LU505940B1

LU505940B1 - Ptc tracing belt and manufacturing method therefor

Info

Publication number: LU505940B1
Application number: LU505940A
Authority: LU
Inventors: Naixin Xu; Yongbin Yang; Liyu Hu; Yilian Li
Original assignee: Anbang Electric Co Ltd
Priority date: 2023-09-12
Filing date: 2023-10-19
Publication date: 2025-03-21
Also published as: CN117024868A; WO2025055053A1; CN117024868B

Abstract

The present invention provides a PTC tracing belt and a manufacturing method therefor. The manufacturing method includes: mixing a molten polymer with a surface coated and modified tetrapod-like zinc oxide whisker, and then performing blending; then co-extruding a mixture and two parallel core wires to coat conductive plastic layers between outer layers of the two core wires and the two core wires; and performing cooling 10 and curing formation to obtain the PTC tracing belt, where a mass ratio of the polymer to the surface coated and modified tetrapod-like zinc oxide whisker is 100 to (5-15). A preparation method for the surface coated and modified tetrapod-like zinc oxide whisker includes: depositing a metal film layer on a surface of a tetrapod-like zinc oxide whisker by means of a physical vapor deposition method.

Description

PTC TRACING BELT AND MANUFACTURING METHOD THEREFOR 0505940

BACKGROUND OF THE INVENTION

[0001] 1. Technical Field

[0002] The present invention relates to the technical field of polymer composites, in particular to a PTC tracing belt and a manufacturing method therefor.

[0003] 2. Description of Related Art

[0004] Conductive polymer composites with a positive temperature coefficient (PTC) effect of resistance may be obtained by blending conductor fillers and polymer matrix materials. These materials are widely applied in the technical fields of heaters, sensors, tracing belts, etc.

[0005] A self-regulating PTC tracing belt is a common application product using a modified material, in which a polymer PTC material has a conductor network connected and conducted at a room temperature inside; and at the room temperature, resistivity in the conductor network is low. Therefore, under the effect of a high-flux current, the PTC tracing belt will heat up rapidly, while heating will lead to volume expansion of a polymer matrix material in the polymer PTC material, and under the effect of expansion, the conducted conductor network will be gradually disconnected, so that a current flux decreases, and the heating is inhibited. In the prior art, carbon black or metal particles are usually used as a conductive filler. Such conductor filler has the effect of rapid reaction speed under a temperature effect, but has a small size itself, and has the problem of poor dispersity in the process that it and the polymer material are dispersed; while with the repeated formation of crystal forms in the expansion process of a polymer body, the poorly dispersed conductor particles will move in a matrix, and a huge difference in the conductor network at this time from an initial stage is eventually caused, which leads to poor performance repeatability of the material and low stability of a product.

[0006] At present, stability improvement in the polymeric PTC tracing belt is mainly based on dispersity improvement in the conductor filler. How to provide a PTC tracing belt with better stability and high performance repeatability has become one of the technical problems to be solved urgently.

BRIEF SUMMARY OF THE INVENTION

[0007] In view of this, the present invention proposes a PTC tracing belt and a manufacturing method therefor, aiming to improve the stability and the repeatability of the

PTC tracing belt. LUS05940

[0008] The technical solution of the present invention is such implemented that: a manufacturing method for a PTC tracing belt of the present invention includes the following steps:

[0009] mixing a molten polymer with a surface coated and modified tetrapod-like zinc oxide whisker, and then performing blending, then co-extruding a mixture and two parallel core wires to coat conductive plastic layers between outer layers of the two core wires and the two core wires; and performing cooling and curing formation to obtain the PTC tracing belt, where a mass ratio of the polymer to the surface coated and modified tetrapod-like zinc oxide whisker is 100 to (5-15). A preparation method for the surface coated and modified tetrapod-like zinc oxide whisker includes: depositing a metal film layer on a surface of a tetrapod-like zinc oxide whisker by means of a physical vapor deposition method.

[0010] In some implementations, an additive, such as a stabilizer, a flame retardant, an antioxidant and a pigment may further be added to the conductive plastic layer.

[0011] In some implementations, the metal film layer deposited on the surface of the surface coated and modified tetrapod-like zinc oxide whisker is a copper film.

[0012] In some implementations, for the surface coated and modified tetrapod-like zinc oxide whisker, a mass ratio of a zinc oxide whisker to metal copper is 1 to (0.001-0.01).

[0013] In some implementations, the surface coated and modified tetrapod-like zinc oxide whisker has a diameter of 0.5-5 um and a length of 10-50 um.

[0014] In some implementations, the polymer is one of polyethylene, polypropylene and polyvinylidene fluoride.

[0015] In some implementations, before depositing the metal film layer on the surface of the tetrapod-like zinc oxide whisker, the manufacturing method further includes: washing the tetrapod-like zinc oxide whisker with hydrochloric acid.

