Glass fiber reinforced PBT / ABS alloy and preparation method and application thereof

Abstract

The invention discloses a glass fiber reinforced PBT / ABS (Polybutylene Terephthalate / Acrylonitrile Butadiene Styrene) alloy which comprises the following components in parts by weight: 100 parts of total weight of PBT and ABS; 5 to 30 parts of glass fiber; wherein the weight ratio of PBT to ABS is (4-1): (1-3), the rubber content in ABS is 8-30 wt%, and the terminal carboxyl group content of PBT is less than or equal to 30 mmol / kg. According to the invention, ABS with specific rubber content and PBT with specific terminal carboxyl group content are selected for compounding, so that the glass fiber reinforced PBT / ABS alloy with good long-term heat aging resistance can be obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a glass fiber reinforced PBT / ABS alloy and a preparation method and application thereof. Background Art

[0002] Polybutylene Terephthalate (PBT) is an important semi-crystalline thermoplastic polyester material. It is widely studied and applied for its excellent performance. It is one of the five major engineering plastics and is widely used in electronics, home appliances, automobiles, textiles and other industries. However, compared with other polyester materials, PBT's performance decays quickly in long-term high temperature resistance experiments. Usually, after 1000 hours of thermal oxidation aging at 190℃, the tensile performance decays to less than 50%.

[0003] In order to improve the heat resistance of PBT and develop polyester materials with long-term high temperature resistance, it is usually necessary to blend materials known to have higher heat resistance with PBT to prepare polyester alloy materials. For example, in patent CN110041667A, a PBT / LCP alloy material was prepared, and the high heat resistance and high crystallization performance of LCP were used to increase the crystallization rate of PBT, and improve the rigidity and heat resistance of PBT. In patent CN114773800A, a PCT / PBT alloy composition was developed, which has high melt fluidity and heat-resistant oxygen aging performance during production. After aging at 200°C for 1000 hours, the performance retention rate is high and it still has a high light emissivity. However, in this scheme, the preferred weight ratio of PCT to PBT resin is between 17-22, indicating that the polyester alloy material is still based on PCT material with good high temperature resistance, while the PBT content is relatively low. Similarly, in patent CN108530887A, polyester material is blended with semi-aromatic polyamide to obtain an alloy material with high heat resistance. In addition to relying mainly on the generally excellent heat resistance of high-temperature resistant nylon, since the compatibility of polyamide and polyester in this system is poor, it is necessary to add aminobenzenesulfonic acid compounds and alcoholamine compounds to promote compatibility in order to achieve higher heat resistance. Summary of the invention

[0004] The object of the present invention is to provide a glass fiber reinforced PBT / ABS alloy with good long-term heat aging resistance.

[0005] The present invention is achieved through the following technical solutions: A glass fiber reinforced PBT / ABS alloy, comprising the following components in parts by weight: The total weight of PBT and ABS is 100 parts; Glass fiber 5-30 parts; The weight ratio of PBT to ABS is (4-1): (1-3), the rubber content in ABS is 8-30wt%, and the terminal carboxyl content of PBT resin is less than 30 mmol / kg; The ratio of the major diameter D to the minor diameter d of the glass fibers such that 70>D / d>35 is less than 20 wt %.

[0006] Preferably, the weight ratio of PBT to ABS is (3-1):(1-2).

[0007] More preferably, the weight ratio of PBT to ABS is (2-1):1.

[0008] Preferably, the terminal carboxyl content of the PBT resin is 15-30 mmol / kg.

[0009] More preferably, the terminal carboxyl content of the PBT resin is 20-30 mmol / kg.

[0010] The present invention has no particular limitation on the intrinsic viscosity of PBT. The intrinsic viscosity of commonly used PBT may be 0.8-1.2 dL / g (25° C.), and the test method is based on GB / T 14190-2017.

[0011] The terminal carboxyl content is tested according to GB / T 14190-2008.

[0012] Preferably, the rubber content in ABS is 10-20wt%.

