JP3534578B2 - Binder and toner for developing electrostatic images - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrostatic charge image developing toner for developing an electrostatic latent image formed in electrophotography, electrostatic recording, electrostatic printing, and the like, and a binder used for the toner. Regarding

[0002]

2. Description of the Related Art Electrophotographic methods used in image forming apparatuses such as laser printers and dry electrostatic copying machines are described in U.S. Pat. No. 2221776, No. 2297791, No. 2357809, etc. As described above, the photoconductive insulating layer is uniformly charged (charging step), then the layer is exposed to light, and an electric latent image is formed by dissipating the charge in the exposed portion (exposure step). Further, a fine image having a colored charge called toner is attached to the latent image to make it visible (developing step), and the obtained visible image is transferred to a transfer material such as transfer paper. (Transfer process), heating,
It comprises a step of permanently fixing (fixing step) by pressure or other suitable fixing method.

Of these, in the fixing step, a contact heating fixing method such as heat roller fixing, a non-contact heating method such as oven fixing, etc. are used. The contact method is characterized by high thermal efficiency, and can lower the temperature required for fixing as compared with the non-contact method, which is effective for energy saving and downsizing of copying machines. However, in the contact-type heat fixing method, a problem of offset development in which a part of the toner melted at the time of fixing is transferred to the heat roller and transferred to the subsequent transfer paper or the like is likely to occur.

In order to prevent this phenomenon, conventionally, the surface of the heat roller is processed with a material having excellent mold release property such as fluorine resin, or a mold release agent such as silicone oil is applied to the surface of the heat roller. I am. However, the method using silicone oil or the like is not preferable because the fixing device becomes large and complicated, which may increase the cost and cause troubles.

Conventionally, a vinyl resin represented by a styrene-acrylic copolymer has been used for this type of toner. In the case of a vinyl-based resin, if the offset resistance is to be improved, the softening point and crosslink density of the resin must be increased, and the low temperature fixability is sacrificed. On the contrary, if low temperature fixability is emphasized, offset resistance and blocking resistance are impaired.

Further, JP-A-49-65232, JP-A-50-28840, and JP-A-50-81342.
As described in Japanese Patent Publication No. JP-A-2003-242, there is known a method of adding paraffin wax, low molecular weight polyolefin or the like as an anti-offset agent at the time of forming a toner, but if the addition amount is too small, there is no effect, and if it is too large, deterioration of the developer occurs. There were problems such as early. Also, when the wax is added at the time of toner formation and strongly mixed in order to uniformly disperse it, the polymer chain of the resin may be broken, so it is not easy to uniformly disperse the wax while maintaining the physical properties of the resin. .

On the other hand, as a binder resin for toner, a polyester resin is used because of its excellent low-temperature fixing property. The polyester resin is inherently good in fixing properties, and as described in US Pat. No. 3,590,000,
It can be sufficiently fixed even in the non-contact fixing method, but it is difficult to use in the heat roller fixing method because the offset phenomenon easily occurs. In addition, JP-A-50-44836, JP-A-57-37353, and JP-A-57-1.
No. 09875 describes polyester resins having improved offset resistance using a polycarboxylic acid, but these also do not have sufficient offset resistance to be used, or have In addition to sacrificing the low temperature fixing property originally possessed by the polyester resin, there is a problem that the pulverizability of the resin and toner is extremely poor.

Therefore, the following attempts have been made to use a mixture of a polyester resin having excellent fixability and a styrene-acrylic resin.

A method of mixing a polyester resin and a styrene-acrylic resin (JP-A-49-6931 and JP-A-5-6931).
4-114245, JP-A-57-70523, JP-A-2-161464); Method for chemically bonding polyester resin and styrene-acrylic resin (JP-A-56-116043); to unsaturated polyester A method of copolymerizing a vinyl monomer (JP-A-57-60339 and JP-A-63-2).
79265, JP-A-1-156759, JP-A-2-
No. 5073); a method of copolymerizing a vinyl monomer with a polyester resin having a (meth) acryloyl group (JP-A-59-59).
45453); a method of copolymerizing a reactive polyester and a vinyl monomer in the presence of a polyester resin (JP-A-2-2966).
No. 4); and a method of blocking a polyester resin and a vinyl resin with an ester bond (JP-A-2-881).

However, since the polyester resin and the styrene-acrylic resin are inherently poor in compatibility, when merely mechanically mixing, depending on the mixing ratio, the resin and the internal additive such as carbon black may be added depending on the mixing ratio. Dispersion becomes poor and chargeability becomes non-uniform, which causes problems such as scumming in image evaluation. Further, when the two types of resins have different molecular weights, the two may have different melt viscosities, which makes it difficult to reduce the dispersed particle size of the resin in the dispersed phase, and thus toner The dispersion of the internal additives such as carbon black is very poor, and there is a problem that the image stability is greatly deteriorated. Further, when polymerizing a vinyl monomer with a reactive polyester, there is a problem that the composition is limited to prevent gelation.

Therefore, the inventors of the present invention, as a developer having both low-temperature fixing property and anti-offset property, used two raw material monomers of a polymerization system in which polymerization reaction is carried out in independent reaction paths in the same reaction vessel. A developer composition using a binder resin has been developed, which is characterized in that the mixture is premixed and the two polymerization reactions are carried out in parallel (Japanese Patent Laid-Open No. 4-142).
No. 301).

Further, the inventors of the present invention produced a binder resin which improves the dispersibility of the resin by further adding a compound capable of reacting with both of the two raw material monomers of the polymerization system in the above-mentioned polymerization reaction. A method was also developed (JP-A-7-9).
No. 8517).

