Glass fiber reinforced flame-retardant polyamide composite material as well as preparation method and application thereof

Abstract

The invention discloses a glass fiber reinforced flame-retardant polyamide composite material which comprises the following components in parts by weight: 49-61 parts of polyamide resin; 19 to 51 parts of glass fiber; 2.9 to 8.1 parts of a brominated polystyrene high polymer; 6.9 to 18.1 parts of a brominated polystyrene oligomer; 2.9 to 8.1 parts of a flame retardant synergist; the weight-average molecular weight of the brominated polystyrene high polymer ranges from 180000 to 250000; the weight-average molecular weight of the brominated polystyrene oligomer ranges from 4000 to 8000; the relative viscosity of the polyamide resin ranges from 2.0 to 2.7; the average reserved length range of the glass fibers is 250-350 microns, and the average diameter range of the glass fibers is 6-12 microns. By compounding the polyamide resin with specific viscosity and the brominated polystyrene with specific different molecular weights, good melt flow stability can be realized, and crystallinity is improved, so that the glass fiber reinforced composite material disclosed by the invention has good dimensional stability after injection molding and has a 1.6 mm flame-retardant effect.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a glass fiber reinforced flame retardant polyamide composite material and a preparation method and application thereof. Background Art

[0002] Flame-retardant nylon materials have good strength and toughness and are widely used in the field of electronics and electrical. In order to achieve a better appearance, the electronics and electrical industry often requires higher mold temperature injection molding, especially for flame-retardant products, which require higher mold temperature because the appearance is worse due to the unstable melt flow stability. Nylon is a crystalline polymer, which causes the size of the demolded parts to gradually decrease as the temperature drops and the time increases, thus causing major problems in assembly.

[0003] At present, many injection molding factories in the market solve this problem by finalizing the molds in the later stage to ensure the stability of the dimensions and smooth assembly in the later stage. Few of them obtain the advantage of strong dimensional stability by modifying the composition. Summary of the invention

[0004] The object of the present invention is to provide a glass fiber reinforced flame retardant polyamide composite material which is 1.6 mm V-0 flame retardant and has strong dimensional stability after injection molding, and a preparation method and application thereof.

[0005] The present invention is achieved through the following technical solutions: A glass fiber reinforced flame retardant polyamide composite material, comprising the following components in parts by weight: 49-61 parts of polyamide resin; Glass fiber 19-51 parts; 2.9-8.1 parts of brominated polystyrene polymer; Brominated polystyrene oligomer 6.9-18.1 parts; Flame retardant synergist 2.9-8.1 parts; The weight average molecular weight of the brominated polystyrene polymer is in the range of 180,000 to 250,000; The weight average molecular weight of the brominated polystyrene oligomer is in the range of 4000-8000; The relative viscosity range of polyamide resin is 2.0-2.7; The average retention length of the glass fibers is in the range of 250-370 microns, and the average diameter is in the range of 6-12 microns.

[0006] In the glass fiber reinforced flame retardant polyamide composite material of the present invention, the content of the polyamide resin can be 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 61 parts, etc.; The glass fiber can be 19 parts, 21 parts, 23 parts, 25 parts, 27 parts, 29 parts, 31 parts, 33 parts, 35 parts, 37 parts, 39 parts, 41 parts, 43 parts, 45 parts, 47 parts, 49 parts, 51 parts, etc.; The content of brominated polystyrene polymer can be 2.9 parts, 3.1 parts, 3.3 parts, 3.5 parts, 3.7 parts, 3.9 parts, 4.1 parts, 4.3 parts, 4.5 parts, 4.7 parts, 4.9 parts, 5.1 parts, 5.3 parts, 5.5 parts, 5.7 parts, 5.9 parts, 6.1 parts, 6.3 parts, 6.5 parts, 6.7 parts, 6.9 parts, 7.1 parts, 7.3 parts, 7.5 parts, 7.7 parts, 7.9 parts, 8.1 parts, etc.; The amount of brominated polystyrene oligomer can be 6.9 parts, 7.1 parts, 7.3 parts, 7.5 parts, 7.7 parts, 7.9 parts, 8.1 parts, 8.3 parts, 8.5 parts, 8.7 parts, 8.9 parts, 9.1 parts, 9.3 parts, 9.5 parts, 9.7 parts, 9.9 parts, 10.1 parts, 10.3 parts, 10.5 parts, 10.7 parts, 10.9 parts, 11.1 parts, 11.3 parts, 11.5 parts, 11.7 parts, 11.9 parts, 12.1 parts, 12.3 parts, 12.5 parts. , 12.7, 12.9, 13.1, 13.3, 13.5, 13.7, 13.9, 14.1, 14.3, 14.5, 14.7, 14.9, 15.1, 15.3, 15.5, 15.7, 15.9, 16.1, 16.3, 16.5, 16.7, 16.9, 17.1, 17.3, 17.5, 17.7, 17.9, 18.1, etc.; The content of the flame retardant synergist can be 2.9 parts, 3.1 parts, 3.3 parts, 3.5 parts, 3.7 parts, 3.9 parts, 4.1 parts, 4.3 parts, 4.5 parts, 4.7 parts, 4.9 parts, 5.1 parts, 5.3 parts, 5.5 parts, 5.7 parts, 5.9 parts, 6.1 parts, 6.3 parts, 6.5 parts, 6.7 parts, 6.9 parts, 7.1 parts, 7.3 parts, 7.5 parts, 7.7 parts, 7.9 parts, 8.1 parts, etc.

