High weatherable transparent styrene composition, and preparation method and application thereof

Abstract

The present application relates to a kind of high weathering transparent styrene composition and its preparation method and application, belong to the composition technical field of high molecular compound.The high weathering transparent styrene composition of the present application includes the following weight parts of component: matrix resin 40~80 parts, chlorinated polyethylene 10~30 parts, glass fiber 10~30 parts;The matrix resin includes polystyrene and styrene-methyl methacrylate copolymer, and the mass ratio of polystyrene and styrene-methyl methacrylate copolymer is ≥1:1.The styrene composition has high transparency and excellent weathering performance while maintaining good toughness and dimensional stability.

Description

Technical Field

[0001] This invention relates to the field of polymer compound composition technology, and more particularly to a highly weather-resistant transparent styrene composition, its preparation method, and its application. Background Technology

[0002] Currently, LED strip lights used in public building decoration are mainly divided into FPC LED strip lights and PCB LED strip lights. The former uses flexible printed circuit boards (FPC) as the carrier and materials such as PVC and PET, and is suitable for advertising decoration, automotive decoration, and home decoration. The latter uses rigid PCBs as the carrier, which can provide a more stable lighting effect and is suitable for places that require fixed installation. The materials required are not only transparent and highly weather-resistant, but also dimensionally stable and have a linear coefficient of thermal expansion similar to that of rigid PCBs to avoid failures caused by significant thermal contraction due to large temperature differences between day and night in winter. However, although commonly used transparent materials (such as polystyrene and polymethyl methacrylate) have good transparency, their weather resistance, dimensional stability, and toughness are poor, making it difficult to meet the application requirements of PCB LED strip lights. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a highly weather-resistant transparent styrene composition.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] In a first aspect, the present invention provides a highly weather-resistant transparent styrene composition, comprising the following components by weight: 40-80 parts of matrix resin, 10-30 parts of chlorinated polyethylene, and 10-30 parts of glass fiber;

[0006] The matrix resin includes polystyrene and styrene-methyl methacrylate copolymer, wherein the mass ratio of polystyrene to styrene-methyl methacrylate copolymer is ≥1:1.

[0007] This invention combines polystyrene and styrene-methyl methacrylate copolymer in a specific ratio as the matrix resin, and combines them with chlorinated polyethylene and glass fiber. The styrene segments in the styrene-methyl methacrylate copolymer are used to improve its compatibility with polystyrene, thereby improving the transparency of the styrene composition. Simultaneously, the methyl methacrylate segments in the styrene-methyl methacrylate copolymer promote the uniform dispersion of glass fiber in the matrix resin and the formation of an interwoven structure, thereby improving the dimensional stability of the styrene composition. Meanwhile, chlorinated polyethylene, while maintaining the transparency and weather resistance of the styrene composition, works together with glass fiber to improve the toughness of the styrene composition. Thus, the styrene composition maintains good toughness and dimensional stability while also possessing high transparency and excellent weather resistance.

[0008] Optionally, the weight percentage of the matrix resin in the above-mentioned high weather-resistant transparent styrene composition is ≥35%; wherein the weight percentage of the matrix resin can be 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, or 80 parts, the weight percentage of chlorinated polyethylene can be 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, or 30 parts, and the weight percentage of glass fiber can be... The specific quantities can be 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, or 30 parts; the mass ratio of polystyrene to styrene-methyl methacrylate copolymer in the matrix resin is (1-5):1, specifically any one or any two of the following: 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, or 5:1.

[0009] As a preferred embodiment of the high weather-resistant transparent styrene composition of the present invention, the components of the high weather-resistant transparent styrene composition include 50-70 parts by weight of matrix resin, 15-25 parts by weight of chlorinated polyethylene, and 15-25 parts by weight of glass fiber.

[0010] In a preferred embodiment of the high weather-resistant transparent styrene composition of the present invention, the mass ratio of polystyrene to styrene-methyl methacrylate copolymer is (1-3):1. Optionally, the mass ratio of polystyrene to styrene-methyl methacrylate copolymer can be any or a combination of 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, and 3:1.

