JPS5945450A - Toner for developing electrostatic image - Google Patents

Abstract

PURPOSE:To obtain an electrostatic image developing toner fixable properly by the heat roll fixing system, by incorporating a positively chargeable substance in a graft copolymer obtained by graft polymerizing a vinyl monomer with a specified unsatd. polyester. CONSTITUTION:An unsatd. polyester is obtained by condensing an equiv. amt. of polyol with a mixture of polybasic acid consisting 5-90mol% unsatd. dibasic acid having an unsatd. bond of C=C, and another polybasic acid, such as satd. dibasic acid. A graft copolymer is obtained by graft polymerizing 99.9-90pts.wt. vinyl monomer with 0.2-10pts.wt. of this unsatd. polyester, and it is used as a binder. The positively chargeable substance, a colorant, and other additives used for the toner components are dispersed into the fine particles of this binder to obtain an electrostatic image developing toner.

Description

[Detailed description of the invention]

The present invention relates to a toner for developing electrostatic images formed in electrophotography, electrostatic printing, electrostatic recording, and the like. Generally, an electrostatic image is developed into a toner image by using a so-called toner consisting of a binder, a colorant, etc., and this toner image is transferred to -11 or transfer paper and then fixed. 'Various types of fixing methods are known, but the contact heating fixing method used in heating roller fixing devices, etc. has a particularly high thermal efficiency compared to the non-contact heating method used in hot plate fixing devices, etc. It is advantageous in that it can be quickly and definitively determined. However, in such a fixing method using a heating roller, the toner must be reliably softened and fixed at the heating temperature, and some of the toner may be transferred to the heating roller (
It is necessary to prevent the occurrence of the so-called offset phenomenon that occurs due to exposure to light, and as a technique for solving such problems, for example,
The publication describes the use of a toner having as a binder a resin made by mixing a low-molecular 12-polymer and a 3-molecular-weight polymer. However, this toner is
Since the binder contains a polymer M'ton, it is effective in preventing the occurrence of offset phenomenon, but it has a high softening point and as a result, it cannot be fixed unless the constant MMn'r degree is considerably high. Therefore, there are many practical problems such as requiring a large amount of energy, requiring a long time to preheat the heating roller, and requiring greater heat resistance and durability than the heating roller. There is. and,
In order to lower the softening point of the toner, increasing the proportion of low-molecular H1/polymer in one binder not only lowers the offset antibacterial property, but also lowers the glass transition point of the binder, making it difficult for the toner to be stored or It begins to aggregate in the developing device. On the other hand, in 11th Publication No. 51-23354, it is described that a crosslinked resin is used as a toner binder in order to prevent the offset phenomenon. Increasing the crosslinking density of the resin to the extent required for this purpose increases the temperature required for fixing, resulting in the same problems as with the toner described above. However, since the resin has a three-dimensional structure, it is difficult to crush it, making it impossible to advantageously produce toner. In addition, the high molecular weight polymers or crosslinked resins mentioned above are extremely hard, and therefore, when a toner containing them as a binder component is used, it may cause fatigue and deterioration of the rollers. is large and the corresponding addition M+, i-ra all"
1. The F1 Kut phenomenon can be easily inherited. It's okay. In order to prevent this polymerization as well as the offset phenomenon, it is effective to supply mold release oil such as silicone oil to the surface of the heating roller, but the mail does not heat up. The odor is emitted and the smell is t'', the appearance is u'! The structure of the fixing device becomes complicated because the inside is contaminated and a mail supply device is required. le H =, the toner is charged by friction, and is attracted to the electrostatic charge image formed by the electrostatic charge of the opposite polarity to the charged polarity using electrostatic attraction, and the current friction is carried out. ．． In the E Kokata JC, method, a negatively chargeable material is preferably used for forming an electrostatic charge image in the method, and therefore, a positively charged material is used with the toner. is static 1 (relative to the state of sleepiness in front of the house Z)
