JP2003342466A - Semiconductive thermoplastic polyurethane composition and seamless belt comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductive thermoplastic polyurethane composition which stably and accurately exhibits a specified volume resistivity in a resistance region of 1×10<SP>6</SP>-1×10<SP>13</SP>Ω cm, has an electric resistance with a small environmental dependence, and is soft and excellent in processibility; and a seamless belt comprising the composition. <P>SOLUTION: This polyurethane composition comprises 100 pts.wt. thermoplastic polyurethane having a type-D durometer hardness H of 5-70, a moisture absorption coefficient W(%) of 0.4-1.5, and a value of H<SP>2</SP>×W of 20-1,800 and 0.1-20 pts.wt. ionic conductive material. The seamless belt is obtained from the composition. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductive thermoplastic polyurethane composition having a low environmental dependence of electric resistance, and an electrophotographic copying machine formed by using the composition.
The present invention relates to a seamless belt suitable for use in printers, fax machines and the like.

[0002]

2. Description of the Related Art In recent years, due to the progress of color electrophotographic technology, full-color copying machines and color printers have been put into practical use, as an intermediate transfer member for transferring a toner image formed on a photoconductor onto a copy paper, or A semi-conductive seamless belt has come to be used as a transfer and conveyance belt. In addition, an electrophotographic copier,
For printers and fax machines, semi-conductive rolls such as a charging roll, a developing roll, a transfer roll, and a cleaner roll, in which a core metal is coated with a semi-conductive resin, are used. These intermediate transfer bodies, transfer conveyor belts, charging rolls, developing rolls, transfer rolls, cleaner rolls, etc. (hereinafter these may be simply referred to as image forming members) are always clear under various conditions of use. A function for obtaining an image is required. More specifically, in addition to the electrical characteristics such as that the electric resistance of each position of the image forming member is uniform and that the change of the electric resistance is small even if the operating environment (temperature, humidity) changes, Performances such as flexibility in the depth direction, small friction coefficient, and good toner releasability are required.

That is, the electric resistance of the image forming member is closely related to the color unevenness, and if the electric resistance varies greatly, a shade of image is partially generated. Further, if the change in the electric resistance due to the change in the environment (temperature, humidity) is large, the shading of the entire image occurs due to the change in the use environment. As described above, since the electric resistance of the image forming member directly affects the image quality, the uniformity of the electric resistance (the variation of the resistance and the small change of the electric resistance due to the environmental change) are different from those of the image forming member. It is the most important characteristic among the various characteristics required.

Further, the cleaner roll is used for the purpose of removing the toner remaining on the photosensitive member or the intermediate transfer member that has not been transferred to the intermediate transfer belt or the printed matter, or the adhered toner from the photosensitive member or the intermediate transfer member. However, the uneven resistance causes uneven removal of the toner and the like, which causes a problem that the unremoved toner and the like stain the image of the printed matter and the back surface of the printed matter. Therefore, the cleaner roll is also required to have the same electric resistance uniformity as described above.

On the other hand, in order to obtain a synthetic resin composition having semiconductivity, it is common to blend an electron conductive material such as carbon black or metal oxide into the synthetic resin. However, although the synthetic resin composition to which these electronically conductive materials are added has the feature that the change in the electrical resistance is small with respect to the change in the operating environment, it exhibits conductivity by contact with the electronically conductive material. Dispersion in a synthetic resin is particularly important, and there is a drawback that variations in electrical resistance tend to occur due to slight differences in processing conditions and addition amounts.

As another method for obtaining a synthetic resin composition having semiconductivity, it is known to add an ion conductive material to the synthetic resin. However, even if the ion conductive material is added to the synthetic resin, the electric resistance may hardly be reduced depending on the kind of the synthetic resin and the processing method. Further, the synthetic resin composition to which the semiconductivity is imparted by adding the ion conductive resin has a feature that the variation of the electric resistance is small, but the electric resistance under high temperature and high humidity and the electric resistance under low temperature and low humidity are high. There is a drawback that the difference with the resistance, that is, the so-called electric resistance greatly depends on the environment.

