JPH10333357A - Resin composition for toner and toner for electrostatic charge development using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a toner for electrostatic charge development excellent in low-temp. fixability without deteriorating shelf stability and having satisfactory developing performance and transferability by using a resin compsn. having a specified structure. SOLUTION: This resin compsn. has a structure represented by the formula and a number average mol.wt. of 2,000-50,000. In the formula, R is H, the residue of benzoic acid or the residue of <=4C fatty acid, R<1> is the residue of >=11C fatty acid, (k) is 0-0.60, m>0, n>0, 0.20<=n/(m+n)<=0.85, k+m+n=1.0 and (x) shows the average degree of polymn. The objective toner is composed essentially of the resin compsn. and a colorant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for a toner used in an electrophotographic method, an electrostatic recording method, an electrostatic printing method and the like, and a toner for developing an electrostatic charge using the same.

[0002]

2. Description of the Related Art In an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or the like, an electrostatic image formed on a support (recording layer) is composed of toner particles containing a binder resin and a colorant as main components. Is visualized by This visible image is fixed on the support as it is, or is fixed after being transferred to an adherend such as paper. For this reason, the toner for electrostatic charge development is required to have not only developability but also good transferability and fixability. In recent years, copiers and printers using the electrophotographic method have become widespread, and are also spreading to ordinary households. In addition, multi-functionalization is progressing, and accordingly, there is an increasing demand for low-energy fixing for the purpose of reducing power consumption and simplifying a fixing mechanism. In recent copiers and printers, a contact heating system such as a hot roll has been widely adopted. This method has the advantages that the thermal efficiency is higher than before, the power of the fixing unit can be reduced and the size can be reduced. As a binder resin of the toner used in this method, a vinyl resin having a wide molecular weight distribution and a cross-linked structure using a trivalent or higher alcohol or acid component as a part of the monomer in order to prevent an offset phenomenon. Polyester resins and the like are known. A colorant, a release agent, a charge control agent, and the like are added to these binder resins to form an electrophotographic toner. In general, these resins having satisfactory storage stability have a melting start temperature of 120 ° C. or higher in a Koka type flow tester, which is far from the requirement for low energy fixing.

[0003] In addition to the binder resin, a graft resin,
Block copolymer resins have been proposed. For example, JP-A-54-63831 discloses a developer containing a grafted product of oxidized starch, and JP-A-56-15740 discloses a developer containing 100 parts by weight of a total of vinyl acetate monomer in the presence of crystalline polyethylene and polypropylene. Containing a resin obtained by grafting or block copolymerizing 1 to 30 parts by weight of a vinyl compound, disclosed in JP-A-63-27855 and JP-A-64-3545.
6 and JP-A-2-93658, a toner containing a resin obtained by grafting or block copolymerizing a crystalline polyester resin with an ionically crosslinked amorphous vinyl polymer having Mw / Mn of 3.5 or more. JP-A-2-10
8067 discloses an electrophotographic developer containing a graft copolymer using a fluorine-containing monomer, and JP-A-3-122660 discloses an α, β-unsaturated ethylene-based polymer comprising an aromatic vinyl monomer, an unsaturated fatty acid or an unsaturated fatty acid. Heat fixing toner comprising a polyolefin graft-modified with a fatty acid ester. JP-A-3-9370 discloses a toner obtained by grafting a crystalline polyester resin and an amorphous vinyl polymer having Mw / Mn of 3.5 or more by a mechanochemical reaction. Resin, JP-A-4-274247 has a number average molecular weight of 150.
A heat-fixing toner comprising a low-molecular-weight polypropylene and a styrene derivative or an unsaturated fatty acid having a Mw / Mn of 4.0 or less and a Mw / Mn of 4.0 or less has been proposed. A resin was used in combination, and a single graft resin was not used as a binder resin. Further, even with these resins, it was not possible to sufficiently satisfy the demand for reduction of power consumption and low energy fixing.

