JP5456633B2 - Toner for electrophotography - Google Patents

Description

  The present invention relates to an electrophotographic toner.

  Electrophotographic toners used in electrophotography include two-component toners and one-component toners. The two-component toner is a toner composed of an insulating toner containing a binder resin, a colorant and the like and a magnetic carrier. The one-component toner includes a magnetic toner containing a magnetic material and a non-magnetic toner not containing a magnetic material. Generally, the magnetic toner is used for black toner, and the non-magnetic toner is used for black toner and color toner.

  Such toner is required to have excellent low-temperature fixability, no offset at low temperatures, and a wide non-offset width. In addition, it is also required that fusion to ground fog, charging blade, etc. be reduced. Therefore, various studies have been made on toners excellent in these characteristics (for example, see Patent Document 1).

JP 2001-222135 A

        The present invention has been made in view of the above circumstances, and provides an electrophotographic toner that has good image density, suppresses fogging to ground fog and blades, has a wide non-offset width, and has low temperature fixability. Let it be an issue.

As a result of intensive studies, the present inventor solved the above problems by using a polyester resin using a specific combination of non-petroleum monomers as a binder resin as a diol component and blending a specific amount of a biodegradable resin. The present inventors have found that this can be done and have completed the present invention.
The toner for electrophotography of the present invention contains at least a binder resin, a biodegradable resin, and a colorant, and the binder resin includes 1,3-propanediol (A) which is a non-petroleum monomer. A polyester resin obtained by using a diol component containing isosorbide (B) which is a non-petroleum monomer, the 1,3-propanediol (A), the isosorbide (B), and the biodegradable resin; The total amount of is 5 to 50% by mass.
The 1,3-propanediol (A) in the polyester resin is preferably 5 to 20% by mass, and the isosorbide (B) is preferably 1 to 20% by mass.
The peak top of the weight average molecular weight of the polyester resin is preferably 2000 to 7000.
The biodegradable resin is at least selected from the group consisting of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (hereinafter referred to as PHBH), polyhydroxyalkanoate other than PHBH, and polylactic acid. One type is preferable.
The electrophotographic toner of the present invention is preferably produced using an open roll type kneader.

  According to the present invention, it is possible to provide an electrophotographic toner having a good image density, suppressing fogging to ground fog and blades, having a wide non-offset width, and low-temperature fixability.

Hereinafter, the present invention will be described in detail.
<Toner for electrophotography>
The toner for electrophotography (hereinafter referred to as toner) of the present invention contains at least a binder resin, a colorant, and a biodegradable resin.

  As the binder resin, a polyester resin obtained by using a diol component containing 1,3-propanediol (A) which is a non-petroleum monomer and isosorbide (B) which is a non-petroleum monomer is used. Generally, a polyester resin is a resin obtained by performing a polycondensation reaction with a diol component composed of at least one diol and a dicarboxylic acid component composed of at least one dicarboxylic acid as main components. As the diol component, a polyester resin produced using at least the non-petroleum monomer 1,3-propanediol (A) and isosorbide (B) is used as the binder resin.

Examples of 1,3-propanediol, which is a non-petroleum monomer, include plant-derived 1,3-propanediol produced from plants such as corn. Examples of such plant-derived 1,3-propanediol include DuPont's trade name: Sastera propanediol.
Isosorbide (= 1,4: 3,6-dianhydro-D-sorbitol), which is a non-petroleum monomer, is a compound represented by the following chemical formula (1) and is produced from, for example, sugars and starch. Specifically, for example, isosorbide can be produced by hydrogenating D-glucose and then dehydrating using an acid catalyst.

  As a diol component, you may use together diols other than said 1, 3- propanediol (A) and isosorbide (B). Such diols include ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, dipropylene glycol, 1, Examples include 5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, and the like. One or more of these can be used.

  Dicarboxylic acid components include aliphatic saturated dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, and sebacic acid, and aliphatic unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, and itaconic acid. , Aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, and isophthalic acid, anhydrides of the various dicarboxylic acids (for example, succinic anhydride, maleic anhydride, phthalic anhydride, etc.) and lower alkyl esters having 1 to 6 carbon atoms ( Examples thereof include succinic acid dimethyl ester, maleic acid diethyl ester, phthalic acid dihexyl ester, and the like, and one or more of these can be used. Of these, phthalic acid and fumaric acid are preferably used.

  As a raw material of the polyester resin, in addition to the diol component and the dicarboxylic acid component described above, if necessary, a trihydric or higher polyhydric alcohol such as glycerin, 2-methylpropanetriol, trimethylolpropane, trimethylolethane, sorbit, sorbitan, Aliphatic monocarboxylic acids such as octanoic acid, decanoic acid, dodecanoic acid, myristic acid, palmitic acid, stearic acid, aliphatic monocarboxylic acids having branched or unsaturated groups, octanol, decanol, dodecanol, myristyl alcohol, palmityl alcohol 1 type of aliphatic monoalcohol such as stearyl alcohol, aromatic monocarboxylic acid such as benzoic acid and naphthalenecarboxylic acid, polyvalent carboxylic acid having 3 or more valences such as trimellitic acid and pyromellitic acid, and acid anhydrides thereof Use more It is possible. Among these, glycerin, trimethylolpropane, stearic acid, trimellitic acid, and benzoic acid are preferable, and trimellitic acid is more preferably used.

