JP3398602B2 - Electrophotographic toner - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner, and more particularly to an electrophotographic polyester resin toner containing a phosphorus-based additive.

[0002]

2. Description of the Related Art In recent years, with the spread of copying machines and printers using the electrophotographic method, energy saving (power consumption reduction) has been mainly aimed at spreading to households and multifunction of copying machines or printers. Reduction), high speed for the purpose of spreading to so-called gray area located at the boundary between the printing machine and the copying machine, low machine pressure, or low roll pressure for simplifying the fixing roll is desired. In addition, copiers equipped with a double-sided copy function and an automatic document feeder have become widespread with the sophistication of copiers, and the fixing temperature is low for electrophotographic toner used in copiers and printers. , An electrophotographic toner that has excellent anti-offset properties and also has excellent fixing strength on transfer paper to prevent stains during double-sided copying and stains on the automatic document feeder. Are required.

Further, the characteristics required for the toner resin are
It largely depends on the fixing process to which the toner is applied. Generally, in the oilless system, characteristics relating to temperature control of the fixing heat roll at the time of toner fixing and image fixing (so-called non-offset characteristics) are required, and various attempts have been made to satisfy the characteristics. In order to satisfy the non-offset characteristics on the low temperature side, a method of blending a crystalline compound having a low melting point (so-called wax) at the time of producing a toner product, a method of controlling the blending amount of a low molecular weight portion, etc. Has been done. On the other hand, the method for satisfying the non-offset characteristic on the high temperature side is mainly based on the study of the blending of the polymer component.

As the toner resin used so far, the olefin resins represented by polystyrene copolymers and the condensation resins represented by polyester resins are mainly used. Although many synthetic methods can be applied to the method for producing the olefin resin, the melt polycondensation reaction is only applied to the method for producing the polyester resin in terms of cost.

With respect to the polyolefin resin for toner, it is possible to use a method of blending a linear high molecular weight component having a molecular weight of more than 1,000,000 as a means for satisfying the non-offset characteristic on the high temperature side. On the other hand, with the polyester resin for toner, a linear polymer having a molecular weight of more than 1,000,000 cannot be easily synthesized.

A major problem in the production of a polyester resin having a crosslinked structure is that the melt viscosity of the resin rises sharply at the end of the polymerization reaction, making it difficult to react under uniform stirring. is there. In order to manage the end point of this reaction, Polymer Bunko 7: Introduction to Synthetic Resins for Paints (May 25, 1974, by Kyozo Kitaoka, published by Polymer Publishing Society)
The method of "Monitoring of polyesterification reaction" described on page 107 of the above is generally used. This method is based on the relationship between resin viscosity, acid value and reaction time.
It is very useful for extrapolating the "acid value-time curve" to predict the arrival time of the reaction end point and grasping the timing of taking out the polyester resin from the manufacturing apparatus. Further, an experimental method for polymer synthesis (March 1, 1972, Takayuki Otsu et al., Published by Kagaku Dojin) shows a laboratory synthetic method for various linear polyesters. Further, as an industrial method, Polymer Engineering Course 17: Polymer Industrial Plant (June 15, 1964, edited by The Society of Polymer Science, published by Jishin Shokan), a typical production method of polyethylene terephthalate (PET), and The manufacturing plant is described.

It is widely known that the resin characteristics of the polyester resin change from moment to moment because the resin temperature of the molten polyester resin is high and the reaction is not completely stopped during the removal of the resin. This problem is an intrinsic problem of polyester (the polycondensation reaction is an equilibrium reaction, the transesterification reaction cannot be controlled, etc.), and many efforts are made to manage the end point of the reaction and avoid the problem of physical property change. Have been paid. For example, in order to shorten the resin take-out time, a method of extruding a molten polyester resin in a pressurized state in a short time with an inert atmosphere gas, or a method of changing the reaction mode in a low melt viscosity state (for example, a low melt viscosity state After taking out the resin once by cooling, crushing and pulverizing it, the method of increasing the molecular weight by the solid-state polymerization method (polymer synthesis experimental method, 196
November 10, 2011, translated by Toshio Hoshino, Naoya Yoda, Tokyo Kagaku Dojin, Chapter 3 Experiment No. 60: Synthesis of polyglycolic acid ester)], a method of changing the stirring and mixing method with increasing viscosity [DuPont company method] BP753,526 (1956), USP 2,72
7,882 (1955), USP 2,758,915 (1956)], the method of changing the stirring method under normal pressure and reduced pressure, etc., the method using a batch type polymerization apparatus (USP 2,647,885), and the screw at the bottom outlet of the reactor. Shaped drive and discharge device is installed to take out resin in a short time (Chemical engineering, 21 , P.278, Shinji Nagata: Double-helical type or guide mixer screw mixer type stirring). Is coming.

