High metal-adhesion nylon 12 modified material, and preparation method and application thereof

Abstract

The application discloses a high-metal-adhesion nylon 12 modified material and a preparation method and application thereof. The modified material comprises the following components in parts by weight: 55-90 parts of nylon 12, 10-40 parts of in-situ grafting adhesion master batch and 0-2 parts of processing aid; wherein the in-situ grafting adhesion master batch comprises the following components in parts by weight: 50-85 parts of nylon 12, 10-40 parts of adhesive resin, 0.4-4 parts of grafting monomer, 0.1-0.4 parts of initiator and 0-2 parts of processing aid. The nylon 12 modified material can effectively improve the adhesion between nylon 12 and metal materials without metal surface treatment or adhesion layer, and can maintain good adhesion force retention rate after extreme hot and humid aging.

Description

Technical Field

[0001] This invention relates to a modified nylon 12 material, and more particularly to a modified nylon 12 material with high metal adhesion, its preparation method, and its application. Background Technology

[0002] In typical applications such as copper core high-voltage electrical busbars, Nylon 12 is very suitable as an insulation layer material due to its excellent insulation, processing, wear resistance and low temperature performance. In addition to the basic material performance requirements, high requirements are also placed on the adhesion performance between nylon resin and metal surface. On the one hand, good and durable adhesion is required, and on the other hand, no glue residue is required when removing the skin at the end.

[0003] Traditional processes often employ metal surface treatments or adhesive layers, such as grinding to remove oxide layers or using corrosive agents like sulfuric acid to increase surface roughness, or using adhesives like epoxy resins or cyanoacrylates. Both methods suffer from complex processes, high equipment requirements, and significantly increased costs. The key to achieving low-cost, efficient, and durable metal bonding lies in how to achieve primerless bonding through polymer blending and modification. Summary of the Invention

[0004] To address the above technical problems, this invention proposes a modified nylon 12 material with high metal adhesion, its preparation method, and its application. The modified nylon 12 material of this invention can effectively improve the adhesion between nylon 12 and metal materials without the need for metal surface treatment or adhesive layers, and maintains good adhesion retention even after extreme humid and hot aging.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A modified nylon 12 material with high metal adhesion, wherein the modified material comprises, by weight, the following components:

[0007] Nylon 12, 55-90 parts, preferably 60-80 parts.

[0008] In-situ grafting masterbatch, 10-40 parts, preferably 20-30 parts.

[0009] Processing aid, 0-2 parts, preferably 1-2 parts;

[0010] The in-situ grafting masterbatch comprises, by weight, the following components:

[0011] Nylon 12, 50-85 parts, preferably 60-80 parts.

[0012] Adhesive resin, 10-40 parts, preferably 20-30 parts.

[0013] Graft monomer, 0.4-4 parts, preferably 1-3 parts.

[0014] Initiator, 0.1-0.4 parts, preferably 0.2-0.3 parts.

[0015] Processing aid, 0-2 parts, preferably 1-2 parts.

[0016] As a preferred example of the present invention, in the modified material and the in-situ grafting masterbatch, the content of terminal amino groups of nylon 12 is 5-30 mmol / kg, preferably 5-20 mmol / kg, the molar ratio of terminal amino groups to terminal carboxyl groups is 1:(1-9), preferably 1:(2-9), and the number average molecular weight is 30,000-50,000, preferably 32,000-40,000.

[0017] As a preferred example of the present invention, the adhesive resin is at least one of ethylene-acrylic acid copolymer (EAA), ethylene-butyl acrylate (EBA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-vinyl acetate copolymer (EVA), and ethylene-methyl methacrylate copolymer (EMMA);

[0018] Preferably, the adhesive resin is one or more of ethylene-acrylic acid copolymers and ethylene-methyl acrylate copolymers with a density of 0.90-0.95 g / cm3 and a melt flow index (MFR) of 0.1-10 g / 10 min under test conditions of 190°C and 2.16 kg.

