JP5057552B2 - Binder resin for electrophotographic toner - Google Patents

Description

  The present invention relates to a binder resin for an electrophotographic toner used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like, and an electrophotographic toner containing the binder resin. .

In recent years, from the pursuit of high image quality, development of a small particle size toner excellent in fixability has been desired. On the other hand, styrene acrylic resin, polyester, and the like are known as toner binder resins. Polyester is excellent in durability and fixability, but has a defect that offset tends to occur. Thus, for the purpose of improving offset resistance, a toner containing a resin obtained by polymerizing a raw material monomer of a condensation polymerization resin such as polyester and a raw material monomer of an addition polymerization resin such as styrene and an acrylic monomer is provided. (See Patent Documents 1 and 2).
JP-A-7-98517 JP 2004-85605 A

  However, when a small particle toner is manufactured by a melt kneading pulverization method using a conventional binder resin, it is difficult to control the pulverization. Further, if the molecular weight of the binder resin is lowered in order to improve the pulverization property, offset becomes a problem.

  An object of the present invention is to provide a binder resin for an electrophotographic toner having good crushability and excellent offset resistance, and a toner containing such a binder resin.

The present invention
[1] A binder resin for an electrophotographic toner obtained by polymerizing at least a raw material monomer of a condensation polymerization resin and a raw material monomer of an addition polymerization resin, wherein the raw material monomer of the addition polymerization resin is styrene. The present invention relates to a binder resin for electrophotographic toners containing at least wt%, and [2] an electrophotographic toner containing the binder resin for electrophotographic toners described in [1] above.

  The binder resin for an electrophotographic toner of the present invention has an excellent effect that the pulverizability is good, and the toner containing the binder resin can suppress the occurrence of offset.

  The binder resin for an electrophotographic toner of the present invention is a binder resin for an electrophotographic toner obtained by polymerizing at least a raw material monomer of a condensation polymerization resin and a raw material monomer of an addition polymerization resin, the addition polymerization system The resin has a great feature in that it contains 90% by weight or more of styrene. That is, it has been found that the use of styrene as the main component monomer of the addition polymerization resin has the surprising effect that the grindability can be improved while maintaining the offset resistance.

  The binder resin of the present invention is a resin obtained by performing a condensation polymerization reaction and an addition polymerization reaction in parallel in the same reaction vessel using at least a raw material monomer of a condensation polymerization resin and a raw material monomer of an addition polymerization resin. Is preferred. The progress and completion of the polycondensation reaction and the addition polymerization reaction do not need to be simultaneous in time, and the reaction temperature and time may be appropriately selected according to each reaction mechanism to advance and complete the reaction. The condensation polymerization reaction and the addition polymerization reaction will be described in detail below.

  As the condensation polymerization resin component obtained by the condensation polymerization reaction, in order to form a polyester, an alcohol component, a carboxylic acid component, and an amide component obtained by condensation polymerization of an alcohol component and a carboxylic acid component from the viewpoint of toner fixing properties. It is at least one selected from the group consisting of a polyester / polyamide obtained by polycondensation of the raw material monomers and a polyamide obtained by polycondensation of the raw material monomers for forming the carboxylic acid component and the amide component. Among these, polyester is more preferable.

  The polyester is not particularly limited, and can be obtained by polycondensing a raw material monomer containing an alcohol component composed of a divalent or higher alcohol and a carboxylic acid component composed of a divalent or higher carboxylic acid compound.

  As the dihydric or higher alcohol, from the viewpoint of storage stability of the toner, the formula (I):

(In the formula, RO is an alkylene oxide, R is an alkylene group having 2 or 3 carbon atoms, x and y are positive numbers indicating the average added mole number of alkylene oxide, and the sum of x and y is 1 to 16) , Preferably 1-10, more preferably 1.5-5)
An alkylene oxide adduct of bisphenol A represented by The content of the alkylene oxide adduct of bisphenol A is preferably 50% by weight or more, more preferably 60% by weight or more, and still more preferably 80% by weight or more in the alcohol component.

  Examples of the alkylene oxide adduct of bisphenol A represented by the formula (I) include polyoxyethylene-2,2-bis (4-hydroxyphenyl) propane and other ethylene oxide adducts having 2 carbon atoms, such as polyoxypropylene Examples thereof include propylene oxide adducts having 3 carbon atoms such as -2,2-bis (4-hydroxyphenyl) propane.

