Anti-cracking flame-retardant tpe elastomer and application in robot cable assembly

Abstract

This invention discloses a crack-resistant and flame-retardant TPE elastomer and its application in robot cable assemblies. The crack-resistant and flame-retardant TPE elastomer comprises the following components in parts by weight: 80-120 parts elastomer, 2-10 parts filler, and 5-15 parts flame retardant; wherein: the elastomer comprises a styrene-butadiene-styrene block copolymer, a thermoplastic polyurethane elastomer, and low-density polyethylene in a weight ratio of 10:(3-10):(1-4); the filler comprises glass fiber and carbon black. This invention improves the crack resistance of the flame-retardant TPE elastomer by using glass fiber and carbon black, and a specific ratio of styrene-butadiene-styrene block copolymer (SBS), thermoplastic polyurethane elastomer (TPU), and low-density polyethylene (LDPE).

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to a crack-resistant and flame-retardant TPE elastomer and its application in robot cable assemblies. Background Technology

[0002] Robots, through automation and intelligent technologies, replace or assist humans in completing dangerous, complex, or repetitive tasks, not only improving efficiency and safety but also expanding the boundaries of human capabilities. Robots are currently used in automotive manufacturing, electronics, machining, home services, physical therapy, scientific research, and disaster relief. Cables are an integral part of a robot's structure, providing a stable power supply to ensure the proper functioning of its components. They are also used for data transmission, sensor connection, and communication. TPE, or thermoplastic elastomer, is a novel polymer material between rubber and plastic, commonly used as cable insulation. Adding flame retardants to TPE can improve the cable's flame-retardant properties, slowing the spread of flames and reducing the rate of fire propagation. However, flame retardants can easily migrate to the TPE surface, forming stress concentration points, increasing the risk of stress cracking, which is detrimental to maintaining the cable's insulation performance and shortening its lifespan.

[0003] Therefore, developing a crack-resistant and flame-retardant TPE elastomer is of great significance. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a crack-resistant and flame-retardant TPE elastomer and its application in robot cable assemblies.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present invention provides a crack-resistant and flame-retardant TPE elastomer, comprising the following components in parts by weight:

[0007] 80-120 parts elastomer, 2-10 parts filler, 5-15 parts flame retardant;

[0008] in:

[0009] The elastomer comprises styrene-butadiene-styrene block copolymer (SBS), thermoplastic polyurethane (TPU), and low-density polyethylene (LDPE) in a weight ratio of 10:(3-10):(1-4).

[0010] The filler includes glass fiber and carbon black.

[0011] This invention improves the crack resistance of flame-retardant TPE elastomers by using glass fiber and carbon black, along with specific proportions of styrene-butadiene-styrene block copolymer (SBS), thermoplastic polyurethane (TPU), and low-density polyethylene (LDPE). On one hand, the specific proportions of SBS, TPU, and LDPE not only allow for uniform mixing to obtain a stable and homogeneous system, but also enable them to entangle and form a stable network structure, which stably fixes the flame retardant and reduces its migration on the material surface, thereby improving the crack resistance of the flame-retardant TPE elastomer. On the other hand, the uniform dispersion of glass fiber and carbon black within the system formed by SBS, TPU, and LDPE reduces the generation of stress concentration points, which is beneficial for improving the crack resistance of the flame-retardant TPE elastomer.

[0012] Preferably, the weight ratio of the styrene-butadiene-styrene block copolymer (SBS), thermoplastic polyurethane (TPU), and low-density polyethylene (LDPE) is 10:3:1, 10:4:1, 10:5:1, 10:6:1, 10:7:1, 10:8:1, 10:9:1, 10:10:1, 10:3:2, 10:4:2, 10:5:2, 10:6:2, 10:7: 2. The range of one or any two of the following: 10:8:2, 10:9:2, 10:10:2, 10:3:3, 10:4:3, 10:5:3, 10:6:3, 10:7:3, 10:8:3, 10:9:3, 10:10:3, 10:3:4, 10:4:4, 10:5:4, 10:6:4, 10:7:4, 10:8:4, 10:9:4, 10:10:4.

[0013] More preferably, the weight ratio of the styrene-butadiene-styrene block copolymer (SBS), the thermoplastic polyurethane elastomer (TPU), and the low-density polyethylene (LDPE) is 10:(6-10):(2-4).

