Flame-retardant HIPS (high impact polystyrene) composite material as well as preparation method and application thereof

Abstract

The invention discloses a flame-retardant HIPS (High Impact Polystyrene) composite material as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The flame-retardant HIPS composite material provided by the invention is prepared from the following components in parts by mass: 38 to 62 parts of GPPS resin, 12 to 28 parts of SEBS rubber, 5 to 15 parts of potassium titanate fiber, 12 to 19 parts of brominated flame retardant, 2.5 to 4 parts of antimony flame retardant and 1 to 7 parts of compatilizer. The average diameter of the potassium titanate fiber is 0.1 to 0.6 mu m; the compatilizer comprises SEBS (styrene-ethylene-butylene-styrene) grafted maleic anhydride. The flame-retardant HIPS composite material provided by the invention still has good rigidity and toughness when being prepared into a thin-wall product, and has excellent flame retardance, and the flame-retardant grade can reach 5VA grade.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and in particular relates to a flame-retardant HIPS composite material and a preparation method and application thereof. Background Art

[0002] Currently, in response to low-carbon and environmental policies and aesthetically pleasing designs, thinner-walled components have become a key development trend for many products, such as televisions and printers. Thinner-walled components are more susceptible to fires caused by heat exposure, placing higher demands on the material's flame retardancy. A 5VA flame retardancy rating, higher than V0, can better meet the fire protection requirements of thinner-walled products.

[0003] GPPS, or general-purpose polystyrene, has high rigidity, high gloss, high fluidity and dimensional stability. However, GPPS has poor toughness, which limits its application in product fields with high toughness requirements. Currently, a widely used method to address the defect of GPPS's poor toughness is to toughen and modify GPPS by adding rubber to prepare high-impact polystyrene (HIPS). However, the oxygen index of HIPS is only 18, which is a flammable material. It is usually necessary to add bromine antimony flame retardant to modify it into flame-retardant HIPS with a V0 flame retardant grade before it can be used in product fields with fire protection requirements. A Chinese patent (CN 112745591B) discloses a flame-retardant high-rigidity PS / PPE composite material and its preparation. The solution uses alloying, bromine-based flame retardant and glass fiber compounding to achieve a 5VA flame retardant grade, but the addition of glass fiber will bring about the appearance problem of floating fiber and deterioration of toughness.

[0004] Currently, most flame-retardant HIPS material options are V0 flame-retardant grade, with a limited number achieving 2.0mm 5VA. With the trend toward thinner-walled products (1.5-2.0mm), the flame-retardant HIPS requirements are also becoming thinner. Furthermore, thinner products also place higher demands on the material's toughness and rigidity. Therefore, developing a 2.0mm 5VA flame-retardant HIPS material that combines both high rigidity and toughness is of great significance. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a flame-retardant HIPS composite material having an excellent 5VA flame retardant grade and excellent toughness and rigidity when preparing thin-walled products (thickness of 1.5-2.0 mm), as well as a preparation method and application thereof.

[0006] To achieve the above objectives, in a first aspect of the present invention, the present invention provides a flame-retardant HIPS composite material, wherein the flame-retardant HIPS composite material comprises the following components in parts by weight:

[0007] 38-62 parts of GPPS resin, 12-28 parts of SEBS rubber, 5-15 parts of potassium titanate fiber, 12-19 parts of brominated flame retardant, 2.5-4 parts of antimony flame retardant, 1-7 parts of compatibilizer;

[0008] The average diameter of the potassium titanate fiber is 0.1-0.6 μm;

[0009] The compatibilizer includes SEBS grafted with maleic anhydride.

[0010] The flame-retardant HIPS composite material provided by the present invention is compounded by selecting components in appropriate weight proportions, and the components have excellent comprehensive effects. The flame-retardant HIPS composite material prepared still has good rigidity and toughness when prepared into thin-walled products, and has excellent flame retardancy. When prepared into thin-walled parts, the flame retardancy grade can reach 5VA level.

