High flow copolymer mx nylon composition and method of making same

Abstract

The application discloses a kind of high flow copolymer MX nylon compositions and its preparation method, the composition includes the following components: a) copolymer MX nylon 30-70 parts;B) glass fiber 30-70 parts;C) nucleating agent 0.05-0.3 parts;D) antioxidant 0.1-1 parts.The application selects viscosity 1.40-2.00 copolymer modified MX nylon, cooperates the glass fiber with the diameter of about 10 microns, antioxidant and nucleating agent to obtain high filling modified molding property better high-strength high-rigid modified composition.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a high-flow copolymer MX nylon composition and its preparation method. Background Technology

[0002] Poly(m-phenylene caproyl)dimethylamine (MXD6) is a semi-aromatic nylon polymerized from m-phenylene dimethylamine (MXDA) and adipic acid. Its main applications are in packaging and modification. Currently, both domestically and internationally, the fillers used for MXD6 reinforcement are primarily glass fiber, carbon fiber, and minerals. It possesses advantages such as high strength, high rigidity, low creep, and low water absorption, and is mainly used in automotive and electrical / electronic components. MXD6 modified filler content can reach up to 60%. The formulation typically includes lubricants to ensure good interfacial contact between the glass fiber reinforcement and the resin matrix, resulting in uniform dispersion of the glass fiber. However, this also reduces the product's heat resistance and crystallization properties. High-flow nylon can improve impregnation properties with high glass fiber filler content, thus improving the product's appearance.

[0003] CN102344670A prepared a high-flowability high-temperature nylon by adding 1-5% of a high-flowability additive. However, the type and function of the high-flowability additive were not clearly defined, and it was added during the polymerization stage, resulting in a long heating history and potential for degradation. Patent CN101148506A improved the product's flowability by copolymerizing 0.3-4% of terminal amine-containing dendritic polypropyleneimide and terephthalic acid into the nylon 6 chain segment. The molar ratio of dendritic polypropyleneimide to terephthalic acid was 1-4 / 1. Dendritic polypropyleneimide is a polyamine-based product, which easily forms crosslinks, leading to uncontrollable reactions.

[0004] Further improving the flow properties of MXD6 material to enable it to be filled with higher amounts, or to achieve better moldability or appearance under high-filler modification, thus expanding its application range, is of great significance. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide a high-flow copolymer MX nylon composition and its preparation method. The MX nylon prepared using the method of this application exhibits better flowability, and the 30-70 part high glass fiber filled modified product prepared therefrom has better molding properties.

[0006] To solve the above technical problems, the present invention provides the following technical solution:

[0007] A high-flow copolymer MX nylon composition comprising the following parts by weight:

[0008]

[0009] As a preferred embodiment, the copolymer MX nylon monomer component of the present invention comprises m-phenylenediamine, adipic acid, and other diamines.

[0010] As a preferred embodiment, the other diamines of the present invention comprise 0.1-0.5% m-phenylenediamine, based on the mass of the copolymer MX nylon monomer, and have the structural formula shown in formula a:

[0011]

[0012] As a preferred embodiment, the other diamines described in this invention comprise one or more of the following: straight-chain aliphatic diamines having 3 to 18 carbon atoms, and / or branched aliphatic diamines and / or alicyclic diamines.

[0013] As a preferred embodiment, the amount of the other diamines used in this invention is 0.1-10% of the mass of the copoly(MX) nylon monomers.

[0014] As a preferred option, the molar ratio of all diamine monomers to all dicarboxylic acid monomers in the copolymer MX nylon monomer is 1-1.001:1.

[0015] As a preferred embodiment, the linear aliphatic diamine of the present invention is selected from one or more of 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine.

[0016] As a preferred embodiment, the branched aliphatic diamine of the present invention is selected from one or more of 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,4-dimethyl-1,6-hexanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, and 5-methyl-1,9-nonanediamine.

[0017] As a preferred embodiment, the copolymer MX nylon of the present invention has a relative viscosity between 1.40 and 2.00 and a melting point between 210 and 235°C.

[0018] As a preferred embodiment, the method for preparing copolymerized MX nylon described in this invention is based on existing mature polycondensation technology, and the preparation method also includes the addition of a capping agent, a catalyst, and water.

[0019] Preferably, the capping agent is selected from one or more monobasic or dibasic acids, and more preferably from one or more of acetic acid, stearic acid, benzoic acid, adipic acid, sebacic acid, and azelaic acid.

