Heat-resistant flame-retardant reinforced polyamide composition as well as preparation method and application thereof

Abstract

The invention discloses a heat-resistant flame-retardant reinforced polyamide composition as well as a preparation method and application thereof, and the heat-resistant flame-retardant reinforced polyamide composition comprises the following raw materials in parts by weight: 30-41 parts of polyamide, 15-20 parts of a flame retardant, 2-5 parts of a synergistic flame retardant, 10-20 parts of syndiotactic polystyrene, 2-8 parts of a compatilizer and 10-30 parts of glass sheets. The polyamide comprises one or more of PA66 (polyamide 66) and PA6 (polyamide 6); the compatilizer comprises maleic anhydride grafted syndiotactic polystyrene; according to the invention, syndiotactic polystyrene with excellent dimensional stability and polyamide are selected for composite modification, so that the obtained composition has the advantages of high dimensional stability, low warpage, excellent mechanical property, flame retardance and heat resistance, simple process, good processability and low cost. And the composite material can meet the fields of automobiles, electronic appliances, traffic equipment, aerospace automobiles, electric tools and sports equipment with high requirements on dimensional stability, warping property, strength, flame retardance and heat resistance.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to a heat-resistant and flame-retardant reinforced polyamide composition, a preparation method and application thereof. Background Art

[0002] Polyamide is an engineering material with excellent performance. It has high strength and excellent heat resistance, chemical resistance, wear resistance, heat and oxygen aging resistance and good processability. It has been widely used in the fields of automobiles, electronic appliances, transportation equipment, aerospace, etc. However, since automobiles, electronic appliances and other products are prone to fire during use, there are high requirements for the flame retardant properties of the material. At the same time, with the acceleration of the lightweight and miniaturization of automobile products, the high performance of electronic and electrical equipment, and the functionalization of mechanical equipment, the demand for polyamide products will be more extensive, especially as a structural material, polyamide has higher requirements for its strength, dimensional stability, low deformation and low warpage, flame retardancy, etc.; but since the amide groups in the polyamide molecular chain are easy to form hydrogen bonds with water molecules, the water absorption rate of polyamide materials is high, the size of the product is prone to large changes, and it is easy to warp and deform. Therefore, the development of a high dimensional stability, low warpage flame retardant reinforced polyamide composite material is of great significance in the fields of automobiles, electronic appliances, transportation equipment, aerospace, etc.

[0003] Syndiotactic polystyrene is a new type of thermoplastic engineering plastic. It not only inherits the excellent properties of general-purpose polystyrene such as low density, excellent electrical properties, good hydrolysis stability and low price, but also syndiotactic polystyrene is a semi-crystalline polymer. Crystallization gives it excellent mechanical properties as well as heat resistance, solvent resistance and dimensional stability. Therefore, syndiotactic polystyrene is being widely used as a new type of engineering plastic.

[0004] Both syndiotactic polystyrene and polyamide are crystalline polymers. Through blending and modification, alloy materials with good heat resistance, low warpage and excellent dimensional stability can be obtained. However, the two are incompatible systems, so suitable modification methods are needed to obtain products with excellent performance. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention proposes a heat-resistant flame-retardant reinforced polyamide composition, a preparation method and application thereof; A heat-resistant flame-retardant reinforced polyamide composition comprises the following raw materials in parts by weight: 30-41 parts of polyamide, 15-20 parts of flame retardant, 2-5 parts of synergistic flame retardant, 10-20 parts of syndiotactic polystyrene, 2-8 parts of compatibilizer and 10-30 parts of glass flakes; The polyamide includes one or more of PA66 and PA6; the compatibilizer includes maleic anhydride grafted syndiotactic polystyrene.

[0006] Preferably, the invention further comprises 0.2 to 0.5 parts by weight of a lubricant, wherein the lubricant comprises one or more of ethylene bisstearamide, pentaerythritol stearate and modified polyethylene wax.