It is also known that when a kneading and pulverizing method is used as a means for forming a toner, the physical properties of the resin change greatly depending on the shear during kneading. It is also known that in the case of polyester resins other than toner applications, an antioxidant such as hindered phenol is added to prevent deterioration of resin physical properties during kneading.

[0009]

As shown in the above-mentioned prior art, in order to obtain a crosslinked polyester resin having stable resin properties, a method of ignoring the essential factors of the polyester was established, and a toner was formed. It is necessary to eliminate the factor of the deterioration of the physical properties of the resin.

An object of the present invention is to improve a method for producing a crosslinked polyester resin (a production method using a condensation reaction by dehydration and / or transesterification reaction), which is a problem of the prior art, and to provide a polyester resin having stable resin properties. Another object of the present invention is to provide a polyester resin toner for electrophotography using the above.

[0011]

[Means for Solving the Problems] The inventors of the present invention have made extensive studies to solve the above-mentioned problems, and when producing a crosslinked polyester resin, a phosphorus compound is added as a stabilizer from the initial stage of the reaction. The inventors have found that the solution can be achieved by the above, and have completed the present invention.

In the present invention, at the time of producing a crosslinked polyester resin, at least one phosphorous material selected from phosphoric acid esters and / or phosphorous acid esters having one or more aromatic substituents is added. An electrophotographic toner using a crosslinked polyester resin as a main binder resin.

[0013] The first of the present invention, in producing a crosslinked polyester resin, a crosslinking resin, characterized in that the addition of phosphorus-based material comprising a polyester resin toner for electrophotography used in the main binder resin , Especially the catalyst, transition
For metal transfer polymerization catalyst and / or transesterification catalyst
In contrast, phosphoric acid esters having one or more aromatic groups and
And / or at least a phosphite ester
The amount of one or more phosphorus-based materials added is 10/1 to 1 by weight.
It is characterized by being in the range of 1/2. this
The result, it is possible to uniformly disperse the phosphorus-based material,
Along with being able to produce a crosslinked polyester resin with stable physical properties, it is possible not only to suppress the deterioration of the physical properties of the polyester resin due to the kneading shear in the toner-forming step by the melt-kneading method, but also to improve the temporal stability of the toner product, which is a great advantage. Have.

The second aspect of the present invention shows the criteria for selecting the phosphorus-based material added during the production of the crosslinked polyester resin. That is, a polyester is prepared by polycondensing one or more difunctional or more carboxylic acids with a difunctional or more alcohol and a trifunctional or more cross-linking agent (polycarboxylic acids and polyhydric alcohols may be used alone or in combination). At the time of manufacturing, it is necessary to add at least one or more phosphoric acid esters and / or phosphorous acid esters having one or more aromatic substituents. By having an aromatic group in the phosphorus-based material, it is possible to increase the vapor pressure of the phosphorus-based material,
Volatilization under the polycondensation reaction conditions performed at high temperature can be suppressed.

The phosphoric acid ester and / or phosphorous acid ester added as a stabilizer to the electrophotographic toner of the present invention includes the following.

[Chemical 1] (In the formula, P represents a phosphorus atom, O represents an oxygen atom, and R ₁ , R
₂ and R ₃ are a hydrogen atom, a halogen, an alkyl group having 20 or less carbon atoms, an aromatic group having no substituent and a carbon number of 20.
An aromatic group having one or more of the following substituents and an aromatic group having one or more halogens are shown, and they may or may not be the same, but one of them is always an aromatic group.)

[0016]

[Chemical 2] (In the formula, P represents a phosphorus atom, O represents an oxygen atom, and R ₄ , R
₅ and R ₆ are a hydrogen atom, a halogen, an alkyl group having 20 or less carbon atoms, an aromatic group having no substituent and a carbon number of 20.
An aromatic group having one or more of the following substituents and an aromatic group having one or more halogens are shown, and they may or may not be the same, but one of them is always an aromatic group.)

The phosphorus compound having the structure represented by the chemical formulas 1 and 2 must have at least one phosphate ester bond having an aromatic group. The reason is that when all are relatively short-chain alkyl groups, it is necessary to consider that pesticide-like odor is likely to be generated, which may cause a serious problem in the working environment. In addition, due to their chemical properties, monoalkyl and dialkyl phosphates tend to have higher acidity than free phosphoric acid, so that care must be taken when handling them.

