JP3214784B2 - Binder resin and toner for electrostatic image development - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image developing toner for developing an electrostatic latent image formed in electrophotography, electrostatic recording, electrostatic printing and the like, and a toner for producing the toner. It is related to a resin.

[0002]

2. Description of the Related Art Conventionally, electrophotography has been disclosed in US Pat.
As described in JP-A-21776, JP-A-2297691, and JP-A-2357809, etc., the photoconductive insulating layer is uniformly charged, and then the layer is exposed, and the charge in the exposed portion is dissipated. To form an electric latent image, and further, a visible image is formed by attaching a fine powder having a colored charge called toner to the latent image (development step). Is transferred onto a transfer material such as transfer paper (transfer step), and then permanently fixed by heating, pressure or other appropriate fixing method (fixing step).

In the fixing step, there are a contact heat fixing method such as heat roller fixing and a non-contact heating method such as oven fixing. The contact method is characterized by good thermal efficiency,
As compared with the non-contact type, the temperature required for the fixing machine can be reduced, which is effective for energy saving and miniaturization of the copying machine. From this point, it is clear that the contact heat fixing method is a useful fixing method, but in this fixing method, the problem of offset development is likely to occur. This phenomenon is that a part of the toner melted at the time of fixing is transferred to the heat roller and is transferred to the subsequent transfer paper or the like.

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

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, in order to improve the offset resistance, the softening point and crosslinking density of the resin must be increased, and low-temperature fixing is sacrificed. Conversely, if low-temperature fixing is emphasized, offset resistance and blocking resistance are hindered.

Also, Japanese Patent Application Laid-Open Nos. 49-65232, 50-28840 and 50-81342
As described in Japanese Patent Application Publication No. H10-146, a method of adding a paraffin wax, a low-molecular-weight polyolefin, or the like as an anti-offset agent is known. ing.

On the other hand, as a binder resin for a toner, a polyester resin is used because of its excellent low-temperature fixability. Polyester resins have good fixability in nature, and as described in US Pat. No. 3,590,000,
In the non-contact fixing method, the toner is sufficiently fixed, but it is difficult to use the heat roller fixing method because an offset phenomenon easily occurs. Also, JP-A-50-44836, JP-A-57-37353, and JP-A-57-1
JP 09875 describes polyester resins having improved offset resistance using polyvalent carboxylic acids, but these still do not have or do not have sufficient offset resistance to be used. However, there is a problem that not only the low-temperature fixability inherent to the polyester resin is sacrificed, but also the pulverizability of the resin and the toner is extremely poor.

Accordingly, the following attempts have been made to use a mixture of a polyester resin having excellent fixing properties and a styrene acrylic resin.

A method of mixing a polyester resin and a styrene acrylic resin (JP-A-49-6931, JP-A-5-6931)
4-114245, JP-A-57-70523, JP-A-2-161664); a method of chemically bonding a polyester resin and a styrene acrylic resin (JP-A-56-116043); A method of copolymerizing a vinyl monomer (JP-A-57-60339, JP-A-63-2
79265, JP-A-1-156759, JP-A-2-
No. 5073); a method of copolymerizing a vinyl-based monomer with a polyester resin having a (meth) acryloyl group (Japanese Patent Laid-Open No.
No. 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 in which a polyester resin and a vinyl resin are blocked by an ester bond (JP-A-2-881).

However, since the polyester resin and the styrene acrylic resin are originally poorly compatible with each other, depending on the mixing ratio, the mixing of the resin and the internal additives such as carbon black may be performed depending on the mixing ratio. Dispersion becomes poor and the chargeability becomes non-uniform, causing adverse effects such as background contamination in image evaluation. Also, when the molecular weights of the two resins are different, a difference may occur between the melt viscosities of the two, which makes it difficult to reduce the dispersed particle size of the resin in the disperse phase. Dispersion of internal additives such as carbon black is very poor, and there is a problem that image stability is largely lacking. Further, when a vinyl monomer is polymerized on the reactive polyester, there is a problem that the composition is restricted in order to prevent gelation.

