JPH05508055A - Method of manufacturing electrical equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Electric equipment manufacturing method The present invention is an electrical device, especially an overcurrent protection device, in which two parallel surfaces are provided. a body of an electrically conductive polymer composition having a resistivity of no more than 100 iΩcm; two electrodes placed in contact with said parallel surfaces, and said polymer composition electrical equipment consisting of a polymeric material and an electrically conductive powder material distributed within the polymeric material. The present invention relates to a method of manufacturing a device.

One type of such electrical device in the form of an overcurrent protector is a PTC element (positive temperature temperature coefficient>, that is, the temperature coefficient of resistivity is positive. The above types of PTC elements The resistance of the device is low, e.g. over the normal operating range of the device which can extend up to 80°C. It is several hundred times smaller and increases slightly with temperature. If the element temperature exceeds this value, For example, when exceeded due to overcurrent, the resistance increases even more rapidly, reaching a critical When the temperature is exceeded, the element has a low resistance but a high resistance that can reach a resistance value of 10kΩ or more. Suddenly changes to anti-state.

Methods traditionally used to prepare bodies of electrically conductive polymers for electrical devices of the above type If the polymer used is in a thermoplastic state, e.g. If there is, it is melted to produce carbon or metal materials or carbon and metal materials in the usual form. This method has many limitations when mixing (compounding) conductive powder materials consisting of a mixture of For example, in order to introduce conductive materials, polymeric materials are required to have relatively low It must have a high viscosity, and even in such cases, the desired sufficiently high content of charcoal It may not be possible to mix elements. It is also possible to perform strong processing during the compounding operation. Conductive materials may be immersed or otherwise affected, resulting in undesirable changes. It's dangerous. After compounding, the resulting mixture may be extruded, compressed, or otherwise formed. When subjected to processing associated with forming with There is a risk that undesirable anisotropy will occur. The above method is used to recycle the final product manufactured. This can cause problems in obtaining certain properties.

After forming the body of the polymeric composition, the body is provided with electrodes according to the method of application. electrode is usually made of metal foil and is applied by pressing it onto the body while heating.

According to the present invention, the above-mentioned limitations associated with the prior art are removed, and the manufacturing of electrical devices is improved. This simplifies the process.

That is, the present invention provides for the production of polymeric materials having a much higher viscosity than previously possible. You can use the fee. Thereby, the type of conductive material and There is much more freedom in choosing the content. conductive material should not be subjected to treatments that would lead to undesirable results, and should not be formed with the risk of anisotropy. It won't happen.

The electrodes can be applied without further operating steps. Particularly important advantages are: The method is that it is possible to obtain a device with electrodes and polymer compositions.

According to the invention, the polymeric material is smaller than 100μ shoulder and at least a polymeric material in a powdered thermoplastic state having a particle size of which 50% is less than 40 μl; , and an electrically conductive powder material with a particle size of less than +00μ1 in a solid dry state. and the polymeric materials in the mixture account for at least 30% of the total volume of those materials. and the electrically conductive powder material accounts for at least 20%, and the mixture is electrically conductive. Press together with a pole and heat to a temperature at which the polymeric material melts at least on the particle surface. heating and simultaneously forming a permanently agglomerated body of the mixture and moving the electrode into the agglomerated body. Favorable results are obtained by fixation on the body. Then the particles of polymeric material are Completely lose their uniqueness.

According to a preferred embodiment of the invention, which gives particularly good reproducibility to the manufactured devices, The mixture of the combined material and the electrically conductive powder material is heated at room temperature or at a temperature at which the polymeric material melts. subjected to a pressing operation at another temperature significantly lower than Thereafter, the mixture in the form of the preformed body is combined with the electrode to form a permanently cohesive body. and! Press and heat to fix the poles.

