CN114230894A

CN114230894A - Manufacturing method for improving voltage resistance of PPTC product with ultralow resistance

Info

Publication number: CN114230894A
Application number: CN202111564953.7A
Authority: CN
Inventors: 王龙; 胡智敏; 韩露; 高连忠
Original assignee: Dongguan Beixin Microelectronics Co ltd; Dongguan Better Electronics Technology Co ltd
Current assignee: Dongguan Beixin Microelectronics Co ltd; Dongguan Better Electronics Technology Co ltd
Priority date: 2021-12-20
Filing date: 2021-12-20
Publication date: 2022-03-25
Anticipated expiration: 2041-12-20
Also published as: CN114230894B

Abstract

The invention discloses a manufacturing method for improving the voltage resistance of a PPTC product with ultralow resistance, which comprises the steps of carrying out experimental comparison on the particle size D (0.9) value of untreated titanium carbide treated by ball milling treatment, dry method and wet method coupling agent treatment, determining that the titanium carbide with the D (0.9) value of 18um obtained by wet method treatment is used as a conductive filler, mixing the titanium carbide with the particle size and high-density polyethylene in an internal mixer at 185 ℃ for 30 minutes at 40 r/min in a melting and blending mode, breaking pull tabs, and pressing to prepare sheets; and punching a wafer by using the sheet, and welding pins to obtain a PPTC test sample, wherein the voltage resistance of the sample is improved from 6V to 12V.

Description

Manufacturing method for improving voltage resistance of PPTC product with ultralow resistance

Technical Field

The invention relates to the technical field of resistance materials, in particular to a manufacturing method for improving the voltage resistance of a PPTC product with ultralow resistance.

Background

Ptc (positive Temperature coefficient) material, which is positive Temperature coefficient material, has a resistivity that gradually increases as its Temperature increases. According to different properties of PTC materials, the PTC materials are mainly divided into two types, namely Ceramic PTC (CPTC) materials and Polymer PTC (PPTC) materials. The PTC effect of the polymer PTC material is observed in carbon black filled low-density polyethylene by Frydman for the first time, and PPTC products manufactured by a PE/carbon black system are technically applied in the 80 th century, and are widely applied to a plurality of fields such as communication, computers, IT, automobiles, batteries, medical appliances, industrial and consumer appliances and the like.

With the change of the application requirements of products, the polymer PTC material is developed and researched on the material matrix and the types of conductive fillers. The material matrix comprises single matrix or blended matrix of polyethylene, polyolefin copolymer, polypropylene, polyvinylidene fluoride and the like. The filler types comprise carbon black, graphite, carbon fiber, metal powder, ceramic powder and the like; among them, titanium carbide fillers are being studied because of their advantages such as oxidation resistance and high conductivity.

When the PPTC has protection effect in a circuit, the resistance of the PPTC rapidly jumps to an ultra-high resistance state to become a poor conductor and bear most of voltage in the circuit, so that the research on improving the voltage resistance of the PPTC has important significance for widening the safe application range of products.

The above information is given as background information only to aid in understanding the present disclosure, and no determination or admission is made as to whether any of the above is available as prior art against the present disclosure.

Disclosure of Invention

The invention provides a manufacturing method for improving the voltage resistance of a PPTC product with ultralow resistance value, which aims to overcome the defects of the prior art.

In order to achieve the above purpose, the present invention provides the following technical solutions:

a manufacturing method for improving the voltage resistance of a PPTC product with an ultra-low resistance value, said method comprising:

grinding titanium carbide by adopting a wet ball milling technology;

analyzing the particle size of the titanium carbide, and determining that the titanium carbide with the D (0.9) value of 18um is preferably used as a conductive filler;

mixing the titanium carbide and the high-density polyethylene in an internal mixer in a melt blending mode at 185 ℃ for 30 minutes at 40 r/min, crushing the pulling piece, and pressing to prepare a sheet;

and punching a wafer by using the sheet, and welding pins to obtain a test sample.

Further, in the manufacturing method for improving the voltage resistance of the ultra-low resistance PPTC product, the step of grinding the titanium carbide by using the wet ball milling technology includes:

forming a mixture of titanium carbide and an organic solvent;

and putting the mixture into ball milling equipment for wet ball milling, taking out after ball milling for 2.5 hours, baking for 1 hour in an oven at 85 ℃, then treating for 30 minutes at 110 ℃ in a vacuum oven, and then dry milling for 15 minutes.

Further, in the manufacturing method for improving the voltage resistance of the ultra-low resistance PPTC product, the organic solvent is isopropanol or ethyl acetate.

Further, in the manufacturing method for improving the voltage resistance of the ultra-low resistance PPTC product, the step of pressing the PPTC product into a sheet includes:

pressing into sheets at 185 deg.C under 15MPa in 0.1mm mould frame, preheating for 15 min, and hot pressing for 15 min. .

