JPH0782254B2 - Binder resin for toner - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binder resin for toners used for developing electrostatic images formed in electrophotography, electrostatic photography, electrostatic recording, etc., especially low temperature fixing. The present invention relates to a binder resin for toner, which has excellent properties and offset resistance.

[0002]

2. Description of the Related Art Generally, an electrostatic image is developed with a toner which is a colored powder to form a toner image, and the toner image is fixed as it is or after being transferred onto a transfer paper or the like.
Usually, a toner is prepared by blending a binder component, a coloring component, and a charge control agent, melting and mixing under heating, and then pulverizing to a predetermined particle size.

Various resins are known as binder components of toners, but recently, they are suitable for high-speed copying because of their large chargeability and excellent low-temperature fixability.
Moreover, a polyester resin binder is attracting attention because it does not obscure the printed surface with a plasticizer when a printed matter is laminated on a vinyl chloride sheet, film or the like (that is, it has excellent plasticizer resistance).

However, the toner using the polyester binder is considered to be advantageous in terms of low-temperature fixability as described above, but when actually examined, it faces a problem that an offset phenomenon easily occurs. The offset phenomenon is that a part of the toner is transferred to the heat roller and stains the surface of the transfer paper supplied thereafter, or the toner transferred to the pressure roller pressed against the heat roller causes the transfer paper to It is a phenomenon that the back side is stained.

Although the low temperature fixing property and the offset preventing property are originally required to contradict each other, it is necessary to prevent the occurrence of the offset phenomenon while maintaining the low temperature fixing property which is a characteristic of the toner using the polyester binder. This is a problem that must be solved before the practical use of a toner using a binder. Various proposals have been made to deal with such a problem, for example, there are the following.

(A) 1,2,4-benzenetricarboxylic acid-polymerized ester of 1,2-benzenedicarboxylic acid polymerized with cyclic 1,2 anhydride and 2,2-dimethyl-1,3-propanediol Using a compound (JP-A-56-168660), (b) (A) alkyl-substituted dicarboxylic acid and / or alkyl-substituted diol,
Non-linear acids having an acid value of 10 to 60 obtained from components containing (B) trivalent or higher polycarboxylic acids and / or trivalent or higher polyols, (C) dicarboxylic acids, (D) etherified diphenols Using a shaped low melting point polyester (JP-A-59-7960),

(C) 40 parts of an etherified diphenol which is propoxylated and / or ethoxylated and has a propoxy group of 50% or more and an aromatic carboxylic acid having a valence of 3 or more.
Amorphous polyester having an acid value of 10 to 100 obtained by reacting with phthalic acids up to mol% is used in combination with a polyvalent metal compound (JP-A-59-29256). However, it has been found that (a), (b) and (c) introduced above have the following drawbacks.

That is, since the above-mentioned binder (a) uses a polymerized esterification product of three specific kinds of compounds, only certain fixed physical properties can be obtained.
There is a constraint that various physical properties required in the market cannot be dealt with. In the toner using the binder of (b) above, by introducing the alkyl-substituted dicarboxylic acid or / and the alkyl-substituted diol which is a soft segment into the polyester skeleton, it is possible to prevent the fixing point from rising and ensure the offset property. However, there is a problem in resin production such that considerable skill is required in polyester production in order to balance both performances.

The toner using the binder of the above (c) is intended to secure high-speed fixing property and anti-offset property by using a polyvalent metal compound together, which is the limit of improvement of polyester. Since the cross-linking is performed by externally compounding the polyvalent metal compound, the performance may not be constant due to a slight difference in the kneading condition, and the combined use of the metal compound may change the charge amount of the toner in some cases. In some cases, it is advantageous to solve the above problems by improving only the polyester as the binder.

However, the drawbacks described above are solved, and (a),
In addition to the binders of (b) and (c), securing other types of binders having both low-temperature fixing property and anti-offset property can expand the range of choices and cope with toner design changes. Therefore, the inventors of the present invention have previously found that a binder resin for toner composed of a polyester resin in which a polyhydric alcohol having a valence of 3 or more and rosin or hydrogenated rosin is used as a part of the condensation component (Japanese Patent Laid-Open No. 63-127253). ) Was developed.

[0011]

However, various physical properties required for binders in the market are expanding more and more, and particularly, low temperature fixing property and offset resistance in a high temperature region are severely demanded, and the present performance of the binder is not always required. It is hard to say that we are in a satisfactory state. Therefore, the advent of a binder resin in which both the low-temperature fixing property and the offset resistance are remarkably improved is very advantageous industrially, and is strongly desired in this industry.

