Polyamide foam material as well as preparation method and application thereof

Abstract

The invention discloses a polyamide foam material as well as a preparation method and application thereof. The polyamide foam material comprises the following raw material components in parts by weight: 85-98 parts of polyamide 5X resin and 0.5-5 parts of a chain extender, the pore size distribution of the foam material is 1.0 to 3.0. According to the invention, polyamide 5X resin is used as a raw material, a polyamide modified material meeting foaming requirements is prepared through chain extension modification, and then the bio-based polyamide foam material is prepared through continuous extrusion, foaming and molding by twin-screw extrusion foaming equipment. Or the polyamide 5X resin is subjected to online chain extension modification and continuous extrusion foaming molding in double-screw extrusion foaming equipment to prepare the bio-based polyamide foam material, and the bio-based polyamide foam material has the characteristics of low foam density, high foaming ratio, high compression strength, uniform average cell diameter and small pore size distribution.

Description

Technical Field

[0001] The invention relates to a polyamide foam material and a preparation method and application thereof. Background Art

[0002] Polymer foam materials have the characteristics of lightness, floating, insulation and cushioning due to the presence of a large number of closed cell structures inside them, which is of great significance for energy conservation, emission reduction and lightweight development. Foam materials made of polystyrene, polyethylene and polyurethane are widely used in the market. However, most foams made of these materials have problems such as poor mechanical properties and low chemical resistance.

[0003] Polyamide is widely used due to its high strength, chemical resistance, and outstanding oil resistance. However, during the continuous extrusion foaming process, the conventional polyamide resin has low tensile viscosity and melt strength, which cannot support the huge stress generated during cell growth, resulting in uneven cell size and low mechanical properties of the foamed material.

[0004] Therefore, there is an urgent need for a new type of polyamide foam material that can be prepared by continuous extrusion foaming, and the obtained foam material has the characteristics of high foaming ratio and excellent mechanical properties. Summary of the invention

[0005] In order to solve the problems in the prior art that polyamide is difficult to foam normally during continuous extrusion foaming, and the foaming ratio is low due to the shrinkage after foaming, a polyamide foam material and its preparation method and application are provided. The polyamide foam material prepared by the present invention has the characteristics of low density, high compression strength, high foaming ratio, uniform average cell diameter and small pore size distribution; its foaming process is simple, and the preferred raw material monomer of polyamide 5X resin is derived from plants, with high bio-based content, which is conducive to reducing dependence on petrochemical resources, and the monomer production and supply are stable, with scale potential, and excellent material performance.

[0006] The invention provides a polyamide foam material, the raw materials of which include the following components in parts by weight: 85-98 parts of polyamide 5X resin and 0.5-5 parts of chain extender; the pore size distribution of the foam material is 1.0-3.0.

[0007] In one embodiment, the polyamide 5X resin is prepared by using pentamethylenediamine, adipic acid or aliphatic long carbon chain dibasic acid as raw materials.

[0008] In the method, the pentamethylenediamine can be of chemical origin or renewable biomass origin, and is preferably 1,5-pentamethylenediamine of biomass origin.

[0009] In a preferred technical solution, the biomass-derived 1,5-pentanediamine is prepared by a biological method; preferably, the biological method includes production by a bio-based raw material through a bioconversion method, production by a petroleum-based raw material through a bioconversion method, or production by a bio-based raw material through a chemical method. The 1,5-pentanediamine of the present invention contains organic carbon from a renewable source that meets the ASTM D6866 standard.

[0010] In one embodiment, the aliphatic long carbon chain dibasic acid has 10 to 18 carbon atoms, and is preferably one or more of sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedicarboxylic acid and hexadecanedioic acid.

[0011] In one embodiment, the polyamide 5X resin is preferably one or more of PA56, PA510, PA511, PA512, PA513, PA514, PA515 and PA516.

[0012] In one embodiment, the melting point of the polyamide 5X resin may be 170-320°C, preferably 180-280°C, more preferably 180-260°C, such as 191°C, 192°C, 197°C, 205°C, 209°C, 210°C, 217°C or 253°C.

[0013] In one embodiment, the relative viscosity of the polyamide 5X resin may be 1.5-3.5, preferably 1.8-2.8, such as 2.13, 2.25, 2.29, 2.32, 2.38, 2.47, 2.51 or 2.7. The relative viscosity is measured by the Ubbelohde viscometer concentrated sulfuric acid (concentration 96%) method.

[0014] In one embodiment, the terminal amino group content of the polyamide 5X resin may be 30-65 mmol / kg, preferably 40-60 mmol / kg, for example 41 mmol / kg, 47 mmol / kg, 48 mmol / kg, 51 mmol / kg, 52 mmol / kg, 54 mmol / kg, 55 mmol / kg or 56 mmol / kg.

[0015] In a specific embodiment, when the polyamide 5X resin is one or more of PA510, PA511, PA512, PA513, PA514, PA515 and PA516, it has the following characteristics: relative viscosity of 1.8-2.8, terminal amino content of 30-65 mmol / kg, preferably 40-60 mmol / kg, melting point of 170-320°C, preferably 180-260°C.

[0016] In another specific embodiment, when the polyamide 5X resin is PA56, it has the following characteristics: relative viscosity of 1.9-2.8; terminal amino group content of 30-65 mmol / kg, preferably 40-60 mmol / kg; melting point of 252-320°C, preferably 252-255°C.

[0017] In one embodiment, the chain extender may be one or more of phosphorus-containing compounds, acid anhydride compounds, epoxy compounds, oxazoline compounds, carbonate compounds, lactam compounds and isocyanate compounds.

[0018] In one embodiment, the phosphorus-containing compound may be one or more of triphenylphosphite (TPP) and tricaprolactam phosphite (PTL).

[0019] In one embodiment, the anhydride compound may be one or more of naphthalenetetracarboxylic dianhydride (NTCDA), pyromellitic dianhydride (PMDA), styrene-maleic anhydride copolymer (SMA), POE-g-MAH, PE-g-MAH, PP-g-MAH, EPDM-g-MAH and EVA-g-MAH, such as pyromellitic dianhydride (PMDA), styrene-maleic anhydride copolymer (SMA) or POE-g-MAH.

[0020] In one embodiment, the epoxy compound may be one or more of styrene-glycidyl methacrylate oligomer, epoxy polysiloxane (EPM) and triglycidyl isocyanurate (TGIC).