[0013] ABS is an acrylonitrile-butadiene-styrene terpolymer. The present invention has no limitation on the contents of the three monomers. The acrylonitrile content ranges from 10-30wt%, the butadiene content ranges from 8-30wt%, and the styrene content ranges from 40-75wt%.

[0014] The ABS that can achieve the purpose of the present invention can be a commercially available product or can be obtained by self-production. The self-production method refers to the method described on pages 20-21 of Zhang Wei's "Study on Compatibility and Flame Retardancy of PC / ABS Alloys".

[0015] The PBT resin capable of achieving the purpose of the present invention can be a commercially available product or obtained by self-production. The self-production method is as follows: a direct esterification method is adopted for synthesis, with terephthalic acid (PTA) and 1,4-butanediol (BDO) as raw materials, tetrabutyl titanate as a catalyst, and both are added into an esterification kettle to complete the esterification reaction at a pressure of 30-40 kPa and a temperature of 230-250° C. The esterified product is subjected to a prepolymerization kettle reaction for 0.5-1 hour, and polycondensed at a vacuum atmosphere of 80-120 Pa and 240-250° C. to obtain the PBT resin. The end carboxyl group is regulated by adjusting the n(BDO) / n(PTA) feed ratio. When n(BDO) / n(PTA)=1.10-1.15, high-end carboxyl PBT is obtained; when n(BDO) / n(PTA)=1.16-1.20, medium-end carboxyl PBT is obtained; when n(BDO) / n(PTA)=1.21-1.23, low-end carboxyl PBT is obtained.

[0016] Preferably, the ratio of the major diameter D to the minor diameter d of the glass fibers (70>D / d>35) is 10-20wt%.

[0017] The long diameter D is the retained length of the glass fiber in the resin matrix, and the short diameter d is the diameter of the glass fiber. The glass fiber that can achieve the purpose of the present invention can be a round glass fiber or a flat glass fiber. In the case of a round glass fiber, the short diameter d is the diameter of the fiber, and in the case of a flat glass fiber, the short diameter d is the longer diameter. The range of the short diameter d that can achieve the purpose of the present invention is 9-15 μm. Moreover, the D / d range of the glass fiber with D / d<35 is preferably 10<D / d<35.

[0018] It is possible to choose whether to add 0-2 parts of auxiliary agent according to actual needs, wherein the auxiliary agent is selected from at least one of an antioxidant, a lubricant, and a weathering agent. The weathering agent may be an ultraviolet resistant agent or the like.

[0019] The preparation method of the glass fiber reinforced PBT / ABS alloy of the present invention comprises the following steps: according to the proportion, each component is extruded and granulated by a twin-screw extruder to obtain the glass fiber reinforced PBT / ABS alloy.

[0020] This patent examines the ratio of the long diameter D to the short diameter d of the glass fiber. Specifically, the test method for the ratio D / d of the long diameter D to the short diameter d of the glass fiber in the glass fiber reinforced PBT / ABS alloy is as follows: take 5g of material and treat it in a 650℃ muffle furnace 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, and measure the long diameter D and short diameter d of the glass fiber in the field of view. Take the data of the long diameter D and short diameter d of 200 glass fibers in the field of view at 5 different positions, and take the average value of D / d.

[0021] The application of glass fiber reinforced PBT / ABS alloy is used in the field of electronics and electrical appliances.

[0022] The present invention has the following beneficial effects: The present invention selects ABS with a specific rubber content and PBT with a specific terminal carboxyl content for compounding. The double bonds of ABS easily form crosslinked products at high temperatures, and the product shows an obvious skin-core effect. ABS forms an obvious barrier layer in the skin layer of the product to block oxygen penetration and subsequent aging, so the core layer ages slowly and the performance is maintained. Furthermore, by controlling the ratio of the number of glass fibers in the alloy to 70>D / d>35, a glass fiber reinforced PBT / ABS alloy with good long-term heat aging resistance can be obtained. DETAILED DESCRIPTION

[0023] 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.