[0004] To reduce the fixing temperature, attempts have been made to lower the glass transition temperature of the binder resin. However, this method could not lower the fixing temperature while satisfying the storage stability of the toner. For this reason, techniques such as surface modification by covering the surface of the toner particles with inorganic fine particles, and encapsulation covering the surface with a polymerizable substance having a high glass transition temperature have been studied. Also, by using a low molecular weight crystalline material such as carnauba wax, Fischer-Tropsch wax, synthetic ester wax, montan wax, etc., it was possible to fix the toner at a slightly low temperature, but the fluidity of the toner decreased. Due to problems, the amount added was limited and the low-temperature fixability was not yet sufficient. Further, low-temperature fixing of the resin composition for toner has been studied by a method of grafting an unsaturated compound to a polyolefin, but with a side reaction of breaking the main chain by a starting radical and a growing radical generated during the reaction,
There was also a problem that the desired grafting did not proceed sufficiently and a resin having a high grafting ratio could not be easily obtained.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a resin composition for a toner which is easy to produce without side reactions, has good low-temperature fixability, developability and transferability, and an electrostatic charge. An object of the present invention is to provide a developing toner.

[0006]

SUMMARY OF THE INVENTION A first aspect of the present invention is as follows.
A toner resin composition having a structure represented by the following formula (1) and having a number average molecular weight (hereinafter abbreviated as Mn) of 2,000 to 50,000.

Embedded image (Wherein, R represents hydrogen, a benzoic acid residue or a fatty acid residue having 4 or less carbon atoms, and R ¹ represents a fatty acid residue having 11 or more carbon atoms. K is in the range of 0 to 0.60; m and n are both greater than 0, and the value of n / (m + n) is 0.20
In the range of 0.85, k + m + n = 1.0. Also,
x represents an average degree of polymerization. The second aspect of the present invention is characterized by comprising at least a resin composition having a structure represented by the above formula (1) and having Mn of 2,000 to 50,000 and a colorant. This is a toner for charge development.

Hereinafter, the present invention will be described in detail. The resin composition for a toner of the present invention may be synthesized by condensing a polymer of the formula (2) shown below and a fatty acid of the formula (3),
The side chain component OCOR ¹ may be introduced into the radical polymerizable monomer to perform radical polymerization, and the synthesis may be performed. However, the above condensation method is preferable because side reactions are easily suppressed. The resin composition for a toner of the present invention has a structure represented by the formula (1), and Mn is 2,0.
00 to 50,000 is required. If Mn is less than 2,000, there is a problem in storage characteristics, and if it exceeds 50,000, the melt viscosity increases, and thus there is a problem that the resin composition is difficult to be uniform. In the resin composition for a toner according to the present invention, the copolymerization ratio of the ethylene portion which is the main chain portion, that is, k in the formula (1) needs to be 0 to 0.60. If the ethylene part copolymerization ratio exceeds 0.60, the differential scanning calorimeter (hereinafter, referred to as
Abbreviated as DSC. ) Sharply decreases the endothermic peak temperature.
Further, for the copolymerization ratio m and n of the vinyl alcohol portion, the value of n / (m + n) indicates the grafting ratio,
0 to 0.85 is required. Further, a preferable value of the grafting ratio is 0.30 to 0.85, more preferably 0.4 to 0.85.
0 to 0.85. When the value of n / (m + n) is less than 0.20, the difference between the melting start temperature of the resin and the endothermic peak temperature is large. If it exceeds 0.85, the crystallinity due to intermolecular hydrogen bonding of the main chain portion of the resin composition becomes high, so that the melting temperature and the thermal decomposition temperature of the resin become close to each other, and it becomes difficult to produce the resin composition for toner.

[0008] The side chain portion O of the resin composition for toner of the present invention
COR ¹ (R ¹ represents a fatty acid residue having 11 or more carbon atoms.)
Is a residue where the fatty acid represented by the formula (3) is condensed, and is specifically shown below. R ¹ —COOH (3) (wherein, R ¹ represents a fatty acid residue having 11 or more carbon atoms.) Further, the resin composition of the present invention has an endothermic peak temperature and a Koka type flow tester in a differential scanning calorimeter. Is preferably 50 ° C. or less, more preferably 40 ° C. or less, and still more preferably 35 ° C. or less.
It is below ° C. If the temperature difference is larger than 50 ° C., the low-temperature fixability deteriorates. Further, it is preferable that the resin composition of the present invention is used in an electrostatic charge developing device in which a fixing method is composed of a hot roll, a hot belt, a hot plate and a combination thereof.

