High and low temperature impact resistant nylon 12 modified material, and preparation method and application thereof

Abstract

The application discloses a nylon 12 modified material resistant to high and low temperature impact and a preparation method and application thereof. The modified material comprises the following components in parts by weight: 48-85 parts of nylon 12, 10-30 parts of in-situ grafted temperature-resistant impact master batch, 5-20 parts of transparent nylon and 0-2 parts of processing aid; wherein the in-situ grafted temperature-resistant impact master batch comprises the following components in parts by weight: 50-88 parts of nylon 12, 10-40 parts of non-polar elastomer, 0.4-4 parts of grafted monomer, 0.1-0.4 parts of initiator and 0-2 parts of processing aid. The application can significantly improve the stability and durability of the nylon 12 modified material under high and low temperature impact cycles, and as a metal insulation layer coating material, the application can not have problems such as cracking in the process of more than 600 high and low temperature impact cycles.

Description

Technical Field

[0001] This invention relates to a modified nylon 12 material, and more particularly to a modified nylon 12 material resistant to high and low temperature impacts, its preparation method, and its application. Background Technology

[0002] Nylon 12 is a polyamide variety with 12 methylene groups between adjacent amide groups. Its long methylene chains and polar amide groups give it the dual characteristics of polyolefins and polyamides. While possessing excellent mechanical strength, wear resistance, and chemical solvent resistance, it overcomes the shortcomings of short-chain nylons, such as dimensional instability and poor low-temperature toughness caused by high water absorption. It has important applications in automobiles, electronics, aerospace, oil pipelines and other fields.

[0003] In typical applications such as copper-core high-voltage electrical busbars, nylon 12 is the preferred material for the insulation layer due to its excellent insulation, abrasion resistance, and low-temperature performance. In addition to the basic material performance requirements, copper busbar insulation materials often need to undergo high and low temperature shock cycling, i.e., experiencing a wide range of temperature changes from low temperatures (e.g., -40℃) to high temperatures (e.g., 120℃) in a very short time. This extreme thermal cycling test is typically used to evaluate the material's performance stability in practical applications, posing a significant challenge to the material's performance.

[0004] During high and low temperature shock cycling, the physical properties of polymer materials change significantly with temperature variations. High temperatures may accelerate the aging process, leading to a decrease in mechanical strength. Simultaneously, at low temperatures, materials may lose toughness, becoming brittle and prone to breakage. Furthermore, under rapid temperature changes, different parts of the material may expand or contract at different rates, resulting in stress concentration. This stress concentration effect is amplified, particularly at material defects (such as cracks and pores), leading to cracking or fracture. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a modified nylon 12 material resistant to high and low temperature impacts, its preparation method, and its applications. This invention significantly improves the stability and durability of the modified nylon 12 material under high and low temperature impact cycling, and as a metal insulating layer coating material, it does not exhibit cracking or other problems during more than 600 high and low temperature impact cycles.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A modified nylon 12 material resistant to high and low temperature impacts, comprising the following components by weight:

[0008] Nylon 12, 48-85 parts, preferably 55-75 parts.

[0009] In-situ grafted high-temperature impact resistant masterbatch, 10-30 parts, preferably 12-20 parts.

[0010] Transparent nylon, 5-20 parts, preferably 8-15 parts.

[0011] Processing aid, 0-2 parts, preferably 1-2 parts;

[0012] The in-situ grafted high-temperature impact resistant masterbatch comprises, by weight, the following components:

[0013] Nylon 12, 50-88 parts, preferably 60-80 parts.

[0014] Nonpolar elastomer, 10-40 parts, preferably 20-30 parts.

[0015] Graft monomer, 0.4-4 parts, preferably 1-3 parts.

[0016] Initiator, 0.1-0.4 parts, preferably 0.2-0.3 parts.

[0017] Processing aid, 0-2 parts, preferably 1-2 parts.