[0021] The styrene-glycidyl methacrylate oligomer is preferably one or more of ADR 4468, ADR 4380 and KL-E4300, for example ADR 4468 or ADR 4380.

[0022] In one embodiment, the oxazoline compound may be one or more of bisoxazoline (BOZ), 3-oxazoline, styrene oxazoline copolymer (RPS) and isoxazoline benzyl ether compounds, such as bisoxazoline (BOZ).

[0023] In one embodiment, the carbonate compound may be Brueggemann M1251 and / or Brueggemann M1253.

[0024] In one embodiment, the lactam compound includes but is not limited to terephthaloyl dicaprolactam (TBC) and terephthaloyl didodecanolactam (TBLL).

[0025] In one embodiment, the isocyanate compound may be one or more of isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI) and polymethylene polyphenyl polyisocyanate (PAPI), for example, diphenylmethane diisocyanate (MDI).

[0026] In a preferred embodiment, the chain extender is one or more of pyromellitic anhydride (PMDA), styrene-maleic anhydride copolymer (SMA), bisoxazoline (BOZ), POE-g-MAH, ADR4468, ADR4380, epoxy polysiloxane (EPM) and diphenyl toluene diisocyanate (MDI); more preferably, it is one or more of pyromellitic anhydride (PMDA), styrene-maleic anhydride copolymer (SMA), POE-g-MAH, ADR4468, epoxy polysiloxane (EPM) and ADR4380; further preferably, it is a combination of at least two or more of pyromellitic anhydride (PMDA), styrene-maleic anhydride copolymer (SMA), POE-g-MAH, ADR4468, epoxy polysiloxane (EPM) and ADR4380; for example, a combination of ADR4468 and POE-g-MAH.

[0027] Wherein, the mass ratio of the ADR4468 to the POE-g-MAH is preferably 1:(1-3), such as 1:1 or 1:2.

[0028] In one embodiment, the raw material of the polyamide foam material may further include an antioxidant.

[0029] The antioxidant may be one or more of antioxidant 1098 , antioxidant 1010 and antioxidant 168 , such as antioxidant 1098 .

[0030] The content of the antioxidant may be 0.01-1 part, preferably 0.05-0.5 part, such as 0.05 part.

[0031] In one embodiment, the raw material of the polyamide foam material may further include a heat stabilizer.

[0032] Wherein, the thermal stabilizer may be CuI and / or H10, such as CuI.

[0033] The content of the heat stabilizer may be 0.01-1 part, preferably 0.05-0.5 part, for example 0.05 part.

[0034] In one embodiment, the raw material of the polyamide foam material may further include a nucleating agent.

[0035] The nucleating agent may be one or more of calcium carbonate, kaolin, talc and mica powder, such as calcium carbonate.

[0036] The content of the nucleating agent may be 0.1-5 parts, preferably 0.5-2 parts, such as 0.5 parts.

[0037] In one embodiment, the raw material of the polyamide foam material may further include a lubricant.

[0038] The lubricant may be one or more of stearic acid and its soap salt, polyethylene wax, polypropylene wax and oxidized polyethylene wax, such as polyethylene wax.

[0039] The content of the lubricant may be 0.2-3 parts, preferably 0.5-2 parts, such as 0.5 parts.

[0040] In one embodiment, the foam density of the polyamide foam material may be 0.050-0.250 g / cm 3 For example, 0.050g / cm 3 , 0.105g / cm 3 、0.110g / cm 3 , 0.120g / cm 3 , 0.135g / cm 3 、0.160g / cm 3 , 0.180g / cm 3 、0.210g / cm 3 or 0.250g / cm 3 .

[0041] In one embodiment, the polyamide foam material may have a foaming ratio of 5-20, such as 2.1, 6.5, 6.8, 9.7, 10.5, 13.9, 16.7 or 20.0.

[0042] In one embodiment, the average cell diameter of the polyamide foam material may be 0.08-0.65 mm, preferably 0.1-0.4 mm, such as 0.080 mm, 0.120 mm, 0.250 mm, 0.260 mm, 0.280 mm, 0.340 mm, 0.520 mm, 0.550 mm or 0.630 mm.

[0043] In one embodiment, the pore size distribution of the polyamide foam material is preferably 1.5-2.5, for example, 1.2, 1.5, 1.8, 2.0, 2.2, 2.4, 2.8.

[0044] In one embodiment, the compressive strength of the polyamide foam material is preferably 0.7-5.0 MPa, such as 0.75 MPa, 1.75 MPa, 1.87 MPa, 2.12 MPa, 2.35 MPa, 2.46 MPa, 3.46 MPa, 4.51 MPa or 5.0 MPa.

[0045] In one embodiment, the polyamide foam material may be in the form of a plate, sheet or beads as required, preferably a foamed plate.

[0046] Preferably, the thickness of the foamed board is ≥10 mm, further 10-80 mm, further 20-70 mm, and further 40-60 mm. The thickness and width of the board can be determined according to specific product requirements.

[0047] In a specific embodiment of the present invention, the present invention provides a method for preparing a polyamide foam material, the method comprising the following steps:

[0048] (1) mixing the raw materials uniformly, and extruding and granulating to obtain a polyamide modified material;

[0049] (2) The polyamide modified material is continuously extruded and foamed by a twin-screw extrusion foaming device to obtain a polyamide foam material.

[0050] In step (1) of the present invention, the types and amounts of the raw materials are as described above.

[0051] In step (1) of the invention, the mixing can be carried out by using a mixing device to mix the raw materials uniformly. The mixing time can be 2-15 minutes, for example, 10 minutes; the mixing speed can be 20-300 rpm, for example, 250 rpm.

[0052] In step (1) of the present invention, preferably, a twin-screw extruder is used for extrusion granulation.

[0053] In the present invention, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones one to six are "180-220°C, 190-280°C, 200-280°C, 200-290°C, 200-320°C, 200-320°C" respectively.

[0054] In the present invention, the twin-screw extruder is expressed in terms of screw speed, and the extrusion speed may be 150-600 rpm, such as 400 rpm.

[0055] In step (1) of the present invention, the relative viscosity of the obtained polyamide modified material can be 2.6-4.5, for example, 2.8, 2.9, 3.1, 3.3, 4.5.

