JP5903899B2 - Method for producing polyester resin for toner, and method for producing toner - Google Patents

Description

  The present invention relates to a method for producing a polyester resin for toner, and a toner.

  In response to recent demands for speeding up, downsizing, and energy savings of printers, heat roller type fixing units have been lowered in temperature. Therefore, a binder resin for toner that can be fixed at a lower temperature while maintaining the storage stability (storage stability) of the toner, the high temperature side offset, and the pulverization property is desired.

  For example, Patent Document 1 describes a method for producing a binder resin for toner in which amorphous polyester resins containing unsaturated double bonds having different softening temperatures are subjected to a crosslinking reaction.

  Patent Document 2 describes a method for producing a binder resin for toner in which crystalline polyester and amorphous polyester are melt-kneaded in the presence of a radical reaction initiator.

International Publication No. 2007/034813 Pamphlet JP 2010-145929 A

However, in the method described in Patent Document 1, since an amorphous resin is used as the low softening temperature resin that contributes to low-temperature fixability, the fixing strength of the toner during low-temperature fixing is insufficient.
Further, in the method of Patent Document 2, since the glass transition temperature of the crystalline polyester is low, the fixing strength and storage stability of the toner during low-temperature fixing are insufficient.

  An object of the present invention is to provide a method for producing a polyester resin for toner, which simultaneously satisfies the fixing strength and storage stability on the low temperature side of the toner, and the high temperature resistance side offset (fixing strength on the high temperature side of the toner), and a toner. .

  The gist of the present invention is that it has an unsaturated double bond, has a crystalline transition resin (resin 1) having a glass transition temperature (Tg) of 40 ° C. or higher, and an unsaturated double bond whose softening temperature is higher than that of resin 1. In the method for producing a polyester resin for toner, a polyester resin (resin 2) is subjected to a crosslinking reaction.

  By using the method for producing a polyester resin for toner of the present invention, a toner having excellent fixing strength and storage stability on the low temperature side and high temperature side of the toner can be obtained.

Regardless of crystallinity and non-crystallinity, a polyester resin is generally obtained by polycondensation of a polycarboxylic acid and a polyol.
A crystalline polyester resin having an unsaturated double bond useful for the present invention (hereinafter referred to as resin 1) and a polyester resin having a softening temperature higher than that of resin 1 (hereinafter referred to as resin 2) will be described.

  Here, the polyester resin having an unsaturated double bond is a polyester resin having a carbon-carbon double bond in the molecule, and has an unsaturated double bond in the main chain and / or side chain of the polyester resin. . In order to have the unsaturated double bond in the main chain and / or side chain of the polyester resin, for example, a polycondensation reaction may be performed using a polycarboxylic acid having an unsaturated double bond and a polyol.

The resin 1 of the present invention needs to have a glass transition temperature (Tg) of 40 ° C. or higher measured using a differential scanning calorimeter (DSC). When the glass transition temperature (Tg) is less than 40 ° C., the fixing strength of the toner at the time of low-temperature fixing and the storage stability of the toner are poor. 45 degreeC or more is more preferable from the point of preservability.
Furthermore, in the present invention, the resin 1 needs to be a crystalline polyester resin. The low temperature fixing strength is manifested by the presence of the crystal portion in the resin. The crystalline polyester resin of the present invention means a crystallization peak (exotherm) between a glass transition temperature and a melting point (endothermic peak) in a measurement based on JIS K7121 using a differential scanning calorimeter (DSC). Means a polyester resin having a peak).

  The resin 1 of the present invention preferably has a heat of fusion at the melting point measured using DSC of 5.0 to 40.0 J / g. When the heat of fusion is less than 5.0 J / g, the crystallinity is lowered after passing through the step of melt-kneading in the presence of the resin 2 and the radical polymerization initiator, and the low-temperature fixing strength tends to be lowered, and exceeds 40.0 J / g And has a high crystallinity and tends to be difficult to be converted into a toner.

  Furthermore, the resin 1 of the present invention preferably has a softening temperature (T4) of 80 to 120 ° C. When the softening temperature (T4) is less than 80 ° C., Tg tends to be less than 40 ° C. at the same time, the storage stability tends to be low, and when it exceeds 120 ° C., the low-temperature fixability tends to be low. From the viewpoint of storage stability and low-temperature fixability, 90 ° C. or higher and 110 ° C. or lower is more preferable.

