JP2013203857A - Polyester resin composition, resin composition for electrophotographic toner, and electrophotographic toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic toner which has an excellent balance between low-temperature fixability and high-temperature offset resistance that are mutually incompatible performances, and to provide a polyester resin composition which hardly causes a drop of softening temperature in the production of the electrophotographic toner.SOLUTION: A polyester resin composition contains: a polyester resin (X) obtained by use of a polybasic acid and a polyhydric alcohol as essential raw material components; and cellulose fibers (Y) as essential components.

Description

  The present invention relates to a polyester resin composition in which a softening point and a viscosity are hardly lowered during the production of an electrophotographic toner, and an electrophotographic toner excellent in a balance between low-temperature fixability and high-temperature offset resistance.

  In heat roll fixing type electrophotographic process machines that are widely used in copying machines, printers, and the like, toners that are excellent in low temperature fixing properties are required to reduce power consumption during printing. As a method for improving the toner low-temperature fixability, a method is known in which a polyester resin that is relatively excellent in low-temperature fixability is used as a binder for the toner and the softening point and melt viscosity of the polyester resin are lowered. In the toner using such a resin, the printing paper surface is likely to be stained due to the occurrence of a high temperature offset in which the melted toner adheres to the heat roll during fixing.

  Known methods for improving the balance between low-temperature fixability and high-temperature offset resistance include a method of increasing the molecular weight distribution (Mw / Mn) of a polyester resin and a method of using a plurality of polyester resins having different molecular weights in combination. . Examples of such a resin composition include 50 parts by mass of a polyester resin having a weight average molecular weight (Mw) of 5,900 obtained by reacting terephthalic acid, ethylene glycol, and neopentyl glycol, and terephthalic acid, ethylene glycol, neopentyl. A polyester resin having a weight average molecular weight (Mw) of 387,400 and a molecular weight distribution (Mw / Mn) of 57.8 obtained by reacting glycol, a bisphenol F-type bifunctional epoxy resin and neodecanoic acid glycidyl ester is used in combination. A technique is known (see Patent Document 1). However, even if such a resin composition is used, it is still difficult to achieve both low-temperature fixability and high-temperature offset resistance at a high level. When the resin composition described in Patent Document 1 is used, In particular, the low-temperature fixability was inferior.

Japanese Patent No. 4581312

  Therefore, the problem to be solved by the present invention is an electrophotographic toner having an excellent balance between low-temperature fixability and high-temperature offset resistance, which are mutually contradictory performances, and a polyester resin composition that is less likely to cause a softening point drop during the production of the electrophotographic toner. To provide things.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have successfully maintained low-temperature fixability by using cellulose fibers in combination with a polyester resin as compared with the case of using only a polyester resin. However, the present inventors have found that high temperature offset resistance can be improved and have completed the present invention.

  That is, the present invention contains a polyester resin (X) obtained using polybasic acid and polyhydric alcohol as essential raw material components and cellulose fiber (Y) as essential components. Related to things.

  The present invention further relates to a resin composition for an electrophotographic toner containing the polyester resin composition.

  The present invention further relates to an electrophotographic toner using the resin composition for electrophotographic toner.

  According to the present invention, compared to conventional electrophotographic toner resins, an electrophotographic toner having an excellent balance between low-temperature fixability and high-temperature offset resistance, which are mutually contradictory performances, and a softening point drop when producing an electrophotographic toner. Can be obtained.

FIG. 1: is an electron micrograph at the time of observing the cellulose fiber (Y) which this contains about the polyester resin composition (13) obtained in Example 13 of this application. FIG. 2 is an electron micrograph of cellulose before crushing (“KC Flock W-50GK” manufactured by Nippon Paper Chemicals Co., Ltd.).

  The polyester resin composition of the present invention contains a polyester resin (X) obtained using polybasic acid and polyhydric alcohol as essential raw material components, and cellulose fiber (Y) as essential components.

  Since the content of the cellulose fiber (Y) in the polyester resin composition of the present invention is such that an electrophotographic toner having an excellent balance between low-temperature fixability and high-temperature offset resistance can be obtained, the polyester resin (X) and the cellulose fiber ( It is preferable that the cellulose fiber (Y) contains both at a ratio of 0.1 to 20 parts by mass with respect to a total of 100 parts by mass with Y), and at a ratio of 1 to 10 parts by mass. It is more preferable to contain both.

  Specifically, the cellulose fiber (Y) used in the present invention is a fiber formed by aggregating a plurality of cellulose molecules, and is arranged such that molecular chains of cellulose molecules are approximately parallel to the long axis direction of the fiber. In general, the molecular chains are gathered together in an entangled state. Since the size of the cellulose fiber (Y) does not inhibit the low-temperature fixability and has a high effect of improving the high-temperature offset resistance, the length in the major axis direction is in the range of 100 to 1,000,000 nm. And the length in the minor axis direction is preferably in the range of 5 to 1,000 nm.

  Here, the length in the major axis direction is a value called fiber length, and refers to the length in the cellulose molecular chain direction in the cellulose fiber (Y). Further, the length in the minor axis direction is a value called fiber width, and refers to the length in the stacking direction of cellulose molecules in the cellulose fiber (Y).

  Examples of the cellulose fiber (Y) used in the present invention include cellulose fibers obtained by crushing various cellulose raw materials (y). Examples of the cellulose raw material (y) include pulp, cotton, paper, regenerated cellulose such as rayon, cupra, polynosic acetate, and the like; bacterial cellulose; animal-derived cellulose such as sea squirt; powdered cellulose obtained by pulverizing pulp, and the like. Can be mentioned. These may be used alone or in combination of two or more. Among these, the powdered cellulose is preferable because it can be easily crushed. Commercially available powdered cellulose includes, for example, “KC Flock” manufactured by Nippon Paper Chemicals, “Theolas” manufactured by Asahi Kasei Chemicals, “Avicel” manufactured by FMC, and the like.

  Examples of the crushing of the cellulose raw material (y) include a method of adding the cellulose raw material (y) to the crushing medium (v) and applying a mechanical cutting force to obtain a crushing mixture (Z).

  Examples of means for imparting mechanical cutting force used when holding the cellulose raw material (y) in the crushing medium (v) include, for example, a bead mill, an ultrasonic homogenizer, a single screw extruder, a twin screw extruder, and a Banbury mixer. And kneading equipment such as a grinder, a pressure kneader, and a Japanese roll. Among them, it is preferable to use a pressure kneader because of high crushing performance.

  At this time, since the ratio of the said cellulose raw material (y) and the said crushing medium (v) improves crushing efficiency, it is the sum total of the said cellulose raw material (y) and the said crushing medium (v). The proportion of the cellulose raw material (y) in the range of 30 to 70 parts by mass is preferable with respect to 100 parts by mass, and the ratio in the range of 35 to 60 parts by mass is more preferable.

  As the crushing medium (v), water in which the cellulose raw material (y) is easily dissolved and various organic solvents are generally used. In the present invention, cellulose fibers crushed in water or an organic solvent may be used, but the obtained pulverized mixture (Z) can be directly used for the polyester resin composition, and the steps of dehydration and desolvation are performed. Since it becomes unnecessary, it is preferable to use various resins such as a polyester resin, an acrylic resin, an epoxy resin, and a silicone resin as the crushing medium (v), and it is particularly preferable to use a polyester resin.

  Examples of the polyester resin (V) that can be used as the crushing medium (v) of the cellulose raw material (y) include a polyester resin obtained by reacting a polybasic acid (a1) and a polyhydric alcohol (b1). It is done.

