JPH049067A - Releasing agent for electrophotographic toner and composition therefor - Google Patents

Abstract

PURPOSE:To contrive the improvements of hot offset resistance and lower temp. fixing property by consisting this agent of an ethylene-propylene series resin with a specific melt viscosity, and constituting a random structure with ethylene and propylene. CONSTITUTION:The agent is consisting of the ethylene-propylene resin with 60-1,000cps melt viscosity at 160 deg.C and the ethylene-propylene has a random structure. As a composition of the ethylene-propylene resin the ethylene content is preferable normally <=25wt.%, particularly preferred from <=10wt.% to >=1wt.% and the propylene content is normally from >=65wt.% to <=99wt.%, preferred from >=90wt.% to <=99wt.%. Hence a sufficient hot setoff temp. is obtained and the excellent releasing agent for electrophotographic toner at the lower temp. fixing property is obtained.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a release agent and composition for electrophotographic toner.

More specifically, the present invention relates to a mold retardant for electrophotographic toners and a composition suitable for use in heat-fixing type copying machines or printers, which have excellent toner releasability.

[Prior Art] Toner of the heat fixing method is fixed on a support by a bee 1-roll. In this case, it is desired that the lower limit temperature of fixing is low. On the other hand, when the roll temperature increases, a phenomenon occurs in which toner sticks to the roll.

It is desirable that the temperature at which this hot offset occurs is high. Generally, as the molecular weight of the binder increases, the hot offset temperature increases, but at the same time, the minimum fixing temperature also increases. Conversely, when the molecular weight decreases, both the hot offset temperature and the lower limit fixing temperature decrease.

In order to satisfy these contradictory performance requirements, a method of adding low molecular weight polypropylene to an electrophotographic toner has been proposed (Japanese Patent Publication No. 3304/1983).

[Problems to be Solved by the Invention] However, when a polyolefin resin such as low molecular weight polypropylene is added, this method not only does not provide a sufficient hot offset temperature, but also reduces the releasability from the heat roll, resulting in scratches caused by separation claws. Furthermore, problems such as filming on the carrier occur.

[Means for Solving the Problems] As a result of intensive studies by the present inventors on a release agent for electrophotographic toners that can obtain a sufficient hot offset temperature, has excellent low-temperature fixing properties, and does not cause filming on carriers. We have arrived at the present invention. That is, the present invention
A release agent for an electrophotographic toner comprising an ethylene-propylene resin having a melt viscosity of 60 to 1000 cps in C, and characterized in that ethylene and propylene have a random structure; and an electron comprising the release agent and a thermoplastic resin. This is a composition for photographic toner.

The ethylene-propylene resin according to the present invention is ethylene-propylene resin.
In addition to propylene, other olefins can also be included as constituents. Other olefins include butene,
Octene etc. can be mentioned.

The composition of the ethylene-propylene resin preferably has an ethylene content of usually 25% by weight or less. Particularly preferably, it is 10% by weight or less and 1% by weight or more. If it exceeds 25% by weight, the mold release effect will be reduced and a sufficient temperature will not be obtained for Offsera 1.

The propylene content is usually 65% or more and 99% by weight.
The content is preferably 90% by weight or more and 99% by weight or less.

The content of other olefins is usually 10% by weight or less, preferably 5% by weight or less. If it exceeds 10% by weight, the release effect will be insufficient when used as a toner.

The ethylene-propylene resin according to the present invention has a random structure of ethylene and propylene. Since it has a random structure, it is possible to obtain a toner with excellent fixing properties at low temperatures.

The melt viscosity of the ethylene-propylene resin according to the present invention at 160°C is 60 to 1000 cps, preferably 7
It is 0 to 500 cps. If the melt viscosity at 160°C exceeds 1000 cps, it may not be possible to obtain a sufficient hot offset temperature when used in electrophotographic toners, and if it is less than 60 cps, the fluidity of the toner will decrease when used in electrophotographic toners. There are things to do. The melt viscosity of the ethylene-propylene resin at 160°C is measured using a Brookfield rotational viscometer. Conditions other than the measurement temperature are in accordance with JIS-1557-1970. An oil bath with a temperature regulator is used to adjust the temperature of the measurement sample.