A plate prefabricated from powdered metal material with a porous structure on the side facing the mixture as the pole. with a structure and a weight to prevent penetration of the polymeric material to the side opposite the mixture. It is preferable to use plates that are impermeable to the coalescing material. When electrodes are used, the polymeric material on the outside of those electrodes has little, if any, insulating properties. Electrodes can be effectively applied to conductive polymer compositions without providing a coating that is only conductive. The polymer material is fixed in the pores of the electrode when it is in its thermoplastic state. The plate, which is completely porous to begin with, passes through its electrodes without passing through the outside. By applying a metal coating on the side, for example electrolytically, it is impervious to the penetration of the polymeric material. The surface layer of the porous electrode, which may be made transparent, is melted using e.g. laser technology. and solidified, leaving the other parts of the electrode unchanged in their porous state. You can also make the outside airtight. Porous surface structure on the side facing the mixture Another method of making the plate airtight and against permeation of polymeric materials is through sintering the plate. In a normally reducing atmosphere, peeling must be lower than the melting temperature of the metal electrode material used. after sintering, the outside of the plate is subjected to polishing or other mechanical treatment. . However, different types of electrodes than those mentioned above may also be used, e.g. The terminal electrode material is applied in a layer to the surface of the conductive polymer composition, after which it is Pressing and heating to form a permanently cohesive body and fix the electrodes. You can leave it. In such cases, the electrodes should also be made hermetic to the penetration of the polymeric material. such measures as, for example, giving them an airtight covering of metallic material on the side opposite the mixture. It is preferable to take such measures by

Advantageously, the metal material of the electrodes consists of nickel or copper, but with sufficient electrical conductivity. Other metal materials in the form of pure metals or metal alloys having a The suitable particle size is 0.5 μl to 20 μl, and the suitable thickness of the electrode is 100 to 100 μl. It is 0 μl. If the electrode is provided with a metal coating, e.g. electrolytically, the coating is copper. It is advantageous to consist of

Copper is present in the electrode in question, regardless of its material when the electrode is based on another. This provides electrical conductivity that is sufficiently distributed in the lateral direction as well. Hermetic sealing of otherwise porous electrodes Advantageously, the surface layer has a thickness in the amount of 3 to 30% of the total electrode thickness.

According to an advantageous embodiment of the invention, crosslinkable linear polymers are used as the polymeric material for the production of the device. When using the crosslinking ability of polymeric materials, polymeric materials and conductive materials together with the electrode to form a permanently cohesive body and fix the electrode. After being subjected to pressing and heating for crosslinking, the polymer material is crosslinked. Greater mechanical and thermal stability of the manufactured device can be achieved .

The polymeric material is preferably polyethylene, polypropylene, polybutene, or It consists of a polyolefin such as a copolymer of tyrene and propylene. particularly preferred is HD polyethylene. However, by making the particle size sufficiently fine, it becomes conductive in a dry state. and forming the mixture into a body of a permanently aggregated polymeric composition; Transforms into a thermoplastic state when pressed and heated to fix the electrode. Other linear polymers that can be used can be used. Examples of such other linear polymers is polyamide, polyethylene terephthalate, polybutene terephthalate, and and polyoxymethylene.

The polymeric material has a crystallinity of at least 5%.

The particle size of the polymeric material is between 5 and 100 μl, in which at least 50% of the material Preferably it has a particle size of less than 0 μl.

Examples of suitable electrically conductive materials in polymeric compositions include electrically conductive materials such as carbon black. Carbon in the form of conductive carbon powder; e.g. nickel, tungsten, molybdenum, cobalt Metal materials such as copper, silver, aluminum and brass: e.g. Z　B　2 and borides such as TiB2; nitrides such as ZrN and TiN; ■20. and oxides such as TiO; carbides such as TaC, WC and ZrC. mixture of two or more similarly exemplified materials, such as a mixture of soot and nickel can be mentioned. The particle size of conductive carbon powder such as carbon black is usually 0. ．． The particle size of the metal material is preferably 0.5 to 100 μl. and the particle size of boride, nitride, oxide, and carbide is preferably 0.01 to 1 00 μl. At least a portion of the electrically conductive powder material is in a cross section of the pores of the electrode. It has a smaller particle size, so that a portion of the powder material is absorbed by the polymer material into the pores of the electrode. Preferably, it can be carried along with the polymeric material as it enters the cell.

