JP2006003680A - Polyester resin for toner and toner for developing electrostatic image - Google Patents

Abstract

In a toner for developing an electrostatic charge image using a polyester resin as a binder resin, without using bisphenol A or a derivative thereof as an alcohol component, it has excellent toner characteristics such as offset resistance and low-temperature fixability, and is inexpensive. Provided are a toner for developing an electrostatic charge image with a small amount of toner used per sheet and a polyester resin for the toner used in the toner.
An acid component is composed of disproportionated rosin and terephthalic acid and / or isophthalic acid, an alcohol component is composed of a glycidyl ester of a tertiary fatty acid and an aliphatic diol having 2 to 10 carbon atoms, and has a hydroxyl value of 20 to An electrostatic charge characterized by containing, as a binder resin, a urethane-modified polyester resin (C) obtained by mixing and reacting a polyester resin (A) of 70 mg KOH / g and a polyvalent isocyanate compound (B). This is an image developing toner.
[Selection figure] None

Description

 The present invention relates to an electrostatic image used for developing an electrostatic charge image in an electrophotographic copying machine, a laser beam printer, an electrostatic recording apparatus or the like in which an image is formed using an electrophotographic method, an electrostatic recording method, or the like. The present invention relates to a toner for developing a charge image and a polyester resin for toner used in the toner for developing an electrostatic image.

 Conventionally, the electrophotographic method or the electrostatic recording method has been widely used as a method for obtaining a copy or a recorded image in a copying machine for copying an original or a printer for outputting a computer including a personal computer or a printer for a facsimile receiving apparatus. Has been. Typical examples of the copying machine and printer using the electrophotographic method or the electrostatic recording method include an electrophotographic copying machine, a laser beam printer, a printer using a liquid crystal array, and an electrostatic printer. In the electrophotographic method or the electrostatic recording method, an electrostatic latent image (electrostatic image) is formed by various means on an electrostatic image carrier such as an electrophotographic photosensitive member or an electrostatic recording member. While developing the image with a developer, the obtained toner image is transferred to a transfer medium such as paper as necessary, and fixed by heating, pressing, heating and pressing, or solvent vapor to obtain a final toner image The toner remaining without being transferred onto the electrostatic image bearing member is removed by the cleaning means. By repeating these steps, a plurality of copies or records can be obtained sequentially.

 As a method for developing the electrostatic latent image, a method using a liquid developer in which a fine toner is dispersed in an electrically insulating liquid (wet development method), a colorant in a binder resin, and a magnetic material as necessary. A method of using dispersed powder toner together with carrier particles, a method of developing without using carrier particles using a magnetic toner in which a magnetic material is dispersed in a binder resin (dry development method), etc. are known. . Among these methods, in recent years, a dry development method using powder toner or magnetic toner is mainly employed.

  By the way, in recent years, electrophotographic copying machines, laser beam printers, and the like have become smaller and more personalized, and at the same time, higher speed has been required, and further reduction in energy has been required. Therefore, various attempts have been made to improve these apparatuses for forming a reliable and high-quality image at high speed and with low energy over a long period of time using a mechanism as simple as possible. In addition to such improvements in the apparatus, various attempts have been made to improve the toner used for development.

  For example, as a device for fixing a toner image, a heat and pressure fixing device using a heating roller, a roll-shaped or long heat-resistant film, a so-called fixing belt is used, and a heating body and a transfer are transferred via the fixing belt. 2. Description of the Related Art A heat and pressure fixing device is widely used in which a sheet development surface is opposed and a transfer sheet is conveyed from the back while being pressed by a pressure roller to heat and fix the sheet. In the fixing method using these heat fixing devices, the heat roller or the fixing belt is in direct contact with the toner image at the time of fixing, so that the heat is efficiently transmitted to the toner, and the toner is melted quickly and smoothly with low energy. Can be done. However, since the molten toner and the heat roller or the fixing belt are in direct contact with each other at the time of fixing, a part of the melted toner is transferred and adhered to the surface of the heat roller or the fixing belt. When the transferred and adhered toner is transferred again to the transferred material when it contacts the transferred material, or when the transferred material does not exist, the transferred and transferred toner is transferred to the pressure roller and transferred to the pressure roll. There is a problem in that when the transferred object passes through the fixing device, a toner adhering to the pressure roll causes a so-called offset phenomenon such that the back surface of the transferred object becomes dirty, and the transferred object becomes dirty.

In order to prevent such toner offset phenomenon, a conventional heat roll surface is formed of a releasable material such as silicone rubber or fluororesin, and a liquid having good releasability such as silicone oil is applied to the surface. Generally, the surface of a hot roll is covered with a releasable liquid film layer. According to this method, the occurrence of the offset phenomenon can be substantially prevented, but a problem arises in that a releasable liquid coating apparatus is required, and the silicone oil evaporates due to heat and contaminates the inside of the apparatus. Also, providing such a releasable liquid coating apparatus is incompatible with the downsizing of the apparatus. For this reason, the releasable liquid is not applied by a coating device, but the toner itself contains a releasable substance, the releasable substance is melted by heating during fixing, and the releasable liquid is supplied from the toner. In order to prevent the offset phenomenon, a number of waxes such as low molecular weight polyethylene, low molecular weight polypropylene, hydrocarbon waxes, natural waxes and modified waxes obtained by modifying them are proposed as such releasable substances. (For example, see Patent Documents 1 and 2).
Japanese Patent Publication No.52-3304 JP-A-60-252360

On the other hand, attempts have been made to prevent the occurrence of the offset by improving the properties of the binder resin of the electrostatic image developing toner. Examples of the binder resin having excellent offset resistance include, for example, a cross-linked polyester obtained by reacting an etherified diphenol, a dicarboxylic acid component, and a trivalent or higher monomer component to form a cross-linked structure. Resin (for example, refer to Patent Document 3), etherified diphenol, dicarboxylic acid component containing specific dicarboxylic acid, and trivalent or higher monomer component containing trimellitic anhydride are reacted to form a crosslinked structure. The resulting cross-linked polyester resin (see, for example, Patent Document 4) is known, but the low-temperature fixability is not always good.
In order to improve this, it is also known to use urethane-modified urethane-modified polyester resin (for example, see Patent Document 5) comprising a polyester resin for high molecular weight and a polyester resin for low molecular weight as a cross-linked polyester resin. However, it is obtained by substantially using a bisphenol A derivative as an essential alcohol component, which is unfavorable for the environment and increases the amount of toner consumed.

