JPH04194946A - Resin composition for toner and toner - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. for toner excellent in low temp. fixing property, offset resistance and blocking resistance by compounding a specified partial ester compd. of polyglycerine into a specified vinyl copolymer resin and further compounding a specified amt. of polyolefin wax thereinto. CONSTITUTION:A vinyl copolymer having 20,000 - 400,000 weight average mol.wt. is used as a binder resin, into which partial ester compd. of polyglycerine with org. carboxylic acid of >=10 carbon number is compounded. Further, 1 - 10pts.wt. of polyolefin wax is compounded to 100pts.wt. of the vinyl polymer. Thus, the obtd. resin compsn. is excellent in low temp. fixing property, offset resistance and blocking resistance.

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 triboelectric fine powder developer is used, which is a mixture of a fine powder called toner, which is a binder resin containing a coloring agent such as carphone black dispersed therein, and a carrier such as iron powder or glass peas. .

Normally, toner charged by friction adheres to an electrostatic latent image on a photoreceptor due to electrical attraction, forming a toner image.
This 1-toner image is then transferred onto a sheet of paper and fixed with a hot pressure roller that has releasability to the toner to form a permanent visible image.

In such a hot pressure roller fixed fixing method, in order to reduce power consumption and increase copying speed, the toner used has low-temperature fixability (the toner adheres to the paper at low temperatures),
The main requirements are performance such as offset and gutter resistance (how much toner is deposited on the hot pressure roller and the toner does not transfer to the paper) and bronking resistance (no agglomeration of +-toner particles).

This type of toner is prepared by combining a binder resin such as a styrene-acrylic copolymer resin with a low molecular weight ester compound having a melting point of 50 to 150°C, such as phthalic acid monoester of hebutadecyl alcohol, pentaerythritol I, tetrastearate 1 to A toner containing the following has been proposed (see Japanese Patent Laid-Open No. 63-66563).

Furthermore, toners containing low molecular weight polypropylene in styrene resin have also been proposed (Japanese Patent Publication No. 52-3304
(see publication).

(Problems to be Solved by the Invention) The previously proposed toners are still insufficient to satisfy all three main performances listed in L in a well-balanced manner.

The former toner has good heat-melting characteristics at low temperatures due to the action of the low molecular weight ester compound, but it has particularly poor adhesion to paper, and in this respect it cannot be said to have good low-temperature fixability. Further, the anti-offset property is also not sufficient.

Further, in the latter toner, the anti-offset property is improved due to the action of the low molecular weight polypropylene, but the low-temperature fixing property in particular is not sufficient. There is also the problem that lower molecular weight polypropylenes than l-ner can be released and contaminate the photosensitive tram.

The present invention solves the above-mentioned problems, and its purpose is to provide a resin composition for a toner and a l-toner that are excellent in low-temperature fixing properties, anti-offset properties, and anti-bronching properties. There is a particular thing.

(Another means to solve the problem) The resin composition for 1 to 1 of the present invention has a weight average molecular weight of 2 to 2.
It is characterized by blending 100 parts by weight of a vinyl polymer of 400,000 yen with a partial ester compound of polyglycerin and an organic carboxylic acid having 10 or more carbon atoms and 1 to 10 parts by weight of polyolefin wax.

Further, the toner of the present invention is characterized by using the above resin composition for toner.

In the present invention, a vinyl polymer is used as the bindu resin. Among various vinyl polymers, copolymers of styrene monomers and (meth)acrylic acid ester monomers are particularly suitable. Also suitable is a single type combination of styrenic monomers.

Among monomers that provide such vinyl polymers, styrene monomers include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, and α-methylstyrene.
Methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert
-butylstyrene, 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, Mn-butyl (meth)acrylate, isobutyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, (meth)acrylate ) Stearyl acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, methyl α-chloroacrylate, and the like. Among these, methyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred.

Furthermore, such monomers 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, mono(meth)phthalate
Acryloyloxypropyl ester; (meth)acrylonitrile, (meth)acrylamide; and other vinyl monomers such as vinyl acetate, vinyl chloride, and ethylene may be copolymerized.

In such a copolymer, the content of the styrene monomer component is preferably set in the range of 60 to 95% by weight, and the content of the (meth)acrylic acid ester monomer is preferably set in the range of 5 to 40% by weight. If the content of the styrene monomer component is less than 60% by weight and the content of the (meth)acrylic acid ester monomer is more than 40% by weight, the bronking resistance and crushability of the toner may deteriorate. be. Further, if the content of the styrene monomer component exceeds 95% by weight and the content of the (meth)acrylic acid ester monomer component falls below 5% by weight, the low-temperature fixability of the toner may deteriorate.