The present invention has been made based on the above-mentioned circumstances, and the object thereof is to provide a belt with good fixing properties and excellent anti-offset properties. Therefore, it is an object of the present invention to provide an electrostatic image developing toner which can be suitably fixed by a heating roller fixing method, and which can achieve good development by controlling the charging characteristics in frictional charging. 9.2 to 10 parts by weight of an unsaturated polyester obtained by condensing a polybasic acid containing 5 to 90 mol of an unsaturated dibasic acid and a polyhydric alcohol, This is achieved by an electrostatic charge r-image developing toner characterized by containing a graft polymer obtained by graft polymerizing parts by weight and a positively chargeable substance.The present invention will be specifically explained below. In the invention, the unsaturated vesicle consists of an unsaturated dibasic acid having an unsaturated bond formed by a carbon-carbon double bond and another polybasic acid, for example, a saturated dibasic acid, and the ratio of the pre-Mj2 unsaturated vesicle 1 dibasic acid is An unsaturated polyester is obtained by condensing 5 to 90 molar mixed polybasic acid with a corresponding amount of polyhydric alcohol, and 99.9 to 99.9 molar vinyl monomers are added to the unsaturated polyester at 0.2 to 10 seams. 90 weight (ni) Okabe wo Granodo ili: r: Zeshime, J41i <
Graph obtained by 11t) 31g f-f;
It is used as a toner component, and contains an IE positively chargeable substance, an annular coloring agent, and other additives for toner components dispersed in the fine particles.
The resulting toner is used as a toner for developing electrostatic images. Since the toner of the present invention has the above-mentioned graft-combined binder, the following effects can be obtained, as will be clear from the examples described below. That is, the graft polymer d- of the binder, in the vinyl system,
90 weight i? Since it contains more than i′, even if the molecule

[2 is extremely low. Furthermore, since the softening point of the binder is low, even when the toner of the present invention is deposited at a low temperature, it has a high melting/fluidity and a high permeability into the paper. °C has a large anchoring effect on paper14)
After fixing, it is difficult to remove from the paper. Furthermore, since the binder has a high molecular weight, the toner of the present invention is strong, and after fixing, the toner has a high molecular weight of 1? Come on, picture jiff
Forming 1 ~ 1 · Dog - is partially due to scratches 11
'11 Sea Cllll11 mound is blurred or visible on fingers etc.
L/ /i-Rizu, 4+ t 7! Near J'Su<, 4
Due to the single-line nature of the 7B fusion u:p, it does not adhere to the heating roller, thereby preventing the occurrence of an offset phenomenon. In addition, the 1-minute f-chain state of the cluster Ijf + union has a relatively large 9th property 2, and therefore, the
The toner will not be scraped and lost due to bending or bending of the paper after the toner removal process. As described above, according to the first aspect of the present invention, sufficient fixing performance can be achieved at low temperatures, and sufficient fixing properties can be obtained.
・Not only can the toner be resistant to 11J), but it also does not require the presence of acid components in the binder, so it has less brittleness, and can therefore be used to prevent crushing in the toner manufacturing process. In the case of contamination, < is favorable in terms of freedom 7
The generation of ultra-fine toner is small, the toner yield is improved, and it can be produced unfavorably, and a good visible image without capri is formed. In addition to the above, the present invention has the following advantages. That is, in the production of a binder, since the unsaturated polyester is susceptible to radical reactions, it can be used to advantageously carry out the graft polymerization of vinyl single ridges with high efficiency. In addition, since the unsaturated polyester to be grafted is obtained by condensation of a polybasic acid containing an unsaturated dibasic acid and a polyhydric alcohol, by changing the type and proportion of the unsaturated dibasic acid, the molecule-lid, A variety of polyesters with different densities or positions of unsaturated groups are available; therefore, by selecting an appropriate unsaturated polyester, by selecting the type of polyhydric alcohol, and by selecting the reaction conditions, the graft polymer can be prepared. By adjusting the molecular weight of
It is possible to obtain a binder having the required properties, and as a result, it is possible to obtain a toner with favorable time resistance. Furthermore, since the toner 11 of the present invention contains a positively chargeable substance of 1.7%, it can be charged to a suitable state in a frictional charging process using stirring or the like performed during treatment. That is, a toner whose binder contains a polyester component has a considerably high degree of negative chargeability due to the properties of the polyester component, and it is difficult to develop an electrostatic charge image due to positive charges as well as a static charge of 1& due to negative charges. It may happen. (-However, since the toner of the present invention contains a positively chargeable substance, its negative chargeability is weakened or it becomes positively chargeable. As a result, electrostatic images caused by negative charges can be developed well. Alternatively, it is possible to develop an electrostatic image with a positive charge using a negatively chargeable electrophotographic photoreceptor using an organic photoconductive substance, and to develop the electrostatic image with a positive charge.
