JPH0786699B2 - Toner for electrostatic image development - Google Patents

Description

The present invention relates to an electrostatic image developing method for developing an electrostatic latent image formed in an electrophotographic method, an electrostatic printing method, an electrostatic recording method or the like. It relates to toner.

[Background of the Invention]

For example, in electrophotography, an electrostatic latent image is usually formed on a latent electrostatic image bearing member made of a photoconductive photoconductor by charging and exposure, and then this electrostatic latent image is formed by toner, which is a colored particle. After development, the obtained toner image is transferred to an image support such as transfer paper and then fixed by heat or pressure to form a visible image.

As a method for fixing the toner image, various methods have been conventionally used, but among them, the heat roller fixing method is preferable.
This heat roller fixing method is a method of fixing a toner image on an image support by transporting an image support such as paper carrying a toner image so as to come into contact with a heated roller. According to this method, it is advantageous in terms of safety and also in terms of energy saving and less heat loss.

However, when the heat roller fixing method is adopted,
At the time of fixing the heat roller, the toner comes into contact with the surface of the heat roller in a molten state. However, a part of the melted toner is transferred and adhered to the surface of the heat roller, and this toner adheres to the image carrier sent next. There is a problem in that a so-called hot offset phenomenon, in which re-transfer occurs and the image is stained, is apt to occur.

Further, in recent years, due to the demand for downsizing of high-speed copying machines or copying machines, it has been strongly desired to develop a toner capable of fixing at a lower temperature than ever before. That is, in a high-speed copying machine, when continuous copying is performed a large number of times, heat of the heat roller is considerably absorbed by the image support, and heat reinforcement cannot be performed in time, and as a result, the temperature of the heat roller decreases and fixing failure occurs. Cheap. In a small copying machine, it is necessary to reduce the capacity of the heater for heating the heat roller to make it a more energy-saving and compact copying machine. However, if the capacity of the heater for heating is reduced, it takes time to heat the heat roller. As a result, the waiting time becomes long, or if continuous copying is performed, heat supply cannot be made in time, and as a result, the temperature of the heat roller is lowered and fixing failure is likely to occur.

Therefore, the toner is strongly required to (1) have excellent hot offset resistance and (2) have excellent low-temperature fixability.

Therefore, conventionally, the following technique has been proposed as a technique for improving the low temperature fixing property while satisfying the hot offset resistance.

A non-linear polyester comprising a monomer containing a monomer having a valence of 3 or more, which has a low content ratio of the monomer having a valence of 3 or more to all the monomers and has an alkenyl group or an alkyl group in its side chain. A technique of using a non-linear polyester obtained by introducing a carboxylic acid having a group as a resin for toner (JP-A-57
-109825, Japanese Patent Application No. 59-109539, JP 59-7
(See Japanese Patent No. 960).

A non-linear polyester comprising a monomer containing a monomer having a valence of 3 or more, which has a low content ratio of the monomer having a valence of 3 or more to all the monomers and has a long-chain aliphatic in the main chain. A technique of using a non-linear polyester having a hydrocarbon group introduced therein as a resin for toner (see Japanese Patent Application Nos. 60-216244 and 60-217995).

[Problems to be solved by the invention]

However, in the above technology and, in the pulverization step which is one of the ordinary toner manufacturing steps, the toner is apt to agglomerate in the pulverizer when pulverized at room temperature,
Therefore, there is a problem that pulverization becomes difficult and a toner having a desired particle size cannot be obtained, resulting in a decrease in production efficiency and an increase in manufacturing cost.

On the other hand, in order to improve the pulverizability, it may be considered to reduce the molecular weight of the resin for toner, but such a method has a problem that the hot offset resistance is lowered, and in the toner, Is required to be able to exist stably as a powder without aggregation under use or storage environment conditions, that is, to have excellent blocking resistance, but in the case of decreasing the molecular weight of the toner resin, Due to the decrease in the glass transition point associated with the decrease in the molecular weight, the toner tends to aggregate and the blocking resistance deteriorates.