Further, in the manufacturing method for improving the voltage resistance of the ultra-low resistance PPTC product, the mass ratio of the titanium carbide to the high-density polyethylene is 12: 1.

compared with the prior art, the embodiment of the invention has the following beneficial effects:

according to the manufacturing method for improving the voltage resistance of the PPTC product with the ultralow resistance, provided by the embodiment of the invention, the titanium carbide with the D (0.9) value of 18um is obtained by performing wet ball milling treatment on the titanium carbide and is used as a conductive filler to prepare the PPTC product, so that the voltage resistance of the PPTC product can be obviously improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic flow chart of a manufacturing method for improving the voltage resistance of a PPTC product with an ultra-low resistance value according to an embodiment of the present invention.

Detailed Description

In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present.

Furthermore, the terms "long", "short", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention, but do not indicate or imply that the referred devices or elements must have the specific orientations, be configured to operate in the specific orientations, and thus are not to be construed as limitations of the present invention.

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

Example one

In view of the defect that the voltage resistance of the existing ultra-low PPTC product is not high, the inventor of the invention actively researches and innovates based on abundant practical experience and professional knowledge in the industry for many years and by matching with the application of theory, so as to create a technology capable of improving the voltage resistance of the PPTC product, and the technology is more practical. After continuous research, design and repeated trial and improvement, the invention with practical value is finally created.

Referring to fig. 1, fig. 1 is a schematic flow chart of a manufacturing method for improving voltage resistance of a PPTC product with an ultra-low resistance value, which is applicable to a scenario of producing a PPTC product according to an embodiment of the present invention. As shown in fig. 1, the manufacturing method for improving the voltage resistance of the ultra-low resistance PPTC product may include the following steps:

and S101, grinding the titanium carbide by adopting a wet ball milling technology.

In this embodiment, the step S101 may be further detailed as follows:

forming a mixture of titanium carbide and an organic solvent;

and putting the mixture into ball milling equipment for wet ball milling, taking out after ball milling for 2.5 hours, baking for 1 hour in an oven at 85 ℃, then treating for 30 minutes at 110 ℃ in a vacuum oven to completely evaporate the organic solvent, and then carrying out dry milling for 15 minutes.

Optionally, the organic solvent is isopropanol or ethyl acetate.

And S102, analyzing the particle size of the titanium carbide, and determining the titanium carbide with the D (0.9) value of 18um as the preferred conductive filler.

S103, mixing the titanium carbide and the high-density polyethylene in an internal mixer in a melt blending mode at 185 ℃ for 30 minutes at 40 r/min, crushing the pull tabs, and pressing to prepare sheets.

The titanium carbide and the high-density polyethylene are premixed in a high-speed mixer and then are put into an internal mixer for mixing.

During mixing, the mass ratio of the titanium carbide to the high-density polyethylene is 12: 1.

alternatively, the high density polyethylene may be replaced with polypropylene, polyvinylidene fluoride, ethylene-vinyl acetate copolymer, maleic anhydride-grafted polyethylene, or the like.

In this embodiment, the "press-bonding into sheets" in the step S103 may be further subdivided into the following steps:

pressing in a flat vulcanizing machine at 185 ℃, 15MPa and 0.1mm of die frame for 15 minutes of preheating and 15 minutes of hot pressing to prepare the sheet.

And S104, punching a wafer by using the sheet, and welding pins to obtain a test sample.

In this embodiment, a sheet is punched to form a circular plate with a diameter of 3.6mm, and then pins are soldered by means of tin immersion, where the pins are copper wires or iron wires with certain strength and are used for pin testing.

When the pin is used for testing, a low resistance tester is used for testing the resistance before welding and the resistance after welding, and a direct current stabilized voltage power supply is used for testing the voltage endurance capability of a finished product.

To demonstrate the feasibility of this example, several specific sets of experiments are described in detail below.

The first scheme is as follows:

experiments 1, 2 and 3, untreated titanium carbide with different particle sizes is selected to fill high-density polyethylene, and the mass ratio of the titanium carbide to the high-density polyethylene is 12: 1.

scheme II:

experiment 4, dry ball milling technology is adopted to grind titanium carbide, 450g of titanium carbide and 450g of grinding beads, and ball milling is carried out in a ball mill for 1 hour.

The third scheme is as follows:

experiment 5, wet ball milling was used to mill titanium carbide without coupling agent, 450g titanium carbide, 110g isopropanol, 450g beads, 1 hour ball milled and then taken out, baked in an oven at 85 ℃ for 1 hour, then treated in a vacuum oven at 110 ℃ for 30 minutes, and then dry milled for 15 minutes.

