A polyester composition, its preparation and use

Abstract

This invention discloses a polyester composition, its preparation method, and its applications, belonging to the field of polymer materials technology. It comprises the following components by weight: 48-88 parts polyester resin, 4-22 parts brominated flame retardant, 0.8-9 parts antimony flame retardant, 0.5-9 parts hydroxyapatite, 6-38 parts glass fiber, and 0-4 parts additives; the glass fiber has a retention length of 150-350 μm. Using polyester resin as a matrix, this invention, through the combined action of brominated flame retardant, antimony flame retardant, hydroxyapatite, and glass fiber, yields a polyester composition with excellent tracking properties and impact strength. The polyester composition also exhibits a good appearance and is suitable for manufacturing electronic and electrical components, particularly connectors, relays, and switches, showing broad application prospects.

Description

Technical Field

[0001] This application relates to the field of polymer materials technology, specifically to a polyester composition, its preparation method, and its application. Background Technology

[0002] Polyester materials such as polybutylene terephthalate (PBT) and polyethylene terephthalate (PET) are widely used in electronic and electrical components (such as connectors, relays, and switches) due to their excellent mechanical properties, electrical insulation, chemical resistance, and processing performance. However, their low CTI value (a measure of a material's tracking performance) limits their application in high-voltage or high-reliability environments.

[0003] To achieve the UL94 V-0 flame retardant standard, PBT typically requires the addition of halogenated flame retardants (bromine-based flame retardants) and antimony-based flame retardants as synergists. This system offers high flame retardant efficiency but has a significant negative impact on the material's electrical properties, especially its crackle retardancy (CTI). Current technologies often improve CTI by adding inorganic fillers, surface lubricants, or adjusting the type of flame retardant, but this often severely sacrifices the material's mechanical properties (especially impact strength), appearance, and flame retardant efficiency.

[0004] Therefore, how to improve the tracking performance of polyester materials has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a polyester composition, its preparation method and application. The polyester composition of this invention has excellent tracking properties and impact strength.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A polyester composition comprising the following components in parts by weight: 48-88 parts polyester resin, 4-22 parts brominated flame retardant, 0.8-9 parts antimony flame retardant, 0.5-9 parts hydroxyapatite, 6-38 parts glass fiber, and 0-4 parts additives; The retained length of the glass fiber is 150~350μm, for example, it can be 150μm, 160μm, 180μm, 200μm, 220μm, 240μm, 250μm, 280μm, 300μm, 320μm, 350μm or any two of these values.

[0007] This invention creatively combines the above-mentioned raw materials, using polyester resin as the matrix, and with the combined action of brominated flame retardants, antimony flame retardants, hydroxyapatite, and glass fiber, obtains a polyester composition with excellent tracking properties and impact strength. Furthermore, the polyester composition has a good appearance and is suitable for manufacturing electronic and electrical components, especially connectors, relays, and switches, showing broad application prospects.

[0008] In the specific flame-retardant system of this application, by adding hydroxyapatite and controlling the retention length of glass fibers within this range, the hydroxyapatite can block the charge migration path generated by the local electric field concentration in the polyester matrix, isolate the contact between the electrode and the matrix, and prevent the expansion of the leakage channel. The glass fibers with the specific retention length are uniformly dispersed in the polyester, cutting the formation path of the leakage channel, forcing the charge migration path to lengthen and the resistance to increase, thereby improving the dimensional stability of the material, reducing surface microcracks caused by thermal deformation, and effectively improving the tracking performance and impact strength of the polyester. At the same time, the specific components of this application, together with the glass fibers with the specific retention length, can prevent the polyester from turning white and spots, and reduce color difference.

[0009] The amount of polyester resin used is 48 to 88 parts, for example, it can be 48 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 86 parts, 88 parts or any two of these values.

[0010] Preferably, the amount of polyester resin used is 50 to 85 parts.

[0011] Preferably, the polyester resin includes at least one of PBT (polybutylene terephthalate), PET (polyethylene terephthalate), PETG (polyethylene terephthalate-1,4-cyclohexanediol), PCT (polyethylene terephthalate-1,4-cyclohexanediol), and PCTG (polyethylene terephthalate-1,4-cyclohexanediol).