  The temperature of the polycondensation reaction when producing the polyester resin is usually 150 to 300 ° C, preferably 180 to 270 ° C, more preferably 180 to 250 ° C. When the reaction temperature is less than 150 ° C., the reaction time becomes long, and when it exceeds 300 ° C., decomposition occurs, which is not preferable.

  The 1,3-propanediol (A) in the polyester resin is preferably 5 to 20% by mass, and the isosorbide (B) is preferably 1 to 7% by mass. By using a polyester resin in each of these ranges as a binder resin, a low-temperature fixable toner having a good image density, suppressing fogging to ground fog and blades, and having a wide non-offset width can be obtained. Can do. The mass% of 1,3-propanediol (A) and isosorbide (B) here is 100 mass% of the total monomer mixture of the polyester raw material (substantially the same as the mass of the resulting polyester resin). Content.

  The molecular weight distribution measured by gel permeation chromatography of the polyester resin described above preferably has a number average molecular weight (Mn) of 1500 to 8000. More preferably, it is 1500-7000. When the number average molecular weight is less than 1500, offset may easily occur or durability may be poor. When the number average molecular weight exceeds 8000, low temperature fixability may be deteriorated.

5000-100000 are preferable and, as for the weight average molecular weight (Mw) of a polyester resin, 5000-60000 are more preferable. If the weight average molecular weight is less than 5,000, offset may easily occur or durability may be poor. If the weight average molecular weight exceeds 100,000, the low-temperature fixability may be deteriorated.
Moreover, it is preferable that the peak top is 2000-7000 about the weight average molecular weight of a polyester resin. A toner using a polyester resin having a peak top of less than 2000 is likely to be fused to the blade, which may cause a decrease in image density, image defects, or offset at high temperatures. On the other hand, if it exceeds 7000, a decrease in the fixing strength of the toner tends to be recognized.

  Moreover, it is preferable that the molecule | numerator of molecular weight less than 1000 contained in a polyester resin is less than 10 mass%. More preferably, it is less than 9 mass%. When the number of molecules having a molecular weight of less than 1000 is 10% by mass or more, the toner may be easily fused to the photoreceptor or the developing roller.

In addition, what is necessary is just to employ | adopt a well-known method, for example, the method using gel permeation chromatography, for measuring the molecular weight distribution and average molecular weight of polymers, such as a polyester resin. A suitable example of the conditions at that time is shown below.
(1) Measurement conditions Temperature: 40 ° C., solvent: tetrahydrofuran, flow rate: 1.0 ml / min
(2) Column: A combination of a plurality of commercially available silica gel columns is used. For example, a combination of two Shodex GPC column KF-806L manufactured by Showa Denko is suitable.
(3) Calibration curve: A calibration curve is prepared using standard polystyrene. As standard polystyrene, for example, Pressure Chemical Co. Manufactured by Toyo Soda Industry Co., Ltd. and having molecular weights of 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , It is appropriate to use 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ and use at least about 10 standard polystyrene.
(4) Detector: An RI (refractive index) detector (for example, SE-31 manufactured by Showa Denko KK) is used.

  The polyester resin preferably has a glass transition temperature (Tg) of 45 to 80 ° C, and more preferably 50 to 70 ° C. When the temperature is lower than 45 ° C., the blocking resistance (storability) of the toner may be deteriorated. When the temperature is higher than 80 ° C., the low-temperature fixability may be deteriorated. Moreover, as a polyester resin, a thing with a flow softening point of 100-135 degreeC is preferable, and a more preferable flow softening point is 100-130 degreeC. If it is less than 105 degreeC, blocking resistance (preservation property) may fall, and if it exceeds 130 degreeC, low temperature fixability may fall.

The glass transition temperature (Tg) here is the temperature of the shoulder portion of the endothermic peak in DSC (differential scanning calorimeter).
The flow softening point means the temperature at the 50% outflow point measured under the following measurement conditions by an elevated flow tester (“CFT-5000” manufactured by Shimadzu Corporation).
Measurement conditions-Plunger: 1 cm ²
・ Die diameter: 1mm
・ Die length: 1mm
・ Load: 20kgf
-Preheating temperature: 50-80 ° C
・ Preheating time: 300 sec
・ Temperature increase rate: 6 ℃ / min

The polyester resin preferably has an acid value of 30 mgKOH / g or less, and more preferably 20 mgKOH / g or less. If the acid value exceeds 30 mgKOH / g, the environmental dependency of charging may increase.
Here, the acid value refers to the number of mg of potassium hydroxide necessary to neutralize 1 g of the resin.

For the binder resin of the toner of the present invention, a specific non-petroleum monomer, that is, a polyester resin using 1,3-propanediol (A) and isosorbide (B) as diol components, and other resins are used in combination. May be. As such other resins, polyester resins other than polyester resins using 1,3-propanediol (A) and isosorbide (B) as diol components, polystyrene resins, styrene acrylic resins, epoxy resins, polyol resins Etc.
The amount of the binder resin in the toner is preferably 40 to 95% by mass in 100% by mass of the toner. Further, when the other resin is used in combination with the polyester resin using 1,3-propanediol (A) and isosorbide (B) as the diol component as the binder resin, the ratio of the other resin is the physical property value of the toner. In consideration of the above, an arbitrary addition amount can be selected.

  As the biodegradable resin, at least one selected from the group consisting of PHBH, polyhydroxyalkanoates other than PHBH, and polylactic acid can be suitably used. Hereinafter, polyhydroxyalkanoates other than PHBH may be referred to as PHA.

