Granulation material for glass sealing, preparation process and application

Abstract

The invention provides a granulation material for glass sealing, a preparation process and application, and belongs to the technical field of packaging materials of batteries and semiconductor products. The preparation method comprises the following steps: adding the surfactant, the binder, the plasticizer and the release agent into the glass powder, uniformly stirring, kneading or banburying and mixing at 50-150 DEG C, and cooling to room temperature under the stirring, kneading or banburying condition, so as to obtain the smooth elastic granulation material with good fluidity. A green body pressed by the granulation material is complete in structure and compact and uniform in texture, has certain elasticity, flexibility and tensile strength, can be directly assembled to a to-be-sealed position without pre-sintering, solves the problem of assembly errors, omits a pre-sintering step, greatly improves the material utilization rate, simplifies the sealing process, improves the production efficiency, and is suitable for large-scale production. And the production cost is reduced. The granulation material can be used for connection and sealing between ceramic-ceramic materials and between ceramic-metal materials, and is wide in application and wide in raw material source.

Description

Technical Field

[0001] The present invention relates to a packaging material for batteries and semiconductor products, in particular to a glass sealing granulation material for inorganic connection and sealing of ceramic-ceramic and ceramic-metal materials, a preparation process and application thereof. Background Art

[0002] The battery pack or battery group of an electric vehicle is composed of several battery cells connected in series and parallel. The battery cell lithium-ion battery includes a battery cell, a battery shell that contains the battery cell, and a battery cover assembly at one end of the battery shell, and positive and negative poles on the cover. Generally, the battery cover assembly is connected to the battery shell by laser welding, but the seal between the electrode pole and the inner wall of the through hole on the battery cover is a weak link, which is prone to leakage, affecting the battery life and causing safety hazards. The most serious case is combustion and explosion.

[0003] The earliest seals for battery electrode poles were made of plastic. Plastic has good electrical insulation and its easy deformation allows it to form close physical contact with the contact surface, thus playing a sealing role. However, plastic is prone to aging and is easily deformed due to alternating stresses caused by temperature changes or vibrations, which greatly reduces the sealing effect, leading to electrolyte leakage or moisture infiltration, causing safety problems. In addition, plastic sealing rings have poor temperature resistance. When the battery temperature is abnormal, they may melt and cause internal flammable gas to overflow and burn.

[0004] Glass sealing is also a sealing method. Its core lies in constructing a through-piece structure, which includes a metal core column, a metal ring-shaped sealing cover and a sealing glass located between the two, and its function is electrical insulation and sealing. Glass sealing has good high temperature resistance and is widely used in the fields of new energy and semiconductor packaging. The commonly used glass sealing process is: glass powder granulation, pressing into a specific shape, pre-sintering and shaping, and melting and sealing. A very important problem faced by this process during use is the assembly problem of the seal. The root cause of this problem is that the glass powder green body prepared by the current technology has low strength and is very brittle after pre-firing. Even if there is a small dimensional tolerance with the workpiece, it is difficult to assemble effectively, resulting in low production efficiency, waste of materials and increased costs. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides an elastic and easy-to-assemble glass blank for sealing, a preparation process and an application thereof, so as to solve the problem of assembling a glass sealing ring blank. The present invention uses a new granulation process and granulation raw materials to prepare a raw material having additive components and contents different from the granulation powder for pressing traditional glass powder. The sealing blank formed by the glass powder granulation material prepared by the present invention has excellent elasticity and strength, and can be placed in a workpiece when there is a certain tolerance between the actual size and the design size of the sealing part, thereby improving material utilization and production efficiency and reducing production costs.

[0006] The present invention achieves the above technical objectives through the following technical means.