998 cm of ethylene-propylene resin according to the present invention
-' absorbance (D99a) and 974 cm-'' absorbance (D99a)
D974) ratio (D9913/D9□4) is 0.75
-0.90. If it exceeds 0.90, the fixing properties may be insufficient when used as an electrophotographic toner, and 0.75
If it is less than this, the toner fluidity may decrease when used as an electrophotographic toner. Absorbance is measured with an infrared spectrophotometer.

The method for producing the ethylene-propylene resin according to the present invention is not particularly limited, but examples include 1): thermally degrading a high-molecular-weight ethylene-propylene random copolymer; and 2): high-molecular-weight ethylene-propylene random copolymer. A method using a propylene random copolymer or an ethylene-propylene resin with an acid value of 50 or less obtained by oxidative decomposition of the resin in 1) above, or 3) a method using ethylene-propylene resin obtained in 1) or 2) above. Examples include a method of modifying with a sexually unsaturated monomer.

In the case of producing by thermal degradation of the high molecular weight ethylene-propylene random copolymer of 6-1), the raw material high molecular weight ethylene-propylene random copolymer usually has a melt index of 0.1-100, preferably 1-50
are used.

Thermal degradation is carried out by heating a high molecular weight ethylene-propylene random copolymer using a tubular reactor etc. that applies heat uniformly.
This can be carried out by passing the temperature between 00 and 450°C for 0.5 to 10 hours. The melt viscosity of the thermally degraded product can be adjusted by the thermally degraded temperature and thermally degraded time. 300°
If it is less than 450°C, it will take time to lower the melt viscosity, and if it exceeds 450°C, the melt viscosity will decrease in a short time, making it difficult to control.

In the case of oxidative decomposition in 2), a) a method of oxidizing the high molecular weight ethylene-propylene random copolymer or the ethylene-propylene resin obtained by thermal degradation in 1) above with oxygen or an oxygen-containing gas (air); A method of oxidizing with ozone-containing oxygen or ozone-containing gas (air), b) oxidative decomposition of a high molecular weight ethylene-propylene random copolymer,
Furthermore, it can be obtained by thermally degrading it. The acid value of the oxide is usually 30 or less, preferably 10 or less. acid value is 3
When it is 0 or more, the mold release effect may become insufficient.

In the case of modification with 3) ethylenically unsaturated monomers, the ethylenically unsaturated monomers include styrene monomers (α-methylstyrene, p-methylstyrene), (meth)acrylic acid ester monomers [alkyl (meth)acrylate [alkyl group having 1 to 18 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate,
butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate], hydroxyl group-containing (meth)acrylate [hydroxylethyl (meth)acrylate, etc.], amino group-containing (meth)acrylate, etc. ) acrylates [dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, etc.], vinyl esters (vinyl #acid, etc.), vinyl ethers (vinyl ethyl ether, etc.), ethylenically unsaturated group-containing aliphatic hydrocarbons (α- olefin, butadiene, etc.), di-I-lyl group-containing vinyl compounds [(meth)acrylonitrile, etc.], nitrogen-containing vinyl compounds (N-vinylpyrrolidone, etc.), unsaturated carboxylic acids or their anhydrides [(meth)acrylic acid, anhydride, maleic acid, itaconic anhydride, etc.].

Silicon-containing monomers (1-lie I to xyvinylsilane, etc.),
Examples include fluorine-containing monomers (perfluorohexaethyl methacrylate, etc.).

Among these, styrenic monomers, unsaturated carboxylic acid anhydrides, and silicon-containing monomers are preferred. The amount of ethylenically unsaturated monomer used for modification is usually 0.1% or more based on the weight of the mold release agent. The method of denaturation is 1)
Examples include a method in which the ethylene-propylene resin 1-b obtained by thermal degradation is treated with a peroxide and an ethylenically unsaturated monomer is added (for example, to form graph I).

