Polystyrene composite material as well as preparation method and application thereof

Abstract

The invention discloses a polystyrene composite material as well as a preparation method and application thereof. The polystyrene composite material comprises the following components in parts by weight: 30-70 parts of hydrogenated HIPS (High Impact Polystyrene) resin; 20 to 60 parts of PPE resin; 5 to 20 parts of a flame retardant; 2 to 10 parts of a toughening agent; the HIPS resin is hydrogenated HIPS resin in which a polybutadiene chain segment in a molecular structure is partially or completely hydrogenated into a polyethylene chain segment. According to the polystyrene composite material disclosed by the invention, an alloy material system formed by blending the hydrogenated HIPS resin and the PPE resin is adopted, so that the intrinsic flame retardance of the material is remarkably improved, the addition amount of the flame retardant and the organic filler can be effectively reduced on the premise of ensuring high flame retardance, and the toughness of the material is remarkably improved; meanwhile, a polyethylene chain segment formed by hydrogenation induces microcell crystallization, so that the rigidity of the composite material can be further improved, and the unification of high rigidity, high toughness and high flame retardance of the flame-retardant modified PS / PPE alloy is realized.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a polystyrene composite material, its preparation method, and its application. Background Technology

[0002] High-impact polystyrene (HIPS) is a commonly used polymer material in fields such as office equipment housings and household appliance components due to its excellent processing flow, good impact toughness, and cost-effectiveness. However, to obtain the required impact resistance, specific toughening components are introduced into the structural design of HIPS materials. While this structural design imparts good toughness, it objectively limits the improvement of its rigidity (modulus), thus restricting its application in applications requiring high structural strength. To compensate for the lack of rigidity in HIPS and improve the overall performance of the material, the existing technology widely adopts the strategy of blending HIPS with polyphenylene ether (PPE) to prepare PS / PPE alloys. PPE resin is known for its excellent rigidity, dimensional stability, heat resistance, and inherently low dielectric constant. By combining the high strength of PPE with the high toughness and processability of HIPS, PS / PPE alloys significantly improve the overall rigidity and heat resistance of the material while maintaining good molding and processing performance, thereby broadening its application range in high-performance applications (such as automotive parts and electronic and electrical components).

[0003] However, when PS / PPE alloys are applied to applications with stringent flame-retardant requirements (such as high-end electronic appliances, charging pile housings, and internal components of new energy vehicles), improving their flame-retardant performance faces significant challenges. This is primarily because HIPS is a relatively flammable material with a low limiting oxygen index (LOI), making it prone to melting and dripping during combustion. This characteristic makes it extremely difficult for the entire PS / PPE alloy system to achieve a high flame-retardant rating. To impart sufficient flame-retardant properties to PS / PPE alloys, a large amount of flame retardant is typically added to the system. Commonly used flame-retardant systems include bromine-antimony synergistic flame-retardant systems or phosphorus-nitrogen halogen-free flame retardants. However, the addition of a large amount of flame retardant severely interferes with the continuity of the matrix resin, significantly reducing the alloy's rigidity (modulus) and toughness (especially impact strength), thus disrupting the original balance of high strength and high toughness inherent in PS / PPE alloys.

[0004] Therefore, existing flame-retardant modified PS / PPE alloys generally face a key technical bottleneck: while pursuing high flame retardancy ratings, it is difficult to avoid a significant decline in the alloy's key mechanical properties (especially high rigidity and high toughness). This contradiction limits the application potential of PS / PPE alloys in higher-end fields with more stringent safety requirements. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a polystyrene composite material that has high rigidity, high toughness and high flame retardancy.

[0006] This invention is achieved through the following technical solution: A polystyrene composite material, comprising the following components by weight: 30-70 parts of hydrogenated HIPS resin; 20-60 parts of PPE resin; 5-20 parts flame retardant; Toughening agent 2-10 parts; The hydrogenated HIPS resin is an HIPS resin in which some or all of the polybutadiene segments in the molecular structure are hydrogenated into polyethylene segments.