  The resin 2 of the present invention is a polyester resin having an unsaturated double bond whose softening temperature is higher than that of the resin 1. Since the softening temperature of the resin 2 is higher than that of the resin 1, the fixing strength on the high temperature side is improved. The difference in softening temperature between the resin 1 and the resin 2 is preferably 20 ° C. or more. When the difference in softening temperature is 20 ° C. or more, the balance between the fixing strength on the low temperature side and the fixing strength on the high temperature side of the toner tends to be good. The lower limit of the difference in softening temperature is more preferably 40 ° C. or higher, and particularly preferably 50 ° C. or higher. Moreover, it is preferable that the upper limit of the difference of softening temperature is 150 degrees C or less. Furthermore, it is preferable that the resin 2 is an amorphous polyester resin from the viewpoint of easy progress of the crosslinking reaction.

  The method for producing the resin 1 and the resin 2 of the present invention is not particularly limited, and a known method can be used. For example, a polycarboxylic acid and a polyol are charged together and polymerized through an esterification reaction or a transesterification reaction and a condensation reaction to produce Resin 1 and Resin 2. In the polymerization of the resin, for example, a polymerization catalyst such as titanium tetrabutoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, germanium dioxide and the like can be used. The polymerization temperature is preferably in the range of 180 to 290 ° C. When the polymerization temperature is 180 ° C. or higher, the productivity tends to be good, and when it is 290 ° C. or lower, the decomposition of the resin and the by-product of volatile components that cause odor tend to be suppressed. The lower limit of the polymerization temperature is more preferably 200 ° C. or higher, and particularly preferably 220 ° C. or higher. The upper limit of the polymerization temperature is more preferably 270 ° C. or less.

  In addition, a polycarboxylic acid and a polyol and a release agent component are charged together and polymerized through an esterification reaction or a transesterification reaction and a condensation reaction to produce a polyester resin, that is, the release agent component is internally added. It is also possible.

  Furthermore, a stabilizer may be added for the purpose of obtaining polymerization stability of the resin 1 and the resin 2. Examples of the stabilizer include hydroquinone, methyl hydroquinone, hindered phenol compounds and the like.

  As the polycarboxylic acid component having an unsaturated double bond, dicarboxylic acid compounds such as maleic acid, fumaric acid, citraconic acid, glutaconic acid, itaconic acid, anhydrides and alkyl esters of these acids are preferable. From the viewpoint of reactivity, at least one selected from the group consisting of fumaric acid, maleic acid, anhydrides of these acids and alkyl esters is preferred, and fumaric acid is more preferred.

  From the viewpoint of reactivity, the amount of the polycarboxylic acid component having an unsaturated double bond is preferably less than 1 to 50 parts by mole, more preferably less than 1 to 40 parts by mole in 100 parts by mole of the polycarboxylic acid component. Less than ˜35 mole parts is particularly preferred, and less than 1-30 mole parts is most preferred.

Polycarboxylic acids other than polycarboxylic acids having an unsaturated double bond include terephthalic acid, isophthalic acid, orthophthalic acid, sebacic acid, adipic acid, succinic acid, glutaric acid, metaconic acid, citraconic acid, glutaconic acid, and cyclohexanedicarboxylic acid. Polycarboxylic acids such as acid, alkenyl succinic acid, malonic acid, linolenic acid, trimellitic acid, pyromellitic acid; alkyl esters of these dicarboxylic acids (monomethyl ester, dimethyl ester, monoethyl ester, diethyl ester, monobutyl ester, Dibutyl ester, etc.); acid anhydrides of these polycarboxylic acids and the like. These polycarboxylic acids can be used alone or in combination of two or more.
Of these, terephthalic acid, isophthalic acid, or alkyl esters thereof are preferred. In particular, terephthalic acid and isophthalic acid are preferable because they have a high reactivity with a carboxylic acid having an unsaturated double bond and tend to improve the storage stability of the toner.

  The amount of the polycarboxylic acid component other than the polycarboxylic acid having an unsaturated double bond is preferably 50 mol parts or more per 100 mol parts of the polycarboxylic acid component. When this content is 50 mol parts or more, the production stability of the polyester resin tends to be good. The lower limit of the content is more preferably 55 mol parts or more, further preferably 60 mol parts or more, particularly preferably 65 mol parts or more, and most preferably 70 mol parts or more from the viewpoint of storage stability. The upper limit is preferably 99 parts by mole or less from the viewpoint of reactivity.

