JP3878537B2 - Dry toner - Google Patents

Description

【００４８】
［評価方法］
▲１▼粉体流動性
ホソカワミクロン製パウダーテスターを用いて静かさ密度を測定した。
流動性の良好なトナーほど静かさ密度は大きい。
▲２▼耐熱保存性
トナーを５０℃×８時間保管後、４２メッシュのふるいにて２分間ふるい、金網上の残存率をもって耐熱保存性とした。
耐熱保存性の良好なトナーほど残存率は小さい。
▲３▼光沢発現温度(ＧＬＯＳＳ)
市販カラー複写機（ＣＬＣ−１；キヤノン製）の定着装置からオイル供給装置を取り除き、定着ロール上のオイルを除去した改造機を用いて定着評価した。定着画像の６０゜光沢が１０％以上となる定着ロール温度をもって光沢発現温度とした。
▲４▼ホットオフセット発生温度(ＨＯＴ)
上記ＧＬＯＳＳと同様に定着評価し、定着画像へのホットオフセットの有無を目視評価した。ホットオフセットが発生した定着ロール温度をもってホットオフセット発生温度とした。
▲５▼帯電量
トナー１ｇと電子写真用フェライトキャリア（パウダーテック（株）製；ＦＬ９６１−１５０）２４ｇとをターブラーシェイカーミキサーを用いて３０分間混合し、帯電量をブローオフ帯電量測定装置（東芝ケミカル製）を用いて測定した。
【００４９】
【発明の効果】
本発明の乾式トナーは以下の効果を奏する。
１．粉体流動性に優れ、現像性、転写性に優れる。
２．耐熱保存性に優れ、かつ、低温定着性と耐ホットオフセット性のいずれにも優れる。
３．カラートナーとした場合の光沢性に優れ、かつ耐ホットオフセット性が優れるため、定着ロールにオイル塗布をする必要がない。
４．カラートナーとした場合の透明性が高く、色調に優れる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dry toner used for electrophotography, electrostatic recording, electrostatic printing, and the like.
[0002]
[Prior art]
Conventionally, as dry toners used for electrophotography, electrostatic recording, electrostatic printing, and the like, toner binders such as styrene resins and polyesters are melt-kneaded together with colorants and finely pulverized.
These dry toners are developed and transferred onto paper or the like and then fixed by heating and melting using a hot roll. At that time, if the temperature of the hot roll is too high, a problem that the toner is excessively melted and fused to the hot roll (hot offset) occurs. On the other hand, if the heat roll temperature is too low, there is a problem that the toner is not sufficiently melted and fixing becomes insufficient. From the viewpoint of energy saving and downsizing of apparatuses such as copying machines, toners having higher hot offset generation temperature (hot offset resistance) and lower fixing temperature (low temperature fixability) are required.
In addition, heat storage stability is required so that the toner is not blocked during storage and at ambient temperature in the apparatus.
In particular, in full-color copying machines and full-color printers, the gloss and color mixing of the image are required, so the toner needs to have a lower melt viscosity, and a sharp-melt polyester toner binder is used. ing. Since such toner easily causes hot offset, conventionally, in a full-color device, silicone oil or the like is applied to a heat roll.
However, the method of applying silicone oil to the hot roll requires an oil tank and an oil application device, which is complicated and large. Moreover, it causes deterioration of the heat roll and requires maintenance every certain period. Furthermore, it is inevitable that oil adheres to copy paper, OHP (overhead projector) film, and the like, especially in OHP, there is a problem of deterioration of color tone due to the adhered oil.
On the other hand, in recent years, there is an increasing need for a toner having a small particle size in order to improve image quality and improve resolution. However, since the conventional kneaded and pulverized toner has an irregular shape, the powder fluidity becomes insufficient when the particle size is small, and it becomes difficult to supply the toner to the developing device, and the transferability is low. A worsening problem arises.
[0003]
Among the above-mentioned problems, (1) a polyester partially crosslinked with a polyfunctional monomer is used as a toner binder to satisfy both heat storage stability, low-temperature fixability and hot offset resistance 57-109825), and (2) those using urethane-modified polyester as a toner binder (Japanese Patent Publication No. 7-101318) have been proposed.
Further, as a means for reducing the amount of oil applied to a hot roll for full color, (3) a product obtained by granulating polyester fine particles and wax fine particles (Japanese Patent Laid-Open No. 7-56390) has been proposed.
[0004]
Furthermore, for improving powder flowability and transferability when the particle size is reduced, (4) after dispersing a vinyl monomer composition containing a colorant, a polar resin and a release agent in water. Suspension polymerized toner (Japanese Patent Laid-Open No. 9-43909), (5) Toner made of polyester resin in water using a solvent (Japanese Patent Laid-Open No. 9-34167) is proposed. ing.
[0005]
[Problems to be solved by the invention]
However, all of the toners disclosed in (1) to (3) are insufficient in powder flowability and transferability, and cannot be improved in image quality by reducing the particle size.
Further, the toners disclosed in (1) and (2) cannot be used because they are still insufficient in both heat-resistant storage stability and low-temperature fixability and do not exhibit gloss for full color.
Further, the toner disclosed in (3) has insufficient low-temperature fixability and does not satisfy the hot offset property in oilless fixing.
The toner disclosed in (4) has an effect of improving powder flowability and transferability, but has a problem that the low-temperature fixability is insufficient and the energy required for fixing increases. This problem is particularly noticeable with full-color toners.
The toner disclosed in (5) also has an effect of improving powder flowability and transferability, but the low-temperature fixability is superior to that of (4), but the hot offset resistance is insufficient. It does not make it unnecessary to apply oil to the roll.
[0006]
[Means for Solving the Problems]
An object of the present invention is to provide a dry toner excellent in powder flowability and transferability when a small particle size toner is used.
Another object of the present invention is to provide a dry toner having excellent heat storage stability, low-temperature fixability, and hot offset resistance.
Furthermore, an object of the present invention is to provide a dry toner having excellent image glossiness when used in a full-color copying machine or the like.
Furthermore, an object of the present invention is to provide a dry toner that does not require oil application to a hot roll.
As a result of intensive studies to achieve the above object, the present invention has been achieved.
