

[Raw materials]

≪ Binder resin &

(Glass transition temperature (Tg) = 58 占 폚, flow softening temperature (T1 / 2) = 135 占 폚)

(Glass transition temperature (Tg) = 50 占 폚, flow softening temperature (T1 / 2) = 103 占 폚)

(Glass transition temperature (Tg) = 58 deg. C, flow softening temperature (T1 / 2) = 155 deg. C)

<Colorant>

Colorant: Carbon black (manufactured by Mitsubishi Chemical Corporation, # 44)

&Lt; Charge control agent &

CCA (1): zirconium salt of salicylic acid (trade name: TN-105, manufactured by Hodogaya Chemical Co., Ltd.)

CCA (2): Salicylic acid zinc salt (BONTORON E-304, manufactured by Orient Chemical Co., Ltd.)

<Release Agent> WAX (1): Carnauba wax (manufactured by Kato Yoko Co., Ltd., trade name: Carnauba wax No. 1)

WAX (2): polypropylene wax (trade name: BISCOL 550 P, manufactured by Sanyo Chemical Co., Ltd.)

<Inorganic filler>

Inorganic filler (1): kaolin clay (BASF, trade name ASP-200)

Inorganic filler (2): heavy calcium carbonate (SOFTON 3200, manufactured by Bihoku Kunka Kogyo Co., Ltd.)

[Toner evaluation method]

[Glass transition temperature]

The glass transition temperature of the toner was measured using a DSC system (differential scanning calorimeter) ([DSC-60], manufactured by Shimadzu Corporation). The sample was heated from a temperature raising rate of 10 캜 / min to 150 캜, then cooled from 150 캜 to a temperature of 30 캜 at a temperature decreasing rate of 10 캜 / min, further heated to 150 캜 at a temperature raising rate of 10 캜 / And a shoulder peak attributed to glass transition of the DSC curve at the time of temperature rise.

[Surface presence rate of inorganic filler]

The presence of the surface of the inorganic filler was observed from an electron microscopic image. The surface presence ratio of the inorganic filler was determined from the infrared absorption spectrum intensity attributable to the inorganic filler. The infrared absorption spectrum intensity was measured at an incident angle of 60 degrees using a FT-IR Spectrum-1 manufactured by Perkin Elmer equipped with an ATR accessory variable angle variable. First, 0.1, 1.0, 5.0 and 10.0 parts by weight of an inorganic filler were previously attached to the toner surface with respect to 100 parts by weight of the toner, and the infrared absorption spectrum intensity of the inorganic filler on the surface existing amount was calculated. The infrared absorption spectrum intensity near the wavelength 914 (cm &lt; -1 &gt;) of the kaolin clay surface is calculated. Next, the infrared absorption spectrum intensity attributable to the inorganic filler of the toner of the present invention was determined, and the abundance amount of the inorganic filler on the surface existing amount of the inorganic filler and the infrared absorption spectrum intensity was determined. Next, the existence ratio (%) of the surface of the inorganic filler was calculated from the ratio of the content of the inorganic filler to the amount of the surface existing amount of the inorganic filler.

[Charge amount]

4% by mass of toner and 96% by mass of copper-zinc ferrite particles coated with a silicone resin and having an average particle diameter of 50 占 퐉 were produced. Then, the developer 6 g was weighed and placed in a hermetically sealable metal cylinder, and the amount of charge was determined by a blow-off method. The charging amount is preferably in the range of -10 to 30 μC / g. When the absolute value of the charge amount is less than 10 mu C / g, background contamination and toner scattering are likely to occur. When the absolute value is more than 40 mu C / g, the image density is lowered.

[Low temperature fixability]

A fixation tester composed of a fixer of a copier MF-4550 manufactured by Ricoh Co., Ltd. using a roller made of polytetrafluoroethylene as a fixation roller, a fixation lower limit temperature at which fixation can be stably performed without a cold offset phenomenon by using Ricoh's T6200 copy printing paper is set to 5 And the fixability at low temperature was evaluated. The mechanical conditions were a sheet conveying line speed of 140 mm / sec, a surface pressure of 1.2 kgf / cm 2, and a nip width of 3 mm.

