Hyperbranched coupling agent, conductive composite material and preparation method and application thereof

Abstract

The invention discloses a hyperbranched coupling agent, a conductive composite material and a preparation method and application of the conductive composite material, and belongs to the technical field of conductive composite materials. The molecular formula of the hyperbranched coupling agent is # imgabs0 #, in the formula, R1 is selected from-CH2OCH2 <-> or-PEG <->, and R2 is selected from-CH3 or-CH3CH2. The hyperbranched coupling agent can be uniformly dispersed in the conductive carbon black, prevents agglomeration of the conductive carbon black, improves the processability of the conductive carbon black, is beneficial to improvement of melt flowability and processability, and further is beneficial to reduction of melt pressure and host current. The conductive composite material containing a carrier, conductive carbon black and the hyperbranched coupling agent has higher melt index, lower filter pressing value and lower surface resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of conductive composite materials, and in particular to a hyperbranched coupling agent, a conductive composite material, and a preparation method and application thereof. Background Art

[0002] Conductive carbon black is a widely used, cost-effective functional filler and the primary component of conductive masterbatch. Carbon black has a low apparent density, a large specific surface area, and weak adhesion to the surface of organic polymer matrices, making it difficult to evenly disperse directly using conventional plastic processing equipment. Failure to properly disperse carbon black in the matrix resin results in poor product performance that fails to meet application requirements.

[0003] Therefore, the selection of appropriate coupling agents, dispersants and other additives is crucial in the production of conductive masterbatches. Commonly used silane coupling agents and titanate coupling agents are difficult to disperse evenly when mixed with carbon black, resulting in their inability to fully exert their coupling and dispersing effects.

[0004] Therefore, how to evenly disperse the coupling agent in carbon black to improve the compatibility between the carrier and carbon black has become a major problem in the production of conductive composite materials.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a hyperbranched coupling agent, a conductive composite material, and a preparation method and application thereof, so as to solve or improve the above technical problems.

[0007] The present invention is achieved in that:

[0008] In a first aspect, the present invention provides a hyperbranched coupling agent having the following molecular formula:

[0009] Wherein, R1 is selected from -CH2OCH2- or -PEG-, and R2 is selected from -CH3 or -CH3CH2.

[0010] In a second aspect, the present invention provides a method for preparing a hyperbranched coupling agent according to the aforementioned embodiment, comprising the following steps: mixing a first monomer and a second monomer under protective atmosphere and reacting the mixture;

[0011] The molar ratio of the first monomer to the second monomer is 1:2 to 1:3; the first monomer includes a silane coupling agent, and the second monomer includes at least one of diethylene glycol and polyethylene glycol;

[0012] The reaction conditions include: an initial reaction temperature of 105° C. to 120° C., and then heating to 160° C. to 180° C. at a heating rate of 8° C. / h to 12° C. / h.

[0013] In a third aspect, the present invention provides an application of a hyperbranched coupling agent as described in the aforementioned embodiment, for example, when the hyperbranched coupling agent is used to prepare a conductive composite material by a twin-screw extrusion granulation method, the filter press value and surface resistance of the conductive composite material are reduced, the melt index of the conductive composite material is increased, and the melt pressure and host current during the preparation process are reduced; wherein the conductive composite material contains conductive carbon black and a carrier.

[0014] In a fourth aspect, the present invention provides a conductive composite material, wherein every 100 parts of raw materials for preparing the conductive composite material include, by weight, 54 to 68 parts of a carrier, 30 to 40 parts of conductive carbon black, and 1 to 4 parts of a hyperbranched coupling agent as described in the above embodiment.

[0015] In an alternative embodiment, the carrier comprises at least one of polyamide 6, PP and PE.

[0016] In an optional embodiment, the preparation raw material further includes 1 to 2 parts of an auxiliary agent; the auxiliary agent includes at least one of a lubricant and an antioxidant.