[0016] In some implementations, after washing the tetrapod-like zinc oxide whisker with the hydrochloric acid, and before depositing the metal film layer on the surface of the tetrapod-like zinc oxide whisker, the manufacturing method further includes: washing the tetrapod-like zinc oxide whisker in a plasma atmosphere.

[0017] In some implementations, in a case of mixing a molten polymer with a surface coated and modified tetrapod-like zinc oxide whisker, and then performing blending, the manufacturing method further includes: adding carbon black, wherein a mass LU505940 ratio of the polymer to the carbon black is 100 to (2-5).

[0018] In another aspect, the present invention further provides a PTC tracing belt manufactured using the above method.

[0019] In some implementations, the PTC tracing belt is further coated with an insulating layer on an outer side of the conductive plastic layer.

[0020] In some implementations, the PTC tracing belt is further coated with a sheath layer on an outer side of the insulating layer.

[0021] In some implementations, the PTC tracing belt may further be provided with a shielding layer between the insulating layer and the sheath layer.

[0022] Compared with the prior art, the PTC tracing belt and the manufacturing method therefor of the present invention have the following beneficial effects:

[0023] In the present invention, the tetrapod-like zinc oxide whisker is used as the matrix for filling a conductor. By depositing the metal layer on the surface of the tetrapod-like zinc oxide whisker, the tetrapod-like zinc oxide whisker is electrically conductive, compared with the conventionally dispersed conductor particles, the dispersion stability of the tetrapod-like whisker in the polymer matrix is stronger; and even in the recycling use process of high cycle times, the relative position stability of the tetrapod-like whisker is good, which may avoid a stability decrease caused by a slip of the conductor filler. Secondly, the tetrapod-like zinc oxide whisker is overlapped well in the polymer matrix after dispersion; and at the room temperature, an initial current value of a tracing zone is large, and a heating response speed is rapid. Thirdly, in the process of heating, the metal film deposited on the surface may also have expansion cracks with the tetrapod-like zinc oxide whisker; and the cracks may also weaken the conduction effect of the conductor network, so that a temperature feedback effect of the PTC tracing belt is good.

DETAILED DESCRIPTION OF THE INVENTION

[0024] The technical solution in the implementations of the present invention is clearly and completely described below in conjunction with the implementations of the present invention and the accompanying drawings. It is obvious that the described implementations are merely a part rather than all of the implementations of the present invention. All other implementations obtained by those of ordinary skill in the art based on the implementations of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0025] Preparation Example 1 LU505940

[0026] A tetrapod-like zinc oxide whisker having a diameter of 0.5-5 um and a length of 10-50 um was added in a vacuum coating machine, keeping a degree of vacuum in the vacuum coating machine at 500 Pa; with argon as working gas and copper as an evaporation source, the copper was heated to 1200°C, and the copper source started to be evaporated, keeping a temperature of the tetrapod-like zinc oxide whisker at 40°C; during evaporation coating, the tetrapod-like zinc oxide whisker was stirred at a stirring speed of 5-30 rpm; and evaporation coating was stopped until a mass ratio of the tetrapod-like zinc oxide whisker to a copper coated film on its surface was 1 to 0.001, so as to obtain a surface coated and modified tetrapod-like zinc oxide whisker.

[0027] Preparation Example 2

[0028] On the basis of Preparation Example 1, other conditions were kept unchanged, but the mass ratio of the tetrapod-like zinc oxide whisker to the copper coated on the surface was 1 to 0.005.

[0029] Preparation Example 3

[0030] On the basis of Preparation Example 1, other conditions were kept unchanged, but the mass ratio of the tetrapod-like zinc oxide whisker to the copper coated on the surface was 1 to 0.01.

[0031] Comparative Preparation Example 1

[0032] On the basis of Preparation Example 1, other conditions were kept unchanged, but the mass ratio of the tetrapod-like zinc oxide whisker to the copper coated on the surface was 1 to 0.0005.

[0033] Comparative Preparation Example 2

[0034] On the basis of Preparation Example 1, other conditions were kept unchanged, but the mass ratio of the tetrapod-like zinc oxide whisker to the copper coated on the surface was 1 to 0.02.

[0035] Preparation Example 3

[0036] On the basis of Preparation Example 1, other conditions were kept unchanged; but the tetrapod-like zinc oxide whisker was washed with hydrochloric acid in advance, then dried to a constant weight, and then subjected to evaporation coating.

[0037] Preparation Example 4

[0038] On the basis of Preparation Example 1, other conditions were kept unchanged; but the tetrapod-like zinc oxide whisker was washed with hydrochloric acid in advance, then dried to a constant weight, then washed for 5 min in an oxygen plasma atmosphere, and then subjected to evaporation coating. LUS05340

[0039] Comparative Preparation Example 3

[0040] On the basis of Preparation Example 1, other conditions were kept unchanged; but aluminum was used as the evaporation source, and a heating temperature 5 for the aluminum during evaporation coating was 400°C.