[0020] Preferably, the amount of the end-capping agent is 0.1-5 wt% of the total mass of all diamines and all dicarboxylic acid monomers of the copolymer MX nylon, more preferably 0.3-2 wt%.

[0021] Preferably, the catalyst is selected from one or more of phosphoric acid, sodium phosphate, sodium hypophosphite, and sodium hypophosphite; the amount of catalyst used is preferably 0.1-1 wt‰ of the total mass of all diamines and all dicarboxylic acid monomers of the copolymerized MX nylon.

[0022] Preferably, the amount of water used is 10-70 wt% of the total mass of all diamines and all dicarboxylic acid monomers of the copolymerized MX nylon.

[0023] As a preferred embodiment, the preparation method of the copolymerized MX nylon of the present invention includes the following steps: adding m-phenylenediamine, adipic acid, other diamines, catalyst, end-capping agent and water into a reaction vessel, purging with nitrogen, and heating to 50-120℃ for 30-60 min for a salt formation reaction, then transferring to a prepolymerization reaction vessel, heating to 150-230℃ for 60-120 min for a prepolymerization reaction, and then continuing to heat to 260-280℃ for 30-120 min for a melt polycondensation reaction to obtain copolymerized MX nylon.

[0024] As a preferred embodiment, the nucleating agent of the present invention is selected from sorbitol-based nucleating agents, suitable examples including but not limited to one or more of 1,3-2,4-dibenzyl sorbitol (DBS), p-methylbenzyl sorbitol (MDBS), di(p-chlorobenzyl)sorbitol (CDBS), di(p-ethylbenzyl)sorbitol (EDBS), 1,3-2,4-di(p-hydroxy)benzyl sorbitol (DHDBS), 1,3-2,4-di(p-nitro)benzyl sorbitol (DNDBS), and 1,3-2,4-di(3,4-dimethylbenzyl)-D-sorbitol (DMDBS).

[0025] As a preferred embodiment, the glass fiber of the present invention has a diameter of 9.5-12.5 micrometers.

[0026] As a preferred embodiment, the antioxidant described in this invention is a composite antioxidant of hindered phenolic antioxidants and phosphate ester antioxidants, with a weight ratio of 1-2:1.

[0027] The preparation method of the high-flow copolymer MX nylon composition of the present invention includes the following steps: according to the proportion, the copolymer MX nylon is mixed evenly with nucleating agent and antioxidant and then added to the extruder from the main feed port of the twin-screw extruder; then glass fiber is added from the side feed port of the extruder; the processing temperature is 255-280℃; and the mixture is extruded and granulated.

[0028] The beneficial effects of this invention are as follows: This invention copolymerizes appropriate amounts of other long straight-chain or branched aliphatic diamines with MXD6 nylon, introducing these flexible segments into the rigid MXD6 segments, thereby lowering the melting point and improving the flexibility and flowability of the MX nylon segments; simultaneously, during the polymerization stage, 0.1-0.5% of diphenylm-2-dimethylamine is added to polymerize into the polyamide long chain, and the hydrogen atoms of the polyamide terminal amine group and the secondary amine in diphenylm-2-dimethylamine can form hydrogen bonds with the oxygen atoms in the ether bonds of the sorbitol nucleating agent added during the modification stage, allowing the polyamide molecular segments to be adsorbed or actively attached to the surface of the sorbitol nucleating agent, making the polyamide molecular segments more stably and orderly arranged on the nucleating agent, thereby improving the crystallinity of the polyamide. The synergistic effect of diphenyl dimethylamine and sorbitol-based nucleating agents promotes a uniform distribution of nucleation sites while improving the crystallization ability of copolymerized MX nylon, compensating for the slow crystallization caused by copolymerization. At the same time, the nucleating agent also provides the additional functions of a flow promoter and a release agent. Therefore, the flexible segments and nucleating agents synergistically improve the flowability of the resin.

[0029] Based on high-flow copolymer MX nylon, the viscosity and melting point of the high-flow copolymer MX nylon are further controlled within a specific range to ensure thorough wetting of high-filler glass fibers. Therefore, the modified material prepared from high-flow copolymer MX nylon of this invention exhibits superior properties, including better moldability and high strength. Attached Figure Description

[0030] Figure 1 This is an image showing the cracked appearance of the slice in Comparative Example 1.

[0031] Figure 2 This is an appearance diagram of the slice with good shapeability in Example 3. Detailed Implementation

[0032] The following examples further illustrate preferred embodiments within the scope of the present invention. These examples are merely illustrative and not intended to limit the scope of the invention, as many variations can be made to the invention without departing from its essence and scope.

