In-situ grafted toughening agent master batch and preparation method thereof, and high-impact hydrolysis-resistant reinforced nylon 12 material and preparation method thereof

Abstract

The invention discloses an in-situ grafted toughening agent master batch and a preparation method thereof, and a high-impact hydrolysis-resistant reinforced nylon 12 material and a preparation method thereof. The in-situ grafted toughening agent master batch comprises the following raw materials in parts by weight: 40-80 parts of nylon 12 resin; 10 to 40 parts of a toughening agent; 1-4 parts of a grafting monomer; 0.1 to 0.5 part of an initiator; 0-3 parts of a processing aid; the glass fiber reinforced nylon 12 composite material can be used for reinforcing modification of a nylon 12 material, has a relatively high glass fiber retention length, can effectively improve normal and low temperature impact performance on the premise of not influencing tensile strength and modulus, and shows a more excellent performance retention rate after aging in a high-temperature cooling liquid.

Description

Technical Field

[0001] The present invention relates to reinforced nylon 12 materials, and in particular to an in-situ grafted toughener masterbatch and a preparation method thereof, and a high-impact hydrolysis-resistant reinforced nylon 12 material and a preparation method thereof, belonging to the technical field of polymer materials. Background Art

[0002] Nylon 12 is a polyamide variety with 12 methylene groups between adjacent amide groups. The long methylene chain and polar amide groups endow it with the dual characteristics of polyolefins and polyamides. While having excellent mechanical strength, wear resistance, chemical solvent resistance and other properties, it overcomes the deficiencies of short-chain nylon such as high water absorption rate, narrow processing window, poor low-temperature toughness, and dimensional instability, and has important applications in the fields of automobiles, electronic appliances, aerospace, oil pipelines, etc.

[0003] Glass fiber has the characteristics of high tensile strength, excellent chemical resistance, non-hygroscopicity, low coefficient of thermal expansion and high thermal conductivity. As a skeleton in the nylon matrix, glass fiber can significantly improve the strength, rigidity and heat resistance temperature of nylon, and among them, short glass fiber is the most widely used. The factors affecting glass fiber reinforced materials include the strength of the matrix resin and the glass fiber itself, the glass fiber content, the glass fiber length and distribution, the glass fiber orientation, and the interfacial bonding between the glass fiber and the matrix resin.

[0004] In typical applications of reinforced nylon 12 materials, such as injection molded parts like pipe joints, buckles, and housings, in addition to the basic rigidity requirements such as tensile and bending properties, toughness requirements are also put forward for the reinforced nylon 12 materials, especially the impact strength performance under low-temperature conditions and hydrolysis liquid aging environments. Conventional methods introduce toughener components in addition to glass fiber to improve the impact strength, but there are problems that the tensile and bending properties are affected to varying degrees, and at the same time, due to the hydrolysis aging of the toughener in the coolant-resistant environment, a higher performance attenuation rate is caused instead.

[0005] Chinese Patent CN101851417A discloses a high-performance glass fiber reinforced nylon composite material and a preparation method thereof. By combining components such as a compatibilizing toughener, whiskers, a nucleating agent, and glass fiber, the tensile performance and bending modulus can be improved, but the toughness decreases; Chinese Patent CN104250438A discloses a toughened and reinforced nylon composite material and a preparation method thereof. Using a polyamide compound loaded with nano-silica as a toughener can improve the impact strength and bending modulus to a certain extent, but nano-silica has problems such as complex preparation processes and small sample amounts, and it is difficult to meet the needs of industrial promotion.

[0006] Therefore, it is still necessary to develop a nylon 12 material with a relatively high glass fiber retention length, and at the same time, it can effectively improve the impact performance, hydrolysis resistance performance, etc. without affecting the tensile strength and modulus. Summary of the Invention

[0007] In view of this, one of the purposes of the present invention is to provide an in-situ graft toughening agent masterbatch and a preparation method thereof, which can be used for the modification of nylon 12 materials.

[0008] Another purpose of the present invention is to provide a high-impact hydrolysis-resistant reinforced nylon 12 material and a preparation method thereof. This material uses the above-mentioned in-situ graft toughening agent masterbatch, has a relatively high glass fiber retention length, can effectively improve the impact performance at normal and low temperatures without affecting the tensile strength and modulus, and at the same time has excellent hydrolysis resistance, weather resistance, dimensional stability and surface quality.

[0009] To achieve the above technical effects, the present invention adopts the following technical solutions:

[0010] In the first aspect, the present invention provides an in-situ graft toughening agent masterbatch, and its raw material weight composition includes:

[0011] Nylon 12 resin, 40 - 80 parts, such as 40, 45, 50, 55, 60, 65, 70, 75, 80 parts, preferably 60 - 70 parts;

[0012] Toughening agent, 10 - 40 parts, such as 10, 15, 20, 25, 30, 35, 40 parts, preferably 20 - 30 parts;

[0013] Graft monomer, 1 - 4 parts, such as 1, 1.5, 2, 2.5, 3, 3.5, 4 parts, preferably 2 - 3 parts;

[0014] Initiator, 0.1 - 0.5 parts, such as 0.1, 0.2, 0.3, 0.4, 0.5 parts, preferably 0.2 - 0.3 parts;

[0015] Processing aid, 0 - 3 parts, 0, 0.1, 0.5, 1, 1.5, 2, 2.5, 3 parts, preferably 1 - 2 parts;

[0016] Furthermore, the terminal amino group content of the nylon 12 resin is 30 - 80 mmol / kg, such as 30, 40, 60, 80 mmol / kg, preferably 40 - 60 mmol / kg;

[0017] The molar ratio of the terminal amino group to the terminal carboxyl group of the nylon 12 resin is 1:1 - 4:1, such as 1:1, 1.5:1, 2:1, 3:1, 4:1, preferably 2:1 - 3:1;

[0018] The number-average molecular weight of the nylon 12 resin is 30000 - 50000, such as 30000, 35000, 40000, 45000, 50000, preferably 32000 - 40000;

[0019] The polydispersity index of the nylon 12 resin is 1.5 - 3.0, such as 1.5, 1.8, 2.0, 2.4, 2.8, 3.0, preferably 1.8 - 2.4.

