JP4678520B2 - Non-magnetic one-component electrostatic charge developing toner resin composition - Google Patents

Description

  The present invention relates to a resin composition for a non-magnetic one-component electrostatic charge developing toner capable of suitably obtaining an electrophotographic toner for a heat fixing system that hardly causes hot offset and has excellent low-temperature fixability.

  The powder toner used in the electrophotographic method has electrical properties such as tribocharging and electrical resistance related to development and transfer performance, thermal properties related to fixing performance and heat resistance (storage stability), and fluidity. In addition, in the properties of the powder such as hardness, an appropriate level according to the use conditions is required.

  Conventionally, as a resin material used for powder toner, polystyrene, styrene-acrylic copolymer, polyester, epoxy resin, butyral resin and the like can be mentioned, and the detailed design of the resin varies depending on its application. Proposals have been made.

  In particular, the heat roller fixing resin is required to improve the fixing performance to the transfer paper and the anti-offset performance. The toner fixing performance is achieved by heating and fusing with a fixing roller or the like and fixing to transfer paper, and the anti-offset performance is that the toner melted by the heating roller does not cause cold offset and loses its viscosity. The hot offset does not occur at the time.

  Many development methods are known as electrophotographic development methods. Broadly speaking, a carrier and toner mixture composed of fine particles (20 to 500 μm) such as iron powder, ferrite, nickel, and glass is used as a developer. There are a two-component development method and a one-component development method using a developer composed only of toner. In either method, generally, a charge is injected into the toner in a triboelectric manner.

  Typical examples of the two-component development method include a cascade method and a magnetic brush method (see, for example, Patent Documents 1 and 2). According to these methods, a stable and good image can be obtained, but on the other hand, contamination of the carrier surface with toner or the like, image quality deterioration due to a change in frictional charging property due to a change in the mixing ratio of the carrier and the toner, etc. It is easy to generate | occur | produce, and the device in various apparatus surfaces and a material surface is needed as the countermeasure.

  The one-component development method avoids such problems of the two-component development method. For example, a method of developing using an electrically insulating magnetic toner is described (for example, see Patent Document 3). ). In these methods, a charge is injected into the toner by frictional charging between the toner particles, the toner carrier and the toner thinning member, or by frictional charging between the toner particles, and the electrostatic latent image on the photosensitive member. It adheres electrostatically to the image.

  This one-component development method can avoid the problems of the two-component development method because the carrier is not used and the device for controlling the mixing ratio of the carrier and the toner is unnecessary. Has the advantage of becoming.

  On the other hand, in the one-component development method, in order to form a magnetic brush layer of toner on a metal sleeve, it is necessary to give the toner itself appropriate magnetic characteristics. Therefore, magnetic materials such as magnetite and ferrite are used as toner constituent components. It is an essential material. The required content of these magnetic materials is somewhat different depending on the development conditions and material types, but 30 to 60% by weight can be said to be general.

  However, the inclusion of a large amount of such a magnetic material that generally has low electrical resistance and is likely to absorb moisture leads to a decrease in electrical resistance and moisture absorption resistance of the toner itself, resulting in stable development performance against environmental changes. This makes it difficult to cause large fluctuations in image density or background level in various usage environments.

  In addition, the one-component developing method has a smaller proportion of the resin material as the binder contained in the toner than the two-component toner, and can be said to be disadvantageous in terms of fixing performance. Furthermore, when considering the use of color images, which are increasing recently, many of the magnetic materials are colored, so that there is a problem that the colors that can be handled are limited or that a clear color image quality is difficult to obtain.

  In order to solve the problems of the one-component development method using such a magnetic toner, a non-magnetic one-component development method that does not require magnetic properties of the toner has been proposed (for example, see Patent Document 4). As such a method, various apparatuses have been studied, but most of them are a method in which toner is attached to a developing sleeve or the like by electrostatic force, and the toner is conveyed to a latent image surface for development. The development method differs greatly in that the magnetic material is not an essential component due to the construction of the toner used, and various problems due to the magnetic material inclusion can be expected to be avoided.

