CN115197577A

CN115197577A - Antistatic silicone rubber composite material, flexible electrostatic shielding bag and preparation method thereof

Info

Publication number: CN115197577A
Application number: CN202210934338.9A
Authority: CN
Inventors: 王超; 陆磊
Original assignee: Zhenjiang Gaomei New Material Co ltd
Current assignee: Zhenjiang Gaomei New Material Co ltd
Priority date: 2022-08-04
Filing date: 2022-08-04
Publication date: 2022-10-18
Anticipated expiration: 2042-08-04
Also published as: CN115197577B

Abstract

The invention discloses an antistatic silicone rubber composite material, a flexible electrostatic shielding bag and a preparation method thereof, wherein the antistatic silicone rubber composite material comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 35-45 parts of fumed silica, 3-8 parts of hydroxyl silicone oil, 0.6-2 parts of zinc stearate, 0.2-0.5 part of vulcanizing agent, 0-3 parts of non-ionic antistatic agent, 2-5 parts of macromolecular antistatic agent and 2-10 parts of conductive filler; wherein the non-ionic antistatic agent is fatty alkanolamide non-ionic antistatic agent; the polymer antistatic agent is one or a combination of more of quaternary ammonium salt type, polyether type, sulfonic acid type or internal ammonium salt type; the conductive filler is a metal conductive filler and a carbon conductive filler which are used in a composite way. The antistatic shielding bag prepared by the method has good antistatic effect, can provide all-dimensional conformal support protection, has a good shockproof function, effectively prevents the risk of collision or falling impact, and has good practical value.

Description

Antistatic silicone rubber composite material, flexible electrostatic shielding bag and preparation method thereof

Technical Field

The invention relates to an antistatic silicone rubber composite material, a flexible electrostatic shielding bag and a preparation method thereof.

Background

With the increasing role of multimedia applications in people's daily life and the increasing closeness of the relationship between computers and consumer electronics, the demand for portability and functionality of electronic products is continuously increasing, which puts higher demands on electrostatic protection of electronic products. Static electricity is an objective natural phenomenon, and is generated in many ways, such as contact, friction, and induction between electrical appliances. Among them, triboelectrification and human static electricity are two major hazards in the electronic industry, often causing unstable operation of electronic and electrical products, even damage. The main reasons are that: 1) The static adsorbs dust, and the insulation resistance of the element is reduced, so that the service life of electronic products and elements is shortened; 2) Electrostatic discharge damages the component, making it have potential damage or directly damaged and unable to work; 3) The electromagnetic field generated by electrostatic discharge is very large in amplitude (up to hundreds of volts/meter), and the frequency spectrum is very wide (from tens of megabytes to thousands of megabytes), so that serious electromagnetic interference and even damage are caused to an electronic generator. For example, the mobile phone often crashes, automatically shuts down, has poor voice quality, large noise, time difference of signal time, key-press error and other problems are mostly related to electrostatic damage. Therefore, electrostatic protection is important for normal use and service life of electronic products.

Silicone rubber has excellent extreme temperature resistance, and thus is one of the preferred elastomers in many extreme environments; and the composite material has excellent dielectric strength, thermal conductivity and fireproof performance, and is widely applied to various fields of aviation, aerospace, communication, electric power, electronics, electric appliances and the like. However, silicone rubber is a good electrical insulator, and conventionally, it is generally used as an insulator in the fields of electric power, electronics, electric appliances, and the like, but is very disadvantageous in terms of antistatic properties, and is not suitable for use particularly when electrostatic discharge protection is required.

Electrostatic discharge (ESD) protection, hereinafter referred to as ESD protection, is of great significance to high-density, miniaturized and complex-function electronic devices such as mobile phones. Electrostatic discharge is a process of discharging electrostatic charges charged on an object, and the most common method of ESD protection is to protect with an electrostatic shielding bag. The anti-static shielding bag is a flexible packaging bag which has an electrostatic shielding performance and can directly contact with the inner surface of a static sensitive product to have an electrostatic leakage performance, and is widely used for packaging various pc boards, computer motherboards, sound cards, video cards, network cards and static sensitive high-tech electronic products.

At present, an aluminum foil material is mostly adopted for an electrostatic shielding bag to achieve an anti-static effect, or an anti-static agent is coated to achieve the electrostatic shielding effect. However, the shielding bag made of aluminum foil is stiff in texture, so that the bag body is bent and collided frequently in the packaging and transportation processes, and the bag body is easily broken; on the other hand, the antistatic agent is a surface treatment agent, the duration of the antistatic effect is short, and the antistatic effect is overdue for the storage and the use of the product. In addition, the existing shielding bag has a single bag type, and different products all use the packaging bag, so that the packaging bag material and space are wasted, and the products cannot be protected along with the shape; in addition, under the conditions of bumping, falling or vibration, the electronic device cannot effectively protect electronic products or elements loaded inside, and the protection requirements of some high-end sensitive devices which are sensitive to static electricity and easy to damage by the static electricity cannot be met.