[0017] In an optional embodiment, the lubricant includes at least one of EVA3 wax and montan wax WE40;

[0018] And / or, the antioxidant includes at least one of antioxidant 1098 and antioxidant 1010 .

[0019] In a fifth aspect, the present invention provides a method for preparing a conductive composite material as described in any one of the aforementioned embodiments, comprising the following steps: mixing the raw materials according to a ratio, followed by twin-screw extrusion, and pelletizing.

[0020] In an optional embodiment, the conductive carbon black is mixed with a hyperbranched coupling agent and an auxiliary agent to obtain a mixture; the mixture and the carrier are fed through different screws in a twin-screw extruder, followed by extrusion and pelletization.

[0021] In an optional embodiment, the extrusion conditions include: a feeding rate of 5 Hz to 7 Hz; the twin-screw extruder is divided into a first temperature zone to a fifth temperature zone, and the temperatures of the first temperature zone to the fifth temperature zone are 210° C. to 230° C., 230° C. to 250° C., 230° C. to 250° C., 230° C. to 250° C., and 230° C. to 250° C., respectively; and the main engine speed is 180 r / min to 250 r / min;

[0022] And / or, the pelletizing conditions include: a pelletizing rate of 5 Hz to 15 Hz.

[0023] The beneficial effects of the present invention include:

[0024] The present invention creatively proposes a hyperbranched coupling agent, which has a certain degree of lubricity, can reduce friction of the polymer matrix, and increase the flow properties of the conductive composite melt. By mixing the hyperbranched coupling agent provided by the present invention with conductive carbon black, the conductive carbon black can be dispersed into stable microparticles with uniform particle size and adsorbed around the microparticles, reducing their surface energy and preventing secondary agglomeration during processing. This ensures that the conductive carbon black is uniformly dispersed in the carrier, improving processability, and simultaneously improving the flow properties (increasing the melt index of the conductive composite and reducing the filter press value) and conductivity (reducing surface resistance) of the composite material, avoiding the problem of increased current and melt pressure in the screw extruder, thereby ensuring both normal production and good quality of the conductive composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a diagram of the filter press experiment results of Example 1. DETAILED DESCRIPTION

[0027] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0028] The hyperbranched coupling agent, conductive composite material, and preparation method and application thereof provided by the present invention are described in detail below.

[0029] The present invention provides a hyperbranched coupling agent, the molecular formula of the hyperbranched coupling agent is as follows:

[0030] Wherein, R1 is selected from -CH2OCH2- or -PEG-, and R2 is selected from -CH3 or -CH3CH2.

[0031] It should be noted that the inventors have found through research that the coupling agent currently commonly used in combination with conductive carbon black is a liquid coupling agent (such as a silane coupling agent or a titanate coupling agent). During the mixing process of the liquid coupling agent with the carbon black, it is easy to cause local agglomeration of the conductive carbon black, making it impossible for the liquid coupling agent to be evenly mixed with the carbon black. The hardness of the conductive carbon black after mixing with the carrier is significantly higher than that of the evenly dispersed conductive carbon black. As a result, during the extrusion granulation process of the conductive composite material, the current and melt pressure of the screw extruder become larger, which not only easily leads to the inability to produce normally, but also even if the conductive composite material is produced, the performance of the conductive composite material is poor.

[0032] The present invention creatively proposes a hyperbranched coupling agent, which can avoid the above-mentioned problems of the liquid coupling agents commonly used in the prior art. For example, the hyperbranched coupling agent provided by the present invention itself has a certain lubricity, which can reduce the friction of the polymer matrix and increase the flowability of the conductive composite melt. By mixing the hyperbranched coupling agent provided by the present invention with conductive carbon black, the conductive carbon black can be dispersed into stable microparticles with uniform particle size and adsorbed around the microparticles, reducing its surface energy, preventing its secondary agglomeration during the processing, and then the special structure slips in the spherical structure between the molecular chains, effectively improving the flowability during the processing, improving the melt index and lubrication performance, ensuring that the conductive carbon black is evenly dispersed in the carrier, improving the processability, and at the same time improving the flowability and conductivity of the composite material, avoiding the problem of increased current and melt pressure of the screw extruder, thereby ensuring both normal production and the good quality of the conductive composite material.