[0056] In the present invention, before adding the polyamide modified material to the twin-screw extrusion foaming equipment for continuous extrusion, the step of drying the polyamide modified material is also included, that is, the polyamide modified material is dried to a moisture content of less than 1000ppm, and then added to the twin-screw extrusion foaming equipment for continuous extrusion molding.

[0057] In step (2) of the invention, preferably, the polyamide modified material is quantitatively added into a twin-screw extrusion foaming device through a feeder; the speed of the feeder is preferably 10-600 kg / h.

[0058] In one embodiment, in step (2) of the present invention, the twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die head.

[0059] In step (2) of the present invention, preferably, the twin-screw extruder in the twin-screw extrusion foaming equipment adopts a six-zone heating mode, and the temperatures of zones one to six are "210-280°C, 210-280°C, 210-280°C, 210-275°C, 180-275°C, 180-275°C" respectively.

[0060] In the present invention, expressed as screw speed, the extrusion speed of the twin-screw extruder in the twin-screw extrusion foaming equipment is 15-300 rpm, for example, 250 rpm.

[0061] Among them, preferably, in the present invention, the aspect ratio of the twin-screw extruder is 28-64:1, further 40-64:1. The present invention is beneficial to improving the mixing and homogenization of the melt and the foaming agent and enhancing the melt cooling effect by adjusting the aspect ratio, which is beneficial to improving the foaming effect.

[0062] In one embodiment, the temperature of the static mixer is close to the melting point of the polyamide resin.

[0063] In one embodiment, the temperature of the static mixer is lower than the melting point of the polyamide resin. Preferably, the temperature difference between the temperature of the static mixer and the melting point of the polyamide resin is no more than 5°C.

[0064] In one embodiment, the temperature of the static mixer is preferably 180-275° C., for example, 220° C. The present invention adjusts the temperature of the static mixer so that the melt temperature is reduced to the melting point of the polyamide resin or slightly lower than the melting point of the polyamide resin, thereby improving the melt strength and gas solubility, thereby improving the foaming ratio.

[0065] In the present invention, the aspect ratio of the static mixer is 2-8: 1, for example, 4: 1. The present invention controls the aspect ratio of the static mixer and thus controls the residence time and residence time distribution of the melt in the foaming device, thereby effectively improving the mixing of the melt and the foaming agent, which is beneficial to improving the foaming effect.

[0066] In one embodiment, the temperature of the extrusion die is close to the melting point of the polyamide resin.

[0067] In one embodiment, the temperature of the extrusion die is lower than the melting point of the polyamide resin. Preferably, the temperature difference between the temperature of the extrusion die and the melting point of the polyamide resin is no more than 5°C.

[0068] In one embodiment, the temperature of the extrusion die is preferably 180-275° C., for example, 220° C. The present invention controls the temperature of the extrusion die to be close to or slightly lower than the melting point of the polyamide resin, which is beneficial to improving the melt strength and die pressure, thereby facilitating the nucleation of the foaming agent cells and reducing the average cell diameter and cell distribution.

[0069] In step (2) of the invention, preferably, the residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 10-30 minutes.

[0070] In step (2) of the invention, before continuous extrusion, a foaming agent is added to the twin-screw extrusion foaming device through a foaming agent filling system, and the foaming agent filling amount is preferably 0.5-5% of the total mass of each raw material, for example 1%. The present invention has no particular limitation on the type of foaming agent, and conventional foaming agents in the art can be used, for example, at least one selected from butane, cyclopentane, n-pentane, CO2, and N2.

[0071] The preparation method provided by the present invention ensures that the performance of the polyamide modified material is stable, the material is easy to cool down, and the production process is stable.

[0072] In another specific embodiment, the present invention further provides a method for preparing a polyamide foam material, the method comprising: adding various raw materials to a twin-screw extrusion foaming device for mixing and modification, and then continuously extruding and foaming through the twin-screw extrusion foaming device.

[0073] In the present invention, each raw material is added to the twin-screw extrusion foaming equipment through a batching system for mixing and modification, and the batching system is composed of a multi-component drying system and a multi-component metering system. The multi-component drying system can be one or more combinations of crystallization drying, hot air drying or vacuum drying. The multi-component metering system can be one or more combinations of a weight-loss metering system or a volumetric metering system, and the feeding speed of the multi-component metering system is preferably 10-600 kg / h.

[0074] In one embodiment, the twin-screw extruder in the twin-screw extrusion foaming equipment adopts an eight-zone heating mode, and the temperatures of zones one to eight are "220-280°C, 220-280°C, 210-280°C, 210-275°C, 180-275°C, 180-275°C, 180-275°C, 180-275°C".

[0075] In one embodiment, the twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die.

[0076] In the present invention, the aspect ratio of the static mixer is 4-12: 1, for example 4: 1. The present invention controls the aspect ratio of the static mixer and thus controls the residence time and residence time distribution of the melt in the device, thereby effectively improving the mixing of the melt and the foaming agent, which is beneficial to improving the foaming effect.

[0077] In the present invention, the aspect ratio of the twin-screw extruder is 32-64:1. By adjusting the aspect ratio, the present invention is conducive to accurately controlling the online modification effect, improving the mixing and homogenization of the melt and the foaming agent, and strengthening the melt cooling effect.

[0078] In the present invention, the process conditions such as the temperature of the static mixer, the temperature of the extrusion die head, the extrusion speed of the twin-screw extruder in the twin-screw extrusion foaming equipment, and the filling amount of the foaming agent are the same as those in the previous preparation method and will not be repeated here.

[0079] In the present invention, before adding the foaming agent to the twin-screw extrusion foaming device through the foaming agent filling system, the relative viscosity of the melt is measured to be 2.6-4.5.

[0080] In the present invention, preferably, the residence time of each raw material in the twin-screw extrusion foaming equipment is 10-30 minutes.

[0081] The preparation method provided by the present invention adopts a twin-screw extrusion foaming device to perform online chain extension modification and foaming molding, and has flexible formula adjustment, high yield, low equipment investment and low production cost.

[0082] The present invention also provides an application of the polyamide foam material in the fields of wind power equipment, construction, furniture, packaging, transportation, etc.

[0083] The present invention also provides an application of the foam material obtained by the preparation method in the fields of wind power equipment, construction, furniture, packaging, transportation, etc.

[0084] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0085] The reagents and raw materials used in the present invention are commercially available.