From such a viewpoint, Japanese Patent Application Laid-Open No.
As described in JP-A No. 01, a raw material monomer mixture of two polymerization systems in which polymerization reactions are performed in independent reaction paths in the same reaction vessel is previously blended, and the two polymerization reactions are performed in parallel. A developer composition using a binder resin characterized by the above has been developed. However, even if such a binder resin is used, there is still room for improvement in obtaining a further low-temperature fixing property with respect to a recent increase in speed, miniaturization, and energy saving of a copying machine.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to solve such problems, and in particular, to provide a toner for developing electrostatic images excellent in low-temperature fixability and offset resistance, and to produce the toner. To provide a binder resin.

[0013]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have found that a binder resin composed of two resins having different softening points, one of which is the same reaction vessel. A resin obtained by performing a polycondensation reaction and an addition polymerization reaction in parallel in one another, and using the other being a polycondensation resin as a binder resin, by producing a toner for electrostatic image development, In particular, they have found that a toner having excellent low-temperature fixability and offset resistance can be obtained, and have completed the present invention.

That is, the gist of the present invention is as follows: (1) A binder resin for toner production obtained by mixing two types of resins (A) and (B) having different softening points as main components. The resin (A) is a mixture of a raw material monomer of a polycondensation resin, a raw material monomer of a vinyl resin, and a mixture containing a compound capable of reacting with any of the raw material monomers. A resin obtained by performing the reaction in parallel, wherein the resin (B) is a polycondensation resin, and the softening point of the resin (A) is 120 to 170 ° C, and the softening point of the resin (B) is 80 to 12
0 ° C., the temperature difference between the softening points of the resin (A) and the resin (B) is 10 ° C. or more, and the weight ratio of the raw monomer of the condensation polymerization resin and the raw monomer of the vinyl resin in the resin (A) ( (Condensation polymerization / vinyl)) is 50/50 to 95/5.
The weight ratio (A / B) of the resin (A) and the resin (B) is 90
/ 10-10 / 90 Der toner production for a binder resin, wherein Rukoto, (2) raw material monomers for a polycondensation resin in the resin (A) is a trivalent or higher carboxylic acid or its anhydride, The binder resin according to the above (1), wherein the binder resin comprises a lower alkyl ester and / or a trivalent or higher alcohol, and (3) the resin (A) and the resin (B) each have a glass transition point of 40. The above (1) or (2), which is up to 80 ° C.
The binder resin according to any one of (1) to (4) , wherein (4) the electrostatic image developing toner containing at least the binder resin and the colorant.
(3) A toner for developing an electrostatic image, which is the binder resin described in any one of (1) to (4) .

In the present invention, the resin (A) has a softening point of 120 to 170 ° C., and the resin (B) has a softening point of 80 to 170 ° C.
Preferably, the softening point of the resin (A) is from 130 to 160 ° C, and the resin (B)
Has a softening point of 85 to 105 ° C. When the softening point of the resin (A) is higher than this range, the low-temperature fixability tends to deteriorate, and when the softening point of the resin (A) is lower than this range, the offset resistance tends to deteriorate. On the other hand, when the softening point of the resin (B) is higher than this range, the low-temperature fixability tends to decrease, and when the softening point of the resin (B) is lower than this range, the offset resistance and the blocking resistance are poor. Tends to worsen.

The temperature difference between the softening points of the resin (A) and the resin (B) is preferably 10 ° C. or more, more preferably 20 to 70 ° C. When the temperature difference of the softening point is smaller than this range, the development of the excellent properties of the resin (A) and the resin (B) is slightly suppressed, and as a result, the low-temperature fixing property, the anti-offset property, and the anti-offset property are improved. Any of the properties of the blocking property may be insufficient.

In the present invention, the softening point refers to a value measured by a Koka type flow tester, which is described in JIS K 7210. In the present invention, the measurement is specifically performed as follows. That is, while a 1 cm ³ sample was heated at a heating rate of 6 ° C./min using a Koka type flow tester (manufactured by Shimadzu Corporation), a load of 20 kg / cm ² was applied by a plunger, and the diameter was 1 mm and the length was 1 mm. Of the plunger, whereby a plunger descent amount (flow value) -temperature curve is drawn and its S
Assuming that the height of the curve is h, the temperature corresponding to h / 2 (the temperature at which half of the resin flows out) is defined as the softening point.