  The alcohol components other than the alkylene oxide adduct of bisphenol A include ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, neopentyl glycol, polyethylene glycol, polypropylene glycol, bisphenol A, hydrogenated bisphenol A, and sorbitol. , Pentaerythritol, glycerol, trimethylolpropane and the like.

  Examples of the divalent or higher carboxylic acid compound include adipic acid, fumaric acid, maleic acid, succinic acid (for example, n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isooctenyl succinic acid, Aliphatic carboxylic acids such as isooctyl succinic acid and the like, succinic acid substituted with alkyl groups having 1 to 20 carbon atoms or alkenyl groups having 2 to 20 carbon atoms, phthalic acid, isophthalic acid, terephthalic acid, 1,2, 4-Benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, aromatic carboxylic acids such as pyromellitic acid, anhydrides of these acids and lower alkyl (C1-3) esters, etc. Is mentioned. Such acids, anhydrides of these acids, and alkyl esters of these acids are collectively referred to herein as carboxylic acid compounds. Among these, from the viewpoint of pulverization and storage stability of the toner, 50% by weight or more of the carboxylic acid component is preferably phthalic acid or terephthalic acid, and more preferably terephthalic acid.

  The polyester is preferably a crosslinked polyester obtained using a trivalent or higher monomer as the alcohol component and / or carboxylic acid component from the viewpoint of the softening point and grindability. The content of the trivalent or higher monomer is preferably 2 to 20 mol%, more preferably 4 to 18 mol% in the total amount of the alcohol component and the carboxylic acid component. As the trivalent or higher monomer, 1,2,4-benzenetricarboxylic acid (trimellitic acid) and its anhydride are preferable.

  The alcohol component may contain a monovalent alcohol, and the carboxylic acid component may contain a monovalent carboxylic acid compound as appropriate from the viewpoints of molecular weight adjustment and offset resistance improvement.

  The polycondensation of the alcohol component and the carboxylic acid component can be performed, for example, in an inert gas atmosphere at a temperature of 180 to 250 ° C. using an esterification catalyst if necessary.

  The polyester / polyamide is obtained by using a raw material monomer for forming an amide component in addition to the alcohol component and the carboxylic acid component, and polycondensing these raw material monomers. The polyamide is obtained by using the carboxylic acid component described above. In addition to the above, a raw material monomer for forming an amide component is used, and these raw material monomers are subjected to condensation polymerization.

  Examples of the raw material monomer used to form the amide component include various known polyamines, aminocarboxylic acids, aminoalcohols, etc., preferably hexamethylenediamine and ε-caprolactam.

  The above raw material monomers also include those normally classified as ring-opening polymerization monomers, but these are hydrolyzed by condensation due to the presence of water or the like produced by the condensation polymerization reaction of other monomers. Therefore, it is considered to be included in the raw material monomer of the condensation polymerization resin in a broad sense.

  On the other hand, raw material monomers for addition polymerization resins used in addition polymerization reactions include styrene compounds such as styrene and α-methylstyrene; ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; Halovinyls such as vinyl; vinyl esters such as vinyl acetate and vinyl propionate; alkyl (carbon number 1 to 18) esters of (meth) acrylic acid, ethylenic monocarboxylic acids such as dimethylaminoethyl (meth) acrylate Examples include esters; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride; N-vinyl compounds such as N-vinylpyrrolidone. Among these, the present invention includes binder resins and toners. From the viewpoint of grindability, at least styrene is used. The content of styrene in the raw material monomer of the addition polymerization resin is 90% by weight or more, preferably 95% by weight or more, more preferably 98% by weight or more, and further preferably substantially 100% by weight. It is.

  In addition, a polymerization initiator, a crosslinking agent, or the like may be used as necessary for the addition polymerization of the raw material monomer of the addition polymerization resin.

  The addition polymerization reaction can be performed by a conventional method, for example, in the presence of a polymerization initiator, a crosslinking agent, or the like, in the presence of an organic solvent or in the absence of a solvent. For example, the temperature condition is preferably 110 to 200 ° C., More preferably, it is 140-170 degreeC.

  Examples of the organic solvent used in the addition polymerization reaction include xylene, toluene, methyl ethyl ketone, and acetone. The amount of the organic solvent used is preferably about 10 to 50 parts by weight with respect to 100 parts by weight of the raw material monomer of the addition polymerization resin.