Therefore, it is a new idea to modify silicone rubber to make it antistatic and apply it in electrostatic discharge protection.

Disclosure of Invention

Aiming at the problems of the existing electrostatic shielding bag and achieving the purpose, the invention provides an antistatic silicon rubber composite material, a flexible electrostatic shielding bag and a preparation method thereof. The specific technical scheme is as follows:

firstly, the invention provides an antistatic silicone rubber composite material, which comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 35-45 parts of fumed silica, 3-8 parts of hydroxyl silicone oil, 0.6-2 parts of zinc stearate, 0.2-0.5 part of vulcanizing agent, 0-3 parts of non-ionic antistatic agent, 2-5 parts of macromolecular antistatic agent and 2-10 parts of conductive filler; wherein the non-ionic antistatic agent is fatty alkanolamide non-ionic antistatic agent; the polymer antistatic agent is one or a combination of more of quaternary ammonium salt type, polyether type, sulfonic acid type or internal ammonium salt type; the conductive filler is a metal conductive filler and a carbon conductive filler which are used in a composite way.

The antistatic silicone rubber composite material comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 35-45 parts of fumed silica, 3-8 parts of hydroxyl silicone oil, 0.6-2 parts of zinc stearate, 0.2-0.5 part of vulcanizing agent, 0-3 parts of coconut oil diethanolamide, 2-5 parts of sulfonic acid, 1-5 parts of oriented carbon nanotube and 1-5 parts of conductive nickel powder.

The invention further provides an antistatic silicone rubber composite material flexible electrostatic shielding bag which comprises the following components in parts by weight: comprises a shielding bag body and a sealing strip; the shielding bag body comprises an internal silica gel supporting layer, an external silica gel protective layer and a fiber reinforced protective layer between the internal silica gel supporting layer and the external silica gel protective layer; the internal silica gel supporting layer and the external silica gel protective layer are prepared from the antistatic silicone rubber composite material; the fiber reinforced protective layer is formed by interweaving metal wires and carbon fibers.

Preferably, the antistatic silicone rubber composite flexible electrostatic shielding bag comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 35 parts of fumed silica, 2 parts of hydroxyl silicone oil, 0.5 part of zinc stearate, 0.3 part of vulcanizing agent, 2 parts of sulfonic acid, 5 parts of oriented carbon nanotube and 5 parts of conductive nickel powder; the external silica gel supporting layer comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 45 parts of fumed silica, 5 parts of hydroxyl silicone oil, 2 parts of zinc stearate, 0.5 part of vulcanizing agent, 3 parts of coconut oil diethanolamide, 5 parts of sulfonic acid, 5 parts of oriented carbon nano tube and 2 parts of conductive nickel powder; in the fiber-reinforced protective layer, the mass ratio of the metal wires to the carbon fibers is 1.

Preferably, the thickness of the internal silica gel support layer of the flexible electrostatic shielding bag made of the antistatic silica gel composite material is 1-10 mm or is set according to the specific shape and specification of the product; the thickness of the external silica gel protective layer is 1-5 mm; the thickness of the fiber reinforced protective layer is 0.1-0.2 mm; the internal silica gel supporting layer and the external silica gel protective layer are respectively integrally formed; the metal wires and the carbon fibers are stranded and then are interwoven in a longitudinal and transverse mode, the density of warp and weft is 100 per 1 square inch, the warp direction is 55, and the weft direction is 45; the sealing strip is arranged on the fiber reinforced protective layer, and the edge of the opening of the built-in silica gel supporting layer is stopped at the inner side of the sealing strip.

In addition, the invention also provides a preparation method of the antistatic silicone rubber composite material flexible electrostatic shielding bag, which comprises the following steps:

1) Preparing materials: the antistatic silicone rubber composite component stock as claimed in any one of claims 1 to 5, for preparing an internal silicone rubber supporting layer and an external silicone rubber protective layer; simultaneously preparing metal wires and carbon fibers for interweaving according to the fiber reinforced protective layer component of any one of claims 3-5;

2) Mixing: adding the components for preparing the internal silica gel supporting layer and the external silica gel protective layer into banburying equipment respectively for mixing to form a mixed rubber material for later use;

3) Interweaving: the metal wires and the carbon fibers are stranded and are longitudinally and transversely interwoven according to the specified warp and weft density to form a fiber reinforced mesh sheet for later use;

