JPH0658540B2 - Thermal fixing type electrophotographic developer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic developer. More specifically, it relates to a heat-fixing type electrophotographic developer having improved adhesion and development to a fixing roller at the time of heat fixing.

[Problems to be solved by conventional techniques and inventions]

A developer for electrophotography, so-called electrostatic toner, is an image forming material at the next stage of charging exposure in electrostatic electrophotography, and is charged fine powder in which carbon black or pigment is dispersed in resin. Generally, an electrostatic toner is a dry two-component type toner used together with a carrier such as iron powder and glass particles, a dispersion type wet toner using an organic solvent such as isoparaffin, and further magnetic fine powder is dispersed in itself. Are classified as dry one-component toners.

The image obtained by being developed on the photosensitive plate with the electrostatic toner is transferred to the paper, and the image directly developed on the paper coated with the photosensitive layer is fixed as it is by heat or solvent vapor. Of these, fixing by a heating roller is a contact-type fixing method, so that the heat efficiency is high, an image can be surely fixed by a heat source of a relatively low temperature, and it is also suitable for high-speed copying, which is preferable.

However, when an image is fixed by contacting a heating body such as a heating roller, there is a possibility that a part of the electrostatic toner adheres to the heating body and is transferred to a subsequent image portion, so-called offset development occurs. Especially in high-speed copying, raising the temperature of the heating element in order to increase the fixing effect and the fixing speed results in making the offset phenomenon more likely to occur. Therefore, for example, when fixing an image formed with a one-component electrostatic toner with a heating roller, the roller surface is impregnated with silicone oil or the silicone oil is supplied to the roller surface to eliminate the offset phenomenon. However, on the contrary, a problem such as contamination of the roll may occur.

On the other hand, as the thermoplastic resin which is the main material of the electrostatic toner,
Polystyrene, polystyrene-based resins such as styrene / (meth) acrylic acid ester copolymers, ketone resins, maleic acid resins, coumarone resins, phenol resins, polyester resins, epoxy resins, terpene resins, styrene / acrylic copolymers, polyvinyl butyral , Polybutylmethacrylate, etc. Among them, polystyrene resin has a good softening point (90 ° C. to 16 ° C.) with good chargeability.
(0 ° C), good fixability, easy cleaning of the photosensitive plate with little contamination, little hygroscopicity, good compatibility with carbon black as a coloring material, easy crushing, etc. So most used. However, since the polystyrene resin having such characteristics is likely to cause the offset phenomenon in high-speed copying as described above, it is desired to develop an electrostatic toner that does not cause the offset phenomenon.

As a method for solving the above problems, (i) a method of improving the thermoplastic resin itself which is the main material of the electrostatic toner, and (ii) the thermoplastic resin which is the main material of the electrostatic toner is as it is. Then, a method of adding a release agent for the purpose of not causing the offset phenomenon can be considered.

In order to solve the above problems by the method (ii) above,
The technique of adding polyolefin wax as a release agent to a styrene-based polymer is disclosed in, for example, JP-B-52-3304, 52-3305, and
57-52574, 58-588664, and JP-A-58-59455. However, even in such a technique, because the compatibility between the polyolefin wax and the styrene resin component is still insufficient, not only the performance as the release agent of the polyolefin wax is not sufficiently exhibited, The toner is likely to agglomerate during storage or copying, and the wax is liable to be released from the toner, which easily leads to contamination of the photosensitive drum and the like, and the fixed image after fixing is also poor in bending resistance. .

The present inventors synthesized various waxes to be added as a release agent in the toner, and studied the development of an excellent toner without the above-mentioned defects, and as a result, a specific resin obtained by grafting acrylonitrile or methacrylonitrile onto polyolefin wax. The inventors have found that the use of as a release agent makes it possible to obtain an electrostatic toner that is unlikely to cause the offset phenomenon, and has reached the present invention. Further, by using a specific resin obtained by grafting acrylonitol or methacrylonitrile to the polyolefin wax of the present invention as a thermoplastic resin which is the main component (binder) of the electrostatic toner, an electrostatic toner which hardly causes the offset phenomenon can be obtained. I also found that I could get it. That is, the inventors have found that the specific resin obtained by grafting acrylonitol or methacrylonitrile onto the polyolefin wax has an excellent performance as a releasing agent and a main material (binder) of the electrostatic toner, and thus arrived at the present invention. Is.

JP-A-57-90642 discloses a pressure fixing toner characterized by containing a homopolymer of ethylene and a graph copolymer of aromatic vinyl and acrylonitrile. The invention is a toner for heat fixing, which is common in that it is a toner, but the properties and the like of the toner originally required for both are completely different. Further, JP-A-58-16250 discloses a toner containing a low-molecular-weight propylene polymer, and the polymer may be a copolymer of propylene and acrylonitrile, but there is practically no disclosure. It has not been.