[0011] In a preferred embodiment of the high weather-resistant transparent styrene composition of the present invention, the styrene-methyl methacrylate copolymer contains 28% to 62% methyl methacrylate by mass. Optionally, the methyl methacrylate by mass content in the styrene-methyl methacrylate copolymer can be any or both of the following ranges: 28%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, and 62%.

[0012] Studies have found that when the mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer is between 28% and 62%, it not only ensures full compatibility with polystyrene to guarantee high transparency, but also improves the compatibility between the matrix resin and glass fiber, thereby promoting uniform dispersion of glass fiber.

[0013] The mass content of methyl methacrylate in styrene-methyl methacrylate copolymer can be determined by Fourier transform infrared spectroscopy (FT-IR). Methyl methacrylate and styrene have their own characteristic absorption peaks in the infrared spectrum. By measuring the intensity of these characteristic absorption peaks, the mass content of methyl methacrylate can be calculated.

[0014] In a preferred embodiment of the high weather-resistant transparent styrene composition of the present invention, the polystyrene has a weight-average molecular weight of 100,000 to 250,000. Optionally, the weight-average molecular weight of the polystyrene can specifically be any one or both of 100,000, 120,000, 140,000, 160,000, 180,000, 200,000, 220,000, and 250,000. The weight-average molecular weight of the polystyrene is measured according to GB / T 21864-2008.

[0015] In a preferred embodiment of the high weather-resistant transparent styrene composition of the present invention, the chlorinated polyethylene conforms to ISO 1133 standard, and has a melt flow rate of 5–15 g / 10 min at 180°C and 10 kg. Optionally, the melt flow rate of the chlorinated polyethylene can specifically be any one or a combination of 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, 8 g / 10 min, 9 g / 10 min, 10 g / 10 min, 11 g / 10 min, 12 g / 10 min, 13 g / 10 min, 14 g / 10 min, and 15 g / 10 min. The chlorinated polyethylene with the above-mentioned melt flow rate can better entangle with the molecular chains of the matrix resin, thereby enhancing the toughening effect.

[0016] In a preferred embodiment of the high weather-resistant transparent styrene composition of the present invention, the chlorinated polyethylene contains 28% to 40% chlorine by mass. Optionally, the chlorine content in the chlorinated polyethylene can be any or both of the following ranges: 28%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, and 40%. The chlorinated polyethylene with the above-mentioned chlorine content not only possesses good elasticity to improve the toughness of the styrene composition, but also imparts good oil resistance, weather resistance, and heat processing stability to the styrene composition. The chlorine content in the chlorinated polyethylene can be measured according to the GB / T 9872-1998 standard.

[0017] As a preferred embodiment of the high weather-resistant transparent styrene composition of the present invention, the high weather-resistant transparent styrene composition further includes 0.1 to 6 parts by weight of an additive; the additive includes at least one selected from coupling agents, antioxidants, lubricants, and weather-resistant agents. Optionally, the weight parts of the additive can specifically be any one or a combination of 0.1 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, and 6 parts.

[0018] Optionally, by weight, the coupling agent is 0.1-0.2 parts, the antioxidant is 0.1-2 parts, the lubricant is 0.1-2 parts, and the weathering agent is 0.2-1 parts; wherein, the coupling agent may be at least one of aminosilane, vinylsilane, and methacryloxysilane; the antioxidant may be at least one of hindered phenolic antioxidant or phosphite antioxidant; the lubricant may be at least one of vinyl bis-stearamide, polysiloxane, calcium stearate, magnesium stearate, zinc stearate, PE wax, and PP wax; and the weathering agent may be at least one of benzotriazole ultraviolet absorbers and hindered amine light stabilizers.

[0019] Secondly, the present invention provides a method for preparing the above-mentioned high weather-resistant transparent styrene composition, comprising the following steps: mixing each component evenly and melting and extruding to obtain the high weather-resistant transparent styrene composition.

