WO2019148370A1 - Silica gel, developing roller and preparation method thereof - Google Patents

Abstract

Disclosed is a silica gel, a developing roller and a preparation method thereof. In parts by weight, the raw materials for preparing the silica gel include 100 parts of raw rubber, 3 to 40 parts of conductive filler, 10 to 45 parts of white carbon black, 0.5 to 10 parts of magnesium carbonate, 0.5 to 20 parts of stabilizer, 0.5 to 3 parts of crosslinking agent, and 0.5 to 1 parts of a vulcanizing agent. The raw rubber is selected from one of the methyl vinyl raw rubber and methyl vinyl silicone oil. The stabilizer is selected from at least one of zinc oxide, titanium oxide, and silicon carbide. A silica gel enabling the preparation of a developing roller having good electrical resistance stability is thus provided.

Description

Silicone, developing roller and preparation method thereof Technical field:

The invention relates to a silica gel, a developing roller and a preparation method thereof.

Background technique:

At present, most of the developing rollers on the market are rubber developing rollers, and the developing roller prepared by rubber has a problem of poor resistance stability, which affects the promotion of rubber developing rollers.

Summary of the invention:

Based on this, it is necessary to provide a silica gel capable of producing a developing roller having a good resistance stability.

In addition, a method for preparing a silica gel, a developing roller, and a method for preparing the same are also provided.

A silica gel, the raw materials for preparing silica gel in parts by mass include:

The raw rubber is selected from the group consisting of methyl vinyl rubber and methyl vinyl silicone oil, and the stabilizer is at least one selected from the group consisting of zinc oxide, titanium oxide and silicon carbide.

A method for preparing silica gel, comprising the steps of:

100 parts of raw rubber, 3 parts to 40 parts of conductive filler, 10 parts to 45 parts of white carbon, 0.5 parts to 10 parts of magnesium carbonate and 0.5 parts to 20 at 150 ° C to 200 ° C under vacuum. Mixing the stabilizer to obtain an intermediate material, wherein the raw rubber is selected from one of methyl vinyl green rubber and methyl vinyl silicone oil, and the stabilizer is selected from at least one of zinc oxide, titanium oxide and silicon carbide. ;

The intermediate material, 0.5 parts to 3 parts of the crosslinking agent, and 0.5 parts to 1 part of the vulcanizing agent are mixed to cause a crosslinking reaction to obtain a silica gel.

A developing roller comprises a shaft core, an elastic layer and a wear layer. The elastic layer covers the core, and the wear layer covers the elastic layer. The material of the elastic layer is the above-mentioned silica gel.

A method for preparing a developing roller, comprising the steps of:

Preparation of silica gel according to the above preparation method of silica gel;

Forming an elastic layer on the core by using silica gel;

A wear layer is formed on the elastic layer.

Details of one or more embodiments of the invention are set forth in the accompanying drawings and description below. Other features, objects, and advantages of the invention will be apparent from the description and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1 is a schematic view showing the structure of a developing roller of an embodiment;

2 is a flow chart showing a method of preparing the developing roller of FIG. 1.

Detailed ways

In order to facilitate the understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the understanding of the present disclosure will be more fully understood.

All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. The terminology used in the description of the present invention is for the purpose of describing particular embodiments, and is not intended to limit the invention.

Referring to FIG. 1 , the developing roller 10 of an embodiment includes a core 110 , an elastic layer 120 , and a wear layer 130 .

The shaft core 110 is a main body structure of the developing roller, and the shaft core 110 is selected from one of a stainless steel shaft and a nickel-plated iron shaft.

The elastic layer 120 is covered on the core 110, and the material of the elastic layer 120 is silica gel. Specifically, the raw materials for preparing the silica gel in terms of mass fractions include:

Among them, the raw rubber glue is selected from one of methyl vinyl raw rubber and methyl vinyl silicone oil. Further, the vinyl group in the methyl vinyl rubber has a mass percentage of 0.05% to 0.5%. Methyl vinyl rubber is the main material of silica gel raw materials. The content of vinyl groups in methyl vinyl rubber is different depending on the composition of raw materials, and the molecular weight of methyl vinyl rubber is also different. Further, the methylvinyl rubber is selected from one of a phenyl-substituted methylvinyl rubber and a fluorine-substituted methylvinyl rubber.

It should be noted that when the raw rubber is methyl vinyl rubber, the obtained silica gel is solid silica gel; when the raw rubber is methyl vinyl silicone oil, the obtained silica gel is liquid silica gel.

The conductive filler is selected from at least one of conductive carbon black, carbon nanotubes, and graphene.

Conductive carbon black and conductive carbon black mainly pass through the point contact between the carbon particles to form a conductive network path to conduct electricity, which belongs to 0-dimensional conductivity. Specifically, the conductive carbon black has a mass fraction of 20 parts to 40 parts.

The carbon nanotubes form a conductive path through the line contact between the carbon nanotubes, which belongs to the one-dimensional conductivity, and the material resistivity is lower. At the same time, the carbon nanotube particle size is very small, and only a small amount of carbon nanotubes can reduce the resistance of the silica gel. rate. Specifically, the mass fraction of the carbon nanotubes is from 2 parts to 7 parts.

Graphene is electrically conductive through the surface contact between graphene sheets. It belongs to 2-dimensional conductivity, and graphene has the lowest resistivity. However, since the graphene sheet aggregation state is much larger than that of carbon nanotubes, the amount of graphene is generally used. More than the carbon nanotubes can achieve the same conductivity. Specifically, the mass fraction of graphene is 5 parts to 20 parts.

Graphene and carbon nanotubes are more suitable for conducting carbon black than conductive carbon black. Only a small amount can achieve lower resistivity; graphene and carbon nanotubes are added with less mass and conductive The filler and the raw rubber are physically mixed. The more the content of the conductive filler, the poorer the compatibility between the silica raw materials, and the problem of compatibility marks when the silica gel is extruded; the particle sizes of graphene and carbon nanotubes are all in the nanometer range. The addition of methyl vinyl rubber greatly improves the plasticity of the silica gel, which is beneficial to the initial setting of the silicone extrusion. The roundness of the inner and outer diameters of the extruded silicone tube is good, and the resistance stability and uniformity after assembly are better. .

Further, the conductive filler is a mixture of conductive carbon black, carbon nanotubes and graphene to reduce the cost of the silica gel, and at the same time, form a composite pathway to achieve zero-dimensional, one-dimensional and two-dimensional composite conduction, improve the dispersion of raw materials in the silica gel, Problems such as conductive efficiency and resistance stability.

Among them, white carbon black is a reinforcing agent, which can improve the basic properties of silica gel, such as tensile strength and tear strength. Further, the mass fraction of the white carbon black is from 20 parts to 40 parts.