[0020] Furthermore, the toughening agent is at least one of ethylene-octene copolymer (POE), ethylene-propylene copolymer (EPR), ethylene-propylene-non-conjugated diene copolymer (EPDM), styrene-butadiene copolymer (SBS), styrene-ethylene-butene-styrene block copolymer (SEBS), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMA), ethylene-butyl acrylate (EBA), preferably one or several of ethylene-methacrylic acid copolymer (EMA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA).

[0021] Furthermore, the graft monomer is at least one of maleic anhydride (MAH) and its derivatives, acrylate (AA) and its derivatives, methacrylic acid, unsaturated fatty acid, methylene succinic acid, glycidyl methacrylate (GMA), styrene (St), divinylbenzene (DVB), bismaleimide (BMI), triallyl isocyanurate (TAIC), preferably at least one of maleic anhydride (MAH), glycidyl methacrylate (GMA), styrene (St), divinylbenzene (DVB), more preferably a composition of at least one of maleic anhydride (MAH), glycidyl methacrylate (GMA) and at least one of styrene (St), divinylbenzene (DVB).

[0022] Furthermore, the initiator is at least one of benzoyl peroxide (BPO), dicumyl peroxide (DCP), 2,5-dimethyl-2,5-di(tert-butylperoxy)ethane (DHBP), 2,3-dimethyl-2,3-diphenylbutane (DMDPB), etc., preferably a compound of dicumyl peroxide (DCP) and benzoyl peroxide (BPO) in a mass ratio of 1:1.

[0023] Furthermore, the processing aids are selected from lubricants and / or antioxidants, which are all conventional selections in the field, and there are no special requirements in the present invention; for example:

[0024] Among them, the lubricant is 0 - 2 parts, such as 1, 0.1, 0.5, 1, 1.5, 2 parts, preferably 0.4 - 1 part; the lubricant is selected from at least one of stearic acid composite esters, montan wax, metal soaps, polyethylene waxes, low molecular weight esters, amide waxes, preferably a compound of stearic acid composite esters and metal soap lubricants in a mass ratio of 1:1;

[0025] Among them, the antioxidant is 0 - 2 parts, such as 1, 0.1, 0.5, 1, 1.5, 2 parts, preferably 0.4 - 1 part; the antioxidant is a compound of a hindered phenol type antioxidant and a phosphite type antioxidant, and more preferably a compound of antioxidant 1010 and antioxidant 168 in a mass ratio of 5:3.

[0026] Second, the present invention provides a method for preparing the in-situ graft toughening agent masterbatch, comprising the following steps:

[0027] (1) Dissolve the graft monomer and the initiator in 3 - 4 times the volume of acetone to prepare a solution;

[0028] (2) Heat the toughening agent to 60 - 80 °C, then add the solution of step (1) and the processing aid, and stir at a temperature below 100 °C for 5 - 10 min to obtain a premix;

[0029] (3) Mix the premix of step (2) with part of the nylon 12 resin evenly, and feed it into a twin-screw extruder through the main feed port, and add the remaining nylon 12 resin through the side feed port, and extrude and pelletize to obtain the in-situ graft toughening agent masterbatch.

[0030] Further, in step (2), the mixing process uses a high-speed mixer, and the mixing speed is 300 - 600 rpm, such as 300, 400, 500, 600 rpm;

[0031] Further, for the twin-screw extruder in step (3), the ratio of the screw length to the diameter is 36:1 - 50:1, such as 36:1, 40:1, 44:1, 48:1, 50:1, preferably 44:1 - 48:1; the extrusion temperature is 210 - 300 °C, such as 210, 230, 250, 270, 290, 300 °C, preferably 250 - 270 °C; the screw speed is 200 - 800 rpm, such as 200, 400, 600, 800 rpm, preferably 500 - 700 rpm;

[0032] Further, for the nylon 12 resin in step (3), the mass ratio of the two additions is 1:1 - 1.2, such as 1:1, 1:1.1, 1:1.2.

[0033] Third, the present invention simultaneously provides the application of the above-mentioned in-situ graft toughening agent masterbatch in the field of nylon 12.

[0034] Preferably, the present invention provides a high-impact hydrolysis-resistant reinforced nylon 12 composite material containing the in-situ graft toughening agent masterbatch, and its raw material weight parts composition includes:

[0035] Nylon 12 resin, 20 - 75 parts, such as 20, 30, 40, 50, 60, 70, 75 parts, preferably 35 - 60 parts;

[0036] In-situ graft toughening agent masterbatch, 6 - 20 parts, such as 6, 8, 10, 12, 14, 16, 18, 20 parts, preferably 10 - 15 parts;

[0037] Glass fiber, 20 - 60 parts, such as 20, 30, 40, 50, 60 parts, preferably 30 - 50 parts;

[0038] Processing aid, 0 - 3 parts, such as 0, 0.1, 0.5, 1, 1.5, 2, 2.5, 3 parts, preferably 1 - 2 parts;

[0039] Furthermore, the terminal amino group content of the nylon 12 resin is 30 - 80 mmol / kg, such as 30, 40, 60, 80 mmol / kg, preferably 40 - 60 mmol / kg;

[0040] The molar ratio of the terminal amino group to the terminal carboxyl group of the nylon 12 resin is 1:1 - 4:1, such as 1:1, 1.5:1, 2:1, 3:1, 4:1, preferably 2:1 - 3:1;

[0041] The number-average molecular weight of the nylon 12 resin is 30000 - 50000, such as 30000, 35000, 40000, 45000, 50000, preferably 32000 - 40000;

[0042] The polydispersity coefficient of the nylon 12 resin is 1.5 - 3.0, such as 1.5, 1.8, 2.0, 2.4, 2.8, 3.0, preferably 1.8 - 2.4.