[0033] Accordingly, the present invention provides a method for preparing the hyperbranched coupling agent, comprising the following steps: mixing a first monomer and a second monomer under protective atmosphere and reacting the mixture.

[0034] The protective atmosphere may be, for example, a nitrogen atmosphere and / or an argon atmosphere.

[0035] In some optional embodiments, the molar ratio of the first monomer to the second monomer can be 1:2 to 1:3, such as 1:2, 1:2.2, 1:2.5, 1:2.8 or 1:3, or other values within the range of 1:2 to 1:3. In some typical embodiments, the molar ratio of the first monomer to the second monomer is 1:2.4 to 1:2.5.

[0036] In some optional embodiments, the first monomer may include a silane coupling agent, such as KH-560 silane coupling agent and KH-561 silane coupling agent.

[0037] In some optional embodiments, the second monomer may include at least one of diethylene glycol (DEG) and polyethylene glycol (PEG), wherein the polyethylene glycol is hydroxyl-terminated polyethylene glycol (HO-PEG-OH). In some typical embodiments, the second monomer is diethylene glycol.

[0038] In some optional embodiments, the reaction conditions include: an initial reaction temperature of 105°C to 120°C, followed by heating to 160°C to 180°C at a heating rate of 8°C / h to 12°C / h.

[0039] The initial reaction temperature may be 105°C, 110°C, 115°C, 118°C or 120°C, or other values within the range of 105°C to 120°C.

[0040] The heating rate may be 8°C / h, 9°C / h, 10°C / h, 11°C / h or 12°C / h, or other values within the range of 8°C / h to 12°C / h.

[0041] The temperature after heating may be 160°C, 165°C, 170°C, 175°C or 180°C, or other values within the range of 160°C to 180°C.

[0042] In some typical embodiments, the reaction conditions include: an initial reaction temperature of 110° C., followed by heating to 170° C. at a heating rate of 10° C. / h.

[0043] After the reaction is completed, small molecules with a molecular weight less than 1000 are removed by dialysis.

[0044] In addition, the present invention also provides an application of the hyperbranched coupling agent, for example, using the hyperbranched coupling agent to prepare a conductive composite material containing conductive carbon black and a carrier.

[0045] Specifically, it can be used to reduce the filter pressure value and surface resistance of the conductive composite material, increase the melt index of the conductive composite material, and reduce the melt pressure and host current during the preparation process when the conductive composite material is prepared by a twin-screw extrusion granulation method.

[0046] In addition, the present invention also provides a conductive composite material, wherein every 100 parts of raw materials for preparing the conductive composite material include 54 to 68 parts of a carrier, 30 to 40 parts of conductive carbon black and 1 to 4 parts of the above-mentioned hyperbranched coupling agent in parts by weight.

[0047] For example, the amount of the carrier can be 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts or 68 parts, etc., or other values within the range of 54 to 68 parts.

[0048] The carrier may illustratively include at least one of polyamide 6, PP, and PE.

[0049] The amount of conductive carbon black can be 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts or 40 parts, etc., or other values within the range of 30 to 40 parts.

[0050] The amount of the hyperbranched coupling agent can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts or 4 parts, etc., or other values within the range of 1 part to 4 parts.

[0051] It should be noted that if the amount of hyperbranched coupling agent used is too much, it will easily lead to a serious reduction in the mechanical properties of the product.

[0052] Furthermore, the raw materials for preparation may further include an auxiliary agent. The amount of the auxiliary agent used may be 1 to 2 parts, such as 1 part, 1.5 parts or 2 parts, or other values within the range of 1 to 2 parts.

[0053] The auxiliary agent may exemplarily include at least one of a lubricant and an antioxidant. The lubricant may exemplarily include at least one of EVA3 wax and montan wax WE40. The antioxidant may exemplarily include at least one of antioxidant 1098 and antioxidant 1010.

