JPH0497163A - Resin composition for toner and toner - Google Patents

Abstract

PURPOSE:To improve low-temp. fixability and blocking resistance by incorporating a specific vinyl polymer, aliphat. alcohol and polyolefin wax as essential components into the above toner. CONSTITUTION:This toner is formed by incorporating 100pts.wt. vinyl polymer having 2 to 400,000wt. average mol. wt. and >=60 deg.C glass transition point, 1 to 40pts.wt. aliphat. alcohol essentially contg. at least 90wt.% 15 to 90C aliphat. alcohol having <=90 deg.C m. p. and 1 to 20pts.wt. polyolefin wax having <=10 penetration number at 25 deg.C into the toner. The low-temp. fixability, offset resistance and blocking resistance are improved in this way and further the staining of a photosensitive drum is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a resin composition for a toner used for developing electrostatic images in electrophotography and the like, and a toner using this resin composition.

(Prior art) As a method for developing electrostatic images in electrophotography,
Dry development method is often used. In this dry development method, a triboelectrically charged fine powder developer is used, which is a mixture of fine powder called toner, which is a resin containing a colorant such as carbon black dispersed therein, and a carrier such as iron powder or glass beads.

Normally, toner charged by friction adheres to an electrostatic latent image on a photoreceptor due to electrical attraction, forming a toner image.
This toner image is then transferred onto a sheet of paper and fixed by a heat-pressure fixing roller that has releasability to the toner to form a permanent visible image.

In this type of heat-pressure fixing heating roller fixed fixing method, in order to reduce power consumption and increase copying speed, the toner used has low-temperature fixability (the toner sticks to the paper at low temperatures) and offset resistance. The main requirements are performance such as (preventing toner from adhering to the heat-pressure fixing roller and transferring to the paper) and blocking resistance (preventing toner particles from agglomerating).

As this type of toner, a toner in which a binder resin contains an alcohol that is solid at room temperature has been proposed (see, for example, Japanese Patent Laid-Open No. 113558/1983). Furthermore, toners containing low molecular weight polypropylene in the binder resin have also been proposed (for example, Japanese Patent Publication No. 52-3304
(see publication).

(Problem B to be Solved by the Invention) However, with the conventional toner described above, it is difficult for bacteria to satisfy all of the above three main performances in a well-balanced manner. For example, the former toner does not particularly have sufficient offset resistance. Furthermore, the latter toner does not particularly have sufficient low-temperature fixability. Furthermore, problems may arise in anti-blocking properties of any toner.

The present invention solves the above problems, and its purpose is to provide a toner resin composition and toner that are excellent in low-temperature fixing properties, anti-offset properties, and anti-blocking properties. .

(Means for Solving the Problems) The resin composition for toner of the present invention has a weight average molecular weight of 2 to 4.
00,000, vinyl polymer with a glass transition point of 60°C or higher 100
parts by weight, 1 to 40 parts by weight of an aliphatic alcohol containing at least 90% by weight of an aliphatic alcohol having 15 to 90 carbon atoms and a melting point of 90°C or less, and 1 part of a polyolefin wax having a penetration depth of 10 or less at 25°C. ~20 parts by weight as a main component.

Further, the toner of the present invention is characterized in that it contains the above resin composition for toner.

Vinyl polymers used in the present invention include copolymers of styrene monomers and (meth)acrylic acid ester monomers, homopolymers of styrene monomers, and homopolymers of (meth)acrylic acid ester monomers. is preferred.

Styrene monomers include styrene, 0-methylstyrene, m-methylstyrene, P-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, Examples include p-n-hexylstyrene, p-n-octylstyrene, p-n-dodecylstyrene, P-methoxystyrene, P-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, and the like. Among these, styrene is preferred.

Examples of (meth)acrylic acid ester monomers include methyl (meth)acrylate, ethyl (meth)acrylate, (
Propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-octyl (meth)acrylate, dodecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylate Examples include lauryl acrylate, stearyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and methyl α-chloroacrylate.

Among these, methyl (meth)acrylate, (meth)
n-butyl acrylate, propyl (meth)acrylate,
2-ethylhexyl (meth)acrylate is preferred.