[0041] Comparative Preparation Example 4

[0042] On the basis of Preparation Example 1, other conditions were kept unchanged; but iron was used as the evaporation source, and a heating temperature for the iron during evaporation coating was 1100°C.

[0043] Comparative Preparation Example 5

[0044] On the basis of Preparation Example 1, other conditions were kept unchanged; but zinc was used as the evaporation source, and a heating temperature for the zinc during evaporation coating was 600°C.

[0045] Comparative Preparation Example 6

[0046] On the basis of Preparation Example 1, other conditions were kept unchanged; but the tetrapod-like zinc oxide whisker was replaced with a nanorod-like zinc oxide whisker having a diameter of 0.5-5 um and a length of 10-50 um.

[0047] Embodiment 1

[0048] 5 parts of the surface coated and modified tetrapod-like zinc oxide whisker prepared in Preparation Example 1 and 100 parts of high-density polyethylene were weight separately, mixed, and then added in a plastic refining machine, where for the plastic refining machine, a heating temperature of a feeding region was 150°C, a heating temperature of a middle section was 170°C, a temperature of an extrusion region was 190°C, and a temperature of a die head was 60°C; and after melt mixing by the plastic refining machine, a product was co-extruded with two parallel copper stranded wires at a die head part of an extruder, so as to obtain a PTC tracing belt coated with a conductive plastic layer on its surface.

[0049] Embodiment 2

[0050] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Preparation Example 1 was used in an amount of 10 parts by weight.

[0051] Embodiment 3

[0052] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Preparation Example 1 was used in an amount of 15 parts by weight. LUS05940

[0053] Comparative example 1

[0054] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Preparation Example 1 was used in an amount of 1 part by weight.

[0055] Comparative Example 2

[0056] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Preparation Example 1 was used in an amount of 20 parts by weight.

[0057] Embodiment 4

[0058] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Preparation Example 2 was used.

[0059] Embodiment 5

[0060] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Preparation Example 3 was used.

[0061] Comparative Example 3

[0062] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Comparative Preparation Example 1 was used.

[0063] Comparative Example 4

[0064] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Comparative Preparation Example 2 was used.

[0065] Embodiment 6

[0066] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Preparation Example 3 was used.

[0067] Embodiment 7

[0068] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Preparation Example 4 was used.

[0069] Embodiment 8

[0070] On the basis of Embodiment 1, other conditions were kept unchanged, LU505940 but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Comparative Preparation Example 3 was used.

[0071] Embodiment 9

[0072] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Comparative Preparation Example 4 was used.

[0073] Embodiment 10

[0074] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Comparative Preparation Example 5 was used.

[0075] Comparative Example 5

[0076] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Preparation Example 1 was replaced with an equal amount of carbon black.

[0077] Embodiment 11

[0078] On the basis of Embodiment 1, other conditions were kept unchanged, but 2 parts of carbon black was further added.

[0079] Embodiment 12

[0080] On the basis of Embodiment 1, other conditions were kept unchanged, but 3 parts of carbon black was further added.

[0081] Embodiment 13

[0082] On the basis of Embodiment 1, other conditions were kept unchanged, but 5 parts of carbon black was further added.

[0083] Comparative Example 6

[0084] On the basis of Embodiment 1, other conditions were kept unchanged, but the surface coated and modified tetrapod-like zinc oxide whisker prepared in

Comparative Preparation Example 6 was used.

[0085] Performance detection

[0086] 1. Stability test:

[0087] The PTC tracing belt prepared in each of above Embodiments 1-10 and

Comparative Examples 1-8 was placed in an oven for heating-cooling cycling treatment, where a highest temperature for heating was 140°C; a heating rate was 10°C/min; after the temperature was raised to 140°C, thermal insulation treatment was performed for 10 min; a temperature for cooling was 30°C; and a cooling rate was 10°C/min. The resistivity at LU505940 30°C was measured before and after 10 cycles, 50 cycles and 100 cycles, respectively.

Measurement results are shown in the following table: 0 cycle 10 cycles 50 cycles 100 cycles

Group (Q-cm) (Q-cm) (Q-cm) (Q-cm) 0 cycle 10 cycles 50 cycles 100 cycles

Group (Q-cm) (Q-cm) (Q-cm) (Q-cm)

Comparative 3.17 5.62 7.74 12.31

Example 1

Comparative 0.02 0.02 0.02 0.02

Example 2

Comparative 1.67 1.74 1.79 1.82

Example 3

Comparative 1.38 1.40 1.41 1.41

Example 4

Comparative 5.88 7.92 15.41 26.69

Example 5

Comparative 3.72 3.74 6.51 6.62

Example 6

[0088] It can be seen from data of the resistivity after the cycles in the above LU505940 embodiments and comparative examples that the PTC tracing belt manufactured by the manufacturing method of the present invention has good repeatability. Compared with conventional use of the conductor filler such as the carbon black, if the tetrapod-like zinc oxide whisker coated with a metal film layer on its surface is used as the conductor filler, a prepared polymeric PTC conductive coating has good performance reproducibility.

