JP2000137346A - Electrostatic charge image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of stains on the photoreceptor and on developing sleeve in an environment of a high temperature while preventing migration to a soft material like polyvinyl chloride by incorporating a nonmigrating plasticizer in the toner comprising a binder resin and a colorant. SOLUTION: This toner comprises the binder resin and the colorant and it contains the nonmigrating plasticizer. The binder resin is a copolymer of styrene with butyl acrylate. The nonmigrating plasticizer is embodied by polyester type plasticizers, such as the ones obtained by reaction of dibasic carboxylic acid, such as adipic acid, azelaic acid, abietic acid, and phthalic acid, with glycols and monovalent alcohols. The binder resin to be used has a molecular weight of 1,000-8,000. The non-migrating plasticizer is contained in an amount of 1-20 weight % of the resin. When <1 weight %, a sufficient effect is not obtainable, and when >20 weight %, a side action, such as offset fixation occurs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used in an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile, and more particularly, to a toner for a soft plastic such as vinyl chloride during storage. The present invention relates to a toner that prevents adhesion and toner contamination of a photoconductor and a developing sleeve.

[0002]

2. Description of the Related Art Images using the electrophotographic process are often filed on soft plastic sheets or laid under desk mats. Some sheets and desk mats are made of soft vinyl chloride, and the phenomenon that toner adheres to the sheet often occurs. Also, when the toner comes into contact with a wiring cord or the like, the toner often fuses to the covering material of the cord. This is presumably because plasticizers such as DBP and DOP contained in soft vinyl chloride and the like migrate into the toner particularly during high-temperature storage, and a fusion phenomenon occurs at the interface at the contact portion.

As a method for preventing the toner from adhering to a soft plastic such as vinyl chloride during storage, there is a means for separating the SP value of a resin from the SP value of a plasticizer such as DBP or DOP used for the soft plastic. Can be More specifically, a method of copolymerizing a monomer having a hydroxyl group [Hitachi Chemical Technical Report (5)] and a method of using a methyl acrylate copolymer are known. This is presumed to be because the resin used for the toner is different from the SP value of the plasticizer, so that the plasticizer does not migrate to the toner even at a high temperature. However, this method has a problem that the cost of the toner increases because a relatively expensive monomer is used.

[0004] On the other hand, a method of incorporating a plasticizer such as DBP or DOP into a resin is also known (Japanese Patent Laid-Open No. 5-107).
799). This is presumed to be due to the small difference in concentration between the plasticizer concentration in the soft plastic, such as vinyl chloride, in contact with the toner and the plasticizer concentration in the toner. However, there is a problem that the DBP or DOP oozes out and the photoreceptor and the developing sleeve are contaminated especially when the toner comes into contact under a high temperature environment.

[0005]

SUMMARY OF THE INVENTION Based on these prior arts, the present invention relates to a toner and a toner resin which prevent contamination of a photosensitive member or a developing sleeve under a high temperature environment while preventing migration to a soft material such as vinyl chloride. Is to supply. In particular, it is an object of the present invention to provide a toner and a resin for toner which prevent migration and prevent contamination of a photosensitive member and a developing sleeve with an inexpensive resin composition such as a copolymer of styrene and butyl acrylate.

[0006]

[Means for Solving the Charge] The present invention comprises the following constitutions.

(1) A toner for developing electrostatic images, characterized in that the toner comprising at least a binder resin and a colorant contains a non-migratory plasticizer. (2) The toner for developing an electrostatic image according to the above (1), wherein the binder resin is a copolymer of styrene and butyl acrylate.

(3) A toner resin for developing an electrostatic image, wherein a non-migratory plasticizer is dispersed in advance. (4) The resin for developing an electrostatic image according to (2), wherein a non-migratory plasticizer is previously dispersed in a copolymer of styrene and butyl acrylate.

(5) The toner for developing an electrostatic image or the resin for a toner according to the above (1) or (2), wherein the non-migratory plasticizer has a molecular weight of 1,000 to 8,000. (6) The toner for developing an electrostatic charge image or the resin for a toner according to the above (1) or (2), wherein the non-migratory plasticizer is 1 to 20 parts by weight based on 100 parts by weight of the binder resin.

The non-migratory plasticizer used in the present invention is a polyester-based plasticizer obtained by reacting a dibasic carboxylic acid such as adipic acid, azelaic acid, sebacic acid or phthalic acid with a glycol or a monohydric alcohol. Is raised. Those having a molecular weight of 1,000 to 8,000 are used.

