JPS59101685A - Toner image fixing method - Google Patents

Abstract

PURPOSE:To prevent offset phenomenon staining a reverse side by incorporating at least a titanic acid deriv. represented by a certain general formula in a material in direct or indirect contact with the outer circumference of a fixing roller. CONSTITUTION:At least a titanic acid deriv. represented by general formula I is incorporated, e.g., in a cleaning material, and a toner image bearing support is fed to a fixing device to fix the toner image. The active group of said titanic acid deriv. reacts with the unsatd. part or other active part of the binder resin of the toner caught with the cleaning material to cause the mutual cross-linking of the molecules of the binder resin, resulting in increase of the mol. wt. and the melt elasticity of the toner. Consequently, although the toner is heated to a temp. higher than the fixing temp. with a fixing heating roller, it is restrained from transferring to the heating roller, and further to a pressing roller, and hence, the offset phenomenon of staining the reverse side is prevented. In formula I , R<1>, R<2> are each alkyl or aryl, and R<3> is H or alkyl.

Description

Detailed Description of the Invention The present invention is applicable to electrophotography, electrostatic recording, electrostatic printing, etc.
The present invention relates to a toner image fixing method for developing a latent image formed on a support with toner and fixing the toner image formed on the support to the support.

In the past, various types of fixing devices have been proposed and known for fixing such toner images. 2. Description of the Related Art A contact heating type fixing device is widely put into practical use, and includes a heat roller for fixing, and a pressure roller that rotates in the same direction while being in pressure contact with the heat roller.

The contact heat fixing method is preferable in various respects as described above, but in this method, since the toner image and the fixing heat roller come into contact with each other, the toner image adheres to the heat roller and There is a disadvantage that the toner adhering to the supporting body holding the succeeding toner image re-adheres, and the fixed image becomes smeared.Therefore, it is necessary to clean/dub the toner adhering to the heated roller, and conventional cleaning webs, cleaning grades,
Cleaning members such as clinic rollers are used.

However, when such a leaning member is provided, a so-called back surface contamination phenomenon occurs. This back-side staining phenomenon occurs when the toner material accumulated on the cleaning member receives excessive heat, and the toner material transfers to the heated roller and stains the surface of the support such as transfer paper that is subsequently fed. Furthermore, this is a phenomenon in which the back surface of the support is stained by the toner material that is transferred to the pressure roller that is being pushed out by the heat roller and transferred to the pressure roller.

When we investigated the cause of this back-side staining phenomenon, we found that the elasticity of the toner during melting has an important relationship with this back-side staining phenomenon. That is, conventionally? As binder resins for toners, for example, thermoplastic resins containing styrene-acrylic copolymers as a main component have been praised, but these resins have low elasticity when melted, so they easily transfer.
For this reason, even if the S is collected by the cleaning member, it may be removed when the heater of the heat roller is turned on, etc.
The toner material deposited on the J-ning member may be at the set temperature of the heat row 2, for example! When heated to a temperature higher than 1110 to 60 degrees Celsius, the heat transfers to the roller, resulting in staining of the back surface. It should be noted that toners whose elasticity at the time of melting is high enough to prevent backside staining from occurring have poor fixing properties (it is difficult to fix them sufficiently).

The present invention has been made based on the above-mentioned circumstances, and it is an object of the present invention to provide a toner image fixing method that does not cause the back surface stain phenomenon.

The purpose of this is to provide a fixing method in which a support supporting a toner image is brought into pressure contact with the fixing roller 2 to fix the toner image on the support. This is achieved by a toner image fixing method characterized in that a small amount of a titanic acid derivative represented by the following general formula (A) is present in a member that directly or indirectly contacts the outer circumferential surface of the fixing roller.

General formula CA] (However, R1 and R2 represent an alkyl group or an aryl group, and R3 represents a hydrogen atom or an alkyl group.) The present invention will be specifically explained below.

What is the toner image of this invention? In a fixing device equipped with a hot roller for fixing to fix the image on the support, a member (also referred to as the above-mentioned A titanic acid derivative represented by the general formula [A] is present, and in this state the support is fed to the fixing device and the toner image supported thereon is fixed. The fixing temperature here is 130~
The temperature is preferably 230°C.

According to the method described above, it is not necessarily clear by what mechanism titanic acid derivatives are effective in preventing the occurrence of backside staining, but it is possible that titanic acid derivatives are effective in preventing the occurrence of backside staining, but they are effective in preventing unsaturated moieties or other active moieties in the binder resin of toner. Due to the reactive bonding, the molecules of the binder resin become cross-linked to each other, increasing the molecular weight. As a result, the elasticity of the toner substance collected on the cleaning member when melted increases, and therefore, the toner substance collected on the cleaning member becomes more elastic when it is melted, and therefore it is fixed by the heat roller for fixing. Even if the toner substance is heated to a temperature higher than the above temperature, the transfer of the toner substance to the heat roller 2 is suppressed, and furthermore, the transfer to the pressure roller is suppressed, and the occurrence of the back surface staining phenomenon is ultimately prevented. Presumed.

