JPH06308765A - Electrophotographic toner resin - Google Patents

Abstract

(57) [Summary] [Structure] Amorphous poly α-hydroxycarboxylic acid obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid Amorphous or semi-crystalline poly α-hydroxycarboxylic acid obtained by dehydration polycondensation with polyol having 3 or more hydroxyl groups in the same molecule or polycarboxylic acid having 3 or more carboxyl groups in the same molecule A resin for electrophotographic toner containing a decomposable polyester resin as a main component obtained by reacting the above, or a polyester composed of the above amorphous or semi-crystalline poly α-hydroxycarboxylic acid and a polyol, and a diisocyanate are reacted. A resin for an electrophotographic toner, which contains a decomposable polyester resin, which is a urethanized polyester obtained as a main component, as a main component. [Effect] The resin for toner of the present invention exhibits good fixability, good pulverizability, hot offset resistance, storability, and positive or negative chargeability, and is excellent as a positive or negative chargeable electrophotographic toner resin. Has performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin for electrophotographic toner, and more particularly to a degradable toner binder resin.

[0002]

2. Description of the Related Art In electrophotography, a photoconductive substance is used to form an electrical latent image on a photoconductor by various means, and then the latent image is developed with a toner and, if necessary, paper. After being transferred onto an image support such as, an image is obtained by fixing with a heating roll or the like. Various resins have been studied as the toner resin used here. Among them, when the polyester resin is melted, the toner additive such as carbon black is well dispersed and wetted on the transfer paper, and the fixability is improved. It is now widely used as a resin for toner for fixing to a heating roll because it has the advantage of being excellent.

Also, in recent years, the amount of plain paper used in copying machines and optical printers has increased dramatically, resulting in an increase in the amount of paper that is discarded and amortized, and from the viewpoint of resource conservation. Is causing serious problems, and recycling and reuse of these plain papers is an important technology from the viewpoint of environmental pollution prevention and resource protection. For this purpose, it is desirable that the toner used in a copying machine or an optical printer is efficiently decomposed by alkaline hydrolysis in the deinking and recycling processes of the paper and separated from the fibers of the paper. In this respect, a styrene-based binder resin which is usually used is difficult to be hydrolyzed by an alkali, while a resin for a toner using a decomposable polyester such as poly α-hydroxycarboxylic acid is a paper-based resin. Has high deinking property and is useful in recycling of WO 92 /
No. 01245 and the like. In addition, when the waste toner or toner resin is buried in the soil,
Conventional toner resins are not biodegradable, and improvements have been demanded from the viewpoint of waste treatment and environmental pollution. Against this point, the toner using the decomposable polyester is decomposed in the soil. JP-A-4-179967, USP 5,
004, 664, etc.

Regarding the method of synthesizing poly α-hydroxycarboxylic acid as a resin for toner, α-hydroxycarboxylic acid is once converted into a cyclic dimer and then separated and purified, and the cyclic dimer is converted into an aluminum catalyst or the like. A polymerization method of ring-opening polymerization in the presence of is known in WO 92/01245 and the like.

[0005]

The crystalline toner resin has a remarkably high viscosity at a temperature lower than the melting point and a remarkably low viscosity at a temperature higher than the melting point. For this reason, the minimum temperature required for the toner to fuse to the paper, that is, the minimum fixing temperature, must be high. A so-called hot offset phenomenon occurs that contaminates the roller surface. In order to achieve both the fixability and the hot offset resistance, it is desired that the toner resin starts to flow at a low temperature and the viscosity of the resin at a high temperature is sufficiently high.

The conventional resin for toner composed of degradable polyester has poor pulverizability, and it is difficult to use it as a binder resin which accounts for 90% of toner having a particle size of about 10 μm, and its improvement is desired. Further, polyesters other than degradable polyesters or styrenic polymers are excellent in grindability, but are inferior in hydrolyzability, alkali degradability and biodegradability, and improvement thereof is demanded.

Further, the lactide and glycolide used for producing a polyester by ring-opening polymerization are generally dehydrated dimers of α-hydroxycarboxylic acid to form a cyclic dimer. The polyester thus obtained is extremely expensive to use as a resin for toner, and a degradable polyester by a direct polymerization method that can obtain a resin for toner at low cost has been demanded. Also,
Since the ring-opening polymerization is a cationic ring-opening polymerization, it is necessary to dehydrate the solvent used, remove ionic species that serve as a polymerization terminator, etc., resulting in poor production efficiency and the monomer species that can be used during polyester production. Is limited to cyclic esters, it is not possible to use polyols and polycarboxylic acids that are commonly used in the production of polyesters, it is not easy to control the physical properties required as a resin for toner, and degradability and physical properties It is also difficult to carry out copolymerization with various monomers in order to control the balance.

Further, since the terminal group of the resin for toner composed of decomposable polyester is a hydroxyl group at one terminal and a carboxyl group at one terminal, when it is used as a raw material resin for toner, the terminal carboxyl group has a strong negative charging property. Toner charge characteristics are limited to strong negative charge or low positive charge,
This is a problem because it cannot be used as a toner for a copying machine equipped with an organic photoconductor.

In this case, if the polycondensation is simply proceeded to reduce the terminal carboxyl group concentration, the molecular weight is increased, and as a result, the pulverizability is deteriorated and a toner having an appropriate particle size is obtained even when it is used for a toner application. This is a problem that cannot be solved, and if you try to grind it forcibly, a high grinding energy is required, and economic efficiency deteriorates.