However, even when a resin in which a styrene resin is suitably dispersed in a polyester resin is produced by these methods, the molecular weight distribution of the vinyl resin, which is the dispersed phase, is narrow, so that the molecular weight of the vinyl resin is low. Then, only the fixability was improved, and there was a limit to the improvement in offset resistance. On the contrary, when the molecular weight is increased, only the offset resistance is improved, and there is a limit to lowering the fixing temperature.

A binder resin prepared by mixing two kinds of resins having different softening points (Japanese Patent Application Laid-Open No. 4-362956) has also been developed. Even in this method, the ratio of the resins to be mixed on the low softening point side is low. However, if the glass transition point on the low softening point side is increased, the blocking resistance is eliminated but the fixing resistance is limited even if the ratio is increased. Occurred. Therefore,
Considering the recent speeding up, downsizing, and energy saving of copying machines, further improvement in low-temperature fixing property and offset resistance is desired.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to solve such problems, and in particular, a binder for producing a toner excellent in low temperature fixing property and offset resistance,
Another object of the present invention is to provide a toner for developing an electrostatic charge image containing the binder.

[0016]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the inventors of the present invention have obtained a mixture of two raw material monomers of a polymerization system having independent reaction paths in one reaction vessel, and A toner having excellent low-temperature fixability and offset resistance is produced by adding a release agent to a compound capable of reacting with any of the two raw material monomers of the polymerization system and mixing them to cause the two polymerization reactions. It has been found that a binder for the above can be obtained, and the present invention has been completed.

That is, the gist of the present invention is (1) a mixture (a) of two raw material monomers of a polymerization system each having an independent reaction path, and a compound (a) capable of reacting with both of the two raw material monomers of the polymerization system. a binder obtained by mixing b) and a releasing agent (c) and allowing the two polymerization reactions to be carried out in the same reaction vessel, wherein the raw material monomer mixture (a) is polyester or polyester.
Selected from the group consisting of
At least one polycondensation resin raw material monomer and vinyl
It is a mixture of raw material monomers of a base resin , wherein the compound (b) is acrylic acid, methacrylic acid, maleic acid, fluorine
Malic acid, hydroxyethyl acrylate and hydroxy
At least one selected from the group consisting of ethyl methacrylate
Also Ri one compound der, the releasing agent (c) is polypropylene
Pyrene wax, polyethylene wax, polypropylene
Polyethylene copolymer wax, ester-based wax
Scan or amide waxes der Ru binder, the softening point of (2) the release agent (c) is 70 to 160 ° C.
(3) the binder as described in (1) above, (3) the release agent (c) used in two polymerization system raw materials
Nomer mixture (a) and starting monomer for the two polymerization systems
The total amount of the compound (b) capable of reacting with any of 100-fold
The above (1) is 0.1 to 1000 parts by weight with respect to parts by weight.
Alternatively, the binder described in (2), (4) the acid value of the binder is 30 KOHmg / g or less.
The binder according to any one of (1) to (3) above, (5) the softening point of the binder is 70 to 160 ° C.
A binder according to any one of (1) to (4), and (6) a binder according to any one of (1) to (5) above.
A toner for developing an electrostatic charge image, which comprises:
It

[0018]

[0019]

[0020]

[0021]

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The binder of the present invention comprises a mixture (a) of two raw material monomers of a polymerization system each having an independent reaction path, and a compound (b) (hereinafter, referred to as “a”) capable of reacting with both of the two raw material monomers of a polymerization system. Both reactive compounds ") and the release agent (c) are mixed and the two polymerization reactions are carried out in the same reaction vessel.

The structure of the binder of the present invention comprises two polymerization system raw material monomers as constitutional units, and two polymerization system resin components partially chemically bonded through both reactive compounds. The release agent is present in the binder in a substantially uniformly dispersed state, and the dispersed particle size of the release agent is preferably 5 μm or less, and particularly preferably 4 μm or less. In the present invention, the dispersed particle size means the average particle size of the release agent dispersed in the resin. Here, the dispersed particle size is obtained by cutting a resin having a particle size of about 0.2 mm with a microtome to a thickness of 150 nm, and obtaining the obtained thin piece with a transmission scanning electron microscope (for example, JOEL (manufactured by JEOL Ltd., “ JEM-200
It can be measured by observing with "0") and performing image analysis by a known method. When an ester wax is used as the release agent, the compatibility with the resin in the binder is excellent, so that a particulate release agent may not be observed.

In the present invention, the two polymerization reactions are
The polymerization reaction is mainly carried out by independent reaction paths, and it is preferable that the reaction is a reaction for producing a condensation polymerization resin and an addition polymerization resin, respectively. Typical examples of the polycondensation resin, polyester, polyester polyamide,
Examples thereof include polyamides, and a typical example of the addition polymerization resin is a vinyl resin obtained by a radical polymerization reaction.

Among these, the polyester component includes a polyhydric alcohol component having a valency of 2 or 3 or more and a carboxylic acid component such as a polyhydric carboxylic acid having a valency of 2 or 3 or more, a carboxylic acid anhydride, or a carboxylic acid ester. It can be obtained as a raw material monomer.

Here, examples of the dihydric alcohol component include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene.
(3.3) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2)
-2,2-Bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0)
Alkylene oxide adducts of bisphenol A such as -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) 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-hexanediol, 1, 4-Cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A and the like can be mentioned.

As the polyhydric alcohol component having a valence of 3 or more,
For example 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-
Examples include 1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene.

Of these dihydric or trihydric or higher polyhydric alcohol components, alkylene oxide adducts of bisphenol A, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol and neopentyl glycol are preferably used. To be In the present invention, these dihydric alcohol components and trihydric or higher polyhydric alcohol components may be used alone or in admixture of two or more.

Examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid,
Dicarboxylic acids such as glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid,
Isododecyl succinic acid, n-octenyl succinic acid, n-
Succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, such as octyl succinic acid, isooctenyl succinic acid, and isooctyl succinic acid, and anhydrides or alkyl (carbon Number 1
12) Esters and the like can be mentioned. Preferably, maleic acid, fumaric acid, terephthalic acid, and succinic acid substituted with an alkenyl group having 2 to 20 carbon atoms are used.

In the present invention, a polyvalent carboxylic acid having a valence of 3 or more or a derivative thereof can be used.
Examples of the polyvalent carboxylic acid component having a valence of 1 or more include 1,2,4-
Benzenetricarboxylic 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-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1, 2,
Examples thereof include 7,8-octanetetracarboxylic acid, pyromellitic acid, empol trimer acid, acid anhydrides thereof, and alkyl (C1-12) esters. Of these, 1,2,4-benzenetricarboxylic acid, that is, trimellitic acid or a derivative thereof, is preferable because it is inexpensive and the reaction control is easy.

The polyvalent carboxylic acid component having a valence of 3 or more is effective in controlling the degree of polymerization of the polycondensation resin, and is 0.2 to 30% by weight, particularly 0.5 to 30% by weight, based on the polycondensation raw material monomer. % Is preferably used.

If the amount of the polyvalent carboxylic acid component having a valence of 3 or more is too large, gelation occurs during the polymerization reaction, and if the amount is too small, a part of the toner becomes a paper on the paper during heat roll fixing. It becomes difficult to prevent the offset phenomenon in which the toner is not completely fixed and adheres to the roller surface and is transferred to the next paper.

When forming the polyester component, an esterification catalyst such as dibutyltin oxide, zinc oxide, stannous oxide or dibutyltin dilaurate can be used appropriately.

Examples of the raw material monomers used for forming the polyester polyamide obtained by the condensation polymerization reaction or the amide component in the polyamide include ethylenediamine, pentamethylenediamine, hexamethylenediamine, diethylenetriamine, iminobispropylamine and phenylenediamine. , Polyamines such as xylylenediamine and triethylenetetramine, aminocarboxylic acids such as 6-aminocaproic acid and ε-caprolactam, and amino alcohols such as propanolamine. Hexamethylenediamine and ε-caprolactam are preferably used.

The above raw material monomers include those usually classified as ring-opening polymerization monomers, but these are hydrolyzed by the presence of water or the like produced by the condensation reaction of other monomers. Since it is subjected to condensation, it is considered to be included in the raw material monomer of the polycondensation resin in a broad sense.

Typical monomers used for forming the vinyl resin obtained by the addition polymerization reaction include:
For example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p
-Styrene or styrene derivatives such as ethylstyrene, 2,4-dimethylstyrene, p-chlorostyrene, vinylnaphthalene; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, isobutylene; vinyl chloride, vinyl bromide , Vinyl fluoride, and other halovinyls; vinyl acetate, vinyl propionate, vinyl formate, vinyl caproate, and other vinyl esters; for example, methyl acrylate, ethyl acrylate, acrylic acid n
-Propyl, isopropyl acrylate, acrylic acid n-
Butyl, isobutyl acrylate, tert-acrylic acid
Butyl, amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methoxyethyl acrylate, 2-hydroxyethyl acrylate, Glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-chloromethyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylic acid Tert-Butyl acid, amyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, decyl methacrylate, lauryl methacrylate, methacrylic acid 2-ethylhexyl, stearyl methacrylate, methoxyethyl methacrylate,
Ethylenic esters such as 2-hydroxyethyl methacrylate, glycidyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride; N-vinylpyrrole, N-
Examples thereof include N-vinyl compounds such as vinylpyrrolidone. In the present invention, preferably styrene, α-methylstyrene, propylene, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, butyl methacrylate,
2-Hydroxyethyl methacrylate is used.

A polymerization initiator is used in the production of the vinyl resin, and examples of such a 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 compounds or diazo Polymerization initiators or peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, dicumyl peroxide, ditertiary butyl peroxide, etc. An oxide type polymerization initiator may be used. In some cases, it is possible to use a cross-linking agent that is commonly used in the production of vinyl resins.

Two or more kinds of polymerization initiators may be mixed and used for the purpose of controlling the molecular weight and the molecular weight distribution of the polymer or the reaction time. 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 monomer of the addition polymerization resin such as vinyl resin.

In the present invention, by lowering the number average molecular weight of the resin produced in one of the reaction paths, it becomes possible to improve the pulverizability of the binder. Particularly, when the number average molecular weight of the addition-polymerized resin portion is 11,000 or less, preferably 2,000 to 10,000, it is effective for improving the pulverizability of the binder. In order to reduce the number average molecular weight to 11,000 or less, a polymerization initiator may be frequently used or a chain transfer agent may be used.

In the present invention, the bireactive compound (b) is used. The bireactive compound has a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group and a secondary amino group in the molecule. The compound having at least one functional group selected from the group consisting of and an ethylenically unsaturated bond is preferable. Among the functional groups, a hydroxyl group and a carboxyl group are more preferable.

Specific examples of the bireactive compound include compounds having the above functional group and an ethylenically unsaturated bond, for example, compounds represented by the following general formula (I).

