JP2006171364A - Binder resin for toner, and electrophotographic toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a binder resin for toner having excellent fixability, offset resistance, storage property, pulverizability, and durable developability even in using a high-speed copying machine and an electrophotographic toner. <P>SOLUTION: The binder resin for toner contains a styrene acrylic resin containing a structure of a carboxyl group origin and a structure of a glycidyl group origin and contains a gel content at 1 to 50% (A) and a crystalline polyester resin (B), in which the weight ratio (A)/(B) of (A) and (B) is 50/50 to 99/1. The toner using the same is excellent in performance, such as fixability, even when used in the high-speed copying machine and an electrophotograph having good reproducibility can be provided even in the copying machine continuously used for a long time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a binder resin for an electrophotographic toner for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like, and a toner using the binder resin.

  In general, as an electrophotographic method in a PPC (Plain Paper Copy) copying machine or printer that transfers a toner image formed on a photoreceptor onto a recording paper, an electrostatic latent image is formed on the photoreceptor, A method of developing a latent image with toner, transferring the toner image onto a fixing sheet such as paper, and then fixing by heating with a heat roll is performed. Since this method performs fixing under heat and pressure, it is quick and has very good thermal efficiency. Therefore, the fixing efficiency is very good. However, in this heat roll method, the heat efficiency is good, but since the surface of the heat roll and the toner are in contact with each other in a molten state, the toner adheres to the surface of the heat roll and retransfers to the next fixing sheet and becomes dirty. There is a problem of (offset phenomenon).

As an example of the offset prevention method, there is a method in which silicon oil is applied to the surface of a heat roll with cloth or paper. However, the installation of the liquid supply device for preventing offset becomes complicated and the equipment becomes complicated. Therefore, the repair and management become complicated, resulting in an increase in cost. There is also a new problem that silicon oil or the like evaporates due to heat and contaminates the inside of the machine. For this reason, development of a toner for a high-speed machine that does not require application of the above-described silicone oil, that is, an oil-less fixing method is desired. In addition, in response to the recent demands for higher copying and printer speeds and lower energy fixing, there is a demand for toner that can be fixed at as low a temperature as possible. Many toners using crystalline polyester have been proposed as methods for improving the fixing property. For example, Patent 2035992 (Patent Document 1) reports a block copolymer or graft copolymer obtained by chemically bonding a crystalline polyester and an ionically crosslinked amorphous styrene acrylic resin. However, ionic crosslinks have a lower bonding force than covalent bonds, and the thermal kneading process at the time of toner production tends to cause crosslinkage breakage and lower viscoelasticity. is there. JP-A-2002-287426 (Patent Document 2) and JP-A-2003-57874 (Patent Document 3) report toners that contain amorphous polyester in crystalline polyester. However, there is a problem in that good offset resistance is not exhibited due to the absence of a crosslinked product and low viscoelasticity. In addition, since the polyester resin has an aromatic main skeleton, the strength of the resin is high, and high energy is required in the pulverization process at the time of toner formation, which requires a long pulverization time, resulting in poor productivity.
Japanese Patent No. 2035992 JP 2002-287426 A JP 2003-57874 A

  Therefore, as described above, in order to satisfy the demand for higher speed and energy saving in the copying machine market, the toner binder has an excellent balance of fixing property and anti-offset property and excellent pulverization property. It is an object of the present invention to provide resins and toners.

  As a result of intensive investigations to solve these problems, the present inventors have found that a toner using a binder resin for toner in which a crosslinked resin having a specific amount of gel and a crystalline polyester are mixed has the above problems. I found out to solve it.

That is, the present invention includes (i) a styrene acrylic resin (A) containing a structure derived from a carboxyl group and a structure derived from a glycidyl group and having a gel content of 1 to 50%, and a crystalline polyester resin (B ), And a weight ratio (A) / (B) of (A) and (B) is 50/50 to 99/1,
(Ii) A toner comprising the above binder resin.

  According to the present invention, a toner binder having an excellent balance between low-temperature fixability and offset resistance can be obtained. Further, the toner produced using the toner binder of the present invention is excellent in storage stability, pulverization property, and durable developability, and has practically excellent performance.

  The binder resin for toner of the present invention contains a styrene-acrylic resin (A) containing 1 to 50% of the gel content and containing a structure derived from a carboxyl group and a structure derived from a glycidyl group, and a crystalline polyester resin (B ), And the weight ratio (A) / (B) of (A) to (B) is 50/50 to 99/1. At this time, the styrene acrylic resin (A) is preferably obtained from a crosslinking agent (D) and a styrene acrylic resin (C) having a functional group selected from a carboxyl group and an acid anhydride group.

  In the present invention, the polymerization may include the meaning of copolymerization, and the polymer may include the meaning of copolymer. The styrene acrylic resin in the present invention is a copolymer of styrenes and (meth) acrylic acids and / or (meth) acrylic esters.

  In the present invention, the crosslinking agent (D) is not limited as long as it has a reactive group that reacts with the styrene acrylic resin (C) described later, but the reactive group is preferably an epoxy group. More preferably, it is a glycidyl group containing vinyl resin (D1) as a crosslinking agent (D), and it is preferable that the epoxy value is 0.005-0.1 equivalent / 100g. It is preferable that the epoxy value is in the above-mentioned range in that an appropriate amount of gel is generated and a toner having excellent offset resistance and durable developability can be obtained.