That is, according to the present invention, in a dry toner comprising a toner binder and a colorant, the Wadell's practical sphericity of the resin toner is 0.90 to 1.00, and the toner binder is a high molecular weight polyester resin (A). It consists of a low molecular weight polyester resin (B), and the ratio (MnA / MnB) of the number average molecular weight (MnA) of the resin (A) to the number average molecular weight (MnB) of the resin (B) is 1.6 or more. And the ratio (MwA / MwB) of the weight average molecular weight (MwA) of the resin (A) to the weight average molecular weight (MwB) of the resin (B) is 5.0 or more, and the resin (A) A dry toner having a number average molecular weight (MnA) of 5000 or more [the resin (A) is a polyester modified with a urethane bond and / or a urea bond, and the resin (A) and the resin (B) is diol alone and Excluding those polyesters consisting of a polycondensate of a carboxylic acid alone. ].
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
In the present invention, Wadell's practical sphericity is a value represented by (diameter of a circle equal to the projected area of the particle) / (diameter of the smallest circle circumscribing the projected image of the particle). It can be measured by observing.
The practical sphericity of Wadell is usually 0.90 to 1.00, preferably 0.95 to 1.00, and more preferably 0.98 to 1.00. In the present invention, the practical sphericity of all the toner particles does not need to be in the above range, and may be within the above range as the number average. The number average is calculated from the values obtained by randomly extracting about 20 of the obtained toner particles.
The toner has a median diameter (d50) of usually 2 to 20 μm, preferably 3 to 10 μm.
[0008]
Examples of the high molecular weight condensation resin (A) and the low molecular weight condensation resin (B) constituting the toner binder include polyester, polyurethane, polyurea, polyamide, and epoxy resin. Of these, polyester, polyurethane and epoxy resin are preferable, and polyester is particularly preferable.
[0009]
Examples of the polyester include a polycondensate of polyol (1) and polycarboxylic acid (2).
Examples of the polyol (1) include a diol (1-1) and a tri- or higher valent polyol (1-2). (1-1) alone or (1-1) and a small amount of (1-2) Mixtures are preferred. The ratio of the mixture is a molar ratio of (1-1) and (1-2), and is usually 100/0 to 100/20, preferably 100/0 to 100/10.
As the diol (1-1),
C2-C18 alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, dodecanediol, etc.); carbon 4 to 1000 alkylene ether glycol (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.);
C5-C18 alicyclic diol (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.);
Bisphenols having 12 to 23 carbon atoms (bisphenol A, bisphenol F, bisphenol S, etc.);
C2-C18 alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, alpha-olefin oxide, etc.) adducts (addition mole number is 2-20) etc. of the said alicyclic diol or bisphenol are mentioned.
Among these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts having 2 to 18 carbon atoms of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols (particularly bisphenol A) (especially 2 to 3 mol adduct of ethylene oxide or propylene oxide), and an alkylene glycol having 2 to 12 carbon atoms (especially ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, neopentyl glycol) It is a combination.
In the case of the combined use, the alkylene oxide adduct of bisphenols is usually at least 30 mol%, preferably at least 50 mol%, particularly preferably at least 70 mol%.
As the trivalent or higher polyol (1-2),
3 to 8 or more polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.);
Trivalent to octavalent or higher phenols (trisphenol PA, phenol novolak, cresol novolak, etc.);
Examples thereof include alkylene oxide adducts having 2 to 18 carbon atoms (number of added moles of 2 to 20) of the above-mentioned trivalent or higher polyphenols.
[0010]
Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2). (2-1) alone and (2-1) with a small amount of ( The mixture of 2-2) is preferred. The ratio of the mixture is a molar ratio of (2-1) and (2-2), and is usually 100/0 to 100/20, preferably 100/0 to 100/10.
As dicarboxylic acid (2-1),
C2-C20 alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, dodecane dicarboxylic acid, dodecenyl succinic acid, dodecyl succinic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid (phthalic acid) Acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.).
Among these, preferred are alkylene dicarboxylic acids having 4 to 20 carbon atoms (especially adipic acid and dodecenyl succinic acid), alkenylene dicarboxylic acids having 4 to 20 carbon atoms (especially maleic acid and fumaric acid), and aromatics having 8 to 20 carbon atoms. Group dicarboxylic acids (especially isophthalic acid and terephthalic acid).
Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, and the like).
In addition, as polycarboxylic acid (2), you may make it react with polyol (1) using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.
[0011]
The ratio of the polyol (1) to the polycarboxylic acid (2) is usually 2/1 to 1/2, preferably 1., as the molar ratio [OH] / [COOH] of the hydroxyl group [OH] to the carboxyl group [COOH]. 5/1 to 1 / 1.5, more preferably 1.3 / 1 to 1 / 1.3.
The process for producing the polyester of the present invention can be obtained by heating polycarboxylic acid and polyol to 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxy titanate and dibutyltin oxide, followed by dehydration condensation. It is also effective to reduce the pressure in order to improve the reaction rate at the end of the reaction.
[0012]
The high molecular weight polyester (A) in the present invention is preferably a polyester modified with a urethane bond and / or a urea bond.
Of the polyesters modified with urethane bonds and / or urea bonds, the polyesters modified with urethane bonds include polycondensates of polyol (1) and polycarboxylic acid (2) and a hydroxyl group-containing polyester, A reaction product with isocyanate (3) and the like can be mentioned.
Examples of the method of adding the hydroxyl group to the polycondensate of (1) and (2) include reacting the number of moles of the hydroxyl group in (1) in excess of the carboxyl group in (2).
[0013]
Examples of the polyol (1) include the diol (1-1) and a trivalent or higher valent polyol (1-2). Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent. The above polycarboxylic acid (2-2) is mentioned. The ratio of the polyol (1) to the polycarboxylic acid (2) is usually 2/1 to 1/1, preferably 1 as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 0.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.
The number average molecular weight of the polyester having a hydroxyl group is usually 1000 to 20000, preferably 1500 to 15000, particularly preferably 2000 to 10,000. The weight average molecular weight is usually 2000 to 50000, preferably 3000 to 30000, and particularly preferably 4000 to 20000.
The hydroxyl value of the polyester having a hydroxyl group is usually 5 to 120, preferably 7 to 70, particularly preferably 10 to 60. The acid value is usually 10 or less, preferably 5 or less, particularly preferably 2 or less.
[0014]
As polyisocyanate (3), C6-C20 aromatic polyisocyanate, C2-C18 aliphatic polyisocyanate, C4-C15 alicyclic (except for carbon in NCO group) Formula polyisocyanate, aromatic aliphatic polyisocyanate having 8 to 15 carbon atoms and modified products of these polyisocyanates (urethane group, carbodiimide group, allophanate group, urea group, burette group, uretdione group, uretoimine group, isocyanurate group, Oxazolidone group-containing modified products) and mixtures of two or more thereof.