  As a toner used for this nonmagnetic one-component development method, for example, an electrophotographic powder toner containing a binder resin, a colorant, and a charge control agent as essential components is known.

  As the toner resin used here, a polyester resin is used because it is necessary to ensure charging stability and durability during continuous printing. However, market demands for excellent low-temperature fixability and anti-offset properties and durability for continuous printing are increasing, and it is difficult to obtain a non-magnetic one-component toner that sufficiently satisfies these characteristics. there were.

U.S. Pat. No. 2,618,552 U.S. Pat. No. 2,874,063 U.S. Pat. No. 4,336,318 Japanese Patent Publication No.41-009475

  An object of the present invention is to obtain a non-magnetic one-component toner that is less likely to cause hot offset, has excellent low-temperature fixability, is stably charged even when continuously printed, and has excellent durability to obtain a good image. Another object of the present invention is to provide a resin composition for non-magnetic one-component toner.

The present inventors have made intensive studies, as a result, the rosin (r), a cresol novolak type or phenol novolak type of polyvalent epoxy compound having a trivalent or more epoxy groups and (e), carboxy in rosin (r) It is obtained by reacting such that the equivalent ratio of the epoxy group in the polyvalent epoxy compound (e) is 0.9 / 1.1 to 1.1 / 0.9, and the hydroxyl value is 50 to 200 mg / KOH. One or more selected from the group consisting of a reaction product (A) in the range of ( 2 ), a dihydric alcohol (B) other than the above (A), a polybasic acid, an anhydride thereof, and a lower alkyl ester thereof. By using a resin composition containing a polyester resin obtained by polycondensation with a polybasic acid (C), a non-magnetic single component having a low fixing start temperature, excellent offset resistance, and good development durability Obtain electrostatic development toner Heading the like be, and have completed the present invention.

That is, the present invention relates to rosin (r) , a cresol novolak type or phenol novolac type polyvalent epoxy compound (e) having a trivalent or higher epoxy group, a carboxy group in the rosin (r) and a polyvalent epoxy. Reaction obtained by making it react so that the equivalent ratio of the epoxy group in a compound (e) may become 0.9 / 1.1-1.1 / 0.9, and the hydroxyl value is the range of 50-200 mg / KOH. One or more polybasic acids (C) selected from the group consisting of the product (A), divalent alcohols (B) other than the above (A), polybasic acids, anhydrides thereof, and lower alkyl esters thereof And a polyester resin obtained by polycondensation of a non-magnetic one-component developing toner.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition which can obtain the nonmagnetic one-component electrostatic charge developing toner which has low temperature fixability, offset resistance, and durability can be provided.

  The rosin (r) used in the present invention is a general term for low-volatile resin acids obtained from trees, and the main component is derived from natural products including abietic acid, which is a kind of tricyclic diterpenes, and isomers thereof. It is a substance. Specific components include neoabietic acid, dehydroabietic acid, pimaric acid, isopimaric acid, and parastrinic acid in addition to abietic acid, and the rosin used in the present invention is a mixture thereof. There are three types of rosins: gum rosin obtained from raw pine resin, wood rosin obtained from pine root, and tall oil rosin obtained from pulp. In the present invention, rosin (disproportionated rosin) obtained by dehydrogenating the rosin to increase the ratio of dehydroabietic acid in the rosin can also be used as the rosin (r). Rosin belongs to a monocarboxylic acid as a chemical structure, and a carboxyl group is representative as a reactive group. As the rosin (r) used in the present invention, one or more rosins selected from the group consisting of gum rosin, wood rosin, tall oil rosin and these disproportionated rosins are preferable. In addition, rosin (r) can be used alone or in combination of two or more at any ratio.

The polyvalent epoxy compound (e) used in the present invention is a compound having a trivalent or higher valent epoxy group in one molecule, and examples thereof include a 3 to 4 valent epoxy compound and a 5 or higher valent epoxy compound. As the polyvalent epoxy compound (e), the ratio [(Mw) / (Mn)] of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is increased, and a toner excellent in offset resistance and low temperature fixability is obtained. Therefore, a polyvalent epoxy compound having a valence of 5 or more is preferable.

