KR20080034278A - Intermediate transfer belt and manufacturing method thereof - Google Patents

Abstract

An intermediate transfer belt and its fabrication method are provided to provide a sufficient physical property without having a fluorine resin layer or an adhesive layer for attachment with the fluorine resin layer. An intermediate transfer belt contains a silicon modified polyimide-based resin or a heat conductive filler and has a thermal conductivity of 5.1 to 7.4W/mK. The heat conductive filler has a thermal conductivity of 20W/mk or greater and an electric resistance of 101Фcm or greater. The heat conductive filler has a spherical shape with a particle diameter of 0.2 to 20 micrometer. The spherical filler contains relatively larger particles with a particle diameter of 5 to 20 micrometer and relatively smaller particles with a particle diameter of 0.2 to 5 micrometer at a ratio of 6~7:4~3. The heat conductive filler is contained by 0.01~30 wt% over the entire solute.

Description

Intermediate transfer belt and manufacturing method

The present invention relates to an intermediate transfer belt used in a laser printer, a facsimile machine and a copying machine, and a manufacturing method thereof, and to an intermediate transfer belt made of a silicone-modified polyimide-based resin and a manufacturing method thereof.

In general, in order to be used as intermediate transfer belts such as laser printers, facsimile machines, and copiers, heat dissipation properties, water repellency, oil repellency, contamination resistance, heat resistance, elastic modulus, release property with paper, antistatic properties, durability, and antistatic properties should be excellent.

In particular, due to the frictional heat between the intermediate transfer belt and the paper loaded during the long-term operation of the devices, due to the frictional heat generated at the interface between them is important heat dissipation characteristics that can efficiently release their heat is important . If the heat dissipation characteristics are not satisfied effectively, the transfer belt may be deformed due to frictional heat generated during long time operation, which may result in a loss of reliability of the product, and residual heat of high temperature remaining without being released in a narrow space. This may affect peripheral component elements, resulting in reduced lifespan and failure of these peripheral component elements.

In addition, for the function of transferring the toner of the intermediate transfer belt, a property having an appropriate volume resistance value is required, and when it is lower or higher than the required volume resistance value, their antistatic properties, transfer properties, image characteristics, and releasability And deterioration of physical properties such as fouling resistance may result in a fatal defect of an image defect.

The polyimide film, which is mainly used as an intermediate transfer belt, has excellent thermal stability, excellent mechanical and electrical properties, and is very sensitive to moisture, and thus decreases electrical insulation reliability over time. Due to the glass transition temperature, there are many restrictions in processing and relatively easy to charge. In addition, since the volume resistance value is higher than the resistance value required as the intermediate transfer belt, it is difficult to use the intermediate transfer belt due to the excessive resistance value.

In Japanese Patent Laid-Open Publication No. 2003-270967, 2002-218339 and 2004-255828, polyamic acid solution, which is a precursor of polyimide, is polymerized, coated on a mold and heat-treated, and then released from paper. And a transfer belt manufacturing method for coating the fluorine-based polymer compound again and heat-treating the same to improve water and oil repellency.

However, this conventional method is suitable for the adhesion between the polyimide layer and the fluorine-based polymer layer used as a substrate for these intermediate transfer belts, and the hassle of coating the fluorinated polymer compound in the semi-cured polyamic acid solution in terms of its manufacturing method. There are many time, economic and physicochemical constraints for practical use, such as the selection of primers and the problem of separation due to their poor adhesion properties.

On the other hand, intermediate transfer belts such as laser printers, facsimile machines, and copiers serve to transfer the toner, so they must be manufactured to be seamless. Conventionally, in order to make the intermediate transfer belt seamlessly, a washing machine method using high-speed rotation using a centrifugal molding method was used. In this way, it was difficult to manufacture a seamless intermediate transfer belt.

Accordingly, the present inventors overcome the process inefficiency of the conventional polyimide tubular belts used as intermediate transfer belts such as laser printers, facsimile machines, and copiers, and provide heat dissipation, antistatic properties, water repellency, oil repellency, economy and transferability. While making efforts to manufacture seamless tubular intermediate transfer belt, which is a kind of single layer type with excellent back light, it is possible to achieve efficient heat dissipation of heat generated during long time operation in a narrow space, water repellent, oil repellent property, antistatic property, paper The present invention has been completed by confirming that a seamless tubular intermediate transfer belt having excellent release property and the like can be produced.