[Outline of Invention]

The present invention is a graft-modified polyolefin wax (A) and a coloring agent (B) obtained by grafting acrylonitol or methacrylonitrile in an amount of 1.0 to 100 parts by weight with respect to 100 parts by weight of polyolefin wax having an intrinsic viscosity of 0.05 to 0.7 dl / g. ) And a heat fixing type phenomenon material for electrophotography.

[Graft-modified polyolefin wax (A)]

The graft modified polyolefin wax (A) constituting the toner of the present invention is a specific modified wax obtained by grafting acrylonitrile or methacrylonitrile onto the polyolefin wax (a). The polyolefin wax (a) used for the graft copolymerization has an intrinsic viscosity [measured in decalin solvent at 135 ° C. The same applies below. ] In the range of 0.05 to 0.8 dl / g, preferably 0.07
To 0.7 dl / g range. In this case, when the polyolefin wax (a) has ethylene as a main polymerization unit, it is preferable to use one having an intrinsic viscosity in the range of 0.05 to 0.5. Among those having α-olefin as the main polymerization unit other than ethylene, those obtained by thermal decomposition are those in the range of 0.05 to 0.8, those obtained by directly polymerizing α-olefin other than ethylene as the main polymerization unit are It is preferable to use one having a range of 0.07 to 0.8. Graft-modified polyolefin wax (A), when used as a release agent, if the intrinsic viscosity of the polyolefin wax (a) is below the lower limit,
Even when the graft-modified polyolefin wax (A) obtained from the polyolefin wax (a) is used as a raw material of the toner composition, the melt viscosity becomes too low, and a sufficient releasing agent effect cannot be obtained, and However, toner aggregation and photoconductor contamination are likely to occur. In addition, raw material polyolefin wax
If the intrinsic viscosity of (a) exceeds the above upper limit, even if the graft-modified polyolefin wax (A) prepared from the polyolefin wax (a) is also used as a toner raw material, the styrene-based polymer described below, etc. However, since the melt viscosity is too high, a sufficient releasing agent effect cannot be obtained. When the graft-modified polyolefin wax (A) is used as a binder, when the intrinsic viscosity of the polyolefin wax (a) is below the lower limit, the graft-modified polyolefin wax (a) obtained from the polyolefin wax is obtained. Even when (A) is used as a raw material of a toner composition, not only becomes a problem in the storage stability of the toner and the staining property to the photoreceptor, but also the melt viscosity is too low, so that a clear image cannot be obtained. . On the other hand, when the intrinsic viscosity of the raw material polyolefin wax (a) exceeds the above upper limit, even if the graft-modified polyolefin wax (A) prepared from the polyolefin wax (a) is also used as a toner raw material, paper Cannot be obtained.

Here, the polyolefin wax (a) is ethylene,
Propylene, 1-butene, 1-hexane, 4-methyl-
An α-olefin homopolymer such as 1-pentene or 1-decene, or a copolymer of two or more α-olefins having an intrinsic viscosity within the above range. For example, a polyolefin wax obtained by thermal decomposition of the above-mentioned α-olefin (co) polymer obtained by a high pressure method or a medium / low pressure polymerization method using a transition metal compound catalyst,
High-pressure polymerized polyolefin wax obtained by radically polymerizing ethylene at high pressure, ethylene or ethylene and ethylene α-olefin in the presence of a transition metal compound catalyst
Polyolefin wax or ethylene / α-olefin copolymer wax, polyolefin wax, propylene / 1-butene copolymer wax, poly-1-butene wax, and poly-4 obtained by low-pressure polymerization
Examples thereof include -methyl-1-pentene wax and propylene-4-methyl-1-pentene copolymer wax. The polyolefin wax mentioned here also includes oxides of polyolefin wax. The oxygen content in this case is usually within 10% by weight. Of these, preferred are polyethylene wax, ethylene / propylene copolymer wax, ethylene / 1-butene copolymer wax, ethylene-4-methyl-1-pentene copolymer wax, polypropylene wax, and propylene. Examples include wax, propylene / 1-butene copolymer wax, and poly-1-butene wax.

The amount of grafted acrylonitrile or methacrylonitrile grafted onto the polyolefin wax (a) is
(a) It is necessary that the amount is 1.0 to 100 parts by weight, preferably 2.0 to 80 parts by weight, based on 100 parts by weight. When the modified polyolefin wax (A) is used as a release agent, if the grafting amount exceeds the above upper limit, the compatibility between the modified polyolefin wax (A) and the binder resin such as styrene resin becomes too large. , It becomes difficult for the modified polyolefin wax in the toner to be released on the surface of the melt at the time of fixing, and the effect as a release agent becomes poor, and if the lower limit is not reached, binding of styrene-based resin, etc. The compatibility with the agent resin becomes poor, and the effects of releasability, cohesion resistance, drum contamination resistance, bending resistance, etc., which are improved with the improvement of compatibility, become smaller. is necessary.

