JPS59200251A - Toner - Google Patents

Abstract

PURPOSE:To obtain a toner suitable for a heat roll fixing method by constituting a toner contg. a silicone oil having an amine at the side chain and having a prescribed MI value. CONSTITUTION:Such a toner contg. a silicone oil having an amine at the side chain and having 0.01-10g/10min MI value is formed. For example, 100pts.(wt) styrene methacrylate/divinyl benzene copolymer (MI value is 1.4g/10min), 60pts. magnetite, 3pts. nigrosine dye, 5pts. PE wax, and 20pts. pulverous powder of silicic acid treated with 40% silicone oil having an amine at the side chain of 830 amine equiv. are mixed, and the mixture is intimately kneaded. The mixture is ground after cooling and the black pulverous powder is botd. On the other hand, 0.4pt. the pulverous powder obtd. by subjecting 100pts. the pulverous powder of silicic acid to a spraying treatment by 20pts. said silicone oil is added to 100pts. the black pulverous powder. The toner suitable for a heat roll fixing system is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new toner suitable for a hot roll fixing method.

In image forming apparatuses such as electrophotographic copying materials, various methods and devices have been developed for the process of fixing toner images on paper or the like. Currently, the most common method using acids is the so-called hot roll fixing method, which applies heat and pressure at the same time.This method involves bringing the image-receiving sheet carrying the toner image into contact with a heated roller to fix the toner image on the image-receiving sheet. This is the way to do it. However, when such a fixing method is used, troubles such as so-called offset tend to occur. Zero offset is an undesirable phenomenon in which a part of the toner image carried on the image receiving sheet is transferred to the roller surface. This is a big problem in developing.

In the currently commonly used hot roll fixing devices, the roller that comes into contact with the toner image usually has at least a surface layer formed of silicone rubber or fluororesin with good release properties, and the surface layer is coated with a layer to prevent offset. In order to prevent fatigue on the roller surface, a release oil such as silicone oil is often applied. However, the method of applying oil has problems such as that the fixing device becomes complicated due to the provision of the oil application system and that the evaporation of the oil causes discomfort to the user. Therefore, it is not preferable to try to prevent offset by applying oil.
Rather, the current situation is that it is desired to develop a toner with good offset resistance and a wide fixing temperature range.

It is true that in the development of a hot roll fixing system, it is not appropriate to require excessive release properties from the roll material and release oil, which are limited in terms of materials, in terms of fixing system design. Developing offset-free toner is important for creating inexpensive and compact fixing devices.

Traditionally, the key points in developing offset-free toner are the viscosity and releasability of the toner when it is melted. In other words, it is necessary to design the toner composition so that the toner has a suitable viscosity with little change in viscosity due to temperature changes during bath melting, and also has releasability against hot rolls. It is. These are, in words,
This is a problem with the thermal and physical properties of the toner.

However, the present inventors have discovered the following phenomenon that cannot be explained solely by the thermal and physical properties of the toner. 100M parts of styrene-butyl methacrylate copolymer, 10 parts by weight of low molecular weight polypropylene, 6N carbon black
Create a toner consisting of parts. This toner is mixed with carrier iron powder to form a negatively charged toner, and a positive latent image is developed and transferred onto plain paper. Let N be the unfixed image obtained. Further, the same toner is mixed with surface-coated carrier iron powder to form a positively charged toner, and a negative latent image is developed and transferred onto plain paper. Let P be the unfixed image obtained. Next, a fixing test was performed on images N and P using a fixing device having a fixing roller whose surface was coated with polytetrafluoroethylene and had a halogen lamp inside, and a pressure roller whose surface was coated with silicone rubber. Ta. The results were as shown in Table 1 below.

Table 1 A. Fixing properties B: Offset resistance ○: Good Δ: Fairly good ×: Poor Also, when the plain paper used for the fixing test is passed through the fixing device, the paper becomes positively charged, and two Charges roller soldiers.