[0019] As a preferred example of the present invention, the grafting monomer is at least one of maleic anhydride (MAH) and glycidyl methacrylate (GMA), or a compound thereof with at least one of styrene (St), divinylbenzene (DVB), bismaleimide (BMI), and triallyl triisocyanurate (TAIC), preferably at least one of maleic anhydride and glycidyl methacrylate.

[0020] As a preferred example of the present invention, the initiator is at least one selected from benzoyl peroxide (BPO), dicumyl peroxide (DCP), 2,5-dimethyl-2,5-dibis(tert-butylperoxy)ethane (DHBP), and 2,3-dimethyl-2,3-diphenylbutane (DMDPB).

[0021] As a preferred example of the present invention, the processing aid is a lubricant and / or an antioxidant;

[0022] Preferably, the lubricant is selected from at least one of stearic acid complex esters, montmorillonite wax, metallic soaps, polyethylene waxes, low molecular weight esters, and amide waxes;

[0023] Preferably, the antioxidant is a hindered phenolic antioxidant and / or a phosphite antioxidant, and more preferably, the two are compounded in a mass ratio of 1:(0.5-2.0). The hindered phenolic antioxidant is selected from one or more of 1010, 1098, and 245; the phosphite antioxidant is selected from one or more of 168, 626, and 686.

[0024] The present invention also provides a method for preparing a high metal adhesion nylon 12 modified material as described above, comprising mixing nylon 12, in-situ grafting masterbatch, and optionally processing aids evenly, extruding, granulating, and obtaining the modified material.

[0025] Preferably, during the extrusion process, the extrusion temperature is 210-280℃, more preferably 240-250℃; the screw speed is 200-800rpm, more preferably 300-500rpm;

[0026] Preferably, the extrusion process is carried out in a twin-screw extruder with a screw length-to-diameter ratio of (36-50):1.

[0027] As a preferred example of the present invention, the method for preparing the in-situ grafting masterbatch includes the following steps:

[0028] 1) After dissolving the grafted monomer and initiator in a solvent, the adhesive resin is heated to 60-80°C and mixed with the above-mentioned dissolved substances and optionally processing aids, and stirred to obtain a premix.

[0029] 2) After mixing the premix with nylon 12, the mixture is extruded and granulated to obtain in-situ grafting masterbatch;

[0030] Preferably, in step 1), the mixing speed of the premix is ​​300-600 rpm, the mixing time is 6-10 min, and the mixing temperature is controlled below 100℃;

[0031] Preferably, in step 2), the extrusion temperature is 210-280℃, more preferably 240-260℃; and the screw speed is 200-800 rpm, more preferably 300-500 rpm.

[0032] Preferably, the extrusion process in step 2) is carried out in a twin-screw extruder with a screw length-to-diameter ratio of (36-50):1;

[0033] Preferably, the solvent is selected from one or more of acetone, ethyl acetate, methanol, ethanol, and isopropanol.

[0034] The present invention also provides an application of the high metal adhesion nylon 12 modified material as described above or the high metal adhesion nylon 12 modified material prepared by the method described above in the fields of new energy vehicles and energy storage, especially in the application of copper core high voltage electrical busbars.

[0035] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0036] (1) The present invention adopts the preparation method of in-situ grafting adhesive masterbatch, which can carry out in-situ reaction between nylon 12 resin and polar monomer while grafting polar monomer onto adhesive resin, thereby effectively improving the grafting efficiency of polar monomer and the bonding effect between nylon 12 resin and adhesive resin.

[0037] (2) The present invention selects nylon 12 with a low ratio of low-end amino and low-end amino-carboxyl as masterbatch raw material. After grafting reaction with polar monomers, a lot of polar groups remain, which can be combined with adhesive resin to further improve the adhesion to metal surfaces. Detailed Implementation

[0038] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0039] The information on the raw materials used in the experimental examples and comparative examples is shown below.

