JP4038160B2 - Method for producing toner for developing electrostatic image - Google Patents

Description

  The present invention relates to a method for producing a toner for developing an electrostatic image having excellent low-temperature fixability and offset resistance.

  As described in Patent Document 1, Patent Document 2, Patent Document 3, etc., as an electrophotographic method used in an image forming apparatus such as a laser printer or a dry electrostatic copying machine, a photoconductive insulating layer is uniformly formed. It is charged (charging process), then the layer is exposed (exposure process), an electric latent image is formed by dissipating the charge of the exposed part, and the latent image is colored with a toner called a toner. Make visible image by attaching fine powder with electric charge (development process), transfer the obtained visible image to transfer material such as transfer paper (transfer process), then heat, pressure or other suitable And a permanent fixing (fixing step) by a simple fixing method. After the toner image is transferred, residual toner on the photoconductor is wiped off in order to clean the surface of the photoconductor (cleaning step).

  Among these, a contact heating fixing method such as heat roller fixing or a non-contact heating method such as oven fixing is used for the fixing step. The contact method is characterized by good thermal efficiency. Compared with the non-contact method, the temperature required for the fixing machine can be lowered, which is effective for energy saving and copying machine miniaturization. However, in this contact-type heat fixing method, there is a problem of offset development in which a part of the toner melted at the time of fixing is transferred to a heat roller and transferred to a subsequent transfer paper or the like.

  In order to prevent this phenomenon, the surface of the heat roller has been conventionally processed with a material having excellent releasability such as fluorine resin, or a release agent such as silicone oil has been applied to the surface of the heat roller. Yes. However, the method using silicone oil or the like is not preferable because the fixing device is large and complicated, which may increase costs and cause trouble.

  Conventionally, a vinyl resin typified by a styrene acrylic copolymer has been used for this type of toner. In the case of a vinyl resin, if it is attempted to improve the offset resistance, the softening point and the crosslinking density of the resin must be increased, and low temperature fixing is sacrificed. On the other hand, if importance is attached to low-temperature fixing, the offset resistance and blocking resistance are impaired.

  Further, as described in Patent Document 4, Patent Document 5, and Patent Document 6, there is known a method of adding paraffin wax, low molecular weight polyolefin or the like as an anti-offset agent. If it is too much, there is a problem that the developer deteriorates quickly.

  On the other hand, as a binder resin for toner, a polyester resin is particularly used as one having excellent low-temperature fixability. Polyester resin is inherently good in fixability, and as described in Patent Document 7, it can be sufficiently fixed even in a non-contact fixing method, but it is difficult to use in a heat roller fixing method because an offset phenomenon easily occurs. It was. Patent Document 8, Patent Document 9, and Patent Document 10 describe polyester resins that have improved offset resistance using polyvalent carboxylic acids, but these are still sufficient for offset resistance. Those having or not having had a problem that the low-temperature fixability inherent in the polyester resin was sacrificed and the grindability of the resin and toner was extremely poor.

  Therefore, the following attempts have been made using a mixture of a polyester resin excellent in fixing properties and a styrene acrylic resin.

(1) A method of mixing a polyester resin and a styrene acrylic resin (Patent Document 11, Patent Document 12, Patent Document 13, Patent Document 14);
(2) A method of chemically bonding a polyester resin and a styrene acrylic resin (Patent Document 15);
(3) A method of copolymerizing a vinyl monomer with unsaturated polyester (Patent Document 16, Patent Document 17, Patent Document 18, Patent Document 19);
(4) A method of copolymerizing a vinyl monomer with a polyester resin having a (meth) acryloyl group (Patent Document 20);
(5) A method of copolymerizing a reactive polyester and a vinyl monomer in the presence of a polyester resin (Patent Document 21); and
(6) A method in which a polyester resin and a vinyl resin are blocked with an ester bond (Patent Document 22).

  However, since the polyester resin and the styrene acrylic resin are inherently poor in compatibility, when simply mechanically mixing, depending on the mixing ratio, dispersion of the internal additives such as the resin and carbon black may be poor when the toner is formed. As a result, the chargeability becomes non-uniform, which causes adverse effects such as background stains in image evaluation. Also, when the molecular weights of the two types of resins are different, there may be a difference in both melt viscosities, which makes it difficult to reduce the dispersed particle size of the resin in the dispersed phase. Dispersion of the internal additive such as carbon black is very poor, and there is a problem that the image stability is largely lacking. Furthermore, when a vinyl monomer is polymerized on the reactive polyester, there is also a problem that the composition is limited to prevent gelation.