[0007] The testing method for the weight average molecular weight of brominated polystyrene is: using gel permeation chromatography.

[0008] Preferably, the relative viscosity of the polyamide resin is in the range of 2.2-2.5, as measured by ISO 307 test standard.

[0009] Preferably, the average retention length of the glass fibers is in the range of 290-335 microns.

[0010] The average retention length of the glass fibers can be adjusted by controlling the length of the glass fiber raw material and / or the rotation speed of the barrel.

[0011] The test method for the average length of glass fiber is as follows: treat the glass fiber reinforced flame retardant polyamide composite material in a muffle furnace at 650-800℃ for 2h to obtain the material ash, take 5-10mg of ash into a watch glass, add 10mL of deionized water and evenly disperse the ash, use a two-dimensional microscope to magnify and observe, measure and calculate the average length and average diameter of the glass fiber in the field of view.

[0012] The flame retardant synergist may be antimony trioxide, and the average particle size range is 0.5-20 microns.

[0013] The average particle size of antimony trioxide is measured by a laser particle size analyzer.

[0014] The polyamide resin is selected from at least one of aliphatic polyamide and semi-aromatic polyamide; the polylactam is selected from PA6; the aliphatic polyamide is selected from one or more of PA66, PA66 / 6 copolymer, PA6 / 66 copolymer, PA56, PA610, PA612, PA1010, PA1012, PA11, and PA12; the semi-aromatic polyamide is selected from one or more of PA6T / 66, PA9T, PAMXD6, and PA6T / 6I.

[0015] It is possible to choose whether to add 0-2 parts of auxiliary agent according to actual conditions, wherein the auxiliary agent is selected from at least one of an antioxidant, a lubricant, and an anti-ultraviolet agent.

[0016] The preparation method of the glass fiber reinforced flame retardant polyamide composite material of the present invention comprises the following steps: mixing the components uniformly according to the proportion, and extruding and granulating through a twin-screw extruder, wherein the screw length-diameter ratio of the twin-screw extruder is 40-48:1, the barrel temperature is 220-270°C, and the screw speed is 200-450rpm.

[0017] The glass fiber reinforced flame retardant polyamide composite material of the present invention is used for preparing electrical parts.

[0018] The present invention has the following beneficial effects: The present invention compounded a polyamide resin with a specific viscosity and brominated polystyrene with specific different molecular weights, and at high temperature, the high molecular weight brominated polystyrene can play a certain anisotropic nucleation role, and at the same time, the polyamide with a specific viscosity and the brominated polystyrene oligomer are matched to strengthen the movement of the molecular chain and promote the rapid crystallization of the PA material. It can achieve good melt flow stability, improve crystallinity, reduce product internal stress, and make the glass fiber reinforced composite material of the present invention have good dimensional stability after injection molding and have a flame retardant effect of 1.6mm. DETAILED DESCRIPTION

[0019] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0020] PA6-1: relative viscosity is 2.0, PA6 M2000, Xinhui Meida; PA6-2: relative viscosity is 2.4dL / g, PA6 M2400, Xinhui Meida; PA6-3: relative viscosity is 2.5, PA6 HY2500A, marine chemical fiber; PA6-4: relative viscosity is 2.7, PA6 HY2800A, marine chemical fiber; PA6-5: relative viscosity is 3.4, PA6 M3400, Xinhui Meida; PA66-1: relative viscosity is 2.1, PA66 U2501, Shanghai INVISTA; PA66-2: relative viscosity is 2.2, PA66 EP122, Zhejiang Huafeng; PA66-3: relative viscosity is 2.4, PA66 U3600 NC01 SS, Shanghai INVISTA; PA66-4: relative viscosity is 2.7, PA66 U4800 NC01 SS, Shanghai INVISTA; PA66-5: relative viscosity is 3.2, PA66 EPR32, Henan Shenma; The glass fiber was purchased from China Jushi Company, with the brand name being glass fiber ECS11-4.5-560A (short fiber), with an average diameter of 11 microns and a length range of 3.5-5.5 mm.