Considering this fact and the results of the retention test above,
The inventor of the present invention conjectures as follows. In other words, as a result of the charging experiment, the paper is positively charged at the time of fixing, so if the toner on the image is positively charged, the toner will move away from the paper and transfer to the fixing roller. When subjected to force, it becomes easier to offset the paper, which is difficult to adhere to. Conversely, if the toner on the image is negatively charged, it will not easily adhere to the paper and will be difficult to offset. Therefore, image N has excellent fixing properties and offset resistance, but image P has poor fixing properties and offset resistance despite using the same toner. It should be noted that in Cloth-1, the image P has poor offset resistance at low temperatures fff (150 to 170°C). It is thought that if the temperature of the fixing roller is high (190 to 200° C.), the toner melts sufficiently and comes into close contact with the paper, so that the influence of the electric force is almost eliminated.

Under these circumstances, efforts were made to develop a toner suitable for the hot roll fixing method.

That is, the present invention was made to solve the above problems, and contains a silicone oil having an amine in the side chain,
The toner has an MI value of 0.01 to 10 g/10 minutes.

The reason why the toner of the present invention is effective in the hot roll fixing method is considered to be due to the following reasons. As mentioned above, the offset phenomenon in hot roll fixing is largely related to the frictional electricity between the roll and a member that supports the unfixed image, such as transfer paper. In other words, if the transfer paper supporting a positively charged unfixed image becomes positively charged due to friction with the fixing roll and pressure roll, it is likely to be offset. In this way, offcents can be reduced. The toner of the present invention contains a silicone oil having a structure having an amine in the side chain, which is partially transferred to the fixing roll and the mouth pressure roll in the fixing process, and as a result, the amine is added to the side chain. It is thought that because the silicone oil having this structure has strong positive chargeability, the negative chargeability of the fixing roll and pressure roll to the transfer paper is reduced or reversed, and offset is reduced.

Another important reason for using this silicone oil in the present invention is that the silicone oil having a structure having an amine in the side chain provides the toner with strong positive chargeability and high humidity stability. Further, the MI value of the toner of the present invention is from 0.01 to ]Og/ICI (preferably 0.
．． 05 to 8 g/10 minutes) is because this is a necessary condition for the toner of the present invention containing the specific silicone oil to have excellent eyebrow setting properties, anti-offset properties, and durability.

In the present invention, the MI value was determined by a manual cutting method using an apparatus described in JIS K7210.

However, the measurement conditions were 1258C1 load of 10 kg and a filling amount of 5 to 8 g.

As the silicone oil having an amine in the side chain used in the present invention, a silicone oil containing a structural unit represented by the formula (I) can generally be used.

1 藏-S i-0- R2...4...(1) Formula (where R,
1R2 represents an alkyl group or an aryl group, R3, R
4 represents hydrogen, an alkyl group, or an aryl group. However, the above alkyl group and aryl group may contain an amine, or may have a substituent such as a halogen within a range that does not impair chargeability. ) Preferred examples of commercially available silicone oils having an amine in the 1R1 chain include the following amino-modified silicone oils. Hidden 5F84
17 (manufactured by Tone Silicone) 1zuo
3500KF393 (manufactured by Shin-Etsu Chemical)
60 360KF857() 7
0 830KF860() 250
7600KF861 (#)
3500 2000KF862()
750 1900KF864 ()
1700 3800KF865()
90 4400KF369 (/J)
20 320KF383'(〃
) 20 320X-22
-3680 (N) 90 8
800X-22-380D (〃 ) 2
300, 3800X-22-380IC (〃
) 3500 3800X-22-3
810B(p) 1300 17
00 In the present invention, the amine equivalent is equivalent M per amine (g/eqiv), which is the value obtained by dividing the molecular weight by the number of amines per molecule.

The content of the silicone oil of the present invention is suitably 0.01 to 20% by weight based on the total amount of the toner.

As the toner binder used in the present invention, any resin polymer with a conventionally known composition can be used as long as the MI value as a toner is the above-mentioned value. For example, styrene polymer, For polymers with a relatively wide molecular weight distribution such as acrylic polymers, polyesters, and polyamides, the MI value of the binder is set at a temperature of 11.
0.2 to 10 g/1 at 0°C and 10 kg load
0 minutes is appropriate.

As the coloring agent, carbon black, iron black, graphite, nigrosine, ultramarine blue, phthalocyanine blue, benzidine yellow, Hansa yellow, quinacridone, metal complex dyes, various lake pigments, etc. may be used.

