JP3222641B2 - Toner for developing electrostatic images - 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 used in electrophotography, electrostatic recording, electrostatic printing, and the like.

[0002]

2. Description of the Related Art In electrophotography, electrostatic recording, electrostatic printing, and the like, an electrostatic image formed on an electrostatic image support is visualized using a toner in which a colorant or the like is dispersed in a resin. I do. The visualized image is fixed as it is on an electrostatic image support, or is fixed after being transferred to another support. That is, the characteristics required of the toner include not only the developing property but also the good transferring property and the fixing property. In particular, in recent years, low energy fixing has been strongly demanded from the viewpoint of energy saving. As the heat fixing method, there are a non-contact heating method such as oven fixing and a contact heat fixing method of heat roller fixing. The contact heating fixing method has a high thermal efficiency, does not require a large amount of electric power in the fixing section, and can be downsized. However, this method has a problem that an offset occurs. The offset is a development in which a part of the toner forming the image is transferred to the surface of the heating roller at the time of fixing, and the transferred toner is transferred onto the next support to be contaminated. In order to prevent this offset development, various proposals as described below have been made and put to practical use.

[0003] For example, it is widely practiced to incorporate a compound having releasability, such as wax, into a toner. Further, it has been proposed to use a high molecular weight polymer as a resin constituting the toner. However, this method increases the softening point and the fixing temperature, and makes the resin tough and difficult to pulverize during toner production. It has problems such as becoming.
In order to improve these problems, it has been proposed to use a polymer having a wide molecular weight distribution from a low molecular weight to a high molecular weight in a toner using a vinyl resin such as styrene. This toner is satisfactory to some extent with respect to the prevention of offset and the fixability, but the fixability at low temperatures is not satisfactory.

On the other hand, a condensation resin represented by a polyester resin gives a polymer having a relatively low molecular weight, and it has been proposed that a toner which can be fixed at a low temperature can be manufactured by using the polymer. However, this method has a problem that the hot offset resistance is insufficient. In order to solve these problems, a toner using a mixture of a high-molecular-weight vinyl resin and a low-molecular-weight polyester resin, which incorporates the characteristics of such a vinyl resin and a condensation resin, is disclosed in No. 114245, JP-A-58-1
No. 1955 and Japanese Patent Application Laid-Open No. 58-14147, etc., but a certain effect is recognized in the hot offset resistance, but since the resin cannot be uniformly mixed, the toner is not uniformly charged in friction. A new problem that it is easy to occur occurs.

[0005] Further, as a monomer component of the polyester resin, a resin having a crosslinked structure using a trivalent or higher alcohol and / or a trivalent or higher carboxylic acid is used as a toner resin to prevent offset. JP-A-54-86342, JP-A-56-1952, JP-A-56-21136, JP-A-56-168660, JP-A-57-37353, JP-A-58-14146,
JP-A-59-30542, JP-A-61-105561
JP-A-61-105563, JP-A-61-124
961 and JP-A-61-27569. However, even in toners using these resins, if the amount of the polyhydric alcohol or polycarboxylic acid added is 30 mol% or less, the crosslinking reaction is not sufficiently performed and the effect of preventing offset is insufficient. For example, it has an effect of preventing offset, but has a problem that unreacted alcoholic hydroxyl groups and carboxyl groups are likely to remain, and the moisture resistance of the toner is greatly reduced.

[0006]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a new toner for developing an electrostatic image, which has improved the problems of the above-mentioned known toners. Still another object of the present invention is to provide an energy-saving type electrostatic image developing toner suitable for a heat fixing method.