Further, the heat roller fixing device usually includes a heat roller, a backup roller arranged so as to be in contact with the heat roller, and a cleaning roller arranged so as to be in contact with the heat roller and for removing dirt on the heat roller. As the number of copying increases, the toner transferred from the heat roller accumulates on the surface of the cleaning roller.

However, when a copying machine having a heat roller fixing device having such a configuration is used to form an image with the toner of the above technology and, when the number of copying reaches several thousand times,
A considerable amount of toner has accumulated on the surface of the cleaning roller. In such a state, if the operation of the copying machine is temporarily stopped and the operation of the copying machine is restarted, the cleaning image will be displayed on the first copy image. There is a problem that the toner adhering to the roller is re-transferred to cause image stain.

This is because the toner attached to the cleaning roller is
Since the self-crosslinking property due to heat is low, it is presumed that the toner adhering to the cleaning roller is remelted and retransferred to the heat roller, especially when the friction between the cleaning roller and the heat roller is large. .

[Object of the Invention]

The present invention has been made based on the above circumstances, and its objects are (1) having excellent hot offset resistance, (2) having excellent low-temperature fixing property,
(3) Satisfactory grindability, a toner can be efficiently obtained by a normal crushing step, (4) Excellent blocking resistance is satisfied, and further, (5) Cleaning is performed. An electrostatic image developing device capable of forming a copied image without causing image stains due to toner adhered to the cleaning roller even when a fixing process is performed by a heat roller fixing device including a roller. To provide toner.

[Means for solving problems]

The electrostatic image developing toner of the present invention contains a first polyester and a second polyester, and the first polyester is a monomer containing a trivalent or higher valent monomer,
And a non-linear polyester satisfying the following conditions A1 and A2, wherein the second polyester is a monomer containing a monomer having a valence of 3 or more and a non-linear polyester satisfying the following conditions B1 and B2. It is characterized by being a linear polyester.

Condition A1; the ratio of trivalent or higher monomers to all monomers is 0.0
Must be at least 5 mol% and less than 15 mol%.

Condition A2: Softening point is 120 ° C or higher and 160 ° C or lower.

Condition B1; the ratio of trivalent or higher valent monomers to all monomers is 15
Must be from mol% to 40 mol%.

Condition B2: Softening point is 80 ° C or higher and 160 ° C or lower.

[Advantageous effects of the invention]

The toner for developing an electrostatic image of the present invention contains the first polyester and the second polyester, each of which has specific characteristics. Therefore, due to their synergistic effect, excellent hot offset resistance and excellent low temperature resistance are obtained. Fixability, excellent crushability,
It has excellent blocking resistance and suppresses the generation of image stains due to the toner resin adhering to the cleaning roller even when the fixing process is performed by the heat roller fixing device having the cleaning roller. You can

That is, the first polyester is a non-linear polyester in which the proportion of monomers having a valence of 3 or more is suppressed to a low level and has a relatively high molecular weight, and has excellent hot offset resistance and excellent low temperature resistance. Although it has a fixing property, on the other hand, the pulverizability is poor. On the other hand, the second polyester is a non-linear polyester having many uncrosslinked parts with a relatively high proportion of monomers having a valence of 3 or more. It has excellent pulverizability and self-crosslinking property by heat, but on the other hand, sufficient low temperature fixing property and hot offset resistance cannot be satisfied at the same time. Therefore, when the first polyester and the second polyester are used alone, the respective drawbacks are remarkably marked, and the toner of the present invention is produced by using the first polyester and the second polyester. In addition, since the presence of the first polyester imparts excellent hot offset resistance, low-temperature fixing property, and blocking resistance, the presence of the second polyester imparts excellent pulverizability. , Self-crosslinking property by heat is imparted, and in the end, pulverizability can be remarkably improved without lowering hot offset resistance and blocking resistance, and a toner having excellent characteristics can be efficiently obtained by an ordinary pulverization process. When the fixing process is performed by a heat roller fixing device that is equipped with a cleaning roller Also, it is possible to form a copy image without the occurrence of image contamination caused by the toner re-melting of the toner adhering to the cleaning roller can be suppressed, excellent effect that is exhibited.