[0020] Optionally, the above preparation method can be carried out by melt extrusion using a twin-screw extruder. The temperature of the first and second zones of the twin-screw extruder is 120℃ to 180℃, the temperature of the third to tenth zones is 180℃ to 220℃, and the screw speed is 200 to 400 rpm.

[0021] Thirdly, the present invention provides the application of the above-mentioned high weather-resistant transparent styrene composition in the preparation of PCB light strips.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] This invention combines polystyrene and styrene-methyl methacrylate copolymer in a specific ratio as the matrix resin, and incorporates chlorinated polyethylene and glass fiber. The styrene segments in the styrene-methyl methacrylate copolymer enhance its compatibility with polystyrene, thereby improving the transparency of the styrene composition. Simultaneously, the methyl methacrylate segments in the styrene-methyl methacrylate copolymer promote the uniform dispersion of glass fiber in the matrix resin, forming an interwoven structure, thus improving the dimensional stability of the styrene composition. Meanwhile, chlorinated polyethylene, while maintaining the transparency and weather resistance of the styrene composition, works synergistically with glass fiber to improve the toughness of the styrene composition. Therefore, the styrene composition maintains good toughness and dimensional stability while also possessing high transparency and excellent weather resistance; the notched impact strength of the cantilever bridge is maintained at 7 KJ / m. 2 The linear thermal expansion coefficient is maintained below 45μm / (m*℃), while the light transmittance is ≥82% and the color difference ΔE before and after aging is ≤1.8. Detailed Implementation

[0024] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0025] Unless otherwise specified, all other materials, reagents, etc. used in the examples and comparative examples are commercially available.

[0026] 1. Raw materials and reagents

[0027] GPPS resin 1, weight average molecular weight is 225,700, grade GPPS EA3300, manufacturer is Yashide Chemical;

[0028] GPPS resin 2, weight average molecular weight is 167,200, grade GP1441, manufacturer INEOS Styrolene;

[0029] SMMA resin 1, MMA content 60%, refractive index 1.53, grade MS-600, manufacturer Nippon Steel Chemicals, Japan;

[0030] SMMA resin 2, MMA content 30%, refractive index 1.56, grade MS-300, manufacturer Nippon Steel Chemicals, Japan;

[0031] SBC resin, grade NSBC220, manufactured by DENKA, Japan;

[0032] Toughening agent 1 (chlorinated polyethylene), chlorine content 35%, melt flow rate 10g / 10min, grade CPE-135C, manufacturer Hangzhou Keli Chemical Co., Ltd.

[0033] Toughening agent 2 (chlorinated polyethylene), chlorine content 30%, melt flow rate 15g / 10min, grade CPE130C, manufacturer Hangzhou Keli Chemical Co., Ltd.

[0034] Toughening agent 3 (SEBS), brand name SEBS YH-502T, manufacturer Baling Petrochemical;

[0035] Toughening agent 4 (LLDPE), grade LLDPE 7042, manufacturer: China Petroleum & Chemical Corporation;

[0036] Glass fiber, grade ECS303W-3-H, manufactured by Chongqing International Composite Materials Co., Ltd.

[0037] The coupling agent is a silane coupling agent (KH-550), which is commercially available;

[0038] The antioxidant is obtained by compounding hindered phenolic antioxidants (commercially available) and phosphite antioxidants (commercially available) in a 1:1 mass ratio;

[0039] The lubricant is N,N'-ethylene bis-stearamide (EBS), which is commercially available.

[0040] 2. Examples 1-8 and Comparative Examples 1-6

[0041] Table 1 shows the weight parts of each component in the high weather-resistant transparent styrene compositions of each embodiment and comparative example.

[0042]

[0043] The preparation method of the above-mentioned high weather-resistant transparent styrene composition includes the following steps:

[0044] According to the formula, all components except glass fiber are added to the twin-screw extruder through the main feed port and the glass fiber is added to the twin-screw extruder through the side feed port. The mixture is melt-extruded to obtain a high weather-resistant transparent styrene composition. The temperature of the first and second zones of the twin-screw extruder is 120℃~180℃, the temperature of the third to tenth zones is 180℃~220℃, and the screw speed is 200~400rpm.