In this respect, the compound having one or more aromatic compounds has no problem of offensive odor, can be handled as a solid or a viscous liquid at room temperature, and it is not necessary to consider a problem in working environment. Furthermore, by adding it together with a catalyst to the production of the polyester resin for toner, there is a great advantage in that the polycondensation reaction can be suppressed. The advantage here means that, when a polyester resin for a toner having a crosslinked structure using a polyfunctional monomer is produced, the effect of broadening the molecular weight distribution is large without increasing the melt viscosity at the end of the reaction all at once. .

In the present invention, phosphoric acid esters and / or
Or at least one selected from phosphites
The above-mentioned addition amount of the phosphorus-based material is not an addition amount with respect to the polyester resin , but is an amount with respect to the weight of the catalyst used for the condensation reaction. That is, the catalyst used in the production of toner crosslinked polyester resin, for the transition metal polymerization catalyst and / or transesterification catalyst, aromatic
It is indicated by the addition amount of phosphoric acid ester and / or phosphorous acid ester having one or more group groups . This addition amount is in the range of 10/1 to 1/2 in terms of weight ratio to the catalyst.
If the addition amount is less than this, the reaction cannot be controlled, and if it is too large, the progress of the reaction is hindered, and it is not possible to obtain a polyester resin having a desired molecular weight distribution. Become longer.

As described above, the amount of the phosphoric acid ester and / or the phosphorous acid ester used in the present invention and the amount of the catalyst used during the production of the polyester are controlled, and the addition timing is limited, that is, the polyester synthesis is performed. Not only can the polycondensation reaction be controlled by adding the monomers constituting the polyester and the phosphoric acid ester and / or the phosphorous acid ester represented by the above chemical formula 1 and / or 2 from the initial stage of production, It has a great advantage in that the deterioration of the physical properties due to the shear when the kneaded toner is formed is suppressed.

On the other hand, if the addition is carried out in the middle of the reaction, in the case of the phosphoric acid ester, the catalyst deactivating action (deactivates the catalytic action) works, the polymerization reaction stops, and the desired polyester resin for toner is obtained. I can't get it. Further, in the case of phosphite ester, the action is completely different from that of phosphite ester, on the contrary, the reaction is promoted, the melt viscosity of the polyester resin increases in an extremely short time, and the uniform reaction cannot be continued. I will end up. It is presumed that the cause is the difference in the Lewis structure of the phosphorus atom. That is, when it is pentavalent (phosphate ester), it only coordinates to the condensation reaction catalyst, but when it is trivalent, it acts like a Lewis acid due to the vacant site of the electron and contributes to the ester bond formation reaction. It is thought to be to do. Therefore, the phosphorus-based material is preferably added at the monomer blending stage during the production of the crosslinked polyester resin.

Examples of the phosphoric acid ester used in the present invention include the following compounds. Phenylphosphonic acid,
Diphenylphosphonic acid, triphenylphosphonic acid, phenylphosphonic acid dichloride, cresyl diphenylphosphonic acid, tricresylphenylphosphonic acid, xylenyldiphenylphosphonic acid, tris (dibromophenyl) phosphonic acid, tris (tribromophenyl) phosphon Examples thereof include acids and condensed phosphoric acid esters thereof. These may be used alone or in combination of two or more.

The following compounds can be exemplified as the phosphite ester used in the present invention. Triphenyl phosphite [Product name: Chelex-P (Sakai Chemical), JP360 (Johoku Chemical), Sumilizer TPP and TPP-R (Sumitomo Chemical), TP-I
(Daihachi Kagaku), ADEKA STAB TPP (Asahi Denka)], tris (nonylphenyl) phosphite [Naugard P (Uniroyal)]
, JP351 (Johoku Chemical), Polyguard HR (Rubber Regenerat
ing), ADEKA STAB 329K (Asahi Denka)], diphenyl phosphite, diphenyl phosphite, tri-o-tolyl phosphite, di-o-tolyl phosphite, tri-m-tolyl phosphite, phosphite Acid di-m-tolyl, tri-p-tolyl phosphite, di-p-tolyl phosphite, di-o-chlorophenyl phosphite, tri-p-chlorophenyl phosphite, di-p-phosphite Chlorophenyl, diphenylisodecyl phosphite [trade name: ADEKA STAB 135A (Asahi Denka)], phenyl diisodecyl phosphite, etc. [trade name: ADEKA STAB 517]
(Asahi Denka), Chelex-D (Sakai Chemical)]. They are,
They can be used alone or in combination of two or more.