[0086] The positive and progressive effects of the present invention are:

[0087] (1) The present invention uses polyamide 5X resin as a raw material, firstly obtains a polyamide modified material that meets the foaming requirements through chain extension modification, and then obtains a bio-based polyamide foam material through continuous extrusion foaming molding by a twin-screw extrusion foaming device, or the polyamide 5X resin is subjected to online chain extension modification and continuous extrusion foaming molding in a twin-screw extrusion foaming device to obtain a bio-based polyamide foam material, which has the characteristics of low foam density, high foaming ratio, high compression strength, uniform average cell diameter, and small pore size distribution. In particular, compared with conventional nylon 6, nylon 66, nylon 610, nylon 612, etc., the foam performance of the polyamide foam material of the present invention is more excellent, and can meet the needs of application fields with high requirements for lightweight in the fields of wind power equipment, construction, furniture, packaging, transportation, etc.

[0088] (2) The polyamide foam material described in the present invention can be obtained in different product forms as needed, such as beads, sheets, plates, etc., and can be suitable for a wider range of application scenarios. In addition, the thickness of the sheets and plates can be controlled within a certain range as needed, which can provide more design freedom for the product.

[0089] (3) The foaming process provided by the present invention is simple; at the same time, the preferred raw material monomers of the polyamide 5X resin are derived from plants and have a high bio-based content, which is beneficial to reducing dependence on petrochemical resources and meets the needs of low-carbon economy and sustainable development. DETAILED DESCRIPTION

[0090] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are selected according to conventional methods and conditions, or according to the product specifications. In the examples and comparative examples of the present invention, the reagents and raw materials used are all commercially available.

[0091] Example 1-PA56+ two-step method

[0092] Weigh 97.3 parts of PA56 (melting point 253°C, viscosity 2.7, terminal amino content 55 mmol / kg), 1.5 parts of chain extender ADR4468, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 5 min, and the mixing rate is 150 rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones one to six are 200°C, 255°C, 260°C, 280°C, 280°C, 280°C, respectively, expressed in screw speed, the extrusion speed is 400 rpm, and the polyamide modified material is obtained by twin-screw extrusion granulation. After drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured. The results are shown in Table 1.

[0093] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 20 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0094] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 270°C, 270°C, 270°C, 260°C, 260°C, and 260°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 260°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 260°C.

[0095] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 200g / h.

[0096] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 18 minutes.

[0097] Example 2-PA56+ two-step method

[0098] Weigh 93.8 parts of PA56 (melting point 253°C, viscosity 2.7, terminal amino content 55 mmol / kg), 2.5 parts of chain extender SMA + 2.5 parts of EPM, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode of 200°C, 255°C, 260°C, 280°C, 280°C, 280°C, expressed in screw speed, the extrusion speed is 400 rpm, and the polyamide modified material is obtained by twin-screw extrusion granulation. After drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured. The results are shown in Table 1.

[0099] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 550 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0100] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 270°C, 270°C, 270°C, 260°C, 260°C, and 260°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 260°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 260°C.

[0101] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 5500g / h.

[0102] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 15 minutes.

[0103] Example 3-PA56+ one-step method

[0104] Weigh 93.8 parts of PA56 (melting point 253°C, viscosity 2.7, terminal amino content 55 mmol / kg), 2.5 parts of chain extender SMA + 2.5 parts of EPM, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax, and dry the above raw materials online through a batching system, and control the moisture content below 500 ppm; then quantitatively feed the dried raw materials into a twin-screw extrusion foaming equipment through a metering system at a feeding speed of 550 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0105] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts an eight-zone heating mode. The temperatures of zones one to eight are 270°C, 270°C, 270°C, 260°C, 260°C, 260°C, 260°C, 260°C, 260°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 52:1, the temperature of the static mixer is 260°C, the aspect ratio is 8:1, and the temperature of the extrusion die is 260°C.

[0106] Before continuous extrusion, the relative viscosity of the melt was measured. The results are shown in Table 1. Then, a foaming agent (CO2) was added to the twin-screw extruder foaming equipment through a foaming agent filling system. The filling amount of CO2 was 5500 g / h.

[0107] The residence time of the above raw materials in the twin-screw extrusion foaming equipment is 15 minutes.

[0108] Example 4-PA510+ two-step method

[0109] Weigh 96.3 parts of PA510 (melting point 217°C, viscosity 2.51, terminal amino group 54 mmol / kg), 1.5 parts of chain extender pyromellitic anhydride (PMDA), 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 1.0 parts of nucleating agent talc, and 0.5 parts of lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones one to six are 200°C, 230°C, 250°C, 250°C, 250°C, 250°C, 250°C, expressed in screw speed, the extrusion speed is 400 rpm, and the polyamide modified material is obtained by twin-screw extrusion granulation. After drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured. The results are shown in Table 1.

[0110] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 50 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0111] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 250°C, 240°C, 230°C, 220°C, 220°C, and 220°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 220°C, the aspect ratio is 2:1, and the temperature of the extrusion die is 220°C.

[0112] Before continuous extrusion, a foaming agent (butane) was added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of butane was 500 g / h.

[0113] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 15 minutes.

[0114] Example 5-PA511+ two-step method

[0115] Weigh 94.8 parts of PA511 (melting point 209°C, viscosity 2.47, terminal amino group 52mmol / kg), 4 parts of chain extender M1251, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer H10, 0.5 parts of nucleating agent kaolin, and 0.5 parts of lubricant polypropylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 10min, and the mixing rate is 90rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones one to six are 200°C, 210°C, 220°C, 220°C, 220°C, 215°C, expressed in screw speed, the extrusion speed is 400rpm, and the polyamide modified material is obtained by twin-screw extrusion granulation. After drying it to a moisture content of less than 1000ppm, its relative viscosity is measured. The results are shown in Table 1.

[0116] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 80 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0117] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 230°C, 230°C, 230°C, 220°C, 210°C, and 210°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 210°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 210°C.

[0118] Before continuous extrusion, a foaming agent (cyclopentane) was added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of cyclopentane was 800 g / h.

[0119] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 20 minutes.

[0120] Example 6-PA512+ two-step method

[0121] Weigh 97.3 parts of PA512 (melting point 210°C, viscosity 2.32, terminal amino group 56 mmol / kg), 1.5 parts of chain extender bisoxazoline (BOZ), 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant oxidized polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones 1 to 6 are 200°C, 210°C, 220°C, 220°C, 220°C, 220°C, respectively, expressed in terms of screw speed, the extrusion speed is 400 rpm, and a polyamide modified material is obtained by twin-screw extrusion granulation. After drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured, and the results are shown in Table 1.