[0010]

In order to satisfy such a demand, the present inventors have developed a resin having excellent properties which can be used for producing a toner having sufficient performance. As a result of diligent studies, they have found an excellent toner resin that could not be achieved by the conventional techniques, and completed the present invention.

That is, the first aspect of the present invention is characterized in that the main component is a degradable polyester resin which is an amorphous poly α-hydroxycarboxylic acid obtained by direct dehydration polycondensation of an α-hydroxycarboxylic acid. Is a resin for electrophotographic toner.

The second aspect of the present invention is mainly composed of a decomposable polyester resin which is an amorphous poly α-hydroxycarboxylic acid having a number average molecular weight of 2000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid. And a resin for electrophotographic toner.

A third aspect of the present invention is to use three or more amorphous poly-α-hydroxycarboxylic acids having a number average molecular weight of 1,000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acids in the same molecule. A resin for electrophotographic toner, characterized in that a main component is a decomposable polyester having 90% or more of the terminal groups being hydroxyl groups, which is obtained by reacting with a polyol having a hydroxyl group.

The fourth aspect of the present invention is to use three or more amorphous poly-α-hydroxycarboxylic acid having a number average molecular weight of 2000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid in the same molecule. Degradability which is a urethanized polyester obtained by reacting a polyester composed of a polyol having a hydroxyl group with a diisocyanate and having 0.8 mol equivalent or more of isocyanate groups added to 1 mol equivalent of the hydroxyl group of the polyester. It is a resin for electrophotographic toner, which is characterized by containing a polyester resin as a main component.

The fifth aspect of the present invention is that the amorphous poly α-hydroxycarboxylic acid having a number average molecular weight of 1,000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid has three or more molecules in the same molecule. 9 of the terminal group obtained by reacting with a polycarboxylic acid having a carboxyl group
A resin for electrophotographic toner, characterized in that a main component is a decomposable polyester resin in which 0% or more is a carboxyl group.

The sixth aspect of the present invention is that the semi-crystalline poly α-hydroxycarboxylic acid having a number average molecular weight of 1,000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid has three or more molecules in the same molecule. A resin for electrophotographic toner, characterized in that a main component is a decomposable polyester resin obtained by reacting with a polyol acid having a hydroxyl group and having 90% or more of the terminal groups being hydroxyl groups.

The seventh aspect of the present invention is that the semi-crystalline poly α-hydroxycarboxylic acid having a number average molecular weight of 2000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid has three or more molecules in the same molecule. Degradability which is a urethanized polyester obtained by reacting a polyester composed of a polyol having a hydroxyl group with a diisocyanate and having 0.8 mol equivalent or more of isocyanate groups added to 1 mol equivalent of the hydroxyl group of the polyester. It is a resin for electrophotographic toner, which is characterized by containing a polyester resin as a main component.

The eighth aspect of the present invention is that the semi-crystalline poly α-hydroxycarboxylic acid having a number average molecular weight of 1,000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid has three or more molecules in the same molecule. A resin for electrophotographic toner, characterized in that a main component is a decomposable polyester resin obtained by reacting a polycarboxylic acid having a carboxyl group with 90% or more of the terminal groups being a carboxyl group.

In the present specification, the "amorphous poly α-hydroxycarboxylic acid" is obtained by direct dehydration polycondensation of a mixture of optical isomers of α-hydroxycarboxylic acid or several α-hydroxycarboxylic acids. It means poly α-hydroxycarboxylic acid having no melting point, and the presence or absence of melting point is D
It can be confirmed by SC and other commonly used thermophysical property measuring devices. In order to obtain such an amorphous poly α-hydroxycarboxylic acid, it is preferable that at least 10 mol% of all α-hydroxycarboxylic acid monomers be occupied by optical isomers, and 20 mol% or more. Is more preferably occupied by optical isomers. In this case, if the amount of the optical isomer is reduced to less than 10 mol%, the melting point appears in the obtained poly α-hydroxycarboxylic acid and the fixing property of the toner is deteriorated, which is not preferable. Amorphous poly α-hydroxycarboxylic acid obtained by other means such as copolymerization of different α-hydroxycarboxylic acids can also be used, and is not limited by the production method or monomer composition.

Further, in the present specification, "semi-crystalline poly α
“-Hydroxycarboxylic acid” means, contrary to the above, a poly α-hydroxycarboxylic acid having a melting point obtained by direct polycondensation of α-hydroxycarboxylic acid. The content of the optical isomer in the monomer is preferably less than 10 mol%, more preferably 0 to 5 mol%, and when the content of the optical isomer is 10 mol% or more, the melting point is It becomes unclear, and the poly α-hydroxycarboxylic acid becomes amorphous.In addition, the crystallinity generally obtained by wide-angle X-ray diffraction is not 100% in the case of a polymer, Since it essentially refers to a semi-crystalline polymer, the semi-crystalline poly α-hydroxycarboxylic acid referred to in the present invention has a melting point regardless of crystallinity, that is, , Refers to all poly α-hydroxy carboxylic acids that can detect the presence of at least a crystalline part in thermophysical property measurement.When using semi-crystalline poly α-hydroxy carboxylic acid, in order to keep the crystallinity low, Although it is unavoidable to use a low molecular weight poly-α-hydroxycarboxylic acid, the glass transition temperature is low as it is, the storability of the toner is deteriorated, and the toner cannot be manufactured because it cannot be pulverized at room temperature. Therefore, it is necessary to increase the molecular weight and increase the glass transition temperature by co-condensing the semi-crystalline poly α-hydroxycarboxylic acid with the polyol or the polycarboxylic acid.