Accordingly, an object of the present invention is to provide a single layer intermediate transfer belt made of a polyimide resin having excellent heat dissipation characteristics.

It is another object of the present invention to provide a method for producing an intermediate transfer belt which is excellent in heat dissipation characteristics and made of polyimide resin and which can be manufactured in a seamless tubular shape of a single layer.

The present invention for achieving the above object is to provide an intermediate transfer belt containing a silicone-modified polyimide resin and a thermally conductive filler, the thermal conductivity is 5.1 ~ 7.4W / mK.

The thermally conductive filler is characterized in that the thermal conductivity is 20W / mK or more, the electrical resistance is 10 ¹ 1cm or more.

The thermally conductive filler is characterized in that the particle diameter of 0.2 ~ 20㎛ when the filler of the spherical shape, the particle size of 5 ~ 20㎛ relatively large particles and particles of 0.2 ~ 5㎛ relatively small particles 6-7 It is characterized by including in ratio of 4-3.

The thermally conductive filler is characterized in that it contains 0.01 to 30% by weight relative to the total solute.

The thermally conductive fillers include single wall carbon nanotubes, multi wall carbon nanotubes, silica, alumina, aluminum borate, silicon carbide, titanium carbide, boron carbide, silicon nitride, boron nitride, Aluminum nitride, titanium nitride, mica, potassium titanate, beryllium titanate, calcium carbonate, magnesium oxide, zirconium oxide, tin oxide, beryllium oxide, aluminum oxide, and aluminum hydroxide.

The intermediate transfer belt of the present invention is characterized in that it further contains an electrically conductive filler.

The intermediate transfer belt of the present invention has a volume resistivity of 10 ⁸ to 10 ¹² Ωcm and a contact angle of 105 ° to 113 °.

The silicone-modified polyimide-based resin is characterized in that the copolymer containing dianhydride, diamine and silicone resin, the silicone resin is characterized in that the number average molecular weight is 600 ~ 2,000.

The silicone resin is contained 10 to 30% by weight relative to the diamine content, it is characterized in that one or two or more selected from polydimethylsiloxane, polydiphenylsiloxane and polymethylphenylsiloxane which is a copolymer thereof.

In addition, the present invention comprises the steps of dissolving dianhydride, diamine, silicone resin in an aprotic superpolar solvent to prepare a silicone-modified polyamic acid solution; Dispersing a thermally conductive filler in the silicone-modified polyamic acid solution; And it provides a method for producing an intermediate transfer belt comprising the step of imidizing by heating the silicone modified polyamic acid solution in which the thermally conductive filler is dispersed into a mold.

The mold is characterized by using a cylindrical structure consisting of a dual structure of the outer cylinder and the inner cylinder.

Dispersing the thermally conductive fillers further comprises dispersing the electrically conductive fillers.

Heat treatment in the step of imidizing is characterized in that carried out at 60 ~ 400 ℃.

Hereinafter, the present invention will be described in more detail.

The polyimide resin for the intermediate transfer belt of the present invention includes a silicone-modified polyimide resin copolymerized with a silicone resin.

The silicone-modified polyimide-based resin is obtained by dissolving dianhydride, diamine and silicone resin in an aprotic superpolar solvent to prepare a silicone-modified polyamic acid solution, followed by heat treatment to imidize it.

The thermally conductive filler is reacted at 0 to 30 ° C. for 30 minutes to 12 hours so that the thermal conductivity of the intermediate transfer belt produced during the preparation of the silicone-modified polyamic acid solution becomes 5.1 to 7.4 W / mK.

If the thickness of the belt is too thin for the purpose of improving its thermal conductivity during the manufacture of the intermediate transfer belt, the rigidity of the belt may be greatly reduced. Thus, the belt may be cracked or crushed due to repeated rotational stress during the printing process. Losing symptoms can occur. In order to induce efficient heat dissipation of heat inevitably generated during long time operation of the intermediate transfer belt, thermally conductive fillers may be introduced into the belt resin to induce heat dissipation effect. At this time, the appropriate thickness of the intermediate transfer belt is 30 to 300 µm.