[0122] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 100 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0123] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 230°C, 220°C, 220°C, 210°C, 220°C, and 210°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 210°C, the aspect ratio is 8:1, and the temperature of the extrusion die is 210°C.

[0124] Before continuous extrusion, a foaming agent (n-pentane) was added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of n-pentane was 1000 g / h.

[0125] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 20 minutes.

[0126] Example 7-PA513+ two-step method

[0127] Weigh 94.3 parts of PA513 (melting point 197°C, viscosity 2.38, terminal amino group 41 mmol / kg), 4.5 parts of chain extender TPP, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent mica, and 0.5 parts of lubricant stearic acid, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then the above mixture is put into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones 1 to 6 are 190°C, 200°C, 210°C, 220°C, 220°C, and 210°C, respectively, expressed in terms of screw speed, and the extrusion speed is 400 rpm. The polyamide modified material is obtained by twin-screw extrusion granulation, and after drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured. The results are shown in Table 1.

[0128] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 20 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0129] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 230°C, 220°C, 210°C, 210°C, 200°C, and 200°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 200°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 200°C.

[0130] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 200g / h.

[0131] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 15 minutes.

[0132] Example 8-PA514+ two-step method

[0133] Weigh 96.3 parts of PA514 (melting point 205°C, viscosity 2.29, terminal amino group 48mmol / kg), 1.5 parts of chain extender diphenyl toluene diisocyanate (MDI), 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 1.5 parts of nucleating agent talc, and 0.5 parts of lubricant calcium stearate, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2min, and the mixing rate is 250rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder uses a six-zone heating mode, and the temperatures of zones 1 to 6 are 190°C, 200°C, 210°C, 220°C, 220°C, and 210°C, respectively, expressed in terms of screw speed, and the extrusion speed is 400rpm. The polyamide modified material is obtained by twin-screw extrusion granulation, and after drying it to a moisture content of less than 1000ppm, its relative viscosity is measured. The results are shown in Table 1.

[0134] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 50 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0135] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 230°C, 220°C, 210°C, 210°C, 200°C, and 200°C, respectively. Expressed in terms of screw speed, the extrusion speed is 150rpm, the aspect ratio of the twin-screw extruder is 48:1, the temperature of the static mixer is 200°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 200°C.

[0136] Before continuous extrusion, a foaming agent (N2) was added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of N2 was 500 g / h.

[0137] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 18 minutes.

[0138] Example 9-PA515+ two-step method

[0139] Weigh 94.8 parts of PA515 (melting point 191°C, viscosity 2.25, terminal amino group 51 mmol / kg), 4 parts of chain extender styrene-maleic anhydride copolymer (SMA), 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder uses a six-zone heating mode, and the temperatures of zones 1 to 6 are 180°C, 190°C, 200°C, 210°C, 210°C, 200°C, expressed in screw speed, and the extrusion speed is 400 rpm. The polyamide modified material is obtained by twin-screw extrusion granulation, and after drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured. The results are shown in Table 1.

[0140] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 150 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0141] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 210°C, 210°C, 210°C, 210°C, 200°C, and 200°C, respectively. Expressed in terms of screw speed, the extrusion speed is 150rpm, the aspect ratio of the twin-screw extruder is 52:1, the temperature of the static mixer is 195°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 195°C.

[0142] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 1500g / h.

[0143] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 25 minutes.

[0144] Example 10-PA516+Two-step method

[0145] Weigh 95.8 parts of PA516 (melting point 192°C, viscosity 2.13, terminal amino group 47 mmol / kg), 2.5 parts of chain extender TBC, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer H10, 1.0 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones 1 to 6 are 180°C, 190°C, 200°C, 210°C, 210°C, 200°C, expressed in screw speed, and the extrusion speed is 400 rpm. The polyamide modified material is obtained by twin-screw extrusion granulation, and after drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured. The results are shown in Table 1.

[0146] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 250 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0147] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 210°C, 210°C, 210°C, 210°C, 200°C, and 200°C, respectively. Expressed in terms of screw speed, the extrusion speed is 200rpm, the aspect ratio of the twin-screw extruder is 60:1, the temperature of the static mixer is 195°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 195°C.

[0148] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 2500g / h.

[0149] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 30 minutes.

[0150] Example 11-PA513+ two-step method

[0151] Weigh 93.8 parts of PA513 (melting point 197°C, viscosity 2.38, terminal amino group 41 mmol / kg), 1.5 parts of chain extender ADR4468 + 3 parts of POE-g-MAH, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 1.0 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder uses a six-zone heating mode, and the temperatures of zones 1 to 6 are 190°C, 200°C, 210°C, 220°C, 220°C, and 210°C, respectively, expressed in terms of screw speed, and the extrusion speed is 400 rpm. The polyamide modified material is obtained by twin-screw extrusion granulation, and after drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured. The results are shown in Table 1.

[0152] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 400 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0153] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 230°C, 220°C, 210°C, 210°C, 200°C, and 200°C, respectively. Expressed in terms of screw speed, the extrusion speed is 50rpm, the aspect ratio of the twin-screw extruder is 32:1, the temperature of the static mixer is 200°C, the aspect ratio is 8:1, and the temperature of the extrusion die is 200°C.

[0154] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 10000g / h.

[0155] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 15 minutes.

[0156] Example 12-PA513+ two-step method

[0157] It is basically the same as Example 7, except that: 96.3 parts of PA513 (melting point 197°C, viscosity 2.38, terminal amino group 41 mmol / kg), 1.5 parts of chain extender RPS, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 1.5 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax are weighed.

[0158] Example 13-PA516+Two-step method

[0159] It is basically the same as Example 10, except that: PA516 (melting point 192°C, viscosity 2.13, terminal amino group 47 mmol / kg) is 96.8 parts, chain extender PAPI is 2.0 parts, thermal stabilizer is 0.1 parts CuI, and nucleating agent is 0.5 parts calcium carbonate.

[0160] Example 14-PA513+ two-step method

[0161] It is basically the same as Example 7, except that the nucleating agent is 0.5 parts of calcium carbonate, the lubricant is 0.5 parts of polyethylene wax, and the injection amount of CO2 is 400g / h.