The resin composition for a toner of the present invention has the formula (2)
And a fatty acid represented by the formula (3) by a condensation reaction. The main chain portion of the resin composition for a toner of the present invention, that is, the polymer represented by the formula (2) comprises partially saponified polyvinyl alcohol, polyethylene vinyl alcohol and a precursor thereof. In this case, the partially saponified polyvinyl alcohol, polyethylene vinyl alcohol and the precursor thereof have Mn of 2,000 or more and 50,000 or less,
Has a glass transition temperature (hereinafter abbreviated as Tg) of 40.
What is -70 degreeC is preferable. If the Tg is lower than 40 ° C., the selection range of the fatty acid represented by the formula (3) is limited in order to satisfy the storage stability of the toner. The precursor may have a benzoic acid residue or a fatty acid residue having 4 or less carbon atoms as a substituent. The polymerization degree x of the polymer is 200 to 1,000, and the partially saponified polyvinyl alcohol preferably has a saponification degree of 80 mol% or less, more preferably 70 mol% or less. When the degree of saponification of the partially saponified polyvinyl alcohol exceeds 80 mol%, the value of the melting temperature and the value of the thermal decomposition start temperature of the partially saponified polyvinyl alcohol are close to each other, so that the resin composition tends to be non-uniform.

The main chain portion of the polymer may be composed of only partially saponified polyvinyl alcohol, in which case n = 0. The polymer is commercially available, and a commercially available polymer can also be used. The partially saponified polyvinyl alcohol is specifically manufactured by Nippon Gohsei Chemical Co., Ltd .: Gosefimer NK-0.
5. In addition to Gosefimer KP-08, etc., polyethylene vinyl alcohol is available from Nippon Synthetic Chemical Co., Ltd. from Denki Kagaku Kogyo Co., Ltd., Shin-Etsu Chemical Co., Ltd., Unitika Chemical Co., Ltd. and Kuraray Co., Ltd .:
In addition to Soarnol E3803, those commercially available from Kuraray Co., Ltd. and having the above-mentioned properties can be used.

The fatty acids represented by the formula (3) used in the present invention include saturated and unsaturated fatty acids having 12 or more carbon atoms, and specifically, lauric acid, myristic acid, myristoleic acid, palmitic acid. , Palmitoleic acid, oleic acid, linoleic acid, linolenic acid (including α- and γ-), ricinoleic acid, stearic acid, 12-hydroxystearic acid, arachidic acid, behenic acid, erucic acid,
Esterified products such as tallow fatty acid, tallow hardened fatty acid, palm oil fatty acid, palm oil hardened fatty acid, sugar fatty acid, vegetable oil fatty acid, fish oil hardened fatty acid, soy hardened fatty acid, montanic acid derived from coal, etc. which are natural mixtures thereof such as lignoceric acid. And derivatives and the like, which can be used alone or in combination depending on physical properties. In addition, long-chain synthetic fatty acids are also commercially available from Petrolite under the trade name: UNISID up to a molecular weight of about 800 and can be used. When an unsaturated fatty acid among the fatty acids represented by the formula (3) is condensed and grafted, side reactions such as an oxidation reaction and a cross-linking reaction may occur. A side reaction can be prevented by adding a radical reaction inhibitor, an antioxidant, or the like, if necessary, but it is premised that the additive does not hinder the condensation reaction.

As the fatty acid represented by the formula (3), the above-mentioned saturated and unsaturated fatty acids can be used, and those having a melting point of 65 to 120 ° C. in DSC are preferable. The resin composition for a toner of the present invention can be produced by any of a melting method and a solution method,
By subjecting the polymer represented by the formula (2) and the fatty acid represented by the formula (3) to a condensation reaction at 150 to 290 ° C. under a nitrogen atmosphere, a resin composition represented by the formula (1) is obtained. The residue obtained by the condensation reaction of the fatty acid represented by the above formula (3) is represented by OCOR ¹ (R ¹ is a fatty acid residue having 11 or more carbon atoms) as a side chain component.