[0018] As some preferred examples of the present invention, in the modified material and the in-situ grafted high-temperature resistant masterbatch, the content of terminal amino groups of nylon 12 is 20-80 mmol / kg, preferably 30-60 mmol / kg, the molar ratio of terminal amino groups to terminal carboxyl groups is (1-9):1, preferably (2-9):1, and the number average molecular weight is 30,000-50,000, preferably 32,000-40,000.

[0019] As some preferred examples of the present invention, the nonpolar elastomer is selected from nonpolar olefin thermoplastic elastomers and styrene thermoplastic elastomers, preferably one or more of ethylene-propylene-nonconjugated diene copolymer (EPDM), ethylene-octene copolymer (POE), styrene-butadiene copolymer (SBS), styrene-ethylene-butene-styrene block copolymer (SEBS), and ethylene-vinyl acetate copolymer (EVA).

[0020] Preferably, the nonpolar elastomer is one or more of the following: ethylene-propylene-nonconjugated diene copolymer, ethylene-octene copolymer, and styrene-ethylene-butene-styrene block copolymer, with a density between 0.85-0.95 g / cm3.

[0021] As some preferred examples of the present invention, the transparent nylon macromolecular backbone contains segments with 8-20 methylene groups between adjacent amide bonds. Preferably, the transparent nylon is selected from one or more of MACM12, PACM12, PA12 / MACMI, and MACM10 / 1010. The transparent nylon can be prepared from at least one polymeric monomer containing 8-20 methylene groups, wherein the preparation method is well known in the art and is not particularly limited herein. For example, the transparent nylon can be obtained by copolymerizing at least one diacid monomer containing 8-20 methylene groups and a diamine monomer, or it can be obtained by ring-opening polymerization of a lactam monomer that meets the methylene group number requirement. For specific details, please refer to general preparation processes in the art.

[0022] As some preferred examples of the present invention, the grafting monomer is at least one of maleic anhydride (MAH) and glycidyl methacrylate (GMA) or a compound of it 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.

[0023] Preferably, 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).

[0024] As some preferred examples of the present invention, the processing aid is a lubricant and / or an antioxidant;

[0025] 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;

[0026] 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). 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.

[0027] The present invention also provides a method for preparing a nylon 12 modified material resistant to high and low temperature impact as described above, comprising mixing nylon 12, in-situ grafted high temperature impact resistant masterbatch, transparent nylon, and optionally processing aids evenly, extruding, granulating, and obtaining the modified material.

[0028] Preferably, during the extrusion process, the extrusion temperature is 210-300℃, more preferably 240-250℃; the screw speed is 200-800rpm, more preferably 300-500rpm.

[0029] Preferably, the extrusion process is carried out in a twin-screw extruder with a screw length-to-diameter ratio of (36-50):1.

[0030] As some preferred examples of the present invention, the method for preparing the in-situ grafted high-temperature shock resistant masterbatch includes the following steps:

[0031] 1) After dissolving the grafted monomer and initiator in a solvent, the nonpolar elastomer is heated to 60-80°C and mixed with the above-mentioned dissolved material and optionally processing aids, and stirred to obtain a premix.

[0032] 2) After mixing the premix with nylon 12, the mixture is extruded and granulated to obtain in-situ grafted high-temperature resistant masterbatch;

[0033] Preferably, in step 1), the mixing speed of the premix is ​​300-600 rpm, the mixing time is 8-15 min, and the mixing temperature is controlled below 100℃;

[0034] Preferably, in step 2), the extrusion temperature is 210-300℃, more preferably 240-260℃; and the screw speed is 200-800 rpm, more preferably 300-500 rpm.

[0035] 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 (44-48):1;

[0036] Preferably, the solvent is selected from one or more of acetone, ethyl acetate, methanol, ethanol, and isopropanol.

[0037] The present invention also provides an application of the high and low temperature resistant modified nylon 12 material as described above or the high and low temperature resistant modified nylon 12 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.