[0162] Example 15-PA513+Two-step method

[0163] It is basically the same as Example 7, except that the temperature of the static mixer is 195°C and the temperature of the extrusion die is 195°C.

[0164] Example 16-PA513+ one-step method

[0165] Weigh 94.3 parts of PA513 (melting point 197°C, viscosity 2.38, terminal amino group 41 mmol / kg), 4.5 parts of chain extender TPP, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent mica, and 0.5 parts of lubricant stearic acid, and dry the above raw materials online through a batching system, and control the moisture content below 500 ppm; then quantitatively feed the dried raw materials into a twin-screw extrusion foaming equipment through a metering system at a feeding speed of 20 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0166] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts an eight-zone heating mode. The temperatures of zones one to eight are 230°C, 220°C, 210°C, 210°C, 200°C, 200°C, 200°C, 200°C, respectively. Expressed in terms of screw speed, the extrusion speed is 50rpm, the aspect ratio of the twin-screw extruder is 48:1, the temperature of the static mixer is 200°C, the aspect ratio is 8:1, and the temperature of the extrusion die is 200°C.

[0167] Before continuous extrusion, the relative viscosity of the melt was measured. The results are shown in Table 1. Then, a foaming agent (CO2) was added to the twin-screw extruder foaming equipment through a foaming agent filling system. The filling amount of CO2 was 200 g / h.

[0168] The residence time of the above raw materials in the twin-screw extrusion foaming equipment is 25 minutes.

[0169] Example 17-PA513+Two-step method

[0170] It is basically the same as Example 7, except that the temperature of the static mixer is 220°C.

[0171] Example 18-PA516+Two-step method

[0172] Basically the same as Example 10, except that the extrusion die temperature is 180°C.

[0173] Example 19-PA513+ one-step method

[0174] It is basically the same as Example 16, except that the aspect ratio of the twin-screw extruder in the twin-screw extrusion foaming equipment is not controlled, and the residence time of the above raw materials in the twin-screw extrusion foaming equipment is 5 minutes.

[0175] Example 20-PA513+Two-step method

[0176] The method is basically the same as Example 7, except that the aspect ratio of the twin-screw extruder in the twin-screw extrusion foaming equipment is controlled to be 24:1, and the residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 12 minutes.

[0177] Comparative Example 1

[0178] Weigh 98.8 parts of PA513 (melting point 197°C, viscosity 2.38, terminal amino group 41 mmol / kg), 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones one to six are 190°C, 200°C, 210°C, 220°C, 220°C, and 210°C, respectively, expressed in terms of screw speed, and the extrusion speed is 400 rpm. The polyamide modified material is obtained by twin-screw extrusion granulation, and after drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured. The results are shown in Table 1.

[0179] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 20 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0180] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 230°C, 220°C, 210°C, 210°C, 200°C, and 200°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 200°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 200°C.

[0181] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 200g / h.

[0182] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 15 minutes.

[0183] Comparative Example 2

[0184] Weigh 94.3 parts of PA513 (melting point 197°C, viscosity 2.38, terminal amino group 41 mmol / kg), 8.0 parts of chain extender TPP, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones 1 to 6 are 190°C, 200°C, 210°C, 220°C, 220°C, and 210°C, respectively, expressed in terms of screw speed, and the extrusion speed is 400 rpm. The polyamide modified material is obtained by twin-screw extrusion granulation; after drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured, and the results are shown in Table 1.

[0185] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 20 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0186] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 230°C, 220°C, 210°C, 210°C, 200°C, and 200°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 200°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 200°C.

[0187] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 200g / h.

[0188] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 15 minutes.

[0189] Comparative Example 3

[0190] Weigh 97.3 parts of polyamide PA6 (purchased from Xinhui Meida, melting point 223°C, viscosity 2.46, terminal amino group 54mmol / kg), 1.5 parts of chain extender ADR4468, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2min, and the mixing rate is 250rpm; then the above mixture is put into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones one to six are 180°C, 220°C, 250°C, 280°C, 280°C, 280°C, respectively, expressed in screw speed, the extrusion speed is 400rpm, and the composition (polyamide modified material) is obtained by twin-screw extrusion granulation; after drying it to a moisture content of less than 1000ppm, its relative viscosity is measured, and the results are shown in Table 1.

[0191] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 20 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0192] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 280°C, 280°C, 280°C, 270°C, 270°C, 270°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 270°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 270°C.

[0193] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 200g / h.

[0194] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 15 minutes.

[0195] Comparative Example 4

[0196] Weigh 97.3 parts of polyamide PA66 (purchased from DuPont, with a viscosity of 2.6, an end amino content of 48 mmol / kg, and a melting point of 260°C), 1.5 parts of chain extender ADR4468, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones one to six are 180°C, 220°C, 250°C, 285°C, 285°C, 285°C, respectively, expressed in screw speed, the extrusion speed is 400 rpm, and a composition (polyamide modified material) is obtained by twin-screw extrusion granulation; after drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured, and the results are shown in Table 1.

[0197] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 20 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0198] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 285°C, 285°C, 285°C, 280°C, 275°C, and 270°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 270°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 270°C.

[0199] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 200g / h.

[0200] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 15 minutes.

[0201] Comparative Example 5

[0202] Weigh 97.3 parts of PA610 (purchased from Evonik, with a viscosity of 2.3, an end amino content of 51 mmol / kg, and a melting point of 220°C), 1.5 parts of chain extender ADR4468, 0.1 parts of antioxidant 1098, 0.1 parts of heat stabilizer CuI, 0.5 parts of nucleating agent calcium carbonate, and 0.5 parts of lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then put the above mixture into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones one to six are 200°C, 230°C, 250°C, 250°C, 250°C, 250°C, 250°C, expressed in screw speed, the extrusion speed is 400 rpm, and the polyamide modified material is obtained by twin-screw extrusion granulation; after drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured, and the results are shown in Table 1.

[0203] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 20 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0204] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 250°C, 240°C, 230°C, 220°C, 220°C, and 220°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 220°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 220°C.

[0205] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 200g / h.

[0206] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 15 minutes.