On the other hand, from the viewpoint of improving the low-temperature fixability of the toner, it is effective to lower the softening temperature (Tm) of the toner binder resin. However, it is known that when Tm is lowered, the glass transition temperature (Tg) of the toner is also lowered at the same time, so that the toner forms a lump in the storage state, and so-called toner blocking and toner offset at the time of fixing easily occur. This is one of the reasons why the fixing temperature cannot be lowered as expected. As a method for simultaneously satisfying this low-temperature fixability and blocking resistance or offset resistance, a method using a polyester resin having a relatively low fixing temperature even when Tm and Tg are high (for example, see Patent Document 6) has been proposed. ing. However, this method does not satisfy the low-temperature fixing property, blocking resistance, offset resistance and the like simultaneously and sufficiently. In addition, examples in which alkylene glycol and etherified diphenol are used in combination as an alcohol component of a polyester resin are known (see, for example, Patent Documents 7 and 8). However, the toner is not sufficiently pulverizable or has a low Tg. The blocking resistance of the obtained toner is not satisfactory.
In addition, a dihydric alcohol is used as an alcohol component, and a non-linear cross-linked polyester resin (see, for example, Patent Document 9) composed of rosin, an unsaturated dicarboxylic acid and another dicarboxylic acid as an acid component, a specific alcohol component or Examples using acid components (see, for example, Patent Documents 10, 11, 12), examples using block polymers (see, for example, Patent Document 13), examples using amorphous polyester and crystalline polyester in combination (for example, Patents) A large number of polyester resins for toner binders have been proposed, such as offset resistance, low temperature fixability, sharp melt properties, blocking resistance, charging properties, pulverization properties, and transparency required as toner properties. Development of a resin for toner that can simultaneously satisfy the characteristics has been made.
JP-A-1-155362 JP-A-57-109825 JP 2000-234011 A JP-A-56-1952 Japanese Patent Laid-Open No. 1-226761 JP-A-1-155360 JP-A-4-70765 Japanese Patent Laid-Open No. 6-27728 Japanese Patent Laid-Open No. 9-278872 Japanese Patent Laid-Open No. 10-268558 JP 2001-324832 A JP 2002-284866 A

  As described above, attempts have been made to produce a toner for developing an electrostatic charge image with good characteristics by using a polyester resin as a binder resin for the toner. Conventionally, a polyester binder resin for toner with good toner characteristics has been used. When obtaining, generally, bisphenol A or a derivative thereof is used as an alcohol component. However, in recent years, it has become clear that bisphenol A is not necessarily used from the viewpoint of environmental hormones, and without using bisphenol A or its derivatives, offset resistance, low-temperature fixability, and sharp melt properties are the same as before. Development of a polyester resin for toner and toner that are excellent in properties such as blocking resistance, charging properties, pulverization properties, and transparency and that can form a good developed image over a long period of time is desired.

  Furthermore, recently, the economics of toner has also been regarded as important, and there has been a demand for provision of an inexpensive toner binder resin. However, conventional toner binders cannot always meet such demands. .

  In addition, from the viewpoint of resource saving, there is a demand for a toner for developing an electrostatic image that can form an image with a high density similar to the conventional one with a small amount of toner.

 In view of such a current situation, the object of the present invention is to provide excellent anti-offset property in fixing by a heat roller fixing or fixing belt system without using bisphenol A or a derivative thereof as an alcohol component, as well as low temperature fixability, sharp melt Toner-modified urethane resin for toner capable of forming good developed image over a long period of time, and toner using the same, and toner properties such as property, blocking resistance, charging property, pulverization property, and transparency are provided. It is.

  Another object of the present invention is to use a polyester resin produced without using bisphenol A or a derivative thereof as an alcohol component as a binder resin, and is resistant to offset during heat roller fixing or fixing by a fixing belt method. In addition to excellent anti-wrapping properties, toner properties such as low-temperature fixability, sharp melt properties, anti-blocking properties, charging properties, pulverization properties, and transparency are excellent, and an electrostatic charge that can form a good developed image over a long period of time. To provide a toner for image development.

  Furthermore, another object of the present invention is to provide a polyester resin for toner which is excellent in properties as a binder resin for toner and is inexpensive, and a toner for developing an electrostatic image using the polyester resin for toner as a binder resin. It is.

  Another object of the present invention is to provide a toner for developing an electrostatic image capable of forming an image having the same density as that of the prior art by using a small amount.

As a result of intensive studies to solve these problems, the present inventors have used a specific polyester resin (A) as a raw material, and formed urethane by reacting it with a polyvalent isocyanate compound (B). It has been found that the above object can be achieved by incorporating the modified polyester resin (C) in the toner for developing an electrostatic image, and the present invention has been completed. That is, the present invention relates to the following inventions (1) to (7).
(1) At least the acid component is composed of disproportionated rosin and terephthalic acid and / or isophthalic acid, the alcohol component is composed of a glycidyl ester of a tertiary fatty acid and an aliphatic diol having 2 to 10 carbon atoms, and has a hydroxyl value of 20 to 20 An electrostatic charge characterized by containing, as a binder resin, a urethane-modified polyester resin (C) obtained by mixing and reacting a polyester resin (A) of 70 mg KOH / g and a polyvalent isocyanate compound (B). This is an image developing toner.
(2) At least the acid component is composed of disproportionated rosin and terephthalic acid and / or isophthalic acid, the alcohol component is composed of a glycidyl ester of a tertiary fatty acid and an aliphatic diol having 2 to 10 carbon atoms, and has a hydroxyl value of 20 to 20 Polyurethane-modified polyester resin (C) obtained by adding polyisocyanate compound (B) to the melt of polyester resin (A) of 70 mg KOH / g, mixing by melt kneading and reacting as a binder resin An electrostatic charge image developing toner.
(3) The toner for developing an electrostatic charge image according to (1) or (2) above, wherein the true density of the urethane-modified polyester resin (C) is 1.1 to 1.3 g / cm 3.
(4) In the production of the urethane-modified polyester resin (C), the polyvalent isocyanate compound (B) is used in a proportion of 0.2 to 1.2 equivalents as an isocyanate group per equivalent of hydroxyl group of the polyester resin (A). The toner for developing an electrostatic image according to any one of (1) to (3) above.
(5) The urethane-modified polyester resin (C) has an acid value of 10 mgKOH / g or less and a hydroxyl value of 15 mgKOH / g or less, according to any one of (1) to (4) above This is a toner for developing an electrostatic image.
(6) Any of (1) to (5) above, wherein the reaction temperature when the polyester resin (A) and the polyvalent isocyanate compound (B) are mixed and reacted is 160 to 200 ° C. The toner for developing an electrostatic image described in 1.
(7) At least the acid component is composed of disproportionated rosin and terephthalic acid and / or isophthalic acid, the alcohol component is composed of a glycidyl ester of a tertiary fatty acid and an aliphatic diol having 2 to 10 carbon atoms, and has a hydroxyl value of 20 to 20 This is a urethane-modified polyester resin (C) for toner obtained by mixing and reacting a polyester resin (A) of 70 mg KOH / g and a polyvalent isocyanate compound (B).