[0012] The amount of the brominated flame retardant is 4 to 22 parts, for example, it can be 4 parts, 5 parts, 6 parts, 8 parts, 10 parts, 12 parts, 14 parts, 15 parts, 16 parts, 18 parts, 20 parts, 22 parts or any two of these values.

[0013] Preferably, the amount of the brominated flame retardant is 5 to 20 parts.

[0014] The amount of the antimony flame retardant is 0.8 to 9 parts, for example, it can be 0.8 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or any two of these values.

[0015] Preferably, the amount of the antimony-based flame retardant is 1 to 8 parts.

[0016] The amount of hydroxyapatite used is 0.5 to 9 parts, for example, it can be 0.5 parts, 0.6 parts, 0.8 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts or any two of these values.

[0017] Preferably, the amount of hydroxyapatite used is 0.8 to 8 parts.

[0018] The amount of glass fiber used is 6 to 38 parts, for example, it can be 6 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 25 parts, 30 parts, 35 parts, 36 parts, 38 parts or any two of these values.

[0019] Preferably, the amount of glass fiber used is 8 to 35 parts.

[0020] The dosage of the adjuvant is 0 to 4 parts, for example, it can be 0 parts, 0.2 parts, 0.5 parts, 0.8 parts, 1 part, 2 parts, 3 parts, 4 parts or any two of these values.

[0021] Preferably, the amount of the auxiliary agent is 0 to 3 parts.

[0022] Preferably, the polyester composition comprises the following components in parts by weight: 50-85 parts polyester resin, 5-20 parts brominated flame retardant, 1-8 parts antimony flame retardant, 0.8-8 parts hydroxyapatite, 8-35 parts glass fiber, and 0-3 parts additives.

[0023] In the polyester composition, the polyester resin has a weight percentage of not less than 50%.

[0024] Preferably, in the polyester composition, the polyester resin has a weight percentage of 50-70%, for example, it can be 50%, 52%, 54%, 55%, 56%, 58%, 60%, 62%, 65%, 68%, 70%, or any two of these values.

[0025] Preferably, the polyester composition comprises the following components in parts by weight: 50-70 parts polyester resin, 10-15 parts brominated flame retardant, 2-6 parts antimony flame retardant, 3-6 parts hydroxyapatite, 15-24 parts glass fiber, and 1-2 parts additives. In particular, when the amount of each raw material is within this range, the tracking performance and impact strength can be further improved.

[0026] Preferably, the intrinsic viscosity of the polyester resin is 0.6~1.3 dl / g, for example, it can be 0.6 dl / g, 0.7 dl / g, 0.8 dl / g, 0.9 dl / g, 1 dl / g, 1.1 dl / g, 1.2 dl / g, 1.3 dl / g or any two of these values. The intrinsic viscosity of the polyester resin is tested according to Method A (capillary viscometer method) in GB / T14190-2017.

[0027] Preferably, the intrinsic viscosity of the polyester resin is 0.67~1.28 dl / g.

[0028] Preferably, the polyester resin comprises a first polyester and a second polyester in a weight ratio of 1:(1~1.5); the intrinsic viscosity of the first polyester is 1~1.3 dl / g; and the intrinsic viscosity of the second polyester is 0.6~0.8 dl / g. By using polyester resins with gradient viscosities, during processing, the resin can quickly penetrate into the gaps between glass fibers, fully wet the glass fibers and hydroxyapatite, and form physical entanglement with the hydroxyl groups on the surface of the glass fibers and hydroxyapatite. This effectively transfers stress, promotes the formation of an interlaced network structure, blocks charge migration paths, effectively improves processing performance, improves the compatibility of glass fibers and hydroxyapatite in the system, and further improves tracking performance and impact strength.

[0029] Preferably, the polyester includes at least one of PBT resin and PET resin.

[0030] Preferably, the average diameter of the glass fiber is 8~17μm, for example, it can be 8μm, 10μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm or any two of these values.

[0031] Preferably, the average diameter of the glass fiber is 10~14μm.

[0032] Preferably, the retained length of the glass fiber is 190~270μm.