In addition, epoxy stearic acid esters (molecular weight: 400 to 500), epoxidized fats and oils obtained by modifying soybean oil and cottonseed oil (molecular weight: about 1,000), and trimellitic acid esters can be used.

Here, if the amount of the non-migratory plasticizer is less than 1 part by weight with respect to 100 parts by weight of the binder resin, a sufficient effect cannot be obtained, and if it is more than 20 parts by weight, side effects such as causing a fixing offset phenomenon are caused. . Therefore, the amount of the non-migratory plasticizer is preferably 1 to 20 parts by weight, more preferably 2 to 10 parts by weight, based on 100 parts by weight of the binder resin. As for other toner materials used in the present invention, all known materials can be used.

As the binder resin, polystyrene,
Polymers of styrene such as poly-p-chlorostyrene and polyvinyltoluene and their substituted polymers; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer Styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene
Butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethacrylic acid Methyl copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer Coalescence, styrene-
Styrene copolymers such as maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral Polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax and the like. Examples of incompatible combinations include a mixture of styrene-butyl acrylate copolymer and resins having greatly different properties such as polyester, epoxy resin, and epoxy polyol resin. Significantly different combinations of groups can also be obtained.

Here, considering from the object of the present invention, preferred resins for the present invention are copolymers of styrene and alkyl acrylate, such as styrene-butyl acrylate copolymer and styrene octyl acrylate copolymer. Particularly preferred.
Examples of the hydrophobic silica fine particles used in the present invention include HDK H2000, HDK H2000 /
4, HDK H 2050EP, HVK21 (or more), R972, R974, RX200, RY20
0, R202, R805, R812 (Nippon Aerosil) and TS720 (Cabot).

As titanium fine particles, P-25 (Nippon Aerosil), STT-30, STT-65C-S (Titanium Industry), TAF-140 (Fuji Titanium Industry), M
T-150W, MT-500B, MT-600B (or more, Taker) and the like.

In particular, as the titanium oxide fine particles subjected to the hydrophobic treatment, anatase type or rutile type crystalline or non-crystalline type can be used, and T-805 (Nippon Aerosil) or rutile type MT -100S, MT-1
There are 00T, MT150A, MT150AFM (above Takei), STT-30A, STT-62S-S (above titanium industry), MT-100S, MT-100T (above taker), IT-S (Ishihara Sangyo) and the like.

In order to obtain hydrophobized silica fine particles, titania fine particles and alumina fine particles, hydrophilic fine particles are treated with a musilane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, octyltrimethoxysilane or the like. Can be obtained. Further, it can be obtained by a polysiloxane treatment. Other additives such as fatty acid metal salts (zinc stearate, aluminum stearate, etc.), other metal oxides (aluminum oxide, tin oxide, antimony oxide, etc.),
It may contain a fluoropolymer or the like.

As the colorant, all known dyes and pigments can be used, for example, carbon black, nigrosine dye,
Iron black, Naphthol yellow S, Hansa yellow (10
G, 5G, G), cadmium yellow, yellow iron oxide,
Loess, graphite, titanium yellow, polyazo yellow, oil yellow, Hansa yellow, (GR, A, RN, R), pigment yellow L, pendidine yellow (G, GR),
Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Tan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Fire Red, Parachlor Ortho Nitroaniline Red, Risor Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4R
H), Fast Scarlet VD, Vulcan Fast Rubin B, Brilliant Scarlet G, Lisor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B,
Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Museum, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake,
Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC),
Indigo, ultramarine, navy blue, anthraquinone blue, fast violet B, methyl violet lake, cobalt violet, manganese violet, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B, naphthol green B , Green gold, acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc oxide, lithopone, and mixtures thereof. The amount used is generally 10
0.1 to 50 parts by weight with respect to 0 parts by weight.

The toner of the present invention may contain a charge control agent, if necessary. As the charge control agent, any known charge control agents can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified) Quaternary ammonium salts), alkyl amides, phosphorus alone or compounds, tungsten alone or compounds, fluorine-based activators, salicylic acid metal salts, and salicylic acid derivative metal salts.