[0054] In some embodiments, the melt index of the conductive composite material is not less than 4.2 g / 10 min; in some embodiments, the filter press value of the conductive composite material is not more than 0.25 g; in some embodiments, the surface resistance of the conductive composite material is not more than 6.3×10 3 Ω.

[0055] In addition, the present invention also provides a method for preparing the conductive composite material, comprising the following steps: mixing the raw materials according to a proportion, then performing twin-screw extrusion, and pelletizing.

[0056] Specifically, the conductive carbon black and the hyperbranched coupling agent are fed into the same screw, and the carrier is fed into another screw.

[0057] When the raw materials for preparing the conductive composite material include conductive carbon black, a hyperbranched coupling agent, a carrier and an auxiliary agent, the preparation method of the conductive composite material includes: mixing the conductive carbon black with the hyperbranched coupling agent and the auxiliary agent to obtain a mixture; feeding the mixture and the carrier through different screws in a twin-screw extruder, followed by extrusion and pelletizing.

[0058] In some optional embodiments, the extrusion conditions include: a feeding rate of 5Hz to 7Hz; the twin-screw extruder is divided into first to fifth temperature zones, and the temperatures of the first to fifth temperature zones are 210℃ to 230℃, 230℃ to 250℃, 230℃ to 250℃, 230℃ to 250℃ and 230℃ to 250℃ respectively; the main engine speed is 180r / min to 250r / min.

[0059] The feeding speed may be 5 Hz, 5.5 Hz, 6 Hz, 6.5 Hz or 7 Hz, or other values within the range of 5 Hz to 7 Hz.

[0060] If the feeding speed is too slow, there will be insufficient material in the screw barrel, low shear force, and it will be unfavorable for the mixing and dispersion of the materials; if the feeding speed is too fast, it will be unfavorable for the plasticization of the resin.

[0061] The temperature of the first temperature zone may be 210°C, 215°C, 220°C, 225°C or 230°C, or other values within the range of 210°C to 230°C.

[0062] If the temperature in the first temperature zone is too low, it will be detrimental to the plasticization of the resin in the later stage; if the temperature in the first temperature zone is too high, it will be detrimental to the smooth feeding of the material and will easily cause bridging.

[0063] The temperatures of the second temperature zone, the third temperature zone, the fourth temperature zone and the fifth temperature zone can independently be 230°C, 235°C, 240°C, 245°C or 250°C, etc., or other values within the range of 230°C to 250°C.

[0064] The main engine speed can be 180r / min, 190r / min, 200r / min, 210r / min, 220r / min, 230r / min, 240r / min or 250r / min, or other values within the range of 180r / min to 250r / min.

[0065] In some optional embodiments, the pelletizing conditions include: a pelletizing rate of 5 Hz to 15 Hz, such as 5 Hz, 7 Hz, 10 Hz, 12 Hz or 15 Hz, etc., or other values within the range of 5 Hz to 15 Hz.

[0066] In some embodiments, the melt pressure during the preparation of the conductive composite material does not exceed 1.2 MPa, and the main current does not exceed 7.3A.

[0067] In some typical embodiments, the conductive composite material simultaneously satisfies the requirements of melt index not less than 4.2 g / 10 min, filter pressure value not more than 0.25 g, surface resistance not more than 6.3×10 3Ω; and the melt pressure during the preparation of the conductive composite material does not exceed 1.2 MPa and the main current does not exceed 7.3 A.

[0068] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0069] Example 1

[0070] This embodiment provides a hyperbranched coupling agent, the molecular formula of which is as follows:

[0071]

[0072] The preparation method of the hyperbranched coupling agent includes placing 44g of diethylene glycol and 40g of KH-560 into a 250mL three-necked flask equipped with a stirrer, thermometer, and reflux condenser. Under nitrogen protection, the initial reaction temperature is 110°C, then the temperature is increased to 170°C at a rate of 10°C / h, and small molecules with a molecular weight below 1000 are removed by dialysis.