[0033] The test method for the retained length and average diameter of glass fibers is as follows: the polyester composition is treated in a muffle furnace at 650~800℃ (e.g. 700℃) for 2h to obtain the material ash. 5~10mg of ash is placed in a petri dish, 10mL of deionized water is added and the ash is evenly dispersed. The average length and diameter of the glass fibers in the field of view are measured and calculated using a two-dimensional microscope.

[0034] Preferably, the average particle size of the hydroxyapatite is 0.06~80μm, for example, it can be 0.06μm, 0.08μm, 0.1μm, 0.2μm, 0.4μm, 0.5μm, 0.8μm, 1μm, 2μm, 4μm, 5μm, 6μm, 8μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm or any two of these values.

[0035] Preferably, the average particle size of the hydroxyapatite is 1~20 μm.

[0036] Preferably, the average particle size of the hydroxyapatite is 3~10 μm.

[0037] The average particle size of hydroxyapatite was obtained according to GB / T 19077.

[0038] Preferably, the brominated flame retardant includes at least one of tetrabromobisphenol A, brominated triazine, brominated epoxy resin, decabromodiphenyl ethane, decabromodiphenyl ether, brominated polyimide, brominated polystyrene, polybrominated styrene, brominated polycarbonate, and brominated polyacrylate.

[0039] Preferably, the antimony-based flame retardant includes at least one of antimony trioxide, antimony pentoxide, and sodium antimonate.

[0040] Preferably, the additives include at least one of lubricants and antioxidants.

[0041] Preferably, the lubricant comprises at least one of aliphatic carboxylic acid esters, erucamide, ethylene bis-stearamide, montan esters, polyethylene wax, and oxidized polyethylene wax.

[0042] The aliphatic carboxylic acid esters include at least one of ethylene glycol stearate and pentaerythritol stearate.

[0043] Preferably, the antioxidant includes at least one of thioester antioxidants, hindered phenolic antioxidants, hydroxylamine antioxidants, phosphite antioxidants, and phosphate antioxidants.

[0044] Preferably, the thioester antioxidant includes at least one of dialkyl thiodipropionate or pentaerythritol tetra(3-lauryl thiopropionate).

[0045] Preferably, the hindered phenolic antioxidant comprises at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, vinyl bis(oxyvinyl)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate] or 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane.

[0046] Preferably, the hydroxylamine antioxidant includes bis(octadecyl)hydroxylamine.

[0047] Preferably, the phosphite antioxidant includes at least one of tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol dibis(2,4-tert-butylphenyl) phosphite.

[0048] Preferably, the phosphate antioxidant includes bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphate.

[0049] Preferably, the polyester composition of the present invention may further include at least one of mineral powder, colorant, weathering agent, antistatic agent, ultraviolet absorber, and processing aid.

[0050] The polyester composition of the present invention may include colorants, and suitable colorants include, but are not limited to, carbon black, titanium dioxide, zinc sulfide, iron oxide red, titanium yellow, bismuth yellow, and combinations thereof.

[0051] The polyester composition of the present invention may include weathering agents, and suitable weathering agents include, but are not limited to, hindered amine light stabilizers.

[0052] The polyester composition of the present invention may include an antistatic agent, and suitable antistatic agents include, but are not limited to, zinc oxide, manganese dioxide, chromium trioxide, and combinations thereof.

[0053] The polyester composition of the present invention may include ultraviolet light absorbers, suitable ultraviolet light absorbers including but not limited to hydroxybenzophenones, benzotriazoles, hydroxybenzotriazines, cyanoacrylates, nanoscale inorganic materials (e.g., titanium oxide, cerium oxide, and zinc oxide), and combinations thereof.

[0054] The polyester composition of the present invention can be processed with aids, and suitable processing aids include, but are not limited to, solid paraffin, liquid paraffin, calcium stearate, magnesium stearate, zinc stearate, barium stearate, and combinations thereof.

[0055] The present invention also provides a method for preparing a polyester composition, comprising the following steps: (1) Weigh each component according to its weight parts; (2) Mix the components except glass fiber and add them to an extruder for melt dispersion. Add the glass fiber through the side feed port, melt extrude, granulate, and obtain the polyester composition.

[0056] The feeding rate is 450~800 kg / h.

[0057] The screw temperatures of the twin-screw extruder from the feed port to the die head are 220~230℃, 230~240℃, 230~240℃, 240~250℃, 250~260℃, 240~250℃, 240~250℃, 230~240℃, and 230~240℃, respectively, and the screw speed is 200~500 rpm.