The statue can be used as a good queen. In the present invention, the graft is used as a toner binder,
? The polybasic acid used to obtain the unsaturated polyester, which is the raw material for lj coalescence, contains 5 to 90 mol, preferably 20 to 80 mol, of a vesicular di41 acid having an unsaturated double bond that serves as a grafting reaction site. It's something to see. When the proportion of the vesicular Waji-1 focal base acid is less than 5 moles, the resulting unsaturated polyester has fewer grafting reaction points, making it difficult to graft-polymerize the vinyl-based ready-to-polymer in the desired proportion. However, since the resulting graft polymer has a low K, toners using this as a binder have poor scratch resistance and anti-offset properties. Further, when the upper Mi2 ratio exceeds 90 moles, the resulting graft polymer has a large molecular weight and a high softening point, resulting in a toner resulting from this having low fixing properties. The unsaturated polyester has a number average molecular tb of 1,000 to
20,000, Special K 5,0 (10~10.(100
3. Tear and heavy dark average molecular composition. old) 0~3 (1,
000, especially 5.0 (10 to 20.000, and the value of the dispersity Mpr7'Mn is preferably 5.0 or less. Number average molecule -) - or xi knight average molecule - Oboro is If the molecular weight is small, naturally it will not be possible to obtain a graft polymer with a large molecular weight, and the toner will have low scratch resistance and offset prevention. If the molecule-6 is too high, the degree of toner fixation will be high. In addition, the softening point of polygon sprue is 80 to 14.
It is preferable that ζ is 1O()~]30c in 0C~lr¥. Moreover, the glass transition point is 40-901. ', especially 50-80
It is preferably U. If vesicles with a softening point of less than 80C or a glass transition point of less than 40C are present, the toner will aggregate and cause problems.
When using a vesicle No. 11 polyester whose softening point exceeds I J oc and whose floating point exceeds 90 C by 1, toner lz, J: toner becomes too hard and has poor fixing properties. There is a direction. The above-mentioned unsaturated polyester υ, an unsaturated dibasic acid and another poly-1fi group, preferably i, i: a polyester obtained by condensing a mixed system with a saturated poly- or La-based acid with a polyalcohol. ). Specific examples of suitably used unsaturated dibasic acids and [7
Examples include t, 1' maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, and others, and are also used in combination with t, l: n, l. A specific example of the saturated polybasic acid used is 6'
For example, tetrachlorophthalic anhydride, het acid, tetrabromo phthalic anhydride, phthalic anhydride, isophthalic acid,
Alephthalic acid, endomethylenetetrahydrophthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, succinic acid, adipic acid, azelaic acid, sebacic acid, other monobasic acids, trimellitic acid, trimellitic anhydride, Via Merit rlt, vinyl anhydride can contain mellitic acid and other saturated polybasic acids, and can be used as a mixture for medium seeds. Specific examples of polyhydric alcohols that are preferably used include ethylene glycol, propylene glycol,
．． 4-butanediol, 1,3-butanediol, didilene glycol, diglobylene glycol) L's
)! /ethylene glycol, 1,5-betanediol, 1,6-penta/dimethyl, neohentyl glycol, hydrogenated bispher/-A. Examples include polyoxyethylene bisphenol A1, polyoxypropylenate bisphenol A1, glycol, glycerin, and polyhydric alcohol, which are used in combination. In the production of vesicular polyester, in addition to the above-mentioned necessary components, a molecular regulator such as benzoic acid, and a reaction catalyst or reaction promoter consisting of a metal-organic compound are added. For production, conventional methods may be used; the reaction is carried out in an inert gas atmosphere at a temperature of, for example, about 200C, and the water produced as the reaction progresses at normal pressure or reduced pressure F. removed by a capacitor. The progress of the reaction is monitored by sequentially measuring the acid value of the reaction product, and the reaction is terminated when the pI/value reaches the desired value of 114. 