The polymeric materials account for 3% of the total volume of these materials in the polymeric composition made up of the mixture. Suitably, the electrically conductive powder material accounts for 0 to 80%, and the electrically conductive powder material accounts for 20 to 70%.

If the electrically conductive material consists of a mixture of carbon and metallic materials, the The content is 65-80% of the total volume of those materials in the device with excellent PTC effect. %, preferably the content of electrically conductive powder material is 20-35%. In the conductive powder material, carbon accounts for 5 to 75% by volume, and metal material accounts for 25 to 95% by volume. It is preferable to

The invention will be explained in detail by describing a number of embodiments.

Example 1 Melt index (MI +90/2) 40g/10min, density 0.9 60g/cz”, particle size 5-90μl, of which more than 50% of the material HD polyethylene with a particle size of 24-36 μl [Blast Ray, Bre, Switzerland] Bar (PLAST-LABOR) S, A, N B from 60111) 75 bodies The bulk part was mixed with 13 parts by volume of nickel powder having a particle size of 7 μl without grooves, 0.040-0. Carbon bra of type N550 (AST Pvl) with a particle size of 048 μl The mixture was mixed with 12 parts by volume of a polymer composition. Pour the mixture into a cylinder room temperature and 70 M in a forming tool with a shaped cavity and one or two movable cylindrical molds. Pressed at a pressure of Pa into a preformed disc with a diameter of 251 m and a height of 1.5 zz. did.

By pressing nickel powder with a particle size of 4 to 7 μl using the same forming tool, the thickness Two electrodes in the form of plates with a diameter of 0.6xrx were made. The press was operated at room temperature and at 70 MPa. Made under pressure. The plate is porous with through-holes. Each board has 20 on one side A copper layer of μ shoulder thickness is applied electrolytically, and the copper layer must be airtight in part. to avoid the presence of through-holes, and two have a radially distributed highly conductive surface. It gave it layers.

The plates of the polymer composition with one nickel-ti plate on each flat collar are again molded. Place the copper layer back into the filling with the copper layer facing outward, and then place the three plates stacked together. First press at room temperature and a pressure of 70 MPa, then press at 150 °C without changing the pressure. To do so. The polymer composition thereby forms a permanently cohesive body to which an electrical The electrode is arranged such that the polymer composition enters the pores of the electrode, or at least the polymeric material and the electrode A set of polymers mechanically fixed with an electrically conductive powder material having a particle size smaller than the pores. The composition has a resistivity of less than 50 zΩcm. The manufactured device is used as a PTC element. It was excellent and suitable for use.

Example 2 The device was manufactured in the manner described in Example 1. However, the copper layer on the outside of the electrode is polymerized. The laminate of the body composition plate and the nickel electrode plate is pressed at room temperature into a cohesive body. The difference is that it was not applied until then. After applying the copper layer on the outside of the electrode, the agglomerated body is 7 It was pressed at a pressure of 0 MPa and a temperature of 150°C.

Example 3 The device was manufactured in the manner described in the Examples. However, instead of providing an airtight copper layer on the outside, First, the electrode plate pressed at room temperature was sintered at approximately 400°C in a hydrogen gas atmosphere for 4 hours. and then sand the side opposite the polymer composition with 320 mesh damp abrasive paper. The difference was in the polishing. Polishing deforms the surface layer, resulting in an airtight became. This results in a porous surface structure on the side facing the polymer composition; An electrode plate without through holes was obtained. Therefore, they are polymer materials during hot pressing. It has become impermeable to water.

Example 4 The device was manufactured in the manner described in Example 1. However, instead of providing a copper layer on the outside , the surface layer of the porous electrode is melted using a laser to a depth of about 50 μm, and then The difference is that it is made airtight by solidifying it. The device can be used as a PTC element. It was excellent and suitable for use.

Example 5 Devices were manufactured using any of the methods described in Examples 1-4. Last using heat treatment After pressing, the polymer composition is made into a polymer material by irradiating the entire device with electrons. A monopolymer composition cross-linked to a length where the degree of cross-linking is 80% has a resistance of less than 501 Ωcyt. had resistance. The device was suitable and excellent for use as a PTC element.