[0207] Comparative Example 6

[0208] Weigh 97.3 parts of PA612 (purchased from DuPont, with a viscosity of 2.0, an end amino content of 43 mmol / kg, and a melting point of 211°C), 1.5 parts of a chain extender ADR4468, 0.1 parts of an antioxidant 1098, 0.1 parts of a heat stabilizer CuI, 0.5 parts of a nucleating agent calcium carbonate, and 0.5 parts of a lubricant polyethylene wax, and mix the above raw materials evenly with a high-speed mixer, the mixing time is 2 min, and the mixing rate is 250 rpm; then the above mixture is put into a twin-screw extruder, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones one to six are 200°C, 210°C, 220°C, 220°C, 220°C, 220°C, respectively, expressed in terms of screw speed, the extrusion speed is 400 rpm, and a polyamide modified material is obtained by twin-screw extrusion granulation; after drying it to a moisture content of less than 1000 ppm, its relative viscosity is measured, and the results are shown in Table 1.

[0209] The polyamide modified material is added to a twin-screw extrusion foaming device through a feeder at a feeding rate of 20 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0210] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts a six-zone heating mode. The temperatures of zones one to six are 230°C, 220°C, 220°C, 210°C, 220°C, and 210°C, respectively. Expressed in terms of screw speed, the extrusion speed is 100rpm, the aspect ratio of the twin-screw extruder is 40:1, the temperature of the static mixer is 210°C, the aspect ratio is 4:1, and the temperature of the extrusion die is 210°C.

[0211] Before continuous extrusion, a foaming agent (CO2) is added to the twin-screw extrusion foaming equipment through a foaming agent filling system, and the filling amount of CO2 is 200g / h.

[0212] The residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 15 minutes.

[0213] Comparative Example 7

[0214] Weigh 97.3 parts of PA612 (purchased from DuPont, with a viscosity of 2.0, an end amino content of 43 mmol / kg, and a melting point of 211°C), 1.5 parts of a chain extender ADR4468, 0.1 parts of an antioxidant 1098, 0.1 parts of a heat stabilizer CuI, 0.5 parts of a nucleating agent calcium carbonate, and 0.5 parts of a lubricant polyethylene wax, and dry the above raw materials online through a batching system, and control the moisture content below 500 ppm; then quantitatively feed the dried raw materials into a twin-screw extrusion foaming equipment through a metering system at a feeding rate of 20 kg / h for continuous extrusion molding to prepare a polyamide foamed sheet.

[0215] The twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die. The twin-screw extruder adopts an eight-zone heating mode. The temperatures of zones one to eight are 230°C, 220°C, 220°C, 210°C, 220°C, 210°C, 210°C, 210°C, 210°C, expressed in terms of screw speed. The extrusion speed is 50rpm, the length-to-diameter ratio of the twin-screw foaming extruder is 48:1, the temperature of the static mixer is 210°C, the length-to-diameter ratio is 8:1, and the temperature of the extrusion die is 210°C.

[0216] Before continuous extrusion, the relative viscosity of the melt was measured. The results are shown in Table 1. Then, a foaming agent (CO2) was added to the twin-screw extruder foaming equipment through a foaming agent filling system. The filling amount of CO2 was 200 g / h.

[0217] The residence time of the above raw materials in the twin-screw extrusion foaming equipment is 25 minutes.

[0218] The polyamide modified materials and foamed sheets of Examples 1-20 and Comparative Examples 1-7 were subjected to performance tests according to the following test methods:

[0219] (1) The relative viscosity of the polyamide modified material is measured by the concentrated sulfuric acid method (concentration of 96%) using an Ubbelohde viscometer. Accurately weigh 0.5±0.0002 g of the dried sample, add 50 mL of concentrated sulfuric acid (96%) to dissolve the polyamide solution, and measure and record the concentrated sulfuric acid flow time t0 and the polyamide solution flow time t in a constant temperature water bath at 25±0.02°C.

[0220] Relative viscosity calculation formula: relative viscosity ηr = t / t0;

[0221] (2) Foam density of foamed board: tested according to international standard ISO 845;

[0222] (3) The expansion ratio of the foamed sheet is calculated by dividing the initial density by the foam density;

[0223] (4) The compressive strength of the foamed sheet is tested according to ISO 844;

[0224] (5) The average pore diameter and average pore size distribution of the foamed sheet were measured using a scanning electron microscope and analyzed using Image-Pro.

[0225] Table 1

[0226]

[0227] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A polyamide foam material, characterized in that: The raw materials of the polyamide foam material include the following components in parts by weight: 85-98 parts of polyamide 5X resin and 0.5-5 parts of chain extender; the pore size distribution of the foam material is 1.0-3.

0.

2. The polyamide foam material according to claim 1, characterized in that The polyamide 5X resin is prepared using pentamethylenediamine, adipic acid or aliphatic long carbon chain dibasic acid as raw materials; the carbon number of the aliphatic long carbon chain dibasic acid is 10 to 18, and the aliphatic long carbon chain dibasic acid is preferably one or more of sebacic acid, undecanedicarboxylic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedicarboxylic acid and hexadecanedioic acid; Preferably, the polyamide 5X resin is one or more of PA510, PA511, PA512, PA513, PA514, PA515 and PA516; And / or, the relative viscosity of the polyamide 5X resin is 1.5-3.5, preferably 1.8-2.8; and / or, the terminal amino group content of the polyamide 5X resin is 30-65 mmol / kg, preferably 40-60 mmol / kg; and / or, the melting point of the polyamide 5X resin is 170-320°C, preferably 180-280°C, more preferably 180-260°C; And / or, when the polyamide 5X resin is one or more of PA56, PA510, PA511, PA512, PA513, PA514, PA515 and PA516, it has the following characteristics: relative viscosity of 1.8-2.8, terminal amino content of 30-65 mmol / kg, preferably 40-60 mmol / kg, melting point of 170-320°C, preferably 180-260°C.