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.

Here, the weight average molecular weight is a value measured by Gel Permeation Chroma 1-Graphie (GPC). If the weight average molecular weight 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, in the present invention, a partial ester compound of polyglycerin and an organic carboxylic acid is used. Polyglycerin is obtained by dehydration condensation of glycerin.
The degree of polycondensation is generally from 2 to 10. As the organic carboxylic acid, a fatty acid having 10 or more carbon atoms or an aromatic acid, preferably a fatty acid having 10 to 40 carbon atoms, is used. Polyglycerin partial ester compounds using organic carboxylic acids having less than 10 carbon atoms have too high compatibility with vinyl polymers, so the vinyl polymers are plasticized and the blocking properties of surfaces 1 to 4 are poor. Become.

These polyglycerin partial ester compounds include:
Polyglycerin monolaurate, polyglycerin dilaure-1, polyglycerin trilaurate, polyglycerin tetralaurate, polyglycerin pentalaurate, polyglycerin hexalaureate-1, polyglycerin more-nostearate, polyglycerin Distearate, polyglycerin 1, ristearate, polyglycerin tetrastearate 1, polyglycerin pentasteary 1,
, polyglycerin hexasteare-1, polyglycerin 1 hepalmitate I, polyglycerin dipalmitate, polyglycerin 1 hepalmitate-1, polyglycerin 1 hepalmitate-1, polyglycerin monobehenate, polyglycerin 1 hehenate, poly Glycerin 1~
Lihehene-1・, Polyglycerin 1 ~ Lihehene 1~,
Examples include polyglycerin 1 to lihehene-1.

These polyglycerin partial ester compounds are added in an amount of 1 to 40 parts by weight per 100 parts by weight of the vinyl copolymer.
It is preferable to mix parts by weight.

If the amount of the polyglycerin partial ester compound is less than 1 part by weight, the low-temperature fixability of the toner will hardly improve. vice versa,
If the blending amount exceeds 40 parts by weight, the charging properties of the toner will be insufficient.

Furthermore, in the present invention, the vinyl-8= Add polyolefin wax to the polymer.

Examples of this polyolefin wax include polypropylene wax, polyethylene wax, and polybutene-1 wax. And the Sendai degree at 25°C is 1
A polyolefin wax having a molecular weight of 0 or less, preferably 4 or less is preferred. Here, the penetration is a value measured in accordance with JIS K 2235 (measured at a temperature of 25° C., a total load of 100 g, and a time of 5 seconds).

If this penetration exceeds 10, the bronking resistance of the toner may deteriorate.

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, in order to produce the resin composition for toner and l/toner, a polyglycerin partial ester compound and a polyolefin wax are blended with the vinyl polymer, and the mixture is processed using a roll mill, a kneader-1 extruder, etc. The method used is to melt and knead the mixture at an appropriate temperature, cool it, and pulverize it.

In addition, a monomer to give a polymer is solution-polymerized in the presence of a polyglycerin partial ester compound, and after the solvent is distilled off, a polyolefin wax is added thereto, and this is subjected to appropriate polymerization using a roll mill, kneader-1 extruder, etc. A method of melting and kneading at high temperature, cooling and pulverizing is also adopted.

In addition, the glass transition point of the composition (measured with a differential scanning calorimeter)
is preferably 45° C. or higher from the viewpoint of toner blocking resistance.

Furthermore, the 1-toner resin composition and toner of the present invention include:
Resins such as polystyrene, polyvinyl acetate, polyvinyl chloride, polyamide resins, polyethylene, polypropylene, polyester resins, acrylic resins, and epoxy resins may be blended within the range that can achieve the object of the present invention. Further, coloring agents such as carbon blank, charge control agents such as spirone black, additives for I-ner such as fatty acid amide, bis fatty acid amide, metal soap, paraffin, and fine silica powder may be added.

(Function) When a vinyl polymer having a weight average molecular weight of 20,000 to 400,000 is used as the binder resin as in the present invention, the above-mentioned basic performance required of the toner can be obtained. When a partial ester compound of polyglycerin and an organic carboxylic acid having 10 or more carbon atoms is blended into this vinyl polymer, this polyglycerin partial ester compound rapidly melts by heating and melts the I. It reduces viscosity and improves fluidity at low temperatures, making it easier to contact paper.

Furthermore, residual OH of the polyglycerin partial ester compound
The base increases compatibility with paper and improves low-temperature adhesion to paper.

In addition, the residual portion of an organic acid such as a fatty acid in the polyglycerin partial ester compound has good mold releasability and improves offset I resistance.