In the production of the resin composition for a toner of the present invention,
A catalyst used for esterification and transesterification can be used. For example, when the reactive group of the polymer represented by the formula (2) is a hydroxyl group, that is, when R is hydrogen,
Known esterification catalysts, specifically, lithium acetate, sodium acetate, magnesium acetate, potassium acetate, calcium acetate, nickel acetate, cobalt acetate, barium acetate, manganese acetate, and hydrates thereof are preferably used. Further, when the reactive group is a lower ester represented by an acetate ester, that is, when R is a fatty acid residue having 1 to 4 carbon atoms or a benzoic acid residue, a known ester exchange reaction catalyst, specifically, Organic tin compounds such as dibutyltin oxide, organic titanium compounds such as titanium tetrapropoxide, zinc acetate and hydrates thereof are preferably used. Among the above catalysts, alkali metal acetates, alkaline earth metal acetates, and transition metal acetates are preferable because of their high reactivity, and more preferable catalysts are sodium acetate, potassium acetate, calcium acetate, magnesium acetate, barium acetate, and acetic acid. Zinc, nickel acetate,
Manganese acetate, cobalt acetate and their hydrates are used.

The electrostatic charge developing toner of the present invention is a particle comprising at least the above-described resin composition for a toner and a colorant, and further containing, if necessary, an additive which is added if necessary. The average particle size is in the range from 5 to 20 μm. An external additive composed of fine particles such as silica may be mixed with the particles obtained in this manner to form a toner for electrostatic charge development. Examples of the coloring agent include carbon black, aniline blue, calco oil blue, chrome yellow, ultramarine blue, Dupont oil red,
Examples include quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate lamp black, rhodamine-B, quinacridone, rose bengal, and mixtures thereof. These colorants need to be contained in a sufficient ratio to form a visible image having a sufficient concentration, and usually 1 to 100 parts by weight of a binder resin composed of a resin composition for a toner. The ratio is about 20 parts by weight.

[0015] Other optional additives include a release agent, a charge controlling agent, a magnetic agent, an external additive and the like.
Examples of the release agent include natural waxes such as carnauba wax, candelilla wax and montan wax, synthetic hydrocarbon waxes such as low molecular weight polypropylene, low molecular weight polyethylene, and Fischer-Tropsch wax, and synthetic ester waxes. Nigrosine dye, quaternary ammonium salt, triphenylmethane,
Resin, pyridinium salt, positive charge control agent such as azine,
There are chromium-based or iron-based metal complex salts and resin-based negative charge control agents. Usually 0.01 to 100 parts by weight of binder resin
Used are up to 10 parts by weight. Examples of the magnetic agent include iron oxide, ferrite, magnetite, and other ferromagnetic substances such as cobalt and nickel, and alloys that exhibit ferromagnetism by heat treatment, such as Heusler alloy. Magnetic powder having an average particle diameter of 1 μm or less is preferably used. You. The magnetic powder imparts magnetism to the toner to form a magnetic toner, and also has a coloring action and a polishing action, and is used as needed. The amount of magnetic powder used varies greatly depending on the development system, but usually 0.01 to 9
0% by weight is used. As the external additive, there are inorganic fine particles such as silica, titanium oxide, and alumina, resin fine particles, and magnetic powder, and fine particles having an average particle size of 1 μm or less, and magnetic powder are preferably used. The inorganic fine particles have an average particle size of 0.1 μm or less. Are more preferred. As the inorganic fine particles such as silica, alumina and titanium oxide, those whose surfaces have been subjected to a hydrophobic treatment are more preferably used. Generally, these external additives are used with an expectation of an improvement in fluidity and storage stability and a polishing action, and the amount of these additives is 0.01 to 100 parts by weight of the toner.
３3 parts by weight.

The toner for electrostatic charge development according to the present invention is mixed with a carrier composed of resin particles containing iron powder, ferrite, granulated magnetite, magnetic powder, or the like to form a two-component developer or a one-component developer not mixed with the carrier. Used as an agent. The carrier generally has an average particle size of 30 to 200 μm, and the carrier surface may be coated with an acrylic resin, a silicone resin, a fluororesin, or the like.
The carrier subjected to the coating treatment is preferably used because the spent resistance is improved.

The resin composition for toner and the toner for electrostatic charge development of the present invention are preferably used in a heat fixing system comprising at least a hot roll, a hot belt or a hot plate. The heat roll, the heat belt and the heat plate in contact with the toner of the fixing device are preferably those whose surfaces are treated with a resin having releasability such as a silicone resin or a fluororesin. Further, a small amount of a release agent such as silicone oil may be adhered to the surface of the fixing device in contact with the toner.

