JPH0411863B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a positively chargeable toner for developing electrostatic images used in fields such as electrophotography and electrostatic recording. (Prior Art) As toners for developing electrostatic images used in the fields of electrophotography and electrostatic recording, toners using styrene/acrylic copolymer resin as a binder resin (Japanese Patent Publication No. 1983-1999-1)
11143), etc.), toners using vinyl resins,
Toner using a bisphenol type epoxy resin obtained by reacting bisphenol and epichlorohydrin as a binder resin (Japanese Patent Application Laid-open No. 57-96354),
Toner using a polyester resin obtained by reacting a glycol having a bisphenol skeleton with a polybasic acid as a binder resin (Japanese Patent Publication No. 52-25420)
However, compared to other resins, vinyl resins can be used in the majority of toners because their physical properties such as molecular weight, glass transition point, and melt viscosity can be manipulated over a wide range, which is extremely advantageous in terms of toner design. is dominated by toners using this vinyl resin as a binder resin. In order to impart preferable positive chargeability to these toners, substances that impart positive chargeability to the binder resin (hereinafter referred to as positive chargeability imparting substances), such as nigrosine dye (Japanese Patent Publication No. 59-11901), triphenyl Methane dye, benzoguanamine resin
No. 192048), quaternary ammonium salts (Japanese Patent Application Laid-open No. 1983-
9154) etc. (Problems to be Solved by the Invention) As mentioned above, toners made of styrene/acrylic copolymer resin, which is a vinyl-based binder resin commonly used in the production of toners, are made from soft vinyl chloride polymers. This tends to cause adhesion, and when printed materials are sandwiched between sheets of soft vinyl chloride polymer, this can cause print defects. Further, when producing a positively chargeable toner by mixing a chargeability imparting substance with a binder resin, the following problems arise. (1) Since the chargeability imparting substance has poor compatibility with the binder resin and is not uniformly dispersed, the charge of each toner particle is distributed over a wide range from positive to negative, which tends to cause fogging on the fixed image. (2) Since the chargeability imparting substance is not well mixed with the binder resin, the substance adheres to the carrier surface or the photoconductor surface, causing a filming phenomenon, a change in print density, fogging, and a decrease in resolution. (3) Since chargeability imparting substances are generally colored, they are not suitable for color toners. (Means for Solving the Problems) The present invention provides a positively charging material for developing electrostatic images comprising a polymer having a vinyl monomer represented by any one of the following structural formulas as a binder resin. Regarding sex toner. (However, in the above formula, R ₁ , X ₁ and X ₂ are each independently hydrogen or a methyl group, R ₂ is an alkylene group having 1 to 6 carbon atoms, R ₃ , R ₄ .R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ are each independently hydrogen, an alkyl group having 1 to 3 carbon atoms, or

[Formula], where R ₁₁ and R ₁₂ are each independently hydrogen or an alkyl group having 1 to 5 carbon atoms, and each of the above structural formulas or each

[Formula] The above polymer is a polymer of at least one vinyl monomer selected from the group consisting of vinyl monomers represented by the following structural formula, a copolymer of two or more types, and a copolymer of two or more vinyl monomers and other vinyl monomers. It is a copolymer of Among the constituent components of the polymer, the vinyl monomer represented by the following structural formula is contained preferably at least 10% by weight, particularly preferably from 10 to 90% by weight, and even more preferably from 20 to 80% by weight. If this amount is too small, the adhesion resistance and positive chargeability to the soft vinyl chloride polymer tend to be insufficient. Here, other vinyl monomers include styrene, α-methylstyrene, p-methylstyrene,
Styrene derivatives such as pt-butylstyrene and p-chlorostyrene, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, decyl methacrylate , undecyl methacrylate, dodecyl methacrylate, glycidyl methacrylate, methoxyethyl methacrylate, propoxyethyl methacrylate, butoxyethyl methacrylate, methoxydiethine glycol methacrylate,
Ethoxydiethylene glycol methacrylate, methoxyethylene glycol methacrylate, butoxytriethylene glycol methacrylate, methoxydipropylene glycol methacrylate, phenoxyethyl methacrylate, phenoxydiethylene glycol methacrylate, phenoxytetraethylene glycol methacrylate, benzyl methacrylate, methacrylate Cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate, N-vinyl-2-pyrrolidone methacrylate, methacrylonitrile, methacrylamide, N-methylolmethacrylamide, ethylmorpholine methacrylate , 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate,