[0043] Furthermore, the glass fiber is an alkali-free chopped glass fiber activated by a silane coupling agent. This type of glass fiber is an existing product, such as Taishan Fiberglass HMG435TM - 4.0, HMG435TM - 3.0, etc.;

[0044] Preferably, the glass fiber has a diameter of 8 - 14 μm, such as 8, 9, 10, 11, 12, 13, 14 μm, preferably 10 - 12 μm; and a length of 2 - 5 mm, such as 2, 3, 4, 5 mm, preferably 3 - 4 mm.

[0045] Furthermore, the processing aid is selected from lubricants and / or antioxidants, which are all conventional selections in the field, and there are no special requirements in the present invention; for example:

[0046] Wherein the lubricant is 0 - 2 parts, such as 1, 0.1, 0.5, 1, 1.5, 2 parts, preferably 0.4 - 1 part; the lubricant is selected from at least one of stearic acid composite esters, montan wax, metal soaps, polyethylene waxes, low - molecular esters, and amide waxes, preferably a compound of stearic acid composite esters and metal soaps lubricants in a mass ratio of 1:1;

[0047] Wherein the antioxidant is 0 - 2 parts, such as 1, 0.1, 0.5, 1, 1.5, 2 parts, preferably 0.4 - 1 part; the antioxidant is a compound of hindered phenol - type and phosphite - type antioxidants, more preferably a compound of antioxidant 1010 and antioxidant 168 in a mass ratio of 5:3.

[0048] Fourthly, the present invention also provides a preparation method of the high - impact hydrolysis - resistant reinforced nylon 12 composite material, comprising the following steps:

[0049] Mix nylon 12 resin, in - situ grafting toughener masterbatch, and processing aids evenly, add them through the main feeding port of a twin - screw extruder, add glass fiber through the side feeding port, and extrude and pelletize to obtain the high - impact hydrolysis - resistant reinforced nylon 12 composite material.

[0050] Furthermore, for the twin - screw extruder, the ratio of screw length to diameter is 36:1 - 50:1, such as 36:1, 40:1, 44:1, 48:1, 50:1, preferably 38:1 - 42:1; the extrusion temperature is 210 - 300 °C, such as 210, 230, 250, 270, 290, 300 °C, preferably 240 - 250 °C; the screw speed is 200 - 800 rpm, such as 200, 400, 600, 800 rpm, preferably 300 - 400 rpm.

[0051] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0052] 1. The present invention uses an in - situ grafting toughener masterbatch, which, in combination with the nylon 12 resin of the present invention, can achieve an in - situ reaction between the nylon 12 resin and the polar group during the process of grafting polar groups on the toughener, significantly enhancing the chemical bonding effect between nylon 12 and the polar groups of the grafting toughener, and at the same time improving the dispersion effect of the grafting toughener in the nylon 12 resin;

[0053] 2. The in - situ grafting toughener masterbatch of the present invention has good compatibility with glass fiber. The introduced polar groups have a bonding effect with the nylon 12 resin selected in the present invention, which can further improve the interfacial bonding force between the resin and the glass fiber, reduce the separation of the glass fiber and the resin during the melt - blending process, and improve the retention length and dispersion effect of the glass fiber after the action of the high - temperature shear force field;

[0054] 3. By using the in-situ grafting toughener masterbatch of the present invention, a more stable rigid framework is formed with glass fibers of a higher retention length in the nylon 12 matrix. It has the characteristic of absorbing and transmitting impact energy to a greater extent when being impacted, improving the impact strength of the nylon 12 reinforced material at normal and low temperatures without reducing the strength and modulus, and achieving a better mechanical property retention rate in a long-term high-temperature hydrolysis environment. Detailed Embodiments

[0055] The following are specific embodiments of the present invention, further describing the technical solutions of the present invention, but the content of the present invention includes but is not limited to these embodiments.

[0056] The sources of the main raw materials in the embodiments and comparative examples of the present invention are as follows. Without special instructions, other raw materials and reagents are obtained through commercial channels on the market:

[0057] Nylon 12A, with a molecular weight of 35103, a polydispersity coefficient of 1.8032, an amino group content at the end of 60 mmol / kg, and a ratio of amino groups at the end to carboxyl groups at the end of 2:1;

[0058] Nylon 12B, with a molecular weight of 33811, a polydispersity coefficient of 2.1653, an amino group content at the end of 40 mmol / kg, and a ratio of amino groups at the end to carboxyl groups at the end of 1:1;

[0059] Nylon 12C, with a molecular weight of 40137, a polydispersity coefficient of 2.0465, an amino group content at the end of 25 mmol / kg, and a ratio of amino groups at the end to carboxyl groups at the end of 1:2;

[0060] The above nylon 12 (A-C) is prepared based on conventional methods, and the methods for regulating the molecular weight and end group content refer to the methods disclosed in patents CN110818892A, CN106188534A, CN116199877A, and CN116925342A;

[0061] Glass fiber A, an alkali-free chopped glass fiber activated with a silane coupling agent, grade HMG435TM-4.0, fiber diameter 10 μm, fiber length 4.0 mm, Taishan Fiberglass;

[0062] Glass fiber B, an alkali-free chopped glass fiber activated with a silane coupling agent, grade HMG435TM-3.0, fiber diameter 10 μm, fiber length 3.0 mm, Taishan Fiberglass;

[0063] Toughener A, EMA, grade AC1125, methyl acrylate content 25 wt%, Dow Chemical;

[0064] Toughener B, POE, grade ENGAGE 8480, Dow Chemical;

[0065] Grafting monomer A, maleic anhydride (MAH), Aladdin Reagent Co., Ltd., Shanghai;

[0066] Grafting monomer B, glycidyl methacrylate (GMA), Aladdin Reagent Co., Ltd., Shanghai;

[0067] Grafting monomer C, styrene (St), Aladdin Reagent Co., Ltd., Shanghai;

[0068] Grafting monomer D, divinylbenzene (DVB), Aladdin Reagent Co., Ltd., Shanghai;

[0069] Initiator A, benzoyl peroxide (BPO), Aladdin Reagent Co., Ltd., Shanghai;

[0070] Initiator B, dicumyl peroxide (DCP), Aladdin Reagent Co., Ltd., Shanghai;

[0071] Graft toughening agent A, ethylene-methacrylic acid copolymer grafted maleic anhydride (GMA-g-MAH), grade A560, DuPont Chemical;

[0072] Graft toughening agent B, ethylene-octene copolymer grafted maleic anhydride (POE-g-MAH), grade MH5040, Mitsui Chemicals;

[0073] Lubricant, metal soap lubricant, calcium stearate, Jinling Chemical Industry;

[0074] Lubricant, stearic acid composite ester, pentaerythritol stearate, Emery Oleochemicals;

[0075] Antioxidant, hindered phenol antioxidant, 1098, BASF;

[0076] Antioxidant, hindered phenol antioxidant, 1010, BASF;

[0077] Antioxidant, phosphite antioxidant, grade 168, BASF.