1υr〈1. By grafting a vinyl-based single 1π compound onto the unsaturated polyester obtained in this manner, a grafted nail aggregate, which is used as a binder for the toner of the present invention, is obtained. The ratio of unsaturated polyester to vinyl rF rod is 0.2-10:998-90, preferably 0.5-8:99.5-92. Specific examples of vinyl-based Qt IN bodies include styrene, 0-methylstyrene, m-methylstyrene, P-butylstyrene, (χ-methylstyrene, p-ethylstyrene, 2+4-dimethylstyrene, p-n-butylstyrene, Styrene, p-tart-butylstyrene, p-n-hexylstyrene, p-n-octylsgrene, p-n-nonylstyrene, p,-n-tethylstyrene, p-rhototethylstyrene, p- Aromatic vinyl monomers such as methoxystyrene, p-phenylstyrene 7, p-chlorostyrene, and 3,4-dimethylstyrene; for example, methyl acrylate, ethyl acrylate, acrylic NR n-butyl,
Isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, lauryl acrylate, 2-ethylhegycyl acrylate, stearyl acrylate, 2-chloroethinopea acrylate, phenyl acrylate, methyl α-chloroacrylate, etc. Acrylic esters; methyl methacrylate, ethyl methacrylate, propinope methacrylate, n-butyl methacrylate, inbutyl methacrylate, methacrylic tllll
Methacrylics such as n-octyl, dodecyl methacrylate, lauryl methacrylate, 2-ebulhexyl methacrylate, suarinope methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc. Nisderyl acids; vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, etc. Vinyl esters; vinyl acetate, vinyl propionate, vinyl benzene, vinyl acetate, etc. I can list the songs by Knee't.The above vinyl monographs may be written by students, but)'j
'l group vinyl monomers 4M, styrenic monomers 60-901, acrylic esters and/or Nisder methacrylates 40-10% M1%
And all unions 1! : I like to use it with '! 1. ．． In this phase, a graft polymer is formed which provides a toner preferable in terms of softening point, impact resistance, anti-offset properties, and non-quadrility. That is, the styrenic monomer is 60,i
When the amount of 1j is less than 1, the graph 1 polymer that is used is easily softened at low +i+A, resulting in a toner with high cohesiveness, and the styrene monomer is less than 90%.
iM: If it exceeds A, the graft polymer described in Publication 1 becomes hard and has a high softening point, making it difficult to handle toner. Grafting reaction can be carried out by bulk polymerization method, solution polymerization method, suspension A
[This can be done legally, using emulsion polymerization methods, etc.
Among these, the suspension-polymerization method is preferred. When using suspension 1
Using 0 to 90 parts as a medium, unsaturated polynisdel, polymerization catalyst, molecular weight regulator, etc. are dissolved in a vinyl-based single fragment. 1. Add to the medium with stirring F and suspend it in the form of fine particles. 4+, 1. The reaction takes place at i. reaction y
! The +'N degree is 50 to 12 (11,'), and the limb stabilizer is removed from the solid by washing with water after the reaction path r and separating with j'. As a catalyst for polymerization in C, azo polymerization initiators such as t↓, peroxides such as benzoyl diperoxide and lauroyl peroxide), intermediate initiators, azopisisobutyroni), and other polymerization The initiator is used in a range of 0, ii, 0, 1, 2, 3, 3, 3, 3, 3, 4, 5, 6, 7, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 12, 12, 12, 12, 10, 10, 10, 10, 10, 0, 10, 10, 0, 10, 0, 0, 0, 0, 0, 0, 3, , . In addition, in molecular additives 1,1 and 17, for example, dodecyl mercaptan, butyl mercaptan, etc. are 0 to 10 to 9 monomers! <Used within the scope of completion. Furthermore, in order to make the polymer obtained by grafting have a three-dimensional cross-linked structure, it is also possible to add a cross-linking agent to the crosslinking system. U,
1.1 (i) Compounds containing two organic functional groups, such as divinylbenzene, divinylbuftanone, derivatives thereof, and other aromatic divinyl compounds; such as ethylene glycol diacrylate, Glycol dimethacrylate, trimethylolpronochloride acrylate, carboxylic acid ester that makes the two-handed bond of the song: 1111 can be mentioned, and its use rA:, nJ; The binder of the toner of the present invention, which is in the range of () to 10 weight scales, is the above-mentioned graft 71!, the combination of the five components and (2
50% of the entire binder should be broken down with the resin of A1.