Among them, magnesium carbonate can improve the dispersibility of the conductive filler. Further, the mass fraction of magnesium carbonate is from 3 parts to 7 parts.

Wherein the stabilizer is at least one selected from the group consisting of zinc oxide, titanium oxide, and silicon carbide.

Zinc oxide is electrically conductive through electron holes and can serve as an electrically conductive bridge for conductive fillers to improve the resistance fluctuation of silica gel at high voltages. Further, the mass fraction of zinc oxide is 5 parts to 15 parts.

Wherein, the crosslinking agent is a hydrogen-containing silicone oil. Further, the mass percentage of hydrogen in the hydrogen-containing silicone oil is 0.05% to 1.5%. The combination of different hydrogen content of hydrogen-containing silicone oil can adjust the hardness and performance of the silica gel. Specifically, the hydrogen-containing silicone oil is hydrogen-containing silicone oil having a mass percentage of hydrogen of 0.1%, and the mass percentage of hydrogen is 0.4. % hydrogen-containing silicone oil and a mixture of hydrogen-containing silicone oil having a mass percentage of 0.8%.

Among them, the more the vulcanizing agent is used as a catalyst, the faster the vulcanization rate is. Further, the parts by mass of the vulcanizing agent are from 0.6 parts to 0.8 parts. Specifically, the vulcanizing agent is selected from at least one of a platinum vulcanizing agent and a bis-four-four vulcanizing agent.

Among them, the main component of the platinum vulcanizing agent is a coordination complex of a platinum atom and tetramethyldivinyldisiloxane. The platinum vulcanizing agent is mainly prepared by reacting chloroplatinic acid, tetramethyldivinyldisiloxane and ethanol. Specifically, the platinum vulcanizing agent has a platinum content of 1000 ppm by mass.

Compared with rubber conductive materials, the above silica gel has excellent resilience and pressure resistance, and stable electrical resistance, and can be applied to most conductive products.

The roughness Ra of the elastic layer 120 is less than 1.5.

The wear layer 130 mainly functions as a wear resistant layer and covers the elastic layer 120. Wherein, the surface roughness Ra of the wear-resistant layer 130 is less than 1.5.

Specifically, the material of the wear layer 130 includes polyurethane, white carbon, and a conductive filler. More specifically, the material of the abrasion resistant layer 130 includes 100 parts of polyurethane, 5 parts to 15 parts of white carbon, and 3 to 40 parts of conductive filler in parts by mass.

Further, the conductive filler is selected from at least one of conductive carbon black, carbon nanotubes, and graphene. Further, the parts by mass of the conductive carbon black are 20 parts to 40 parts; the parts by mass of the carbon nanotubes are 2 parts to 7 parts; and the parts by mass of the graphene are 5 parts to 20 parts.

In general, by adding white carbon black and a conductive filler having different particle diameters to the polyurethane, the surface roughness and resistance uniformity of the developing roller 10 can be adjusted.

Specifically, the wear layer 130 has a thickness of 5 μm to 15 μm. More specifically, the wear layer 130 has a thickness of 7 μm to 12 μm.

The above developing roller 10 has at least the following advantages:

(1) It has been proved by experiments that the raw material formula of the above silica gel is reasonable, and the developing roller prepared by the above silica gel has good resistance stability; at the same time, the raw rubber and the stabilizer are used in the above ratio, and the raw rubber is selected from methyl vinyl One of raw rubber and methyl vinyl silicone oil, the stabilizer is selected from at least one of zinc oxide, titanium oxide and silicon carbide, which can improve the resistance fluctuation of the silica gel at a high voltage, so that the resistance of the developing roller The voltage changes less and the resistance is better.

(2) The above-mentioned ratio of magnesium carbonate is added to the raw material of the silica gel, and by blending with the conductive filler, the dispersibility of the conductive filler in the silica gel can be effectively improved, so that the uniformity of the resistance of the developing roller is better, and the print quality is better. .

(3) The above-mentioned ratio of stabilizer is added to the raw material of the above silica gel, which not only promotes the dispersion effect of the conductive filler, improves the resistance uniformity of the silica gel, but also serves as an electron transfer bridge for the conductive filler to improve the resistance of the silica gel at a high voltage. The volatility is such that the resistance of the developing roller varies less with voltage and the resistance is better.

(4) The conductive filler in the above silica gel raw material is a mixture of conductive carbon black, carbon nanotubes and graphene, and the conductive filler added is greatly reduced under the same resistivity requirement; at the same time, carbon nanotubes and graphene particles and density It is small, not easy to settle, and the dispersion of the conductive filler is better to improve the resistance stability and uniformity of the developing roller.

Referring to FIG. 2, a method for preparing a developing roller according to an embodiment includes:

Step S210: 100 parts of raw rubber, 3 parts to 40 parts of conductive filler, 10 parts to 45 parts of white carbon, 0.5 parts to 10 parts of magnesium carbonate and 0.5 at 150 ° C to 200 ° C under vacuum. The parts to 20 parts of the stabilizer are mixed to obtain an intermediate material.

Among them, the vacuum under vacuum conditions is 0.08-0.1 Mpa to extract the low molecules produced by the rubber mixing process.

Among them, the raw rubber is selected from one of methyl vinyl raw rubber and methyl vinyl silicone oil. Further, the content of the vinyl group in the methylvinyl rubber is 0.05 to 0.5%. Further, the methylvinyl rubber is selected from one of a phenyl-substituted methylvinyl rubber and a fluorine-substituted methylvinyl rubber.

It should be noted that when the raw rubber is methyl vinyl rubber, the prepared silica gel is solid silica gel; when the raw rubber is methyl vinyl silicone oil, the prepared silica gel is liquid silica gel.

The conductive filler is selected from at least one of conductive carbon black, carbon nanotubes, and graphene. Further, the parts by mass of the conductive carbon black are 20 parts to 40 parts; the parts by mass of the carbon nanotubes are 2 parts to 7 parts; and the parts by mass of the graphene are 5 parts to 20 parts. Further, the conductive filler is a mixture of conductive carbon black, carbon nanotubes, and graphene.

Wherein, the mass fraction of the white carbon black is 20 parts to 40 parts; and the mass part of the magnesium carbonate is 3 parts to 7 parts.

Wherein the stabilizer is at least one selected from the group consisting of zinc oxide and titanium oxide. Further, the mass fraction of zinc oxide is 5 parts to 15 parts.

Among them, the mixing time is 1.5h to 3.0h.

It should be noted that, before the step S210, the step of mixing the raw rubber, the conductive filler, the silica, the magnesium carbonate and the stabilizer under normal pressure is further included. Specifically, the conductive filler, white carbon black, magnesium carbonate and a stabilizer are respectively added to the raw rubber, and stirred for 40 minutes to 60 minutes to obtain a mixture, wherein the stirring speed is 28 r/min. Further, the conductive filler, white carbon black, magnesium carbonate and a stabilizer are added to the raw rubber at least three times.