Furthermore, if necessary, nigrosine, substituted quaternary ammonium salt, dimethylamine ethyl methacrylate polymer,
Vinyl pyridine polymers, acrylamide polymers, basic dyes and their lakes, colloidal silica, low molecular weight polyethylene, low molecular weight polypropylene, bisamides, higher fatty acids and their metal salts, etc. may be added.

In order to make the above-mentioned toner a magnetic toner, ferromagnetic elements and alloys and compounds containing these may be used, such as magnetite, hematite, and ferrite.
- Substances conventionally known as magnetic materials such as alloys and compounds of cobalt, nickel, and manganese, and other ferromagnetic alloys may be added. Furthermore, if necessary, it may be mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite powder, etc., and used as a developer for electrical latent images. Colloidal silica fine powder or an abrasive such as cerium oxide may be added to prevent toner from sticking.

In the present invention, the silicone oil having an amine in its side chain may be present in any form, including in the toner particles or attached to the entrance surface of the toner particles.

In a preferred embodiment, the BET specific surface area determined by the nitrogen adsorption method is 0.5 mVg or more (preferably 0.5 to 400 m2).
//g) The silicone oil of the present invention is preferably present in the toner particles or on the surface of the toner particles in the form of adsorption on the surface of the inorganic fine powder. Such inorganic fine powders include, for example, alumina, titanium dioxide, barium titanate, magnesium titanate, titanium t)S:calcium, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, and limestone. , various inorganic oxide pigments,
Chromium oxide, cerium oxide, red iron oxide, iron oxide, iron sand,
Various ferrites such as γ-ferrite, barium ferrite, strontium ferrite, rare earth ferrite,
Examples include antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, calcium carbonate, and fine silicic acid powder.

The electrophotographic process to which the toner of the present invention is applied includes electrical negative potential f4! For example, the process of forming ``4'' includes the Carlson method, in which a negative charge is imparted to an N-type photoconductor such as a zinc oxide photoconductor or a seven-layer organic conductor, and imagewise exposure is performed.
There are well-known methods such as the NP method, in which a photoreceptor having three layers (insulating layer, P-type photoconductor, and conductive substrate) is negatively charged, then positively charged or AC neutralized at the same time as image exposure, and then the entire surface is exposed. . Examples of methods for developing an electrically negative latent image include the magnetic brush method described in U.S. Pat.
Examples include a method using an insulating magnetic toner, a powder cloud method, a touchdown development method, an impression method, and a method using a high-resistance magnetic toner, which is described in Japanese Patent Application Laid-open No. 42141 (Japanese Unexamined Patent Publication No. 42141). The hot roll fixing step may be performed using, for example, a fixing roller whose surface is coated with a fluororesin, silicone rubber, or silicone resin that has a heat source inside, and if necessary, a fixing roller that has a heat source inside and whose surface is coated with a fluororesin, silicone rubber, or silicone resin. Pressure rollers covered with a cone resin and a metal sheet are arranged approximately parallel to each other, and approximately 0.01 to 10 kg7/cI is applied between both rollers.
There is a method of thermally fixing an image passing between both rollers by applying a linear pressure of about n. In this process, if necessary, a roller for supplying thermal energy,
A cleaner for removing offset toner, a means for applying oil, etc. may be provided. Further, if necessary, there is a step of transferring the developed image on the latent image carrier onto a transfer member, and for that purpose, a corona transfer method, a bias roll transfer method, a magnetic transfer method, etc. can be used. In this case, it is usually necessary to clean the remaining toner on the latent image carrier, and for this purpose, a blade cleaning method, a fur brush cleaning method, a magnetic brush cleaning method, etc. can be used.

In the above explanation, an electrically negative latent image means a latent image that is electrically negative with respect to the developing electrode, and a latent image that has a negative charge,
``Reversal development is performed not only for images but also for latent images with positive charges.'' Section 8 also includes this.

The present invention will be described in detail with reference to Examples below.

[Example 1] Styrene-butyl methacrylate-divinylbenzene (
Weight ratio 70:30:0.5) copolymer (M, I).