[0073] Example 2

[0074] This example differs from Example 1 in that the first monomer used in the hyperbranched coupling agent is KH-561 silane coupling agent. 44 g of diethylene glycol and 46 g of KH-561 were placed in a 250 mL three-necked flask equipped with a stirrer, thermometer, and reflux condenser. Under nitrogen, the initial reaction temperature was 120°C, then increased to 180°C at a rate of 10°C / h. Dialysis was then performed to remove small molecules with a molecular weight below 1000.

[0075] Example 3

[0076] This example differs from Example 1 in that the second monomer used in the hyperbranched coupling agent is hydroxyl-terminated polyethylene glycol (HO-PEG-OH) with a number average molecular weight of 400. 50 g of HO-PEG-OH and 12 g of KH-561 were placed in a 250 mL three-necked flask equipped with a stirrer, thermometer, and reflux condenser. Under nitrogen protection, the initial reaction temperature was 120°C, then increased to 180°C at a rate of 8°C / h. Small molecules with a molecular weight below 1000 were then removed by dialysis.

[0077] Example 4

[0078] This embodiment differs from Example 1 in that the method for preparing a hyperbranched coupling agent provided in this embodiment comprises: placing KH-560 and diethylene glycol at a molar ratio of 1:2 into a 250 mL three-necked flask equipped with a stirrer, thermometer, and reflux condenser. Under nitrogen protection, the initial reaction temperature is 120°C, then raised to 160°C at a rate of 8°C / h. Small molecules with a molecular weight below 1000 are then removed by dialysis.

[0079] Example 5

[0080] This embodiment differs from Example 1 in that the method for preparing a hyperbranched coupling agent provided in this embodiment comprises: placing KH-560 and diethylene glycol at a molar ratio of 1:3 into a 250 mL three-necked flask equipped with a stirrer, thermometer, and reflux condenser. Under nitrogen protection, the initial reaction temperature is 115°C, then raised to 170°C at a rate of 12°C / h. Small molecules with a molecular weight below 1000 are then removed by dialysis.

[0081] Example 6

[0082] This embodiment provides a conductive composite material, wherein the raw materials for preparing the conductive composite material are composed of 64 parts of polyamide 6, 33 parts of conductive carbon black, 1 part of EVA3 wax, 1.5 parts of the hyperbranched coupling agent provided in Example 1, and 0.5 parts of antioxidant 1098.

[0083] The preparation method of the conductive composite material comprises:

[0084] S1: Drying polyamide 6 and conductive carbon black separately;

[0085] S2: Add the dried conductive carbon black, EVA3 wax, hyperbranched coupling agent and antioxidant into a high-pressure mixer in proportion, and stir at 100°C and 150 rpm for 30 minutes to obtain a mixture;

[0086] S3: Add the dried polyamide 6 into a high-speed mixer according to the proportion and stir at 100 r / min for 5 minutes;

[0087] S4: The mixed materials from steps S2 and S3 were transported to the feed hopper of a twin-screw extruder using an elevator and fed at a feeding rate of 6 Hz. The temperatures of the five temperature zones of the twin-screw extruder were set to 220°C, 240°C, 245°C, 240°C, and 240°C, respectively. The main engine speed was 200 r / min. The extruded materials were pelletized in a water tank at a rate of 6 Hz to obtain a conductive composite material.

[0088] Example 7

[0089] The difference between this embodiment and embodiment 6 is that the raw materials for preparing the conductive composite material are composed of 63.5 parts of polyamide 6, 32.5 parts of conductive carbon black, 1 part of EVA3 wax, 2.5 parts of the hyperbranched coupling agent provided in embodiment 1, and 0.5 parts of antioxidant 1098.