  Examples of the polyol include ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, diethylene glycol, 2-methyl-1, 3-propanediol, triethylene glycol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, D-isosorbide, L-isosorbide, isomannide, 1,2-cyclohexanedimethanol, 1,4-cyclohexane Dimethanol, 1,4-cyclohexanediol, sorbitol, 1,2,3,6-hexanetetralol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, erythritan, 1,2,4-butanetriol, 1, 2,5-pentanthrio Glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, mannitol, 1,10-decanediol, 1,12-dodecanediol, polyethylene glycol, Hydrogenated bisphenol A, hydrogenated bisphenol A ethylene oxide adduct and propylene oxide adduct, polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.0 ) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.2) -polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) Nyl) propane, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.4) -2,2-bis (4-hydroxyphenyl) propane, poly Oxypropylene (3.3) -2,2-bis (4-hydroxyphenyl) propane spiroglycol, cyclodecane dimethanol, tricyclodecane dimethanol, tripentaerythritol, trehalose, cyclodextrin compound, lignin, lignophenol, etc. These may be used alone or in combination of two or more.

Among these, divalent polyols are preferable from the viewpoint of storage stability of the toner. Among the divalent polyols, ethylene glycol, neopentyl glycol, 1,2-propanediol, 1,4-cyclohexanedimethanol, polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) ) Propane is preferred.
Moreover, in order to carry out the crosslinking reaction of the polyester resin effectively, it is preferable that 1,4-cyclohexanedimethanol is included as a polyol component of the resin 2.

  Furthermore, in the present invention, a monovalent carboxylic acid or a monovalent alcohol is charged together and polymerized through an esterification reaction or a transesterification reaction, and a condensation reaction to adjust the amount of terminal functional groups of the polyester resin. It is.

  Examples of monovalent carboxylic acids include aromatic carboxylic acids having 30 or less carbon atoms such as benzoic acid and p-methylbenzoic acid, aliphatic carboxylic acids having 30 or less carbon atoms such as stearic acid and behenic acid, and cinnamic acid. Oleic acid, linoleic acid, linolenic acid and the like.

  Examples of monohydric alcohols include aromatic alcohols having 30 or less carbon atoms such as benzyl alcohol, and aliphatic alcohols having 30 or less carbon atoms such as oleyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol, and behenyl alcohol.

  When polymerizing the polyester of the resin 1, it is preferable to use 10 to 35 mol parts of a polyol having 3 or more carbon atoms with respect to 100 mol parts of the polycarboxylic acid component. If it is less than 10 mol parts, it becomes a crystalline resin having a high melting point, and it tends to be difficult to make a toner. On the other hand, when it exceeds 35 mol parts, it becomes an amorphous resin and the low-temperature fixing strength tends to be lowered. Examples of the polyol having 3 or more carbon atoms that can easily control crystallinity include neopentyl glycol, 1,2-propanediol, 1,4-cyclohexanedimethanol, polyoxyethylene- (2.0) -2,2-bis ( 4-hydroxyphenyl) propane.

  In addition, the total amount of polyol is preferably 150 parts by mole or less, preferably 80 parts by mole or more, 120 parts per 100 parts by mole of the polycarboxylic acid component, from the viewpoint of the balance between the glass transition temperature (Tg) and the softening temperature (T4). The molar part or less is particularly preferable. The molar ratio of the polycarboxylic acid and the polyol (polyol / polycarboxylic acid) related to the resin 1 is preferably higher than the polycarboxylic acid from the viewpoint of easily adjusting the molecular weight of the polyester by distilling off the alcohol. .

  When the polyester of the resin 2 is polymerized, it is preferable to use 80 mol parts or more of polyol with respect to 100 mol parts of the acid component constituting the resin 2. When this content is 80 mol parts or more, the production stability of the polyester resin tends to be good. As for the lower limit of this content, 90 mol part or more is more preferable. The upper limit is preferably 180 parts by mole or less, and more preferably 170 parts by mole or less. When the amount is 170 mol parts or less, the production stability of the polyester resin tends to be good.

In the present invention, the unsaturated double bonds in the polyester resins of the resin 1 and the resin 2 are subjected to a crosslinking reaction to generate an intermolecular carbon-carbon bond.
When the resin 1 and the resin 2 are subjected to a cross-linking reaction, a part thereof is changed to a cross-linking component having a high cross-linking density that is not dissolved in THF (THF insoluble component), and a part of the cross-linking is a low cross-linking density that is dissolved in THF. It changes to a component and the rest remains unreacted. As a result, the resin obtained by the crosslinking reaction contains a THF-insoluble component (crosslinking component that does not dissolve in THF) and a THF soluble component (a crosslinking component that dissolves in THF and an unreacted polyester resin). Since the THF-insoluble component is crosslinked at a high density, the toner has an effect of imparting higher elasticity to the toner, and the high-temperature offset resistance of the toner is further improved.