  Examples of the trivalent to tetravalent epoxy compound include glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, pentaerythritol tetraglycidyl ether, hydroquinone diglycidyl ether, and the like. Of these, bisphenol A type epoxy resins are preferred because of their good plasticizer resistance.

  Examples of the pentavalent or higher epoxy compound include a cresol novolac type epoxy resin, a phenol novolak type epoxy resin, a polymer or copolymer of a vinyl compound having an epoxy group, an epoxidized resorcinol-acetone condensate, and a partially epoxidized polymer. Butadiene and the like. Among these, a cresol novolac type epoxy resin having a valence of 5 or more and a phenol novolac type epoxy resin having a valence of 5 or more are more preferable because of good reactivity.

  Examples of the cresol novolac type epoxy resin include Epicron N-660, N-665, N-680, N-690, N-695 and the like manufactured by Dainippon Ink and Chemicals, Inc. Examples of the phenol novolac type epoxy resin include Epicron N-740, N-770, N-775, and N-865 manufactured by Dainippon Ink and Chemicals, Inc.

  Further, two or more of the 3 to 4 valent epoxy compounds and the 5 or more valent epoxy compounds may be used in combination.

  The reaction product (A) used in the present invention is a reaction product of rosin (r) and a polyvalent epoxy compound (e). The reaction proceeds mainly by a ring-opening reaction between the carboxyl group of rosin (r) and the epoxy group of the polyvalent epoxy compound (e). In that case, as reaction temperature, it is the range of 60-280 degreeC, Preferably it is the range of 150-250 degreeC. During the reaction, a catalyst that promotes the ring-opening reaction of the epoxy group may be added. Examples of the catalyst that can be used include amines such as ethylenediamine, triethylamine, and 2-methylimidazole, quaternary ammonium salts such as butyltrimethylammonium chloride, and triphenylphosphine. Progress of the reaction can be confirmed mainly by a decrease in the acid value, and the reaction can be appropriately completed when the stoichiometric end point of reaction or the vicinity thereof is reached.

  The reaction ratio between the rosin (r) and the polyvalent epoxy compound (e) is not particularly limited, but the equivalent ratio of the carboxy group in the rosin (r) and the epoxy group in the polyvalent epoxy compound (e) is 0.9. It is preferable to make it react so that it may become /1.1-1.1/0.9.

  The reaction product (A) used in the present invention preferably has an acid value of 0.1 to 50 mg / KOH, and more preferably 0.5 to 15 mg / KOH. The hydroxyl value is preferably 50 to 200 mg / KOH, more preferably 75 to 150 mg / KOH. The glass transition temperature (Tg) by differential scanning calorimetry (DSC) method is preferably 35 to 90 ° C, more preferably 40 to 80 ° C. The softening point by the ring and ball method is preferably 50 to 150 ° C, more preferably 70 to 120 ° C.

  The polyester resin used in the present invention is one or more polybasic acids selected from the group consisting of the reaction product (A), polyhydric alcohol (B), polybasic acid, anhydrides thereof, and lower alkyl esters thereof. It is a polyester resin obtained by condensation polymerization of (C). The polyester can be prepared by a well-known conventional method.

  Examples of the polyhydric alcohol (B) include ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, diethylene glycol, and dipropylene glycol. Aliphatic diols such as triethylene glycol and neopentyl glycol; Bisphenol A derivatives such as bisphenol A and polyalkylene oxide adducts of bisphenol; Divalent alcohols such as alicyclic diols such as cyclohexanedimethanol Kind,

Examples include trivalent or higher alcohols such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and 2-methylpropanetriol.

  In the present invention, aliphatic monoepoxy compounds such as Cardura E10 “monoglycidyl ester of branched fatty acid manufactured by Shell Chemical Co.” can also be used as diols.