  Examples of the polybasic acid (a1) include fats such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, hexahydrophthalic acid, and 1,4-cyclohexanedicarboxylic acid. Group dicarboxylic acids;

  Maleic acid, maleic anhydride, citraconic acid, dimethylmaleic acid, cyclopentene-1,2-dicarboxylic acid, 1-cyclohexene-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, fumarate Aliphatic unsaturated dicarboxylic acids such as acid, mesaconic acid, itaconic acid, glutaconic acid;

  Aliphatic tricarboxylic acids such as 1,2,5-hexanetricarboxylic acid and 1,2,4-cyclohexanetricarboxylic acid;

  Aromatic dicarboxylic acids such as phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid;

  Trimellitic acid, trimellitic anhydride, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, pyromellitic anhydride and other trifunctional aromatic polycarboxylic acids Can be mentioned. These may be used alone or in combination of two or more.

  Among the polybasic acids (a1), various dicarboxylic acids are preferable because an electrophotographic toner having both high-temperature offset resistance and low-temperature fixability can be obtained. In particular, aromatic dicarboxylic acids are more preferable, and terephthalic acid and isophthalic acid are particularly preferable in that an electrophotographic toner excellent in high temperature offset resistance can be obtained. In terms of excellent crushing efficiency of the cellulose raw material (y), aliphatic dicarboxylic acids are more preferable, and sebacic acid and adipic acid are particularly preferable.

  Moreover, the said polyester resin (V) may contain the monocarboxylic acid in the raw material component as needed. Monocarboxylic acids include, for example, methanoic acid, ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid An acid, a benzoic acid, etc. are mentioned.

  Examples of the polyhydric alcohol (b1) include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, and 2,2-dimethyl-3-isopropyl. -1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, Neopentyl glycol, 1,6-hexanediol, 1,4-bis (hydroxymethyl) cyclohesane, trimethylolethane, trimethylolpropane, 2,2,4-trimethyl-1,3-pentanediol, glycerin, hexanetriol, Aliphatic polyols such as pentaerythritol;

  Ether glycols such as polyoxyethylene glycol and polyoxypropylene glycol;

  Modification obtained by ring-opening polymerization of the aliphatic polyol and various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether Polyether polyols;

  A lactone-based polyester polyol obtained by a polycondensation reaction between the aliphatic polyol and various lactones such as ε-caprolactone;

  Bisphenols such as bisphenol A, bisphenol B, bisphenol F, bisphenol S;

  Examples thereof include alkylene oxide adducts of bisphenol obtained by adding ethylene oxide, propylene oxide and the like to the bisphenol. These may be used alone or in combination of two or more.

  Among these polyhydric alcohols (b1), the aliphatic polyol is preferable because of its excellent crushing efficiency of the cellulose raw material (y), and diethylene glycol, 1,3-propanediol, neopentyl glycol, 1,6-hexanediol. Is more preferable.

Moreover, the said polyester resin (V) may contain a monoalcohol in the raw material component as needed. Examples of the monoalcohol include hexanol, 2-ethylhexanol, octanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol, n-tetradecanol, n-pentadecanol, n-heptadecanol, n -Octadecanol, n-nonadecanol, eicosanol, 5-ethyl-2-nonanol, trimethylnonyl alcohol, 2-hexyldecanol, 3,9-diethyl-6-tridecanol, 2-isoheptylisoundecanol, 2-octyldodecanol Nord, 2-decyltetradecanol and the like.

  Further, sebacic acid mentioned as the polybasic acid (a1) and 1,3-propanediol mentioned as the polyhydric alcohol (b1) are attracting attention as bio raw materials produced from natural products. Usually, polyester resins mainly composed of these resins have a very flexible resin skeleton. Therefore, an electrophotographic toner obtained using the polyester resin cannot obtain sufficient high-temperature offset resistance. According to the invention, an electrophotographic toner having both high-temperature offset resistance and low-temperature fixability can be obtained even when these bio-raw materials are used as main raw materials.

When manufacturing the said polyester resin (V) from the raw material which uses the said polybasic acid (a1) and the said polyhydric alcohol (b1) as an essential component, the manufacturing method is the said polybasic acid (a1), for example. The ratio [(N _A ) / (N _OH )] of the number of moles (N _A ) of carboxyl groups contained in and the number of moles of hydroxyl groups (N _OH ) contained in the polyhydric alcohol (b1) is 1.00. A method is used in which both are used in a ratio in the range of /1.10 to 1.00 / 1.20 and the reaction is carried out in the presence of an esterification catalyst such as dibutyltin oxide at a temperature of 180 to 260 ° C.

  Among the polyester resins (V), those having a weight average molecular weight (Mw) in the range of 1,000 to 5,000 are preferable because the cellulose raw material (y) is excellent in crushing efficiency, and 1,500 to What is in the range of 3,000 is more preferable.

  The acid value of the polyester resin (V) is excellent in the crushing efficiency of the cellulose raw material (y), and the cellulose fibers (Y) obtained after crushing can be stably present in a fine fiber state. The range is preferably 50 mg KOH / g, more preferably 3 to 25 mg KOH / g.

  Further, the hydroxyl value of the polyester resin (V) is excellent in the crushing efficiency of the cellulose raw material (y), and the cellulose fibers (Y) obtained after crushing can be stably present in a fine fiber state. The range is preferably 30 to 120 mgKOH / g, and more preferably 50 to 100 mgKOH / g.

  In this invention, the crushing mixture (Z) obtained by crushing the said cellulose raw material (y) in the said polyester resin (V) can be used as a raw material of the polyester resin composition of this invention as it is. This detailed method will be described later.

  Since the polyester resin (X) contained in the polyester resin composition of the present invention provides an electrophotographic toner having an excellent balance between low-temperature fixability and high-temperature offset resistance, its weight average molecular weight (Mw) is 10,000. Is preferably in the range of ˜350,000, more preferably in the range of 50,000 to 200,000, and particularly preferably in the range of 100,000 to 180,000.

  Further, the polyester resin (X) has a relatively large molecular weight distribution (Mw / Mn) because the high molecular weight component contributes to the improvement of the high temperature offset resistance and the low molecular weight component contributes to the improvement of the low temperature fixing property. Some are preferred. Specifically, the molecular weight distribution (Mw / Mn) is preferably in the range of 2 to 55, more preferably in the range of 15 to 50, and particularly preferably in the range of 30 to 45.

  In the present invention, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the polyester resin are values measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation
+ Tosoh Corporation TSK-GEL SuperHZM-M x 4
Detector: RI (differential refractometer)
Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 0.35 ml / min Standard: Monodispersed polystyrene Sample: Filtered 0.2% by mass tetrahydrofuran solution in terms of resin solids with a microfilter (100 μl)

  The polyester resin composition of the present invention contains the polyester resin (X) and cellulose fibers (Y) having a number average molecular weight (Mn) in the range of 35,000 to 150,000 as essential components. The manufacturing method is not particularly limited. Specific examples include those obtained by any one of the following methods (1) to (4).

Method (1)
After adding the pulverized mixture containing cellulose fibers (Y) obtained by pulverizing the cellulose raw material (y) in water or an organic solvent to the separately produced polyester resin (X), dehydration or solvent removal step How to go through.

Method (2)
A method of directly crushing cellulose raw material (y) in polyester resin (X).

Method (3)
A method in which a pulverized mixture (Z) obtained by pulverizing a cellulose raw material (y) in the polyester resin (V) is added to a polyester resin raw material and further reacted.

Method (4)
A method of adding separately produced polyester resin (X ′) to a pulverized mixture (Z) obtained by pulverizing cellulose raw material (y) in polyester resin (V).

  Among the methods (1) to (4), the method (3) or the method (4) is preferable because it can be more easily produced. Furthermore, since it becomes a polyester resin composition in which cellulose fibers (Y) are more uniformly and stably mixed, and an electrophotographic toner having excellent high-temperature offset resistance can be obtained, those obtained by the method (3) are particularly preferable.