  PHBH is an aliphatic polyester having a repeating structure composed of a 3-hydroxyalkanoate represented by the following formula (2). PHBH is a polymer synthesized by microorganisms using vegetable oil as a main raw material.

[—CHR—CH ₂ —CO—O—] (2)

Here, R is an alkyl group represented by C _n H _{2n + 1} . N is 1 and 3. That is, PHBH is a combination of 3-hydroxybutyrate (also referred to as 3HB) in which n is 1 in formula (1) and 3-hydroxyhexanoate (also referred to as 3HH) in which n is 3. It is a polymer.
The composition ratio of 3-hydroxybutyrate and 3-hydroxyhexanoate in PHBH, that is, 3-hydroxybutyrate / 3-hydroxyhexanoate is 99/1 to 80/20 (mol / mol) Is preferred.

PHA is a polymer (aliphatic polyester) of hydroxyalkanoate, and in this specification, means a substance other than the above-mentioned PHBH.
Examples of hydroxyalkanoates include 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 3-hydroxypropionate, 4-hydroxybutyrate, 4-hydroxyvalerate, 5-hydroxyvalerate, 3 -Hydroxyhexanoate (3HH), 3-hydroxyheptanoate, 3-hydroxyoctanoate, 3-hydroxynonanoate, 3-hydroxydecanoate and the like. PHA may be a homopolymer of these hydroxyalkanoates or a copolymer of two or more of these, but a copolymer of two or more of these is preferred.

  Specific examples of PHA include PHB, which is a 3HB homopolymer, and PHBV, which is a 2-component copolymer of 3HB and 3HV, and a 3-component copolymer PHBHV of 3HB, 3HV and 3HH (see Japanese Patent No. 2777757). Etc.). In particular, a copolymer having 3HH as a monomer component is preferable in terms of having degradability and soft properties as a biodegradable resin. For example, in the case of PHBHV, the composition ratio of each monomer unit is not particularly limited. For example, the content of 3HB units is 1 to 95 mol%, the content of 3HV units is 1 to 96 mol%, and the content of 3HH units is 3HH units. The content is preferably in the range of 1 to 30 mol%.

Polylactic acid (hereinafter sometimes referred to as PLA) is mainly composed of a lactic acid component, and includes a lactic acid copolymer and a blend polymer in addition to a polylactic acid homopolymer. The weight average molecular weight of polylactic acid is generally 2 to 500,000. Further, the constituent molar ratio (L / D) of the L-lactic acid unit and the D-lactic acid unit in the polylactic acid may be any ratio of 100/0 to 0/100.
Further, in order to obtain a toner having higher fixing strength and fluidity in a lower temperature range, it contains 75 mol% to 98 mol% of either L-lactic acid or D-lactic acid. It is preferable. More preferably, it contains 80 to 95 mol% of either L-lactic acid or D-lactic acid. If it is less than 75 mol%, the polylactic acid will be in an amorphous state, and the fixing strength of the resulting toner will be reduced, which tends to cause offset. On the other hand, if it exceeds 98 mol%, the polylactic acid becomes highly crystalline, the flow starting point becomes high, and further, it melts sharply at the melting point of the polylactic acid, and the carrier (in the case of a two-component toner) or other charging member. Tend to cause fusion to occur.

  The lactic acid copolymer is obtained by copolymerizing a lactic acid monomer or other component copolymerizable with lactide. Examples of such other components include dicarboxylic acids having two or more ester bond-forming functional groups, polyhydric alcohols, hydroxycarboxylic acids, lactones, etc., and various polyesters and various polyethers composed of these various components. And various polycarbonates. Examples of the dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, and isophthalic acid. Examples of polyhydric alcohols include aromatic polyhydric alcohols such as those obtained by addition reaction of bisphenol with ethylene oxide, ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, glycerin, sorbitan, trimethylolpropane, neo Examples include aliphatic polyhydric alcohols such as pentyl glycol, ether glycols such as diethylene glycol, triethylene glycol, polyethylene glycol, and polypropylene glycol. Examples of the hydroxycarboxylic acid include glycolic acid, hydroxybutylcarboxylic acid, and others described in JP-A-6-184417. Examples of the lactone include glycolide, ε-caprolactone glycolide, ε-caprolactone, β-propiolactone, δ-butyrolactone, β- or γ-butyrolactone, pivalolactone, δ-valerolactone, and the like.

  Polylactic acid can be synthesized by a conventionally known method. For example, direct dehydration condensation from a lactic acid monomer or a lactic acid cyclic dimer as described in JP-A-7-33861, JP-A-59-96123, Polymer Proceedings Proceedings Vol. 44, pages 3198-3199 It can be synthesized by ring-opening polymerization of lactide. When direct dehydration condensation is performed, any lactic acid of L-lactic acid, D-lactic acid, DL-lactic acid, or a mixture thereof may be used. Moreover, when performing ring-opening polymerization, you may use any lactide of L-lactide, D-lactide, DL-lactide, or these mixtures. Lactide synthesis, purification and polymerization procedures are described, for example, in US Pat. No. 4,057,537, published European Patent Application No. 261572, Polymer Bulletin, 14, 491-495 (1985) and Makromol Chem. 187, 1611-1628 (1986), etc.

