A glass fiber reinforced flame-retardant polyamide composite material, a preparation method and application thereof

Abstract

The application discloses a glass fiber reinforced flame-retardant polyamide composite material, which comprises the following components in parts by weight: polyamide resin 49-61 parts; glass fiber 19-51 parts; brominated polystyrene high polymer 2.9-8.1 parts; 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 high polymer ranges from 180,000 to 250,000; the weight average molecular weight of the brominated polystyrene oligomer ranges from 4,000 to 8,000; the relative viscosity of the polyamide resin ranges from 2.0 to 2.7; the average retention length of the glass fiber ranges from 250 to 350 microns, and the average diameter ranges from 6 to 12 microns. The application can realize good melt flow stability and improve crystallinity by compounding the polyamide resin with specific viscosity and the brominated polystyrene with specific different molecular weights, so that the glass fiber reinforced composite material has good size stability after injection molding and has a flame-retardant effect of 1.6 mm.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a glass fiber reinforced flame-retardant polyamide composite material, its preparation method, and its application. Background Technology

[0002] Flame-retardant nylon materials possess excellent strength and toughness, making them widely used in the electronics and electrical industries. However, for optimal aesthetics, these industries often require high mold temperatures for injection molding, especially for flame-retardant products. The unstable melt flow can negatively impact the final appearance, necessitating even higher mold temperatures. Since nylon is a crystalline polymer, the dimensions of the molded part gradually decrease as the temperature drops and time increases after demolding, leading to significant assembly problems.

[0003] Currently, many injection molding plants address this issue by using post-molding molds to ensure dimensional stability and smooth assembly. Few plants achieve the advantage of strong dimensional stability through modification of the injection molding composition. Summary of the Invention

[0004] The purpose of this invention is to provide a glass fiber reinforced flame-retardant polyamide composite material with 1.6mm V-0 flame retardancy and strong dimensional stability after injection molding, as well as its preparation method and application.

[0005] This invention is achieved through the following technical solution:

[0006] A glass fiber reinforced flame-retardant polyamide composite material, comprising the following components by weight:

[0007] 49-61 parts of polyamide resin;

[0008] 19-51 parts glass fiber;

[0009] 2.9-8.1 parts of brominated polystyrene polymer;

[0010] Brominated polystyrene oligomers: 6.9-18.1 parts;

[0011] Flame retardant synergist 2.9-8.1 parts;

[0012] The weight-average molecular weight range of the brominated polystyrene polymer is 180,000 to 250,000.

[0013] The weight-average molecular weight range of the brominated polystyrene oligomers is 4000-8000;

[0014] The relative viscosity range of polyamide resin is 2.0-2.7;

[0015] The average retained length of the glass fiber ranges from 250 to 370 micrometers, and the average diameter ranges from 6 to 12 micrometers.

[0016] In the glass fiber reinforced flame retardant polyamide composite material of the present invention, the content of 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.

[0017] The fiberglass can be in the following quantities: 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.

[0018] 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.

[0019] The content of brominated polystyrene oligomers 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. Quantities of 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.

[0020] 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.

[0021] The weight-average molecular weight of brominated polystyrene was determined by gel permeation chromatography.

[0022] Preferably, the relative viscosity of the polyamide resin is in the range of 2.2-2.5, as tested according to ISO 307 standard.

[0023] Preferably, the average retention length of the glass fiber is in the range of 290-335 micrometers.

[0024] The average retention length of glass fiber can be adjusted by controlling the length of the glass fiber raw material and / or the rotational speed of the screw.

[0025] The method for testing the average length of glass fiber is as follows: glass fiber reinforced flame retardant polyamide composite material is treated in a muffle furnace at 650-800℃ for 2 hours to obtain the material ash. 5-10 mg of ash is placed in a petri dish, 10 mL of deionized water is added and the ash is evenly dispersed. The average length and average diameter of the glass fiber in the field of view are measured and calculated using a two-dimensional microscope.

[0026] The flame retardant synergist can be antimony trioxide, with an average particle size range of 0.5-20 micrometers.

[0027] The average particle size of antimony trioxide was measured using a laser particle size analyzer.

[0028] 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.

[0029] Depending on the actual situation, it may be optional to add 0-2 parts of an additive, which is selected from at least one of antioxidants, lubricants, and UV stabilizers.

[0030] The preparation method of the glass fiber reinforced flame retardant polyamide composite material of the present invention includes the following steps: mixing each component evenly according to the formula, and granulating by extrusion through a twin-screw extruder, wherein the length-to-diameter ratio of the screw of the twin-screw extruder is 40~48:1, the barrel temperature is 220~270℃, and the screw speed is 200~450rpm.