[0040] Nylon 12-A, with terminal amino group content of 12 mmol / kg, a molar ratio of terminal amino to terminal carboxyl groups of 1:4, and a molecular weight of 38642, is prepared as follows:

[0041] 100,000 g of dodecyl lactam monomer, 175 g of capping agent (hexanoic acid), 20 g of catalyst (sodium hypophosphite), 500 g of antioxidant 1098: antioxidant 168 (1:1 ratio), and 15,000 g of water were added to the polymerization reactor. The air in the reactor was replaced with nitrogen nine times. The temperature was raised to 240°C and maintained at that temperature and pressure for 2 hours. After slowly depressurizing to atmospheric pressure, the pressure was evacuated to -0.095 MPa and polycondensation was continued for 2 hours. Nylon 12-A was then discharged.

[0042] Nylon 12-B, with terminal amino group content of 16 mmol / kg, a molar ratio of terminal amino to terminal carboxyl groups of 1:2, and a molecular weight of 44211, is prepared as follows:

[0043] 100,000g of dodecyl lactam monomer, 88g of capping agent (hexanoic acid), 10g of catalyst (sodium hypophosphite), 500g of antioxidant 1098: antioxidant 168 (1:1 ratio), and 10,000g of water were added to the polymerization reactor. The air in the reactor was replaced with nitrogen nine times. The temperature was raised to 260℃ and maintained at that temperature and pressure for 2 hours. After slowly depressurizing to atmospheric pressure, the pressure was evacuated to -0.095 MPa and polycondensation was continued for 3 hours. Nylon 12-B was then discharged.

[0044] Nylon 12-C, with terminal amino group content of 7 mmol / kg, a molar ratio of terminal amino to terminal carboxyl groups of 1:9, and a molecular weight of 36574, is prepared as follows:

[0045] 100,000 g of dodecyl lactam monomer, 200 g of capping agent (hexanoic acid), 22 g of catalyst (sodium hypophosphite), 500 g of antioxidant 1098: antioxidant 168 (1:1 ratio), and 15,000 g of water were added to the polymerization reactor. The air in the reactor was replaced with nitrogen nine times. The temperature was raised to 240°C and maintained at that temperature and pressure for 2 hours. After slowly depressurizing to atmospheric pressure, the pressure was evacuated to -0.095 MPa and polycondensation was continued for 2 hours. Nylon 12-C was then discharged.

[0046] Nylon 12-D, with terminal amino group content of 25 mmol / kg, a molar ratio of terminal amino to terminal carboxyl groups of 1:1, and a molecular weight of 40569, is prepared as follows:

[0047] 100,000g of dodecanoic acid monomer, 500g of antioxidant 1098: antioxidant 168 (1:1 ratio), and 15,000g of water were added to the polymerization reactor. The air in the reactor was replaced with nitrogen nine times. The temperature was raised to 240℃ and maintained at that temperature and pressure for 2 hours. After slowly depressurizing to atmospheric pressure, the pressure was evacuated to -0.095 MPa and polycondensation was continued for 3 hours. Nylon 12-D was then discharged.

[0048] Nylon 12-E, with terminal amino group content of 42 mmol / kg, a molar ratio of terminal amino to terminal carboxyl groups of 3:1, and a molecular weight of 37856, is prepared as follows:

[0049] 100,000g of dodecyl lactam monomer, 88g of n-hexylamine as end-capping agent, 10g of sodium hypophosphite catalyst, 500g of antioxidant 1098: antioxidant 168 (1:1 ratio), and 15,000g of water were added to the polymerization reactor. The air in the reactor was replaced with nitrogen nine times. The temperature was raised to 240℃ and maintained at that temperature and pressure for 2 hours. After slowly depressurizing to atmospheric pressure, the pressure was evacuated to -0.095 MPa and polycondensation was continued for 2 hours. Nylon 12-E was then discharged.