Examples of the bifunctional or higher functional alcohol used for producing the crosslinked polyester resin of the present invention include the following. Diethanolamine, ethylene glycol, diethylene glycol, propylene glycol, isopropylene glycol, octane diol,
2,2-diethyl-1,3-propanediol, spiroglycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 2-butyl-2-
Ethyl-1,3-propanediol, 1,6-hexanediol, hexylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, hydrobenzoin, bis (β-hydroxyethyl) terephthalate, A diol such as bis (hydroxybutyl) terephthalate, polyoxyethylenated bisphenol A, polyoxypropyleneated bisphenol A, polyoxyethylenated biphenol, polyoxypropyleneated biphenol, etc., which may be used alone or in combination of two or more kinds, It is not limited.

As the trihydric alcohol, glycerol, 1,2,4-butanetriol, 2-ethyl-
2- (hydroxymethyl) -1,3-propanediol, 1,2,6-trihydroxyhexane, 2,5-dimethyl-1,2,6-hexanetriol, sorbitan, 1,2,5-pentanetriol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane and the like can be shown.

As the tetrahydric alcohol, pentaerythritol, pentaerythritol ethylene oxide and the like molar adducts and polyadducts thereof, pentaerythritol propylene oxide adducts and polyadducts thereof,
1,2,3,6-hexanetetrol, 1,2,7,8
-Octanetrol, etc. can be indicated. Furthermore, dipentaerythritol,
Tripentaerythritol, natural sugars, natural polysaccharides and their derivatives are indicated.

Further, examples of the difunctional or higher functional carboxylic acid used for producing the polyester resin of the present invention include the following. For example, fumaric acid, maleic acid, succinic acid, itaconic acid, mesaconic acid, citraconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexenedicarboxylic acid, adipic acid, sebacic acid, dodecanedioic acid, naphthalenedicarboxylic acid, biphenyl. -4,4-dicarboxylic acid, 2,3-piperazine-dicarboxylic acid, iminodicarboxylic acid, imidazole-
4,5-dicarboxylic acid, piperidinecarboxylic acid, N-phenylpyrazoledicarboxylic acid, pyridinedicarboxylic acid, carbazole-3,6-dicarboxylic acid, 9-methylcarbazole-3,6-dibutyric acid, carbazole-3,6
-Γ, γ'-diketobutyric acid and the like and lower alkyl diesters thereof may be used alone or in admixture of two or more.

Examples of the trivalent or higher carboxylic acid include trimellitic acid, 1,2,4-cyclohexanetricarboxylic acid,
1,2,4-naphthalene tricarboxylic acid, 2,5,7-
Naphthalene tricarboxylic acid, pyridine tricarboxylic acid,
Pyridine-2,3,4,6-tetracarboxylic acid, 1,
2,7,8-Tetracarboxylic acid, butanetetracarboxylic acid and the like are exemplified, and there are acid anhydrides thereof and lower alkyl esters thereof.

When further addition of functionality is desired due to the properties of the resin, the phenolic hydroxyl group-containing dicarboxylic acid may be partially replaced with the dicarboxylic acid component. Examples of such dicarboxylic acid having a phenolic hydroxyl group include the following compounds. 4-hydroxyisophthalic acid, 5-hydroxyisophthalic acid, 4,6-
Dihydroxyisophthalic acid, 2,5-dihydroxy-
1,4-benzenediacetic acid, chelidamic acid, bis (2-hydroxy-3-carboxyphenyl) methane and their acid anhydrides or lower alkyl esters can be used.

The catalyst used in these polycondensation reactions is a dehydration catalyst used in polyester production,
A transesterification reaction catalyst, a transition metal-based polymerization catalyst and a co-catalyst can be used, and they can be used alone or in combination as long as no harmful by-product gas or harmful substances are emitted.
Examples of the transition metal-based polymerization catalyst include titanium compounds such as tetra-n-butyl titanate, germanium compounds such as germanium oxide, tin compounds such as dibutyltin oxide, manganese compounds such as manganese oxide, and the like.
As the transesterification catalyst, for example, a calcium compound such as calcium acetate, a magnesium compound such as magnesium acetate, a zinc compound such as zinc acetate, or the like is used.

