JPH0447308B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a toner for developing electrostatic images used in electrophotography, electrostatic recording, and the like. Methods for developing electrostatic latent images are broadly classified into liquid development methods and dry development methods, and the present invention relates to toner used in the dry development method. Furthermore, methods for fixing the developed toner image on a support such as paper include methods that use heat such as a heat roll method, flash method, high frequency heating method, and oven method, methods that use a pressure roll, and methods that use organic Methods using solvents are known. The present invention particularly relates to a method for producing toner suitable for hot roll fixing. (Prior art) In recent electrophotographic copying machines, the thermal roll fixing method is most commonly used because it has good thermal efficiency, excellent fixing properties, produces good images, and can be made smaller. ing. In particular, a hot roll fixing method is generally used for high-speed fixing. However, in this fixing method, a so-called offset phenomenon occurs in which the toner softens and becomes sticky due to heating, and a portion of the toner adheres to the surface of the hot roll. Conventionally, various fixing devices and fixing methods have been proposed in order to prevent this offset phenomenon.
For example, a fixing device is used in which the surface of a hot roll is formed of a material with excellent mold releasability, such as a fluororesin, and the surface is further coated with a liquid for preventing offset, such as silicone oil. Although this device is extremely effective in preventing the offset phenomenon, the anti-offset liquid is heated and deteriorates in quality, producing a strange odor, and also requires a device to supply the anti-offset liquid, making it difficult to use with copying machines. The disadvantages are that the copying machine is large in size, the mechanism of the copying machine is complicated, and high precision is required to ensure stability, making it expensive. For this reason, methods for preventing the offset phenomenon are being considered, since no offset prevention liquid is required, or only a small amount is required so that supply, etc., is not a problem. For example, Japanese Patent Laid-Open No. 49-65231 describes that the offset phenomenon can be prevented by incorporating a small amount of low molecular weight polypropylene into the toner. In addition, various studies have been made regarding binders for toner; for example, in Japanese Patent Publication No. 51-23354,
It is described that a crosslinkable polymer is used as the binder resin. Furthermore, JP-A-50-134652 discloses the use of a resin having a large molecular weight distribution as a binder. Others, JP-A-58-
Publication No. 68752 and Japanese Patent Application Laid-Open No. 1983-102246,
It is described that a vinyl polymer obtained by graft copolymerizing a modified epoxy resin having a vinyl group and a polyester resin having a vinyl group is used as a binder. (Problems to be Solved by the Invention) However, when low molecular weight polypropylene is used as an anti-offset agent, the toner tends to become non-uniform, causing fogging and scattering, so it is preferable to limit its use to as little as possible. Further, when a crosslinkable polymer or a graft copolymer is used, fixing properties generally decrease, and this tendency becomes more pronounced especially when fixing is performed at a high speed. When a resin with a large molecular weight distribution is used, it is possible to prevent offset without impairing fixing properties, but it is generally not easy to produce such a resin, and there are problems in that it is less economical. An object of the present invention is to solve these problems and provide a toner that is free from fogging and scattering, has excellent fixing properties in a hot roll fixing system, and is also excellent in preventing offset. (Means for Solving the Problems) The present invention provides at least one monomer in one molecule obtained by polymerizing a vinyl monomer containing an ester of acrylic acid or methacrylic acid as an essential component containing a hydroxyl group. In the presence of a vinyl polymer containing a hydroxyl group, the general formula (): group, acyloxy group, alkylamino group or arylamino group, Z represents an alkyl group or aryl group, n is the number of bonds in Y and is 1, 2 or 3, m is the number of bonds in Z and is 0, 1 or 2 and n
+m is 3)
0.1-50% by weight and other vinyl monomers 99.9-50%