  The catalyst used for the polymerization reaction at this time is not particularly limited, but a known lactic acid polymerization catalyst can be used. For example, tin lactate, tin tartrate, dicaprylate, dilaurate, dipalmitate, distearate, dioleate, α-naphthoate, β-naphthoate, octylate, tin powder, tin oxide Tin compounds such as zinc powder, zinc halide, zinc oxide, organic zinc compounds; titanium compounds such as tetrapropyl titanate; zirconium compounds such as zirconium isopropoxide; antimony compounds such as antimony trioxide; Examples thereof include bismuth compounds such as bismuth (III); aluminum compounds such as aluminum oxide and aluminum isopropoxide. Among these, a catalyst made of tin or a tin compound is particularly preferable from the viewpoint of activity. The amount of these catalysts used is, for example, about 0.001 to 5% by mass with respect to lactide when ring-opening polymerization is performed. The polymerization reaction can be usually performed at a temperature of 100 to 220 ° C. in the presence of the catalyst, although it varies depending on the catalyst type. It is also preferable to carry out two-stage polymerization as described in JP-A-7-247345.

  As the biodegradable resin, at least one selected from the group consisting of the above-described PHBH, polyhydroxyalkanoates other than PHBH, and polylactic acid can be suitably used, but it is preferable to use at least PHBH.

In the toner of the present invention, the total amount of 1,3-propanediol (A), isosorbide (B) and biodegradable resin is 5 to 50% by mass, preferably 10 to 50% by mass, in 100% by mass of the toner. It is. In the toner in which the total amount of 1,3-propanediol (A), isosorbide (B), and biodegradable resin is less than 5% by mass, offset generation at a high temperature becomes remarkable. On the other hand, if it exceeds 50% by mass, the fixing strength is lowered and the toner productivity is deteriorated. In the present invention, 100% by mass of the toner is an amount including an external additive attached to the surface of the toner particles.
Further, the content of the biodegradable resin is preferably 5 to 20% by mass in 100% by mass of the toner.

As the colorant, a black pigment can be used for a black toner, and a magenta pigment, a cyan pigment, a yellow pigment, and the like can be used for a color toner.
Carbon black can be used as the black pigment. Carbon black can be used without being limited by the number average particle diameter, oil absorption, PH, etc., and the following are commercially available products. For example, trade names: REGAL 400, 660, 330, 300, SRF-S, STERING SO, V, NS, and R manufactured by Cabot Corporation of the United States can be given. Moreover, the brand name made from Columbian Carbon Japan: RAVEN H20, MT-P, 410, 420, 430, 450, 500, 760, 780, 1000, 1035, 1060, 1080. In addition, trade names manufactured by Mitsubishi Chemical Corporation: # 5B, # 10B, # 40, # 2400B, MA-100, and the like can be given. These carbon blacks can be used alone or in combination of two or more.

    Examples of the magenta pigment include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 163, 202, 206, 207, 209; I. Pigment violet 19; C.I. I. Butlet 1, 2, 10, 13, 15, 23, 29, 35, etc. can be used. These magenta pigments can be used alone or in combination of two or more.

    Examples of cyan pigments include C.I. I. Pigment Bull-2, 3, 15, 16, 17; I. Bat Bull-6; I. Acid Bull-45 etc. can be used. These cyan pigments can be used alone or in combination of two or more.

    Examples of yellow pigments include C.I. I. Pigment Yellow-1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 74, 83, 93, 94, 97, 155 180, etc. can be used. These yellow pigments can be used alone or in combination of two or more.

Among these pigments for color toners, magenta pigments are C.I. from the viewpoint of color mixing and color reproducibility. I. Pigment Red 57 and 122 are cyan pigments. I. Pigment Blue 15 is yellow pigment is C.I. I. Pigment Yellow 17, 93, 155, and 180 can be preferably used.
As the pigment for the color toner, a so-called master batch which is dispersed in a high concentration in a resin that can be a binder resin in advance may be used.

The carbon black content in the black toner is preferably in the range of 0.1 to 20% by mass, more preferably 1 to 10% by mass, and still more preferably 1 to 5% in 100% by mass of the black toner. % By mass, particularly preferably 1 to 3% by mass. When the carbon black content is less than the above range, the image density is lowered, and when it exceeds the above range, the image quality is liable to be lowered, and the toner moldability is also lowered.
In addition to carbon black, black magnetic powder such as iron oxide and ferrite can be used as the black pigment.

    The content of the color toner pigment in the color toner is preferably in the range of 1 to 20% by mass, particularly preferably 4.5 to 8% by mass in 100% by mass of the color toner. When the content of the color toner pigment is less than the above range, the image density is lowered, and when it exceeds the above range, the charging stability is deteriorated and the image quality is liable to be lowered. It is also disadvantageous in terms of cost.

In addition to the binder resin, biodegradable resin, and colorant, a release agent, a charge control agent, magnetic powder, an additive, and the like can be added to the toner as optional components. Hereinafter, each component will be described.
Examples of the release agent include polyolefin waxes such as polyethylene wax, polypropylene wax, polybutene wax and modified polyethylene wax, synthetic waxes such as Fischer-Tropsch wax, paraffin waxes such as natural paraffin, micro wax and synthetic paraffin, and microcrystalline wax. Petroleum wax, carnauba wax, candelilla wax, rice wax, hydrogenated castor oil, acidic olefin wax, maleic acid ethyl ester, maleic acid butyl ester, stearic acid methyl ester, stearic acid butyl ester, palmitic acid cetyl ester, ethylene montanate Ester wax, stearamide, oleic acid made of fatty acid ester such as glycol ester or partially saponified product thereof Bromide, palmitic acid amide, lauric acid amide, behenic acid amide, methylene bis stearamide, amide waxes such as ethylene bis stearamide and the like.