The toner for developing an electrostatic charge image of the present invention does not use bisphenol A or a bisphenol A derivative such as an ethylene oxide adduct of bisphenol A as an alcohol component of a polyester resin that is a binder resin of the toner. Preferably, an environmentally friendly toner can be obtained.
Further, according to the polyester resin for toner of the present invention, even without using bisphenol A or a derivative of bisphenol A, offset resistance, low-temperature fixability, sharp melt resistance, blocking resistance, and charging characteristics that are the same as or higher than conventional ones. In addition, a toner having characteristics such as pulverization and transparency can be obtained. As a result, the storage stability of the toner classified product is improved, and a good developed image can be formed over a long period from the beginning of development without causing a decrease in fluidity of the toner during development and blocking of the toner.
Furthermore, since bisphenol A or a derivative thereof is not used in the present invention, a polyester resin for toner can be produced at a low cost, and the polyester resin for toner of the present invention uses bisphenol A or a derivative thereof as an alcohol component. Since the true density of the resin is smaller than that of the conventional resin, development with a toner prepared using this resin can reduce the amount of toner used per sheet and reduce the copying cost.
Further, the crosslinking reaction with isocyanate is highly reactive and is performed in a stable state in a short time, and a stable polyester resin for toner with little variation during production can be obtained.

The present invention will be described in detail below.
As described above, the urethane-modified polyester resin (C), which is the binder resin of the electrostatic charge image developing toner of the present invention, has a specific composition and a polyester resin (A) having a hydroxyl value and a polyvalent isocyanate compound (B). ) As a raw material.
Then, the urethane-modified polyester resin (C) is obtained by adding the polyvalent isocyanate compound (B) to the polyester resin (A) and mixing and reacting them by melt kneading.

 The polyester resin (A) is composed of a disproportionated rosin that is an acid component, terephthalic acid and / or isophthalic acid, a glycidyl ester of a tertiary fatty acid that is an alcohol component, and an aliphatic diol having 2 to 10 carbon atoms. It is a polyester resin obtained by polycondensation of these four components, and it is important that the hydroxyl value is 20 to 70 mgKOH / g.

The disproportionation rosin used as the acid component of the polyester resin (A) may be produced by any conventionally known production method. For example, rosin is used as a disproportionation catalyst such as a Pd carbon catalyst. A method of saponifying the reaction product by reacting in the presence of 250 to 300 ° C., 5 to 15 kg / cm ² , and 2 to 6 hours in the presence is included.
Commonly available gum rosin, tall oil rosin, and the like have a lot of abietic acid containing a conjugated double bond and are very easily oxidized. Therefore, it is preferable to disproportionate in order to prevent discoloration and alteration due to air oxidation. . Here, abietic acid is disproportionated to dehydroabietic acid and dihydroabietic acid.

  Moreover, terephthalic acid and isophthalic acid consist of terephthalic acid, isophthalic acid and their lower alkyl esters. Examples of lower alkyl esters of terephthalic acid and isophthalic acid include, for example, dimethyl terephthalate, dimethyl isophthalate, diethyl terephthalate, diethyl isophthalate, dibutyl terephthalate, and dibutyl isophthalate. Dimethyl acid and dimethyl isophthalate are preferred. On the other hand, these dicarboxylic acids or lower alkyl esters thereof may be used alone or in combination of two or more.

 The molar ratio of disproportionated rosin (1) to terephthalic acid and / or isophthalic acid (2) is preferably (1) / (2) = 0.1 to 0.5, more preferably 0.15. ~ 0.3. When the molar ratio of the disproportionated rosin (1) and terephthalic acid and / or isophthalic acid (2) is lower than 0.1, the fixability tends to deteriorate and fog tends to occur. If it exceeds .5, the offset resistance tends to deteriorate and the image density tends to decrease.

  In addition, in the acid component of the polyester resin (A), other dicarboxylic acids can be used together with terephthalic acid and isophthalic acid as long as the object of the present invention is not impaired. These other dicarboxylic acids include benzene dicarboxylic acids such as phthalic acid and phthalic anhydride; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid; succinic acid substituted with an alkyl group having 16 to 18 carbon atoms. Acids; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, itaconic acid, glutaconic acid; cyclohexane dicarboxylic acid; naphthalenedicarboxylic acid; diphenoxyethane-2,6-dicarboxylic acid and lower monoesters of these acids; Examples include diesters and acid anhydrides. Since these dicarboxylic acids greatly affect the fixing property and blocking resistance of the toner, they are used in an appropriate amount in consideration of the required performance of the toner.

  As an example of the glycidyl ester of the tertiary fatty acid used as an alcohol component of a polyester resin (A), what is represented by the following general formula (1) is mentioned, for example.

(In the formula, R ¹ , R ² and R ³ represent an alkyl group.)
In the above formula, the carbon number of R ¹ , R ² and R ³ and the total number of carbon atoms of these groups are not particularly limited, but neodecanoic acid glycidyl ester having a total carbon number of R ¹ + R ² + R ³ is preferably 8. .

  In addition, rosin glycidyl ester may be used together with glycidyl ester of tertiary fatty acid.

 Examples of the aliphatic diol having 2 to 10 carbon atoms include, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4 -Butanediol, 2,3-butanediol, 1,4-butenediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 2-ethyl-2-methylpropane-1 , 3-diol, 2-butyl-2-ethylpropane-1,3-diol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2 , 4-Dimethyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,7-heptanediol, 1,8-octane Diol, 1,9-nonanediol, 1,10-decanediol, 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropanoate, diethylene glycol, triethylene glycol, dipropylene glycol, etc. Is mentioned. As the aliphatic diol, neopentyl glycol is preferable from the viewpoint of reactivity with acid and glass transition temperature of the resin. These aliphatic diols may be used alone or in combination of two or more.

 The molar ratio of the tertiary fatty acid glycidyl ester (3) and the aliphatic diol (4) having 2 to 10 carbon atoms is preferably (3) / (4) = 0.05 to 0.3. More preferably, it is 0.1-0.2. When the molar ratio of the tertiary fatty acid glycidyl ester (3) and the aliphatic diol (4) having 2 to 10 carbon atoms is lower than 0.05, fog is likely to occur, and when the molar ratio exceeds 0.3, Tends to deteriorate the offset resistance and blocking resistance. By using rosin glycidyl ester together with glycidyl ester of tertiary fatty acid, offset resistance and blocking resistance are improved. The rosin glycidyl ester is preferably used in an amount of 2 to 50 mol% in the component (b), and the glycidyl ester of a tertiary fatty acid is preferably used in an amount of 5 to 30 mol% in the component (b). The molar ratio (2) / (4) of the aliphatic diol of the alcohol component (4) to the dicarboxylic acid of the component (2) of the acid component is the molar ratio (1) of the acid components (1) and (2). Although it varies depending on the value of / (2) and the molar ratio (3) / (4) of alcohol components (3) and (4), it is usually preferably 0.8 to 1.2.