Further, when the modified polyolefin wax (A) is used as a binder, if the grafting exceeds the upper limit, the phenomenon of adhesion to the heat fixing roller occurs when this is used as a toner raw material, and the graft amount is less than the lower limit. If it is lower than the above range, the colorant is poorly dispersed and the fixability to paper is insufficient, which is not preferable.

In addition, the intrinsic viscosity of modified polyolefin wax (A) is usually
0.03 to 0.9 dl / g, 0.08 to 0.8 dl / g
It is preferably in the range of g.

The graft-modified polyolefin wax (A) of the present invention may be obtained by a known method. For example, a method in which the polyolefin wax is directly melted or melted in a solvent, and acrylonitrile or methacrylonitrile is added with or without a radical initiator for grafting can be exemplified. Radical initiators include organic peroxides, organic peresters such as benzoyl peroxide, dichlorobenzoin peroxide, dicumyl peroxide, di-tert-butyl peroxide,
2,5-Dimethyl-2,5-di (peroxybenzoate) hexyne-3,1,4-bis (tert-butylperoxyisopropyl) benzene, lauroyl peroxide, tert-
Butyl peracetate, 2,5-dimethyl-2,5-di (tert
-Butylperoxy) hexyne-3,2,5-dimethyl-
2,5-di- (tert-butylperoxy) hexane, tert-
Butyl benzoate, tert butyl perphenyl acetate, tert-butyl perisobutyrate, tert-butyl peru sec-octoate, tert-butyl perpivalate, cumyl perpiperate and tert-butyl perdiethyl acetate, other azo compounds, for example Azobis-
There are isobutyl nitrile and dimethylazoisobutyrate. Among these, dicumyl peroxide, di-tert
-Butyl peroxide, 2,5-dimethyl-2,5-di (tert
-Butylperoxy) hexyne-3,2,5-dimethyl-
Dialkyl peroxides such as 2,5-di (tert-butylperoxy) hexane and 1,4-bis (tert-butylperoxyisopropyl) benzene are preferred. The temperature during the reaction is usually 130 ° C to 350 ° C, preferably 135 ° C to 300 ° C.
It is in the range of ° C.

The graft-modified polyolefin wax (A) includes vinyl monomers (C) other than acrylonitrile, such as (meth) acrylic acid ester, vinyl chloride, maleic anhydride, styrene, vinyltoluene, and α-methyl. Styrene or the like may be grafted. Particularly preferred among these are styrene-based monomers such as styrene, vinyltoluene, and α-methylstyrene. Regarding the grafting amount of these other vinyl monomers (C), the total grafting amount of acrylonitol or methacrylonitrile (b) and (c) is 3 to 120 parts by weight with respect to 100 parts by weight of polyolefin wax (a). It is preferably part. Also,
The ratio of (b) and (c) to be grafted can be arbitrarily selected, but it is preferable that the weight ratio (c) / (b) does not exceed 2.5 in general.

[Binder resin when using modified polyolefin wax (A) as a release agent]

Examples of the binder (thermoplastic) resin such as a styrene-based polymer used in the toner of the present invention are styrene-based resins as described in JP-A-50-27546, that is, a polymer consisting of a styrene-based single polymer. Alternatively, the copolymerization of a styrene monomer and another vinyl monomer can be used as it is. That is, as the monomer for forming the copolymer, p-chlorostyrene, vinylnaphthalene, for example, ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene, for example, vinyl chloride, vinyl bromide, vinyl fluoride. Vinyl halides such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, etc., such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-acrylate. Octyl, dodecyl acrylate, 2-chloro-ethyl acrylate, phenyl acrylate, α-methyl acrylate, methyl methacrylate, ethyl methacrylate, n-methacrylate
Butyl and other α-methylene aliphatic monocarboxylic acid esters, acrylonitrile, methacrylonitrile, acrylamide, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether, such as vinyl methyl ketone, vinyl hexyl ketone, methyl iso There are vinyl ketones such as propenyl ketone, and N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone. Can be copolymerized with the body. Suitable stainless steel polymers have a number average molecular weight of greater than about 2000, particularly preferably 3000 to 30,000, and their styrene content is at least about 25% by weight based on the total weight of the styrene polymer. Is preferred.

Examples of other thermoplastic resins include polyester resins, ketone resins, maleic acid resins, coumarone resins,
Examples thereof include a phenol resin, an epoxy resin, a terpene resin, polyvinyl butyral, polybutyl methacrylate, polyvinyl chloride, polyethylene, polypropylene, polybutadiene, and an ethylene-vinyl acetate copolymer.