[0031] The glass fiber reinforced flame-retardant polyamide composite material of the present invention is used to manufacture electrical components.

[0032] The present invention has the following beneficial effects:

[0033] This invention utilizes a blend of polyamide resin of specific viscosity and brominated polystyrene of varying molecular weights. At high temperatures, the high molecular weight brominated polystyrene exhibits a certain anisotropic nucleation effect. Simultaneously, the matching of polyamide and brominated polystyrene oligomers of specific viscosities enhances molecular chain movement and promotes rapid crystallization of the PA material. This results in good melt flow stability, improved crystallinity, and reduced internal stress in the product. Consequently, the glass fiber reinforced composite material of this invention exhibits good dimensional stability after injection molding and a flame-retardant effect of 1.6 mm. Detailed Implementation

[0034] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0035] PA6-1: Relative viscosity is 2.0, PA6 M2000, Xinhui Meida;

[0036] PA6-2: Relative viscosity is 2.4 dL / g, PA6 M2400, Xinhui Meida;

[0037] PA6-3: Relative viscosity is 2.5, PA6 HY2500A, marine chemical fiber;

[0038] PA6-4: Relative viscosity is 2.7, PA6 HY2800A, marine chemical fiber;

[0039] PA6-5: Relative viscosity is 3.4, PA6 M3400, Xinhui Meida;

[0040] PA66-1: Relative viscosity is 2.1, PA66 U2501, Shanghai Invista;

[0041] PA66-2: Relative viscosity is 2.2, PA66 EP122, Zhejiang Huafeng;

[0042] PA66-3: Relative viscosity 2.4, PA66 U3600 NC01 SS, Shanghai Invista;

[0043] PA66-4: Relative viscosity 2.7, PA66 U4800 NC01 SS, Shanghai Invista;

[0044] PA66-5: Relative viscosity is 3.2, PA66 EPR32, Henan Shenma;

[0045] The glass fiber was purchased from China Jushi Company, with the grade ECS11-4.5-560A (short fiber), an average diameter of 11 micrometers, and a length range of 3.5-5.5 mm.

[0046] Brominated polystyrene oligomer A: SAYTEX 5010, Mw molecular weight 5000, Albemarle, USA;

[0047] Brominated polystyrene oligomer B: Phlamoon-103L, Mw molecular weight 4000, Taizhou Baili Chemical Co., Ltd.

[0048] Brominated polystyrene polymer-1: XZ-6700, Mw molecular weight 240,000, Shandong Brothers;

[0049] Brominated polystyrene polymer-2: BPS 7010, molecular weight 190,000, Shandong Tianyi;

[0050] Antimony trioxide: purchased from Flashstar Antimony Industry.

[0051] Lubricant: Stearyl stearate, LOXIOL G32, Corning (Germany). Preparation method of glass fiber reinforced flame-retardant polyamide composites in the examples and comparative examples: The components were mixed evenly according to the specified ratio, and then extruded and granulated using a twin-screw extruder. The twin-screw extruder had a screw length-to-diameter ratio of 44:1, a barrel temperature of 220~270℃, and a screw speed of 200~450 rpm (specific speeds are shown in the table).

[0052] Test methods:

[0053] (1) The test method for the average length of glass fiber is as follows: glass fiber reinforced flame retardant polyamide composite material is treated in a muffle furnace at 650-800℃ for 2h to obtain the ash content of the material. Take 5-10mg of ash and put it in a petri dish. Add 10mL of deionized water and make the ash evenly dispersed. Use a two-dimensional microscope to magnify and observe, and measure and calculate the average length of glass fiber in the field of view.

[0054] (2) Flame retardancy: 1.6mm thick injection molded burning test strips were used to test the burning performance of the material using UL 94 standard.

[0055] (3) Dimensional stability: Using an injection molding machine, the temperatures from the nozzle to the discharge port are 275℃, 270℃, 260℃, and 250℃ respectively. Medium pressure and medium speed are used to inject a 100×100×2mm square plate. After being left to stand naturally for one week, the dimensional change rate is tested (compared with the dimensions just out of the cavity).

[0056] (4) Cantilever beam notched impact strength: Injection molded ISO 180 standard specimens to test the notched impact strength of cantilever beams.