[Specific configuration of the invention]

 The specific configuration of the present invention will be described below.

The electrostatic image developing toner of the present invention basically contains, as essential components, the first polyester and the second polyester.

The first polyester is a non-linear polyester composed of a monomer containing a trivalent or higher valent monomer and satisfying the conditions A1 and A2.

Further, the second polyester is a non-linear polyester which is composed of a monomer containing a trivalent or higher valent monomer and which satisfies the above conditions B1 and B2.

In the first polyester, 3 for all monomers
When the proportion of the monomer having a valency or more is too large, the low temperature fixability is deteriorated, while when the proportion is too small, the hot offset resistance is deteriorated.

In the second polyester, 3 for all monomers
When the proportion of the monomer having a valency or more is too large, the low temperature fixability and the pulverizability are deteriorated, while when the proportion is too small, image stains due to the toner adhering to the cleaning roller occur.

In the first polyester, when the softening point Tsp is excessively high, low-temperature fixability and pulverizability are deteriorated, while when the softening point Tsp is excessively low, hot offset resistance is deteriorated.

In the second polyester, when the softening point Tsp is excessively high, the low temperature fixability is deteriorated, while the softening point Tsp is low.
When is too small, the hot offset resistance deteriorates.

Further, the first polyester preferably has a chloroform insoluble content of 0% by weight or more and 25% by weight or less. When this chloroform-insoluble content is too large, the low-temperature fixability may decrease.

The blending weight ratio of the first polyester to the second polyester is preferably 90:10 to 30:70, and particularly preferably 80:20 to 40:60. If the blending weight ratio of the first polyester is too large, the pulverizability tends to decrease, while if the blending weight ratio is too small, the hot offset resistance and blocking resistance tend to decline.

It is preferable that the first polyester and the second polyester each further comprise a monomer containing a diol component represented by the following general formula (1).

General formula (1) (R represents an ethylene group or a propylene group, x and y are integers, and the average value of the sum of the two is 2 to
7 ) By containing such a diol component as a constitutional unit, in the toner, hot offset resistance,
The low-temperature fixability and blocking resistance are further improved.

Also, the first polyester has a glass transition point Tg
Is preferably 45 to 85 ° C.

By selecting a material having a glass transition point Tg in such a range, more excellent low-temperature fixing property and blocking resistance can be obtained. That is, when the glass transition point Tg is excessively high, the low temperature fixability may decrease, while when the glass transition point Tg is excessively low, the blocking resistance may deteriorate.

Further, the second polyester has a glass transition point Tg
Is preferably 40 to 80 ° C. By selecting a material having a glass transition point Tg in such a range, more excellent low-temperature fixing property and blocking resistance can be obtained. That is, when the glass transition point Tg is excessively high, the low temperature fixability may be lowered, while when the glass transition point Tg is excessively low, the blocking resistance may be lowered.

The softening point Tsp of the second polyester is preferably lower than the temperature 20 ° C. higher than the softening point Tsp of the first polyester. By selecting one having such a preferable range, it becomes possible to obtain a toner having further excellent pulverizability.

In the present invention, the monomers used in the synthesis of the first polyester and the second polyester can basically include those shown in the following (a) and (b), but they are necessary. Other monomers may be used depending on the above.

(A) A divalent alcohol monomer and a divalent carboxylic acid monomer as components constituting the basic skeleton of polyester, that is, the main chain.

(B) Trivalent or higher polyhydric alcohol monomer and / or trivalent or higher polyvalent carboxylic acid monomer involved in non-linearization, that is, branching or reticulation of polyester.

As the divalent alcohol monomer in (a) above,
For example, etherified bisphenol, ethylene glycol,
Diethylene glycol, triethylene glycol, 1,2
-Propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol,
1,4-butenediol, 1,5-pentanediol, 1,6-
Hexanediol, 1,4-dichlorohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A and the like can be used.

Of these, etherified bisphenols can be preferably used, and specific examples thereof include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (3.3)-
2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2 -Bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,
2-bis (4-hydroxyphenyl) propane or the like can be used.