  In the present invention, the glycidyl group-containing vinyl resin (D1) is usually obtained by polymerizing a monomer having a polymerizable double bond and a monomer having a glycidyl group and a polymerizable double bond.

  Specific examples of the monomer having a polymerizable double bond include styrenes such as styrene, p-methylstyrene, α-methylstyrene, and vinyl toluene; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, Acrylic esters such as octyl acrylate, cyclohexyl acrylate, stearyl acrylate, benzyl acrylate, furfuryl acrylate, hydroxyethyl acrylate, hydroxybutyl acrylate, dimethylaminomethyl acrylate, dimethylaminoethyl acrylate; methacrylic Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, octyl methacrylate, cyclohexyl methacrylate, stearyl methacrylate, benzyl methacrylate, full-free methacrylate , Methacrylates such as hydroxyethyl methacrylate, hydroxybutyl methacrylate, dimethylaminomethyl methacrylate, dimethylaminoethyl methacrylate; dimethyl fumarate, dibutyl fumarate, dioctyl fumarate, dimethyl maleate, Examples include diesters of unsaturated dibasic acids such as dibutyl maleate and dioctyl maleate; amides such as acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N-substituted acrylamide, and N-substituted methacrylamide. Among these, particularly preferable vinyl monomers include styrenes, acrylic esters, methacrylic esters, dialkyl esters of fumaric acid, acrylonitrile, acrylamide, methacrylamide, and the like. These compounds may be used alone or in combination of two or more.

  On the other hand, specific examples of the monomer having a glycidyl group and a polymerizable double bond include glycidyl acrylate, β-methyl glycidyl acrylate, glycidyl methacrylate, and β-methyl glycidyl methacrylate. Glycidyl acid, β-methyl glycidyl methacrylate.

  The method for polymerizing these compounds is not particularly limited, and suspension polymerization, emulsion polymerization, bulk polymerization, solution polymerization and the like can be used. In particular, bulk polymerization and solution polymerization are preferable because they can be produced without using a dispersant or a dispersion aid.

  Solvent polymerization solvents are used alone or in combination from aromatic hydrocarbons such as benzene, toluene, ethylbenzene, orthoxylene, metaxylene, paraxylene, cumene, etc., but other solvents are selected to adjust the molecular weight. It is also possible.

  The polymerization may be performed using a polymerization initiator, or so-called thermal polymerization may be performed without using a polymerization initiator. As the polymerization initiator, generally, any one that can be used as a radical polymerization initiator can be used. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2, Azo initiators such as 4-dimethylvaleronitrile), dimethyl-2,2′-azobisisobutyrate, 1,1′-azobis (1-cyclohexanecarbonitrile); methyl ethyl ketone peroxide, acetylacetone peroxide, cyclohexanone peroxide Ketone peroxides such as oxides; hydroperoxides such as peroxyketals such as 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane; di-t-butyl peroxide; such as t-butyl cumyl peroxide, di-cumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane Alkyl peroxides; diacyl peroxides such as isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide; di-isopropyl peroxydicarbonate, di-2-ethylhexylperoxydicarbonate, di- Peroxydicarbonates such as n-propylperoxydicarbonate and di-2-ethoxyethylperoxycarbonate; sulfonyl peroxides such as acetylcyclohexylsulfonyl peroxide; t-butylperoxyacetate, t-butylperoxyiso Examples thereof include peroxyesters such as butyrate, t-butylperoxyneodecanoate, cumylperoxyneodecanoate, and t-butylperoxy-2-ethylhexanoate. They can be used alone or in combination of two or more. The type and amount of the polymerization initiator used in the present invention can be appropriately selected depending on the reaction temperature, monomer concentration, etc., and usually 0.01 to 10 parts by weight per 100 parts by weight of the monomer.

  The cross-linking agent (D) of the present invention is particularly preferably a cross-linking agent having a styrene acrylic resin structure from the viewpoints of reaction control, freedom of physical property design, cost and the like.

  In the present invention, the crystalline polyester (B) is a polyester resin in which the heat of fusion of crystals is observed by differential scanning calorimetry (DSC). The melting peak temperature of the crystalline polyester resin (B) of the present invention is preferably 50 to 170 ° C, more preferably 80 to 110 ° C. It is preferable that the melting peak temperature is in the above-described range from the viewpoint of improving the storage stability and fixability of the toner. In the present invention, the melting peak is measured by using a differential scanning calorimeter (DSC-Q1000 manufactured by TA Instrument), heated to 200 ° C., and cooled to 0 ° C. for 5 minutes from that temperature. It measured by measuring with. The melting point peak temperature is calculated according to JIS K7121 “Plastic transition temperature measurement method”.

  The crystalline polyester (B) of the present invention is preferably a resin obtained by polycondensation of an aliphatic diol and an aliphatic dicarboxylic acid. The aliphatic diol preferably has 2 to 6 carbon atoms, more preferably 4 to 6 carbon atoms. The aliphatic dicarboxylic acid preferably has 2 to 22 carbon atoms, more preferably 6 to 20 carbon atoms.

  Examples of the aliphatic diol having 2 to 6 carbon atoms include 1,4-butanediol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4 -Butenediol, 1,5-pentanediol and the like are preferable.