Examples of the α-hydroxycarboxylic acid referred to in the present invention include glycolic acid, D- and L-forms of lactic acid, oxybutyric acid, malic acid, mandelic acid, tartaric acid or a mixture thereof, preferably glycolic acid. , Lactic acid, and more preferably lactic acid.

Further, the direct dehydration polycondensation referred to in the present invention is
A ring-opening polymerization of glycolide or lactide is a production method which is carried out by a radically different method. The ring-opening polymerization is basically polyaddition, whereas this method is polycondensation. In the direct dehydration polycondensation of the present method, the desired polymer can be produced by subjecting the α-hydroxycarboxylic acid to polycondensation under reflux of a solvent at a temperature at which cyclic dimerization of the α-hydroxycarboxylic acid does not occur. When a polymer having a relatively high molecular weight is to be obtained, dehydration polycondensation can be carried out in the presence of a solvent.

To describe the direct dehydration polycondensation in more detail, in this method, for example, a condensation catalyst such as tin powder is added to α-hydroxycarboxylic acid, and an ether solvent such as diphenyl ether or anisole or other azeotropic dehydration solvent is added. The solvent and water are distilled off under reduced pressure at a temperature of around 130 ° C. to 150 ° C., and the distilled solvent is separated from water by a water separator or the like, and then a column filled with a dehydrating agent such as molecular sieve 3A. The target poly α-hydroxycarboxylic acid can be obtained by returning it to the reactor in a substantially anhydrous state.

The poly α-hydroxy carboxylic acid obtained by this method differs from the poly α-hydroxy carboxylic acid obtained by ring-opening polymerization of a dimer in its higher-order structure. That is, the poly α-hydroxycarboxylic acid obtained by ring-opening polymerization of a dimer is composed of only those having an even degree of polymerization, whereas in the direct method, the degree of polymerization is composed of all integers.

Further, in the case of obtaining a copolymer of D-form and L-form, in the case of a dimer ring-opening polymer, copolymerization of a D-form cyclic dimer and an L-form cyclic dimer or a racemic form Although the ring-opening polymerization of can be carried out, the sequence of monomer components is always the sequence of dyads as a unit segment,
The direct polycondensation method of this method has a sequence in which D-form monomers and L-form monomers are completely randomly arranged.

In the present invention, as the polyol used for the reaction with poly α-hydroxycarboxylic acid, glycerin, trimethylolpropane, trimethylolethane,
Examples include pentaerythritol, dipentaerythritol, and the like. The number of hydroxyl groups in the polyol is preferably 3 or more in the same molecule, and when it is 2, it is not preferable because the hot offset resistance of the toner decreases.

In the present invention, examples of the polycarboxylic acid used for the reaction with the poly α-hydroxycarboxylic acid include polycarboxylic acids such as trimellitic acid and pyromellitic acid, and their acid anhydrides and lower esters. You can The number of carboxyl groups in the polycarboxylic acid is preferably 3 or more in the same molecule, and when the number is 2, it is not preferable because the hot offset resistance of the toner decreases.

When polyester is used as a toner resin, the chargeability of the resin often has a strong influence on the charge polarity and charge amount of the toner, which is mainly due to the chargeability of the end groups of the polyester. Therefore, it was necessary to thoroughly study the kind of the terminal group even in the case of the poly α-hydroxycarboxylic acid of the present invention. As a result of further study on this point, when used in a toner for positive charging, if the ratio of the hydroxyl group ends in the total terminal groups is less than 90%, the amount of positive charge is reduced, which is not preferable.
Further, it has been found that when used in a toner for negative charging, if the ratio of the acid terminals in the total terminal groups is less than 90%, the negatively charged amount decreases, which is not preferable.

Further, in the present invention, the diisocyanate used for the reaction with the polyester is a compound having two isocyanate groups in one molecule, and is particularly used for further polymerizing the degradable polyester having a hydroxyl group at the terminal group. To be done. Examples of diisocyanates include hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), methylene bisphenyl diisocyanate (MDI), and isophorone diisocyanate (IPD).
I), tetramethylxylylene diisocyanate (TM)
Examples thereof include diisocyanates such as XDI). The amount of the diisocyanate used is preferably 0.8 mol equivalent or more per 1 mol equivalent of the hydroxyl group of the polyester, and if it is less than 0.8 mol equivalent, the effect of polymerization by the isocyanate cannot be sufficiently exerted. In particular, the storage stability of the toner and the offset resistance are not sufficiently improved, which is not preferable.

In the present invention, the number average molecular weight of the poly α-hydroxycarboxylic acid is preferably from 2000 to 7,000. If it is less than 2000, the pulverization is extremely difficult, which is not preferable. If it exceeds 7,000, the pulverizability is deteriorated. It is not preferable because it is difficult to obtain a fine toner, and it is necessary to change the pulverization conditions. Polyol having 3 or more hydroxyl groups in the same molecule or 3 in the same molecule
When copolymerizing a polycarboxylic acid having more than one carboxyl group, the number average molecular weight of the poly α-hydroxycarboxylic acid used is preferably 1,000 to 7,000, and 1
If it is less than 000, the storability of the produced polyester is deteriorated, and if it exceeds 7,000, the pulverizability of the produced polyester is deteriorated and it is difficult to obtain a fine toner. Therefore, it is not preferable because the pulverization conditions and the like need to be changed. .
In the case of a urethanized polyester obtained by reacting a polyester composed of a poly α-hydroxycarboxylic acid and a polyol having three or more hydroxyl groups in the same molecule with a diisocyanate, the number of poly α-hydroxycarboxylic acids used The average molecular weight is preferably 2,000 to 7,000. If it is less than 2,000, the amount of diisocyanate required becomes too large, so that the positively charged amount of the urethanized polyester produced is too high, and if it exceeds 7,000, the pulverizability of the urethanized polyester produced is deteriorated. Then, it is difficult to obtain a fine toner and it is necessary to change the pulverization conditions and the like, which is not preferable.