In the present invention, the weight ratio (A / B) of the resin (A) and the resin (B) is 90/10 to 10/90.
And more preferably 80/20 to
20/80. When the weight ratio of the resin (A) is larger than the above range, the low-temperature fixing property and the smoothness of the fixing surface tend to be reduced. On the other hand, when the compounding weight ratio of the resin (A) is smaller than the above range, Has a tendency for offset resistance and blocking resistance to deteriorate.

The binder resin for producing a toner of the present invention is obtained by mixing two kinds of resins, resin (A) and resin (B), as main components. Powders and pellets are simply mixed, both resins are uniformly mixed and dispersed by melt-kneading, then powdered or pelletized by pulverization, etc. Every aspect of the present invention is possible.

Further, by blending the resin (A) and the resin (B) at the above blending weight ratio, the resin (A)
It is possible to form a wide molecular weight distribution which cannot be obtained only by increasing the ratio of the polycondensation-based monomer in the toner, and to obtain a toner for electrostatic image development having excellent low-temperature fixability and offset resistance.

In the present invention, the resin (A) and the resin (B) preferably have a glass transition point of 40 to 80 ° C., more preferably 50 to 70 ° C.
By selecting a material having a glass transition point in such a range, more excellent low-temperature fixability, smoothness of the fixing surface, and blocking resistance can be obtained. That is, when the glass transition point is higher than the above range, the fixability tends to deteriorate, and when the glass transition point is lower than the above range, the blocking resistance tends to decrease.

The glass transition point in the present invention is measured as follows. That is, the temperature was raised to 200 ° C. using a differential scanning calorimeter (manufactured by Seiko Denshi Kogyo), left at that temperature for 3 minutes, and then lowered at a rate of 10 ° C./mi.
The sample cooled to room temperature at n.
When measured at n., the temperature at the intersection of the extension of the base line below the glass transition point and the tangent line indicating the maximum slope from the peak rising portion to the peak apex is defined as the glass transition point (Tg). And

In the present invention, the softening point and the glass transition point of each resin can be easily adjusted by adjusting the polymerization initiator and the amount of the catalyst in the starting monomer mixture or selecting the reaction conditions. Can be.

The resin (A) in the present invention is prepared by using a raw material monomer of a condensation polymerization resin, a raw material monomer of a vinyl resin, and a mixture containing a compound capable of reacting with any of these raw material monomers in the same reaction vessel. It is obtained by performing a polymerization reaction and an addition polymerization reaction in parallel.

In the present invention, as the polycondensation resin, for example, one or more selected from the group consisting of polyester, polyester / polyamide and polyamide are 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 the raw material monomer of the polyester, 2
A monovalent or trivalent or higher alcohol, a divalent or trivalent or higher carboxylic acid or an acid anhydride thereof, and a lower alkyl ester are used. Here, when offset resistance is particularly 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 valent polyfunctional compound. Accordingly, in the present invention, from the viewpoint of offset resistance, it is preferable that the starting monomer contains a trivalent or higher carboxylic acid or an acid anhydride thereof, a lower alkyl ester, and / or a trivalent or higher alcohol. Hereinafter, in the present specification, these trivalent or higher-valent monomer monomers may be referred to as a crosslinking agent.

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, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) alkylene oxide adduct 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,
Examples thereof include 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, and hydrogenated bisphenol A.

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

Examples of the trivalent 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 and the like 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, succinic acid, adipic acid, sebacic acid, and azelaic acid. , Malonic acid, n-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octenylsuccinic acid, n-octylsuccinic acid, isooctenylsuccinic acid, isooctylsuccinic acid,
And anhydrides or lower alkyl esters of these acids. 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 or its anhydride and lower alkyl ester include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid and 1,2,4-naphthalenetricarboxylic acid. 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, empole trimer acid, and acid anhydrides and lower alkyl esters thereof. Of these, in particular 1,2,4-
Benzenetricarboxylic acid, that is, trimellitic acid or a derivative thereof is preferably used because it is inexpensive and the reaction control is easy.

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

As a raw material monomer for polyester / polyamide or polyamide, a raw material monomer for forming an amide component is required in addition to the above-mentioned raw material monomer.
Examples of such raw material monomers include polyamines such as ethylenediamine, pentamethylenediamine, hexamethylenediamine, diethylenetriamine, iminobispropylamine, phenylenediamine, xylylenediamine, and triethylenetetramine; and aminocarboxylic acids such as 6-aminocaproic acid and ε-caprolactam. Examples include acids, amino alcohols such as propanolamine, and the like. Of these, hexamethylenediamine and ε-caprolactam are preferably used.