[0011] Specifically, in the first aspect, GPPS resin is used as the matrix resin, and potassium titanate fibers of suitable mass parts and suitable average diameter range are added thereto. It can not only play the role of fiber reinforcement by forming an inorganic skeleton, but also effectively improve the flame retardancy and rigidity of the product. At the same time, under the action of SEBS rubber and compatibilizer, it has good compatibility with GPPS resin, which can effectively ensure that the prepared product also has excellent toughness. In the second aspect, SEBS rubber is not sensitive to temperature during processing. When SEBS rubber of suitable mass parts is added to GPPS resin, it can play the role of mutual penetration of entangled segments, form a network structure, improve the melt strength of the product, thereby reducing the risk of burn-through and dripping, and then effectively improve the flame retardancy of the product, reaching the 5VA flame retardant grade of thin-walled products. In addition, it can also effectively improve the toughness of the product and achieve the effect of excellent rigid-tough balance of the product. In the third aspect, the present invention selects SEBS grafted maleic anhydride as a compatibilizer to effectively improve the compatibility of GPPS resin and potassium titanate fiber, which is beneficial for potassium titanate fiber to fully play its role, and at the same time, cooperates with SEBS rubber to effectively improve the rigid-tough balance and flame retardancy of the product. Fourthly, the present invention selects appropriate amounts of brominated flame retardants and antimony flame retardants by weight, and the two flame retardants work together to achieve good flame retardancy in the system of the present invention.

[0012] For example, the HIPS resin may be any point value or any two point range value between 38-62 parts, such as 40-60 parts, or 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, etc.; the SEBS rubber may be any point value or any two point range value between 12-28 parts, such as 15-25 parts, or 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, etc.; the potassium titanate fiber may be any point value or any two point range value between 5-15 parts, such as 7-13 parts, or The content of the brominated flame retardant can be any point value or any two-point range value between 12-19 parts, such as 14-18 parts, or 12 parts, 14 parts, 16 parts, 18 parts, 19 parts, etc.; the content of the antimony flame retardant can be any point value or any two-point range value between 2.5-4 parts, such as 2.8-3.6 parts, or 2.5 parts, 3 parts, 3.5 parts, 4 parts, etc.; the content of the compatibilizer can be any point value or any two-point range value between 1-7 parts, such as 2-5 parts, or 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, etc.

[0013] Preferably, in the flame-retardant HIPS composite material, the mass percentage of GPPS resin is ≥34%.

[0014] More preferably, in the flame-retardant HIPS composite material, the mass percentage of GPPS resin is 40-55%.

[0015] It should be noted that the average diameter of the potassium titanate fibers is obtained through scanning electron microscopy.

[0016] Exemplarily, the average diameter of the potassium titanate fiber may be any point value or any two point range values between 0.1-0.6 μm, such as 0.2-0.5 μm, 0.2-0.35 μm, 0.35-0.5 μm, or 0.1 μm, 0.15 μm, 0.2 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.45 μm, 0.5 μm, 0.55 μm, 0.6 μm, etc.

[0017] Preferably, the average diameter of the potassium titanate fibers is 0.3-0.4 μm.

[0018] The present invention found that the average diameter of potassium titanate fibers affects their compatibility in the GPPS resin matrix. When the average diameter of potassium titanate fibers is reduced to a certain extent, the toughness of the resulting product will be better, but due to the weakening of the reinforcement effect, the rigidity and flame retardancy of the resulting product will show a downward trend to a certain extent; conversely, when the average diameter of potassium titanate fibers is increased to a certain extent, the toughness of the resulting product will decrease. Therefore, when the average diameter of potassium titanate fibers is further selected to be 0.3-0.4μm, the resulting product has a higher flame retardant grade and better rigidity and toughness.

[0019] As a preferred embodiment of the flame-retardant HIPS composite material of the present invention, the average length of the potassium titanate fibers in the flame-retardant HIPS composite material is 3-8 μm.