4) Injection molding: the mixed rubber material with the built-in silica gel supporting layer and the mixed rubber material with the external silica gel protective layer are remilled, the remixed mixed rubber material with the built-in silica gel supporting layer is laid in a flat plate mould or a prefabricated profile mould, a fiber reinforced net piece is placed after prepressing and flattening, then the remixed mixed rubber with the external silica gel protective layer is laid, and a flat plate die pressing is adopted;

5) Pre-vulcanizing: pre-vulcanizing the mixed rubber and the fiber reinforced mesh after injection molding under a certain vulcanization condition, and processing a sealing strip to be adhered;

6) Folding and molding: folding the pre-vulcanized mixed rubber and the fiber reinforced mesh sheet through a forming mold, removing the allowance area of the inner mold, and molding to form a shielding bag body;

7) And (3) secondary vulcanization: and vulcanizing the folded and molded mixed rubber, the fiber reinforced net and the mold again, and obtaining the antistatic silicon rubber composite flexible electrostatic shielding bag after the vulcanization is finished and the demolding is carried out.

The feeding sequence and the mixing time of the components for preparing the internal silica gel supporting layer and the external silica gel protective layer in the mixing in the step 2) of the flexible electrostatic shielding bag made of the antistatic silicone rubber composite material are as follows: preheating an internal mixer to 80 ℃, stabilizing for a period of time, adding methyl vinyl silicone rubber for mixing 1min, adding hydroxyl silicone oil for mixing 1.5min, adding fumed silica for mixing 3min, adding zinc stearate for mixing 1.5min, adding sulfonic acid for mixing 2min, adding oriented carbon nanotubes for mixing 1.5min, adding conductive nickel powder for mixing 5min, adding coconut oil diethanolamide for mixing 1min; and raising the temperature to 150-180 ℃, fully mixing for 2-3 h, performing vacuum heat treatment for 20-40 min, controlling the rotation direction of the internal mixer to be unchanged, and cooling and discharging to obtain the mixed rubber material for preparing the internal silica gel supporting layer and the external silica gel protective layer.

Preferably, in the injection molding in the step 4), the remilling is to place the mixed rubber material with the silica gel supporting layer inside or the mixed rubber material with the silica gel protective layer outside in an open mill, add a vulcanizing agent, and thin pass for 15-20 times for vulcanization; the mold structure for vulcanization molding of the electrostatic shielding bag is as follows: comprises an inner die and an outer die, wherein both the inner die and the outer die are provided with folding areas; the cavity of the inner die cavity is designed according to the requirements of users, and is provided with a detachable allowance area; the outer mould is in the form of a foldable flat plate.

Preferably, the conditions of the pre-vulcanization in the step 5) are as follows: molding and vulcanizing for 10-15 min under the pressure of 12-15 MPa and the temperature of 175-185 ℃.

Preferably, the secondary vulcanization conditions in step 7) are as follows: the reaction is carried out in a constant temperature oven, the temperature is controlled to be 190-200 ℃, and the time is controlled to be 4-6 h.

The invention has the beneficial effects that:

1) The antistatic silicone rubber composite material improves the conductivity of the silicone rubber material by the composite modification of the oriented carbon nano tube and the conductive nickel powder and the unique preparation method, so that the antistatic silicone rubber composite material is suitable for the package protection of electronic products, can release redundant static electricity of the electronic products and elements, avoids the damage of electronic circuits or electronic components caused by the static electricity, and improves the safety of product storage and transportation.

2) The invention firstly provides the method for preparing the anti-static shielding bag by adopting the modified silicon rubber material, which not only has good shielding function and good anti-static effect, but also can provide all-dimensional conformal supporting protection for electronic products and components, simultaneously has good shockproof function, effectively prevents the electronic products or the components in the content from being collided or dropped and impacted, and can meet the packaging requirements of high-end electronic products.

3) The anti-static shielding bag realizes the shape change of electronic products and components through the built-in silica gel supporting layer, and provides all-dimensional supporting protection; the fiber reinforced protective layer arranged in the middle not only provides good puncture resistance for the shielding bag, but also protects the articles in the bag from being isolated from an electrostatic field, prevents electrostatic accumulation and avoids electrostatic harm; and the external silica gel protective layer with excellent conductivity can lead out static electricity in the bag.

4) The internal silica gel supporting layer and the external silica gel protective layer are modified by the oriented carbon nano tube and the conductive nickel powder, and the principle is as follows: the carboxyl residue of the sulfonic acid stimulates the activity of the conductive nickel powder, the good ferromagnetic property of the conductive nickel powder can form a good conductive network, the oriented carbon nano tubes are guided to be directionally dispersed in the nickel powder network by combining with the directional mixing in the preparation process to form a meticulous shielding structure, and the nonionic antistatic agent and the macromolecular antistatic agent are added, so that the conductive performance of the silica gel material is fully improved, redundant static electricity of electronic products and elements is released, the damage of electronic circuits or electronic elements caused by the static electricity is avoided, and the safety of the products in the transportation and transfer process is improved.

