JPH0234031B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a toner for developing electrostatic latent images formed in electrophotography, electrostatic printing, electrostatic recording, and the like. [Prior Art] For example, in electrophotography, an electrostatic latent image is usually formed on a latent image carrier made of a photoconductive photoreceptor by charging and exposure, and then this electrostatic latent image is developed with toner. Then, the obtained toner image is transferred to a support such as transfer paper, and then fixed by heating, pressure, etc. to form a visible image. Formation of a visible image via such an electrostatic image is preferably achieved at high speed, and from this point of view, conventionally, a heat roller fixing method has been used in the fixing process, which has high thermal efficiency and is advantageous compared to other methods. Widely adopted. However, in recent years, there has been a strong demand for even higher speeds, and in order to achieve this, it is essential to fix toner images at high speeds. However, in order to fix a toner image at high speed in a hot roller fixing method, the toner used for development is required to have good low-temperature fixability. It is necessary to lower the softening point of However, if the softening point of the toner binder is lowered, part of the toner that makes up the image will transfer to the surface of the heat roller during fixing, and this will transfer again to the transfer paper that is sent next, staining the image. , the so-called offset phenomenon tends to occur more easily. For this reason, monomers containing etherified bisphenol monomers, dicarboxylic acid monomers, trivalent or higher polyhydric alcohol monomers, and/or trivalent or higher polyvalent carboxylic acid monomers A toner containing as a binder a polyester consisting of a non-linear copolymer obtained from a polymeric body component and a non-linear copolymer has been proposed (see JP-A-57-37353 and JP-A-57-208559). Such technology involves converting a linear polyester consisting of an etherified bisphenol monomer and a dicarboxylic acid monomer into a polyhydric alcohol monomer having a valence of 3 or more and/or a polyhydric carboxylic acid monomer having a valence of 3 or more. The toner is made to have offset prevention performance by containing as a binder a polyester obtained by crosslinking with a monomer component containing. However, such toners have a slightly high softening point, making it difficult to achieve good low-temperature fixing and making it impossible to achieve sufficient high-speed fixing. [Problems to be solved by the invention] On the other hand, etherified bisphenol monomers, dicarboxylic acid monomers, trihydric or higher polyhydric alcohol monomers, and/or trivalent or higher polyhydric carbon A nonlinear copolymer obtained from a monomer component containing an acid monomer, which has 3 to 22 carbon atoms in its side chain.
A toner containing a polyester having a saturated or unsaturated aliphatic hydrocarbon group as a binder has been proposed (Japanese Patent Application Laid-open No. 109825/1982, Japanese Patent Application No. 109539/1982, and 7960/1983). (see publication). Such toners exhibit sufficient fixing performance in low-speed fixing or medium-speed fixing, but, for example,
When high-speed fusing is performed continuously on A3 size paper at a fusing speed of 50 sheets/min or more, the interval between sheets passing through the heat roller is extremely short, so a large amount of heat is absorbed from the heat roller to the paper, causing the heat roller to This causes a significant temperature drop, which causes the problem that some of the above-mentioned toners tend to be insufficiently fixed. On the other hand, in order to improve the low-temperature fixability, it is possible to reduce the molecular weight of the binder and reduce the viscosity of the toner during fixing, but such measures also reduce the offset prevention performance of the toner, and furthermore, However, there is a problem in that the toner tends to aggregate and the behavior of the toner as a unit particle is inhibited, making it impossible to achieve good development. [Object of the Invention] The present invention has been made based on the above-mentioned circumstances, and its object is to have excellent offset prevention performance, excellent low-temperature fixing properties, and excellent high-speed fixing. It is an object of the present invention to provide a toner for electrostatic image development which is capable of achieving good development by being resistant to agglomeration and capable of stably behaving as unit particles. [Means for Solving the Problems] The electrostatic image developing toner of the present invention contains a divalent alcohol monomer, a divalent carboxylic acid monomer, and 1 to 30 mol% of the alcohol component. 1 in the trivalent or higher polyhydric alcohol monomer and/or acid component