% by weight, and further polymerized in the presence or absence of water, resulting in a polymer or hydrolysis treatment of this polymer (however, the polymer obtained by polymerizing in the absence of water may be The present invention relates to a method for producing a toner for developing an electrostatic image, characterized in that a binder is a polymer that has been subjected to hydrolysis treatment) and/or a crosslinked polymer. First, a vinyl polymer containing at least one hydroxyl group in one molecule will be explained. This polymer is obtained by polymerizing an ester of acrylic acid or methacrylic acid containing a hydroxyl group or a mixture of this and another vinyl monomer in the presence of a polymerization initiator. Examples of esters of acrylic acid or methacrylic acid containing a hydroxyl group include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxy-3-phenyloxypropyl acrylate, 2-hydroxyethyl methacrylate, Hydroxypropyl methacrylate, 2-hydroxy-3-phenyloxypropyl methacrylate, methoxydiethylene glycol acrylate, ethoxydiethylene glycol acrylate, methoxyethylene glycol acrylate, butoxytriethylene glycol acrylate, methoxydipropylene glycol acrylate, acrylic acid Phenoxydiethylene glycol, phenoxytetraethylene glycol acrylate, methoxydiethylene glycol methacrylate, methoxyethylene glycol methacrylate, butoxytriethylene glycol methacrylate, methoxycypropylene glycol methacrylate, phenoxydiethylene glycol methacrylate, phenoxymethacrylate Examples include cytotraethylene glycol. Examples of other vinyl monomers include styrene, α-methylstyrene, p-methylstyrene,
Styrene derivatives such as pt-butylstyrene and p-chlorostyrene, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate , nonyl methacrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, glycidyl methacrylate, methoxyethyl methacrylate, propoxyethyl methacrylate, butoxyethyl methacrylate, phenoxyethyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, methacrylic acid Tetrahydrofurfuryl, dicyclopentenyl methacrylate, N-vinyl methacrylate
2-pyrrolidone, methacrylonitrile, methacrylamide, N-methylolmethacrylamide, acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, acrylic acid Octyl, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, glycidyl acrylate, methoxyethyl acrylate, propoxyethyl acrylate, butoxyethyl acrylate, phenoxyethyl acrylate, benzyl acrylate,
Cyclohexyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, N-vinyl-2-pyrrolidone acrylate, glycidyl acrylate, acrylonitrile, acrylamide, N-methylol acrylamide, diacetone acrylamide , vinylpyridine and the like. Other crosslinkable monomers include divinylbenzene, reaction products of glycol and methacrylic acid or acrylic acid, such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1 , 5-pentanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, neopentyl glycol hydroxypivalate Ester dimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate,
Pentaerythritate tetramethacrylate, trismethacryloxyethyl phosphate, bis(methacryloyloxyethyl)hydroxyethyl isocyanurate, tris(methacryloyloxyethyl)isocyanurate, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4 -butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate,
Neopentyl glycol diacrylate, diethylene glycol acrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, neopentyl glycol diacrylate hydroxypivalate, trimethylolethane triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritate tetraacrylate, trisacryloxyethyl phosphate, bis(methacryloyloxyethyl)hydroxyethyl isocyanurate, tris(methacryloyloxyethyl)isocyanurate, half-esterified product of glycidyl methacrylate and methacrylic acid or acrylic acid, Esterified product of bisphenol type epoxy resin and methacrylic acid or acrylic acid,
Vinyl monomers having two or more vinyl groups in one molecule, such as esters of glycidyl acrylate and methacrylic acid or acrylic acid, can also be used. The content ratio of hydroxyl groups in the vinyl polymer containing at least one hydroxyl group in one molecule is preferably 5 to 200 in terms of the hydroxyl value of the polymer,
In particular, 10 to 100 is preferable. If the hydroxyl value is less than 5, the crosslinking reaction described below tends to proceed insufficiently, and if it exceeds 200, the storage stability of the toner tends to deteriorate due to a decrease in moisture resistance. Further, when a crosslinkable monomer is used, it is preferably 5% by weight or less based on the total amount of the constituent vinyl monomers. Polymerization initiators used in the polymerization include benzoyl peroxide, 2-ethylhexyl perbenzoate, lauroyl peroxide, di-tert-butyl peroxide, cumene hydroperoxide, methyl ethyl ketone peroxide, and 4,4,6-trimethylcyclohexanone di-tert. -butyl peroxyketal, cyclohexanone peroxide, methyl cyclohexanone peroxide, acetylacetone peroxide, cyclohexanone di-tert-butyl peroxyketal, 2-octanone di-tert-butyl peroxyketal, acetone di-tert-butyl peroxyketal, diisopropyl hydroperoxide, acetyl peroxide, isobutyryl peroxide,
Peroxide radical initiators such as octanoyl peroxide, 2,2'-azobisisobutyronitrile, 2,
2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4
-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, and 1-1'-azobis(cyclohexane-1-carbonitrile). In addition, polymerization methods include suspension polymerization, solution polymerization,