Further, in recent years, color printers and color copiers are required to have high performance such as high image quality, high speed printing, and paper compatibility due to diversification of paper. There has been a problem that the image forming member made of a relatively hard synthetic resin such as polyimide, polycarbonate, and fluororesin, which has been widely used in the past, cannot meet such demand.

Under such circumstances, synthetic resins having flexibility such as synthetic rubber, silicone rubber, and thermoplastic elastomer are attracting attention. Of these, thermoplastic elastomers are polymeric materials that have thermoplastic hard segments and soft segments that have rubber elasticity, and that are thermoplastic and have rubber elasticity. The application to is being studied.

As a method of imparting semiconductivity to a thermoplastic elastomer, an electronically conductive material is added as in the case of other synthetic resins. Although it has the feature that the change in electrical resistance is small with respect to the change in the electrical conductivity, it is particularly important to disperse it in the resin because the conductivity appears due to the contact of the electronically conductive material. There is a drawback that variations in electrical resistance easily occur due to differences. In addition, when an ion conductive material is added to a thermoplastic elastomer, there are thermoplastic elastomers that easily develop semiconductivity and thermoplastic elastomers that do not, and a thermoplastic elastomer with semiconductivity has electrical resistance. There is a great deal of dependence on the environment, and improvements have been desired.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation, and is 1 × 10 ⁶ to 1 × 10 ¹³ Ω.
-A semi-conductive thermoplastic elastomer that not only can stably and accurately develop a predetermined volume resistivity in the cm resistance region, but also has low environmental dependence of electrical resistance, has excellent workability, and is flexible It is an object to provide a composition and a seamless belt made of the composition.

[0011]

Means for Solving the Problems As a result of intensive studies by the present inventors for imparting semiconductivity to various thermoplastic elastomers, a specific thermoplastic polyurethane and an ion conductive material were combined in a specific ratio. The present inventors have found that not only the composition exhibits excellent semiconductivity, but also that the change in electric resistance due to changes in the environment (temperature, humidity) is small. That is, in the present invention, the hardness (type D) obtained by the durometer hardness test is H,
When the moisture absorption rate at 30 ° C.-80% RH is W (%), the H value is 5 to 70, the W value is 0.4 to 1.5,
100 parts by weight of thermoplastic polyurethane having an H ² × W value of 20 to 1800, and an ion conductive material of 0.1 to 2
The present invention relates to a semiconductive thermoplastic polyurethane composition characterized by comprising 0 parts by weight.

[0012] The present invention relates to a semiconductive thermoplastic polyurethane composition, wherein the ion conductive material comprises polyethylene oxide or a polyethylene oxide copolymer and an ionic electrolyte.

The present invention relates to the semiconductive thermoplastic polyurethane composition, wherein the polyethylene oxide copolymer is a copolymer of ethylene oxide and propylene oxide.

The present invention relates to the semiconductive thermoplastic polyurethane composition, wherein the ionic electrolyte is at least one selected from alkali metal thiocyanates and halogen oxyacid salts.

[0015] A seamless belt comprising the semiconductive thermoplastic polyurethane composition as described in any one of [1] to [3].

The present invention relates to a seamless belt having a multi-layer structure having at least one layer comprising the semiconductive thermoplastic polyurethane composition described in any one of (1) to (3) above.