5) Because the invention is provided with the two layers of shielding of the internal silica gel supporting layer and the external silica gel protective layer, the resistance of the inner surface and the outer surface of the shielding bag and smaller internal induction electric energy are ensured; the middle fiber reinforced protective layer is formed by interweaving metal wires and carbon fibers, the metal wires can ensure electric conduction, a Faraday cage induction cover effect is well formed, and a static isolation effect is ensured; the carbon fiber has good toughness, and the puncture resistance of the shielding bag is improved; and the metal wire and the carbon fiber are interwoven, the warp and weft density is 100/1 square inch, the warp direction is 55, the weft direction is 45, the lamination of the internal silica gel supporting layer and the external silica gel protective layer in the later vulcanization is ensured, the whole is formed, and the electrostatic shielding effect is ensured.

6) The shielding bag can be processed into any shape according to the requirements of users, has stable performance, good aging-resistant tensile strength and impact strength, softness and toughness, can be recycled for many times, and has good practical value.

Drawings

FIG. 1 is a schematic structural view of a mold for vulcanization molding of an electrostatic shielding bag according to the present invention;

fig. 2 is a schematic cross-sectional view of the die for vulcanization molding of the electrostatic shielding bag after being laid with silica gel and folded.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments.

Wherein, the example 1 is the antistatic liquid silicone rubber and the preparation method thereof, and the examples 2 to 6 are the verification analysis of the improvement point and the improvement effect of the formula and the preparation process of the antistatic liquid silicone rubber described in the example 1.

Example 1

This example is the preparation of an antistatic silicone rubber composite. The antistatic silicone rubber composite material comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 35 parts of fumed silica, 2 parts of hydroxyl silicone oil, 0.5 part of zinc stearate, 0.3 part of vulcanizing agent, 2 parts of sulfonic acid, 5 parts of oriented carbon nanotube and 5 parts of conductive nickel powder; the preparation method comprises the following steps:

preheating an internal mixer to 80 ℃, stabilizing for a period of time, adding methyl vinyl silicone rubber for 1min, adding hydroxyl silicone oil for mixing for 1.5min, adding fumed silica for mixing for 3min, adding zinc stearate for mixing for 1.5min, adding sulfonic acid for mixing for 2min, adding oriented carbon nanotubes for mixing for 1.5min, adding conductive nickel powder for mixing for 5min; and then raising the temperature to 150 ℃ for fully mixing for 3h, then carrying out vacuum heat treatment for 30min, controlling the rotation direction of the internal mixer to be unchanged, and cooling and discharging to obtain the mixed rubber material.

And then adding a vulcanizing agent into an open mill, thinly passing through for 15 times, and vulcanizing to obtain the antistatic silicone rubber composite material.

Example 2

This example also prepared an antistatic silicone rubber composite. The components of the composition by weight portion are as follows: 100 parts of methyl vinyl silicone rubber, 45 parts of fumed silica, 5 parts of hydroxyl silicone oil, 2 parts of zinc stearate, 0.5 part of vulcanizing agent, 3 parts of coconut oil diethanolamide, 5 parts of sulfonic acid, 5 parts of oriented carbon nano tube and 2 parts of conductive nickel powder. The preparation method comprises the following steps:

preheating an internal mixer to 80 ℃, stabilizing for a period of time, adding methyl vinyl silicone rubber for mixing 1min, adding hydroxyl silicone oil for mixing 1.5min, adding fumed silica for mixing 3min, adding zinc stearate for mixing 1.5min, adding sulfonic acid for mixing 2min, adding oriented carbon nanotubes for mixing 1.5min, adding conductive nickel powder for mixing 5min, adding coconut oil diethanolamide for mixing 1min; and then raising the temperature to 180 ℃ for fully mixing for 2h, then carrying out vacuum heat treatment for 40min, controlling the rotation direction of the internal mixer to be unchanged, cooling and discharging to obtain the mixed rubber material.

And then adding a vulcanizing agent into an open mill, thinly passing through for 20 times, and vulcanizing to obtain the antistatic silicone rubber composite material.