Any known polymerization method such as emulsion polymerization or bulk polymerization can be employed. Next, the organic titanium compound represented by the general formula () will be explained. The organic titanium compound in the present invention is an organic titanium compound represented by the general formula (). In the general formula (), X is a group having a copolymerizable carbon-carbon double bond, such as a vinyl group,
Alkenyl groups such as allyl group and butenyl group, cycloalkenyl group such as cyclohexenyl group, cyclopentadienyl group, cyclohexadienyl group, γ-
Unsaturated acyloxyalkyl group such as methacryloxypropyl group, unsaturated acyloxyalkoxy group such as γ _- methacryloxyethylpropyl ether group, _CH2 =C( _CH3 )COO( _CH2 ) _2OCH2CH- (OH )
_CH2O ( _CH2 ) _3- and the like. Among these, the most preferred are unsaturated acyloxyalkyl groups such as γ-methacryloxypropyl group or unsaturated acyloxyalkoxy groups such as γ-methacryloxyethylpropyl ether group. The group Y is a hydrolyzable group selected from alkoxy groups such as methoxy, ethoxy, butoxy, aryloxy and acyloxy groups such as formyloxy, acetoxy or propionyloxy. A group that decomposes to produce a hydroxyl group, -NHCH ₃ ,
Alkylamino or arylamino groups such _{as -NHC2H5} and -NH _{( C6H5} ). The group Y is
When n is 2 or 3, they may be the same or different. The group Z is an alkyl group such as methyl, ethyl, propyl, butyl, tetradecyl, octadecyl, or an aryl group such as phenyl, benzyl, tolyl. Base Z
may be the same or different when m is 2. As the organic titanium compound represented by the above general formula (), a particularly preferable compound is the general _formula (): ' is an alkoxy group or an aryloxy group),
Among these, the most preferred is γ-methacryloxypropyltrimethoxytitanium. Other vinyl monomers to be copolymerized with the organic titanium compound of general formula () include other vinyl monomers described in the explanation of vinyl polymers containing at least one hydroxyl group in one molecule. In addition, the crosslinking monomers described in the description of the polymer can also be used if necessary. Among these, preferable vinyl monomers having one vinyl group in one molecule include styrene, styrene derivatives, methacrylic esters, acrylic esters, etc. Alkyl esters of methacrylic acid or acrylic acid having 1 to 8 carbon atoms in the alkyl group are preferred. When using a crosslinkable monomer having two or more vinyl groups in one molecule, it is preferably 5% by weight or less based on the total amount of the organic titanium compound and other vinyl monomers. The above-described organic titanium compound and other vinyl monomers are polymerized in the presence of a vinyl polymer containing at least one hydroxyl group in one molecule. This polymerization is preferably carried out as follows by impregnating a vinyl polymer containing at least one hydroxyl group in one molecule with an organic titanium compound and other vinyl monomers. Impregnation in the present invention refers to adding a monomer to a system in which a polymer exists, or adding a polymer to a system in which a monomer exists, and causing the monomer to be absorbed into the polymer. Note that the impregnation temperature is 50℃.
It is preferable to carry out at the following temperature. In the polymerization, a polymerization initiator such as that described in connection with the production of the vinyl polymer can be used. In addition, polymerization methods include suspension polymerization, solution polymerization,
Polymerization can be carried out by any known polymerization method such as emulsion polymerization or bulk polymerization. Among the above polymerization methods, water-soluble polymers such as partially saponified polyvinyl alcohol, alkylcellulose, hydroxyalkylcellulose, carboxyalkylcellulose, polyacrylamide, polyvinylpyrrolidone, polyacrylic acid and its alkali metal salts, polymethacrylic acid and its alkali metal salts, etc. Aqueous suspension polymerization using poorly soluble inorganic dispersants such as polymeric dispersants, calcium phosphate, hydroxyapatite, magnesium phosphate, magnesium pyrophosphate, calcium carbonate, barium sulfate, and hydrophobic silica is economical and stable during production. It is preferable from the viewpoint of In the above polymerization, in suspension polymerization or emulsion polymerization using an aqueous medium, polymerization is naturally carried out in the presence of water, but polymerization may be carried out in the presence of water in other polymerization methods as well. Polymerization temperature is 60~