[0033] The main raw materials used in the embodiments of the present invention are all obtained from common commercially available raw materials.

[0034] The performance testing method used in this embodiment of the invention:

[0035] Relative viscosity: Prepare a concentrated sulfuric acid solution with a nylon chip concentration of 0.01 g / ml, and measure the relative viscosity using an Ubbelohde viscometer.

[0036] Flowability evaluation: The dried modified granules were extruded into a spiral die using a single screw extruder to obtain a spiral sample. The sample length was read to evaluate the flowability of the modified composition.

[0037] Melting point: According to the ISO 11357 test method, the heating and cooling rate of the DSC instrument is set to 10℃ / min, the heating and cooling range is 0-300℃, and the peak value of the second heating melting point is read as the melting point.

[0038] Mechanical property testing: Mechanical properties were tested according to ISO standards. Tensile strength was tested according to ISO 527-2:2012 standard at a tensile speed of 50 mm / min. Impact strength was measured as the impact strength of a simply supported beam.

[0039] Preparation Example 1

[0040] Preparation of copolymerized MX nylon: 2055.64 g (15.093 mol) of m-phenylenediamine, 2457.83 g (15.955 mol) of adipic acid, 90 g (0.774 mol) of hexamethylenediamine, 22.5 g (0.088 mol) of di-m-phenylenediamine, 5 g of sodium phosphate, 13.95 g of adipic acid and 2000 g of water were added to a reactor. After nitrogen purging, the temperature was raised to 80 °C for 30 min of salt formation reaction. Then the temperature was raised to 180 °C and the pressure was maintained for 120 min of prepolymerization reaction. Then the pressure was released to atmospheric pressure and the temperature was raised to 260 °C for melt polycondensation reaction purged with nitrogen for 90 min to obtain copolymerized MX nylon with a melting point of 227 °C and a relative viscosity of 1.97.

[0041] Preparation Example 2

[0042] Preparation of copolymerized MX nylon: 2050.61g (15.057mol) of m-phenylenediamine, 2405.10g (16.458mol) of adipic acid, 235g (1.364mol) of 5-methyl-1,9-nonanediamine, 9.4g (0.037mol) of m-phenylenediamine dicondensate, 14.1g of sodium hypophosphite, 23.5g of benzoic acid, and 1410g of water were added to a reactor. After nitrogen purging, the temperature was raised to 75℃ for 55min of salt formation reaction. Then, the temperature was raised to 200℃ and held under pressure for 70min of prepolymerization reaction. Then, the pressure was released to atmospheric pressure, and the temperature was raised to 265℃ for melt polycondensation and nitrogen purging reaction for 60min to obtain copolymerized MX nylon with a melting point of 214℃ and a relative viscosity of 1.82.

[0043] Preparation Example 3

[0044] Preparation of copolymerized MX nylon: 2373.25 g (17.426 mol) of m-phenylenediamine, 2586.65 g (17.700 mol) of adipic acid, 25 g (0.215 mol) of 3-methyl-1,5-pentanediamine, 15 g (0.059 mol) of m-phenylenediamine dicondensate, 50 g of phosphoric acid, 100 g of azelaic acid and 3500 g of water were added to a reaction vessel. After nitrogen purging, the temperature was raised to 120 °C for 45 min of salt formation reaction. Then the temperature was raised to 230 °C and the pressure was maintained for 60 min of prepolymerization reaction. Then the pressure was released to atmospheric pressure and the temperature was raised to 280 °C for melt polycondensation and nitrogen purging reaction for 35 min to obtain copolymerized MX nylon with a melting point of 233 °C and a relative viscosity of 1.41.

[0045] Preparation Example 4

[0046] Preparation of copolymerized MX nylon: 1883.92 g (13.833 mol) of m-phenylenediamine, 2431.40 g (16.637 mol) of adipic acid, 480 g (2.786 mol) of 1,10-decanediamine, 4.8 g (0.019 mol) of m-phenylenediamine dicondensate, 24 g of sodium hypophosphite, 48 g of stearic acid and 480 g of water were added to a reaction vessel. After nitrogen purging, the temperature was raised to 50 °C for 60 min of salt formation reaction. Then the temperature was raised to 150 °C and the pressure was maintained for 90 min of prepolymerization reaction. Then the pressure was released to atmospheric pressure and the temperature was raised to 270 °C for melt polycondensation reaction purged with nitrogen for 120 min to obtain copolymerized MX nylon with a melting point of 210 °C and a relative viscosity of 1.65.