  It should be noted that the cross-linking component dissolved in THF is generated because the resin 1 before the cross-linking reaction, gel permeation chromatography (hereinafter abbreviated as GPC) distribution curve of resin 2 and the THF of the polyester resin after the cross-linking reaction. This can be confirmed by comparing the GPC distribution curves of the soluble component. That is, since a crosslinking component that dissolves in THF is generated by the crosslinking reaction, the GPC distribution curve after the crosslinking reaction has a tail on the higher molecular weight side than the GPC distribution curve before the crosslinking reaction, and the molecular weight distribution (Mw after the crosslinking reaction) / Mn) is larger than the molecular weight distribution (Mw / Mn) before the crosslinking reaction.

  The content of the THF-insoluble component is preferably 5% by mass or more in the binder resin of the toner. When the THF-insoluble content is 5% by mass or more, the high-temperature offset resistance of the toner tends to be good. The lower limit of the content of THF-insoluble matter is particularly preferably 10% by mass or more. Moreover, it is preferable that the upper limit of content of this THF insoluble content is 40 mass% or less. When the THF-insoluble content is 30% by mass or less, the low-temperature fixability of the toner tends to be good. The upper limit of the content of THF-insoluble matter is particularly preferably 35% by mass or less.

  The form of the crosslinking reaction is, for example, a reaction in which an unsaturated double bond in a polyester resin is reacted by a radical addition reaction, a cation addition reaction, an anion addition reaction, or the like to generate an intermolecular carbon-carbon bond, Formation of an intermolecular bond by a condensation reaction, polyaddition reaction, transesterification reaction or the like of the polyvalent carboxylic acid group, polyhydric alcohol group, polyvalent epoxy group, or polyvalent isocyanate group. Among these, a reaction in which an unsaturated double bond in a polyester resin is reacted by a radical addition reaction, a cation addition reaction, an anion addition reaction, or the like to generate an intermolecular carbon-carbon bond is preferable.

Reactions in which unsaturated double bonds in the polyester resin are reacted by radical addition reaction, cation addition reaction, anion addition reaction, etc. to generate an intermolecular carbon-carbon bond are performed by thermal reaction, photoreaction, redox reaction, etc. It can proceed by the active species generated. Of these, thermal reaction is preferable, and radical reaction is particularly preferable. As the radical reaction, a radical reaction initiator may be used, or a radical reaction initiator may not be used. In particular, a method using a radical reaction initiator is preferable from the viewpoint of effectively causing a crosslinking reaction.
As the radical reaction initiator, an azo compound or an organic peroxide is used. Among them, an organic peroxide is preferable because it has high initiator efficiency and does not generate a cyanide byproduct.

  Examples of the organic peroxide include benzoyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α-bis (t-butylperoxy) diisopropylbenzene, 2, 5-dimethyl-2,5-bis (t-butylperoxy) hexane, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di-t-butylperoxyhexine-3, Acetyl peroxide, isobutyryl peroxide, octaninoroxide, decanolyl peroxide, lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, m-toluyl peroxide, t-butylperoxyisobutyrate, t-butylperoxyneodecanoate, cumylperoxyneodecanoate, t-butylperoxy -Oxy-2-ethylhexanoate, t-butylperoxy 3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxybenzoate, t-butylperoxyisopropyl carbonate, t -Butyl peroxy acetate etc. are mentioned.

  Among these, a radical reaction initiator having a high hydrogen abstraction ability is particularly preferred because the crosslinking reaction proceeds efficiently and the amount used is small. Preferred examples of the radical initiator having a high hydrogen abstraction ability include benzoyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α-bis (t-butylperoxy ) Diisopropylbenzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, di-t-hexyl peroxide and the like. As for the usage-amount of a radical reaction initiator, 0.01-10 mass parts is preferable with respect to 100 mass parts of polyester resins. When the amount of the radical reaction initiator used is 0.01 parts by mass or more, the crosslinking reaction tends to proceed, and when it is 10 parts by mass or less, the odor tends to be good. The amount used is preferably 3 parts by mass or less, more preferably 1 part by mass or less, and particularly preferably 0.5 parts by mass or less.

  In addition, by adding the radical reaction initiator diluted with a diluent, there is a tendency to suppress the self-induced decomposition of the radical reaction initiator, ensuring high safety during the production of the polyester resin, and radicals due to self-induced decomposition. Wasteful consumption of the reaction initiator is suppressed, and the amount of radical reaction initiator used can be reduced.