[0020] It should be noted that the average length of the potassium titanate fibers in the flame-retardant HIPS composite material is measured by burning the flame-retardant HIPS composite material into ash and then observing under a microscope.

[0021] As a preferred embodiment of the flame-retardant HIPS composite material of the present invention, the flame-retardant HIPS composite material includes the following components in parts by mass: 50-55 parts of GPPS resin, 18-20 parts of SEBS rubber, 8-10 parts of potassium titanate fiber, 15-16 parts of brominated flame retardant, 3-4 parts of antimony flame retardant, and 4-5 parts of compatibilizer.

[0022] The present invention has found that the mass fraction of the components in the flame-retardant HIPS composite material will affect the comprehensive performance of the product. When the mass fraction of the components is further selected to be within the above range, the comprehensive performance of the obtained product is better.

[0023] As a preferred embodiment of the flame-retardant HIPS composite material of the present invention, the melt index of the GPPS resin at 220° C. / 10 kg is 25-105 g / min.

[0024] It should be noted that the melt index of the GPPS resin is obtained by referring to ISO 1133-1:2022 Plastics. Thermoplastic melt mass flow rate test, and the test conditions are 220°C / 10kg.

[0025] Exemplarily, the melt index of the GPPS resin may be any point value or any two point range value between 25-105 g / min, such as 32-97 g / 10min, 32-56 g / 10min, 56-97 g / 10min, etc., or may be 25 g / 10min, 35 g / 10min, 45 g / 10min, 55 g / 10min, 65 g / 10min, 75 g / 10min, 85 g / 10min, 95 g / 10min, 105 g / 10min, etc.

[0026] The present invention has found that the melt index of GPPS resin not only affects the melt strength of the product, but also affects its wetting effect on potassium titanate fiber; when the melt index of GPPS resin is further selected to be between 25-105g / min, the overall effect of the obtained product is better.

[0027] As a preferred embodiment of the flame-retardant HIPS composite material of the present invention, the mass percentage of styrene in the SEBS rubber is 18-45%.

[0028] It should be noted that the mass percentage of styrene in the SEBS rubber is obtained by measuring the bound styrene in styrene-butadiene rubber using a refractive index method (ASTM D5775-95:2023).

[0029] Exemplarily, in the SEBS rubber, the mass percentage of styrene can be any point value or any two point range values between 18-45%, such as 20-42%, 20-32%, 32-42%, etc., or can be 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, etc.

[0030] The present invention has found that the mass percentage of styrene in SEBS rubber affects its ability to toughen and form an entangled network structure, thereby affecting the flame retardancy and toughness of the SEBS rubber for the product. When the mass percentage of styrene in the SEBS rubber is further selected within the above range, the overall performance of the obtained product is better.

[0031] As a preferred embodiment of the flame-retardant HIPS composite material of the present invention, the grafting rate of SEBS grafted with maleic anhydride is 0.8-2.2%.

[0032] It should be noted that the grafting rate of SEBS grafted with maleic anhydride is obtained by testing using an acid-base titration method.

[0033] Exemplarily, the grafting rate of the SEBS grafted maleic anhydride can be any point value or any two point range values between 0.8-2.2%, such as 1-2%, 1-1.6%, 1.6-5%, etc., or can be 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, etc.

[0034] The present invention has found that the grafting rate of SEBS grafted maleic anhydride affects its compatibility between GPPS resin and potassium titanate fiber. When the grafting rate of SEBS grafted maleic anhydride is further selected to be within the above range, the comprehensive effect of the obtained product is better.

[0035] As a preferred embodiment of the flame-retardant HIPS composite material of the present invention, the brominated flame retardant includes at least one of tris(tribromophenoxy)triazine, brominated epoxy, decabromodiphenylethane, brominated polyimide, brominated polystyrene, polybrominated polystyrene, brominated polycarbonate and brominated polyacrylate.