  In the polyester resin (A), a crosslinked structure can be formed by using a trivalent or higher polycarboxylic acid or a trivalent or higher polyol in addition to the acid component and the alcohol component. Examples of tricarboxylic or higher polycarboxylic acids include trimellitic acid, pyromellitic acid, 1,2,4-cyclohexanetricarboxylic acid, naphthalenetricarboxylic acid, butanetricarboxylic acid, hexanetricarboxylic acid, tetra (methylenecarboxyl) methane, and octane. Examples thereof include tetracarboxylic acid, benzophenone tetracarboxylic acid and anhydrides thereof, and among them, trimellitic anhydride is preferable from the viewpoint of reactivity. Examples of the trihydric or higher polyols include polyhydric alcohols such as glycerol, diglycerol, sorbitol, sorbitan, butanetriol, trimethylolethane, trimethylolpropane, pentaerythritol, among them pentaerythritol, trimethylol. Propane and the like are preferred.

  It is important that the hydroxyl value of the polyester resin (A) is 20 to 70 mgKOH / g. By satisfying this range, it can react well with the polyvalent isocyanate compound to carry out urethane crosslinking (isocyanate crosslinking). This is because the hydroxyl group in the polyester resin (A) reacts with the isocyanate group in the polyvalent isocyanate compound (B) to generate a urethane bond. Here, when the hydroxyl value of the polyester resin (A) is smaller than 20 mgKOH / g, sufficient urethane crosslinking reaction cannot be performed. On the other hand, if it exceeds 70 mgKOH / g, the hydroxyl group is excessive, so that the hydroxyl group is excessively left. When the toner is used, there are problems such as a decrease in charge amount, occurrence of image fogging, and a decrease in environmental stability. In other words, the polyvalent isocyanate compound (B) is excessively used, and the cross-linking reaction proceeds too much, so that the fixability of the toner is deteriorated. The number average molecular weight of the tetrahydrofuran (THF) soluble part of the polyester resin (A) is 1,000 to 6,000, preferably 2,000 to 4,000.

  The polyester resin (A) is prepared by a known and commonly used production method using the predetermined acid component and alcohol component as raw materials, and any of transesterification or direct esterification can be applied as the reaction method. In addition, polycondensation can be promoted by a method of increasing the reaction temperature by pressurization, a depressurization method, or a method of flowing an inert gas under normal pressure. In the above reaction, a known and commonly used reaction catalyst such as at least one metal compound selected from antimony, titanium, tin, zinc and manganese may be used to accelerate the reaction. Specific examples of the reaction catalyst include di-n-butyltin oxide, stannous oxalate, antimony trioxide, titanium tetrabutoxide, manganese acetate, and zinc acetate. The amount of these reaction catalysts added is usually preferably about 0.001 to 0.5 mol% in the obtained polyester resin.

  In the production method of the polyester resin (A), a direct esterification method can be employed even at normal pressure during the above various reactions. In this direct esterification method, for example, the alcohol component is charged in its entirety at the start of the reaction, and the acid component is charged after the temperature is raised to about 160 ° C. Di-n-butyltin oxide, stannous oxalate, antimony trioxide and the like are used as the reaction catalyst, and the addition amount is suitably 0.01 to 0.1 mol% with respect to the total acid component. In this case, a sufficient reaction rate can be obtained even at normal pressure, but the reaction temperature can be increased by applying a pressurizing operation. The promotion of the reaction by depressurization operation is applied in the case where almost no unreacted alcohol is consumed at the end of the reaction, and the removal of the generated water is delayed. The promotion of the reaction by passing through an inert gas can be applied to any process of the reaction in such an amount that it minimizes the dissipation of alcohol out of the system. The reaction is terminated after confirming that the softening point of the resin has reached a predetermined temperature.

 The polyvalent isocyanate compound (B) is a substance that serves as a crosslinking agent and a material for increasing the molecular weight when obtaining the urethane-modified polyester resin (C). The cross-linking reaction using polyvalent isocyanate is performed by addition reaction between hydroxyl group and isocyanate group in the polyester resin, and obtains urethane bond. It is very reactive, especially in short reaction time in the melt-kneading process. It is a suitable compound for crosslinking to a molecular weight or increasing the molecular weight.

 On the other hand, the polyvalent isocyanate compound (B) is a compound having a divalent or higher valent isocyanate group, such as hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylene diisocyanate. The isocyanate represented by following (A)-(E) can be mentioned.

 The amount of these polyvalent isocyanate compounds (B) used is usually 0.2 to 1.2 equivalents, preferably 0.6 to 1.2 equivalents of isocyanate groups per hydroxyl group equivalent of all polyester resins. Amount, particularly preferably 0.7 to 1.0 equivalent.

  The addition reaction with these polyisocyanate compounds (B) has the effect of increasing the non-offset property by crosslinking, branching and increasing the molecular weight of the polyester resin (A), and the content thereof is the acid component (a) or alcohol. Depending on the ratio of the component (1) / (2) in the component (b), the ratio of the component (3) / (4), the use ratio of the acid component (a) and the alcohol component (b) or the acid component (2) It varies depending on the proportion of the component and the component (4) of the alcohol component and the number of functional groups of the alcohol.

  In addition, by performing urethane modification by isocyanate crosslinking, it is possible to obtain a resin having high intermolecular bonding strength and high strength. Further, since the reaction between isocyanate and hydroxyl group is an addition reaction as described above, it is a clean reaction without any by-products. The reaction temperature at the time of melt kneading is preferably in the range of 160 to 200 ° C. When the temperature is lower than 160 ° C., the crosslinking reaction does not easily proceed, and when the temperature exceeds 200 ° C., the urethane bond is broken.

In order to obtain the urethane-modified polyester resin (C) of the present invention, it is obtained by melt-mixing the polyester resin (A) and the polyvalent isocyanate compound. The melt of the polyester resin (A) is kneaded and this kneading is performed. A method in which the polyvalent isocyanate compound (B) is added to the product, and melt-kneaded and sufficiently mixed is preferable.
As a specific method for performing this melt mixing, the polyester resin (A) is injected into a uniaxial or biaxial extruder at a constant speed, and at the same time, the polyvalent isocyanate compound (B) is also injected at a constant speed, or uniaxial. Or the method of inject | pouring a polyester resin (A) and a polyvalent isocyanate compound (B) in order with respect to the feed direction of a biaxial extruder is mention | raise | lifted. And it is preferable to make it react, knead | mixing conveyance at the temperature of 160-200 degreeC. At this time, the polyester resin (A), which is a reaction raw material charged or injected into a single-screw or twin-screw extruder, is directly injected into a single-screw or twin-screw extruder as it is without cooling from the polyester resin reaction vessel. Alternatively, it may be performed by cooling, crushing or beading the resin once produced and supplying it to a uniaxial or biaxial extruder. However, in the present invention, the method for producing the urethane-modified polyester resin (C) is not limited to these specifically exemplified methods, and raw materials are charged into a conventionally known method such as a reaction vessel to be in a solution state. Of course, it can be performed by an appropriate method such as a method of heating to temperature and mixing.
The urethane-modified polyester resin (C) used in the present invention preferably contains 0.1 to 25% gel. For this gel, 5 g of resin was mixed with 100 ml of ethyl acetate for 4 hours, and then allowed to stand for 1 day. Then, the supernatant was gently collected with a dropper, and the amount of the obtained dissolved polymer was measured with a nonvolatile content. It is obtained.