[0021] Brominated polystyrene oligomer A: SAYTEX 5010, Mw molecular weight 5000, Albemarle Corporation, USA; Brominated polystyrene oligomer B: Phlamoon-103L, Mw 4000, Taizhou Baili Chemical Co., Ltd.; Brominated polystyrene polymer-1: XZ-6700, Mw 240000, Shandong Brothers; Brominated polystyrene polymer-2: BPS 7010, Mw 190000, Shandong Tianyi; Antimony trioxide: purchased from Shanxing Antimony Industry.

[0022] Lubricant: stearyl stearate, LOXIOL G32, Koning, Germany. Example and Comparative Example Preparation method of glass fiber reinforced flame retardant polyamide composite material: according to the ratio, the components are mixed evenly, and extruded into granules by a twin-screw extruder, the screw aspect ratio of the twin-screw extruder is 44:1, the barrel temperature is 220-270°C, and the screw speed is 200-450rpm (see the table for specific speeds).

[0023] Various test methods: (1) The test method for the average length of glass fibers is as follows: treat the glass fiber reinforced flame retardant polyamide composite material in a muffle furnace at 650-800°C for 2 hours to obtain the material ash, take 5-10 mg of ash and place it in a watch glass, add 10 mL of deionized water and evenly disperse the ash, use a two-dimensional microscope to magnify and observe, and measure and calculate the average length of the glass fibers in the field of view.

[0024] (2) Flame retardancy: 1.6 mm thick combustion specimens were injection molded and the UL 94 standard was used to test the combustion performance of the material.

[0025] (3) Dimensional stability: Use an injection molding machine with the temperature from the nozzle to the discharge port set at 275°C, 270°C, 260°C, and 250°C, respectively. Use medium pressure and medium speed to mold a 100×100×2 mm square plate. Leave it naturally for a week and test the dimensional change rate (compared with the size just out of the cavity).

[0026] (4) Izod notched impact strength: Injection molding ISO 180 standard specimens to test the Izod notched impact strength.

[0027] Table 1: Weight parts of each component and test results of glass fiber reinforced composite materials of Examples 1-6 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 PA6-1 50 55 60 55 PA6-2 55 PA6-3 55 Fiberglass 20 35 50 35 35 35 Brominated polystyrene polymer-1 10 5 3 5 5 Brominated polystyrene polymer-2 5 Brominated polystyrene oligomer A 9 12 18 12 12 12 Antimony trioxide 8 5 3 5 5 5 Lubricants 0.3 0.3 0.3 0.3 0.3 0.3 Screw speed, rpm 250 250 250 250 250 250 Average length of glass fiber, μm 342 333 330 335 332 336 Flame retardant V-0 V-0 V-0 V-0 V-0 V-0 Dimensional change rate% 0.039 0.040 0.035 0.036 0.036 0.038 <![CDATA[Notched impact strength, kJ / m 2 > 8.2 10.8 13.3 10.5 10.9 11.2 Table 2: Weight of each component and test results of glass fiber reinforced composite materials of Examples 7-11 Example 7 Example 8 Example 9 Example 10 Embodiment 11 Polyamide Grade PA6-4 PA66-1 PA66-2 PA66-3 PA66-4 Polyamide content 55 55 55 55 55 Fiberglass 35 35 35 35 35 Brominated polystyrene polymer-1 5 5 5 5 5 Brominated polystyrene oligomer A 12 12 12 12 12 Antimony trioxide 5 5 5 5 5 Lubricants 0.3 0.3 0.3 0.3 0.3 Screw speed, rpm 250 250 250 250 250 Average length of glass fiber, μm 334 340 337 338 335 Flame retardant V-0 V-0 V-0 V-0 V-0 Dimensional change rate% 0.041 0.039 0.037 0.037 0.040 <![CDATA[Notched impact strength, kJ / m 2 > 11.3 10.3 10.5 10.8 10.6 It can be seen from Examples 2 / 5-11 that the dimensional stability is better when the viscosity range of the polyamide resin is preferred.

[0028] Table 3: Weight parts of each component and test results of glass fiber reinforced composite materials of Examples 12-16 Example 12 Example 13 Embodiment 14 Embodiment 15 Example 16 PA6-1 55 55 55 55 55 Fiberglass 35 35 35 35 35 Brominated polystyrene polymer-1 5 5 5 5 5 Brominated polystyrene oligomer A 12 12 12 12 Brominated polystyrene oligomer B 12 Antimony trioxide 5 5 5 5 5 Lubricants 0.3 0.3 0.3 0.3 0.3 Screw speed, rpm 450 380 300 220 220 Average length of glass fiber, μm 268 292 320 356 368 Flame retardant V-0 V-0 V-0 V-0 V-0 Dimensional change rate% 0.032 0.034 0.035 0.045 0.047 <![CDATA[Notched impact strength, kJ / m 2 > 10.1 10.3 10.5 10.9 11.1 It can be seen from Examples 2 / 12-15 that the preferred average length of glass fiber has a moderate dimensional change rate and notched impact strength.