Experiment 6, wet ball milling was used to mill titanium carbide without coupling agent, 450g titanium carbide, 110g isopropanol, 450g beads, 2.5 hours of ball milling, taken out, baked in an oven at 85 ℃ for 1 hour, then treated in a vacuum oven at 110 ℃ for 30 minutes, and dry milled for 15 minutes.

The mass ratio of the titanium carbide to the high-density polyethylene is 12: 1.

and the scheme is as follows:

experiment 7, wet ball milling was used to grind titanium carbide, titanate coupling agent, titanium carbide 450g and titanate coupling agent 3.15g (mass ratio 0.7%) were added, the titanate coupling agent was first dissolved in 155ml isopropanol, beads were milled 450g, ball milled for 2.5 hours and then taken out, baked in an oven at 85 ℃ for 1 hour, then treated in a vacuum oven at 110 ℃ for 30 minutes, and dry milled for 15 minutes.

Experiment 8, wet ball milling technology is used to grind titanium carbide, the mass ratio of the coupling agent to the titanium carbide is increased to 1.4%, and the processing method is the same as experiment 7.

and (4) experimental conclusion:

it can be seen that, in experiments 1, 2 and 3, the particle size of titanium carbide is represented by the value of D (0.9), and as the value decreases, the resistance of the sample gradually decreases, and the breakdown burning phenomenon occurs in the withstand voltage, but the proportion decreases as the value of D (0.9) decreases. Experiments 4 and 5 respectively adopt a dry grinding method and a wet grinding method to treat the titanium carbide, so that the numerical value of D (0.9) of the titanium carbide is reduced, the pressure resistance is gradually improved, the wet treatment method is superior to the dry treatment method, the wet grinding time is prolonged in experiment 6, and the performance test of 12V and 40A can be passed when the D (0.9) value of the titanium carbide is 18.81 um. In addition, experiments 7 and 8 study that when the titanium carbide is treated by the wet method, carbonate coupling agents with different mass ratios are added, the voltage resistance capability passes the 12V test, but as the addition amount of the titanate coupling agent is increased, the resistance of the sample is gradually increased, and the conductivity of the titanium carbide is reduced by the coupling agent.

According to the manufacturing method for improving the voltage resistance of the PPTC product with the ultralow resistance value, provided by the embodiment of the invention, the titanium carbide with the particle size D (0.9) value of 18um is obtained by performing wet ball milling treatment on the titanium carbide and is used as a conductive filler to prepare the PPTC product, so that the voltage resistance of the PPTC product can be obviously improved.

The foregoing description of the embodiments has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same elements or features may also vary in many respects. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Numerous details are set forth, such as examples of specific parts, devices, and methods, in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In certain example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises" and "comprising" are intended to be inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed and illustrated, unless explicitly indicated as an order of performance. It should also be understood that additional or alternative steps may be employed.

When an element or layer is referred to as being "on" … … "," engaged with "… …", "connected to" or "coupled to" another element or layer, it can be directly on, engaged with, connected to or coupled to the other element or layer, or intervening elements or layers may also be present. In contrast, when an element or layer is referred to as being "directly on … …," "directly engaged with … …," "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship of elements should be interpreted in a similar manner (e.g., "between … …" and "directly between … …", "adjacent" and "directly adjacent", etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region or section from another element, component, region or section. Unless clearly indicated by the context, use of terms such as the terms "first," "second," and other numerical values herein does not imply a sequence or order. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Spatially relative terms, such as "inner," "outer," "below," "… …," "lower," "above," "upper," and the like, may be used herein for ease of description to describe a relationship between one element or feature and one or more other elements or features as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below … …" can encompass both an orientation of facing upward and downward. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted.

Claims

1. A manufacturing method for improving the voltage resistance of a PPTC product with ultra-low resistance is characterized by comprising the following steps:

grinding titanium carbide by adopting a wet ball milling technology;

analyzing the particle size distribution of the titanium carbide and determining the titanium carbide with a D (0.9) value of 18um as a preferred conductive filler;

2. The method as claimed in claim 1, wherein the step of grinding the titanium carbide by wet ball milling comprises:

forming a mixture of titanium carbide and an organic solvent;

3. The method as claimed in claim 2, wherein the organic solvent is isopropyl alcohol or ethyl acetate.

4. The method as claimed in claim 1, wherein the step of pressing the PPTC substrate into a sheet comprises:

pressing in a flat vulcanizing machine at 185 deg.C, 15MPa, 0.1mm mold frame, preheating for 15 min, and hot pressing for 15 min to obtain the final product.

5. The manufacturing method for improving the voltage resistance of the ultra-low resistance PPTC product as claimed in claim 1, wherein the mass ratio of the titanium carbide to the high-density polyethylene is 12: 1.