Accordingly, the present inventors have previously prepared a raw material monomer mixture of two polymerization systems in which a polymerization reaction is performed in an independent reaction path in the same reaction vessel as a developer having both low-temperature fixability and offset resistance. A developer composition using a binder resin characterized by blending and performing the two polymerization reactions in parallel was developed (Patent Document 23).
However, when this method is applied to a combination of a polyester resin and a styrenic resin, the fixing temperature can be lowered while maintaining offset resistance. In view of energy saving, it is considered that there is room for improvement in terms of obtaining further low-temperature fixability and offset resistance.
US Pat. No. 2,221,776 US Pat. No. 2,297,691 U.S. Pat. No. 2,357,809 JP 49-65232 A JP 50-28840 A JP 50-81342 A US Patent No. 3590000 JP 50-44836 A JP 57-37353 A JP-A-57-109875 Japanese Patent Laid-Open No. 49-6931 JP 54-114245 A JP-A-57-70523 JP-A-2-161464 Japanese Patent Laid-Open No. 56-116043 JP-A-57-60339 JP-A 63-279265 Japanese Patent Laid-Open No. 1-156759 JP-A-2-5073 JP 59-45453 A JP-A-2-29664 JP-A-2-881 JP-A-4-142301

  An object of the present invention is to solve such problems, and to provide a method for producing a toner for developing an electrostatic image that is particularly excellent in low-temperature fixability and offset resistance.

  As a result of diligent research to achieve the above object, the present inventors have used a raw material monomer of a condensation polymerization resin, a raw material monomer of an addition polymerization resin, and a mixture containing a compound that can react with any of these raw material monomers. A resin obtained by mixing and dispersing a high molecular weight addition polymerization resin and a low molecular weight condensation resin in a resin obtained by performing a condensation polymerization reaction and an addition polymerization reaction in the same reaction vessel in parallel. By using the toner, it was found that a toner having excellent low-temperature fixability and offset resistance can be obtained by producing a toner for developing an electrostatic image, and the present invention has been completed.

That is, the gist of the present invention is as follows.
[1] Condensation polymerization reaction and addition polymerization reaction are carried out in parallel in the same reaction vessel using a mixture containing a raw material monomer of a condensation polymerization resin, a raw material monomer of an addition polymerization resin, and a compound capable of reacting with any of these raw material monomers. A binder resin comprising a resin (1) obtained by performing the process, a resin (2) which is an addition polymerization resin, and a resin (3) which is a condensation polymerization resin, the addition polymerization of the resin (1) The resin part and the resin (2) are compatible, the condensation polymerization resin part of the resin (1) and the resin (3) are compatible, and the content of the resin (1) is in the total binder resin. A method for producing an electrostatic charge image developing toner comprising a binder resin of 20 to 50% by weight, the resin (1), the resin (2) and the resin (3) together with at least a colorant For electrostatic image development characterized by melting and kneading steps Toner production method,
[2] The production method according to [1], wherein the resin (2) has a weight average molecular weight of 100,000 or more,
[3] The production method according to [1] or [2], wherein the resin (3) has a weight average molecular weight of 30,000 or less,
[4] The raw material monomer of the condensation polymerization resin in the resin (1) and the resin (3) contains a trivalent or higher carboxylic acid or its acid anhydride, a lower alkyl ester, and / or a trivalent or higher alcohol. the method of manufacturing the above [1] to [3], wherein any one, characterized, and [5] resin (1) and the resin (3) polycondensation resin in the said a polyester Le [1] to [4] The production method according to any one of the above.

  According to the present invention, in the heat roller fixing method, it is possible to produce an electrostatic image developing toner that can be fixed at a low temperature without using an offset preventing liquid even when fixing at high speed.

  In the binder resin of the present invention, the addition polymerization resin portion of the resin (1) and the resin (2) are compatible, and the condensation polymerization resin portion of the resin (1) and the resin (3) are compatible. It is characterized by. First, each resin will be described below in order.

  The resin (1) in the present invention is a polycondensation reaction in the same reaction vessel using a mixture of a raw material monomer for a condensation polymerization resin, a raw material monomer for an addition polymerization resin, and a compound that can react with any of these raw material monomers. And an addition polymerization reaction in parallel.

In the present invention, as the condensation polymerization resin, for example, at least one selected from the group consisting of polyester, polyester-polyamide, and polyamide is used.
Therefore, the raw material monomer of the condensation polymerization resin is not particularly limited as long as these resins can be obtained by condensation polymerization.