[0029] It can be seen from the above examples that the glass fiber reinforced composite material of the present invention has a flame retardancy of 1.6 mm V-0, a dimensional change rate after injection molding of less than 0.05%, and a notched impact strength of more than 8 kJ / m 2 .

[0030] Table 4: Weight parts of each component and test results of comparative glass fiber reinforced composite materials Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 PA6-1 55 55 50 55 PA6-5 55 PA66-5 55 Fiberglass 35 35 35 35 20 35 Brominated polystyrene polymer-1 5 5 17 10 5 Brominated polystyrene oligomer A 12 12 17 9 12 Antimony trioxide 5 5 5 5 8 5 Lubricants 0.3 0.3 0.3 0.3 0.3 0.3 Screw speed, rpm 250 250 250 250 500 200 Average length of glass fiber, μm 333 329 331 337 239 397 Flame retardant V-0 V-0 V-0 V-0 V-0 V-0 Dimensional change rate% 0.11 0.10 0.051 0.11 0.031 0.054 <![CDATA[Notched impact strength, kJ / m 2 > 12.3 11.2 9.6 13.5 7.1 11.3 It can be seen from Comparative Examples 1 / 2 that when the viscosity of the polyamide resin is too high, the dimensional stability is poor.

[0031] It can be seen from Comparative Example 3 that when only brominated polystyrene polymer is selected, the dimensional stability is poor and the notched impact strength is low.

[0032] It can be seen from Comparative Example 4 that when only brominated polystyrene oligomer is selected, the dimensional stability is very poor.

[0033] It can be seen from Comparative Example 5 that when the average retention length of the glass fiber is too short, the notched impact strength is low.

[0034] It can be seen from Comparative Example 6 that when the average retention length of the glass fiber is too long, the dimensional change rate is too large.

Claims

1. A glass fiber reinforced flame retardant polyamide composite material, characterized in that: By weight, it includes the following components: 49-61 parts of polyamide resin; Glass fiber 19-51 parts; 2.9-8.1 parts of brominated polystyrene polymer; Brominated polystyrene oligomer 6.9-18.1 parts; Flame retardant synergist 2.9-8.1 parts; The weight average molecular weight of the brominated polystyrene polymer is in the range of 180,000 to 250,000; The weight average molecular weight of the brominated polystyrene oligomer is in the range of 4000-8000; The relative viscosity range of polyamide resin is 2.0-2.7; The average retention length of the glass fibers is in the range of 250-370 microns, and the average diameter is in the range of 6-12 microns.

2. The glass fiber reinforced flame retardant polyamide composite material according to claim 1, characterized in that: The relative viscosity of polyamide resin is in the range of 2.2-2.

5.

3. The glass fiber reinforced flame retardant polyamide composite material according to claim 1, characterized in that: Preferably, the average retention length of the glass fibers is in the range of 290-335 microns.

4. The glass fiber reinforced flame retardant polyamide composite material according to claim 1, characterized in that: The flame retardant synergist is selected from antimony trioxide, and the average particle size ranges from 0.5 to 20 microns.

5. The glass fiber reinforced flame retardant polyamide composite material according to claim 1, characterized in that: The polyamide resin is selected from at least one of aliphatic polyamide and semi-aromatic polyamide; the polylactam is selected from PA6; the aliphatic polyamide is selected from one or more of PA66, PA66 / 6 copolymer, PA6 / 66 copolymer, PA56, PA610, PA612, PA1010, PA1012, PA11, and PA12; the semi-aromatic polyamide is selected from one or more of PA6T / 66, PA9T, PAMXD6, and PA6T / 6I.

6. The glass fiber reinforced flame retardant polyamide composite material according to claim 1, characterized in that: By weight, the invention also includes 0-2 parts of auxiliary agents, wherein the auxiliary agents are selected from at least one of antioxidants, lubricants and anti-ultraviolet agents.

7. The method for preparing the glass fiber reinforced flame retardant polyamide composite material according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: mixing the components uniformly according to the proportion, and extruding and granulating the components through a twin-screw extruder, wherein the screw length-diameter ratio of the twin-screw extruder is 40-48:1, the screw barrel temperature is 220-270°C, and the screw speed is 200-450rpm.

8. Use of the glass fiber reinforced flame retardant polyamide composite material according to any one of claims 1 to 6, characterized in that: Used to prepare electrical parts.