The endothermic onset temperature, endothermic peak temperature and Tg in the present invention are DSC: DSC manufactured by Seiko Denshi Kogyo KK
Using -120, heating and quenching at 10 ° C./min were repeated twice, and the temperature was obtained from an endothermic curve at the time of the second heating. Tg is a midpoint value, which is the midpoint between the endothermic start temperature and the endothermic peak temperature. The melting start temperature and the flow softening point were measured by using a high rise type flow tester: CFT-500 manufactured by Shimadzu Corporation. The point was taken as the flow softening temperature. Measurement conditions; plunger: 1 cm ² die Diameter × length: 1 × 1 mm Load: 20 kgf Preheating temperature, time: 50-80 ° C., 300 seconds Heating rate: 6 ° C./min The molecular weight is measured by the osmotic pressure method. And polystyrene was used as a standard.

Hereinafter, the present invention will be described in more detail with reference to examples.

【Example】

Synthesis Example 1 [Synthesis example using partially saponified polyvinyl alcohol and stearic acid (graft rate: 60 mol%)] In a 500 ml round bottom separable flask, 56.66 g of partially saponified polyvinyl alcohol (trade name, manufactured by Nippon Synthetic Chemical Company; Gosefimer NK-05: 500 degrees of polymerization, 70 mol% of saponification, 61.degree. C. of Tg, 227.59 g of stearic acid (endothermic peak temperature of 65.degree. C.), 2.20 g of zinc acetate hydrate, and under a nitrogen gas atmosphere At 150 ° C. to melt the contents. Next, the temperature was raised to 20 ° C., the temperature was maintained for 1 hour, and the condensation reaction was repeated. After the reaction was performed at 270 ° C. until a predetermined amount of by-product water and acetic acid were not generated, the reaction vessel was allowed to cool to 220 ° C., The melt was removed. The endothermic onset temperature of the obtained resin composition for toner of the present invention is 37.6 ° C., the endothermic peak temperature is 41.8 ° C., the melting onset temperature is 59.7 ° C., the flow softening point is 70.8 ° C., and the melting onset is started. The difference between the temperature and the endothermic peak temperature was 17.9 ° C.
Was 32,500 and the grafting ratio was 60 mol%.

Synthesis Example 2 [Synthesis example using polyethylene vinyl alcohol and behenic acid (graft rate: 40 mol%)] Instead of the partially saponified polyvinyl alcohol used in Synthesis Example 1, polyethylene vinyl alcohol (manufactured by Nippon Synthetic Chemical Co., Ltd.) Name: Soarnol E3803, Tg 58 ° C)
18. The present invention was carried out in the same manner as in Example 1 except that 18.98 g, 42.35 g of behenic acid (endothermic peak temperature 77 ° C.) was used instead of stearic acid, and 0.80 g of calcium acetate was used instead of zinc acetate hydrate. A resin composition for a toner was obtained.
The endothermic start temperature of the obtained resin composition is 53.2 ° C, the endothermic peak temperature is 60.2 ° C, the melting start temperature is 71.4 ° C,
The flow softening point was 89.2 ° C, the difference between the melting onset temperature and the endothermic peak temperature was 11.2 ° C, Mn was 34,300, and the grafting ratio was 40 mol%.

Synthesis Example 3 [Synthesis example using polyethylene vinyl alcohol and stearic acid (graft rate: 80 mol%)] Instead of the partially saponified polyvinyl alcohol used in Synthesis Example 1, polyethylene vinyl alcohol (a product of Nippon Synthetic Chemical Company) Name; Soarnol E3803) 37.97
g, 227.59 g of stearic acid was added to 2.80 g of sodium acetate hydrate in place of zinc acetate hydrate, and
A toner resin composition of the present invention was obtained in the same manner as in Example 1 except that the amount was changed to 1.10 g. The endothermic onset temperature of the obtained resin composition is 39.2 ° C, the endothermic peak temperature is 43.5 ° C,
Melting start temperature is 44.5 ° C., and flow softening point is 59.7.
° C, the difference between the melting onset temperature and the endothermic peak temperature is 1.0 ° C,
Mn was 47,800 and the grafting ratio was 80 mol%.

