JP2002338801A - Conductive member for oa equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive member for OA equipment which exhibits a stable electric conductivity in the volume resistivity range of 10<6> -10<12> Ωcm independently of its production conditions or molding method and without being affected by a slight difference in the amount of a conductive substance added. SOLUTION: This conductive member is prepared by molding a composition comprising a polyurethane and lithium trifluoromethanesulfonate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus such as a copying machine, a facsimile, and a printer, and a blade, a roller for charging, developing, transferring, fixing, discharging, cleaning, feeding, and conveying an electrostatic recording apparatus. The present invention relates to a conductive member for OA equipment suitable as a belt.

[0002]

2. Description of the Related Art An electrophotographic apparatus such as a copying machine, a facsimile, a printer and the like and an electrostatic recording apparatus are composed of various parts. Among them, a blade, a roller and a belt are charged, developed and transferred in an electrophotographic process. It is indispensable as a part that plays a role of fixing, static elimination, cleaning, paper feeding, conveyance, and the like. Although these parts are widely used polyurethane material, its function 10 ⁴ to 10
^In many cases, a conductivity of about ¹² Ω · cm must be imparted.

Conventionally, in order to impart conductivity to a polyurethane member for OA parts, an electron conductive material such as carbon black, carbon fiber, carbon flake, metal powder, metal fiber, or metal oxide whisker has been added to polyurethane. And then dispersing or adding and dissolving an ion-conductive substance such as an ammonium salt or a perchlorate to mold a polyurethane material obtained.

However, in the method of adding and dispersing carbon black, metal powder, and the like, slight changes in the amounts of these substances added, slight changes in conditions such as material temperature, molding temperature, molding time, and the like, Since the form of the conductive path changes depending on the method, the conductivity greatly fluctuates. Particularly, in a region where the volume resistance value is 10 < ⁶ > to 10 < ¹¹ > [Omega] .cm, the conductive property is stable without variation over the entire molded product. It was extremely difficult to impart the property. Further, when these substances are added to the polyurethane material, the viscosity of the system is remarkably increased, so that molding may be difficult or the mechanical properties of the molded product itself may be impaired. Furthermore, since the specific gravity of these substances is generally higher than the specific gravity of polyurethane, these substances may have settled during storage or molding, so that desired conductivity may not be obtained.

On the other hand, in a method in which an ionic conductive substance such as an ammonium salt or a perchlorate is added to a polyurethane as a conductive agent, even if a large amount of the conductive agent is added, the electric resistance cannot be sufficiently reduced. However, a molded product having the desired electric resistance could not be obtained. In addition, since the electric resistance of these conductive agents fluctuates greatly even when the amount of addition is slightly changed, it is necessary to control the amount of addition strictly at the time of compounding, which lowers the productivity of molded products and increases production costs. Had become.

[0006]

[0008] In view of the above situation, regardless of the production conditions and molding methods, also regardless of the slight deviation of the amount of the conductive material, 10 ⁶ to 10 ¹² Omega
O that exhibits stable conductivity in the volume resistance region of cm
It is an object to provide a conductive member for an A device.

[0007]

SUMMARY OF THE INVENTION The present invention is a conductive member for OA equipment formed by molding a composition comprising polyurethane and lithium trifluoromethanesulfonate. Hereinafter, the present invention will be described in detail.

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, it has been found that polyurethane obtained by adding and dissolving lithium trifluoromethanesulfonate can be used regardless of molding conditions and molding methods, and that a conductive material can be used. Was found to exhibit stable conductivity in a volume resistance region of 10 ⁶ to 10 ¹² Ω · cm without being influenced by a slight deviation in the amount of addition of, and the present invention was completed.

The composition used in the present invention comprises polyurethane and lithium trifluoromethanesulfonate. The polyurethane is obtained by reacting a polyol with a polyisocyanate. Examples of the polyol include poly (ethylene adipate)
Polyol, poly (butylene adipate) polyol,
Condensed polyester polyols represented by poly (ethylenebutylene adipate) polyol; lactone-based polyester polyols represented by poly (caprolactone) polyol and poly (β-methylγ-valerolactone) polyol; poly (oxytetramethylene) polyol; Poly (ether) polyol represented by poly (propylene) polyol; olefin polyol represented by poly (isoprene) polyol and poly (butadiene) polyol; poly (carbonate) polyol, castor oil-based polyol, acrylic polyol, dimer acid-based polyol , Silicon-based polyols and fluorine-based polyols.