Hydroxybutyl methacrylate, methacrylic acid 2
-Hydroxy-3-phenyloxypropyl, diacetone acrylamide, acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate,
Hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, glycidyl acrylate, methoxyethyl acrylate, propoxyethyl acrylate, butoxyethyl acrylate, methoxy acrylate Diethylene glycol, ethoxydiethylene glycol acrylate, methoxyethylene glycol acrylate, butoxytriethylene glycol acrylate, methoxydipropylene glycol acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxytetraethylene glycol acrylate, benzyl acrylate , cyclohexyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, N-vinyl-2-pyrrolidone acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, Having one vinyl group in one molecule, such as 2-hydroxy-3-phenyloxypropyl acrylate, glycidyl acrylate, acrylonitrile, acrylamide, N-methylol acrylamide, diacetone acrylamide, ethylmorpholine acrylate, vinylpyridine, etc. Vinyl monomers, divinylbenzene, reaction products of glycol and methacrylic acid or acrylic acid, such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,5-pentane Diol methacrylate, 1,6-hexanediol methacrylate, neopentyl glycol dimethacrylate, diethylene glycol methacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate,
Tripropylene glycol dimethacrylate, hydroxypivalic acid neopentyl glycol ester dimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, trismethacryloxyethyl phosphate, bis(methacryloyl) (oxyethyl) hydroxyethyl isocyanurate, tris(methacryloyloxyethyl) isocyanurate, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1 , 6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene diacrylate, hydroxypivalate neopentyl glycol diacrylate, trimethylolethane triacrylate, Methylolpropane triacrylate, pentaerythritate triacrylate, pentaerythritate tetraacrylate, trisacryloxyethyl phosphate, bis(methacryloyloxyethyl)hydroxyethyl isocyanurate, tris(methacryloyloxyethyl)isocyanurate, glycidyl methacrylate and methacrylic acid or a half ester of acrylic acid, a half ester of bisphenol type epoxy resin and methacrylic acid or acrylic acid, a half ester of glycidyl acrylate and methacrylic acid or acrylic acid, etc.
Vinyl monomers having two or more vinyl groups in the molecule can be mentioned. Among these vinyl monomers, particularly preferred vinyl monomers having one vinyl group in one molecule include styrene, styrene derivatives, methacrylic esters, acrylic esters, etc. Preferred are alkyl esters of methacrylic acid or acrylic acid having 5 carbon atoms. As vinyl monomers having two or more vinyl groups in one molecule, divinylbenzene, dimethacrylates and diacrylates of methylene glycol having 2 to 6 carbon atoms, etc. are preferable, and these contain 0 to 20% by weight of all vinyl monomers. %
used. These vinyl monomers having one vinyl group in one molecule and the vinyl monomers having two vinyl groups in one molecule can be used alone or in combination of two or more types. The above vinyl monomer can be polymerized by solution polymerization, bulk polymerization,
Polymerization can be carried out by any method such as emulsion polymerization or suspension polymerization. Polymerization initiators used in the polymerization of vinyl monomers include acetyl peroxide, decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, and perdicarbonate. Diisopropyl, di-2-ethyl-hexyl perdicarbonate, acetylcyclohexane sulfonyl peroxide, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, tert-butyl peracetate, tert-perisobutyrate Known polymerization initiators include butyl, azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, tert-butyl per-2-ethylhexanoate, and tert-butyl perbenzoate. These are preferably used in an amount of 0.1 to 15% by weight based on the total amount of vinyl monomers. Further, it is preferable to use the vinyl monomer dissolved therein. The polymer preferably has a glass transition point of 40 to 40.
The temperature is 120°C, particularly preferably 50 to 100°C.
If the glass transition point is too low, caking will easily occur during toner storage or in the developing machine, and
Toner tends to become fine powder due to friction and collisions in the developing machine. On the other hand, if the glass transition point is too high, it becomes difficult to crush, making it difficult to crush during the production of toner, and the fixing strength to transferred materials tends to decrease. In the present invention, the above polymer is used as a binder resin, but other polymers may also be used in combination. Other polymers include polymers or copolymers of other vinyl monomers mentioned above, KR-
216, KR-220, KR152, KR-271, KR-255
(Manufactured by Shin-Etsu Chemical Co., Ltd.), SR-2400, SR-
Silicone resins such as 2406, SH-840 (manufactured by Toray Silicone Co., Ltd.) or Nosolex (cdF)
norbornene polymers such as C-200A, C-250A (manufactured by Mitsubishi Chemical Corporation), etc.