In addition, such vinyl thread picks include (meth)acrylic acid, α-ethyl acrylic acid, crotonic acid, isocrotonic acid, β-methylcrotonic acid, fumaric acid, maleic acid,
Itaconic acid; succinic acid mono(meth)acryloyloxyethyl ester, succinic acid mono(meth)acryloyloxypropyl ester, glutaric acid mono(meth)acryloyloxyethyl ester, phthalic acid mono(meth)acryloyloxyethyl ester, phthalic acid mono(meth)acryloyloxyethyl ester (Meth)acryloyloxypropyl ester; (meth)acrylonitrile, (meth)acrylamide; and vinyl heptanomers such as vinyl acetate, vinyl chloride, and ethylene may also be copolymerized.

The vinyl polymer used in the present invention can be produced by conventionally known polymerization methods such as solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization.

Further, the vinyl polymer used in the present invention has a weight average molecular weight of 20,000 to 400,000, preferably 40,000 to 300,000, and a glass transition point of 60°C or higher, preferably 65°C or higher. Here, the weight average molecular weight is a value measured by gel permeation chromatography (GPC). Moreover, the glass transition point is a value measured by a differential scanning calorimeter (DSC). If the weight average molecular weight of the vinyl polymer is less than 20,000, the offset resistance will be poor, and if the weight average molecular weight is more than 400,000, the low temperature fixing property will be poor. Further, if the glass transition point is less than 60° C., the blocking resistance of the toner deteriorates.

Furthermore, in the present invention, an aliphatic alcohol having 15 to 90 carbon atoms and a melting point of 90° C. or lower is used.

When an aliphatic alcohol having 14 or less carbon atoms is used, the compatibility with the vinyl polymer increases, the vinyl polymer becomes plasticized, and the blocking resistance of the toner deteriorates. Further, if the number of carbon atoms is 91 or more or the melting point exceeds 90° C., the melt viscosity becomes high and the low-temperature fixability of the toner deteriorates.

Such aliphatic alcohols include pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, docosanol, tetracosanol, hexacosanol, octacosanol, triancosanol, dotriancosanol,
and N5P-9210 (alcohol type Wanx) manufactured by Nippon Seirosha.

Such aliphatic alcohol usually contains some aliphatic alcohol having 14 or less carbon atoms as an impurity. When the above-mentioned aliphatic alcohol used in the present invention contains more than 10% by weight of an aliphatic alcohol having 14 or less carbon atoms, the compatibility with the vinyl polymer increases and the vinyl polymer becomes plastic. The blocking resistance of the toner deteriorates. Therefore, in the present invention, the number of carbon atoms is 1.
An aliphatic alcohol containing at least 90% by weight of an aliphatic alcohol having a melting point of 90° C. to 90° C. is used.

Further, such aliphatic alcohol is blended in an amount of 1 to 40 parts by weight per 100 parts by weight of the vinyl polymer. If the amount of aliphatic alcohol blended is less than 1 part by weight,
There is almost no improvement in the low temperature fixing properties of the toner. On the other hand, if it exceeds 40 parts by weight, sufficient charging will not be obtained.

Further, in the present invention, a polyolefin wax having a penetration degree at 25° C. of 10 or less, preferably 4 or less is used. Examples of the polyolefin wax include polypropylene wax, polyethylene wax, polybutene-1 wax, and the like. Here, the penetration is JIS K 2
Measured in accordance with 235 (temperature 25℃ 1 total load 100g,
This is the value measured at a time of 5 seconds). If this penetration exceeds 10, the blocking resistance of the toner deteriorates.

Such polyolefin wax is used in an amount of 1 to 10 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the vinyl polymer.
It is blended in a range of 7 parts by weight.

If the amount of polyolefin wax blended is less than 1 part by weight, sufficient offset resistance cannot be obtained. On the other hand, if the amount exceeds 10 parts by weight, the polyolefin wax is likely to be released from the toner, resulting in staining the photosensitive drum.

In the present invention, to produce the toner resin composition and toner, a vinyl polymer is blended with an aliphatic alcohol and a polyolefin wax, and this is heated at an appropriate temperature using a roll mill, kneader 1 extruder, etc. A method of melt-kneading, cooling and pulverization, or solution polymerization of a vinyl monomer in the presence of an aliphatic alcohol, adding polyolefin wax to the system and stirring, then distilling off the solvent,
Preferred methods include melt-kneading this at an appropriate temperature using a roll mill, kneader-extruder, etc., cooling it, and pulverizing it.

The toner resin composition and toner of the present invention may include polystyrene, polyvinyl acetate, polyvinyl chloride, polyamide resin, polyethylene, polypropylene, polyester resin, acrylic resin, Resins such as epoxy resins and other toner additives may be blended.