Examples of the polyisocyanate include tolylene diisocyanate (TDI), 4,4'-
Diphenylmethane diisocyanate (MDI), liquid M
DI, xylylene diisocyanate (XDI) naphthylene-1,5-diisocyanate (NDI), hexamethylene diisocyanate (HDI), hydrogenated TDI, hydrogenated MDI, isophorone diisocyanate (IPDI) lysine diisocyanate (LDI), isopropylidene bis (4 -Cyclohexyl isocyanate), norbornane diisocyanate and the like.

When reacting the polyol with the polyisocyanate, a curing agent may be further added. The curing agent is not particularly limited and includes, for example, aliphatic, aromatic, alicyclic and heterocyclic low molecular weight glycols; triols such as trimethylolpropane and glycerin;
Polyhydric alcohols such as pentaerythritol and sorbitol; methylene bis-o-chloroaniline (MOCA)
And amine compounds represented by

When reacting the polyol with the polyisocyanate, in order to accelerate the curing reaction,
A catalyst may be blended. The catalyst is not particularly limited as long as it promotes the urethane-forming reaction, and a catalyst such as an amine compound or an organometallic compound generally used for urethane molding can be used.

The present invention is characterized in that lithium trifluoromethanesulfonate is used as a conductive agent. Since this conductive agent has a characteristic that the change in electric resistance with respect to the change in the added amount is small as compared with other conductive agents,
Even without strict control of the amount added during compounding,
Since a molded product having almost constant conductivity can be obtained, it contributes to an improvement in productivity of the molded product.

Lithium trifluoromethanesulfonate is characterized in that it can be uniformly dissolved in polyurethane and can be directly dissolved in a polyol or a curing agent as a raw material thereof. In a system in which fillers such as carbon black and metal powder are dispersed as a conductive agent, good formation of conductive paths by the filler is indispensable, and formation of conductive paths is incomplete or cuts may occur in conductive paths. In many cases, the electric resistance is not stable or a desired electric resistance cannot be provided. In addition, since the viscosity of these fillers significantly increases with an increase in the amount of the filler, molding may be difficult or impossible. Lithium trifluoromethanesulfonate can be uniformly dissolved in polyurethane, does not require the formation of a conductive path by contact between conductive agents or agglomeration, and does not show a significant increase in viscosity with an increase in the amount added. Therefore, according to the lithium trifluoromethanesulfonate used in the present invention, a molded product exhibiting stable electric resistance can be easily manufactured.

In the present invention, the compounding amount of lithium trifluoromethanesulfonate is 0.002 to 0.005% of the above composition.
It is preferably 15% by weight. When the content is less than 0.002% by weight, it becomes difficult to impart conductivity, and the variation in electric resistance value increases. On the other hand, if it exceeds 15% by weight,
In addition to affecting the mechanical properties of the polyurethane, the cost increases. More preferably, 0.004 to 10% by weight
It is.

The method of molding the conductive member for OA equipment of the present invention is not particularly limited, and includes, for example, normal pressure casting, reduced pressure casting, centrifugal molding, rotational molding, extrusion molding, injection molding, and the like.
Reaction injection molding (RIM), spin coating and the like can be mentioned.

In a conductive member in which carbon black, metal powder and the like are dispersed, carbon black particles and metal powder having a higher specific gravity than polyurethane are settled during storage of the material, during molding, and depending on the shape of the molded product. Due to uneven distribution, it has been difficult to stably impart uniform conductivity to the molded product. This tendency was particularly strong when the material was molded by centrifugal molding in which a large centrifugal force was applied.
In addition, the dispersed particles may stay in the nozzles and pipes of the casting machine, causing a problem. Accordingly, it is necessary to change the kind and amount of the conductive agent depending on the shape and the molding method of the molded product, or to precisely control the production conditions, for example.

In the conductive member for OA equipment of the present invention, since lithium trifluoromethanesulfonate is uniformly dissolved as a conductive agent in the polyurethane, the molded product can be formed without strict control of the manufacturing conditions regardless of the molding method. To the desired conductivity.

The conductive member for OA equipment of the present invention may be appropriately colored, and the present invention does not deny the further addition of a conventionally known conductive agent such as carbon black.