  A polyhydric alcohol (B) may be used independently and may use 2 or more types together. In addition, monoalcohols such as stearyl alcohol may be used as necessary.

  Among the polyhydric alcohols (B) used in the present invention, the ratio [(Mw) / (Mn)] between the weight average molecular weight (Mw) and the number average molecular weight (Mn) is large, and is excellent in offset resistance and low temperature fixability. A divalent alcohol is preferred because a toner is obtained.

  As polybasic acid (C) used by this invention, the acid anhydride of polybasic acid and these lower alkyl esters can also be used as polybasic acid (C), for example. Examples of the polybasic acid (C) include saturated polybasic acids and unsaturated polybasic acids.

  Examples of the saturated polybasic acid, saturated polybasic acid and lower alkyl ester of saturated polybasic acid include, for example, adipic acid, sebacic acid, orthophthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, succinic anhydride, Dibasic acids such as alkyl succinic acid having 8 to 18 carbon atoms, alkyl succinic anhydride, alkenyl succinic acid, alkenyl succinic anhydride; trimellitic acid, trimellitic anhydride, cyanuric acid, pyromellitic acid, pyromellitic anhydride And trivalent polybasic acids. Examples of the alkyl mentioned here include alkyl esters having 8 to 18 carbon atoms.

  Examples of the unsaturated polybasic acid include maleic acid, maleic anhydride, and fumaric acid.

  The polybasic acid (C) may be used alone or in combination of two or more. In addition, monobasic acids such as benzoic acid and p-tert-butylbenzoic acid may be used as necessary.

  Among the polybasic acids (C) used in the present invention, the ratio [(Mw) / (Mn)] between the weight average molecular weight (Mw) and the number average molecular weight (Mn) increases, and is excellent in offset resistance and low-temperature fixability. A divalent basic acid is preferable because a toner is obtained, and isophthalic acid and terephthalic acid are more preferable.

  Furthermore, as the above-mentioned polybasic acid (C), those in which part or all of the carboxy group is alkenyl ester or allyl ester can also be used.

  Moreover, although not a polyhydric alcohol component, the epoxy compound which has a 1 or more epoxy group in 1 molecule can also be used for the preparation of the polyester resin used by this invention as a raw material which prepares a polyester resin. For example, a bisphenol type epoxy resin, a novolac type epoxy resin, etc. are mentioned.

  The polyester resin used in the present invention is obtained by condensation polymerization of a reaction product (A) of rosin (r) and a polyvalent epoxy compound (e), a polyhydric alcohol (B) and a polybasic acid (C). The amount of the reaction product (A) used at this time is such that the ratio [(Mw) / (Mn)] of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is as large as 10 to 100, for example. Since a toner excellent in offset property and low-temperature fixability can be obtained, 0.1 to 40 parts by weight per 100 parts by weight in total of the reaction product (A), polyhydric alcohol (B) and polybasic acid (C). Preferably, 0.5 to 10 parts by weight is more preferable.

  The polyester resin used in the present invention is optionally produced by a known polycondensation reaction method. For example, in the presence of an esterification catalyst (dibutyltin oxide, tetrabutyltitanate, paratoluenesulfonic acid, etc.) or in the presence of a transesterification catalyst (lead compound, tin compound, zinc compound, etc.), The transesterification reaction using an alkyl ester, normal pressure dehydration reaction, reduced pressure and vacuum dehydration reaction, solution polycondensation method, solid phase polycondensation reaction, etc. may be used. The polyesterification reaction at this time can be traced by measuring the acid value, hydroxyl value, viscosity or softening point (ring and ball method).

  As an apparatus used at this time, for example, a batch-type production apparatus such as a reaction vessel equipped with a nitrogen inlet, a thermometer, a stirring device, a rectifying tower, etc. can be preferably used, or a deaeration port is provided. Extruders, continuous reactors, kneaders and the like can also be used. In the dehydration condensation, the esterification reaction can be promoted by reducing the pressure of the reaction system as necessary. Furthermore, a known and commonly used catalyst can be added to accelerate the esterification reaction.