In order to manufacture a composite material having excellent heat dissipation properties, a method of efficiently filling a thermally conductive filler in a matrix of the composite material is required, and filling is performed by the shape, size, and content ratio of the thermally conductive fillers filled. Density can vary. Heat transfer is a transfer of energy due to temperature difference. There are three types of transfer methods of conduction, convection, and radiation. All of them increase in thermal conductivity in proportion to the area where the transfer phenomenon occurs.

In the case of a composite material having heat dissipation, heat is transmitted by conduction heat transfer, and the amount of heat transferred is increased in proportion to the cross-sectional area of the composite material, inversely proportional to thickness, and proportional to temperature difference.

If such a phenomenon is collectively shown, it can be represented by Fourier's thermal conductivity as shown in the following formula.

Where A is the area of the composite material, T is the temperature, X is the thickness of the composite material, q is the amount of heat transferred by conduction, and k is the thermal conductivity of the composite material of the material.

In consideration of the above-described matters, the thermally conductive filler preferably has a thermal conductivity of 20 W / mK or more.

In addition, the thermally conductive filler preferably has an electrical resistivity of 10 ¹ Ωcm or more. If the electrical resistivity is lower than this value, the volume resistance of the transfer belt is very low, so that a volume resistance value that is not suitable for use as a transfer belt is reduced. There is a problem.

The thermally conductive filler may be, for example, single wall carbon nanotubes, multi wall carbon nanotubes, silica, alumina, aluminum borate, silicon carbide, titanium carbide, boron carbide, silicon nitride, At least one selected from inorganic fillers such as boron nitride, aluminum nitride, titanium nitride, mica, potassium titanate, beryllium titanate, calcium carbonate, magnesium oxide, zirconium oxide, tin oxide, beryllium oxide, aluminum oxide and aluminum hydroxide Use in combination.

The form of the thermally conductive filler is not particularly limited, and may be in the form of spherical shape, needle shape and plate shape. However, in the case of the needle-shaped shape, the packing density is not effectively reduced, and the packing density is reduced. In the case of the plate-shaped shape, it has a different thermal conductivity in each axial direction, so that the high-charged shape is most preferable.

It is preferable that the size of the filler is 0.2-20 micrometers in a spherical shape, 0.5-5 micrometers in a needle shape, and 0.5-10 micrometers in a plate shape. Particularly, in the case of the spherical filler, it is preferable to use relatively large particles having a particle size of 5 to 20 μm and particles having a relatively small particle size of 0.2 to 5 μm at a ratio of 6 to 7: 4 to 3. This is because a relatively small amount of filler is efficiently packed and filled between the empty spaces of the filler having a large particle size, so that a thermally conductive network capable of dissipating heat is uniformly formed.

The intermediate transfer belt forms not only the unique thermal conductivity of each of these thermally conductive fillers, but also forms a heat transfer path that can dissipate heat when they are uniformly dispersed in the belt while maintaining an appropriate content ratio.

In addition, the content of the thermally conductive filler for efficient thermal conductivity is preferably from 0.01 to 30% by weight relative to the total solute.

On the other hand, in addition to the thermally conductive filler may further include an electrically conductive filler that can adjust the volume resistance value of the polyimide resin. As the electrically conductive filler, it is preferable to use 2 to 35% by weight of one or more selected from ketjen black, acetylene black, and furnace black based on the total solute. In addition, it may further include a metal filler such as Dentall TM-200 doped (supported) with aluminum, nickel, silver, or mica, and 0.1 to 5% by weight of the total solute may be used.

Diane hydride and diamine for preparing a silicone-modified polyimide resin is not particularly limited as long as it is used in the production of polyimide resin, for example, 1,4-phenylenediamine (1,4-PDA) as the diamine , 1,3-phenylenediamine (1,3-PDA), 4,4'-methylenedianiline (MDA), 4,4'-oxydianiline (ODA), 4,4'-oxyphenylenediamine ( OPDA) may be used, and the dianhydride may be 1,2,4,5-benzenetetracarboxylic dianhydride (PMDA), 3,3 ', 4,4'-biphenyltetracarboxylic. Dianhydride (BTDA), 4,4'- oxydiphthalic anhydride (ODPA), 4,4'- hexafluoro isopropylidene diphthalic anhydride, etc. can be used. Diamine and dianhydride are normally used in equimolar amounts.

