JPS58149060A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To improve an electrophotographic toner, by using a resin mixture contg. a norbornene polymer as a binder resin. CONSTITUTION:Polynorbornene obtd. by ring opening polymn. of bicyclo 2,2,1 heptene-2 is embodied as a binder resin, and the norbornene polymer has a small rate of viscosity drop in relation to temp. rise as compared with ordinary toner resins and low stickiness of the melt. Since the cohesion of the toner itself becomes stronger than that of the adhesion of the toner to the roll in fixing, the toner hardly tends to stick to the roll. The other resin to be mixed with said resin is, preferably, a styrene resin from the view point of compatibility. A pigment or a dye can be added to the toner in a concn. enough to form a clear visible image on a recording material. In addition, other additives may be added to enhance kneading dispersibility and crushability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner for developing an electrostatic ffI image in one electron beam. Conventionally, many methods have been known as electrophotographic methods, but in general, photoconductive substances are used. A certain charge is applied to the photosensitive plate used, and the photosensitive plate is irradiated with the light source of the 1iii moat to be copied, forming an electrostatic charge of 11 m1.◎This electrostatic charge is concentrated with a filler and visualized. Generally, the image is transferred onto a transfer sheet such as paper, depending on the membership fee, and then heat-fixed. Furthermore, an electrostatic recording method is also known in which a charge is directly applied to an insulating layer to form an electrostatic charge 411# and a 3#i image is formed.

A mixture of colored powder called toner and iron powder, glass beads, etc. called carrier is used as a developer for developing the electrostatic a-moat.

Toner is generally used as a finely ground mixture of binder resin and colorant, but natural or synthetic resins are generally used as the binder resin, such as phenol resin, modified rosin, coumaron resin, and evoki resin. , polyester resin, polystyrene! MW1, styrene-butadiene copolymer, acrylic resin, polyacrylic ester resin, etc. are used alone or as a mixture of two or more types. Also, as a coloring agent, carbon black, organic pigment, dye, trioxide, etc. Iron (F@1Oa), Bae/Gara (F town 0
．． ) etc. are often used.

Heat these y/IIIliMk and the coloring agent to 18M,
The mixture is kneaded, cooled, and then coarsely pulverized using a hammer mill or the like, and then pulverized to a particle size of about 40 μm from VK5 μm to obtain an electrophotographic toner.

1 with these toners! Methods for fixing controlled toner on gold paper or the like include a heat chamber/vap type and a heat acetyl type. One type heat chamber has a problem with thermal efficiency, and as copying machines have become faster in recent years, they are no longer used. On the other hand, one type of heat roller has come to be commonly used as a fixing method to cope with higher speeds. In this method, the powder toner is passed between a pair of rollers and fixed by heat and pressure. However, this method tends to cause so-called offset m*, in which a part of the toner image adheres to the roll surface 11iK when the toner pile comes into contact with the roll. It has been effective in supplying liquids. However, in this case, a device is required to always supply a fixed amount of mold release liquid, and the device is also complicated. Moreover, problems such as oil leakage and generation of negative air due to heating tend to occur.
Ru. Therefore, recently, a method of performing constant M' with a heating roller without using a mold release liquid has been studied. For example, Tokukai#
849-42554, etc., a method of crosslinking a binder resin as in % JP-A No. 49-101051, or JP-A-50-68.
There are methods such as adding a rubbery substance such as No. 141.

However, as a result of various studies conducted by the present inventors, it has been found that when a releasing substance is added, a so-called filming phenomenon occurs in which a film of the releasing substance is formed on the surface of the photosensitive plate.
Crosslinking the binder II resin, which causes problems with fogging and image quality, results in rapid pulverization, and the problem of dispersion of the dye, which is compatible with the binder fIN resin and the binder fIN resin, is less likely to occur. This affects the charging stability and tends to cause problems such as -f phenomenon density changes or fogging. Furthermore, if all the rubbery substances are added, agglomeration tends to occur during storage, causing problems in fluidity. In this way, even if each of the conventional methods is adopted individually, the effect is small, so the reality is that a combination of two or more is put into practical use. You will face various problems. Therefore, the development of an improved toner that does not impair other physical properties of the toner is awaited.The object of the present invention is to solve the above-mentioned drawbacks, i.e., when a fixing roller that does not supply a release liquid is used. However, it is an object of the present invention to provide an electrophotographic toner that can efficiently and consistently adhere to a heated roller without causing toner offset. [Achieved by a toner using a tree layer mixture containing]