[0042]

[Chemical 5]

In the formula, R ¹ , R ² and R ³ may be the same or different and each represents a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, an alkoxy group, an aryl group or a vinyl group, and R ¹ and R ² , R ² and R ³ may together form a ring. The alkyl group, alkoxy group, aryl group, vinyl group, or ring may each have a substituent. A and B may be the same or different and each is a single bond, an alkylene group represented by the general formula (II) or a phenylene group represented by the general formula (III),

[0044]

[Chemical 6]

(R ⁴ , R ⁵ and R ⁶ may be the same or different and each represents a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, an alkoxy group, an aryl group or a vinyl group, and R ⁴ and R ⁵ are They may together form a ring, and the above alkyl group, alkoxy group, aryl group, vinyl group, or ring may each have a substituent, R ⁷ is a single bond or lower alkylene. integer .m 0-5 showing the radical, n represents shown) an integer of 0 to 2, X and Y may be the same or different, respectively, -R ^8, -OR ⁹ or -COOR ¹⁰ (R ⁸ , R ⁹
And R ¹⁰ represents a hydrogen atom or a lower alkyl group which may have a substituent).

Here, it is necessary that these bireactive compounds can react with both the raw material monomer of the condensation polymerization type resin and the raw material monomer of the addition polymerization type resin. If there are two or more types,
It suffices if it can react with at least one of them.

Among the groups represented by R ^{1 to} R ⁶ , examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a chlorine atom and a bromine atom are particularly preferable. The alkyl group is preferably a linear or branched one having 1 to 6 carbon atoms, particularly 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, Examples thereof include a tert-butyl group. These alkyl groups are phenyl group, naphthyl group,
It may be substituted with a hydroxyl group, an epoxy group, a primary amino group, a secondary amino group or the like. Further, as the alkoxy group,
For example, methoxy group, ethoxy group, n-propoxy group, i
-Propoxy group, t-butoxy group and the like can be mentioned, and these groups may be substituted with a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group, a secondary amino group or the like. Examples of the aryl group include a phenyl group, a naphthyl group, a benzyl group, and the like. These groups include a methyl group, an ethyl group, a methoxy group, an ethoxy group, a carboxyl group, a hydroxyl group, an epoxy group, a primary amino group, and a primary amino group. It may be substituted with a 2-amino group or the like. Further, the vinyl group may be substituted with a hydroxyl group, a phenyl group, an alkyl group, an alkoxy group, a carboxyl group, an epoxy group, a primary amino group, a secondary amino group or the like. The ring formed by R ¹ and R ² , R ² and R ³ , and R ⁴ and R ⁵ together includes a hydroxyl group, a carboxyl group,
It may be substituted with an epoxy group, a primary amino group, a secondary amino group or the like. R ⁷ is a single bond or 1 to 4 carbon atoms.
A lower alkylene group of R ⁸ and R ⁹
And R ¹⁰ is preferably a lower alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and more preferably a hydrogen atom. Examples of the lower alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group and the like, and these lower alkyl groups are substituted with a hydroxyl group, an epoxy group, a primary amino group, a secondary amino group or the like. May be.

Typical examples of the compound represented by the general formula (I) include the following compounds (1) to (38), but the compounds are not limited to these.

[0049]

[Chemical 7]

[0050]

[Chemical 8]

[0051]

[Chemical 9]

[0052]

[Chemical 10]

Further, lower alkyl (C1-4) esters of the above-mentioned ethylenic carboxylic acids, anhydrides of the above-mentioned ethylenic dicarboxylic acids and the like can be mentioned.

The both-reactive compound is effective for reducing the dispersed particle size of the resin in the dispersed phase after the reaction and improving the printing characteristics, and is effective for controlling the polycondensation raw material monomer to 0.
It is preferred to use 5-10% by weight, especially 0.5-5% by weight.

The present invention is characterized in that a release agent (c) is used in addition to the two raw material monomers of the polymerization system and the bireactive compound. Examples of the release agent include polypropylene wax and Polyethylene wax, polyolefin wax such as polypropylene polyethylene copolymer wax, carnauba wax, wax wax, beeswax, spermaceti wax, ester wax such as montan wax, amide wax such as fatty acid amide wax, and the like,
Among these, polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax, ester wax and amide wax are preferably used. Further, those having a relatively low molecular weight, particularly those having a molecular weight of 500 to 15,000 as measured by the vapor permeation method are preferable, and a differential scanning calorimeter (manufactured by Seiko Denshi Kogyo KK, DSC
It is preferable that the softening point measured according to 210) is 70 to 160 ° C, particularly 70 to 150 ° C.

The amount of the release agent used is preferably 0.1 to 1000 parts by weight, and preferably 0.1 to 1000 parts by weight, based on 100 parts by weight of the total amount of the two raw material monomer mixtures of the polymerization system and the bireactive compound.
100 parts by weight is more preferable, 0.1 to 20 parts by weight is particularly preferable, and 0.5 to 10 parts by weight is the most preferable. When it is at least the lower limit value, the low-temperature offset disappearance temperature becomes low, and the high-temperature offset generation temperature becomes high. When it is at most the upper limit value, filming on the photoconductor during printing and generation of spent on the carrier are prevented. Therefore, an excellent image can be formed.

In the present invention, the release agent as described above is added during the polymerization of the binder so that the release agent is added to the binder.
Preferably, the dispersed particle diameter is 5 μm or less, and when the toner is made into a toner, the dispersed particle diameter is further reduced, so that the releasability of the obtained toner is improved and the adhesion of the toner to the photoconductor is suppressed. As a result, a toner having excellent offset resistance can be obtained.

Further, in the conventional toner, it is difficult to mix the above-mentioned releasing agent at the time of making it into a toner, and it is difficult to improve the dispersibility of the releasing agent. However, in the present invention, Can be added at the time of producing the binder, and by adding these, the low temperature fixing property becomes further excellent.