[0012]

However, as a result of earnest studies to solve the above problems, the present invention has revealed that a condensation component consisting of a dibasic acid component, a tribasic or higher polybasic acid component and a polyhydric alcohol component is used. A maleated rosin-modified polyhydric alcohol (ab) which is constituted and is obtained by reacting a maleated rosin compound (a) with a trihydric or higher polyhydric alcohol (b).
Conforms to such a purpose in which the binder made of the polyester resin (X) introduced as part of the condensation component is
The inventors have found that they are particularly excellent in terms of low-temperature fixability and offset resistance, and have completed the present invention.

The present invention will be described in detail below. In the present invention, a maleated rosin-modified polyhydric alcohol (a
b) is used as part of the condensation component and is incorporated into the polymer. Maleated rosin modified polyhydric alcohol (a
The b) is obtained by reacting the maleated rosin compound (a) with the polyhydric alcohol (b) having a valence of 3 or more. The compound (a) in maleated rosin is a natural rosin (which contains abietic acid as a main component, and also neoabietic acid, dihydroabietic acid, tetrahydroabietic acid, d-pimaric acid, iso-d-pimaric acid, dehydroabieticin. Substances containing acids) or their constituents, isomerized rosin,
It is obtained by adding maleic anhydride to dimerized rosin, polymerized rosin, disproportionated rosin or hydrogenated products thereof.

Examples of the polyhydric alcohol (b) having 3 or more valences include glycerin, trimethylolpropyne, 1,2,6.
Examples thereof include hexanetriol, trimethylolethane, pentaerythritol, dipentaerythritol, tripentaerythritol, and sorbitol. The reaction between the maleated rosin compound (a) and the polyhydric alcohol having 3 or more valences (b) is carried out in the presence of a catalyst and, if necessary, a solvent,
It is carried out in an inert gas atmosphere at 150 to 280 ° C. while removing the produced water. The maleated rosin-modified polyhydric alcohol (ab) constitutes a polyhydric alcohol component. However, the polyhydric alcohol component may have a residue of a carboxyl group.

The proportion of the maleated rosin-modified polyhydric alcohol (ab) in the polyhydric alcohol component is preferably in the range of 3 to 50 mol%, and when it is less than 3 mol%, the low-temperature fixing property and offset resistance are low. On the other hand, if it exceeds 50 mol%, the degree of condensation does not sufficiently increase and the offset prevention property as a binder becomes insufficient.

In the present invention, the dibasic acid component constituting the polyester resin (X) is terephthalic acid, isophthalic acid, phthalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, trimethyladipine. Acid, pimelic acid, 2,2-dimethylglutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3- Cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, 1,
4-naphthalic acid, diphenic acid, 4,4'-oxybenzoic acid, diglycolic acid, thiodipropion, 2,5-
Examples thereof include naphthalene dicarboxylic acid. These polybasic acids may be acid anhydrides, esters, chlorides and the like.

Examples of the tribasic or higher polybasic acid component include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic dianhydride, 4-methylcyclohexene-1,2,
Examples thereof include 3-tricarboxylic acid anhydride and trimesic acid.

As the polyhydric alcohol component constituting the polyester resin (X), ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1, 5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-
Decanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2-ethyl-2-butyl-1,3- Propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3-
Methyl-1,5-pentanediol, 2,2,4, trimethyl-1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2, Two
4,4-Tetramethyl-1,3-cyclobutanediol, 4,4'-thiodiphenol, 4,4'-methylenediphenol, 4,4 '-(2-norbornylidene) diphenol, 4,4'- Dihydroxybiphenol, o
-, M- and p-dihydroxybenzene, 4,4'-isopropylidenephenol, 4,4'-isopropylidenebis (2,6-dichlorophenol), 2,5-naphthalenediol and p-xylenediol, cyclopentane Examples include etherified diphenols such as -1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, and bisphenol A-alkylene oxide adducts. In some cases, a small amount of polyhydric alcohol having 3 or more valences can be used together.

The condensation reaction is usually carried out by first removing the dibasic acid, the polyhydric alcohol and the maleated rosin-modified polyhydric alcohol under an inert gas atmosphere at a temperature of 150 to 280 ° C. while removing water produced. At the stage when distilled water is no longer produced, a polybasic acid having a valence of 3 or more is charged into the system and reacted to carry out crosslinking. The use of the tribasic or higher polybasic acid improves the physical properties of the binder.

Toner is prepared by blending the polyester resin (X) and the colorant (Y) with additives such as a charge control agent, a fluidity improver, a release agent and a plasticizer, if necessary. This can be achieved by mixing and then pulverizing to a predetermined particle size. It should be noted that, within the range not impairing the gist of the present invention, other polyester resin (X) may be used in combination with other polyerter-based or non-polyerter-based toner binders.