In the case of using a raw material monomer of polyester / polyamide or polyamide, in order to partially crosslink in the molecule of the binder resin, it is necessary to use a trifunctional or higher polyfunctional compound as in the case of polyester. is necessary. In this case, a carboxylic acid having a valency of 3 or more, an acid anhydride thereof, or a lower alkyl ester is mainly used.

In the present invention, the trivalent or higher valent monomer is effective for controlling the degree of polymerization of the resin (A). In particular, if it is not necessary to reduce the dispersed particle size of the resin (A), the condensation polymerization resin Is preferably used in an amount of 0.2 to 30% by weight, especially 0.5 to 30% by weight, based on the starting monomer.

If the amount of these trivalent or higher-valent monomers is too large, gelation will occur during the polymerization reaction. This is not preferable because it is difficult to prevent the offset phenomenon that the toner does not completely adhere to the paper but adheres to the roller surface and transfers to the next paper.

As the raw material monomer of the vinyl resin in the present invention, for example, styrene, o-methylstyrene,
Styrene or styrene derivatives such as m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-chlorostyrene, vinylnaphthalene; for example, ethylene, propylene, butylene, isobutylene, etc. Ethylenically unsaturated monoolefins; for example, vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl formate,
Vinyl esters such as vinyl caproate; for example, 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, 2-hydroxyethyl acrylate, acrylic acid Glycidyl, 2-chloroethyl acrylate, phenyl acrylate, α-methyl methyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-methacrylate −
Butyl, amyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, decyl methacrylate, lauryl methacrylate,
2-ethylhexyl methacrylate, stearyl methacrylate, methoxyethyl methacrylate, 2-methyl methacrylate
Ethylenic esters such as hydroxyethyl, glycidyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride; N-vinylpyrrole And N-vinyl compounds such as N-vinylpyrrolidone.

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

A polymerization initiator is used when polymerizing the raw material monomer of the vinyl resin. Examples of the polymerization initiator include 2,2′-azobis (2,4-dimethylvaleronitrile) and 2,2′-azobis (2,4-dimethylvaleronitrile). 2'-azobisisobutyronitrile, 1,
1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, other azo or diazo polymerization initiators, or benzoyl peroxide, methyl ethyl ketone per Peroxide polymerization initiators such as oxide, isopropylperoxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, and dicumyl peroxide.

For the purpose of controlling the molecular weight and molecular weight distribution of the polymer, or the purpose of controlling the reaction time, two or more kinds of polymerization initiators can be mixed and used. The polymerization initiator is used in an amount of 0.1 to 20 parts by weight, preferably 1 to 1 part by weight, based on 100 parts by weight of the raw material monomer of the vinyl resin.
0 parts by weight.

In the present invention, a compound capable of reacting with either the raw material monomer of the polycondensation resin or the raw material monomer of the vinyl resin (hereinafter sometimes abbreviated as “bireactive compound”) is used. Examples thereof include those represented by the following general formulas (I) and (II). Some of these bi-reactive compounds partially overlap the above-mentioned raw material monomers.

[0043]

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[Wherein R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom, a hydroxyl group, an alkyl group which may have a substituent, an alkoxy group, an aryl group or a vinyl group, or a halogen atom. And these may be combined to form a ring. A and B are the same or different and each represents an alkylene group represented by the general formula (III) or a general formula (IV)
A phenylene group represented by

[0045]

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(R ⁴ , R ⁵ and R ⁶ are the same or different and each represent a hydrogen atom, a hydroxyl group, an alkyl group which may have a substituent, an alkoxy group, an aryl group, a vinyl group or a halogen atom; May together form a ring, m represents a number from 0 to 5, and n represents a number from 0 to 2.)
X and Y are the same or different, and —COOR ⁷ or —OR ⁸ (R ⁷ and R ⁸ have a hydrogen atom or a hydroxyl group
Represents a lower alkyl group).

Here, it is necessary that these compounds can react with any of the two raw material monomers of the polymerization system. When there are two or more raw material monomers of one polymerization system, at least one of them is required. It only needs to be able to react with one.