[0038] The modified nylon 12 material provided by this invention contains in-situ grafted high-temperature shock resistant masterbatch and transparent nylon. On the one hand, during the blending and extrusion process, it can simultaneously graft polar monomers onto the non-polar elastomer and carry out in-situ reaction between high-end amino-content nylon 12 and polar monomers, effectively improving the bonding effect between nylon 12 and non-polar elastomer, reducing the internal stress of the material under high and low temperature changes, and avoiding cracking. On the other hand, as an amorphous nylon material, transparent nylon can better absorb the internal stress caused by temperature shock, and by reducing the material's coefficient of thermal expansion (CTE), it can reduce the internal stress caused by the difference in coefficient of thermal expansion, thereby avoiding the generation of cracks. Detailed Implementation

[0039] 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.

[0040] The raw material information used in the experimental examples and comparative examples is shown below:

[0041] Nylon 12-A, with terminal amino group content of 42 mmol / kg, a terminal amino to terminal carboxyl group ratio of 4:1, and a molecular weight of 38719; the preparation method is as follows:

[0042] 100,000g of dodecyl lactam monomer, 175g of n-hexylamine as end-capping agent, 20g 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-A was then discharged.

[0043] Nylon 12-B, with terminal amino group content of 35 mmol / kg, a terminal amino to terminal carboxyl group ratio of 2:1, and a molecular weight of 42319; the preparation method is as follows:

[0044] 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 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 2 hours. Nylon 12-B was then discharged.

[0045] Nylon 12-C, with terminal amino group content of 60 mmol / kg, a terminal amino to terminal carboxyl group ratio of 9:1, and a molecular weight of 37065; the preparation method is as follows:

[0046] 100,000g of dodecyl lactam monomer, 200g of n-hexylamine as end-capping agent, 22g of sodium hypophosphite catalyst, 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 2 hours. Nylon 12-C was then discharged.

[0047] Nylon 12-D, with terminal amino group content of 25 mmol / kg, a terminal amino group to terminal carboxyl group ratio of 1:1, and a molecular weight of 39461; the preparation method is as follows:

[0048] 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.

[0049] Nylon 12-E, with terminal amino group content of 15 mmol / kg, a terminal amino to terminal carboxyl group ratio of 1:2, and a molecular weight of 42290; the preparation method is as follows:

[0050] 100,000 g of dodecyl lactam monomer, 88 g of capping agent (hexanoic acid), 10 g of catalyst (sodium hypophosphite), 500 g of antioxidant 1098: antioxidant 168 (1:1 ratio), and 10,000 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 260°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 3 hours. Nylon 12-E was then discharged.

[0051] EPDM resin: Grade 3092M, density 0.860 g / cm3, Mitsui Chemicals;

[0052] POE resin: Grade 3040, density 0.920 g / cm3, ExxonMobil;

[0053] SEBS resin: Grade G1651, density 0.908 g / cm3, Kraton (USA);

[0054] EAA resin: Grade 2002, density 0.930 g / cm3, Dow Chemical;

[0055] EMA resin: Grade AC1125, density 0.944 g / cm3, Dow Chemical;

[0056] Graft toughening agent VA1803: EPDM grafted MAH, density 0.860 g / cm3, ExxonMobil;

[0057] Maleic anhydride (MAH): Shanghai Aladdin;

[0058] Glycidyl methacrylate (GMA): Shanghai Aladdin;

[0059] Benzoyl peroxide (BPO): Shanghai Aladdin;

[0060] Dicumyl peroxide (DCP): Shanghai Aladdin;

[0061] PACM12: Transparent nylon, grade 9704, Evonik;

[0062] MACM12: Transparent nylon, grade TR90, EMS;

[0063] PA12 / MACMI: Transparent nylon, grade TR55, EMS;

[0064] MACM10 / 1010: Transparent nylon, TRXE4010, EMS;

[0065] Pentaerythritol stearate: Imuryl;

[0066] E-wax lignite wax, Clariant;

[0067] Polyethylene wax AC 540, Honeywell;

[0068] Antioxidant 1010: Hindered phenolic antioxidant, Rianon;

[0069] Antioxidant 1098: Hindered phenolic antioxidant, Leylan;

[0070] Antioxidant 245: Hindered phenolic antioxidant, Rianon;

[0071] Antioxidant 168: Phosphite antioxidant, Leylan;

[0072] Antioxidant 626: Phosphite antioxidant, Rianon;

[0073] Antioxidant 686: Phosphite antioxidant, Rianon.