[0078] The present invention will be further described below through specific examples. The following examples are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the following examples.

[0079] The following will be described in the form of specific examples. Unless otherwise specified, the raw materials are in parts by weight.

[0080]

Preparation Example 1

[0081] Prepare the in-situ graft toughening agent masterbatch A, and the steps are as follows:

[0082] (1) Dissolve 1.2 parts of grafting monomer A MAH, 1.2 parts of grafting monomer C St, 0.12 part of initiator A BPO, and 0.12 part of initiator B DCP in 3 times the volume of acetone solvent, and stir at room temperature for 0.5 h to prepare a solution;

[0083] (2) Raise the temperature of 25 parts of toughening agent A EMA to 60 °C by high-speed stirring (rotation speed: 500 rpm) in a high-speed mixer, then add 0.5 part of antioxidant 1010, 0.3 part of antioxidant 168, 0.2 part of calcium stearate, and 0.2 part of pentaerythritol stearate. Then add the solution from step (1), and stir for 8 min at a temperature below 100 °C. Finally, allow the solution mixed with graft monomers and initiators to penetrate into the toughening agent to obtain a premix.

[0084] (3) Mix the premix from step (2) with 40 parts of nylon 12A and add it to the main feed port. The remaining 31 parts of nylon 12A are added through the fourth side feed port. The aspect ratio of the twin-screw extruder is 48:1, the extrusion temperature is 240 - 250 °C, and the screw rotation speed is 500 rpm to obtain in-situ graft toughening agent masterbatch A.

[0085]

Preparation Example 2

[0086] The steps for preparing in-situ graft toughening agent masterbatch B are as follows:

[0087] (1) Dissolve 1.5 parts of graft monomer B GMA, 1.5 parts of graft monomer C St, and 0.3 part of initiator B DCP in 3 times the volume of acetone solvent, and stir at room temperature for 0.5 h to prepare a solution.

[0088] (2) Raise the temperature of 30 parts of toughening agent B POE to 70 °C by high-speed stirring (rotation speed: 400 rpm) in a high-speed mixer, then add 0.4 part of antioxidant 1010, 0.4 part of antioxidant 168, 0.2 part of calcium stearate, and 0.2 part of pentaerythritol stearate. Then add the solution from step (1), and stir for 10 min at a temperature below 100 °C. Finally, allow the solution mixed with graft monomers and initiators to penetrate into the toughening agent to obtain a premix.

[0089] (3) Mix the premix from step (2) with 35 parts of nylon 12A and add it to the main feed port. The remaining 30 parts of nylon 12A are added through the fourth side feed port. The aspect ratio of the twin-screw extruder is 48:1, the extrusion temperature is 240 - 250 °C, and the screw rotation speed is 400 rpm to obtain in-situ graft toughening agent masterbatch B.

[0090]

Preparation Example 3

[0091] The steps for preparing in-situ graft toughening agent masterbatch C are as follows:

[0092] (1) Dissolve 3 parts of graft monomer A MAH and 0.3 part of initiator DCP in 3 times the volume of acetone solvent, and stir at room temperature for 0.5 h to prepare a solution.

[0093] (2) Raise the temperature of 30 parts of toughening agent B (POE) to 80 °C by high-speed stirring (at a rotation speed of 400 rpm) using a high-speed mixer, then add 0.5 parts of antioxidant 1010, 0.3 parts of antioxidant 168, 0.2 parts of calcium stearate, and 0.2 parts of pentaerythritol stearate. Then add the solution from step (1) and stir for 8 minutes at a temperature below 100 °C. Finally, allow the solution mixed with graft monomers and initiators to penetrate into the toughening agent to obtain a premix;

[0094] (3) Mix the premix from step (2) with 40 parts of nylon 12B evenly and add it to the main feed port. The remaining 25 parts of nylon 12B are added through the fourth side feed port. The length-diameter ratio of the twin-screw extruder is 48:1, the extrusion temperature is 240 - 250 °C, and the screw rotation speed is 500 rpm to prepare the in-situ graft toughening agent masterbatch C.

[0095]

Prepare Comparative Example 1

[0096] Prepare the in-situ graft toughening agent masterbatch D, and the steps are as follows:

[0097] Mix 68 parts of nylon 12A, 30 parts of graft toughening agent A (GMA-g-MAH), 0.3 parts of antioxidant 1010, 0.3 parts of antioxidant 168, 0.4 parts of calcium stearate, and 0.4 parts of pentaerythritol stearate by high-speed stirring (at a rotation speed of 300 rpm) for 5 minutes, then add it to the main feed port, and feed it into a twin-screw extruder for pelletizing. The length-diameter ratio of the screw is 48:1, the extrusion temperature is 240 - 250 °C, and the screw rotation speed is 400 rpm to prepare the graft toughening agent masterbatch D.