[0036] As a preferred embodiment of the flame-retardant HIPS composite material of the present invention, the antimony-based flame retardant includes antimony trioxide.

[0037] As a preferred embodiment of the flame-retardant HIPS composite material of the present invention, the flame-retardant HIPS composite material further comprises 0.1-1 parts of an antioxidant and 0.1-1 parts of a lubricant.

[0038] Illustratively, the antioxidant includes at least one of a hindered phenol antioxidant, a hindered amine antioxidant, and a phosphite antioxidant.

[0039] Illustratively, the lubricant includes at least one of a stearamide lubricant and a zinc stearate lubricant.

[0040] In a second aspect of the present invention, the present invention provides a method for preparing the flame-retardant HIPS composite material, which comprises the following steps: mixing the components uniformly and then melt-extruding to obtain the flame-retardant HIPS composite material.

[0041] As a preferred embodiment of the preparation method of the present invention, the temperature of the melt extrusion is 180-200° C. and the rotation speed is 200-300 rpm.

[0042] In a third aspect of the present invention, the present invention provides use of the flame-retardant HIPS composite material in preparing flame-retardant thin-walled parts.

[0043] For example, the flame-retardant HIPS composite material is used in the preparation of thin-walled TV front frames and air-conditioning electronic control boxes.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The flame-retardant HIPS composite material provided by the present invention is prepared by selecting appropriate components by weight and ensuring synergy between the components. The resulting flame-retardant HIPS composite material maintains good rigidity and toughness when fabricated into thin-walled products, and exhibits excellent flame retardancy, with a flame retardancy rating of up to 5VA. Furthermore, the preparation method of the flame-retardant HIPS composite material provided by the present invention is simple to operate, making it suitable for practical production. DETAILED DESCRIPTION

[0046] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0047] Unless otherwise specified, the reagents, methods, and equipment used in the present invention are all conventional reagents, methods, and equipment in the art; and unless otherwise specified, the raw materials used in parallel experiments are from the same batch of raw materials.

[0048] GPPS-1: GPPS-500NT, melt index 56g / 10min, PetroChina Dushanzi Petrochemical Company;

[0049] GPPS-2: 818K, melt index 32g / 10min, Delta Chemical Co., Ltd.

[0050] GPPS-3: GPPS123P, melt index 97g / 10min, Shanghai Secco Petrochemical Co., Ltd.

[0051] SEBS-1: SEBS 6151, 32% styrene by mass, Taiwan Rubber Corporation;

[0052] SEBS-2: H1052, styrene mass percentage is 20%, Asahi Kasei Co., Ltd., Japan;

[0053] SEBS-3: H1051, 42% styrene by mass, Asahi Kasei Co., Ltd., Japan;

[0054] SBS: SBS YH-791E, 30% styrene by mass, from Sinopec Baling Petrochemical Company;

[0055] Potassium titanate fiber 1: P791970, average diameter 0.35 μm, Shanghai MacLean Biochemical Technology Co., Ltd.;

[0056] Potassium titanate fiber 2: P790560, average diameter 0.20 μm, Shanghai MacLean Biochemical Technology Co., Ltd.;

[0057] Potassium titanate fiber 3: TISMO D, average diameter 0.50 μm, Otsuka Chemical Co., Ltd.

[0058] Potassium titanate fiber 4: N790558, average diameter 0.04 μm, Shanghai MacLean Biochemical Technology Co., Ltd.

[0059] Potassium titanate fiber 5: K2TiO3, average diameter 0.90 μm, Shanghai Dianyang Industrial Co., Ltd.