When the resin for electrophotographic toner of the present invention is used in an electrophotographic toner composition, a suitable colorant and an additive are blended with the above-mentioned resin for toner as necessary to form a composition.

Specific examples of colorants, additives and the like that can be used in this composition are as follows: Suitable colorants include:
Examples thereof include carbon black, aniline blue, alkoyl blue, chrome yellow, ultramarine blue, quinoline yellow, methylene blue, phthalocyanine blue, malachite green, rose bengal and magnetite.

As the additive, for example, colloidal silica, zinc stearate, low molecular weight polypropylene, stearic acid amide, methylenebisstearamide, magnetic powder, and various charge control agents known in the art can be used. .

Further, for the production of toner, the above resins and other compounds are premixed with a Henschel mixer or the like, and then melt-kneaded with a kneader or the like at a temperature of 100 to 180 ° C., and the obtained lumps are crushed and classified to be electrophotographic. Can be used as a toner for use.

[0035]

EXAMPLES The present invention will be described in detail with reference to Examples and Comparative Examples. In the description of Examples and Comparative Examples, “part” means part by weight unless otherwise specified. The measurement method of the data in each table was as follows: Molecular weight: Monodisperse standard polystyrene was used as a standard,
Number average molecular weight determined by gel permeation chromatography (GPC) using tetrahydrofuran as an eluent and a refractometer as a detector, glass transition temperature: glass transition temperature determined by a differential scanning calorimeter, acid value: JIS K5400 method, hydroxyl value: acetic anhydride method value, volume average particle diameter: volume average particle diameter obtained by Coulter counter, fixing rate: commercial copying machine (60 sheets per minute) ,
Fixing ratio is the reflection density ratio of the residual toner after the cellophane tape peeling test on the surface of the copy. Hot offset temperature: Surface temperature of the fixing roller at the time of offset, storability: Visually determined by the following criteria Rank: 1: No aggregation, 2: Partially aggregated, loosen by shaking the container lightly, 3: Partially aggregated, loosen by shaking the container vigorously, 4: Shake the container strongly There is cohesion that does not loosen. Charge amount: The charge amount obtained with a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co.).

Examples 1 to 7 Two-liter four-necked tube equipped with a stirrer, a thermometer, a water separator, a column filled with molecular sieve 3A, a nitrogen inlet tube and a reflux condenser for the α-hydroxycarboxylic acid shown in Table 1. The mixture was placed in a flask, 100 g of diphenyl ether was refluxed under reduced pressure of 66.5 hPa at a temperature of 150 ° C. for dehydration polycondensation, and then the solvent was distilled off under reduced pressure to obtain the poly α-hydroxycarboxylic acid shown in Table 1.

6 parts of carbon black MA-100 (manufactured by Mitsubishi Kasei Co., Ltd.) and polypropylene wax VISCOL 660P (Sanyo Chemical Co., Ltd.) per 100 parts of poly α-hydroxycarboxylic acid (resin for toner) obtained by the above method 3 parts by a Henschel mixer, and then melt-kneaded at 160 ° C. with a biaxial kneader PCM30 (made by Ikegai Tekko Co., Ltd.) to obtain a lumped toner composition. After roughly crushing this composition with a hammer mill, a jet crusher (IDS2 type manufactured by Nippon Pneumatic Co., Ltd.)
Finely pulverized in, then classified by air flow, average particle size 10 μm
(5 μm or less 3% by weight, 20 μm or more 2% by weight) toner particles were obtained. The pulverizability of the toner was judged by measuring the volume average particle diameter after pulverization under the condition that the supply rate of the coarse powder to the jet pulverizer was constant. The fixing property and offset property of this toner were evaluated by using a commercially available copying machine to examine the degree of contamination of the heat roller. Also, ferrite carrier F53-15
95 parts of 0 (manufactured by Nippon Iron Powder Co., Ltd.) and 5 parts of toner were mixed with a V blender for 30 minutes, and the charge amount of the toner was measured by a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co., Ltd.). Further, a mixture of this toner and 0.1% of hydrophobic silica (Aerosil R972 manufactured by Nippon Aerosil Co., Ltd.) is stored in an environment of a temperature of 40 ° C. and a relative humidity of 60% for 24 hours, and then the storability of the particles is changed. I checked. The results are shown in Table 1.

The offset properties were good for all toners, but there was a large difference in the fixability between crystalline and amorphous ones, and amorphous poly α-hydroxycarboxylic acid was good.

Further, the resin for degradable toner of the present invention was decomposed in soil at 20 to 25 ° C. for 20 weeks to show biodegradability, and was suspended in an alkaline aqueous solution of pH 14 at 50 ° C. for 24 hours. It was completely decomposed into monomers and alkali hydrolyzability was observed.