The binder of the present invention can be obtained by carrying out the two polymerization reactions in the same reaction vessel using the above raw material monomer mixture, the bireactive compound and the releasing agent. However, in the present invention, in the step of "performing two polymerization reactions in the same reaction vessel",
Although the two polymerization reactions are carried out in parallel, the progress and completion of the polymerization reaction do not have to be simultaneous in time, and the reaction temperature and time are appropriately selected according to each reaction mechanism,
The reaction may proceed independently and be completed.

For example, in the production method of the present invention, the raw material monomer of the condensation polymerization type resin, the raw material monomer of the addition polymerization type resin, the both-reactive compound, the releasing agent and the polymerization initiator are mixed, and first, the radical polymerization is mainly performed. It is preferable to obtain an addition polymerization type resin component having a functional group capable of performing a polycondensation reaction by the reaction, then raise the reaction temperature, and then form the condensation polymerization type resin component mainly by the polycondensation reaction. It should be noted that the releasing agent has the same effect as long as it is present even in a small amount in any of the polymerization steps, but is preferably present from the beginning of the polymerization, particularly from the beginning of the polymerization of the raw material monomer of the addition polymerization resin. This is desirable because the effect of uniform dispersion of the releasing agent in the binder thus obtained can be enhanced.

As a typical production method, for example, a mixture of a raw material monomer of vinyl resin, a bireactive compound, and a polymerization initiator is added to a mixture of a raw material monomer of polyester, polyester-polyamide or polyamide and a releasing agent. After premixing, radical polymerization reaction is carried out under a temperature condition suitable for radical polymerization to complete the polymerization reaction which produces a vinyl resin component having a functional group capable of polycondensation reaction, and then the reaction temperature is raised, followed by condensation. A method of completing the formation of the polycondensation resin component by performing a polymerization reaction can be mentioned.

Here, the temperature condition suitable for the addition polymerization reaction depends on the kind of the polymerization initiator used, but it is 50 to 1
It is usually carried out in the temperature range of 80 ° C. The temperature range suitable for increasing the degree of polymerization of the polycondensation reaction is usually 190 to
270 ° C. As described above, the method of advancing two independent reactions in one reaction vessel can effectively obtain a binder having improved compatibility of two kinds of resins.

In the present invention, the weight ratio of the polycondensation resin to the addition polymerization resin, that is, the weight ratio of the polycondensation resin monomer to the addition polymerization resin monomer, is usually from the viewpoint of dispersibility of the addition polymerization resin. 50/50 to 95/5,
It is preferably 60/40 to 95/5.

It is desirable that the binder thus obtained has a softening point of 70 to 160 ° C., preferably 90 to 160 ° C., measured using a Koka type flow tester (manufactured by Shimadzu Corporation). The glass transition temperature derived from the above two polymer resins was 40 to 9 as measured using a differential scanning calorimeter.
It is desirable that the temperature is 0 ° C, preferably 45 to 80 ° C.
It is desirable that the acid value (JIS K0070) is 30 KOHmg / g or less, preferably 25 KOHmg / g or less. The softening point, the glass transition temperature and the acid value of the binder can be easily adjusted within these ranges by adjusting the polymerization initiator, the amount of catalyst and the like in the raw material monomer mixture or selecting the reaction conditions.

The electrostatic image developing toner of the present invention is a toner containing at least a binder and a colorant, wherein the binder contains the binder of the present invention. To do. Such a toner is manufactured by using, for example, a binder, a colorant, and if necessary, a charge control agent, a magnetic material and the like.

As the colorant used in the present invention, various carbon blacks produced by thermal black method, acetylene black method, channel black method, lamp black method and the like, and grafts in which the surface of carbon black is coated with resin Carbon Black, Nigrosine Dye, Phthalocyanine Blue, Permanent Brown FG,
Brilliant First Scarlet, Pigment Green B, Rhodamine-B Base, Solvent Red 49,
Solvent Red 146, Solvent Blue 35 and the like and mixtures thereof can be mentioned, and it is usually preferable to use about 1 to 15 parts by weight relative to 100 parts by weight of the binder.

As the charge control agent used as necessary, either positive or negative charge control agents can be used. The specific examples of the positive charge control agent are not particularly limited, and examples thereof include a nigrosine dye "Nigrosine Base E".
"X", "Oil Black BS", "Oil Black S"
O "," Bontron N-01 "," Bontron N-0 "
7 "," Bontron N-11 "(above, manufactured by Orient Chemical Co., Ltd.); triphenylmethane dye containing a tertiary amine as a side chain; quaternary ammonium salt compound, for example," Bontron P-51 "(Orient Chemical) ), Cetyl trimethyl ammonium bromide, "COPY CHARGE PX
VP435 "(manufactured by Hoechst) and the like; polyamine resins such as" AFP-B "(manufactured by Orient Chemical Co.); imidazole derivatives such as" PLZ-2001 "and" PLZ-80 ".
01 ”(above, manufactured by Shikoku Kasei) and the like. Preferably, Bontron N-07 can be used.

Specific examples of the negative charge control agent include:
Without being particularly limited, for example, metal-containing azo dyes such as “Varifast Black 3804” and “Bontron S
-31 "," Bontron S-32 "," Bontron S-
34 ”,“ Bontron S-36 ”(above, manufactured by Orient Chemical Co., Ltd.),“ T-77 ”,“ Eisenspirone Black TRH ”(manufactured by Hodogaya Chemical Co., Ltd.); copper phthalocyanine dye; metal complex of alkyl derivative of salicylic acid , "Bontron E-81", "Bontron E-82",
Examples thereof include "Bontron E-84" and "Bontron E-85" (all manufactured by Orient Chemical Co., Ltd.); quaternary ammonium salts such as "COPY CHARGE NX VP434" (manufactured by Hoechst); nitroimidazole derivatives. Preferably, Bontron S-34, T-77, and Eisenspiron Black TRH can be used. The above charge control agent is 0.1 to 8.0% by weight, preferably 0.2
It is desirable to use ~ 5.0% by weight.