Among these waxes, Fischer-Tropsch wax, acidic olefin wax, ester wax, paraffin wax, and polypropylene wax are preferable, and ester wax, paraffin wax, and polypropylene wax are particularly preferable. Moreover, these mold release agents can be used individually or in combination of 2 or more types. You may mix the mold release agent from which a softening point (melting | fusing point) differs.
Further, from the softening point, a release agent having a relatively low softening point or a low melting point, specifically, a softening point (melting point) of 50 to 170 ° C., more preferably 70 to 160 ° C. is preferable. When the softening point is less than 50 ° C., the toner has insufficient blocking resistance and storage stability, and when it exceeds 170 ° C., the fixing start temperature is undesirably increased.

  The content of the release agent is preferably in the range of 0.1 to 10% by mass, preferably 0.5 to 7% by mass, more preferably 1 to 5% by mass in 100% by mass of the toner. It is. If the content of the release agent is less than the above range, the toner release function is insufficient and the toner tends to adhere to the heat fixing roller. As a result, image offset and paper wrapping may occur. There is a possibility that the fixing resin of the image is lowered due to difficulty in melting the resin. On the other hand, if the above range is exceeded, the release agent may be detached from the toner and may adhere to various members in the image forming apparatus such as a copying machine or a printer. May cause malfunctions.

Examples of the charge control agent include a positive charge control agent and a negative charge control agent.
Examples of positively chargeable charge control agents include modified products of nigrosine and fatty acid metal salts, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, Diorganotin oxide such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide, diorganotin borate such as dibutyltin borate, dioctyltin borate, dicyclohexyltin borate, pyridium salt, azine, triphenylmethane compounds and cationic functional groups And low molecular weight polymers. These positively chargeable charge control agents may be used alone or in combination of two or more. As these positively chargeable charge control agents, nigrosine compounds and quaternary ammonium salts are preferably used.

  Examples of negatively chargeable charge control agents include acetylacetone metal complexes, monoazo metal complexes, organometallic compounds such as naphthoic acid or salicylic acid metal complexes or salts, chelate compounds, and low molecular weight polymers having an anionic functional group. It is done. These negatively chargeable charge control agents can be used alone or in combination of two or more. As these negatively chargeable charge control agents, salicylic acid metal complexes and monoazo metal complexes are preferably used.

    The content of the charge control agent can usually be selected in the range of 0.1 to 5% by mass in 100% by mass of the toner, preferably 0.5 to 4% by mass, and more preferably 1 to 4% by mass. The charge control agent is preferably colorless or light color for color toners.

    When the magnetic toner is used, examples of the magnetic powder include metals such as cobalt, iron, nickel, aluminum, copper, iron, nickel, magnesium, tin, zinc, gold, silver, selenium, titanium, tungsten, zirconium, and others. Metal alloys, metal oxides such as aluminum oxide, iron oxide and nickel oxide, ferrite, magnetite and the like can be used. The addition amount of the magnetic powder is usually 1 to 70% by mass, preferably 5 to 60% by mass, and more preferably 10 to 50% by mass in 100% by mass of the toner. The average particle size of the magnetic powder is preferably 0.01 to 3 μm.

    Examples of additives include stabilizers (for example, UV absorbers, antioxidants, heat stabilizers, etc.), flame retardants, antifogging agents, dispersants, nucleating agents, and plasticizers (phthalate esters, fatty acid plastics). Agents, phosphoric acid plasticizers, etc.), polymer antistatic agents, low molecular antistatic agents, compatibilizers, conductive agents, fillers, fluidity improvers, and one of these as required The above may be added.

An external additive may be attached to the surface of the toner from the viewpoint of imparting fluidity.
As the external additive, inorganic fine particles such as silica, alumina, talc, clay, calcium carbonate, magnesium carbonate, titanium oxide, carbon black powder, and magnetic powder are preferable, and they may be used alone or in combination of two or more. Of inorganic fine particles, silica can be particularly preferably used. Silica is not particularly limited to its average particle diameter, BET specific surface area, surface treatment and the like, and can be appropriately selected according to the use. However, the BET specific surface area is preferably in the range of 50 to 400 m ² / g, and the surface-treated hydrophobic Silica is preferred.

In addition to the inorganic fine particles, resin fine powders such as polytetrafluoroethylene resin powder and polyvinylidene fluoride resin powder may be used in combination with the toner and adhered as an external additive.
In the case of using inorganic fine particles or resin fine powder as an external additive, the amount can be appropriately selected from the range of 0.01 to 8% by mass, preferably 0.3 to 3% by mass, in 100% by mass of the toner. . By using the external additive within such a range, the fluidity and charging stability of the toner are improved, and a uniform image can be formed.

    The toner of the present invention is not limited to the development method, and can be used for a non-magnetic one-component development method, a magnetic one-component development method, a two-component development method, and other development methods. When the toner for magnetic one-component development is used, the above-described magnetic powder is mixed with the binder resin. When the toner for a two-component development system is used, the toner of the present invention is used by mixing with a carrier. Among these, from the viewpoint of simplicity of the image forming apparatus and cost, it is preferably used as a toner for a non-magnetic one-component development system.

    In the case of the toner for the two-component development system, for example, nickel, cobalt, iron oxide, ferrite, iron, glass beads, etc. can be used as the carrier. These carriers may be used alone or in combination of two or more. The average particle size of the carrier is preferably 20 to 150 μm. Further, the surface of the carrier may be coated with a coating agent such as a fluorine resin, an acrylic resin, or a silicone resin.