  As a raw material monomer for polyester, a divalent or trivalent or higher alcohol, a divalent or trivalent or higher carboxylic acid, its acid anhydride, or a lower alkyl ester is used. Here, particularly when offset resistance of the toner is required, it is effective to partially crosslink in the molecule of the binder resin, and this can be achieved by using a trifunctional or higher polyfunctional compound. Therefore, in the present invention, from the viewpoint of offset resistance, it is preferable to contain a trivalent or higher carboxylic acid or acid anhydride, a lower alkyl ester, and / or a trivalent or higher alcohol as a raw material monomer. This also applies to the resin (3) described later.

  Examples of the dihydric alcohol component include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4-hydroxyphenyl) propane, and polyoxypropylene. Ethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6 ) -2,2-bis (4-hydroxyphenyl) alkylene oxide adducts of bisphenol A such as propane, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4 -Butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexa Diol, 1,4 - cyclohexane dimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A, and the like.

  Of these, an alkylene oxide adduct of bisphenol A, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, and neopentyl glycol are preferably used.

Examples of the trihydric or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Can be mentioned.
Of these, glycerol and trimethylolpropane are preferably used.

  In the present invention, these dihydric alcohols and trihydric or higher alcohols can be used alone or in combination.

Examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, and azelain. Examples include acids, malonic acids, alkenyl succinic acids such as n-dodecenyl succinic acid, alkyl succinic acids such as n-dodecyl succinic acid, anhydrides of these acids, and lower alkyl esters.
Of these, maleic acid, fumaric acid, terephthalic acid, adipic acid, and alkenyl succinic acid are preferably used.

  Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and 1,2,4-butanetricarboxylic acid. 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7 , 8-octanetetracarboxylic acid, pyromellitic acid, emporic trimer acid, their acid anhydrides, lower alkyl esters and the like. Of these, 1,2,4-benzenetricarboxylic acid, that is, trimellitic acid or a derivative thereof is particularly preferable because it is inexpensive and easy to control the reaction.

  In the present invention, these divalent carboxylic acids and the like and trivalent or higher carboxylic acids can be used alone or in combination.

  In addition to the above raw material monomers, raw material monomers for forming amide components are necessary as raw material monomers for polyester / polyamide and polyamide. Examples of such raw material monomers include ethylenediamine, pentamethylenediamine, hexamethylenediamine, and diethylenetriamine. And polyamines such as iminobispropylamine, phenylenediamine, xylylenediamine and triethylenetetramine, aminocarboxylic acids such as 6-aminocaproic acid and ε-caprolactam, and amino alcohols such as propanolamine. Of these, hexamethylenediamine and ε-caprolactam are preferably used.

  Even in the case of using a polyester / polyamide or polyamide raw material monomer, a trifunctional or higher polyfunctional compound can be used in the same manner as in the case of polyester in order to partially crosslink in the molecule of the binder resin. In that case, trivalent or higher carboxylic acids or their acid anhydrides and lower alkyl esters are mainly used.

  Examples of the raw material monomer of the addition polymerization resin in the present invention include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p. -Styrene or styrene derivatives such as chlorostyrene and vinylnaphthalene; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; for example vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, Vinyl esters such as vinyl formate and vinyl caproate; for example, acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, Amyl acrylate Cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methoxyethyl acrylate, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate , Α-methyl chloroacrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, amyl methacrylate, methacrylic acid Cyclohexyl acid, n-octyl methacrylate, isooctyl methacrylate, decyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate Ethyl, monocarboxylic acids such as methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and esters thereof; for example, acrylonitrile, methacrylonitrile, Substituted ethylenic monocarboxylic acid such as acrylamide; ethylenic dicarboxylic acid such as dimethyl maleate and its substituted; vinyl ketones such as vinyl methyl ketone; vinyl ethers such as vinyl methyl ether; vinylidene chloride such as vinylidene chloride Vinylidene halides; for example, N-vinyl compounds such as N-vinylpyrrole and N-vinylpyrrolidone.

  Of these, styrene, α-methylstyrene, propylene, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate are preferably used. .

  When polymerizing the raw material monomer of the addition polymerization resin, a crosslinking agent can be used as necessary. Examples of the crosslinking agent for the addition polymerization monomer include divinylbenzene, divinylnaphthalene, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, and 1,6-hexylene glycol. Dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4-methacryloxydiethoxyphenyl) propane, 2,2'-bis (4-acryloxydiethoxy) Phenyl) propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, dibromoneopentyl General crosslinking agents such as glycol dimethacrylate and diallyl phthalate can be used as appropriate (in combination of two or more if necessary). Of these, divinylbenzene and polyethylene glycol dimethacrylate are preferably used.