(Function) The toner resin composition and toner of the present invention contain a specific vinyl polymer, a specific aliphatic alcohol, and a specific polyolefin wax as main components in specific proportions, and the vinyl polymer The basic performance required for toner can be obtained. The aliphatic alcohol melts quickly when heated to lower the fusing temperature of the toner to the paper, and the polyolefin wax melts quickly when heated to improve the releasability of the toner from the fixing roll. Furthermore, the aliphatic alcohol prevents the release of polyolefin wax in the toner, and prevents the toner from adhering to and staining the photosensitive drum.

(Example) Examples and comparative examples of the present invention are shown below.

3! Put 900g of toluene in a separable flask,
Further, 75 g of docosanol containing 0.5% by weight or less of an aliphatic alcohol having 14 or less carbon atoms was added, and after replacing the gas phase with nitrogen gas, the system was heated to the boiling point of toluene. While stirring while toluene was refluxing, a mixture of 400 g of styrene, 50 g of methyl methacrylate, 50 g of n-butyl acrylate, and 1 g of azobisisobutyronitrile as a polymerization initiator was added dropwise over 2.5 hours. Solution polymerization was carried out while

After the addition was completed, the mixture was further aged for 10 hours while stirring at the boiling temperature of toluene. After that, the temperature of the system was increased to 180℃.
Toluene was distilled off under reduced pressure while gradually raising the temperature to 100.degree. C. to produce a styrene-methyl methacrylate-n-butyl acrylate copolymer containing docosanol.

The styrene-methyl methacrylate-acrylic ff1n-butyl copolymer obtained under the same conditions except for not adding docosanol has a styrene component of 80% by weight.
, methyl methacrylate component 10% by weight, acrylic acid n-
Consists of 10% by weight of butyl component, weight average molecular weight 70,000,
The glass transition point is 67°C.

Toner and Toner ``The above docosanol-containing styrene-methyl methacrylate-n-butyl acrylate copolymer was kneaded at 160°C for 10 minutes in a kneader purged with nitrogen gas, and then cooled and pulverized. did.

Carbon black (MAlo) was added to 100 parts by weight of this pulverized material.
o: manufactured by Mitsubishi Kasei Corporation) and 4 parts by weight of polypropylene wax with a penetration degree of 2 are melt-kneaded, cooled and coarsely pulverized,
Furthermore, it is finely pulverized with a jet mill to obtain an average particle size of approximately 13 to 1.
A toner powder of 5 μm was prepared. This toner powder contains 0 hydrophobic silica fine powder (R-972: manufactured by Nippon Aerosil Co., Ltd.).
．． A toner was produced by adding 6 parts by weight.

(1) Collect 10 g of anti-blocking toner into a 100- sample bottle, leave it in a constant temperature bath at 50°C for 16 hours, and then use a powder tester (manufactured by Hosokawa Micron). The blocking resistance was evaluated. A case where no aggregation (caking) of the toner particles was observed was indicated by ◯, and a case where aggregation (caking) was observed was indicated by ×. A toner in which no aggregation (caking) is observed under these conditions is considered an excellent toner.

(2) Make a developer by uniformly mixing 4 parts by weight of low-temperature fixing toner with 96 parts by weight of iron powder carrier having an average particle size of about 50 to 80 μm, and use this developer and a commercially available electrophotographic copying machine (Fuji Xerox 3
500) to evaluate the low temperature fixability.

Copies were obtained by changing the temperature of the fixing roll of an electrophotographic copying machine. The resulting copy was rubbed with a typewriter eraser, and the lowest fixing roll temperature at which the density of the copy did not change was determined as the minimum fixing temperature. Toners with this temperature of about 160° C. or less are considered to be excellent.

(3) Offset resistance Copies were obtained by changing the temperature of the fixing roll of an electrophotographic copying machine. In this case, after obtaining a copy, a blank sheet of paper was supplied, and the toner stain on the blank sheet was visually determined. The lowest temperature at which toner stains occur on white paper is indicated as the offset generation temperature. Note that this test was conducted at 2
Canceled at 00°C. Toners with this temperature of about 200° C. or higher can be said to be excellent.

(4) Contamination on the photosensitive drum After 2000 copies were continuously made, the contamination on the photoconductor drum of the electrophotographic copying machine (which causes image blurring and a decrease in image density) was visually determined.

The case where no dirt was observed on the photosensitive drum was indicated by O, and the case where dirt was observed was indicated by x. Note that the charged state of the toner particles was stable, and the obtained image was clear without any haze. The above results are summarized in Table 1.