  The hydroxyl value of the urethane-modified polyester resin (C) of the present invention is preferably 15 mgKOH / g or less. Also from the examples, good results are obtained at a numerical value of a hydroxyl value of 1.4 to 13.4 mgKOH / g. If the hydroxyl value is greater than 15 mgKOH / g, the hydrophilicity increases, so that problems such as a decrease in image density, a decrease in charge amount, and toner scattering in the machine occur particularly in a high humidity environment.

  The acid value of the urethane-modified polyester resin (C) of the present invention is preferably 10 mgKOH / g or less. Also from the examples, good results are obtained at a numerical value of an acid value of 3.0 to 9.8 mgKOH / g. If the acid value is greater than 10 mgKOH / g, the hydrophilicity increases as the hydroxyl value, which causes problems such as a decrease in image density, a decrease in charge amount, and toner scattering in the machine, particularly in a high humidity environment. End up.

  The urethane-modified polyester resin (C) of the present invention has a softening temperature of 115 to 150 ° C, preferably 120 to 145 ° C. This is because when the softening temperature is less than 115 ° C., the cohesive strength of the resin is extremely reduced, while when it exceeds 150 ° C., the melt flow and low-temperature fixability of the toner using the resin are reduced. This is because it is not suitable for a toner binder.

Further, the urethane-modified polyester resin (C) of the present invention may be of the type having a single molecular weight distribution curve, but the low molecular weight condensation polymer component (tetrahydrofuran soluble component) of any polyester resin. The number average molecular weight of 1,000 to 6,000) and the urethane-modified polyester resin (C) of the present invention may be of any type having a double molecular weight distribution curve. By having a low molecular component, the low-temperature fixability can be improved.
From the viewpoint of preventing toner aggregation, the urethane-modified polyester resin (C) of the present invention has a glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of 45 to 70 ° C., preferably 50 to 70 ° C. What is 65 degreeC is desirable.
Furthermore, the true density of the urethane-modified polyester resin (C) of the present invention is preferably 1.1 to 1.3 g / cm ³ . When the true density of the resin is low, the toner can be used in a small amount when an image having the same density is formed, and as a result, economical copying can be performed.

 In the toner for developing an electrostatic charge image of the present invention, in addition to the binder resin containing the urethane-modified polyester resin (C), other known binder resins, charge control agents, and colorings as long as the performance is not impaired. Materials that are usually used in the production of toner, such as an agent, a wax, a magnetic substance, and an external additive (abrasive, fluidizing agent, conductivity-imparting agent, lubricant) can be included.

The binder resin of the toner for developing an electrostatic charge image of the present invention may be the above urethane-modified polyester resin (C) alone, but as described above, two or more of the above polyester resins may be used in combination. Other binder resins can be used in combination.
As the other binder resin that can be used together with the urethane-modified polyester resin (C), any binder resin may be used as long as it is known as a binder resin of a toner for developing an electrostatic charge image conventionally. For example, polystyrene, poly-p-chloro Styrene such as styrene and polyvinyltoluene and homopolymers of substituted styrene; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer , Styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl Methyl ketone copolymer, Styrene copolymers such as tylene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer; polyvinyl chloride, phenol resin, natural modified phenol resin, natural resin modified maleic acid resin, acrylic Resins, methacrylic resins, polyvinyl acetate, silicone resins, polyester resins other than the urethane-modified polyester resin (C), polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumarone indene resin, Examples include petroleum resins and crosslinked resins such as styrene copolymers.
These binder resins used in combination may be blended with the urethane-modified polyester resin (C) and the materials described below at the time of toner production.

The toner for developing an electrostatic charge image of the present invention contains a positive or negative charge control agent, if necessary, depending on the polarity of the electrostatic latent image to be developed. Typical examples of charge control agents include those that give positive charge to the toner, such as nigrosine base, a mixture of nigrosine base modified with resin acid, a mixture of nigrosine base modified with stearic acid, and the like. Electron donating substances such as basic dyes such as dyes, quaternary ammonium salt compounds, organic tin oxides, polymers having amino groups, and the like, which also give negative charge to toners, are metal complexes of monoazo dyes, chromium-containing dyes Examples thereof include metal-containing dyes such as organic dyes (copper phthalocyanine green, chromium-containing monoazo dyes), metal complexes of aryloxycarboxylic acids such as salicylic acid, and divalent or trivalent metal salt compounds thereof.
Among these charge control agents, as the negative charge control agent, a metal salt of an aromatic hydroxycarboxylic acid represented by the following general formula (2), more preferably 3,5-di-tert-butylsalicylic acid or 3- Preferred examples thereof include metal salts of hydroxy-2-naphthoic acid such as calcium, trivalent chromium and iron.
Particularly, a metal salt compound of an aromatic hydroxycarboxylic acid has 2 to 3 —OH groups (hydroxyl groups) in one molecule and reacts with a carboxyl group which is an acid component in the polyester resin. The charge control agent is a preferable charge control agent because it can disperse the charge control agent satisfactorily and can promote the crosslinking and molecular weight increase of the polyester resin by this reaction, thereby improving the fixability.
These charge control agents may be used in an appropriate amount depending on the kind of the charge control agent, and are usually used in an amount of about 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

(Wherein R ⁴ , R ⁵ and R ⁶ represent a hydrogen atom, a saturated or unsaturated linear or branched alkyl group, or an aryl group which is the residue of an aromatic hydrocarbon group, or R ⁴ And R ⁵ , or R ⁵ and R ⁶ are bonded to each other to form a condensed ring which may have a saturated or unsaturated linear or branched alkyl group.

  As the colorant that can be used in the toner for developing an electrostatic image of the present invention, any colorant known to be used in the production of conventional toners can be used. Examples of these colorants include carbon black, aniline black, acetylene black, and iron black as black colorants, and phthalocyanine, rhodamine, quinacridone, and triarylmethane as colorants for color. Various dyes such as anthraquinone, azo, diazo, methine, allylamide, thioindigo, naphthol, isoindolinone, diketopyrrolopyrrole, benzimidazolone, these metal complex compounds, Examples include lake compounds. These can be used alone or in admixture of two or more.