  As aliphatic dicarboxylic acids having 2 to 22 carbon atoms, unsaturated aliphatic dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, oxalic acid, malonic acid, succinic acid, adipic acid, decanediolic acid Saturated aliphatic dicarboxylic acids such as undecanediolic acid, dodecanedioic acid, hexadecanedioic acid, octadecanedioic acid, and eicosandioic acid, their acid anhydrides, alkyl (1 to 3 carbon atoms) esters, and the like.

  The crystalline polyester (B) can be obtained, for example, by reacting an alcohol component and a carboxylic acid component in an inert gas atmosphere, preferably at a temperature of 120 to 230 ° C. In this reaction, a known esterification catalyst or polymerization inhibitor may be used as necessary. Further, the reaction may be accelerated by reducing the pressure of the reaction system in the latter half of the polymerization reaction. As for the molar ratio at the time of making an alcohol component and a carboxylic acid component react, it is preferable that alcohol component / carboxylic acid component is 50 / 50-60 / 40, and it is still more preferable that it is 50 / 50-55 / 45. By using more alcohol component than carboxylic acid component, the terminal of crystalline polyester becomes easy to become a hydroxyl group.

  The styrene acrylic resin (C) in the present invention comprises a styrene acrylic resin (H) and a styrene acrylic resin (L) described later.

  The styrene acrylic resin (C) in the present invention preferably has a compound having a polymerizable double bond and, if necessary, a functional group selected from a carboxyl group and an acid anhydride group, and a polymerizable double bond. It is obtained by polymerizing with the monomer it has. The polymerization method and polymerization conditions are the same as in the above-described method for producing the crosslinking agent (D).

  Specific examples of the monomer having a functional group selected from the carboxyl group and acid anhydride group and a polymerizable double bond include the following compounds.

  Examples of the monomer having a carboxyl group or an acid anhydride group include acrylic acid, methacrylic acid, maleic acid, fumaric acid, cinnamic acid, monomethyl fumarate, monoethyl fumarate, monopropyl fumarate, monobutyl fumarate and fumaric acid. Monoesters of unsaturated dibasic acids such as monooctyl, monomethyl maleate, monoethyl maleate, monopropyl maleate, monobutyl maleate, monooctyl maleate and the like are preferable, preferably acrylic acid, methacrylic acid, fumaric acid, Examples thereof include monomethyl fumarate, monoethyl fumarate, monopropyl fumarate, monobutyl fumarate, monooctyl fumarate, maleic anhydride, itaconic anhydride and the like.

  The styrene acrylic resin (H) in the present invention has a weight average molecular weight of more than 50,000 and not more than 1,000,000, preferably 100,000 to 700,000, more preferably 300,000 to 600,000. And content of the functional group chosen from a carboxyl group and an acid anhydride group is 0.1-2.0 mol per kg of resin, Preferably it is 0.1-1.0 mol. That is, the styrene acrylic resin (H) is a component that mainly reacts with the crosslinking agent (D) to increase its molecular weight or gel. When the weight average molecular weight is in the above range, the reaction with the cross-linking agent (D) occurs moderately, and the high molecular weight and gelation after the reaction occur sufficiently, so that sufficient mechanical strength is obtained and durability is ensured. It is preferable because the property is improved. Furthermore, since an appropriate viscosity is obtained, it is preferable from the viewpoint that sufficient offset resistance can be obtained. When the functional group content is in the above range, the amount of components to be cross-linked is moderate, so that moderate viscosity, high molecular weight, and gelation occur, and offset resistance, fixability and grindability are good. This is preferable.

  The styrene acrylic resin (L) in the present invention has a weight average molecular weight of 4,000 to 50,000, preferably 5,000 to 30,000, more preferably 8,000 to 20,000, and a functional group selected from a carboxyl group and an acid anhydride group. The group content is less than 0.7 mol per kg of resin, preferably less than 0.5 mol, more preferably less than 0.3 mol. That is, the styrene acrylic resin (L) is a component that hardly reacts with the crosslinking agent (D). When the weight average molecular weight is less than 4000, the mechanical strength is weak, the durability is deteriorated, and the offset is sometimes deteriorated because the viscosity is low. On the other hand, when the weight average molecular weight is larger than 50000, the styrene acrylic resin (H) substantially increases, and the fixability and grindability deteriorate. When the functional group content is 0.7 mol or more per kg of the resin, the reaction amount per molecule becomes large, and the fixing property may be deteriorated due to a decrease in low molecular weight components.

  In the present invention, the weight ratio (A) / (B) of the styrene acrylic resin (A) and the crystalline polyester (B) in the binder resin for toner is preferably 50/50 to 99/1, and preferably 70/30 to 99/1 is more preferable, and 80/20 to 95/5 is particularly preferable. The crystalline polyester (B) is in the above-mentioned range because the gel content is appropriate and a toner having good fixability at low temperature, grindability, storage stability, and offset resistance can be obtained. preferable.

  In the present invention, the weight ratio (H) / (L) of the vinyl polymer (H) to the vinyl polymer (L) is 5/95 to 50/50, preferably 20/80 to 40/60. is there. It is preferable that the weight ratio is in the above-described range in that the fixing property and the offset resistance are improved due to an appropriate viscosity.

  In the styrene acrylic resin (C) and the crosslinking agent (D) in the present invention, the weight ratio of (C) / (D) is preferably 99/1 to 75/25. The weight ratio (C) / (D) is in the above-mentioned range because (C) and (D) react appropriately to form a gel, thereby improving the offset resistance and the fixing property. preferable.