  As the diluent for the radical reaction initiator, a release agent is particularly preferable. By including the release agent in the polyester resin for toner in advance, the dispersibility of the release agent becomes better than when the release agent is added at the time of toner formation.

  As the release agent, hydrocarbon release agents are preferable, for example, aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, and paraffin wax; aliphatic hydrocarbons such as polyethylene oxide wax And oxides of these waxes; or their block compounds.

  Among these, those having a melting point of 120 ° C. or less are preferable because they can be easily mixed with a radical reaction initiator and tend to further improve the low-temperature fixability of the toner. As a mold release agent having a melting point of 120 ° C. or lower, paraffin wax is most preferable, and HNP series manufactured by Nippon Seiki Co., Ltd .: for example, HNP-3 (melting point 64 ° C.), HNP-5 (melting point 62 ° C.), HNP-9, 10 (melting point 75 ° C.), HNP-11 (melting point 68 ° C.), HNP-12 (melting point 67 ° C.), HNP-51 (melting point 77 ° C.), SP series: SP-0165 (melting point 74 ° C.), SP- 0160 (melting point 71 ° C.), SP-0145 (melting point 62 ° C.), HNP-3 (melting point 64 ° C.), FT series: FT-0070 (melting point 72 ° C.), FT-0165 (melting point 73 ° C.) and the like.

  Examples of a method for preparing a radical reaction initiator diluted with a release agent include, for example, a method in which a liquid radical reaction initiator is mixed with a release agent liquefied by heating, and a solid radical reaction initiator in a liquid release agent. And a method in which a liquid radical reaction initiator is soaked into a solid release agent. Among them, from the viewpoint of uniformity and dispersibility of the radical reaction initiator, a method of mixing a liquid radical reaction initiator with a liquefied release agent, or a radical reaction initiator that is solid with a liquefied release agent A method of dissolving the is preferable.

The mixing ratio of the resin 1 and the resin 2 is preferably 70/30 to 99/1 (mass mixing ratio). When the mixing ratio is within the above range, the balance between the fixing strength on the low temperature side and the fixing strength on the high temperature side of the toner tends to be good.
When the resin 1 and the resin 2 are melt-kneaded in the presence of a radical reaction initiator, the polyester resin in a molten state immediately after polymerization may be kneaded and a radical reaction initiator may be added. Then, after obtaining the solid polyester resin 1 and resin 2, the resin obtained by melt-kneading resin 1 and resin 2 may be pulverized, and a radical reaction initiator may be further added to perform melt-kneading again. .
As an apparatus for performing melt kneading, an apparatus similar to the polycondensation step of the polyester resin may be used, but a melt mixing apparatus is preferable from the viewpoint of uniformly mixing the polyester resin and the radical reaction initiator in a short time.

  Examples of the melt mixing apparatus include continuous melt mixing apparatuses such as a single screw extruder, a twin screw extruder, a continuous closed mixer, a gear extruder, a disk extruder and a roll mill extruder, and a static mixer; Banbury mixer, Brabender mixer And batch hermetic melt mixing devices such as Haake mixers. Among these, the continuous melt mixing apparatus is preferable because the radical reaction initiator can be efficiently dispersed in the polyester resin in a short time. Moreover, when adding a radical reaction initiator to the polyester resin in the molten state immediately after superposition | polymerization and performing a crosslinking reaction, it is preferable that the melt mixing apparatus is connected with the polycondensation reaction kettle.

  Next, the toner using the polyester resin obtained by the production method of the present invention will be described. The toner of the present invention can be obtained by blending the polyester resin with a colorant, a charge control agent, a release agent, a flow modifier, a magnetic substance, and the like as necessary.

  Colorants include carbon black, nigrosine, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine dyes, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dye, monoazo, disazo, Examples thereof include condensed azo dyes or pigments. These dyes and pigments can be used alone or in admixture of two or more. In the case of a full-color toner, yellow includes benzidine yellow, monoazo dyes, condensed azo dyes, magenta, quinacridone, rhodamine dyes, monoazo dyes, cyan, phthalocyanine blue, and the like. The content of the colorant is preferably 2 to 10% by mass in the toner from the viewpoint of the color tone, image density, and thermal characteristics of the toner.

  Examples of the charge control agent include a quaternary ammonium salt as a positive charge control agent and a basic or electron donating organic substance, and as a negative charge control agent, a metal chelate, a metal-containing dye, an acid or electron withdrawing property. Organic materials and the like. In the case of color toners, it is important that the charge control agent is colorless or light color and does not cause any color tone problems on the toner. Examples include metal salts, metal complexes, amides of salicylic acid or alkylsalicylic acid with chromium, zinc, aluminum, etc. A compound, a phenol compound, a naphthol compound, etc. are mentioned. Furthermore, a vinyl polymer having a styrene, acrylic acid, methacrylic acid or sulfonic acid group may be used as the charge control agent.