Example 6 Electrodes were made in the manner described in Example 1, Example 3, or Example 4. those The electrode was combined with the polymer composition described in Example 1 in powdered form, i.e. without preforming. At the same time, in the cavity of a forming tool of the type described in Example 1, an electric current was placed on both sides of the polymer composition. 9 polymer composition with the poles placed and the airtight layer (Examples 1 and 4) facing outward. The electrodes were pressed at a pressure of 70 MPa and a temperature of 150°C. The polymer composition is It had an ungrooved resistivity of 50xΩcx. The device is used as a PTC element. It was suitable and excellent.

Example 7 Devices were manufactured using any of the methods described in Examples 1-6. However, the points mentioned there Instead of polyethylene, melt index is 70g/10min, density 0.91 6g/cz', particle size 5-35μl, of which the particle size is 10-14μl. LD polyethylene (HX from Blast Labor S, A, 16H) is used. The polymer composition has an ungrooved resistivity of 501Ωcx was. The manufactured device was suitable and excellent for use as a PTC element.

Example 8 Devices were manufactured using either the methods described in Examples 1.2.3.4 or 6. however Instead of the polyethylene mentioned there, melt index (M I 230 15) is 100g/10 minutes, density 0.905g/c+vco, particle size 5-90μl Of these, polypropylene particles with a particle size of 24 to 36 μl account for more than 50% of the material. (PBO580 from Blast Labor S, A) and hot plate. The difference is that the reaction was carried out at 170°C.

Example 9 Devices were manufactured using any of the methods described in Examples 1-8. However, it was mentioned there Electrically conductive powder in the form of 13 parts by volume of nickel powder and 12 parts by volume of carbon black The point is that 50 parts by volume of ZrN having a particle size of less than 45 μm was used instead of the powder material. It was different. The polymer composition had a resistivity of less than 50 ohms C1.

Example 10 The device was manufactured in the manner described in Example 9. However, instead of ZrN, 6~lOμ The difference was that TiN with a particle size smaller than 1 was used. The polymer composition is 35Ω It had a resistivity of less than C11.

Example 11 Devices were manufactured using any of the methods described in Examples 1-8. However, it was mentioned there Electrically conductive powder in the form of 13 parts by volume of nickel powder and 12 parts by volume of carbon black Instead of the powder material, 13 parts by volume of the same carbon black and a particle size of 6-10 μl were added. The hexapolymer composition differed in that it used 52 parts by volume of TiN with 35 zΩc It had a resistivity of less than m.

Example 12 The device was manufactured in the manner described in Example 1O. However, instead of TiN, 45μl The difference was that ZrB2 with a smaller particle size was used. The polymer composition is 3 It had a resistivity of less than 0Ωcm.

Example 13 The device was manufactured in the manner described in Example 9. However, instead of ZrN, use 45 μl. The difference was that TiB with a smaller particle size was used.

Example 14 Devices were manufactured using any of the methods described in Examples 1-8. However, it was mentioned there Electrically conductive powder in the form of 13 parts by volume of nickel powder and 12 parts by volume of carbon black The difference is that 120 parts by volume of the same type of soot as in Example 1 was used instead of the powder material. It had become.

Example 15 Devices were manufactured using any of the methods described in Examples 1-8. However, it was mentioned there Electrically conductive powder in the form of 13 parts by volume of nickel powder and 12 parts by volume of carbon black Instead of the powder material, 60 parts by volume of nickel powder of the same type as in Example 1 was used. The difference was that

In all cases described in Examples 1-15, the particles of polymeric material have completed their identity. Totally lost.