Further, an antioxidant may be added during the production of the polyester resin and / or the production of the toner, as long as the action of the phosphorus-based material is not impaired. Examples of phenolic antioxidants include 2,6-t-butyl-
p-cresol, butylated hydroxyanisole, 2,
6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5-dihydroxyphenyl) propionate, 2,2'-methylenebis (4-methyl-6-t-)
Butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol), 4,4'-thiobis (3-methyl-6-butylphenol), 4,4'-
Butylidene bis (3-methyl-6-butylphenol), 3,9-bis [1,1-dimethyl-2- [β-
(3-t-Butyl-4-hydroxy-5-methylphenyl) propionoxy] ethyl] 2,4,8,10-tetraoxaspiro [5,5] undecane, 1,1,3-
Tris- (2-methyl-4-hydroxy-5-t-butylphenylbutane, 1,3,5-trismethyl-2,
4,6-Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3
-(3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, 3,3'-bis (4'-hydroxy-3'-t-butylphenyl) butyric acid] glycol ester , 1,3,5-Tris (3 ', 5'-di-t-butyl-4'-hydroxybenzyl) S-triazine-2,4,6- (1H, 3
H, 5H) trione, and tocophenols.

As the sulfur type antioxidant, dilauryl-
3,3-thiodipropionate, dimyristyl-3,3
-Thiodipropionate, distearyl-3,3-thiodipropionate and the like.

Furthermore, examples of phosphorus-based materials other than those mentioned above applicable to the present invention include 4,4-butylidene-bis [3-methyl-6-t-butylphenyltridecyl] phosphorous acid, 9,10- Dihydroxy-9-oxa-10
-Phosphaphenanthrene-10-oxide, 10-
(3,5-di-t-butyl-4-hydroxybenzyl)
-9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-
9,10-dihydro-9-oxa-10-phosphaphenanthrene, tris (2,4-di-t-butylphenyl) phosphorous acid, cyclic neopentanetetraylbis (2,4-di-t-butyl) Phenyl) phosphorous acid, cyclic neopentanetetraylbis (2,6-di-t
-Butyl-4-methyloctyl) phosphorous acid and the like can be exemplified.

Next, the electrophotographic toner of the present invention will be described in more detail. The electrophotographic toner of the present invention is produced by mixing other resin colorants, magnetic materials, charge control agents, and other additives in addition to the crosslinked polyester resin, and hot-melt kneading, pulverizing, and classifying. it can. Supermixer for mixing, uniaxial extrusion kneader for hot melt kneading,
Biaxial extrusion kneader, extruder, roller mixer, Banbury mixer, pressure kneader, etc. are used.
A jet mill is used for pulverization, and a dry airflow classifier is used for classification.

As the binder resin for the electrophotographic toner of the present invention, in addition to the above-mentioned crosslinked polyester resin, a styrene resin, a styrene acrylic copolymer resin, a polyester resin, a polyethylene resin, an epoxy resin, a silicone resin. Resins such as polyamide resin and polyurethane resin may be blended.

Examples of the colorant used in the present invention include carbon black, aniline blue, phthalocyanine blue, quinoline yellow, malachite green, lamp black, rhodamine-B and quinacridone. The amount of the colorant added is 1 to 20% by weight based on the resin. As the charge control agent, for a positively charged toner, a nigrosine dye, an ammonium salt, a pyridinium salt, an azine or the like is added in an amount of 0.1 to 10% by weight based on the resin. A toner using a polyester resin generally gives a negative charging property, but when a charge control agent for a negative charging toner is added if necessary, a chromium complex, an iron complex or the like is used. When the negative chargeability is too strong, it is possible to control the neutralization by adding the above-mentioned positively chargeable charge control agent or the like.

The magnetic substance used in the toner of the present invention includes a ferromagnet such as ferrite, magnetite, a ferromagnet such as iron, cobalt, nickel or the like, a compound containing these elements, or a ferromagnetic element. Alloys which, although not, exhibit ferromagnetism when subjected to an appropriate heat treatment, such as manganese-copper-aluminum,
Examples include alloys of the type called Heusler alloys containing manganese and copper, such as manganese-copper-tin, or chromium dioxide. These magnetic materials have an average particle size of 0.1 to
It is evenly dispersed in the binder resin in the form of 1 micron fine powder. The content is 20 to 70 per 100 parts by weight of the toner.
Parts by weight, preferably 40 to 70 parts by weight.

The electrophotographic toner of the present invention is mixed with a carrier composed of ferrite powder or iron powder to form a two-component developer. When the magnetic substance is contained, it may be used as a one-component developer without mixing with a carrier, or may be mixed with a carrier and used as a two-component developer. Further, it can be used for a non-magnetic one-component developing method.