  The content of the charge control agent is preferably 0.5 to 5% by mass in the toner. When the content of the charge control agent is 0.5% by mass or more, the charge amount of the toner tends to be a sufficient level, and when the content is 5% by mass or less, a decrease in the charge amount due to aggregation of the charge control agent is suppressed. It tends to be.

  As the mold release agent, carnauba wax, rice wax, beeswax, polypropylene wax, polyethylene wax, synthetic ester wax, paraffin wax, taking into account the toner releasability, storage stability, fixability, color developability, etc. Fatty acid amides, silicone waxes and the like can be appropriately selected and used. These can be used alone or in combination of two or more.

  The melting point of the release agent can be appropriately selected and used in consideration of the toner performance. The content of the release agent is preferably 0.3 to 15% by mass in the toner because it affects the toner performance.

  Additives such as flow modifiers include fine powder silica, alumina, titania and other fluidity improvers, magnetite, ferrite, cerium oxide, strontium titanate, conductive titania and other inorganic powders, styrene resins, acrylics Examples thereof include resistance adjusting agents such as resins and lubricants, and these are used as an internal additive or an external additive.

  The content of these additives is preferably 0.05 to 10% by mass in the toner. When the content of these additives is 0.05% by mass or more, a toner performance-modifying effect tends to be sufficiently obtained, and when it is 10% by mass or less, the image stability of the toner tends to be good. is there.

  Further, as the binder resin, a binder resin other than the polyester resin of the present invention may be used as long as the effects of the present invention are not impaired. For example, a styrene resin, a styrene-acrylic resin, a cyclic olefin resin, a methacrylic acid resin An epoxy resin can be used, and these can be used alone or in admixture of two or more.

  The toner of the present invention can be used as any one of a magnetic one-component developer, a non-magnetic one-component developer, and a two-component developer.

  Regarding the method for producing the toner of the present invention, the binder resin and the compound described above are mixed, and then melt-kneaded with a twin screw extruder or the like, coarsely pulverized, finely pulverized, and classified. Toner particles that are manufactured by performing an addition treatment (pulverization method), the above-described binder resin and compound are dissolved and dispersed in a solvent, granulated in an aqueous medium, the solvent is removed, washed, and dried. The method (chemical method) etc. which are obtained by performing the external addition process of an inorganic particle etc. as needed are mentioned.

  The particle diameter of the toner of the present invention is preferably in the range of 3 to 15 μm, more preferably in the range of 5 to 10 μm. This tends to improve the productivity when the thickness is 3 μm or more. Further, when the particle diameter is 15 μm or less, high image quality tends to be obtained.

  Examples of the present invention are shown below. The evaluation methods for the resin and toner shown in this example are as follows.

<Softening temperature (T4)>
For resin 1, using a flow tester (CFT-500D manufactured by Shimadzu Corp.), in a 1.0 g resin sample with a 1 mmφ × 1 mm nozzle, a load of 294 N, and a uniform heating rate of 6 ° C./min. The temperature when 4 mm of the spilled out was measured.

  For resin 2, using a flow tester (CFT-500D manufactured by Shimadzu Corp.), in a 1.0 g resin sample with a 1 mmφ × 10 mm nozzle, a load of 294 N, and a heating rate of 3 ° C./min. The temperature when 4 mm of the spilled out was measured.

<Glass transition temperature (Tg)>
Using a differential differential calorimeter (DSC-60, manufactured by Shimadzu Corporation), measurement was performed from the intersection of the base line of the chart and the tangent line of the endothermic curve at a heating rate of 5 ° C./min. The measurement sample was a sample that was melted at 280 ° C. above the melting point of the crystalline resin for 1 minute and then rapidly cooled using dry ice.

<Melting point (Tm), heat of fusion>
Using a differential scanning calorimeter (DSC-60 manufactured by Shimadzu Corporation), 10 mg of the sample was heated at a heating rate of 10 ° C./min, measured in accordance with JIS K7121, and the standard (9.1 “of melting temperature”) was measured. The melting peak value described in “How to obtain”) was obtained and used as the crystalline melting point Tm, and the heat of fusion (J / g) was obtained from the endothermic peak area at the crystalline melting point Tm of the DSC chart.