[0058] The present invention also provides an application of the described polyester composition in the preparation of automotive parts, electronic and electrical components, household goods, household appliances, gardening equipment, and medical technology equipment.

[0059] The present invention also provides an automotive part made from the polyester composition described above.

[0060] The beneficial effects of this invention are as follows: This invention uses polyester resin as a matrix, and under the combined action of brominated flame retardants, antimony flame retardants, hydroxyapatite, and glass fiber, a polyester composition with excellent tracking properties and impact strength is obtained. The polyester composition also has a good appearance and is suitable for manufacturing electronic and electrical components, especially connectors, relays, and switches, and has broad application prospects. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0063] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0064] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0065] The raw materials used in the examples and comparative examples are described below: PBT-1: Intrinsic viscosity 0.80 dl / g, grade PBT GX112, Sinopec Yizheng Chemical Fiber Co., Ltd.

[0066] PBT-2: Intrinsic viscosity 0.67 dl / g, grade PBT GX112, Sinopec Yizheng Chemical Fiber Co., Ltd.

[0067] PBT-3: Intrinsic viscosity 1.28 dl / g, grade PBT GL236, Sinopec Yizheng Chemical Fiber Co., Ltd.

[0068] PBT-4: Intrinsic viscosity 1.0 dL / g, grade PBT TH6100, from Tunhe, Lanshan, Xinjiang.

[0069] Brominated epoxy resin: Grade F-2100H, Israel Chemicals.

[0070] Brominated polystyrene: Grade CG-701, Shandong Tianyi.

[0071] Antimony trioxide: Commercially available.

[0072] Sodium antimonate: Commercially available.

[0073] Hydroxyapatite-1: Average particle size is 10μm, product number TX21249-100g, Yingxin Laboratory.

[0074] Hydroxyapatite-2: average particle size 3 μm, grade BUDIT T31, Budenheim Chemical Company.

[0075] Hydroxyapatite-3: average particle size 80 μm, product number M58583, Myriel Biochemical Company.

[0076] Hydroxyapatite-4: average particle size 0.06 μm, product number 919101, Sigma-Aldrich.

[0077] Diethylaluminum hypophosphite: Grade OP 1230, Clariant.

[0078] Talc powder: Model SDC-9489, average particle size 4μm, Liaoning Xinda.

[0079] Fiberglass: average diameter 13μm, ECS13-3-534A, Jushi Group.

[0080] Lubricant: Pentaerythritol stearate, commercially available.

[0081] Antioxidant: Antioxidant 1010, commercially available.

[0082] Colorant: PE2718, Cabot.

[0083] Unless otherwise specified, all components, raw materials, or instruments used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0084] Examples 1-17, Comparative Examples 1-7 The formulations of the polyester compositions of Examples 1-17 and Comparative Examples 1-7 are shown in Tables 1 and 2 (all figures are parts by weight).

[0085] The preparation methods of the polyester compositions in Examples 1-17 and Comparative Examples 1-7 all include the following steps: (1) The polyester resin is pre-dried at 130°C for 5 hours. The dried polyester resin is then mixed with other components except glass fiber in a high-speed mixer in proportion. (2) The above mixture is fed into a twin-screw extruder. Glass fiber is added through the side feed port. Under the conveying and shearing action of the twin-screw extruder, the mixture is fully melted, plasticized, kneaded and mixed, extruded through the die head, and granulated to obtain a polyester composition.

[0086] In the above preparation method, the feed rate of the twin-screw extruder is 500 kg / hour; the screw temperatures of each section of the twin-screw extruder from the feed port to the die head are 220℃, 230℃, 240℃, 240℃, 250℃, 240℃, 240℃, 230℃, and 230℃, respectively, and the screw speed is 200-500 rpm.

[0087] Among them, Examples 9-11 and Comparative Examples 6-7 are compared with Example 3 in only one way, except that the screw speed is different. The retention length of glass fiber is adjusted by adjusting the screw speed. The higher the screw speed, the smaller the retention length of glass fiber.

[0088] Table 1 Table 2 Performance testing 1. Notched impact strength: Cantilever beam notched impact strength (Type A notch): according to ISO 180-2000, 25℃.