[0007] Preferably, the degree of hydrogenation of the hydrogenated HIPS resin is 10%-100%; more preferably, it is 50%-80%.

[0008] This invention provides a method for testing the degree of hydrogenation: using deuterated chloroform as a solution, the change in double bond content before and after hydrogenation of the sample is measured by nuclear magnetic resonance, and the degree of hydrogenation is calculated by the rate of change of peak area. The determination of the degree of hydrogenation can be found in the literature "Determination of the Degree of Hydrogenation in Hydrogenated Nitrile-Butadiene Rubber (HNBR)".

[0009] The hydrogenated HIPS can be commercially available or prepared using existing technology. Preparation methods include, but are not limited to, the following: dissolving HIPS resin in cyclohexane solution, placing it in a high-pressure reactor, introducing hydrogen gas, reacting with a catalyst at 55-65°C for 50-100 minutes, distilling off excess solvent after the reaction, and extruding and granulating the resulting product to obtain hydrogenated HIPS resin. The desired degree of hydrogenation can be obtained by controlling conditions such as hydrogenation reaction time, reactor hydrogen pressure, and catalyst dosage.

[0010] Preferably, the mass-to-volume ratio (kg / L) of HIPS resin to cyclohexane is 1:(5-12), the filling coefficient of the high-pressure reactor is 0.25-0.5, and the hydrogen pressure ranges from 1 to 5 MPa; the amount of catalyst used is 0.1%-0.5% of the HIPS resin.

[0011] The catalyst is selected from at least one of organonitrile compounds and organoaluminum compounds; preferably, the catalyst is a compound catalyst of organonitrile compound and organoaluminum compound, and the compounding ratio is preferably 1:(5-10) by mass of organonitrile compound and organoaluminum compound.

[0012] Furthermore, the organonickel compound is preferably nickel carboxylate; the organoaluminum compound is preferably diisobutylaluminum.

[0013] The mass content of hydrogenated HIPS resin in the polystyrene composite material of the present invention is not less than 30%.

[0014] Preferably, the PPE resin has a melt index of 2-25 g / 10 min at 315°C and 10 kg.

[0015] Preferably, the mass ratio of the hydrogenated HIPS resin to the PPE resin is (0.25-4):1, and more preferably (1-2.5):1.

[0016] Preferably, the flame retardant includes a primary flame retardant and a synergistic flame retardant.

[0017] The main flame retardant is selected from brominated flame retardants, preferably at least one of brominated epoxy, brominated triazine, decabromodiphenyl ethane, brominated polystyrene, and octabromoether, and more preferably at least one of brominated triazine, brominated polystyrene, and octabromoether.

[0018] The preferred synergistic flame retardant is antimony trioxide.

[0019] The preferred mass ratio of the primary flame retardant to the synergistic flame retardant in the flame retardant is (1-4):1.

[0020] The flame retardant content in the polystyrene composite material of the present invention is 7%-13% by mass.

[0021] Preferably, the toughening agent is selected from hydrogenated styrene-butadiene block copolymer.

[0022] According to the material performance requirements, the polystyrene composite material of the present invention, by weight, further includes 0-10 parts of inorganic filler and 0-2 parts of additives. The weight parts of the inorganic filler can be 0 parts, 2 parts, 4 parts, 6 parts, 8 parts, or 10 parts, or specific values ​​between the above points; the weight parts of the additives can be 0 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, or 2.0 parts, or specific values ​​between the above points; preferably, 4-10 parts of inorganic filler and 0.1-2 parts of additives.

[0023] Preferably, the inorganic filler is selected from at least one of barium sulfate, talc, wollastonite, and mica.

[0024] Preferably, the additive is selected from at least one of lubricants and antioxidants. Suitable lubricants include, but are not limited to, silicone lubricants, ester lubricants, and amide lubricants. Suitable antioxidants include, but are not limited to, at least one of hindered phenolic antioxidants, phosphite antioxidants, or hindered amine light stabilizers; antioxidants can be used alone or in combination, for example, a composite antioxidant system composed of hindered phenolic antioxidants and phosphite antioxidants. This invention does not impose special requirements on the type and source of lubricants and antioxidants; those skilled in the art can select the types of lubricants and antioxidants to add according to actual needs.