As is clear from the data in Table 1, the toner resin of the present invention exhibits good fixability which is thought to be due to the low heat flow initiation temperature, and exhibits excellent performance as an electrophotographic toner resin. Have

[0041]

[Table 1]

Examples 8 to 12 The α-hydroxycarboxylic acid shown in Table 2 was dehydrated and polycondensed in the same manner as in Examples 1 to 7 except that the reflux solvent was not used, and the amorphous polycarboxylic acid shown in Table 2 was obtained. α-Hydroxycarboxylic acid was obtained.

To 100 parts of the amorphous poly α-hydroxycarboxylic acid (resin for toner) obtained by the above method, 6 parts of carbon black MA-100 (manufactured by Mitsubishi Kasei Co., Ltd.) and polypropylene wax VISCOL 660P (Sanyo Chemical Co., Ltd.) 3 parts (manufactured by Kogyo Co., Ltd.) were dispersed and mixed by a Henschel mixer, and then melt-kneaded at 160 ° C. by a biaxial kneader PCM30 (manufactured by Ikegai Tekko KK) to obtain a lumped toner composition. After roughly crushing this composition with a hammer mill, a jet crusher (IDS2 manufactured by Nippon Pneumatic Co., Ltd.)
Type) and finely pulverized, then classified by air flow to obtain an average particle size of 10μ
m (5 μm or less 3% by weight, 20 μm or more 2% by weight) toner particles were obtained. The pulverizability of the toner was judged by measuring the volume average particle diameter after pulverization under the condition that the supply rate of the coarse powder to the jet pulverizer was constant. The fixing property and offset property of this toner were evaluated by using a commercially available copying machine to examine the degree of contamination of the heat roller. Also, ferrite carrier F95-1
00 (manufactured by Nippon Steel Powder Co., Ltd.) and 5 parts of toner by V
After mixing for 30 minutes with a blender, the charge amount of the toner was measured with a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co., Ltd.). Further, a mixture of this toner and 0.1% of hydrophobic silica (Aerosil R972 manufactured by Nippon Aerosil Co., Ltd.) is stored in an environment of a temperature of 40 ° C. and a relative humidity of 60% for 24 hours, and then the storability of the particles is changed. I checked. The results are shown in Table 2.

As is clear from the data in Table 2, the degradable polyester resin of the present invention has good pulverizability, storability and negative chargeability, and has excellent performance as a negatively chargeable electrophotographic toner resin. There is.

[0045]

[Table 2]

Examples 13 to 24 Amorphous poly α-hydroxy carboxylic acids shown in Table 3 were prepared by dehydration polycondensation in the same manner as in Examples 1 to 7 except that no reflux solvent was used. After obtaining the acid, the polyhydric alcohol shown in Table 3 was added and the polycondensation was continued until the acid value reached a predetermined value to obtain the polyester shown in Table 3.

Carbon black MA-100 was added to 100 parts of the polyester (resin for toner) obtained by the above method.
After 6 parts (manufactured by Mitsubishi Kasei Co., Ltd.) and 3 parts of polypropylene wax VISCOL 660P (manufactured by Sanyo Kasei Kogyo Co., Ltd.) were dispersed and mixed by a Henschel mixer, 160 by a biaxial kneader PCM30 (manufactured by Ikegai Tekko KK). Melt kneading at 0 ° C. to obtain a lumped toner composition. This composition was roughly crushed by a hammer mill, then finely crushed by a jet crusher (IDS2 type manufactured by Nippon Pneumatic Co., Ltd.), and then classified by air flow to have an average particle size of 10 μm (5 μm or less 3% by weight,
Toner particles of 20 μm or more and 2% by weight) were obtained. The pulverizability of the toner was judged by measuring the volume average particle diameter after pulverization under the condition that the supply rate of the coarse powder to the jet pulverizer was constant.
The fixing property and offset property of this toner were evaluated by using a commercially available copying machine to examine the degree of contamination of the heat roller. Further, 95 parts of ferrite carrier F53-150 (manufactured by Nippon Iron Powder Co., Ltd.) and 5 parts of toner were mixed with a V blender for 30 minutes, and then the toner charge amount was measured by a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co., Ltd.). . Further, this toner was stored in an environment of a temperature of 40 ° C. and a relative humidity of 60% for 24 hours, and then the storability was examined from the agglomerated state of the particles. The results are shown in Table 3.

As is clear from the data in Table 3, the resin of the present invention has good grindability, hot offset resistance, storability and positive chargeability, and exhibits excellent performance as a positively chargeable resin for electrophotographic toner. I found it to have.

[0049]

[Table 3]

Examples 25 to 38 Amorphous poly α-hydroxy carboxylic acids shown in Table 4 were prepared by dehydration polycondensation in the same manner as in Examples 1 to 7 except that the reflux solvent was not used. After obtaining the acid, the polyhydric alcohol shown in Table 4 was added and the polycondensation was continued until the acid value reached a predetermined value to obtain the polyester shown in Table 4. 1000 g of this polyester resin was reacted with the diisocyanate shown in Table 4 in a molten state to obtain a urethanized polyester resin shown in Table 4.