[0007] A preparation process of a granulated material for glass sealing, characterized in that it comprises the following steps: Step 1. Add glass powder into a stirrer, kneader or internal mixer for stirring, kneading or internal mixing, and preheat to 50-150°C; Step 2. While maintaining the stirring, kneading or banburying temperature, add a surfactant to the preheated glass powder, wherein the amount of the surfactant added is 1wt%-3wt% of the mass of the glass powder; after adding the surfactant, continue stirring, kneading or banburying for 10min-360min; Step 3. Add a binder, a plasticizer and a release agent, wherein the binder is a high molecular polymer, and the amount added is 2wt%-5wt% of the mass of the glass powder, the amount added of the plasticizer is 0.5wt%-1.5wt% of the mass of the glass powder, and the amount added of the release agent is 2wt%-4wt% of the mass of the glass powder; after adding the binder, plasticizer and release agent, continue stirring, kneading or banburying for 30-720 minutes; Step 4. Stop heating and continue stirring, kneading or mixing until the material cools to room temperature to obtain a powdery or granular granulated material.

[0008] Furthermore, in step 1, a double planetary mixer is used for stirring, the speed of the mixer is 0-100 r / min, and the stirring time is 20-120 min.

[0009] Furthermore, the surfactant described in step 2 is one of stearic acid and oleic acid or a mixture of both.

[0010] Furthermore, the high molecular polymer is one or more of low-density polyethylene, polypropylene, polyvinyl chloride, acrylic resin, and polyvinyl alcohol.

[0011] Furthermore, the plasticizer is one or more of dibutyl phthalate (DBP), dioctyl phthalate (DOP), epoxidized soybean oil, tricresyl phosphate (TCP), triphenyl phosphate (TPP), dioctyl sebacate, and chlorinated paraffin.

[0012] Furthermore, the release agent is one or more of paraffin, emulsified paraffin, microcrystalline paraffin, beeswax, and zinc stearate.

[0013] Furthermore, the pressing pressure of the pressing molding is 5-300 MPa, and the mold temperature is 0°C-100°C.

[0014] The granulated material for glass sealing prepared by the above-mentioned granulated material preparation process is characterized in that it is formed by stirring, kneading or banburying glass powder, surfactant, binder, plasticizer and release agent at a temperature of 50-150°C and then granulating; the binder is a high molecular polymer, and the added amounts of the surfactant, binder, plasticizer and release agent are 1wt%-3wt%, 2wt%-5wt%, 0.5wt%-1.5wt% and 2wt%-4wt% of the mass of the glass powder, respectively.

[0015] The application of the granulated material for glass sealing is characterized in that it is used for connection and sealing between ceramic-ceramic materials and ceramic-metal materials. The granulated material is pressed and formed into an elastic and easy-to-assemble glass blank, and the glass blank is directly assembled to the part to be sealed, and sealing is achieved after high-temperature sintering.

[0016] Furthermore, it is used for electrode sealing of lithium batteries, sodium-sulfur batteries, sodium-nickel batteries, and solid fuel cells, or chip packaging.

[0017] The present invention adds a high molecular polymer material, such as polyethylene, polypropylene, etc., to the glass powder. Such materials have excellent mechanical properties due to their long molecular chains and are easy to obtain. By introducing the high molecular polymer material into the glass powder, the mechanical properties of the granulated material and the body made of the granulated material, such as elasticity, are greatly improved. At the same time, in order to overcome the problem that the surface properties of the high molecular polymer material and the glass powder are quite different and difficult to be compounded together, a surfactant is added to solve the compatibility problem between the two. The surfactant has a special molecular structure: its polar group can be well combined with the glass powder, and the non-polar group can be well combined with organic matter. Through the surfactant, a bridge can be established between the glass powder and the high molecular binder, and the two can be coupled and well combined. Since the molecules of the binder are large and the cohesive force is strong, it is difficult to open them during the mixing process. In order to make the binder molecules well dispersed in the entire material system, a certain amount of plasticizer needs to be added. The main function of the plasticizer is to embed between the high molecular chains and promote the mutual sliding of the high molecular chains. This can not only promote the combination of the high molecular binder and the glass powder in the mixing stage, but also promote the sliding of the granulated material during the molding process and reduce pores. The release agent is mainly a wax material, which has poor compatibility with metals and is conducive to removing the raw materials from the mold after pressing and molding.