Examples of the colorant (Y) include carbon black, nigrosine dye, aniline black, chalco oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate. , Lamp Black, Rose Bengal, etc. Among these, carbon black is particularly important. To obtain a magnetic toner, a magnetic material exhibiting magnetism or magnetizability, for example, fine powder of a metal such as iron, manganese, nickel, cobalt, or chromium, ferrite, permalloy, or the like may be added to the toner.

[0022]

[Working] The maleinized rosin-modified polyhydric alcohol (ab) introduced into the polyelter resin (X) can be fixed to the polyelter resin (X) even at a relatively low temperature but does not adhere to a heat roll. From the viewpoint of thermal characteristics, they give contradictory properties. Therefore, a toner obtained by using the polyelter resin (X) of the present invention as a main component of a binder for a toner and adding a colorant (Y) and, if necessary, a charge control agent and other components to the toner, maintains low-temperature fixability. , The effect of very effectively preventing the occurrence of the offset phenomenon.

[0023]

EXAMPLES Next, the binder for toner of the present invention will be further described with reference to examples. Below, "part" and "%" are
It is expressed on a weight basis. Example 1 <Production of Binder> [First Step Reaction (Production of Maleated Rosin-Modified Polyhydric Alcohol)] 0.45 mol of gum rosin (molecular weight = 330) and 0.2 mol of maleic anhydride were placed in a flask equipped with a packed column. , 0.35 mol of glycerin was charged and 0.0
With 1% dibutyltin oxide in a nitrogen stream 1
The reaction was carried out at 80 to 270 ° C. until no distilled water came out.

[Second step reaction] Then, the internal temperature is set to 160 ° C.
Terephthalic acid 0.5 mol, isophthalic acid 0.5
Mol, bisphenol A propionene oxide adduct 0.4 mol, ethylene glycol 0.7 mol, diethylene glycol 0.2 mol and 0.02% of dibutyltin oxide to the whole system were charged, and the temperature was raised to 180 to 270 ° C. The reaction was carried out in a nitrogen stream. When effluent was no longer produced, 0.25 mol of trimellitic anhydride was additionally charged to continue the reaction, and the reaction was terminated when the acid value reached 30 KOHmg / g. When the properties of the obtained polyelter resin are measured as shown below, the acid value is 30 KOHmg / g,
The glass transition temperature was 66 ° C., the softening point (Ts) was 80 ° C., and the flow starting point (Tfb) was 110 ° C.

[0025]

<Preparation and Evaluation of Toner> 90 parts of the polyester resin obtained above, 7.5 parts of carbon black (carbon black # 44 manufactured by Mitsubishi Kasei Kogyo Co., Ltd.), polypropylene wax (Viscole # manufactured by Sanyo Chemical Co., Ltd.) 550P) 2 parts, charge control agent (manufactured by Orient Chemical,
0.5 parts of Bontron S-34) was powder-mixed, supplied to a twin-screw kneader (PCM30 manufactured by Ikegai Iron Works Co., Ltd.), and kneaded at a temperature of 140 ° C. and a rotation speed of 100 rpm, and then passed through a cooling roll. After cooling, it was roughly crushed with a hammer mill to a particle size of 0.8 mm or less. Next, this powder was finely pulverized and classified at 200 g / hr using a supersonic jet pulverizer equipped with a classifier (LABO JET manufactured by Nippon Pneumatic Mfg. Co., Ltd.) to obtain a toner having an average particle size of 7 to 15 μm.

Measurement of charge amount 5 parts of the toner composition obtained above and 95 parts of iron powder (TEFV-200 / 300 manufactured by Nippon Iron Powder Co., Ltd.) were placed in an empty ball mill and stirred to blow-off powder charge amount. The amount of charge was measured using a measuring device (Model TB-200 manufactured by Toshiba Chemical Co., Ltd.).

Image Test 5 parts of the toner obtained above and iron powder (EF manufactured by Nippon Iron Powder Co., Ltd.)
(V-150 / 250) 95 parts by weight of the mixture, an image was produced by an electronic copying machine equipped with a selenium photosensitive drum, transferred to plain paper, and then heated at a peripheral speed of 200 mm / with a heat roll coated with a fluororesin. After fixing in sec, the temperature of the heat roll was changed and the fixability and offset property (toner adhesion state of the heat roll) of the toner on the paper were judged. Image density Image density was measured using R-D914 manufactured by Macbeth (filter wheel is black). Toner suitability evaluation results are summarized in Table 1.