  The binder resin of the present invention is a polycondensation system in addition to the condensation polymerization resin raw material monomer and the addition polymerization resin raw material monomer from the viewpoint of improving the dispersibility of additives such as a release agent in the toner. A resin (hybrid resin) obtained using a compound capable of reacting with both the raw material monomer of the resin and the raw material monomer of the addition polymerization resin (both reactive monomers) is preferable. Therefore, in the present invention, the condensation polymerization reaction and the addition polymerization reaction are preferably carried out in the presence of both reactive monomers. As a result, the hybrid resin has a partial condensation polymerization resin component and addition polymerization resin component. The addition polymerization resin component is more finely and uniformly dispersed in the condensation polymerization resin component.

  As the both reactive monomers, in the molecule, at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group and a secondary amino group, preferably a hydroxyl group and / or A compound having a carboxyl group, more preferably a carboxyl group, and an ethylenically unsaturated bond is preferred. By using such a bireactive monomer, the dispersibility of the resin that becomes the dispersed phase can be further improved. . Both reactive monomers are preferably at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid and maleic anhydride, but from the viewpoint of reactivity, acrylic acid, methacrylic acid and Fumaric acid is more preferred.

  In the present invention, the both reactive monomers are handled as raw material monomers for the condensation polymerization resin. The amount of the both reactive monomers used is preferably 1 to 20% by weight, more preferably 5 to 15% by weight in the carboxylic acid component which is a raw material monomer for the condensation polymerization resin.

  In the present invention, the weight ratio of the condensation polymerization resin to the addition polymerization resin, that is, the weight ratio of the condensation polymerization resin raw material monomer to the addition polymerization resin raw material monomer (condensation polymerization resin raw material monomer / addition polymerization resin). The raw material monomer) is preferably 55/45 to 95/5, more preferably 60/40 to 95/5, since the continuous phase is preferably a condensation polymerization resin and the dispersed phase is an addition polymerization resin. 70/30 to 90/10 is more preferable.

  From the viewpoint of improving the fixability, the toner of the present invention preferably contains a release agent. From the viewpoint of improving the dispersibility of the wax, the binder resin of the present invention is shrunk in the presence of the wax. A resin obtained by polymerizing a raw material monomer of a polymerization resin and a raw material monomer of an addition polymerization resin containing styrene is preferable.

  Examples of the wax include aliphatic hydrocarbon waxes such as low molecular weight polypropylene, low molecular weight polyethylene, low molecular weight polypropylene polyethylene copolymer, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, and oxides thereof, carnauba wax, and montan wax. , Ester waxes such as sazol wax and their deoxidized wax, fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, etc., among these, from the viewpoint of releasability and stability, Aliphatic hydrocarbon waxes are preferred.

  The amount of the wax added is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the total amount of raw material monomers used in the production of the binder resin.

  The addition timing of the wax is not particularly limited, and may be at the beginning of the polymerization or in the middle of the polymerization reaction.

  The softening point of the binder resin of the present invention is preferably from 70 to 170 ° C., more preferably from 80 to 150 ° C., further preferably from 80 to 140 ° C., more preferably from the viewpoints of low-temperature fixability, fixable area, and storage stability. Is 90-130 ° C. In the present specification, the softening point is measured by the method described in Examples described later.

  The binder resin of the present invention is excellent in grindability, and a toner excellent in offset resistance can be obtained using such a binder resin. Therefore, the present invention further provides a toner containing the binder resin of the present invention.

  The toner of the present invention may contain two or more kinds of binder resins. In that case, at least one kind may be the binding resin of the present invention, but all are preferably the binding resin of the present invention. The binder resin of the present invention is 40 to 100% by weight, preferably 70 to 100% by weight, more preferably 90 to 100% by weight, and still more preferably substantially from the viewpoint of dispersibility of the wax. It is desirable to contain 100%. Examples of other binder resins include epoxy resins, polycarbonates, polyurethanes, styrene-acrylic resins, and the like, and they may be contained within a range that does not impair the effects of the present invention.

  In addition to the binder resin, the toner of the present invention includes a colorant, a release agent, a charge control agent, a magnetic powder, a conductivity regulator, an extender pigment, a reinforcing filler such as a fibrous substance, an antioxidant, and an anti-aging agent. In addition, additives such as a fluidity improver and a cleaning property improver may be appropriately contained.

