A polystyrene material and its preparation method and application

Abstract

The invention discloses a polystyrene material and a preparation method and application thereof, belonging to the technical field of polymer materials. The polystyrene material comprises the following components by weight: 50 to 85 parts of polystyrene resin; 10 to 40 parts of high-flow polystyrene resin; 3 to 12 parts of styrene-butadiene-styrene block copolymer; 0 to 10 parts of filler; 0.5 to 5 parts of lubricant; 0.1 to 2 parts of processing aid; the melt mass flow rate of the polystyrene resin is 1 to 4 g / 10 min, the melt mass flow rate of the high-flow polystyrene resin is 5 to 10 g / 10 min, the test standard is ISO 1133-2011, and the test conditions are 200°C and 5 kg. The polystyrene material of the invention has high fluidity while satisfying the requirement that the material has high toughness, and can also effectively reduce the flow marks of the polystyrene material, so that the polystyrene material has high performance and good appearance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and more specifically, to a polystyrene material and a preparation method and application thereof. Background Art

[0002] High impact polystyrene (HIPS) is a thermoplastic material made of elastomer-modified polystyrene. The two-phase system consisting of a rubber phase and a continuous polystyrene phase has developed into an important polymer commodity in the world. This general product has a wide range of impact properties and processing properties, making it widely used in the automotive, appliance, electrical products, furniture, household appliances, telecommunications, electronics, computers, disposables, medicine, packaging and entertainment markets.

[0003] When PS materials are recycled, their impact properties are significantly reduced due to the breakage of molecular chains or the failure of their toughening system. Therefore, toughening agents are often added to reinforce and improve the performance of the materials when they are recycled. However, the addition of toughening agents often leads to reduced fluidity of the modified materials and increased viscoelasticity of the materials, which in turn leads to flow marks. In particular, PS materials used to prepare televisions and liquid crystal displays cannot simultaneously guarantee high performance, high fluidity, and low flow marks due to the large product volume.

[0004] The prior art discloses a polystyrene toughening material, comprising polystyrene, a polyethylene toughening agent, a compatibilizer, polyvinyl butyral and an antioxidant. Although the polystyrene toughening material improves the tensile strength, tensile strength and aging resistance of the polystyrene material, it does not solve the problem of high flow marks caused by the large amount of toughening agent added. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defects and shortcomings of existing polystyrene materials that cannot take into account high performance, high fluidity and low flow marks, and to provide a polystyrene material that, through the synergistic effect of a lubricant and a high-flow polystyrene resin, satisfies the requirement that the material has high toughness while also having high fluidity and can effectively reduce the flow marks of the polystyrene material, so that the polystyrene material has high performance and good appearance.

[0006] Another object of the present invention is to provide a method for preparing a polystyrene material.

[0007] Another object of the present invention is to provide an application of a polystyrene material in preparing a television set and a liquid crystal display housing.

[0008] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0009] A polystyrene material, comprising the following components by weight:

[0010]

[0011] Among them, the melt mass flow rate of polystyrene resin is 1-4 g / 10 min, the melt mass flow rate of high flow polystyrene resin is 5-10 g / 10 min, the test standard is ISO 1133-2021, and the test conditions are 200°C and 5 kg;

[0012] The styrene-butadiene-styrene block copolymer includes a first styrene-butadiene-styrene block copolymer and a second styrene-butadiene-styrene block copolymer, wherein the oil content of the first styrene-butadiene-styrene block copolymer is 0%; the oil content of the second styrene-butadiene-styrene block copolymer is 20-50%; the mass ratio of the first styrene-butadiene-styrene block copolymer to the second styrene-butadiene-styrene block copolymer is (0.2-1):1.

[0013] The oil content is tested by thermogravimetric (TG) analysis of styrene-butadiene-styrene block copolymers, and the weight lost within 215-300°C is the oil content.

[0014] It should be noted that:

[0015] The optimized synergistic effect of the polystyrene material lubricant, high-flow polystyrene resin and styrene-butadiene-styrene block copolymer of the present invention can satisfy the requirement that the material has high toughness and high flowability while effectively reducing the flow marks of the polystyrene material, thereby making the polystyrene material have high performance and good appearance.

[0016] The mechanism of action of each component of the polystyrene material of the present invention is as follows:

[0017] Styrene-butadiene-styrene block copolymer (SBS) can significantly improve the toughness of polystyrene resin and increase the impact strength of the material.

[0018] Among them, although the first styrene-butadiene-styrene block copolymer can significantly improve the impact strength of the system, it can also reduce the fluidity of the system.

[0019] In order to reduce the effect of the first styrene-butadiene-styrene block copolymer on the fluidity of the system, the fluidity of the system is improved by the second styrene-butadiene-styrene block copolymer. However, if the oil content of the second styrene-butadiene-styrene block copolymer is too high, the tensile strength and flexural modulus of the material will be significantly reduced.