Silicone resins have the properties of organic and inorganic compounds at the same time and are used to impart stain resistance, water repellency, oil repellency, and releasability with paper. Among them, polydimethylsiloxane, polydiphenylsiloxane and copolymers thereof, polymethylphenylsiloxane One or more selected ones may be used, and a number average molecular weight of 600 to 2000 may minimize microphase separation occurring during polyimide polymerization. The content is preferably used to 10 to 30% by weight based on the diamine content.

Particularly preferred silicone resins in the present invention are polydiphenylsiloxanes in which Si—O bonds consisting of Si and O atoms bonds form a polymer backbone, and two bulky organic substituents, a phenyl group, are bonded to atoms of Si. Polydiphenylsiloxane, the second most used compound in the silicone industry, after polydimethylsiloxane, is a phenyl group in which both substituents bonded to Si atoms are high, and the glass transition temperature, thermal stability, and mechanical properties of polydimethylsiloxane are higher than those of polydimethylsiloxane. This is known to be excellent. In addition, polydiphenyl siloxane is a polymer compound modified with polydiphenyl siloxane due to its nonpolarity and low surface energy. The siloxane component of the polydiphenyl siloxane is separated from the polymer and moved to the air-polymer interface, and thus the siloxane is deposited on the surface of various polymers. As a result, the surface of the polymer has excellent water and oil repellency and releasability. Such characteristics are also observed in two-phase copolymers and blends. However, in the present invention, the silicone resin is not limited to polydiphenylsiloxane.

In preparing a silicone-modified polyamic acid solution, when the silicone resin is used in an amount less than 10% by weight based on the diamine content, the water repellent and oil repellent properties are not greatly improved, and the effect of improving the resistance to water, which is a disadvantage of the polyimide, is insufficient. , When used in excess of 30% by weight has a problem that the mechanical strength is sharply reduced due to the influence of the silicone resin having a relatively flexible properties compared to the polyimide.

The solvent may be selected from aprotic superpolar solvents such as N, N-dimethylformamide (DMF), dimethylacetamide (DMAc), and N-methylpyrrolidinone (NMP).

The prepared silicone-modified polyamic acid solution is introduced into a mold and heat-treated to imidize.

The mold is not particularly limited, but a cylindrical mold is used in order to prevent the intermediate transfer belt of the present invention from being seamless, and preferably a cylindrical Teflon mold composed of a double structure of an outer cylinder and an inner cylinder. Therefore, the thickness of the belt can be adjusted using the difference between the diameter of the outer cylinder and the inner cylinder, the preferred thickness of the belt is 30 ~ 300㎛.

The heat treatment is performed stepwise at 50 ~ 400 ℃, first pre-baking (pre-baking) at 50 ~ 100 ℃ 10 to 120 minutes to remove the solvent and water remaining on the surface first. After maintaining the temperature increase rate of 2 ~ 10 ℃ per minute and finally post-curing to 350 ~ 400 ℃ by completely removing the solvent and water present on the surface to proceed and complete the imidization and solidification at the same time The transfer belt of the film is prepared.

The manufactured transfer belt has a thermal conductivity of 5.1 to 7.4 W / mK, and has a volume resistance value in the range of 10 ⁸ to 10 ¹² Ωcm, which is an intermediate resistance value, thereby improving antistatic property, antistatic property, and printability. Intermediate transfer belts for semiconductive laser printers, facsimiles and copiers can be manufactured.

In addition, the manufactured transfer belt is preferably a contact angle of 105 ° ~ 113 °. Here the contact angle refers to the angle that the liquid has when it is thermodynamically equilibrated on the solid surface, measured by the droplets sessile on the solid surface, the low contact angle indicates that the sample is hydrophilic, and the high contact angle indicates that the sample is hydrophobic. That means having In general, in the case of polyimide-based polymer compounds, their contact angles have a contact angle of less than 20 ° to 70 °, so that the water and oil repelling properties are deteriorated, thereby exhibiting properties that are very vulnerable to moisture. There is a need to improve the resistance to moisture.