The conductive member for OA equipment of the present invention includes:
The conductive member is not particularly limited as long as it is a conductive member used for OA equipment, and examples thereof include a conductive blade, a conductive roller, and a conductive belt. Such a conductive blade, a conductive roller, and a conductive belt are also one aspect of the present invention.

[0021]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 A poly (ethylenebutylene adipate) polyol having an average molecular weight of 2,000 and a functional group number of 2, which was dehydrated and defoamed under heating and reduced pressure, and was previously prepared with an average molecular weight of 20
By reacting a poly (ethylene butylene adipate) polyol having 2 functional groups with MDI
A prepolymer having an O% of 16%, and 1,4-formate in which lithium trifluoromethanesulfonate was previously dissolved.
A curing agent consisting of a mixture of butanediol and trimethylolpropane in a weight ratio of 7: 3 was added to the ratio of the number of moles of hydroxyl groups in the polyol, the number of moles of isocyanate groups in the prepolymer, and the number of moles of hydroxyl groups in the curing agent. Is 1: 2.7:
The mixture was weighed to 1.6, mixed with stirring, manually poured into a 130 ° C. mold having a 2 mm thick spacer, and cured at the same temperature for about 1 hour. Thereafter, the molded product was taken out of the mold and aged at room temperature for 12 hours to obtain a thickness of 2 m.
m sheet-shaped sample was obtained. The amount of lithium trifluoromethanesulfonate added was 0.01% based on the total amount.
It was adjusted to 3% by weight.

Example 2 A sample was obtained in the same manner as in Example 1 except that the amount of lithium trifluoromethanesulfonate was adjusted to 0.050% by weight based on the total amount.

Example 3 The amount of lithium trifluoromethanesulfonate added was 1.50% by weight based on the total amount.
A sample was obtained in the same manner as in Example 1 except that the following conditions were satisfied.

Example 4 The amount of lithium trifluoromethanesulfonate added was 3.20% by weight based on the total amount.
A sample was obtained in the same manner as in Example 1 except that the following conditions were satisfied.

Example 5 Lithium trifluoromethanesulfonate was dissolved in advance, dehydrated and defoamed under heating and reduced pressure, and a poly (ethylenebutylene adipate) polyol having an average molecular weight of 2,000 and a functional group of 2 was previously dissolved in a poly (ethylene butylene adipate) polyol. 2000, by reacting a poly (ethylene butylene adipate) polyol having 2 functional groups with MDI
A prepolymer having a CO% of 16% and a curing agent comprising a mixture of 1,4-butanediol and trimethylolpropane in a weight ratio of 7: 3 were mixed with the number of moles of hydroxyl groups in the polyol and the isocyanate group in the prepolymer. , And the mixture was stirred and mixed so that the ratio of the number of moles of hydroxyl group to the number of moles of hydroxyl group in the curing agent was 1: 2.7: 1.6, and was manually poured into a 130 ° C. mold having a 2 mm thick spacer. It was molded and cured at the same temperature for about 1 hour. Thereafter, the molded product was taken out of the mold and aged at room temperature for 12 hours to obtain a sheet sample having a thickness of 2 mm. The amount of lithium trifluoromethanesulfonate was adjusted to 8.60% by weight based on the total amount.

Example 6 Lithium trifluoromethanesulfonate was previously dissolved in water, dehydrated and defoamed under heating and reduced pressure, and a poly (ethylenebutylene adipate) polyol having an average molecular weight of 2,000 and a functional group number of 2 was prepared in advance. 2000, by reacting a poly (ethylene butylene adipate) polyol having 2 functional groups with MDI
A prepolymer having a CO% of 16% and a curing agent comprising a mixture of 1,4-butanediol and trimethylolpropane in a weight ratio of 7: 3 were mixed with the number of moles of hydroxyl groups in the polyol and the isocyanate group in the prepolymer. , And the mixture was stirred and mixed so that the ratio of the number of moles of hydroxyl group to the number of moles of hydroxyl group in the curing agent was 1: 2.7: 1.6, and was manually poured into a 130 ° C. mold having a 2 mm thick spacer. It was molded and cured at the same temperature for about 1 hour. Thereafter, the molded product was taken out of the mold and aged at room temperature for 12 hours to obtain a sheet sample having a thickness of 2 mm. The amount of lithium trifluoromethanesulfonate was 15.00% by weight based on the total amount.
It was made to become.