[0060] Brominated flame retardant 1: FR-245, brominated triazine, commercially available;

[0061] Brominated flame retardant 2: F-3014, brominated epoxy, commercially available;

[0062] Antimony flame retardant: S-05N, antimony trioxide, commercially available;

[0063] Compatibilizer 1: SEBS grafted with maleic anhydride, SEBS 7131, maleic anhydride grafting rate 1.6%, TSRC;

[0064] Compatibilizer 2: SEBS grafted with maleic anhydride, SEBS MD6684, maleic anhydride grafting rate 1.0%, Kraton, USA;

[0065] Compatibilizer 3: SEBS grafted maleic anhydride TAIPOL 7126, maleic anhydride grafting rate 2.0%, TSRC;

[0066] Compatibilizer 4: methyl methacrylate-butadiene-styrene copolymer (MBS), M-521, Kaneka Chemical Co., Ltd., Japan;

[0067] Antioxidant: a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1, where antioxidant 1010 and antioxidant 168 are commercially available products;

[0068] Lubricant: Stearic acid amide lubricant, commercially available.

[0069] Examples 1-11 and Comparative Examples 1-8

[0070] The embodiments and comparative examples of the present invention provide a flame-retardant HIPS composite material. The component contents (parts by weight) of the flame-retardant HIPS composite material are shown in Table 1-2.

[0071] Table 1

[0072]

[0073] Table 2

[0074]

[0075] The preparation method of the flame-retardant HIPS composite material provided in Example 1 is:

[0076] The components were mixed evenly and then melt-extruded to obtain a flame-retardant HIPS composite material; wherein, the temperatures of each zone of melt extrusion were 180°C, 190°C, 190°C, 190°C, 195°C, 195°C, and 200°C, respectively, the screw speed was 250 r / min, and the screw aspect ratio was 55:1.

[0077] The preparation methods of the flame-retardant HIPS composite materials provided in Examples 2-11 and Comparative Examples 1-8 are consistent with that in Example 1, except that no relevant components are added.

[0078] It should be noted that the average length of the potassium titanate fibers in the flame-retardant HIPS composite materials prepared in the examples and comparative examples is 4-7 μm, which is not very different and will not be listed one by one.

[0079] Effect Examples

[0080] The present invention verifies the performance of the flame-retardant HIPS composite material prepared in the examples and comparative examples; including the following aspects:

[0081] 1. Flame retardancy test: The test standard refers to "UL 94-2018 Tests for Flammability of Materials for Equipment and Appliance Components". The thickness of the burning sample includes three thickness levels: 1.5mm, 2.0mm, and 2.5mm. Among them, 1.5mm and 2mm are the thickness levels of thin-walled products;

[0082] 2. Flexural modulus (rigidity): Refer to ISO 178-2010 Plastics — Determination of flexural properties;

[0083] 3. Izod notched impact strength (toughness): The standard refers to "ISO 180-2000 Plastics - Determination of Izod impact strength", and the notch type is A-type notch;

[0084] The test results are shown in Table 3;

[0085] Table 3

[0086]

[0087] As can be seen from Table 3, when the technical solution provided by the present invention is adopted, the obtained products have good flame retardancy, as well as excellent rigidity and toughness; specifically, the obtained products can meet the 2.0mm5VA flame retardant grade, and some can meet the 1.5mm5VA flame retardant grade. The flexural modulus of the obtained products is above 2845MPa, and the notched cantilever impact strength is above 7.0kJ / m 2 above;

[0088] It can be seen from Example 1, Examples 10-11, and Comparative Example 1 that the type of compatibilizer used in the present invention affects the overall performance of the product. When the compatibilizer used in Comparative Example 1 is not the SEBS grafted maleic anhydride of the present invention, the flame retardancy of the obtained product decreases, and the 5VA flame retardancy of the thin-walled product cannot be achieved, and only 2.5mm 5VA flame retardancy can be achieved. In addition, the notched Izod impact strength of the obtained product also shows a significant downward trend. It can be seen from Example 1 and Comparative Example 4 that when no compatibilizer is added, the flame retardancy of the obtained product decreases significantly, and the 5VA flame retardancy of the thin-walled product cannot be achieved. The notched Izod impact strength of the product also shows a significant downward trend.