The temperature is 120°C, preferably 70-90°C. In this polymerization, the organic titanium compound represented by the general formula () and other vinyl monomers can be used as polymerization components, and the amount of the organic titanium compound is 0.1 to 50% relative to the total amount of these. % by weight is used, with 1 to 5% by weight being optimal. If the amount of the organic titanium compound used is too small, the crosslinking reaction described below will not occur sufficiently. If the amount of the organic titanium compound is too large, the crosslinking reaction described below may occur excessively. The mixture of the organic titanium compound and other vinyl monomers is preferably used in an amount of 25 to 400 parts by weight based on 100 parts by weight of the total monomers used for producing the hydroxyl group-containing polymer. Next, the polymerization in the present invention and the polymer obtained by hydrolyzing and/or crosslinking this polymer will be explained. The polymer obtained by the above polymerization, when polymerized in the absence of water, has residues of the organic titanium compound represented by the general formula () excluding the copolymerizable double bond. However, when polymerized in the presence of water, the group Y in the residue is hydrolyzed and a new group capable of crosslinking reaction, such as a hydroxyl group, is introduced. Here, it is preferable that the amount of water used is equal to or more than the equivalent amount of the group Y in the general formula (). This hydrolysis occurs during polymerization. After completion of polymerization, these polymers may be heated in the presence of water to proceed with the above-mentioned hydrolysis. In particular, when polymerization is started in the absence of water, water is added during the polymerization, or after the polymerization is completed, the polymer is heated in the presence of water to be hydrolyzed. In this way, when the above polymerization is carried out in the presence of water, the polymer obtained without any special hydrolysis treatment has a group formed by hydrolyzing the group Y (hereinafter referred to as a crosslinkable group). ), but when the polymerization is carried out in the absence of water, in order to obtain a polymer having a crosslinkable group, the polymer obtained by the polymerization is heated in the presence of water. Decomposition treatment is required. Note that hydrolysis of the group Y occurs at 50°C. Hydrolysis is preferably carried out at 50-100°C. A polymer having a crosslinkable group causes a crosslinking reaction between polymer molecules by a reaction between the crosslinkable groups at 110 to 180°C, and becomes a crosslinked polymer. This crosslinking reaction
It progresses even at 100℃. A crosslinking treatment in which a polymer having a crosslinkable group is heated is necessary for the crosslinking reaction, but this treatment can be carried out without any special steps and can be carried out in the toner manufacturing process of the present invention and/or in the toner according to the present invention. This can be done by heating in the developing/fixing process used. In the manufacturing process, a polymer having a crosslinkable group, a colorant and/or
Alternatively, the crosslinking reaction can be carried out in the process of melting and kneading the magnetic powder and other additives as necessary,
In this case, in order to facilitate melt-kneading, it is preferable not to allow the crosslinking reaction to proceed much until then. In the above development/fixing step, the crosslinking reaction can be caused by heating, especially during fixing. In addition, it is thought that the above-mentioned crosslinking reaction partially proceeds during hydrolysis treatment and/or polymerization depending on the temperature. In the present invention, other polymers can be used as a binder in addition to the above-mentioned polymers and the polymers obtained by hydrolyzing and/or crosslinking these polymers. When used together, the organic titanium compound component is 0.1 to 50% by weight based on the total amount of binder.
It is preferable to use it so that As other polymers, conventionally known vinyl polymers, polyesters, and other commonly used binders for toners can be used. Examples of the vinyl polymer include polymers of other vinyl monomers mentioned above, and the preferable polymers of vinyl monomers mentioned above are particularly preferred. In the present invention, the binder is preferably adjusted to have a weight average molecular weight of 30,000 to 100,000, a dispersity of 1.5 to 40, and a glass transition point of 50 to 100°C. In addition to the binder, the toner for developing an electrostatic image containing a binder according to the present invention may appropriately contain other additives such as a colorant and/or magnetic powder and, if necessary, a charge control agent. do. As the coloring agent, conventionally known pigments or dyes such as carbon black, iron oxide pigment, phthalocyanine blue, phthalocyanine green, rhodamine 6G lake, watching-lead barium, and watching-lead strontium can be used. It is used in an appropriately selected range of 60% by weight. Magnetic powders include metal powders such as iron, manganese, nickel, and cobalt;
There are ferrites such as cobalt and zinc, and those with an average particle size of 10 μm or less, especially 1 μm or less are preferable.
It is usually used in toners in amounts of 30 to 70% by weight.