In addition, the transfer belt of the present invention is preferably elastic modulus of 2.2 ~ 4.5 GPa. If the elastic modulus is low, there is a concern that mechanical deformation may occur when the intermediate transfer belt is used for a long time, and if the elastic modulus is high, the mechanical strength is deteriorated.

Hereinafter, examples of the present invention will be described in more detail, but the scope of the present invention is not limited to these examples.

<Example 1>

Injecting nitrogen into a four-necked flask equipped with a mechanical stirrer, a reflux condenser and a nitrogen inlet, 47 g of PMDA and 43 g of 4,4-oxydianiline were dissolved in 380 g of an aprotic superpolar solvent, with a number average molecular weight. The polydiphenylsiloxane having the aminopropyl group introduced into the 750 sock end was added in an amount of 10% by weight based on the weight of 4,4-oxydianiline and completely dissolved. Here, as a thermally conductive filler, spherical alumina (Al ₂ O ₃ ) having a thermal conductivity of 105 W / mK and an electrical resistance of 10 ² Ωcm was added at 3% by weight based on the total solute weight, and at this time, the particle diameter was 6 μm. And 0.5 µm of alumina were mixed at a mixing ratio of 7: 3. In addition, 1.5 wt% of Ketjenblack was mixed with respect to the total solute weight as the electrically conductive filler, and reacted for 1 hour at room temperature while dispersing in the solution through an ultrasonic disperser, thereby containing a polydiphenylsiloxane containing a thermally conductive filler and an electrically conductive filler. A modified polyamic acid solution was prepared.

After the polydimethylsiloxane modified polyamic acid solution prepared above was introduced into a cylindrical Teflon mold composed of a double structure of an outer cylinder and an inner cylinder, prebaking was performed at 70 ° C. for 1 hour to first remove the solvent and water remaining on the belt surface. , The inner cylinder was separated from the outer cylinder. Thereafter, by post-curing to 350 ° C. while maintaining a temperature increase rate of 5 ° C. per minute, the solvent and water remaining on the surface and inside were completely removed.

The prepared polydiphenylsiloxane modified polyimide intermediate transfer belt had a thickness of 65 μm.

<Example 2>

In Example 1, a polydiphenylsiloxane-modified polyimide-based intermediate transfer belt was prepared in the same manner, except that 6 µm and 0.5 µm of alumina were used as the thermally conductive filler in a ratio of 6: 4.

<Example 3>

In Example 1, a polydiphenylsiloxane-modified polyimide-based intermediate transfer belt was prepared in the same manner, except that alumina having a particle diameter of 6 μm and 0.5 μm was used as a compounding ratio of 3: 7.

Example 4

In Example 1, a polysilicon was prepared in the same manner, except that 3 wt% of alumina having a needle shape, 5 μm in length, 100 W / mK in thermal conductivity, and 10 ² Ωcm in electrical resistance was added alone. Diphenylsiloxane modified polyimide intermediate transfer belt was prepared.

<Example 5>

In Example 1, the same method as the thermal conductive filler, except that 3 wt% of boron nitride having a plate shape, a length of 5 μm, a thermal conductivity of 156 W / mK, and an electrical resistance of 10 ² μmcm alone was added. A polydiphenylsiloxane modified polyimide intermediate transfer belt was prepared.

<Example 6>

In Example 1, polydiphenylsiloxane was prepared in the same manner, except that alumina having a particle diameter of 6 μm and 0.5 μm was mixed at a compounding ratio of 7: 3 as a thermally conductive filler, and added at 1.5% by weight based on the total solute weight. A modified polyimide intermediate transfer belt was prepared.

<Example 7>

In Example 1, polydiphenylsiloxane was prepared in the same manner, except that alumina having a particle diameter of 6 μm and 0.5 μm was mixed at a compounding ratio of 7: 3 as a thermally conductive filler, and was added at 0.01% by weight based on the total solute weight. A modified polyimide intermediate transfer belt was prepared.

<Example 8>

In Example 1, a polydiphenylsiloxane-modified polyimide-based intermediate transfer belt was prepared in the same manner except that Ketjenblack was not included as the electrically conductive filler.

Example 9

In Example 1, a polydimethylsiloxane-modified polyimide-based intermediate transfer belt was prepared in the same manner except that polydimethylsiloxane having an aminopropyl group introduced into the sock end having a number average molecular weight of 620 was used.