As the divalent carboxylic acid monomer in the above (a),
For example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, rhododecenylsuccinic acid, isododecese. Nylsuccinic acid, n-dodecylsuccinic acid, isododezylsuccinic acid, n-octenylsuccinic acid, n-octylsuccinic acid, anhydrides or lower alkyl esters of these acids and the like can be used.

Examples of the trihydric or higher polyhydric alcohol monomer in (b) include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,
4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-tri Hydroxymethylbenzene or the like can be used.

Examples of the trivalent or more polyvalent carboxylic acid monomer in (b) above include 1,2,4-benzenetricarboxylic acid and 2,5,7
-Naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxy Propane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxylic) methane, 1,2,7,8-octanetetracarboxylic acid,
Pyromellitic acid, enpol trimer acid, anhydrides or lower alkyl esters of these acids and the like can be used.

In the synthesis of the first polyester and the second polyester, the polyester has a long-chain aliphatic hydrocarbon unit for introducing a long-chain aliphatic hydrocarbon unit into the main chain and / or side chain of the polyester. It is also preferable to use a divalent or higher valent alcohol monomer or a divalent or higher carboxylic acid monomer having the long-chain aliphatic hydrocarbon unit. The long chain in the long-chain aliphatic hydrocarbon unit is
A straight chain is one having 3 or more carbon atoms, preferably 3 to 30. Especially in terms of low temperature fixability
22 is preferable. A divalent or higher valent alcohol monomer or a divalent or higher carboxylic acid monomer having a long-chain aliphatic hydrocarbon unit in the main chain is a non-linear polyester main chain having 1 to 60 of the constituent units of the main chain. It is preferable to use such a proportion that long-chain aliphatic hydrocarbon units are present in the range of mol%, preferably 5 to 50 mol%. Further, the proportion of the divalent or higher valent alcohol monomer or the divalent or higher carboxylic acid monomer having a long chain aliphatic hydrocarbon unit in the side chain is 1 to 50 mol% with respect to the total amount of the monomers. Is preferable, and 10 to 30 mol% is particularly preferable.

Further, in the synthesis of the first polyester and the second polyester, a monomer for introducing an unsaturated aliphatic hydrocarbon unit into the main chain of the polyester can also be used.

In the present invention, the softening point Tsp and the glass transition point Tg are defined as the values measured as follows.

<Softening point Tsp> Using a Koka-type flow tester "CFT-500" (manufactured by Shimadzu Corporation), the diameter of the die pores is 1 mm, the pressure is 20 kg / cm ² , and the heating rate is 6 ° C / min. ^The softening point is defined as the temperature corresponding to half the height from the outflow start point to the outflow end point when the sample ³ is melted and flowed out.

<Glass transition point Tg> 100 using a differential scanning calorimeter (Seiko Denshi Kogyo)
After raising the temperature to ℃, leaving it at that temperature for 3 minutes, cooling the sample to room temperature at a temperature decrease rate of 10 ℃ / min,
When measured at ℃ / min, the temperature at the intersection of the extension line of the baseline below the glass transition point and the tangent line showing the maximum slope from the rising part of the peak to the apex of the peak is defined as the glass transition point Tg. Define.

In the present invention, the chloroform-insoluble matter means a filter-paper-impermeable matter when a sample is dissolved in chloroform, and can be obtained as follows.

That is, a sample was finely pulverized, and 5.00 g of a sample powder obtained by filtering this with a 40-mesh sieve was collected and placed in a container with a capacity of 150 ml together with 5.00 g of filter aid Radiolite (# 700). 100 g of chloroform is poured into the container, placed on a ball mill stand and rotated for 5 hours or more to sufficiently dissolve the sample in chloroform. On the other hand, place a filter paper (No.2) with a diameter of 7 cm in the pressure filter, pre-coat 5.00 g of radiolite evenly on it, and add a small amount of chloroform to bring the filter paper into close contact with the filter. Pour the contents of the container into the filter. Further, the container is thoroughly washed with 100 ml of chloroform and poured into a filter so that deposits do not remain on the container wall. After that, the upper lid of the filter is closed and filtration is performed. Filtration is performed under a pressure of 4 kg / cm ² or less, and after the outflow of chloroform is stopped, 100 ml of chloroform is newly added to wash the residue on the filter paper,
Pressure filtration is performed again.