  The number average molecular weight and weight average molecular weight in the present invention are determined by the GPC method, and are converted molecular weights in which a calibration curve is prepared with monodisperse standard polystyrene. The measurement conditions are as follows.

GPC equipment; SHODEX GPC SYSTEM-21 (High Performance Liquid Chromatograph made by Showa Denko KK)
Detector: SHODEX RI SE-31 (Refractive index measuring device manufactured by Showa Denko KK)
Column ； SHODEX GPCA-80M * 2 + KF-802 * 1 (Showa Denko)
Solvent; Tetrahydrofuran (THF)
Flow rate: 1.2 ml / min.
Sample concentration: 0.002 g-resin / ml-THF
(Filter with a membrane filter immediately before measurement to remove insoluble parts, etc.)
Sample volume: 100 μl

  As a method for producing the binder resin for toner of the present invention, a styrene acrylic resin (A) obtained by reaction of a crosslinking agent (D) and a styrene acrylic resin (C) and a crystalline polyester (B) are used. The method of mixing is mentioned. As a method of reacting the crosslinking agent (D) and the styrene acrylic resin (C), is a method of reacting by melting and kneading the crosslinking agent (D) and the styrene acrylic resin (C). Any conventionally known method can be adopted as the heating and melting method, but a method using a twin-screw kneader is particularly preferable. Specifically, the following method can be exemplified. That is, the styrene acrylic resin (C) and the crosslinking agent (D) are mixed with a Henschel mixer or the like, and then melt-kneaded and reacted using a biaxial kneader. The temperature at the time of melt kneading and reaction varies depending on the type of the crosslinking agent (D) and the styrene acrylic resin, but is in the range of 100 ° C to 240 ° C, preferably 150 ° C to 220 ° C. In addition to the biaxial kneader described above, a reaction vessel equipped with a stirrer can be used.

  The styrene acrylic resin (A) obtained by the above method has a gel component. The content of the gel component is 1% to 50%, preferably 3% to 35%, more preferably 5% to 30%. It is preferable that the content of the gel component is in the above-mentioned range since the fixing property at a low temperature required for high-speed copying with good fluidity and good offset resistance can be obtained.

In the present invention, the gel component content is defined as a value measured as follows. Resin 2.5 g and ethyl acetate 47.5 were put into a 100 ml sample tube, and the sample tube was stirred for 12 hours at a rotation speed of 50 rpm and 22 ° C., and then allowed to stand at 22 ° C. for 12 hours. Thereafter, the weight after drying 5 g of the supernatant of the sample tube at 150 ° C. for 1 hour is weighed (Xg) and calculated according to the following formula.
Gel component (%) = ((2.5 / 50−X / 5) / (2.5 / 50)) × 100

  As a method for mixing the crystalline polyester (B) and the styrene acrylic resin (A), any conventionally known method can be adopted. Specifically, the following method can be exemplified. That is, mixing at the time of manufacturing the vinyl polymer (H), mixing at the time of manufacturing the vinyl polymer (L), or mixing at the time of manufacturing the crosslinking agent (D), or mixing the crosslinking agent (D) and the styrene acrylic resin (C). Mixing at the time of melt kneading or mixing using a cross-linked resin (C) and a blender machine. In addition, any combination of the above mixing methods has the same effect.

  The binder resin for toner of the present invention may contain components other than the styrene acrylic resin (A) and the crystalline polyester (B) as long as the effect is not impaired. An example of a component that may be contained is wax. As the wax, polypropylene wax and polyethylene wax are preferable. The use of a polypropylene wax having a melting point of 130 ° C. to 150 ° C. is preferable in terms of improving offset resistance due to a releasing agent effect. In addition, it is preferable to use a low melting point polyethylene wax from the viewpoint of improving the fixability by reducing the viscosity. Here, the polyethylene wax and the polypropylene wax may be used alone or in combination. The content of the wax in the toner binder resin is preferably 0.5% by weight to 10% by weight, more preferably 0.5% by weight to 7% by weight, and particularly preferably 1% by weight to 5% by weight. %. It is preferable that the content of the wax is in the above-mentioned range in that sufficient storage stability can be obtained. Specific product names of those corresponding to polyolefin wax include Mitsui Chemicals high wax 800P, 400P, 200P, 100P, 720P, 420P, 320P, 405MP, 320MP, 4051E, 2203A, 1140H, NL800, NP055, NP105, NP505, NP805, etc. However, the present invention is not limited to this.

  Further, within the range not inhibiting the effect of the present invention, for example, polyvinyl chloride, polyvinyl acetate, polyolefin, polyester, polyvinyl butyral, polyurethane, polyamide, rosin, modified rosin, terpene resin, phenol resin, aliphatic hydrocarbon A part of resin, aromatic petroleum resin, paraffin wax, polyolefin wax, fatty acid amide wax, vinyl chloride resin, styrene-butadiene resin, chroman-indene resin, melamine resin and the like may be used. The amount is usually 0.1 to 40 parts by weight with respect to 100 parts by weight of the binder resin for toner. In addition, known charge control agents such as nigrosine, quaternary ammonium salts and metal-containing azo dyes can be appropriately selected and used. The amount used is usually 0.1 to 10 parts by weight per 100 parts by weight of the binder resin for toner.