  The polyester resin used in the present invention is preferably a polyester resin having a glass transition temperature (Tg) of 50 to 90 ° C., and more preferably a polyester resin having a temperature of 55 to 85 ° C., because a toner having better low-temperature fixability can be obtained. . In addition, a polyester resin having a softening point (ring and ball method) of 90 to 210 ° C. is preferable, and a polyester resin having a temperature of 120 to 190 ° C. is more preferable because better hot offset properties can be obtained.

  Accordingly, a polyester resin having a glass transition temperature (Tg) of 50 to 90 ° C. and a softening point (ring and ball method) of 90 to 210 ° C. is preferable, a glass transition temperature (Tg) of 55 to 85 ° C., and Moreover, a polyester resin having a softening point (ring ball method) of 120 to 190 ° C. is more preferable.

  The polyester resin used in the present invention is preferably a polyester having a weight average molecular weight (Mw) of 100,000 to 700,000, and preferably 150,000 to 500,000 because a toner having excellent low-temperature fixability and hot offset resistance can be obtained. Polyester is more preferred. In addition, the polyester resin used in the present invention preferably has a number average molecular weight (Mn) of 2,000 to 8,000 because it maintains a good glass transition temperature and, as a result, a good storage-stable toner is obtained. 2,500 to 7,500 polyesters are more preferred.

  Furthermore, the polyester resin used in the present invention has a high-temperature offset resistance and a low-temperature fixability because the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is high. The polyester resin is preferably 10 to 100 in terms of (Mw / Mn) and more preferably 20 to 80.

In addition, the molecular weight (Mw and Mn) of the resin in the present invention is a value obtained by measuring a component dissolved in tetrahydrofuran by GPC.

In the present invention, the values of the weight average molecular weight (Mw) and the number average molecular weight (Mn) are measured under the following measurement conditions.
GPC device: HLC-8120GPC manufactured by Tosoh Corporation
Column: TSK-GEL G-5000HXL manufactured by Tosoh Corporation
G-4000HXL
G-3000HXL
G-2000HXL
Solvent: Tetrahydrofuran Concentration: 0.5% by weight
Flow velocity: 1.0ml / min

  The resin composition for a nonmagnetic one-component electrostatic charge developing toner of the present invention may contain the polyester resin, but a release agent, a colorant, a charge control agent and the like can be added as necessary.

  Examples of the mold release agent include various waxes. For example, natural waxes such as montan wax, carnauba wax, candelilla wax and rice wax, synthetic waxes such as polypropylene wax and polyethylene wax can be used.

  In particular, in heat roller fixing applications, a release agent can be used for the purpose of preventing troubles due to toner contamination on the heat roller (offset). Examples of such a release agent include various waxes. For example, natural waxes such as montan wax, carnauba wax, candelilla wax and rice wax; synthetic waxes such as polypropylene wax and polyethylene wax can be used. Suitable waxes include, for example, biscol 660P and biscol 550P (manufactured by Sanyo Chemical Industries, Ltd.), which are synthetic polypropylene waxes.

  The weight ratio of the release agent in the resin composition for non-magnetic one-component developing toner of the present invention is not particularly limited, but usually 0.3 to 15 parts by weight, preferably 100 to 15 parts by weight of the release agent per 100 parts by weight of the toner resin composition. Is 1 to 5 parts by weight.

  Examples of the colorant include various non-magnetic organic pigments and inorganic pigments, such as carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, phthalocyanine blue, lamp black, rose bengara, quinacridone red, A watching red etc. can be mentioned, It can use by 1 type, or 2 or more types of combination.

  The weight ratio with the colorant in the resin composition for a non-magnetic one-component developing toner of the present invention is not particularly limited, but is usually 1 to 60 parts by weight, preferably 3 to 100 parts by weight of the toner resin composition. 30 parts by weight.