The present inventors have added an ion conductive material.
Environment of electrical resistance of semiconductive thermoplastic polyurethane compositions
The relationship between dependence and properties of thermoplastic polyurethanes
I examined it in detail. The result is a semiconductive thermoplastic polyurethane
The environmental dependence of the electrical resistance of resin compositions depends on the thermoplastic polyurethane.
It has a weak correlation with the moisture absorption rate of
And there is a stronger correlation between the product of hardness and moisture absorption.
Furthermore, it is extremely strong in the product of the square value of hardness and the moisture absorption rate.
I found a correlation. That is, the present invention
The hardness (type D) measured by the lometer hardness test is H, 30 ° C
When the moisture absorption rate at -80% RH is W (%),
The value is in the range of 5 to 70, and the value of W is in the range of 0.4 to 1.5
To H^TwoXW value in the range of 20-1800, more preferred
The thermoplastic polyurethane in the range of 80-1700
100 parts by weight, 0.1 to 20 parts by weight of ion conductive material
The semi-conductive thermoplastic polyurethane composition is 1 × 1
0 ⁶~ 1 x 10^ThirteenΩ · cm range, especially 1 × 10⁷~
1 x 10¹²Variation in electrical resistance in the range of Ω · cm
Excellent electricity with low environmental impact and low environmental dependence
It has been found to have characteristics.

The seamless belt provided by the present invention is obtained by extruding the above-mentioned semiconductive thermoplastic polyurethane composition through an annular die. Therefore, the seamless belt provided by the present invention has a range of 1 × 10 ⁶ to 1 × 10 ¹³ Ω · cm, particularly 1 × 1.
It exhibits a stable volume resistivity in the range of 0 ⁷ to 1 × 10 ¹² Ω · cm, and is characterized by not only a small variation in electric resistance but also a small environmental dependency of electric resistance.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The hardness (type D) according to the present invention is measured by a durometer hardness test using a durometer, and a portion 10 mm or more away from the end of a test piece having a thickness of 10 mm or more is measured by JISK6253. Do it in compliance. The moisture absorption rate is determined by the following test method. That is, the thermoplastic polyurethane is 75 mm × 25 mm, and the thickness is 3.0.
mm into a test piece, and the weight when the test piece was dried in an atmosphere at 50 ° C. to a constant weight was W ₀ (g),
The moisture absorption rate W (%) is calculated from the following formula, where W ₁ (g) is the weight after standing at 30 ° C. and 80% relative humidity until a constant weight is obtained. W (%) = 100 × (W ₁ −W ₀ ) / W ₀

As mentioned above, the heat transfer used in the present invention
Plastic polyurethane has hardness measured by durometer hardness test.
Value of H when (Type D) is H and moisture absorption rate is W (%)
Is 5 to 70, and the value of W is 0.4 to 1.5. And
Further H^TwoThe value of × W is 20 to 1800, more preferably
80-1700. H^TwoThe value of × W is 20 to 1800
Is in the range of
Thermoplastic polyurethane with relatively low hardness is preferred
In addition, thermoplastic polyurethane with low moisture absorption is preferred.
It can be said to be better. H^TwoThe value of × W is 1800
If it exceeds the above range, it is possible to obtain a composition whose electric resistance is less dependent on the environment.
The above-mentioned object of the present invention cannot be achieved. On the contrary, H ^TwoThe value of × W is
Below 20, the composition is too soft for practical use.
A molded product having sufficient strength cannot be obtained.

The thermoplastic polyurethane is a polymer synthesized from a diol and a diisocyanate, and has a soft segment and a hard segment in the molecule and exhibits thermoplasticity and elasticity. The above-mentioned diols are 1,4
-Butanediol, 1,6-hexanediol, short-chain diols such as ethylene glycol, polyethers having hydroxyl groups at both ends, polyesters having hydroxyl groups at both ends, and long-chain diols such as polycarbonate having hydroxyl groups at both ends. To be Examples of the above-mentioned diisocyanate include diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, hexamethylene diisocyanate, and toluylene diisocyanate.

On the other hand, as the ion conductive material used in the present invention, polyethylene oxide, polyethylene oxide copolymer, polyether ester amide, polyether ester, ionomer (alkali metal salt of carboxylic acid in side chain, sulfonic acid Examples thereof include polymers having an alkali metal salt, a quaternary ammonium salt, and the like, ionic electrolytes, and the like, and these can be used alone or in combination of two or more kinds. The amount of addition is 0.1 to 20 parts by weight, more preferably 1 to 10 parts by weight, based on 100 parts by weight of the thermoplastic polyurethane. If the amount of the ion conductive material added is less than 0.1 part by weight, a composition exhibiting desired semiconductivity cannot be obtained, which is not preferable, and conversely, the amount added is 2%.
If it exceeds 0 parts by weight, the electric resistance corresponding to the added amount will not be lowered, and the environmental resistance of the electric resistance will increase, which is not preferable.