Further, when the toner is produced, a property improver such as a fluidity improver such as hydrophobic silica may be added. However, when the binder of the present invention is used, these properties are improved. It is not necessary to add the improving agent, and even when it is added, the addition amount may be small.

In the production of the toner of the present invention, the binder, the colorant and, in some cases, the property improving agent are uniformly dispersed and then melt-kneaded, cooled, pulverized and classified by a known method to obtain an average value. A toner having a particle size of 5 to 15 μm can be obtained. The toner may be a non-magnetic one-component developer, or by mixing a magnetic powder, that is, an iron oxide-based carrier, a spherical iron oxide-based carrier or a ferrite-based carrier as it is, or by mixing it with a resin or the like. It is also possible to use a dry two-component developer.

In order to produce a magnetic toner, magnetic particles may be added to the binder obtained by the present invention. As the magnetic particles, for example, ferrite, magnetite and other iron, cobalt, nickel and other ferromagnets or alloys showing ferromagnetism, compounds containing these elements, or containing no ferromagnetism elements, an appropriate heat treatment is applied. Examples thereof include alloys that exhibit ferromagnetism, such as manganese-copper-aluminum, manganese-copper-tin, and other types of alloys called Heusler alloys containing manganese and copper, or chromium dioxide. A compound containing a ferromagnetic element is preferably used, and magnetite is particularly preferably used. These magnetic materials have a dispersed particle size of 0.1
It is desirable that the powder is uniformly dispersed in the toner in the form of a fine powder of ˜1 μm, and its content is 100 parts by weight of the binder.
It is desirable that the amount is 20 to 70 parts by weight, preferably 30 to 70 parts by weight.

[0072]

The present invention will be described in more detail with reference to Examples, Comparative Examples and Test Examples, but the present invention is not limited to these Examples.

The acid value of the obtained binder and the glass transition temperature were measured by the following methods.

[Acid Value] It is measured according to the method described in JIS K0070.

[Glass Transition Temperature (Tg)] 2 using a differential scanning calorimeter (DSC210, manufactured by Seiko Instruments Inc.)
When the sample was heated to 00 ° C, left at that temperature for 3 minutes, and then cooled to room temperature at a temperature lowering rate of 10 ° C / min. The temperature at the intersection of the extension line of the baseline and the tangent line showing the maximum slope between the rising portion of the peak and the apex of the peak is defined as the glass transition temperature.

The dispersed particle size of the release agent in the obtained binder was measured by the following method. [Dispersed Particle Size] A resin having a particle size of about 0.2 mm was cut with a microtome to a thickness of 150 nm, and the obtained thin piece was subjected to a transmission scanning electron microscope (for example, JOEL (manufactured by JEOL Ltd.,
It can be measured by observing with "JEM-2000") and performing image analysis by a known method.

Example 1 665 g of styrene as a vinyl-based resin monomer, 127 g of 2-ethylhexyl acrylate, and 32 g of dicumyl peroxide as a polymerization initiator were placed in a dropping funnel. As a polyester monomer, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 1444 g, isododecenyl succinic anhydride 47 g, terephthalic acid 378 g, 1,2,4-benzenetricarboxylic acid 135 g , 40 g of fumaric acid as a bireactive compound, 5 dibutyltin oxide as an esterification catalyst
g and a polypropylene wax having a softening point of 149 ° C. as measured by a differential scanning calorimeter (DSC210 manufactured by Seiko Denshi Kogyo Co., Ltd., manufactured by Sanyo Kasei Co., Ltd., Viscole 550).
P, number average molecular weight by vapor permeation method: 4000) 144
g (5 parts by weight to 100 parts by weight of the charged monomer),
Place in a glass 5 liter four-necked flask equipped with a thermometer, a stainless stirrer, a flow-down condenser, and a nitrogen introduction tube, and place it in a mantle heater under a nitrogen atmosphere under a nitrogen atmosphere.
While stirring at a temperature of 60 ° C., the vinyl resin monomer and the polymerization initiator were added dropwise from a dropping funnel over 1 hour. 1
After aging the addition polymerization reaction for 2 hours while maintaining the temperature at 60 ° C., the temperature was raised to 230 ° C. to carry out the condensation polymerization reaction. As for the degree of polymerization, a Koka type flow tester (manufactured by Shimadzu Corporation) was used.
Following the softening point measured according to STM E28-67, the reaction was terminated when the softening point reached 135 ° C. The glass transition temperature (Tg) of the obtained resin is
Glass transition temperature derived from two polymer resins is 61.5
C., the glass transition temperature derived from the release agent was 148.0 ° C., and the acid value was 9.5 KOHmg / g. The obtained resin is referred to as Binder A. The dispersed particle size of the release agent in the binder A was 1.5 μm.