[0018] The glass sealing granules of the present invention increase the organic matter content in the granules to between 5wt% and 12wt%, while the organic matter content in the existing granules is only 0.5wt% to 2.5wt%. The present invention uses a polymer with high mechanical properties and plasticity as a binder to increase the elasticity, flexibility and tensile strength of the pressed green body, which is not easy to break. Not only can it be put into the workpiece when there is a certain tolerance between the actual size and the design size of the sealing part, it can effectively solve the assembly problem of the glass sealing ring green body; and because the green body pressed by the granules has a high strength, it does not need to be pre-burned and can be directly assembled to the position to be sealed, omitting the pre-sintering step after the traditional green body is pressed and formed; it greatly improves the material utilization rate, simplifies the sealing process, improves the production efficiency, and reduces the production cost.

[0019] The present invention cools the high-temperature material to room temperature under stirring, kneading or banburying conditions, and can directly obtain granular or powdered granules, and the particle size of the granules is larger and smoother than that of the glass powder, and the fluidity is better, so that the texture of the pressed green body is tighter and more uniform in the subsequent pressing and forming process. Compared with the traditional glass liquid spray granulation, the granules obtained by this process have more uniform mixing of the components, more discrete distribution, and higher raw material utilization. And the granules of the present invention use mechanical heating stirring, kneading or banburying, so the material mixing efficiency is higher and the energy consumption is greatly reduced.

[0020] In summary, the glass ring green body prepared by the present invention has better mechanical properties, and the whole process is simple, less energy consumption and higher efficiency. Compared with the traditional spray granulation, it greatly saves equipment, energy consumption, site and manpower. In addition, the polymer binder used in the present invention is easy to obtain, and even waste plastics can be used, so the process can recycle resources and is beneficial to environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The glass ring blank is prepared by pressing the granulated material of the present invention.

[0022] Figure 2 This is an assembly diagram of a glass ring blank prepared by pressing the granulated material described in the present invention.

[0023] Figure 3 Difficult-to-form glass rings pressed from pellets with low binder content.

[0024] Figure 4 The present invention relates to a sealing component prepared by using the granulated material of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto. Example 1

[0026] Step 1. Add 10 kg of glass powder into the kneader, set the heating temperature to 120°C, the speed to 180 r / min, and heat while stirring; Step 2. When the temperature stabilizes, add 100 g of surfactant oleic acid to the heated glass powder, and continue stirring for 30 minutes; Step 3. Weigh 100g of low-density polyethylene and 100g of polyvinyl alcohol as a binder; 50g of DOP (dioctyl phthalate) as a plasticizer and 200g of paraffin as a release agent and add them to the glass powder, and continue kneading for 360min at 120°C. The speed of the kneading machine is still set to 180r / min. Step 4. Stop heating and continue stirring until the blank cools to room temperature; Step 5. Take out the cooled granulated material, which is now in granular form and has very good fluidity; Step 6. Place the granulated material in a dry pressing mold for molding, with a maximum molding pressure of 160 MPa and a holding time of 30 seconds. The resulting glass ring blank is as follows: Figure 1 As shown. The molding is intact, the surface is smooth, the texture is uniform, not easy to break, and has a certain elasticity. Figure 2 It is a glass ring pressed from granules with a low binder content of 2.5wt%. It is difficult to shape and easy to break.

[0027] Step 7. Assemble the pressed glass ring green body into a glass sealing tool, and then place the tool into a muffle furnace. Through a high-temperature sintering process, organic matter in the green body is removed and the glass powder is melted to achieve a sealing effect. Figure 3 The sealing assembly prepared in this embodiment. 1#-4# in Table 1 are the sealing test results of the sealing structure prepared in this embodiment. The airtightness of the tooling after glass sealing can reach 10 -9 Level, meeting product usage requirements. Example 2