Specific examples of the aromatic polyisocyanate include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, and 2,4 ′. -And / or 4,4'-diphenylmethane diisocyanate (MDI), crude MDI [crude diaminophenylmethane [condensation product of formaldehyde with an aromatic amine (aniline) or mixtures thereof; diaminodiphenylmethane and a small amount (eg 5 to 20 wt.] %) Of trifunctional or higher polyamines] phosgenates: polyallyl polyisocyanate (PAPI)], 1,5-naphthylene diisocyanate, 4,4 ′, 4 ″ -triphenylmethane triisocyanate, m- and p-isocyanatophenylsulfonyl isocyanate Such as theft and the like.
[0015]
Specific examples of the aliphatic polyisocyanate include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, Lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate And aliphatic polyisocyanates.
[0016]
Specific examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4′-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis (2 -Isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate, 2,5- and / or 2,6-norbornane diisocyanate and the like.
[0017]
Specific examples of the aromatic aliphatic polyisocyanate include m- and / or p-xylylene diisocyanate (XDI), α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI), and the like.
Examples of the modified polyisocyanate include modified MDI (urethane-modified MDI, carbodiimide-modified MDI, trihydrocarbyl phosphate-modified MDI, etc.), modified polyisocyanates such as urethane-modified TDI, and mixtures of two or more thereof [for example, Combination of modified MDI and urethane-modified TDI (isocyanate-containing prepolymer)].
Among these, preferred are aromatic polyisocyanates having 6 to 15 carbon atoms, aliphatic polyisocyanates having 4 to 12 carbon atoms, and alicyclic polyisocyanates having 4 to 15 carbon atoms, and particularly preferred are TDI, MDI, HDI, hydrogenated MDI, and IPDI.
Moreover, when reacting polyester which has a hydroxyl group, and polyisocyanate (3), another polyol can also be used together.
The ratio of the polyisocyanate (3) is usually 1/2 to 2/1 as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the total [OH] of the polyester having a hydroxyl group and other polyols. The ratio is preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2.
[0018]
Polyester modified with a urethane bond can be produced by the following method.
The polyol (1) and the polycarboxylic acid (2) are heated to 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and the generated water is distilled off as necessary. Thus, a polyester having a hydroxyl group is obtained. Next, this is reacted with polyisocyanate (3) and, if necessary, a polyol at 50 to 140 ° C. to obtain a polyester modified with a urethane bond. When reacting (3), a solvent can be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to the isocyanate (3), such as tetrahydrofuran (such as tetrahydrofuran).
[0019]
Examples of the polyester modified with a urea bond include a reaction product of a polyester prepolymer (a) having an isocyanate group and an amine (b). Examples of the polyester prepolymer (a) having an isocyanate group include a polycondensate of a polyol (1) and a polycarboxylic acid (2) and a polyester having an active hydrogen-containing group, which is further reacted with a polyisocyanate (3). Is mentioned.
Examples of the active hydrogen-containing group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), a carboxyl group, and the like. Among these, an alcoholic hydroxyl group is preferable.
The polyester having an alcoholic hydroxyl group can be obtained by using an excess of polyol as in the case of the polyester modified with the urethane bond. On the other hand, a polyester having a carboxyl group can be obtained by using an excessive amount of polycarboxylic acid.
Examples of the polyol (1), polycarboxylic acid (2), and polyisocyanate (3) include those similar to the polyester modified with the urethane bond, and preferred ones are also the same.
The ratio of the polyisocyanate (3) is usually 5/1 to 1/1, preferably 4 as the equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. / 1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1.
The NCO content (NCO equivalent) is usually 500 to 10000, preferably 700 to 8000, and particularly preferably 1000 to 5000.
[0020]
As amines (b), diamine (b1), tri- or hexavalent or higher polyamine (b2), amino alcohol (b3), amino mercaptan (b4), amino acid (b5), and amino groups of b1 to b5 (B6) etc. that are blocked.
Examples of the diamine (b1) include aromatic diamines having 6 to 23 carbon atoms (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines having 5 to 20 carbon atoms (4,4′-diamino). -3,3 'dimethyldicyclohexylmethane, diaminocyclohexane, isophoronediamine, etc.); and aliphatic diamines having 2 to 18 carbon atoms (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.).
Examples of the triamine to hexavalent or higher polyamine (b2) include diethylenetriamine and triethylenetetramine.
Examples of the amino alcohol (b3) include those having 2 to 12 carbon atoms, and specific examples thereof include ethanolamine and hydroxyethylaniline.
Examples of the amino mercaptan (b4) include those having 2 to 12 carbon atoms, and specific examples include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of the amino acid (b5) include those having 2 to 12 carbon atoms, and specific examples include aminopropionic acid and aminocaproic acid.
The b1 to b5 blocked amino groups (b6) include ketimine compounds and oxazoline compounds obtained from the amines b1 to b5 and ketones having 3 to 8 carbon atoms (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) Etc.
Among these amines (b), preferred are (b1) (especially 4,4′diaminodiphenylmethane, isophoronediamine and ethylenediamine) and a mixture of (b1) and a small amount of (b2) (especially diethylenetriamine). More preferably, the amino group of these amines is blocked.
The ratio of the mixture is usually 100/0 to 100/10, preferably 100/0 to 100/5, as the molar ratio of (b1) and (b2).
[0021]
Furthermore, if necessary, the molecular weight of the urea-modified polyester can be adjusted using a reaction terminator. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
The ratio of amines (b) is equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in prepolymer (a) having isocyanate groups and amino groups [NHx] in amines (b). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2.
[0022]
In the present invention, the polyester modified with a urea bond may contain a urethane bond together with a urea bond.
The ratio of urea bond to urethane bond is usually 10/0 to 1/9, preferably 8/2 to 2/8, and more preferably 6/4 to 3/7.
Polyester modified with a urea bond can be produced by the following method.
In the same manner as described above, a polyester having a hydroxyl group is obtained, and then polyisocyanate (3) is reacted at 40 to 140 ° C. to obtain a prepolymer having an isocyanate group. This is reacted with amines (or blocked ones) at 0 to 140 ° C. to obtain a polyester modified with a urea bond. When making it react, a solvent can also be used if necessary. Examples of the usable solvent include the same solvents as described above.
[0023]
Examples of the polyurethane in the present invention include a polyaddition product of polyol (1) and polyisocyanate (3).
Examples of the polyol (1) include the diol (1-1) and a trivalent or higher valent polyol (1-2).