polyester carbonates such as Iupilon-1000 (manufactured by Mitsubishi Kosikagaku Co., Ltd.), or xylene resins such as Lignol R-70, R-120, R-140, and P-2 (manufactured by Lignite Co., Ltd.) Or Epicote 604, 1004, 1007, 1009, 1010, YL-903,
906 (manufactured by Ciel), Epomitsu R304, R307,
Epoxy resin such as R309 (manufactured by Mitsui Petrochemical Industries, Ltd.) or Nitzpol BR1220, 1032,
Diene resins such as 1441, IR2200, NBR, 2057S, 2007J (manufactured by Nippon Zeon Co., Ltd.) or
Polyester resin or phenolic resin such as ATR2005, 2009, 2010 (manufactured by Kao Soap Co., Ltd.),
Alternatively, there are coumaron resins, amide resins, amide-imide resins, butyral resins, amino resins, urethane resins, etc.
These other polymers are used in the toner in amounts ranging from 0 to 30% by weight. The toner of the present invention contains a colorant and/or magnetic powder. Coloring agents include carbon black, acetylene black, Hansa Yellow G, cadmium yellow, molybdenum orange, permanent orange, red iron oxide, rhodamine lake B, first violet B, methyl violet lake, dark blue, phthalocyanine blue, chrome green, and pigment green. B, zinc oxide, titanium oxide, nigrosine dye, methylene blue, rose bengal, quinoline yellow, ultramarine blue,
Conventionally known pigments or dyes include chrome yellow, aniline blue, calco oil blue, rhodamine 6G lake, watching red barium, watching hot strontium, malachite green oxalate, Dupont oil red, and mixtures thereof. These are 1 to 60 in the toner.
It is preferable to appropriately select and use it within the range of weight %. When the toner of the present invention is used as a one-component toner, magnetic powder is added. Magnetic powders include metal powders such as iron, manganese, nickel, and cobalt, aluminum, cobalt,
Copper iron, lead, magnesium, nickel, tin, zinc,
Alloys and mixtures of metals such as antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, aluminum oxide, iron oxide, copper oxide, nickel oxide, zinc oxide, titanium oxide, magnesium oxide, Metal compounds containing metal oxides such as chromium oxide, or alloys that exhibit ferromagnetism when heat treated, such as whisker color alloys such as manganese-copper-aluminum, manganese-copper-tin, etc., can be used. It can be contained in an amount of 30 to 70% by weight. The particle size of the magnetic powder is preferably 10 μm or less, particularly preferably 1 μm or less. In the case of a one-component toner, generally no colorant is added, but the colorant may be added in an amount of 10% by weight or less in the toner. The toner for developing an electrostatic image according to the present invention may contain other additives, if necessary. As other additives, fluidity improvers, cleaning improvers or offset inhibitors may also be added. The fluidity improver serves to impart high fluidity to the toner, facilitate continuous supply of the toner, and form a visible image of good quality. Hydrophobic silica powder is most suitable as the fluidity improver.
Such hydrophobic silica powder is made by combining fine powder of silicon dioxide whose surface silicon atoms are silanol groups, such as octyltrichlorosilane, decyltrichlorosilane, nonyltrichlorosilane, 4-
Isopropylphenyltrichlorosilane, 4-
tert-butylphenyltrichlorosilane, dimethyldichlorosilane, dipentyldichlorosilane,
Dihexyldichlorosilane, dioctyldichlorosilane, dinonyldichlorosilane, didecyldichlorosilane, didodecyldichlorosilane, 4-
tert-butylphenyl octyldichlorosilane,
Dioctyldichlorosilane, didecenyldichlorosilane, dinonenyldichlorosilane, di-2-ethylhexyldichlorosilane, di-3,3-dimethylpentyldichlorosilane, trimethylchlorosilane, trihexylchlorosilane, trioctyl By reacting with compounds such as chlorosilane, tridecylchlorosilane, dioctylchlorosilane, octyldimethylchlorosilane, 4-isopropylphenyldiethylchlorosilane, hydrophobic groups are formed on the surface silicon atoms of silicon dioxide particles via oxygen atoms. It is a combination of These hydrophobic silica powders have an average particle size of
It is preferably within the range of 1 mμ to 100 μm, especially
It is preferably between 2 mμ and 50 μm. If it is less than 1 mμ, the powder tends to scatter and is difficult to handle, and if it exceeds 100 μm, it tends to damage the photoreceptor. Such hydrophobic silica powder is
R972, Silica D-17, R812, RA200H, RX-
It is commercially available under trade names such as C (manufactured by Nippon Aerosil Co., Ltd.) and Taranox 500 (manufactured by Tulco). Although a toner may be manufactured by blending the hydrophobic silica powder as described above with other toner materials,
In particular, it is preferable to once manufacture a toner using toner materials excluding hydrophobic silica powder, and then add hydrophobic silica powder. When hydrophobic silica powder is added, it is preferable to add the hydrophobic silica powder in an amount of 0.01 to 15% by weight based on the toner powder not containing the hydrophobic silica powder. Particularly preferred is an addition amount of 0.1 to 10% by weight.