  Further, in the toner for developing an electrostatic charge image of the present invention, a magnetic powder may be added as necessary to form a magnetic toner. As the magnetic powder internally added to these toners, any powders of alloys, oxides, compounds and the like containing ferromagnetic elements that are conventionally used in the production of magnetic toners can be used. Examples of these magnetic powders include magnetic iron oxides such as magnetite, maghemite, and ferrite, or compounds of divalent metals and iron oxides, metals such as iron, cobalt, and nickel, or aluminums of these metals, cobalt, copper, Examples include powders of alloys of metals such as lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, and mixtures of these powders. These magnetic powders preferably have an average particle diameter of 0.05 to 2.0 μm, more preferably about 0.1 to 0.5 μm. The content of the magnetic powder in the toner is about 5 to 200 parts by weight, preferably 10 to 150 parts by weight, with respect to 100 parts by weight of the thermoplastic resin. Further, the saturation magnetization of the toner is preferably 15 to 35 emu / g (measuring magnetic field: 1 kilo-Oersted). In the toner for developing an electrostatic image of the present invention, the magnetic powder also functions as a colorant. When the magnetic powder is used, it is not necessary to use another colorant, but it is necessary. For example, carbon black, copper phthalocyanine, iron black, etc. may be used together.

  In the toner for developing an electrostatic image of the present invention, a wax having a melt viscosity at 140 ° C. of 100 mPa · s (CS) or less and an acid value of 2 mgKOH / g or less is used as a release agent, for example, 0.5 to 10 It can be contained by weight. Examples of such waxes include fatty acid esters such as polypropylene wax, polyethylene wax, paraffin wax, fatty acid amide wax, carnauba wax, and montan wax, partially saponified fatty acid ester wax, and fatty acid metal salts. When the melt viscosity at 140 ° C. of the wax exceeds 100 mPa · s, there is a problem that the low temperature fixability is poor, and when the acid value of the wax exceeds 2 mgKOH / g, a low molecular weight substance is mixed in the wax. In many cases, this low molecular weight product is not preferable because it causes problems such as odor generation during fixing and deterioration of storage stability of the toner.

  The wax and the polyester resin for toner are usually not compatible with each other, and it may be difficult to uniformly disperse the wax in the polyester resin for toner. In such a case, a compatibilizer can be added to the toner for developing an electrostatic charge image of the present invention. Examples of the compatibilizer include a copolymer comprising an ethylene unit, a (meth) acrylic acid ester unit, and a (meth) acrylic acid glycidyl ester unit and / or a carbon monoxide unit, and containing 55% by weight or more of an ethylene unit. It is done. These compatibilizers may be used alone, for example, a copolymer comprising an ethylene unit, a (meth) acrylic acid ester unit and a (meth) acrylic acid glycidyl ester unit, an ethylene unit, and (meth) acrylic acid. Two or more types of copolymers may be used in combination, such as in combination with a copolymer comprising an ester unit and a carbon monoxide unit. The amount of the polyethylene unit in the copolymer is more preferably 57 to 85% by weight. The amount of the (meth) acrylic acid ester unit is 5 to 44% by weight, preferably 10 to 35% by weight, and the amount of the (meth) acrylic acid glycidyl ester unit and the carbon monoxide unit is 1 to 30% by weight. , Preferably 2 to 20% by weight.

  Examples of the (meth) acrylic acid ester constituting the copolymer include methyl acrylate, ethyl acrylate, nbutyl acrylate, isobutyl acrylate, methyl methacrylate, isobutyl methacrylate, and nbutyl methacrylate. Examples of the copolymer include Elvalloy HP771 and PT (Mitsui / DuPont Polychemical), which can be easily obtained from the market. The compatibilizer is preferably used in an amount of 0.2 to 2 times that of the wax.

  The toner for developing an electrostatic charge image according to the present invention may further contain known additives used in the production of the toner, such as a lubricant, a fluidizing agent, an abrasive, a conductivity imparting agent, and an image peeling preventing agent, if necessary. Can be added internally or externally. Examples of these additives include polyvinylidene fluoride and zinc stearate as a lubricant, and silica, aluminum oxide, titanium oxide, silicon aluminum co-oxide produced by a dry method or a wet method as a fluidity improver. , Silicon-titanium co-oxide and those hydrophobized, etc., and abrasives include silicon nitride, cerium oxide, silicon carbide, strontium titanate, tungsten carbide, calcium carbonate and those hydrophobized. Examples of the conductivity imparting agent include carbon black and tin oxide. In addition, fine powders of fluorine-containing polymers such as polyvinylidene fluoride are preferable from the viewpoints of fluidity, abrasiveness, charge stability, and the like.

  In the present invention, it is preferable to contain hydrophobized silica, silicon aluminum co-oxide, and silicon titanium co-oxide fine powder as external additives. Examples of the hydrophobic treatment of these fine powders include treatment with a silane coupling agent such as silicon oil, tetramethyldisilazane, dimethyldichlorosilane, and dimethyldimethoxysilane. The amount of the hydrophobized fine powder such as silica subjected to hydrophobization treatment is 0.01 to 20%, preferably 0.03 to 5%, based on the developer weight.

 The particle diameter of the toner for developing an electrostatic charge image of the present invention is preferably that having a weight average particle diameter of 3 to 15 μm. In particular, a toner having a particle size of 5 μm or less is contained in 12 to 60% by number, a toner having a particle size of 8 to 12.7 μm is contained in 1 to 33% by number, and a toner having a particle size of 16 μm or more is 2. From the viewpoint of development characteristics, it is more preferable that the content is 0% by weight or less and the weight average particle diameter of the toner is 4 to 11 μm. The toner particle size distribution can be measured using, for example, a Coulter counter.

 The electrostatic image developing toner of the present invention can be produced by a conventionally known method. In general, the above-described toner constituent materials are sufficiently mixed by a mixer such as a ball mill or a Henschel mixer, and then kneaded thoroughly using a thermal kneader such as a hot roll kneader, a uniaxial or biaxial extruder. After cooling and solidification, it is preferably produced by a method of coarsely pulverizing mechanically using a pulverizer such as a hammer mill and then finely pulverizing with a jet mill or the like, followed by classification. The classified toner is sufficiently mixed with an external additive if necessary using a mixer such as a Henschel mixer, and is used as the electrostatic image developing toner of the present invention.