[0020] Therefore, the present invention improves the impact strength, fluidity, tensile strength and flexural modulus of the system at the same time by controlling the relative content of the first styrene-butadiene-styrene block copolymer and the second styrene-butadiene-styrene block copolymer.

[0021] In order to meet the requirements of material toughness, styrene-butadiene-styrene block copolymer is added. The lubricant has good fluidity and can reduce the flow marks of the material. High-flow polystyrene resin also has good fluidity. The two can work together to improve the fluidity of the system and significantly reduce the flow marks caused by the addition of a large amount of styrene-butadiene-styrene block copolymer, while maintaining the material's high mechanical properties.

[0022] If the amount of lubricant added is too little, it will not improve the fluidity of the material and reduce flow marks. If the amount of lubricant added is too much, it will cause precipitation and even aggravate flow marks and other appearance defects.

[0023] If the amount of high-flow polystyrene resin used is too small, flow marks cannot be eliminated; if the amount of high-flow polystyrene resin used is too large, the impact strength of the material will be significantly reduced.

[0024] The melt mass flow rate of the high-flow polystyrene resin in the high-flow polystyrene resin affects the flow properties of the material. If the melt mass flow rate of the high-flow polystyrene resin is too large, the impact strength of the material will be significantly reduced; if the melt mass flow rate of the high-flow polystyrene resin is too small, the flow marks cannot be eliminated.

[0025] Preferably, the following components are included by weight:

[0026]

[0027] In order to further reduce the flow marks of the material and have higher impact strength, preferably, the melt mass flow rate of the high flow polystyrene resin is 6 to 9 g / 10 min.

[0028] In order to further reduce the flow marks of the material and avoid appearance defects, preferably, the oil content of the second styrene-butadiene-styrene block copolymer is 30-38%.

[0029] In order to further reduce the flow marks of the material and have a higher impact strength, preferably, the mass ratio of the first styrene-butadiene-styrene block copolymer to the second styrene-butadiene-styrene block copolymer is (0.3-0.75):1.

[0030] Preferably, the lubricant is one or more of amide, stearate, PE wax or PP wax lubricants.

[0031] More preferably, the lubricant is amide.

[0032] The filler not only plays a role in toughening the rigid particles, but also improves the dimensional stability of the material. In specific applications, the filler can be one or more of calcium carbonate, talcum powder, barium sulfate, kaolin or glass fiber.

[0033] Preferably, the filler is barium sulfate.

[0034] Preferably, the butadiene content in the polystyrene resin is 4-6 wt%.

[0035] In practical applications, the polystyrene resin can be recycled extruded polystyrene resin (PCR-PS).

[0036] Since the molecular chain of the recycled extruded polystyrene resin is severely broken, the toughness is significantly reduced. The invention is particularly suitable for improving the performance and reducing the flow marks of the recycled extruded polystyrene resin whose raw material is a low impact strength.

[0037] Preferably, the other processing aid is an antioxidant, and the antioxidant is a hindered phenol antioxidant and / or a phosphate antioxidant.

[0038] The polystyrene material of the present invention can be prepared by a common plastic material preparation method, which specifically comprises the following steps: uniformly mixing the components, melting and extruding and granulating the components at 160-190° C. through a twin-screw extruder to obtain the polystyrene material.

[0039] The polystyrene material prepared by the present invention has good impact strength, high fluidity and low flow marks, and can be widely used in the preparation of plastic products. The present invention especially protects the application of the polystyrene material in the preparation of housings of televisions and liquid crystal displays.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The polystyrene material of the present invention can satisfy the requirements of high toughness and high fluidity through the optimized synergistic effect of lubricant, high-flow polystyrene resin and styrene-butadiene-styrene block copolymer, while effectively reducing the flow marks of the polystyrene material, so that the polystyrene material has high performance and good appearance.

[0042] The impact strength of the polystyrene material of the present invention can reach 9.1-14KJ / m 2 , and the melt mass flow rate is 6.2-9.8g / 10min, and the tiger skin grade can reach 1-2, the tensile strength is 21-29.5MPa, and the bending modulus is 1970-2290MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 These are pictures of tiger skin patterns at levels 1, 2, and 3 along the direction of the arrows. DETAILED DESCRIPTION

[0044] The present invention is further described below in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0045] Polystyrene resin 1: Recycled refrigerator board material, tensile strength is 20MPa, bending modulus is 1800MPa, impact strength is 7KJ / m 2 , the butadiene content of the polystyrene resin 1 is 4 wt %, and the melt mass flow rate is 4 g / 10 min;

[0046] Polystyrene resin 2, brand name MA5210, tensile strength 27MPa, flexural modulus 2000MPa, impact strength 12KJ / m 2 , melt mass flow rate is 4g / 10min, butadiene in polystyrene resin 2 is 7wt%; manufacturer is; Jiangsu Yashide;