[0074] 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.

[0075] The following is a description of specific embodiments. Unless otherwise specified, all raw materials are in parts by weight.

[0076] [Preparation Example 1]

[0077] In-situ grafted high-temperature shock resistant masterbatch A was prepared according to the following method:

[0078] (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;

[0079] (2) Stir 30 parts of EPDM resin at high speed (400 rpm) using a high-speed mixer to raise the temperature to about 60°C, then add the solution from step (1) and 2 parts of pentaerythritol stearate, mix at 100°C or below for 8 minutes to obtain a premix.

[0080] (3) The premixed material and 64.7 parts of Nylon 12-A were mixed evenly by a low-speed mixer and then added to the main feed port 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 grafted heat-resistant masterbatch A.

[0081] [Preparation Example 2]

[0082] In-situ grafted high-temperature shock resistant masterbatch B was prepared according to the following method:

[0083] (1) Dissolve 3 parts GMA and 0.3 parts BPO in 8 parts ethyl acetate solvent and stir at room temperature for 0.5 h to prepare a solution;

[0084] (2) Stir 20 parts of SEBS resin at high speed (400 rpm) using a high-speed mixer to raise the temperature to about 60°C, then add the solution from step (1) and 1 part of E wax lignite wax, mix at 100°C or below for 6 minutes to obtain a premix.

[0085] (3) The premixed material and 75.7 parts of Nylon 12-B were mixed evenly by a low-speed mixer and then added to the main feed port 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 grafted heat-resistant masterbatch B.

[0086] [Preparation Example 3]

[0087] In-situ grafted high-temperature shock resistant masterbatch C was prepared according to the following method:

[0088] (1) Dissolve 2 parts MAH and 0.2 parts initiator DCP in 3 times the volume of acetone solvent and stir at room temperature for 0.5 h to prepare a solution;

[0089] (2) Stir 30 parts of POE resin at high speed (300 rpm) using a high-speed mixer to raise the temperature to about 60°C, then add the solution from step (1) and 2 parts of polyethylene wax, mix at 100°C or below for 6 minutes to obtain a premix.

[0090] (3) The premixed material and 65.8 parts of Nylon 12-C were uniformly mixed by a low-speed mixer and then added to the main feed port 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 grafted heat-resistant masterbatch C.

[0091] [Preparation Example 4]

[0092] In-situ grafted high-temperature shock resistant masterbatch D was prepared according to the following method:

[0093] (1) Dissolve 2 parts MAH and 0.2 parts initiator DCP in 4 times the volume of isopropanol solvent and stir at room temperature for 1 hour to prepare a solution;

[0094] (2) Stir 40 parts of SEBS resin at high speed (300 rpm) using a high-speed mixer to raise the temperature to about 60°C, then add the solution from step (1) and 2 parts of polyethylene wax, mix at 100°C or below for 6 minutes to obtain a premix.

[0095] (3) The premixed material and 56.8 parts of Nylon 12-D were uniformly mixed by a low-speed mixer and then added to the main feed port for extrusion granulation. The length-to-diameter ratio of the twin-screw extruder was 40:1, the extrusion temperature was 210-220℃, and the screw speed was 500rpm, thus obtaining in-situ grafted heat-resistant masterbatch D.

[0096] [Preparation Example 5]

[0097] In-situ grafted high-temperature shock resistant masterbatch E was prepared according to the following method:

[0098] (1) Dissolve 1 part MAH and 0.3 parts initiator BPO in 4 times the volume of acetone solvent and stir at room temperature for 1 hour to prepare a solution;

[0099] (2) Stir 10 parts of EPDM resin at high speed (300 rpm) using a high-speed mixer to raise the temperature to about 60°C, then add the solution from step (1) and 2 parts of polyethylene wax, mix at 100°C or below for 6 minutes to obtain a premix.