! -” to L- a polymeric composition disposed between two electrodes, with a polymeric material and a polymeric composition distributed within the polymeric material; Electrical devices with polymeric compositions consisting of electrically conductive powder materials, especially for The protective device is made of said polymeric material and is smaller than 100 μl and contains at least a polymeric material in a powdered thermoplastic state with a particle size of which 50% is less than 40 μl; , and an electrically conductive powder material with a particle size of less than 100μ1 in a solid dry state. the polymeric materials in the mixture occupy at least 3% of the total volume of the materials. 0%, the electrically conductive powder material accounts for at least 20%, and the mixture pressing the compound together with an electrode and melting the polymer material at least on the particle surface. The electrodes are subjected to heating to a temperature that simultaneously forms a permanently agglomerated body of the mixture. It is produced by fixing it on its agglomerated body.

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Claims (16)

[Claims] 1. In electrical equipment, especially overcurrent protection devices, when two parallel surfaces are provided, at most a body of an electrically conductive polymer composition having a resistivity of 100 mΩcm, and said parallel two electrodes placed in contact with a surface where the polymer composition is manufacturing an electrical device comprising a body material and an electrically conductive powder material distributed in the polymeric material; in the polymeric material, wherein the polymeric material is smaller than 100 μm; Polymerization of a powdered thermoplastic state having a particle size of at least 50% less than 40 μm The body material and the electrically conductive powder material with a particle size of less than 100 μm are mixed in a solid dry state. into a mixture, the polymeric materials in the mixture occupying a small proportion of the total volume of the materials. and the electrically conductive powder material accounts for at least 20%. , press the mixture together with an electrode and press the polymer material at least on the particle surface. subjecting to heating to a temperature that melts and at the same time forms a permanently cohesive body of the mixture; , a method for manufacturing an electrical device, characterized in that an electrode is fixed to its agglomerated body. 2. The mixture is heated at room temperature or other temperature significantly below the temperature at which the polymeric material melts. a preformed body at the same time, and then a mixture in the form of the preformed body. together with the electrode to form a permanent cohesive body and a press and a press to fix the electrode. A method according to claim 1, characterized in that it is subjected to heating. 3. As an electrode, the side facing the mixture has a porous structure, and the side facing away from the mixture has a porous structure. using a prefabricated plate from powdered metal material that is airtight to the penetration of the polymeric material. The method according to claim 1 or 2, characterized in that: 4. On the side opposite the mixture, the plate provides an airtight covering of metal material on that side. 4. The method according to claim 3, wherein the method is gas-tight. 5. On the opposite side of the plate from the mixture, the plate has a molten solidified surface layer of powdered metal material. Claim 3, characterized in that it is made airtight by being formed on its side. How to put it on. 6. By sintering the plate and subsequent mechanical treatment of the side opposite the mixture, the plate is The lack of through-holes makes it impermeable to the penetration of polymeric materials. The method according to claim 3, characterized in that: 7. A mixture of cross-linkable linear polymers and electrodes as the polymer material pressed and heated to form a permanently agglomerated body and fix the electrodes. 7. The method according to claim 1, wherein the polymeric material is crosslinked after the crosslinking. Method described. 8. Claims 1 to 7, characterized in that a polyolefin is used as the polymer material. The method described in any one of the above. 9. 9. The method according to claim 8, characterized in that polyethylene is used as the polymer material. Method. 10. the polymeric material accounts for at least 30-80% of the total volume of materials in the mixture , wherein the electrically conductive powder material accounts for 20 to 70%. The method described in any one of the above. 11. the polymeric material accounts for at least 65-80% of the total volume of materials in the mixture , wherein the electrically conductive powder material accounts for 20 to 35%. The method according to any one of the above. 12. The use of carbon in the form of carbon black as an electrically conductive powder material 12. A method according to any one of claims 1 to 11, characterized in that: 13. It is characterized by using a metal material as the electrically conductive powder material in the mixture. 12. The method according to any one of claims 1 to 11. 14. Carbon and gold in the form of carbon black as electrically conductive powder materials in the mixture According to any one of claims 1 to 11, characterized in that a mixture with a metallic material is used. How to put it on. 15. Claim 13 or 14, characterized in that the metal material is made of nickel. the method of. 16. Carbon accounts for 5-75% of the total volume of materials in the mixture, and metallic materials account for 25-75% of the total volume of materials in the mixture. 15. The method according to claim 14, characterized in that it accounts for 95%.