[0007]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned various problems, and an outline of the present invention is to provide a toner for developing an electrostatic image mainly comprising a binder resin and a colorant.
The binder resin is made of a phenolic hydroxyl group-containing polyester resin, and the epoxy compound is added to the unreacted carboxyl group and the phenolic hydroxyl group of the binder resin in an amount of 1%.
A toner for developing an electrostatic image, wherein the toner is added in an amount of from 00 to 1 mol%. Further, the polyester resin, di <br/> ol component (A), a dicarboxylic acid or a lower alkyl ester (B), and phenolic hydroxyl group-containing carboxylic acid or lower alkyl ester thereof (C), city by polycondensing the The object is achieved by providing a toner for developing an electrostatic image using the resin as a binder resin.

[0008] In the present invention, the lower alkyl is
It means an alkyl group having 1 to 6 carbon atoms. The diol component (A) constituting the phenolic hydroxyl group-containing polyester resin in the present invention includes diethanolamine, ethylene glycol, diethylene glycol, propylene glycol, isoprene glycol, octanediol, 2,2-diethyl-1,3-propanediol, Spiro glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 2-butyl-
2-ethyl-1,3-propanediol, 1,6-hexanediol, hexylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol,
Hydrobenzoin, bis (β-hydroxyethyl) terephthalate, bis (hydroxybutyl) terephthalate, polyoxyethylenated bisphenol A, polyoxypropylene-modified bisphenol A, polyoxyethylenated biphenol, polyoxypropylene-modified biphenol, and the like can be given. .

The dicarboxylic acid or its lower alkyl ester (B) includes fumaric acid, maleic acid, succinic acid, itaconic acid, mesaconic acid, citraconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid,
Cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, adipic acid, sebacic acid, dodecanediacid, naphthalenedicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, 2,3-piperazinedicarboxylic acid, iminodicarboxylic acid, imidazole-4,5 -Dicarboxylic acid, piperidine dicarboxylic acid, pyrazole dicarboxylic acid, N-methyl pyrazole dicarboxylic acid, N-phenyl pyrazole dicarboxylic acid, pyridine dicarboxylic acid, carbazole-
3,6-dicarboxylic acid, 9-methylcarbazole-3,
Examples thereof include 6-dicarboxylic acid, carbazole-3,6-dibutyric acid, carbazole-3,6-γ, γ′-diketobutyric acid and lower alkyl esters thereof.

As the phenolic hydroxyl group-containing carboxylic acid or its lower alkyl ester (C), any of monocarboxylic acid, dicarboxylic acid, tricarboxylic acid and their lower alkyl esters can be used. Examples of the phenolic hydroxyl group-containing monocarboxylic acid include o-hydroxybenzoic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, o-hydroxyphenyl acetic acid, m-hydroxyphenyl acetic acid,
p-hydroxyphenylacetic acid, o-hydroxycinnamic acid, m-hydroxycinnamic acid, p-hydroxycinnamic acid, 3,4-dihydroxycinnamic acid, procatechuic acid,
Gallic acid, phenolphthalein, 4-hydroxyanthraquinone-2-carboxylic acid, hydroxy-o-toluic acid, hydroxy-m-toluic acid, hydroxy-p-
Examples include toluic acid, hydroxy-1-naphthoic acid, hydroxy-2-naphthoic acid, p-oxymethylene acid and the like.

The phenolic hydroxyl group-containing dicarboxylic acids include 4-hydroxyisophthalic acid, 5-hydroxyisophthalic acid, 4,6-dihydroxyisophthalic acid,
5-dihydroxy-1,4-benzenediacetate, keridamic acid, bis (2-hydroxy-3-carboxyphenyl)
Examples thereof include methane, hydroxyterephthalic acid, 3-hydroxyphthalic acid, and 4-hydroxyphthalic acid. Examples of the phenolic hydroxyl group-containing tricarboxylic acid include phenol-2,4,6-tricarboxylic acid (hydroxytrimesic acid), 5-hydroxytrimellitic acid, and the like.
Among these phenolic hydroxyl group-containing carboxylic acids,
In particular, dicarboxylic acids and lower alkyl esters thereof are preferable because they satisfy properties as a resin for a toner, such as heat melting property and pulverizability. The content of the phenolic hydroxyl group-containing carboxylic acid is 1 mol% to 100 mol%, preferably 5 mol% to 50 mol% of the acid component.

