JPH09169917A - Antistatic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a (transparent) antistatic resin composition good in dispersibility of electrodoncutive powder therein, and causing little variation in the electroconducivity of the composition depending on thedispersion condition for the electroconductive powder in the resin. SOLUTION: This antistatic resin composition is obtained by dispersing unstaturatedly fluorinated carbon black having >=0.5 fluorination degree as the electroconductive powder in a resin and is case of obtaining the transparent composition the carbon black having >=0.7 fluorination degree is dispersed within 1-10wt.% content in the composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antistatic resin composition, and more specifically, a member requiring antistatic properties in the field of image forming apparatus such as electrophotographic apparatus,
For example, the present invention relates to an antistatic resin composition that can be used as a charging roller, a transfer roller, a fixing roller, a protective layer of an electrophotographic photosensitive member, or the like.

[0002]

2. Description of the Related Art As an antistatic resin composition, it is known that a conductive powder is dispersed in a resin, and as the conductive powder, a metal powder such as aluminum, iron, zinc or tin,
Metal oxide powders such as tin oxide, antimony oxide and indium oxide, or carbon black are widely used. When metal powders or metal oxide powders are dispersed in resin coatings, the powders have a large specific gravity and a large structural difference from the resin, so they tend to settle and the conductive powder is added to the resin. It is difficult to obtain an antistatic resin composition having good dispersibility in which the body is uniformly dispersed. When carbon black is used as the conductive powder, the specific gravity is smaller than that of the metal powder or the metal oxide powder, and the structural difference from the resin is small, so that the dispersibility is relatively good. But,
Due to the presence of secondary aggregates of carbon black, the conductivity of the antistatic resin composition varies depending on the conditions under which the carbon black is dispersed in the resin. In addition, since carbon black is black, it is difficult to obtain a transparent antistatic resin composition when transparency is required.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to charge an electrically conductive powder having a good dispersibility and causing little variation in the electrical conductivity depending on the dispersion condition of the electrically conductive powder in a resin. It is providing a preventive resin composition. Further, another object of the present invention is that the dispersibility of the conductive powder is good, and the conductivity is less likely to vary depending on the dispersion condition of the conductive powder in the resin. It is providing a preventive resin composition.

[0004]

The above-mentioned object of the present invention is achieved by the antistatic resin composition described in the claims. That is, the invention of claim 1 is an antistatic resin composition comprising a conductive powder dispersed in a resin, wherein the conductive powder is an unsaturated fluorinated carbon black having a fluorination degree of 0.5 or more. It is an antistatic resin composition characterized by being present. The invention of claim 2 provides an antistatic resin composition comprising a resin and conductive powder dispersed therein,
The antistatic resin composition is characterized in that it contains 1 to 10 wt% of unsaturated fluorinated carbon black as a conductive powder having a fluorination degree of 0.7 or more. The invention of claim 3 has a volume resistivity of 10 ^{8 to} 10 ¹³ Ω · cm.
The antistatic resin composition is characterized by:

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
An embodiment of the present invention corresponding to claim 1 is an antistatic resin composition in which a conductive powder is dispersed in a resin, wherein the conductive powder has a fluorination degree of 0.5 or more and is unsaturated. A characteristic is that it is made of carbon black. According to this embodiment, by dispersing unsaturated fluorinated carbon black having a fluorination degree of 0.5 or more in the resin, the dispersibility becomes good, and the conductivity does not vary depending on the dispersion conditions. An antistatic resin composition can be obtained. Further, in the embodiment corresponding to claim 2, in the antistatic resin composition in which the conductive powder is dispersed in the resin, the conductive powder has a fluorination degree of 0.7 or more and is unsaturated. It is characteristic that it contains 1 to 10 wt% of carbon black. Thus, the resin has a fluorination degree of 0.
Dispersion of 1 to 10 wt% of unsaturated fluorinated carbon black of 7 or more provides good dispersibility, less variation in conductivity due to dispersion conditions, and transparency, antistatic Resin composition can be obtained. The embodiment corresponding to claim 3 is characterized in that the volume resistivity is 10 ^{8 to} 10 ¹³ Ω · cm, and the volume resistivity is 10 ^{8 to} 10 ¹³
When it is Ω · cm, it becomes suitable as an antistatic resin composition.