Compared with the conventional carbon black conductor filler, it can still maintain a normal temperature conductivity close to the initial state after 100 heating cycles. It can be found through experimental comparison that if the copper is used as a coating metal material, it has better stability and repeatability than other metals, which may be related to the conductivity and the self-healing ability of the copper. Next, the copper has higher stability than the aluminum and the iron, and is not easily oxidized.

[0089] The PTC tracing belt before and after the above stability test is electrically heated, and an upper temperature limit of its temperature self-regulating is tested. Following data are obtained: (CC) (CC) (CC) (CC)

Data from comparative examples are as follows: 0 cycle 10 cycles 50 cycles 100 cycles

Group

Lew SE

Comparative U505940 88 65 52 50

Example 1

Comparative

Example 2

Comparative 136 134 131 128

Example 3

Comparative 142 142 141 141

Example 4

Comparative 133 124 110

Example 5

Comparative 52 51 43 40

Example 6

[0090] It can be seen from the heating performance test that when a type and an amount of the whisker are within a preferred range of the present invention, and the preparation conditions of the whisker are within the preferred range, the obtained PTC tracing belt shows good heating stability; whereas if the amount of the whisker is too small or the amount of the surface coating is weakly low, or if the tetrapod-like zinc oxide whisker coated with the metal film layer is not used, the corresponding PTC tracing belt is weakened in heating performance sharply, and does not have good reproducibility at the same time. In the above Comparative Example 2, the tracing belt is overheated and subjected to wire burning after energization, and the temperature self-regulating effect cannot be achieved. Therefore, there is no data record.

The foregoing is only preferred exemplary implementations of the present invention and is not intended to be limiting of the present invention, and any modifications, equivalent substitutions, improvements and the like within the spirit and principles of the present invention are intended to be embraced by the protection range of the present invention.

Claims

Claims LU505940

1. À manufacturing method for a PTC tracing belt, comprising the following steps: mixing a molten polymer with a surface coated and modified tetrapod-like zinc oxide whisker, and then performing blending; then co-extruding a mixture and two parallel core wires to coat conductive plastic layers between outer layers of the two core wires and the two core wires; and performing cooling and curing formation to obtain the PTC tracing belt, where a mass ratio of the polymer to the surface coated and modified tetrapod-like zinc oxide whisker is 100 to (5-15). A preparation method for the surface coated and modified tetrapod-like zinc oxide whisker includes: depositing a metal film layer on a surface of a tetrapod-like zinc oxide whisker by means of a physical vapor deposition method.

2. The manufacturing method for the PTC tracing belt according to claim 1, wherein the metal film layer deposited on the surface of the surface coated and modified tetrapod-like zinc oxide whisker is a copper film.

3. The manufacturing method for the PTC tracing belt according to claim 2, wherein for the surface coated and modified tetrapod-like zinc oxide whisker, a mass ratio of a zinc oxide whisker to metal copper is 1 to (0.001-0.01).

4. The manufacturing method for the PTC tracing belt according to claim 1, wherein the surface coated and modified tetrapod-like zinc oxide whisker has a diameter of 0.5-5 um and a length of 10-50 um.

5. The manufacturing method for the PTC tracing belt according to claim 1, wherein the polymer is one of polyethylene, polypropylene and polyvinylidene fluoride.

6. The manufacturing method for the PTC tracing belt according to claim 1, before depositing the metal film layer on the surface of the tetrapod-like zinc oxide whisker, further comprising: washing the tetrapod-like zinc oxide whisker with hydrochloric acid.

7. The manufacturing method for the PTC tracing belt according to claim 6, after washing the tetrapod-like zinc oxide whisker with the hydrochloric acid, and before depositing the metal film layer on the surface of the tetrapod-like zinc oxide whisker, further comprising: washing the tetrapod-like zinc oxide whisker in a plasma atmosphere.

8. The manufacturing method for the PTC tracing belt according to claim 1, in a case of mixing a molten polymer with a surface coated and modified tetrapod-like zinc oxide whisker, and then performing blending, further comprising: adding carbon black, wherein a mass ratio of the polymer to the carbon black is 100 to (2-5).

9. A PTC tracing belt manufactured using the manufacturing method for the PTC LU505940 tracing belt according to any one of claims 1 to 8.