[0100] (3) The premixed material and 84.7 parts of Nylon 12-A were mixed evenly by a low-speed mixer and then added to the main feed port for extrusion granulation. The length-to-diameter ratio of the twin-screw extruder was 40:1, the extrusion temperature was 260-270℃, and the screw speed was 300rpm, to obtain in-situ grafted heat-resistant masterbatch E.

[0101] [Compare with Example 1]

[0102] In-situ grafted high-temperature shock resistant masterbatch F was prepared using essentially the same method as in Preparation Example 1, except that the EPDM resin was replaced with an equal amount of EAA resin (polar resin).

[0103] [Compare with Example 2]

[0104] In-situ grafted high-temperature shock resistant masterbatch G was prepared using essentially the same method as in Preparation Example 1, except that the EPDM resin was replaced with an equal amount of EMA resin (polar resin).

[0105] [Compare with Example 3]

[0106] In-situ grafted high-temperature shock resistant 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.

[0107] Examples 1-5 and Comparative Examples 1-5 are used to prepare Nylon 12 modified materials.

[0108]

Example 1

[0109] Weigh 69 parts of Nylon 12-A, 20 parts of in-situ grafted heat-resistant masterbatch A, 10 parts of MACM12, 0.5 parts of compound antioxidant (1098 / 168 mass ratio of 1:1), and 0.5 parts of pentaerythritol stearate, and mix them in a low-temperature mixer for 6 minutes to obtain a premix.

[0110] (2) 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 300rpm to obtain Nylon 12 modified material.

[0111]

Example 2

[0112] Weigh 53 parts of Nylon 12-B, 30 parts of in-situ grafted high-temperature impact-resistant masterbatch B, 15 parts of PACM12, 1 part of compound antioxidant (1098 / 168 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.

[0113] The premixed material was fed into a twin-screw extruder through the main feed port for melt blending and granulation. The twin-screw extruder had a screw length-to-diameter ratio of 40:1, an extrusion temperature of 260-270℃, and a screw speed of 500rpm to obtain modified Nylon 12 material.

[0114]

Example 3

[0115] Weigh out 73 parts of Nylon 12-C, 20 parts of in-situ grafted high-temperature impact-resistant masterbatch C, 10 parts of PA12 / MACMI, 1 part of compound antioxidant (1098 / 168 mass ratio of 1:1), and 1 part of E wax lignite wax. Mix them in a low-temperature mixer for 6 minutes to obtain a premix.

[0116] The premixed material was fed into a twin-screw extruder through the main feed port for melt blending and granulation. The twin-screw extruder had 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.

[0117]

Example 4

[0118] Weigh out 69 parts of Nylon 12-D, 10 parts of in-situ grafted high-temperature impact-resistant masterbatch D, 10 parts of MACM10 / 1010, 0.5 parts of compound antioxidant (1098 / 168 mass ratio of 1:1), and 0.5 parts of polyethylene wax, and mix them in a low-temperature mixer for 4 minutes to obtain a premix.

[0119] The premixed material was fed into a twin-screw extruder through the main feed port for melt blending and granulation. The twin-screw extruder had a screw length-to-diameter ratio of 40:1, an extrusion temperature of 220-230℃, and a screw speed of 400rpm to obtain modified Nylon 12 material.

[0120]

Example 5

[0121] Weigh 48 parts of Nylon 12-A, 40 parts of in-situ grafted heat-resistant masterbatch E, 10 parts of PACM12, 1 part of compound antioxidant (1098 / 168 mass ratio of 1:1), and 1 part of pentaerythritol stearate, and mix them in a low-temperature mixer for 8 minutes to obtain a premix.

[0122] 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 400rpm to obtain modified Nylon 12 material.