The composition of the present invention comprises a mold release agent made of an ethylene-propylene resin having the random structure described above and a thermoplastic resin. As the thermoplastic resin, styrene resin, styrene-(meth)acrylate copolymer, polyester resin, epoxy resin, etc. can be used.

The composition ratio of the mold release agent and the thermoplastic resin in the composition of the present invention can be arbitrarily selected.

The release agent and composition for electrophotographic toner of the present invention can contain the thermoplastic resin, colorant, various additives, etc. as necessary to form an electrophotographic toner.

Colorants include carbon, iron black, benzidine yellow,
Examples include quinacudrine, rhodamine B, and phthalocyanine. As the magnetic powder, powder of a ferromagnetic metal such as iron, cobalt, or nickel, or magnetite, hematite, ferrite, or the like may be used.

Furthermore, various additives include charge control agents such as glosine and quaternary ammonium salts.

The release agent and composition of the present invention may be added during toner production, or the release agent may be added in the form of a premixed mixture with the thermoplastic resin.

The production of electrophotographic toner is as follows: 1) After dry blending the toner components, the toner components are melt-kneaded, then coarsely pulverized, and finally pulverized using a jet pulverizer, and further classified to form a fine powder with a particle size of usually 2 to 20μ. 2) It can also be obtained by suspension polymerizing the monomers constituting the thermoplastic resin in the presence of the other toner components to obtain a fine powder with a particle size of usually 2 to 20 μm. In particular, the manufacturing method is not limited to these.

The electrophotographic toner is mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite, etc., if necessary, and used as a developer for an electrical latent image. Furthermore, hydrophobic colloidal silica fine powder can also be used to improve the fluidity of the powder.

The electrophotographic toner is heated in a heat fixing heat roll section of a copying machine, such as a heat fixing type copying machine or a printer, so that it can be applied to a support (paper, polyester film, etc.).
and is used as a recording material.

[Examples] The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto.

In the examples, all parts represent parts by weight.

Example 1 A high molecular weight ethylene-propylene random copolymer (ethylene content: 3% ffi) was thermally degraded at 360 to 365°C for 100 minutes while being passed continuously through a tube equipped with a static mixer, and the absorbance was Ratio (D998/
D9□4) is 0085. Melt viscosity at 160°C is 85
A cps ethylene-propylene resin was obtained. This is referred to as the mold release agent (1) of the present invention.

Comparative Example 1 While continuously passing a high molecular weight polypropylene homopolymer through a tube incorporating a static mixer,
Thermal degradation was performed at 65°C for 100 minutes, and the absorbance ratio (D9
98/D9□4) was 0096. A propylene resin having a melt viscosity of 1500 cps at 160°C was obtained. This is referred to as a comparative mold release agent (1).

Comparative Example 2 A high molecular weight ethylene-propylene copolymer (ethylene containing ffi 40% by weight) was heated at 360-365°C for 10 minutes while continuously passing through a tube incorporating a static mixer.
Thermal degradation was performed for 0 minutes, and the absorbance ratio (Dqqa/D9□
4) is 0085. Melt viscosity at 160°C is 50 cp
A propylene resin of s was obtained. Compare this with mold release agent (2)
shall be.

Production Example 1 660 parts of styrene and 340 parts of butyl acrylate were thermally polymerized at 130 to 180°C without using a solvent or a polymerization initiator to obtain a thermoplastic resin. Tg of thermoplastic resin is 53℃,
Number average molecular weight is 11,000, weight average molecular weight is 7,000
It was 0. Molecular weight was determined by GPC method. GPC
The molecular weight measurement of styrenic resin by the method was carried out under the following conditions.

Equipment: Toyo Soda HLC802A column:
TSK gel GMH62 measurement temperature: 40'
C Sample solution 20. 5wt% THF solution solution injection amount =
200 μm Detection device: Refractive index detector Example A Using the release agent of Example 1 and the thermoplastic resin of Production Example 1, an electrophotographic toner was produced by the following method. Furthermore, an electrophotographic developer was produced.