Of the above, styrene polymers or polyester resins are preferable.

[Resin that may be added in addition to the case where the modified polyolefin wax (A) is used as an adhesive]

The thermoplastic resin which is the main material of the electrostatic toner does not necessarily have to be the acrylonitrile or the methacrylonitrile grafted polyolefin wax (A) in total amount, and the thermoplastic resin has a content of 20% by weight or more, preferably 50% by weight or more. If so, an electrostatic toner having an improved offset phenomenon is obtained. Examples of the thermoplastic resin for electrostatic toner that is used as a mixture with the modified polyolefin wax (A) include various thermoplastic resins exemplified above as the binder.

(Coloring material (B))

The coloring material (B) used in the electrostatic toner of the present invention is carbon black, phthalocyanine blue, aniline blue, alcohol oil blue, chrome yellow, ultramarine blue, quinoline yellow, lamp black, rose bengal, diazo yellow, rhodamine B lake, Carmin 6
B, one or more pigments or dyes such as quinacridone derivatives. If necessary, oil-soluble dyes such as azine type nigrosine, indyuline, azo type, anthraquinone type, triphenylmethane type, xanthene type and phthalocyanine type dyes may be used in combination for the purpose of complementary color and charge control.

[Other ingredients]

The toner of the present invention may contain other components in addition to the components (A) and (B) or the above-mentioned thermoplastic resin, as long as the effects of the present invention are not impaired. For example, other toner additives such as a charge control agent and a plasticizer may be included. The addition amount of these is arbitrary and appropriate. Further, when the modified polyolefin wax (A) is synthesized, a polymer containing acrylonitrile or methacrylonitrile produced as a by-product during the graft reaction may be contained.

[Toner Preparation Method of the Present Invention]

When the electrostatic toner of the present invention is used as a two-component electrostatic toner, the graft-modified polyolefin wax is used.
(A), the colorant (B) and optionally the thermoplastic resin of the above-exemplified examples are mixed by a known method such as a ball mill or an attritor, and then kneaded with a heating two rolls, a heating kneader, an extruder, or the like, It is cooled and solidified, coarsely crushed with a hammer mill, crusher, etc., then finely pulverized with a ball mill, attritor, etc. by adding a jet mill, a vibration mill or water, and an average particle size of about 5
35μ is used as the electrostatic toner. When the two-component electrostatic toner is used as a developing material, it is used in combination with a carrier. A known carrier is, for example, a diameter of 200 to 700 μ.
Silica sand, glass beads, iron balls or magnetic material powders of iron, nickel, cobalt and the like can be used. In the case of using the modified polyolefin wax (A) as a releasing agent in a two-component electrostatic toner Modified polyolefin wax
The amount of (A) is 1 to 20 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the thermoplastic resin including the binder resin. In addition, the modified polyolefin wax
When (A) is used as a binder, the amount of modified polyolefin wax (A) is the sum of (A) and the thermoplastic resin to be added.
20 parts by weight or more, preferably 50 parts by weight or more is added to 100 parts by weight.

When the electrostatic toner of the present invention is used as a one-component electrostatic toner, the modified polyolefin wax (A), the colorant (B), and if necessary, the thermoplastic resin and the magnetic material powder described above are used. Can be adjusted by the same method as that for preparing the two-component electrostatic toner. As the magnetic material powder added to the one-component electrostatic toner, magnetite fine powder of 1 μm or less is usually used. Powders of metals such as iron, nickel and nickel, their alloys, oxides, ferrites and mixtures thereof can also be used. The amount of each component in a one-component electrostatic toner is usually a modified polyolefin wax.
The total amount of the thermoplastic resin including (A) and the magnetic material may be 100 parts by weight, and the magnetic material may be mixed in a ratio of 40 to 70 parts by weight. If the amount of the magnetic material is too large, the electric resistance of the electrostatic toner decreases, the charge retention of the electrostatic toner deteriorates, and the image may blur. Further, the softening point of the electrostatic toner becomes high, which may make appropriate fixing difficult. On the other hand, when the amount of the magnetic material is too small, the function as the electrostatic toner is lost and the required charging ability is not easily obtained.
The modified polyolefin wax is added to the entire resin even in the case of one-component electrostatic toner.
The amount of (A) added is the same as in the case of the two-component electrostatic toner. If necessary, a known charge control agent may be added to the one-component electrostatic toner or the two-component electrostatic toner.