6 parts of carbon black MA-100 (manufactured by Mitsubishi Kasei Co., Ltd.) and polypropylene wax VISCOL 660P (manufactured by Sanyo Kasei Co., Ltd.) based on 100 parts of the urethanized polyester resin (resin for toner) obtained by the above method. After dispersing and mixing 3 parts with a Henschel mixer, a twin-screw kneader PCM30 (made by Ikegai Tekko Co., Ltd.)
Was melt-kneaded at 160 ° C. to obtain a lumped toner composition. This composition was roughly crushed with a hammer mill, then finely crushed with a jet crusher (IDS2 type manufactured by Nippon Pneumatic Co., Ltd.), and then classified by air flow to obtain an average particle size of 10 μm (5
Toner particles having a particle size of 3 μm or less and 20 μm or more and 2% by weight or less are obtained. The pulverizability of the toner was judged by measuring the volume average particle diameter after pulverization under the condition that the supply rate of the coarse powder to the jet pulverizer was constant. The fixing property and offset property of this toner were evaluated by using a commercially available copying machine to examine the degree of contamination of the heat roller. Also, ferrite carrier F53-150
After mixing 95 parts (manufactured by Nippon Iron Powder Co., Ltd.) and 5 parts of toner with a V blender for 30 minutes, the charge amount of the toner was measured by a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co., Ltd.). Furthermore, this toner is used at a temperature of 40 ° C. and a relative humidity of 60%.
After storing in the above environment for 24 hours, the storability was examined from the aggregated state of the particles. The results are shown in Table 4.

As is clear from the data in Table 4, the resin of the present invention has good grindability, hot offset resistance, storability and positive chargeability, and exhibits excellent performance as a positively chargeable resin for electrophotographic toner. I found it to have.

[0053]

[Table 4]

Examples 39 to 48 The α-hydroxycarboxylic acids shown in Table 5 were dehydrated and polycondensed in the same manner as in Examples 1 to 7 except that the reflux solvent was not used to obtain amorphous poly α-hydroxycarboxylic acid. After obtaining the acid, the polycarboxylic acid shown in Table 5 was added and the polycondensation was continued until the acid value reached a predetermined value to obtain the polyester shown in Table 5.

Carbon black MA-100 was added to 100 parts of the polyester (resin for toner) obtained by the above method.
After 6 parts (manufactured by Mitsubishi Kasei Co., Ltd.) and 3 parts of polypropylene wax VISCOL 660P (manufactured by Sanyo Kasei Kogyo Co., Ltd.) were dispersed and mixed by a Henschel mixer, 160 by a biaxial kneader PCM30 (manufactured by Ikegai Tekko KK). Melt kneading at 0 ° C. to obtain a lumped toner composition. This composition was roughly crushed by a hammer mill, then finely crushed by a jet crusher (IDS2 type manufactured by Nippon Pneumatic Co., Ltd.), and then classified by air flow to have an average particle size of 10 μm (5 μm or less 3% by weight,
Toner particles of 20 μm or more and 2% by weight) were obtained. The pulverizability of the toner was judged by measuring the volume average particle diameter after pulverization under the condition that the supply rate of the coarse powder to the jet pulverizer was constant.
The fixing property and offset property of this toner were evaluated by using a commercially available copying machine to examine the degree of contamination of the heat roller. Further, 95 parts of ferrite carrier F95-100 (manufactured by Nippon Iron Powder Co., Ltd.) and 5 parts of toner were mixed for 30 minutes by a V blender, and then the charge amount of the toner was measured by a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co., Ltd.). . Further, this toner was stored in an environment of a temperature of 40 ° C. and a relative humidity of 60% for 24 hours, and then the storability was examined from the agglomerated state of the particles. The results are shown in Table 5.

As is clear from the data in Table 5, the resin of the present invention has good grindability, hot offset resistance, storability and negative chargeability, and exhibits excellent performance as a negatively chargeable electrophotographic toner resin. I found it to have.

[0057]

[Table 5]

Examples 49 to 60 Semi-crystalline poly α-hydroxycarboxylic acids were prepared by dehydration polycondensation of α-hydroxycarboxylic acids shown in Table 6 in the same manner as in Examples 1 to 7 except that the reflux solvent was not used. After obtaining the acid, the polyhydric alcohol shown in Table 6 was added and the polycondensation was continued until the acid value reached a predetermined value to obtain the polyester shown in Table 6.

Carbon black MA-100 was added to 100 parts of the polyester (resin for toner) obtained by the above method.
After 6 parts (manufactured by Mitsubishi Kasei Co., Ltd.) and 3 parts of polypropylene wax VISCOL 660P (manufactured by Sanyo Kasei Kogyo Co., Ltd.) were dispersed and mixed by a Henschel mixer, 160 by a biaxial kneader PCM30 (manufactured by Ikegai Tekko KK). Melt kneading at 0 ° C. to obtain a lumped toner composition. This composition was roughly crushed by a hammer mill, then finely crushed by a jet crusher (IDS2 type manufactured by Nippon Pneumatic Co., Ltd.), and then classified by air flow to have an average particle size of 10 μm (5 μm or less 3% by weight,
Toner particles of 20 μm or more and 2% by weight) were obtained. The pulverizability of the toner was judged by measuring the volume average particle diameter after pulverization under the condition that the supply rate of the coarse powder to the jet pulverizer was constant.
The fixing property and offset property of this toner were evaluated by using a commercially available copying machine to examine the degree of contamination of the heat roller. Further, 95 parts of ferrite carrier F53-150 (manufactured by Nippon Iron Powder Co., Ltd.) and 5 parts of toner were mixed with a V blender for 30 minutes, and then the toner charge amount was measured by a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co., Ltd.). . Further, this toner was stored in an environment of a temperature of 40 ° C. and a relative humidity of 60% for 24 hours, and then the storability was examined from the agglomerated state of the particles. The results are shown in Table 6.