Furthermore, for 100 parts by weight of vinyl polymer, = 11
= When 1 to 10 parts by weight of polyolefin wax is blended, this polyolefin wax melts rapidly by heating and improves the releasability of the toner from the fixing roll. Furthermore, the polyglycerin partial ester compound prevents the release of polyolefin wax and prevents toner from adhering to and staining the photosensitive drum.

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

A vinyl copolymer having a weight average molecular weight of 200,000 and consisting of 70% by weight of a styrene component, 15% by weight of methyl methacrylate, and 15% by weight of n-butyl acrylate was produced by a conventional method. 100 parts by weight of this vinyl copolymer and 10 parts by weight of polyglycerol distearate were kneaded at 160'C for 10 minutes in a kneader purged with nitrogen gas, and then cooled and pulverized to produce pulverized product A. was created.

To 100 parts by weight of this pulverized material A, 4 parts by weight of polypropylene 13-wax (Viscol 660-P, manufactured by Mitsubishi Chemical Corporation), 5 parts by weight of carbon blank (MA-100, manufactured by Mitsubishi Chemical Corporation), and a charge control agent ( 1 part by weight of Subiron Black TR (formerly manufactured by Hodogaya Chemical Co., Ltd.) is melt-kneaded, cooled, coarsely ground, and further finely ground in a diene mill to produce a toner composition with an average particle size of approximately 12 to 15 μm. did. The glass transition point of this composition was 60°C. Furthermore, this l
・Hydrophobic silica fine powder (It-972
0.3 parts by weight (manufactured by Nippon Aerosil Co., Ltd.) was added to produce a toner.

(1) Make a developer by uniformly mixing 4 parts by weight of a low-temperature fixing toner with 96 parts by weight of an iron powder carrier having an average particle size of about 50 to 8011 m,
This developer and a commercially available electrophotographic copying machine (Mill DC-50)
55) was used 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 comb, and the lowest fixing roll temperature at which the density of the copy did not change was determined as the minimum fixing temperature. This temperature is low (about 160
°C or less) is considered an excellent toner.

(2) 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 paper was supplied, and the toner stain on the blank paper was determined visually. The lowest temperature at which toner stains occur on white paper is shown as the offset generation temperature. Note that this test was terminated at 2001-9°C in consideration of the heat resistance of the fixing roll. A toner with a high temperature (approximately f (i0°C or higher)) is an excellent toner.

(3) Blocking resistance The toner LOg was collected in a 100 mm sample bottle, and after leaving it in a constant temperature bath at 50°C for 8 hours, the bronking resistance was evaluated using a powder tester (manufactured by Bokkawa Micron). . Cases in which no aggregation (caking) was observed in particles 1 to N were indicated by ◯, and cases in which aggregation (caking) was observed were indicated by x. A toner that shows no aggregation (caking) under these conditions can be said to be an excellent toner.

(4) Fixing Strength A copy was obtained by setting the temperature of the fixing roll of an electrophotographic copying machine to 160°C. Place cellophane tape with a width of 25 mm on the top of this copy, and then tape a tape with a diameter of 10 cm and a width of 5 mm from the bottom of the copy.
(m, weight 1. kg) An iron roll wrapped with rubber was made to reciprocate three times.Then, the cellophane tape was peeled off, and the case where the copied image remained on the paper without being transferred to the cellophane tape was indicated by O, and it was transferred to the cellophane tape. Cases are indicated by x.Those which do not transfer to the cellophane tape under these conditions can be said to be excellent.

(5) Contamination on the photosensitive drum After 5,000 copies were made in succession, the lη deviation of the photosensitive tram of the electrophotographic copying machine (which causes image blurring and a decrease in image density) was visually determined.

Cases in which no stains were observed on the photosensitive drum were indicated by ◯, and cases in which stains were observed were indicated by ×.

The above results are summarized in Table 1.

Backyard flame I 3! Put 900g of toluene in a separable flask,
100 g of polyglycerin 1 lihehe* -+- was added to this, and after replacing the gas phase with nitrogen gas, the system was heated to the boiling point of 1, luene. While stirring while toluene was refluxing, 400 g of styrene and 55 g of methyl methacrylate were added.
Solution polymerization was carried out by dropping a mixture of 0 g of n-butyl acrylate, 45 g of n-butyl acrylate, 5 g of divinylhenzene as a crosslinking agent, and 2 g of azobisisobutyronitrile as a polymerization initiator over 2.5 hours.

After the dropwise addition was completed, the mixture was further aged for 4 hours while stirring at a temperature at which I.luene was refluxed. Then, increase the system temperature to 180°.
After gradually increasing the temperature to C, toluene was distilled off under reduced pressure, and the mixture was cooled and pulverized to prepare a pulverized product B.

