KR20090059296A - Semiconductive resin composition and image forming intermediate transfer belt using the same - Google Patents

Abstract

A semiconductive resin composition for a transfer belt is provided to ensure excellent electric conductivity, dispersibility, toner exfoliation and anti-fouling property while maintaining mechanical properties. A semiconductive resin composition for a transfer belt comprises (A) a thermoplastic matrix resin 100.0 parts by weight and (B) carbon nanotube 0.1~5 parts by weight. The thermoplastic matrix resin(A) is polyolefin resin, polyacetal resin, acrylic resin, polymethacrylic resin, polycarbonate resin, styrene resin, polyester resin, polyphenylene ether resin, polyarylate resin, polyamide resin, polyarylsulfone resin, polyetherimide resin, polyether sulfone resin, fluorinated vinylidene resin, polysulfone resin, and liquid crystal polymer resin or a copolymer or a mixture of at least two kinds thereof.

Description

Semiconductive resin composition for transfer belt and transfer belt for image forming apparatus using same {Semiconductive Resin Composition and Image Forming Intermediate Transfer Belt Using the Same}

Field of invention

The present invention relates to a semiconductive resin composition for a transfer belt and a transfer belt for an image forming apparatus using the same. More specifically, the present invention relates to a transfer belt for an image forming apparatus having a uniform resistance characteristic by applying carbon nanotubes to a semiconductive resin composition for a transfer belt and having excellent elastic modulus.

Background of the Invention

Background Art In recent years, color information such as photographs and images can be easily handled by high performance and high capacity of information devices such as PCs, digital video, digital cameras, and mobile phones with cameras. In addition, colorization of printers as output devices is rapidly progressing, and in particular, demands for high speed, high quality, compactness, and high reliability of color printers are increasing. One important part of achieving these needs is an intermediate transfer belt.

BACKGROUND ART Electrophotographic apparatuses such as copiers and printers have been required to cope with color, high quality, high speed, compactness, and general purpose paper. In order to achieve these, the intermediate transfer belt method is adopted for the transfer process of the electrophotographic apparatus, and the semiconductive intermediate transfer belt becomes an important component.

In general, resins such as polycarbonate (PC), polyvinylidene fluoride (PVDF), polyamideimide (PAI), polyimide (PI) resin, and rubber (Rubber) are used as the material of the intermediate transfer belt. The transfer belt for an image forming apparatus has a large resistivity (surface resistivity) in the circumferential direction of the belt and a resistivity (volume resistivity) in a thickness direction smaller than the surface resistivity. No change, high tensile modulus in the circumferential direction of the belt, smooth surface and large contact angle, make it easy to transfer the toner from the belt to the transfer material (paper) (excellent peeling toner), photosensitive drum, toner, etc. It is desired that the chemicals not be contaminated chemically (excellent non-polluting) and flame retardant.

The semiconductive thermoplastic resin composition used for producing the intermediate transfer belt is usually prepared by mixing and dispersing a conductive additive such as carbon black in the thermoplastic resin. However, in the case of the conductive additive such as carbon black, it is difficult to sufficiently secure the electrical conductivity of the semiconductive thermoplastic resin to a desired degree unless a considerable amount is added (10% or more by weight). On the other hand, when a large amount of the conductive additive is added, the basic physical properties of the thermoplastic matrix resin, for example, mechanical properties such as impact resistance, elastic modulus can be greatly reduced.

Japanese Patent No. 2560727 mentions a method of dispersing carbon black in polyimide and using it in a transfer belt. However, this method is cumbersome to be pretreated in solution to disperse more than 10% by weight of carbon black.

In the case of U.S. Patent No. 5,021,036, 5-20% by weight of acetylene black or the like is dispersed in polycarbonate to obtain a transfer belt. However, the transfer belt is accompanied with a dispersion problem of high content filler and a decrease in physical properties.

In general, the film forming the transfer belt may be obtained by dispersing the carbon black content in a resin such as polycarbonate, polyimide, polyamideimide, or fluororesin by about 10-20% by weight. However, when an excessive amount of carbon black is used, uniform dispersion is difficult and the physical properties of the film to be used as the transfer belt film are reduced.

In order to solve the above problems, the present inventors apply carbon nanotubes to the thermoplastic matrix resin as the conductive dispersant, thereby realizing excellent conductivity even with a small amount of the conductive dispersant and lowering the content of the conductive dispersant. To develop a semiconductive resin composition for a transfer belt having excellent dispersibility, uniform resistance, peeling toner property, and non-pollution without inhibiting the viscosity and elastic properties of the polymer resin, and to develop a transfer belt for an image forming apparatus using the same. will be.

An object of the present invention is to provide a semiconductive resin composition for a transfer belt having a uniform resistance characteristics and conductivity, and a transfer belt for an image forming apparatus using the same.