[0050] EAA resin: Grade 2002, density 0.930 g / cm3, melt flow index (MFR) 10 g / 10 min (190℃ + 2.16 kg), Dow Chemical;

[0051] EBA resin: Grade AC3427, density 0.926 g / cm3, melt flow index (MFR) 4.0 g / 10 min (190℃ + 2.16 kg), Dow Chemical;

[0052] EMA resin: Grade AC1125, density 0.944 g / cm3, melt flow index (MFR) 0.5 g / 10 min (190℃ + 2.16 kg), Dow Chemical;

[0053] EPDM resin: Grade 3092M, density 0.860 g / cm3, Mooney viscosity (ML 1+4, 125℃) 61 MU, Mitsui Chemicals;

[0054] POE resin, grade 3040, density 0.920 g / cm3, melt flow index (MFR) 6.0 g / 10 min (190℃ + 2.16 kg), ExxonMobil;

[0055] Graft adhesive AX8900: EMA grafted with GMA, density 0.940 g / cm3, melt index (MFR) 6.0 g / 10 min (190℃ + 2.16 kg), SK Chemicals;

[0056] Maleic anhydride (MAH): Shanghai Aladdin;

[0057] Glycidyl methacrylate (GMA): Shanghai Aladdin;

[0058] Benzoyl peroxide (BPO): Shanghai Aladdin;

[0059] Dicumyl peroxide (DCP): Shanghai Aladdin;

[0060] Pentaerythritol stearate: Imuryl;

[0061] E-wax lignite wax, Clariant;

[0062] Polyethylene wax AC 540, Honeywell;

[0063] Antioxidant 1010: Hindered phenolic antioxidant, Rianon;

[0064] Antioxidant 1098: Hindered phenolic antioxidant, Leylan;

[0065] Antioxidant 245: Hindered phenolic antioxidant, Rianon;

[0066] Antioxidant 168: Phosphite antioxidant, Leylan;

[0067] Antioxidant 626: Phosphite antioxidant, Rianon;

[0068] Antioxidant 686: Phosphite antioxidant, Rianon.

[0069] The present invention will be further illustrated below with specific embodiments. The following embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments.

[0070] The following is a description of specific embodiments. Unless otherwise specified, all raw materials are in parts by weight.

[0071] [Preparation Example 1]

[0072] In-situ grafting masterbatch A was prepared according to the following method:

[0073] (1) Dissolve 3 parts MAH and 0.3 parts DCP in 10 parts acetone solvent and stir at room temperature for 0.5 h to prepare a solution;

[0074] (2) Stir 30 parts of EAA resin at high speed (400 rpm) using a high-speed mixer to raise the temperature to about 60°C, add the solution obtained in step (1) and 1 part of pentaerythritol stearate, mix at 100°C or below for 8 minutes to obtain a premix.

[0075] (3) The premixed material and 65.7 parts of Nylon 12-A were mixed evenly by a low-speed mixer and then fed into the main feed port of a twin-screw extruder for extrusion granulation. The length-to-diameter ratio of the twin-screw extruder was 40:1, the extrusion temperature was 240-250℃, and the screw speed was 400rpm, to obtain in-situ grafting masterbatch A.

[0076] [Preparation Example 2]

[0077] In-situ grafting masterbatch B was prepared according to the following method:

[0078] (1) Dissolve 2 parts MAH and 0.2 parts DCP in 8 parts ethyl acetate solvent and stir at room temperature for 0.5 h to prepare a solution;

[0079] (2) Stir 20 parts of EBA resin at high speed (300 rpm) using a high-speed mixer to raise the temperature to about 60°C, then add the solution obtained in step (1) and 1 part of E wax lignite wax, mix at 100°C or below for 6 minutes to obtain a premix.

[0080] (3) The premixed material and 75.8 parts of Nylon 12-B were mixed evenly by a low-speed mixer and then fed into the main feed port of a twin-screw extruder for extrusion granulation. The length-to-diameter ratio of the twin-screw extruder was 40:1, the extrusion temperature was 230-240℃, and the screw speed was 400rpm, to obtain in-situ grafting masterbatch B.