The weight average molecular weight of a double vinyl copolymer solution-polymerized without using polyglycerin 1 and lehenate was 60,000.

In place of 100 parts by weight of the pulverized material A of Example 1, the above pulverized material B was used.
100 parts by weight was used. Other than that, a resin composition for l/toner and a toner were produced in the same manner as in Example 1. Note that the glass transition point of the composition was 56°C. The performance of this toner was evaluated in the same manner as in Example 1. The results are summarized in Table 1.

Implementation ■ 100 parts by weight of polystyrene with a vertical weight average molecular weight of 40,000 and 1 to 7 parts by weight of polyglycerin dilaure were kneaded at 160°C for 10 minutes in a kneader purged with nitrogen gas, and then cooled. A pulverized material C was prepared by pulverization.

In place of 100 parts by weight of the pulverized product A of Example 1, the above pulverized product C was used.
100 parts by weight was used. Further, 4 parts by weight of polypropylene wax in Example 1 was replaced with 6 parts by weight of polyethylene wax (Sunwax 161-P, manufactured by Sanyo Chemical Co., Ltd.). Resin composition for toner and 1 and toner were produced in the same manner as in Example 1 except for the above. The glass transition point of this composition was 65.C. The performance of this toner was evaluated in the same manner as in Example 1. The results are summarized in Table 1.

In Example 1, 4 parts by weight of polypropylene wax was not used. Other than that, the same procedure as in Example 1 was carried out. The results are summarized in Table 1. In this case, the glass transition point of the composition was 60°C.

In Example 3, 7 parts by weight of polyglycerol dilaurate was not used. Other than that, the same procedure as in Example 3 was carried out. The results are summarized in Table 1. In this case,
The glass transition point of the composition was 65°C.

In Example 1, 100 parts by weight of a vinyl copolymer having a weight average molecular weight of 200,000 and consisting of 70% by weight of a styrene component, 15% by weight of a methyl methacrylate component, and 15% by weight of an n-butyl acrylate component was added. Instead, 100 parts by weight of a vinyl copolymer having the same components and having a weight average molecular weight of 500,000 was used. Other than that, the same procedure as in Example 1 was carried out. The results are summarized in Table 1. In this case, the glass transition point of the composition was 64°C.

Comparative Side 11 In Example 1, 100 parts by weight of a vinyl copolymer having a weight average molecular weight of 200,000 and consisting of 70% by weight of a styrene component, 15% by weight of a methyl methacrylate component, and 15% by weight of an n-butyl acrylate component Instead, 100 parts by weight of a vinyl copolymer having the same components and having a weight average molecular weight of 10,000 was used. Other than that, the same procedure as in Example 1 was carried out. The results are summarized in Table 1. In this case, the glass transition point of the composition was 46°C.

Upper axis column Y In Example 2, polyglycerin trihenene 1 to 1
00g, polyglycerin 2-ethylhexane-
1 to 100 g was used. Other than that, the same procedure as in Example 2 was carried out. The results are summarized in Table 1. In this case, the glass transition point of the composition was 56°C.

In Example 2, 4 parts by weight of polypropylene wax was replaced with 20 parts by weight of the same polypropylene wax. Other than that, the same procedure as in Example 2 was carried out. The results are summarized in Table 1.

In this case, the glass transition point of the composition was 56°C.

In Example 3, 7 parts by weight of henyl stearate was used in place of 7 parts by weight of polyglycerol dilaurate.

Other than that, the same procedure as in Example 3 was carried out. The results are summarized in Table 1.

In this case, the glass transition point of the composition was 65°C.

(The following is a blank space) (Effects of the Invention) As stated in the second series, the resin composition for toner of the present invention contains 100 parts by weight of a vinyl polymer having a weight average molecular weight of 20,000 to 400,000,
Partial ester compound of polyglycerin and organic carboxylic acid having 10 or more carbon atoms, and polyolefin wax 1 to 1
0 parts by weight.

In this way, by blending a specific polyglycerin partial ester compound with a specific vinyl copolymer resin and further blending a specific amount of polyolefin wax, it is possible to create a resin without reducing offset resistance and freonking resistance. 1 hener is obtained which has excellent low-temperature fixability and also prevents staining of photosensitive l/lam. Further, the charged state of the toner particles is stable, and the obtained image is clear and has no haze.

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. Vinyl polymer 100 having a weight average molecular weight of 20,000 to 400,000
A resin composition for a toner, which contains, in parts by weight, a partial ester compound of polyglycerin and an organic carboxylic acid having 10 or more carbon atoms, and 1 to 10 parts by weight of a polyolefin wax. 2. A toner using the resin composition for toner according to claim 1.