  Examples of the charge control agent include known conventional charges such as nigrosine dyes, quaternary ammonium salts, trimethylethane dyes, copper phthalocyanine, perylene, quinacridone, azo pigments, heavy metal-containing acid dyes such as metal complex azo dyes. A control agent can be mentioned and it can use 1 type or in combination of 2 or more types.

  The weight ratio with the charge control agent in the resin composition for non-magnetic one-component development toner of the present invention is not particularly limited, but is preferably 0.5 per 100 parts by weight of the toner resin composition. -3 parts by weight is desirable.

  Further, the resin composition for non-magnetic one-component developing toner of the present invention may be a conventionally known resin such as a styrene resin, a styrene-acrylic copolymer resin, an epoxy resin, or the like as long as the effects of the present invention are not lost. An appropriate amount of polyester resin, silicone resin, polyurethane resin or the like can be blended. The compounding quantity is about 1-30 weight part normally with respect to 100 weight part of this polyester resin.

  The toner obtained using the resin composition for a non-magnetic one-component toner of the present invention can be obtained by any known and commonly used production method. For example, it can be obtained by melt-kneading the binder resin and the colorant at a temperature equal to or higher than the melting point of the binder resin, pulverizing, and classifying. Of course, you may manufacture by a method other than this.

  In obtaining the non-magnetic one-component electrostatic charge developing toner of the present invention, various auxiliary agents such as a fluidity improver can be further added in any step of the production. It is effective that the fluidity improver adheres to the surface of the toner.

  The toner obtained using the resin composition for a non-magnetic one-component toner of the present invention can be obtained by any known and commonly used production method. For example, it can be obtained by melt-kneading the polyester resin and the colorant at a temperature equal to or higher than the melting point of the polyester resin, pulverizing and classifying. Of course, you may manufacture by a method other than this.

  The toner powder obtained in the present invention can be used as it is as a non-magnetic one-component toner, but by adding silica externally, the powder fluidity can be further improved, which is practically preferable. .

  Silica includes those having a relatively large average particle diameter and those having a relatively small average particle diameter, and these may be used alone or in combination. As the external addition amount of silica, the charge amount is necessary and sufficient, and the photosensitive drum is not damaged and the environmental characteristics of the toner are not deteriorated. Therefore, 0.1 to 5 parts by weight with respect to 100 parts by weight of the toner particles. 0.0 part by weight is practically favorable.

  As a one-component development method using a non-magnetic toner, there is a contact-type non-magnetic one-component development method in which development is performed by bringing a developing sleeve carrying a developer into contact with a photosensitive drum having an electrostatic latent image.

  The non-magnetic one-component toner obtained by using the resin composition for non-magnetic one-component developing toner of the present invention allows the toner to pass between the developing sleeve and the charging member pressed against the developing sleeve, and frictionally charges the toner. Thus, it can be used particularly effectively in a contact-type non-magnetic one-component developing method for developing an electrostatic latent image formed on the surface of a photoreceptor.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. In the examples, “parts” and% are based on weight except for fixing strength.

Synthesis Example 1 (Synthesis of reaction product of rosin and polyvalent epoxy compound)
Gum rosin (acid value 167 mg / KOH) 740 g, Epicron N-695 [Cresol novolac type epoxy resin manufactured by Dainippon Ink & Chemicals, Inc.] 428 g and Triphenylphosphine 1.2 g are made into a glass 2-liter four-necked flask. The mixture was gradually heated under a nitrogen stream and reacted at 22 ° C. for 5 hours to obtain a reaction product. The obtained reaction product (R-1) has an acid value of 4.9 mg / KOH, a hydroxyl value of 112 mg / KOH, a softening point (ring and ball method) of 138 ° C., and a glass transition temperature by differential scanning calorimetry (DSC). (Tg) was 80 ° C.