It may have λ in a range of less than 100%. If here! Examples of the wood content of J include 1, polynisder, polyamide, polyurethane, polyurea, epoxy 4F+4 fat, phenol-formalin gel 1 fat, and others, which may be used alone or in combination of two or more. It will be done. Front i Graft vehicle chassis T, Self) λ [140U Nira-k
The bath melt viscosity If is 1 ( ) 4 to 107 voids (L is preferable 0) The toner of the present invention, the binder and 113
iE. Contains 1' opening and 44'-. Positive chargeability%1・
T! I and (2 te includes -zo sai t・) ``I thing 1・'
The IL band of the 1st day's ``I can't get the talent I need.''
L < (tyu bow!+i, 1/,) ”)Re, :1
v is a substance T4 whose negative chargeability is weakened by 1.
Specific examples of t- and 1 to te], yll is 4, 4',
4”-Meboulidine) Lis (N I N-dimethylaniline), Mesolupai H Reno I- (C. ■, ed. 42535), Crystal Bay No.
, I. 42555), Visitory 1 Blue 11 (C,
1, & 44045), its 111A aminotriphenylmethane dyes, e.g. Examples include chlorite, simiristyl dimethyl chloride, and other quaternary ammonium salt compounds. These positively chargeable substances are used singly or in combination in a range of 0.1 to 10% by weight, preferably 105 to 4% by weight. The toner of the present invention contains d7, a colorant and a coloring additive. Any suitable pigment or dye can be used as the colorant here. Colorant and 1. So, carbon black, nigrosine dye (C, 1, boiled 504), 51, agoniline blue (C,
i. A 50405 ), Calco oil blue (C, 1, flat azoec R1t+e 3 ), chrome yellow (C
, 1, A1.4090), ultramarine blue (C,
1, A77.103), DuPont Oil Red (C, I
, A26105), quinoline yellow (C,1,A
47005) medilene blue chloride (C1I,
A52015), Phthalocyanine Blue (C,1,
74160), malachite green oxalay) (C
,I. Cup 420 (10), lamp black (C, 1,
77266), Rose Bengal (C, 1, A4543)
5), mixtures thereof, and others. These colorants are adjusted so that they are contained in a proportion of about 3 to 20% by weight in the toner as a final product. , a charge control agent, a flow qdJ agent, an IT liquid resin, etc. can be added. Examples of anti-offset agents include V, for example, low molecular weight polyolefins with a number average molecular weight of 500 to 1.
0,000 and a softening point of 100 to 180C is preferable. The toner of the present invention can be manufactured using a conventionally known method, for example, by kneading toner materials with a heated roll, heated extruder, etc. [7] After that, cooling, crushing, and classifying the toner materials. can. In this specification, the softening point refers to the measuring strip 1/I'' using Koka Type Flow Tester 1-CFT-500 Model (manufactured by Shima (P-Seisaku Shin)) at an evening f weight of 20 kf7hn 2.
, the nozzle diameter is 1 + n, the nozzle M is 1 degree, the preheating is 80 C for 1 degree, the heating rate is 6 U/minute, and the sample amount is 1 Yen (weight expressed as intrinsic specific gravity x 1 side 3...). When measuring and recording, the plunger of the flow tester descends f? 4 Knee t) The height of the figure 8 1 C line in the knee λ degree curve (softening flow curve),! Melt viscosity means 6 (11) as in 7 above,
The viscosity V'I is calculated using the following formula using the data. P: Test pressure (dyne/shin 2) ■,: Nozzle length crn) R: Nozzle radius (cm) Q:! Mu h (mt/sec) General However, cross-sectional area of A Nijilinda (2) ΔX: Measurement stroke rcX, ) Δt: Measurement time and glass transition point
(manufactured by Rigaku Denki Co., Ltd.) was used to measure the temperature at a heating rate of 10 C/min.