    Further, the toner of the present invention may be a monochrome toner (black toner) or a full color toner. The above-mentioned carbon black can be used as a colorant for a non-magnetic toner for monochrome, and the black color of the above-described magnetic powder can be used as a colorant for a magnetic toner for monochrome. Things can be used. In the full-color toner, the above-described color pigment can be used as a colorant.

<Manufacturing method>
The toner of the present invention comprises a mixing step of mixing optional components as necessary in addition to a binder resin, a biodegradable resin and a colorant, and a kneading step of thermally melting and kneading the mixture obtained by the mixing step. And a pulverizing and classifying step of pulverizing the kneaded product obtained in the kneading step. An optional step of adding an external additive to the pulverized toner may be provided after the pulverization and classification step.

(Mixing process)
In the mixing step, a mixture can be prepared using a mixing device such as a double cone mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, or a Nauter mixer.

(Kneading process)
In the kneading step, the mixture is hot-melt kneaded to uniformly disperse the colorant, biodegradable resin, and optional components in the binder resin to obtain a kneaded product. In the kneading step, a batch type (for example, a pressure kneader, a Banbury mixer, etc.) or a continuous type hot melt kneader may be used. An extruder is preferred. For example, open roll type continuous kneader, KTK type twin screw extruder manufactured by Kobe Steel Co., Ltd., TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by Kay Sea Kay Co., Ltd., PCM type manufactured by Ikekai Tekko Co., Ltd. A twin screw extruder, a twin screw extruder manufactured by Kuriyama Seisakusho, a co-kneader manufactured by Buss, etc. are preferred.
Among these, when an open roll type continuous kneader is used, even a biodegradable resin that is poorly compatible with the polyester resin for toner can be uniformly dispersed.

In the open roll type continuous kneader, two rolls, a front roll and a back roll, are arranged in parallel, and the raw material passes through the gap between the two rolls, and kneading is performed by mechanical shearing force at that time. It is. In addition, this roll has a spiral groove and a lateral groove, and these grooves are provided in the vicinity of the other end of the roll from the action of causing the raw material to bite into the gap between the rolls and the raw material supply unit provided in the vicinity of one end of the roll. There exists an effect | action which accelerates | stimulates conveying a kneaded material to the provided kneaded material discharge | emission part. The raw material can be appropriately supplied not only from the roll end but also from the first half, middle and second half of the roll according to the characteristics of the raw material.
The open roll type continuous kneader can exhibit heating and cooling functions by passing a heating medium such as oil or hot water through the front roll and a cooling medium such as water through the back roll. Thereby, kneading can be performed at an appropriate temperature, and by performing cooling together with kneading, it is not necessary to employ a cooling process as a separate process, and the process can proceed directly to the pulverization process.
As an open roll type continuous kneader, “Needex (trade name)” manufactured by Nippon Coke Kogyo Co., Ltd. can be used.

(Crushing classification process)
In the pulverizing and classifying step, the kneaded material in a hot-melt state obtained from the kneader is cooled and solidified, and then pulverized and classified to obtain a classified toner.
The pulverization is performed by coarsely pulverizing with a crusher, hammer mill, feather mill or the like, then finely pulverizing with a jet mill, high-speed rotor rotary mill or the like, and pulverizing to a predetermined toner particle size step by step.
Then, the toner is classified by an inertia class elbow jet, a centrifugal class microplex, a DS separator, a dry air classifier or the like to obtain a classified toner having a volume average particle diameter of 3 to 15 μm.
The coarse powder obtained at the time of classification may be returned to pulverization, and the obtained fine powder may be returned to the kneading step and reused.

(External addition process)
When attaching an external additive to the surface of the toner, a predetermined amount of the classified toner obtained in the pulverization and classification step and the external additive are blended to give a shearing force to powder such as a Henschel mixer or a super mixer. An external addition step of stirring and mixing with a high-speed stirrer (external additive machine) is performed. At this time, heat is generated inside the external additive machine, and aggregates are easily generated. Therefore, it is preferable to adjust the temperature by cooling the periphery of the container part of the external additive machine with water. Furthermore, it is preferable to control the material temperature inside the container of the external additive machine to a management temperature that is about 10 ° C. lower than the glass transition temperature of the binder resin.

  As described above, at least the binder resin, the biodegradable resin, and the colorant are contained, and the binder resin includes 1,3-propanediol (A) that is a non-petroleum monomer and a non-petroleum monomer. A polyester resin obtained using a diol component containing isosorbide (B), and the total amount of 1,3-propanediol (A), isosorbide (B), and biodegradable resin is 5 to 5. The toner of 50% by mass uses a polyester resin using a specific combination of non-petroleum monomers as a binder resin as a diol component, and a specific amount of a biodegradable resin is blended. Good, suppressed fogging to ground and blades, wide non-offset width, and excellent low-temperature fixability.