[0090] Example 8

[0091] The difference between this embodiment and embodiment 6 is that the raw materials for preparing the conductive composite material are composed of 64.5 parts of polyamide 6, 33 parts of conductive carbon black, 1 part of EVA3 wax, 1 part of the hyperbranched coupling agent provided in embodiment 1, and 0.5 part of antioxidant 1098.

[0092] Example 9

[0093] The difference between this embodiment and embodiment 6 is that the raw materials for preparing the conductive composite material are composed of 67.5 parts of polyamide 6, 30 parts of conductive carbon black, 1 part of EVA3 wax, 1 part of the hyperbranched coupling agent provided in embodiment 1, and 0.5 parts of antioxidant 1098.

[0094] Example 10

[0095] The difference between this embodiment and embodiment 6 is that the raw materials for preparing the conductive composite material are composed of 61.5 parts of polyamide 6, 35 parts of conductive carbon black, 1 part of EVA3 wax, 2 parts of the hyperbranched coupling agent provided in embodiment 1, and 0.5 parts of antioxidant 1098.

[0096] Example 11

[0097] The difference between this embodiment and embodiment 6 is that the raw materials for preparing the conductive composite material are composed of 60.5 parts of polyamide 6, 35 parts of conductive carbon black, 1 part of EVA3 wax, 3 parts of the hyperbranched coupling agent provided in embodiment 1, and 0.5 parts of antioxidant 1098.

[0098] Example 12

[0099] The difference between this embodiment and embodiment 6 is that the raw materials for preparing the conductive composite material are composed of 54.5 parts of polyamide 6, 40 parts of conductive carbon black, 1 part of EVA3 wax, 4 parts of the hyperbranched coupling agent provided in embodiment 1, and 0.5 parts of antioxidant 1098.

[0100] Example 13

[0101] The difference between this embodiment and embodiment 6 is that the extrusion conditions include: the feeding rate is 5 Hz; the temperatures of the first to fifth temperature zones of the twin-screw extruder are 210°C, 235°C, 245°C, 240°C and 240°C respectively; the main engine speed is 180 r / min; and the pelletizing rate is 5 Hz.

[0102] Example 14

[0103] The difference between this embodiment and embodiment 6 is that the extrusion conditions include: the feeding rate is 7 Hz; the temperatures of the first temperature zone to the fifth temperature zone of the twin-screw extruder are 230°C, 240°C, 250°C, 250°C and 245°C respectively; the main engine speed is 240 r / min; and the pelletizing rate is 15 Hz.

[0104] Example 15

[0105] The difference between this embodiment and embodiment 6 is that the hyperbranched coupling agent used is the hyperbranched coupling agent provided in embodiment 2.

[0106] Example 16

[0107] The difference between this embodiment and embodiment 6 is that the hyperbranched coupling agent used is the hyperbranched coupling agent provided in embodiment 3.

[0108] Comparative Example 1

[0109] The difference between this comparative example and Example 6 is that the hyperbranched coupling agent is directly replaced by an equal amount of KH-560.

[0110] Comparative Example 2

[0111] The difference between this comparative example and Example 6 is that the hyperbranched coupling agent is directly replaced by an equal amount of titanate coupling agent TC-9.

[0112] Comparative Example 3

[0113] The difference between this comparative example and Example 7 is that the hyperbranched coupling agent is directly replaced by an equal amount of KH-560.

[0114] Comparative Example 4

[0115] The difference between this comparative example and Example 6 is that the raw materials for preparing the conductive composite material are composed of 64.5 parts of polyamide 6, 34 parts of conductive carbon black, 1 part of EVA3 wax and 0.5 part of antioxidant 1098.

[0116] That is, in this comparative example, the raw materials for preparing the conductive composite material do not contain any coupling agent.

[0117] Comparative Example 5

[0118] The difference between this comparative example and Example 6 is that the raw materials for preparing the conductive composite material consist of 64 parts of polyamide 6, 34 parts of conductive carbon black, 1 part of EVA3 wax, 0.5 parts of the hyperbranched coupling agent provided in Example 1, and 0.5 parts of antioxidant 1098.