After the above operation is completed, put the filter paper and all of the residue and the radiolide on the aluminum foil and put it in the vacuum dryer, and dry it for 10 hours under the conditions of temperature 80 to 100 ° C and pressure 100 mmHg, The total weight a (g) of the dry solid thus obtained was measured, and the chloroform-insoluble matter x
(% By weight) is calculated.

The chloroform-insoluble matter thus obtained is a high molecular weight polymer component or a crosslinked polymer component in polyester.

In the toner of the present invention, the first polyester and the second polyester are contained as essential components, but in addition, a colorant and, if necessary, other additives are contained. Further, other resin may be contained as necessary.

As other additives, particularly low molecular weight polyolefin can be preferably used. Specifically, low molecular weight polyethylene, polypropylene and the like can be preferably used, and those having a softening point by the ring and ball method of 70 to 150 ° C, more preferably 120 to 150 ° C are particularly preferable. By containing such a low molecular weight polyolefin, pulverizability and hot offset resistance are further improved.

Examples of the colorant include carbon black, nigrosine dye (CI No.50415 B), aniline blue (CIN
o.50405), Calco Oil Blue (CINo. azoic Blue
3), Chrome Yellow (CINo.14090), Ultramarine Blue (CINo.77103), DuPont Oil Red (C.
I.No.26105), quinoline yellow (CINo.47005), methylene blue chloride (CINo.52015), phthalocyanine blue (CINo, 74160), malachide green oxalate (CINo.42000), lamp black (CINo.7).
7266), Rose Bengal (CI No.45435), mixtures thereof, and the like. The content ratio of these colorants is preferably about 1 to 20 parts by weight with respect to 100 parts by weight of the toner.

Further, when the magnetic toner is used, a magnetic material is used. As the magnetic material, iron, ferrite, magnetite or other iron, cobalt, nickel or other ferromagnetic metals or alloys or compounds containing these elements, or a suitable heat treatment containing no ferromagnetic elements Examples of alloys that become elastic by application of alloys, such as manganese-copper-aluminum, manganese-copper-tin, and other types of alloys called Heusler alloys containing manganese and copper, or chromium dioxide. it can. It is preferable that these magnetic materials are contained in the toner particles uniformly dispersed in the form of fine powder having an average particle diameter of 0.1 to 1 μm. The content ratio of such a magnetic material is usually in the toner.
The amount is preferably 20 to 70 parts by weight, more preferably 25 to 50 parts by weight, based on 100 parts by weight.

The toner of the present invention can be manufactured, for example, by the following method. That is, a colorant was added to what was added with the above-mentioned first and second polyesters or other resins, which are essential components, and other additives were added, if necessary, and these were premixed. Thereafter, by melt-kneading, cooling, coarsely pulverizing, further finely pulverizing, and then classifying, a toner composed of particle powder having a desired particle diameter can be obtained.

The toner of the present invention may form a two-component developer in combination with a carrier, or a magnetic toner containing a magnetic material may be composed of only the magnetic toner.
It may constitute a component developer.

[Specific Example]

Hereinafter, specific examples of the present invention will be described, but the present invention is not limited to these examples.

<Structure of Polyester> The materials having the formulations shown in Table 1 below are put in a four-necked flask having a capacity of 2 liters, which is equipped with a thermometer, a stainless steel stirrer, a glass nitrogen introduction tube, and a downflow condenser. Was set in a mantle heater and reacted under a nitrogen atmosphere at a temperature of 200 ° C. with stirring. The progress of the reaction was monitored while measuring the acid value, and the reaction was stopped when the acid value reached a predetermined value, and then cooled to room temperature to obtain each polyester composed of a pale yellow solid.