  These crosslinking agents are used in an amount of 0.01 to 15% by weight, preferably 0.1 to 10% by weight, based on the raw material monomer of the addition polymerization resin. When the amount of these crosslinking agents used is large, the toner is difficult to melt by heat, and the fixability at the time of heat fixing or heat pressure fixing is inferior. Also, if the amount used is small, it will be difficult to prevent the offset phenomenon of sticking to the surface of the heat roller and transferring to the next paper.

  In addition, a polymerization initiator is used when polymerizing the raw material monomer of the addition polymerization resin. Examples of the polymerization initiator include 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2 ′. -Azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, other azo or diazo polymerizations Initiators or peroxide polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, dicumyl peroxide It is done.

These may be used by mixing two or more kinds of polymerization initiators for the purpose of adjusting the molecular weight and molecular weight distribution of the polymer.
The amount of the polymerization initiator used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the raw material monomer of the addition polymerization resin.

In the present invention, in order to obtain a resin in which a condensation polymerization resin and an addition polymerization resin are chemically bonded, a compound that can react with any of the monomers of both resins (hereinafter referred to as “both reactive compounds”) is used. Polymerize.
Examples of such a bireactive compound include compounds such as fumaric acid, acrylic acid, methacrylic acid, citraconic acid, maleic acid, and dimethyl fumarate in the monomers of the above condensation polymerization resins and addition polymerization resins. Is mentioned. Of these, fumaric acid, acrylic acid, and methacrylic acid are preferably used.
The amount of both reactive compounds used is 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the total amount of raw material monomers.

  The production method of the resin (1) using the raw materials as described above is a method in which the condensation polymerization reaction and the addition polymerization reaction are performed in the same reaction vessel in parallel. The reaction does not need to be progressed and completed simultaneously in time, which means that the reaction temperature and reaction time can be appropriately selected according to each reaction mechanism to sequentially advance and complete the reaction.

  For example, as a typical production process of the resin (1), a mixture of styrene or a styrene / acrylic copolymer raw material monomer and a polymerization initiator in a mixture of a polyester resin raw material monomer and a bireactive compound, etc. First, complete the polymerization reaction to obtain styrene or styrene / acrylic resin by radical polymerization reaction, then raise the reaction temperature and complete the polymerization reaction to obtain polyester resin by condensation polymerization There is a way to make it. In this way, a binder resin in which two types of resins are mixed and dispersed can be obtained by a method in which two independent reactions proceed in parallel in a reaction vessel.

In the present invention, the resin (1) preferably has a softening point of 95 to 170 ° C and a glass transition temperature of 50 to 80 ° C. The softening point and glass transition temperature of the binder resin can be easily adjusted by adjusting the amount of the polymerization initiator or catalyst in the raw material monomer mixture or selecting the reaction conditions.
The resin (1) obtained by the above method usually has a continuous phase composed of a condensation polymerization resin portion and a dispersed phase composed of an addition polymerization resin portion. The resin (2) and the resin (3) are easily compatible with each other.

Next, the resin (2) will be described.
The resin (2) is an addition polymerization resin, and examples thereof include homopolymers and copolymers obtained by addition polymerization of addition polymerization monomers. As such an addition polymerization monomer, the same raw material monomer as the addition polymerization resin exemplified in the description of the resin (1) is used. In addition, the same polymerization initiator, crosslinking agent and the like are used.

  In the present invention, the weight average molecular weight of the resin (2) is preferably 100,000 or more, more preferably 300,000 or more. When the molecular weight of the resin (2) is lower than this range, there is a tendency that sufficient offset resistance cannot be secured, which is not preferable.

Further, the addition polymerization resin having the same or similar chemical structure as the addition polymerization resin part of the resin (1) so that the addition polymerization resin part of the resin (1) and the resin (2) are easily compatible. Are preferably used.
The resin (2) can be produced by a generally known solution polymerization method, emulsion polymerization method, suspension polymerization method, bulk polymerization method, dispersion polymerization method or the like.

Next, the resin (3) will be described.
Resin (3) is a condensation polymerization resin, for example, one or more selected from the group consisting of polyester, polyester / polyamide, and polyamide is suitably used, and a homopolymer obtained by condensation polymerization of a condensation polymerization monomer Any of the copolymers may be used. As such a condensation polymerization monomer, those similar to alcohols, carboxylic acids, amine compounds and the like exemplified in the description of the resin (1) are used.

In the present invention, the weight average molecular weight of the resin (3) is preferably 30,000 or less, and more preferably 20,000 or less. When the molecular weight of the resin (3) is higher than this range, there is a tendency that sufficient low-temperature fixability cannot be secured, which is not preferable.
The condensation polymerization resin having the same or similar chemical structure as that of the condensation polymerization resin portion of the resin (1) so that the condensation polymerization resin portion of the resin (1) and the resin (3) are easily compatible. Are preferably used.
The resin (3) can be produced by a generally known bulk polymerization method or the like.