Hereinafter, the method (3) will be described in detail.
In the said method (3), a cellulose fiber (Y) is mixed uniformly and stably in the resin composition obtained by passing through the process of adding the crushing mixture (Z) to the polyester resin raw material, and making it react further. be able to. In the method (3), the polyester resin (V) used as the crushing medium (v) is one of the raw materials for the polyester resin (X). Here, when the polyester resin (V) has a carboxyl group or a hydroxyl group, the polyester resin (V) and the polyester resin raw material can be further reacted to increase the molecular weight. The weight average molecular weight (Mw) of the polyester resin (X) finally obtained also when (V) is a relatively low molecular weight having a weight average molecular weight (Mw) in the range of 1,000 to 5,000. ) Can be adjusted to the above preferred value.

  More specifically, the method (3) includes, for example, the following method.

Method (3-1)
A method in which a pulverized mixture (Z) is added and reacted in an unreacted polyester resin raw material containing polybasic acid (a2) and polyhydric alcohol (b2) as essential components.

Method (3-2)
An unreacted polyester resin raw material containing polybasic acid (a2) and polyhydric alcohol (b2) as essential components is reacted to obtain a polyester resin intermediate, and the crushed mixture (Z) is added to the polyester resin intermediate And a method of undergoing a further reaction step.

  Examples of the polybasic acid (a2) used in the method (3-1) or (3-2) include various polybasic acids exemplified as the polybasic acid (a1). These may be used alone or in combination of two or more. Of these, dicarboxylic acids are preferable because an electrophotographic toner having both high-temperature offset resistance and low-temperature fixability can be obtained. Among them, aromatic dicarboxylic acids are more preferable, and terephthalic acid and isophthalic acid are particularly preferable.

  Moreover, in the said method (3-1) or (3-2), you may use monocarboxylic acid as needed. Examples of the monocarboxylic acid include various monocarboxylic acids exemplified as the raw material for the polyester resin (V).

  Examples of the polyhydric alcohol (b2) used in the method (3-1) or (3-2) include various polybasic acids exemplified as the polyhydric alcohol (b1). These may be used alone or in combination of two or more. Among these, the aliphatic polyol is preferable, and ethylene glycol, 1,3-propanediol, and neopentyl glycol are more preferable in that an electrophotographic toner excellent in grindability can be obtained. Further, in terms of obtaining an electrophotographic toner having particularly good charging stability, the bisphenol and a diol having a bisphenol skeleton such as an alkylene oxide adduct of the bisphenol are preferable, and an alkylene oxide adduct of bisphenol is more preferable. Therefore, it is more preferable to use the aliphatic polyol and the diol having the bisphenol skeleton in combination in order to obtain an electrophotographic toner having both grindability and charge stability.

    Moreover, in the said method (3-1) or (3-2), you may use monoalcohol as needed. Examples of the monoalcohol include various monoalcohols exemplified as the raw material of the polyester resin (V).

  Further, sebacic acid mentioned as the polybasic acid (a2) and 1,3-propanediol mentioned as the polyhydric alcohol (b2) are attracting attention as bio raw materials produced from natural products. Usually, polyester resins obtained using these as the main raw materials have a very flexible resin skeleton, and therefore electrophotographic toners obtained using these cannot obtain sufficient high-temperature offset resistance. However, according to the invention of the present application, even when these bio-raw materials are used as main raw materials, an electrophotographic toner having both high high-temperature offset resistance and low-temperature fixability can be obtained.

In the method (3-1), when the polybasic acid (a2) and the polyhydric alcohol (b2) are used as raw materials for the polyester resin, the production method includes, for example, the polybasic acid (a2). When the number of moles of the carboxyl group to be used is (N _A ) and the number of moles of the hydroxyl group contained in the polyhydric alcohol (b2) is (N _OH ), the ratio between the two [(N _A ) / (N _OH )] Is 1.00 / 0.95-1.00 / 1.10 using each raw material, unreacted polybasic acid (a2), unreacted polyhydric alcohol (b2), and crushing The method of making a mixture (Z) react in presence of esterification catalysts, such as a dibutyl tin oxide, by the temperature conditions of 180-260 degreeC is mentioned.

In the said method (3-2), when using the said polybasic acid (a2) and the said polyhydric alcohol (b2) as a raw material of a polyester resin, the manufacturing method contains the said polybasic acid (a2), for example When the number of moles of the carboxyl group to be used is (N _A ) and the number of moles of the hydroxyl group contained in the polyhydric alcohol (b2) is (N _OH ), the ratio between the two [(N _A ) / (N _OH )] Is 1.00 / 0.95 to 1.00 / 1.10 using each raw material, and the polybasic acid (a2) and the polyhydric alcohol (b2) are mixed at 180 to 260 ° C. Under a temperature condition, in the presence of an esterification catalyst such as dibutyltin oxide, a polyester intermediate is obtained by reacting until the acid value in the system is 25 mgKOH / g or less, and then the polyester resin intermediate is crushed mixture Add (Z), and How to respond and the like.

  In the said method (3-1) or (3-2), when using the said polybasic acid (a2) and the said polyhydric alcohol (b2) as a raw material of a polyester resin, the usage-amount of each raw material is unreacted. The cellulose fiber (Y) contained in the pulverized mixture (Z) is 0.1% relative to 100 parts by mass of the polybasic acid (a2), the unreacted polyhydric alcohol (b2), and the crushed mixture (Z). The ratio is preferably in the range of 1 to 20 parts by mass, and more preferably in the range of 1 to 10 parts by mass.

  Moreover, in the said method (3-1) or (3-2), you may use a polyfunctional epoxy compound (c2) as a polyester resin raw material. The polyfunctional epoxy compound (c2) works as a crosslinking component of the polyester resin, and by using this, a polyester resin having a large molecular weight distribution (Mw / Mn) can be obtained. In such a polyester resin, the high molecular weight component contributes to the improvement of the high temperature offset resistance, and the low molecular weight component contributes to the improvement of the low temperature fixability. This is preferable because the low-temperature fixability is combined at a higher level. That is, the polyester resin (X) contained in the polyester resin composition of the present invention is preferably obtained by reacting polybasic acid, polyhydric alcohol, and polyfunctional epoxy compound as essential components.

  Examples of the polyfunctional epoxy compound (c2) used in the method (3-1) or (3-2) include ethylene glycol diglycidyl ether, 2,2 ′-(2,6-dioxaheptane-1,7- Diyl) bisoxirane, 1,4-bis (glycidyloxy) butane, 2,3-butylene glycol diglycidyl ether, 1,5-pentylene glycol diglycidyl ether, 1,6-bis (glycidyloxy) hexane, Aliphatic diglycidyl ethers such as 1,7-heptylene glycol diglycidyl ether, 1,8-octylene glycol diglycidyl ether;

  An aliphatic polyglycidyl ether having three or more epoxy groups in the molecular structure, such as trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether;

  Contains glycidyl group-containing compounds such as glycidyl (meth) acrylate and glycidyl α-ethyl (meth) acrylate, and vinyl groups such as butadiene, methyl (meth) acrylate, ethyl (meth) acrylate, and dimethyl fumarate An epoxy group-containing vinyl polymer obtained by polymerizing an aliphatic compound;

  Bisphenol A diglycidyl ether, bisphenol B diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, 1,4-naphthalenediol diglycidyl ether, 1,5-naphthalenediol diglycidyl ether, 2,6-naphthalenediol Aromatic diglycidyl ethers such as diglycidyl ether and naphthalene-2,6-dimethanol diglycidyl ether;

Aromatic polyglycidyl ethers having 3 or more epoxy groups in the molecular structure, such as 4,4 ', 4 "-methylidynetrisphenol triglycidyl ether;

  Novolac epoxy resins such as phenol novolac epoxy resins, cresol novolac epoxy resins, bisphenol novolac epoxy resins;

  Glycidyl group-containing compounds such as glycidyl (meth) acrylate and glycidyl α-ethyl (meth) acrylate, aromatic compounds containing vinyl groups such as styrene, butadiene, methyl (meth) acrylate, Examples thereof include an epoxy group obtained by polymerizing an aliphatic compound containing a vinyl group such as ethyl (meth) acrylate and dimethyl fumarate, and a vinyl polymer containing an aromatic ring. These may be used alone or in combination of two or more.

