Styrene-butadiene copolymer composition as well as preparation method and application thereof

Abstract

The invention relates to a styrene-butadiene copolymer composition as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The styrene-butadiene copolymer composition is prepared from the following components in parts by weight: 40 to 65 parts of styrene-butadiene copolymer, 9 to 34 parts of styrene-methyl methacrylate copolymer A, 20 to 40 parts of heat-resistant modifier, 5 to 10 parts of phase state regulating agent and 0.5 to 5 parts of haze regulating agent. The styrene-butadiene copolymer composition not only has good heat resistance, but also has relatively high transparency and is easy to demould.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a styrene-butadiene copolymer composition and a preparation method and application thereof. Background Art

[0002] Styrene-butadiene copolymer (SB), also known as K material or K resin, is copolymerized by styrene and butadiene, has good transparency, glossiness and impact resistance, and is widely used in various transparent products. However, the heat resistance of styrene-butadiene copolymer is relatively poor, and it generally cannot be used for a long time in a high temperature environment, resulting in limited application in high temperature fields. At present, the heat resistance of styrene-butadiene copolymer is mainly improved by adding high-rigidity polymers and blending and modifying styrene-butadiene copolymer; for example, the prior art (CN109666240A) discloses a high-rigidity light-diffusing K resin material and a preparation method thereof, with styrene-butadiene copolymer as the base resin, and the rigidity of the composite material is enhanced by adding polystyrene and styrene-acrylonitrile copolymer to improve the heat resistance, and the silicone light diffusing agent is used to reduce the haze of the composite material; although the heat resistance of styrene-butadiene copolymer is improved to a certain extent, it is difficult to maintain a high transparency. Meanwhile, it is found in the actual application process that the composition or composite material obtained by blending and modifying a polymer such as polystyrene, styrene-acrylonitrile copolymer or styrene-methyl methacrylate copolymer with a styrene-butadiene copolymer still has the problem of poor demoulding performance (difficult to demould). Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a styrene-butadiene copolymer composition and a preparation method and application thereof.

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

[0005] In a first aspect, the present invention provides a styrene-butadiene copolymer composition, comprising the following components by weight: 40 to 65 parts of a styrene-butadiene copolymer, 9 to 34 parts of a styrene-methyl methacrylate copolymer A, 20 to 40 parts of a heat-resistant modifier, 5 to 10 parts of a phase regulator, and 0.5 to 5 parts of a haze regulator;

[0006] The mass content of butadiene in the styrene-butadiene copolymer is 25% to 30%;

[0007] The weight percentage of the styrene-butadiene copolymer in the styrene-butadiene copolymer composition is preferably ≥30%; the styrene-butadiene copolymer has a melt mass flow rate of 4 to 10 g / 10 min at 200° C. and 5 kg according to ISO 1133-1:2022 standard, specifically 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, 8 g / 10 min, or 9 g / 10 min.

[0008] The mass content of butadiene in the above styrene-butadiene copolymer can be specifically 26%, 27%, 28%, 29%, and the mass content of butadiene in the styrene-butadiene copolymer can be regulated by adjusting the feed ratio of the polymerization monomer (butadiene). The mass content of butadiene in the styrene-butadiene copolymer can be determined by the Weenys method, and specific reference can be made to "Analysis of the content of bound butadiene in styrene-butadiene copolymer by improved Weenys method" (Synthetic Rubber Industry, 1995, 18(2):113).

[0009] Styrene-butadiene copolymer can be purchased or prepared by oneself, and can be specifically selected from ASAFLEX 830 (manufactured by Asahi Kasei), ASAFLEX825 (manufactured by Asahi Kasei), KR03 (manufactured by Styrolution), KR05 (manufactured by Styrolution), and the like.

[0010] The mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer A is 20% to 30%;

[0011] The mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer A can specifically be 21%, 23%, 25%, 27%, and 29%. The mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer A can be regulated by adjusting the polymerization monomer (methyl methacrylate) feed ratio.

[0012] The heat-resistant modifier is at least one of styrene-maleic anhydride copolymer, styrene-acrylate-maleic anhydride copolymer, and styrene-acrylonitrile-maleic anhydride copolymer;

[0013] The heat-resistant modifier is a copolymer of at least one of styrene, acrylate, and acrylonitrile and maleic anhydride, which can be purchased or prepared by oneself, and can be prepared specifically by the following preparation method: at least one of styrene, acrylate, or acrylonitrile is used as a polymerization monomer, and is copolymerized with maleic anhydride under the initiation of diisopropylbenzene peroxide (DCP).