In the general formulas (I) and (II), among the groups represented by R ^{1 to} R ⁶ , the alkyl group may be a straight-chain or branched-chain one having 1 to 6, particularly 1 to 4 carbon atoms. Are preferable, for example, methyl group, ethyl group, n-propyl group, i-
Examples thereof include a propyl group, an n-butyl group, and a tert-butyl group. These alkyl groups may be substituted with a phenyl group, a naphthyl group, a hydroxyl group or the like. Examples of the alkoxy group include a methoxy group, an ethoxy group, and an n-
Examples include a propoxy group, an i-propoxy group, a t-butoxy group, and the like, and these groups may be substituted with a hydroxyl group, a carboxyl group, or the like. Examples of the aryl group include a phenyl group, a naphthyl group, a benzyl group, and the like, and these groups may be substituted with a methyl group, an ethyl group, a methoxy group, an ethoxy group, a carboxyl group, a hydroxyl 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, or the like. 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 lower alkyl group represented by R ⁷ and R ⁸ has 1 to 4 carbon atoms, examples of which include a methyl group and an ethyl group. These groups are substituted with a hydroxyl group or the like. It may be.

Both types represented by the general formulas (I) and (II)
Representative compounds are as follows:
(1)-(13), (15)-(20), (22)-
(36) is illustrated.

[0051]

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[0052]

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[0053]

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[0054] anhydrides of the above SL ethylenic dicarboxylic acids and the like to further.

The amount of these bireactive compounds to be used is generally 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on all starting monomers. If the amount used is less than this range, the two polymer systems tend to be incompatible with each other and tend to be a resin having a large sea-island structure. Is not preferred.

In the method for producing the resin (A) using the above-described raw materials, a condensation polymerization reaction and an addition polymerization reaction are performed in the same reaction vessel in parallel. In such a method, 2
The progress and completion of the two polymerization reactions do not need to be simultaneous at the same time, and the reaction may be proceeded and completed by appropriately selecting the reaction temperature and time according to each reaction mechanism.

Specifically, the polymerization reaction is carried out, for example, under a temperature condition suitable for an addition polymerization reaction, by mixing a raw material monomer of a vinyl resin, a crosslinking agent, and a polymerization initiator in a mixture of raw material monomers of polyester, polyester / polyamide or polyamide. A step of partially conducting a polycondensation reaction in parallel with the addition polymerization reaction by dropping a mixture of agents, and a step of maintaining only the temperature of the obtained mixture under the above conditions to complete only the addition polymerization reaction,
Then, the reaction temperature is increased to increase the degree of polymerization of the polycondensation reaction.

Here, the temperature condition suitable for the addition polymerization reaction depends on the type of the polymerization initiator to be used.
Usually performed in a temperature range of 80 ° C. The optimum temperature range for increasing the degree of polymerization of the polycondensation reaction is usually 190 to 190.
270 ° C. As described above, a binder resin in which two kinds of resins are effectively 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, when the polymerization reaction is carried out in parallel, the weight ratio (condensation polymerization / vinyl) of the monomer for the condensation polymerization resin and the monomer for the vinyl resin is 50.
/ 50 to 95/5, more preferably 70/30 to 90/10. When the ratio of the raw material monomer of the polycondensation resin is smaller than this range, the vinyl resin tends to be hardly dispersed in the polycondensation resin. If the ratio of the raw material monomer of the polycondensation resin is larger than this range, the characteristics of the vinyl resin cannot be utilized, and the charge stability of the toner tends to be impaired.

Next, the resin (B) in the present invention will be described. The resin (B) is a polycondensation resin, and specific examples include polyester, polyester / polyamide, and polyamide.

The resin (B) is the same as the resin (A) described above.
Of the raw material monomers described above, the same monomer as the raw material monomer for the polycondensation-based resin is used, and is usually obtained by a known method. For example, in the case of polyester, polycondensation is carried out using a divalent or trivalent or higher alcohol, a divalent or trivalent or higher carboxylic acid or an acid anhydride thereof, and a lower alkyl ester by utilizing an esterification reaction or a transesterification reaction. Just do it.