  As the colorant, dyes and pigments used as toner colorants can be used. Carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, solvent red 49, Solvent Red 146, Solvent Blue 35, Quinacridone, Carmine 6B, Disazo Yellow, etc., and these can be used alone or in admixture of two or more. The toner of the present invention includes black toner, color toner, Any of full-color toners may be used. The content of the colorant is preferably 1 to 40 parts by weight and more preferably 2 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  As the mold release agent, the above-mentioned wax can be exemplified. Among these, aliphatic hydrocarbon waxes and ester waxes are preferable from the viewpoint of releasability and stability, and these may be contained alone or in admixture of two or more. The content of the release agent is preferably 0.5 to 10 parts by weight and more preferably 1 to 5 parts by weight with respect to 100 parts by weight of the binder resin. From the viewpoint of improving dispersibility, the release agent may be used together with the resin raw material monomer during the production of the binder resin, and may be internally added to the binder resin.

  Charge control agents include nigrosine dyes, triphenylmethane dyes containing tertiary amines as side chains, quaternary ammonium salt compounds, polyamine resins, imidazole derivatives and other positively chargeable charge control agents and metal-containing azo dyes, copper Examples include negatively chargeable charge control agents such as phthalocyanine dyes, metal complexes of alkyl derivatives of salicylic acid, and boron complexes of benzylic acid.

  The content of the charge control agent is preferably 0.1 to 5 parts by weight and more preferably 0.5 to 2 parts by weight with respect to 100 parts by weight of the binder resin.

Magnetic powder includes ferromagnetic materials such as cobalt, iron and nickel, alloys of metals such as cobalt, iron, nickel, aluminum, lead, magnesium, zinc and manganese, Fe ₃ O ₄ , γ-Fe ₃ O ₄ and cobalt Metal oxides such as added iron oxide, various ferrites such as Mn—Zn ferrite and Ni—Zn ferrite, magnetite, hematite and the like can be used alone or in combination. Furthermore, the surface of these magnetic components may be treated with a surface treatment agent such as a silane coupling agent or a titanate silane coupling agent, or may be polymer-coated.

  When the toner of the present invention is a magnetic toner, the content of the magnetic powder is preferably 10 to 90 parts by weight with respect to 100 parts by weight of the binder resin from the viewpoint of the dispersibility of the magnetic powder and the charging environment. 20 to 80 parts by weight is more preferable, and 30 to 70 parts by weight is more preferable. Further, a known colorant such as carbon black or phthalocyanine blue may be used in combination for adjusting the color and the charge amount.

The toner of the present invention can be produced by a known method such as a kneading and pulverizing method, a spray drying method, or a polymerization method. However, since the binder resin is excellent in pulverizing properties, a pulverized toner obtained by a kneading and pulverizing method is preferable. As a general method of the kneading and pulverization method, for example, a binder resin, and a release agent, a charge control agent, an additive such as magnetic powder, and the like are uniformly mixed with a mixer such as a Henschel mixer and a ball mill, Examples of the method include melt kneading with a closed kneader or a single or twin screw extruder, cooling, pulverizing, and classification. Furthermore, a fluidity improver such as hydrophobic silica may be added to the coarsely pulverized product in the production process or the surface of the obtained toner, if necessary. The volume median particle size (D ₅₀ ) of the toner of the present invention is preferably 3 to 15 μm, more preferably 4 to 8 μm. In the present invention, the volume-median particle size (D ₅₀ ) means a particle size at which the cumulative volume frequency calculated by the volume fraction is 50% when calculated from the smaller particle size.

  The toner of the present invention can be used alone as a developer or mixed with a carrier as a two-component developer, but contains magnetic powder from the viewpoint of good dispersibility of the toner additive. It can be suitably used as a magnetic one-component developing toner. Further, the toner of the present invention can be suitably used for a high-speed machine having a linear speed of 200 mm / sec (A4 paper 40 sheets / min) or more, more preferably 250 to 350 mm / sec.

[Softening point of resin]
Using a flow tester (Shimadzu Corporation, CFT-500D), a 1 g sample was heated at a heating rate of 6 ° C / min, and a load of 1.96 MPa was applied by a plunger and extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. . The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[Melting point of release agent]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), the temperature was raised to 200 ° C, and the sample was cooled to 0 ° C at a temperature drop rate of 10 ° C / min. The maximum peak temperature of heat of fusion is taken as the melting point.