  Among these, the novolak type epoxy resin is preferable because an electrophotographic toner excellent in the balance between the low-temperature fixability and the high-temperature offset resistance can be obtained. The novolac type epoxy resin preferably has a nucleus number of 3 to 10, more preferably 4 to 8. Further, the number average molecular weight (Mn) is preferably in the range of 400 to 2,500, and more preferably in the range of 800 to 2,000.

  In the said method (3-1) or (3-2), you may use a monoepoxy compound in the raw material component as needed. Examples of the monoepoxy compound include fats such as butyl glycidyl ether, 2-ethoxyethyl glycidyl ether, pentyl glycidyl ether, hexyl glycidyl ether, heptyl glycidyl ether, octyl glycidyl ether, 2-ethylhexyl glycidyl ether, nonyl glycidyl ether, and decyl glycidyl ether. Monoglycidyl ether; phenyl glycidyl ether, cresyl glycidyl ether, 4-butylphenyl glycidyl ether, monoglycidyl ether having an aromatic ring in the molecular structure such as glycidyl-2-naphthyl ether;

  Aliphatic monoglycidyl esters such as cyclopropylmethyl 2,2-dimethylpropionate, glycidyl neodecanoate, glycidyl stearate;

  Aromatic α-olefin oxides such as styrene oxide are exemplified. These may be used alone or in combination of two or more.

  Among these, the aliphatic monoglycidyl ester is preferable, and neodecanoic acid glycidyl ester is particularly preferable in that a polyester resin having more excellent wax dispersibility can be obtained.

  When the polyfunctional epoxy compound (c2) is used in the method (3-1) or (3-2), that is, the polyester resin (X) of the present invention comprises a polybasic acid, a polyhydric alcohol, and a polyfunctional epoxy compound. When an essential raw material component is used, a polyester resin composition capable of combining low-temperature fixability and high-temperature offset resistance at a higher level can be obtained. Therefore, a polyfunctional epoxy is used with respect to 100 parts by mass of the raw material of the polyester resin (X). It is preferable to use a compound (c2) in the range of 0.05-5 mass parts, and it is more preferable to use it in the range of 0.1-3 mass parts. More specifically, the polyfunctional epoxy is used with respect to a total of 100 parts by mass of the polybasic acids (a1) and (a2), the polyhydric alcohols (b1) and (b2), and the polyfunctional epoxy compound (c2). It is preferable to use a compound (c2) in the range of 0.05-5 mass parts, and it is more preferable to use it in the range of 0.1-3 mass parts.

In the method (3-1), when the polybasic acid (a2), the polyhydric alcohol (b2), and the polyfunctional epoxy compound (c2) are used as raw materials for the polyester resin, the production method thereof is, for example, the polybasic acid (a2) the sum of the number of moles of carboxyl groups contained in the (N _a), the polyhydric alcohol (b2) the number of moles of hydroxyl groups contained in the the (N _OH), the polyfunctional epoxy compound ( When the sum of the number of moles (N _E ) of the epoxy group contained in c) is (N _OH + N _E ), the ratio [(N _A ) / (N _OH + N _E )] is 1.00 / 0. These are used in a ratio ranging from .95 to 1.00 / 1.10, and unreacted polybasic acid (a2), unreacted polyhydric alcohol (b2), unreacted polyfunctional epoxy compound (c2) And crushing mixture (Z) A method of reacting in the presence of an esterification catalyst such as dibutyltin oxide under a temperature condition of 260 ° C. can be mentioned.

In the method (3-2), when the polybasic acid (a2), the polyhydric alcohol (b2), and the polyfunctional epoxy compound (c2) are used as raw materials for a polyester resin, the production method thereof is, for example, the polybasic acid (a2) the sum of the number of moles of carboxyl groups contained in the (N _a), the polyhydric alcohol (b2) the number of moles of hydroxyl groups contained in the the (N _OH), the polyfunctional epoxy compound ( c2) is the number of moles of epoxy groups containing (when the sum of the _{N E)} and _(N OH + N _E), these ratios _{[(N a) / (N} OH + N E)] 1.00 / 0 These are used at a ratio in the range of .95 to 1.00 / 1.10, and the polybasic acid (a2), the polyhydric alcohol (b2) and the polyfunctional epoxy compound (c2) are subjected to a temperature condition of 180 to 260 ° C. Bottom, dibutyltin oxide In the presence of an esterification catalyst such as a catalyst, a polyester intermediate is obtained by reacting until the acid value in the system is 25 mgKOH / g or less, and then the crushed mixture (Z) is added to the polyester resin intermediate, Furthermore, the method of making it react is mentioned.

  In the method (3-1) or (3-2), when the polybasic acid (a2), the polyhydric alcohol (b2) and the polyfunctional epoxy compound (c2) are used as raw materials for the polyester resin, the respective raw materials Is used with respect to a total of 100 parts by mass of the unreacted polybasic acid (a2), the unreacted polyhydric alcohol (b2), the unreacted polyfunctional epoxy compound (c2) and the crushing mixture (Z). The ratio of the cellulose fibers (Y) contained in the pulverized mixture (Z) is preferably 0.1 to 20 parts by mass, and more preferably 1 to 10 parts by mass. .

Next, the method (4) will be described in detail.
The said method (4) manufactures the said crushing mixture (Z) and the polyester resin (X ') separately, respectively, and is a simpler method. Examples of the polyester resin (X ′) used in the method (3) include those obtained by reacting a polybasic acid (a3) and a polyhydric alcohol (b3) as essential components.

  Examples of the polybasic acid (a3) include various polybasic acids exemplified as the polybasic acid (a1). These may be used alone or in combination of two or more. Of these, dicarboxylic acids are preferable because an electrophotographic toner having both high-temperature offset resistance and low-temperature fixability can be obtained. Among them, aromatic dicarboxylic acids are more preferable, and terephthalic acid and isophthalic acid are particularly preferable.

  The polyester resin (X ′) may use a monocarboxylic acid as a raw material, if necessary. Examples of the monocarboxylic acid include various monocarboxylic acids exemplified as the raw material for the polyester resin (V).

  Examples of the polyhydric alcohol (b3) include various polybasic acids exemplified as the polyhydric alcohol (b1). These may be used alone or in combination of two or more. Among these, the aliphatic polyol is preferable, and ethylene glycol, 1,3-propanediol, and neopentyl glycol are more preferable in that an electrophotographic toner excellent in grindability can be obtained. Further, in terms of obtaining an electrophotographic toner having particularly good charging stability, the bisphenol and a diol having a bisphenol skeleton such as an alkylene oxide adduct of the bisphenol are preferable, and an alkylene oxide adduct of bisphenol is more preferable. Therefore, it is more preferable to use the aliphatic polyol and the diol having the bisphenol skeleton in combination in order to obtain an electrophotographic toner having both grindability and charge stability.

  The polyester resin (X ′) may use monoalcohol as a raw material as necessary. Examples of the monoalcohol include various monoalcohols exemplified as the raw material of the polyester resin (V).

  Further, sebacic acid mentioned as the polybasic acid (a3) and 1,3-propanediol mentioned as the polyhydric alcohol (b3) are attracting attention as bio raw materials produced from natural products. Usually, polyester resins obtained using these as the main raw materials have a very flexible resin skeleton, and therefore electrophotographic toners obtained using these cannot obtain sufficient high-temperature offset resistance. However, according to the invention of the present application, even when these bio-raw materials are used as main raw materials, an electrophotographic toner having both high high-temperature offset resistance and low-temperature fixability can be obtained.