[0098]

Prepare Comparative Example 2

[0099] Prepare the in-situ graft toughening agent masterbatch E, and the steps are as follows:

[0100] Mix 38 parts of nylon 12C, 30 parts of graft toughening agent B (POE-g-MAH), 0.3 parts of antioxidant 1010, 0.3 parts of antioxidant 168, 0.2 parts of calcium stearate, and 0.2 parts of pentaerythritol stearate by high-speed stirring (at a rotation speed of 400 rpm) for 5 minutes, then add it to the main feed port. The remaining 30 parts of nylon 12C are added through the fourth side feed port, and feed it into a twin-screw extruder for pelletizing. The length-diameter ratio of the screw is 48:1, the extrusion temperature is 240 - 250 °C, and the screw rotation speed is 400 rpm to prepare the graft toughening agent masterbatch E.

[0101]

Example 1

[0102] Prepare a high-impact hydrolysis-resistant reinforced nylon 12 composite material, and the steps are as follows:

[0103] Mix 59 parts of nylon 12A, 10 parts of in-situ graft toughening agent masterbatch A, 0.4 parts of compound antioxidant (a compound of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1), and 0.4 parts of compound lubricant (a compound of stearic acid composite ester and metal soap with a mass ratio of 1:1) evenly, and feed them into a twin-screw extruder through the main feed port for granulation. Add 30 parts of glass fiber A from the side feed port and use a twin-screw extruder for granulation; the length-diameter ratio of the extruder screw is 42:1, the extrusion temperature is 240 - 250 °C, the screw speed is 300 rpm, and high-impact hydrolysis-resistant reinforced nylon 12 composite particles are obtained.

[0104]

Example 2

[0105] To prepare high-impact hydrolysis-resistant reinforced nylon 12 composite, the steps are as follows:

[0106] Mix 59 parts of nylon 12A, 10 parts of in-situ graft toughening agent masterbatch B, 0.6 parts of compound antioxidant (a compound of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1), and 0.8 parts of compound lubricant (a compound of stearic acid composite ester and metal soap with a mass ratio of 1:1) evenly, and feed them into a twin-screw extruder through the main feed port for granulation. Add 30 parts of glass fiber A from the side feed port and use a twin-screw extruder for granulation; the length-diameter ratio of the extruder screw is 42:1, the extrusion temperature is 250 - 260 °C, the screw speed is 400 rpm, and high-impact hydrolysis-resistant reinforced nylon 12 composite particles are obtained.

[0107]

Example 3

[0108] To prepare high-impact hydrolysis-resistant reinforced nylon 12 composite, the steps are as follows:

[0109] Mix 59 parts of nylon 12A, 10 parts of in-situ graft toughening agent masterbatch C, 0.6 parts of compound antioxidant (a compound of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1), and 0.4 parts of compound lubricant (a compound of stearic acid composite ester and metal soap with a mass ratio of 1:1) evenly, and feed them into a twin-screw extruder through the main feed port for granulation. Add 30 parts of glass fiber A from the side feed port and use a twin-screw extruder for granulation; the length-diameter ratio of the extruder screw is 42:1, the extrusion temperature is 240 - 250 °C, the screw speed is 300 rpm, and high-impact hydrolysis-resistant reinforced nylon 12 composite particles are obtained.

[0110]

Comparative Example 1

[0111] Prepare reinforced nylon 12 particles according to the method in Example 1, with the difference that: replace the in-situ graft toughening agent masterbatch A with graft toughening agent masterbatch D.

[0112]

Comparative Example 2

[0113] Prepare the reinforced nylon 12 particles according to the method in Example 1, with the difference that: the in-situ graft toughener masterbatch A is replaced by the graft toughener masterbatch E.

[0114]

Example 4

[0115] Prepare the high-impact hydrolysis-resistant reinforced nylon 12 composite material, and the steps are as follows:

[0116] Mix 49 parts of nylon 12A, 20 parts of in-situ graft toughener masterbatch A, 0.4 part of compound antioxidant (a compound of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1), and 0.6 part of compound lubricant (a compound of stearic acid composite ester and metal soap with a mass ratio of 1:1) evenly, and feed them into a twin-screw extruder through the main feed port for granulation. Add 30 parts of glass fiber A from the side feed port and use a twin-screw extruder for granulation; the length-diameter ratio of the extruder screw is 42:1, the extrusion temperature is 240 - 250 °C, and the screw speed is 400 rpm to obtain the high-impact hydrolysis-resistant reinforced nylon 12 composite material particles.

[0117]

Example 5

[0118] Prepare the high-impact hydrolysis-resistant reinforced nylon 12 composite material, and the steps are as follows:

[0119] Mix 59 parts of nylon 12A, 10 parts of in-situ graft toughener masterbatch A, 0.5 part of compound antioxidant (a compound of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1), and 0.5 part of compound lubricant (a compound of stearic acid composite ester and metal soap with a mass ratio of 1:1) evenly, and feed them into a twin-screw extruder through the main feed port for granulation. Add 30 parts of glass fiber B from the side feed port and use a twin-screw extruder for granulation; the length-diameter ratio of the extruder screw is 42:1, the extrusion temperature is 240 - 250 °C, and the screw speed is 400 rpm to obtain the high-impact hydrolysis-resistant reinforced nylon 12 composite material particles.

[0120]

Comparative Example 3

[0121] Prepare the reinforced nylon 12 particles according to the method in Example 1, with the difference that: 20 parts of in-situ graft toughener masterbatch A are replaced by an equal amount of nylon 12A.

[0122]

Comparative Example 4

[0123] Prepare the high-impact hydrolysis-resistant reinforced nylon 12 composite material, and the steps are as follows:

[0124] Mix 65 parts of nylon 12A, 4 parts of graft toughening agent A GMA-g-MAH, 0.4 parts of compound antioxidant (a compound of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1), and 0.6 parts of compound lubricant (a compound of stearic acid compound ester and metal soap with a mass ratio of 1:1) evenly, and feed them into a twin-screw extruder through the main feed port for granulation. Add 30 parts of glass fiber B from the side feed port and use a twin-screw extruder for granulation; the length-diameter ratio of the extruder screw is 42:1, the extrusion temperature is 240 - 250 °C, the screw speed is 400 rpm, and high-impact hydrolysis-resistant reinforced nylon 12 composite material particles are obtained.