[0089] It can be seen from Examples 1-3, Comparative Examples 2-3, and Comparative Example 5 that the mass fraction of a component affects the overall performance of the product. When the amount of SEBS rubber added in Comparative Example 2 is too low, the flame retardant grade of the resulting product is significantly reduced, and the 5VA flame retardant grade of the thin-walled product cannot be achieved, and the notched Izod impact strength of the product also shows a significant downward trend. When the amount of SEBS rubber added in Comparative Example 3 is too much, the flame retardant grade of the resulting product is significantly reduced, and the 5VA flame retardant grade of the thin-walled product cannot be achieved, and the flexural modulus of the product also shows a certain downward trend. When the compatibilizer is added in Comparative Example 5 too much, the flame retardant grade of the resulting product is significantly reduced, and the 5VA flame retardant grade of the thin-walled product cannot be achieved.

[0090] It can be seen from Example 1, Examples 8-9, and Comparative Examples 6-7 that the average diameter of the potassium titanate fibers used will affect the overall performance of the product. When the average diameter of the potassium titanate fibers in Comparative Example 6 is too small, the flame retardancy of the obtained product is significantly reduced, and the 5VA flame retardancy of the thin-walled product cannot be achieved. When the average diameter of the potassium titanate fibers in Comparative Example 7 is too large, the Izod notched impact strength of the obtained product is significantly reduced.

[0091] It can be seen from Example 1 and Comparative Example 8 that when SBS is used instead of SEBS, the flame retardancy of the obtained product is significantly reduced, and the 5VA flame retardancy of the thin-walled product cannot be achieved. In addition, the notched Izod impact strength of the product also shows a certain downward trend.

[0092] Finally, it should be noted that the above embodiments are intended to illustrate the technical solutions of the present invention rather than 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 the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A flame retardant HIPS composite material, characterized in that: The flame retardant HIPS composite material comprises the following components in parts by mass: 38-62 parts of GPPS resin, 12-28 parts of SEBS rubber, 5-15 parts of potassium titanate fiber, 12-19 parts of brominated flame retardant, 2.5-4 parts of antimony flame retardant, 1-7 parts of compatibilizer; The average diameter of the potassium titanate fiber is 0.1-0.6 μm; The compatibilizer includes SEBS grafted with maleic anhydride.

2. The flame-retardant HIPS composite material according to claim 1, characterized in that: The flame-retardant HIPS composite material comprises the following components in parts by mass: 50-55 parts of GPPS resin, 18-20 parts of SEBS rubber, 8-10 parts of potassium titanate fiber, 15-16 parts of brominated flame retardant, 3-4 parts of antimony flame retardant, and 4-5 parts of compatibilizer.

3. The flame-retardant HIPS composite material according to claim 1, characterized in that: The GPPS resin has a melt index of 25-105 g / min at 220° C. / 10 kg.

4. The flame-retardant HIPS composite material according to claim 1, characterized in that: The mass percentage of styrene in the SEBS rubber is 18-45%.

5. The flame-retardant HIPS composite material according to claim 1, characterized in that: The grafting rate of the SEBS grafted with maleic anhydride is 0.8-2.2%.

6. The flame-retardant HIPS composite material according to claim 1, characterized in that: The brominated flame retardant includes at least one of tris(tribromophenoxy)triazine, brominated epoxy, decabromodiphenylethane, brominated polyimide, brominated polystyrene, polybrominated styrene, brominated polycarbonate and brominated polyacrylate; And / or, the antimony-based flame retardant includes antimony trioxide.

7. The flame-retardant HIPS composite material according to claim 1, characterized in that: The flame retardant HIPS composite material further comprises 0.1-1 parts of antioxidant and 0.1-1 parts of lubricant.

8. The method for preparing the flame-retardant HIPS composite material according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: mixing the components uniformly and then melting and extruding them to obtain a flame-retardant HIPS composite material.

9. Use of the flame-retardant HIPS composite material according to any one of claims 1 to 7 in the preparation of flame-retardant thin-walled parts.

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