Step S220: kneading the intermediate material, 0.5 parts to 3 parts of the crosslinking agent, and 0.5 parts to 1 part of the vulcanizing agent to cause a crosslinking reaction to obtain a silica gel.

Wherein, the crosslinking agent is a hydrogen-containing silicone oil. Further, the mass percentage of hydrogen in the hydrogen-containing silicone oil is 0.05% to 1.5%. Specifically, the hydrogen-containing silicone oil is a hydrogen-containing silicone oil having a hydrogen content of 0.1% by mass, a hydrogen-containing silicone oil having a hydrogen content of 0.4% by mass, and a hydrogen-containing silicone oil having a mass percentage of 0.8% by weight. .

Further, the parts by mass of the vulcanizing agent are from 0.6 parts to 0.8 parts. Specifically, the vulcanizing agent is selected from at least one of a platinum vulcanizing agent and a bis-four-four vulcanizing agent. More specifically, the platinum vulcanizing agent has a platinum content of 1000 ppm by mass.

Among them, the number of times of opening is 20 to 40 times. Specifically, the open mill is used for the opening and the open mill is milled by two rolls.

Among them, the crosslinking reaction is a hydrosilylation reaction. Specifically, the raw rubber and the hydrogen-containing silicone oil undergo a hydrosilylation reaction under the catalysis of a vulcanizing agent to form a spatial crosslinked network. The external appearance of the cross-linking reaction is the solidification of the silica gel raw material.

It should be noted that the silica gel obtained after adding the platinum vulcanizing agent needs to be used up on the same day, otherwise the silica gel will be burnt and cannot be used.

Step S230: forming an elastic layer on the core by using silica gel.

In one embodiment, when the raw rubber is methyl vinyl rubber, the step of forming an elastic layer on the core by using silica gel is specifically:

Step S231: molding the silica gel and vulcanizing it to obtain a silicone tube;

Wherein, the step S231 is specifically: extruding the silica gel using an extruder, and performing a vulcanization on the hot channel to obtain a silicone tube, wherein the extruder has a rotation speed of 2 r/min to 20 r/min, and the temperature of the hot channel is 280 ° C. ~600 ° C, a period of vulcanization (time of the silicone tube overheating channel) is 1min ~ 10min.

Specifically, the hot channel is divided into an ultra-high temperature section and a high temperature section, the ultra-high temperature section is 0.5 m long, the temperature is 600 ° C, the high temperature section is 8 m long, and the temperature is 280 ° C. For example, the speed of movement of the silicone tube in the hot aisle is 2 m/min, and the time of the first vulcanization is 4.25 min.

Step S232: The silicone tube is sleeved on the shaft core, and then vulcanized in two stages to form an elastic layer.

The second step of vulcanization is specifically: heating and vulcanizing the silicone tube by using an oven, wherein the temperature of the oven is 200 ° C, and the time of the second stage of vulcanization (the time of the silicone tube in the oven) is 2 h.

Wherein, the thickness of the elastic layer is determined according to the product requirements of the desired developing roller, and then the inner and outer extrusion caliber of the appropriate extruder are selected to extrude the desired silicone tube. For example, if the outer diameter of the developing roller core is 8 mm and the outer diameter of the developing roller is 16 mm, the inner diameter of the extruded silicone tube is 6 mm to 7 mm, the outer diameter is 16.5 mm, the inner diameter is smaller than the axial core, and the rubber roller and the core are assembled after assembly. In order to have a certain torque, to prevent slipping, the outer diameter is slightly larger, which is convenient for later grinding.

It should be noted that before the step of sheathing the silicone tube on the shaft core, the step of cutting the silicone tube is also included.

In another embodiment, the step of forming an elastic layer on the core by using silica gel is specifically:

Step S236: Applying an adhesive to the shaft core and drying.

Among them, the adhesive can be bonded to the shaft core. Specifically, the adhesive is selected from one of Chemlock adhesive CH607 and Chemlock adhesive CH608.

Among them, the drying temperature is 80 ° C, and the drying time is 15 min.

Step S237: The silica gel is coated on the core and vulcanized to obtain an elastic layer.

In one embodiment, when the raw rubber is methyl vinyl rubber, the step of coating the silica gel on the core is specifically: extruding the silica gel and the core using a T-type head of the extruder, The silica gel is directly coated on the core, wherein the extruder has a rotation speed of 5 r/min to 15 r/min.

It should be noted that silica gel is different from rubber extrusion. Silica gel is relatively soft. Generally, cooling water is required to cool the barrel and screw to prevent the silica gel from softening due to overheating. The temperature of the cooling water is 20 °C.

In another embodiment, when the raw rubber is methyl vinyl silicone oil, the step of coating the silica gel on the core is specifically: placing the core into the middle of the developing roller mold, and then injecting the silica into the developing roller mold to The silica gel is coated on the core.

The temperature of vulcanization in step S237 is from 180 ° C to 220 ° C, and the time of vulcanization is from 2 h to 4 h.

Among them, the adhesive can bond the elastic layer to the core, so that the elastic layer does not slide relative to the axial core.

Step S240: forming a wear layer on the elastic layer.

The step of forming the wear layer on the elastic layer is specifically: spraying the slurry on the elastic layer to form a wear resistant layer, wherein the slurry comprises polyurethane, white carbon black and conductive filler. Specifically, the slurry includes 100 parts of polyurethane, 5 parts to 15 parts of white carbon, and 3 to 40 parts of conductive filler in parts by mass. Further, the conductive filler is selected from at least one of conductive carbon black, carbon nanotubes, and graphene. Further, the parts by mass of the conductive carbon black are 20 parts to 40 parts, the parts by mass of the carbon nanotubes are 2 parts to 7 parts, and the parts by mass of the graphene are 5 parts to 20 parts.

It should be noted that, after spraying the slurry on the elastic layer, a step of heat curing is further included, wherein the heating temperature is 160 ° C, and the heating time is 1 h. Specifically, heating is performed using an oven.

Further, the wear layer has a surface roughness Ra of less than 1.5.

Specifically, the wear layer 130 has a thickness of 5 μm to 15 μm. More specifically, the wear layer 130 has a thickness of 7 μm to 12 μm.

It should be noted that before the formation of the wear layer on the elastic layer, the step of trimming the elastic layer is also included. Specifically, the step of trimming the elastic layer is specifically: grinding the elastic layer to a predetermined size and surface roughness, and cutting the burrs of the elastic layer. Specifically, the roughness Ra of the elastic layer after grinding is less than 1.5 to facilitate control of the surface roughness of the developing roller. More specifically, the elastic burr is cut using a cutter to make the developing roller more regular.