When the polyester resin (X ′) is obtained by reacting the polybasic acid (a3) with the polyhydric alcohol (b3), the production method thereof is, for example, that the polybasic acid (a3) is If the number of moles of the carboxyl group containing the _{(N a),} and the number of moles of hydroxyl group containing the polyhydric alcohol (b3) is an _{(N OH),} the ratio of the two _{[(N a) / (N} OH) ] In the ratio of 1.00 / 0.95 to 1.00 / 1.10, and the reaction is performed in the presence of an esterification catalyst such as dibutyltin oxide under the temperature condition of 180 to 260 ° C. The method of letting it be mentioned.

  The polyester resin (X ′) may use a polyfunctional epoxy compound (c3) as a raw material. The polyfunctional epoxy compound (c3) works as a crosslinking component of the polyester resin, and by using this, a polyester resin having a large molecular weight distribution (Mw / Mn) can be obtained. In such a polyester resin, the high molecular weight component contributes to the improvement of the high temperature offset resistance, and the low molecular weight component contributes to the improvement of the low temperature fixability. This is preferable because the low-temperature fixability is combined at a higher level. That is, the polyester resin (X) contained in the polyester resin composition of the present invention is preferably obtained by reacting polybasic acid, polyhydric alcohol, and polyfunctional epoxy compound as essential components.

  Examples of the polyfunctional epoxy compound (c3) include various epoxy compounds exemplified as the polyfunctional epoxy compound (c2). These may be used alone or in combination of two or more. Among these, the novolak type epoxy resin is preferable because an electrophotographic toner excellent in the balance between the low-temperature fixability and the high-temperature offset resistance can be obtained. The novolac type epoxy resin preferably has a nucleus number of 3 to 10, more preferably 4 to 8. Further, the number average molecular weight (Mn) is preferably in the range of 400 to 2,500, and more preferably in the range of 800 to 2,000.

  The polyester resin (X ′) may use a monoepoxy compound as a raw material, if necessary. Examples of the monoepoxy compound include various monoepoxy compounds exemplified in the description of the method (3). These may be used singly or in combination of two or more, but the aliphatic monoglycidyl ester is preferred, and neodecanoic acid glycidyl ester is preferred in that a polyester resin having more excellent wax dispersibility is obtained. Particularly preferred.

  When the polyester resin (X ′) contains a polybasic acid (a3), a polyhydric alcohol (b3), and a polyfunctional epoxy compound (c3) as essential raw material components, the low-temperature fixability and the high-temperature offset resistance are further improved. Since a polyester resin composition that can be used at a high level is obtained, the polyfunctional epoxy compound (c3) is used in the range of 0.05 to 5 parts by mass with respect to 100 parts by mass of the raw material of the polyester resin (X ′). It is preferable to use in the range of 0.1 to 3 parts by mass. More specifically, 0.05 parts of the polyfunctional epoxy compound (c3) is added to 100 parts by mass of the polybasic acid (a13), the polyhydric alcohol (b3), and the polyfunctional epoxy compound (c3). It is preferable to use in the range of -5 mass parts, and it is more preferable to use in the range of 0.1-3 mass parts.

When the polyester resin (X ′) is obtained by reacting the polybasic acid (a3), the polyhydric alcohol (b3), and the polyfunctional epoxy compound (c3), the production method thereof is: for example, the polybasic acid (a3) the number of moles of carboxyl groups contained in the (N _a), the polyhydric alcohol (b2) the number of moles of hydroxyl groups contained in the the (N _OH), the polyfunctional epoxy compound ( When the sum of the number of moles (N _E ) of the epoxy group contained in c) is (N _OH + N _E ), the ratio [(N _A ) / (N _OH + N _E )] is 1.00 / 0. A method of using these in a ratio ranging from .95 to 1.00 / 1.10 and reacting them in the presence of an esterification catalyst such as dibutyltin oxide under a temperature condition of 180 to 260 ° C. can be mentioned.

  The polyester resin composition of the present invention is excellent in low temperature fixability, high temperature offset resistance, and storage stability under high humidity and high temperature conditions, and has a glass transition temperature (Tg) of 50 to 80 ° C. A range is preferable. The softening point is preferably in the range of 90 to 180 ° C.

  The polyester resin composition of the present invention described above can be suitably used for electrophotographic toner applications. Examples of the resin composition for an electrophotographic toner of the present invention include those containing the above-described polyester resin composition of the present invention and a colorant.

  The colorant is for coloring the electrophotographic toner to a desired color, such as carbon black, aniline blue, calcoy blue, chrome yellow, ultramarine blue, phthalocyanine blue, lamp black, rose bengara, quinacridone red, and watching. Examples include red. These may be used alone or in combination of two or more. The colorant is preferably used in the range of 1 to 30 parts by mass in 100 parts by mass of the resin composition for an electrophotographic toner of the present invention.

  In addition to the colorant, the electrophotographic toner resin composition of the present invention may contain a resin other than the polyester resin (X), and additives such as a charge control agent and a release agent.

  Examples of the resin other than the polyester resin (X) include styrene resins, styrene-acrylic copolymer resins, epoxy resins, other polyester resins, silicone resins, and polyurethane resins. When the resin composition for electrophotographic toner contains these resins, it is preferable that the other resin is in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the polyester resin (X).

  The charge control agent is used for the purpose of adjusting the charge amount of the electrophotographic toner. For example, digrosine dye, quaternary ammonium salt, trimethylethane dye, copper phthalocyanine, perylene, quinacridone, azo pigment, And metal complex azo dyes. The electrophotographic toner of the present invention preferably has a charge amount in the range of −70 μC / g to −30 μC / g. When the charge control agent is used, it is preferably used in the range of 0.5 to 5 parts by mass in 100 parts by mass of the resin composition for an electrophotographic toner of the present invention.

  The release agent is used for the purpose of reinforcing the high temperature offset resistance of the electrophotographic toner, and examples thereof include various waxes such as montan wax, carnauba wax, candelilla wax, rice wax, polypropylene wax, and polyethylene wax.

  Examples of the electrophotographic toner of the present invention include those obtained by melt-kneading the resin composition for an electrophotographic toner of the present invention under a temperature condition of 100 to 160 ° C., pulverizing and classifying.

  By further adding silica to the electrophotographic toner thus obtained, higher powder fluidity can be improved. In this case, it is preferably used in the range of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the electrophotographic toner.

  Hereinafter, the present invention will be described in more detail with reference to specific synthesis examples and examples.

Measurement of weight average molecular weight (Mw) and number average molecular weight (Mn) of polyester resin In the examples of the present invention, the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyester resin are determined by gel permeation chromatography under the following conditions. It is a value measured by graphy (GPC).

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation
+ Tosoh Corporation TSK-GEL SuperHZM-M x 4
Detector: RI (differential refractometer)
Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 0.35 ml / min Standard: Monodispersed polystyrene Sample: Filtered 0.2% by mass tetrahydrofuran solution in terms of resin solids with a microfilter (100 μl)

Measurement of Glass Transition Temperature (Tg) In the examples of the present invention, the glass transition temperature (Tg) is a shoulder value measured under the following conditions.
Measuring device: Seiko Electronics Co., Ltd. DSC220C
Measurement conditions: 10 ° C./min, Sample: About 10 mg of sample is put in an aluminum container and covered.
Measuring method: DSC (Suggested scanning calorimetry) method

Measurement of softening point In the examples of the present invention, the softening point is a value measured under the following conditions.
Measuring equipment: Koka type flow tester [Shimadzu Corporation "CFT-500D"]
Measurement conditions: temperature rising rate 6 ° C./min, nozzle 1.0 mmΦ × 1 mm, load 10 kgf, sample amount 1.5 g, measurement start temperature 50 ° C.
The temperature (T1 / 2) when the plunger of the flow tester came to the middle point in the process from the start of the outflow to the end of the outflow was taken as the softening point.