  The resin thus obtained can be cooled and pulverized to obtain a binder resin for toner. Any conventionally known method can be adopted as the cooling and pulverizing method. However, as a cooling method, a steel belt cooler or the like can be used for rapid cooling.

  The binder resin for toner in the present invention can be made into a toner by a known method in combination with a colorant, if necessary, a charge control agent, a release agent, and a pigment dispersant. Examples of the colorant include black pigments such as carbon black, acetylene black, lamp black, magnetite, yellow lead, yellow iron oxide, Hansa Yellow G, quinoline yellow lake, permanent yellow NCG, molybdenum orange, Vulcan orange, indanthrene, Known as Brilliant Orange GK, Bengala, Brilliant Carmine 6B, Fritherin Lake, Methyl Violet Lake, Fast Violet B, Cobalt Blue, Alkaline Blue Lake, Phthalocyanine Blue, Fast Sky Blue, Pigment Green B, Malachite Green Lake, Titanium Oxide, Zinc Hana, etc. And organic pigments. The amount is usually 5 to 250 parts by weight based on 100 parts by weight of the toner binder resin.

  In the present invention, any conventionally known method can be adopted as a method for producing the toner. For example, a toner binder resin, a colorant, a charge adjusting agent, a wax and the like are premixed in advance, kneaded in a heated and melted state using a twin-screw kneader, cooled and finely pulverized using a fine pulverizer, and then air. The particles are classified by a type classifier, and particles in the range of 8 to 20 μ are usually collected to obtain a toner. The heating and melting conditions in the above-described biaxial kneader are preferably such that the resin temperature at the discharge part of the biaxial kneader is less than 165 ° C. and the residence time is less than 180 seconds. The cooling method is preferably a rapid cooling using a steel belt cooler or the like.

  In the electrophotographic toner of the present invention, the content of the binder resin for toner is preferably 50% by weight to 99% by weight, and more preferably 60% by weight to 99% by weight.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Hereinafter, “parts” represents parts by weight unless otherwise specified.

[Production Example of Crosslinking Agent (D)]
Production Example D-1
Into a flask purged with nitrogen of 75 parts of xylene, the temperature was raised, and under reflux of xylene, 65 parts of styrene, 30 parts of n-butyl acrylate, 5 parts of glycidyl methacrylate, di-t- 1 part of butyl peroxide was continuously added over 5 hours, and the reflux was further continued for 1 hour. Thereafter, the internal temperature was kept at 130 ° C., 0.5 part of di-t-butyl peroxide was added and the reaction was continued for 2 hours to complete the reaction, thereby obtaining a polymerization solution. This was flashed in a vessel at 160 ° C. and 10 mmHg, and the solvent was distilled off to obtain a crosslinking agent D-1. The physical properties are shown in Table-1.

Production Example D-2
A crosslinking agent A-2 was obtained in exactly the same manner as in Production Example D-1, except that 0.65 part of glycidyl methacrylate was used in Production Example D-1. The physical properties of the product obtained are shown in Table 1.

Production Example D-3
A crosslinking agent D-3 was obtained in exactly the same manner as in Production Example D-1, except that 13 parts of glycidyl methacrylate was used in Production Example D-1. The physical properties of the product obtained are shown in Table 1.

Production Example D-4
A crosslinking agent D-4 was obtained in exactly the same manner as in Production Example D-1, except that 0.39 part of glycidyl methacrylate was used in Production Example D-1. The physical properties of the obtained product are shown in Table-2.

Production Example D-5
A crosslinking agent D-5 was obtained in exactly the same manner as in Production Example D-1, except that 19.5 parts of glycidyl methacrylate was used in Production Example D-1. The physical properties of the obtained product are shown in Table-2.

[Production Example of Styrene Acrylic Resin (C)]
Production Example C-1
A solution of 82 parts of styrene, 17 parts of n-butyl acrylate, 1.0 part of methacrylic acid and 75 parts of xylene solvent in which 3 parts of di-t-butyl peroxide are uniformly dissolved per 100 parts of styrene, A low molecular weight polymerization liquid (L) was obtained by continuous supply at a rate of 750 ml / hour to a 5 L reactor maintained at an internal temperature of 190 ° C. and an internal pressure of 6 kg / cm ² .

  Separately, as a vinyl monomer, 74.2 parts of styrene, 23.5 parts of n-butyl acrylate, and 2.3 parts of methacrylic acid were charged into a flask purged with nitrogen, and the temperature was raised to 120 ° C. and kept at the same temperature. Bulk polymerization was carried out for 10 hours. The polymerization rate at this time was 51%. Subsequently, 50 parts of xylene was added, and 50 parts of 0.1 part of xylene of dibutyl peroxide, which had been mixed and dissolved in advance, was continuously added over 8 hours while maintaining at 130 ° C. Further, 0.2% by weight of the total amount of styrene, n-butyl acrylate and methacrylic acid using 1,1-bis (t-butylperoxy) -3,3,5 trimethylcyclohexane was added and the reaction was performed for 2 hours. Continued. Thereafter, 0.5% by weight of the total amount of styrene, n-butyl acrylate and methacrylic acid using 1,1-bis (t-butylperoxy) -3,3,5 trimethylcyclohexane was added and held for 2 hours. To complete the reaction to obtain a high molecular weight polymerization liquid (H).