[0047] Prepare comparison ratio 5

[0048] Following the formulation of Example 3, without adding diphenyl dimethylamine and reducing the amount of its corresponding adipic acid by 8.57 g (0.059 mol), copolymer MX nylon was prepared by polymerization, with a melting point of 235°C and a relative viscosity of 1.41.

[0049] Prepare comparison ratio 6

[0050] Following the formulation of Example 3, without adding 3-methyl-1,5-pentanediamine and reducing the amount of its corresponding adipic acid (31.44 g, 0.215 mol), copolymer MX nylon was prepared by polymerization, with a melting point of 229°C and a relative viscosity of 1.41.

[0051] According to the group ratios shown in the table below, the copolymer MX nylon, nucleating agent, antioxidant and glass fiber are mixed evenly and then added to the extruder through the main feed port of the twin-screw extruder. Then the glass fiber is added through the side feed port of the extruder. The processing temperature is set within the range of 255-280℃. Finally, the mixture is extruded and granulated, and then processing tests are performed.

[0052] Table 1. Experimental formulations for examples and comparative examples.

[0053]

[0054] Table 2. Test results for the examples and comparative examples.

[0055] sample Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Tensile strength (MPa) 220 280 300 320 200 210 210 Flexural strength MPa 360 400 440 480 320 350 340 Notched impact strength J / m2 15 14 17 16 5 8 9 Helix length 530 480 460 410 390 395 400 Slice shape good good good good cracking cracking cracking

[0056] As can be seen from the examples, the mechanical properties of the product gradually increase with the increase of the filler content; as can be seen from the comparative examples and examples, the MX modified composition obtained by the present invention has higher strength and better moldability.

[0057] The above embodiments are only for illustrating the technical concept and features of the present invention and should not be construed as limiting the scope of protection of the present invention. All changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-flow copolymer MX nylon composition, comprising the following parts by weight: a) 30-70 parts copolymerized MX nylon; b) 30-70 parts glass fiber; c) 0.05-0.3 parts of nucleating agent; d) 0.1-1 part antioxidant; The copolymer MX nylon monomer composition includes m-phenylenediamine, adipic acid, and other diamines; The other diamines include di(m-phenylene dimethylamine); the amount of di(m-phenylene dimethylamine) used is 0.1-0.5%, based on the mass of the copoly(MX) nylon monomer.

2. The composition according to claim 1, characterized in that, The other diamines also include one or more of the following: straight-chain aliphatic diamines having 3 to 18 carbon atoms, and / or branched aliphatic diamines and / or alicyclic diamines.

3. The composition according to claim 2, characterized in that, The amount of the other diamines used is 0.1-10% of the total mass of the copoly(MX) nylon monomers.

4. The composition according to claim 2, characterized in that, The straight-chain aliphatic diamine is selected from one or more of 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine; the branched aliphatic diamine is selected from one or more of 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,4-dimethyl-1,6-hexanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, and 5-methyl-1,9-nonanediamine.

5. The composition according to claim 1, characterized in that, The relative viscosity of the copolymer MX nylon is between 1.40 and 2.00, and the melting point is between 210 and 235°C.

6. The composition according to claim 1, characterized in that, The preparation method of the copolymerized MX nylon includes the following steps: adding m-phenylenediamine, adipic acid, other diamines, catalyst, end-capping agent and water into a reaction vessel, purging with nitrogen, heating to 50-120℃ for 30-60 min for salt formation reaction, then transferring to a prepolymerization reaction vessel, heating to 150-230℃ for 60-120 min for prepolymerization reaction, and then continuing to heat to 260-280℃ for 30-120 min for melt polycondensation reaction to obtain copolymerized MX nylon.

7. The composition according to claim 6, characterized in that, The capping agent is selected from one or more monobasic acids or dibasic acids.

8. The composition according to claim 6, characterized in that, The capping agent is selected from one or more of acetic acid, stearic acid, benzoic acid, adipic acid, sebacic acid, and azelaic acid.

9. A method for preparing the composition according to any one of claims 1-8, comprising the following steps: According to the ratio, the copolymerized MX nylon is mixed evenly with nucleating agent and antioxidant and then added to the extruder through the main feed port of the twin-screw extruder. Then, glass fiber is added from the side feed port of the extruder. The processing temperature is 255-280℃, and the product is extruded and granulated.

Images