  The binder resin in the toner is formed by mixing the condensation resin portion of the resin (1) and the condensation resin of the resin (3) to form a continuous phase. The addition polymerization resin portion of the resin (1) and the resin ( The addition polymerization resin of 2) is compatible with each other to form a dispersed phase. In some cases, both phases are uniformly mixed to form a uniform phase.

  At this time, in the cross-sectional observation of the binder resin, the average diameter of the dispersed phase is preferably 2 μm or less, and more preferably 1.0 μm or less. When the dispersed phase is larger than this range, the mechanical strength of the toner becomes too weak, and if printing is continued, the binder resin is broken and fine powder increases, resulting in poor stability over time. The diameter of the dispersed phase is measured by cutting the toner with a microtome and observing the obtained flakes with a transmission scanning electron microscope.

  In the present invention, since the condensation resin component in the toner is a continuous phase, the ratio of the condensation resin component to the addition polymerization resin component in the binder resin is 30/70 to 95/5, particularly 70/30 to The range is preferably 90/10. If the ratio of the addition polymerization resin exceeds this range, the fixability tends to be poor, and if it is less than this range, the stability of the image to the environment tends to be poor, such being undesirable. The content of the resin (2) or the resin (3) is appropriately selected without particular limitation as long as it is an amount that satisfies this ratio.

Moreover, it is preferable that content of resin (1) is 1 to 50 weight% in all the binder resin, More preferably, it is 20 to 50 weight%. If the amount is less than this range, the compatibility between the resins (2) and (3) tends to be lowered and dispersion failure tends to occur. If the amount is more than this range, sufficient low-temperature fixability and offset resistance tend not to be exhibited.
The binder resin of the present invention is produced by melting and kneading with a twin screw extruder or the like using the resin (1) to the resin (3).

  The toner for developing an electrostatic image of the present invention is characterized in that the binder resin as described above is used in at least an electrostatic image developing toner comprising a binder resin and a colorant. The toner of the present invention is obtained by uniformly kneading a colorant into the binder resin of the present invention obtained as described above, or the resin (1) to the resin (3) before mixing, and then melt-kneading by a known method. Manufactured by cooling, crushing, classifying, etc. At this time, a charge control agent, a magnetic substance, and the like can be blended as necessary.

  As the colorant used, conventionally known inorganic pigments such as carbon black and iron black, chromatic dyes and organic pigments can be used. Usually, it is preferable to use about 1 to 15 parts by weight with respect to 100 parts by weight of the binder resin.

  Moreover, as a charge control agent used as needed, either a positive or negative charge control agent can be used. The positive charge control agent is not particularly limited. For example, nigrosine dyes such as “Nigrosine Base EX”, “Oil Black BS”, “Oil Black SO”, “Bontron N-01”, “Bontron N-11” (Above, manufactured by Orient Chemical Co., Ltd.); triphenylmethane dye containing a tertiary amine as a side chain, quaternary ammonium salt compound such as “Bontron P-51” (manufactured by Orient Chemical Co., Ltd.), cetyltrimethylammonium bromide and the like; A polyamine resin such as “AFP-B” (manufactured by Orient Chemical Co., Ltd.) can be used.

Specific examples of the negative charge control agent are not particularly limited. For example, metal-containing azo dyes “Varifast Black 3804”, “Bontron S-31”, “Bontron S-32”, “Bontron” "S-34", "Bontron S-36" (manufactured by Orient Chemical Co., Ltd.), "Eisenspiron Black T-77" (Hodogaya Chemical Co., Ltd.), etc .; copper phthalocyanine dyes, metal complexes of alkyl derivatives of salicylic acid, such as “Bontron E-82”, “Bontron E-84”, “Bontron E-85” (manufactured by Orient Chemical Co., Ltd.) and the like can be mentioned. Preferably, Eisenspiron Black T-77 can be used.
It can also be used in combination with a positively chargeable charge control agent. If the amount of positively chargeable charge control agent used is ½ or less of the amount of negatively chargeable charge control agent used, 50,000 sheets or more Even if copying is performed continuously, a good visible image can be obtained without a decrease in density.

  The above charge control agent can be used in an amount of 0.1 to 8.0% by weight, preferably 0.2 to 5.0% by weight, based on the binder resin.

  When the toner is produced, a property improving agent such as a wax such as polyolefin is added as an offset preventing agent. However, when the resin according to the present invention is used as a binder resin, the property improving agent may not be added. Even when it is added, the addition amount is small.