[0081] [Preparation Example 3]

[0082] In-situ grafting masterbatch C was prepared according to the following method:

[0083] (1) Dissolve 3 parts GMA and 0.3 parts BPO in 10 parts isopropanol solvent and stir at room temperature for 0.5 h to prepare a solution;

[0084] (2) Stir 30 parts of EMA resin at high speed (400 rpm) using a high-speed mixer to raise the temperature to about 60°C, then add the solution obtained in step (1) and 2 parts of polyethylene wax, mix at 100°C or below for 8 minutes to obtain a premix.

[0085] (3) The premixed material and 64.7 parts of Nylon 12-C were uniformly mixed by a low-speed mixer and then fed into the main feed port of a twin-screw extruder for extrusion granulation. The length-to-diameter ratio of the twin-screw extruder was 40:1, the extrusion temperature was 250-260℃, and the screw speed was 500rpm, to obtain in-situ grafting masterbatch C.

[0086]

Preparation Example 4

[0087] In-situ grafting masterbatch D was prepared according to the following method:

[0088] (1) Dissolve 3 parts GMA and 0.2 parts BPO in 10 parts acetone solvent and stir at room temperature for 0.5 h to prepare a solution;

[0089] (2) Stir 40 parts of EAA resin at high speed (300 rpm) using a high-speed mixer to raise the temperature to about 60°C, then add the solution obtained in step (1) and 2 parts of pentaerythritol stearate, mix at 100°C or below for 8 minutes to obtain a premix.

[0090] (3) The premixed material and 55.8 parts of Nylon 12-D were mixed evenly by a low-speed mixer and then fed into the main feed port of a twin-screw extruder for extrusion granulation. The length-to-diameter ratio of the twin-screw extruder was 40:1, the extrusion temperature was 240-250℃, and the screw speed was 500rpm, thus obtaining in-situ grafting masterbatch D.

[0091]

Preparation Example 5

[0092] In-situ grafting masterbatch E was prepared according to the following method:

[0093] (1) Dissolve 1 part MAH and 0.3 parts DCP in 8 parts methanol solvent and stir at room temperature for 0.5 h to prepare a solution;

[0094] (2) Stir 10 parts of EMA resin at high speed (400 rpm) using a high-speed mixer to raise the temperature to about 60°C, then add the solution obtained in step (1) and 1 part of E wax lignite wax, mix at 100°C or below for 8 minutes to obtain a premix.

[0095] (3) The premixed material and 84.7 parts of Nylon 12-B were mixed evenly by a low-speed mixer and then fed into the main feed port of a twin-screw extruder for extrusion granulation. The length-to-diameter ratio of the twin-screw extruder was 40:1, the extrusion temperature was 230-240℃, and the screw speed was 400rpm, to obtain in-situ grafting masterbatch E.

[0096] [Compare with Example 1]

[0097] In-situ grafting masterbatch F was prepared using essentially the same method as in Preparation Example 1, except that EAA resin was replaced with an equal amount of EPDM resin.

[0098] [Compare with Example 2]

[0099] In-situ grafting masterbatch G was prepared using essentially the same method as in Preparation Example 1, except that EAA resin was replaced with an equal amount of POE resin.

[0100] [Compare with Example 3]

[0101] In situ grafting masterbatch H was prepared using a method essentially the same as that used in Preparation Example 1, except that Nylon 12-A resin was replaced with an equal amount of Nylon 12-E resin.

[0102] Examples 1-5 and Comparative Examples 1-5 are used to prepare Nylon 12 modified materials.

[0103]

Example 1

[0104] Weigh 79 parts of Nylon 12-A, 20 parts of in-situ grafting masterbatch A, 0.5 parts of compound antioxidant (1098 and 168 in a mass ratio of 1:1), and 0.5 parts of pentaerythritol stearate. Mix them in a low-temperature mixer for 6 minutes to obtain a premix.