[0045] 3. Performance Testing

[0046] 1) Cantilever beam notched impact strength: Tested according to GB / T 1843-2008 standard, notch type A;

[0047] 2) Light transmittance: Tested according to GB / T 2410-2008 standard, the sample is a square plate obtained by injection molding with a thickness of 2mm;

[0048] 3) Weather resistance test: The test was conducted in accordance with ISO 4892-2:2013 standard. The sample was a standard color plate with a thickness of 2mm. The color difference ΔE before and after xenon lamp aging for 360h was tested.

[0049] 4) Linear thermal expansion coefficient: Tested according to ASTM E831-06 standard. The sample is a strip with a thickness of 2 mm and a length of 8 mm, in the direction of flow.

[0050] Table 2. Performance of the high weather-resistant transparent styrene compositions in each example and comparative example.

[0051]

[0052]

[0053] According to the data in Table 2, the impact strength of the cantilever bridge notch in Examples 1-8 remains at 7 KJ / m. 2 The linear thermal expansion coefficient remains below 45 μm / (m*℃), while the light transmittance is ≥82% and the color difference ΔE before and after aging is ≤1.8, indicating that the styrene composition of the present invention maintains good toughness and dimensional stability while also possessing high transparency and excellent weather resistance. Meanwhile, as shown in Example 1 and Comparative Example 1, although replacing SMMA resin with SBC resin in combination with GPPS resin can also give the styrene composition good toughness and dimensional stability, it significantly reduces its transparency and weather resistance. According to Example 1, Comparative Examples 2 and 3, using SEBS as a toughening agent leads to poor transparency and weather resistance in the styrene composition; while using LLDPE as a toughening agent leads to a significant reduction in both toughness and weather resistance. Comparative Example 4 also shows that even when GPPS resin and SMMA resin are combined as the matrix resin, a low mass ratio between the two can result in poor light transmittance in the styrene composition. As can be seen from Comparative Examples 5 and 6, even if the matrix resin itself has high light transmittance, it is difficult for the styrene composition to maintain good dimensional stability and weather resistance while also possessing good toughness and high transparency when using polystyrene or styrene-methyl methacrylate copolymer as the matrix resin alone.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A highly weather-resistant transparent styrene composition, characterized in that, By weight, it includes the following components: 50-70 parts of matrix resin, 15-25 parts of chlorinated polyethylene, and 15-25 parts of glass fiber; The matrix resin includes polystyrene and styrene-methyl methacrylate copolymer, wherein the mass ratio of polystyrene to styrene-methyl methacrylate copolymer is ≥1:1; and the mass content of methyl methacrylate in styrene-methyl methacrylate copolymer is 45%~62%.

2. The high weather-resistant transparent styrene composition as described in claim 1, characterized in that, The mass ratio of the polystyrene to the styrene-methyl methacrylate copolymer is (1~3):

1.

3. The high weather-resistant transparent styrene composition as described in claim 1, characterized in that, The weight-average molecular weight of the polystyrene is 100,000 to 250,000.

4. The high weather-resistant transparent styrene composition as described in claim 1, characterized in that, The chlorinated polyethylene has a melt flow rate of 5~15g / 10min at 180℃ and 10kg.

5. The high weather-resistant transparent styrene composition as described in claim 1, characterized in that, The chlorinated polyethylene contains 28% to 40% chlorine by mass.

6. The high weather-resistant transparent styrene composition according to any one of claims 1 to 5, characterized in that, The high weather-resistant transparent styrene composition also includes 0.1 to 6 parts by weight of additives; The additives include at least one of coupling agents, antioxidants, lubricants, and weather-resistant agents.

7. A method for preparing the high weather-resistant transparent styrene composition according to any one of claims 1 to 6, characterized in that, The process includes the following steps: mixing the components evenly, melting and extruding to obtain a highly weather-resistant transparent styrene composition.

8. The use of the high weather-resistant transparent styrene composition according to any one of claims 1 to 6 in the preparation of PCB light strips.

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