The toner for developing an electrostatic image according to the present invention is a toner for developing an electrostatic image comprising at least a binder resin and a colorant, wherein the resin (A) and the resin (B) described above are used as the binder resin. It is characterized by the following. In order to produce such a toner, for example, the binder resin, a colorant, and if necessary, a charge control agent, a magnetic substance, and the like are used.

Examples of the coloring agent used in the present invention include various types of carbon black produced by a thermal black method, an acetylene black method, a channel black method, a lamp black method, etc., and a graft obtained by coating the surface of carbon black with a 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, and the like can be mentioned. Usually, it is preferable to use about 1 to 15 parts by weight based on 100 parts by weight of the binder resin.

Both positive and negative charge control agents can be used as needed. Specific examples of the positive charge control agent are not particularly limited. For example, as a nigrosine dye, “Nigrosine base E
X "," Oil Black BS "," Oil Black S "
O "," Bontron N-01 "," Bontron N-0 "
7 "," Bontron N-11 "(all manufactured by Orient Chemical Co., Ltd.)" Copy BluePR "(manufactured by Hoechst)
Etc .; triphenylmethane dyes containing a tertiary amine as a side chain, quaternary ammonium salt compounds such as "Bontron P-51" (manufactured by Orient Chemical Co., Ltd.), cetyltrimethylammonium bromide, "COPY CHARGE PXVP435"
(Manufactured by Hoechst) and the like; polyamine resins such as "AFP
-B "(manufactured by Orient Chemical Co., Ltd.), an imidazole derivative,
For example, “PLZ-2001”, “PLZ-8001”
(Above, manufactured by Shikoku Chemicals) and the like. Preferably, Bontron N-07 can be used.

Further, specific examples of the negative charge control agent include:
There is no particular limitation, for example, metal-containing azo dyes such as “Varifast Black 3804” and “Bontron S”
-31 "(all manufactured by Orient Chemical Co., Ltd.)," T-77 "
(Manufactured by Hodogaya Chemical Co., Ltd.), "Bontron S-32", "Bontron S-34", "Bontron S-36" (above,
Orient Chemical Co., Ltd.), "Eizen Spiron Black T
RH "(manufactured by Hodogaya Chemical Co., Ltd.) and the like; copper phthalocyanine dyes, metal complexes of alkyl derivatives of salicylic acid, such as" Bontron E-81 "and" Bontron E-82 ";
"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), and nitroimidazole derivatives. Preferably, Bontron S-34, T-77 and Eizen Spiron Black TRH can be used. The above charge control agent is used in an amount of 0.1 to 8.0% by weight, preferably 0.1% by weight, based on the binder resin.
Use 2 to 5.0% by weight.

It is preferable to use a wax such as polyolefin as an offset preventing agent.
It is preferable to use 1 to 5 parts by weight with respect to 00 parts by weight.
Here, examples of the polyolefin include polyethylene and polypropylene, and those having a relatively low molecular weight, particularly those having a molecular weight of 3,000 to 1,500 by a vapor permeation method.
0 is preferred. The softening point by the ring and ball method is 70.
To 150 ° C, particularly preferably 120 to 150 ° C.

In conventional toners, it is difficult to mix these waxes due to poor compatibility.
In the present invention, they can be easily blended, and by blending them, the low-temperature fixability can be further improved.

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

After uniformly dispersing the binder resin obtained according to the present invention and a colorant, and in some cases, a property improving agent, the mixture is melt-kneaded, cooled, pulverized, and classified by a known method to give an average particle size of 5 to 5. A toner of 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. And a dry two-component developer.

In order to produce a magnetic toner, magnetic particles may be added to the binder resin obtained according to the present invention. The magnetic particles include, for example, ferrite, magnetite and other iron, cobalt, nickel and other ferromagnetic metals or alloys or compounds containing these elements, or do not contain ferromagnetic elements, but should be subjected to appropriate heat treatment. Alloys that exhibit ferromagnetism, such as manganese-copper-aluminum, manganese-copper-tin, and other alloys of the type called Heusler alloys containing manganese and copper, or chromium dioxide, and the like. Preferably, a compound containing a ferromagnetic element is used, and particularly, magnetite is preferably used. These magnetic materials are uniformly dispersed in the core material in the form of fine powder having an average particle size of 0.1 to 1 μm. And its content is 20 per 100 parts by weight of binder resin.
7070 parts by weight, preferably 30-70 parts by weight.