Among the above-mentioned ion conductive materials, it is preferable to use polyethylene oxide or a polyethylene oxide copolymer in combination with an ionic electrolyte. As polyethylene oxide or a polyethylene oxide copolymer, polyethylene oxide having a number average molecular weight of 3,000 or more, a copolymer of ethylene oxide and propylene oxide, and partial cross-linking in which polyethylene oxides are partially bonded with diisocyanate or polybasic acid Examples thereof include polyethylene oxide and a partially crosslinked polyethylene oxide copolymer in which polyethylene oxide and polypropylene oxide are partially bonded with diisocyanate or a polybasic acid. When the number average molecular weight of polyethylene oxide or polyethylene oxide copolymer is less than 3000, the polyethylene oxide or polyethylene oxide copolymer added into the thermoplastic polyurethane may bleed out to the surface of the seamless belt.

As the ionic electrolyte used in the present invention, alkali metal thiocyanates, phosphates, sulfates, salts obtained from alkali metals and halogen-containing oxyacids may be used alone or in combination. You can
Of these, lithium perchlorate, sodium perchlorate, potassium perchlorate, lithium thiocyanate, sodium thiocyanate, and potassium thiocyanate are particularly preferable. The addition amount is preferably 0.01 to 3.0 parts by weight, and more preferably 0.01 to 2.5 parts by weight.
If the amount of the ionic electrolyte added exceeds 3.0 parts by weight, not only the thermal decomposition of polyethylene oxide or the polyethylene oxide copolymer is promoted during processing, but also the environmental resistance of the electric resistance of the obtained seamless belt is increased. Undesirably increases.

In addition to the above-mentioned ion conductive materials, the semi-conductive thermoplastic polyurethane composition of the present invention may optionally contain electron conductive materials, antioxidants, and heat stabilizers within the range that does not impair their characteristics. Agents, anti-blocking agents, lubricants, compatibilizers, processing aids, pigments, foaming agents, reinforcing materials and the like can be added. In addition, a small amount of other synthetic resin may be added if necessary.

The seamless belt of the present invention is obtained by using the above-mentioned semiconductive thermoplastic polyurethane composition composed of thermoplastic polyurethane and ion conductive material in a conventional kneader, roll, Banbury mixer, twin-screw kneader, etc. Kneading, granulating, and feeding this to an extruder equipped with an annular die,
It can be obtained by extruding a tube and cutting it into a predetermined length. Furthermore, the semiconductive thermoplastic polyurethane composition and other synthetic resin are supplied to a coextruder equipped with a multi-layer annular die, to obtain a multi-layer tube by extrusion, by cutting it into a predetermined length, A multilayer seamless belt having at least one layer formed by molding the semiconductive thermoplastic polyurethane composition can also be used. In this case, the thickness of the layer formed by molding the semiconductive thermoplastic polyurethane composition is preferably 50 μm or more.

The single-layer or multi-layer seamless belt of the present invention may be formed into a small diameter, which may be coated with a metal cored bar and heat-fused to form a roll. Alternatively, a method of supplying the semiconductive thermoplastic polyurethane composition of the present invention to an extruder equipped with a coating die and directly coating the core metal with the resin is also possible. Further, a plurality of single-layer or multi-layered seamless belts formed into a small diameter are superposed on a core metal, heated, and fused to have at least one layer formed by molding the semiconductive thermoplastic polyurethane composition. You can also get a roll. Even in this case, the thickness of the layer formed by molding the semiconductive thermoplastic polyurethane composition is 50 μm.
The above is preferable.