Value 1.4 g/10 min, 110°Cl Okg load)1
00 parts by weight, 60 parts by weight of magnetite, 3 parts by weight of nigrosine dye, 5 parts by weight of polyethylene wax and 25°C.
Fine silicic acid powder (specific surface area approximately 130 m2//
g) 20 parts by weight were mixed and melt-kneaded using a roll mill. After cooling, the mixture was coarsely pulverized in a hammer mill, and then jet-pulverized (finely pulverized in a mill). Then, it was classified using an air classifier to obtain black fine powder with a particle size of about 5 to 20 μm.

On the other hand, silicic acid fine powder synthesized by dry method (specific surface area approximately 1
30n12//g) while stirring 100 parts by weight,
The temperature was maintained at approximately 250°C and 20 parts by weight of a silicone oil having an amine in the side chain having a viscosity of 70 cps at 25°C and an amine equivalent of 830 were sprayed and processed for 10 minutes.

A toner was prepared by adding 0.4 parts by weight of the treated silicic acid fine powder to 100 parts by weight of the black fine powder.

This toner (7) had an MI value of 2.6 (125°Cl
0kg load).

FIG. 1 shows an embodiment of an image forming apparatus to which the toner of the present invention can be applied.

Reference numeral 1 denotes an OPC photoreceptor, which consists of an OPC photosensitive layer and a grounded conductive substrate, and rotates at a constant speed in the direction of the arrow. (
Here, the charging device (linear velocity 100 mm/sec)2 is a well-known charging device, which discharges a -7 KV negative polarity corona to apply a negative charge onto the photoreceptor 1.

A light image irradiation device 3 projects an original image, a light image, or a light beam modulated by an image signal, thereby forming a negative latent image on the photoreceptor 1. The formed negative latent image is developed using the developing device 4. The toner 4all in the developing device is made of 100 parts by weight of styrene-butyl methallylate copolymer and has a melt viscosity of 280c at 140°C.
A developing sleeve 4b made of SUS is made of positively charged magnetic toner consisting of 10 parts by weight of PS polypropylene, 2 parts by weight of nigrosine dye, 600 parts by weight of magnetic powder, and 2 parts by weight of colloidal silica, and has a magnet 4C fixed inside. By rotating in the direction of the arrow at approximately the same linear speed as the photoreceptor 1,
Iron blade 4d and sleeve 4b set to 250μ
It passes through the gap and is coated onto the sleeve 4b. The coated toner is transferred from the sleeve 4b to the photoreceptor 1 according to the pattern of the latent image at the minimum gap between the photoreceptor 1 and the sleeve 4b.

Here, the gap between the sleeve 4b and the photoreceptor 1 is set to 250μ, and a DC bias of -150μ and an AC bias of 1.2 KHz and 1.5 KV are applied to the sleeve 4b. The generated developed image is transferred onto transfer paper 6, which is one type of plain paper, by a 17 KV charging device 5. Next, the image is fixed by a fixing device 7 having a fixing roller 7a coated with polytetrafluoroethylene and having an internal heat source and a pressure roller 7b coated with silicone rubber. Note that 7c is a cleaner impregnated with oil.

On the other hand, the remaining toner on the photoreceptor 1 that has not been transferred is removed from the photoreceptor 1 by a cleaner 8.

The resulting image was clear. A running test of 20,000 sheets was conducted, and the image was good, and the amount of offset toner attached to the cleaner 7c was extremely small. The pressure roller was still positively charged.

[Comparative Example 1] A black fine powder was obtained in the same manner as in Example 1, except that the silicone oil having an amine in the side chain was not contained. A toner was prepared by adding 0.4 weight of fine silicic acid powder (specific surface area 130 mX/g, untreated) synthesized by the dry method of Example 1 to 100 weight of this black fine powder. When this toner was used in the same manner as in Example 1, only poor images were obtained.

[Comparative Example 2] 100 parts by weight of the black fine powder of Comparative Example 1 was mixed with 0.00 parts by weight of silicic acid fine powder (specific surface area: 90 m2/'g untreated) synthesized by a wet method.
4 parts by weight were added to prepare a toner. When this toner was used in the same manner as in Example 1, a good image was obtained. A running test of 20,000 sheets was conducted, but there was a large amount of offset. The pressure roller was still negatively charged.