[0007] Preferably, the molecular weight of the syndiotactic polystyrene is in the range of 10,000-500,000 and the melting point is in the range of 270-280°C.

[0008] Preferably, the synergistic flame retardant includes one or more of melamine polyphosphate, zinc borate and aluminum phosphite.

[0009] Preferably, the glass sheet has a thickness of 0.1-1.0 μm and a D50 particle size of 100-1000 μm.

[0010] Preferably, the flame retardant comprises a halogen-free dialkyl phosphinate.

[0011] Preferably, the invention further comprises 0.1 to 0.5 parts by weight of an antioxidant, wherein the antioxidant comprises one or more of a hindered phenol antioxidant, a thioether antioxidant and a phosphite antioxidant.

[0012] A method for preparing a heat-resistant flame-retardant reinforced polyamide composition comprises the following steps: Drying 30-41 parts of polyamide; 10-20 parts of syndiotactic polystyrene, 2-8 parts of compatibilizer, 15-20 parts of flame retardant, 2-5 parts of synergistic flame retardant, 0.1-0.5 parts of antioxidant and 0.2-0.5 parts of lubricant are mixed, and then the treated polyamide is added to obtain a mixed material; The mixture and 10 to 30 parts of glass flakes are melted, extruded, granulated, water-cooled, blow-dried and then pelletized to obtain a heat-resistant flame-retardant reinforced polyamide composition.

[0013] Preferably, the drying temperature is 110° C. and the drying time is 4 hours.

[0014] Application of the heat-resistant flame-retardant reinforced polyamide composition or the heat-resistant flame-retardant reinforced polyamide composition prepared by the preparation method in the production of electronic appliances, transportation equipment, electric tools and sports equipment.

[0015] Syndiotactic polystyrene and a compatibilizer are added to the formula to improve the compatibility of syndiotactic polystyrene and polyamide, and a compound high-efficiency flame retardant and glass fiber sheets are added to prepare a composition, so that the polyamide composition has the characteristics of high dimensional stability, low warpage, high strength, high flame retardancy and the like.

[0016] Compared with the prior art, the present invention selects syndiotactic polystyrene with excellent dimensional stability and polyamide for composite modification, and the dimensional stability of the obtained composition is much higher than that of a single polyamide material. At the same time, the addition of suitable compatibilizers, glass fiber sheets, flame retardants, and synergists can significantly improve the mechanical properties, flame retardancy and heat resistance of the composition. The process is simple and the processing performance is good, which meets the requirements of automobiles, electronic appliances, transportation equipment, aerospace vehicles, power tools and sports equipment for high dimensional stability, strength, flame retardancy and heat resistance. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Example 1 A high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following raw materials in parts by weight: 37 parts of polyamide PA66, 20 parts of syndiotactic polystyrene, 8 parts of a compatibilizer, 10 parts of a glass fiber sheet, 20 parts of a halogen-free flame retardant aluminum diethylphosphinate, 4 parts of a synergist MPP, 1 part of a synergist zinc borate, 0.2 parts of an antioxidant 1098, 0.3 parts of an antioxidant S-9228 and 0.5 parts of ethylene bisstearamide.

[0019] A method for preparing a high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following steps: S1, drying polyamide PA66 at 110°C for 4h; S2, adding syndiotactic polystyrene, compatibilizer, flame retardant, synergist, antioxidant 1098, antioxidant S-9228 and ethylene bis stearamide into a high-speed mixer and mixing at 1500 r / min for 3 min, adding polyamide PA66 treated by S1 into a high-speed mixer and mixing at 1500 r / min for 8 min to obtain a mixed material; S3. Add the mixed material in S2 from the main feeding port of the twin-screw extruder, add the glass sheet from the side feeding port of the twin-screw extruder, and after melting, extrusion, granulation, water cooling, blow drying and pelletizing, obtain a high dimensional stability and high heat resistance flame retardant reinforced polyamide composition, wherein the nine-zone processing temperatures of the twin-screw extruder are: the temperature of zones 1 and 2 is 250-270°C, the temperature of zones 3 to 7 is 240-260°C, the temperature of zones 8 and 9 is 250-270°C, the head temperature is 270-280°C, and the screw speed is 400rpm.