[0119] That is, the amount of hyperbranched coupling agent used is reduced, and the amount of conductive carbon black used is increased.

[0120] Comparative Example 6

[0121] The difference between this comparative example and Example 6 is that the raw materials for preparing the conductive composite material are composed of 61 parts of polyamide 6, 33 parts of conductive carbon black, 1 part of EVA3 wax, 4.5 parts of the hyperbranched coupling agent provided in Example 1, and 0.5 parts of antioxidant 1098.

[0122] That is, the amount of conductive carbon black used is reduced, and the amount of hyperbranched coupling agent used is increased.

[0123] Comparative Example 7

[0124] The difference between this comparative example and Example 6 is that the raw materials for preparing the conductive composite material are composed of 72 parts of polyamide 6, 25 parts of conductive carbon black, 1 part of EVA3 wax, 1.5 parts of the hyperbranched coupling agent provided in Example 1, and 0.5 parts of antioxidant 1098.

[0125] That is, the amount of conductive carbon black used is reduced and the amount of carrier used is increased.

[0126] Comparative Example 8

[0127] The difference between this comparative example and Example 6 is that the raw materials for preparing the conductive composite material are composed of 52 parts of polyamide 6, 45 parts of conductive carbon black, 1 part of EVA3 wax, 1.5 parts of the hyperbranched coupling agent provided in Example 1, and 0.5 parts of antioxidant 1098.

[0128] That is, the amount of hyperbranched coupling agent used increases and the amount of carrier used decreases.

[0129] Comparative Example 9

[0130] The difference between this comparative example and Example 6 is that the feeding speed is 4 Hz.

[0131] Comparative Example 10

[0132] The difference between this comparative example and Example 6 is that the feeding speed is 8 Hz.

[0133] Comparative Example 11

[0134] The difference between this comparative example and Example 6 is that the temperature of the first temperature zone is 240°C.

[0135] Test example

[0136] The process performance and conductivity of the conductive composite materials prepared in Examples 6 to 16 and Comparative Examples 1 to 11 were tested, and the results are shown in Tables 1 and Figure 1 The test items and methods are as follows:

[0137] ①. Melt index test standard is ASTM D1238, test conditions are 260℃, 2.16kg, unit is g / 10min.

[0138] ②、Filter pressure value test standard refers to BS EN13900-5:2005.

[0139] A 1000-mesh filter was used and the filter press tester temperature was set at 280°C. 500 g of the prepared conductive composite material was added to the filter press tester. The starting pressure and maximum pressure were recorded, and the filter pressure value (FPV) was calculated using the following formula:

[0140] FPV=(P max -P s ) / m c , where FPV is the filter pressure value, in bar / g; P s is the starting pressure, in bar; P max is the maximum pressure, the unit is bar; m c is the dosage of conductive carbon black used in the test, in g.

[0141] ③. Surface resistance is tested using a surface resistance tester. The conductive composite material is dried and measured directly after drying. The unit is Ω.

[0142] ④. Melt pressure: parameter in the material preparation process, unit is MPa.

[0143] ⑤. Main machine current: parameter in the material preparation process, unit is A.

[0144] Table 1 Test results

[0145]

[0146]

[0147] As can be seen from Table 1, the hyperbranched coupling agent provided by the embodiment of the present invention is applied to the conductive composite material containing conductive carbon black, which is beneficial to improving the melt fluidity and processing performance, reducing the melt pressure and host current, and improving the conductive properties of the conductive composite material.

[0148] From the comparison between Example 6 and Example 16, it can be seen that when the hyperbranched coupling agent prepared by combining KH-560 and diethylene glycol is used to prepare a conductive composite material containing conductive carbon black, it has better effect than the hyperbranched coupling agent prepared by combining other silane coupling agents and a second monomer.

[0149] By comparing Example 6 with Comparative Examples 1-2, and Example 7 with Comparative Example 3, it can be seen that the hyperbranched coupling agent provided by the above examples has significantly better effects than conventional coupling agents when used to prepare conductive composite materials containing conductive carbon black.