〔The invention's effect〕

Whether the modified polyolefin wax of the present invention is used as a release agent or a binder, the heat-fixing type electrophotographic developer of the present invention is peeled off from a heating roll or the like not only at a conventional temperature but also at a high temperature. Since it is excellent in the property, the offset phenomenon hardly occurs even if the fixing speed is increased by heating the heating roll or the like at a high temperature. Therefore, it is suitable for high-speed copying. Further, since it is excellent in fixing property to paper, sufficiently excellent performance can be obtained even when the temperature of a heating roll or the like is low, which is also suitable for energy-saving copying. Further, it has low cohesiveness, excellent phenomenon characteristics, and excellent bending resistance after fixing.

When the graft-modified polyolefin wax used in the present invention is used as a release agent, the modified polyolefin wax is not only excellent in compatibility with a binder resin such as a styrene-based polymer, but also various additives are added. It also has excellent compatibility or affinity with agents such as pigments and dyes, charge control, and plasticizers. Therefore, it also has the functions of enhancing the dispersibility in these binder resins, enhancing the physical uniformity of the toner such as load controllability, and improving the performance as a developer.

The effects of the present invention will be described more specifically with reference to the following examples. In addition, Examples 1 to 7 and Comparative Examples 1 to 5 are experimental examples showing the effect when the modified polyolefin wax (A) of the present invention is used as a release agent, and Examples 8 to 12 and Comparative Example 6 Nos. 7 to 7 are experimental examples showing the effect when the modified polyolefin wax (A) of the present invention is used as a binder.

〔Example〕

Example 1 (Preparation of acrylonitrile-grafted polyolefin wax) Intrinsic viscosity [η] 0.23 dl polymerized by Ziegler type catalyst
/ G polyethylene wax (homopolymer) (polyethylene wax used in the following examples are all polymerized by Ziegler type catalyst.) 500 g was charged into a 1.5 l glass reactor at 160 ° C. Dissolved. Then
Acrylonitrile 100 with stirring while maintaining the system temperature at 160 ° C
g and di-t-butyl peroxide (hereinafter referred to as DTBPO
8.8 g and 8.8 g are continuously added dropwise over 3 hours using separate dropping funnels, and after stirring at 160 ° C. for 1 hour, degassing is performed in a 10 mmHg vacuum for 1 hour in a molten state to remove volatile components. Removed and then cooled, then 20g of this
Dissolve it in 0 ml of para-xylene and mix the resulting solution with N, N at 60 ℃.
-Add to 600 ml of dimethylformamide (DMF) with stirring and cool to room temperature. 50 more solid parts
It was washed twice with 0 ml DMF and dried. The acrylonitrile content of the obtained solid part was quantified by ¹ H-NMR. The amount of graft thus obtained was 15.3 parts by weight based on 100 parts by weight of acrylonitrile-grafted polyethylene wax (that is, polyethylene wax.
(a) 18.1 parts by weight of acrylonitrile with respect to 100 parts by weight, and similarly, the value in parentheses () indicates the graft amount per 100 parts by weight of wax (a)). The acrylonitrile-grafted polyethylene wax is referred to as SW-1.

(Toner Adjustment and Copy Test) Styrene / n-butyl methacrylate copolymer (SANYO KASEI KOGYO Co., Ltd., Hymer SBM-600) 85 parts by weight, SW-1
4 parts by weight, 9 parts by weight of carbon black (manufactured by Mitsubishi Kasei Co., Ltd., diamond black SH), and 2 parts by weight of alloy dye (BASF made Zaboon Fast Black B) were mixed in a hole mill for 24 hours, then kneaded with a hot roll and cooled. Crush and classify 13
~ 15μ electrostatic toner was made. Next average particle size 50-80
The iron powder of μ was mixed as a carrier at a ratio of 120 parts by weight of electrostatic toner to 100 parts by weight of the carrier, developed on a selenium photoconductor by a conventionally known electrophotographic method, transferred onto a transfer paper, and 180 ° C. It was heat-fixed with the heating roll of. As a result, even after 5000 times of copying, a clear copy image was obtained as in the initial stage without any offset phenomenon or contamination, and almost no contamination of the heat roll or the photosensitive drum was observed.

Example 2 In the same manner as in Example 1, 500 g of polypropylene wax (homopolymer) of [η] 0.14 dl / g polymerized with a Ziegler type catalyst was added to 60 g of acrylonitrile, 55 g of styrene,
By adding 10.0 g of DTBPO (however, the reaction temperature is 170 ° C), 9.9 parts by weight of the acrylonitrile component (12.1
Parts by weight) and styrene / acrylonitrile-grafted polypropylene wax containing 8.0 parts by weight (9.7 parts by weight) of a styrene component. (SW-2) Next, 7 parts by weight of the SW-2, Heimer SBM-600
Was used in the same manner as in Example 1 except that 82 parts by weight, 9 parts by weight of diamond black and 2 parts by weight of savon-first black were used, and a copying test was conducted. As a result, even after 1,000 times of copying, it was as clear as the initial stage and the offset phenomenon,
A copy image without contamination was obtained, and contamination of the heat roll and the photosensitive drum was hardly recognized.