[0029] Example 2 <Production of Binder> The reaction of the first step (preparation of maleated rosin-modified polyhydric alcohol)] in the packed column flask, disproportionated rosin (molecular weight = 32
0) 0.55 mol, maleic anhydride 0.2 mol, and trimethylolpropane 0.5 mol were charged, and 180% in a nitrogen stream together with 3% xylene for all systems and 0.01% dibutyltin oxide for all systems. The reaction was carried out at ˜270 ° C. until xylene and distillate did not come out.

[Second step reaction] Then, the internal temperature is set to 160 ° C.
Terephthalic acid 0.5 mol, isophthalic acid 0.5
Mol, 0.4 mol of bisphenol A propionene oxide adduct, 0.7 mol of ethylene glycol, 0.2 mol of diethylene glycol and 0.02% of dibutyltin oxide with respect to the whole system were charged, and the amount was 180 in a nitrogen stream.
The reaction was carried out by raising the temperature to ˜270 ° C. When the effluent stopped flowing, 0.25 mol of trimellitic anhydride was additionally charged to continue the reaction, and the reaction was terminated when the acid value reached 35 KOHmg / g. When the properties of the obtained polyelter resin are measured as shown below, the acid value is 28 KOHmg / g,
The glass transition temperature was 64 ° C., the softening point (Ts) was 78 ° C., and the flow starting point (Tfb) was 108 ° C. Using the binder obtained above, a toner was manufactured and evaluated in the same manner as in Example 1. The results are summarized in Table 1.

Example 3 <Production of Binder> In a flask equipped with a packed column, a maleinized rosin compound glycerin ester (Harimac R-1) was prepared.
00, manufactured by Harima Chemicals) 0.15 mol, terephthalic acid 0.5 mol, isophthalic acid 0.5 mol, bisphenol A ethylene oxide adduct 0.6 mol, ethylene glycol 0.5 mol, diethylene glycol 0.2 mol. The reaction was performed with 0.02% of dibutyltin oxide in a nitrogen stream at 180 to 270 ° C with respect to the entire charged system, and 0.25 mol of trimellitic anhydride was additionally charged when the effluent water stopped flowing. And acid value is 30KO
The reaction was terminated when the concentration reached Hmg / g. The properties of the obtained polyelter resin are measured as shown below, the acid value is 30 KOHmg / g, the glass transition temperature is 68 ° C, the softening point (Ts) is 83 ° C, and the flow starting point (Tfb) is 115 ° C.
Met. Using the resin, a toner was produced and evaluated in the same manner as in Example 1. The results are summarized in Table 1.

Comparative Example 1 Maleic rosin resin (Harimac T-80, manufactured by Harima Kasei Co.) 0.15 mol, terephthalic acid 0.5 mol, isophthalic acid 0.5 mol, bisphenol A propylene oxide adduct 0.4 mol , Ethylene glycol 0.7 mol, diethylene glycol 0.2 mol and 0.02% of dibutyltin oxide with respect to the whole system were charged, and 180
The temperature was raised to ˜270 ° C. and the reaction was carried out in a nitrogen stream. Before the effluent water stopped flowing out, the viscosity increased violently and the reaction could not be continued.

Comparative Example 2 <Manufacture of Binder> Maleic rosin compound glycerin ester in Example 3 was omitted and the acid value was 3
2 KOHmg / g, glass transition temperature was 62 ° C., softening point (Ts) was 79 ° C., and flow starting point (Tfb) was 108 ° C. Using the resin, a toner was manufactured and evaluated in the same manner as in Example 1. The results are summarized in Table 1.

[0034]

[Table 1]

[0035]

The toner using the binder of the present invention is
Not only does it have excellent low-temperature fixability, it also has offset resistance and good storage stability. As described above, the present invention provides a binder of a different type from the conventional one, which is extremely excellent in low temperature fixing property and offset resistance.
Since the selection options are expanded to that extent, various physical properties required in the market can be dealt with and meet the demands of this industry.

Claims (2)

[Claims] 1. A maleated rosin compound (a) and a polyhydric alcohol (b) having a valence of 3 or more, which comprises a condensation component composed of a dibasic acid component, a tribasic or higher polybasic acid component and a polyhydric alcohol component. Binder resin for toner comprising, as a main component, a polyester in which a maleated rosin-modified polyhydric alcohol (ab) obtained by reacting with is introduced as a part of the condensation component. 2. The proportion of maleated rosin-modified polyhydric alcohol (ab) in the polyhydric alcohol component is 3 to 50.
The binder resin for toner according to claim 1, wherein the binder resin is mol%.