<Example 10>

In Example 1, a polydiphenylsiloxane-modified polyimide intermediate in the same manner except for using a mica having a needle length of 5 μm, a thermal conductivity of 20 W / mK, and an electrical resistance of 10 ¹ Ωcm instead of alumina A transfer belt was prepared.

<Example 11>

In Example 1, a polydiphenylsiloxane modified polyimide-based intermediate transfer belt was prepared in the same manner except that 5 wt% of polydiphenylsiloxane was added to 4,4-oxydianiline.

<Example 12>

In Example 1, a polydiphenylsiloxane-modified polyimide-based intermediate transfer belt was prepared in the same manner except that 35 wt% of polydiphenylsiloxane was added to 4,4-oxydianiline by weight.

Comparative Example 1

In Example 1, a polydiphenylsiloxane modified polyimide-based intermediate transfer belt was prepared in the same manner except that alumina, which is a thermally conductive filler, was not added.

Comparative Example 2

In Example 1, a polydiphenylsiloxane-modified polyimide-based intermediate transfer belt was prepared in the same manner except that 36 wt% of alumina, a thermally conductive filler, was added.

Comparative Example 3

In Example 1, a polyimide intermediate transfer belt was prepared in the same manner except that no polydiphenylsiloxane was added.

<Comparative Example 4>

In Example 1, a polydiphenylsiloxane-modified polyimide-based intermediate transfer belt was prepared in the same manner except that Ketjenblack having a thermal conductivity of 75 W / mK and an electrical resistance of 10 ⁰ m 3 was used instead of alumina.

Comparative Example 5

In Example 1, a polydiphenylsiloxane-modified polyimide-based intermediate transfer belt was prepared in the same manner except that molybdenum powder having a thermal conductivity of 12 W / mK and an electrical resistance of 10 ¹ kcm was used instead of alumina.

Comparative Example 6

A polyimide-based intermediate transfer belt was prepared in the same manner as in Comparative Example 3, and a primer, which is a silicone-based component, was applied by spray, followed by 2% by weight of ketjen black and 0.5% by weight of Dentall TM-200. The siloxane was spray coated three times. Finally, after the spray coating, the sample was cured at 350 ° C. for 10 to 60 minutes to prepare a silicone-modified polyimide-based intermediate transfer belt of three layers of polyimide, primer, and polydimethylsiloxane.

Physical properties of the intermediate transfer belts prepared in Examples and Comparative Examples were evaluated by the following methods, and the results are shown in Table 1 below.

(1) thermal conductivity

FL5000 thermal conductivity analyzer was used to measure polyethylene foam, silicone rubber, quartz glass and Zirconia based on ASTM E1461.

(2) volume resistance

Using a resistance meter manufactured by Mitsubishi Chemical, voltage was continuously applied to the sample. The voltage applied to the sample was measured while varying the voltage to 10V, 100V, 250V, 500V and 1000V. In addition, in order to measure the volume resistance, a sample was installed on a substrate of a metal material, and measured at intervals of 10 to 30 seconds for each sample. In this case, a ring-shaped probe (probe) was used. .

(3) contact angle

In order to measure the water repellent and oil repellent properties of the silicone-modified polyimide intermediate transfer belt, their contact angles were measured. The contact angle was measured using DCA 3115, CAHN's Dynamic Contact Angle Meter, at room temperature of 25 ° C. The solution was dipped in deionized distilled water and 6 µl of ethylene glycol on the surface of the sample in the form of a sessile drop, and the contact angle was measured through a monitor in which the interface between the sample surface and the droplet was enlarged. Was obtained.

(4) modulus of elasticity

The elastic modulus of the silicone-modified polyimide intermediate transfer belt was measured according to JIS K 6301 using Instron's universal testing machine Model 1000.