[0071]

EXAMPLES The present invention will be described in more detail with reference to Production Examples, Examples and Comparative Examples, but the present invention is not limited to these Examples and the like. In addition, the softening point and glass transition point of the obtained binder resin were measured by the above-mentioned methods.

Production Example of Resin (A) The raw materials of the polycondensation resins shown in A-1 to A-5 in Table 1 were mixed with a 3 liter equipped with a thermometer, a stainless steel stirring rod, a falling condenser, and a nitrogen inlet tube. Into a four-necked flask,
While stirring at a temperature of 135 ° C. in a nitrogen atmosphere in a mantle heater, a mixture of vinyl resin raw materials in advance was dropped from a dropping funnel over 4 hours. The mixture was aged for 5 hours while maintaining the temperature at 135 ° C., and heated to 230 ° C. to react. The degree of polymerization was traced from the softening point in accordance with ASTM E28-67, and when the softening point was reached, the reaction was terminated, withdrawn from the vessel, cooled and pulverized. Table 2 shows the softening point and glass transition point of the obtained resin.

Production Example of Resin (B) The materials shown in B-1 to B-2 in Table 1 were converted into four 3 liter ports equipped with a thermometer, a stainless steel stirring rod, a falling condenser, and a nitrogen inlet tube. The flask was placed in a mantle heater, and heated to a temperature of 2 under a nitrogen atmosphere.
The reaction was carried out while stirring at 20 ° C. The degree of polymerization is ASTM
Pursuit was performed from the softening point in accordance with E28-67. When the softening point was reached, the reaction was terminated, extracted, cooled, and pulverized. Table 2 shows the softening point and glass transition point of the obtained resin.

[0074]

[Table 1]

BPA.PO: Polyoxyperylene (2.2) -2,2-bis (4-human peroxyphenyl) fluoro BPA.EO: Polyoxyethylene (2.2) -2,2-bis (4-human peroxyphenyl) perfluoro FA : Fumaric acid (amphoteric compound) AA: acrylic acid (amphoteric compound) i-DSA: isododecenyl succinic anhydride TPA: terephthalic acid TMA: 1,2,4-benzenetricarboxylic anhydride HMDA: hexamethylenediamine DBO: Dibutyltin oxide St: Styrene EHA: 2-ethylhexyl acrylate AIBN: Azobisisobutyronitrile DCP: Dicumyl peroxide

[0076]

[Table 2]

Examples 1 to 8 and Comparative Examples 1 to 4 In each of the examples and comparative examples, a total of 100 parts by weight of the binder resin having the combination and the compounding amount shown in Table 3 was added to carbon black "Mogal L" (Cabot 7 parts by weight of low-molecular-weight polypropylene “Viscol 660”
P "(softening point: 130 ° C, manufactured by Sanyo Kasei Kogyo Co., Ltd.) and 2 parts by weight of the charge control agent" Bontron S-34 "(manufactured by Orient Chemical Co., Ltd.) are premixed and then twin-screw extruded. The mixture was melted and kneaded by a machine, cooled, and subjected to ordinary pulverization and classification steps to produce an untreated toner having an average particle size of 10 μm.

To 100 parts by weight of the obtained untreated toner, 0.3 parts by weight of hydrophobic silica “H-2000” (manufactured by Wacker Chemical Co., Ltd.) was mixed and adhered using a Henschel mixer, and toners 1 to 8 were added. And Comparative Toners 1 to 4.

A developer was obtained by mixing 39 parts by weight of each of the above toners and 1261 parts by weight of ferrite powder (average particle diameter: 100 μm) coated with styrene / methyl methacrylate resin.

Test Example An improved version of a commercially available two-component dry copying machine (FT-4080, manufactured by Ricoh) for this developer (rotational speed of the fixing roller was set to 255 mm / sec, and the temperature of the heat roller in the fixing device was reduced). The initial image was obtained by using the above-mentioned apparatus, which was made variable and the oil coating apparatus was removed, and the performance was evaluated by the following method.