It should be noted that, before step 230, the step of sifting the intermediate material is also included, wherein the mesh number of the mesh is 100 mesh and 150 mesh. Specifically, a screen is placed at the head using a preformer or an extruder.

The above preparation method of the developing roller has at least the following advantages:

(1) Most of the developing rollers on the market are prepared by using chlorohydrin rubber or imported liquid silica gel, but the cost of chlorohydrin rubber and imported liquid silica gel is relatively high, which leads to the expensive price of most developing rollers on the market. The developing roller is cheaper than the developing roller prepared from the chlorohydrin rubber and the imported liquid silica gel, so as to lower the price of the developing roller, and is more advantageous for the marketing and application of the developing roller.

(2) The current developing roller is mainly prepared by a compression molding process and an injection molding process. However, the injection molding die has a high input cost, and the development roller is easily caused by the dispersibility of the carbon powder in the silica gel on the market and the orientation of the molecular chain of the silica gel. The uniformity of the resistance is deteriorated; the material for injection molding is liquid silica gel, and the carbon powder has a tendency to settle toward the bottom of the mold, which also causes uneven distribution of the resistance of the developing roller. In the above preparation method of the developing roller, the developing roller is prepared by a continuous extrusion process, which greatly improves the production efficiency of the developing roller, reduces the production cost, and improves the uniformity of the resistance of the developing roller.

The following are specific examples:

Example 1

The preparation method of the developing roller of this embodiment is as follows:

(1) 20 parts by weight of conductive carbon black, 2 parts of carbon nanotubes, 5 parts of graphene, 20 parts of silica, 5 parts of magnesium carbonate and 8 parts of zinc oxide, at least Adding to 100 parts of methyl vinyl green rubber (80 parts of methyl vinyl rubber with a molecular weight of 600,000 and a mass percentage of vinyl of 0.05%), a molecular weight of 300,000 and a mass percentage of vinyl The mixture was stirred in a portion of 0.4% methylvinyl rubber (20 parts), the stirring speed was 28 r/min, and the stirring time was 40 min to obtain a mixture.

(2) The mixture was stirred at 180 ° C under a vacuum of 0.1 Mpa to obtain an intermediate material, and then the intermediate material was sieved, wherein the mesh number of the sieve was 100 mesh and 150 mesh.

(3) In the mass part, the intermediate material, 1 part of the hydrogen-containing silicone oil, and 0.7 part of the platinum vulcanizing agent were placed in an open roll mill for 20 times to carry out a crosslinking reaction to obtain a silica gel. Wherein the hydrogen-containing silicone oil is a hydrogen-containing silicone oil having a mass percentage of hydrogen of 0.1%, a hydrogen-containing silicone oil having a hydrogen content of 0.4% by mass, and a hydrogen-containing silicone oil having a mass percentage of 0.8% by weight, The platinum vulcanizing agent has a platinum content of 1000 ppm.

(4) The silica gel was extruded into a silicone tube using an extruder, wherein the extruder was rotated at 10 r/min.

(5) The silicone tube is cut and placed on the shaft core, and then the silicone tube is subjected to the first vulcanization by the superheat passage, and then the second vulcanization is performed using the oven to form an elastic layer. Among them, the hot channel includes the ultra-high temperature section and the high temperature section, the temperature of the ultra-high temperature section is 600 ° C, the temperature of the high temperature section is 280 ° C, the time of the superheat passage of the silicone tube is 1 min to 10 min, the temperature of the oven is 200 ° C, and the silicone tube is The time in the oven is 2h.

(6) The elastic layer was ground so that the surface roughness of the elastic layer was less than 1.5, and the burrs of the elastic layer were cut using a cutter. Spraying the slurry on the elastic layer to form an abrasion resistant layer, wherein the slurry comprises 100 parts of polyurethane, 10 parts of silica, 20 parts of conductive carbon black, 2 parts of carbon nanotubes, and 5 parts of graphene, the wear layer has a thickness of 9 μm.

Example 2

The preparation method of the developing roller of this embodiment is as follows:

(1) In parts by mass, 30 parts of conductive carbon black, 20 parts of silica, 5 parts of magnesium carbonate and 8 parts of zinc oxide are added to 100 parts of methyl vinyl raw rubber at least three times. (80 parts of methyl vinyl rubber with a molecular weight of 600,000 and a mass percentage of vinyl of 0.05%, 20 parts of methyl vinyl rubber with a molecular weight of 300,000 and a mass percentage of vinyl of 0.4%) The stirring was carried out, the stirring speed was 28 r/min, and the stirring time was 40 min, and a mixture was obtained.

(2) The mixture was stirred at 180 ° C under a vacuum of 0.1 Mpa to obtain an intermediate material, and then the intermediate material was sieved, wherein the mesh number of the sieve was 100 mesh and 150 mesh.

(3) In the mass part, the intermediate material, 1 part of the hydrogen-containing silicone oil, and 0.7 part of the platinum vulcanizing agent were placed in an opener for 20 times to carry out a crosslinking reaction to obtain a silica gel. Wherein the hydrogen-containing silicone oil is a hydrogen-containing silicone oil having a mass percentage of hydrogen of 0.1%, a hydrogen-containing silicone oil having a hydrogen content of 0.4% by mass, and a hydrogen-containing silicone oil having a mass percentage of 0.8% by weight, The platinum vulcanizing agent has a platinum content of 1000 ppm.

(4) The silica gel was extruded into a silicone tube using an extruder, wherein the extruder was rotated at 10 r/min.

(5) The silicone tube is cut and placed on the shaft core, and then the silicone tube is subjected to the first vulcanization by the superheat passage, and then the second vulcanization is performed using the oven to form an elastic layer. Among them, the hot channel includes the ultra-high temperature section and the high temperature section, the temperature of the ultra-high temperature section is 600 ° C, the temperature of the high temperature section is 280 ° C, the time of the superheat passage of the silicone tube is 1 min to 10 min, the temperature of the oven is 200 ° C, and the silicone tube is The time in the oven is 2h.

(6) The elastic layer was ground so that the surface roughness of the elastic layer was less than 1.5, and the burrs of the elastic layer were cut using a cutter. Spraying the slurry on the elastic layer to form an abrasion resistant layer, wherein the slurry comprises 100 parts of polyurethane, 10 parts of silica, 20 parts of conductive carbon black, 2 parts of carbon nanotubes, and 5 parts of graphene, the wear layer has a thickness of 9 μm.

Example 3

The preparation method of the developing roller of this embodiment is as follows:

(1) In parts by mass, 30 parts of conductive carbon black, 20 parts of silica, and 8 parts of zinc oxide are added to 100 parts of methylvinyl rubber (at a molecular weight of 600,000 and at least three times). Stirring and stirring of a vinyl group having a mass percentage of 0.05% by weight of methyl vinyl rubber (80 parts, a molecular weight of 300,000 and a vinyl group of 0.4% by weight of methyl vinyl) The rotation speed was 28 r/min, and the stirring time was 40 min to obtain a mixture.