3. The polyamide foam material according to claim 1, characterized in that: The chain extender is one or more of phosphorus-containing compounds, acid anhydride compounds, epoxy compounds, oxazoline compounds, carbonate compounds, lactam compounds and isocyanate compounds; Further, the phosphorus-containing compound includes but is not limited to triphenylphosphite (TPP) and tricaprolactam phosphite (PTL); And / or, the acid anhydride compound is one or more of naphthalenetetracarboxylic dianhydride (NTCDA), pyromellitic dianhydride PMDA, styrene-maleic anhydride copolymer SMA, POE-g-MAH, PE-g-MAH, PP-g-MAH, EPDM-g-MAH or EVA-g-MAH; And / or, the epoxy compound is one or more of styrene-glycidyl methacrylate oligomer, epoxy polysiloxane EPM and triglycidyl isocyanurate TGIC; the styrene-glycidyl methacrylate oligomer is preferably one or more of ADR 4468, ADR 4380 and KL-E4300; And / or, the oxazoline compound is one or more of bisoxazoline BOZ, 3-oxazoline, styrene oxazoline copolymer (RPS) and isoxazoline benzyl ether compounds; And / or, the carbonate compound is Brueggemann M1251 and / or Brueggemann M1253; And / or, the lactam compounds include but are not limited to terephthaloyl dicaprolactam (TBC) and terephthaloyl didodecanolactam (TBLL). And / or, the isocyanate compound is one or more of isophorone diisocyanate IPDI, toluene diisocyanate TDI, diphenylmethane diisocyanate MDI, dicyclohexylmethane diisocyanate HMDI, hexamethylene diisocyanate HDI and polymethylene polyphenyl polyisocyanate PAPI.

4. The polyamide foam material according to claim 1, characterized in that The raw materials of the polyamide foam material also include antioxidants, heat stabilizers, nucleating agents and lubricants; The antioxidant is one or more of antioxidant 1098, antioxidant 1010 and antioxidant 168; and / or, the content of the antioxidant is 0.01-1 part, preferably 0.05-0.5 part; And / or, the thermal stabilizer is CuI and / or H10; and / or, the content of the thermal stabilizer is 0.01-1 part, preferably 0.05-0.5 part; and / or, the nucleating agent is one or more of calcium carbonate, kaolin, talc and mica powder; and / or, the content of the nucleating agent is 0.1-5 parts, preferably 0.5-2 parts; And / or, the lubricant is one or more of stearic acid and its soap salt, polyethylene wax, polypropylene wax and oxidized polyethylene wax; and / or, the content of the lubricant is 0.2-3 parts, preferably 0.5-2 parts.

5. The polyamide foam material according to any one of claims 1 to 6, characterized in that: The foam density of the polyamide foam material is 0.050-0.250 g / cm 3 ; And / or, the foaming ratio of the polyamide foam material is 5-20; and / or, the average cell diameter of the polyamide foam material is 0.08-0.65 mm, preferably 0.1-0.4 mm; And / or, the pore size distribution of the polyamide foam material is 1.5-2.5; And / or, the compressive strength of the polyamide foam material is 0.7-5.0 MPa; And / or, the polyamide foam material may be in the form of a plate, sheet or bead, preferably a foamed plate, the thickness of the foamed plate is ≥10 mm, preferably 10-80 mm, further 20-70 mm, further 40-60 mm.

6. A method for preparing a polyamide foam material according to any one of claims 1 to 5, characterized in that: Prepared by the following method (i) or (ii): Method (I): The raw materials are mixed uniformly, extruded and granulated to obtain a polyamide modified material, and then the polyamide modified material is continuously extruded and foamed by a twin-screw extrusion foaming device. Method (ii): adding the raw materials to a twin-screw extrusion foaming device for mixing and modification, and then continuously extruding and foaming through the twin-screw extrusion foaming device.

7. The method for preparing a polyamide foam material according to claim 6, characterized in that: In method (1), a twin-screw extruder is used for extrusion granulation; Preferably, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones 1 to 6 are "180-220°C, 190-280°C, 200-280°C, 200-290°C, 200-320°C, 200-320°C" in sequence; Preferably, the twin-screw extruder is expressed in terms of screw speed, and the extrusion speed is 150-600 rpm; And / or, in method (1), the relative viscosity of the obtained polyamide modified material is 2.6-4.

5.

8. The method for preparing a polyamide foam material according to claim 6, characterized in that: In method (1), the twin-screw extrusion foaming equipment includes a twin-screw extruder, a static mixer and an extrusion die head; Preferably, the twin-screw extruder adopts a six-zone heating mode, and the temperatures of zones 1 to 6 are "210-280°C, 210-280°C, 210-280°C, 210-275°C, 180-275°C, 180-275°C" in sequence; Preferably, the twin-screw extruder is expressed in terms of screw speed, and the extrusion speed is 15-300 rpm; Preferably, the aspect ratio of the twin-screw extruder is 28-64:1, further 40-64:1; The temperature of the static mixer is close to the melting point of the polyamide resin, preferably 180-275°C; Preferably, the aspect ratio of the static mixer is 2-8:1; The temperature of the extrusion die is close to the melting point of the polyamide resin, preferably 180-275°C; And / or, the residence time of the polyamide modified material in the twin-screw extrusion foaming equipment is 10-30 minutes.

9. The method for preparing a polyamide foam material according to claim 6, characterized in that: In mode (ii), the twin-screw extrusion foaming equipment comprises a twin-screw extruder, a static mixer and an extrusion die head; Preferably, the twin-screw extruder adopts an eight-zone heating mode, and the temperatures of zones 1 to 8 are "220-280°C, 220-280°C, 210-280°C, 210-275°C, 180-275°C, 180-275°C, 180-275°C, 180-275°C" in sequence; Preferably, the twin-screw extruder is expressed in terms of screw speed, and the extrusion speed is 15-300 rpm; Preferably, the aspect ratio of the twin-screw extruder is 32-64:1; The temperature of the static mixer is close to the melting point of the polyamide resin, preferably 180-275°C; Preferably, the aspect ratio of the static mixer is 4-12:1; The temperature of the extrusion die is close to the melting point of the polyamide resin, preferably 180-275°C; And / or, the residence time of each raw material in the twin-screw extrusion foaming equipment is 10-30 minutes.

10. The method for preparing a polyamide foam material according to claim 6, characterized in that: In method (1) and method (2), the type and amount of the raw material are the raw materials as described in any one of claims 1 to 5; and / or, and / or, before continuous extrusion, adding a foaming agent to the twin-screw extrusion foaming device through a foaming agent filling system, wherein the amount of the foaming agent added is 0.5-5% of the total mass of the raw materials; Preferably, the foaming agent is selected from at least one of butane, cyclopentane, n-pentane, CO2, and N2.

11. Use of the polyamide foam material according to any one of claims 1 to 5 or the foam material prepared by the preparation method according to any one of claims 6 to 10 in the fields of wind power equipment, construction, furniture, packaging, transportation, etc.

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