[0024] The sources of raw materials used in the present invention are as follows: PBT-A: terminal carboxyl content 25mmol / kg, homemade, n(BDO) / n(PTA) feed ratio 1.19:1, intrinsic viscosity 1.0dL / g (25℃); PBT-B: terminal carboxyl content 13mmol / kg, homemade, n(BDO) / n(PTA) feed ratio 1.22:1, intrinsic viscosity 1.0dL / g (25℃); PBT-C: terminal carboxyl content 43mmol / kg, homemade, n(BDO) / n(PTA) feed ratio 1.10:1, intrinsic viscosity 1.0dL / g (25℃); ABS-A: rubber content 8.8wt%, AN content 20.1wt%, homemade; ABS-B: rubber content 11.7wt%, AN content 19.3wt%, homemade; ABS-C: rubber content 18.5wt%, AN content 17.9wt%, homemade; ABS-D: rubber content 30.0wt%, AN content 15.3wt%, homemade; ABS-E: rubber content 35.2wt%, AN content 14.3wt%, homemade; ABS-F: rubber content 25.1wt%, AN content 29.6wt%, homemade.

[0025] The short diameter d of glass fiber A is 13μm, round glass fiber, brand ECS13-03-540H, and raw materials with different long diameters D are obtained by short cutting and screening: Glass fiber A-1: ​​the major diameter D range is 480-600 μm; Glass fiber A-2: The major diameter D ranges from 350 to 450 μm.

[0026] The short diameter d of glass fiber B is 10μm, round glass fiber, brand ECS10-03-568H, and raw materials with different long diameters D are obtained by short cutting and screening: Glass fiber B-1: the major diameter D range is 380-500 μm; Glass fiber B-2: The major diameter D ranges from 200 to 350 μm.

[0027] Antioxidant: Antioxidant 1010, commercially available.

[0028] Embodiment and comparative example Preparation method of glass fiber reinforced PBT / ABS alloy: According to the ratio, each component is extruded and granulated by a twin-screw extruder, the rotation speed is 300 rpm, the temperature of each section of the barrel is 220-240°C in zone 1, 230-245°C in zone 2, 235-245°C in zone 3, 235-250°C in zone 4, 220-240°C in zone 5, 220-240°C in zone 6, 210-230°C in zone 7, 200-220°C in zone 8, 200-220°C in zone 9, and 220-240°C in zone 10 to obtain a glass fiber reinforced PBT / ABS alloy.

[0029] Various test methods: (1) Long-term heat aging resistance: The injection molded tensile specimens were placed in a 170°C heat aging oven for long-term aging, and the aging time when the performance retention rate decayed to 50% was tested.

[0030] (2) Glass fiber 70>D / d>35 ratio: Take 5g of glass fiber reinforced PBT / ABS alloy and treat it in a muffle furnace at 650℃ 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, and measure the long diameter D (retained length) and short diameter d (glass fiber diameter) of the glass fiber in the field of view. Take the data of the long diameter D and short diameter d of 200 glass fibers in the field of view at 5 different positions, and calculate the ratio of D / d>35.

[0031] Table 1: Weight parts of each component of glass fiber reinforced PBT / ABS alloy of Examples 1-8 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 PBT-A 80 75 66.7 50 33.3 25 66.7 66.7 ABS-A 20 25 33.3 50 66.7 75 33.3 33.3 Glass Fiber A-1 4 4 4 4 4 4 3 Glass Fiber A-2 16 16 16 16 16 16 17 Glass fiber B-1 4 Glass fiber B-2 16 D / d>35 ratio, % 17.6 18.4 17.9 18.1 18.3 18.4 13.9 19.7 Antioxidants 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Long-term heat aging resistance, h 3425 4400 5823 5550 4228 3180 5435 5520 It can be seen from Examples 1-6 that the preferred weight ratio of PBT to ABS has better long-term heat aging resistance.