Further, conventionally known polycarboxylic acids and polyols can be added as one component during the synthesis of the polyester resin. As these polycarboxylic acids,
Trimellitic acid, pyromellitic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid,
Pyridinetricarboxylic acid, pyridine-2,3,4,6-
Examples thereof include tetracarboxylic acid, 1,2,7,8-tetracarboxylic acid and acid anhydrides thereof. In addition, glycerin, trimethylolpropane, trimethylolethane, triethanolamine, pentaerythritol, sorbitol, glycerol, 1,3,
5-trihydroxymethylbenzene and the like can be mentioned.

The phenolic hydroxyl group-containing polyester resin referred to in the present invention has a glass transition temperature of 5 as measured by DSC.
It is desirable that the flow softening point measured by a flow tester is 0 ° C. or higher and 80 ° C. to 150 ° C. The main component of the binder resin constituting the present invention is a reaction product of the phenolic hydroxyl group-containing polyester resin and the epoxy compound described below, and the reaction product is an unreacted carboxyl group of the polyester resin and phenol. The epoxy compound is reacted by adding 100 to 1 mol% to the total of the hydroxyl groups. Further, as the epoxy compound used in the present invention, a compound having one or more epoxy groups in the molecule is applied, for example, phenylglycidyl ether, bisphenol A type epoxy resin, phenol novolak type epoxy resin, diglycidyl adipate,
Examples include, but are not limited to, ethylene glycol diglycidyl ether, hydroquinone diglycidyl ether, glycerin triglycidyl, tetraglycidoxytetraphenylethane, diglycidyl phthalate, pentaerythitol tetraglycidyl ether, dicyclopentadiene oxide, and the like. Not something.

The toner for developing an electrostatic image of the present invention is produced by dispersing and mixing a colorant, a charge controlling agent, and, if necessary, a magnetic powder and other binder resin in the binder resin, and pulverizing the mixture.
Colorants include carbon black, aniline blue,
Phthalocyanine blue, quinoline yellow, malachite green, lamp black, rhodamine-B, quinacridone and the like can be used, and usually 1 to 20% by weight based on the resin.
Is added. As the charge control agent, for positively charged toner, nigrosine dye, ammonium salt, pyridinium salt,
0.1 to 10% by weight of azine or the like is added to the resin.
A toner using a polyester resin generally gives a negative charge. When a charge control agent for a negative charge toner is added as necessary, a chromium complex, an iron complex, or the like is used. When the negative chargeability is too strong, it is also possible to control the neutralization by adding the positive chargeability control agent. Other resins to be blended as needed include styrene resin,
Styrene / acrylate copolymer resin, polyester resin, epoxy resin, polyethylene wax, polypropylene wax, etc. can be applied to the present invention.

[0015]

EXAMPLES Next, typical examples of synthesis of the binder resin used in the present invention and examples of toners using the same will be described, but the present invention is not limited to these examples. (Synthesis Example 1) 316 g (1 mol) of 2,2'-bis [4- (2-hydroxyethyleneoxy) phenyl] propane, 97 g (0.5 mol) of dimethyl isophthalate,
105 g of dimethyl 5-hydroxyisophthalate (0.
5 mol), 2.5 g of zinc acetate and 2.5 g of titanium tetraisopropoxide were placed in a four-necked round-bottom flask equipped with a stirrer, a condenser and a nitrogen gas inlet tube, and nitrogen gas was passed through the nitrogen gas inlet tube. Heated to 200 ° C. while introducing. After the outflow of methyl alcohol was completed, the temperature was raised to 230 ° C. over 1 hour, and the reaction was further performed for 4 hours.
The glass transition temperature of this resin measured by DSC was 63
℃, flow softening point measured by Koka type flow tester is 1
05 ° C.