(2) The mixture was stirred at 180 ° C under a vacuum of 0.1 Mpa to obtain an intermediate material, and then the intermediate material was sieved, wherein the mesh number of the sieve was 100 mesh and 150 mesh.

(3) In the mass part, the intermediate material, 1 part of the hydrogen-containing silicone oil, and 0.7 part of the platinum vulcanizing agent were placed in an open roll mill for 20 times to carry out a crosslinking reaction to obtain a silica gel. Wherein the hydrogen-containing silicone oil is a hydrogen-containing silicone oil having a mass percentage of hydrogen of 0.1%, a hydrogen-containing silicone oil having a hydrogen content of 0.4% by mass, and a hydrogen-containing silicone oil having a mass percentage of 0.8% by weight, The platinum vulcanizing agent has a platinum content of 1000 ppm.

(4) The silica gel was extruded into a silicone tube using an extruder, wherein the extruder was rotated at 10 r/min.

(5) The silicone tube is cut and placed on the shaft core, and then the silicone tube is subjected to the first vulcanization by the superheat passage, and then the second vulcanization is performed using the oven to form an elastic layer. Among them, the hot channel includes the ultra-high temperature section and the high temperature section, the temperature of the ultra-high temperature section is 600 ° C, the temperature of the high temperature section is 280 ° C, the time of the superheat passage of the silicone tube is 1 min to 10 min, the temperature of the oven is 200 ° C, and the silicone tube is The time in the oven is 2h.

(6) The elastic layer was ground so that the surface roughness of the elastic layer was less than 1.5, and the burrs of the elastic layer were cut using a cutter. Spraying the slurry on the elastic layer to form an abrasion resistant layer, wherein the slurry comprises 100 parts of polyurethane, 10 parts of silica, 20 parts of conductive carbon black, 2 parts of carbon nanotubes, and 5 parts of graphene, the wear layer has a thickness of 9 μm.

Example 4

The preparation method of the developing roller of this embodiment is as follows:

(1) In parts by mass, 30 parts of conductive carbon black, 20 parts of silica, and 5 parts of magnesium carbonate are added to 100 parts of methylvinyl rubber (at a molecular weight of 600,000 and at least three times). Stirring and stirring of a vinyl group having a mass percentage of 0.05% by weight of methyl vinyl rubber (80 parts, a molecular weight of 300,000 and a vinyl group of 0.4% by weight of methyl vinyl) The rotation speed was 28 r/min, and the stirring time was 40 min to obtain a mixture.

(2) The mixture was stirred at 180 ° C under a vacuum of 0.1 Mpa to obtain an intermediate material, and then the intermediate material was sieved, wherein the mesh number of the sieve was 100 mesh and 150 mesh.

(3) In the mass part, the intermediate material, 1 part of the hydrogen-containing silicone oil, and 0.7 part of the platinum vulcanizing agent were placed in an open roll mill for 20 times to carry out a crosslinking reaction to obtain a silica gel. Wherein the hydrogen-containing silicone oil is a hydrogen-containing silicone oil having a mass percentage of hydrogen of 0.1%, a hydrogen-containing silicone oil having a hydrogen content of 0.4% by mass, and a hydrogen-containing silicone oil having a mass percentage of 0.8% by weight, The platinum vulcanizing agent has a platinum content of 1000 ppm.

(4) The silica gel was extruded into a silicone tube using an extruder, wherein the extruder was rotated at 10 r/min.

(5) The silicone tube is cut and placed on the shaft core, and then the silicone tube is subjected to the first vulcanization by the superheat passage, and then the second vulcanization is performed using the oven to form an elastic layer. Among them, the hot channel includes the ultra-high temperature section and the high temperature section, the temperature of the ultra-high temperature section is 600 ° C, the temperature of the high temperature section is 280 ° C, the time of the superheat passage of the silicone tube is 1 min to 10 min, the temperature of the oven is 200 ° C, and the silicone tube is The time in the oven is 2h.

(6) The elastic layer was ground so that the surface roughness of the elastic layer was less than 1.5, and the burrs of the elastic layer were cut using a cutter. Spraying the slurry on the elastic layer to form a wear resistant layer, wherein the slurry comprises 100 parts of polyurethane, 10 parts of white carbon black, 20 parts of conductive carbon black, 2 parts of carbon nanotubes, and 5 parts of graphene. The thickness of the wear layer was 9 μm.

Example 5

The preparation method of the developing roller of this embodiment is as follows:

(1) In parts by mass, 30 parts of conductive carbon black and 20 parts of white carbon black are added to 100 parts of methyl vinyl raw rubber at least three times (molecular weight is 600,000 and the mass percentage of vinyl is Stirring was carried out at a speed of 28 r/min, which was 0.05% of methyl vinyl rubber (80 parts, a molecular weight of 300,000 and a vinyl group of 0.4% by mass of methyl vinyl). The stirring time was 40 min to obtain a mixture.

(2) The mixture was stirred at 180 ° C under a vacuum of 0.1 Mpa to obtain an intermediate material, and then the intermediate material was sieved, wherein the mesh number of the sieve was 100 mesh and 150 mesh.

(3) In the mass part, the intermediate material, 1 part of the hydrogen-containing silicone oil, and 0.7 part of the platinum vulcanizing agent were placed in an open roll mill for 20 times to carry out a crosslinking reaction to obtain a silica gel. Wherein the hydrogen-containing silicone oil is a hydrogen-containing silicone oil having a mass percentage of hydrogen of 0.1%, a hydrogen-containing silicone oil having a hydrogen content of 0.4% by mass, and a hydrogen-containing silicone oil having a mass percentage of 0.8% by weight, The platinum vulcanizing agent has a platinum content of 1000 ppm.

(4) The silica gel was extruded into a silicone tube using an extruder, wherein the extruder was rotated at 10 r/min.

(5) The silicone tube is cut and placed on the shaft core, and then the silicone tube is subjected to the first vulcanization by the superheat passage, and then the second vulcanization is performed using the oven to form an elastic layer. Among them, the hot channel includes the ultra-high temperature section and the high temperature section, the temperature of the ultra-high temperature section is 600 ° C, the temperature of the high temperature section is 280 ° C, the time of the superheat passage of the silicone tube is 1 min to 10 min, the temperature of the oven is 200 ° C, and the silicone tube is The time in the oven is 2h.

(6) The elastic layer was ground so that the surface roughness of the elastic layer was less than 1.5, and the burrs of the elastic layer were cut using a cutter. Spraying the slurry on the elastic layer to form an abrasion resistant layer, wherein the slurry comprises 100 parts of polyurethane, 10 parts of silica, 20 parts of conductive carbon black, 2 parts of carbon nanotubes, and 5 parts of graphene, the wear layer has a thickness of 9 μm.