 The electrostatic image developing toner of the present invention can be mixed with a carrier and used as a two-component developer, or can be used as a one-component developer or a microtoning developer containing magnetic powder in the toner. . When the toner of the present invention is used as a two-component developer, any conventionally known carrier can be used as the carrier. Examples of the carrier that can be used include magnetic powders such as iron powder, ferrite powder, and nickel powder, glass beads, and the like, or those whose surfaces are treated with a resin or the like. Examples of the resin covering the carrier surface include styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, acrylic acid ester copolymer, methacrylic acid ester copolymer, fluorine-containing resin, silicone-containing resin, and polyamide. Examples thereof include a resin, an ionomer resin, a polyphenylene sulfide resin, and a mixture thereof. Among these, fluorine-containing resins and silicone-containing resins are particularly preferable because they hardly form spent toner.

 Hereinafter, the present invention will be described more specifically with reference to examples. However, the following examples are merely for illustrating the present invention, and the present invention is not limited to those described in these examples.

The acid value, hydroxyl value, glass transition temperature (Tg), softening point, and true density of the resins in the following examples and comparative examples are as follows.
(Acid value and hydroxyl value)
The acid value refers to the number of milligrams of potassium hydroxide necessary to neutralize the acid groups contained in 1 g of a sample. The hydroxyl value refers to the number of milligrams of potassium hydroxide necessary to neutralize acetic acid bonded to a hydroxyl group when 1 g of a sample is acetylated.
(Glass-transition temperature)
The glass transition temperature is measured by using a differential scanning calorimeter (DSC-50, manufactured by Shimadzu Corporation) with an extension of the baseline below Tg when measured at a heating rate of 20 ° C./min, and an endothermic curve near Tg. The temperature at the intersection of tangents.
(Softening point)
The softening point was measured using an elevated flow tester (CFT-500D, manufactured by Shimadzu Corporation) with a load of 30 kg, a nozzle diameter of 1 mm, a nozzle length of 10 mm, a preheating temperature of 80 ° C. for 5 minutes, and a heating rate of 3 The temperature at the time of h / 2 when the height of the S-shaped curve in the plunger descent amount-temperature curve of the flow tester is h, when measured as ° C / min and the sample amount is 1 g.
(True density)
The true density refers to a value measured by a vapor phase substitution method using a dry automatic densimeter (Shimadzu-Micromeritics Accupic 1330 (10 cm ³ )). The measurement conditions are as follows.
Measurement gas: Helium Introduced pressure: Purge and run 19.5 psig (134.35 Kpag)
Equilibrium judgment pressure: 0.0050 psig / min (0.0345 Kpag / min)
Temperature and humidity: 23 ° C / 50% RH

Manufacture of polyester resin (A)
[Resin Production Example A-1]
Polyester resin raw material alcohol component 88.7 mol% neopentyl glycol, 12.1 mol% neodecanoic acid glycidyl ester, 18.2 mol% disproportionated rosin as raw acid component, stirring device, heating device, thermometer, minute A stainless steel reaction vessel equipped with a distillation apparatus and a nitrogen gas introduction tube was charged and heated to 160 ° C. with stirring to melt the contents. After melting, 81.8 mol% of terephthalic acid and 0.03 mol% of di-n-butyltin oxide are charged as raw acid components so that the temperature at the top of the fractionator does not exceed 100 ° C. While removing condensed water out of the system with a nitrogen gas stream, the temperature was gradually raised to 240 ° C. to carry out the esterification reaction, and when the hydroxyl value became around 40 mgKOH / g, the reaction product was extracted from the flask, cooled, By pulverizing, a polyester resin A-1 was obtained. The characteristic values are shown in Table 1. In addition, the composition amount mol% of each monomer is mol% with respect to all the acid components.

[Resin Production Examples A-2 to A-3, A-5 to A-11]
Polyester resins A-2 to A-3, A-5 according to Production Example A-1, except that the types and amounts (molar ratio) of the carboxylic acid compound and alcohol compound used in the raw material are those shown in Table 1. A-11 was produced. The physical property values of the obtained polyester resin are shown in Table 1.

[Resin Production Example A-4]
A polyester resin raw material alcohol component of neopentyl glycol 79.6 mol%, neodecanoic acid glycidyl ester 12.2 mol%, trimethylolpropane 6.8 mol%, disproportionated rosin 18.2 mol% as a raw acid component A stainless steel reaction vessel equipped with a device, a heating device, a thermometer, a fractionation device, and a nitrogen gas introduction tube was charged and heated to 160 ° C. with stirring to melt the contents. After melting, 81.8 mol% of terephthalic acid and 0.03 mol% of di-n-butyltin oxide are charged as raw acid components so that the temperature at the top of the fractionator does not exceed 100 ° C. While removing condensed water out of the system with a nitrogen gas stream, the temperature was gradually raised to 240 ° C. to carry out the esterification reaction, and when the hydroxyl value became around 40 mgKOH / g, the reaction product was extracted from the flask, cooled, By pulverizing, polyester resin A-4 was obtained. The characteristic values are shown in Table 1. In addition, the composition amount mol% of each monomer is mol% with respect to all the acid components.

Manufacture of urethane-modified polyester resin (C)
[Resin Production Example C-1]
Polyester resin A-1 is supplied to a twin-screw kneader (KEX-40, manufactured by Kurimoto Iron Works, Ltd.) at a flow rate of 10 kg / hr, melt-kneaded and conveyed, and tolylene diisocyanate is supplied at a flow rate of 500 g / hr (NCO / OH equivalent ratio is equivalent to 0.80. NCO / OH equivalent ratio) = (NCO group equivalent / hr of feed tolylene diisocyanate) / (OH group equivalent / hr of feed resin) ((500/176) x2 / ((40x10) /56.11) = 0.80) Further, kneading was continued to carry out the reaction, followed by extrusion and cooling to obtain urethane-modified polyester resin C-1. Table 2 shows the physical property values of this urethane-modified polyester resin C-1.

[Resin Production Examples C-2 to 11]
According to Resin Production Example C-1, urethane-modified polyester resins C-2 to C-11, except that the types and mixing ratios of the polyester resin (A) and the polyvalent isocyanate compound (B) and the production conditions are as shown in Table 2. Got. Table 2 shows physical property values of the urethane-modified polyester resins C-2 to C-11.

(Component) (Blending amount)
Polyester resin C-1 100 parts Magnetic substance (magnetite) 84 parts Charge control agent (chromium salt compound of aromatic hydroxycarboxylic acid) 2 parts Low molecular weight polypropylene 3 parts After the above materials are uniformly mixed, kneaded, pulverized and classified Thus, negatively charged toner particles having an average particle size of 10.4 μm were obtained. Next, 0.3 parts of silica fine powder treated with dimethyldichlorosilane, 0.5 parts of calcium carbonate fine powder treated with aminosilane, and 0.5 parts of silicon nitride fine particles were added to and mixed with 100 parts of the toner particles. A negatively chargeable magnetic toner was obtained.