Further, in order to use the toner of the present invention as a magnetic toner, magnetic powder may be contained. As such magnetic powder, a substance that is magnetized by being placed in a magnetic field is used, and examples thereof include powders of ferromagnetic metals such as iron, cobalt, and nickel, and alloys and compounds such as magnetite hematite and ferrite. The content of the magnetic powder is about 15 to 70% by weight with respect to the toner weight.
Further, the toner of the present invention is mixed with carrier particles such as iron powder, glass beads, nickel powder, and ferrite powder as required, and used as a developer for an electric latent image.

  Further, when the toner is produced, a property improver such as a fluidity improver such as hydrophobic silica can be added.

  The toner of the present invention can be applied to various development methods. For example, a magnetic brush developing method, a cascade developing method, a method using a conductive magnetic toner, a method using a high resistance magnetic toner, a fur brush developing method, a powder cloud method, an impression developing method and the like can be mentioned.

  Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples, Comparative Examples, and Test Examples, but the present invention is not limited to these Examples and the like. In addition, the glass transition temperature (Tg) of the obtained resin, the molecular weight by gel permeation chromatography (hereinafter abbreviated as “GPC”), and the average diameter of the dispersed phase were measured according to the following conditions.

Glass transition temperature (Tg)
The sample was heated to 100 ° C. using a differential scanning calorimeter (DSC 200, manufactured by Seiko Denshi Kogyo Co., Ltd.), left at that temperature for 3 minutes, and then cooled to room temperature at a cooling rate of 10 ° C./min. When measured at a temperature rate of 10 ° C./min., The temperature at the intersection of the base line extension below the glass transition temperature and the tangent line indicating the maximum slope from the peak rise to the peak apex The transition temperature (Tg) was used.

Molecular weight measurement by GPC Stabilize the column in a constant temperature bath of 40 ° C., flow chloroform at 1 ml / min as an eluent, and inject 100 μl of a chloroform solution of the sample adjusted to a sample concentration of 0.05 to 0.5% by weight. And measured. The molecular weight of the sample was calculated from its molecular weight distribution determined from the retention time based on a calibration curve prepared in advance. The calibration curve at this time was prepared by using several types of monodisperse polystyrene as standard samples.
Analytical column: GMHXL + G3000HXL (manufactured by Tosoh Corporation)

Average diameter of dispersed phase A resin having a diameter of 0.2 mm was cut to a thickness of 150 nm with a microtome, and the obtained flakes were obtained with a transmission scanning electron microscope (JEOL (JEOL Ltd., “JEM-2000”)). It was measured by making observations.

Resin production example 1
410 g of styrene, 90 g of 2-ethylhexyl acrylate as a monomer of the addition polymerization resin, and 20 g of azobisisobutyronitrile as a polymerization initiator are placed in a dropping funnel. Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane (780 g), fumaric acid (24 g), isododecenyl succinic anhydride (76 g), terephthalic acid (250 g) and dibutyltin oxide (2 g) were placed in a glass 5-liter four-necked flask. Add a thermometer, a stainless steel stir bar, a flow-down condenser, and a nitrogen introduction tube, and stir at a temperature of 135 ° C in a nitrogen atmosphere in a mantle heater, and add monomer of addition polymerization resin from the previous dropping funnel And the polymerization initiator was dripped over 1 hour. The mixture was aged for 2 hours while maintaining the temperature at 135 ° C., and the temperature was raised to 220 ° C. for reaction. The degree of polymerization was monitored from the softening point according to ASTM E28-67, and the reaction was terminated when the softening point reached 105 ° C.
The obtained resin was a pale yellow solid, and the glass transition temperature (Tg) was 60 ° C. with one peak. This resin is referred to as Resin A.

Resin production example 2
As addition monomer, 400 g of styrene, 180 g of 2-ethylhexyl acrylate, 15 g of α-methylstyrene dimer as a chain transfer agent, and 25 g of dicumyl peroxide as a polymerization initiator are placed in a dropping funnel. Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 800 g, acrylic acid 9.3 g, 1,2,4-benzenetricarboxylic acid 60 g, isophthalic acid 250 g, and dibutyltin oxide 2 g The flask was placed in a 5-liter four-necked flask, and a thermometer, a stainless stir bar, a flow-down condenser, and a nitrogen inlet tube were attached. The following operations and polymerization conditions are the same as in Resin Production Example 1.

  When the obtained resin was evaluated in the same manner as in Resin Production Example 1, the glass transition temperature was 58 ° C. with one peak. This resin is referred to as Resin B.