[0020] Example 2 A high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following raw materials in parts by weight: 30 parts of polyamide PA66, 15 parts of syndiotactic polystyrene, 5 parts of a compatibilizer, 20 parts of a glass fiber sheet, 17 parts of a halogen-free flame retardant aluminum diethylphosphinate, 2 parts of a synergist MPP, 1 part of a synergist zinc borate, 0.1 parts of an antioxidant 1098, 0.5 parts of an antioxidant S-9228 and 0.2 parts of pentaerythritol stearate.

[0021] A method for preparing a high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following steps: S1, drying polyamide PA66 at 110°C for 4h; S2, adding syndiotactic polystyrene, compatibilizer, flame retardant, synergist, antioxidant 1098, antioxidant S-9228 and pentaerythritol stearate into a high-speed mixer and mixing at 1500 r / min for 3 min, adding polyamide PA66 treated by S1 into a high-speed mixer and mixing at 1500 r / min for 8 min to obtain a mixed material; S3. Add the mixed material in S2 from the main feeding port of the twin-screw extruder, add the glass sheet from the side feeding port of the twin-screw extruder, and after melting, extrusion, granulation, water cooling, blow drying and pelletizing, obtain a high dimensional stability and high heat resistance flame retardant reinforced polyamide composition, wherein the nine-zone processing temperatures of the twin-screw extruder are: the temperature of zones 1 and 2 is 250-270°C, the temperature of zones 3 to 7 is 240-260°C, the temperature of zones 8 and 9 is 250-270°C, the head temperature is 270-280°C, and the screw speed is 400rpm.

[0022] Example 3 A high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following raw materials in parts by weight: 41 parts of polyamide PA66, 10 parts of syndiotactic polystyrene, 2 parts of a compatibilizer, 30 parts of a glass fiber sheet, 15 parts of a halogen-free flame retardant aluminum diethylphosphinate, 1 part of a synergist MPP, 1 part of a synergist zinc borate, 0.5 parts of an antioxidant 1098, 0.2 parts of an antioxidant S-9228 and 0.5 parts of a modified polyethylene wax.

[0023] A method for preparing a high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following steps: S1, drying polyamide PA66 at 110°C for 4h; S2, adding syndiotactic polystyrene, compatibilizer, flame retardant, synergist, antioxidant 1098, antioxidant S-9228 and modified polyethylene wax into a high-speed mixer and mixing at 1500 r / min for 3 min, adding polyamide PA66 treated by S1 into the high-speed mixer and mixing at 1500 r / min for 8 min to obtain a mixed material; S3. Add the mixed material in S2 from the main feeding port of the twin-screw extruder, add the glass sheet from the side feeding port of the twin-screw extruder, and after melting, extrusion, granulation, water cooling, blow drying and pelletizing, obtain a high dimensional stability and high heat resistance flame retardant reinforced polyamide composition, wherein the nine-zone processing temperatures of the twin-screw extruder are: the temperature of zones 1 and 2 is 250-270°C, the temperature of zones 3 to 7 is 240-260°C, the temperature of zones 8 and 9 is 250-270°C, the head temperature is 270-280°C, and the screw speed is 400rpm.

[0024] Example 4 A high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following raw materials in parts by weight: 41 parts of polyamide PA6, 10 parts of syndiotactic polystyrene, 2 parts of a compatibilizer, 30 parts of a glass fiber sheet, 15 parts of a halogen-free flame retardant aluminum diethylphosphinate, 1 part of a synergist MPP, 1 part of a synergist zinc borate, 0.5 parts of an antioxidant 1098, 0.2 parts of an antioxidant S-9228 and 0.5 parts of a modified polyethylene wax.