Examples of the present invention will be described below, but the present invention is not limited to these examples.
(Binder resin)
As the binder resin, the following polyester resins (1) to (4) were used.
Polyester resin (1): In the resin, 1,3-propanediol (A) of the non-petroleum monomer as the diol component is 20% by mass, and isosorbide (B) of the non-petroleum monomer is 20% by mass, Fumaric acid and phthalic acid are used as the dicarboxylic acid component, trimellitic acid is included as the crosslinking component, the flow softening point is 125 ° C., the acid value is 11.7 mg KOH / g, the Mw peak top is 2450, and the Tg (shoulder) is 61 ° C. Is a polyester resin.
Polyester resin (2): In the resin, 1,3-propanediol (A) of the non-petroleum monomer as the diol component is 5% by mass, and isosorbide (B) of the non-petroleum monomer is 1% by mass, Fumaric acid and phthalic acid are used as the dicarboxylic acid component, trimellitic acid is included as the crosslinking component, the flow softening point is 125 ° C., the acid value is 13.1 mg KOH / g, the Mw peak top is 2500, and the Tg (shoulder) is 60 ° C. Is a polyester resin.
Polyester resin (3): Resin polymerized using ethylene glycol, bisphenol A PO adduct as diol component, fumaric acid, phthalic acid, trimellitic acid as dicarboxylic acid component, flow softening point 110 ° C, acid Polyester resin having a valence of 9.1 mg KOH / g, Mw peak top of 1900, and Tg of 58 ° C.
Polyester resin (4): Resin polymerized using ethylene glycol, bisphenol A PO adduct as diol component, fumaric acid, phthalic acid, trimellitic acid as dicarboxylic acid component, flow softening point 140 ° C, acid A polyester resin having a value of 5.4 mg KOH / g, Mw peak top of 7500, and Tg of 65 ° C.

[Example 1]
(Manufacture of toner)
Using a Henschel mixer (trade name: “Henschel Mixer 20L” manufactured by Mitsui Mining Co., Ltd.), the following components were uniformly mixed for 5 minutes under the condition of 2000 rpm (mixing step). Then, the obtained mixture was melt-kneaded with an open roll kneader (manufactured by Nippon Coke Kogyo Co., Ltd., trade name: “NIDEX MOS160”) (kneading step).
The kneading conditions are as follows.
Rotation speed: F roll = 50 rpm, B roll = 30 rpm
Temperature: F roll temperature upstream side = 120 ° C, downstream side = 100 ° C, B roll = 30 ° C
Discharge rate: 15 kg / hr

-Binder resin; polyester resin (1) 81 parts by mass-Colorant: Carbon black 5 parts by mass (trade name: "Sunblack 200" manufactured by Asahi Carbon Co., Ltd.)
・ Charge control agent: 1 part by mass of iron complex (monoazo metal complex) (trade name: “T-77” manufactured by Hodogaya Chemical Co., Ltd.)
・ Release agent: Polypropylene wax 2 parts by mass Release agent: Ester wax 2 parts by mass (trade name: “WEP-8” manufactured by NOF Corporation)
・ PLA 2 parts by mass ・ PHBH 5 parts by mass

Next, the cooled kneaded material was coarsely pulverized with a hammer mill, and finely pulverized with a jet mill (manufactured by Hosokawa Micron Corporation, trade name: “200 APG”).
Then, it was classified with a dry air classifier (trade name: “100ATP” manufactured by Hosokawa Micron Corporation) to obtain a classified toner having a volume average particle diameter of 6.5 μm and a circularity of 0.925 (pulverization classification step).

To 98 parts by mass of the obtained classified toner, the following external additive composed of silica and titanium oxide was added and mixed with a 10 L Henschel mixer for 5 minutes at a rotational speed of 2500 rpm to obtain an evaluation toner (external addition step). .
Silica 1.7 parts by mass (manufactured by CABOT, average primary particle size 10.5 nm, specific surface area 200 m ² / g)
・ 0.3 parts by mass of titanium oxide (manufactured by Fuji Titanium Co., Ltd., primary particle size 300 nm, specific surface area 9 m ² / g, treatment agent silicone oil)

[Example 2]
A toner for evaluation of Example 2 was obtained in the same manner as in Example 1 except that the binder resin was changed to the polyester resin (2).

[Example 3]
An evaluation toner of Example 3 was obtained in the same manner as in Example 1 except that the binder resin was 68 parts by mass, PLA was 10 parts by mass, and PHBH was 10 parts by mass.

[Example 4]
A toner for evaluation of Example 4 was obtained in the same manner as in Example 1 except that PHA5 parts by mass and PHBH10 parts by mass were used instead of PLA2 parts by mass and PHBH5 parts by mass, and the binder resin was 73 parts by mass. It was.
As the PLA, one having a weight average molecular weight of 30,000 and Tg of 60 ° C. was used.

[Comparative Example 1]
A toner for evaluation of Comparative Example 1 was obtained in the same manner as Example 1 except that the binder resin was polyester resin (3).

[Comparative Example 2]
A toner for evaluation of Comparative Example 2 was obtained in the same manner as Example 1 except that the binder resin was polyester resin (4).

[Comparative Example 3]
For evaluation of Comparative Example 4 in the same manner as in Example 1, except that PLA 12 parts by mass and PHBH 15 parts by mass were used instead of PLA 2 parts by mass and PHBH 5 parts by mass, and the content of the binder resin was 61 parts by mass. A toner was obtained.

Table 1 shows the ratio of the total amount of 1,3-propanediol (A), isosorbide (B), and biodegradable resin in the whole toner in Examples and Comparative Examples.