The characteristic values of each polyester are shown in Table 2 below.

<Examples and Comparative Examples> In each Example and Comparative Example, a total of 100 parts by weight of polyester having the combinations and blending amounts shown in Table 3 below,
Of carbon black "Mogal L" (manufactured by Cabot)
10 parts by weight and low molecular weight polypropylene "Viscor 660"
P ”(softening point Tsp: 130 ° C., manufactured by Sanyo Chemical Industry Co., Ltd.) by premixing with 5 parts by weight, and then an average particle diameter of 10 μm is obtained by a usual method including the steps of melting, kneading, cooling, pulverizing and classifying. A toner consisting of particle powder was produced.

In the crushing step, the lump after kneading is roughly crushed,
Furthermore, it was selected by 9.2 mesh pass (nominal size 2 mm) / 16 mesh on (nominal size 1 mm), and then finely pulverized by a jet type pulverizer.

<Evaluation> (1) Powder pulverization In the production of the above toner, the pulverizability was determined by the average particle size of the pulverized product obtained when the pulverization processing speed in the pulverization step was 100 g / min. The average particle size is 10 μm
Those having a mean particle size of less than 10 μm were evaluated as “◯”, and those having an average particle size of 10 μm or more were evaluated as “x”.

(2) Minimum fixing temperature A heat roller whose surface layer is made of Teflon (polytetrafluoroethylene manufactured by DuPont) and a silicone rubber "KE-".
Using a heat roller fixing device consisting of a backup roller formed by covering the surface of the roller formed by "1300RTV" (manufactured by Shin-Etsu Chemical Co., Ltd.) with a Teflon tube, temperature of 10
Under the environmental conditions of ℃ and relative humidity of 20%, the operation of fixing the toner image by each of the above-mentioned toners transferred to the transfer paper of 64 g / m ² at the linear velocity of 70 mm / sec, the set temperature of the heat roller is 250 ℃. It went from gradually decreasing.

The obtained fixed image was rubbed with Kimwipe, and the lowest set temperature for the fixed image showing sufficient rubbing resistance was defined as the lowest fixing temperature. The heat roller fixing device used here does not have a silicone oil supply mechanism.

(3) Hot offset generation temperature According to the measurement of the above-mentioned minimum fixing temperature, the toner image is transferred and the fixing process is performed by the above-mentioned heat roller fixing device, and then the blank transfer paper is fixed under the same condition with the heat roller. The operation of sending to a container and visually observing whether or not toner stains occur is repeated with the set temperature of the heat roller of the heat roller fixing device sequentially lowered, and the minimum set temperature at which toner stain occurs is repeated. The hot offset generation temperature was used.

(4) Presence or absence of image stains due to toner adhering to the cleaning roller Under the environmental conditions of temperature 20 ° C and relative humidity 50%, using the above heat roller fixing device, transfer to A3 size transfer paper of 64g / m ² Transfer the toner image from each of the above toners to a linear velocity of 70 mm
Repeat the operation of fixing at 5000 / sec continuously for 5000 times, and then set the heat roller temperature to 220 ℃ and the backup roller temperature to 100 ℃, and of course, fix the above A3 size blank transfer paper to the heat roller. Repeatedly feeding 10 sheets into the container, and visually observing the blank transfer paper that passed through the heat roller fixing device. When there was a problem in practical use, it was designated as "x".

The above results are also shown in Table 3 below.

In addition, each of the above toners 1 to 9 has a temperature of 55 ° C.
The toner was allowed to stand for 2 hours under an environmental condition of 26%, and the blocking resistance was evaluated depending on whether or not agglomerates were generated in each toner. As a result, no agglomerates were observed and the blocking resistance was excellent.

As can be understood from the above results, the toners 1 to 1 of the invention are
No. 9 has excellent hot offset resistance, excellent low-temperature fixability, excellent pulverizability, and excellent blocking resistance, and is subjected to fixing treatment by a heat roller fixing device equipped with a cleaning roller. Also, it is possible to form a copied image without causing image stain due to the toner attached to the cleaning roller. Therefore,
A toner having excellent characteristics can be efficiently obtained by a normal pulverization process.