If the amount added is less than 0.01% by weight, the effect of improving fluidity will not appear, and even if it is added in excess of 15% by weight, the effect will not increase accordingly. The cleaning performance improver prevents the so-called filming phenomenon in which a portion of the toner components adheres to the surface of the photoreceptor or carrier, and serves to form a clear visible image without fogging even after continuous use over a long period of time. Cleanability improvers include metal salts of saturated or unsaturated fatty acids such as maleic acid, stearic acid, oleic acid, palmitic acid, caproic acid, linoleic acid, ricinoleic acid or ricinoleic acid with zinc, magnesium, calcium, cadmium, salts with lead, nickel, cobalt, copper or aluminum, especially zinc stearate,
Calcium stearate or magnesium stearate is preferred. When a cleaning performance improver is used, it is particularly preferred that the cleaning performance improvement agent is added in the same manner as the hydrophobic silica powder described above. The fatty acid metal salt is 0.01 to 25% by weight, especially based on the toner powder not containing the fatty acid metal salt and the hydrophobic silica powder.
It is preferable to add 0.1 to 10% by weight. 0.01% by weight
If it is less than that, the effect of improving cleaning performance will not appear.
However, adding more than 25% by weight does not increase the effect. It is advantageous to fix the toner image on the image support by a general heat fixing method, and this heat fixing method includes a non-contact heat fixing method such as open fixing, and a contact heating method such as hot roll fixing. The contact heat fixing method has advantages such as high thermal efficiency, miniaturization of equipment, and low power consumption. However,
In the contact heat fixing method, when the image support carrying the toner image passes through the hot roll, a part of the toner image is transferred to the hot roll, and after the hot roll has rotated once, the transferred toner image is transferred again to the image support. There is a serious problem of contamination. The offset preventive agent does not cause offset even in the hot roll fixing method and serves to form a high quality image. Offset inhibitors include ethylene, propylene, butene, pentene, hexene, heptene,
Polymers of olefin monomers such as octene, nonene, decene, 3-methyl-1-butene, 3-methyl-2-pentene, 3-propyl-5-methyl-2-hexene, or the above-mentioned olefin monomers and acrylics. Copolymers with acids, methacrylic acid, vinyl acetate, etc., lower alcohol esters of fatty acids such as butyl stearate and propyl stearate, Casta Wax A (manufactured by Ito Oil Co., Ltd.), Diamond Wax (made by Shin Nippon Chemical Co., Ltd.) Polyhydric alcohol esters of fatty acids such as palm acetate (manufactured by NOF Corporation), Hoechstwax E, Hoechstwax-OP (manufactured by Hoechst Aktiengesellschaft), carnauba wax, etc. Higher alcohol ester, Bisamide Blast Flow (manufactured by Nitto Chemical Industry Co., Ltd.), Amide 6L, 7S and 6H
(manufactured by Kawaken Fine Chemical Co., Ltd.), Hoechst Wax C (manufactured by Hoechst Aktiengesellschaft)
alkylene bis fatty acid amide compounds such as, zinc stearate, calcium stearate, magnesium stearate, barium stearate, copper stearate, aluminum stearate, zinc oleate, magnesium oleate, zinc caprylate, magnesium caprylate, zinc linoleate , fatty acid metal salts such as calcium linoleate, diene resins with a weight average molecular weight of 50,000 or more such as Nitzpol NBR, 2057S, 2007J, BR1220, hydroxy group-containing vinyl resins, carboxyl group-containing vinyl resins, etc. When an anti-offset agent is added, the anti-offset agent is preferably blended with other toner materials to produce the toner. The anti-offset agent is preferably added to the toner in an amount of 0.1 to 50% by weight, especially 1 to 30% by weight. If it is less than 0.1% by weight, the effect of preventing offset will not appear, and if it is added in excess of 50% by weight, the effect will not increase. In the present invention, the fluidity improver, cleaning performance improver and offset inhibitor as described above may be added alone or in combination. The above-mentioned materials can be mixed, for example, by the following method to produce a toner for developing electrostatic images. The weighed materials are premixed using a W cone, V blender, Henschel mixer, etc., and then kneaded using a pressure kneader, Banbury mixer, hot roll, extruder, etc. at a temperature at which the resin melts. After cooling, it is coarsely ground using a feather mill, pin mill, pulverizer, hammer mill, etc. Next, the particles are sieved using an Akiyukatsu or Alpine classifier to adjust the particle size to preferably 5 to 30 μm. The toner of the present invention can be applied to various known developing methods. Further, the toner of the present invention can be used by various fixing methods,