A non-linear polyester obtained from a monomer component containing ~30 mol% of a trivalent or higher polycarboxylic acid monomer, and 30 mol% or more of the acid component is an aromatic dicarboxylic acid monomer. and has an unsaturated aliphatic hydrocarbon group having 3 to 22 carbon atoms in the side chain, and the main chain constitutes a straight chain in the range of 5 to 20 mol% of the constituent units of the main chain. It is characterized by containing a non-linear polyester having long chain aliphatic hydrocarbon units having 5 to 20 carbon atoms as a binder. According to such a toner, the binder is a non-linear polyester having a specific ester structure as a backbone, has a specific aliphatic hydrocarbon group in its side chain, and has a specific main chain (main skeleton). Since the toner is made of polyester having long-chain aliphatic hydrocarbon units in the type and proportion of Moreover, the decrease in the glass transition point Tg is suppressed, and the toner becomes resistant to agglomeration and has excellent blocking resistance. Therefore, the toner can behave stably as unit particles without agglomeration, and good development can be achieved.Fixing can be done at a sufficiently high speed without the offset phenomenon caused by the hot roller fixing method. good fixation can be achieved. The present invention will be explained in detail below. In the present invention, a divalent alcohol monomer, a divalent carboxylic acid monomer, and 1 to 30 mol% of a trihydric or higher polyhydric alcohol monomer in the alcohol component and/or A non-linear polyester obtained from a monomer component containing 1 to 30 mol% of a trivalent or higher polycarboxylic acid monomer, and 30 mol% or more of the acid component is an aromatic dicarboxylic acid monomer. which has an unsaturated aliphatic hydrocarbon group having 3 to 22 carbon atoms in its side chain, and whose main chain has a straight chain in the range of 5 to 20 mol% of the constituent units of the main chain. A non-linear polyester having a long chain aliphatic hydrocarbon unit having 5 to 20 carbon atoms is used as a binder, and a coloring agent or additives used as necessary are contained in this binder. Consists of toner for electrophotographic development. Monomer components used in the synthesis of polyester used as a binder in the present invention include:
Those shown in (a) to (d) below are used. (a) Divalent alcohol monomers and divalent carboxylic acid monomers as the main components of the basic skeleton (main chain) of polyester. (b) 1 to 30 mol % of trihydric or higher polyhydric alcohol monomers in the total alcohol components and/or 1 to 30 mole % of the total acid components involved in nonlinearization, that is, branching or network formation of the polyester; 30 mol% of trivalent or higher polyhydric carboxylic acid monomer. (c) The aliphatic group for introducing an unsaturated aliphatic hydrocarbon group having 3 to 22 carbon atoms that constitutes a branched atomic chain bonded to the side chain, that is, the basic skeleton (main chain) of the polyester. A divalent or higher alcohol monomer having a hydrocarbon group and/or a divalent or higher carboxylic acid monomer having the aliphatic hydrocarbon group. (d) A dihydric or higher alcohol monomer having a long chain aliphatic hydrocarbon unit and/or a long chain aliphatic hydrocarbon unit constituting a part of the basic skeleton (main chain) of the polyester. Or a divalent or higher carboxylic acid monomer having the long-chain aliphatic hydrocarbon unit. Incidentally, the long chain in the long chain aliphatic hydrocarbon unit refers to one having 5 to 20 carbon atoms constituting a straight chain, whereby preferable low-temperature fixability can be obtained. When a material having an excessive number of carbon atoms is used, blocking resistance tends to decrease. Examples of the divalent alcohol monomer in (a) above include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, Diols such as 1,4-butenediol; 1,4-bis(hydroxymethyl)cyclohexane, bisphenol A, hydrogenated bisphenol A, etherified bisphenol and the like can be mentioned. Among these, etherified bisphenols are particularly preferred, and specific examples include polyoxypropylene (2,2)-2,2-bis(4'-hydroxyphenyl)propane, polyoxyethylene (2)-2, 2-bis(4'-hydroxyphenyl)propane, polyoxypropylene(6)-