Further, a bending resistance test was conducted. The solid black image area after fixing was repeatedly bent 500 times, and the fixing degree before and after the bending was visually determined by peeling with a cellophane tape. As a result, it was found that there was almost no change after the bending test, and the bending resistance was excellent.

Example 3 In the same manner as in Example 1, 500 g of polypropylene wax having [η] of 0.31 dl / g and ethylene content of 3.2 mol% polymerized with a Ziegler type catalyst was added to 60 g of methacrylonitrile and D.
By adding 5.0 g of TBPO (reaction temperature 1
70 ° C.) Acrylonitrile-grafted polypropylene wax (SW-3) having an acrylonitrile amount of 8.3 parts by weight (9.1 parts by weight) was obtained.

Then, in place of using SW-1 in Example 1, the SW-3
A toner was prepared and a copying test was conducted in the same manner as in Example 1 except that was used.

As a result, even after 5000 times of copying, a copy image as clear as the initial stage and free from offset phenomenon and contamination can be obtained.
Almost no contamination of the heat roll and the photosensitive drum was observed.

Furthermore, the temperature change of the fluidity of the toner was examined. The toner was placed on a shere and the fluidity was visually determined. As a result, it was found that the fluidity of the one kept at 50 ° C for 48 hours was almost the same as that of the one kept at room temperature, and the fluidity was excellent even in the high temperature environment.

Example 4 In the same manner as in Example 1, [η] 0.21 dl / g, ethylene 4-methyl-1-pentene copolymer wax 500 g having a 4-methyl-1-pentene content of 10 mol%, 500 g of acrylonitrile, Nibirutoluene 70 g and DTBPO 11.5 g were added, and the amount of acrylonitrile grafted was 11.4 parts by weight (14.9
By weight, a vinyltoluene graft amount of 12.0 parts by weight (15.7 parts by weight) was obtained to obtain acrylonitrile / vinyltoluene grafted ethylene-4-methyl-1-pentene copolymer wax (SW-4).

Then, in place of using SW-1 in Example 1, the SW-4
A toner was prepared and a copying test was conducted in the same manner as in Example 1 except that was used.

As a result, even after 5000 times of copying, a copy image as clear as the initial stage and free from offset phenomenon and contamination can be obtained.
Almost no contamination of the heat roll and the photosensitive drum was observed.

Example 5 In the same manner as in Example 1, 500 g of polypropylene wax (homopolymer) of [η] 0.22 dl / g polymerized with a Ziegler type catalyst, 500 g of acrylonitrile and DTBPO40 were used.
by adding g (however, the reaction temperature is 170 ° C,
(Dripping time: 6 hours) Acrylonitrile-grafted polypropylene wax (SW-1) having an acrylonitrile-grafted amount of 43.0 parts by weight (75.4 parts by weight) was obtained.

Then, instead of using SW-1 in Example 1, the SW-5
A toner was prepared and a copying test was conducted in the same manner as in Example 1 except that was used.

As a result, even after 3000 times of copying, a copy image as clear as the initial stage and free from offset phenomenon and contamination can be obtained.
Almost no contamination of the heat roll and the photosensitive drum was observed.

Furthermore, the temperature change of the fluidity of the toner was examined in the same manner as in Example 3. As a result, the results obtained by holding the toner at 50 ° C. for 48 hours competed with those at the room temperature and the flowability was slightly deteriorated, but no lumps were generated, suggesting that there is no problem in practical use.

Example 6 In the same manner as in Example 1, 500 g of [η] 0.19 dl / g polybutene-1 wax (homopolymer) polymerized with a Ziegler type catalyst, 65 g of acrylonitrile, 23 g of styrene,
DTBPO 7.3g was added, acrylonitrile graft amount 10.5 parts by weight (12.3 parts by weight), styrene graft amount 4.0
Part by weight (4.7 parts by weight) of acrylonitrile / styrene-grafted polybutene-1 wax (SW-6) was obtained.

Then, instead of using SW-2 in Example 2, the SW-6
The toner was adjusted and the copy test was conducted in the same manner as in Example 2 except that was used.

As a result, even after 5000 times of copying, a copy image as clear as the initial stage and free from offset phenomenon and contamination can be obtained.
Almost no contamination of the heat roll and the photosensitive drum was observed.

Further, a bending resistance test was conducted in the same manner as in Example 2. As a result, it was found that the retention rate of fixing degree before and after the bending test was extremely high, and the bending resistance test was also excellent.