Example 3

This example is the preparation of an antistatic silicone rubber composite flexible electrostatic shielding bag. The electrostatic shielding bag comprises a shielding bag body and a sealing strip; the shielding bag body comprises an internal silica gel supporting layer, an external silica gel protective layer and a fiber reinforced protective layer between the internal silica gel supporting layer and the external silica gel protective layer. The components of the built-in silica gel supporting layer are the same as those in the embodiment 1; the components of the external silica gel protective layer are the same as those of the embodiment 2. The preparation method comprises the following steps:

1) Preparing materials: preparing the components according to the formula of the embodiment 1 to prepare a built-in silica gel supporting layer; preparing the components according to the formula of the embodiment 2 to prepare an external silica gel protective layer; simultaneously preparing metal wires and carbon fibers to prepare the fiber reinforced protective layer.

2) Mixing: mixing the component materials of the built-in silica gel supporting layer in an internal mixer according to the method of the embodiment 1 to obtain a mixed rubber material of the built-in silica gel supporting layer for later use; and (3) mixing the components of the external silica gel protective layer in an internal mixer according to the method in the embodiment 2 to obtain the mixed rubber material of the external silica gel supporting layer for later use. The component of the external silica gel protective layer contains coconut oil diethanolamide which is a non-ionic antistatic agent to enhance the antistatic effect.

3) Interweaving: and (3) stranding the prepared metal wires and the carbon fibers and then interlacing the stranded metal wires and the carbon fibers in a longitudinal and transverse mode to form a fiber reinforced mesh sheet for later use. The metal wire is preferably a copper wire, a silver-copper alloy or other alloys with good conductivity; the doubling ratio of the metal wire to the carbon fiber is 1. The interweaving mode adopts criss-cross tiling interweaving; the preferred warp and weft density is 100 per 1 square inch, wherein the warp direction is 55 and the weft direction is 45; the thickness of the woven fiber reinforced mesh sheet is about 0.1-0.2 mm. Guarantee that milk pierces through the laminating of guaranteeing later stage vulcanization built-in silica gel supporting layer and external silica gel protective layer simultaneously, make it form wholly, guarantee the electrostatic shielding effect.

4) Injection molding: remilling the mixed rubber material with the built-in silica gel supporting layer and the mixed rubber material with the external silica gel protective layer; putting the mixed rubber material with the silica gel supporting layer in an open mill, adding a vulcanizing agent, and thinly passing for 15 times; placing the mixed rubber material with the external silica gel protective layer into an open mill, adding a vulcanizing agent, and thinly passing for 20 times; and then paving the remilled mixed rubber material with the built-in silica gel supporting layer in a flat plate mould or a prefabricated profile mould, placing a fiber reinforced mesh after prepressing and flattening, paving the remilled mixed rubber with the external silica gel protective layer, and adopting a flat plate die pressing. The mold structure for vulcanization molding of the electrostatic shielding bag is as follows: comprises an inner die and an outer die, wherein both the inner die and the outer die are provided with folding areas; the cavity of the inner die cavity is designed according to the requirements of users, and is provided with a detachable allowance area; the outer mould is in the form of a foldable flat plate. As shown in fig. 1 and 2, the inner mold is provided with a film cavity with a certain thickness, the cavity can be a flat plate type, and can also be designed according to the molded surface of a product to be packaged, and the thickness is also designed according to the product and the requirements of customers, and is controlled to be 1-10 mm; the edge of the net is provided with a detachable allowance plate, so that the fiber reinforced mesh and the external silica gel protective layer can be conveniently paved and adhered. The residual plate is provided with a certain depth to control the thickness of the external silica gel protective layer, and the thickness of the external silica gel protective layer is controlled to be 1-5 mm. After the mixed rubber material of built-in silica gel supporting layer is spread in the interior mould and is flattened, place the fibre reinforcing net piece, notice the fibre symmetry setting of net piece, then add and spread external silica gel protective layer mixed rubber material, cover outer mould at last and flatten on external silica gel protective layer mixed rubber material, the glue film in folding district can establish thickly. The folding areas of the inner die and the outer die are arranged in the middle, and the width of the folding areas is determined according to the thickness of the inner silica gel and the thickness of the outer silica gel and the product to be packaged. In addition, the inner mold and the outer mold can be provided with positioning devices for positioning the silica gel layer and positioning after folding, and the silica gel layer can be fixed through positioning pins after folding or fixed in other suitable modes in the field, so that two surfaces of the prepared shielding bag are attached neatly and reach the specification standard of the electrostatic shielding bag.

5) Pre-vulcanizing: carrying out primary vulcanization molding on the mixed rubber and the fiber reinforced mesh after injection molding under a pre-vulcanization condition, wherein the specific conditions are as follows: molding and vulcanizing for 10-15 min under the pressure of 12-15 MPa and the temperature of 175-185 ℃. After the pre-vulcanization molding, the residual plates at the two ends of the inner die are detached, and the sealing strips are adhered to the fiber reinforced mesh for the fold-over molding.