2,2-bis(4'-hydroxyphenyl)propane, polyoxypropylene (1,3)-2,2-
Examples include bis(4'-hydroxyphenyl)propane. Examples of the divalent carboxylic acid monomer in (a) above include terephthalic acid, isophthalic acid, cyclohexanedicarboxylic acid, fumaric acid, maleic acid,
Examples include citraconic acid, adipic acid, sebacic acid, anhydrides or lower alkyl esters of these acids. Among these, aromatic dicarboxylic acid monomers are preferred, and by using this aromatic dicarboxylic acid monomer, it is possible to suppress a decrease in the glass transition point Tg of polyester. Examples of such aromatic dicarboxylic acid monomers include terephthalic acid, isophthalic acid, cyclohexanedicarboxylic acid, and anhydrides or lower alkyl esters of these acids. The proportion of the aromatic dicarboxylic acid monomer used is 30 mol% or more based on the total acid component. When the proportion of this aromatic dicarboxylic acid monomer is too small, the glass transition point Tg of the resulting polyester becomes too low, resulting in toner agglomeration that tends to be agglomerated, resulting in low blocking resistance and poor storage stability or developability. There are cases. Examples of the trihydric or higher polyhydric alcohol monomer in (b) above include sorbitol, 1,2,3,
6-hexanetetrol, 1,4-sorbitan,
Pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,
4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-triol Examples include hydroxymethylbenzene. The proportion of the trivalent or higher polyhydric alcohol used is preferably 1 to 30 mol% based on the total alcohol component. If the usage ratio is too high, the toner's low-temperature fixing properties tend to deteriorate.
On the other hand, if it is too small, the non-linearization of the polyester may be insufficient and the toner offset prevention performance may deteriorate. Examples of the trivalent or higher polycarboxylic acid monomer in (b) above include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid,
1,2,4-naphthalenetricarboxylic acid, 1,
2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxylpropane, tetra(methylenecarboxyl)methane,
Examples include 1,2,7,8-octane tetracarboxylic acid, empol trimer acid, and anhydrides of these acids. The proportion of the polycarboxylic acid monomer having a valence of 3 or more is 1 to 30 mol % based on the total acid component. When the proportion used is too large, the low-temperature fixing properties of the toner tend to be insufficient, and when the proportion used is too small, the non-linearity of the polyester may be insufficient, resulting in insufficient offset prevention performance of the toner. The divalent or higher alcohol monomer having an unsaturated aliphatic hydrocarbon group having 3 to 22 carbon atoms in the above (c) is a monomer having 3 to 22 carbon atoms, in which a part of the divalent or higher alcohol monomer has 3 to 22 carbon atoms. Examples include those substituted with unsaturated aliphatic hydrocarbon groups. Also mentioned above
As the divalent or higher carboxylic acid monomer having an unsaturated aliphatic hydrocarbon group having 3 to 22 carbon atoms in (c), some of the divalent or higher carboxylic acid monomers have 3 to 22 carbon atoms. Examples include those substituted with an unsaturated aliphatic hydrocarbon group, and specific examples include n-dodecenylsuccinic acid and isododecenylsuccinic acid. 2 having these unsaturated aliphatic hydrocarbon groups having 3 to 22 carbon atoms
The proportion of alcohol monomers with higher valence or higher valence and/or carboxylic acid monomer with higher valence 2 or higher having an unsaturated aliphatic hydrocarbon group having 3 to 22 carbon atoms is the sum of both relative to the entire monomer component. It is preferably 0.5 to 50 mol%, more preferably 1 to 35 mol%. If the proportion of these used is too large, the toner tends to aggregate and the blocking resistance tends to be poor. Examples of the divalent or higher alcohol monomer having a long-chain aliphatic hydrocarbon unit in (d) above include propylene glycol, 1,4-butanediol, 1,6-hexanediol, and the like. Examples of the divalent or higher carboxylic acid monomer having a long-chain aliphatic hydrocarbon unit in (d) above include glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. can. These divalent or more alcohol monomers or divalent or more carboxylic acid monomers having long-chain aliphatic hydrocarbon units are added to the main chain of the nonlinear polyester by adding 5 to 20 of the constituent units of the main chain.