[Volume-median particle size of toner (D ₅₀ )]
Measuring machine: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 100μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter)
Electrolyte: Isoton II (Beckman Coulter, Inc.)
Dispersion: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB: 13.6) is dissolved in the electrolytic solution to a concentration of 5% by weight to obtain a dispersion.
Dispersion conditions: 10 mg of a measurement sample is added to 5 mL of the above dispersion, and dispersed for 1 minute with an ultrasonic disperser, then 25 mL of electrolyte is added, and further dispersed for 1 minute with an ultrasonic disperser. Prepare a dispersion.
Measurement conditions: By adding the sample dispersion to 100 mL of the electrolytic solution, the particle size of 30,000 particles is adjusted to a concentration that can be measured in 20 seconds, and then 30,000 particles are measured, Determine the volume-median particle size (D ₅₀ ).

Resin production examples 1 to 4 (Examples 1 to 4)
Four-necked 10 liters equipped with 10 g of tin octylate as a raw material monomer and esterification catalyst for polyesters other than trimellitic anhydride and acrylic acid shown in Table 1 and equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple The flask was placed in a flask and subjected to a condensation polymerization reaction at 230 ° C. for 8 hours. Furthermore, after reacting at 8 kPa for 1 hour and cooling to 160 ° C., a mixture of acrylic acid, a raw material monomer of vinyl resin and a polymerization initiator shown in Table 1 was dropped over 1 hour with a dropping funnel. After dropping, the addition polymerization reaction was aged for 1 hour while maintaining the temperature at 160 ° C., and then the temperature was raised to 200 ° C. and maintained at 10 kPa for 1 hour to remove the vinyl-based resin raw material monomer. Thereafter, trimellitic anhydride shown in Table 1 was added and reacted for 1 hour, and then a crosslinking reaction was performed at 40 kPa until a predetermined softening point was reached to obtain a resin.

Resin Production Example 5 (Example 5)
Four-necked 10 liters equipped with 10 g of tin octylate as a raw material monomer and esterification catalyst for polyesters other than trimellitic anhydride and acrylic acid shown in Table 1 and equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple The flask was placed in a flask and subjected to a condensation polymerization reaction at 230 ° C. for 8 hours. Further, the reaction is carried out at 8 kPa for 1 hour, Fischer-Tropsch wax “Sazol H105” (manufactured by Sazol) shown in Table 1 is added, and after cooling to 160 ° C., acrylic acid and vinyl resin raw material monomers shown in Table 1 And the mixture of the polymerization initiator was dripped over 1 hour with the dropping funnel. After dropping, the addition polymerization reaction was aged for 1 hour while maintaining the temperature at 160 ° C., and then the temperature was raised to 200 ° C. and maintained at 10 kPa for 1 hour to remove the vinyl-based resin raw material monomer. Thereafter, trimellitic anhydride shown in Table 1 was added and reacted for 1 hour, and then a crosslinking reaction was performed at 40 kPa until a predetermined softening point was reached to obtain a resin.

Resin Production Examples 6-9 (Comparative Examples 1-2 and Examples 6-7)
Using the raw materials shown in Table 1, a reaction was carried out in the same manner as in Resin Production Example 1 to obtain a resin.

Test Example 1 [Crushability]
Resins 1-9 are coarsely pulverized with “NEW ROTOPLEX” (HOSOKAWA / ALPINE), passed through a sieve of 16 mesh (opening: 1 mm), and passed through a sieve of 22 mesh (opening: 710 μm) Not obtained resin powder. 10.00g of the obtained resin powder is precisely weighed, pulverized for 30 seconds with a mill & mixer MM-I type (manufactured by Hitachi Living Supply Co., Ltd.), passed through a sieve of 30 mesh (opening: 500 μm), and does not pass The weight (A) g of the resin is precisely weighed and the formula:
Residual rate = (A) / resin weight before grinding (10.00 g) × 100
Thus, the residual rate was obtained. This operation was performed three times, and the average value of the residual rate at each time was calculated. The average value obtained was used as the grindability index, and evaluated according to the following evaluation criteria. As a result, the pulverizability was as follows: Resins 1, 4 and 5 were ◎, Resins 2 and 8 and an equivalent mixture of Resin 9 were ○, Resins 3 and 6 were Δ, and Resin 7 was ×.