(Synthesis Example 2) 2,2'-bis [4- (2-
Hydroxyethyleneoxy) phenyl] propane 18
9.6 g (0.6 mol), 10,4 g-bis (2-hydroxyethyleneoxy) phenyl 109.6 g (0.4
Mol), 155.2 g of dimethyl isophthalate (0.8
Mol), dimethyl 5-hydroxyisophthalate 42 g
(0.2 mol) was reacted in the same manner as in Synthesis Example 1. DS
The glass transition temperature of the resin measured at C was 73 ° C, and the flow softening point was 112 ° C.

(Synthesis Example 3) Resin 10 obtained in Synthesis Example 1
1.4 parts by weight of an o-cresol novolak type epoxy compound (YDCN-701 manufactured by Toto Kasei Co., Ltd.) based on 0 parts by weight (5 mol% per total of unreacted carboxyl groups and phenolic hydroxyl groups of the resin of Synthesis Example 1) Mixed)
A biaxial melt-kneading was performed at 180 ° C. for 1 hour to prepare a reaction product. The resin had a glass transition temperature of 64 ° C and a flow softening point of 111 ° C. The sum of unreacted carboxyl groups and phenolic hydroxyl groups can be calculated by the method described in "Organic Compound Confirmation Method I" by Eiichi Funakubo, Yokendo (Showa 57).
It was measured by the ts-keen titration method.

(Synthesis Example 4) To 100 parts by weight of the resin of Synthesis Example 1, 1.3 parts by weight of a bisphenol A type epoxy compound (E-850 manufactured by Dainippon Ink and Chemicals, Inc.) was used. 5 mol% based on the total amount of unreacted carboxyl groups and phenolic hydroxyl groups)
The mixture was biaxially melted and kneaded at 1 ° C. for 1 hour to prepare a reaction product. The resin has a glass transition temperature of 64 ° C. and a flow softening point of 1
16 ° C.

(Comparative Synthesis Example) A resin synthesized similarly using only 1 mol of dimethyl isophthalate without using dimethyl 5-hydroxyisophthalate of Synthesis Example 1 had a glass transition temperature of 63 ° C. and a flow softening point of 107 ° C.

Example 1 100 parts by weight of resin of Synthesis Example 1 5 parts by weight of carbon black (MA-100 manufactured by Mitsubishi Kasei Co., Ltd.) 2 parts by weight of iron complex salt dye Epoxy compound (bisphenol A type epoxy resin manufactured by Dainippon Ink and Chemicals, Inc.) E-850) 1.3 parts by weight The mixture having the above composition was melt-kneaded at about 150 ° C. using a twin-screw kneader. (The epoxy compound in this case is equivalent to 5 mol% based on the total amount of unreacted carboxyl groups and phenolic hydroxyl groups of the resin of Synthesis Example 1.) After cooling the melt-kneaded product, it is pulverized and classified. Average particle size 10μ
m of toner particles were obtained. 0.5 part by weight of hydrophobic colloidal silica was externally added to 100 parts by weight of this toner to obtain the toner of the present invention. A two-component developer was prepared by mixing 5 parts by weight of the above toner and 95 parts by weight of a ferrite carrier. After loading the developer in a commercially available copying machine and taking an image, the fixing device is composed of a fixing roller coated with a fluorine resin on the surface and a pressure roller coated on the surface with a silicone rubber. The toner image was thermally fixed at a speed of 200 m / sec. As a result, Macbeth reflection densitometer RD
The image density according to 914 was 1.5 or more, there was no background stain on the non-image area, and a good image was always maintained without offset even in continuous copying of 100,000 sheets. Further, when the solid image having an image density of 1.6 was rubbed ten times with a sand eraser, the toner remaining rate was 85%, and it was confirmed that the toner had sufficiently satisfactory fixing properties.