In the present invention, the 4Ir resin to be mixed with the norbornene polymer as a binder resin is polyamide IIW.
I, polyurethane resin, epoxy IIJ&, polyester resin, polyolefin resin, styrene type 1M side, etc., but styrene type resin is particularly preferred from the point of view of compatibility with norbornene type polymer. may be a homopolymer of styrene or a copolymer of styrene with another vinyl monomer (the styrene content is usually 25% by weight or more). Monomers include olefins, vinyl halides, vinyl esters, unsaturated carbs;
Norbornene-based polymers used in the present invention include /[(esters, anhydrides), glycidyl compounds, vinyl ethers, vinyl ketos, N-vinyl compounds, dienes, nido, lyl, compounds containing two or more vinyl groups, etc. The combined habicyclo(2,2,1)butene-2 and/l or its derivatives are prepared by a conventional method (for example, Japanese Patent Publication No. 55800/1983).
It is a polymer obtained by ring-opening polymerization or copolymerization according to the method described in No. , 1) hebutene-2, ethyl-5-bicyclo(12,1)hebutene-2 monomer in alkali such as butylene/-2; methoxy-5
-bicyclo(2,2,1)hebutene-2, ethoxy-5
-bisic112(2,2,1)hebutene-2oal=
+ 4 C 5-Biaclo(2,2,1)hebutene-
2-based monomer; cyano-5-bicyclo(2,2,1)hebutene-2: bicyclo(2,2,1)hebutene-2-5carboxylic acid ester monomer; bicyclo(241)hepte/ Examples include -2-5,6 dihydrocarbon/@O diester monomers and mixtures thereof. Typical polymers include polynorbornene, which is a ring-opening polymer of 1-2 to bicyclo(221). 0 Such norbornene-based polymers have a temperature characteristic of 11M viscosity and a temperature characteristic of 11M viscosity of general toner @ fat and 88 Unlike styrene resin, for example, the melt viscosity decreases less as the temperature rises, and the melt becomes less sticky. By mixing such a norbornene-based polymer into the binder resin, the offset resistance of the toner in the fixing temperature range can be greatly improved. Toner roller due to increased cohesive force
adhesion to the surface is less likely to occur.

The amount of norbornene-based polymer added is appropriately determined depending on its type and molecular weight, as well as the offset and pulverizability of the toner, but usually the total amount is required to prevent the offset phenomenon without losing the properties of the toner. It is necessary to add at least 4 (more than 11% by weight, preferably 5% by weight) to the total binder resin. Also, if it exceeds 50% by weight to the total binder resin, the temperature at which the offset phenomenon occurs will be too high, Since it exceeds the possible temperature increase range, there is no point in adding it, and the crushability is also somewhat deteriorated.The molecular weight of the norbornene/norbornene polymer is usually ~000 to 5.5% on a weight average from the viewpoint of offset resistance. [1[I Q, OOO preferably 50Q, 000 to 2.OOQ, 000.

Note that from the viewpoint of dispersibility, it is preferable that the amount of glue is small.O The toner of the present invention is desirably colored with a suitable coloring agent, that is, a pigment or a dye. Toner colorants are known, such as carbon black, nigrosine 6, aniline t1 calco oil blue, chrome yellow, ultramarine blue, quinoline yellow, methylene blue chloride, monastral blue, malachite green oxalate,
These include Lampblack, Rose Bengal, Monastralette, Stan Black BM, Spiron Black TOH and mixtures thereof. The pigment or dye is applied to the toner onto the brass member. It can be present in the toner at a sufficient concentration to highly pigment the toner to form an Al11I oJ visual image.

The toner of the present invention may further contain other additives for improving kneading and dispersibility and crushability.