Example 2 480 g of styrene as a monomer of vinyl resin, 85 g of butyl acrylate, 20 g of acrylic acid as a bireactive compound, and dicumyl peroxide 2 as a polymerization initiator.
3 g was placed in a dropping funnel. As the polyester monomer, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 980 g, polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) Propane 228g, isododecenyl succinic anhydride 200g, terephthalic acid 248g, 1,2,4-
144 g of benzenetricarboxylic acid, 5 g of dibutyltin oxide as an esterification catalyst, polyethylene wax having a softening point of 105 ° C. by a differential scanning calorimeter (DSC210, manufactured by Seiko Denshi Kogyo KK) as a release agent (SPRAY 105, manufactured by Sazol, vapor infiltration) Number average molecular weight by the method: 1100) 121 g (5 parts by weight with respect to 100 parts by weight of charged monomer), a glass 5 liter four-necked flask equipped with a thermometer, a stirrer made of stainless steel, a flow-down condenser and a nitrogen introduction tube. In a mantle heater under a nitrogen atmosphere with stirring at a temperature of 160 ° C., the vinyl resin monomer, the bireactive compound and the polymerization initiator were added dropwise from a dropping funnel over 1 hour. After aging the addition polymerization reaction for 2 hours while maintaining the temperature at 160 ° C, the temperature was raised to 230 ° C to cause the polycondensation reaction. The degree of polymerization was traced by the softening point measured using a Koka type flow tester (manufactured by Shimadzu Corporation), and the reaction was terminated when the softening point reached 132 ° C. Glass transition temperature (Tg) of the obtained resin
Has a glass transition temperature of 5 derived from two polymer resins.
8.5 ° C, glass transition temperature derived from release agent is 95.0
C. and the acid value was 23.3 KOH mg / g. The obtained resin is used as a binder B. The dispersed particle size of the release agent in the binder B was 2 μm.

Example 3 In Example 2, instead of polyethylene wax,
Differential scanning calorimeter (DSC21 manufactured by Seiko Instruments Inc.
0) the ester-based wax having a softening point of 83 ° C. (manufactured by Sazol, Carnauba wax, number average molecular weight by vapor permeation method: 800) is used as a release agent.
The reaction was performed in the same manner as in Example 2, and the reaction was terminated when the softening point measured using a Koka type flow tester (manufactured by Shimadzu Corporation) reached 125 ° C. The glass transition temperature (Tg) of the obtained resin has one peak at 52.3 ° C.,
The acid value was 21.5 KOHmg / g. The obtained resin is used as a binder C. In this example, an ester wax was used as a mold release agent, but it is considered that the ester wax has a high compatibility with the resin, so that the peak of the glass transition temperature becomes one. Therefore, in the binder C, no particulate release agent was observed.

Comparative Example 1 A resin was obtained by carrying out the same reaction as in Example 1 except that polypropylene wax was not used. The glass transition temperature (Tg) of the obtained resin was 61.5 ° C. with one peak, and the acid value was 9.8 KOHmg / g.
Met. The obtained resin is used as a binder D.

Comparative Example 2 A resin was obtained by carrying out the reaction in the same manner as in Example 2 except that the polyethylene wax was not used.
The glass transition temperature (Tg) of the obtained resin was 59.0 ° C. with one peak, and the acid value was 22.5 KOHmg / g. The obtained resin is used as a binder E.

Example 4 300 g of styrene as a vinyl resin monomer, 55 g of 2-ethylhexyl acrylate, 15 g of acrylic acid as a bireactive compound, and 15 g of ditertiary butyl peroxide as a polymerization initiator were placed in a dropping funnel. .
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) as a polyester monomer
720 g of propane, polyoxyethylene (2.2)-
2,2-bis (4-hydroxyphenyl) propane 29
5 g, isododecenyl succinic anhydride 258 g, terephthalic acid 145 g, 1,2,4-benzenetricarboxylic acid 1
32 g and dibutyltin oxide 4 as esterification catalyst
g, 970 g of polyethylene wax (SPRAY 105, manufactured by Sazol Co., Ltd.) used in Example 2 as a release agent (50 parts by weight with respect to 100 parts by weight of charged monomer), a thermometer, a stirrer made of stainless steel, a downflow condenser and nitrogen. Put in a glass 5 liter four-necked flask equipped with an introduction tube, and in a mantle heater under a nitrogen atmosphere, 160
The vinyl resin monomer, the bireactive compound and the polymerization initiator were added dropwise from a dropping funnel over one hour while stirring at a temperature of ° C. After aging the addition polymerization reaction for 2 hours while maintaining the temperature at 160 ° C, the temperature was raised to 230 ° C to cause the polycondensation reaction. The degree of polymerization was traced by a softening point measured according to ASTM E28-67 using a Koka type flow tester (manufactured by Shimadzu Corporation), and the reaction was terminated when the softening point reached 120 ° C. Regarding the glass transition temperature (Tg) of the obtained resin, the glass transition temperature derived from the two polymerization resins is 53.5 ° C., the glass transition temperature derived from the release agent is 93.2 ° C., and the acid value is It was 21.5 KOHmg / g. The obtained resin is used as a binder F. The dispersed particle size of the release agent in the binder F was 4 μm.

Test Example 1 Materials having the compositions shown in Table 1 were premixed with a Henschel mixer, kneaded with a twin-screw extruder, cooled, and then subjected to normal pulverization and classification steps to obtain an untreated toner 1 having an average particle size of 11 μm. Got 8.

[0084]

[Table 1]

The obtained untreated toners 1 to 5 are respectively
Toners 1 to 5 were prepared by mixing and adhering 0.1 part by weight of hydrophobic silica "H-2000" (Wacker Chemical Co., Ltd.) to 00 parts by weight using a Henschel mixer. Similarly,
Silica was also attached to untreated toners 6 to 8 to make comparative toners 1 to 3, respectively. 39 parts by weight of each of the above toners,
A developer was prepared by mixing 1261 parts by weight of ferrite powder (average particle size 100 μm) coated with styrene / methyl methacrylate resin, and a commercially available electrophotographic copying machine (photoreceptors were toners 1 to 3 and comparative toners). Amorphous selenium for 1-3, organic photoconductor for toner 4,
The rotation speed of the fixing roller was set to 255 mm / sec, the temperature of the heat roller in the fixing device was made variable, and the oil application device was removed.
According to the method described below, toner fixability, image density,
The offset resistance and printing durability were evaluated.