[0047] High flow polystyrene resin 1 is high flow GPPS, brand 123P, melt mass flow rate 8g / 10min, manufactured by Shanghai Saike;

[0048] High flow polystyrene resin 2 is high flow GPPS, with a grade of GPPS-500, a melt mass flow rate of 5 g / 10 min, and a manufacturer of Dushanzi Petrochemical;

[0049] High flow polystyrene resin 3 is low flow GPPS, brand 818K, melt mass flow rate 2g / 10min, and the manufacturer is Taiwan Chemical Fiber in Taiwan, China;

[0050] High flow polystyrene resin 4 is high flow GPPS, with a grade of GP1441, a melt mass flow rate of 11 g / 10 min, and a manufacturer of Total of France;

[0051] The first styrene-butadiene-styrene block copolymer, brand name SBS YH-792E, oil content 0%, manufacturer is Sinopec Baling Petrochemical;

[0052] The second styrene-butadiene-styrene block copolymer 1, brand name Globalprene 1475, oil content 33%, manufacturer Huizhou Li Changrong Rubber;

[0053] The second styrene-butadiene-styrene block copolymer 2 has an oil content of 50% and is made by filling rubber oil with SBS YH-792E;

[0054] The second styrene-butadiene-styrene block copolymer 3 has an oil content of 20% and is made by filling rubber oil with SBS YH-792E;

[0055] Rubber oil, cycloparaffin oil, brand KDN4006, manufacturer is PetroChina;

[0056] Filler 1, barium sulfate, is commercially available and the same one was used in all examples and comparative examples;

[0057] Lubricant 1 is amide, brand EBS B50, manufacturer PT.CMS CHEMICAL INDONESIA;

[0058] Lubricant 2 is stearic acid, brand name zincstearate (bs-2818); manufacturer is Zhongshan Huamingtai;

[0059] Lubricant 3 is PE wax, brand 617A, manufactured by Honeywell;

[0060] Antioxidants: hindered phenol antioxidants and phosphite antioxidants, the mass ratio of hindered phenol antioxidants to phosphite antioxidants is 1:2; commercially available and the same one is used in all examples and comparative examples.

[0061] Examples 1 to 12

[0062] A polystyrene material, comprising the following components by weight:

[0063] Polystyrene resin; high flow polystyrene resin; first styrene-butadiene-styrene block copolymer; second styrene-butadiene-styrene block copolymer; filler; lubricant; processing aid;

[0064] The specific content of each component is shown in Table 1 below.

[0065] Table 1 Polystyrene material composition of each embodiment (by weight)

[0066] Components 1 2 3 4 5 6 Polystyrene resin 1 50 50 50 50 50 85 High Flow Polystyrene Resin 1 33 33 33 33 10 40 The first styrene-butadiene-styrene block copolymer 3 1.7 3.5 1.2 5.1 1.3 Second styrene-butadiene-styrene block copolymer 1 4 5.3 3.5 5.8 6.9 1.7 filler 3 3 3 3 10 0 Lubricant 1 1.5 1.5 1.5 1.5 5 0.5 Antioxidants 0.3 0.3 0.3 0.3 0.1 2

[0067] Table 1

[0068]

[0069]

[0070] The preparation method of the above polystyrene material is as follows:

[0071] The components are mixed uniformly, melt-extruded and granulated by a twin-screw extruder, and dried to obtain the polystyrene material;

[0072] The temperature of the twin-screw extruder is divided into ten zones, with the temperature of zones one to two being 120°C to 170°C, the temperature of zones three to five being 160°C to 180°C, and the temperature of zones six to ten being 170°C to 190°C.

[0073] Comparative Examples 1 to 8

[0074] A polystyrene material, comprising the following components by weight:

[0075] Polystyrene resin; high flow polystyrene resin; first styrene-butadiene-styrene block copolymer; second styrene-butadiene-styrene block copolymer; filler; lubricant; processing aid;

[0076] The specific content of each component is shown in Table 2 below.

[0077] Table 2 Polystyrene material composition of each comparative example (by weight)

[0078]

[0079]

[0080] The preparation method of the above polystyrene material is the same as that in Example 1, which will not be described again here.

[0081] Results

[0082] The polystyrene materials of the above embodiments and comparative examples were tested by the following performance testing methods:

[0083] (1) Izod notched impact strength: According to ISO 180:2019 standard method, notch type is type A.

[0084] (2) Melt mass flow rate: According to ISO 1133-1:2011 standard method, the test conditions are 200°C and 5 kg.

[0085] (3) Tiger skin pattern: A 360T injection molding machine was selected, and then a large-size spiral mold was used to evaluate tiger skin pattern. The tiger skin pattern evaluation mold was a wide spiral mold with a width of 40 mm and a thickness of 2 mm.