[Evaluation criteria for grindability]
◎: Grindability index is less than 5 ○: Grindability index is 5 or more and less than 10 △: Grindability index is 10 or more, less than 15 ×: Grindability index is 15 or more

Toner Production Examples 1-8 (Examples 8-13 and Comparative Examples 3-4)
The toner materials shown in Table 2 were stirred and mixed with a Henschel mixer, and then melt-kneaded using a co-rotating twin screw extruder having a total kneading part length of 1560 mm, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm. The rotation speed of the roll was 200 r / min, the heating temperature in the roll was 120 ° C., the feed rate of the mixture was 10 kg / hour, and the average residence time was about 18 seconds. The obtained kneaded material was rolled and cooled with a cooling roller, then pulverized with a jet mill, and classified to obtain a powder having a volume-median particle size (D ₅₀ ) of 6 μm.

  Using a Henschel mixer, 100 parts by weight of the obtained powder, 1.5 parts by weight of hydrophobic silica “Aerosil R-972” (manufactured by Nippon Aerosil) and 1.0 part by weight of hydrophobic titanium oxide “TiSr” (manufactured by Fuji Titanium) After mixing, a magnetic toner was obtained.

Test Example 2 [Offset resistance]
250 g of the toner shown in Table 2 was mounted on “Laser Jet 4200” (manufactured by HP), and an image of 2 cm × 12 cm and 0.6 mg / cm ^{2 was} unfixed. For the obtained image, the fixing machine of the copier “AR-505” (manufactured by Sharp Corporation) is improved so that the total fixing pressure of the offline fixing machine is 392 Pa (fixing speed 250 mm / sec: A4 paper) 50 copies / minute) was used, and a fixing test was performed on “CopyBond SF-70NA” (75 g / m ² , manufactured by Sharp Corporation) while gradually increasing the fixing temperature from 100 ° C. to 240 ° C. in 10 ° C. increments. The offset was visually observed, and the temperature at which the offset occurred was evaluated according to the following evaluation criteria. The results are shown in Table 2.

[Evaluation criteria for offset]
Temperature range where offset does not occur between 100 and 240 ° C ◎: 90 ° C or more ○: 70 ° C or more, less than 90 ° C △: 50 ° C or more, less than 70 ° C ×: less than 50 ° C

  From the above results, it can be seen that the toner containing the binder resin of Example has a high offset occurrence temperature and is good.

Toner Production Example 9 (Example 14)
In Toner Production Example 1, in the same manner as in Toner Production Example 1, except that 5 parts by weight of a colorant “ECB301” (manufactured by Dainichi Seika Co., Ltd.) is added to 100 parts by weight of the binder resin instead of magnetic powder. A non-magnetic toner was obtained. The obtained toner was tested for offset resistance in the same manner as described above, and as a result, good results were obtained. In addition, “Microline 5400” (manufactured by Oki Data Corporation) was used for image output for toner evaluation. It can be seen that the binder resin of the present invention can be suitably used in non-magnetic toners.

  The binder resin for toner of the present invention is suitably used as a binder resin for toner used for developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method and the like.

Claims (3)

A binder resin for an electrophotographic toner obtained by condensation polymerization of at least a raw material monomer of a condensation polymerization resin and addition polymerization of a raw material monomer of an addition polymerization resin, wherein the raw material monomer of the addition polymerization resin is: Containing 95% by weight or more of styrene, the weight ratio of the raw material monomer of the condensation polymerization resin to the raw material monomer of the addition polymerization resin (the raw material monomer of the condensation polymerization resin / the raw material monomer of the addition polymerization resin) is 70/30 ~ 90/10 (however, when a compound capable of reacting with both the raw material monomer of the condensation polymerization resin and the raw material monomer of the addition polymerization resin (both reactive monomers) is used, the amount of both reactive monomers used is reduced. treated as the amount of raw material monomers for polymerization resin), an electrophotographic toner binder resin, the polycondensation resin is a condensation polymerization of an alcohol component and a carboxylic acid component A polyester obtained Te, the dually reactive monomer is acrylic acid and / or methacrylic acid, an electrophotographic toner binder resin. A resin obtained by polycondensation of a raw material monomer of a condensation polymerization resin and addition polymerization of a raw material monomer of an addition polymerization resin is further used as a raw material monomer of a condensation polymerization resin and a raw material monomer of an addition polymerization resin. reacting the compound capable of (dually reactive monomer) according to claim 1 Symbol placement electrophotographic toner binder resin is a resin obtained by polymerizing in the presence of. Electrophotographic toner comprising a claim 1 or 2 electrophotographic toner binder resin according.