[0123] Comparative Example 1

[0124] Nylon 12 modified materials were prepared using essentially the same method as in Example 1, except that the in-situ grafted high-temperature-resistant masterbatch A was replaced with an equal amount of in-situ grafted high-temperature-resistant masterbatch F.

[0125] Comparative Example 2

[0126] Nylon 12 modified materials were prepared using essentially the same method as in Example 1, except that the in-situ grafted high-temperature-resistant masterbatch A was replaced with an equal amount of in-situ grafted high-temperature-resistant masterbatch G.

[0127] Comparative Example 3

[0128] Nylon 12 modified materials were prepared using essentially the same method as in Example 1, except that the in-situ grafted high-temperature resistant masterbatch A was replaced with an equal amount of in-situ grafted high-temperature resistant masterbatch H, and Nylon 12-A was replaced with an equal amount of Nylon 12-E.

[0129] Comparative Example 4

[0130] Nylon 12 modified materials were prepared using essentially the same method as in Example 1, except that transparent nylon MACM12 was not added.

[0131] Comparative Example 5

[0132] Nylon 12 modified materials were prepared using essentially the same method as in Example 1, except that the in-situ grafted high-temperature shock resistant masterbatch A was replaced with 6 parts of grafted toughening agent VA1801.

[0133] Comparative Example 6

[0134] Nylon 12 modified materials were prepared using essentially the same method as in Example 1, except that in-situ grafted high-temperature shock-resistant masterbatch A and transparent nylon MACM12 were not added.

[0135] 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:

[0136] (1) High and low temperature impact refers to the relevant standards GB / T 25085 and GB / T 2423.22. A sample of no less than 50cm in length is cut from the part with a rubber insulation layer thickness of 0.6mm and a nickel-copper plated specification of 16x3mm. The bending includes at least two continuous vertical bends and one horizontal bend. Each test group includes 5 samples. The part specifications and bending process are exactly the same for different test groups.

[0137] The specific test conditions for high and low temperature shock are: low temperature -40℃±3℃, high temperature 125℃±3℃, each temperature is maintained for 0.5h, temperature switching is within 30s, 600 cycles are performed, and after the cycle, it is left to stand for 4h in a normal temperature and humidity environment. After the test, there should be no cracks in the appearance, and the insulation performance should meet the following standards: test voltage 1KV, DC, 60s, insulation resistance greater than 500MΩ; test voltage 2.5KV, DC, 60s, leakage current less than 1mA.

[0138] (2) 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.

[0139] Table 1. Test results of high / low temperature impact performance of modified Nylon 12 materials

[0140]

[0141]

[0142] The test results above show that the nylon 12 modified materials provided in Examples 1-5 of this invention exhibited no cracking under the extremely harsh high / low temperature impact cycling test conditions described above, and also demonstrated excellent pressure resistance. Comparative Examples 1 and 2, using in-situ grafted high-temperature impact masterbatches prepared from elastomers with polar groups, showed varying degrees of apparent cracking in the parts after high / low temperature impact cycling. The cracks occurred at stress concentration points during horizontal or vertical bending, and the cracked parts failed the pressure resistance test. Comparative Example 3, using low-end amino nylon 12 resin, showed varying degrees of cracking in all five samples. Comparative Example 4, without the addition of transparent nylon, had only one sample that did not crack and passed the pressure resistance test, but it still showed a significant difference compared to Example 1. In Comparative Example 5, where a grafted toughening agent was used instead of in-situ grafted high-temperature impact masterbatch A, only two samples did not crack and passed the pressure resistance test. Comparative Example 6, without the addition of transparent nylon and in-situ grafted high-temperature impact masterbatch, showed poor high-temperature impact resistance of the modified nylon 12 material, and all the parts exhibited deep-cut cracks, failing the subsequent pressure resistance test.