In the general formula (A), R1 and R2 represent the same or different alkyl groups, or k represents an aryl group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a hegetyl group, Examples of aryl groups include octyl, decyl, dodecyl, tetradecyl, hexadecyl, and octadecyl groups, and examples of aryl groups include phenyl, tolyl, xylyl, and
-butylphenyl group, naphthyl group, etc. R3 represents a hydrogen atom or an alkyl group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and the like.

Specific examples of the titanic acid derivative represented by the general formula (A) shown in 01-2 include the following.

Exemplary compound (A-1) 1 "Glen Act 7" (manufactured by Ajinomoto Co., Ltd.) [A-2] 1 "Glen Act 11" (manufactured by Ajinomoto Co., Ltd.) [A-3-,] (A-4) CA-5) Toners suitably used in carrying out the method of the present invention include polymers or copolymers obtained from acrylic esters or methacrylic esters, which are generally preferred as binders for this type of toner, such as The styrene monomer for the styrene component in this styrene-acrylic copolymer includes, for example, styrene, 0- Methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tcrt-
Butylstyrene, pn-hexylstere, pn-
Octylstyrene, p-n-/nylstyrene p-n-
Tesilstyrene/, p-n-)" Tesilstyrene, p
-Methoxystin V7, p-phenyls f V ;/,
Examples include p-chlorstyrene, 3.4-)chlorstereno, and the like. Examples of the acrylic monomer for the acrylic component σ) in the stainless-acrylic copolymer include methyl acrylate, ethyl acrylate, and n-ph acrylate.

Chill, isobutyl acrylate, acrylic chloride.

n-octyl acrylate, dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-chloroacrylic methyl, methyl methacrylate, methacrylate Acid ether, globyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methacrylate α-methylene aliphatic monocarbo/acid esters such as acrylated phenyl, dimethylaminoether methacrylate, and diethylaminoethyl methacrylate; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide, and seven others. be able to. These monomers can be used alone or in combination.

If the titanic acid derivative represented by the general formula (A) is a liquid itself, it may be left as is, but if it is a solid, it may be in a liquid state as a whole, such as a solution or a dispersion. The members that come into direct or indirect contact with the outer peripheral surface of the heat roller for fixing are constructed of a liquid holding body made of a porous material, or are constructed in combination with a liquid holding body, and a liquid titanic acid derivative is applied to this liquid holding body. It is preferable to impregnate and retain.

Specifically, as shown in FIG. 1, there is a fixing heat roller l provided with a coating layer made of Teflon cI7 on the outer peripheral surface of the metal drum, and a metal drum disposed so as to be in pressure contact with the heat roller l. Pressure-welding o consisting of a silicone rubber layer provided on the outer peripheral surface of
-92, and a heater 3 is provided in the internal space of the heat roller l.
The footwear is further provided with 4 cleaning rollers that are in contact with and follow the heat roller 1, and the cleaning roller 4 is made of silicone foam rubber on the outer peripheral surface of the metal shaft core 5. A liquid retaining layer 6 is formed, and a surface layer 7 made of heat-resistant nylon felt is provided on the outer peripheral surface of the liquid retaining layer 6, and the liquid retaining layer 6 is made of a titanic acid derivative represented by the general formula [A]. Let's keep it impregnated. P is a support, T is a toner image, and W is a support passage.

When using an apparatus with such a configuration, the cleaning roller 4 is placed on its outer circumferential surface and collects the toner deposited on the heated roller 21, so that toner substances are deposited on the outer circumferential surface. However, since the titanic acid derivative has leached from the internal liquid retaining layer 6 to the outer peripheral surface of the cleaner/growler 4, the toner collected on the outer peripheral surface or the toner substance deposited on the outer peripheral surface So that its elasticity increases when melted,
As a result, even if the heater 3 of the heat roller 1 is turned on and the toner material on the cleaning roller 4 is heated and melted, it is prevented from being transferred to the heat roller l, and as a result, the toner material on the cleaning roller 4 is prevented from being transferred to the heat roller l. Transfer of toner material is inhibited, and the occurrence of backside staining can be prevented.