As for the melting characteristics of the electrophotographic toner, the melting start temperature is preferably 60 ° C. or higher and 105 ° C. or lower in order to improve the fixability at lower temperatures. If the melting start temperature is lower than 60 ° C., the blocking property of the toner may be deteriorated and storage stability may be deteriorated, which is not preferable. On the other hand, if the temperature exceeds 105 ° C., the low-temperature fixability deteriorates, which is not preferable. Further, in order to have a sufficient fixing non-offset width, it is preferable that the decrease in melt viscosity at a high temperature is small, and the difference between the softening point and the melting start temperature is 15 ° C or higher and 45 ° C or higher.
The following is preferable. If it is less than 15 ° C, the non-offset width of fixing (non-offset temperature width) becomes narrower, and 4
If it exceeds 5 ° C, the offset resistance can be maintained good, but the low-temperature fixability deteriorates, which is not preferable. To improve the low-temperature fixability, the melting start temperature should be 60 ° C or higher 1
Most preferably, it is not higher than 00 ° C.

The melting start temperature referred to here means the temperature drop of the plunger under the following measuring device and measuring conditions. Further, the softening point means the midpoint from the temperature at which the plunger starts to fall to the temperature at which it ends. Measuring instrument; Shimadzu's advanced flow tester CFT-
500 Measurement conditions; Plunger: 1cm, Die diameter: 1m
m, die length: 1 mm, load: 20 kgF, preheating temperature: 50 to 80 ° C., preheating time: 300 sec, heating rate: 6 ° C./min.

[0041]

EXAMPLES The present invention will be described in more detail based on the synthetic examples of the resins used in the present invention and the examples of the present invention, but the present invention is not limited to these examples. The parts used in the evaluation are parts by weight.

Example 1 Bisphenol A / Propylene oxide 2 mol adduct 3
44 g (1 mol), terephthalic acid 49.4 g (0.9 mol), pentaerythritol 13.6 g (0.1 mol)
And eicosane diacid 20.5 g (0.06 mol) and dibutyltin oxide 0.50 g, triphenyl phosphite 0.3.
Add 05g to a glass 1 liter 4-neck flask,
A thermometer, a stirrer, a flow-down condenser and a nitrogen introduction tube were attached, the mixture was heated by a mantle heater, and heated and stirred under a nitrogen stream at a reaction temperature of 200 ° C. After the outflow of water was completed, the temperature was raised to 230 ° C. over about 1 hour, and the reaction was further continued under heating and stirring for 2 hours. After the outflow of water was completed, the pressure inside the reactor was reduced to 5 Torr, and the stirring torque before the pressure was reduced to 4
The reaction was terminated when the doubled torque was reached, and the reduced pressure was released to obtain polyester resin A for toner.

Example 2 Bisphenol A / Propylene oxide 2 mol adduct 8
6.0 g (250 mmol), isophthalic acid 40.11
g (241.5 mmol), trimethylolpropane 4.46 g (33.25 mmol), eicosane diacid 7.70 g (22.5 mmol), dibutyltin oxide 125 mg, and triphenyl phosphite 100 mg with a stirrer and nitrogen. A 4-neck 500 ml round-bottom separable flask equipped with a gas line was charged and allowed to react at 230 ° C. under normal pressure for 8 hours. When the generation of by-product water stopped, the pressure inside the reactor was reduced to 5 Torr, and the stirring torque before the pressure was reduced to 4
The reaction was terminated when the doubled torque was reached, and the reduced pressure was released to obtain polyester resin B for toner.

Example 3 A polyester resin C for toner was obtained in the same manner as in Example 2, except that 100 mg of triphenyl phosphite was replaced by 100 mg of diphenyl orthophosphate (diphenylphosphonic acid).

Example 4 A toner polyester resin D was obtained in the same manner as in Example 1, except that 0.05 g of triphenyl phosphite was replaced with 0.05 g of trisnonylphenyl phosphite.

Comparative Example 1 Polyester resin E was obtained by carrying out the same reaction as in Example 1 without adding 0.05 g of triphenyl phosphite. When the reaction end point is reached, the resin melt viscosity increases,
It wound up on the stirring shaft.

Comparative Example 2 100 mg of diphenyl orthophosphate obtained in Example 3 was replaced with orthophosphoric acid 1
Polyester resin F was reacted in the same manner instead of 00 mg.
Got

Comparative Example 3 A polyester G resin was obtained by the same reaction as in Example 1, except that 0.05 g of triphenyl phosphite was replaced with 0.05 g of phosphorous acid and the other components were not changed.