<THF insoluble matter>
About 2 g of Celite 545 (manufactured by Kishida Chemical Co., Ltd.) is placed in a cylindrical glass filter 1GP100 (manufactured by Shibata Chemical Co., Ltd.) having an inner diameter of 3.5 cm, and the glass filter is used until the height of the Celite 545 layer does not change. I tapped it lightly on the cork stand. This operation was repeated four times, and Celite 545 was filled into a glass filter so that the height of the Celite 545 layer was 2 cm from the filter surface. The glass filter filled with Celite 545 was dried at 105 ° C. for 3 hours or more and weighed (Yg). Next, about 0.5 g of the sample is placed in an Erlenmeyer flask and precisely weighed (Xg), then 50 ml of THF (tetrahydrofuran) is added, and heated in a 70 ° C water bath for 3 hours to dissolve the sample under reflux of THF I let you. This solution was put into a glass filter packed with Celite 545 and suction filtered. The glass filter capturing the THF-insoluble matter was dried at 80 ° C. for 3 hours or more, the weight was weighed (Zg), and the THF-insoluble matter was calculated according to the following formula.
THF-insoluble matter = {(ZY) / X} × 100 (mass%)

<Toner fixing strength>
Using an apparatus in which the copier “PAGEPREST N4-612II” (manufactured by Casio Electronics Co., Ltd.) was remodeled into a type capable of changing the fixing temperature, an unfixed image was imaged and a low temperature fixing temperature region test was performed. The fixing roller used here is a fixing roller to which silicone oil is not applied, and has a nip width of 3 mm and a linear speed of 30 mm / second.

  While lowering the set temperature of the heat roller by 5 ° C, visually check whether the image printed on the top of A4 plain paper (manufactured by Daishowa Paper: BM64T) adheres to the roller and stains the bottom margin of the paper. A fixed image paper was obtained by fixing at 200 ° C. and 130 ° C. without causing stains. The fixed images at 200 ° C. and 130 ° C. were subjected to a rubbing test, and the fixing strength was evaluated from the toner resin residual ratio before and after toner fixing.

The toner resin residual ratio was obtained by using the printing paper used for the fixing temperature evaluation, and pasting sand paper (Belster Abrasives Industry Co., Ltd., Fine # 800) with the printed part cut into a width of 30 mm × a length of 50 mm. A 2 kg weight was used to rub off from the bottom 10 times, and the amount of light in the printed part before and after this operation was measured with a Macbeth light meter, and the toner fixing strength was calculated from the measured value.
Toner resin residual ratio (%) = (light quantity after peeling test) / (light quantity before test) × 100 (%)

The fixing strength evaluation criteria for the high temperature side (200 ° C.) and the low temperature side (130 ° C.) are shown below.
Resin residual rate after rubbing test: 90% or more: very good Resin remaining rate after rubbing test: 80% or more and less than 90%: Good Resin remaining rate after rubbing test: 60% or more and less than 80%: Slightly inferior Resin remaining after rubbing test Rate less than 60%: Inferior

<Storability of toner>
About 5 g of toner is weighed and put into a sample bottle, which is left in a dryer kept at 45 ° C. for about 24 hours, and the degree of toner aggregation is evaluated by inverting the sample bottle and dispersing it when it is tapped. And used as an index of preservation. The evaluation criteria were as follows.
Disperse if sample bottle is inverted or tapped once: very good Disperse if sample bottle is inverted and tapped 2-4 times: good Disperse if sample bottle is inverted and tapped 5 times or more: inferior

Production Example 1
1000 ppm of tetra-n-butoxytitanium with respect to the polycarboxylic acid, polyol, and polycarboxylic acid having the charged composition shown in Table 1 was charged into a reaction vessel equipped with a distillation column. Next, the temperature was raised and heated so that the temperature in the reaction system became 265 ° C., this temperature was maintained, and the esterification reaction was carried out until no water was distilled from the reaction system. Next, the temperature in the reaction system was set to 220 ° C., the pressure in the reaction vessel was reduced, and the condensation reaction was carried out while distilling the polyalcohol from the reaction system.

  The polymerization end point was the esterification reaction end point, about 2 g of the resin was sampled during the condensation reaction, Tg measurement was performed, and the time when the predetermined Tg shown in Table 1 was reached was defined as the polymerization end point. The reaction product was rapidly cooled to Tg or less with a belt cooler and taken out to obtain a crystalline polyester resin (resin 1A). Table 1 shows the characteristic values of the resin 1A.

Production Examples 2-6
1000 ppm of tetra-n-butoxytitanium with respect to the polycarboxylic acid component, the polyol component, and the total acid component having the charging composition shown in Table 1 was put into a reaction vessel equipped with a distillation tower, and the same method as in Production Example 1 was used. To obtain a polyester resin. The characteristic values of the obtained polyester resin are shown in Table 1.