[0025] A method for preparing a high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following steps: S1, drying polyamide PA6 at 110°C for 4h; S2, adding syndiotactic polystyrene, compatibilizer, flame retardant, synergist, antioxidant 1098, antioxidant S-9228 and modified polyethylene wax into a high-speed mixer and mixing at 1500 r / min for 3 min, adding polyamide PA6 treated by S1 into the high-speed mixer and mixing at 1500 r / min for 8 min to obtain a mixed material; S3. Add the mixed material in S2 from the main feeding port of the twin-screw extruder, add the glass sheet from the side feeding port of the twin-screw extruder, and after melting, extrusion, granulation, water cooling, blow drying and pelletizing, obtain a high dimensional stability and high heat resistance flame retardant reinforced polyamide composition, wherein the nine-zone processing temperatures of the twin-screw extruder are: the temperature of zones 1 and 2 is 230-240°C, the temperature of zones 3 to 7 is 220-230°C, the temperature of zones 8 and 9 is 230-240°C, the head temperature is 230-240°C, and the screw speed is 400rpm.

[0026] Comparative Example 1 A high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following raw materials in parts by weight: 43 parts of polyamide PA66, 10 parts of syndiotactic polystyrene, 30 parts of glass fiber sheets, 15 parts of halogen-free flame retardant aluminum diethylphosphinate, 1 part of synergist MPP, 1 part of synergist zinc borate, 0.5 part of antioxidant 1098, 0.2 part of antioxidant S-9228 and 0.5 part of modified polyethylene wax.

[0027] A method for preparing a high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following steps: S1, drying polyamide PA66 at 110°C for 4h; S2, adding syndiotactic polystyrene, flame retardant, synergist, antioxidant 1098, antioxidant S-9228 and modified polyethylene wax into a high-speed mixer and mixing at 1500 r / min for 3 min, adding polyamide PA66 treated by S1 into the high-speed mixer and mixing at 1500 r / min for 8 min to obtain a mixed material; S3. Add the mixed material in S2 from the main feeding port of the twin-screw extruder, add the glass sheet from the side feeding port of the twin-screw extruder, and after melting, extrusion, granulation, water cooling, blow drying and pelletizing, obtain a high dimensional stability and high heat resistance flame retardant reinforced polyamide composition, wherein the nine-zone processing temperatures of the twin-screw extruder are: the temperature of zones 1 and 2 is 250-270°C, the temperature of zones 3 to 7 is 240-260°C, the temperature of zones 8 and 9 is 250-270°C, the head temperature is 270-280°C, and the screw speed is 400rpm.

[0028] Comparative Example 2 A high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following raw materials in parts by weight: 51 parts of polyamide PA66, 2 parts of a compatibilizer, 30 parts of a glass fiber sheet, 15 parts of a halogen-free flame retardant aluminum diethylphosphinate, 1 part of a synergist MPP, 1 part of a synergist zinc borate, 0.5 parts of an antioxidant 1098, 0.2 parts of an antioxidant S-9228 and 0.5 parts of a modified polyethylene wax.

[0029] A method for preparing a high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following steps: S1, drying polyamide PA66 at 110°C for 4h; S2, adding compatibilizer, flame retardant, synergist, antioxidant 1098, antioxidant S-9228 and modified polyethylene wax into a high-speed mixer and mixing at 1500 r / min for 3 min, adding polyamide PA66 treated by S1 into the high-speed mixer and mixing at 1500 r / min for 8 min to obtain a mixed material; S3. Add the mixed material in S2 from the main feeding port of the twin-screw extruder, add the glass sheet from the side feeding port of the twin-screw extruder, and after melting, extrusion, granulation, water cooling, blow drying and pelletizing, obtain a high dimensional stability and high heat resistance flame retardant reinforced polyamide composition, wherein the nine-zone processing temperatures of the twin-screw extruder are: the temperature of zones 1 and 2 is 250-270°C, the temperature of zones 3 to 7 is 240-260°C, the temperature of zones 8 and 9 is 250-270°C, the head temperature is 270-280°C, and the screw speed is 400rpm.