6) Folding and molding: the method comprises the following steps of folding a pre-vulcanized mixed rubber and a fiber reinforced mesh sheet through a forming die, removing an inner die allowance plate, laminating an external silica gel protective layer mixed rubber material, brushing a vulcanizing agent layer again for ensuring adhesiveness, supplementing a certain amount of external silica gel protective layer mixed rubber material, and forming a shielding bag body after molding.

7) And (3) secondary vulcanization: and vulcanizing the folded and molded mixed rubber and the fiber reinforced net together with the mold again, wherein the secondary vulcanization conditions are as follows: the preparation is carried out in a constant temperature oven, the temperature is controlled to be 190-200 ℃, and the time is controlled to be about 4-6 h. And (4) after vulcanization is finished, demolding to obtain the antistatic silicon rubber composite material flexible electrostatic shielding bag.

Comparative example 1 containing no conductive nickel powder

This example is to prepare an antistatic silicone rubber composite flexible electrostatic shielding bag. The electrostatic shielding bag structure was in accordance with example 3. But the built-in silica gel supporting layer comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 35 parts of fumed silica, 2 parts of hydroxyl silicone oil, 0.5 part of zinc stearate, 0.3 part of vulcanizing agent, 2 parts of sulfonic acid and 5 parts of oriented carbon nano tube; the external silica gel supporting layer comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 45 parts of fumed silica, 5 parts of hydroxyl silicone oil, 2 parts of zinc stearate, 0.5 part of vulcanizing agent, 3 parts of coconut oil diethanolamide, 5 parts of sulfonic acid and 5 parts of oriented carbon nanotubes; the preparation method is the same as in example 3.

Comparative example 2 containing no aligned carbon nanotubes

This example also illustrates the preparation of an antistatic silicone rubber composite flexible electrostatic shielding bag. The electrostatic shielding bag structure was in accordance with example 3. But the built-in silica gel supporting layer comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 35 parts of fumed silica, 2 parts of hydroxyl silicone oil, 0.5 part of zinc stearate, 0.3 part of vulcanizing agent, 2 parts of sulfonic acid and 5 parts of conductive nickel powder; the external silica gel supporting layer comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 45 parts of fumed silica, 5 parts of hydroxyl silicone oil, 2 parts of zinc stearate, 0.5 part of vulcanizing agent, 3 parts of coconut oil diethanolamide, 5 parts of sulfonic acid and 2 parts of conductive nickel powder; the preparation method is the same as in example 3.

Comparative example 3 contains no conductive nickel powder and aligned carbon nanotubes

This example also illustrates the preparation of an antistatic silicone rubber composite flexible electrostatic shielding bag. The electrostatic shielding bag structure was the same as in example 3. But the built-in silica gel supporting layer comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 35 parts of fumed silica, 2 parts of hydroxyl silicone oil, 0.5 part of zinc stearate, 0.3 part of vulcanizing agent and 2 parts of sulfonic acid; the external silica gel supporting layer comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 45 parts of fumed silica, 5 parts of hydroxyl silicone oil, 2 parts of zinc stearate, 0.5 part of vulcanizing agent, 3 parts of coconut oil diethanolamide and 5 parts of sulfonic acid; the preparation method is the same as in example 3.

Comparative example 4 contains no conductive nickel powder, aligned carbon nanotube and antistatic agent

This example also illustrates the preparation of an antistatic silicone rubber composite flexible electrostatic shielding bag. The electrostatic shielding bag structure was the same as in example 3. But the built-in silica gel supporting layer comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 35 parts of fumed silica, 2 parts of hydroxyl silicone oil, 0.5 part of zinc stearate and 0.3 part of vulcanizing agent; the external silica gel supporting layer comprises the following components in parts by weight: 100 parts of methyl vinyl silicone rubber, 45 parts of fumed silica, 5 parts of hydroxyl silicone oil, 2 parts of zinc stearate and 0.5 part of vulcanizing agent; the preparation method is the same as in example 3.

Comparative example 5 No fiber-reinforced mesh sheet

This example also illustrates the preparation of an antistatic silicone rubber composite flexible electrostatic shielding bag. The electrostatic shielding bag structure was not provided with a fiber reinforced mesh as compared to example 3. The components of the internal silica gel support layer and the external silica gel support layer are the same as those in embodiment 3; the preparation method is the same as in example 3.

Effects of the invention

In this example, the performance of the electrostatic shielding bags prepared in example 3 and comparative examples 1 to 5 was measured, and each index was performed according to GB/T39588-2020, and the specific results are shown in Table 1.