Additives for improving crosstalk dispersion include, for example, higher fatty acids such as stearic acid, oleic acid, palmitic acid, linoleic acid, ricinoleic acid, or caprylic acid, zinc, manganese, iron, cobalt, nickel, copper, and magnesium. metal salts such as, higher fatty acids having 28 or more carbon atoms, natural or synthetic paraffins, fatty acid esters or partially saponified products thereof, alkylene bis fatty acid amides such as ethylene bisstearoyl amide, such as polyethylene, poly-10 pyrene. Examples include low molecular weight polyalkyrefs such as. One or more of these compounds may be contained in the toner in an appropriate combination.The amount of these compounds added to the toner is generally 0 to 25 parts by weight, preferably 2 to 25 parts by weight per 1σ50 parts by weight of the resin component of the toner. 10 parts by weight of O. Similarly, O-phthalic or phthalic acid esters, such as dicyclohexyl phthalate, diphenyl phthalate, dihydroabiethyl phthalate, jetoxyethyl phthalate, dimethyl isophthalate, e.g. Benzoic acid esters such as penzoate, pentaerythritol tetrabe/soate, saccharose benzoate, chryceryl tribenzoate, )'J dicycloxyl citrate, toeha P-) luenesul 7o/amide, N-cyclo Nato sulfonamides, triphenyl phosphate, chlorinated paraffins, chlorinated polyphenyl, polyethylene glycol, such as 7-tene oil, paraffin oil, aromatic These compounds can be added as crosstalk dispersion improvers such as mineral oils and silicone oils.The amount of these compounds added to the toner is generally 0 to 50 parts by weight, preferably TF5 to 40 parts by weight, based on 100 parts by weight of the resin component of the toner. Parts by weight can be added.

Natural rosin or synthetic rosin can be used as an additive to improve grindability. The amount of these compounds added to the toner is generally 0 to 30 parts by weight, preferably 5 to 20 parts by weight, per 100 parts by weight of the machine side component of the toner. This toner is an excellent toner that does not generate offset noise, but it also has good pulverization and dispersion properties, is fixed at 11 Fi # brightness, has little capri, and does not cause filming on the photosensitive plate for a long period of time. Next, the present invention will be described as an example.5! In addition, all parts and parts in the examples are based on weight.

'1 Example 1 Boristile/II fat (Esso company, Pikov stick D
-125) 70 parts, carbon black (manufactured by Yamet Co., Ltd., Su-Gal 400R) 8 parts, polynorbornene (cap
30 parts of Nosolex (manufactured by Ohimi Co., Ltd., molecular weight 2 million), 2 parts of metal-containing dye (manufactured by Orient Chemical Co., Ltd., Bondron 5-51), and 1 part were prepared in a ball mill for 24 hours.
#I-kneaded for 1200150 minutes in a roll mill, cooled, coarsely pulverized, finely pulverized, classified the toner having a particle size of about 5 to 25μ, and added 100 parts of polystyrene resin without adding polynorbornene as in the case of the sample. A comparative sample was a toner that was treated in the same way as the sample above except for the following.

10 parts of these toners were mixed with 90 parts of iron powder carrier each having an average particle size of about 50-80 microns to form two developers. These developers were then used to electrostatically develop the powder by conventional electrophotographic methods. The toner was transferred onto a transfer paper, and the front side was made of polyfluoroethylene, and a metal roller and a silicone roller with a /':2-f intershape were applied to the ms direction of the transfer paper. The toner image was fused and fixed by pressure contact with a heating fixing roller 1200 to 210C consisting of 1200 to 210C. After performing the operation, a transfer paper without toner gI was brought into pressure contact with a fixing roller under the same conditions as above, and stains caused by toner offset on the transfer paper were observed.

As a result, when the comparative sample toner was used, significant stains due to toner offset were observed on the transfer paper, but when the inventive sample toner was used, no stains were generated on the KFi transfer paper and no toner offset occurred. It was observed that no phenomenon occurred. Furthermore, the same thing happened when the foot-wearing operation 'frs, ooo' was repeated.