[0030] Comparative Example 3 A high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following raw materials in parts by weight: 53 parts of polyamide PA66, 30 parts of glass fiber sheets, 15 parts of halogen-free flame retardant aluminum diethylphosphinate, 1 part of synergist MPP, 1 part of synergist zinc borate, 0.5 part of antioxidant 1098, 0.2 part of antioxidant S-9228 and 0.5 part of modified polyethylene wax.

[0031] A method for preparing a high-dimensional stability and high-heat-resistant flame-retardant reinforced polyamide composition comprises the following steps: S1, drying polyamide PA66 at 110°C for 4h; S2, adding flame retardant, synergist, antioxidant 1098, antioxidant S-9228 and modified polyethylene wax into a high-speed mixer and mixing at 1500 r / min for 3 min, adding polyamide PA66 treated by S1 into a high-speed mixer and mixing at 1500 r / min for 8 min to obtain a mixed material; S3. Add the mixed material in S2 from the main feeding port of the twin-screw extruder, add the glass sheet from the side feeding port of the twin-screw extruder, and after melting, extrusion, granulation, water cooling, blow drying and pelletizing, obtain a high dimensional stability and high heat resistance flame retardant reinforced polyamide composition, wherein the nine-zone processing temperatures of the twin-screw extruder are: the temperature of zones 1 and 2 is 250-270°C, the temperature of zones 3 to 7 is 240-260°C, the temperature of zones 8 and 9 is 250-270°C, the head temperature is 270-280°C, and the screw speed is 400rpm.

[0032] The high dimensional stability and high heat resistance flame retardant reinforced polyamide compositions prepared in the above Examples 1 to 4 and the polyamide materials prepared in Comparative Examples 1 to 3 were tested for tensile strength, flexural strength, notched cantilever beam impact strength, flame retardancy, dimensional expansion rate after water absorption, etc. The test standards and performance test results are shown in Table 1: Table 1 Relevant performance tests of polyamide compositions in Examples and Comparative Examples Note: 1. Expansion rate is the size change rate before and after boiling at 80℃ for 24 hours. The calculation formula is expansion rate = (size of sample after boiling - size of sample before boiling) / size of sample before boiling.

[0033] 2. In Table 1, * indicates the degree of warping. The more *, the more serious the warping. As can be seen from Table 1, by comparing Example 3 with Comparative Example 1, and Comparative Example 2 with Comparative Example 3, it can be seen that after adding syndiotactic polystyrene and compatibilizer at the same time, the overall mechanical properties of the material remain good, without a significant decrease, the deformation warpage is low, and after the composition is boiled in water at 80°C for 24 hours, the dimensional expansion rate of the material is smaller and the dimensional stability is higher; in addition, it can be seen from the comparison that Comparative Example 3 without adding syndiotactic polystyrene and compatibilizer has the best mechanical properties, but the dimensional expansion rate of the material after boiling is the highest, indicating that the dimensional stability of the material is poor and the warpage is serious; Compared with Example 3, Comparative Example 1 and Comparative Example 2, in which one of the components is added alone, the mechanical properties and dimensional stability are reduced to a certain extent, and the deformation warpage is serious; Comparing Example 3 with Comparative Example 1 and Comparative Example 2, the high dimensional stability and high heat-resistant flame-retardant reinforced polyamide composition prepared by the present invention by adding syndiotactic polystyrene and a compatibilizer has a certain improvement in tensile strength, flexural strength, impact strength and thermal deformation data compared with the comparative example, and when the composition is boiled in water at 80°C for 24 h, the dimensional expansion rate of the material is smaller and the dimensional stability is higher; at the same time, it can be seen from Comparative Examples 1-4 that with the increase of the content of syndiotactic polystyrene and the compatibilizer, the dimensional expansion rate of the composition is smaller and the dimensional stability is higher.