Another object of the present invention is to provide a semiconductive resin composition for a transfer belt having excellent electrical conductivity while maintaining mechanical properties, and a transfer belt for an image forming apparatus using the same.

Another object of the present invention is to provide a semiconductive resin composition for a transfer belt having a large surface resistivity and excellent dispersibility and a transfer belt for an image forming apparatus using the same.

Still another object of the present invention is to provide a semiconductive resin composition for a transfer belt having excellent peeling toner and non-pollution property, and a transfer belt for an image forming apparatus using the same.

Another object of the present invention is to provide a semiconductive resin composition for a transfer belt and a transfer belt for an image forming apparatus using the same, which can lower the content of the conductive dispersant and thus lower the raw material cost.

The above and other objects of the present invention can be achieved by the present invention described in detail.

Summary of the Invention

Semi-conductive resin composition for a transfer belt according to the invention (A) 100 parts by weight of a thermoplastic matrix resin; And (B) 0.1 to 5 parts by weight of carbon nanotubes.

In one embodiment, the carbon nanotubes (B) have a diameter of 0.5 to 100 nm, a length of 0.01 μm to 100 μm, and an aspect ratio (L / D) of 100 to 1,000.

In this invention, the transfer belt for image forming apparatuses using the said resin composition is provided.

In one embodiment, the transfer belt has a surface resistance of 10 ⁸ to 10 ¹² Ω / sq at an applied voltage of 100 to 250 V.

The transfer belt has a thickness of 50 to 150 µm.

Hereinafter, each component of the semiconductive resin composition used for the transfer belt for image forming apparatus of this invention is demonstrated in detail as follows.

Detailed Description of the Invention

(A) matrix resin

As the matrix resin used in the semiconductive resin composition of the present invention, any thermoplastic resin capable of extrusion or injection molding can be used. The thermoplastic general purpose plastics and thermoplastic engineering plastics are used without limitation.

Specific examples of the thermoplastic resin include polyolefin resin, polyacetal resin, acryl resin, polymethacryl resin, polycarbonate resin, styrene resin, polyester resin, polyphenylene ether resin, polyarylate resin, polyamide Resins, polyarylsulfone resins, polyetherimide resins, polyethersulfone resins, vinylidene fluoride resins, polysulfone resins and liquid crystalline polymer resins, and the like, but are not necessarily limited thereto. The resin may be used alone or in the form of two or more copolymers or mixtures. The specific construction and manufacturing method of each of these thermoplastic resins is well known to those skilled in the art.

Polyolefin resins such as polyethylene resins, polypropylene resins, copolymer resins of ethylene and vinyl acetate, and copolymer resins of ethylene and methyl methacrylate; Styrene resins such as polystyrene resins, rubber-reinforced polystyrene resins, styrene-acrylonitrile copolymer resins, acrylonitrile-butadiene-styrene graft copolymer resins, and the like; Polyamide resins; Polyester resins such as polyethylene terephthalate and polybutylene terephthalate; Thermoplastic engineering plastics such as polycarbonate resin.

The polyethylene terephthalate or polybutylene terephthalate is copolymerized with polytetramethylene glycol (PTMG), polyethylene glycol (PEG), polypropylene glycol (PPG), low molecular weight aliphatic polyester or aliphatic polyamide to further improve impact strength. Or a modified polyethylene terephthalate or modified polybutylene terephthalate blended with an impact enhancing component.

In one embodiment of the present invention, a blend of polycarbonate and polyester is used as the matrix resin.

(B) carbon nanotubes

Carbon nanotubes of the present invention have high mechanical strength, high Young's Modulus and high aspect ratio mechanical properties, and thus are preferably used as conductive dispersants for semiconductive resin compositions for transfer belts. Can be applied.

In addition, the carbon nanotubes are materials having high electrical conductivity and high thermal stability. When the carbon nanotubes are applied to a polymer composite, carbon nanotubes-polymer composites having improved mechanical, thermal and electrical properties may be manufactured.

The method of synthesizing carbon nanotubes is an arc-discharge, laser ablation, plasma chemical vapor deposition, thermal chemical vapor deposition, electrolysis, etc. However, in the present invention, all of the obtained carbon nanotubes may be used regardless of the synthesis method.

The carbon nanotubes may be divided into single wall carbon nanotubes, double wall carbon nanotubes, and multiwall carbon nanotubes according to the number of walls thereof. Carbon nanotubes used in the present invention is not limited to the kind, but it is preferable to use multi-walled carbon nanotubes in terms of economics and workability.

The size of the carbon nanotubes used in the present invention is preferably 0.5 to 100 nm in diameter, and preferably 1 to 15 nm. The length of the carbon nanotubes is preferably 0.01 to 100 μm, more preferably 0.5 to 10 μm. More preferably, electrical conductivity is within the diameter and length range.