The present invention relates to a semiconductive composition in which an ion conductive material is added to a thermoplastic elastomer, and a seamless belt comprising the composition. The greatest feature of the present invention is the thermoplastic elastomer. The use of a specific thermoplastic polyurethane as. That is, when the hardness (type D) by the durometer hardness test is H and the moisture absorption rate at 30 ° C.-80% RH is W (%), the H value is in the range of 5 to 70, and the W value is 0. .4 ~
The use of a thermoplastic polyurethane having a value of H ² × W in the range of 20 to 1800 is in the range of 1.5. This condition means that the use of thermoplastic polyurethane having a low hardness and a low moisture absorption rate is suitable for solving the problem of the present invention. When adding an ion conductive material to the thermoplastic elastomer, it can be understood that the moisture absorption of the thermoplastic elastomer affects the environmental dependence of the electrical resistance, but the conditions shown in the present invention are:
It is shown that hardness rather than moisture absorption has a greater effect on the environmental dependence of electrical resistance. Thermoplastic polyurethane, which has high hardness, has a large proportion of hard segments and a large interaction between molecular chains. Therefore, it is considered that the movement of molecular chains is not easily affected by temperature and humidity. However, surprisingly, thermoplastic polyurethanes with low hardness, that is, thermoplastic polyurethanes with a high proportion of soft segments and small interactions between molecular chains, are less susceptible to the effects of temperature and humidity. The present invention was found and led to the present invention.

[0029]

EXAMPLES Next, the present invention will be described in detail with reference to Examples. In addition, in this example, unless otherwise specified, the electric resistance was HRS using HIRESTA manufactured by Mitsubishi Chemical Corporation.
Evaluation was carried out by measuring the volume resistivity with a probe under an applied voltage of 500 V, 23 ° C. and 50% RH.

Also, environmental dependence, moisture absorption rate, hardness (type
D) was measured as follows. <Environmental dependency> Volume resistivity at 10 ° C-30% RH
(LL) and volume resistivity at 30 ° C.-80% RH
(HH) is measured, and the ratio (LL / HH) of both measured values is calculated.
It <Hygroscopic rate> Dimensions are 75 mm x 25 mm, thickness 3.0 mm
The test piece was dried at 50 ° C. to a constant weight and weighed.
Amount W₀(G), constant at 30 ° C and 80% relative humidity
W₁(G) and the following formula
Ask. W (%) = 100 × (W₁-W₀) / W₀ <Hardness (Type D)> Hardness by durometer hardness test
The measurement of (Type D) uses a durometer and has a thickness of 10
Area 10 mm or more away from the end of the test piece of mm or more
Was measured according to JIS K6253.

As the thermoplastic polyurethane, those shown in Table 1 were used.

[0032]

[Table 1]

The following materials were used as the ion conductive material. -Polyethylene oxide copolymer (CP-2000,
Sumitomo Seika) ・ Partially cross-linked polyethylene oxide (Aqua Coke, Sumitomo Seika) ・ Polyether ester amide (PAS40T, Toray) ・ Quaternary ammonium salt-containing polymer (Reolex AS
-170, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.-Potassium salt ionomer (SD110, manufactured by Mitsui DuPont Chemicals) -Lithium perchlorate (manufactured by Wako Pure Chemical Industries)

[Examples 1 to 6] 100 parts by weight of the thermoplastic polyurethane shown in Table 2, 2 parts by weight of polyethylene oxide copolymer, and 0.2 parts by weight of lithium perchlorate were kneaded with a kneader, pelletized, and then blown. A film was formed by the method to obtain a thermoplastic polyurethane tube having a thickness of 200 μm. Table 2 shows the volume resistivity of the obtained tube and its environmental dependence (LL / HH).

Comparative Examples 1 to 5 100 parts by weight of the thermoplastic polyurethane or thermoplastic elastomer shown in Table 2, 2 parts by weight of polyethylene oxide copolymer, and 0.2 parts by weight of lithium perchlorate were kneaded with a kneader, After pelletization, a film is formed by the inflation method to a thickness of 2
A 00 μm thermoplastic elastomer tube was obtained. The volume resistivity of the obtained tube and its environmental dependence (L
L / HH) is shown in Table 2 (however, Comparative Examples 4 and 5 were not evaluated for environmental dependence because of their large volume resistivity as described later).