division Thermal Conductivity (W / mK) Volume resistance (Ω㎝) Contact angle (°) Modulus of elasticity (GPa) Example 1 7.33 3.53 × 10 ¹⁰ 109 3.30 Example 2 6.92 3.07 × 10 ¹⁰ 111 3.15 Example 3 6.27 1.11 × 10 ¹⁰ 105 3.07 Example 4 5.10 2.32 × 10 ¹⁰ 105 3.03 Example 5 6.31 1.21 × 10 ¹⁰ 112 3.05 Example 6 5.95 3.23 × 10 ¹⁰ 107 3.02 Example 7 5.27 1.22 × 10 ¹⁰ 108 3.02 Example 8 7.01 7.08 × 10 ¹⁶ 110 3.13 Example 9 6.95 3.24 × 10 ¹⁰ 108 2.60 Example 10 5.33 5.22 × 10 ¹⁰ 107 3.01 Example 11 7.00 4.11 × 10 ¹⁰ 75 3.31 Example 12 7.35 3.46 × 10 ¹⁰ 114 2.10 Comparative Example 1 3.01 8.07 × 10 ¹¹ 101 3.00 Comparative Example 2 8.33 7.53 × 10 ⁵ 112 3.5 Comparative Example 3 7.09 1.58 × 10 ¹⁰ 67 2.80 Comparative Example 4 6.75 2.56 × 10 ⁴ 103 2.95 Comparative Example 5 4.53 5.75 × 10 ¹⁰ 106 3.00 Comparative Example 6 4.31 6.13 × 10 ¹⁰ 103 2.60

As a result of measuring the physical properties, in Comparative Example 1 in which the thermally conductive filler was not introduced, in Comparative Example 2 in which the thermal conductivity was too low, the thermal conductivity was too high and the volume resistivity was very low, resulting in a color laser printer. It becomes difficult to implement an image of toner.

In the case of the thermally conductive fillers, spherical alumina having a particle size of 6 μm and 0.5 μm, respectively, was introduced at a ratio of 7: 3 or 6: 4, and the thermal conductivity was the best.

On the other hand, as shown in Example 3, when the alumina having a small particle size is injected in a relatively large amount compared to the alumina having a large particle size, the alumina having a large particle size is larger than the alumina having a small particle size. It can be seen that the thermal conductivity is reduced compared to Examples 1 and 2 introduced, and therefore, the alumina packing density in Example 3 is not as efficient as in Examples 1 and 2.

And in Example 4 using the needle-shaped alumina and Example 5 in which the plate-shaped boron nitride was introduced, the same content ratio as in Example 1 3% by weight was introduced and the filler itself had similar thermal conductivity. In the conductive film made, it can be seen that the heat dissipation characteristics are relatively reduced. This suggests that even in the case of the same alumina, the needle shape is not efficiently charged and the packing density is reduced, so that the thermal conduction network is not uniformly formed. Since the particle shape of has a plate-like structure, it has excellent heat dissipation characteristics of 156 W / mK in the a-axis direction, while having a low thermal conductivity of 2 W / mK in the c-axis direction. It could not be filled with high, suggesting that the heat dissipation characteristics were relatively low compared to the examples and comparative examples using the spherical alumina.

In addition, in the case of Comparative Example 4 using a filler having a thermal conductivity of 75 W / mK but having an electrical resistivity of 10 ⁰ Ωcm, the volume resistance value was very reduced to 2.56 × 10 ⁴ , and the electrical resistance was 10 ¹ Ωcm but the thermal conductivity was 12 W / In the case of the comparative example 5 using the mK filler, the thermal conductivity is very low to 4.53, it can be seen that it is not suitable for use as an intermediate transfer belt, respectively.

In addition, when the electrically conductive filler is added, the volume resistance value is in the range of 10 ⁸ to 10 ¹² Ωcm, and the volume resistance value suitable for use as an intermediate transfer belt such as a laser printer, a facsimile machine, and a copier is shown. However, in Example 8, in which the conductive filler was not added, the volume resistance value was greatly increased, and thus defects in image defects may occur due to deterioration of physical properties such as antistatic properties, transfer properties, image properties, mold release properties, and stain resistance. It can be seen.

On the other hand, as the silicon is introduced into the polyimide main chain 10% by weight or more compared to the diamine content it can be seen that the contact angle of the silicone-modified polyimide-based intermediate transfer belt of the copolymer form all increased to 105 or more. In other words, by imparting hydrophobic properties due to the silicone modification, it can be seen that it increases the low resistance to moisture, which is a fatal disadvantage of polyimide, and also increases the releasability with the paper loaded. On the other hand, in Comparative Examples 3 and 11, which were not denatured or introduced, the contact angles were very low at 67 ° and 75 °, respectively, so that the water fragility of the polyimide was not improved. In addition, in Comparative Example 6 in which the polydiphenylsiloxane was physically spray-coated, the contact angle was not improved, and the elastic modulus was reduced compared to the chemical introduction of the silicon compound into the polyimide main chain. In the case of Example 12 in which the deformation is feared and the amount of silicon introduced is excessive, it can be seen that the mechanical strength decreases.