Example 2 100 parts by weight of the resin of Synthesis Example 2 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei) 2 parts by weight of iron ditertiary butylsalicylate Epoxy compound (bisphenol A type epoxy resin manufactured by Dainippon Ink and Chemicals, Inc.) E-850) 1.0 part by weight The mixture having the above composition was melt-kneaded in the same manner as in Example 1 to obtain the toner of the present invention. (Note that the epoxy compound in this case is equivalent to 5 mol% based on the total amount of unreacted carboxyl groups and phenolic hydroxyl groups of the resin of Synthesis Example 1.) The grindability is better than that of the resin of Example 1. Was. Subsequently, a two-component developer was prepared in the same manner as in Example 1, and imaging and heat fixing were performed. The copy was evaluated in the same manner as in Example 1. As a result, no offset occurred and the fixability was satisfactory. Also, good images were maintained in continuous copying.

Example 3 50 parts by weight of resin of Synthesis Example 3 50 parts by weight of resin of Comparative Synthesis Example 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.) 2 parts by weight of chromium complex salt dye (TRH manufactured by Hodogaya Chemical Industry Co., Ltd.) Part The mixture having the above composition was melt-kneaded in the same manner as in Example 1 to obtain the toner of the present invention. The pulverizability of the cooled melt-kneaded product was as good as in Example 2. Then, Example 1
A two-component developer was prepared in the same manner as described above, and the image was taken and fixed by heat.
The copy was operated and evaluated as in Example 1. There was no occurrence of offset, and the fixability was satisfactory. Also, good images were maintained in continuous copying.

Example 4 100 parts by weight of the resin of Synthesis Example 4 7 parts by weight of phthalocyanine blue pigment 2 parts by weight of chromium ditertiary butylsalicylate 2 parts by weight of the mixture having the above composition was subjected to hot melt kneading using a biaxial kneader in the same manner as in Example 1. The mixture was cooled, pulverized and classified to obtain the toner of the present invention. Next, the obtained toner was mixed with a ferrite carrier to prepare a two-component developer. When the copied image was evaluated by imaging and heat fixing in the same manner as in Example 1, a cyan image having no fixation and good fixability was obtained. Also, good images were maintained in continuous copying.

Comparative Example 1 Resin of Comparative Synthesis Example 100 parts by weight Carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.) 5 parts by weight Chromium complex dye (TRH manufactured by Hodogaya Chemical Industry Co., Ltd.) 2 parts by weight A two-component developer for comparison was prepared in exactly the same manner as in Example 1, and was imaged and heat-fixed. The obtained copy was evaluated in the same manner as in Example 1, and as a result, occurrence of offset was recognized.

Comparative Example 2 A two-component developer for comparison was prepared in the same manner as in Example 1 except that the epoxy compound was removed from the mixture having the composition. The obtained copy was evaluated in the same manner as in Example 1. As a result, no offset was generated when fixing was performed at a fixing roller surface temperature of 120 ° C., but an offset was generated at 170 ° C.

[0026]

According to the present invention, the binder resin comprises a specific phenolic hydroxyl group-containing polyester resin, and the epoxy compound is used in an amount of 100 to 100% based on the total amount of unreacted carboxyl groups and phenolic hydroxyl groups of the binder resin. Since 1 mol% was added, a toner having satisfactory fixability without offset was obtained.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-163348 (JP, A) JP-A-56-1952 (JP, A) JP-A-58-127938 (JP, A) JP-A-4- 85549 (JP, A) JP-A-60-263952 (JP, A) JP-A-61-264356 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/08

Claims (1)

(57) [Claims] 1. An electrostatic charge developing toner comprising a binder resin and a colorant as main components, wherein the binder resin is a diol component.
(A), dicarboxylic acid or lower alkyl ester thereof
(B), and a phenolic hydroxyl group-containing carboxylic acid or
Is a phenolic hydroxyl group-containing polyester resin obtained by polycondensation of the lower alkyl ester (C), and the epoxy compound is used for the sum of unreacted carboxyl groups and phenolic hydroxyl groups of the binder resin. A toner for electrostatic charge development, wherein 100 to 1 mol% is added.