Resin production example 3
550 g of xylene was placed in a 5 liter glass four-necked flask equipped with a thermometer, a stainless steel stir bar, a falling condenser and a nitrogen inlet tube, and the temperature was raised to 135 ° C. after nitrogen substitution.
800 g of styrene, 300 g of n-butyl acrylate, and 30 g of dicumyl peroxide as a polymerization initiator were placed in a dropping funnel, dropped over 1 hour, and aged at 135 ° C. for 2 hours. Thereafter, the temperature was raised to 200 ° C., xylene was distilled off under reduced pressure, extracted into a vat, pulverized after cooling.

When the obtained resin was evaluated in the same manner as in Resin Production Example 1, the softening point based on ASTM E28-67 was 130 ° C., and the glass transition temperature was 65 ° C. The number average molecular weight of the resin by GPC was 80,000. This resin is referred to as Resin C.

Resin production example 4
Add 1400 g of ion-exchanged water and 7 g of 50% aqueous solution of dioctylsulfosuccinate sodium salt to a 5 liter glass four-necked flask equipped with a thermometer, a stainless steel stir bar, a downflow condenser and a nitrogen blowing tube, and raise the temperature to 80 ° C. Then, 7 g of potassium persulfate was dissolved in 50 g of ion-exchanged water and charged, and after that, a mixed liquid of 760 g of styrene and 240 g of n-butyl acrylate was put into a dropping funnel and dropped over 1 hour. After dropping, the mixture was aged at 70 ° C. for 1.5 hours, and then salted out, washed and dried to obtain a resin.
When the obtained resin was evaluated in the same manner as in Resin Production Example 1, the softening point was 145 ° C. and the glass transition temperature was 68 ° C. The weight average molecular weight of the resin by GPC was 250,000. This resin is referred to as Resin D.

Resin production example 5
714 g polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 663 g polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 518 g isophthalic acid, 70 g isooctenyl succinic acid , 80 g of 1,2,4-benzenetricarboxylic acid and 3 g of dibutyltin oxide are placed in a glass 5-liter four-necked flask, fitted with a thermometer, a stainless steel stirring bar, a flow-down condenser and a nitrogen inlet tube. The reaction was continued while stirring at 210 ° C. under a nitrogen stream, and the reaction was terminated when the softening point reached 100 ° C.
The obtained resin was a pale yellow solid and was evaluated in the same manner as in Resin Production Example 1. As a result, the glass transition temperature was 61 ° C. Moreover, the weight average molecular weight of the resin by GPC was 12000. This resin is referred to as Resin E.

Examples 1-3, Comparative Examples 1-3
The materials with the following composition are premixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.), melt-kneaded with a twin screw extruder, cooled and coarsely pulverized, then pulverized with a jet mill, and further using an air classifier Thus, an untreated toner having an average particle diameter of 10 μm was obtained.

Composition Example 1
Resin A 20 parts by weight Resin D 20 parts by weight Resin E 60 parts by weight Carbon black “Regal 330R” (manufactured by Cabot Corp.) 6 parts by weight Negative charge control agent “Eisenspiron Black T-77” 2 parts by weight
(Hodogaya Chemical Co., Ltd.)
Low molecular weight polypropylene “NP-055” (Mitsui Petrochemical Co., Ltd.) 2 parts by weight

Example 2
Resin B 20 parts by weight Resin D 20 parts by weight Resin E 60 parts by weight Carbon black “Regal 330R” (manufactured by Cabot Corporation) 6 parts by weight Negative charge control agent “Eisenspiron Black T-77” 2 parts by weight
(Hodogaya Chemical Co., Ltd.)
Low molecular weight polypropylene "Biscol 550P" 2 parts by weight
(Manufactured by Sanyo Chemical Co., Ltd.)

Example 3
Resin A 20 parts by weight Resin C 20 parts by weight Resin E 60 parts by weight Carbon black “Regal 330R” (manufactured by Cabot Corp.) 6 parts by weight Negative charge control agent “Eisenspiron Black T-77” 2 parts by weight
(Hodogaya Chemical Co., Ltd.)
Low molecular weight polypropylene “NP-055” (Mitsui Petrochemical Co., Ltd.) 2 parts by weight

Comparative Example 1
Resin D 100 parts by weight Carbon black “Regal 330R” (manufactured by Cabot) 6 parts by weight Negatively chargeable charge control agent “Eisenspiron Black T-77” 2 parts by weight
(Hodogaya Chemical Co., Ltd.)
Low molecular weight polypropylene “NP-055” (Mitsui Petrochemical Co., Ltd.) 2 parts by weight