[0089] 2. CTI: CTI is tested according to IEC 60112:2003 standard, with a sample thickness of 3 mm and a voltage step of 25V.

[0090] 3. Appearance: Injection molded 100*100*3 mm square plate. According to ISO 7724 standard, five points (center point of 9*9 grid) are taken at the four corners and the center to test the color and obtain the L, a, b values. The color difference ΔE between the center and the four corners is calculated. The range of the color difference at the four points is the standard for judging the uniformity of the sample's appearance color.

[0091] Table 3 As can be seen from Table 3, the polyester composition of the present invention has excellent tracking properties, impact strength, and good appearance. The polyester composition is suitable for manufacturing electronic and electrical components, especially connectors, relays, and switches. The notched impact strength of the polyester composition is ≥5.4 kJ / m. 2 CTI≥350V, ΔE≤1.1.

[0092] Comparative Examples 1-4 show that by controlling the amount of each component to be: 48-88 parts polyester resin, 4-22 parts brominated flame retardant, 0.8-9 parts antimony flame retardant, 0.5-9 parts hydroxyapatite, 6-38 parts glass fiber, and 0-4 parts additives, this application effectively improves the tracking performance and impact strength of the polyester composition and improves the color difference.

[0093] Comparing Example 3 with Comparative Examples 1-5, it can be seen that the glass fiber of a specific length and hydroxyapatite of this application synergistically improve the tracking performance, impact strength, and color difference.

[0094] Comparing Example 3 with Comparative Examples 6-7, it can be seen that by controlling the retention length of the glass fiber to 150-350 μm, this application effectively improves the tracking performance and impact strength.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polyester composition, characterized in that, It includes the following components in parts by weight: 48-88 parts polyester resin, 4-22 parts brominated flame retardant, 0.8-9 parts antimony flame retardant, 0.5-9 parts hydroxyapatite, 6-38 parts glass fiber, and 0-4 parts additives; The retained length of the glass fiber is 150~350μm.

2. The polyester composition according to claim 1, characterized in that, It includes the following components by weight: 50-70 parts polyester resin, 10-15 parts brominated flame retardant, 2-6 parts antimony flame retardant, 3-6 parts hydroxyapatite, 15-24 parts glass fiber, and 1-2 parts additives.

3. The polyester composition according to claim 1, characterized in that, The retained length of the glass fiber is 190~270μm.

4. The polyester composition according to claim 1, characterized in that, The average particle size of the hydroxyapatite is 0.06~80μm.

5. The polyester composition according to claim 1, characterized in that, The intrinsic viscosity of the polyester resin is 0.6~1.3 dl / g.

6. The polyester composition according to claim 1, characterized in that, The polyester resin comprises a first polyester and a second polyester in a weight ratio of 1:(1~1.5); The intrinsic viscosity of the first polyester is 1~1.3 dl / g; The intrinsic viscosity of the second polyester is 0.6~0.8 dl / g.

7. The polyester composition according to claim 1, characterized in that, Satisfy at least one of the following (a) to (c): (a) The brominated flame retardant includes at least one of tetrabromobisphenol A, brominated triazine, brominated epoxy resin, decabromodiphenyl ethane, decabromodiphenyl ether, brominated polyimide, brominated polystyrene, polybrominated styrene, brominated polycarbonate, and brominated polyacrylate. (b) The antimony-based flame retardant includes at least one of antimony trioxide, antimony pentoxide, and sodium antimonate; (c) The additives include at least one of antioxidants and lubricants.

8. A method for preparing the polyester composition according to any one of claims 1 to 7, characterized in that, Includes the following steps: (1) Weigh each component according to its weight parts; (2) Mix the components except glass fiber and add them to an extruder for melt dispersion. Add the glass fiber through the side feed port, melt extrude, granulate, and obtain the polyester composition.

9. The use of the polyester composition according to any one of claims 1 to 7 in the preparation of automotive parts, electronic and electrical components, household goods, household appliances, gardening equipment or medical technology devices.

10. A product characterized in that, Products made from the polyester composition according to any one of claims 1 to 7 include automotive parts, electronic and electrical components, household goods, home appliances, gardening equipment, or medical technology equipment.

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