As polyisocyanate (3), aromatic polyisocyanate having 6 to 20 carbon atoms (excluding carbon in NCO group, the same shall apply hereinafter), aliphatic polyisocyanate having 2 to 18 carbon atoms, and having 4 to 15 carbon atoms. Alicyclic polyisocyanates, aromatic aliphatic polyisocyanates having 8 to 15 carbon atoms, and modified products of these polyisocyanates (urethane groups, carbodiimide groups, allophanate groups, urea groups, burette groups, uretdione groups, uretoimine groups, isocyanurates Group, an oxazolidone group-containing modified product, etc.) and a mixture of two or more thereof.
[0024]
Examples of the polyurea in the present invention include a reaction product of the polyisocyanate (3) and the amines (b).
Examples of the amines (b) include the diamine (b1), a polyamine (b2) having 3 to 6 or more valences, an amino alcohol (b3), an amino mercaptan (b4), an amino acid (b5), and b1 to b5. Examples thereof include an amino group blocked (b6).
Among these amines (b), preferred are (b1) (especially 4,4′diaminodiphenylmethane, isophoronediamine and ethylenediamine) and a mixture of (b1) and a small amount of (b2) (especially diethylenetriamine). The ratio of the mixture is usually 100/0 to 100/10, preferably 100/0 to 100/5, as the molar ratio of (b1) and (b2).
[0025]
Furthermore, if necessary, the molecular weight of the polyurea can be adjusted using a reaction terminator. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
[0026]
The ratio of amines (b) is the isocyanate group in polyisocyanate (3).
The molar ratio [NCO] / [NHx] of [NCO] to the amino group [NHx] in the amine (b) is usually 1/2 to 2/1, preferably 1.5 / 1 to 1/1. 5, more preferably 1.2 / 1 to 1 / 1.2.
When b3 to b5 are used as the amines (b), the molar ratio [NCO] / [YHx] of the total [YHx] of the amino group and hydroxyl group, mercapto group or carboxyl group in (b) is usually 1 / It is 2-2 / 1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2.
By setting the molar ratio within the above range, the molecular weight of the polyurea increases and the hot offset resistance is improved.
[0027]
Examples of the polyamide include polycondensates of polycarboxylic acid (2) and amines (b).
Examples of the polycarboxylic acid (2) include the dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2).
Examples of the amines (b) include the diamine (b1), a polyamine (b2) having 3 to 6 or more valences, an amino alcohol (b3), an amino mercaptan (b4), an amino acid (b5), and b1 to b5. Examples thereof include an amino group blocked (b6).
[0028]
Examples of the epoxy resin include addition condensates of bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.) and epichlorohydrin.
[0029]
The ratio (MnA / MnB) of the number average molecular weight of (A) and (B) must be 1.6 or more. Preferably it is 1.9 or more, More preferably, it is 2.1-33, Most preferably, it is 2.3-28. If it is less than 1.6, the hot offset resistance is insufficient when the low temperature fixability is improved, and the low temperature fixability is insufficient when the hot offset resistance is improved.
The number average molecular weight (MnA) of (A) is usually 5000 or more, preferably 6000 to 100,000, and more preferably 6500 to 60,000.
The number average molecular weight (MnB) of (B) is usually 1000 to 5000, preferably 1300 to 4000, and more preferably 1500 to 3500.
The ratio (MwA / MwB) of the weight average molecular weight of (A) and (B) must be 2.0 or more. Preferably it is 2.5-100, More preferably, it is 4.0-70, Most preferably, it is 5.0-50. If it is less than 2.0, the hot offset resistance is insufficient when the low temperature fixability is improved, and the low temperature fixability is insufficient when the hot offset resistance is improved.
The weight average molecular weight (MwA) of (A) is usually 5000 or more, preferably 6,000 to 1,000,000, more preferably 8,000 to 500,000.
The weight average molecular weight (MwB) of (B) is usually 1000 to 50000, preferably 1500 to 20000, and more preferably 2000 to 20000.
The weight ratio of (A) to (B) is usually 5/95 to 60/40, preferably 8/92 to 55/45, more preferably 10/90 to 50/50, particularly preferably 15/85 to 40 /. 60.
[0030]
In the dry toner of the present invention, the toner binder preferably has at least two peaks in the molecular weight distribution measured by gel filtration chromatography (GPC).
Furthermore, in the molecular weight distribution obtained by GPC measurement, it is preferable that each has at least one peak in a region having a peak molecular weight of less than 20,000 and a region having a peak molecular weight of 30,000 or more.
Here, the molecular weight distribution is measured by preparing a calibration curve of molecular weight with standard polystyrene using gel permeation chromatography (hereinafter abbreviated as GPC) using tetrahydrofuran (hereinafter abbreviated as THF) as a solvent.
Specific molecular weight measurement conditions are as follows.
Apparatus: HLC-802A manufactured by Toyo Soda
Column: 2 TSK gel GMH6 (manufactured by Toyo Soda)
Measurement temperature: 25 ° C
Sample solution: 0.5 wt% THF solution
Solution injection volume: 200 μl
Detector: Refractive index detector
The molecular weight calibration curve is based on standard polystyrene (molecular weights 842,44,28,290,109,350,000, 190,000, 964,000, 37,000, 196,000, 91,000, 2 98,000, 870, 500).
[0031]
In the dry toner of the present invention, the difference (SPA-SPB) between the SP value (SPA) of the high molecular weight condensation resin (A) constituting the toner binder and the SP value (SPB) of the low molecular weight condensation resin (B). ) Is usually 0.1 or more, preferably 0.2 or more, more preferably 0.3 or more, from the viewpoint of hot offset resistance. The SP value can be calculated by a known Fedors method.
In the present invention, the glass transition point (Tg) of the toner binder is usually 35 to 85 ° C., preferably 45 to 70 ° C., from the viewpoint of heat-resistant storage stability and low-temperature fixability of the toner.
As the storage elastic modulus of the toner binder, the temperature (TG ′) at which the measurement frequency is 20 Hz is 10000 dyne / cm 2 is usually 100 ° C. or higher, preferably 110 to 200 ° C. from the viewpoint of hot offset resistance.
As the viscosity of the toner binder, the temperature (Tη) at 1000 poise at a measurement frequency of 20 Hz is usually 180 ° C. or less, preferably 90 to 160 ° C. from the viewpoint of low-temperature fixability.
That is, from the viewpoint of achieving both low temperature fixability and hot offset resistance, TG ′ is preferably higher than Tη. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or higher. More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more.
Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 100 ° C. or less. More preferably, it is 90 degrees C or less, Most preferably, it is 80 degrees C or less.