When a colorant and magnetic powder are used together, the magnetic powder may be less than 30% by weight. As the charge control agent, nigrosine dye, fatty acid-modified nigrosine dye, metal-containing nigrosine dye, metal-containing fatty acid-modified nigrosine dye, 3,5-di-
Positive and negative charge control agents such as chromium complexes of tert-butylsalicylic acid and chromium complexes of azo dyes can be used and are typically used in the toner at 0 to 20% by weight. Other additives include silica powder, hydrophobic silica powder, polyolefin, paraffin wax, fluorocarbon compound, fatty acid ester,
Partially saponified fatty acid esters, fatty acid metal salts, etc. can be used, and these are usually used in the toner in amounts of 0 to 10% by weight. The above-mentioned polymer or a polymer obtained by hydrolyzing and/or crosslinking this polymer, a coloring agent and/or
Alternatively, a toner for developing an electrostatic image can be produced by mixing the magnetic powder and, if necessary, other additives and another polymer as a binder, for example, by the following method. After premixing the weighed materials using a W cone, V blender, Henschel mixer, etc., use a pressure kneader, Banbury mixer, hot roll, extruder, etc. to adjust the temperature at which the binder melts (e.g. 130 to 180°C). ) to knead the bottom. After cooling, it is coarsely ground using a feather mill, pin mill, pulverizer, hammer mill, etc., and then finely ground using jet air. Next, the particles are sieved using an Akiyukatsu or Alpine classifier to adjust the particle size to preferably 5 to 30 μm. Note that a fluidity modifier such as silica powder can also be simply mixed. In the present invention, an organic titanium compound represented by the general formula () and other vinyl monomers are polymerized in the presence of water to a vinyl polymer containing at least one hydroxyl group in one molecule. When the resulting polymer is melt-kneaded with the addition of a colorant, magnetic powder, etc., an electrostatic image developing toner can be obtained without special hydrolysis and crosslinking steps. (Function) In the toner for developing electrostatic images obtained by the present invention, the hydroxyl groups of the vinyl polymer containing hydroxyl groups and the groups capable of crosslinking by hydrolysis of the organic titanium compound are appropriately crosslinked during melt-kneading, fixing, etc. Because it reacts and becomes three-dimensional, it has an excellent offset prevention effect. In addition, this three-dimensionalization will not impair the fixing properties of the toner unless harsh conditions such as heating to high temperatures are applied when there are too many crosslinkable groups, and the three-dimensionalization will progress further during fixing. So,
The offset prevention effect can be further improved. Furthermore, since crosslinking reactions can be suppressed during the production of the polymer, gelation can be prevented from occurring during the production. (Example) Next, the present invention will be explained in detail based on an example.
The present invention is not limited to this. Examples 1 to 8 and Comparative Examples 1 to 4 () Manufacture of binder A stirrer equipped with stirring blades, a cooling tube, a gas introduction tube, and a thermometer were attached to the cylindrical separable flask of 3, and ions were injected into the flask. 1000 ml of exchanged water, 50 g of Supertite 10 (trademark of hydroxyapatite water dispersant manufactured by Nippon Kagaku Kogyo Co., Ltd.), 5 g of 1% sodium dodecylbenzenesulfonate aqueous solution, and a monomer (A) mixture of the composition shown in Table 1. benzoyl peroxide
A solution containing 40g was added. Next, nitrogen gas was started to flow into the flask, and the mixture was stirred at room temperature for about 30 minutes to stabilize the dispersion. Subsequently, the temperature was raised to 90°C over about 1 hour, the mixture was stirred for 4 hours, and then stirred at 95°C for 2 hours to complete polymerization. Thereafter, it was cooled to 50°C, and benzoyl peroxide 40 was added to the monomer (B) mixture having the composition shown in Table 1.
A solution containing g was added to the flask and impregnated into the polymer. Subsequently, the temperature was raised to 90°C over about 1 hour, the mixture was stirred for 4 hours, and then stirred at 95°C for 2 hours to complete polymerization. Thereafter, the mixture was cooled to 50° C. while stirring, and 10 ml of concentrated hydrochloric acid was added to bring the pH of the aqueous phase to 3 or less. Filter this under reduced pressure,
After washing three times with 500 ml of ion-exchanged water, the beads were dried overnight in a dryer at 50°C to obtain polymer beads (binder). Table 1 shows the weight average molecular weight, number average molecular weight, dispersity and glass transition point of the obtained polymer. The weight average molecular weight and number average molecular weight were measured by gel permeation chromatography using a standard polystyrene calibration curve, and the glass transition point was measured by DSC method.

【table】

[Table] (2) Manufacture of toner and developer 450 g of polymer beads, 40 g of Carbon Black #44 (manufactured by Mitsubishi Chemical Industries, Ltd.), 10 g of Viscoel 550P (trademark of low molecular weight polypropylene manufactured by Sanyo Chemical Industries, Ltd.)
and Oil Black BY (Orient Chemical Industry Co., Ltd.)