Toner Preparation Method Thermoplastic resin 87 parts Release agent of Example 1 4 parts Carbon black 8 parts (HA-100 manufactured by Mitsubishi Chemical Industries, Ltd.) Charge control agent
1 part (Spiron Black TRH manufactured by Hodogaya Chemical Industry Co., Ltd.) The above mixture was powder-blended and then kneaded in a Labo Plus 1-mill at 140°C and 30 rpm for 10 minutes, and the kneaded product was mixed in a jet mill PJM], 00 ( (manufactured by Nippon Pneumatic Co., Ltd.). Fine powder of 2 μm or less was cut from the finely pulverized material using an airflow classifier (powder air classifier) iSD (manufactured by Nippon Pneumatic Co., Ltd.). Add Aerosil R97 to 1000 parts of the obtained powder.
2 (Nippon Aerosil) were uniformly mixed to obtain a toner.

Developer Preparation Method XII 1 25 parts of hener and electrophotographic carrier iron powder (1
A developer was obtained by mixing 1,000 parts of genuine iron powder and 1: F-100).

Comparative Use Examples B and C Developers were obtained in the same manner as in Use Example A, except that the release agent of Example 1 was replaced with the release agents of Comparative Examples 1 and 2.

Table 1 shows the evaluation results for each developer.

Table 1 - Evaluation results of developer Hot 2I offset Using a commercially available heat fixing type copying machine, evaluation was made at the temperature of the heat roll at which hot I offset 1 occurs.

E 2200C or higher
1-62,000C or more and less than 220°C P 200°C end Single seedling low temperature fixability Using a commercially available heat fixing type copying machine, the fixing strength at a heat roll temperature of 170°C was determined by the tape peeling method.

evaluated.

E Residual rate 90% or more 0 80% or more but less than 90% P Less than 80% Filming on carrier After mixing the developer in a turbo shrieker mixer for 3 hours at OO rpm, remove toner particles adhering to the carrier surface. Observed with a microscope.

The release agent of the present invention has the advantage that the electrophotographic toner containing the release agent not only has excellent hot offset properties, but also is less prone to scratch marks and has less 1-ner adhesion to the carrier (filming on the carrier). It could be confirmed.

[Effects of the Invention] When the mold release agent of the present invention is used as an electrophotographic toner containing the same, it not only has excellent hot offset resistance but also low-temperature fixing properties, and further reduces the amount of filming material attached to the carrier. Its usefulness is extremely high as it can prevent the increase.

Patent applicant: Sanyo Chemical Industries, Ltd.

Claims (1)

[Claims] 1. Melt viscosity at 160°C is 60 to 1000 cps
A mold release agent for electrophotographic toner, comprising an ethylene-propylene resin having a random structure of ethylene and propylene. 2. 998cm of ethylene-propylene resin ^-^1
The ratio of the absorbance at (D_9_9_8) and the absorbance at 974 cm^-^1 (D_9_7_4) (D_9_9_8/D_9
_7_4) is 0.75 to 0.90, the release agent for electrophotographic toner according to claim 1. 3. The release agent for electrophotographic toner according to claim 1 or 2, wherein the ethylene content is 25% or less based on the weight of the ethylene-propylene resin. 4. Ethylene-propylene resin is high molecular weight ethylene-
4. The release agent for electrophotographic toner according to claim 1, which is obtained by thermal degradation of a propylene co-random polymer. 5. The mold release agent for electrophotographic toner according to any one of claims 1 to 4, wherein the ethylene-propylene resin is obtained by oxidative decomposition and has an acid value of 30 or less. 6. The release agent for electrophotographic toner according to any one of claims 1 to 4, wherein the ethylene-propylene resin is modified with an ethylenically unsaturated monomer. 7. An electrophotographic toner composition comprising the release agent according to any one of claims 1 to 6 and a thermoplastic resin.