The mole % range of long chain aliphatic hydrocarbon units is used in proportions such that long chain aliphatic hydrocarbon units are present. If the proportion of long-chain aliphatic hydrocarbon units in the main chain of the non-linear polyester is too small, sufficient low-temperature fixing properties cannot be obtained in the toner, while if the proportion is too large, the glass transition point Tg is too low and the toner is It tends to agglomerate, resulting in low blocking resistance, and at the same time, the softening point becomes too low, reducing the toner's ability to prevent offset. In the present invention, the main chain of the polyester used as the binder of the toner may contain, for example, an unsaturated aliphatic hydrocarbon unit in addition to the above-mentioned components. Monomers for introducing such unsaturated aliphatic hydrocarbon units include dihydric or higher alcohol monomers having unsaturated aliphatic hydrocarbon units and/or dihydric or higher alcohol monomers having unsaturated aliphatic hydrocarbon units. There is a carboxylic acid monomer having a higher valence than that of the former, and the former divalent or higher alcohol monomer having an unsaturated aliphatic hydrocarbon unit includes butenediol, and the latter unsaturated aliphatic hydrocarbon unit. Examples of the divalent or higher carboxylic acid monomer having units include fumaric acid, maleic acid, citraconic acid, mesaconic acid, itaconic acid, and glutaconic acid. The monomer having these unsaturated aliphatic hydrocarbon units is the sum of the unsaturated aliphatic hydrocarbon units and the long chain aliphatic hydrocarbon units (d) above,
It is preferably used in a proportion such that it is present in the main chain of the non-linear polyester in an amount of 1 to 30 mol%, preferably 5 to 20 mol% of the constituent units of the main chain. When the proportion of unsaturated aliphatic hydrocarbon units is too large, the glass transition point Tg is too low and the toner tends to aggregate, resulting in poor blocking resistance.At the same time, the softening point is also too low, making the toner The offset prevention performance of The electrostatic image developing toner of the present invention is a particle powder comprising a specific polyester as described above as a binder, and a coloring agent or additives used as necessary in the binder. Examples of the coloring agent include carbon black, nigrosine dye (CI No. 50415B), aniline blue (CI No. 50405), and calco oil blue (C.
I.No.azoec Blue3), Chrome Yellow (CINo.
14090), Ultramarine Blue (CINo.77103),
DuPont Oil Red (CI No. 26105), Quinoline Yellow (CI No. 47005), Methylene Blue Chloride (CI No. 52015), Phthalocyanine Blue (C.
I.No.74160), malachite green oxalate (CINo.42000), lamp black (CINo.77266),
Mention may be made of Rose Bengal (CI No. 45435), mixtures thereof, and others. It is preferable that these colorants are contained in a sufficient proportion to form a visible image of sufficient density, and usually about 1 to 20 parts by weight per 100 parts by weight of the binder. Examples of other additives include offset inhibitors, fluidity improvers, and charge control agents. Examples of offset inhibitors include polyolefin waxes, carnauba waxes, and alkylene bis fatty acid amide compounds. Examples of fluidity improvers include fine silica powder. Further, when forming a magnetic toner, a magnetic substance is contained in the binder together with or in place of the colorant. Such magnetic materials include ferrite, magnetite, iron, cobalt, nickel, and other ferromagnetic metals or alloys, or compounds containing these elements, or materials that do not contain ferromagnetic elements but are subjected to appropriate heat treatment. Alloys that exhibit ferromagnetic properties due to ferromagnetic properties, such as alloys called Heusler alloys containing manganese and copper such as manganese-copper-aluminum and manganese-copper-tin, chromium dioxide, and others can be used. . These magnetic materials have an average particle size