TABLE 1 results of testing the Performance of the Electrostatic Shielding bags

As can be seen from the above table, the sealing strength of the electrostatic shielding bags of the embodiments meets the specification, but the puncture resistance strength of the electrostatic shielding bags does not meet the requirement without the fiber reinforced mesh; in addition, for the surface resistance, the fiber reinforced mesh containing the metal wires also contributes to the conductivity of the bag body; and the surface resistance of the carbon nano tube can meet the specified standard of the shielding bag only when the oriented carbon nano tube and the conductive nickel powder are used simultaneously. The activity of the conductive nickel powder forms a conductive network after being excited by carboxyl residues of sulfonic acid, and the conductive network is combined with the oriented carbon nano tube to ensure that a shielding structure is compact and the surface resistivity is reduced, and the surface resistivity is further reduced by metal wires in the fiber reinforced mesh to form a good Faraday cage to shield static electricity and ensure that the induced electricity energy in the Faraday cage is in a lower level, so that the prepared electrostatic shielding bag meets the production standard and meets the use requirement.

According to the invention, by adding the non-ionic antistatic agent (coconut oil diethanolamide used for an external protective layer), the high-molecular antistatic agent (sulfonic acid) and the conductive filler prepared from the conductive nickel powder and the oriented carbon nanotube, the conductivity of the silica gel material is fully improved, redundant static electricity of electronic products and elements is released, damage to electronic circuits or electronic components caused by static electricity is avoided, and the safety of the products in the transportation and transfer processes is improved. The invention firstly provides the preparation of the anti-static shielding bag by adopting the modified silicon rubber material, which not only has good shielding function and plays a good role of anti-static, but also can provide all-dimensional conformal supporting protection for electronic products and components, and simultaneously has good shockproof function, thereby effectively preventing the risk that the electronic products or the components in the bag are collided or dropped and impacted, and meeting the packaging requirements of high-end electronic products. The anti-static shielding bag realizes the shape change of electronic products and components through the built-in silica gel supporting layer, and provides all-dimensional supporting protection; the fiber reinforced protective layer arranged in the middle provides good puncture resistance for the shielding bag, protects articles in the shielding bag from being isolated from an electrostatic field, prevents static accumulation and avoids static damage; the external silica gel protective layer with excellent conductivity can lead out static electricity in the bag, provides a new idea and a new idea for development and application of the electrostatic shielding bag, and has good use value and important economic value

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. Furthermore, it should be understood that although the present specification describes embodiments, this does not include only one embodiment, and such description is for clarity only, and those skilled in the art should be able to make the specification as a whole, and the embodiments may be appropriately combined to form other embodiments understood by those skilled in the art.

Claims

1. An antistatic silicone rubber composite material is characterized in that: the components of the composition by weight portion are as follows:

100 parts of methyl vinyl silicone rubber,

35 to 45 portions of gas-phase white carbon black,

3 to 8 portions of hydroxyl silicone oil,

0.6 to 2 portions of zinc stearate,

0.2 to 0.5 portion of vulcanizing agent,

0 to 3 parts of non-ionic antistatic agent,

2 to 5 parts of a polymer antistatic agent,

2-10 parts of conductive filler;

wherein the nonionic antistatic agent is a fatty alkanolamide nonionic antistatic agent;

the polymer antistatic agent is one or a combination of more of quaternary ammonium salt type, polyether type, sulfonic acid type or internal ammonium salt type;

the conductive filler is a metal conductive filler and a carbon conductive filler which are used in a composite way.

2. The antistatic silicone rubber composite material according to claim 1, characterized in that: the antistatic silicone rubber composite material comprises the following components in parts by weight:

100 parts of methyl vinyl silicone rubber,

35 to 45 portions of gas-phase white carbon black,

3 to 8 portions of hydroxyl silicone oil,

0.6 to 2 portions of zinc stearate,

0.2 to 0.5 portion of vulcanizing agent,

0 to 3 parts of coconut oil diethanolamide,

2 to 5 portions of sulfonic acid, and the like,

1 to 5 parts of oriented carbon nano-tube,

1-5 parts of conductive nickel powder.

3. The utility model provides an antistatic silicon rubber combined material flexible electrostatic shielding bag which characterized in that: the components of the composition by weight portion are as follows: comprises a shielding bag body and a sealing strip; the shielding bag body comprises an internal silica gel supporting layer, an external silica gel protective layer and a fiber reinforced protective layer between the internal silica gel supporting layer and the external silica gel protective layer;

the internal silica gel supporting layer and the external silica gel protective layer are prepared from the antistatic silicone rubber composite material according to claim 1 or 2;

the fiber reinforced protective layer is formed by interweaving metal wires and carbon fibers.