Example 6

The preparation method of the developing roller of this embodiment is as follows:

(1) 7 parts of carbon nanotubes, 45 parts of silica, 7 parts of magnesium carbonate and 15 parts of zinc oxide are added to 100 parts of methylvinyl rubber in three parts by mass ( 80 parts of methyl vinyl rubber having a molecular weight of 600,000 and a vinyl content of 0.05% by mass, 20 parts of methyl vinyl rubber having a molecular weight of 300,000 and a vinyl content of 0.4% by mass) Stirring was carried out, the stirring speed was 28 r/min, and the stirring time was 40 min, and a mixture was obtained.

(2) The mixture was stirred at 150 ° C and a vacuum of 0.08 MPa for 1.5 h to obtain an intermediate material, and then the intermediate material was sieved, wherein the mesh number of the sieve was 100 mesh and 150 mesh.

(3) In the mass part, the intermediate material, 0.5 part of the hydrogen-containing silicone oil, and 0.5 part of the platinum vulcanizing agent were placed in an open mill for 20 times to carry out a crosslinking reaction to obtain a silica gel. Wherein the hydrogen-containing silicone oil is a hydrogen-containing silicone oil having a mass percentage of hydrogen of 0.1%, a hydrogen-containing silicone oil having a hydrogen content of 0.4% by mass, and a hydrogen-containing silicone oil having a mass percentage of 0.8% by weight, The platinum vulcanizing agent has a platinum content of 1000 ppm.

(4) The silica gel was extruded into a silicone tube using an extruder, wherein the extruder was rotated at 2 r/min.

(5) The silicone tube is cut and placed on the shaft core, and then the silicone tube is subjected to the first vulcanization by the superheat passage, and then the second vulcanization is performed using the oven to form an elastic layer. Among them, the hot channel includes the ultra-high temperature section and the high temperature section, the temperature of the ultra-high temperature section is 600 ° C, the temperature of the high temperature section is 280 ° C, the time of the superheating passage of the silicone tube is 1 min, the temperature of the oven is 200 ° C, and the silicone tube is in the oven. The time is 2h.

(6) The elastic layer was ground so that the surface roughness of the elastic layer was less than 1.5, and the burrs of the elastic layer were cut using a cutter. Spraying the slurry on the elastic layer to form a wear-resistant layer, wherein the slurry comprises 100 parts of polyurethane, 15 parts of white carbon and 7 parts of carbon nanotubes in parts by mass, and the thickness of the wear-resistant layer is 5 μm. .

Example 7

The preparation method of the developing roller of this embodiment is as follows:

(1) In parts by mass, 40 parts of conductive carbon black, 10 parts of silica, 0.5 parts of magnesium carbonate, and 0.5 parts of zinc oxide are added to 100 parts of methylvinyl rubber at least three times ( 80 parts of methyl vinyl rubber having a molecular weight of 600,000 and a vinyl content of 0.05% by mass, 20 parts of methyl vinyl rubber having a molecular weight of 300,000 and a vinyl content of 0.4% by mass) Stirring was carried out, the stirring speed was 28 r/min, and the stirring time was 60 min, and a mixture was obtained.

(2) The mixture was stirred at 200 ° C under a vacuum of 1.0 MPa to obtain an intermediate material, and then the intermediate material was sieved, wherein the mesh number of the sieve was 100 mesh and 150 mesh.

(3) In the mass part, the intermediate material, 3 parts of the hydrogen-containing silicone oil, and 1 part of the platinum vulcanizing agent were placed in an open roll mill for 40 times to carry out a crosslinking reaction to obtain a silica gel. Wherein the hydrogen-containing silicone oil is a hydrogen-containing silicone oil having a mass percentage of hydrogen of 0.1%, a hydrogen-containing silicone oil having a hydrogen content of 0.4% by mass, and a hydrogen-containing silicone oil having a mass percentage of 0.8% by weight, The platinum vulcanizing agent has a platinum content of 1000 ppm.

(4) The silica gel was extruded into a silicone tube using an extruder, wherein the extruder was rotated at 20 r/min.

(5) The silicone tube is cut and placed on the shaft core, and then the silicone tube is subjected to the first vulcanization by the superheat passage, and then the second vulcanization is performed using the oven to form an elastic layer. Among them, the hot channel includes the ultra-high temperature section and the high temperature section, the temperature of the ultra-high temperature section is 600 ° C, the temperature of the high temperature section is 280 ° C, the time of the silicone tube superheat passage is 10 min, the temperature of the oven is 200 ° C, and the silicone tube is in the oven. The time is 2h.

(6) The elastic layer was ground so that the surface roughness of the elastic layer was less than 1.5, and the burrs of the elastic layer were cut using a cutter. Spraying the slurry on the elastic layer to form a wear-resistant layer, wherein the slurry comprises 100 parts of polyurethane, 5 parts of white carbon and 40 parts of conductive carbon black in parts by mass, and the thickness of the wear-resistant layer is 15 μm. .

Example 8

The preparation method of the developing roller of this embodiment is as follows:

(1) In parts by mass, 20 parts of graphene, 25 parts of silica, 10 parts of magnesium carbonate and 20 parts of zinc oxide are added to 100 parts of methyl vinyl rubber in at least three times (molecular weight 80 parts of methyl vinyl rubber with a mass percentage of 0.05% and a vinyl group of 80%, a molecular weight of 300,000 and a vinyl vinyl content of 0.4% by weight of the vinyl vinyl 200%) Stirring was carried out, the stirring speed was 28 r/min, and the stirring time was 50 min to obtain a mixture.

(2) The mixture was stirred at 180 ° C under a vacuum of 1.0 MPa to obtain an intermediate material, and then the intermediate material was sieved, wherein the mesh number of the sieve was 100 mesh and 150 mesh.

(3) In the mass part, the intermediate material, 1 part of the hydrogen-containing silicone oil, and 0.6 part of the platinum vulcanizing agent were placed in an open mill for 40 times to carry out a crosslinking reaction to obtain a silica gel. Wherein the hydrogen-containing silicone oil is a hydrogen-containing silicone oil having a mass percentage of hydrogen of 0.1%, a hydrogen-containing silicone oil having a hydrogen content of 0.4% by mass, and a hydrogen-containing silicone oil having a mass percentage of 0.8% by weight, The platinum vulcanizing agent has a platinum content of 1000 ppm.

(4) The silica gel was extruded into a silicone tube using an extruder, wherein the extruder was rotated at 10 r/min.

(5) The silicone tube is cut and placed on the shaft core, and then the silicone tube is subjected to the first vulcanization by the superheat passage, and then the second vulcanization is performed using the oven to form an elastic layer. Among them, the hot channel includes the ultra-high temperature section and the high temperature section, the temperature of the ultra-high temperature section is 600 ° C, the temperature of the high temperature section is 280 ° C, the time of the superheating passage of the silicone tube is 5 min, the temperature of the oven is 200 ° C, and the silicone tube is in the oven. The time is 2h.