Carbon nanotubes used in the present invention have a large aspect ratio (L / D) due to the size as described above, L / D is preferably 100 or more, preferably L / D is 100 to 1,000.

The carbon nanotubes are used in an amount of 0.1 to 5 parts by weight, preferably 0.2 to 3 parts by weight, and most preferably 0.3 to 1.5 parts by weight, based on 100 parts by weight of the thermoplastic matrix resin. If carbon nanotubes are used in an amount of 0.1 parts by weight, sufficient conductivity may not be obtained. If the carbon nanotubes are used in an amount of more than 5 parts by weight, dispersibility may be reduced, transfer ability may not be expressed due to high conductivity, and physical properties of the resin may be reduced. Can be.

In the semiconductive resin composition for a transfer belt of the present invention, a usual additive required according to a use may be added. Examples of the additives include reaction stabilizers, transesterification inhibitors, ultraviolet absorbers, heat stabilizers, antioxidants, flame retardants, lubricants, dyes, pigments, plasticizers, impact modifiers, and the like. The additives may be used alone or in combination of two or more thereof.

In the present invention, the additive may be included in the range of 10 parts by weight or less, preferably 0.001 to 10 parts by weight with respect to 100 parts by weight of the thermoplastic matrix resin (A).

Since the semiconductive resin composition of the present invention has uniform resistance and conductivity, and has high surface resistivity, excellent dispersibility, peeling toner and non-pollution property while maintaining mechanical properties, it is preferably used for a transfer belt for an image forming apparatus. Can be.

The present invention provides a transfer belt for an image forming apparatus using the semiconductive resin composition.

The transfer belt for an image forming apparatus of the present invention can be produced by a conventional method by extruding a semiconductive resin composition.

For example, the components and optionally additives are mixed simultaneously, then melt extruded in an extruder and prepared in the form of pellets. The prepared pellet is put into a uniaxial extruder to which a die of a ring form is attached, and the resin composition melted at the inlet of the die is solidified while passing through a cooling system through a ring-shaped die to obtain a transfer belt in a cylindrical form. At this time, the resin exiting the mold is rapidly cooled by using water, air, or a cooling device to be amorphous. That is, the resin exiting the extruder has a cylindrical shape, which is a desired shape, and then passes through a metal mold and a cooling device. At this time, the resin absorbs heat and lowers the deformation and crystallization degree of the shape. In addition, the resin coming out of the metal mold is pulled at a constant speed to produce a thin film cylinder shape. The stretching speed is suitably 1 m / min to 7 m / min.

The thickness of the transfer belt 50-150 micrometers, Preferably it is 70-150 micrometers, More preferably, it is 80-120 micrometers.

The transfer belt for an image forming apparatus manufactured by extruding the semiconductive resin composition of the present invention has a surface resistance value of 10 ⁸ to 10 ¹² Ω / sq, preferably 1 × 10 ^{10 to} 1 × 10 at an applied voltage of 100 to 250 V. ¹² Ω / sq. In general, semiconductivity refers to a low conductivity, unlike an electrically conductive metal material. Particularly, in the case of a polymer material, the conductive filler is added to exhibit insulation but a weak conductivity, and may exhibit conductivity close to a metal at low conductivity depending on the amount thereof. However, since the conductivity required in the transfer belt for an image forming apparatus of the present invention is not a high conductivity such as a metal but a low conductivity (10 ⁸ to 10 ¹² Ω / sq) region, a polymer resin having conductivity in such a region is referred to as a semiconductive resin. It was.

The transfer belt using the semiconductive resin composition may be used not only in a single layer form but also in a multilayer form.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

The specification of each component and the additive used in the Example and comparative example of this invention is as follows.

(A) matrix resin

  A1) Polycarbonate: Bisphenol-A polycarbonate having a weight average molecular weight (Mw) of 25,000 was used (Teijin Panlite 1250WP).

  A2) Polybutylene terephthalate: A polymer obtained by condensation polymerization of 1,4-butanediol and terephthalic acid or dimethyl terephthalate was used, and polybutylene terephthalate having an intrinsic viscosity of 1.0 was used (Chang Chun PBT1200-211H).

  A3) Polybutylene naphthalate: A polymer obtained by condensation polymerization of 1,4-butanediol with naphthalic acid or dimethyl naphthalate was used, and polybutylene naphthalate having an intrinsic viscosity of 1.1 was used (Teijin Chemical TQB-OT).

(B) carbon nanotubes

NCc 7000 manufactured by Nanocyl, Belgium, used a multi-walled carbon nanotube with a diameter of 10 to 15 nm and a length of 1 to 25 µm.

(C) carbon black

Ketjen black 600JD from Mitsubishi Chemical, Japan was used.