Here, the measurement conditions of dynamic viscoelasticity are as follows.
Apparatus: RDS-7700II dynamic spectrometer manufactured by Rheometrics Inc., USA
Test Fix Chair: 25mmΦ cone plate used
Measurement temperature: 100 ° C to 240 ° C
Measurement frequency: 20 Hz (125.6 rad / sec)
Distortion: 5% fixed
[0032]
Known dyes, pigments and magnetic powders can be used as the colorant of the present invention. Specifically, as dyes, Sudan Black SM, First Yellow-G, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Priliant Green, Oil Yellow GG, Kaya Set YG, Orazol Brown B, Oil Pink OP, etc. Examples of pigments include carbon black, benzidine yellow, pigment yellow, Indian first orange, Irgasin red, varanitoaniline red, toluidine red, carmine FB, pigment orange R, lake red 2G, phthalocyanine blue, pigment blue, phthalocyanine Examples of the magnetic powder include magnetite and iron black. Among these, preferred are a colorant selected from the group consisting of cyan, magenta and yellow dyes, and a colorant selected from the group consisting of cyan, magenta and yellow pigments.
The content of the colorant is usually 2 to 15% by weight, preferably 3 to 10% by weight.
Further, a wax may be contained together with the toner binder and the colorant.
Known waxes can be used as the wax of the present invention, such as polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax, sasol wax, etc.); carbonyl group-containing wax, etc. It is done. Of these, carbonyl group-containing waxes are preferred.
Carbonyl group-containing waxes include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18. -Octadecandiol-bis-stearate, etc.); polyalkanol esters (tristearyl trimellitic acid, distearyl maleate, etc.); polyalkanoic acid amides (ethylenediamine dibehenylamide, etc.); polyalkylamides (trimellitic acid tristearylamide) And dialkyl ketone (such as distearyl ketone).
Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred.
The melting point of the wax of the present invention is usually from 40 to 160 ° C., preferably from 50 to 120 ° C., more preferably from 60 to 90 ° C., from the viewpoints of heat resistant storage stability and cold offset during fixing at a low temperature.
Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point from the viewpoint of hot offset resistance and low-temperature fixability.
The wax content in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight, and particularly preferably 10 to 25% by weight.
In the dry toner of the present invention, a charge control agent and a fluidizing agent can also be used.
As the charge control agent, known ones, that is, nigrosine dye, quaternary ammonium salt compound, quaternary ammonium base-containing polymer, metal-containing azo dye, salicylic acid metal salt, sulfonic acid group-containing polymer, fluorine-containing polymer, halogen-substituted aromatic Examples thereof include a ring-containing polymer.
The content of the charge control agent is usually 0 to 5% by weight.
As the fluidizing agent, known materials such as colloidal silica, alumina powder, titanium oxide powder, and calcium carbonate powder can be used.
[0033]
The dry toner can be produced by the following methods (1) to (3).
(1) Sphericalizing of pulverized toner
A method in which a toner material composed of a toner binder and a colorant is melt-kneaded and then finely pulverized and then mechanically spheronized using a hybridizer, mechanofusion, or the like.
(2) Spray drying method
A method of obtaining a spherical toner by dissolving and dispersing a toner material in a solvent in which a toner binder is soluble and then removing the solvent using a spray drying apparatus.
(3) Dispersion granulation method (for example, the method described in JP-A-9-15902)
After the toner material is dissolved and dispersed in a solvent in which the toner binder is soluble, the toner material is dispersed in a poor solvent (for example, water, water-methanol) of the toner binder with stirring, and then the solvent is distilled off to form toner particles. A method of obtaining spherical toner by liquid separation and drying.
Among these, (3) the dispersion granulation method is preferable, and the dispersion granulation method in which the poor solvent serving as the dispersed phase is an aqueous medium is particularly preferable.
In addition, as a simple method for obtaining a high molecular weight polyester, a polyester having an isocyanate group in advance and a blocked amine (elongating agent) together with other components (low molecular weight polyester, pigment, additive, etc.) are used as an organic solvent. A method of forming a high-molecular-weight polyester by an extension reaction between the dispersion step and the solvent removal step is preferable after being dissolved and dispersed in water.
Examples of the solvent that dissolves the toner binder in advance used in the dispersion granulation method in an aqueous medium include ethyl acetate, acetone, and methyl ethyl ketone.
Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.
Examples of the dispersant include an organic dispersant such as a water-soluble polymer (α) and a surfactant (β), an inorganic dispersant (γ), and the like. Examples of (α) include nonionic water-soluble polymer (α-1), anionic water-soluble polymer (α-2), and cationic water-soluble polymer (α-3).
Examples of (α-1) include polyvinyl alcohol, hydroxyethyl cellulose, polyacrylamide, and modified polyether. Examples of (α-2) include polystyrene sulfonate, polyacrylate, carboxymethylcellulose soda salt, and the like. Examples of (α-3) include polystyrene quaternary ammonium salts, polyvinyl imidazoline hydrochloride, polyallylamine hydrochloride, and the like. Examples of (β) include sodium lauryl sulfate and sodium oleate. Examples of (γ) include calcium carbonate powder, calcium phosphate powder, and silica fine powder. Two or more dispersants can be used in combination.
The content of the dispersant is usually 0.1 to 20% by weight, preferably 0.5 to 10% by weight.
When a dispersant is used, the dispersant can remain on the surface of the toner particles. However, it is preferable from the charged surface of the toner that the solvent is removed by washing after removing the solvent.
Further, from the viewpoint of easy washing and removal, the dispersant used is preferably an organic dispersant such as a water-soluble polymer (α) and a surfactant (β).
[0034]
The dry toner of the present invention may be mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite, magnetite, and ferrite whose surface is coated with a resin (acrylic resin, silicone resin, etc.) as necessary. Used as an image developer. In addition, instead of carrier particles, it can be rubbed with a member such as a charging blade to form an electrical latent image.
The dry toner in the present invention is fixed on a support (paper, polyester film, etc.) by various known fixing methods to form a recording material.
Examples of the fixing method include an infrared lamp method, a xenon flash method, a planar heater method, a heating roller fixing method, a heat belt fixing method, and a high-frequency fixing method; a pressure fixing method; a solvent fixing method. The heat fixing method is preferable, the xenon flash method, the planar heater method, the heating roller fixing method, and the heat belt fixing method are more preferable, and the heat roller fixing method and the heat belt fixing method are particularly preferable.
[0035]
Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto. Hereinafter, a part shows a weight part. Examples 1 to 5 are reference examples.