It is uniformly dispersed in the binder in the form of fine particles of 0.1-1 μm. The content ratio of the magnetic material is preferably 20 to 70 parts by weight, more preferably 40 to 70 parts by weight per 100 parts by weight of toner. The electrostatic image developing toner of the present invention also has the ability to prevent the occurrence of so-called toner filming phenomenon in which toner substances adhere to the surface of carrier particles or the surface of a latent image carrier and deteriorate these functions. A property improver may be included for the purpose of imparting various properties such as the ability to improve the pulverization property in the pulverization process, which is one of the normal toner manufacturing processes, or the ability to improve the triboelectric charging property of the toner. . As such a property improver, for example, a resin which is an uncrosslinked polymer and does not contain chloroform-insoluble matter can be preferably used. Examples of such resins include styrenes such as styrene and parachlorostyrene; vinylnaphthalene;
Vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl benzoate,
Vinyl esters such as vinyl butyrate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-chloroacrylate methylene aliphatic carboxylic acid esters such as methyl acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate; acrylonitrile; methacrylonitrile; acrylamide; vinyl methyl ether, vinyl isobutyl ether,
Vinyl ethers such as vinyl ethyl ether;
Vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-
A homopolymer obtained by polymerizing monomers such as N-vinyl compounds such as vinylpyrrolidone, a copolymer obtained by copolymerizing a combination of two or more of the above monomers, or a combination of these homopolymers and copolymers. mixtures, and also non-vinyl resins such as non-vinyl thermoplastic resins such as rosin-modified phenol-formalin resins, oil-modified epoxy resins, polyurethane resins, cellulose resins, and polyether resins, or mixtures of these with the above-mentioned vinyl resins. etc. can be mentioned. These resins may be contained in a proportion of, for example, 90% by weight or less of the binder, as long as the effects of the present invention are not impaired. According to the electrostatic image developing toner of the present invention, images can be formed by applying various developing methods. Specifically, for example, (a) a magnetic brush of a one-component or two-component developer is supported on a developer transporting carrier in a state where the layer thickness is larger than the gap between the development areas;
A contact magnetic brush method in which the magnetic brush is carried into a development area and the electrostatic latent image is rubbed by the magnetic brush while toner particles or particle groups in the magnetic brush are attached to the electrostatic latent image to perform development; (B) A magnetic brush of a one-component or two-component developer is supported on a developer transport carrier in a state where the layer thickness is smaller than the gap between the developing areas, and this magnetic brush is carried into the developing area and the developing area is vibrated, for example. Jumping magnetic brush method, (iii) cascade method, in which toner particles or particle groups in a magnetic brush are caused to fly by applying an electric field or the like, and the toner particles or particle groups are attached to an electrostatic latent image for development; A developing method such as the following can be applied. [Example] Examples of the present invention will be described below, but the present invention is not limited to these examples. (Manufacture of binder) (1) Binder A (for comparison) Γ Polyoxypropylene (2,2)-2,2-
Bis(4'-hydroxyphenyl)propane
490g Γ Polyoxyethylene (2)-2,2-bis(4'-
Hydroxyphenyl) propane 160g Γ Terephthalic acid 224g Γ n-dodecenylsuccinic anhydride 48g Γ 1,6-hexanediol 12g Γ Fumaric acid 10g Γ Diisopropyl orthotitanate (esterification catalyst) 0.8g The above substances were measured with a thermometer, Place it in a round bottom flask with a capacity of 1 equipped with a stainless steel stirrer, a glass nitrogen gas inlet tube, and a flow-down condenser, set the flask on a mantle heater, and introduce nitrogen gas through the nitrogen gas inlet tube. Temperature: 230°C while maintaining an inert atmosphere inside the flask