Example 7 In the same manner as in Example 1, 500 g of polypropylene wax having [η] 0.41 dl / g, 40 g of acrylonitrile and DT
Acrylonitrile graft amount by adding 3.3g of BPO
6.2 parts by weight (6.6 parts by weight) of acrylonitrile-grafted polypropylene wax (SW-7) was obtained.

Next, polyester resin (SANYO CHEMICAL INDUSTRIES HAIMER ES
508) 48 parts by weight, carbon black (Mitsubishi Kasei Kogyo M
2 parts by weight of A-100), 48 parts by weight of magnetic powder (Titanium Kogyo Mabiro Black BL-500), and 2 parts by weight of SW-7 were mixed by a ball mill for 24 hours and kneaded by a heating roll for 1 hour,
After that, it was finely pulverized with a jet mill and heat-treated with a spray dryer, and a zigzag classifier was used to obtain a magnetic toner having an average particle size of 15 μm. The magnetic toner was used to develop on a selenium photoreceptor by a conventionally known electrophotographic method, transfer it onto a transfer paper, and a durability test of 5000 times of copying was carried out at a heating roll temperature of 200 degrees. As a result, a good copy image was obtained without stains on the heating roll.

Comparative Example 1 In the same manner as in Example 1, 500 g of [η] 0.22 g / dl polypropylene wax (homopolymer) polymerized with a Ziegler type catalyst was added to 5.0 g of acrylonitrile and DTBPO 0.5.
g and added thereto, and reacted by heating at 170 ° C. for 2 hours to give an acrylonitrile-grafted polypropylene wax (SW-
8) was obtained.

Next, a toner was prepared and a copying test was conducted in the same manner as in Example 2 except that SW-8 was used instead of SW-2 in Example 2.

As a result, the sharpness of the image started to decrease after about 4000 times. At the same time, a polypropylene wax film (filming phenomenon) was partially observed on the surface of the photoconductor drum and the iron powder carrier.

Further, when a bending resistance test was performed in the same manner as in Example 2, remarkable toner peeling was observed along the bending line, which was inferior to that in Example 2.

Comparative Example 2 In the same manner as in Example 1, 300 g of polyethylene wax having [η] 0.11 dl / g, 350 g of acrylonitrile and DTB were used.
18.5 g of PO was added and the mixture was heated at 160 ° C. for 8 hours to obtain an acrylonitrile-grafted polypropylene wax (SW-9) with a graft amount of 52.0 parts by weight (108.3 parts by weight).

Then, instead of using SW-2 in Example 2, the SW-9
The toner was adjusted and the copy test was conducted in the same manner as in Example 2 except that was used. As a result, the releasability from the hot roll was poor, and the offset phenomenon and the contamination of the copy paper were observed.

Furthermore, when the temperature change of the fluidity of the toner was examined in the same manner as in Example 3, it was suggested that the toner having a temperature of 50 ° C. causes lumps of about 5 mm square or more and the fluidity is poor, which is a problem in practical use. The result is.

Comparative Example 3 [η] 1.36 dl / g and ethylene content 3.2 mol% of polypropylene were charged into an oclave with an internal volume of 1 liter, and pyrolysis was carried out at 340 ° C. for 13.5 hours while passing a slight amount of nitrogen.
[Η] 0.04 dl / g polypropylene wax was obtained.

Then, the polypropylene wax was used in the same manner as in Example 1 to obtain acrylonitrile-grafted polypropylene wax (SW-10) having an acrylonitrile graft amount of 14.7 parts by weight (17.2 parts by weight).

Next, in Example 1, in place of using SW-1, the S
A toner was prepared and a copying test was conducted in the same manner as in Example 1 except that W-10 was used.

As a result, the releasability from the hot roll is extremely poor, and also
A large amount of filming phenomenon was observed on the photoconductor drum and iron powder carrier.

Comparative Example 4 In the same manner as in Example 1, 500 g of polyethylene wax having [η] 0.82 dl / g, 70 g of acrylonitrile and DTB.
5.8 g of PO was added, and the mixture was heated at 180 ° C. for 2 hours to obtain acrylonitrile-grafted polyethylene wax (SW-11) having an acrylonitrile graft amount of 11.8 parts by weight (13.4 parts by weight).

Next, in Example 1, instead of using SW-1, the SW was used.
The toner was adjusted in the same manner as in Example 1 except that −11 was used, and 1000 copying tests were performed.

As a result, the releasability from the hot roll was poor, and the offset phenomenon and the contamination of the copy paper were observed.

Comparative Example 5 300 g of polypropylene used for adjusting SW-10 of Comparative Example 3 was charged into an autoclave having an internal volume of 1 l, and pyrolysis was carried out at 340 ° C. for 2.2 hours while circulating a slight amount of nitrogen.
The obtained polypropylene wax [η] is 0.10 dl / g.
It was.