<Evaluation 1>
Each toner for evaluation (nonmagnetic one-component toner) in Examples and Comparative Examples is filled in a cartridge, and is a non-magnetic one-component four-pass developing type printer with a printing rate of 5% and a printing speed of 5 pages / min. A printing durability test was performed up to one sheet.
At this time, the temperature of the fixing roll of the printer was set to 170 ° C.
Then, the image density and background fog at the time of the printing durability test were evaluated as follows. Also, the presence or absence of toner fusion to the charging blade after printing was confirmed by observing the contact surface with a microscope.
The results are shown in Table 2.
(Image density)
The density of a solid image of 25 mm × 25 mm was measured with a spectral color difference meter (trade name: 939, manufactured by X-rite).
(Ground fog)
Using a whiteness meter (manufactured by Nippon Denshoku Industries Co., Ltd., trade name: ColorMeter2000), the difference between the whiteness of the non-image area at the time of the printing test and the whiteness before the printing test is calculated as the value of the background fog. did.
(Storage stability)
The storage stability was evaluated by the presence or absence of lumps after standing in a constant temperature bath at 50 ° C. for 3 days. The evaluation criteria are: no lump generation: ○, slight lump: Δ, strong lump: x.

As shown in Table 2, in each example, a decrease in image density due to the printing durability test, toner fusion to the charging blade after the printing durability test was not observed, and the background fogging value was good, and the long There was no problem with the actual machine characteristics.
On the other hand, in Comparative Example 1, since the polyester resin (3) was used, the toner fusion to the charging blade became noticeable, and an image defect caused by this occurred. Therefore, the evaluation was stopped when 2000 sheets were printed. .
In Comparative Examples 2 and 3, there was no problem in the print image quality, but when the print portion was rubbed strongly with a finger, a phenomenon that the toner peeled off from the paper occurred and the fixing strength was insufficient.

<Evaluation 2>
(Fixing test)
Mn—Mg—Sr ferrite with an average particle size of 35 μm coated with acrylic resin (PMMA) was used as a carrier (composition was Fe ₂ O ₃ : MnO: MgO: SrO = 73: 23: 3.5: 0.5, resin The developer was prepared with a coating ratio of 1.5% by mass) and a mixing ratio with the toner: carrier = toner = 93% by mass: 7% by mass.
Using this developer, a strip-shaped unfixed image having a length of 3 cm and a width of 6 cm was produced on A4 transfer paper by a commercially available copying machine (SF-9800, manufactured by Sharp Corporation). The toner adhesion amount on the transfer paper was adjusted to about 1.6 mg / cm ² depending on the toner concentration, the surface potential of the photoreceptor, the development potential, the exposure amount, the transfer conditions, and the like.
Next, a fixing machine in which a heat fixing roll whose surface layer is made of polytetrafluoroethylene and a pressure fixing roll whose surface layer is made of silicone rubber rotates in a pair, a roll pressure is 1 kgf / cm ² , The roll speed was adjusted to 100 mm / sec, and the surface temperature of the heat fixing roll was increased stepwise from 100 to 220 ° C. at intervals of 5 ° C., and the above-mentioned unfixed image was held at each surface temperature. The toner image on the transfer paper was fixed.
At the time of fixing, observation was made as to whether or not the transfer paper having an unfixed image was wound around the surface of the heat fixing roll, and the low temperature side winding generation temperature and the high temperature side winding generation temperature were confirmed.
At the same time, it was observed whether or not toner contamination occurred in the blank portion, and a temperature region where the contamination did not occur was defined as a non-offset temperature region.
Further, the fixing strength, that is, the fixing strength when fixing at 150 ° C., 170 ° C., and 190 ° C. was derived as follows.
The surface temperature of the heat fixing roll of the fixing machine was set to 150 ° C., 170 ° C., and 190 ° C., respectively, and the toner image patches with different amounts of adhesion on the paper were fixed. Then, after measuring the image density of the formed fixed image using a spectral color difference meter (product name: 939, manufactured by X-rite), the fixed image is applied with a sand eraser while applying a weight of 1 kg. Then, the image density was measured in the same manner. The fixing strength was calculated from the obtained measurement value according to the following formula, and the portion where the image density was most drastically decreased was defined as the minimum remaining rate.
Minimum remaining rate (%) = (image density of fixed image after rubbing / image density of fixed image before rubbing) × 100
The results are shown in Table 3.

As shown in Table 3, in Examples 1 to 4, a sufficient non-offset width and fixing strength were obtained.
In contrast, in Comparative Example 1, a decrease in the high temperature non-offset region was confirmed, and in Comparative Examples 2 and 3, a decrease in the fixing strength was confirmed. In Comparative Examples 2 and 3, an increase in the low temperature non-offset region was also observed.

  According to the present invention, it is possible to provide a toner having a good image density, suppressed fogging to ground fog and blades, a wide non-offset width, and low-temperature fixability. This toner has excellent compatibility with the environment.

Claims (5)

Containing at least a binder resin, a biodegradable resin, and a colorant;
The binder resin contains a polyester resin obtained by using a diol component containing 1,3-propanediol (A) which is a non-petroleum monomer and isosorbide (B) which is a non-petroleum monomer,
An electrophotographic toner, wherein a total amount of the 1,3-propanediol (A), the isosorbide (B), and the biodegradable resin is 5 to 50% by mass.   2. The electrophotography according to claim 1, wherein the 1,3-propanediol (A) in the polyester resin is 5 to 20% by mass, and the isosorbide (B) is 1 to 20% by mass. Toner.   The toner for electrophotography according to claim 1 or 2, wherein the peak top of the weight average molecular weight of the polyester resin is 2000 to 7000.   The biodegradable resin is at least selected from the group consisting of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (hereinafter referred to as PHBH), polyhydroxyalkanoate other than PHBH, and polylactic acid. The toner for electrophotography according to claim 1, wherein the toner is one type.   The electrophotographic toner according to claim 1, wherein the toner is produced using an open roll type kneader.