Comparative Example 4 Polyester resin H was obtained by replacing 0.05 g of triphenyl phosphite of Example 1 with 0.05 g of triethyl phosphite and reacting in the same manner without changing the other composition.

[Physical Property Evaluation Method] In order to compare the physical properties of the obtained crosslinked polyester resins, resin melt characteristic evaluation by a flow tester (see 0040), 1) measurement of molecular weight distribution by GPC method (method and evaluation method) Is shown below), 2) glass transition temperature is measured by the DSC method (methods and evaluation methods are shown below), 3) acid value is measured, and 4) thermal stability of polyester resin is evaluated. The results are shown in.

1) Method for measuring and evaluating molecular weight distribution by GPC method GPC was measured using a column: Shodx KF-80M at a temperature of 25 ° C. and a solvent (THF) of 1 ml / min.
Was flowed, and a THF sample solution having a concentration of 0.4 g / dl was injected as a sample weight of 8 mg to measure a polystyrene-equivalent molecular weight. Also, in this measurement, the reliability of the measurement is
NBS706 polystyrene standard sample (Mw = 28.8 ×
104, Mn = 13.7 × 104, Mw / Mn = 2.1
It was confirmed that the Mw / Mn of 1) was 2.11 ± 0.10.

2) Method for measuring and evaluating glass transition temperature by DSC method Using DSC: DSC-120 manufactured by Seiko Instruments Inc.,
The glass transition temperature: Tg was determined from the endothermic curve during the second temperature increase by repeating the temperature increase of 10 ° C./min and the rapid cooling twice. The Tg referred to here is the value of the midpoint temperature of the endothermic start temperature and the endothermic peak temperature.

3) Method for measuring acid value The polyester resins obtained in the examples and comparative examples were pulverized with a table mill and dried in 50 ml of dry THF.
Add 00 mg, 300 mg, 400 mg and leave at room temperature for one day. The polymer solution is titrated with a phenolphthalein-ethanol solution as an indicator with an N / 100-potassium hydroxide ethanol solution, and calculated by the following formula. The test score was 5 at each concentration, and the results were averaged to obtain the acid value (unit: mgKOH / g).

[Equation 1] Acid value = N / 100 × (factor) × (titration amount)
× 56.1 / sample weight

4) Method for evaluating thermal stability of polyester resin Polyester resin 10 to 2 obtained after completion of polymerization reaction
0 g is left in a nitrogen atmosphere at 230 ° C. for 5 hours to evaluate the thermophysical properties and the change in molecular weight. Evaluation criteria Excellent: Thermophysical properties and molecular weight are not deteriorated Good: Thermophysical properties and molecular weight are not noticeably changed A: Toner physical properties are changed within a range that can be satisfied. Impossible: Physical properties change so much that it is difficult to satisfy toner characteristics.

[Tonerization Evaluation] The tonerization conditions and the tonerization evaluation method are shown below. [Tonerization Method] Next, the polyester resin for toner of each of the examples and comparative examples and other raw materials were mixed with a supermixer in the following mixing ratio, melt-kneaded, pulverized and classified to have an average particle diameter. Having a particle size of 11 μm, hydrophobic silica (trade name: R-972, manufactured by Nippon Aerosil Co., Ltd.) 0.3
A part of the toner was adhered to the resin with a Henschel mixer to obtain a negatively chargeable electrophotographic toner. Further, the characteristics of the above electrophotographic toner such as Tg were evaluated, and the results are shown in Table 1.
It was shown to.

[0056] [Toner formulation] Polyester resin 97 parts Carbon black (MA-100 manufactured by Mitsubishi Chemical Corporation) 6.5 parts Chromium complex salt dye (TRH manufactured by Hodogaya Chemical Co., Ltd.) 2 parts Low molecular weight polypropylene (Sanyo Kasei Co., Ltd. Viscole 330P) 3 parts

[Toner Material Fixation Evaluation Method] The following tests were conducted on the above-mentioned Examples and Comparative Examples. (1) Non-offset temperature region and non-offset temperature range 4 parts of the electrophotographic toner obtained in the above-mentioned Examples and Comparative Examples and a ferrite carrier not coated with a resin (Powdertec's trade name; FL-1020) 96 To prepare a two-component developer. Next, using the developer, a commercially available copying machine (SF-9800 manufactured by Sharp Corporation)
Thus, a plurality of belt-shaped unfixed images having a length of 2 cm and a width of 5 cm were formed on the A4 transfer paper. Next, a heat fixing roll having a surface layer made of Teflon and a pressure fixing roll having a surface layer made of silicone rubber are paired and rotated, and a roll pressure of 1 kg / cm ² and a roll speed of 200 are applied.
The surface temperature of the heat-fixing roll was changed stepwise so as to fix the toner image on the transfer paper having the unfixed image at each surface temperature. At this time, it was observed whether or not toner stains were generated in the margins, and the temperature region where stains did not occur was taken as the non-offset temperature region, and the difference between the maximum and minimum values in the non-offset temperature region was taken as the non-offset temperature width.