Production Example 1
Production of polyester resin (V-1) In a four-necked flask having a stirrer, a temperature sensor, and a rectifying tube, 300 parts by mass of 1,3-propanediol, 700 parts by mass of sebacic acid, and 0.5 parts by mass of dibutyltin oxide Part was added. While stirring in a dry nitrogen stream, the temperature was gradually raised and reacted at 240 ° C. for 17 hours to obtain a polyester resin (V-1). The number average molecular weight (Mn) of the polyester resin (V-1) was 1,100, the weight average molecular weight (Mw) was 2,200, the hydroxyl value was 81 mgKOH / g, and the acid value was 18 mgKOH / g.

Production Example 2
Production of polyester resin (V-2) 450 parts by mass of 1,6-hexanediol was placed in a four-necked flask having a stirrer, a temperature sensor, and a rectifying tube, heated and melted, 550 parts by mass of terephthalic acid, and 0.5 parts by weight of dibutyltin oxide was added. The temperature was gradually raised while stirring in a nitrogen stream, and the mixture was reacted at 240 ° C. for 17 hours to obtain a polyester resin (V-2). The number average molecular weight (Mn) of the polyester resin (V-2) was 1,200, the weight average molecular weight (Mw) was 2,200, the hydroxyl value was 79 mgKOH / g, and the acid value was 15 mgKOH / g.

Production Example 3
Production of polyester resin (V-3) 480 parts by mass of 1,6-hexanediol was placed in a four-necked flask having a stirrer, a temperature sensor, and a rectifying tube, heated and melted, 520 parts by mass of adipic acid, and 0.5 parts by weight of dibutyltin oxide was added. While stirring in a dry nitrogen stream, the temperature was gradually raised and reacted at 240 ° C. for 17 hours to obtain a polyester resin (V-3). The number average molecular weight (Mn) of the polyester resin (V-3) was 1,200, the weight average molecular weight (Mw) was 2,200, the hydroxyl value was 80 KOH / g, and the acid value was 15 mgKOH / g.

Production Example 4
Production of polyester resin (V-4) In a four-necked flask having a stirrer, a temperature sensor, and a rectifying tube, 510 parts by mass of diethylene glycol, 260 parts by mass of adipic acid, 230 parts by mass of maleic acid and 0.5 parts by mass of dibutyltin oxide. Part was added. While stirring in a dry nitrogen stream, the temperature was gradually raised and reacted at 240 ° C. for 17 hours to obtain a polyester resin (V-4). The number average molecular weight (Mn) of the polyester resin (V-4) was 1,300, the weight average molecular weight (Mw) was 2,500, the hydroxyl value was 82 KOH / g, and the acid value was 7 mgKOH / g.

Production Example 5
Manufacture of Crushing Mixture (Z-1) 600 parts by mass of polyester resin (V-1) obtained in Production Example 1 and 400 parts by mass of powdered cellulose (“KC Flock 50GK” manufactured by Nippon Paper Chemicals Co., Ltd.) are pressurized. Using a kneader (“DS1-5GHH-H” manufactured by Moriyama Seisakusho), pressure kneading is performed for 300 minutes under a condition of 600 rpm to obtain a crushed mixture (Z-1) containing 40% by mass of cellulose fibers (Y). It was.

Production Examples 6-8
Manufacture of crushing mixture (Z-2)-(Z-4) Except having changed polyester resin (V-1) into polyester resin (V-2)-(V-4), it is the same as that of manufacture example 5. Thus, crushed mixtures (Z-2) to (Z-4) were obtained.

Example 1
Production of polyester resin composition (1) In a four-necked flask having a stirrer, a temperature sensor, and a rectifying tube, 87 parts by mass of ethylene glycol and ethylene oxide adduct of bisphenol A (hydroxyl value 345 mgKOH / g) 228 parts by mass 254 parts by mass of a propylene oxide adduct of bisphenol A (hydroxyl value 311 mg KOH / g) was added and dissolved by heating, and then 431 parts by mass of terephthalic acid and 0.5 parts by mass of dibutyltin oxide were added. Dry nitrogen was flowed into the flask, the temperature was gradually raised while stirring, and the mixture was reacted at 255 ° C. for 17 hours to obtain a polyester resin intermediate having an acid value of 20 mgKOH / g. To this, 50 parts by mass of the pulverized mixture (Z-1) obtained in Production Example 5 was added and stirred and mixed at 225 ° C. for 1 hour to obtain a polyester resin composition (1). The polyester resin composition (1) obtained had a glass transition temperature (Tg) of 58 ° C., a softening point (T1 / 2) of 100 ° C., and an acid value of 11 mgKOH / g.

  The obtained polyester resin composition (1) was dissolved in THF, and cellulose fibers (Y1) were taken out as insoluble matter to obtain a THF solution of the polyester resin (X1). The number average molecular weight (Mn) of the polyester resin (X1) was 3,200, and the weight average molecular weight (Mw) was 7,500.

  The obtained polyester resin composition (1) was suspended in acetone so that the concentration of cellulose fibers was 0.1% by mass, and using a homomixer (“TK Homomixer Type A” manufactured by Special Machinery Co., Ltd.). Dispersion treatment was performed for 20 minutes at 1500 rpm. The obtained dispersion was spread on glass to dry acetone, and the shape of cellulose fibers remaining on the glass was observed using a scanning electron microscope. Observation under a 10,000-fold condition confirmed the presence of cellulose fibers whose length in the minor axis direction, i.e., the fiber width, was released to 100 nm or less.

Example 2
Manufacture of polyester resin composition (2) In a four-necked flask having a stirring bar, a temperature sensor, and a rectifying tube, 84 parts by mass of ethylene glycol and ethylene oxide adduct of bisphenol A (hydroxyl value: 345 mgKOH / g) 222 parts by mass 247 parts by mass of a propylene oxide adduct of bisphenol A (hydroxyl value: 311 mg KOH / g) and 15 parts by mass of a cresol novolac type epoxy resin (average number of cores: 7.6) were dissolved by heating, and then terephthalic acid 432 parts by mass and 0.5 parts by mass of dibutyltin oxide were added. Dry nitrogen was flowed into the flask, the temperature was gradually raised while stirring, and the mixture was reacted at 255 ° C. for 25 hours to obtain a polyester resin intermediate having an acid value of 20 mgKOH / g. To this, 50 parts by mass of the pulverized mixture (Z-1) obtained in Production Example 5 was added, and the mixture was stirred and mixed at 225 ° C. for 1 hour to obtain a polyester resin composition (2). The resulting polyester resin composition (2) had a glass transition temperature (Tg) of 63 ° C., a softening point (T1 / 2) of 133 ° C., and an acid value of 10 mgKOH / g.

  The obtained polyester resin composition (2) was dissolved in THF, and cellulose fibers (Y2) were taken out as insoluble matter to obtain a THF solution of the polyester resin (X2). The number average molecular weight (Mn) of the polyester resin (X2) was 3,700, and the weight average molecular weight (Mw) was 160,000.

  The obtained polyester resin composition (2) was suspended in acetone so that the concentration of cellulose fibers was 0.1% by mass, and using a homomixer (“TK Homomixer Type A” manufactured by Special Machinery Co., Ltd.). Dispersion treatment was performed for 20 minutes at 1500 rpm. The obtained dispersion was spread on glass to dry acetone, and the shape of cellulose fibers remaining on the glass was observed using a scanning electron microscope. Observation under a 10,000-fold condition confirmed the presence of cellulose fibers whose length in the minor axis direction, i.e., the fiber width, was released to 100 nm or less.