Comparative Example 2
Resin E 100 parts by weight Carbon black “Regal 330R” (manufactured by Cabot) 6 parts by weight Negative charge control agent “Eisenspiron Black T-77” 2 parts by weight
(Hodogaya Chemical Co., Ltd.)
Low molecular weight polypropylene “NP-055” (Mitsui Petrochemical Co., Ltd.) 2 parts by weight

Comparative Example 3
Resin D 25 parts by weight Resin E 75 parts by weight Carbon black “Regal 330R” (manufactured by Cabot Corp.) 6 parts by weight Negative charge control agent “Eisenspiron Black T-77” 2 parts by weight
(Hodogaya Chemical Co., Ltd.)
Low molecular weight polypropylene “NP-055” (Mitsui Petrochemical Co., Ltd.) 2 parts by weight

With respect to 100 parts by weight of each of the untreated toners obtained in Examples 1 to 3 and Comparative Examples 1 to 3, 0.3 parts by weight of hydrophobic silica “AEROSIL R-972” (produced by Nippon Aerosil Co., Ltd.) In addition, the toners 1 to 3 and comparative toners 1 to 3 were prepared by mixing and adhering using a Henschel mixer.
A developer was prepared by mixing 66 parts by weight of each of the above toners and 2134 parts by weight of ferrite powder (average particle size 100 μm) coated with a silicone resin.

Test Example Commercially available two-component dry copying machine (manufactured by Sharp Corporation, modified SF9800 for this developer (photosensitive material is amorphous selenium, fixing roller rotation speed is set to 450 mm / sec, heat in fixing device) The roller temperature was made variable and the oil applicator was removed, and the fixability and the like were evaluated by the following method.

(1) Minimum fixing temperature A 500 g load is placed on a sand eraser with a bottom surface of 15 mm x 7.5 mm, and the image fixed through the fixing machine is rubbed 5 times, before and after being rubbed with a Macbeth reflection densitometer. The reflection density was measured, and the fixing roller temperature when the fixing rate according to the following definition exceeded 70% was defined as the minimum fixing temperature.

Fixing rate (%) = [(Image density after rubbing) / (Image density before rubbing)] × 100

  The temperature of the fixing roller was controlled between 120 to 240 ° C., and the fixing property was evaluated.

(2) Offset generation temperature Fixing is performed repeatedly with the set temperature of the fixing roller being sequentially increased, and the temperature at which the toner stain first disappears on the low temperature side is defined as the low temperature offset disappearance temperature. The lowest temperature at which contamination occurred was defined as the high temperature offset generation temperature.

  The results are shown in Table 1.

As is apparent from the above results, the toners 1 to 3 of the present invention had a small average diameter of the dispersed phase in the toner, and all had excellent offset resistance and excellent low-temperature fixability.
On the other hand, the comparative toner 1 uses only the addition polymerization resin as the binder resin, so that the low-temperature fixability is inferior, and the comparative toner 2 uses only the condensation polymerization resin as the binder resin. In particular, the offset resistance was inferior, and the comparative toner 3 was inferior in the offset resistance because it simply used a mixture of an addition polymerization resin and a condensation polymerization resin.

Claims (5)

Condensation polymerization reaction and addition polymerization reaction are carried out in parallel in the same reaction vessel using a mixture containing a raw material monomer of a condensation polymerization resin, a raw material monomer of an addition polymerization resin, and a compound capable of reacting with any of these raw material monomers. A resin (1) obtained by this, a resin (2) which is an addition polymerization resin, and a resin (3) which is a condensation polymerization resin , wherein the addition polymerization resin portion of the resin (1) And the resin (2) are compatible, the condensation polymerization resin portion of the resin (1) and the resin (3) are compatible, and the content of the resin (1) is 20-50 in the total binder resin. A method for producing a toner for developing an electrostatic charge image, comprising a binder resin having a weight percent, wherein the resin (1), the resin (2) and the resin (3) are melted and kneaded together with at least a colorant. A toner for developing an electrostatic image, characterized by comprising the step of: Manufacturing method.   The production method according to claim 1, wherein the weight average molecular weight of the resin (2) is 100,000 or more.   The production method according to claim 1 or 2, wherein the resin (3) has a weight average molecular weight of 30,000 or less. The raw material monomer of the condensation polymerization resin in the resin (1) and the resin (3) contains a trivalent or higher carboxylic acid or its acid anhydride, a lower alkyl ester, and / or a trivalent or higher alcohol. The manufacturing method in any one of Claims 1-3 . Polycondensation resin in the resin (1) and the resin (3) The production method according to claim 1-4, wherein one is a polyester Le.