Examples 1-7

After mixing each component with the composition shown in Table 1, the mixture was prepared, and the said mixture was thrown into the twin screw extruder of L / D = 36 and φ = 45 mm (extruder diameter), and it prepared into the pellet type resin composition. The resin composite obtained was introduced into a uniaxial extruder with a die in a ring form, and the resin composition dissolved at the inlet of the die was solidified while passing through a cooling system through a ring die. Table 1 shows the surface resistance and thickness of the transfer belt.

Comparative Examples 1 and 2

A transfer belt was manufactured in the same manner as in Example 1 except that carbon black instead of carbon nanotubes was used as a composition shown in Table 1 below. Table 1 shows the surface resistance and thickness of the transfer belt.

The physical properties of the transfer belt prepared above were evaluated by the following method, and the evaluation results are shown in Table 1.

1) Surface resistance (Ω / sq): Measured by a four-point method using Hiresta UP (MCP-HT450) manufactured by Mitsubishi Chemical. The four-point method is typically a method well known to those of ordinary skill in the art.

2) Thickness (㎛) was measured using a contact type measuring device (Mitutoyo micrometer).

3) Impact strength (1/8 ", kgf cm / cm): Notched (notch) to the test piece was evaluated according to ASTM D 256 at 23 ℃.

TABLE 1

Examples 8-18

As the matrix resin, polyethylene resin, polymethylmethacrylic resin, ABS resin, polyphenylene ether resin, polyamide resin, polyarylsulfone resin, polyetherimide resin, polyethersulfone resin, fluorinated vinylidene resin, polysulfone resin, Except for using the polyurea resin was carried out in the same manner as in Example 1 to prepare a transfer belt, it was confirmed that the surface resistance is in the range of 10 ⁸ ~ 10 ¹² Ω / sq.

In Table 1, when only carbon black was used as a result of Comparative Example 1, the conductivity after forming the film was about 10 ¹⁰ Ω / sq, but to express the conductivity of about 18 parts by weight of carbon black is added It should be known. In addition, when using a carbon black similar to the carbon nanotubes as in Comparative Example 2, it can be seen that the surface resistance is high and the impact strength is lowered, which is not suitable for the purpose of the present invention. However, in the case of carbon nanotubes, conductivity is expressed even at a low content of about 0.7%, and when 1% is used, conductivity of about 10 ¹⁰ Ω / sq that can be used as an image forming transfer belt can be seen. When the carbon nanotubes were mixed in the polymer matrix in the result of the embodiment, the addition of a small amount of carbon nanotubes showed excellent conductivity and prevented the degradation of mechanical properties due to the use of a large amount of additives.

As a result of the above, it can be seen that the application to the transfer belt for image formation using the electrically conductive thermoplastic resin composition according to the embodiments of the present invention.

The present invention has the effect of providing a transfer belt for an image forming apparatus having electrical conductivity, large surface resistivity and excellent dispersibility while maintaining mechanical properties.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (8)

(A) 100 parts by weight of the thermoplastic matrix resin; And (B) 0.1 to 5 parts by weight of carbon nanotubes; Semiconductive resin composition for a transfer belt consisting of. The method of claim 1, wherein the thermoplastic matrix resin (A) is a polyolefin resin, polyacetal resin, acrylic resin, polymethacryl resin, polycarbonate resin, styrene resin, polyester resin, polyphenylene ether resin, polyarylene Resins, polyamide resins, polyarylsulfone resins, polyetherimide resins, polyethersulfone resins, fluorinated vinylidene resins, polysulfone resins and liquid crystalline polymer resins, or copolymers or mixtures of two or more thereof. Semiconductive resin composition for transfer belt. The semiconducting resin for a transfer belt according to claim 1, wherein the carbon nanotubes (B) have a diameter of 0.5 to 100 nm, a length of 0.01 μm to 100 μm, and an aspect ratio (L / D) of 100 to 1,000. Composition. The additive of claim 1, wherein the resin composition is selected from the group consisting of reaction stabilizers, transesterification inhibitors, ultraviolet absorbers, heat stabilizers, antioxidants, flame retardants, lubricants, dyes, pigments, plasticizers, impact modifiers, and mixtures thereof. Semiconducting resin composition for a transfer belt further comprises. The semiconductive resin composition for a transfer belt according to claim 4, wherein the additive is included in an amount of 0.001 to 10 parts by weight based on 100 parts by weight of the thermoplastic matrix resin (A). The transfer belt for image forming apparatus to which the resin composition of any one of Claims 1-5 was applied. 7. The transfer belt according to claim 6, wherein the transfer belt has a surface resistance of 10 ⁸ to 10 ¹² ? / Sq at an applied voltage of 100 to 250 V. The method of claim 6, wherein the thickness of the transfer belt It is 50-150 micrometers, The transfer belt for image forming apparatuses characterized by the above-mentioned.