4. The antistatic silicone rubber composite flexible electrostatic shielding bag according to claim 3, wherein:

the built-in silica gel supporting layer comprises the following components in parts by weight:

100 parts of methyl vinyl silicone rubber,

35 parts of gas-phase white carbon black,

2 parts of hydroxyl silicone oil, namely 2 parts of,

0.5 part of zinc stearate,

0.3 part of a vulcanizing agent,

2 parts of sulfonic acid, namely, sodium sulfonate,

5 parts of oriented carbon nano-tubes,

5 parts of conductive nickel powder;

the external silica gel supporting layer comprises the following components in parts by weight:

100 parts of methyl vinyl silicone rubber,

45 parts of gas-phase white carbon black,

5 parts of hydroxyl silicone oil, namely,

2 parts of zinc stearate, namely, 2 parts of zinc stearate,

0.5 part of a vulcanizing agent,

3 parts of coconut oil diethanolamide, namely,

5 parts of sulfonic acid, namely, a sulfonic acid solution,

5 parts of oriented carbon nano-tubes,

2 parts of conductive nickel powder;

in the fiber-reinforced protective layer, the mass ratio of the metal wires to the carbon fibers is 1.

5. The antistatic silicone rubber composite flexible electrostatic shielding bag according to claim 3 or 4, characterized in that:

the thickness of the built-in silica gel supporting layer is 1-10 mm or set according to the specific shape and specification of the product;

the thickness of the external silica gel protective layer is 1-5 mm;

the thickness of the fiber reinforced protective layer is 0.1-0.2 mm;

the internal silica gel supporting layer and the external silica gel protective layer are respectively integrally formed;

the metal wires and the carbon fibers are stranded and then are interwoven in a longitudinal and transverse mode, the density of warp and weft is 100 per 1 square inch, the warp direction is 55, and the weft direction is 45;

the sealing strip is arranged on the fiber reinforced protective layer, and the edge of the opening of the built-in silica gel supporting layer is stopped at the inner side of the sealing strip.

6. A preparation method of an antistatic silicone rubber composite material flexible electrostatic shielding bag is characterized by comprising the following steps: the method comprises the following steps:

5) Pre-vulcanizing: pre-vulcanizing and molding the mixed rubber and the fiber reinforced mesh subjected to injection molding under a certain vulcanization condition, and processing and adhering a sealing strip;

6) Folding and molding: folding the pre-vulcanized mixed rubber and the fiber reinforced mesh sheet through a forming die, removing the allowance area of the inner die, and shaping to form a shielding bag body;

7. The antistatic silicone rubber composite flexible electrostatic shielding bag according to claim 6, wherein: the mixing in the step 2) comprises the following steps of:

preheating an internal mixer to 80 ℃, after stabilizing for a period of time, adding methyl vinyl silicone rubber for 1min, adding hydroxyl silicone oil for mixing for 1.5min, adding fumed silica for mixing for 3min, adding zinc stearate for mixing for 1.5min, adding sulfonic acid for mixing for 2min, adding oriented carbon nanotubes for mixing for 1.5min, adding conductive nickel powder for mixing for 5min, adding coconut oil diethanolamide for mixing for 1min;

and raising the temperature to 150-180 ℃, fully mixing for 2-3 h, performing vacuum heat treatment for 20-40 min, controlling the rotation direction of the internal mixer to be unchanged, and cooling and discharging to obtain the mixed rubber material for preparing the internal silica gel supporting layer and the external silica gel protective layer.

8. The antistatic silicone rubber composite flexible electrostatic shielding bag of claim 6, wherein: in the step 4), injection molding is carried out, wherein the remilling is that the mixed rubber material with the built-in silica gel supporting layer or the mixed rubber material with the built-out silica gel protective layer is placed in an open mill, a vulcanizing agent is added, and the mixture is subjected to thin pass for 15-20 times and is used for vulcanization;

the mold structure for vulcanization molding of the electrostatic shielding bag is as follows: comprises an inner die and an outer die, both of which are provided with folding areas; the cavity of the inner die cavity is designed according to the requirements of users, and is provided with a detachable allowance area; the outer mould is in the form of a foldable flat plate.

9. The antistatic silicone rubber composite flexible electrostatic shielding bag of claim 6, wherein: the pre-vulcanization condition in the step 5) is as follows: and (3) carrying out mould pressing vulcanization for 10-15 min under the conditions of the pressure of 12-15 MPa and the temperature of 175-185 ℃.

10. The antistatic silicone rubber composite flexible electrostatic shielding bag of claim 6, wherein: the secondary vulcanization condition in the step 7) is as follows: the reaction is carried out in a constant temperature oven, the temperature is controlled to be 190-200 ℃, and the time is controlled to be 4-6 h.