The reaction was carried out under stirring. When the water produced by the reaction stopped flowing out, the acid value was measured to be 1.5. Further, 35 g of 1,2,4-benzenetocarboxylic acid anhydride was added and reacted for about 8 hours, and the reaction was terminated when the acid value reached 12. The obtained resin was a pale yellow solid, and the softening point of this resin was measured with a "Flow Tester CFT-500" (manufactured by Shimadzu Corporation) and was found to be 130°C. (2) Binder B Γ Polyoxypropylene (2,2)-2,2-
Bis(4′-hydroxyphenyl)propane
490g Γ Polyoxyethylene (2)-2,2-bis(4'-
Hydroxyphenyl)propane 130g Γ Terephthalic acid 210g Γ n-dodecenylsuccinic anhydride 48g Γ 1,6-hexanediol 24g Γ Fumaric acid 29g Γ Diisopropyl orthotitanate (esterification catalyst) 0.8g The above substances were used to produce Binder A. The reaction was carried out in the same manner as above, and 35 g of 1,2,4-benzenetricarboxylic acid anhydride was added, and the reaction was continued for about 8 hours. When the acid value reached 12, the reaction was terminated. The obtained resin was a pale yellow solid, and the softening point of this resin was measured with a "Flow Tester CFT-500" (manufactured by Shimadzu Corporation) and was found to be 124°C. (3) Binder C Γ Polyoxypropylene (2,2)-2,2-
Bis(4'-hydroxyphenyl)propane
490g Γ Polyoxyethylene (2)-2,2-bis(4'-
Hydroxyphenyl)propane 160g Γ Terephthalic acid 224g Γ n-dodecenylsuccinic anhydride 48g Γ 1,6-hexanediol 12g Γ Sebacic acid 18g Γ Diisopropyl orthotitanate (esterification catalyst) 0.8g The above substances are used to produce binder A. The reaction was carried out in the same manner as above, and 35 g of 1,2,4-benzenetricarboxylic acid anhydride was added and the reaction was continued for about 8 hours, and the reaction was terminated when the acid value reached 10. The obtained resin was a pale yellow solid, and the softening point of this resin was measured with a "Flow Tester CFT-500" (manufactured by Shimadzu Corporation) and was found to be 122°C. (4) Binder D (for comparison) Γ Polyoxypropylene (2,2)-2,2-
Bis(4'-hydroxyphenyl)propane
482g Γ Polyoxyethylene (2)-2,2-bis(4'-
Hydroxyphenyl) propane 190g Γ Terephthalic acid 210g Γ n-dodecenylsuccinic anhydride 48g Γ Adipic acid 31g Γ Diisopropyl orthotitanate (esterification catalyst) 0.8g The above substances were reacted in the same manner as in the production of binder A, and , 35 g of 1,2,4-benzenetricarboxylic acid anhydride were added thereto, and the mixture was reacted for about 8 hours, and the reaction was terminated when the acid value reached 12. The obtained resin was a pale yellow solid, and the softening point of this resin was measured with a "Flow Tester CFT-500" (manufactured by Shimadzu Corporation) and was found to be 126°C. (5) Binder E (for comparison) Γ Polyoxypropylene (2,2)-2,2-
Bis(4'-hydroxyphenyl)propane
490g Γ Polyoxyethylene (2)-2,2-bis(4'-
Hydroxyphenyl) propane 160g Γ Terephthalic acid 241g Γ n-dodecenylsuccinic anhydride 74g Γ 1,6-hexanediol 12g Γ Fumaric acid 10g Γ Diisopropyl orthotitanate (esterification catalyst) 0.8g The above substances are used to produce binder A. The reaction was carried out in the same manner as above, and 13 g of pentaerythritol was added and the reaction was continued for about 8 hours, and the reaction was terminated when the acid value reached 13. The obtained resin was a pale yellow solid, and the softening point of this resin was measured with a "Flow Tester CFT-500" (manufactured by Shimadzu Corporation) and was found to be 130°C. (6) Binder F (for comparison) Γ Polyoxypropylene (2,2)-2,2-
Bis(4'-hydroxyphenyl)propane
490g Γ Polyoxyethylene (2)-2,2-bis(4'-
(Hydroxyphenyl)propane 195g Γ Terephthalic acid 188g Γ n-dodecenylsuccinic anhydride 26.8g Γ Diisopropyl orthotitanate (esterification catalyst) 0.8g The above substances were heated at 250°C in the same equipment as used for the production of Binder A. After reacting for about 5 hours, the acid value was 2.0. Furthermore, 78.8 g of trimellitic anhydride was added at 200° C., and the reaction was allowed to proceed for about 4 hours, followed by another 2 hours under reduced pressure, and the reaction was terminated when the acid value reached 18. The obtained resin was a pale yellow solid, and the softening point of this resin was measured with a "Flow Tester CFT-500" (manufactured by Shimadzu Corporation) and was found to be 135°C. (7) Binder G (for comparison) Γ Polyoxypropylene (2,2)-2,2-