[0028] Step 1. Add 5 kg of glass powder into the internal mixer, set the heating temperature to 140°C, the speed to 120 r / min, and heat while stirring; Step 2. When the temperature stabilizes, add 75 g of surfactant stearic acid to the heated glass powder, and continue stirring for 30 minutes; Step 3. Weigh 75g of low-density polyethylene and 50g of acrylic resin as a binder; 30g of DBP (dibutyl phthalate) as a plasticizer and 80g of paraffin as a release agent and add them to the glass powder, and continue to mix at 120°C for 300min. The speed of the mixer is still set to 120r / min. Step 4. Stop heating and continue stirring until the blank cools to room temperature; Step 5. Take out the cooled mixture, which is now in granular form and has very good fluidity; Step 6. Place the mixture in a dry pressing mold for molding, with a maximum molding pressure of 100 MPa and a holding time of 30 seconds; Step 7. Assemble the pressed glass ring green body into the glass sealing tool, and then put the tool into the muffle furnace, and heat it to remove organic matter and melt the glass powder to achieve the sealing effect. 5#-8# in Table 1 are the sealing test results of the sealing structure prepared in this embodiment. The airtightness of the tool after glass sealing can reach 10 -9 Level, meeting product usage requirements.

[0029] Table 1 Glass sealing samples and sealing effects

[0030] The embodiments are preferred implementations of the present invention, but the present invention is not limited to the above-mentioned implementations. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essential content of the present invention belong to the protection scope of the present invention.

Claims

1. A process for preparing granulated material for glass sealing, characterized in that: The following steps are involved: Step 1. Add glass powder into a stirrer, kneader or internal mixer for stirring, kneading or internal mixing, and preheat to 50-150°C; Step 2. While maintaining the stirring, kneading or banburying temperature, add a surfactant to the preheated glass powder, wherein the amount of the surfactant added is 1wt%-3wt% of the mass of the glass powder; after adding the surfactant, continue stirring, kneading or banburying for 10min-360min; Step 3. Add a binder, a plasticizer and a release agent, wherein the binder is a high molecular polymer, and the amount added is 2wt%-5wt% of the mass of the glass powder, the amount added of the plasticizer is 0.5wt%-1.5wt% of the mass of the glass powder, and the amount added of the release agent is 2wt%-4wt% of the mass of the glass powder; after adding the binder, plasticizer and release agent, continue stirring, kneading or banburying for 30-720 minutes; Step 4. Stop heating and continue stirring, kneading or mixing until the material cools to room temperature to obtain a powdery or granular granulated material.

2. The process for preparing the granulated material for glass sealing according to claim 1, characterized in that: In step 1, a double planetary mixer is used for stirring, the speed of the mixer is 0-100 r / min, and the stirring time is 20-120 min.

3. The process for preparing the granulated material for glass sealing according to claim 1, characterized in that: The surfactant described in step 2 is one of stearic acid and oleic acid or a mixture of both.

4. The process for preparing the granulated material for glass sealing according to claim 1, characterized in that: The high molecular polymer is one or more of low-density polyethylene, polypropylene, polyvinyl chloride, acrylic resin, and polyvinyl alcohol.

5. The process for preparing the granulated material for glass sealing according to claim 1, characterized in that: The plasticizer is one or more of dibutyl phthalate (DBP), dioctyl phthalate (DOP), epoxidized soybean oil, tricresyl phosphate (TCP), triphenyl phosphate (TPP), dioctyl sebacate, and chlorinated paraffin.

6. The process for preparing the granulated material for glass sealing according to claim 1, characterized in that: The release agent is one or more of paraffin, emulsified paraffin, microcrystalline paraffin, beeswax, and zinc stearate.

7. The process for preparing the granulated material for glass sealing according to claim 1, characterized in that: The pressing pressure of the pressing molding is 5-300MPa, and the mold temperature is 0℃-100℃.

8. A granulated material for glass sealing, characterized in that: The granulated material is prepared according to the preparation process of any one of claims 1 to 7.

9. The use of the granulated material for glass sealing according to claim 8, characterized in that: Used for connection and sealing between ceramic-ceramic materials and ceramic-metal materials, the granulated material is pressed and formed into an elastic and easy-to-assemble glass blank, which is directly assembled to the part to be sealed and sealed after high-temperature sintering.

10. The use of the granulated material for glass sealing according to claim 9, characterized in that: Used for electrode sealing of lithium batteries, sodium-sulfur batteries, sodium-nickel batteries, solid fuel cells, or chip packaging.

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