Example 2 Copolymer sog of 7 (l of styre/and 30 l of loop tyl acrylate), polynorbornene (oaFc)
20 parts of Hi-Otori Nosolex), 8% of Carmen Black (Regal 400R, manufactured by Cabot), gold-containing dye (Bondore 5-51, manufactured by Orient Chemical Co., Ltd.)
) 2@f After preliminary preparation in a ball mill for 24 hours, SS kneading was carried out in a roll mill at 1200 for 20 minutes. Since this kneaded product did not stick to the roll, it was concluded that the two types of combination used had good compatibility. Next, a toner was prepared by processing in the same manner as in Example 1 and used as a sample. A toner was prepared as a comparative sample by the same procedure as above, except that 100 parts of styrene/-louptyl acrylate copolymer was used without adding polynorbornene.Using these two types of toner, the fixing roller The same operations as in Example 1 were performed, except that a silicone rubber roller color forming Rouleau 5- was used and the fusing temperature was 190 to 200 C, and the offset properties of each toner were examined. As a result, it was found that a significant offset phenomenon occurred when the toner of the comparative sample was used, but it was found that no toner offset phenomenon occurred when the toner of the present invention sample was used.

Example 3 Epoxy l1jii' (manufactured by Shell, Ebiko) 100
4) 70 parts, polynorbornene (aay Chigi・
Co., Ltd., Endo Kagaku Co., Ltd., Bondron 8-31) were mixed and processed in the same manner as in Example 1 to prepare a toner. A toner was prepared as a comparative sample by the same procedure as above except that the amount of fir was changed to 100 parts.

Using these two types of toners, we performed the same operations as in Example 1 of the actual ljA and examined the offset properties of each toner.As a result, when the comparative sample toner was used, a significant toner offset phenomenon occurred. However, when the toner of the sample of the present invention was used, it was observed that no toner offset effect occurred at all. 5
82 M), 80 parts of polynorbornene (0 (IFChi-M, Nosolex), 20 parts of carbon black (
Regal 400R (manufactured by Cabot), 8 parts, metal-containing dye (
Two parts of Bontron B-51 (manufactured by Orient Chemical Co., Ltd.) were mixed and treated in the same manner as in Example 1 to prepare a toner, which was used as a sample. A toner was prepared as a comparison sample using the same procedure as above except that 100 parts of polyester resin was used without adding polynorbornene polymer. These two types of toner were used, and the fixing roller was made of silicone rubber. Use a roller and set the fusing temperature to 190-200C
The same operations as in Example 1 were carried out except that the offset properties of each toner were examined. As a result, it was found that a significant toner offset phenomenon occurred when the comparative sample toner was used, but when the inventive sample toner was used, the toner offset phenomenon did not occur. Admitted.

Example 5 Su? V780 Hakuto 2-ethylhexyl acrylate) 2
90 parts of a copolymer with a molecular weight of about 200,000 consisting of 01, 10 parts of polynorbornene (0 (IPChimi, Nornlex), 8 parts of carbon platter (Regal 400R, manufactured by Cabot), metal-containing dye (manufactured by Orient Chemical Co., Ltd.) , Bontron B-51) and treated in the same manner as in Example 1 to prepare a toner and use it as a sample.Styrene-2-ethylhexyl acrylate copolymer was mixed without adding borinorborne/l- A toner was prepared as a comparison sample by performing the same operation as above except that the volume was 100 parts.

Using these two types of toner, the same operations as in Example 1 were performed to examine the offset properties of each toner.As a result, when the toner of the comparison sample was used, a significant toner offset phenomenon occurred. However, when the toner of the present invention sample was used, it was confirmed that the toner offset phenomenon did not occur at all.
Ten thousand copolymer 95i1S, polynorbornene (CaPO
The same procedure as in Example 1 was carried out by mixing 5 parts of Norn Rex, manufactured by hjmis, 8 parts of carbon black (Regal 400R, manufactured by Nakayabot Co., Ltd.), and 2 parts of metal-containing dye (manufactured by Orient Chemical Co., Ltd., Bontron 8-51). Process and create all toner,
It was used as a sample. A toner was prepared as a comparative sample by the same procedure as above except that 100 parts of styrene-butadiene copolymer was used without adding any polynorbornene polymer. These two types of toner were used as a fixing roller. Use a silicone rubber roller and set the fusing temperature to 190-200.
As Example C, the other operations were the same as in Example 1, and the offset properties of each toner were examined. As a result, it was found that a significant toner offset phenomenon occurred when the toner of the comparison sample was used, but it was found that no toner offset phenomenon occurred when the toner of the present invention sample was used. Admitted.

Patent applicant: Zeon Corporation

Claims (1)

[Claims] An electrophotographic toner characterized in that a @ fat mixture containing a norbornene polymer is used as a binding fat.