[0150] By comparing Example 6 with Comparative Example 4, it can be seen that without the coupling agent, the conductive composite material cannot be effectively prepared.

[0151] By comparing Example 6 with Comparative Examples 5 to 8 and Comparative Examples 9 to 11, it can be seen that if the material ratio of the conductive composite material or the preparation conditions are inappropriate, the overall performance of the conductive composite material will also deteriorate.

[0152] In summary, the hyperbranched coupling agent with a specific molecular formula proposed in the present invention can be evenly dispersed in conductive carbon black, preventing agglomeration of the conductive carbon black and improving its processing properties. This helps improve melt flowability and processing performance, thereby reducing melt pressure and host current. Conductive composite materials containing a carrier, conductive carbon black, and the hyperbranched coupling agent exhibit high melt index, low filter press value, and low surface resistivity.

[0153] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A hyperbranched coupling agent, characterized in that The molecular formula of the hyperbranched coupling agent is as follows: Wherein, R1 is selected from -CH2OCH2- or -PEG-, and R2 is selected from -CH3 or -CH3CH2.

2. A method for preparing a hyperbranched coupling agent according to claim 1, characterized in that: The following steps are involved: Under protective atmosphere conditions, the first monomer and the second monomer are mixed and reacted; The molar ratio of the first monomer to the second monomer is 1:2 to 1:3; the first monomer includes a silane coupling agent, and the second monomer includes at least one of diethylene glycol and polyethylene glycol; The reaction conditions include: an initial reaction temperature of 105° C. to 120° C., and then heating to 160° C. to 180° C. at a heating rate of 8° C. / h to 12° C. / h.

3. A use of the hyperbranched coupling agent according to claim 1, characterized in that: The hyperbranched coupling agent is used to reduce the filter pressure value and surface resistance of the conductive composite material, increase the melt index of the conductive composite material, and reduce the melt pressure and host current during the preparation process when the conductive composite material is prepared by a twin-screw extrusion granulation method; wherein the conductive composite material contains conductive carbon black and a carrier.

4. A conductive composite material, characterized in that In parts by weight, every 100 parts of raw materials for preparing the conductive composite material comprises 54 to 68 parts of a carrier, 30 to 40 parts of conductive carbon black, and 1 to 4 parts of the hyperbranched coupling agent according to claim 1.

5. The conductive composite material according to claim 4, characterized in that The carrier includes at least one of polyamide 6, PP and PE.

6. The conductive composite material according to claim 4 or 5, characterized in that: The preparation raw materials further include 1 to 2 parts of auxiliary agents; the auxiliary agents include at least one of a lubricant and an antioxidant.

7. The conductive composite material according to claim 6, characterized in that The lubricant includes at least one of EVA3 wax and montan wax WE40; And / or, the antioxidant includes at least one of antioxidant 1098 and antioxidant 1010.

8. A method for preparing the conductive composite material according to any one of claims 4 to 7, characterized in that: The method comprises the following steps: mixing the prepared raw materials according to a proportion, then performing twin-screw extrusion, and pelletizing.

9. The preparation method according to claim 8, characterized in that Conductive carbon black is mixed with a hyperbranched coupling agent and an auxiliary agent to obtain a mixture; the mixture and a carrier are fed through different screws in a twin-screw extruder, and then extruded and pelletized.

10. The preparation method according to claim 8 or 9, characterized in that: Extrusion conditions include: a feeding rate of 5 Hz to 7 Hz; the twin-screw extruder is divided into first to fifth temperature zones, and the temperatures of the first to fifth temperature zones are 210° C. to 230° C., 230° C. to 250° C., 230° C. to 250° C., 230° C. to 250° C., and 230° C. to 250° C., respectively; and the main engine speed is 180 r / min to 250 r / min; And / or, the pelletizing conditions include: a pelletizing rate of 5 Hz to 15 Hz.

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