  Next, after mixing 100 parts of the above high molecular weight polymerization liquid (H) and 122 parts of the low molecular weight polymerization liquid (L), this was flashed in a vessel at 190 ° C. and 10 mmHg to distill off the solvent and the like to remove styrene acrylic. Resin C-1 was obtained. The physical properties of the obtained styrene acrylic resin are shown in Table-1.

Production Example C-2
When producing the low molecular weight polymerization liquid (L) in Production Example C-1, the styrene acrylic system was the same as C-1 except that 9.5 parts of di-t-butyl peroxide was used per 100 parts of styrene. Resin C-2 was obtained. The physical properties of the product obtained are shown in Table 1.

Production Example C-3
When producing the low molecular weight polymerization liquid (L) in Production Example C-1, the styrene acrylic system was the same as C-1 except that 0.5 part of di-t-butyl peroxide was used per 100 parts of styrene. Resin C-3 was obtained. The physical properties of the product obtained are shown in Table 1.

Production Example C-4
When producing the low molecular weight polymerization liquid (L) in Production Example C-1, 82 parts of styrene, 17 parts of n-butyl acrylate, 1.0 part of methacrylic acid, 77.6 parts of styrene, and n-butyl acrylate Styrene acrylic resin C-4 was obtained in exactly the same manner as C-1, except that 17 parts and 5.4 parts of methacrylic acid were used. The physical properties of the product obtained are shown in Table 1.

Production Example C-5
When producing the low molecular weight polymerization liquid (L) in Production Example C-1, 82 parts of styrene, 17 parts of n-butyl acrylate, 1.0 part of methacrylic acid, 83 parts of styrene, 17 parts of n-butyl acrylate Except that, styrene acrylic resin C-5 was obtained in the same manner as C-1. The physical properties of the product obtained are shown in Table 1.

Production Example C-6
In production example C-1, when producing a high molecular weight polymerization liquid (H), 75 parts of xylene was charged into a flask purged with nitrogen, the temperature was raised, and 67.7 parts of styrene previously mixed and dissolved under reflux of xylene. 30 parts of n-butyl acrylate and 2.3 parts of methacrylic acid are continuously added over 0.4 part of di-t-butyl peroxide over 5 hours, and the reflux is continued for 1 hour. Thereafter, the inner temperature was maintained at 130 ° C., and 0.2 weight of the total amount of styrene, n-butyl acrylate and methacrylic acid using 1,1-bis (t-butylperoxy) -3,3,5 trimethylcyclohexane. % Reaction was continued for 2 hours. Thereafter, 0.5% by weight of the total amount of styrene, n-butyl acrylate and methacrylic acid using 1,1-bis (t-butylperoxy) -3,3,5 trimethylcyclohexane was added and held for 2 hours. The styrene acrylic resin C-6 was obtained in exactly the same manner as C-1, except that the reaction was completed to obtain a polymerization solution. The physical properties of the obtained product are shown in Table 1.

Production Example C-7
When producing the high molecular weight polymerization liquid (H) in Production Example C-1, 74.2 parts of styrene, 23.5 parts of n-butyl acrylate, 2.3 parts of methacrylic acid, 76.4 parts of styrene, acrylic Styrene acrylic resin C-7 was obtained in the same manner as C-1, except that 23.5 parts of acid n-butyl and 0.1 part of methacrylic acid were used. The physical properties of the product obtained are shown in Table 1.

Production Example C-8
When producing the high molecular weight polymerization liquid (H) in Production Example C-1, 74.2 parts of styrene, 23.5 parts of n-butyl acrylate, 2.3 parts of methacrylic acid, 61.5 parts of styrene, acrylic Styrene acrylic resin C-8 was obtained in the same manner as C-1, except that 23.5 parts of acid n-butyl and 15 parts of methacrylic acid were used. The physical properties of the product obtained are shown in Table 1.

Production Example C-9
Styrene acrylic resin C-9 was obtained in the same manner as C-1, except that 16 parts of high molecular weight polymerization liquid (H) and 166 parts of low molecular weight polymerization liquid (L) were used in Production Example C-1. The physical properties of the product obtained are shown in Table 1.

Production Example C-10
Styrene acrylic resin C-10 was obtained in the same manner as C-1, except that 167 parts of high molecular weight polymerization liquid (H) and 88 parts of low molecular weight polymerization liquid (L) were used in Production Example C-1. The physical properties of the product obtained are shown in Table 1.

Production Example C-11
When producing the low molecular weight polymerization liquid (L) in Production Example C-1, the styrene acrylic system was the same as C-1 except that 14.5 parts of di-t-butyl peroxide was used per 100 parts of styrene. Resin C-11 was obtained. The physical properties of the obtained product are shown in Table-2.

Production Example C-12
When producing the low molecular weight polymerization liquid (L) in Production Example C-1, the styrene acrylic type was the same as C-1 except that 0.3 part of di-t-butyl peroxide was used per 100 parts of styrene. Resin C-12 was obtained. The physical properties of the obtained product are shown in Table-2.

Production Example C-13
When producing the low molecular weight polymerization liquid (L) in Production Example C-1, 82 parts of styrene, 17 parts of n-butyl acrylate, 1.0 part of methacrylic acid were converted to 76.8 parts of styrene, and n-butyl acrylate. Styrene acrylic resin C-13 was obtained in the same manner as C-1, except that 17 parts and 6.2 parts of methacrylic acid were used. The physical properties of the obtained product are shown in Table-2.