Bis(4'-hydroxyphenyl)propane
420g Γ Polyoxyethylene (2)-2,2-bis(4'-
Hydroxyphenyl) propane 130g Γ Terephthalic acid 179g Γ n-dodecenylsuccinic anhydride 48g Γ 1,6-hexanediol 48g Γ Fumaric acid 42g Γ Diisopropyl orthotitanate (esterification catalyst) 0.8g The above substances are used to produce binder A. The reaction was carried out in the same manner as above, and 35 g of 1,2,4-benzenetricarboxylic acid anhydride was added and the reaction was continued for about 8 hours, and the reaction was terminated when the acid value reached 10. The obtained resin was a pale yellow solid, and the softening point of this resin was measured with a "Flow Tester CFT-500" (manufactured by Shimadzu Corporation) and was found to be 112°C. (8) Binder H (for comparison) 700 g of polyoxypropylene (2,2)-2,2-bis(4-hydroxyphenyl)propane,
130g of fumaric acid and n-dodecenylsuccinic anhydride
Put 53.4 g of hydroquinone and 0.1 g of hydroquinone into a four-necked glass flask with a capacity of 1, attach a thermometer, a stainless steel stirring bar, a flowing condenser, and a nitrogen gas inlet tube, and heat in a mantle heater for 230 g.
The temperature was raised to ℃. When the water produced by the reaction stopped flowing out, the acid value was measured to be 1.5. Furthermore, 63.4 g of trimellitic anhydride was added and reacted for about 8 hours, and the reaction was terminated when the acid value reached 20. The obtained resin was a pale yellow solid, and its softening point as measured by the ring and ball method was 120°C. (9) Binder I (for comparison) Put 545 parts of polyoxypropylene (2.5)-2,2-bis(4-hydroxyphenyl)propane into a four-necked flask, add a stirrer, condenser, thermometer, and introduce nitrogen gas. After attaching the tube and setting it on a mantle heater, purging the inside of the reaction vessel with nitrogen gas, the contents were heated to a temperature of 50°C, and added with 108 parts of terephthalic acid, 24 parts of adipic acid, and an alkyl group having 12 carbon atoms. 77 parts of substituted succinic acid and 38 parts of trimellitic acid were added, and the mixture was heated to 210°C with stirring. After about 5 hours, while removing the reaction water, the acid was added every hour to check the end point of the reaction. The reaction was followed by value measurement, and when the acid number reached approximately 30, the reaction was cooled to room temperature. Example 1 Binder B 100 parts by weight Carbon black 10 parts by weight Example 2 Binder C 100 parts by weight Carbon black 10 parts by weight Comparative example 1 Binder A (for comparison) 100 parts by weight Carbon black 10 parts by weight Comparative example 2 Binder D (for comparison) 100 parts by weight Carbon black 10 parts by weight Comparative example 3 Binder E (for comparison) 100 parts by weight Carbon black 10 parts by weight Comparative example 4 Binder A (for comparison) 20 parts by weight Binder F (for comparison) 80 parts by weight Carbon black 10 parts by weight Comparative example 5 Binder F (for comparison) 100 parts by weight Carbon black 10 parts by weight Comparative example 6 Binder G (for comparison) 100 parts by weight Carbon black 10 parts by weight Comparative example 7 Binder H (for comparison) 100 parts by weight Carbon Black 10 parts by weight Comparative Example 8 Binder I (for comparison) 100 parts Carbon Black 10 parts by weight In each of the Examples and Comparative Examples, materials of the indicated formulation were melted, kneaded, cooled, pulverized, A toner consisting of particles having an average particle size of 10 μm was obtained by a conventional toner manufacturing method involving classification. The toners obtained in Examples 1 and 2 are referred to as "Toner 1" and "Toner 2," respectively, and the toners obtained in Comparative Examples 1 to 8 are designated as "Comparative Toner 1" to "Comparative Toner 8," respectively. ”. For each of these toners, the minimum fixing temperature and offset generation temperature were determined, and the cohesiveness was also investigated. Regarding the minimum fixing temperature, we used a heated roller whose surface layer was made of Teflon (polytetrafluoroethylene manufactured by Dupont) and a silicone rubber "KE-".