Examples 3-13
Production of polyester resin compositions (3) to (13) Polyester resin composition in the same manner as in Example 2, except that the polyester raw material components used and the pulverized mixture (Z) were changed as shown in Table 1 or 2. Products (3) to (13) were obtained. The glass transition temperature (Tg), softening point (T1 / 2) and acid value of the obtained polyester resin composition, and the shape of the polyester resin (X) and cellulose fiber (Y) contained in the polyester resin composition are shown. Shown in 1 or 2.

Example 14
Manufacture of polyester resin composition (14) In a four-necked flask having a stirring bar, a temperature sensor, and a rectifying tube, 84 parts by mass of ethylene glycol and ethylene oxide adduct of bisphenol A (hydroxyl value 345 mgKOH / g) 222 parts by mass 247 parts by mass of a propylene oxide adduct of bisphenol A (hydroxyl value: 311 mg KOH / g) and 15 parts by mass of a cresol novolac type epoxy resin (average number of cores: 7.6) were dissolved by heating, and then terephthalic acid 432 parts by mass, 100 parts by mass of the pulverized mixture (Z-1) obtained in Production Example 5 and 0.5 parts by mass of dibutyltin oxide were added. Dry nitrogen was flowed into the flask, the temperature was gradually raised while stirring, and the mixture was reacted at 255 ° C. for 25 hours to obtain a polyester resin composition (14). The obtained polyester resin composition (14) had a glass transition temperature (Tg) of 64 ° C., a softening point (T1 / 2) of 132 ° C., and an acid value of 10 mgKOH / g.

  The obtained polyester resin composition (14) was dissolved in THF, cellulose fibers (Y14) were taken out as insoluble matter, and a THF solution of the polyester resin (X14) was obtained. The number average molecular weight (Mn) of the polyester resin (X14) was 3,700, and the weight average molecular weight (Mw) was 150,000.

  The obtained polyester resin composition (14) was suspended in acetone so that the concentration of the cellulose fiber was 0.1% by mass, and using a homomixer (“TK Homomixer Type A” manufactured by Special Machinery Co., Ltd.). Dispersion treatment was performed for 20 minutes at 1500 rpm. The obtained dispersion was spread on glass to dry acetone, and the shape of cellulose fibers remaining on the glass was observed using a scanning electron microscope. Observation under a 10,000-fold condition confirmed the presence of cellulose fibers whose length in the minor axis direction, i.e., the fiber width, was released to 100 nm or less.

Example 15
Production of polyester resin composition (15) A polyester resin composition (15) was obtained in the same manner as in Example 14 except that the polyester raw material used was changed as shown in Table 2. The polyester resin composition (15) obtained had a glass transition temperature (Tg) of 65 ° C., a softening point (T1 / 2) of 132 ° C., and an acid value of 11 mgKOH / g. In addition, the polyester resin composition (15) contained in the polyester resin (X15) had a number average molecular weight (Mn) of 3,600 and a weight average molecular weight (Mw) of 150,000.

  In addition, the obtained polyester resin composition (15) was suspended in acetone so that the concentration of cellulose fibers was 0.1% by mass, and a homomixer (“TK Homomixer Type A” manufactured by Special Machinery Co., Ltd.) was used. The dispersion treatment was performed for 20 minutes under the condition of 1500 rpm. The obtained dispersion was spread on glass to dry acetone, and the shape of cellulose fibers remaining on the glass was observed using a scanning electron microscope. Observation under a 10,000-fold condition confirmed the presence of cellulose fibers whose length in the minor axis direction, i.e., the fiber width, was released to 100 nm or less.

Example 16
Production of electrophotographic toner (1) 90 parts by mass of the obtained polyester resin composition (1), 4 parts by mass of carbon black (“MA-11” manufactured by Mitsubishi Chemical Corporation), charge control agent (“Bontron S34 manufactured by Orient Chemical Co., Ltd.) ") 1 part by mass and 3 parts by mass of carnauba wax as a release agent were mixed with a Henschel mixer and then kneaded with a biaxial kneader to obtain a kneaded product. The kneaded material thus obtained was finely pulverized, and then classified so that components having an average particle diameter of 9.5 to 10.5 μm and a particle diameter of 0.5 μm or less were 1% or less. One part by mass of silica (“R972” manufactured by Nippon Aerosil Co., Ltd.) was added to the pulverized product after classification, mixed with a Henschel mixer, and then sieved to obtain a mixture. 5 parts by mass of the obtained mixture and 95 parts by mass of a silicone resin-coated ferrite carrier were mixed and stirred to obtain an electrophotographic toner (1). The softening point (T1 / 2) of the obtained electrophotographic toner was 103 ° C.

Evaluation of Electrophotographic Toner (1) The following various evaluation tests were conducted on the electrophotographic toner (1). The evaluation results are shown in Table 3 below.

1. Method for evaluating hot offset resistance An electrophotographic toner using a modified copier (“IMAGIO” manufactured by Ricoh Co., Ltd.) and changing the setting temperature of the heat roll from 160 ° C. to 215 ° C. in increments of 5 ° C. Using (1), solid printing was performed at a printing speed of 90 mm / sec. The lowest temperature at which the printed part can be visually confirmed to be offset again on the same sheet was taken as the offset start temperature. The higher this temperature, the better the offset resistance.
◎: When the offset start temperature is 210 ° C or higher ○: When the offset start temperature is 170 ° C or higher and lower than 210 ° C ×: When the offset start temperature is lower than 170 ° C

2. Evaluation of low-temperature fixability Using a modified copier (“IMAGIO” manufactured by Ricoh Co., Ltd.), changing the setting temperature of the heat roll from 120 ° C. to 150 ° C. in increments of 5 ° C. Using 1), solid printing was performed at a printing speed of 90 mm / sec. Gently put a mending tape (3M “810”) on the solid print part, and after reciprocating the tape surface uniformly 5 times with a 120 g weight, slowly peel off vertically from the end of the tape. The image density on the printed surface was measured with a Macbeth densitometer (RD-918). The ratio of the density value after the test to the density value before the test was calculated, and the temperature at which the calculated value was 80% or more was determined as the fixing start temperature. It shows that low temperature fixability is so favorable that this temperature is low.
◎: 90% or more ○: 80% or more, less than 90% ×: less than 80%

The fixing start temperature and hot offset resistance were evaluated under the following heat roller fixing machine conditions.
Roll material: Upper; Polytetrafluoroethylene, Lower; Silicone Upper roll load: 7Kg / 350mm
Nip width: 4mm
Paper threading speed: 90mm / sec

3. Evaluation of softening point depression The softening point of the polyester resin composition (1) and the softening point of the electrophotographic toner (1) were measured by the above method, and the electrophotographic toner was determined from the softening point of the polyester resin composition (1). Evaluation was performed based on the value obtained by subtracting the softening point of (1). The smaller this value is, the smaller the softening point depression during the production of the electrophotographic toner is preferable.
A: −2 ° C. or higher and 2 ° C. or lower ×: Over 2 ° C.

Examples 17-30
Electrophotographic toners (2) to (15) were obtained in the same manner as in Example 16 except that the polyester resin composition (1) used was changed to the polyester resin compositions (2) to (15). Various evaluation tests were performed in the same manner as in Example 16. The evaluation results are shown in Table 3 below.

Example 31
Production of polyester resin (X′1) In a four-necked flask having a stirrer, a temperature sensor, and a rectifying tube, 84 parts by mass of ethylene glycol and an ethylene oxide adduct of bisphenol A (hydroxyl value: 345 mg KOH / g) 222 parts by mass 247 parts by mass of a propylene oxide adduct of bisphenol A (hydroxyl value: 311 mg KOH / g) and 15 parts by mass of a cresol novolac type epoxy resin (average number of cores: 7.6) were dissolved by heating, and then terephthalic acid 432 parts by mass and 0.5 parts by mass of dibutyltin oxide were added. Dry nitrogen was flowed into the flask, the temperature was gradually raised while stirring, and the mixture was reacted at 255 ° C. for 25 hours to obtain a polyester resin (X′1).