The fluorinated carbon black used in the present invention is obtained by reacting carbon black such as channel black, furnace black or acetylene black, graphite, pitch, activated carbon and the like with fluorine gas at an appropriate temperature. Fluorinated carbon black that has been completely fluorinated (saturated fluorinated carbon black) is (C
F) _X , which is actually (CFn) _X 1 ≦ n <
It is in the state of 1.2. This is because excess fluorine is adsorbed on the outside of the carbon black crystals. The fluorinated carbon black that has been completely fluorinated is an insulating substance, but the fluorinated carbon black that has not been completely fluorinated (unsaturated fluorinated carbon black) is close to carbon black by adjusting the value of n. It is possible to obtain from fluorinated carbon black having a volume specific resistance to fluorinated carbon black having a volume specific resistance which is close to insulating property.

As described above, in the partially fluorinated carbon black, the degree of fluorination is 0.5 or more and the unsaturated fluorinated carbon black is dispersed in the resin or the resin solution to obtain good dispersibility. In addition, the conductivity of the antistatic resin composition is less likely to vary depending on the dispersion conditions, and the antistatic region is 10
An antistatic resin composition having a volume resistivity of ⁸ to 10 ¹³ Ω · cm can be easily obtained. As the resin used in the present invention, for example, polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, Examples thereof include, but are not limited to, melamine resin, polyamide resin, butyral resin, and fluororesin. In particular, when the resin contains 1 to 10 wt% of unsaturated fluorinated carbon black having a fluorination degree of 0.7 or more, the dispersibility is good, and the conductivity may vary depending on the dispersion conditions. It is possible to obtain an antistatic resin composition having a small amount and further transparency.

<Example 1> The present invention will be described below with reference to specific examples, but the present invention is not limited thereto. Example 1 Carbon black (acetylene black) was treated with a mixed gas of fluorine and nitrogen at 260 ° C. and the degree of fluorination was changed to 0.3, 0.5, 0.7, 0.
A fluorinated carbon black of 9,1.1 was obtained (in which case the degree of fluorination was saturated at 1.1). 5 parts by weight of each fluorinated carbon black having these degrees of fluorination was dispersed together with 5 parts by weight of an acrylic resin and 90 parts by weight of a toluene by a ball mill for 48 hours, and then applied on a SUS foil and dried to form a film having a thickness of 10 μm. An antistatic resin composition in the form of a strip was obtained.
With respect to each antistatic resin composition thus obtained, the dispersion state of the fluorinated carbon black was observed by an optical microscope, and the degree of fluorination was 0.5, 0.7,
The dispersibility was good in the antistatic resin composition using 0.9 or 1.1 fluorinated carbon black,
The dispersibility was poor in the antistatic resin composition using fluorinated carbon black having a fluorination degree of 0.3.

When the volume resistivity of these antistatic resin compositions was measured, the degree of fluorination was 0.
In the antistatic resin composition using fluorinated carbon black of 5, 0.7 and 0.9, the volume resistivity is 10
^It was in the range of ⁸ to 10 ¹³ Ω · cm and was suitable as an antistatic resin composition. Further, the respective fluorinated carbon blacks having the above fluorination degree and the non-fluorinated carbon blacks were dispersed with toluene in a ball mill for 48 hours, and the particle size distribution (number average particle diameter) was measured. Table 1 shows the results. The particle size distribution was measured by a centrifugal sedimentation type measuring device. As shown in Table 1, those having a degree of fluorination of 0.5 or more have a small number average particle diameter. This is because when the degree of fluorination exceeds 0.5, the fluorination of the carbon black surface is almost completed. It is believed that this is because the carbon black gradually spreads into the inside of the carbon black, secondary aggregates (structures) between the carbon blacks are not formed, and the inside of the carbon black is fluorinated and carbon black particles are formed. It is considered that the carbon black particles are destroyed and the size of the carbon black particles themselves is reduced, and the dispersibility is improved by these.