The evaluation was evaluated as?, When the fixing lower limit temperature was 140 占 폚 or less,? When it was in the range of 140 占 폚 to 150 占 폚, and when it was 150 占 폚 or more.

[Preservability]

The toner was stored at 50 占 폚 for 8 hours, and then the toner was stuck in a 42 mesh sieve for 2 minutes to measure the residual ratio on the wire net. The heat-resistant preservability was evaluated as?, When the residual ratio was less than 10%,?, When the residual ratio was 10% or more and less than 30%, and when the residual ratio was 30% or more,

[Image evaluation]

Using an imagio Neo 450 (manufactured by Ricoh Co., Ltd.), 5000 sheets were continuously printed on an A4 size paper at a printing speed of 33 sheets / min and a printing density of 6%. After printing, the following evaluation was carried out.

[Image Blur]

The blank image was stopped during development, and the developed developer on the photoconductor was subjected to tape transfer, and the difference from the image density of the untransferred tape was measured using a 938 spectrodensitometer (manufactured by X-Rite). The evaluation was evaluated as? When the difference was less than 0.010,? When the difference was 0.010 or more and less than 0.030, and X when the difference was 0.030 or more.

[Image density]

After outputting a black solid image, the image density was measured using a 938 spectrodensitometer (manufactured by X-Rite). The evaluation was evaluated as?, When the image density was 1.40 or more,?, When the image density was 1.20 or more and less than 1.40, and when the image density was less than 1.20,

[Overall evaluation]

The low-temperature fixability, storage stability, and image evaluation were evaluated by the following criteria.

In the comprehensive evaluation, when? Is less than two,? Is determined. When there are three or more,?, And if there is at least one, it is determined as x.

[Example 1]

Production examples of toner and evaluation results of the toner thus prepared will be specifically described below. The binder resin (1), the binder resin (2), the colorant, the charge controlling agent (1), the releasing agent (1) and the inorganic filler (1) As shown in Fig. The raw materials were weighed to a total of 5 kg in the ratio shown in Table 1, and then mixed for 3 minutes in a high-speed mixer to obtain a mixture of raw materials. Next, the obtained mixture of the raw materials was melted and kneaded at a temperature of 120 占 폚, a discharge rate of 10 Kg / hr and a rotational speed of 150 rpm using a closed continuous kneading extruder (L / D = 30) To obtain a kneaded product.

Then, this melt-kneaded product was pulverized with a mechanical pulverizer, and then classified with a gas-phase classifier to obtain toner base particles having a volume average particle diameter of 9.5 占 퐉. Next, 1.0 part by weight of hydrophobic silica (R974, manufactured by Aero Instruments Co., Ltd.) was added to 100 parts by weight of the obtained toner base particles, and the mixture was stirred and mixed at a peripheral speed of 40 m / sec for 3 minutes using a high- The toners of Examples 1 to 4 were obtained. Toner physical properties and image characteristics of the obtained toner were evaluated, and the results are shown in Table 1.

[Example 2]

The toner of Example 2 was obtained in the same manner as in Example 1 except that the binder resin, the colorant, the charge control agent, the releasing agent and the inorganic filler shown in Table 1 were used in the ratios shown in Table 1 as the raw materials of the toner, Physical properties and image characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]

The toner of Example 3 was obtained in the same manner as in Example 1 except that the binder resin, coloring agent, charge control agent, release agent and inorganic filler shown in Table 1 were used in the ratios shown in Table 1 as the raw materials of the toner, Physical properties and image characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]

The toner of Example 4 was obtained in the same manner as in Example 1 except that the binder resin, the colorant, the charge control agent, the releasing agent and the inorganic filler shown in Table 1 were used in the ratios shown in Table 1 as the raw materials of the toners, Physical properties and image characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 5]

The toner of Example 5 was obtained in the same manner as in Example 1 except that the binder resin, the colorant, the charge control agent, the releasing agent and the inorganic filler shown in Table 1 were used in the ratios shown in Table 1 as the raw materials of the toner, Physical properties and image characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]

Except that the binder resin, the colorant, the charge control agent and the releasing agent shown in Table 2 (the inorganic filler was not used in Comparative Example 1) were used as the raw materials of the toners in the ratios shown in Table 2, 1, and the toner physical properties and image characteristics of the toner were evaluated in the same manner as in Example 1. [ The results are shown in Table 2.