In particular, the main vinyl polymer is styrene methacrylate, which is composed of 70% by weight of styrene component, 15% by weight of methyl methacrylate component, and 15% by weight of n-butyl acrylate component, and has a weight average molecular weight of 200,000 and a glass transition point of 68°C. A methyl acid-n-butyl acrylate copolymer was used.

100 parts by weight of the above vinyl copolymer and 10 parts by weight of hexadecanol containing 0.5% by weight or less of an aliphatic alcohol having 14 or less carbon atoms were heated at 160°C for 10 minutes in a kneader purged with nitrogen gas. After kneading for a minute, it was cooled and ground. To 100 parts by weight of this pulverized material, 5 parts by weight of carbon blank (MA-100: manufactured by Mitsubishi Kasei Corporation) and 4 parts by weight of polypropylene wax with a penetration degree of 2 were melt-kneaded, cooled, coarsely pulverized, and further finely ground using a jet mill. A toner powder having an average particle size of about 13 to 15 μm was prepared by pulverization.

To this toner powder, 0.6 parts by weight of hydrophobic silica fine powder (R-972, manufactured by Nippon Aerosil Co., Ltd.) was added to produce a toner.

The performance of this toner was evaluated in the same manner as in Example 1. The results are summarized in Table 1.

As the vinyl polymer, 100 parts by weight of polystyrene having a weight average molecular weight of 40,000 and a glass transition point of 90° C. was used. Further, as the aliphatic alcohol, 20 parts by weight of dotriancontanol containing 0.5% by weight or less of an aliphatic alcohol having 14 or less carbon atoms was used. Further, 6 parts by weight of polyethylene wax with a penetration level of 2 was used as the polyolefin wax. Other than that, the same procedure as in Example 2 was carried out.

The results are summarized in Table 1.

The same procedure as in Example 2 was carried out except that no polypropylene wax was used. The results are summarized in Table 1.

Comparison Example 3 was carried out in the same manner as in Example 3, except that no dotriancontanol was used. The results are summarized in Table 1.

As the vinyl polymer, a styrene-methyl methacrylate-n-butyl acrylate copolymer having a weight average molecular weight of 500,000 and a glass transition point of 80° C. was used.

Other than that, the same procedure as in Example 2 was carried out. The result is the first
They are summarized in the table.

As the vinyl polymer, a styrene-methyl methacrylate-n-butyl acrylate copolymer having a weight average molecular weight of 10,000 and a glass transition point of 55° C. was used.

Other than that, the same procedure as in Example 2 was carried out. The result is the first
They are summarized in the table.

Docosanol containing 15% by weight of an aliphatic alcohol having 14 or less carbon atoms was used as the pentafatty alcohol for comparison. Other than that, the same procedure as in Example 1 was carried out. The results are summarized in Table 1.

As the aliphatic alcohol, an aliphatic alcohol having about 100 carbon atoms and containing 0.5% by weight or less of aliphatic alcohol having 14 carbon atoms or less was used. Also, 4 parts by weight of polypropylene wax was changed to 20 parts by weight. Other than that, the same procedure as in Example 1 was carried out. The results are summarized in Table 1.

(The following is a blank space) (Effects of the Invention) As mentioned above, the toner resin composition and toner of the present invention contain 100% by weight of a vinyl polymer having a weight average molecular weight of 20,000 to 400,000 and a glass transition point of 60° C. or higher as a main component. and at least 90% by weight of an aliphatic alcohol with a carbon number of 15 to 90 and a melting point of 90°C or less.
40 parts by weight, and 1 to 20 parts by weight of polyolefin wax having a penetration of 10 or less at 25°C, and within such a specific range, it has no effect on low temperature fixing properties, offset resistance, and blocking resistance. Excellent, and also prevents staining of the photosensitive tram. Furthermore, the charged state of the toner particles is stable, and the resulting images are clear and free of fog.

Therefore, the toner resin composition and toner of the present invention can be suitably used in electrophotographic copying machines using a heat-pressure roller fixing method ranging from low speeds to high speeds.

Claims (1)

[Claims] 1. 100 parts by weight of a vinyl polymer with a weight average molecular weight of 20,000 to 400,000 and a glass transition point of 60°C or higher, and a carbon number of 15 to 90.
, at least 90% aliphatic alcohol with a melting point of 90°C or less
1 to 40 parts by weight of aliphatic alcohol containing 2% by weight;
Polyolefin wax with a penetration rate of 10 or less at 5°C 1~
A toner resin composition containing 20 parts by weight as a main component. 2. A toner containing the toner resin composition according to claim 1.