[0032] Table 2: Weight parts of each component of glass fiber reinforced PBT / ABS alloy of Examples 9-16 Example 9 Example 10 Embodiment 11 Example 12 Embodiment 13 Embodiment 14 Embodiment 15 Example 16 PBT-A 66.7 66.7 66.7 66.7 66.7 66.7 66.7 PBT-B 66.7 ABS-A 33.3 33.3 33.3 33.3 ABS-B 33.3 ABS-C 33.3 ABS-D 33.3 ABS-F 33.3 Glass Fiber A-1 4 4 4 4 4 0 2 1.5 Glass Fiber A-2 16 16 16 16 16 20 18 Glass fiber B-2 18.5 D / d>35 ratio, % 18.0 18.6 17.5 18.1 17.9 0 8.8 6.9 Antioxidants 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Long-term heat aging resistance, h 6158 6275 5900 5983 5862 4316 4830 4475 It can be seen from Examples 3 / 9-12 that the long-term heat aging resistance is better when the rubber content of ABS is preferred.

[0033] It can be seen from Example 3 / 13 that the preferred PBT terminal carboxyl content has better long-term heat aging resistance.

[0034] It can be seen from Examples 3 / 7 / 14 / 15 that the long-term heat aging resistance is better when the ratio of the major diameter D to the minor diameter d of the glass fiber is preferably 70>D / d>35.

[0035] Table 3: Weight parts of each component of glass fiber reinforced PBT / ABS alloy in comparative example Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 PBT-A 83.3 20 66.7 66.7 66.7 PBT-C 66.7 ABS-A 16.7 80 33.3 33.3 33.3 ABS-E 33.3 Glass Fiber A-1 4 4 4 4 6 20 Glass Fiber A-2 16 16 16 16 14 D / d>35 ratio, % 17.7 18.2 18.4 17.8 24.7 86.1 Antioxidants 0.5 0.5 0.5 0.5 0.5 0.5 Long-term heat aging resistance, h 2260 2036 2028 1086 2785 2004 It can be seen from Comparative Examples 5-6 that when the ratio of the major diameter D to the minor diameter d of the glass fiber is 70>D / d>35, the long-term heat aging resistance is seriously reduced.

[0036] It can be seen from Comparative Example 1 / 2 that when the weight ratio of PBT to ABS is not within the range of the present invention, the long-term heat aging resistance is poor.

Claims

1. A glass fiber reinforced PBT / ABS alloy, characterized in that: By weight, it includes the following components: The total weight of PBT and ABS is 100 parts; Glass fiber 5-30 parts; The weight ratio of PBT to ABS is (4-1): (1-3), the rubber content in ABS is 8-30wt%, and the terminal carboxyl content of PBT resin is less than or equal to 30 mmol / kg; The ratio of the major diameter D to the minor diameter d of the glass fibers such that 70>D / d>35 is less than 20 wt %.

2. The glass fiber reinforced PBT / ABS alloy according to claim 1, characterized in that: The weight ratio of PBT to ABS is (3-1):(1-2).

3. The glass fiber reinforced PBT / ABS alloy according to claim 2, characterized in that: The weight ratio of PBT to ABS is (2-1):

1.

4. The glass fiber reinforced PBT / ABS alloy according to claim 1, characterized in that: The terminal carboxyl content of PBT resin is 15-30 mmol / kg.

5. The glass fiber reinforced PBT / ABS alloy according to claim 4, characterized in that: The terminal carboxyl content of PBT resin is 20-30 mmol / kg.

6. The glass fiber reinforced PBT / ABS alloy according to claim 1, characterized in that: The rubber content in ABS is 10-20wt%.

7. The glass fiber reinforced PBT / ABS alloy according to claim 1, characterized in that: The ratio of the major diameter D to the minor diameter d of the glass fibers is 70>D / d>35, and the ratio is 10-20wt%.

8. The glass fiber reinforced PBT / ABS alloy 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 weathering agents.

9. The method for preparing the glass fiber reinforced PBT / ABS alloy according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: according to the proportion, each component is extruded and granulated by a twin-screw extruder to obtain a glass fiber reinforced PBT / ABS alloy.

10. The use of the glass fiber reinforced PBT / ABS alloy according to any one of claims 1 to 8, characterized in that: Used in the field of electronics and electrical appliances.