[0086] like Figure 1 As shown, observe the position where the tiger skin pattern appears. If the tiger skin pattern appears above 620mm, the level is 1. If the tiger skin pattern appears between 580-620mm, the level is 2. If the tiger skin pattern appears between 0-580mm, the level is 3. The higher the level, the more obvious the tiger skin pattern. The higher the tiger skin pattern level, the more obvious the flow mark.

[0087] (4) Tensile strength: in accordance with ISO 527:2019 standard method.

[0088] (5) Flexural modulus: in accordance with ISO 178:2016 standard method.

[0089] The specific test results are shown in Table 3 below:

[0090]

[0091]

[0092] From the above data, it can be seen that the impact strength of the present invention can reach 9.1-14KJ / m 2 , and the melt mass flow rate is 6.2-9.8g / 10min, and the tiger skin grade can reach 1-2, the tensile strength is 21-29.5MPa, and the bending modulus is 1970-2290MPa.

[0093] It can be seen from the examples and comparative example 1 that without adding high-flow polystyrene resin, the tiger stripe grade is level 3 and the flow marks cannot be eliminated.

[0094] It can be seen from the examples and comparative example 2 that excessive use of high-flow polystyrene resin can effectively reduce flow marks, but will result in too low impact strength of the material.

[0095] It can be seen from the examples and comparative example 3 that the melt mass flow rate of the high flow polystyrene resin is too low, the tiger skin grade is level 3, and the flow marks cannot be eliminated.

[0096] It can be seen from the examples and comparative example 4 that if the melt mass flow rate of the high-flow polystyrene resin is too high, the impact strength of the material will be significantly reduced.

[0097] It can be seen from the examples and comparative example 5 that only adding the first styrene-butadiene-styrene block copolymer cannot improve both the impact strength and the fluidity at the same time.

[0098] It can be seen from the examples and comparative example 6 that only adding the second styrene-butadiene-styrene block copolymer will result in a significant decrease in the tensile strength and flexural modulus of the material.

[0099] It can be seen from the examples and comparative example 7 that the mass ratio of the first styrene-butadiene-styrene block copolymer and the second styrene-butadiene-styrene block copolymer is too small, and the tensile strength and flexural modulus of the material are too low.

[0100] It can be seen from the examples and comparative example 8 that the mass ratio of the first styrene-butadiene-styrene block copolymer to the second styrene-butadiene-styrene block copolymer is too large, and the melt mass flow rate is too low.

[0101] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A polystyrene material, characterized in that: By weight, it includes the following components: The melt mass flow rate of the polystyrene resin is 1 to 4 g / 10 min, the melt mass flow rate of the high flow polystyrene resin is 5 to 10 g / 10 min, the test standard is ISO 1133-2011, and the test conditions are 200°C and 5 kg. The styrene-butadiene-styrene block copolymer comprises a first styrene-butadiene-styrene block copolymer and a second styrene-butadiene-styrene block copolymer, wherein the first styrene-butadiene-styrene block copolymer has an oil content of 0%; the second styrene-butadiene-styrene block copolymer has an oil content of 20-50%; the mass ratio of the first styrene-butadiene-styrene block copolymer to the second styrene-butadiene-styrene block copolymer is (0.2-1):1; The test method for oil content is: perform thermogravimetric analysis on styrene-butadiene-styrene block copolymer, and the weight lost between 215 and 300°C is the oil content.

2. The polystyrene material according to claim 1, characterized in that: The melt mass flow rate of the high flow polystyrene resin is 6 to 9 g / 10 min.

3. The polystyrene material according to claim 1, characterized in that: The second styrene-butadiene-styrene block copolymer has an oil content of 30-38%.

4. The polystyrene material according to claim 1, characterized in that: The mass ratio of the first styrene-butadiene-styrene block copolymer to the second styrene-butadiene-styrene block copolymer is (0.3-0.75):

1.

5. The polystyrene material according to claim 1, characterized in that: The lubricant is one or more of amide, stearate, PE wax or PP wax lubricants.

6. The polystyrene material according to claim 1, characterized in that: The filler is barium sulfate.

7. The polystyrene material according to claim 1, characterized in that: The butadiene content in the polystyrene resin is 4-6 wt%.

8. The polystyrene material according to claim 1, characterized in that: The other processing aid is an antioxidant, and the antioxidant is a hindered phenol antioxidant and / or a phosphate antioxidant.

9. The method for preparing the polystyrene material according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: mixing the components uniformly, melting and extruding the components at 160-190° C. through a twin-screw extruder to obtain the polystyrene material.

10. Use of the polystyrene material according to any one of claims 1 to 8 in preparing television housings and liquid crystal display housings.

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