[0057] Table 1: Weight parts and test results of each component in glass fiber reinforced composite materials of Examples 1-6

[0058] 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 lubricant 0.3 0.3 0.3 0.3 0.3 0.3 Screw speed, revolutions per minute 250 250 250 250 250 250 Average length of glass fiber, μm 342 333 330 335 332 336 Flame retardancy 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[Izod impact strength, kJ / m 2 > 8.2 10.8 13.3 10.5 10.9 11.2

[0059] Table 2: Weight parts and test results of each component in glass fiber reinforced composite materials of Examples 7-11

[0060] Example 7 Example 8 Example 9 Example 10 Example 11 Polyamide designation 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 lubricant 0.3 0.3 0.3 0.3 0.3 Screw speed, revolutions per minute 250 250 250 250 250 Average length of glass fiber, μm 334 340 337 338 335 Flame retardancy V-0 V-0 V-0 V-0 V-0 Dimensional change rate % 0.041 0.039 0.037 0.037 0.040 <![CDATA[Izod impact strength, kJ / m 2 > 11.3 10.3 10.5 10.8 10.6

[0061] As can be seen from Examples 2 / 5-11, the dimensional stability is better when the viscosity range of the polyamide resin is preferred.

[0062] Table 3: Weight parts of each component and test results of glass fiber reinforced composite materials in Examples 12-16

[0063] Example 12 Example 13 Example 14 Example 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 lubricant 0.3 0.3 0.3 0.3 0.3 Screw speed, revolutions per minute 450 380 300 220 220 Average length of glass fiber, μm 268 292 320 356 368 Flame retardancy V-0 V-0 V-0 V-0 V-0 Dimensional change rate % 0.032 0.034 0.035 0.045 0.047 <![CDATA[Izod impact strength, kJ / m 2 > 10.1 10.3 10.5 10.9 11.1

[0064] As can be seen from Examples 2 / 12-15, the preferred glass fiber average length has a moderate rate of dimensional change and notched impact strength.

[0065] As can be seen from the above embodiments, the glass fiber reinforced composite material of the present invention has a V-0 flame retardancy of 1.6 mm, a dimensional change rate of less than 0.05% after injection molding, and a notched impact strength greater than 8 kJ / m. 2 .

[0066] Table 4: Weight parts of each component and test results of comparative glass fiber reinforced composite materials

[0067] 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 lubricant 0.3 0.3 0.3 0.3 0.3 0.3 Screw speed, revolutions per minute 250 250 250 250 500 200 Average length of glass fiber, μm 333 329 331 337 239 397 Flame retardancy 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[Izod impact strength, kJ / m 2 > 12.3 11.2 9.6 13.5 7.1 11.3

[0068] As shown in Comparative Example 1 / 2, when the viscosity of polyamide resin is too high, its dimensional stability is poor.

[0069] As shown in Comparative Example 3, when only brominated polystyrene polymer is used, the dimensional stability is poor and the notched impact strength is low.

[0070] As shown in Comparative Example 4, the dimensional stability is very poor when only brominated polystyrene oligomers are used.

[0071] As shown in Comparative Example 5, when the average retention length of the glass fiber is too short, the notched impact strength is low.

[0072] As can be seen from Comparative Example 6, 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; 19-51 parts glass fiber; 2.9-7.1 parts of brominated polystyrene polymer; Brominated polystyrene oligomers: 8.9-18.1 parts; Flame retardant synergist 2.9-8.1 parts; The weight-average molecular weight range of the brominated polystyrene polymer is 180,000 to 250,000. The weight-average molecular weight range of the brominated polystyrene oligomers is 4000-8000; The relative viscosity range of polyamide resin is 2.0-2.7, as tested according to ISO 307 standard. The average retained length of the glass fiber ranges from 268 to 370 micrometers, and the average diameter ranges from 6 to 12 micrometers.

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

5.

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

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, with an average particle size range of 0.5-20 micrometers.

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 aliphatic polyamide is selected from one or more of PA66, PA66 / 6 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, The polyamide resin is selected from polylactam, and the polylactam is selected from PA6.

7. The glass fiber reinforced flame-retardant polyamide composite material according to claim 1, characterized in that, The product also includes 0-2 parts by weight of additives, wherein the amount of additives is not 0, and the additives are selected from at least one of antioxidants, lubricants, and UV stabilizers.

8. The method for preparing the glass fiber reinforced flame-retardant polyamide composite material according to any one of claims 1-7, characterized in that, The process includes the following steps: mixing the components evenly according to the formula, and granulating them by extrusion through a twin-screw extruder. The length-to-diameter ratio of the screw in the twin-screw extruder is 40~48:1, the barrel temperature is 220~270℃, and the screw speed is 200~450rpm.

9. The application of the glass fiber reinforced flame-retardant polyamide composite material according to any one of claims 1-7, characterized in that, Used for manufacturing electrical components.