[0143] Table 2. Test results of mechanical properties of Nylon 12 modified materials

[0144] Example Tensile modulus / MPa Tensile breaking strength / MPa Elongation at break (%) Example 1 1270 290 53.8 Example 2 1274 300 53.3 Example 3 1266 320 55.7 Example 4 1324 317 57.3 Example 5 1309 309 56.2 Comparative Example 1 1270 340 56.3 Comparative Example 2 1230 330 55.9 Comparative Example 3 1300 290 56.2 Comparative Example 4 1290 340 55.3 Comparative Example 5 1280 320 57.1 Comparative Example 6 1370 240 51.1

[0145] 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.

[0146] 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 modified nylon 12 material resistant to high and low temperature impacts, characterized in that, The modified material comprises, by weight, the following components: Nylon 12, 48-85 parts, preferably 55-75 parts. In-situ grafted high-temperature impact resistant masterbatch, 10-30 parts, preferably 12-20 parts. Transparent nylon, 5-20 parts, preferably 8-15 parts. Processing aid, 0-2 parts, preferably 1-2 parts; The in-situ grafted high-temperature impact resistant masterbatch comprises, by weight, the following components: Nylon 12, 50-88 parts, preferably 60-80 parts. Nonpolar elastomer, 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 nylon 12 modified material resistant to high and low temperature impact according to claim 1, characterized in that, In the modified material and the in-situ grafted high-temperature impact resistant masterbatch, the content of terminal amino groups of nylon 12 is 20-80 mmol / kg, preferably 30-60 mmol / kg, the molar ratio of terminal amino groups to terminal carboxyl groups is (1-9):1, preferably (2-9):1, and the number average molecular weight is 30,000-50,000, preferably 32,000-40,000.

3. The nylon 12 modified material resistant to high and low temperature impact according to claim 1, characterized in that, The nonpolar elastomer is selected from nonpolar olefin thermoplastic elastomers and styrene thermoplastic elastomers, preferably one or more of ethylene-propylene-nonconjugated diene copolymers, ethylene-octene copolymers, styrene-butadiene copolymers, styrene-ethylene-butene-styrene block copolymers, and ethylene-vinyl acetate copolymers. Preferably, the nonpolar elastomer is one or more of the following: ethylene-propylene-nonconjugated diene copolymer, ethylene-octene copolymer, and styrene-ethylene-butene-styrene block copolymer, with a density between 0.85-0.95 g / cm3.

4. The nylon 12 modified material resistant to high and low temperature impact according to any one of claims 1-3, characterized in that, The transparent nylon macromolecular backbone contains 8-20 methylene segments between adjacent amide bonds, and preferably the transparent nylon is selected from one or more of MACM12, PACM12, PA12 / MACMI, and MACM10 / 1010.

5. The nylon 12 modified material resistant to high and low temperature impact according to any one of claims 1-4, 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; Preferably, 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 nylon 12 modified material resistant to high and low temperature impact according to any one of claims 1-5, characterized in that, 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 for preparing a high and low temperature impact-resistant modified nylon 12 material as described in any one of claims 1-6, characterized in that, The modified material is prepared by uniformly mixing nylon 12, in-situ grafted high-temperature impact-resistant masterbatch, transparent nylon, and optionally processing aids, extruding, and granulating. Preferably, during the extrusion process, the extrusion temperature is 210-300℃, 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 and low temperature impact-resistant modified nylon 12 material according to claim 7, characterized in that, The preparation method of the in-situ grafted high-temperature shock resistant masterbatch includes the following steps: 1) After dissolving the grafted monomer and initiator in a solvent, the nonpolar elastomer is heated to 60-80°C and mixed with the above-mentioned dissolved material 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 grafted high-temperature resistant masterbatch; Preferably, in step 1), the mixing speed of the premix is ​​300-600 rpm, the mixing time is 8-15 min, and the mixing temperature is controlled below 100℃; Preferably, in step 2), the extrusion temperature is 210-300℃, 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 (44-48):1; Preferably, the solvent is selected from one or more of acetone, ethyl acetate, methanol, ethanol, and isopropanol.

9. The application of a high and low temperature resistant modified nylon 12 material as described in any one of claims 1-6 or a high and low temperature resistant modified nylon 12 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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