[0025] The present invention also provides a method for preparing the above-mentioned polystyrene composite material, comprising the following steps: according to the formula, each component is added to a mixer and mixed evenly, and then melt-extruded and granulated by a twin-screw extruder at 230-280°C to prepare the polystyrene composite material.

[0026] This invention also provides the application of the above-mentioned polystyrene composite material in office equipment, electrical equipment, and security devices. Specifically, it is applicable to printers, scanners, meter boxes, electrical control boxes, smoke detectors, and surveillance cameras.

[0027] The present invention has the following beneficial effects: The polystyrene composite material of this invention employs an alloy system of hydrogenated HIPS resin and PPE resin blend, which significantly improves the intrinsic flame retardancy of the material. It effectively reduces the amount of flame retardant and organic filler added while maintaining high flame retardancy, preserving the integrity of the HIPS / PPE phase interface and significantly improving the material's toughness. Simultaneously, the partially hydrogenated polyethylene segments in the hydrogenated HIPS resin induce micro-crystallization, serving as physical cross-linking points, which further improves the rigidity of the composite material. This achieves a unified high rigidity, high toughness, and high flame retardancy in the flame-retardant modified PS / PPE alloy, effectively broadening the application fields of PS / PPE alloy materials. Detailed Implementation

[0028] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0029] The raw materials used in the embodiments and comparative examples of the present invention are described below, but are not limited to these materials: Hydrogenated HIPS Resin 1: The degree of hydrogenation is 80%. The preparation method is as follows: 1 kg of HIPS resin (PS 350K, Taiwan Guoqiao Chemical Co., Ltd.) is dissolved in 8 L of cyclohexane solution, placed in a high-pressure reactor, hydrogen gas is introduced, and the reaction is carried out at 60 °C using 2 g of nickel carboxylate / diisobutylaluminum composite catalyst (composite ratio of 1:5) for 90 minutes. After the reaction is completed, the excess solvent is evaporated under vacuum at 80 °C, and the granules are obtained by extrusion.

[0030] Hydrogenated HIPS resin 2: The degree of hydrogenation is 60%. The preparation method is as follows: 1 kg of HIPS resin (PS 350K, Taiwan Guoqiao Chemical) is dissolved in 8 L of cyclohexane solution, placed in a high-pressure reactor, hydrogen gas is introduced, and 2 g of nickel carboxylate / diisobutylaluminum composite catalyst (composite ratio of 1:5) is used at 60 °C for 70 minutes. After the reaction is completed, excess solvent is evaporated under vacuum at 80 °C, and the granules are obtained by extrusion to prepare hydrogenated HIPS resin.

[0031] Hydrogenated HIPS resin 3: The degree of hydrogenation is 30%. The preparation method is as follows: 1 kg of HIPS resin (PS 350K, Taiwan Guoqiao Chemical) is dissolved in 8 L of cyclohexane solution, placed in a high-pressure reactor, hydrogen gas is introduced, and 2 g of nickel carboxylate / diisobutylaluminum composite catalyst (composite ratio of 1:5) is used at 60 °C for 60 minutes. After the reaction is completed, excess solvent is evaporated under vacuum at 80 °C, and the granules are obtained by extrusion. Hydrogenated HIPS resin is prepared.

[0032] Hydrogenated HIPS resin 4: The degree of hydrogenation is 100%. The preparation method is as follows: 1 kg of HIPS resin (PS 350K, Taiwan Guoqiao Chemical Co., Ltd.) is dissolved in 8 L of cyclohexane solution, placed in a high-pressure reactor, hydrogen gas is introduced, and the reaction is carried out at 60 °C using 2 g of nickel carboxylate / diisobutylaluminum composite catalyst (composite ratio of 1:5) for 100 minutes. After the reaction is completed, the excess solvent is evaporated under vacuum at 80 °C, and the hydrogenated HIPS resin is obtained by extrusion granulation through an extruder.

[0033] HIPS Resin 5: PS 350K, from Taiwan's Kuo Chiao Chemical Co., Ltd.