[0036]

[Table 2]

The thermoplastic polyurethanes (TPU-1 to TPU-6) used in Examples 1 to 6 had an H ² × W value calculated from the moisture absorption rate and hardness of 20 to 1800. The obtained tube exhibited a volume resistivity with no variation in the semiconductive region, and the environment dependency of the volume resistivity was as small as 50 times or less. On the other hand, Comparative Examples 1 to 3
Thermoplastic polyurethane (TPU-7 to TPU-
In 9), the value of H ² × W calculated from its moisture absorption rate and hardness exceeds 1800, and the volume resistivity of the obtained tube shows a semi-conductive region and its variation is small, but the resistivity is low. The environment dependency of was as large as 100 times or more.
Further, in Comparative Examples 4 and 5, thermoplastic elastomers other than thermoplastic polyurethane are used. However, in these thermoplastic elastomers, the volume resistance was increased even though the same amount of ion conductive material as in Examples 1 to 6 was added. The decrease in the rate was extremely small. From the above results, as the thermoplastic elastomer, a thermoplastic polyurethane having a value of H ² × W of 1800 or less is used, and a semiconductive thermoplastic polyurethane composition obtained by adding an ion conductive material to this specific thermoplastic polyurethane is It can be seen that not only the uniform electric resistance of the semiconductive region is exhibited, but also its environmental dependence is small.

[Examples 7 to 12] TPU-1 and the ion-conductive materials shown in Table 3 were kneaded with a kneader and pelletized, and then a tube having a thickness of 200 µm was obtained in the same manner as in Example 1. Table 4 shows the volume resistivity of the obtained tube and its environmental dependence.

COMPARATIVE EXAMPLE 6 TPU-1, polyethylene oxide and lithium perchlorate shown in Table 3 were kneaded in a kneader and pelletized, and then a thickness of 2 was obtained in the same manner as in Example 1.
A 00 μm tube was obtained. Table 4 also shows the volume resistivity of the obtained tube and its environmental dependence.

[0040]

[Table 3]

[0041]

[Table 4]

As is clear from Examples 7 to 12, when TPU-1 which is a thermoplastic polyurethane having a value of H ² × W calculated from the moisture absorption rate and hardness of 1800 or less is used, the ion conductivity is increased. When a polymer having an ethylene oxide chain and an ionic electrolyte are used as materials (Examples 7, 8, 11, and 12), when a polymer having a quaternary ammonium salt in the side chain is used (Example 9), When a polymer having a potassium salt in the chain is used (Example 1
0), both show not only the volume resistivity of the semi-conductive region by addition of the ion conductive material, but also its environmental dependence is small. On the other hand, in Comparative Example 6 in which a large amount of polyethylene oxide copolymer was added,
Not only is the decrease in volume resistivity small (compared with Example 12) even if the amount of addition is further increased (compared with Example 12), but the environmental dependence becomes worse, which is not preferable.

[Example 13] TPU-1, 5 parts by weight of a polyethylene oxide copolymer, and 0.5 parts by weight of lithium perchlorate were kneaded with a kneader and pelletized, and then the peripheral length was 250 mm in the same manner as in Example 1. A tube having a thickness of 200 μm was obtained. The obtained tube was cut into a length of 330 mm to obtain a semiconductive seamless belt. The volume resistivity of this seamless belt is 4.3 × 10 ⁸ Ω · cm, and the ratio of the maximum value and the minimum value of the volume resistivity in one seamless belt is 2.5 times, and the volume resistance at 10 ° C. 30% RH. Rate is 3
It was 16 times the volume resistivity at 0 ° C. and 80% RH.