[Comparative Example 3] A black fine powder was obtained in the same manner as in Example 1, except that a silicone oil made of polydimethylsiloxane was used instead of the silicone oil having an amine in the side chain. After that, the same procedure as in Comparative Example 2 was carried out, and the amount of offset was large. The pressure roller was negatively charged.

[Example 2] Viscosity at 25°C 50 Cpss Amine equivalent 36
When the same procedure as in Example 1 was carried out except that a silicone oil having an amine in the side chain of 0 was used, a clear image without fogging was obtained, and the amount of offset was small. The pressure roller is positive [Example 3] Styrene-butyl methacrylate-dimethylaminoethyl methacrylate-divinylbenzene (weight ratio 70:
25:5:0.6) copolymer (MI value 0, 9 g
710 minutes, 110'C1ok load) 70 parts by weight, Stinnputadiene (weight ratio 85:15) copolymer (MI
Value 0.4g/10min, 110'010kg load) 30 parts by weight, phthalocyanine blue, 4 parts by weight of low molecular weight polypropylene, and viscosity at 25°C 3500
cl) s1 30 parts by weight of silicic acid fine powder (specific surface area: about 90 m2//g) treated with 30 weight percent of silicone oil having an amine in the side chain with an amine equivalent of 3800 was mixed.Example 1 In substantially the same manner as above, blue fine powder having a particle size of approximately 5 to 20 μm was obtained.

12 parts by weight of the above blue fine powder, 0.3 parts by weight of treated silicic acid fine powder, and carrier iron powder (trade name, EFV2)
50/400, manufactured by Nippon Tetsuko Co., Ltd.) were mixed to prepare a developer. On the other hand, a negative electrostatic latent gap is formed on the OPCG light body, this is developed with the developer described above (17), and the resulting powder image is transferred to plain paper. (composed of a fuser roll coated with silicone rubber and a pressure roll whose surface was coated with silicone rubber).

A clear blue image with no fog was obtained. A running test of 20,000 sheets was conducted, and the amount of offset was small and good.

[Examples 4' to 7] Silicone oil 40 having an amine in the side chain of Example 1
Instead of weight percent, viscosity, amine equivalent, and throughput are used (3500 cps, respectively).

2000.50 weight percent), (20 cps, 3
20.30% by weight), (250cps, 76
00.45 weight percent), (2300 cps, 38
Example 1 was carried out in substantially the same manner as in Example 1, except that a silicone oil having an amine in the side chain (0.00.40% by weight) was used, and good results were obtained. The toner MI values are 2.9, 2, 3, 2, 8, and 2.5, respectively.
was.

[Examples 8 to 10] Silicone oil 40 having an amine in the side chain of Example 1
:l! Instead of silicic acid fine powder treated with ffi percent, the throughput, fine powder, and specific surface area are respectively (2
02fi percent, titanium oxide, 10 mVg),
(30Xi?'-1y), calcium carbonate, i smV
g), (60i 44%, silica, 3oom
When the same procedure as in Example 1 was carried out except that Vg), good results were obtained. Toner M
The I values were 3.9, 3, 2, and 1.8, respectively.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an embodiment of an image forming apparatus to which the toner of the present invention can be applied. 1 is a photoreceptor, 4 is a developing device, 4a is a toner, 6 is an ID transfer paper, 7 is a fixing device, 7a is a fixing roller, and 7b is a pressure roller. Applicant: Canon Co., Ltd. Agent: Gi Marushima ``1''; Proceedings: Seiichi Neichi (spontaneous) July 26, 1981 Patent Application No. 74554 2, Title of the Invention Relationship between Toner 3 and the person making the amendment Patent applicant address 3-30-2 Shimomaruko, Ota-ku, Tokyo Name (100
)Representative of Canon Co., Ltd. Ryu Kaku Part 4, Agent address: 3-30-25 Shimomaruko, Ota-ku, Tokyo 148, Specification subject to amendment 6, Contents of the amendment (1) The scope of the claims is attached in the attached document. Correct as expected. 2. Claims (1) A toner containing silicone oil having an amine in its side chain and having an MI value of 0.01 to 10 g/10 minutes. -0

Claims (1)

[Claims] Contains silicone oil with amine in the side chain, MI
A toner having a value of 0.01 to 10 g/10 minutes.