FIG. 2 shows a liquid supply roller lli and a roll 12.1 having the same structure as the chestnut 727 growler 4 in FIG. 1.
According to this example, the toner material collected and deposited on the cleaning web 14 has elasticity when melted. As a result, the occurrence of the back surface staining phenomenon is reliably prevented, and the service life of the cleaning/gripping web 14 is lengthened.

The one shown in FIG. 3 has 20 brush-type cleaning rollers.
A liquid holding material 21 is provided, and this liquid holding material 21 is impregnated with a titanic acid derivative.

Also in this example, the same effects as in the example of FIG. 1 can be obtained.

As described above, according to the present invention, when a toner image is fixed by a contact heating fixing method, the toner material collected in the cleaning section after being deposited on the fixing heat roller is melted. Since the elasticity is increased, the toner substance does not transfer to the heat roller, which would otherwise occur if the elasticity did not increase, and therefore, there is no further transfer to the pressure roller, thereby preventing the back surface staining phenomenon from occurring. As a result, a clearly fixed visible image can always be obtained. In addition, in order to prevent the back surface staining phenomenon, it is not necessary to use a binder resin of the toner that has high elasticity when melted (therefore, it is possible to avoid sacrificing the fixing properties of the toner itself. Even at this point, a good visible image is formed.

It goes without saying that the method of the present invention can be carried out using an apparatus having a configuration other than that of the illustrated example, and is not limited to the apparatus that supplies the titanic acid derivative to the cleaning member as in the illustrated example, for example, For example, a roller-shaped member holding a titanic acid derivative may be brought into contact with the outer circumferential surface of the heating roller (in this case, the toner adhering to the heating roller comes into contact with the titanic acid derivative and then removed from the cleaning member). It is preferable that the member holding the titanic acid derivative be provided in contact with the area of the heating roller of the bowl upstream of the cleaning area of the cleaning member.

As already mentioned, it is preferable to use the titanic acid derivative as a liquid as a whole, but in this case, a suitable carrier liquid can be used, and it is preferable that the carrier liquid is stable against heat. . Furthermore, if the carrier liquid has release properties, this carrier liquid will also be supplied to the surface of the heat roller, even if only slightly, so that the toner of the toner image to be fixed on the fixing unit will be transferred to the heat roller. It has the effect of suppressing adhesion. From this point of view, it is preferable to use silicone Meilke as the carrier liquid. The ratio of the carrier liquid such as silicone mail and the titanic acid derivative varies depending on the at type of the binder resin of the toner, but is selected from the range of l:99 to 99:1, and is usually 95 to 50:5 to 50. .

Examples of the present invention will be described below.

Example 1, Carbon gI! An electrophotographic copying machine with one-leg landing roller "U"
- Using a modified BixVJ (Konishi Roku Photo Industry Co., Ltd. #), the exemplified compound (A-1) was added to the fixing roller in an amount of 1% by lO.
A 3,000-copy test was conducted using a developer consisting of a toner impregnated with a toner containing styrene-acrylic acid ester resin as a main component.

As a result, almost no stains were observed on the front and back surfaces of the 3,000 copies obtained. After completing the copy test, the toner material on the cleaner/growler was solidified.

On the other hand, in a copy test conducted in the same way, the fuser port was impregnated with only silicone oil. When the number of copies reached 2000, stains appeared on the back side of the copies.

Example 2 In place of the exemplified compound (A=1) in Example 1, 3 was prepared in the same manner as in Example 1 except that exemplified compound (A-z) w was used.
A copy test was conducted 000 times.

As a result, almost no stains were observed on the front and back surfaces of the 3,000 copies obtained. Furthermore, the toner material on the cleaner/growler after the copy test was solidified and became one piece.

On the other hand, in a copy test in which the fixing roller was impregnated only with silicone oil and conducted in the same manner, stains appeared on the back side of the copy after the number of copies reached 2,000.

[Brief explanation of the drawing]

FIGS. 1 to 3 are explanatory sectional views each showing an example of the structure of a fixing device suitably used in carrying out the method of the present invention. l... Heat roller 2... Pressure roller 3...
Heater 4...Cleaning roller 5...
Axial core 6...Liquid retention layer 7...Surface layer
11...Liquid supply roller 12.13...Roll 14...Cleaning web 20...Brush type cleaning roller 21...Liquid retaining material Year 1 Figure 2 Figure 30

Claims (1)

[Scope of Claims] 1)) In a fixing method in which a support supporting a toner image is brought into pressure contact with a fixing roller to fix the toner image on the support, the toner image is directly or indirectly contacted with the outer circumferential surface of the fixing roller. A toner image fixing method characterized in that a small amount of a titanic acid derivative represented by the following general formula (A) is present in a member. General formula [A] (wherein R and R represent an alkyl group or an aryl group, R represents a hydrogen atom or an alkyl group.)