1300RTV" (manufactured by Shin-Etsu Chemical Co., Ltd.), an electrophotographic copying machine "U-Bix5000" (manufactured by Konishiroku Photo Industry Co., Ltd.) equipped with a fixing device consisting of a back-up roller made of a rubber layer covered with a Teflon tube
, set the linear speed of the heat roller to 200 mm/sec,
Then, with the temperature of the heat roller initially set at 240°C, the toner image transferred to the 64 g/m ² transfer paper was continuously and repeatedly fixed.
℃ and 20% relative humidity until the temperature of the heat roller drops to 140℃. The lowest fixing temperature was set. Note that the fixing device used here does not have a silicone oil supply mechanism. In addition, to measure the offset occurrence temperature, the toner image is transferred and fixed using the above-mentioned fixing device in accordance with the measurement of the minimum fixing temperature, and then a blank transfer paper is sent to the fixing device under the same conditions. The operation of observing whether or not toner stains occur is repeated while the temperature of the heat roller of the fixing device is successively lowered, and the offset is set at the lowest temperature of the heat roller when toner stains occur. The temperature was taken as the generation temperature. Regarding blocking resistance, each sample was left for 48 hours at a temperature of 55°C and a relative humidity of 40%, and the presence or absence of aggregation and its degree were evaluated. The above results are shown in Table 1.

〔Effect of the invention〕

As explained above, according to the electrostatic image developing toner of the present invention, the binder contains a monomer containing a trivalent or higher polyhydric alcohol monomer and/or a trivalent or higher polyvalent carboxylic acid monomer. A non-linear polyester obtained from a body component, which has a specific aliphatic hydrocarbon group in its side chain and whose main chain has a specific proportion of long-chain aliphatic hydrocarbon units. As a result, the toner has excellent offset prevention performance and has a low softening point, making it possible to achieve sufficient low-temperature fixing.
Moreover, the decrease in the glass transition point Tg is suppressed, and the toner has excellent blocking resistance, which is less likely to cause agglomeration. As a result, the toner can behave stably as unit particles without agglomeration, and good development can be achieved.
The hot roller fixing method makes it possible to achieve good fixing at a sufficiently high speed without causing offset phenomena. The reason why the electrostatic image developing toner of the present invention has the above-mentioned excellent properties has not been strictly elucidated, but the polyester used as the binder is
polyhydric alcohol monomer and/or 3
A non-linear polyester whose main skeleton is an ester structure obtained from a monomer component containing a polycarboxylic acid monomer with a polyvalent carboxylic acid monomer or higher, while a part of the skeleton is formed from a specific proportion of long-chain aliphatic hydrocarbon units. Moreover, since it contains a specific aliphatic hydrocarbon group in its side chain, it has a low softening point and can be fixed at a sufficiently low temperature, and it also has excellent elasticity when melted. Part of the reason is thought to be that although the toner has excellent offset prevention performance, the glass transition point Tg does not decrease and the toner does not easily aggregate.

Claims (1)

[Claims] 1. A divalent alcohol monomer, a divalent carboxylic acid monomer, and 1 to 30 mol% of a trivalent or higher polyhydric alcohol monomer and/or an acid in the alcohol component. A non-linear product obtained from a monomer component containing 1 to 30 mol% of a trivalent or higher polycarboxylic acid monomer, and in which 30 mol% or more of the acid component is an aromatic dicarboxylic acid monomer. A polyester having an unsaturated aliphatic hydrocarbon group having 3 to 22 carbon atoms in its side chain, and whose main chain is linear in a range of 5 to 20 mol% of the constituent units of the main chain. A toner for electrostatic image development, comprising as a binder a nonlinear polyester having a long chain aliphatic hydrocarbon unit having 5 to 20 carbon atoms.