For example, it can be used in so-called oil-less and oil-coated heat roll methods, flash methods, open methods, pressure fixing methods, and the like. Furthermore, the toner of the present invention can be used in various cleaning methods, such as the so-called fur brush method and blade method. (Example) Next, an example of the present invention will be shown. Examples 1 to 10 and Comparative Examples 1 to 2 (1) Synthesis of copolymer 200 parts by weight of water and 0.3 parts by weight of a suspending agent (Denka Bhopal W-24, manufactured by Denki Kagaku Kogyo Co., Ltd.) were placed in a reaction vessel. After the preparation was uniformly dissolved, the temperature was raised to 90℃, and while stirring, a solution of vinyl monomer having the composition shown in Table 1 with 2% by weight of benzoyl peroxide, a weight initiator, based on the vinyl monomer was added for 2 hours. Add dropwise to perform suspension polymerization, then continue stirring while
It was held at 90°C for 10 hours. After cooling and filtering, the mixture was thoroughly dried to obtain a copolymer. Table 1 shows the glass transition points of the copolymers. (2) Manufacture of toner The materials shown in Table 2 were premixed in bulk using a Henschel mixer, and then melted and kneaded at 90°C using a uniaxial kneader. The cooled kneaded material was then finely pulverized using a pin mill and a jet mill, and classified using vibration and a sieve to obtain a toner having an average particle size of 10 to 15 μm. (3) Manufacture and testing of developer With 3 parts by weight of toner and an apparent density of 3.5 to 4.5 g/ ^cm3 ,
A developer was obtained by mixing with 97 parts by weight of iron oxide powder containing 90% by weight or more of powder diameters of 44 to 177 μm. A selenium drum rotating at a circumferential speed of about 20 cm/sec was uniformly positively charged with a corona voltage of +6 KV, information was written with a He-Ne laser, and reversal development was performed using the developer using a magnetic brush method. Then, it was fixed using a pressure roll fixing machine. This is a microphotometer
Table 3 shows the results measured using MPM type (manufactured by Union Optical Co., Ltd.). The print quality after printing 200,000 sheets was judged by changes in print density, increase in fog, etc. Print defects due to soft vinyl chloride polymer were tested by sandwiching printed matter between soft vinyl chloride polymer sheets containing 30% by weight of dioctyl phthalate under conditions of temperature 40°C, load 100gf/cm ² , and test time 300 hours. . The toner's caking resistance is at a temperature of 50℃ and a humidity of 60%.
The RH test was conducted under conditions of 18 hours. As is clear from Table 3, when printing with the developer using the toners of Examples 1 to 6, prints with good fixing strength (as judged from print density and fog density) were obtained, and 200,000 sheets were printed. No deterioration in print quality was observed even in this case. Furthermore, no printing defects were caused by the soft vinyl chloride polymer, and the caking resistance was also good. On the other hand, the toner of Comparative Example 1 did not show positive charging, and the toner of Comparative Example 2 had poor print quality and poor caking resistance as printing continued. Also, printing defects occurred due to the soft vinyl chloride polymer.

[Table] Γ Values in the table (excluding Tg) indicate parts by weight Γ Glass transition temperature measurement conditions Thermomechanical analysis method Pernation mode Load 70gf Heating rate 10℃/min Vinyl monomer A in Table 1 ~I is:

【table】

【table】

[Table] (Effects of the invention) The chargeable toner for developing electrostatic images according to the present invention is a toner that can control charge without using a charge control agent, which has been a problem in the past. By not doing so, it is possible to eliminate fogging, flaking, and changes in print density, and it is less likely to adhere to the soft vinyl chloride polymer.

Claims (1)

[Scope of Claims] 1. A positively chargeable toner for developing electrostatic images, which contains a polymer having a vinyl monomer represented by any of the following structural formulas as a binder resin. However, in the above formula, R ₁ , X ₁ and X ₂ are each independent hydrogen or methyl group, R ₂ is an alkylene group having 1 to 6 carbon atoms, R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and
R ₁₀ is each independently hydrogen, an alkyl group having 1 to 3 carbon atoms, or [Formula], where R ₁₁ and R ₁₂ are each independently hydrogen or an alkyl group having 1 to 5 carbon atoms; , each of the above structural formulas or each has at least one [formula])