Production Example 7
500 ppm of tetra-n-butoxytitanium with respect to the polycarboxylic acid component, polyol component, and total acid component of the feed composition shown in Table 1, and 2000 ppm of hindered phenolic compound with respect to the total acid component (Asahi Denka Kogyo Co., Ltd.) ): Adeka Stub AO-60) was put into a reaction vessel equipped with a distillation column. Next, the temperature increase was started, and the reaction system was heated so that the temperature in the reaction system became 240 ° C. This temperature was maintained, and the esterification reaction was continued until no water was distilled from the reaction system. Next, the temperature in the reaction system was set to 220 ° C., the pressure in the reaction vessel was reduced, and the condensation reaction was carried out while distilling the polyol component from the reaction system. The reaction was continued until the viscosity of the reaction system increased with the reaction and the torque of the stirring blade reached a value indicating the desired softening temperature. And when the predetermined torque was shown, the reaction product was taken out and cooled to obtain a polyester resin (resin 2A). Table 1 shows the characteristic values of the resin 2A.

Example 1
A release agent (manufactured by Nippon Seiki Co., Ltd.) in which 10 parts by mass of 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane (Nippon Oil Co., Ltd.) was heated to 75 ° C. and melted. SP-0160) was added to 90 parts by mass, and the resulting mixture was cooled and pulverized to prepare a radical reaction initiator (I) diluted with a release agent.
Next, 90 parts by mass of resin 1A and 10 parts by mass of resin 2A are supplied to a twin-screw extruder (PCM-29: L / D = 30, manufactured by Ikegai Co., Ltd.). The mixture was melt-mixed with a residence time of 5 minutes, pulverized after cooling. 0.8 parts by mass of the radical reaction initiator (I) diluted with a release agent is mixed with this pulverized product, supplied to the twin-screw extruder, and melted at an external temperature setting of 180 ° C. for a residence time of about 3 minutes. Kneading was performed to obtain a polyester resin (resin 3A). Table 2 shows the characteristic values of the resin 3A.
Resin 3A: 93 parts by weight, 3 parts by weight of quinacridone pigment (E02 made by Clariant) as a colorant, 1 part by weight of negatively chargeable charge control agent LR-147 (made by Nippon Carlit), carnauba wax (manufactured by Toyo Petroride) ) 3 parts by mass of powder mixed, external temperature setting using a twin screw extruder: Resin 3A T4 + 10 ° C., melt kneading at a residence time of 1 minute, coarsely pulverized, then finely pulverized with a jet mill pulverizer, A fine powder having an average particle size of 5 μm was obtained using a classifier. Silica (R-972 manufactured by Nippon Aerosil Co., Ltd.) was added to the obtained fine powder so as to be 0.2 parts by mass, and mixed with a Henschel mixer to obtain a toner. Table 2 shows the evaluation results of the toner.

Examples 2-5 and Comparative Examples 1-2
Melt kneading was performed in the same manner as in Example 1 with the types and blending amounts of Resin 1 and Resin 2 listed in Table 2 to obtain Resins 3B to 3G. Table 2 shows the characteristic values of the resins 3B to 3G. Resins 3B to 3G were converted into toners by the same method as in Example 1, and the performance was evaluated. Table 2 shows the evaluation results of the toner.

  From the result of Comparative Example 1, since a non-crystalline resin (resin 1E) was used as the resin 1, the low-temperature side fixing strength of the toner was insufficient.

  From the result of Comparative Example 2, since a crystalline resin (resin 1F) having a glass transition temperature (Tg) of 40 ° C. or lower is used as the resin 1, the fixing strength and storage stability on the low temperature side of the toner are poor. .

Claims (3)

It has an unsaturated double bond, has a glass transition temperature (Tg) of 40 ° C. or higher , and is obtained using 10 to 35 mol parts of a polyol having 3 or more carbon atoms with respect to 100 mol parts of the polycarboxylic acid component. A method for producing a polyester resin for toner, in which a crystalline polyester resin (resin 1) and a polyester resin (resin 2) having an unsaturated double bond having a softening temperature higher than that of the resin 1 are subjected to a crosslinking reaction.   2. The method for producing a polyester resin for toner according to claim 1, wherein a mass mixing ratio of the resin 1 and the resin 2 is resin 1 / resin 2 = 70/30 to 99/1. Using polyester resin for a toner obtained by the method according to claim 1 or 2, method for producing a toner for electrophotography.