(1) Toner fixability: The toner fixability is evaluated by the minimum fixing temperature. Here, the minimum fixing temperature is a reflection densitometer of Macbeth Inc. before and after rubbing 5 times on the image fixed through a fixing machine, placing a load of 500 g on a sand eraser having a bottom surface of 15 mm x 7.5 mm, and rubbing. The optical reflection density is measured according to the following, and it means the temperature of the fixing roller when the fixing rate exceeds 70% according to the following definition.

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

The fixing roller temperature is controlled between 100 and 240 ° C. to evaluate the fixing property. The results are shown in Table 2.
Shown in.

(2) Image density: Using a reflection densitometer manufactured by Macbeth Co., the optical reflection density of an image fixed in a temperature range in which offset does not occur and sufficient fixing is measured. The results are shown in Table 2.

(3) Offset resistance: Offset resistance is evaluated by measuring the low temperature offset disappearance temperature and the high temperature offset generation temperature. That is, the temperature of the surface of the heat roller is raised in the range of 70 to 240 ° C. to perform a copy test, and the adhesion of the toner on the surface of the heat roller is visually evaluated at each temperature. The results are shown in Table 2.

[0091]

[Table 2]

(4) Printing durability: Printing durability was 500,000 under normal environment (23 ° C., 50% RH) and high temperature and high humidity (35 ° C., 85% RH) using the above copying machine. Copies are made, and the change in the amount of charge before and after that is evaluated. Also, the occurrence of background stain during the printing durability test is evaluated. Here, the charge amount is measured by a blow-off type charge amount measuring device, that is, a specific charge measuring device equipped with a Faraday cage, a condenser, and an electrometer. The measurement method is
First, the developer prepared above is added with W (g) (0.15 to 0.2).
0 g) is placed in a brass-type measuring cell equipped with a 500-mesh (a size that does not allow carrier particles to pass) stainless steel mesh. Next, after sucking from the suction port for 5 seconds, the air pressure is blown for 5 seconds at an air pressure of 0.6 kgf / cm ² to remove only the toner from the cell.

The voltage of the electrometer 2 seconds after the start of the blow at this time is V (volt). If the electric capacity of the condenser is C (μF), the specific charge of this toner is Q /
m is calculated by the following equation. Q / m (μC / g) = C × V / m

Here, m is the weight of the toner contained in the developer in W (g), where T (g) is the weight of the toner in the developer and D (g) is the weight of the developer. In that case, the toner density of the sample is expressed as T / D × 100 (%), and m is calculated by the following equation. m (g) = W × (T / D) The results are shown in Table 3.

[0095]

[Table 3]

From the results shown in Tables 2 and 3, all the toners of the present invention have good image fixability and offset resistance.
In the printing durability test, the change in charge amount under normal environment (23 ° C., 50% RH) and high temperature and high humidity (35 ° C., 85% RH) is small, and the image quality is good. However, Comparative Toners 1 and 2 which do not use the binder of the present invention have good hot offset properties but lack printing durability, and Comparative Toner 3 has good printing durability, but is hot. The offset property is poor.

[0097]

EFFECTS OF THE INVENTION By using the binder of the present invention, it is possible to fix at a low temperature without using an offset preventive liquid even when fixing at a high speed in a heat roller system, even though it has excellent low-temperature fixing property and anti-offset property. It is possible to obtain a toner for developing an electrostatic image.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI G03G 9/08 365 G03G 9/08 365 9/087 321 384 (56) Reference JP-A-7-239572 (JP, A) Kaihei 7-64330 (JP, A) JP 61-124960 (JP, A) JP 4-95968 (JP, A) JP 62-143060 (JP, A) JP 60-37562 ( JP, A) JP 56-87051 (JP, A) JP 61-124965 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 85/00 G03G 9/00 -9/18

Claims (6)

(57) [Claims] 1. A mixture (a) of two raw material monomers of a polymerization system each having an independent reaction route, a compound (b) capable of reacting with both of the two raw material monomers of a polymerization system, and a releasing agent (c). ) Are mixed and the two polymerization reactions are carried out in the same reaction vessel,
The raw material monomer mixture (a) is polyester, poly
Selected from the group consisting of ester polyamide and polyamide
With at least one raw material monomer of polycondensation resin
It is a mixture of raw material monomers of a vinyl resin , wherein the compound (b) is acrylic acid, methacrylic acid, maleic acid,
Fumaric acid, hydroxyethyl acrylate and hydroxy
Less selected from the group consisting of cyethylmethacrylate
Both Ri one compound der, the release agent (c), polyps
Ropylene wax, polyethylene wax, polypropylene
Len polyethylene copolymer wax, ester-based wax
Scan or amide waxes der Ru binder. 2. The softening point of the release agent (c) is 70 to 160 ° C.
Binder according to claim 1 Symbol mounting, characterized in that it. 3. The total amount of the compound (b) capable of reacting with the mixture of the two raw material monomers of the polymerization system (a) and the amount of the compound (b) used as the release agent (c) is 1
The binder according to claim 1 or 2, which is 0.1 to 1000 parts by weight with respect to 00 parts by weight. 4. A binder according to claim 1 to 3, wherein any acid value of the binder is less than 30 KOHmg / g. 5. A binder according to claim 1-4, wherein either the softening point of the binder is 70 to 160 ° C.. 6. The method of claim 1-5 toner for developing electrostatic images which is characterized by containing a binder according to any one.