[0014] Preferably, the polyurethane thermoplastic elastomer (TPU) includes at least one of polyester-type TPU and polyether-type TPU.

[0015] Preferably, the low-density polyethylene (LDPE) has a melt mass flow rate (MFR) of 4-15 g / 10 min at 190°C and 2.16 kg.

[0016] More preferably, the melt mass flow rate of the low-density polyethylene (LDPE) at 190°C and 2.16 kg is one or any two of the following values: 4 g / 10 min, 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, 8 g / 10 min, 9 g / 10 min, 10 g / 10 min, 11 g / 10 min, 12 g / 10 min, 13 g / 10 min, 14 g / 10 min, and 15 g / 10 min.

[0017] More preferably, the low-density polyethylene (LDPE) has a melt mass flow rate of 4-8 g / 10 min at 190°C and 2.16 kg.

[0018] In this invention, the melt mass flow rate (MFR) of low-density polyethylene (LDPE) at 190°C and 2.16 kg was measured according to ISO 1133-2022 standard.

[0019] Preferably, the weight ratio of glass fiber to carbon black is 1:(0.5-2).

[0020] More preferably, the weight ratio of glass fiber to carbon black is one or any two of the following: 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2.

[0021] More preferably, the weight ratio of glass fiber to carbon black is 1:(1-2), specifically 1:(1.2-2).

[0022] Preferably, the glass fiber has an average length of 2-6 mm and an average diameter of ≤15 μm.

[0023] More preferably, the average length of the glass fiber is one or any two of the following: 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, and 6mm.

[0024] More preferably, the average length of the glass fiber is 2-4 mm.

[0025] More preferably, the average diameter of the glass fiber is ≤ one or any two of the following: 15μm, 14μm, 13μm, 12μm, 11μm, 10μm, 9μm, 8μm, 7μm, 6μm, 5μm, 4μm, 3μm, 2μm, 1μm, 0.5μm, and 0.1μm.

[0026] More preferably, the average diameter of the glass fiber is 3-15 μm, specifically 10-15 μm.

[0027] In this invention, the method for measuring the average length of the glass fiber is as follows: take 100 glass fibers, measure the length of the glass fibers with a microscope and calculate their arithmetic mean, and use this as the average length of the glass fiber.

[0028] Preferably, the carbon black has a D50 particle size of 15-110 nm.

[0029] More preferably, the D50 particle size of the carbon black is one or any two of the following: 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, 100nm, 101nm, 102nm, 103nm, 104nm, 105nm, 106nm, 107nm, 108nm, 109nm, and 110nm.

[0030] More preferably, the D50 particle size of the carbon black is 20-100 nm.

[0031] More preferably, the D50 particle size of the carbon black is 60-100 nm.

[0032] In this invention, the D50 particle size of the carbon black is measured using a laser particle size analyzer according to the GB / T19077-2016 standard.

[0033] Preferably, the flame retardant includes at least one of halogenated flame retardants, phosphorus-based flame retardants, and nitrogen-based flame retardants.

[0034] More preferably, the halogenated flame retardant includes at least one of the bromine-based flame retardant and the chlorine-based flame retardant.

[0035] More preferably, the brominated flame retardant includes at least one of decabromodiphenyl ether (DBDPO), tetrabromobisphenol A bis(2,3-dialkylpropyl) ether (TBAB), and octabromodiphenyl ether (OBDPO).

[0036] More preferably, the phosphorus-based flame retardant includes at least one of inorganic phosphorus-based flame retardants and organic phosphorus-based flame retardants.

[0037] More preferably, the inorganic phosphorus-based flame retardant includes at least one of red phosphorus, ammonium phosphate, and ammonium polyphosphate (APP).

[0038] More preferably, the organophosphorus flame retardant includes at least one of phosphate esters and phosphonates.

[0039] In this invention, the phosphate esters include at least one of triphenyl phosphate, tricresyl phosphate, propylbenzene phosphate, butadiene phosphate, and toluene diphenyl phosphate; the phosphonates include diphenylisopropylphenyl phosphonate.

[0040] More preferably, the nitrogen-based flame retardant includes at least one of melamine, dicyandiamide, and guanidine salt.

[0041] More preferably, the guanidine salt includes at least one of guanidine carbonate, guanidine phosphate, guanidine condensed phosphate, and guanidine aminosulfonate.

[0042] Preferably, the elastomer is in the range of one or any two of the following weight parts: 80 parts, 82 parts, 85 parts, 87 parts, 88 parts, 90 parts, 92 parts, 95 parts, 97 parts, 98 parts, 100 parts, 102 parts, 105 parts, 107 parts, 108 parts, 110 parts, 112 parts, 115 parts, 117 parts, 118 parts, and 120 parts; the filler is in the range of 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, and 6 parts. The weight of the flame retardant is within the range of one or any two of the following: 5 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts; the weight of the flame retardant is within the range of one or any two of the following: 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, 12.5 parts, 13 parts, 13.5 parts, 14 parts, 14.5 parts, 15 parts.

[0043] Preferably, in the crack-resistant and flame-retardant TPE elastomer, the weight percentage of the elastomer is ≥70%, specifically 75-95%.

[0044] Preferably, in the crack-resistant flame-retardant TPE elastomer, the weight percentage of the flame retardant is ≤20%, specifically 2-16%.

[0045] Secondly, the present invention provides a method for preparing a crack-resistant and flame-retardant TPE elastomer, comprising:

[0046] Mix the components, extrude and granulate to obtain crack-resistant and flame-retardant TPE elastomer.

[0047] Preferably, the method for preparing the crack-resistant and flame-retardant TPE elastomer includes the following steps:

[0048] S1. Mix styrene-butadiene-styrene block copolymer (SBS), thermoplastic polyurethane elastomer (TPU), and low-density polyethylene (LDPE) to obtain an elastomer for later use;

[0049] S2. Mix glass fiber and carbon black to obtain the filler, for later use;

[0050] S3. Mix elastomer, filler, and flame retardant, then extrude and granulate to obtain crack-resistant and flame-retardant TPE elastomer.

[0051] Preferably, the extrusion granulation temperature is 180-220℃.

[0052] Thirdly, the present invention provides an application of crack-resistant and flame-retardant TPE elastomer in robot cable assemblies.

[0053] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0054] This invention improves the crack resistance of flame-retardant TPE elastomers by using glass fiber and carbon black, along with specific proportions of styrene-butadiene-styrene block copolymer (SBS), thermoplastic polyurethane (TPU), and low-density polyethylene (LDPE). On one hand, the specific proportions of SBS, TPU, and LDPE not only allow for uniform mixing to obtain a stable and homogeneous system, but also enable them to entangle and form a stable network structure, which stably fixes the flame retardant and reduces its migration on the material surface, thereby improving the crack resistance of the flame-retardant TPE elastomer. On the other hand, the uniform dispersion of glass fiber and carbon black within the system formed by SBS, TPU, and LDPE reduces the generation of stress concentration points, which is beneficial for improving the crack resistance of the flame-retardant TPE elastomer. Detailed Implementation

[0055] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0056] The experimental methods in the following examples and comparative examples, where specific conditions are not specified, are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are all commercially available from the conventional market.

[0057] The reagents used in the various embodiments and comparative examples of this invention are as follows:

[0058] SBS-1, styrene-butadiene-styrene block copolymer; YH-792, Baling Petrochemical;

[0059] SBS-2, styrene-butadiene-styrene block copolymer, 4402, Yanshan Petrochemical;

[0060] TPU-1, polyurethane thermoplastic elastomer, polyester-type TPU, WHT-1180, Wanhua Chemical;

[0061] TPU-2, polyurethane thermoplastic elastomer, polyether-type TPU, WHT-M870, Wanhua Chemical;

[0062] LDPE-1, low-density polyethylene, has a melt flow rate of 8 g / 10 min at 190°C and 2.16 kg; LDPE 722, Dow Chemical.

[0063] LDPE-2, low-density polyethylene, has a melt flow rate of 4 g / 10 min at 190℃ and 2.16 kg; LDPE 2426K, CNOOC Shell.

[0064] LDPE-3, low-density polyethylene, melt flow rate of 15 g / 10 min at 190°C and 2.16 kg, EXCEED 0015XC, ExxonMobil;

[0065] ABS, ABS 8434, Gaoqiao Petrochemical;

[0066] HDPE, high-density polyethylene, has a melt mass flow rate of 7.5 g / 10 min at 190℃ and 2.16 kg. 8008, Dushanzi Petrochemical.

[0067] Glass fiber-1, with an average length of 4 mm and an average diameter of 13 μm, was obtained by cutting and shredding glass fiber-3 (ECS13-06-558, China Jushi Co., Ltd.);

[0068] Glass fiber-2, with an average length of 2 mm and an average diameter of 13 μm, was obtained by cutting and shredding glass fiber-3 (ECS13-06-558, China Jushi Co., Ltd.);

[0069] Glass fiber-3, average length 6mm, average diameter 13μm, ECS13-06-558, China Jushi Co., Ltd.;

[0070] Carbon black-1, with a D50 particle size of 60 nm, is obtained by crushing and screening Cabot's carbon black N550.

[0071] Carbon black-2, with a D50 particle size of 100 nm, was obtained by screening Cabot's carbon black N550.

[0072] Carbon black-3, with a D50 particle size of 20 nm, is obtained by crushing and screening Cabot's carbon black N550.

[0073] Carbon nanotubes, 1-2 nm in diameter and 1-3 μm in length, XFS05, Xianfeng Nano;

[0074] Flame retardant-1, octabromodiphenyl ether, commercially available;

[0075] Flame retardant-2, tricresyl phosphate, commercially available;

[0076] In this invention, the melt mass flow rate (MFR) of low-density polyethylene (LDPE) and high-density polyethylene (HDPE) at 190°C and 2.16 kg was measured according to the ISO 1133-2022 standard.

[0077] In this invention, the method for measuring the average length of the glass fiber is as follows: take 100 glass fibers, measure the length of the glass fibers with a microscope and calculate their arithmetic mean, and use this as the average length of the glass fiber;

[0078] In this invention, the D50 particle size of the carbon black is measured using a laser particle size analyzer according to the GB / T19077-2016 standard.

[0079] Examples 1-17 and Comparative Examples 1-8

[0080] Examples 1-17 and Comparative Examples 1-8 provide different crack-resistant and flame-retardant TPE elastomers, which differ only in the type and amount of each component. By weight, Examples 1-17 and Comparative Examples 1-8 include the components shown in Table 1-2.

[0081] The preparation methods of crack-resistant and flame-retardant TPE elastomers in Examples 1-17 and Comparative Examples 1-8 include the following steps:

[0082] S1. Mix styrene-butadiene-styrene block copolymer (SBS), thermoplastic polyurethane elastomer (TPU), and low-density polyethylene (LDPE) to obtain an elastomer for later use;

[0083] S2. Mix glass fiber and carbon black to obtain the filler, for later use;

[0084] S3. Mix elastomer, filler and flame retardant, and extrude and granulate using a twin-screw extruder at 190±5℃ to obtain crack-resistant and flame-retardant TPE elastomer;

[0085] The length-to-diameter ratio of the twin-screw extruder is 40:1;

[0086] Table 1. Weight parts of each component in the crack-resistant and flame-retardant TPE elastomers of Examples 1-17

[0087]

[0088]

[0089] Table 2. Weight parts of each component in the crack-resistant and flame-retardant TPE elastomers of Comparative Examples 1-8

[0090]

[0091]

[0092] Performance testing

[0093] The following performance tests were conducted on the crack-resistant and flame-retardant TPE elastomers of each embodiment and comparative example:

[0094] 1. Crack resistance test

[0095] At 270°C, the crack-resistant and flame-retardant TPE elastomers of each embodiment or comparative example were injection molded into test samples with dimensions of 100mm×10mm×3mm. The samples were then soaked in glacial acetic acid for 7 minutes, removed, and the surface of the test samples was wiped dry with filter paper. The number of cracks and the maximum width of the cracks were observed and recorded. The qualified standard for the number of cracks was ≤8. The qualified standard for the maximum width of the cracks was ≤30mm.

[0096] 2. Flame retardant test

[0097] At 270°C, the crack-resistant and flame-retardant TPE elastomers of each embodiment or comparative example were injection molded into test samples with dimensions of 12.5mm × 125mm × 2mm. Flame retardancy tests were conducted according to the UL94-2018 standard, and the flame retardancy rating was recorded. The flame retardancy ratings from low to high are UL94HB (denoted as HB), UL94V-2 (denoted as V2), UL94V-1 (denoted as V1), UL94V-0 (denoted as V0), and UL94-5V (denoted as 5V). V1 and above are considered qualified.

[0098] 3. Impact strength test

[0099] At 270°C, the crack-resistant and flame-retardant TPE elastomers of each embodiment or comparative example were injection molded into test samples with dimensions of 63.5mm × 12.7mm × 3.2mm. The cantilever beam notched impact strength was tested according to ASTM D256-2010 standard, and the impact strength data was recorded.

[0100] The experimental results are shown in the table below:

[0101] Table 3 Performance test results of each embodiment and comparative example

[0102]

[0103]

[0104] As shown in Table 3, this invention improves the crack resistance of flame-retardant TPE elastomers by using glass fiber and carbon black, along with specific proportions of styrene-butadiene-styrene block copolymer (SBS), thermoplastic polyurethane (TPU), and low-density polyethylene (LDPE). On one hand, the specific proportions of SBS, TPU, and LDPE not only allow for uniform mixing to obtain a stable and homogeneous system, but also enable them to entangle and form a stable network structure, which can stably fix the flame retardant and reduce its migration on the material surface, thereby improving the crack resistance of the flame-retardant TPE elastomer. On the other hand, the uniform dispersion of glass fiber and carbon black in the system formed by SBS, TPU, and LDPE reduces the generation of stress concentration points, which is beneficial to improving the crack resistance of the flame-retardant TPE elastomer. Furthermore, the crack-resistant flame-retardant TPE elastomer exhibits the following characteristics: number of cracks ≤ 8, maximum crack width ≤ 30 mm, flame retardancy rating ≥ V1, and impact strength ≥ 600 kJ·m. -2 .

[0105] 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 flame-retardant, anti-cracking TPE elastomer, characterized in that, The components include the following parts by weight: 80-120 parts elastomer, 2-10 parts filler, 5-15 parts flame retardant; in: The elastomer comprises a styrene-butadiene-styrene block copolymer, a polyurethane thermoplastic elastomer, and low-density polyethylene in a weight ratio of 10:(3-10):(1-4). The filler includes glass fiber and carbon black; The polyurethane thermoplastic elastomer includes at least one of polyester-type TPU and polyether-type TPU; The low-density polyethylene has a melt mass flow rate of 4-15 g / 10 min at 190°C and 2.16 kg. The weight ratio of glass fiber to carbon black is 1:(0.5-2); The glass fiber has an average length of 2-6 mm and an average diameter of ≤15 μm. The carbon black has a D50 particle size of 15-110 nm.

2. The anti-cracking flame retardant TPE elastomer according to claim 1, wherein, The weight ratio of the styrene-butadiene-styrene block copolymer, the polyurethane thermoplastic elastomer, and the low-density polyethylene is 10:(6-10):(2-4).

3. The crack-resistant and flame-retardant TPE elastomer as described in claim 1, characterized in that, Includes at least one of the following (1)-(2): (1) The melt flow rate of the low-density polyethylene at 190℃ and 2.16kg is 4-8g / 10min; (2) The weight ratio of the glass fiber to the carbon black is 1:(1-2).

4. The crack-resistant and flame-retardant TPE elastomer as described in claim 1, characterized in that, Includes at least one of the following (1)-(3): (1) The average length of the glass fiber is 2-4 mm; (2) The average diameter of the glass fiber is 3-15 μm; (3) The D50 particle size of the carbon black is 60-100nm.

5. The crack-resistant and flame-retardant TPE elastomer as described in claim 1, characterized in that, The flame retardant includes at least one of halogenated flame retardants, phosphorus-based flame retardants, and nitrogen-based flame retardants.

6. The crack-resistant and flame-retardant TPE elastomer as described in claim 5, characterized in that, Includes at least one of the following (1)-(3): (1) The halogenated flame retardant includes at least one of the bromine-based flame retardant and the chlorine-based flame retardant; (2) The phosphorus-based flame retardant includes at least one of inorganic phosphorus-based flame retardants and organic phosphorus-based flame retardants; (3) The nitrogen-based flame retardant includes at least one of melamine, dicyandiamide, and guanidine salt.

7. A method for preparing the crack-resistant and flame-retardant TPE elastomer according to any one of claims 1-6, characterized in that, include: Mix the components, extrude and granulate to obtain crack-resistant and flame-retardant TPE elastomer.

8. The application of the crack-resistant and flame-retardant TPE elastomer according to any one of claims 1-6 in robot cable assemblies.

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