Production of polyester resin composition (16) 90 parts by mass of the polyester resin composition (X ′) and 9 parts by mass of the pulverized mixture (Z-2) obtained in Production Example 6 were mixed with a Henschel mixer to obtain a polyester resin. A composition (16) was obtained. The polyester resin composition (16) obtained had a glass transition temperature (Tg) of 65 ° C., a softening point of (T1 / 2) of 131 ° C., and an acid value of 10 mgKOH / g. Moreover, the obtained polyester resin composition (16) was dissolved in THF, cellulose fiber (Y16) was taken out as an insoluble matter, and the THF solution of the polyester resin (X16) was obtained. The number average molecular weight (Mn) of the polyester resin (X16) was 4,000, and the weight average molecular weight (Mw) was 170,000.

  The obtained polyester resin composition (16) was suspended in acetone so that the concentration of the cellulose fiber was 0.1% by mass, and using a homomixer (“TK Homomixer Type A” manufactured by Special Machinery Co., Ltd.). Dispersion treatment was performed for 20 minutes at 1500 rpm. The obtained dispersion was spread on glass to dry acetone, and the shape of cellulose fibers remaining on the glass was observed using a scanning electron microscope. Observation under a 10,000-fold condition confirmed the presence of cellulose fibers whose length in the minor axis direction, i.e., the fiber width, was released to 100 nm or less.

Production of electrophotographic toner (16) 90 parts by mass of the obtained polyester resin (X′1), 4 parts by mass of carbon black (“MA-11” manufactured by Mitsubishi Chemical Corporation), charge control agent (“Bontron S34 manufactured by Orient Chemical Co., Ltd.) ”) 1 part by mass, 5 parts by mass of carnauba wax as a release agent, and 9 parts by mass of the pulverized mixture (Z-2) obtained in Production Example 6 were mixed with a Henschel mixer and then kneaded with a biaxial kneader. A kneaded product was obtained. The kneaded material thus obtained was finely pulverized, and then classified so that components having an average particle diameter of 9.5 to 10.5 μm and a particle diameter of 0.5 μm or less were 1% or less. One part by mass of silica (“R972” manufactured by Nippon Aerosil Co., Ltd.) was added to the pulverized product after classification, mixed with a Henschel mixer, and then sieved to obtain a mixture. 5 parts by mass of the obtained mixture and 95 parts by mass of a silicone resin-coated ferrite carrier were mixed and stirred to obtain an electrophotographic toner (16). The softening point (T1 / 2) of the obtained electrophotographic toner (16) was 135 ° C.

Evaluation of electrophotographic toner (16)
The obtained electrophotographic toner (16) was subjected to various evaluation tests in the same manner as in Example 16. The evaluation results are shown in Table 3 below.

Comparative Example 1
Manufacture of polyester resin (α) In a four-necked flask having a stirrer, a temperature sensor, and a rectifying tube, 127 parts by mass of ethylene glycol and 214 parts by mass of neopentyl glycol were charged and dissolved by heating, and then 659 masses of terephthalic acid. Parts and 0.5 parts by weight of dibutyltin oxide were added. Dry nitrogen was flowed into the flask, the temperature was gradually raised while stirring, and the mixture was reacted at 255 ° C. for 25 hours to obtain a polyester resin (α). The obtained polyester resin (α) has a glass transition temperature (Tg) of 52 ° C., a softening point (T1 / 2) of 100 ° C., an acid value of 5 mg KOH / g, a number average molecular weight (Mn) of 2,300, and a weight average. The molecular weight (Mw) was 5,900.

Production of polyester resin (β) In a four-necked flask having a stirrer, a temperature sensor, and a rectifying tube, ethylene glycol 148 parts by mass, neopentyl glycol 165 parts by mass, bisphenol F type epoxy resin (epoxy equivalent 175 g / eq) 11 After adding mass part and 20 mass parts of neodecane sanglycidyl ester and heating and dissolving them, 656 mass parts of terephthalic acid and 0.5 mass part of dibutyltin oxide were added. Dry nitrogen was flowed into the flask, the temperature was gradually raised while stirring, and the mixture was reacted at 255 ° C. for 25 hours to obtain a polyester resin (β). The resulting polyester resin (β) has a glass transition temperature (Tg) of 70 ° C., a softening point of 200 ° C., an acid value of 5 mgKOH / g, a number average molecular weight (Mn) of 6,500, and a weight average molecular weight (Mw) of 380. 000.

  45 parts by mass of the polyester resin (α) and 45 parts by mass of the polyester resin (β) were mixed to obtain a polyester resin composition (1 ′). The resulting polyester resin composition (1 ') had a softening point (T1 / 2) of 152 ° C.

Production of electrophotographic toner (1 ′) 90 parts by mass of the polyester resin composition (1 ′), 4 parts by mass of carbon black (“MA-11” manufactured by Mitsubishi Chemical Corporation), charge control agent (“Bontron S34 manufactured by Orient Chemical Co., Ltd.) ") 1 part by mass and 3 parts by mass of carnauba wax as a release agent were mixed with a Henschel mixer and then kneaded with a biaxial kneader to obtain a kneaded product. The kneaded material thus obtained was finely pulverized, and then classified so that components having an average particle diameter of 9.5 to 10.5 μm and a particle diameter of 0.5 μm or less were 1% or less. One part by mass of silica (“R972” manufactured by Nippon Aerosil Co., Ltd.) was added to the pulverized product after classification, mixed with a Henschel mixer, and then sieved to obtain a mixture. 5 parts by mass of the obtained mixture and 95 parts by mass of a silicone resin-coated ferrite carrier were mixed and stirred to obtain an electrophotographic toner (1). The softening point of the obtained electrophotographic toner was 150 ° C.

Evaluation of electrophotographic toner (1 ')
The obtained electrophotographic toner (1 ′) was subjected to various evaluation tests in the same manner as in Example 16. The evaluation results are shown in Table 3 below.

Claims (10)

A polyester resin composition comprising a polyester resin (X) obtained using polybasic acid and polyhydric alcohol as essential raw material components and cellulose fibers (Y) as essential components. The cellulose fiber (Y) has a length in the range of 100 to 1,000,000 nm in the major axis direction and a length in the range of 5 to 1,000 nm in the minor axis direction. Polyester resin composition. The said cellulose fiber (Y) contains both in the ratio used as the range of 0.1-20 mass parts with respect to a total of 100 mass parts of polyester resin (X) and the said cellulose fiber (Y). Polyester resin composition. The polyester resin composition according to claim 1, wherein the polyester resin (X) has a molecular weight distribution (Mw / Mn) in the range of 2 to 55. The polyester resin composition according to claim 1, wherein the polyester resin (X) is obtained by reacting a polybasic acid, a polyhydric alcohol, and a polyfunctional epoxy compound as essential raw material components. The cellulose fiber (Y) is obtained by crushing and mixing a cellulose raw material (y) in a polyester resin (V) having a weight average molecular weight (Mw) in the range of 1,000 to 5,000, The polyester resin composition according to claim 1. The polyester resin composition according to claim 6, wherein the polyester resin (V) has a hydroxyl value in the range of 30 to 120 mgKOH / g and an acid value in the range of 1 to 50 mgKOH / g. The cellulose raw material (y) is pulverized and mixed in a polyester resin (V) having a weight average molecular weight (Mw) in the range of 1,000 to 5,000 to obtain a pulverized mixture (Z). A polyester resin raw material containing an acid (a2), a polyhydric alcohol (b2), and a polyfunctional epoxy compound (c2) and the pulverized mixture (Z) are obtained by reacting them as essential components. The polyester resin composition according to 1. An electrophotographic toner resin composition comprising the polyester resin composition according to claim 1 and a colorant. An electrophotographic toner comprising the resin composition for an electrophotographic toner according to claim 9.

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