[0036]
【Example】
Example 1
(Synthesis of isocyanate group-containing prepolymer)
724 parts of bisphenol A ethylene oxide 2-mole adduct, 276 parts of isophthalic acid and 2 parts of dibutyltin oxide are placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and reacted at 230 ° C. for 8 hours at normal pressure. Then, after reacting for 5 hours while dehydrating at a reduced pressure of 10 to 15 mmHg, the mixture was cooled to 80 ° C. and reacted with 188 parts of isophorone diisocyanate in ethyl acetate for 2 hours to obtain an isocyanate group-containing prepolymer having a weight average molecular weight of 12,000. Obtained.
(Synthesis of blocked amines)
In a reaction vessel equipped with a stir bar and a thermometer, 30 parts of isophoronediamine and 70 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain a ketimine compound.
(Synthesis of low molecular weight polyester)
In the same manner as above, 724 parts of bisphenol A ethylene oxide 2-mole adduct, 138 parts of terephthalic acid and 138 parts of isophthalic acid were polycondensed at 230 ° C. for 6 hours under normal pressure, and then reacted for 5 hours while dehydrating at a reduced pressure of 10 to 15 mmHg. Thus, a low molecular weight polyester (B-1) having a number average molecular weight of 1900 and a weight average molecular weight of 4000 was obtained.
(Create toner)
15.4 parts of the above isocyanate group-containing prepolymer, 64 parts of (B-1) and 78.6 parts of ethyl acetate were placed in a beaker, and dissolved by stirring. Next, 20 parts of pentaerythritol tetrabehenate and 4 parts of cyanine blue KRO (manufactured by Sanyo Dye) were added and stirred at 12000 rpm with a TK homomixer at 60 ° C. to uniformly dissolve and disperse. Finally, 2.7 parts of ketimine compound was added and dissolved. This is a toner material solution.
In a beaker, 706 parts of ion-exchanged water, 294 parts of hydroxyapatite 10% suspension (Superite 10 manufactured by Nippon Chemical Industry Co., Ltd.) and 0.2 part of sodium dodecylbenzenesulfonate were uniformly dissolved. Next, the temperature was raised to 60 ° C., and the toner material solution was added and stirred for 10 minutes while stirring at 12000 rpm with a TK homomixer. The mixture is then transferred to a Kolben equipped with a stirrer and a thermometer, heated to 98 ° C., the solvent is removed while undergoing a urea reaction, filtered, washed, dried, air-classified, and particle size Toner particles having a d50 of 6 μm were obtained. Subsequently, 100 parts of the toner particles were mixed with 0.5 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil) using a sample mill to obtain the toner (1) of the present invention. The practical sphericity of the toner particles was 0.98.
The toner binder component in the toner (1) had Tg of 52 ° C., Tη of 123 ° C., TG ′ of 132 ° C., and peak molecular weights of 4500 and 70000. The high molecular weight polyester (A-1) in the toner binder had a number average molecular weight of 6000 and a weight average molecular weight of 64,000. MnA / MnB was 3.2 and MwA / MwB was 16.
The difference (SPA-SPB) between the SP value (SPA) of (A-1) and the SP value (SPB) of (B-1) in the toner binder was 0.31. The evaluation results are shown in Table 1.
[0037]
Example 2
(Toner binder synthesis)
343 parts of bisphenol A ethylene oxide 2-mole adduct, 166 parts of isophthalic acid and 2 parts of dibutyltin oxide are placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and reacted at 230 ° C. for 8 hours at normal pressure. The mixture was further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg, then cooled to 110 ° C., 17 parts of isophorone diisocyanate was added in toluene, the reaction was performed at 110 ° C. for 5 hours, then the solvent was removed, and the number average molecular weight 6500 A high molecular weight urethane group-containing polyester (A-2) having a weight average molecular weight of 72,000 was obtained.
In the same manner as described above, 570 parts of bisphenol A ethylene oxide 2-mole adduct and 217 parts of terephthalic acid were polycondensed at 230 ° C. for 6 hours under normal pressure, and a low molecular weight polyester having a number average molecular weight of 2000 and a weight average molecular weight of 4200 (B-2 )
200 parts of (A-2) and 800 parts of (B-2) were dissolved and mixed in 2000 parts of ethyl acetate to obtain an ethyl acetate solution of toner binder (2).
Part of the mixture was dried under reduced pressure to isolate the toner binder (2). Tg was 55 ° C., Tη was 128 ° C., TG ′ was 140 ° C., and peak molecular weights were 5000 and 80000. MnA / MnB was 3.3 and MwA / MwB was 17.
The difference (SPA-SPB) between the SP value (SPA) of (A-2) and the SP value (SPB) of (B-2) in the toner binder was 0.27.
[0038]
(Create toner)
In a beaker, 240 parts of the ethyl acetate solution of the toner binder (2), 20 parts of pentaerythritol tetrabehenate (melting point: 81 ° C., melt viscosity: 25 cps), 4 parts of cyanine blue KRO (manufactured by Sanyo Dye) are placed at 60 ° C. The mixture was stirred at 12000 rpm with a TK homomixer and uniformly dissolved and dispersed.
In a beaker, 706 parts of ion-exchanged water, 294 parts of hydroxyapatite 10% suspension (Superite 10 manufactured by Nippon Chemical Industry Co., Ltd.) and 0.2 part of sodium dodecylbenzenesulfonate were uniformly dissolved. Next, the temperature was raised to 60 ° C., and the toner material solution was added and stirred for 10 minutes while stirring at 12000 rpm with a TK homomixer. The mixture is then transferred to a Kolben equipped with a stir bar and a thermometer, and the temperature is raised to 98 ° C. to remove the solvent. After filtering, washing and drying, air classification is performed, and toner particles having a particle size d50 of 6 μm are obtained. Obtained. Subsequently, 100 parts of the toner particles were mixed with 0.5 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil) using a sample mill to obtain the toner (2) of the present invention. The practical sphericity of the toner particles was 0.96. The evaluation results are shown in Table 1.
[0039]
Example 3
(Toner binder synthesis)
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 330 parts of bisphenol A propylene oxide 2-mole adduct, 166 parts of isophthalic acid and 2 parts of dibutyltin oxide were placed and reacted at 230 ° C. for 8 hours at normal pressure. The reaction was further carried out at a reduced pressure of 10 to 15 mmHg for 5 hours to obtain a high molecular weight polyester (A-3) having a number average molecular weight of 8000 and a weight average molecular weight of 35,000.