[0125]

Example 6

[0126] To prepare a high-impact hydrolysis-resistant reinforced nylon 12 composite material, the steps are as follows:

[0127] Mix 39 parts of nylon 12A, 10 parts of in-situ graft toughening agent masterbatch A, 0.6 parts of compound antioxidant (a compound of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1), and 0.4 parts of compound lubricant (a compound of stearic acid compound ester and metal soap with a mass ratio of 1:1) evenly, and feed them into a twin-screw extruder through the main feed port for granulation. Add 50 parts of glass fiber A from the side feed port and use a twin-screw extruder for granulation; the length-diameter ratio of the extruder screw is 42:1, the extrusion temperature is 240 - 250 °C, the screw speed is 400 rpm, and high-impact hydrolysis-resistant reinforced nylon 12 composite material particles are obtained.

[0128]

Example 7

[0129] To prepare a high-impact hydrolysis-resistant reinforced nylon 12 composite material, the steps are as follows:

[0130] Mix 29 parts of nylon 12A, 20 parts of in-situ graft toughening agent masterbatch A, 0.4 parts of compound antioxidant (a compound of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1), and 0.6 parts of compound lubricant (a compound of stearic acid compound ester and metal soap with a mass ratio of 1:1) evenly, and feed them into a twin-screw extruder through the main feed port for granulation. Add 50 parts of glass fiber B from the side feed port and use a twin-screw extruder for granulation; the length-diameter ratio of the extruder screw is 42:1, the extrusion temperature is 240 - 250 °C, the screw speed is 400 rpm, and high-impact hydrolysis-resistant reinforced nylon 12 composite material particles are obtained.

[0131]

Comparative Example 5

[0132] To prepare a high-impact hydrolysis-resistant reinforced nylon 12 composite material, the steps are as follows:

[0133] Mix 49 parts of nylon 12A, 0.6 parts of compound antioxidant (a compound of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1), and 0.4 parts of compound lubricant (a compound of stearic acid compound esters and metal soaps with a mass ratio of 1:1) evenly, and feed them into a twin-screw extruder through the main feed port for granulation. Add 50 parts of glass fiber A from the side feed port and use a twin-screw extruder for granulation; the length-diameter ratio of the extruder screw is 42:1, the extrusion temperature is 240 - 250 °C, the screw speed is 500 rpm, and high-impact hydrolysis-resistant reinforced nylon 12 composite particles are obtained.

[0134]

Comparative Example 6

[0135] To prepare a high-impact hydrolysis-resistant reinforced nylon 12 composite material, the steps are as follows:

[0136] Mix 46 parts of nylon 12A, 3 parts of graft toughening agent B POE-g-MAH, 0.6 parts of compound antioxidant (a compound of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1), and 0.4 parts of compound lubricant (a compound of stearic acid compound esters and metal soaps with a mass ratio of 1:1) evenly, and feed them into a twin-screw extruder through the main feed port for granulation. Add 50 parts of glass fiber B from the side feed port and use a twin-screw extruder for granulation; the length-diameter ratio of the extruder screw is 42:1, the extrusion temperature is 250 - 260 °C, the screw speed is 400 rpm, and high-impact hydrolysis-resistant reinforced nylon 12 composite particles are obtained.

[0137] The reinforced nylon 12 particles prepared in the examples and comparative examples were tested for performance according to the following standards or methods:

[0138] The tensile properties were tested according to the ISO527 standard, where the test speed for tensile strength was set at 5 mm / min and the test speed for tensile modulus was set at 1 mm / min;

[0139] The notched impact strength was tested according to the ISO179 standard, where the low-temperature notched impact test was carried out after freezing the notched samples at -30 °C for 4 h;

[0140] In the coolant aging test, the medium was a solution prepared by mixing coolant and water in a ratio of 1:1. The test temperature was 135 °C, and after the test time reached 1000 h, the tensile properties and notched impact strength of the samples were tested respectively (the notches were made before aging), and compared with the properties of the samples before aging.

[0141] The test results of the reinforced PA12 prepared in Examples 1 - 7 and Comparative Examples 1 - 6 are as follows:

[0142] Table 1 - Mechanical properties of reinforced PA12 materials in examples and comparative examples

[0143]

[0144]

[0145] It can be seen from the test results in Table 1 that an enhanced nylon 12 system with good mechanical properties and glass fiber retention length can be obtained through the above-mentioned formulation composition and preparation method. The nylon 12 resin, the type of toughening agent, the preparation method of the in-situ grafted toughening agent masterbatch, glass fiber, etc. will all have different effects on the product performance.

[0146] The comparison of Examples 1, 2 and 3 shows that through the preparation method of the in-situ grafted toughening agent masterbatch, high reaction activity is shown with nylon 12 resins with high-end amino content and the ratio of terminal amino group / terminal carboxyl group, corresponding to excellent tensile properties, impact strength and relatively high glass fiber retention length of the enhanced nylon 12 system.

[0147] The comparison of Examples 1, 3 and Comparative Example 1 shows that by directly adding a grafted toughening agent to prepare a compatibilizing toughening agent masterbatch, the tensile properties and impact strength show a certain decline compared with the method of preparing the masterbatch of the in-situ grafted toughening agent.

[0148] The comparison of Examples 1, 2 and Comparative Example 2 shows that when the nylon 12 resin has a low-end amino content, the impact strength decreases, which is related to the reduction of the reaction activity between nylon 12 and the graft copolymer.

[0149] The comparison of Example 4 and Comparative Example 3 shows that when 20 parts of the in-situ grafted toughening agent masterbatch are added, the tensile modulus is affected to a certain extent, and the impact strength still remains at a relatively high level; while when the toughening agent masterbatch is not added, the tensile properties change little, but the impact strength and glass fiber retention length decrease significantly.

[0150] The comparison of Example 5 and Comparative Example 4 shows that directly adding the grafted toughening agent to the preparation process of the enhanced nylon 12 material will have a certain negative impact on the glass fiber retention length and impact strength.

[0151] The comparison of Example 6 and Comparative Example 5 shows that in a 50-part glass fiber reinforced system, when the toughening agent masterbatch is not added, the impact strength and glass fiber retention length also decrease significantly.