On the other hand, Comparative Toner 1 does not use trivalent or higher valent monomers at all in the production of the first polyester, and therefore is inferior in pulverizability and hot offset resistance, and is caused by the toner attached to the cleaning roller. The resulting image stains easily cause image defects.

Comparative Toner 2 was used in the manufacture of the first polyester 3
Since the use ratio of the monomer having a valency or more is too large, the low temperature fixability is inferior.

Comparative Toner 3 was used in the manufacture of the second polyester
Since the use ratio of the monomer having a valency or more is too small, the hot offset resistance is inferior, and the image sticking due to the toner adhering to the cleaning roller is likely to result in an image defect.

Comparative Toner 4 was used in the manufacture of the second polyester 3
Since the proportion of monomers with a valency or higher is too high, pulverizability,
The low temperature fixability is poor.

The comparative toner 5 is inferior in hot offset resistance because the softening point Tsp of the first polyester is too small.

Comparative Toner 6 has poor pulverizability because the softening point Tsp of the first polyester is too large.

Comparative toner 7 is inferior in hot offset resistance because the softening point Tsp of the second polyester is too small.

The comparative toner 8 is inferior in pulverizability and low-temperature fixability because the softening point Tsp of the second polyester is too large.

Since the comparative toner 9 does not contain the second polyester, it is inferior in pulverizability and low-temperature fixability, and image stains are caused by the toner adhering to the cleaning roller, and image defects are likely to occur.

Comparative toners 10 and 11 have a low softening point and do not contain the first polyester, and therefore have poor hot offset resistance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoru Ikeuchi 2970 Ishikawa-cho, Hachioji-shi, Tokyo Inside Konishi Rokusha Shinkogyo Co., Ltd. (72) Hideyo Nishikawa 1334 Minato Minato, Wakayama, Wakayama Kao Stock Company (72) Inventor Shingo Tanaka 1334 Minato Minato, Wakayama Prefecture Wakayama Research Institute, Wakayama Research Institute (72) Inventor Kuniyasu Kawabe 1334 Minato Minato, Wakayama Prefecture Wakayama Research Institute, Wakayama Research Institute (56) References JP-A-56-65146 (JP, A) JP-A-60-214368 (JP, A) JP-A-50-99742 (JP, A) JP-A-54-114245 (JP, A) JP-A-58-196549 (JP , A) JP-A-60-247247 (JP, A) JP-A-57-37353 (JP, A)

Claims (5)

[Claims] 1. A first polyester and a second polyester are contained, wherein the first polyester is a monomer containing a monomer having a valence of 3 or more, and the following conditions A1 and A2: The second polyester is a non-linear polyester satisfying the following conditions B1 and B2, which is composed of a monomer containing a trivalent or higher valent monomer. Characteristic toner for electrostatic image development. Condition A1; the ratio of trivalent or higher monomers to all monomers is 0.0
Must be at least 5 mol% and less than 15 mol%. Condition A2: Softening point is 120 ° C or higher and 160 ° C or lower. Condition B1; the ratio of trivalent or higher valent monomers to all monomers is 15
Must be from mol% to 40 mol%. Condition B2: Softening point is 80 ° C or higher and 160 ° C or lower. 2. The compounding weight ratio of the first polyester and the second polyester is 90:10 to 30:70, preferably 80:20 to 40:60. 6. The toner for developing an electrostatic image according to the item. 3. The first polyester and the second polyester each of which is composed of a monomer containing a diol component represented by the following general formula (1). 6. The toner for developing an electrostatic image according to the item. General formula (1) (R represents an ethylene group or a propylene group, x and y are integers, and the average value of the sum of the two is 2 to
7 ) 4. The glass transition point of the first polyester is 45 to
85 ° C, the glass transition point of the second polyester is 40 ~
The toner for electrostatic image development according to any one of claims 1 to 3, which has a temperature of 80 ° C. 5. The electrostatic image developing toner according to claim 1, wherein the toner contains a low molecular weight polyolefin.