The charge amount of the negatively chargeable magnetic toner was measured to evaluate the chargeability, and the storage stability was also evaluated. The results are shown in Table 3.
Further, using this negatively chargeable magnetic toner, a live-action test was conducted using a commercially available copying machine (GP216F manufactured by Canon Inc.) having a hot-pressure roll structure as a fixing device, and image density (initial and 10,000). Image density after sheet), fog (initial and 10,000 sheets fog value), consumption, fixing property, and offset resistance were evaluated. The results are shown in Table 3.

  Measurement and evaluation of charge amount, storage stability test and evaluation, image density measurement, fog density measurement, toner consumption measurement, fixing property test and evaluation, offset resistance test and evaluation are as follows: It was done like that.

(Measurement and evaluation of charge amount)
Cu—Zn ferrite carrier particles having an average particle size of 80 to 120 μm and a toner sample are weighed at a ratio of the toner concentration of 5% by weight with respect to the whole and mixed with a ball mill or the like, and then the toner is measured with a blow-off charge measuring device. The charge amount of was calculated. Specifically, the measurement was performed by the following method.
After weighing 19.0 g of Cu-Zn ferrite carrier core (trade name F-100) manufactured by Powder Tech Co., Ltd. and 1.0 g of the dried toner sample into a 50 cc plastic bottle and shaking 5 times, a ball mill (Shinei Koki Sangyo) (PLASTIC PLANT SKS type) was used, and mixing was performed for 30 minutes under the condition of the actual rotation value of 230 rotations (the poly bottle main body was 120 rotations).
The obtained sample after mixing was subjected to charge amount measurement using a blow-off charge amount measuring device manufactured by Toshiba Chemical Corporation. At this time, the blow pressure was 1 kgf / cm ² , the maximum value was read at a measurement time of 20 seconds, and the mesh was 400 mesh. The measurement environment was 23 ° C. and 50% RH.

(Storage stability test and evaluation)
40 g of toner is sealed in a 200 ml glass container, left in a constant temperature bath at 50 ° C. for 24 hours, and then observed by checking the toner blocking property. △ was assigned to those to be treated, and × was designated to be aggregates that were not easily loosened.

(Measurement of image density)
The image density was measured using a Macbeth photometer. The concentration may be 1.35 or more.

(Measurement of fog density)
This was done by measuring the reflectance with a photovolt. 1.5% or less is a good value.

(Measurement of toner consumption)
This is expressed as the number of tonergrams consumed per 1,000 sheets in an actual copy of a document with a blackening rate of 6%.

(Fixability test and evaluation)
The fixed image was rubbed with an eraser (dragonfly pencil MONO), and the value calculated by [image density after rubbing / image density before rubbing] × 100 was expressed as the fixing strength. 85% or more is a good value.

(Offset resistance test and evaluation)
After continuous copying of 200 images for fixing test, the sheet was stopped for 5 minutes, and then 20 blank sheets were passed through, and the evaluation was made based on the condition of the white paper. In the evaluation results, “O” indicates that no paper stain occurred, and “X” indicates that the paper stain occurred.

(Examples 2-7, Comparative Examples 1-4)
A negatively chargeable magnetic toner was obtained and evaluated in the same manner as in Example 1 except that the urethane-modified polyester resin shown in Table 3 was used. The results are shown in Table 3.

(Example 8)
(Component) (Blending amount)
Polyester resin C-1 100 parts Magnetic material (magnetite) 82 parts Charge control agent (Nigrosine base) 3 parts Low molecular weight polyethylene 3 parts After the above materials are uniformly mixed, they are kneaded, pulverized and classified to obtain an average particle size of 10. 5 μm positively charged toner particles were obtained. Next, 0.3 part of silica fine powder treated with aminosilane was added to 100 parts of the toner particles and mixed to obtain a positively chargeable magnetic toner. The charge amount measured under the same conditions as above was +12.5 μc / g.

  Further, using this positively chargeable magnetic toner, a live-action test was conducted using a commercially available copying machine (NP3050 manufactured by Canon Inc.) having a structure of a hot pressure roll as a fixing device, and image density (initial and 10,000). When evaluation of image density after sheet), fog (fogging value after initial and 10,000 sheets), fixing property, and offset resistance was evaluated, good results were obtained. The initial image density was 1.36 after 1.10000 sheets, 1.35 after fogging, the initial fog was 0.7 after 10000 sheets, and the fixing ratio was 90%, and no occurrence of offset was observed.

The toner for developing an electrostatic charge image of the present invention can be preferably used in an electrophotographic dry developer, a copying machine using a toner, a printer, and the like, and does not use a bisphenol A derivative whose binder resin in the toner is an environmental hormone. Therefore, it is preferably used as an environmental countermeasure toner.

Claims (7)

  At least the acid component is composed of disproportionated rosin and terephthalic acid and / or isophthalic acid, the alcohol component is composed of a glycidyl ester of a tertiary fatty acid and an aliphatic diol having 2 to 10 carbon atoms, and has a hydroxyl value of 20 to 70 mgKOH / g. For developing an electrostatic charge image, which contains, as a binder resin, a urethane-modified polyester resin (C) obtained by mixing and reacting a polyester resin (A) and a polyvalent isocyanate compound (B) toner.   At least the acid component is composed of disproportionated rosin and terephthalic acid and / or isophthalic acid, the alcohol component is composed of a glycidyl ester of a tertiary fatty acid and an aliphatic diol having 2 to 10 carbon atoms, and has a hydroxyl value of 20 to 70 mgKOH / g. The polyester resin (A) is a polyester resin (A), and the polyisocyanate compound (B) is added, mixed by melt kneading and reacted to contain a urethane-modified polyester resin (C) obtained as a binder resin. A toner for developing an electrostatic charge image.   3. The electrostatic charge image developing toner according to claim 1, wherein the true density of the urethane-modified polyester resin (C) is 1.1 to 1.3 g / cm <3>.   In the production of the urethane-modified polyester resin (C), the polyvalent isocyanate compound (B) is used in an amount of 0.2 to 1.2 equivalents as an isocyanate group per equivalent of hydroxyl group of the polyester resin (A). The toner for developing an electrostatic charge image according to claim 1.   The electrostatic charge image developing toner according to any one of claims 1 to 4, wherein the urethane-modified polyester resin (C) has an acid value of 10 mgKOH / g or less and a hydroxyl value of 15 mgKOH / g or less.   The electrostatic charge image according to any one of claims 1 to 5, wherein a reaction temperature when the polyester resin (A) and the polyvalent isocyanate compound (B) are mixed and reacted is 160 to 200 ° C. Development toner.   At least the acid component is composed of disproportionated rosin and terephthalic acid and / or isophthalic acid, the alcohol component is composed of a glycidyl ester of a tertiary fatty acid and an aliphatic diol having 2 to 10 carbon atoms, and has a hydroxyl value of 20 to 70 mgKOH / g. A urethane-modified polyester resin (C) for toner obtained by mixing and reacting a polyester resin (A) and a polyvalent isocyanate compound (B).