[0105] The premixed material is fed into a twin-screw extruder through the main feed port for melt co-extrusion granulation. The twin-screw extruder has a screw length-to-diameter ratio of 40:1, an extrusion temperature of 240-250℃, and a screw speed of 300rpm to obtain modified Nylon 12 material.

[0106]

Example 2

[0107] Weigh 68 parts of Nylon 12-B, 30 parts of in-situ grafting masterbatch B, 1 part of compound antioxidant (1010 and 168 in a mass ratio of 1:1), and 1 part of E wax lignite wax, and mix them in a low-temperature mixer for 8 minutes to obtain a premix.

[0108] The premixed material is fed into a twin-screw extruder through the main feed port for melt blending and granulation. The twin-screw extruder has a screw length-to-diameter ratio of 40:1, an extrusion temperature of 230-240℃, and a screw speed of 400rpm to obtain modified Nylon 12 material.

[0109]

Example 3

[0110] Weigh 78 parts of Nylon 12-C, 20 parts of in-situ grafting masterbatch C, 1 part of compound antioxidant (245 and 686 in a mass ratio of 1:1), and 1 part of polyethylene wax, and mix them in a low-temperature mixer for 8 minutes to obtain a premix.

[0111] The premixed material is fed into a twin-screw extruder through the main feed port for melt blending and granulation. The twin-screw extruder has a screw length-to-diameter ratio of 40:1, an extrusion temperature of 250-260℃, and a screw speed of 300rpm to obtain modified Nylon 12 material.

[0112]

Example 4

[0113] Weigh out 89 parts of Nylon 12-D, 10 parts of in-situ grafting masterbatch D, 0.5 parts of compound antioxidant (245 and 626 in a mass ratio of 1:1), and 0.5 parts of E wax lignite wax. Mix them in a low-temperature mixer for 8 minutes to obtain a premix.

[0114] The premixed material is fed into a twin-screw extruder through the main feed port for melt blending and granulation. The twin-screw extruder has a screw length-to-diameter ratio of 40:1, an extrusion temperature of 240-250℃, and a screw speed of 400rpm to obtain modified Nylon 12 material.

[0115]

Example 5

[0116] Weigh 58 parts of Nylon 12-B, 40 parts of in-situ grafting masterbatch E, 1 part of compound antioxidant (1098 and 168 in a mass ratio of 1:1), and 1 part of polyethylene wax, and mix them in a low-temperature mixer for 6 minutes to obtain a premix.

[0117] The premixed material is fed into a twin-screw extruder through the main feed port for melt blending and granulation. The twin-screw extruder has a screw length-to-diameter ratio of 40:1, an extrusion temperature of 240-250℃, and a screw speed of 400rpm to obtain modified Nylon 12 material.

[0118] Comparative Example 1

[0119] Nylon 12 modified materials were prepared using essentially the same method as in Example 1, except that the in-situ grafting masterbatch A was replaced with an equal amount of in-situ grafting masterbatch F.

[0120] Comparative Example 2

[0121] Nylon 12 modified materials were prepared using essentially the same method as in Example 1, except that the in-situ grafting masterbatch A was replaced with an equal amount of in-situ grafting masterbatch G.

[0122] Comparative Example 3

[0123] Nylon 12 modified materials were prepared using essentially the same method as in Example 1, except that the in-situ grafting masterbatch A was replaced with an equal amount of in-situ grafting masterbatch H, and the nylon 12-A resin was replaced with an equal amount of nylon 12-E resin.

[0124] Comparative Example 4

[0125] Nylon 12 modified material was prepared using essentially the same method as in Example 1, except that the in-situ grafting masterbatch A was replaced with 6 parts of EAA resin.