[0152] The comparison of Example 7 and Comparative Example 6 shows that in a 50-part glass fiber reinforced system, when the 4.0 mm glass fiber is replaced with 3.0 mm, the influence on the tensile properties and impact strength is less than that of a 30-part glass fiber reinforced system.

[0153] Table 2 Performance retention rate of Examples and Comparative Examples of enhanced PA12 materials after 1000 h of coolant environment aging

[0154] Tensile modulus retention rate Tensile strength retention rate Notched impact strength retention rate Example 1 75.10％ 84.55％ 63.89％ Example 2 73.82％ 79.44％ 58.11％ Example 3 71.07％ 80.59％ 55.24％ Comparative example 1 70.13％ 78.77％ 42.05％ Comparative example 2 68.67％ 75.43％ 39.83％ Example 4 71.17％ 79.32％ 57.02％ Example 5 71.99％ 82.16％ 51.41％ Comparative example 3 70.99％ 79.04％ 36.05％ Comparative example 4 68.64％ 76.68％ 42.92％ Example 6 77.24％ 84.59％ 64.67％ Example 7 75.59％ 84.15％ 63.07％ Comparative example 5 72.19％ 78.07％ 46.49％ Comparative example 6 72.40％ 76.84％ 48.57％

[0155] As can be seen from the test results in Table 2, the reinforced nylon 12 material with the above-mentioned formulation composition and preparation method still has a high retention rate of tensile modulus, tensile strength, and notched impact strength after 1000 h of hydrolysis-resistant environmental aging. This is mainly due to the good hydrolysis resistance characteristics of nylon 12 resin and glass fiber itself. However, the product performance retention rate, especially the impact strength retention rate, is also affected by the material formulation and preparation method.

[0156] The comparison of Examples 1, 2, and 3 shows that through the preparation method of in-situ grafted toughener masterbatch, the reinforced nylon 12 system has excellent tensile properties and impact strength, and still maintains a high performance retention rate after 1000 h of coolant environmental aging.

[0157] The comparison of Examples 1, 3, and Comparative Example 1 shows that the impact performance retention rate decreases significantly when the grafted toughener is directly added compared with the preparation method of in-situ grafted toughener masterbatch.

[0158] The comparison of Examples 1, 2, and Comparative Example 2 shows that when the in-situ grafted toughener masterbatch is used in the case of low amino content of nylon 12 resin, the impact strength retention rate also decreases significantly.

[0159] The comparison of Example 4 and Comparative Example 3 shows that when 20 parts of in-situ grafted toughener masterbatch are added, the impact strength retention rate remains at a high level; when the in-situ grafted toughener masterbatch is not added, the tensile property retention rate decreases slightly, and the impact strength retention rate decreases significantly.

[0160] The comparison of Example 5 and Comparative Example 4 shows that directly adding the grafted toughener by skipping the preparation process of the toughener masterbatch will affect the chemical bonding effect between nylon 12 and the toughener, and thus affect the hydrolysis resistance of the reinforced nylon 12 material.

[0161] The comparison of Example 6 and Comparative Example 5 shows that in a 50-part glass fiber reinforced system, an appropriate content of in-situ grafted toughener masterbatch can also improve the hydrolysis resistance of the material. Moreover, different glass fiber lengths have little effect on the tensile property and impact strength retention rates. However, changing the amount of in-situ grafted toughener masterbatch will have varying degrees of negative effects on the hydrolysis resistance characteristics and tensile / impact property retention rates of the final reinforced nylon 12 material.

[0162] The comparison of Example 7 and Comparative Example 6 shows that after replacing the 4.0 mm glass fiber with 3.0 mm, the changes in the tensile property and impact strength retention rates of the 50-part glass fiber reinforced system and the 30-part glass fiber reinforced system are not significant.

[0163] It should be noted that the above is only the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An in-situ graft toughening agent masterbatch, characterized in that, The raw material weight parts composition includes: Nylon 12 resin, 40 - 80 parts, preferably 60 - 70 parts; Toughening agent, 10 - 40 parts, preferably 20 - 30 parts; Graft monomer, 1 - 4 parts, preferably 2 - 3 parts; Initiator, 0.1 - 0.5 parts, preferably 0.2 - 0.3 parts; Processing aid, 0 - 3 parts, preferably 1 - 2 parts.

2. The in-situ graft toughening agent masterbatch according to claim 1, wherein The terminal amino group content of the nylon 12 resin is 30 - 80 mmol / kg, preferably 40 - 60 mmol / kg; and / or The molar ratio of the terminal amino group to the terminal carboxyl group of the nylon 12 resin is 1:1 - 4:1, preferably 2:1 - 3:1; and / or The number average molecular weight of the nylon 12 resin is 30000 - 50000, preferably 32000 - 40000; and / or The polydispersity coefficient of the nylon 12 resin is 1.5 - 3.0, preferably 1.8 - 2.

4.

3. The in-situ graft toughening agent masterbatch according to claim 1, characterized in that The toughening agent is at least one of ethylene - octene copolymer (POE), ethylene - propylene copolymer (EPR), ethylene - propylene - non - conjugated diene copolymer (EPDM), styrene - butadiene copolymer (SBS), styrene - ethylene - butene - styrene block copolymer (SEBS), ethylene - vinyl acetate copolymer (EVA), ethylene - acrylic acid copolymer (EAA), ethylene - ethyl acrylate copolymer (EEA), ethylene - methacrylic acid copolymer (EMA), ethylene - butyl acrylate (EBA), preferably one or several of ethylene - methacrylic acid copolymer (EMA), ethylene - acrylic acid copolymer (EAA), ethylene - ethyl acrylate copolymer (EEA); and / or The graft monomer is at least one of maleic anhydride (MAH) and its derivatives, acrylate (AA) and its derivatives, methacrylic acid, unsaturated fatty acid, methylene succinic acid, glycidyl methacrylate (GMA), styrene (St), divinylbenzene (DVB), bismaleimide (BMI), triallyl isocyanurate (TAIC), preferably at least one of maleic anhydride (MAH), glycidyl methacrylate (GMA), styrene (St), divinylbenzene (DVB), more preferably a composition of at least one of maleic anhydride (MAH), glycidyl methacrylate (GMA) and at least one of styrene (St), divinylbenzene (DVB); and / or The initiator is at least one of benzoyl peroxide (BPO), dicumyl peroxide (DCP), 2,5 - dimethyl - 2,5 - bis(tert - butylperoxy)ethane (DHBP), 2,3 - dimethyl - 2,3 - diphenylbutane (DMDPB), etc., preferably a compound of dicumyl peroxide (DCP) and benzoyl peroxide (BPO) in a mass ratio of 1:

1.