As is clear from the data in Table 6, the resin of the present invention has good grindability, hot offset resistance, storability and positive chargeability, and exhibits excellent performance as a positively chargeable electrophotographic toner resin. I found it to have.

[0061]

[Table 6]

Examples 61 to 75 The α-hydroxycarboxylic acids shown in Table 7 were dehydrated and polycondensed in the same manner as in Examples 1 to 7 except that the reflux solvent was not used to give semi-crystalline poly α-hydroxycarboxylic acids. After obtaining the acid, the polyhydric alcohol shown in Table 7 was added and the polycondensation was continued until the acid value reached a predetermined value to obtain the polyester shown in Table 7. 1000 g of this polyester resin was reacted with the diisocyanate shown in Table 7 in a molten state to obtain a urethanized polyester resin shown in Table 7.

6 parts of carbon black MA-100 (manufactured by Mitsubishi Kasei Co., Ltd.) and polypropylene wax VISCOL 660P (manufactured by Sanyo Kasei Co., Ltd.) with respect to 100 parts of the urethanized polyester resin (resin for toner) obtained by the above method. After dispersing and mixing 3 parts with a Henschel mixer, a twin-screw kneader PCM30 (made by Ikegai Tekko Co., Ltd.)
Was melt-kneaded at 160 ° C. to obtain a lumped toner composition. This composition was roughly crushed with a hammer mill, then finely crushed with a jet crusher (IDS2 type manufactured by Nippon Pneumatic Co., Ltd.), and then classified by air flow to obtain an average particle size of 10 μm (5
Toner particles having a particle size of 3 μm or less and 20 μm or more and 2% by weight or less are obtained. The pulverizability of the toner was judged by measuring the volume average particle diameter after pulverization under the condition that the supply rate of the coarse powder to the jet pulverizer was constant. The fixing property and offset property of this toner were evaluated by using a commercially available copying machine to examine the degree of contamination of the heat roller. Also, ferrite carrier F53-150
After mixing 95 parts (manufactured by Nippon Iron Powder Co., Ltd.) and 5 parts of toner with a V blender for 30 minutes, the charge amount of the toner was measured by a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co., Ltd.). Furthermore, this toner is used at a temperature of 40 ° C. and a relative humidity of 60%.
After storing in the above environment for 24 hours, the storability was examined from the aggregated state of the particles. The results are shown in Table 7.

As is clear from the data in Table 7, the resin of the present invention has good grindability, hot offset resistance, storability and positive chargeability, and exhibits excellent performance as a positively chargeable resin for electrophotographic toner. I found it to have.

[0065]

[Table 7]

Examples 76 to 85 The α-hydroxycarboxylic acids shown in Table 8 were dehydrated and polycondensed in the same manner as in Examples 1 to 7 except that the reflux solvent was not used to give semi-crystalline poly α-hydroxycarboxylic acids. After obtaining the acid, the polycarboxylic acid shown in Table 8 was added and the polycondensation was continued until the acid value reached a predetermined value to obtain the polyester shown in Table 8.

Carbon black MA-100 was added to 100 parts of the polyester (resin for toner) obtained by the above method.
After 6 parts (manufactured by Mitsubishi Kasei Co., Ltd.) and 3 parts of polypropylene wax VISCOL 660P (manufactured by Sanyo Kasei Kogyo Co., Ltd.) were dispersed and mixed by a Henschel mixer, 160 by a biaxial kneader PCM30 (manufactured by Ikegai Tekko KK). Melt kneading at 0 ° C. to obtain a lumped toner composition. This composition was roughly crushed by a hammer mill, then finely crushed by a jet crusher (IDS2 type manufactured by Nippon Pneumatic Co., Ltd.), and then classified by air flow to have an average particle size of 10 μm (5 μm or less 3% by weight,
Toner particles of 20 μm or more and 2% by weight) were obtained. The pulverizability of the toner was judged by measuring the volume average particle diameter after pulverization under the condition that the supply rate of the coarse powder to the jet pulverizer was constant.
The fixing property and offset property of this toner were evaluated by using a commercially available copying machine to examine the degree of contamination of the heat roller. Further, 95 parts of ferrite carrier F95-100 (manufactured by Nippon Iron Powder Co., Ltd.) and 5 parts of toner were mixed for 30 minutes by a V blender, and then the charge amount of the toner was measured by a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co., Ltd.). . Further, this toner was stored in an environment of a temperature of 40 ° C. and a relative humidity of 60% for 24 hours, and then the storability was examined from the agglomerated state of the particles. The results are shown in Table 8.

As is clear from the data in Table 8, the resin of the present invention has good grindability, hot offset resistance, storability and negative chargeability, and exhibits excellent performance as a negatively chargeable electrophotographic toner resin. I found it to have.

[0069]

[Table 8]

Examples 86 to 90 Production examples of binder resins by cationic ring-opening polymerization are shown below. As a cyclic dimer starting material of α-hydroxycarboxylic acid shown in Table 9, polymerization was carried out by the method described in WO 92/01245. The solvent was vacuum-dried from the obtained polymer solution to obtain polyesters shown in Table 9.