[0126] Comparative Example 5

[0127] Nylon 12 modified materials were prepared using essentially the same method as in Example 1, except that the in-situ grafting masterbatch A was replaced with 6 parts of grafting adhesive AX8900.

[0128] Comparative Example 6

[0129] Nylon 12 modified materials were prepared using essentially the same method as in Example 1, except that in-situ grafting masterbatch A was not added.

[0130] The performance of the modified nylon 12 materials provided in the above embodiments and comparative examples of the present invention was tested as follows. The main test methods are as follows:

[0131] (1) Metal peel force was tested in accordance with GB / T 25085 standard. A 30cm long sample was cut from a part with a modified nylon 12 material layer thickness of 0.6mm and a nickel-copper plated size of 16x2.5mm. After trimming, a 15cm long piece of rubber was manually peeled off. The bottom of the part was clamped at one end of a tensile testing machine, and the peeling rubber was clamped at the other end. The peeling was stretched at a 180-degree angle to the part. The stretching speed was set to 50mm / min. The metal peel force was recorded as the average force value of 4 samples. All samples were tested using the same specifications and process.

[0132] (2) In order to test the metal bonding stability of modified nylon 12 material under extreme conditions, a double 85 aging test was carried out with reference to GB / T 2423.50 standard. The aging was accelerated at 85℃ and 85%RH. After the test time reached 168h, the metal peel force test was carried out on the sample in the same way and compared with the sample before aging.

[0133] (3) Tensile properties were tested in accordance with ISO527 standard, with the speed for testing tensile strength set at 5 mm / min and the speed for testing tensile modulus set at 1 mm / min.

[0134] Table 1. Metal peel force test results of Nylon 12 modified materials

[0135]

[0136] The test results above show that the Nylon 12 modified material provided by this invention has strong metal adhesion properties and can maintain high metal peeling force under extreme humid and hot aging conditions.

[0137] Comparative Examples 1 and 2, prepared with non-polar toughening agents, showed significantly lower metal bonding performance compared to toughening agents with polar groups. After extreme damp heat aging, the modified material 12 lost its metal peel strength. Comparative Example 3, using high-end amino nylon 12 resin, showed a significant decrease in metal bonding performance compared to low-end amino nylon 12 resin. Comparative Examples 4 and 5, prepared without in-situ grafted adhesive masterbatches, showed a significant decrease in adhesive strength compared to modified materials obtained using in-situ adhesive masterbatches. Comparative Example 6, with only lubricant and antioxidant added, lacked metal peel strength.

[0138] Table 2. Test results of mechanical properties of Nylon 12 modified materials

[0139] Example Tensile modulus / MPa Tensile breaking strength / MPa Elongation at break (%) Example 1 1270 340 56.3 Example 2 1230 330 54.2 Example 3 1267 320 55.8 Example 4 1300 290 58.0 Example 5 1290 330 56.7 Comparative Example 1 1270 320 52.8 Comparative Example 2 1260 300 55.4 Comparative Example 3 1273 320 56.0 Comparative Example 4 1270 270 51.6 Comparative Example 5 1290 320 55.9 Comparative Example 6 1390 250 50.5

[0140] The test results above show that the mechanical properties of the Nylon 12 modified material provided by this invention are comparable to those of the comparative examples, and there is no significant performance degradation.

[0141] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A high metal bondable nylon 12 modified material characterized in that, The modified material comprises, by weight, the following components: Nylon 12, 55-90 parts, preferably 60-80 parts. In-situ grafting masterbatch, 10-40 parts, preferably 20-30 parts. Processing aid, 0-2 parts, preferably 1-2 parts; The in-situ grafting masterbatch comprises, by weight, the following components: Nylon 12, 50-85 parts, preferably 60-80 parts. Adhesive resin, 10-40 parts, preferably 20-30 parts. Graft monomer, 0.4-4 parts, preferably 1-3 parts. Initiator, 0.1-0.4 parts, preferably 0.2-0.3 parts. Processing aid, 0-2 parts, preferably 1-2 parts.