In the present invention, the amount of the charge control agent used is determined by the type of binder resin, the presence or absence of additives used as required, and the toner production method including the dispersion method, and is uniquely limited. However, preferably, 0.1 to 100 parts by weight of the binder resin
Used in the range of 10 parts by weight. More preferably, 0.
The range of 5 to 5 parts by weight is good. If the amount is less than 0.1 part by weight, the negative charge of the toner is insufficient, which is not practical. If the amount is more than 10 parts by weight, the chargeability of the toner is too large, and the electrostatic attraction with the carrier and the charging member is increased, so that the fluidity of the developer is reduced and the image density is reduced.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the resin are shown below.
The present invention is not limited to this. All parts are parts by weight.

[0022]

[Table 1]

N-BA; normal butyl acrylate;
TOTM; tri-2-ethylhexyl trimellitate, 2
-EHA; 2-ethylhexyl acrylate, MMA; methyl methacrylate, polymer plasticizer a; azinic acid-ethylene glycol type having a molecular weight of about 7000. The present invention will be described in more detail by the following examples. Although described, the present invention is not limited to this. All parts are parts by weight.

[0024]

[Table 2]

NP055: polypropylene wax manufactured by Mitsui Chemicals, Inc. 550P: polypropylene wax manufactured by Sanyo Chemicals, MA-100: carbon black manufactured by Mitsubishi Chemical,
S-34: an azo dye manufactured by Orient Chemical Co., E-84; a salicylic acid derivative manufactured by Orient Chemical Co., Ltd.

After mixing the above-mentioned materials by a mixer, they were melt-kneaded by a two-roll mill, and the kneaded product was rolled and cooled. Then, it is pulverized by a jet mill and subjected to air classification, and has a volume average particle size of 7.5.
A μm toner was obtained. Furthermore, hydrophobic silica (R97
2, Nippon Aerosil) was added in an amount of 0.5 wt% and mixed with a mixer to obtain respective toners.

An image was formed from the obtained toner of each color using an experimental machine having a one-component developing device shown in FIG. The obtained image sample is sandwiched between soft vinyl chloride sheets (a piece obtained by cutting a desk mat w-type manufactured by Plus Inc. into a thin piece), left in a 50 ° C. environment for 45 hours while applying a load of 1 kg, and after slowly cooling, the sheet is peeled off. Was observed. Table 3 shows the results. In addition, an image was formed after performing a spin test for 8 hours in a 36 ° C. environment using an experimental machine having a one-component developing apparatus shown in FIG. Table 3 shows the image evaluation results.

[0028]

[Table 3]

In Comparative Example 2, when the developing sleeve was wiped with alcohol, the background stain on the wiped portion disappeared. Therefore, it is estimated that the background stain was caused by sleeve contamination.

[0030]

According to the present invention, it is possible to provide a toner and a resin for toner which prevent migration of a photosensitive material and a developing sleeve under a high temperature environment while preventing migration to a soft material such as vinyl chloride. In particular, a toner and a resin for a toner which can prevent migration and prevent contamination of the photosensitive member and the developing sleeve with an inexpensive resin composition such as a copolymer of styrene-butyl acrylate can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a one-component developing device suitable for carrying out the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Toner tank 2 Toner carrier 3 Toner layer thickness regulating member 4 Toner supply member 5 Photoconductor 6 Stirrer blade 7 Toner 8 Development interval

Continued on the front page (72) Inventor Masato Igarashi 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Noritaka 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Kosuke Suzuki 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Kumi Hasegawa 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. 2H005 AA01 AA06 CA04 CA08 CA30 EA06 EA07

Claims (6)

[Claims] 1. A toner for developing an electrostatic image, comprising a non-migratory plasticizer in a toner comprising at least a binder resin and a colorant. 2. The toner according to claim 1, wherein the binder resin is a copolymer of styrene and butyl acrylate. 3. An electrostatic image developing toner resin, wherein a non-migratory plasticizer is dispersed in advance. 4. The resin for developing an electrostatic charge image according to claim 2, wherein a non-migratory plasticizer is previously dispersed in a copolymer of styrene and butyl acrylate. 5. The toner or toner resin for developing an electrostatic image according to claim 1, wherein the non-migratory plasticizer has a molecular weight of 1,000 to 8,000. 6. The electrostatic image developing toner or toner resin according to claim 1, wherein the non-migratory plasticizer is 1 to 20 parts by weight based on 100 parts by weight of the binder resin.