[0034] PPE resin 1: Melt index of 10g / 10min at 315℃ and 10kg, PPE LXR 045, Nantong Xingchen Synthetic Materials Co., Ltd.; PPE resin 2: Melt index of 30g / 10min at 315℃ and 10kg, PPE LXR 040, Nantong Xingchen Synthetic Materials Co., Ltd. Flame retardant 1: Main flame retardant, brominated triazine, FR-245, Israel Chemicals; Flame retardant 2: Synergistic flame retardant, antimony trioxide, S-12N, Guangzhou Shanxing Antimony Industry Co., Ltd.; Toughening agent 1: Hydrogenated styrene-butadiene block copolymer, SEBS 7553, Lee Chang Yung Chemical Industry Co., Ltd.; Toughening agent 2: Styrene-butadiene block copolymer, SBS 8036, Guangdong Zhonghe High-tech Technology Co., Ltd.; Toughening agent 3: Thermoplastic polyurethane elastomer, TPU E180, Meiri New Materials Co., Ltd.; Inorganic filler: Barium sulfate, Qingdao Dongfeng Chemical Co., Ltd.; Additives: Amide lubricant, EBS B50, Guangzhou Runfeng Chemical.

[0035] Preparation methods of polystyrene composite materials in the examples and comparative examples: According to the formula, the components are added to the mixer and mixed evenly. Then, the mixture is melt-extruded and granulated through a twin-screw extruder. The screw temperature is set as follows: Zone 1: 230℃, Zone 2: 250℃, Zone 3: 255℃, Zone 4: 265℃, Zone 5: 275℃, Zone 6: 275℃, Zone 7: 280℃, Zone 8: 280℃; Die temperature: 270℃, Rotation speed: 300r / min, Feed rate: 50kg / h. Polystyrene composite material is then prepared.

[0036] Relevant performance testing methods: (1) Bending modulus: According to standard ISO 178:2001, standard specimen: length: 80mm, width: 10.0mm, thickness: 4.0mm; test conditions 2mm / min, unit: MPa.

[0037] (2) Notched impact strength: ISO 180:2000, standard specimen: length: 80mm, width: 10.0mm, thickness: 4.0mm, unit: kJ / m 2 .

[0038] (3) Flame retardant performance: UL94 standard, sample thickness 1.6mm.

[0039] Table 1: Distribution ratios (by weight) and related performance test results for each group in Examples 1-10 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Hydrogenated HIPS Resin 1 55 45 60 30 65 56 Hydrogenated HIPS resin 2 55 55 Hydrogenated HIPS resin 3 55 Hydrogenated HIPS Resin 4 55 PPE resin 1 30 40 25 55 20 25 30 30 30 PPE resin 2 30 Flame retardant 1 6 6 6 6 6 8 5 6 6 6 Flame retardant 2 4 4 4 4 4 5 3 4 4 4 Toughening agent 1 4 4 4 4 4 8 6 4 4 4 Inorganic packing 4 Additives 1 1 1 1 1 1 1 1 1 Flexural modulus 4100 3920 4340 3810 4450 4270 4180 4020 3890 4400 Notched impact strength 13.0 13.5 12.0 14.1 11.7 12.3 14.6 13.5 13.9 11.3 Flame retardant properties V-0 V-0 V-0 V-0 V-0 V-0 V-1 V-0 V-1 V-0 Table 2: Distribution ratios (by weight) and related performance test results for each group in Comparative Examples 1-5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Hydrogenated HIPS Resin 1 55 55 HIPS resin 5 55 55 56 PPE resin 1 30 25 30 30 PPE resin 2 30 Flame retardant 1 6 8 5 6 6 Flame retardant 2 4 5 3 4 4 Toughening agent 1 4 8 6 Toughening agent 2 4 Toughening agent 3 4 Inorganic packing 4 Additives 1 1 1 1 Flexural modulus 3000 3230 2840 4010 3860 Notched impact strength 14.6 13.1 14.9 10.7 9.2 Flame retardant properties Unqualified V-1 Unqualified V-0 V-0 As can be seen from the above examples and comparative results, the polystyrene composite material of the present invention, using an alloy material system of hydrogenated HIPS resin and PPE resin blend, significantly improves the intrinsic flame retardancy of the material. It can effectively reduce the amount of flame retardant and organic filler added while ensuring high flame retardancy, thus significantly improving the material's toughness. Simultaneously, the polyethylene segments formed by hydrogenation induce micro-crystallization, which further improves the rigidity of the composite material, thereby achieving both high rigidity (flexural modulus ≥ 3800 MPa) and high toughness (notched impact strength ≥ 11 kJ / m²). 2 Polystyrene composites with high flame retardancy (1.6mm V-1 rating or higher).