(6) The elastic layer was ground so that the surface roughness of the elastic layer was less than 1.5, and the burrs of the elastic layer were cut using a cutter. The slurry was sprayed on the elastic layer to form an abrasion resistant layer, wherein the slurry included 100 parts of polyurethane, 10 parts of white carbon and 20 parts of graphene, and the thickness of the abrasion resistant layer was 7 μm.

Example 9

The preparation method of the developing roller of this embodiment is as follows:

(1) In terms of parts by mass, 20 parts of conductive carbon black, 3 parts of carbon nanotubes, 30 parts of white carbon black, 3 parts of magnesium carbonate, and 5 parts of zinc oxide are added to 100 parts of A in three portions. Vinyl vinyl rubber (80 parts of methyl vinyl rubber with a molecular weight of 600,000 and a vinyl content of 0.05% by mass, methyl ethylene having a molecular weight of 300,000 and a vinyl content of 0.5% by mass) Stirring was carried out in 20 parts of the basal gum, the stirring speed was 28 r/min, and the stirring time was 50 min to obtain a mixture.

(2) The mixture was stirred at 180 ° C under a vacuum of 1.0 MPa to obtain an intermediate material, and then the intermediate material was sieved, wherein the mesh number of the sieve was 100 mesh and 150 mesh.

(3) In the mass part, the intermediate material, 2 parts of the hydrogen-containing silicone oil, and 0.8 part of the platinum vulcanizing agent were placed in an open mill for 40 times to carry out a crosslinking reaction to obtain a silica gel. Wherein the hydrogen-containing silicone oil is a hydrogen-containing silicone oil having a mass percentage of hydrogen of 0.1%, a hydrogen-containing silicone oil having a hydrogen content of 0.4% by mass, and a hydrogen-containing silicone oil having a mass percentage of 0.8% by weight, The platinum vulcanizing agent has a platinum content of 1000 ppm.

(4) Applying Kmlock adhesive CH607 to the core, and then drying, wherein the drying temperature is 80 ° C, and the drying time is 15 min.

(5) Extrusion of the silica gel and the shaft core using the T-type head of the extruder, so that the silica gel is directly coated on the shaft core, wherein the extruder has a rotation speed of 10 r/min and the extrusion speed is 20 ° C. Cooling water cools the barrel and screw. The silica gel and the shaft core were then placed in an oven and vulcanized at 220 ° C for 4 h to obtain an elastic layer.

(6) The elastic layer was ground so that the surface roughness of the elastic layer was less than 1.5, and the burrs of the elastic layer were cut using a cutter. Spraying the slurry on the elastic layer to form a wear resistant layer, wherein the slurry comprises 100 parts of polyurethane, 12 parts of white carbon black, 20 parts of conductive carbon black and 3 parts of carbon nanotubes, and the wear layer has a thickness of 12 μm. .

Example 10

The preparation method of the developing roller of this embodiment is as follows:

(1) In parts by mass, 20 parts of conductive carbon black, 10 parts of graphene, 25 parts of white carbon black, 5 parts of magnesium carbonate, and 10 parts of titanium oxide are added to 100 parts of A in three portions. The mixture was stirred in a vinyl silicone oil at a stirring speed of 28 r/min and a stirring time of 50 minutes to obtain a mixture.

(2) The mixture was stirred at 180 ° C under a vacuum of 1.0 MPa to obtain a base rubber, and then the base rubber was sieved, wherein the mesh number of the sieve was 100 mesh and 150 mesh.

(3) In terms of parts by mass, 49 parts of the base rubber is mixed with 1 part of the hydrogen-containing silicone oil to form the A component, and 49.5 parts of the base rubber is mixed with 0.5 part of the platinum catalyst to form the B component, wherein the hydrogen-containing silicone oil A hydrogen-containing silicone oil having a hydrogen content of 0.1% by mass, a hydrogen-containing silicone oil having a hydrogen content of 0.4% by mass, and a hydrogen-containing silicone oil having a mass percentage of 0.8% by weight.

(4) Applying the Kmlock adhesive CH608 to the core, and then drying, wherein the drying temperature is 80 ° C, and the drying time is 15 min.

(5) Put the core into the middle of the developing roller mold, then vacuum the A component and the B component, mix and inject into the developing roller mold, and then vulcanize in an oven at 200 ° C for 30 min. After cooling, put it again at 200 ° C. The mixture was vulcanized in an oven for 2 h to obtain an elastic layer.

(6) The elastic layer was ground so that the surface roughness of the elastic layer was less than 1.5, and the burrs of the elastic layer were cut using a cutter. The slurry was sprayed on the elastic layer and cured by heating at 160 ° C for 1 h to form a wear-resistant layer, wherein the slurry included 100 parts of polyurethane, 10 parts of silica, and 20 parts of conductive carbon black in parts by mass. And 10 parts of graphene, the wear layer has a thickness of 10 μm.

test:

(1) The compression set property of the silica gel obtained in Example 1 was measured by the method of ISO815, and as a result, the low temperature pressure change (70 ° C * 22 H * 25%) was less than 2%, and the high temperature pressure change (180 ° C * 22 H * 25%) was 6.2%, indicating that the silica gel obtained in Example 1 has excellent pressure resistance properties.

(2) The rebound resilience of the silica gel obtained in Example 1 was examined by the method of ISO 4662, and as a result, the rebound resilience was 70%, indicating that the silica gel obtained in Example 1 had excellent resilience.

(3) Dynamic volume resistance detection

The two poles of the resistance detector were respectively connected to the core and the wear layer of the developing roller obtained in Examples 1 to 10, and a pressure of 500 g was applied to both ends of the developing roller, and the developing roller was rotated to simulate the working environment of the developing roller. Then, a 100V stable voltage is applied to the two poles of the resistance detector to detect the resistance of the developing roller during operation, that is, the dynamic volume resistance R. The results are shown in Table 1.

(4) Static volume resistance detection

The two poles of the resistance detector were respectively connected to the core and the wear layer of the developing roller obtained in Examples 1 to 10, and a pressure of 500 g was applied to both ends of the developing roller, and then 5 V and 1000 V were respectively applied to the two poles of the resistance detector. Stabilize the voltage, check the static volume resistance R5V of the developing roller at 5V and the static resistance R1000V at 1000V, and calculate logR5V-logR1000V. The results are shown in Table 1.

The two poles of the resistance detector were respectively connected to the core and the wear layer of the developing roller obtained in Examples 1 to 10, and the pressure of the wear layer of the developing roller was 500 g, and then a stable voltage of 100 V was applied to both ends of the resistance detector. And rotate the developing roller 6 times, each rotation 60 °, get 6 static volume resistance R', select the maximum value R'max and the minimum value R'min, and calculate logR'max-logR'min, see the result Table 1.