Next, in Example 2, the toner was adjusted and the copying test was performed in the same manner as in Example 2 except that the above polypropylene wax was used in place of SW-2.

As a result, the sharpness of the image started to decrease from the 3500th copy. At the same time, a polypropylene wax film (filming phenomenon) was partially observed on the surface of the photosensitive drum and the iron powder carrier.

Furthermore, when the temperature change of the fluidity of the toner was examined at the same time as in Example 3, the toner after holding at 50 ° C. produced lumps of about 5 mm square or more, and the fluidity was extremely poor, which was practically used. The result suggests that there is a problem.

Example 8 100 parts by weight of acrylonitrile / styrene-grafted polybutene-1 wax (SW-6) prepared in Example 6, 5 parts by weight of carbon black (trade name: Diamond Black SH, manufactured by Mitsubishi Kasei), alloy dye (manufactured by BASF) The electrostatic toner consisting of 2 parts by weight of the Zombon fastest black B) was prepared in the same manner as in Example 1. Next average particle size 50-80
Iron powder of μ was mixed as a carrier at a ratio of 120 parts by weight of electrostatic toner to 100 parts by weight of carrier, and it was transferred onto a selenium photoreceptor by a conventionally known electrophotographic method, transferred, and heat-fixed with a heating roll. . As a result, even after 2000 times of copying, a copy image which was as clear as the initial stage and free from the offset phenomenon and contamination was obtained, and the contamination of the hot roll and the drum was not recognized.

Example 9 50 parts by weight of SW-150 obtained in Example 1, 50 parts by weight of low molecular weight polystyrene (commercial product: Hymer ST-95, Sanyo Kasei KK) and 5 parts by weight of the carbon black used in Example 1 and alloy dye 2 Parts by weight were kneaded and pulverized in the same manner as in Example 8 to obtain an electrostatic toner (including a carrier). Then, copying was carried out 10000 times in the same manner as in Example 8, and as a result, a clear image was obtained as in the initial stage, without any offset phenomenon, contamination, etc., and no contamination of the hot roll or drum was observed.

Comparative Example 6 An electrostatic toner was obtained in the same manner as in Example 8 except that low molecular weight polystyrene (trade name: Hymer ST-95, Sanyo Kasei KK) was used in place of SW-6 used in Example 8.
Then, 1000 times were copied in the same manner as in Example 8, and
The peeling from the hot roll was inferior, and the offset phenomenon and copy paper contamination were observed.

Example 10 40 parts by weight of SW-1 (acrylonitrile-grafted polyethylene wax) used in Example 1, magnetic powder (trade name: Maviroblack BL-500, Titanium Industry KK): 50 parts by weight,
Ethylene / vinyl acetate copolymer (Brand name: Evaflex, 460, Mitsui Polychemical KK): 10 parts by weight and carbon black (Brand name MA-100 * Mitsubishi Kasei KK): 2
Part by weight is mixed with a ball mill for 24 hours and then mixed with a heating roll.
After kneading for a while, the mixture was finely pulverized with a jet mill and then heat-treated with a spray dryer, and a magnetic toner having an average particle size of 15 μ was obtained with a zigzag classifier. Using the magnetic toner, a phenomenon was observed on a selenium photoreceptor by a conventionally known electrophotographic method, transferred onto a transfer paper, the heating roll temperature was set to 200 ° C., and a durability test of 5000 times of copying was performed. As a result, good copy images were obtained without stains on the heating roll and drum.

Example 11 SW-1 in place of 140 parts by weight of SW-140 used in Example 10
25 parts by weight and low molecular weight polystyrene used in Example 9:
A magnetic toner was prepared in the same manner as in Example 10 except that a mixture of 25 parts by weight was used as the resin component. as a result
Even after the 2000th copy, a good copy image was obtained without contamination of the heating roll and the drum.

Comparative Example 7 A magnetic toner was prepared in the same manner as in Example 10 except that 40 parts by weight of the low molecular weight polyethylene used in Comparative Example 6 was used instead of 140 parts by weight of SW-140 in Example 10. As a result 1000
In the copying machine, the heating roll was contaminated and the copied image was not clear.

Example 12 40 parts by weight of SW-5 used in Example 5 was used in place of 40 parts by weight of SW-1 in Example 10, and toner was prepared in the same manner as in Example 10 below. I made a copy. As a result, even after the copying, the heating roll and the drum were not contaminated, and a good copied image was obtained.

Claims (1)

[Claims] 1. A graft-modified polyolefin wax prepared by grafting acrylonitrile or methacrylonitrile within a range of 1.0 to 100 parts by weight with respect to 100 parts by weight of a polyolefin wax having an intrinsic viscosity of 0.05 to 0.8 dl / g.
A heat-fixing type electrophotographic developer comprising (A) and a coloring material (B).