When the glass transition point is defined as the temperature at the intersection of the extension line of the baseline below the glass transition point of the C thermogram and the tangent line showing the maximum slope from the rising part of the peak to the apex point of the peak. It means candy. Number one in a polymer? , Mn per molecule, and average molecular weight per molecule can be measured by various methods, and there are slight variations depending on the measurement method. In accordance with i) of this specification, Mn and Miao are defined as fl]11 obtained by the following rectangular measurement method. That is, each of these first and other libraries was measured using gel permeation chromatography (GPC) as described below. 10 minutes 1.2+M
Measurement is performed by injecting 3 mg of a tetrahydrofuran sample solution with a concentration of about 15/5 ml (calculated by sample weight replacement) at a flow rate of 12. When measuring the molecular liquid of a sample, the measurement conditions are such that the desired molecular weight of the sample falls within the range where the logarithm of the molecular weight and the count number of a calibration curve created using several types of monodisperse polystyrene standard samples are a straight line. select. In addition, in this measurement, the reliability was checked under the above measurement conditions /ζNB5706 boristyrene standard sample
, 7X10', Le=28.8X10'). The GPC column used in the above may be any column as long as it satisfies the above conditions, but examples include rTSK-GEI heat, "GMIX (6)" (
(manufactured by Toyo Soda). The image forming member to which the toner of the present invention is applied is not particularly limited as long as it can hold an electrostatic charge image on its surface. Photoconductive members such as negatively charged photoreceptors coated on a conductive support, and dielectric recording materials coated with an insulating resin on a conductive support can be suitably used. . In order to form an electrostatic charge image on this image forming member, for example, a method of uniformly charging the surface of the 1IIIj image forming member with a charger and then performing imagewise exposure, an electrostatic recording needle or an ion flow method is used. A method of forming a direct image on the imaging member by means such as a control electrode, etc. may be used. Implementation of the Present Invention 15.1 V (Then 1411. Light 1 ゛, this) 1 et al. 1) Light is inhibited (not. [Made of unsaturated polyester] [Light] Table 1 shows the composition of 7 dos l (component composition) according to the conventional polyester manufacturing method (+Y-, Fukufu nH2 (1 (1
℃T reaction Why is the produced water removed thoroughly?
When the acid value of the polyester produced (7) reaches 17, the reaction is terminated and the vesicle No. 11 of the five gods is formed.
Polynisple A~1.8 is manufactured/this. Among these, unsaturated polynisdel I) and 11; have a proportion of vesicular Ill dibase acid of less than 5 mol % and more than 90 mol %, respectively. Table 1 [Production of graft polymer] Temperature Fit, stirrer and gas introduction pipe were changed.
11i-1/. In one flask, add 3% by weight of dispersion stabilizer/(iQ Tsunorununo・()) and 1100 tons of
) Add all 300 parts of steamed seedling water to the flask, fill it with 300 parts of steamed seedling water, add nitrogen gas to the gas inlet tube, and maintain an atmosphere of scum in the flask, as shown in Table 2. The composition shown in 11 was added and allowed to hang, and in this state, the temperature of the system was raised to 800G to carry out graft polymerization, and after 8 hours, the system was cooled to solidify. The molds are separated in a furnace and washed repeatedly, and then dried to produce 8 kinds of craft polymers 1 to 1.