[0034] In summary, in the present invention, syndiotactic polystyrene with excellent dimensional stability is selected for composite modification with polyamide, and the dimensional stability and warpage of the obtained composition are much higher than those of a single polyamide material. At the same time, the addition of suitable compatibilizers, glass fiber sheets, flame retardants, and synergists can significantly improve the mechanical properties, flame retardancy and heat resistance of the composition. The process is simple and the processing performance is good, which meets the requirements of automobiles, electronic appliances, transportation equipment, aerospace vehicles, power tools and sports equipment for high dimensional stability, warpage deformation, strength, flame retardancy and heat resistance.

[0035] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0036] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A heat-resistant flame-retardant reinforced polyamide composition, characterized in that: The invention comprises the following raw materials in parts by weight: 30-41 parts of polyamide, 15-20 parts of flame retardant, 2-5 parts of synergistic flame retardant, 10-20 parts of syndiotactic polystyrene, 2-8 parts of compatibilizer and 10-30 parts of glass flakes; The polyamide includes one or more of PA66 and PA6; the compatibilizer includes maleic anhydride grafted syndiotactic polystyrene.

2. The heat-resistant flame-retardant reinforced polyamide composition according to claim 1, characterized in that: The invention also includes 0.2 to 0.5 parts by weight of a lubricant, wherein the lubricant includes one or more of ethylene bis stearamide, pentaerythritol stearate and modified polyethylene wax.

3. The heat-resistant flame-retardant reinforced polyamide composition according to claim 1, characterized in that: The molecular weight of the syndiotactic polystyrene is in the range of 10,000-500,000 and the melting point is in the range of 270-280°C.

4. The heat-resistant flame-retardant reinforced polyamide composition according to claim 1, characterized in that: The synergistic flame retardant includes one or more of melamine polyphosphate, zinc borate and aluminum phosphite.

5. The heat-resistant flame-retardant reinforced polyamide composition according to claim 1, characterized in that: The glass sheet has a thickness of 0.1-1.0 μm and a D50 particle size of 100-1000 μm.

6. The heat-resistant flame-retardant reinforced polyamide composition according to claim 1, characterized in that: The flame retardant includes a halogen-free dialkyl phosphinate.

7. The heat-resistant flame-retardant reinforced polyamide composition according to claim 1, characterized in that: The invention also comprises 0.1 to 0.5 parts by weight of an antioxidant, wherein the antioxidant comprises one or more of a hindered phenol antioxidant, a thioether antioxidant and a phosphite antioxidant.

8. A method for preparing a heat-resistant, flame-retardant, reinforced polyamide composition, characterized in that: The following steps are involved: Drying 30-41 parts of polyamide; 10-20 parts of syndiotactic polystyrene, 2-8 parts of compatibilizer, 15-20 parts of flame retardant, 2-5 parts of synergistic flame retardant, 0.1-0.5 parts of antioxidant and 0.2-0.5 parts of lubricant are mixed, and then the treated polyamide is added to obtain a mixed material; The mixture and 10 to 30 parts of glass flakes are melted, extruded, granulated, water-cooled, blow-dried and then pelletized to obtain a heat-resistant flame-retardant reinforced polyamide composition.

9. The method for preparing the heat-resistant flame-retardant reinforced polyamide composition according to claim 8, characterized in that: The drying temperature is 110° C. and the drying time is 4 hours.

10. Use of the heat-resistant flame-retardant reinforced polyamide composition according to any one of claims 1 to 7 or the heat-resistant flame-retardant reinforced polyamide composition prepared by the preparation method according to any one of claims 8 to 9 in the production of electronic appliances, transportation equipment, electric tools and sports equipment.

Images