200 parts of (A-3) and 800 parts of low molecular weight polyester (B-2) described in Example 2 were dissolved and mixed in 2000 parts of ethyl acetate to obtain an ethyl acetate solution of toner binder (3).
Part of the mixture was dried under reduced pressure to isolate the toner binder (3). Tg was 53 ° C., Tη was 123 ° C., TG ′ was 136 ° C., and the peak molecular weights were 5000 and 38000. MnA / MnB was 4.0, and MwA / MwB was 8.3.
The difference (SPA-SPB) between the SP value (SPA) of (A-3) and the SP value (SPB) of (B-2) in the toner binder was 0.36.
(Create toner)
A toner (3) of the present invention was obtained in the same manner as in Example 2 except that the toner binder (3) was used. The practical sphericity of the toner particles was 0.97. The evaluation results are shown in Table 1.
[0040]
Example 4
(Create toner)
In a beaker, 240 parts of an ethyl acetate solution of the toner binder (3) described in Example 3, 20 parts of pentaerythritol tetrabehenate (melting point: 81 ° C., melt viscosity: 25 cps), 4 parts of cyanine blue KRO (manufactured by Sanyo Dye) are placed. The mixture was stirred at 12000 rpm with a TK homomixer at 60 ° C. and uniformly dissolved and dispersed.
In a beaker, 485 parts of ion exchange water and 75 parts of a polyacrylate type anionic water-soluble polymer aqueous solution (Caribbon B manufactured by Sanyo Chemical Industries, Ltd.) were uniformly dissolved. Next, the temperature was raised to 60 ° C., and the toner material solution was added and stirred for 10 minutes while stirring at 12000 rpm with a TK homomixer. The mixture is then transferred to a Kolben equipped with a stir bar and a thermometer, and the temperature is raised to 98 ° C. to remove the solvent. After filtering, washing and drying, air classification is performed, and toner particles having a particle size d50 of 6 μm are obtained. Obtained. Subsequently, 100 parts of toner particles were mixed with 0.5 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.) using a sample mill to obtain toner (4) of the present invention. The practical sphericity of the toner particles was 0.97. The evaluation results are shown in Table 1.
[0041]
Example 5
(Create toner)
In a beaker, 240 parts of an ethyl acetate solution of the toner binder (3) described in Example 3, 20 parts of pentaerythritol tetrabehenate (melting point: 81 ° C., melt viscosity: 25 cps), 4 parts of cyanine blue KRO (manufactured by Sanyo Dye) are placed. The mixture was stirred at 12000 rpm with a TK homomixer at 60 ° C. and uniformly dissolved and dispersed.
In a beaker, 532 parts of ion-exchanged water and 28 parts of a modified polyether type nonionic water-soluble polymer (a compound in which 25 mol of a styrenated phenol ethylene oxide adduct is joined to both ends of polyethylene glycol (Mw 6000) with tolylene diisocyanate). The solution was uniformly dissolved. Next, the temperature was raised to 60 ° C., and the toner material solution was added and stirred for 10 minutes while stirring at 12000 rpm with a TK homomixer. The mixture is then transferred to a Kolben equipped with a stir bar and a thermometer, and the temperature is raised to 98 ° C. to remove the solvent. After filtering, washing and drying, air classification is performed, and toner particles having a particle size d50 of 6 μm are obtained. Obtained. Subsequently, 100 parts of toner particles were mixed with 0.5 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.) using a sample mill to obtain toner (5) of the present invention. The practical sphericity of the toner particles was 0.97. The evaluation results are shown in Table 1.
[0042]
Example 6
(Toner binder synthesis)
719 parts of bisphenol A ethylene oxide 2-mole adduct, 352 parts of terephthalic acid and 3 parts of dibutyltin oxide are placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and reacted at 230 ° C. for 8 hours at normal pressure. The reaction was further carried out at a reduced pressure of 10 to 15 mmHg for 5 hours to obtain a high molecular weight polyester (A-4) having a number average molecular weight of 7800 and a weight average molecular weight of 30000.
In the same manner as above, 301 parts of bisphenol A ethylene oxide 2 mol adduct, 481 parts of tebisphenol A propylene oxide 2 mol adduct, 152 parts of terephthalic acid, 106 parts of fumaric acid, 2 parts of hydroquinone, 3 parts of dibutyltin oxide, The polycondensation is carried out at 200 ° C. for 10 hours, then reacted at 180 ° C. under reduced pressure of 100 mmHg. When the acid value reaches 8, 27 parts of trimellitic anhydride is added and reacted for 1 hour under atmospheric pressure sealing, A low molecular weight polyester (B-3) having an average molecular weight of 2,000 and a weight average molecular weight of 5,000 was obtained.
450 parts of (A-4) and 550 parts of (B-3) were dissolved and mixed in 2000 parts of ethyl acetate to obtain an ethyl acetate solution of toner binder (4).
Part of the mixture was dried under reduced pressure to isolate the toner binder (4). Tg was 60 ° C., Tη was 123 ° C., TG ′ was 135 ° C., and peak molecular weights were 6500 and 38000. MnA / MnB was 3.9 and MwA / MwB was 6.
The difference (SPA-SPB) between the SP value (SPA) of (A-4) and the SP value (SPB) of (B-3) in the toner binder was 0.63.
[0043]
(Create toner)
Similar to Example 2, using 240 parts of ethyl acetate solution of toner binder (4), 20 parts of carnauba wax (melting point 84 ° C., melt viscosity 23 cps), 4 parts of cyanine blue KRO (manufactured by Sanyo Dye) in a beaker. Thus, the toner (6) of the present invention was obtained. The practical sphericity of the toner particles was 0.98. The evaluation results are shown in Table 1.
[0044]
Example 7
(Toner binder synthesis)
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet tube, 649 parts of bisphenol A ethylene oxide 2-mol adduct, 248 parts of dodecenyl succinic anhydride, 153 parts of terephthalic acid, 2 parts of hydroquinone, and 3 parts of dibutyltin oxide The mixture was reacted at 230 ° C. for 8 hours at normal pressure, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg to obtain a high molecular weight polyester (A-5) having a number average molecular weight of 6700 and a weight average molecular weight of 34,000.
In the same manner as above, 515 parts of bisphenol A ethylene oxide 2 mol adduct, 236 parts of tebisphenol A propylene oxide 2 mol adduct, 281 parts of terephthalic acid, and 3 parts of dibutyltin oxide were polycondensed at 200 ° C. for 10 hours under normal pressure. Next, the mixture was reacted at 180 ° C. under a reduced pressure of 100 mmHg, and when the acid value reached 2, 26 parts of trimellitic anhydride was added and reacted for 1 hour under sealed at normal pressure to obtain a number average molecular weight of 2200 and a weight average molecular weight of 5700. A low molecular weight polyester (B-4) was obtained.