(2) Fixing Strength The surface temperature of the heat fixing roll of the fixing machine was set to 130 ° C., and the toner image on the transfer paper on which the unfixed image was formed was fixed. Then, the image density of the formed fixed image was measured using a reflection densitometer (RD-914 manufactured by Macbeth Co., Ltd.), the fixed image was rubbed with a cotton pad, and then the image was similarly formed. The concentration was measured. From the obtained measured values, the fixing strength was calculated by the following formula and used as a low temperature fixing toner index. The results are also shown in Table 1.

[Formula 2] Fixing strength = (image density of fixed image after rubbing / image density before rubbing) × 100

3) Evaluation of toner storability 20 g of pulverized toner was transferred to a glass petri dish, placed in a convection constant temperature bath set at 50 ° C. for 3 days and night, and visually evaluated. Evaluation criteria: ⊚: no problem, ∘: good, Δ: slightly blocked but easily crushable, ×: blocking (uncrushable).

[0060]

[Table 1]

[Evaluation Results] It is apparent from the evaluation results in Table 1 that the polyester resins of Examples 1 to 4 have sufficient toner physical properties. On the other hand, in spite of the similar composition, in the comparative example, the toner evaluation results of the polyester resin obtained by the presence or absence of the phosphorus-based material specified in the present invention were significantly different. From Example 1 and Comparative Example 1, the effect of the phosphorus-based material is that the reaction is suppressed (suppresses a sharp increase in resin melt viscosity).
There is a big difference in the deterioration of physical properties at the time of making into toner (preserving property which is an important property of toner and securing safety time at the time of resin production). From Example 2 and Comparative Example 2, it can be seen that when the phosphorus-based material is added, the polymerization proceeds, the molecular weight distribution expands, and the thermophysical properties are greatly improved. Further, from Comparative Example 3, the phosphorus-based material having no aromatic group / alkyl group only deactivates the catalyst, and the effectiveness of the phosphorus-based material specified in the present invention is clarified. . From Comparative Example 4, not only was it confirmed that thermal stability could not be obtained unless the phosphorus-based material contained an aromatic group, but also an offensive odor, which is a major problem as a toner, was observed.

[0062]

EFFECTS OF THE INVENTION The polyester resin undergoes a great change in the physical properties of the resin when kept in a temperature range of 200 ° C. or higher for a long time. However, in the present invention, not only the polyester resin for toner can be easily obtained without causing a change in the physical properties of the resin, but also the deterioration of the physical properties of the resin during kneading can be prevented.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-183267 (JP, A) JP-A-8-152743 (JP, A) JP-A-8-30026 (JP, A) JP-A-58- 127938 (JP, A) JP 1-173051 (JP, A) JP 7-43933 (JP, A) JP 8-305086 (JP, A) JP 2-302432 (JP, A) JP 58-91761 (JP, A) JP 64-24827 (JP, A) JP 63-280729 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (2)

(57) [Claims] 1. A catalyst, a transition metal-based polymerization catalyst and / or an ester for producing a crosslinked polyester resin for a toner.
The addition amount of at least one or more phosphorus-based material selected from phosphoric acid esters and / or phosphite esters having one or more aromatic groups to the catalyst for exchange reaction is
An electrophotographic toner using a cross-linked polyester resin as a main binder resin, characterized in that the amount ratio is in the range of 10/1 to 1/2 . 2. The phosphorus-based material is (mono, di or tri)
Phenylphosphonic acid, phenylphosphonic acid dichloride, cresyl diphenylphosphonic acid, tricresylphenylphosphonic acid, xylenyldiphenylphosphonic acid, tris (di or tribromophenyl) phosphonic acid, triphenyl phosphite, phosphorous acid Tris (nonylphenyl), diphenyl phosphite, tri (-o-, -m- or -p-) tolyl phosphite, di (-o-, -m- or -p-) tolyl phosphite, The toner for electrophotography according to claim 1, which is di-o-chlorophenyl phosphate, tri-p-chlorophenyl phosphite, di-p-chlorophenyl phosphite, diphenylisodecyl phosphite or phenyldiisodecyl phosphite.