Production Example C-14
In the production example C-1, 75 parts of xylene were charged into a nitrogen-substituted flask when producing a high molecular weight polymerization liquid (H), and the mixture was heated to 70 parts of styrene previously mixed and dissolved under reflux of xylene, acrylic acid. 30 parts of n-butyl and 0.6 part of di-t-butyl peroxide are continuously added over 5 hours, and the reflux is continued for another hour. Thereafter, the inner temperature was maintained at 130 ° C., and 0.2 weight of the total amount of styrene, n-butyl acrylate and methacrylic acid using 1,1-bis (t-butylperoxy) -3,3,5 trimethylcyclohexane. % Reaction was continued for 2 hours. Thereafter, 0.5% by weight of the total amount of styrene, n-butyl acrylate and methacrylic acid using 1,1-bis (t-butylperoxy) -3,3,5 trimethylcyclohexane was added and held for 2 hours. The styrene-acrylic resin C-14 was obtained in exactly the same manner as C-1, except that the reaction was completed and a polymerization solution was obtained. The physical properties of the obtained product are shown in Table 2.

Production Example C-15
When producing the high molecular weight polymerization liquid (H) in Production Example C-1, 74.2 parts of styrene, 23.5 parts of n-butyl acrylate, 2.3 parts of methacrylic acid, 76.2 parts of styrene, acrylic Styrene acrylic resin C-15 was obtained in the same manner as C-1, except that 23.5 parts of acid n-butyl and 0.3 part of methacrylic acid were used. The physical properties of the obtained product are shown in Table-2.

Production Example C-16
When producing the high molecular weight polymerization liquid (H) in Production Example C-1, 74.2 parts of styrene, 23.5 parts of n-butyl acrylate, 2.3 parts of methacrylic acid, 53.5 parts of styrene, acrylic Styrene acrylic resin C-16 was obtained in the same manner as C-1, except that 23.5 parts of acid n-butyl and 23 parts of methacrylic acid were used. The physical properties of the obtained product are shown in Table-2.

Production Example C-17
Styrene acrylic resin C-17 was obtained in exactly the same manner as C-1, except that 10 parts of high molecular weight polymerization liquid (H) and 170 parts of low molecular weight polymerization liquid (L) were used in Production Example C-1. The physical properties of the obtained product are shown in Table-2.

Production Example C-18
Styrene acrylic resin C-18 was obtained in exactly the same manner as C-1, except that 183 parts of high molecular weight polymerization liquid (H) and 79 parts of low molecular weight polymerization liquid (L) were used in Production Example C-1. The physical properties of the obtained product are shown in Table-2.

Production Example C-19
In Production Example C-1, C-1 except that 100 parts of a high molecular weight polymerization liquid (H), 122 parts of a low molecular weight polymerization liquid (L), and 3 parts of polypropylene wax NP105 (high wax manufactured by Mitsui Chemicals, Inc.) were mixed. Styrene acrylic resin C-19 was obtained in exactly the same manner.

(Production of crystalline polyester (B))
Production Example B-1
33 parts of 1,4-butanediol, 77 parts of octadecanedioic acid and 0.05 parts of dibutyltin oxide were placed in a 2 liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube and a stirrer at 230 ° C. For 5 to 10 hours, and further under reduced pressure of 8.0 kPa or less. The physical properties of the obtained product are shown in Tables -1.

Production Example B-2
4 parts of 2 liters equipped with 72.5 parts of propylene oxide adduct of bisphenol A, 10 parts of terephthalic acid, 17.5 parts of fumaric acid and 0.1 part of dibutyltin oxide, equipped with nitrogen introduction tube, dehydration tube and stirrer The mixture was placed in a neck flask and reacted at 230 ° C. for 5 to 10 hours, and then further reacted under reduced pressure of 8.0 kPa or less. The physical properties of the product obtained are shown in Table 1.

Production Example B-3
39 parts of 1,4-butanediol, 5 parts of 1-6-hexanediol, 56 parts of fumaric acid and 0.1 part of hydroquinone were added to a 2-liter four-necked flask equipped with a nitrogen inlet tube, a dehydration tube and a stirrer. The mixture was reacted at 160 ° C. for 5 to 10 hours, heated to 200 ° C. for 1 hour, and further reacted under a reduced pressure of 8.0 kPa or less. The physical properties of the product obtained are shown in Table 1.

(Production of styrene acrylic resin (A))
Production Example A-1
After mixing 8 parts of the crosslinking agent obtained in Production Example D-1 and 92 parts of the styrene acrylic resin obtained in Production Example C-1, using a Henschel mixer, a biaxial kneader (KEXN S-40 type, Kurimoto Iron Works) In the biaxial kneader discharge section with a resin temperature of 200 ° C. and a residence time of 90 seconds. Then, it cooled and grind | pulverized and the styrene acrylic resin (A-1) was obtained. As a cooling method, a steel belt cooler (NR3-Hi double cooler, manufactured by Nippon Belting Co., Ltd.) was used, and the cooling water temperature was 10 ° C., the cooling water amount was 90 L / min, and the belt speed was 6 m / min. The physical properties of the resin are shown in Table-1.

Production Examples A-2 to A-26
Styrene acrylic resins (A-2) to (Similar to Production Example 1) except that the types and amounts of the crosslinking agent (D) and the styrene acrylic resin (C) were changed to the conditions shown in Tables 1 and 2. (A-26) was obtained.