[0014] The phase regulator is at least one of polystyrene and styrene-methyl methacrylate copolymer B, and the melt fluidity of the styrene-methyl methacrylate copolymer B is higher than that of the styrene-methyl methacrylate copolymer A;

[0015] Polystyrene can be purchased, specifically G-32 (manufacturer Toyo); the mass content of methyl methacrylate in styrene-methyl methacrylate copolymer B is 10% to 30%, specifically 12%, 15%, 18%, 20%, 23%, 25%, 28%.

[0016] The haze control agent is at least one of polymethyl methacrylate and styrene-methyl methacrylate copolymer C, and the mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer C is ≥60%.

[0017] Polymethyl methacrylate can be purchased, specifically CM-207 (manufacturer Chi Mei).

[0018] The above-mentioned styrene-methyl methacrylate copolymer A, B or C can be purchased or homemade, specifically NAS21 (manufacturer Styrol), MS-300 (Nippon Steel Chemical, Japan); or prepared by the following preparation method: diisopropylbenzene peroxide (DCP), methyl methacrylate and styrene are mixed in a mass ratio of 0.1: (8-12): (85-95) and then suspended and polymerized in an inert atmosphere. When the suspended particles become hard, the temperature of the reaction system is increased to 95-105° C. and maintained for 1.5-2.5 hours to promote the completion of the polymerization reaction. After the reaction is completed, the reaction system is washed with water and dried for use.

[0019] The invention uses a styrene-butadiene copolymer with a specific butadiene content as a base resin, and a styrene-methyl methacrylate copolymer with a specific methyl methacrylate content, adopts a specific heat-resistant modifier to improve the heat resistance of the composition, and combines a low-refractive-index haze regulator to balance the refractive index of the blending system, thereby achieving high light transmittance (≥85%) and low haze (≤10%). At the same time, the rheological properties (high fluidity) of the phase regulator are utilized to promote uniform dispersion of each component, optimize the surface phase distribution of the composition, and reduce the surface viscosity and adsorption, so that the styrene-butadiene copolymer composition has good heat resistance, high transparency and easy demoulding performance (≤625N).

[0020] Optionally, the weight proportion of the styrene-butadiene copolymer in the above-mentioned styrene-butadiene copolymer can be 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, and 64 parts; the weight proportion of styrene-methyl methacrylate copolymer A can be 10 parts, 15 parts, 20 parts, 25 parts, and 30 parts; the weight proportion of the heat-resistant modifier can be 21 parts, 23 parts, 25 parts, 27 parts, 29 parts, 31 parts, 33 parts, 35 parts, 37 parts, and 39 parts; the weight proportion of the phase regulator can be 6 parts, 7 parts, 8 parts, and 9 parts; and the weight proportion of the haze regulator can be 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, and 4.5 parts.

[0021] As a preferred embodiment of the styrene-butadiene copolymer composition of the present invention, the mass ratio of the phase regulator to the styrene-butadiene copolymer is 1:(5-10). Optionally, the mass ratio of the phase regulator to the styrene-butadiene copolymer can be 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5.

[0022] As a preferred embodiment of the styrene-butadiene copolymer composition of the present invention, the mass ratio of the haze control agent to the heat-resistant modifier is 1:(10-60), more preferably 1:(15-30). Optionally, the mass ratio of the haze control agent to the heat-resistant modifier can be 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55.

[0023] As a preferred embodiment of the styrene-butadiene copolymer composition of the present invention, the mass content of maleic anhydride in the heat-resistant modifier is ≥20%; more preferably, the mass content of maleic anhydride in the heat-resistant modifier is 20% to 30%. The mass content of maleic anhydride in the heat-resistant modifier can be obtained by adjusting the feed ratio of maleic anhydride as a polymer monomer. The mass content of maleic anhydride in the heat-resistant modifier can be determined by acid-base titration.

[0024] As a preferred embodiment of the styrene-butadiene copolymer composition of the present invention, according to ISO 1133-1:2022 standard, at 200°C and 5kg, the melt mass flow rate difference between the styrene-methyl methacrylate copolymer B and the styrene-methyl methacrylate copolymer A is ≥8g / 10min, preferably 8-16g / 10min.

[0025] As a preferred embodiment of the styrene-butadiene copolymer composition of the present invention, according to ISO 1133-1:2022 standard, at 200°C and 5kg, the melt mass flow rate of the styrene-methyl methacrylate copolymer A is 2 to 4 g / 10min, and the melt mass flow rate of the styrene-methyl methacrylate copolymer B is ≥12 g / 10min (preferably 12 to 18 g / 10min).