Carbon black MA-1 was added to 100 parts of the polyester (resin resin) obtained by the above method.
6 parts of 00 (manufactured by Mitsubishi Kasei Co., Ltd.) and 3 parts of polypropylene wax VISCOL 660P (manufactured by Sanyo Kasei Co., Ltd.) are dispersed and mixed by a Henschel mixer, and then 16 by a biaxial kneader PCM30 (manufactured by Ikegai Tekko KK).
Melt kneading at 0 ° C. gave a lumpy toner composition. This composition was roughly crushed with a hammer mill, then finely crushed with a jet crusher (IDS2 type, manufactured by Nippon Pneumatic Co., Ltd.), and then classified by air flow to have an average particle size of 10 μm (5 μm or less 3% by weight, 20 μm or more 2). % By weight) of toner particles are obtained. The pulverizability of the toner was judged by measuring the volume average particle diameter after pulverization under the condition that the supply rate of the coarse powder to the jet pulverizer was constant. The fixing property and offset property of this toner were evaluated by using a commercially available copying machine to examine the degree of contamination of the heat roller. Further, 95 parts of ferrite carrier F95-100 (manufactured by Nippon Iron Powder Co., Ltd.) and 5 parts of toner were mixed for 30 minutes by a V blender, and then the charge amount of the toner was measured by a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co., Ltd.). . Further, this toner was stored in an environment of a temperature of 40 ° C. and a relative humidity of 60% for 24 hours, and then the storability was examined from the agglomerated state of the particles. The results are shown in Table 9.

As is clear from the data in Table 9, the toner using the poly α-hydroxycarboxylic acid obtained by the ring-opening polymerization is the same as the toner using the toner resin of the present invention obtained by direct dehydration polycondensation. Offset resistance is inferior in comparison, and poly α-obtained by direct dehydration polycondensation of the present invention
It is clear that the hydroxycarboxylic acid has significantly better performance than the poly α-hydroxycarboxylic acid obtained by the ring-opening polymerization method.

[0073]

[Table 9]

[0074]

The toner resin of the present invention exhibits good fixability, which is thought to be due to the low heat flow initiation temperature, and has good crushability, hot offset resistance, storage stability, and positive or negative chargeability. Thus, it has excellent performance as a resin for positively or negatively chargeable electrophotographic toner.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (31) Priority claim number Japanese Patent Application No. 5-38059 (32) Priority date Hei 5 (1993) February 26 (33) Country of priority claim Japan (JP) (31) Priority Claim number Japanese Patent Application No. Hei 5-38060 (32) Priority Date Hei 5 (1993) February 26 (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. Hei 5-38061 (32) Priority Hihei 5 (1993) February 26 (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 5-38062 (32) Priority Day Hei 5 (1993) February 26 (33) ) Priority claiming country Japan (JP) (31) Priority claiming number Japanese Patent Application No. 5-38063 (32) Priority date Hei 5 (1993) February 26 (33) Priority claiming country Japan (JP)

Claims (8)

[Claims] 1. A resin for an electrophotographic toner, which comprises a decomposable polyester resin which is an amorphous poly α-hydroxycarboxylic acid obtained by direct dehydration polycondensation of an α-hydroxycarboxylic acid as a main component. 2. A number-average molecular weight of 2000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid.
A resin for electrophotographic toner, characterized in that the main component is a decomposable polyester resin which is an amorphous poly α-hydroxycarboxylic acid. 3. A number average molecular weight of 1,000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid.
As a main component, a degradable polyester resin having 90% or more of the terminal groups is a hydroxyl group, which is obtained by reacting the amorphous poly α-hydroxycarboxylic acid with a polyol having 3 or more hydroxyl groups in the same molecule. A resin for electrophotographic toner, which is characterized by: 4. A number-average molecular weight of 2000-7000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid.
Of amorphous polyester poly (α-hydroxycarboxylic acid) and a polyol having 3 or more hydroxyl groups in the same molecule, and diisocyanate were reacted to obtain 1 mol equivalent of hydroxyl groups of polyester. A resin for an electrophotographic toner, which comprises, as a main component, a decomposable polyester resin which is a urethanized polyester to which an isocyanate group of 8 mol equivalent or more is added. 5. A number average molecular weight of 1,000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid.
Decomposable polyester resin obtained by reacting amorphous poly α-hydroxycarboxylic acid with polycarboxylic acid having 3 or more carboxyl groups in the same molecule, wherein 90% or more of the terminal groups are carboxyl groups A resin for electrophotographic toner, which is mainly composed of: 6. A number-average molecular weight of 1,000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid.
The main component is a degradable polyester resin obtained by reacting the semi-crystalline poly α-hydroxycarboxylic acid of 1 with a polyol acid having 3 or more hydroxyl groups in the same molecule and having 90% or more of the terminal groups being hydroxyl groups. A resin for electrophotographic toner, which is characterized by: 7. A number average molecular weight of 2000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid.
Obtained by reacting a diisocyanate with a polyester consisting of the semi-crystalline poly α-hydroxycarboxylic acid and a polyol having 3 or more hydroxyl groups in the same molecule,
7. A degradable polyester resin, which is a urethanized polyester having 0.8 mol equivalent or more of isocyanate groups added to 1 mol equivalent of hydroxyl groups of the polyester, as a main component. The resin for electrophotographic toner described. 8. A number average molecular weight of 1,000 to 7,000 obtained by direct dehydration polycondensation of α-hydroxycarboxylic acid.
Degradable polyester resin obtained by reacting semi-crystalline poly α-hydroxy carboxylic acid with polycarboxylic acid having 3 or more carboxyl groups in the same molecule, wherein 90% or more of the terminal groups are carboxyl groups A resin for electrophotographic toner, which is mainly composed of: