A flame retardant TPE material and preparation method thereof

Abstract

The present invention belongs to the field of polymer flame retardant materials, and specifically relates to a flame retardant TPE material and a preparation method thereof. The flame retardant TPE material of the present invention comprises the following raw materials by weight: 30 to 50 parts of styrene thermoplastic elastomer, 10 to 20 parts of polyolefin resin, 5 to 10 parts of filler oil, 15 to 20 parts of inorganic filler, 1 to 3 parts of flame retardant X, 0.1 to 1 part of antioxidant, and 1 to 2 parts of coupling agent. The TPE material obtained by the present invention has excellent flame retardant properties and mechanical properties. When the amount of flame retardant added is less than 3wt%, a V‑0 flame retardant grade can be achieved, and its LOI value is as high as 38.1%.

Description

Technical Field

[0001] The invention belongs to the field of polymer flame retardant materials, and in particular relates to a flame retardant TPE material and a preparation method thereof. Background Art

[0002] TPE, also known as thermoplastic elastomer, is a material that has the elasticity of rubber at room temperature and plasticity at high temperatures. Its chemical composition contains resin segments and rubber segments. The resin segments can form physical crosslinking points due to the interchain forces, while the rubber segments have high elasticity segments. TPE materials not only have the high strength, high elasticity, and high resilience of rubber, but also have the characteristics of plastic processing. TPE is widely used in many fields such as the automotive industry, medical treatment, health food, wires and cables, toys, adhesives, etc. due to its excellent colorability, weather resistance, soft touch, fatigue resistance and temperature resistance.

[0003] SEBS is currently a new type of TPE with a wide range of uses. It is a new type of modified TPE made by moderately and selectively hydrogenating the unsaturated double bonds in the polybutadiene segment of the SBS molecule in the presence of a catalyst, and hydrogenating the polybutadiene block into polyethylene (E) segments and polybutene (B) segments. Compared with traditional vulcanized rubber, SEBS lacks the vulcanization process, and the dual structure of the soft segment and the hard segment makes it have the properties of both plastic and rubber. SEBS is made by opening the double bonds of SBS and hydrogenating them, and the chemical bonds are more stable. Therefore, compared with SBS, SEBS has better tolerance to ozone, heat, ultraviolet rays, etc. and aging resistance, and also has good solubility, excellent electrical insulation properties and miscibility.

[0004] SEBS is an excellent material for manufacturing wires, cable sheaths and insulating tapes due to its excellent electrical insulation properties. However, as an alkane polymer, SEBS has a high carbon content, is easy to burn, and has serious fire hazards. In order to improve its safety performance, it is necessary to perform flame retardant modification on it and improve its flame retardant properties, which has become an important issue that people need to solve urgently. Adding flame retardants is a common method to improve flame retardant properties. Flame retardants mainly include halogen-containing flame retardants, inorganic flame retardants and organic halogen-free flame retardants. Although halogen-containing flame retardants have high flame retardant efficiency, they release a large amount of toxic gases and emit black smoke when they burn; the flame retardant efficiency of inorganic flame retardants is generally low, and the amount of addition is large. The flame retardant effect of them when used alone is not ideal. Usually, they need to be used in combination with other organic flame retardants to greatly improve the flame retardant effect; organic halogen-free flame retardants are more environmentally friendly than halogen-containing flame retardants, but most of the current organic flame retardants have low flame retardant efficiency and large addition amounts. Based on this, it is urgent to develop more TPE materials with excellent flame retardant properties and mechanical properties. Summary of the invention

[0005] The main purpose of the present invention is to provide a flame retardant TPE material and a preparation method thereof, wherein the flame retardant contained in the material has a more efficient and environmentally friendly flame retardant effect. In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A flame retardant TPE material, comprising the following raw materials in parts by weight:

[0007] 30-50 parts of styrene thermoplastic elastomer

[0008] Polyolefin resin 10-20 parts

[0009] Filling oil 5-10 parts

[0010] Inorganic filler 15-20 parts

[0011] Flame retardant x1~3 parts

[0012] Antioxidant 0.1-1 part

[0013] 1-2 parts of coupling agent

[0014] The chemical structural formula of the flame retardant X is:

[0015] In some embodiments, the styrene-based thermoplastic elastomer is a styrene-ethylene-butylene-styrene triblock copolymer SEBS, and the styrene content thereof is 10-60%.

[0016] In some embodiments, the styrenic thermoplastic elastomer is selected from one or more of SEBS G1650, SEBS G1651, SEBS G6933, SEBS 4033, SEBS 4055 and SEBS YH502T;

[0017] In some embodiments, the polyolefin resin is selected from one or both of a polypropylene resin and a polyethylene resin.

[0018] In some embodiments, the polyolefin resin is selected from one or more of polypropylene 5090T, polypropylene EPC30R, and polyethylene 7042;

[0019] In some embodiments, the extender oil is selected from one or more of liquid paraffin, naphthenic oil, and white oil;

[0020] In some embodiments, the inorganic filler is selected from one or more of talc powder, barium sulfate, calcium carbonate and mica powder; and the particle diameter D50 of the inorganic filler is 1 to 2 μm.

[0021] In some embodiments, the coupling agent is selected from one or more of KH-550, KH-560, KH-570, KH-792, and KH-791.

[0022] In some embodiments, the antioxidant is selected from one or more of antioxidant 1010 , antioxidant 1076 , antioxidant 168 , and antioxidant 1035 .

[0023] On the other hand, the present invention also provides a method for preparing the flame retardant TPE material, comprising the following steps:

[0024] Step S1: accurately weighing styrene-based thermoplastic elastomer, polyolefin resin, filler oil, inorganic filler, flame retardant X, antioxidant, and coupling agent according to mass parts for later use;

[0025] Step S2: putting the styrene-based thermoplastic elastomer and the filler oil into a low-speed mixer according to the formula ratio and stirring for 5 to 10 minutes, and standing for 5 to 10 hours for standby use, so that the styrene-based thermoplastic elastomer is fully filled with oil and swollen;

[0026] Step S3: firstly add the oil-filled styrene thermoplastic elastomer, polyolefin resin, inorganic filler, flame retardant X, antioxidant and coupling agent into a high-speed mixer, and mix them uniformly at a low speed of 400-600 r / min to obtain a premix; add the premix into a twin-screw extruder, and obtain a flame-retardant TPE material through melt extrusion and granulation, wherein the melt processing temperature of the twin-screw extruder is set as follows: 180°C in zone 1, 190°C in zone 2, 200°C in zone 3, 200°C in zone 4, 210°C in zone 5, 210°C in zone 6, 205°C in zone 7, 200°C in zone 8, 190°C in zone 9, 190°C in zone 10, 180°C in zone 11, and the die head temperature is 180°C; the screw speed is 300-500 r / min.

[0027] The present invention has the following beneficial effects:

[0028] The TPE material of the present invention has excellent flame retardant properties and mechanical properties. First, the new flame retardant X used in the present invention contains flame retardant elements such as N, P, and B, which can achieve synergistic and efficient flame retardancy and effectively improve the flame retardant efficiency. When the addition amount is less than 3wt%, the V-0 flame retardant grade can be achieved, and its LOI value is as high as 38.1%, which is better than other common flame retardants in the field. In addition, the flame retardant X of the present invention contains a special structure of triphenylpyrrole, and its introduction can improve the mechanical properties of the TPE material. DETAILED DESCRIPTION

[0029] The technical scheme of the present invention is further described below through specific examples. It should be understood that the specific examples described herein are only used to help understand the present invention and are not used for specific limitations of the present invention. The experimental methods used in the following examples are conventional methods unless otherwise specified; the materials used in the following examples, etc., unless otherwise specified, the raw materials in the examples of this application are purchased through commercial channels; the instruments and equipment used in the following examples, unless otherwise specified, all use the parameters recommended by the manufacturer; the methods used in the examples are conventional methods in the art.

[0030] Preparation Example 1: Preparation of Flame Retardant X

[0031] Step 1: Preparation of intermediate compound C

[0032]

[0033] Compound A (0.1 mol), compound B (0.12 mol), and cuprous chloride (0.02 mol) were added to a round-bottom flask, followed by evacuation and nitrogen filling for 3 times. The mixture was heated to 140°C, the raw materials were melted and mixed evenly, and the reaction was stirred for 12 hours. After the reaction, the reaction mixture was cooled to room temperature, and then a 5% dilute hydrochloric acid aqueous solution (50 mL) was added, and the mixture was extracted with dichloromethane (200 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain a crude product. The crude product was separated and purified by column chromatography to obtain the intermediate compound C as a white solid with a yield of 58.4% and a HPLC purity of 99.5%.

[0034] LC-MS(ESI):[M+H] + =574.3.

[0035] Step 2: Preparation of flame retardant X

[0036]

[0037] The raw material compound D (DOPO, 0.1 mol) was dissolved in tetrahydrofuran (200 mL), and then the initiator AIBN (0.005 mol) and the intermediate C (0.1 mol) obtained in Preparation Example 1 were added in sequence. The temperature was raised to 60°C and stirred for reaction for 24 hours under a nitrogen environment. After the reaction, the crude product was concentrated under reduced pressure, and the crude product was separated and purified by column chromatography to obtain flame retardant X with a yield of 90.1% and an HPLC purity of 99.6%.

[0038] LC-MS (ESI): [M+H] + =790.4.

[0039] 1H-NMR (500MHz, CDCl3): δ (ppm): 8.06-7.91 (m, 5H), 7.65-7.54 (m, 5H), 7.43-7.30 (m, 6H ), 7.16-7.08(m, 4H), 6.41(s, 2H), 3.15-3.10(m, 2H), 2.90-2.82(m, 2H), 1.25(s, 24H).

[0040] Example 1

[0041] A flame retardant TPE material, comprising the following raw materials in parts by weight:

[0042] SEBS G1650 (Kraton) 50 copies

[0043] Polypropylene 5090T 15 parts

[0044] 10 parts of No. 26 white oil

[0045] Mica powder 15 parts

[0046] Flame retardant x 2 parts

[0047] Antioxidant 1010 0.5 parts

[0048] KH-550 1 copy

[0049] The chemical structural formula of the flame retardant X is:

[0050] The preparation method of the above TPE material comprises the following steps:

[0051] Step S1: accurately weigh 40 parts of SEBS G1650, 15 parts of polypropylene 5090T, 10 parts of No. 26 white oil, 15 parts of mica powder, 2 parts of flame retardant X, 0.5 parts of antioxidant 1010, and 1 part of KH-550 by mass, and set aside;

[0052] Step S2: SEBS G1650 and No. 26 white oil are put into a low-speed mixer according to the formula ratio and stirred for 10 minutes, and then left to stand for 5 hours to allow SEBS to fully swell with oil;

[0053] Step S3: first add oil-filled SEBS, polypropylene 5090T, mica powder, flame retardant X, antioxidant 1010, and coupling agent KH-550 into a high mixer, and mix them at a low speed of 400 r / min to obtain a premix; add the premix into a twin-screw extruder, and obtain a flame-retardant TPE material through melt extrusion and granulation, wherein the melt processing temperature of the twin-screw extruder is set to: 180°C for zone 1, 190°C for zone 2, 200°C for zone 3, 200°C for zone 4, 210°C for zone 5, 210°C for zone 6, 205°C for zone 7, 200°C for zone 8, 190°C for zone 9, 190°C for zone 10, 180°C for zone 11, and a die head temperature of 180°C; the screw speed is 300 r / min.

[0054] Example 2

[0055] A flame retardant TPE material, comprising the following raw materials in parts by weight:

[0056] SEBS G1650 (Kraton) 45 parts

[0057] Polyethylene 7042 20 parts

[0058] 10 parts of No. 26 white oil

[0059] 15 parts talcum powder

[0060] Flame retardant x 2 parts

[0061] Antioxidant 168 1 part

[0062] KH-560 1.5 parts

[0063] The chemical structural formula of the flame retardant X is:

[0064] The preparation method of the above TPE material comprises the following steps:

[0065] Step S1: accurately weigh 45 parts of SEBS G1650, 20 parts of polyethylene 7042, 10 parts of No. 26 white oil, 15 parts of talcum powder, 2 parts of flame retardant X, 1 part of antioxidant 168, and 1.5 parts of KH-560 by mass for later use;

[0066] Step S2: SEBS G1650 and No. 26 white oil are put into a low-speed mixer according to the formula ratio and stirred for 10 minutes, and then left to stand for 5 hours to allow SEBS to fully swell with oil;

[0067] Step S3: firstly add the oil-filled SEBS G1650, polyethylene 7042, talcum powder, flame retardant X, antioxidant 168, and coupling agent KH-560 into a high-speed mixer, and mix them uniformly at a low speed of 400 r / min to obtain a premix; add the premix into a twin-screw extruder, and obtain a flame-retardant TPE material through melt extrusion and granulation, wherein the melt processing temperature of the twin-screw extruder is set to: 180° C. for zone 1, 190° C. for zone 2, 200° C. for zone 3, 200° C. for zone 4, 210° C. for zone 5, 210° C. for zone 6, 205° C. for zone 7, 200° C. for zone 8, 190° C. for zone 9, 190° C. for zone 10, 180° C. for zone 11, and a die head temperature of 180° C.; and the screw speed is 300 r / min.

[0068] Example 3

[0069] A flame retardant TPE material, comprising the following raw materials in parts by weight:

[0070] SEBS YH502T 45 parts

[0071] Polypropylene 5090T 15 parts

[0072] 10 parts of No. 26 white oil

[0073] 20 parts of talcum powder

[0074] Flame retardant x 2 parts

[0075] Antioxidant 1076 0.5 parts

[0076] KH-550 2 pcs

[0077] The chemical structural formula of the flame retardant X is:

[0078] The preparation method of the above TPE material comprises the following steps:

[0079] Step S1: accurately weigh 40 parts of SEBS YH502T, 15 parts of polypropylene 5090T, 10 parts of No. 26 white oil, 20 parts of talcum powder, 2 parts of flame retardant X, 0.5 parts of antioxidant 1076, and 2 parts of KH-550 by mass for standby use;

[0080] Step S2: SEBS YH502T and No. 26 white oil are put into a low-speed mixer according to the formula ratio and stirred for 10 minutes, and then left to stand for 5 hours to allow SEBS to be fully oil-filled and swollen;

[0081] Step S3: first add the oil-filled SEBS YH502T, polypropylene 5090T, talcum powder, flame retardant X, antioxidant 1076, and coupling agent KH-550 into a high-speed mixer, and mix them evenly at a low speed of 400 r / min to obtain a premix; add the premix into a twin-screw extruder, and obtain a TPE material through melt extrusion and granulation, wherein the melt processing temperature of the twin-screw extruder is set to: 180° C. for zone 1, 190° C. for zone 2, 200° C. for zone 3, 200° C. for zone 4, 210° C. for zone 5, 210° C. for zone 6, 205° C. for zone 7, 200° C. for zone 8, 190° C. for zone 9, 190° C. for zone 10, 180° C. for zone 11, and a die head temperature of 180° C.; and the screw speed is 300 r / min.

[0082] Comparative Example 1

[0083] On the basis of Example 1, the flame retardant X was replaced by the common flame retardant tris(N,N-tetramethylene)phosphoramide. Other operating steps and conditions were the same as those in Example 1.

[0084] Performance Testing

[0085] The TPE materials of Examples 1-3 and Comparative Example 1 were processed into standard specimens by injection molding, and the mechanical properties and flame retardant properties were tested according to the following test standards. The results are shown in Table 1.

[0086] 1) Tensile strength and elongation at break: the test standard is ASTM D412;

[0087] 2) Limiting oxygen index (LOI): the test standard is GB / T 2406.2-2009;

[0088] 3) Vertical burning performance: Test standard UL-94.

[0089] Table 1 Test results of flame retardant TPE materials

[0090] Serial number Example 1 Example 2 Example 3 Comparative Example 1 Tensile strength(Mpa) 15.1 15.4 16.2 13.8 Elongation at break (%) 525 533 548 496 Limiting oxygen index 37.4 36.8 38.1 26.5 Flame retardant grade V-0 V-0 V-0 V-2

[0091] As can be seen from Table 1, the TPE material prepared by the present invention has excellent flame retardant properties while maintaining good mechanical properties. First, the flame retardant X used in the present invention contains flame retardant elements such as N, P, and B, which can achieve synergistic and efficient flame retardancy and effectively improve the flame retardant efficiency. When the addition amount is less than 3wt%, the V-0 flame retardant grade can be achieved, and its LOI value is as high as 38.1%, which is better than other common flame retardants in the field. In addition, the flame retardant X of the present invention contains a special structure of triphenylpyrrole, and its introduction can improve the mechanical properties of TPE materials.

[0092] The various aspects, embodiments, and features of the present invention should be considered to be illustrative in all respects and not limiting of the present invention, and the scope of the present invention is defined solely by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention. In the preparation method of the present invention, the order of the steps is not limited to the order listed, and for those of ordinary skill in the art, without creative effort, the sequence of the steps is also within the scope of the present invention. In addition, two or more steps or actions may be performed simultaneously.

[0093] Finally, it should be noted that the specific embodiments described herein are merely examples of the present invention, and are not intended to limit the implementation methods of the present invention. A person skilled in the art of the present invention may make various modifications or supplements to the specific embodiments described, or replace them in a similar manner. It is not necessary and impossible to provide all examples of all implementation methods here. However, these obvious changes or modifications derived from the essential spirit of the present invention still fall within the scope of protection of the present invention, and interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A flame retardant TPE material, comprising the following raw materials in parts by weight: 30~50 parts of styrene thermoplastic elastomer Polyolefin resin 10~20 parts Filling oil 5~10 parts Inorganic filler 15~20 parts Flame retardant X 1~3 parts Antioxidant 0.1~1 part Coupling agent 1~2 parts The chemical structural formula of the flame retardant X is: .

2. The flame retardant TPE material according to claim 1, characterized in that: The styrene-based thermoplastic elastomer is a styrene-ethylene-butylene-styrene triblock copolymer SEBS, and the styrene content of the copolymer is 10-60%.

3. The flame retardant TPE material according to claim 2, characterized in that: The styrene-based thermoplastic elastomer is selected from one or more of SEBS G1650, SEBS G1651, SEBS G6933, SEBS 4033, SEBS 4055 and SEBS YH502T.

4. The flame retardant TPE material according to claim 1, characterized in that: The polyolefin resin is selected from one or both of polypropylene resin and polyethylene resin.

5. The flame retardant TPE material according to claim 4, characterized in that: The polyolefin resin is selected from one or more of polypropylene 5090T, polypropylene EPC30R, and polyethylene 7042.

6. The flame retardant TPE material according to claim 1, characterized in that: The extender oil is selected from one or more of liquid paraffin, naphthenic oil and white oil.

7. The flame retardant TPE material according to claim 1, characterized in that: The inorganic filler is selected from one or more of talc powder, barium sulfate, calcium carbonate and mica powder; the particle diameter D50 of the inorganic filler is 1-2 μm.

8. The flame retardant TPE material according to claim 1, characterized in that: The coupling agent is selected from one or more of KH-550, KH-560, KH-570, KH-792 and KH-791.

9. The flame retardant TPE material according to claim 1, characterized in that: The antioxidant is selected from one or more of antioxidant 1010 , antioxidant 1076 , antioxidant 168 and antioxidant 1035 .

10. A method for preparing the flame-retardant TPE material according to any one of claims 1 to 9, characterized in that: The preparation method comprises the following steps: Step S1: accurately weighing styrene-based thermoplastic elastomer, polyolefin resin, filler oil, inorganic filler, flame retardant X, antioxidant, and coupling agent according to mass parts for later use; Step S2: putting the styrene-based thermoplastic elastomer and the filler oil into a low-speed mixer according to the formula ratio and stirring for 5 to 10 minutes, and standing for 5 to 10 hours before use, so that the styrene-based thermoplastic elastomer is fully filled with oil and swollen; Step S3: firstly, adding the oil-filled styrene thermoplastic elastomer, the polyolefin resin, the inorganic filler, the flame retardant X, the antioxidant, and the coupling agent into a high-speed mixer, and uniformly mixing them at a low speed of 400-600 r / min to obtain a premix; adding the premix into a twin-screw extruder, and obtaining a flame-retardant TPE material through melt extrusion and granulation, wherein the melt processing temperature of the twin-screw extruder is set as follows: 180° C. for zone 1, 190° C. for zone 2, 200° C. for zone 3, 200° C. for zone 4, 210° C. for zone 5, 210° C. for zone 6, 205° C. for zone 7, 200° C. for zone 8, 190° C. for zone 9, 190° C. for zone 10, 180° C. for zone 11, and a die head temperature of 180° C.; and the screw speed is 300-500 r / min.

Images