As described above, the present invention provides an intermediate transfer belt having a single layer intermediate transfer belt using a silicone-modified polyimide resin, and having excellent heat dissipation characteristics, excellent electrical characteristics and water repellency, and suitable mechanical strength. Can be.

In addition, the present invention can provide sufficient physical properties as an intermediate transfer belt even without adding a fluorine resin layer and an adhesive layer for adhesion with the fluorine resin, and can efficiently manufacture an intermediate transfer belt having excellent heat dissipation characteristics, electrical characteristics, and water repellency. It can provide a manufacturing method that can maximize the efficiency of the process.

Claims (17)

An intermediate transfer belt containing a silicone-modified polyimide resin and a thermally conductive filler and having a thermal conductivity of 5.1 to 7.4 W / mK. The method of claim 1, Thermally conductive fillers are intermediate transfer belts, characterized in that the thermal conductivity is 20W / mK or more, the electrical resistance is 10 ¹ Ωcm or more. The method of claim 1, Thermally conductive filler is an intermediate transfer belt, characterized in that the spherical filler having a particle diameter of 0.2 ~ 20㎛. The method of claim 3, wherein The spherical filler is an intermediate transfer belt, characterized in that it comprises a relatively large particles with a particle diameter of 5 ~ 20㎛ and particles having a relatively small particle diameter of 0.2 ~ 5㎛ in the ratio of 6-7: 4-3. The method of claim 1, Thermally conductive filler is an intermediate transfer belt, characterized in that contained 0.01 to 30% by weight relative to the total solute. The method of claim 1, Thermally conductive fillers include single wall carbon nanotubes, multi wall carbon nanotubes, silica, alumina, aluminum borate, silicon carbide, titanium carbide, boron carbide, silicon nitride, boron nitride, and nitride Intermediate transfer belt, characterized in that one or more selected from aluminum, titanium nitride, mica, potassium titanate, beryllium titanate, calcium carbonate, magnesium oxide, zirconium oxide, tin oxide, beryllium oxide, aluminum oxide and aluminum hydroxide. . The method of claim 1, The intermediate transfer belt, characterized in that it further contains an electrically conductive filler. The method of claim 1, The intermediate transfer belt, characterized in that the volume resistance value is in the range of 10 ⁸ ~ 10 ¹² Ω㎝. The method of claim 1, Intermediate transfer belt, characterized in that the contact angle is 105 ° ~ 113 °. The method of claim 1, The silicone-modified polyimide resin is an intermediate transfer belt, characterized in that the copolymer containing dianhydride, diamine and silicone resin. The method of claim 10, The silicone resin is an intermediate transfer belt, characterized in that the number average molecular weight of 600 ~ 2,000. The method of claim 10, The silicone resin is an intermediate transfer belt, characterized in that it contains 10 to 30% by weight relative to the diamine content. The method of claim 10, The silicone resin is an intermediate transfer belt, characterized in that one or a combination of two or more selected from polydimethylsiloxane, polydiphenylsiloxane and polymethylphenylsiloxane which is a copolymer thereof. Preparing a silicone-modified polyamic acid solution by dissolving dianhydride, diamine and silicone resin in an aprotic superpolar solvent; Dispersing a thermally conductive filler in the silicone-modified polyamic acid solution; And A method for producing an intermediate transfer belt comprising the step of imidizing by heating a silicone-modified polyamic acid solution in which a thermally conductive filler is dispersed into a mold. The method of claim 14, The mold is a manufacturing method of the intermediate transfer belt, characterized in that using a cylindrical structure consisting of a double structure of the outer cylinder and the inner cylinder. The method of claim 14, Dispersing the thermally conductive fillers further comprises the dispersion of the electrically conductive fillers. The method of claim 14, The heat treatment in the step of imidizing the manufacturing method of the intermediate transfer belt, characterized in that carried out at 60 ~ 400 ℃.