400 parts of (A-5) and 600 parts of (B-4) were dissolved and mixed in 2000 parts of ethyl acetate to obtain an ethyl acetate solution of toner binder (5).
A portion was dried under reduced pressure to isolate the toner binder (5). Tg was 60 ° C., Tη was 123 ° C., TG ′ was 135 ° C., and peak molecular weights were 6600 and 37000. MnA / MnB was 3.0, and MwA / MwB was 6.0.
The difference (SPA-SPB) between the SP value (SPA) of (A-5) and the SP value (SPB) of (B-4) in the toner binder was 0.75.
[0045]
(Create toner)
In the same manner as in Example 5, using 240 parts of the ethyl acetate solution of toner binder (5), 20 parts of carnauba wax (melting point: 84 ° C., melt viscosity: 23 cps), and 4 parts of cyanine blue KRO (manufactured by Sanyo Dye). A toner (7) of the present invention was obtained. The practical sphericity of the toner particles was 0.98. The evaluation results are shown in Table 1.
[0046]
Comparative Example 1
(Toner binder synthesis)
Bisphenol A ethylene oxide 2-mole adduct 354 parts and 166 parts of isophthalic acid were polycondensed using 2 parts of dibutyltin oxide as a catalyst to obtain a comparative toner binder (1) having a number average molecular weight of 3700 and a weight average molecular weight of 8,000. Comparative toner binder (1) had Tg of 57 ° C., Tη of 136 ° C., and TG ′ of 133 ° C. The peak molecular weight was 8900.
(Create toner)
In a beaker, put 100 parts of the above comparative toner binder (1), 200 parts of ethyl acetate solution, 4 parts of cyanine blue KRO (manufactured by Sanyo Dye), stir at 12,000 rpm with a TK homomixer at 50 ° C., and dissolve uniformly. , Dispersed. Next, the toner was converted into a toner in the same manner as in Example 1 to obtain a comparative toner (1) having a particle diameter d50 of 6 μm. The practical sphericity of the toner particles was 0.98. The evaluation results are shown in Table 1.
[0047]
[Table 1]

[0048]
[Evaluation methods]
(1) Powder flowability
Quiet density was measured using a Hosokawa Micron powder tester.
The toner with better fluidity has a higher quietness density.
(2) Heat-resistant storage stability
After the toner was stored at 50 ° C. for 8 hours, it was sieved with a 42 mesh sieve for 2 minutes, and the residual ratio on the wire mesh was regarded as heat resistant storage stability.
A toner having better heat-resistant storage stability has a lower residual ratio.
(3) Gloss expression temperature (GLOSS)
Fixation evaluation was performed using a modified machine in which the oil supply device was removed from the fixing device of a commercially available color copying machine (CLC-1; manufactured by Canon) and the oil on the fixing roll was removed. The fixing roll temperature at which the 60 ° gloss of the fixed image was 10% or more was defined as the gloss development temperature.
(4) Hot offset generation temperature (HOT)
Fixation was evaluated in the same manner as in the above GLOSS, and the presence or absence of hot offset on the fixed image was visually evaluated. The fixing roll temperature at which hot offset occurred was defined as the hot offset occurrence temperature.
(5) Charge amount
1 g of toner and 24 g of ferrite carrier for electrophotography (manufactured by Powdertech Co., Ltd .; FL961-150) were mixed for 30 minutes using a tumbler shaker mixer, and the charge amount was measured using a blow-off charge amount measuring device (manufactured by Toshiba Chemical). Measured.
[0049]
【The invention's effect】
The dry toner of the present invention has the following effects.
1. Excellent powder fluidity, excellent developability and transferability.
2. Excellent heat-resistant storage stability and excellent low-temperature fixability and hot offset resistance.
3. When the color toner is used, the glossiness is excellent and the hot offset resistance is excellent. Therefore, it is not necessary to apply oil to the fixing roll.
4). When used as a color toner, the transparency is high and the color tone is excellent.

Claims (12)

  In a dry toner composed of a toner binder and a colorant, the Wadell's practical sphericity of the resin toner is 0.90 to 1.00, and the toner binder comprises a high molecular weight polyester resin (A) and a low molecular weight polyester resin ( B), the ratio (MnA / MnB) of the number average molecular weight (MnA) of the resin (A) to the number average molecular weight (MnB) of the resin (B) is 1.6 or more, and the resin ( The ratio (MwA / MwB) of the weight average molecular weight (MwA) of A) to the weight average molecular weight (MwB) of the resin (B) is 5.0 or more, and the number average molecular weight (MnA) of the resin (A) Is a dry toner, wherein the toner is 5000 or more. [Polyester in which the resin (A) is a polyester modified with a urethane bond and / or urea bond, and the polyester in which the resin (A) and the resin (B) are a polycondensate of a diol alone and a dicarboxylic acid alone Except those that are ]   2. The dry toner according to claim 1, wherein the toner binder has at least two peaks in the molecular weight distribution measured by gel filtration chromatography (GPC).   2. A difference (TG′−Tη) between a temperature (TG ′) at which a storage elastic modulus at a measurement frequency of 20 Hz of the toner binder is 10,000 dyne / cm 2 and a temperature (Tη) at which a viscosity is 1000 poise is 0 ° C. or more. Or the dry toner of 2.   The dry toner according to any one of claims 1 to 3, wherein the toner binder has a glass transition point (Tg) of 35 to 85 ° C.   The dry toner according to any one of claims 1 to 4, wherein a difference (SPA-SPB) between an SP value (SPA) of the resin (A) and an SP value (SPB) of the resin (B) is 0.1 or more. .   The dry toner according to claim 1, wherein a weight ratio of the resin (A) to the resin (B) is 5/95 to 60/40.   The dry toner according to claim 1, wherein the resin (A) and the resin (B) are polyesters composed of a polycondensate of a polyol and a polycarboxylic acid.   The dry toner according to claim 1, wherein the toner is particles formed from a dispersion of a toner material in an aqueous medium.   The dry toner according to claim 8, wherein the dispersion uses an organic dispersant.   The dry toner according to claim 9, wherein the organic dispersant is one or more selected from the group consisting of a water-soluble polymer and a surfactant.   The dry toner according to claim 1, wherein the colorant is a colorant selected from the group consisting of cyan, magenta, and yellow dyes.   The dry toner according to claim 1, which is used as a dry toner for heat fixing.