Synthesis example 2 (same as above)
Hartle X [Hallima Kasei Co., Ltd. tall oil rosin, acid value 167 mg / KOH] 448 g, Epicron N-740 [Dainippon Ink Chemical Co., Ltd. phenol novolac type epoxy resin] 291 g and triphenylphosphine 0 .8 g was put into a 1-liter glass four-necked flask, heated gradually under a nitrogen stream, and reacted at 230 ° C. for 3 hours to obtain a reaction product. The obtained reaction product (R-2) had an acid value of 3.5 mg / KOH, a hydroxyl value of 103 mg / KOH, a softening point (ring and ball method) of 122 ° C., and a Tg of 66 ° C. by DSC method.

Synthesis Example 3: (Same as above)
Bandis T-100H [disproportionated rosin, manufactured by Harima Kasei Co., Ltd., acid value 165 mg / KOH] 701 g, Epicron N-695 [cresol novolac type epoxy resin manufactured by Dainippon Ink & Chemicals, Inc.] and triphenyl Phosphine (1.2 g) was put in a glass 2-liter four-necked flask, heated gradually under a nitrogen stream, and reacted at 230 ° C. for 2 hours. The obtained reaction product (R-3) had an acid value of 6.1 mg / KOH, a hydroxyl value of 105 mg / KOH, a softening point (ring and ball method) of 118 ° C., and a Tg of 61 ° C. by DSC method.

Synthesis Example 4 (Synthesis of polyester resin)
A glass 2-liter four-necked flask containing 1140 g of polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, 498 g of terephthalic acid, 45 g of (R-1) and 1.0 g of dibutyltin oxide. The mixture was gradually heated under a nitrogen stream, reacted at 240 ° C. for 7 hours, then the temperature was lowered to 230 ° C., and reacted under reduced pressure of 40 mmHg for 3 hours to obtain a polyester resin. The obtained polyester resin 1 was a solid at room temperature, an acid value of 9 mg / KOH, a softening point of 160 ° C, and a Tg of 67 ° C by DSC method. As a result of measuring the molecular weight distribution by GPC, the weight average molecular weight (Mw) was 365,000, the number average molecular weight (Mn) was 4,700, and Mw / Mn = 77.7.

Synthesis Examples 5-6 (same as above)
Polyester resins 2 and 3 were obtained in the same manner as in Synthesis Example 4 except that the formulation shown in Table 1 was used. The obtained polyester resins are both solid at room temperature, and their acid values, softening points, Tg, Mw, Mn and Mw / Mn are shown in Table 2.

Synthesis Examples 7 and 8 (Synthesis of polyester resin for comparison)
Comparative polyester resins 1 ′ and 2 ′ were produced in the same manner as in Synthesis Example 4 except that the blending shown in Table 3 was used. The obtained resins were both solid at room temperature, and their acid values, softening points, Tg, Mw, Mn and Mw / Mn are shown in Table 4.

Abbreviations in Tables 1 and 3 are as follows.
BPA-PO: bisphenol A propylene oxide 2.2 mol adduct BPA-EO: bisphenol A ethylene oxide 2.2 mol adduct EG: ethylene glycol NPG: neopentyl glycol TPA: terephthalic acid IPA: isophthalic acid TMP: trimethylolpropane TMA: trimellitic anhydride

  Example 1 92 parts by weight of polyester resin 1 obtained in Production Example 1, 5 parts by weight of carbon black MA-11 (Mitsubishi Chemical), 1 part by weight of Bontron S34 (charge control agent made by Orient Chemical) and Biscol 550P (Sanyo Kasei) 2 parts by weight of polypropylene wax) were mixed with a Henschel mixer and then kneaded with a biaxial kneader to obtain a kneaded product. Non-magnetic one-component electrostatic charge developing toner 1 obtained by mixing 100 parts of the pulverized and classified toner powder thus obtained and 3 parts of silica R972 (manufactured by Nippon Aerosil Co., Ltd.) with a Henschel mixer, followed by sieving. Got. The obtained nonmagnetic one-component electrostatic charge developing toner 1 was evaluated for fixing start temperature, offset resistance, and development durability according to the following evaluation methods. The evaluation results are shown in Table 6.