(Example 7) The same formulation as in Example 3 was used.
It was manually poured into a 160 ° C. mold having a 2 mm thick spacer and cured at the same temperature for about 1 hour. Thereafter, the molded product was taken out of the mold and aged at room temperature for 12 hours to obtain a 2 mm sheet sample.

Example 8 The same formulation as in Example 3 was used.
It was cured for about 1 hour in a centrifugal molding machine at 130 ° C. Thereafter, the molded product was taken out of the centrifugal molding machine and aged at room temperature for 12 hours to obtain a sheet sample having a thickness of 2 mm.

Comparative Example 1 Carbon black having a particle size of 40 nm and a DBP absorption of 190 ml / 100 g was kneaded and dispersed in poly (ethylenebutylene adipate) polyol having an average molecular weight of 2,000 and a functional group number of 2, and dehydrated under heating and reduced pressure.
The defoamed product was previously reacted with a poly (ethylene butylene adipate) polyol having an average molecular weight of 2,000 and a functional group number of 2 and MDI to give an NCO% of 16%, 1,4-butanediol and tri- A curing agent consisting of a mixture of methylol propane in a weight ratio of 7: 3 was mixed with a mole of hydroxyl groups in the carbon black-dispersed polyol, a mole number of isocyanate groups in the prepolymer, and a mole number of hydroxyl groups in the curing agent. 1: 2.7: 1.6
The mixture was weighed, stirred and mixed so as to obtain a mixture.
Cured for hours. After this, remove the molded product from the mold,
After aging at room temperature for 12 hours, a sheet sample having a thickness of 2 mm was obtained. The amount of carbon black added was 2.90% by weight based on the total amount.

Comparative Example 2 A sample was obtained in the same manner as in Comparative Example 1, except that the amount of carbon black was 3.20% by weight based on the total amount.

Comparative Example 3 The same compound as in Comparative Example 2 was used.
It was cured for about 1 hour in a centrifugal molding machine at 130 ° C. Thereafter, the molded product was taken out of the centrifugal molding machine and aged at room temperature for 12 hours to obtain a sheet sample having a thickness of 2 mm.

The samples obtained in Examples 1 to 8 and Comparative Examples 1 to 3 were subjected to the following conductivity tests. Table 1 shows the results
It was shown to. [Evaluation of conductivity] Resistance tester (Advantest, R
8340A). (1) Volume resistance value The volume resistance value when a voltage of 250 V was applied to the sample for 30 seconds was evaluated. The measurement was performed at 15 points on the entire surface of the sample, and the arithmetic average value was defined as a volume resistance value. (2) Variation in volume resistance The maximum and minimum values obtained by plotting the volume resistance values at 15 locations measured in (1) on logarithmic graph paper having a scale of 1 × 10 ^X (X represents an integer). Was evaluated based on the scale width.

[0034]

[Table 1]

[0035]

According to the present invention, which has the constitution described above, regardless of the molding conditions and molding methods, also regardless of the slight variations in the added amount of conductive material, of 10 ⁶ ~10 ¹² Ω · cm OA showing stable electric resistance in the volume resistance range
A conductive member for equipment can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G03G 15/08 501 G03G 15/08 501D 3J103 504 504A 4F071 15/16 103 15/16 103 4J002 15/20 103 F / term (reference) FA01 HA28 HB12 HB14 HB45 HB46 JA25 JA26 MA03 MA12 MA17 MA20 MB04 3J103 AA02 FA14 FA18 GA57 GA58 GA60 HA20 HA48 HA60 4F071 AA53 AC14 AF36 AH16 4J002 CK021 EV256 FD116 GQ05

Claims (6)

[Claims] 1. A conductive member for OA equipment, which is formed by molding a composition comprising polyurethane and lithium trifluoromethanesulfonate. 2. The conductive member for OA equipment according to claim 1, wherein the amount of lithium trifluoromethanesulfonate is 0.002 to 15% by weight of the composition. 3. The conductive member for OA equipment according to claim 1, wherein a volume resistance value when a voltage of 250 V is applied for 30 seconds is 10 ⁶ to 10 ¹² Ω · cm. 4. The conductive member for OA equipment according to claim 1, wherein the conductive member is a conductive blade. 5. The conductive member for OA equipment according to claim 1, wherein the conductive member is a conductive roller. 6. The conductive member for OA equipment according to claim 1, wherein the conductive member is a conductive belt.