2. The high metal bondable nylon 12 modified material of claim 1, wherein, In the modified material and the in-situ grafting masterbatch, the nylon 12 has a terminal amino content of 5-30 mmol / kg, preferably 5-20 mmol / kg, a molar ratio of terminal amino to terminal carboxyl groups of 1:(1-9), preferably 1:(2-9), and a number average molecular weight of 30,000-50,000, preferably 32,000-40,000.

3. The high metal bondable nylon 12 modified material of claim 1, wherein, The adhesive resin is at least one of ethylene-acrylic acid copolymer, ethylene-butyl acrylate, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-vinyl acetate copolymer, and ethylene-methyl methacrylate copolymer. Preferably, the adhesive resin is one or more of ethylene-acrylic acid copolymers and ethylene-methyl acrylate copolymers with a density of 0.90-0.95 g / cm3 and a melt flow index (MFR) of 0.1-10 g / 10 min under test conditions of 190°C and 2.16 kg.

4. The high metal bondable nylon 12 modified material according to any one of claims 1-3, characterized in that, The grafting monomer is at least one of maleic anhydride and glycidyl methacrylate, or a compound thereof with at least one of styrene, divinylbenzene, bismaleimide and triallyl triisocyanurate, preferably at least one of maleic anhydride and glycidyl methacrylate.

5. The high metal bondable nylon 12 modified material according to any one of claims 1-4, characterized in that, The initiator is at least one selected from benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-dibis(tert-butylperoxy)ethane, and 2,3-dimethyl-2,3-diphenylbutane.

6. The high metal bondable nylon 12 modified material according to any one of claims 1-5, wherein, The processing aid is a lubricant and / or an antioxidant; Preferably, the lubricant is selected from at least one of stearic acid complex esters, montmorillonite wax, metallic soaps, polyethylene waxes, low molecular weight esters, and amide waxes; Preferably, the antioxidant is a hindered phenolic antioxidant and / or a phosphite antioxidant, and more preferably, the two are compounded in a mass ratio of 1:(0.5-2).

7. A method of producing a high metal bondable nylon 12 modified material as claimed in any one of claims 1 to 6, characterised in that, The modified material is prepared by mixing nylon 12, in-situ grafting masterbatch, and optionally processing aids evenly, extruding, and granulating. Preferably, during the extrusion process, the extrusion temperature is 210-280℃, more preferably 240-250℃; the screw speed is 200-800rpm, more preferably 300-500rpm; Preferably, the extrusion process is carried out in a twin-screw extruder with a screw length-to-diameter ratio of (36-50):

1.

8. The method for preparing the high metal adhesion modified nylon 12 material according to claim 7, characterized in that, The preparation method of the in-situ grafting masterbatch includes the following steps: 1) After dissolving the grafted monomer and initiator in a solvent, the adhesive resin is heated to 60-80°C and mixed with the above-mentioned dissolved substances and optionally processing aids, and stirred to obtain a premix. 2) After mixing the premix with nylon 12, the mixture is extruded and granulated to obtain in-situ grafting masterbatch; Preferably, in step 1), the mixing speed of the premix is ​​300-600 rpm, the mixing time is 6-10 min, and the mixing temperature is controlled below 100℃; Preferably, in step 2), the extrusion temperature is 210-280℃, more preferably 240-260℃; and the screw speed is 200-800 rpm, more preferably 300-500 rpm. Preferably, the extrusion process in step 2) is carried out in a twin-screw extruder with a screw length-to-diameter ratio of (36-50):1; Preferably, the solvent is selected from one or more of acetone, ethyl acetate, methanol, ethanol, and isopropanol.

9. The application of a high metal adhesion nylon 12 modified material as described in any one of claims 1-6 or a high metal adhesion nylon 12 modified material prepared by the method described in any one of claims 7-8 in the fields of new energy vehicles and energy storage, especially in copper core high voltage electrical busbars.

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