■ is manufactured 1-. ξ, σ) Back, kraft polymer V and ■1 are those in which the ratio of heavy gun i1 + polyester is more than 2% JO heavy and ()1 weight is less than 1't%, i fr-graso t- ? fi combination V11 and) 1
11 is each t] unsaturated polynispur or unsaturated polyimil x
7. Too little or too much dibasic acid component. . Table 2 Example graft polymers 86 parts by weight, 2 parts by weight of methyl violet, and carbon black "Mogal L
A mixture of 10 parts by weight of low softening point polypropylene [VISCOL 660P43] was melt-kneaded using two rolls, cooled, pulverized using a jet mill, and classified using a zigzag classifier. A total of four types of toners of the present invention having an average particle size of 12 microns were manufactured. These were combined [toners 1-j to "toner 4"] to produce 6F4 types of specific axis toners in the same manner as in the examples except that each of Comparative Example Graft Polymers V to ■ was used. These are referred to as "-comparison toner-1" to "-comparison toner-4." Experimental Example A copolymer obtained by copolymerizing each of 5 parts M of the / A developer is prepared by mixing 1 part of a 95-weight carrier coated with powder particles, and this developer is used to mount an organic photoreceptor and equip it with a negative corona charger. A copy test was conducted using a modified copying machine rU-Bix VJ (manufactured by Konishiroku Photo Industry Co., Ltd.), and a fixability test and an offset test were also conducted. M, dumb 1 and are shown in Table 3. In the fixation test, the electrostatic charge image formed by the conventional electrophotographic method (29) was developed with the above-mentioned developer, and the resulting toner image was transferred onto transfer paper. Warm with Teflon (polytetrafluoroethylene manufactured by DuPont)
The heating lawn and the surface layer are made of silicon, rKE-1
A fixing device equipped with a compression roller consisting of 300R'l', V, and J (manufactured by Shin-Etsu Chemical Co., Ltd.) increases the linear speed by 1.
50"/H Set the d1 temperature of the L2 heating roller to a moderate temperature to fix the toner image7.
, the external low temperature TF at which fixing is possible in the heating roller was determined. In the offset test, one toner image obtained in the same manner as in the fixing test was transferred onto transfer paper, and after the toner image was fixed by the above-mentioned fixing device, a blank transfer paper was operated under the same conditions. By feeding the transfer paper to the fixing device in which the transfer paper is set, and observing whether or not toner stains occur on the transfer paper, it is determined whether an offset phenomenon has occurred or not. One experiment was conducted at various temperatures. Then, the lowest set temperature at which the offset phenomenon occurs (minimum offset occurrence temperature To) f: was determined. (30) Table 3 (Part 1) Table 3 (Part 2) Note that the minimum temperature TF at which fixing is possible is such that the toner in the image area did not peel off even if the adhesive tape was attached to the copied image and then peeled off. It is the lowest temperature. As is clear from the following results, according to the toner of the present invention, not only the initial period but also I 00 (l 0 after 0 copies).
? However, if there is a good copy image free of capri and cracks,
Also, the temperature at which fixing is possible is low, and offset prevention 1]-
It is also a toner with excellent properties. On the other hand, the comparative toner in which the component proportion of unsaturated polyester in the graft polymer of the binder is too large is caused by the capri and wrinkles in the copied image, which are recognized to be due to the large #lt property and the generation of charged particles of opposite polarity. According to comparative toner 2, in which the component proportion of unsaturated polynisder is too small, conversely,
Low offset prevention property, 1.Durability is low, 1. O
After f'+00 copying, the copied image becomes a reddish color like Capri and That. In addition to the above, a toner was obtained in the same manner as in Example 1, except that methyl violet, which is a positively charged substance, was removed. ζ,
I made a developer using this and conducted a similar copying test, but no image was formed and no image was formed. Agent Ui・10. Dog, ll“ Masahiko ・□:
,,,', ,,,, :・\4ha゛

Claims (1)

[Claims] 1) 1 polyester 0.2 to 10'M to a vesicle obtained by condensing a polybasic acid containing 5 to 90 mol of an unsaturated dibasic acid and a polyhydric alcohol. A toner for developing an electrostatic image, comprising a graft polymer obtained by graft polymerizing a vinyl monomer 99,8 to 90 double kick part, and a positively chargeable substance. 2) The toner for developing an electrostatic image according to claim 1, wherein the vinyl monomer contains 60% by weight or more of a styrene monomer.