After heat-melting and kneading 15 g of nigrosine dye manufactured by Nigrosine Co., Ltd. at 130 to 150° C. using a PCM-30 kneader, the mixture was coarsely ground using a hammer mill, and then finely ground using a jet air mill. This was classified to obtain a toner having a particle size of 5 to 30 μm and an average particle size of 14 μm. Next, 50 g of this toner and 950 g of EFV200/300 (amorphous iron oxide powder carrier manufactured by Nippon Tetsuko Co., Ltd.) were mixed and thoroughly shaken to prepare a developer. (3) Evaluation of toner (a) Storage stability Approximately 5 g of toner was stored in a constant temperature and humidity chamber at 55° C. and 90% humidity for 24 hours so that it had a uniform thickness on a glass shear plate. This was sieved through a 100 mesh wire mesh,
The passing weight was measured and judged based on the following criteria. 5: Passing 95% by weight or more 4: Passing 70% by weight or more and less than 95% by weight 3: 30 〃 70 〃 2: 5 〃 30 〃 1: Passing less than 5% by weight (b) Fixing properties and offset prevention properties Copying developer I put the machine SF755 (manufactured by Sharp Co., Ltd.) into a modified test machine and created an unfixed image with the top 1/3 of an A4 size sheet covered in black. This unfixed image was fixed using a Teflon roll fixing tester at a linear speed of 900 cm/min (A4 size, approx. 30 sheets/min) while changing the temperature in 10°C steps from 100 to 240°C. Tested. The fixing temperature was set to the lowest temperature at which the image density change rate was 10% or less after removing cellophane tape from the fixed black solid area. The offset occurrence density was defined as the lowest temperature at which the image density of the white paper portion where the offset of the black solid portion occurred was 0.2% or more compared to the black solid portion. (c) Actual machine copying test The developer was placed in a copying machine SF755 (manufactured by Sharp Co., Ltd.), and a continuous copying test of 10,000 sheets was conducted to observe the initial image and changes in the image. The evaluation results of the toner are shown in Table 2 below.

【table】

[Table] (4) Polymer crosslinking confirmation test The polymer beads (binder) obtained in Examples 1 to 8 and the polymer beads were heated and melt-kneaded at 130 to 150°C using a PCM-30 kneader. 1 g of each of the crosslinked polymers was taken and heated under reflux in 200 ml of tetrahydrofuran for 10 hours, and the proportion (wt%) of insoluble matter was determined. The same experiment was performed several times. The results are shown in Table 3.

[Table] (Effects of the Invention) The toner for developing electrostatic images obtained according to the present invention is free from fog and scattering, and has excellent fixing properties and anti-offset properties.

Claims (1)

[Scope of Claims] 1. A vinyl polymer containing at least one hydroxyl group in one molecule obtained by polymerizing a vinyl monomer containing an ester of acrylic acid or methacrylic acid as an essential component. In the presence of a combination, the general formula (): XTiYnZm () (wherein, group or an arylamino group, Z represents an alkyl group or an aryl group, n is the number of bonds in Y and is 1, 2 or 3, m is the number of bonds in Z and is 0, 1 or 2, n
+m is 3)
0.1-50% by weight and other vinyl monomers 99.9-50%
% by weight, and further polymerized in the presence or absence of water, resulting in a polymer or hydrolysis treatment of this polymer (however, the polymer obtained by polymerizing in the absence of water may be 1. A method for producing a toner for developing an electrostatic image, characterized in that a binder is a polymer that has been subjected to a hydrolysis treatment) and/or a crosslinking treatment. 2. An organic titanium compound represented by the general formula () and other vinyl monomers are blended in the presence of a vinyl polymer in which the polymer contains at least one hydroxyl group in one molecule, The method for producing an electrostatic image developing toner according to claim 1, which is obtained by impregnating and polymerizing in the presence or absence of water. 3. The polymer contains an organic titanium compound represented by the general formula () and other vinyl monomers in the presence of a vinyl polymer containing at least one hydroxyl group in one molecule, and further The method for producing an electrostatic image developing toner according to claim 1, which is obtained by polymerizing in the presence of water. 4 The polymer is aqueous by blending an organic titanium compound represented by the general formula () and other vinyl monomers in the presence of a vinyl polymer containing at least one hydroxyl group in one molecule. The method for producing an electrostatic image developing toner according to claim 1, which is obtained by suspension polymerization in a medium. 5. The method for producing an electrostatic image developing toner according to claim 1, further comprising adding a colorant and/or magnetic powder and melting and kneading the mixture.