<Evaluation of fixing start temperature>
Solid printing was performed by changing the set temperature of the heat roll from 80 ° C. to 210 ° C. in 5 ° C. increments. When a solidity test is performed on a solid print portion, the image density before and after the test is measured with a Macbeth densitometer (RD-918), and the ratio of the density value after peeling to the value before the test is displayed in%. The temperature at which the ratio becomes 80% or more was determined as the fixing start temperature. The lower this temperature, the better the low-temperature fixability of the non-magnetic one-component electrostatic charge developing toner. The fastness test was performed using a Gakushin type friction fastness tester (load: 200 g, rubbing operation: 5 strokes).

<Evaluation method of offset start temperature>
When the set temperature of the heat roll was changed from 80 ° C. to 210 ° C. in increments of 5 ° C., the solid print portion was offset again on the same paper and displayed at the lowest temperature that can be visually confirmed. The higher this temperature, the better the offset resistance.

The fixing start temperature and offset resistance were evaluated under the following heat roller fixing machine conditions.
Roll material: Top; Polytetrafluoroethylene, Bottom: Silicon Upper roll load: 7Kg / 350mm
Nip width: 4mm
Paper threading speed: 280 cm / sec

<Development durability evaluation method>
The exclusive toner was removed from the cartridge of a commercially available printer, and the resulting non-magnetic one-component electrostatic charge developing toner 1 was filled into the washed cartridge, and continuous printing was performed for 10 hours. A state where the toner layer on the developing sleeve was uniform and no defect was generated was judged as ◯, and a case where a non-uniform portion such as a streak occurred was judged as x.

Examples 2-4 and Comparative Examples 1-2
Nonmagnetic one-component electrostatic charge developing toners 2 to 4 and comparative nonmagnetic one-component electrostatic charge development toners 1 'to 2' were prepared in the same manner as in Example 1 except for the formulation shown in Table 5. In the same manner as in Example 1, the fixing start temperature, offset resistance, and development durability were evaluated. The evaluation results are shown in Table 6.

Footnotes in Table 5 MA-11: Carbon Black MA-11
S34: Bontron S34
550P: Biscol 550P
R972: Silica R972

Claims (7)

Rosin (r), cresol novolak type or phenol novolak type having a trivalent or more epoxy groups polyepoxy compound and (e), rosin (r) carboxyl groups and a polyhydric epoxy compound in (e) in the A reaction product (A) obtained by reacting such that the equivalent ratio of epoxy groups is 0.9 / 1.1 to 1.1 / 0.9, and having a hydroxyl value in the range of 50 to 200 mg / KOH ; A polycondensation of a dihydric alcohol (B) other than (A) with one or more polybasic acids (C) selected from the group consisting of polybasic acids, anhydrides thereof and lower alkyl esters thereof. A resin composition for a non-magnetic one-component developing toner, comprising a polyester resin obtained in the above manner. The resin composition for a non-magnetic one-component electrostatic charge developing toner according to claim 1, wherein the rosin (r) is at least one rosin selected from the group consisting of gum rosin, wood rosin, tall oil rosin and disproportionated rosin. The resin composition for a non-magnetic one-component electrostatic charge developing toner according to claim 1, wherein the polyvalent epoxy compound (e) is a cresol novolac type epoxy resin having a valence of 5 or more and / or a phenol novolac type epoxy resin having a valence of 5 or more. The non-magnetic one-component electrostatic charge development according to claim 1, wherein the polybasic acid (C) is at least one polybasic acid selected from the group consisting of divalent basic acids, anhydrides thereof, and lower alkyl esters thereof. Resin composition for toner. 2. The polyester resin according to claim 1, wherein the polyester resin is a polyester resin having a ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of 10 to 100. A resin composition for magnetic one-component developing toner. The resin composition for a non-magnetic one-component developing toner according to claim 1, wherein the polyester resin is a polyester resin having a glass transition temperature of 55 to 85 ° C and a softening point of 90 to 210 ° C. The resin composition for non-magnetic one-component developing toner according to any one of claims 1 to 7, comprising a releasing agent.