Example 2 Carbon black (furnace black) was treated at 260 ° C. with a mixed gas of fluorine and nitrogen, and the degree of fluorination was reduced to 0 by changing the treatment time.
Fluorinated carbon blacks of 3, 0.5, 0.7, 0.9 and 1.15 were obtained (in this case the degree of fluorination was saturated at 1.15). 5 parts by weight of each fluorinated carbon black having the above fluorination degree and 5 parts by weight of non-fluorinated carbon black were added to 95 parts by weight of polyethylene, and kneading was carried out using a three-roll mill, and each kneading time was changed to charge each of them. An inhibitory resin composition was obtained. FIG. 1 shows the relationship between the kneading time and the volume resistivity of the antistatic resin composition using each carbon black. Further, three rolls were used by changing the compounding amount of each fluorinated carbon black having the above fluorination degree and non-fluorinated carbon black.
The mixture was kneaded for minutes to obtain respective antistatic resin compositions. FIG. 2 shows the relationship between the compounding amount and the volume resistivity of the antistatic resin composition using each carbon black.
Shown in As is clear from FIG. 1, the antistatic resin composition obtained by kneading an unsaturated fluorinated carbon black having a fluorination degree of 0.5 or more has a volume specific resistance of the same even if the kneading time is changed. The antistatic resin composition has a small change and the volume resistivity is less affected by the kneading conditions. It is considered that unsaturated fluorinated carbon black having a degree of fluorination of 0.5 or more has a small amount of secondary aggregates of carbon blacks. Further, as is clear from FIG. 2, the antistatic resin composition obtained by kneading unsaturated fluorinated carbon black having a fluorination degree of 0.5 or more has a volume resistivity depending on the blending amount of the carbon black. 10 ⁸ to 10 ¹³ Ω, which is the antistatic region
An antistatic resin composition having a volume resistivity of cm can be easily obtained. <Example 3> Polyurethane resin containing 1,3,5,10,20,30 wt% of fluorinated carbon black having a fluorination degree of 0.3 obtained in Example 1 (blending amount with respect to the resin). The paint was dispersed by a ball mill for 48 hours, then applied on a polypropylene sheet and dried,
5μ thickness when peeled off from polypropylene sheet
Six types of film-shaped antistatic resin compositions of m were obtained. Further, the fluorination degrees obtained in Example 2 were 0.5, 0.
Using 7 and 0.9 fluorinated carbon blacks, 6 kinds of antistatic resin compositions were obtained for each fluorinated carbon black in the same manner as above. The haze value of the antistatic resin composition thus obtained was measured using a fully automatic direct reading haze computer (manufactured by Suga Test Instruments Co., Ltd.). The relationship between the degree of fluorination of fluorinated carbon black and the blending amount of fluorinated carbon black in the antistatic resin composition and the haze value (%) is shown in Table 2 of FIG.
Shown in The numbers in parentheses indicate haze values. Table 2
As is clear from the above, the degree of fluorination is 0.7 or more, and the amount of unsaturated fluorinated carbon black is 1 to 10 wt.
% Of the antistatic resin composition has a haze value of 10% or less, which makes it possible to obtain an antistatic resin composition having good transparency. This has a fluorination degree of 0.
It is considered that, in the case of fluorinated carbon black of 7 or more, since the secondary agglomeration is particularly small in the unsaturated carbon black, the continuous black portion disappears and the particle size becomes small, so that light is easily transmitted. However, because some carbon chains due to secondary aggregation remain, the hue becomes black or brown, and this is why the haze value decreases even if the blending amount of fluorinated carbon black exceeds 10 wt%. Conceivable. The results of measuring the volume resistivity of these antistatic resin compositions are shown in Table 3 of FIG. As is clear from Table 3, these had a volume resistivity suitable as an antistatic resin composition.

[0011]

As described above, according to the present invention, in the antistatic resin composition in which the conductive powder is dispersed in the resin, the conductive powder has a fluorination degree of 0.5 or more and is unsaturated. By using a certain fluorinated carbon black, an antistatic resin composition having good dispersibility of conductive powder and less variation in conductivity depending on the dispersion condition of the conductive powder in the resin can be obtained. Obtainable. Further, according to the present invention, in the antistatic resin composition in which the conductive powder is dispersed in the resin, the conductive powder has a fluorination degree of 0.7.
As described above, 1 to 1 of unsaturated fluorinated carbon black is used.
By containing 0 wt%, the dispersibility of the conductive powder is good, and the conductivity does not vary depending on the dispersion condition of the conductive powder in the resin, and the antistatic resin has transparency. A composition can be obtained.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the kneading time and the volume resistivity of antistatic resin compositions using each carbon black.

FIG. 2 is a graph showing the relationship between the blending amount and the volume resistivity of the antistatic resin composition using each carbon black.

FIG. 3 is a diagram showing the relationship between the degree of fluorination of fluorinated carbon black and the blending amount of fluorinated carbon black in the antistatic resin composition and the haze value (%).

FIG. 4 is a view showing a result of measuring volume resistivity of an antistatic resin composition.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03G 15/16 103 G03G 15/16 103

Claims (3)

[Claims] 1. An antistatic resin composition comprising a conductive powder dispersed in a resin, wherein the conductive powder is unsaturated fluorinated carbon black having a fluorination degree of 0.5 or more. And an antistatic resin composition. 2. An antistatic resin composition in which a conductive powder is dispersed in a resin, wherein the conductive powder contains 1 to 1 of fluorinated carbon black whose degree of fluorination is 0.7 or more and which is unsaturated. An antistatic resin composition containing 10 wt%. 3. The volume resistivity is 10 ^{8 to} 10 ¹³ Ω · c.
The antistatic resin composition according to claim 1 or 2, wherein m is m.