(1) Fixing Property The fixing property of the toner was evaluated based on the minimum fixing temperature. Here, the minimum fixing temperature is 15 mm × 7.
A load of 500 g was placed on a 5 mm sand eraser, and the image fixed through a fixing device was rubbed five times back and forth, and before and after rubbing, the optical reflection density was measured with a Macbeth reflection densitometer.
This refers to 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 temperature of the fixing roller was controlled between 100 ° C. and 240 ° C., and the fixing property was evaluated.

(2) Hot Offset Occurrence Temperature According to the measurement of the minimum fixing temperature, the toner image is transferred and the fixing process is performed by the fixing roller described above. Sent to
The operation of visually observing whether or not toner stains occurred was repeated while the set temperature of the fixing roller was gradually increased, and the lowest set temperature at which toner stains occurred was defined as the hot offset occurrence temperature.

(3) Blocking resistance 10 g of toner was placed in a 100 ml glass bottle,
It was left for 2 weeks under environmental conditions of 0 ° C. and a relative temperature of 26%, and evaluated according to the following criteria. ：: No blocking was observed at all. Δ: Soft caked state. ×: Hard caked. The results are shown in Table 3.

[0086]

[Table 3]

As can be understood from the above results, all of the toners 1 to 8 of the present invention have excellent offset resistance, excellent low-temperature fixability, and excellent blocking resistance. And an excellent toner can be obtained. On the other hand, Comparative toner 1 has a softening point of resin (A) of 1
Since the temperature is lower than 20 ° C., the offset resistance and the blocking resistance are poor. Comparative toner 2 is inferior in low-temperature fixability, anti-offset property, and anti-blocking property because the difference in softening point between resin (A) and resin (B) is less than 10 ° C. Comparative toner 3 has a softening point of resin (B) of 120.
C. or higher, the low-temperature fixability is poor. The comparative toner 4 does not contain the resin (B), and thus has poor low-temperature fixability.

[0088]

By using the binder resin of the present invention, it is possible to obtain an electrostatic image developing toner which is excellent in blocking resistance and can be fixed at a low temperature without using an offset preventing liquid in a heat roller fixing system. Can be.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Eiji Morimoto 161 Tsubo, Shimotsu-cho, Seagrass-gun, Wakayama Prefecture (72) Inventor Tetsuhiro Semura 5-1-45 Fukiage, Wakayama-shi, Wakayama Prefecture 6-1-55, Komatsubara, Wakayama-shi (56) References JP-A-4-142301 (JP, A) JP-A-2-29664 (JP, A) JP-A-64-65592 (JP, A) JP-A-5 JP-A-34975 (JP, A) JP-A-57-171345 (JP, A) JP-A-64-15755 (JP, A) JP-A-62-195682 (JP, A) JP-A-5-303236 (JP, A) ) JP-A-6-102701 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03C 9/08

Claims (4)

(57) [Claims] 1. A resin (A) and a resin (B) having different softening points.
A binder resin for toner production obtained by mixing the two types of resins as main components, wherein the resin (A) is a raw material monomer of a condensation polymerization resin, a raw material monomer of a vinyl resin, and a raw material monomer of the raw material monomer. A resin obtained by performing a polycondensation reaction and an addition polymerization reaction in parallel in the same reaction vessel using a mixture containing a compound capable of reacting with any of them, wherein the resin (B) is a polycondensation resin, and Resin (A) has a softening point of 120 to 170 ° C., and resin (B) has a softening point of 80 to 1
20 ° C., the temperature difference between the softening points of the resin (A) and the resin (B) is 10 ° C. or more, and the weight ratio of the raw monomer of the condensation polymerization resin and the raw monomer of the vinyl resin in the resin (A) ( (Condensation polymerization / vinyl)) is 50/50 to 95/5.
The weight ratio (A / B) of the resin (A) and the resin (B) is 90
/ 10-10 / 90 Der Rukoto characterized toner production for the binder resin. 2. A method according to claim 1, wherein the raw material monomer of the polycondensation resin in the resin (A) contains a trivalent or higher carboxylic acid or an acid anhydride thereof, a lower alkyl ester, and / or a trivalent or higher alcohol. The binder resin according to claim 1. Wherein resin (A) and the resin glass transition point of (B) is each a 40 to 80 ° C. claim 1 or 2, wherein the binder resin. 4. An electrostatic image developing toner containing at least a binder resin and a colorant, wherein the binder resin is the binder resin according to any one of claims 1 to 3. Electrophotographic image development toner.