[0040] As can be seen from the comparison of Examples 1 / 2 / 3 / 4 / 5, the preferred mass ratio of hydrogenated HIPS resin to PPE resin is (1-2.5):1. Within this ratio range, a better balance can be achieved between the rigidity and toughness of the material.

[0041] As can be seen from the comparison of Examples 1 / 8 / 9 / 10, the hydrogenation degree of hydrogenated HIPS resin is preferably 50%-80%. By selecting a suitable degree of hydrogenation, the material can achieve high rigidity and toughness, while also taking into account high flame retardancy.

[0042] Comparative Examples 1 / 2 / 3, using unhydrogenated HIPS resin, showed a significant decrease in material rigidity and failed to achieve the required flame retardant performance at lower flame retardant contents.

[0043] Comparative examples 4 / 5, using SBS or TPU toughening agents, showed low compatibility of the material system, poor toughening effect, and reduced material rigidity and toughness.

Claims

1. A polystyrene composite material, characterized in that, By weight, it includes the following components: 30-70 parts of hydrogenated HIPS resin; 20-60 parts of PPE resin; 5-20 parts flame retardant; Toughening agent 2-10 parts; The hydrogenated HIPS resin is an HIPS resin in which some or all of the polybutadiene segments in the molecular structure are hydrogenated into polyethylene segments.

2. The polystyrene composite material according to claim 1, characterized in that, The degree of hydrogenation of the hydrogenated HIPS resin is 10%-100%; preferably 50%-80%.

3. The polystyrene composite material according to claim 1, characterized in that, The PPE resin has a melt index of 2-100 g / 10 min at 315°C and 10 kg, preferably 10-50 g / 10 min.

4. The polystyrene composite material according to claim 1, characterized in that, The mass ratio of hydrogenated HIPS resin to PPE resin is (0.25-4):1, preferably (1-2.5):

1.

5. The polystyrene composite material according to claim 1, characterized in that, The flame retardant includes a primary flame retardant and a synergistic flame retardant; the primary flame retardant is selected from at least one of brominated epoxy, brominated triazine, decabromodiphenyl ethane, brominated polystyrene, tetrabromobisphenol A, and octabromoether, preferably at least one of brominated triazine, brominated polystyrene, and octabromoether; the synergistic flame retardant is selected from antimony trioxide.

6. The polystyrene composite material according to claim 5, characterized in that, The mass ratio of the primary flame retardant to the synergistic flame retardant in the flame retardant is (1-4):

1.

7. The polystyrene composite material according to claim 1, characterized in that, The toughening agent is selected from hydrogenated styrene-butadiene block copolymer.

8. The polystyrene composite material according to claim 1, characterized in that, The product, by weight, also includes 0-10 parts inorganic filler and 0-2 parts additives; preferably 4-10 parts inorganic filler and 0.1-2 parts additives; the inorganic filler is selected from at least one of barium sulfate, talc, wollastonite, and mica; the additives are selected from at least one of antioxidants or lubricants.

9. A method for preparing the polystyrene composite material according to any one of claims 1-8, characterized in that, The process includes the following steps: according to the formula, each component is added to a mixer and mixed evenly, and then melt-extruded and granulated at 230-280℃ using a twin-screw extruder to prepare a polystyrene composite material.

10. The use of the polystyrene composite material according to any one of claims 1-8 in office equipment, electrical equipment or security devices.