[Comparative Example 2]

The toner of Comparative Example 2 was obtained in the same manner as in Example 1 except that the binder resin, the coloring agent, the charge control agent, the releasing agent and the inorganic filler shown in Table 2 were used in the ratios shown in Table 2 as the raw materials of the toners, Toner physical properties and image characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 3]

A toner of Comparative Example 3 was obtained in the same manner as in Example 1 except that the binder resin, the colorant, the charge control agent, the releasing agent and the inorganic filler shown in Table 2 were used in the ratios shown in Table 2 as the raw materials of the toners, Toner physical properties and image characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 4]

A toner of Comparative Example 4 was obtained in the same manner as in Example 1 except that the binder resin, the colorant, the charge control agent, the releasing agent and the inorganic filler shown in Table 2 were used in the ratios shown in Table 2 as the raw materials of the toner, Toner physical properties and image characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 2.

As is apparent from Table 1, the toners of Examples 1 to 4 are excellent in low temperature fixability and storage stability, and also have excellent image quality. On the other hand, the toner of Comparative Example 1 shown in Table 2 was not added with an inorganic filler, so that the fixing property at low temperature was excellent, but the storage stability deteriorated. In the toner of Comparative Example 2, since the inorganic filler was added in an amount of 20 parts by weight, the low-temperature fixability deteriorated and the toner charge amount decreased, resulting in image fogging. In the toner of Comparative Example 3, since the toner had a glass transition temperature of 60 캜, the toner had good storage stability but poor low-temperature fixability. In addition, the toner of Comparative Example 4 had a glass transition temperature of 48 캜, so that the low temperature fixability was good, but the storage stability deteriorated.

Claims (11)

A toner for developing electrostatic images comprising at least a binder resin, a colorant and at least one inorganic filler selected from calcium carbonate, kaolin clay, talc and barium sulfate, wherein the toner has a glass transition temperature of 50 to 58 占 폚 And the content of the inorganic filler is in the range of 1 to 10 parts by weight based on 100 parts by weight of the toner, and a part of the inorganic filler is present on the surface of the toner base particle and the ratio of the inorganic filler present on the surface of the toner base particle is Wherein the content of the inorganic filler is in the range of 5 to 40% with respect to the content of the inorganic filler. The electrostatic latent image toner according to claim 1, wherein the inorganic filler has a number average particle diameter of 0.1 to 10 占 퐉. The toner for electrostatic charge image developing according to claim 1, wherein the inorganic filler is surface-treated with at least one treating agent selected from a silane coupling agent, a surfactant, and a metallic soap. The electrostatic latent image toner according to claim 1, wherein the binder resin comprises a binder resin having a glass transition temperature of 48 to 55 캜. The electrostatic latent image toner according to claim 1, wherein the binder resin comprises a polyester resin. The toner for electrostatic charge image developing according to claim 1, wherein the toner is obtained by pulverizing and classifying a melt-kneaded product obtained by melt-kneading the toner material. The toner for electrostatic charge image developing according to claim 1, wherein the binder resin comprises a binder resin contained in toner base particles assembled in an aqueous medium. A one-component developer for electrostatic charge image, comprising toner base particles and an external additive of the toner for electrostatic charge image developing according to any one of claims 1 to 5. A two-component developer for electrostatic charge images, comprising toner base particles and carrier particles of the toner for electrostatic charge image developing according to any one of claims 1 to 5.  An image forming apparatus comprising the developing means having the one-component developer for electrostatic charge image according to claim 8 mounted thereon. An image forming apparatus comprising the developing means on which the two-component developer for electrostatic charge image according to claim 9 is mounted.