Example 1
Toner binder resin was prepared by mixing 85 parts of styrene acrylic resin A-1 and 15 parts of crystalline polyester resin B-1 with a Henschel mixer for 2 minutes. Thereafter, 8 parts of carbon black MA100 (Mitsubishi Kasei), 5 parts of polypropylene wax (Biscol 550P) and 1 part of Eisenspiron Black TRH as a charge control agent are added, mixed again with a Henschel mixer, and then a twin-screw kneader (PCM -30 type, manufactured by Ikekai Machinery Co., Ltd.), the kneading machine was kneaded at a discharge temperature of 150 ° C. and a residence time of 30 seconds. Subsequently, the toner was cooled, ground and classified to obtain a toner having a thickness of about 7 μm. Table 1 shows the results obtained by mixing 3 parts of the toner and 97 parts of the carrier to obtain a developer, remodeling a commercially available high-speed copying machine, and writing and evaluating the image.

Examples 2-18 and Comparative Examples 1-14
A binder resin for toner and a toner were obtained in the same manner as in Example 1 except that the types and amounts used of the styrene acrylic resin (A) and the polyester resin (B) were changed to the conditions shown in Tables 1 and 2. Performance was evaluated. Table 1 shows the results of the examples, and Table 2 shows the results of the comparative examples.

<Toner Evaluation Method>
1) Fixability
Copy at a copy speed of 72 sheets / minute by changing the temperature of the fixing roll in increments of 5 ° C., and 1 kgf with sand eraser (plastic sand eraser “MONO” manufactured by Dragonfly Pencil Co., Ltd.) between the copied solid black part and white background. The blackness of the solid black portion was measured with an ink densitometer, and the residual ratio of the toner was expressed as a density ratio, and the evaluation was made at the lowest temperature at which 60% or more remained.
◎; 130 ° C or less ○; higher than 130 ° C and 140 ° C or lower Δ; higher than 140 ° C and lower than 150 ° C ×; higher than 150 ° C

2) Offset resistance The temperature at which offset phenomenon occurs when copying was evaluated.
A: 230 ° C. or higher ○: 220 ° C. or higher lower than 230 ° C; 210 ° C. or higher lower than 220 ° C. x; lower than 210 ° C.

3) Preservability The degree of aggregation of the powder was visually evaluated after the toner was left for one week in an environment of 50 ° C. and 50% relative humidity.
◎: Not aggregated at all ○: Slightly aggregated, but loosen when the container is shaken lightly Δ: There are aggregates that do not unravel even when the container is shaken well ×: Completely agglomerated

4) Grindability A part of the biaxially kneaded and cooled sample was collected and pulverized at the time of toner production, and pulverized with a jet mill to a particle size of 10 mesh under 16 mesh on. The particle size distribution was measured with a Coulter counter, and the particle size ratio of 5 to 20 μm was determined and evaluated.
◎; 85% or more ○; 70% or more and less than 85% Δ; 50% or more and less than 70% ×; less than 50%

5) Durability developability After copying 10,000 sheets continuously with a commercially available high-speed copying machine (72 pages / min copy speed) using a toner, a base paper having a line having a line width of 100 μm was copied to check reproducibility. The above-mentioned base paper was previously observed on a paper with a microscope, and the line width was measured at five points. The line width of the copy paper after copying and fixing this paper was also measured at five points. The average of the line widths of the base paper and the copy paper was determined, and the following evaluation was made based on the difference between the line width of the base paper and the line width of the copy paper.
Line width increase δ = Copy paper line width−Base paper line width ○; δ <5 μm
Δ: 5 ≦ δ <10 μm
×: δ ≧ 10 μm

Table 1 shows the results of Examples, and Table 2 shows the results of Comparative Examples.

Claims (5)

A styrene-acrylic resin (A) containing a structure derived from a carboxyl group and a structure derived from a glycidyl group and having a gel content of 1 to 50%, and a crystalline polyester resin (B), (A) A binder resin for toner, wherein the weight ratio (A) / (B) of (B) to (B) is 50/50 to 99/1.
The styrene acrylic resin (A) is obtained by a reaction of a styrene acrylic resin (C) that satisfies all the requirements (I) to (III) and a crosslinking agent (D). The binder resin for toner according to 1.
(I) It consists of a styrene acrylic resin (H) and a styrene acrylic resin (L), and the weight ratio (H) / (L) between the styrene acrylic resin (H) and the styrene acrylic resin (L) is 5 / 95 to 50/50.
(II) The styrene acrylic resin (H) has a weight average molecular weight of more than 50000 and 1000000 or less, and a content of a functional group selected from a carboxyl group and an acid anhydride group is 0.1 to 1 kg per resin. 2.0 mol.
(III) The styrene acrylic resin (L) has a weight average molecular weight of 4000 to 50000, and a content of a functional group selected from a carboxyl group and an acid anhydride is less than 0.7 mol per kg of the resin.
3. The binder resin for toner according to claim 1, wherein the crosslinking agent (D) is a glycidyl group-containing vinyl resin (D1) having an epoxy value of 0.005 to 0.1 equivalent / 100 g.
The binder resin for toner according to any one of claims 1 to 3, wherein the crystalline polyester resin (B) has a melting point peak temperature of 50 to 170 ° C.
An electrophotographic toner comprising the toner binder resin according to claim 1.