(4) Segment resistance detection

One electrode of the resistance detector is respectively connected to the axis core of the developing roller obtained in Embodiments 1 to 10, and then the wear layer of the developing roller is equally divided into 10 segments in the axial extension direction, and the other electrode of the resistance detector is separately Connected to each of the 10 sections of the wear layer of the developing roller, apply a pressure of 1 kg on the developing roller, and apply a stable voltage of 100 V at both poles of the resistance detector to detect each segment (1, 2, 3... 8, 9, 10) volume resistance R", then rotate the developing roller 4 times, each rotation 90 °, get 40 segment volume resistance value R", select the maximum value R"max and minimum value R" Min, and calculate logR "max-logR" min, the results are shown in Table 1.

Table 1 The resistance test results of the developing rolls obtained in Examples 1 to 10

Example	logR	logR5V-logR1000V	logR’max-logR’min	logR"max-logR"min
1	6.34	1.82	0.065	0.075
2	6.72	1.87	0.093	0.104

3	6.63	2.24	0.124	0.140
4	6.58	2.83	0.133	0.145
5	6.53	3.78	0.384	0.425
6	6.20	1.71	0.054	0.065
7	5.23	2.97	0.194	0.215
8	5.43	1.79	0.060	0.072
9	6.44	2.28	0.114	0.130
10	6.24	1.85	0.072	0.084

As can be seen from Table 1, the developing roller obtained in Example 1 was compared with the developing roller obtained in Example 2, and Example 1 obtained the log R5V-logR1000V, logR'max-logR'min and logR"max-logR of the developing roller. "min is smaller, indicating that the addition of carbon nanotubes and graphene is more advantageous for the dispersion of the silica raw material, so that the development roller obtained in Example 1 has better resistance stability and uniformity. Further, although the logRs of Example 1 and Example 2 are similar, the conductive filler used in Example 1 is less, indicating that the carbon nanotubes and graphene have lower resistivity.

Comparing the developing roller obtained in Example 2 with the developing roller obtained in Example 3, the log R5V-logR1000V, logR'max-logR'min and logR"max-logR"min of the developing roller of Example 2 were small, indicating Magnesium carbonate can improve the dispersibility of the conductive filler, so that the resistance of the developing roller obtained in Example 2 varies with voltage, and the stability and uniformity of the resistor are good.

Comparing the developing roller obtained in Example 3 with the developing roller obtained in Example 5, the logR5V-logR1000V of Example 3 was small, indicating that zinc oxide can improve the resistance fluctuation of the developing roller at a high voltage, so that Example 3 was obtained. The resistance of the developing roller varies little with voltage; at the same time, logR'max-logR'min and logR"max-logR"min are also small, indicating that zinc oxide can also improve the stability and uniformity of the resistance of the developing roller.

Comparing the developing roller obtained in Example 4 with the developing roller obtained in Example 5, the logR5V-logR1000V, logR'max-logR'min and logR"max-logR"min of Example 4 were all small, further indicating magnesium carbonate. The dispersibility of the conductive filler can be improved, the resistance of the developing roller varies with voltage, and the stability and uniformity of the resistor are good.

The technical features of the above-described embodiments may be arbitrarily combined. For the sake of brevity of description, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be considered as the scope of this manual.

The above-described embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims (14)

1. A silica gel, the raw materials for preparing the silica gel in parts by mass include:

   

   Wherein the raw rubber is selected from the group consisting of methyl vinyl raw rubber and methyl vinyl silicone oil, and the stabilizer is at least one selected from the group consisting of zinc oxide, titanium oxide and silicon carbide.
2. The silica gel according to claim 1, wherein the vinyl group in the methyl vinyl rubber has a mass percentage of 0.05% to 0.5%.
3. The silica gel according to claim 1, wherein the conductive filler is at least one selected from the group consisting of conductive carbon black, carbon nanotubes, and graphene.
4. The silica gel according to claim 3, wherein the conductive filler is a mixture of conductive carbon black, carbon nanotubes, and graphene.
5. The silica gel according to claim 1, wherein the crosslinking agent is a hydrogen-containing silicone oil.
6. The silica gel according to claim 5, wherein the hydrogen-containing silicone oil has a hydrogen content of 0.05% to 1.5% by mass.
7. The silica gel according to claim 1, wherein the vulcanizing agent is at least one selected from the group consisting of a platinum vulcanizing agent and a bis-four-four vulcanizing agent.
8. The silica gel according to claim 7, wherein the platinum vulcanizing agent has a platinum content of 1000 ppm by mass.
9. A method for preparing silica gel, comprising:

   100 parts of raw rubber, 3 parts to 40 parts of conductive filler, 10 parts to 45 parts of white carbon, 0.5 parts to 10 parts of magnesium carbonate and 0.5 parts to 20 at 150 ° C to 200 ° C under vacuum. The stabilizer is mixed to obtain an intermediate material, wherein the raw rubber is selected from one of methyl vinyl green rubber and methyl vinyl silicone oil, and the stabilizer is selected from the group consisting of zinc oxide, titanium oxide and silicon carbide. At least one type;

   The intermediate material, 0.5 parts to 3 parts of a crosslinking agent, and 0.5 parts to 1 part of a vulcanizing agent are mixed to cause a crosslinking reaction to obtain a silica gel.
10. The method for preparing a silica gel according to claim 9, wherein the step of mixing the intermediate material, 0.5 parts to 3 parts of the crosslinking agent, and 0.5 parts to 1 part of the vulcanizing agent further comprises The intermediate material is passed through a 100 mesh sieve to a 150 mesh sieve.
11. A developing roller, comprising: a shaft core, an elastic layer and an abrasion resistant layer, the elastic layer covering the core, the wear layer covering the elastic layer, wherein the elasticity The material of the layer is the silica gel according to any one of claims 1 to 8.
12. A method for preparing a developing roller, comprising:

    The method for preparing a silica gel according to any one of claims 9 to 10, wherein the silica gel is prepared;

    Forming an elastic layer on the shaft core by using the silica gel;

    A wear layer is formed on the elastic layer.
13. The method of preparing a developing roller according to claim 12, wherein when the raw rubber is methyl vinyl rubber, the step of forming an elastic layer on the core by using the silica gel is:

    Forming the silica gel and vulcanizing it to obtain a silicone tube;

    The silicone tube is sleeved on the shaft core and then vulcanized in two stages to form the elastic layer.
14. The method of manufacturing a developing roller according to claim 12, wherein the step of forming an elastic layer on the core by using the silica gel is:

    Applying an adhesive to the shaft core and drying;

    The silica gel is coated on the core and vulcanized to form the elastic layer.

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