4. The in-situ graft toughening agent masterbatch according to claim 1, characterized in that, The processing aid is selected from lubricants and / or antioxidants; Preferably, the lubricant is 0 - 2 parts, preferably 0.4 - 1 part; Preferably, the lubricant is selected from at least one of stearic acid composite esters, montan wax, metal soaps, polyethylene waxes, low molecular weight esters, and amide waxes, and preferably a compound of stearic acid composite esters and metal soaps lubricants in a mass ratio of 1:1; Preferably, the antioxidant is 0 - 2 parts, preferably 0.4 - 1 part; Preferably, the antioxidant is a compound of a hindered phenol type antioxidant and a phosphite type antioxidant, and more preferably a compound of antioxidant 1010 and antioxidant 168 in a mass ratio of 5:

3.

5. A method for preparing the in-situ graft toughening agent masterbatch according to any one of claims 1-4, characterized in that, It comprises the following steps: (1) Dissolve the graft monomer and the initiator in acetone with a volume 3 - 4 times that of the monomer and the initiator to prepare a solution; (2) Heat the toughening agent to 60 - 80 °C, then add the solution from step (1) and the processing aid, and stir at a temperature below 100 °C for 5 - 10 min to obtain a premix; (3) Mix the premix from step (2) with a part of nylon 12 resin evenly, feed it into a twin - screw extruder through the main feed port, and add the remaining nylon 12 resin through the side feed port, and extrude and pelletize to obtain an in - situ grafted toughening agent masterbatch.

6. The preparation method according to claim 5, characterized in that, In step (2), the mixing process uses a high - speed mixer with a mixing speed of 300 - 600 rpm; and / or For the twin - screw extruder in step (3), the ratio of screw length to diameter is 36:1 - 50:1, preferably 44:1 - 48:1; the extrusion temperature is 210 - 300 °C, preferably 250 - 270 °C; the screw speed is 200 - 800 rpm, preferably 500 - 700 rpm; and / or For the nylon 12 resin in step (3), the mass ratio of the two additions is 1:1 - 1.

2.

7. The application of the in - situ grafted toughening agent masterbatch according to any one of claims 1 - 4 or the in - situ grafted toughening agent masterbatch prepared by the method according to claim 5 or 6 in the field of nylon 12.

8. A high-impact hydrolysis-resistant reinforced nylon 12 composite material, characterized in that, Containing the in - situ grafted toughening agent masterbatch according to any one of claims 1 - 4 or the in - situ grafted toughening agent masterbatch prepared by the method according to claim 5 or 6, the raw material weight parts composition includes: Nylon 12 resin, 20 - 75 parts, preferably 35 - 60 parts; In - situ grafted toughening agent masterbatch, 6 - 20 parts, preferably 10 - 15 parts; Glass fiber, 20 - 60 parts, preferably 30 - 50 parts; Processing aid, 0 - 3 parts, preferably 1 - 2 parts.

9. The high-impact hydrolysis-resistant reinforced nylon 12 composite material according to claim 8, characterized in that, The terminal amino group content of the nylon 12 resin is 30 - 80 mmol / kg, preferably 40 - 60 mmol / kg; The molar ratio of the terminal amino group to the terminal carboxyl group of the nylon 12 resin is 1:1 - 4:1, preferably 2:1 - 3:1; The number - average molecular weight of the nylon 12 resin is 30000 - 50000, preferably 32000 - 40000; The polydispersity coefficient of the nylon 12 resin is 1.5 - 3.0, preferably 1.8 - 2.4; and / or The glass fiber is an alkali - free chopped glass fiber activated by a silane - type coupling agent, preferably Taishan Fiberglass HMG435TM - 4.0, HMG435TM - 3.0; Preferably, for the glass fiber, the diameter is 8 - 14 μm, preferably 10 - 12 μm; the length is 2 - 5 mm, preferably 3 - 4 mm; and / or The processing aid is selected from lubricants and / or antioxidants; Preferably, the lubricant is 0 - 2 parts, preferably 0.4 - 1 part; Preferably, the lubricant is selected from at least one of stearic acid composite esters, montan wax, metal soaps, polyethylene waxes, low molecular weight esters, and amide waxes, preferably a compound of stearic acid composite esters and metal soap lubricants in a mass ratio of 1:1; Preferably, the antioxidant is 0 - 2 parts, preferably 0.4 - 1 part; Preferably, the antioxidant is a compound of a hindered phenol type antioxidant and a phosphite type antioxidant, more preferably a compound of antioxidant 1010 and antioxidant 168 in a mass ratio of 5:

3.

10. A method for preparing the high-impact hydrolysis-resistant reinforced nylon 12 composite material according to claim 8 or 9, characterized in that, Comprising the following steps: Mix nylon 12 resin, in-situ graft toughening agent masterbatch, and processing aids evenly, add them through the main feeding port of a twin-screw extruder, add glass fiber through the side feeding port, and extrude and pelletize to obtain a high impact hydrolysis-resistant reinforced nylon 12 composite material; Preferably, for the twin-screw extruder, the screw length-diameter ratio is 36:1 - 50:1, preferably 38:1 - 42:1; the extrusion temperature is 210 - 300 °C, preferably 240 - 250 °C; the screw speed is 200 - 800 rpm, preferably 300 - 400 rpm.

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