Synthesis Example 4 [Synthesis Example Using Partially Saponified Polyvinyl Alcohol and Stearic Acid (Graft Ratio 80
Mol%)] partially saponified polyvinyl alcohol used in Synthesis Example 1: partially saponified polyvinyl alcohol (trade name, manufactured by Nippon Synthetic Chemical Company;
GOHSEFIMER NK-08: Degree of polymerization 800, Tg60
C.) The toner resin composition of the present invention was obtained in the same manner as in Example 1 except that the amount was changed to 56.66 g. The endothermic onset temperature of the obtained resin composition is 46.6 ° C., and the endothermic peak temperature is 4
7.3 ° C, melting start temperature 64.5 ° C, flow softening point 78.3 ° C, difference between melting start temperature and endothermic peak temperature is 1
7.2 ° C., Mn was 45,600, and the grafting ratio was 80 mol%.

Synthesis Example 5 [Synthesis example using polyethylene vinyl alcohol and behenic acid (graft rate: 80 mol%)] Instead of the partially saponified polyvinyl alcohol used in Synthesis Example 1, polyethylene vinyl alcohol (a product of Nippon Synthetic Chemical Company) Name; Soarnol E3803) 18.98
g, behenic acid 81.42 g instead of stearic acid,
A resin composition for toner of the present invention was obtained in the same manner as in Synthesis Example 1, except that 1.62 g of calcium acetate was used instead of hydrated zinc acetate. The endothermic start temperature of the obtained resin composition is 53.7 ° C, the endothermic peak temperature is 58.6 ° C, the melting start temperature is 58.6 ° C, the flow softening point is 74.0 ° C, the melting start temperature and the endothermic peak temperature. Is 0 ° C., and Mn is 4780.
0, the grafting ratio was 80 mol%.

Synthesis Example 6 [Synthesis example using polyethylene vinyl alcohol and behenic acid (graft rate: 60 mol%)] Instead of the partially saponified polyvinyl alcohol used in Synthesis Example 1, polyethylene vinyl alcohol (a product of Nippon Synthetic Chemical Company) Name; Soarnol E3803) 18.98
g, behenic acid 63.34 g instead of stearic acid,
A resin composition for toner of the present invention was obtained in the same manner as in Synthesis Example 1 except that 1.26 g of calcium acetate was used instead of hydrated zinc acetate. The endothermic start temperature of the obtained resin composition is 53.1 ° C, the endothermic peak temperature is 60.6 ° C, the melting start temperature is 63.0 ° C, the flow softening point is 79.44 ° C, the melting start temperature and the endothermic peak temperature. Is 2.4 ° C., and Mn is 44.
200, and the grafting ratio was 60 mol%.

Using the toner resin compositions obtained in Synthesis Examples 1 to 6, a toner for electrostatic charge development of the present invention was prepared according to the following composition and procedure. Example 1 (The product name is Bontron N04, manufactured by Orient Chemical Co., Ltd.) The above formulation was mixed with a Henschel mixer (manufactured by Mitsui Miike Industries Co., Ltd.). The mixture was melt-kneaded at a set temperature of 100 ° C. using a twin-screw kneader, and then jet-pulverized and air-flow classified to obtain toner particles having an average particle size of 8.5 μm. The toner particles 100
0.3 parts by weight of hydrophobic silica (trade name: Cabosil TS-530 manufactured by Cabot Corporation) was mixed with the parts by weight with a Henschel mixer to obtain the toner for electrostatic charge development of the present invention. Examples 2 to 6 In the same manner as in Example 1 except that the resin composition obtained in Synthesis Examples 2 to 6 was used instead of the resin composition for toner obtained in Synthesis Example 1, Examples 2 to 6 were used. Was obtained.

Comparative Example 1 A commercially available non-crosslinked polyester resin (trade name D manufactured by Nippon Carbide Industry Co., Ltd.) was used in place of the resin composition for toner of Synthesis Example 1.
Comparative Example 1 was used in the same manner as in Example 1 except that -001) was used.

Comparative Example 2 A styrene / acrylate resin (styrene / butyl acrylate, copolymerization ratio = 65/35, Mw 250,000, Mn 800) was used in place of the toner resin composition of Synthesis Example 1.
A comparative electrostatic charge developing toner was obtained in the same manner as in Example 1 except that 0) was used. Further, 5 parts by weight of the toners obtained in Examples 1 to 6 and Comparative Examples 1 and 2 and 95 parts by weight of a ferrite carrier (FL-1020 manufactured by Powder Tech) were mixed to obtain a two-component developer.