[Example 14] TPU-1, 5 parts by weight of a polyethylene oxide copolymer, and 0.5 parts by weight of lithium perchlorate were kneaded with a kneader and pelletized. A tube having a thickness of 300 μm was obtained. The obtained tube was cut into a length of 400 mm, covered with a core metal having a diameter of 12 mm, and heated at 180 ° C. to fuse the thermoplastic polyurethane to the core metal to obtain a semiconductive roll. This electrical resistance (the resistance between the core metal and the roll surface is 3.
1 × 10 ⁷ Ω, the ratio of the maximum value and the minimum value of the electric resistance in one roll is 2.9 times, the volume resistivity at 10 ° C.-30% RH is the volume resistivity at 30 ° C.-80% RH. 14
It was double.

As described above, the semiconductive thermoplastic polyurethane composition of the present invention is a specific thermoplastic polyurethane to which an ion conductive material is added, and the film obtained from the composition is semiconductive. In addition to exhibiting a uniform volume resistivity in the conductive region, its environmental dependence is small. Further, a seamless belt or roll made of the composition also exhibits the same characteristics, and can form an excellent image when it is mounted on an electrophotographic copying machine, printer or the like.

[0046]

As described above, the semiconductive thermoplastic polyurethane composition of the present invention, and the seamless belt and roll made of the composition are obtained by blending an ion conductive material with a specific thermoplastic polyurethane. ,
Not only can the electric resistance of the semi-conductive region be expressed accurately and uniformly, but also the fluctuation of the electric resistance due to changes in temperature and humidity,
In other words, it has the characteristic of being less dependent on the environment. Further, since the seamless belt using the semiconductive thermoplastic polyurethane composition of the present invention uses thermoplastic polyurethane, it has flexibility in the thickness direction as well, and has high image quality, high speed printing, and various paper types. It also satisfies high-level performance requirements such as paper compatibility, and is suitable for use in electrophotographic copying machines, printers, and the like.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01B 1/16 H01B 1/16 Z // (C08L 75/04 C08L 71:02 71:02) (72) Inventor Yoshihiro Tange 1515 Nakatsu-cho, Marugame City, Kagawa Okura Industrial Co., Ltd. F-term in the company (reference) 2H171 FA26 FA30 GA01 GA02 GA15 GA24 PA04 PA08 QA24 QC05 TA03 TA05 TA10 TB13 UA03 UA10 UA13 UA22 VA04 2H200 JB07 JB45 JB46 JB46 JB46 JB46 JB46 JC15 JC16 JC17 MA04 MA12 MB02 MB04 MB06 MC02 4F071 AA51X AA53 AA76 AB15 AB23 AF26 AH17 BA01 BB09 BC05 4J002 BB232 CF092 CH022 CK031 CK041 CL082 DE196 DG036 DH046 FD116 GQ02 5G301 DA17 DA28 DA18 DA28

Claims (6)

[Claims] 1. A hardness (type D) measured by a durometer hardness test is H, and a moisture absorption rate at 30 ° C.-80% RH is W.
(%), H value is 5 to 70 and W value is 0.4
To 1.5, 100 parts by weight of thermoplastic polyurethane having a value of H ² × W of 20 to 1800, and 0.1 to 20 parts by weight of an ion conductive material, a semiconductive thermoplastic polyurethane. Composition. 2. The semiconductive thermoplastic polyurethane composition according to claim 1, wherein the ion conductive material comprises polyethylene oxide or a polyethylene oxide copolymer and an ionic electrolyte. 3. The semiconductive thermoplastic polyurethane composition according to claim 2, wherein the polyethylene oxide copolymer is a copolymer of ethylene oxide and propylene oxide. 4. The semiconductive thermoplastic polyurethane composition according to claim 2 or 3, wherein the ionic electrolyte is one or more selected from thiocyanates of alkali metals and oxyacid salts of halogens. . 5. A seamless belt comprising the semiconductive thermoplastic polyurethane composition according to any one of claims 1 to 4. 6. A seamless belt having a multilayer structure, comprising at least one layer comprising the semiconductive thermoplastic polyurethane composition according to any one of claims 1 to 4.