The thermal characteristics of the toners for developing electrostatic charge obtained in Examples 1 to 6 and Comparative Examples 1 and 2 were measured with a DSC and a Koka type flow tester, and the results are shown in Table 1.

[Table 1]

(Evaluation of Low-Temperature Fixing Ability) The above two-component developer was A4 coated with a commercial copying machine (trade name: ED-1210, manufactured by Toshiba Corporation).
A plurality of unfixed images were prepared on transfer paper. Next, using a heat roll type (upper and lower silicone resin roller, silicone oil coating type) fixing device of a Canon CLC-200 copier, using an external fixing device modified so that the roller temperature and paper feeding speed can be freely set. Paper feed speed 2
The unfixed image was fixed at each temperature by setting the roller temperature at 00 mm / sec and changing the roller temperature stepwise.
The image density of the formed fixed image was measured with a reflection densitometer RD-914 manufactured by Macbeth. Thereafter, the fixed image was rubbed with an eraser (load: 1 kg, 3 reciprocations), the image density after rubbing was measured, and the fixing strength was calculated by the following equation to be used as an index of low energy fixing. The obtained fixing strength is shown in Table 2. Fixing strength (%) = (image density after rubbing / image density before rubbing) × 100

(Evaluation of Storage Stability) 20 g of the toners of Examples 1 to 6 and Comparative Examples 1 and 2 were put in a polyethylene bottle.
Stored at 45 ° C. for 7 days. After allowing to cool, it was taken out of the bottle and visually observed for the degree of aggregation. The lump was loosely touched with a finger and loosened to the extent that there was no problem in practical use.

[0031]

[Table 2]

Embodiment 7 A magnetic electrostatic charge developing toner was obtained in the same manner as in Example 1 except that the average particle diameter was changed to 7.5 μm by changing the above formulation. The toner was imaged with a heat belt fixing type Hewlett-Packard LaserJet IVL. It was confirmed that 1000 images were continuously taken in a room and a good image was obtained, and that both the developability and the transferability were good.

[0033]

According to the present invention, by using the resin composition represented by the formula (1) as a toner for electrostatic charge development, excellent low-temperature fixability without deteriorating storage stability and excellent developability and transferability are obtained. The present invention can provide a simple electrostatic charge developing toner.

Claims (8)

[Claims] 1. A resin composition for toner having a structure represented by the following formula (1) and having a number average molecular weight of 2,000 to 50,000. Embedded image (Wherein, R represents hydrogen, a benzoic acid residue or a fatty acid residue having 4 or less carbon atoms, and R ¹ represents a fatty acid residue having 11 or more carbon atoms. K is in the range of 0 to 0.60; m and n are both greater than 0, and the value of n / (m + n) is 0.20
In the range of 0.85, k + m + n = 1.0. Also,
x represents an average degree of polymerization. ) 2. An electrostatic charge developing device comprising at least a resin composition having a structure represented by the above formula (1) and having a number average molecular weight of 2,000 to 50,000 and a colorant. toner. 3. A polymer represented by the following formula (2) having a glass transition temperature of 40 to 70 ° C. as measured by a differential scanning calorimeter, and an endothermic peak temperature represented by the following formula (3) and measured by a differential scanning calorimeter: The resin composition for toner according to claim 1, wherein the fatty acid having a temperature of 65 to 120C is formed by a condensation reaction. Embedded image (Where k, m, n, x and R are as defined above). R ¹ —COOH (3) (wherein, R ¹ is as defined above). 4. A toner for electrostatic charge development comprising at least the resin composition according to claim 3 and a colorant. 5. The resin composition for a toner according to claim 1, wherein a temperature difference between an endothermic peak temperature in a differential scanning calorimeter and a melting start temperature in a Koka type flow tester is 50 ° C. or less. 6. The electrostatic charge developing toner according to claim 2, wherein the temperature difference between the endothermic peak temperature in the differential scanning calorimeter and the melting start temperature in the Koka type flow tester is 50 ° C. or less. 7. The resin composition for a toner according to claim 1, wherein the resin composition is used in a heat fixing system comprising at least a heat roll, a heat belt or a hot plate. 8. The electrostatic charge developing toner according to claim 2, wherein the toner is used in a heat fixing system comprising at least a heat roll, a heat belt or a heat plate.