[0026] As a preferred embodiment of the styrene-butadiene copolymer composition of the present invention, the components of the styrene-butadiene copolymer composition further include 0.2 to 5 parts by weight of a processing aid; the processing aid is at least one of an antioxidant, a weathering agent, and a colorant.

[0027] As a preferred embodiment of the styrene-butadiene copolymer composition of the present invention, the antioxidant is at least one of a hindered phenol antioxidant, a phosphite antioxidant, and a thioether antioxidant. Optionally, the hindered phenol antioxidant can be specifically selected from SONOX 1010, CHINOX 1076, etc., the phosphite antioxidant can be specifically selected from SONOX 168, SONOX 626, etc., and the thioether antioxidant can be specifically selected from RIANOX 412S, etc.

[0028] As a preferred embodiment of the styrene-butadiene copolymer composition of the present invention, the weathering agent is at least one of a benzophenone ultraviolet light absorber, a benzotriazole ultraviolet light absorber, and a hindered amine light stabilizer.

[0029] As a preferred embodiment of the styrene-butadiene copolymer composition of the present invention, the colorant is at least one of a pigment colorant, a dye colorant, and a light diffusing agent.

[0030] In a second aspect, the present invention provides a method for preparing the above-mentioned styrene-butadiene copolymer composition, comprising the following steps: mixing the components evenly and then melt-extruding to obtain the styrene-butadiene copolymer composition; wherein, a twin-screw extruder can be used for melt extrusion, the melt extrusion temperature is 160 to 250°C, and the screw speed of the twin-screw extruder is 200 to 800 rpm.

[0031] In a third aspect, the present invention provides the use of the above-mentioned styrene-butadiene copolymer composition in the preparation of transparent containers, panels and other parts of household appliances, consumer electronic products, automobiles or electronic and electrical products.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention uses a styrene-butadiene copolymer with a specific butadiene content as a base resin, and simultaneously matches a styrene-methyl methacrylate copolymer with a specific methyl methacrylate content, and combines it with a specific heat-resistant modifier, a phase regulator and a haze regulator, so that the styrene-butadiene copolymer composition has good heat resistance, high transparency and easy demoulding performance. DETAILED DESCRIPTION

[0034] 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.

[0035] Unless otherwise specified, other materials, reagents, etc. used in the examples and comparative examples can be obtained from commercial sources.

[0036] 1. Raw materials and reagents

[0037] 1) Styrene-butadiene copolymer 1 (SB-1): the mass content of butadiene in the styrene-butadiene copolymer is 30%, the brand is ASAFLEX 830, and the manufacturer is Asahi Kasei;

[0038] 2) Styrene-butadiene copolymer 2 (SB-2): the mass content of butadiene in the styrene-butadiene copolymer is 25%, the brand is ASAFLEX825, and the manufacturer is Asahi Kasei;

[0039] 3) Styrene-butadiene copolymer 3 (SB-3): The mass content of butadiene in the styrene-butadiene copolymer is 15%, the brand is 800S, and the manufacturer is Asahi Kasei;

[0040] 4) Styrene-butadiene copolymer 4 (SB-4): The mass content of butadiene in the styrene-butadiene copolymer is 45%, the brand is 687, and the manufacturer is Yingquan Chemical.

[0041] 5) Styrene-methyl methacrylate copolymer 1 (SM-1): the mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer is 20%, the melt mass flow rate is 2.5 g / 10 min, the brand is NAS21, and the manufacturer is Benling;

[0042] 6) Styrene-methyl methacrylate copolymer 2 (SM-2): the mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer is 30%, the melt mass flow rate is 2.8 g / 10 min, the brand is MS-300, and the manufacturer is Nippon Steel Chemical;

[0043] 7) Styrene-methyl methacrylate copolymer 3 (SM-3): the mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer is 10%, and the melt mass flow rate is 3.0 g / 10 min;

[0044] The above-mentioned styrene-methyl methacrylate copolymer 3 is prepared by the following preparation method:

[0045] 0.1 parts by weight of diisopropylbenzene peroxide (DCP), 10 parts by weight of methyl methacrylate and 90 parts by weight of styrene are subjected to suspension polymerization under stirring and nitrogen protection. When the suspended particles become hard, the temperature of the reaction system is increased to 100°C and maintained for 2 hours to promote the completion of the polymerization reaction. After the reaction is completed, the mixture is washed with water and dried for use.

[0046] 8) Heat-resistant modifier 1 (HT-1) is styrene-maleic anhydride copolymer: the mass content of maleic anhydride in the styrene-maleic anhydride copolymer is 25%, the brand is SMA-725, and the manufacturer is Jiaxing Huawen;

[0047] 9) Heat-resistant modifier 2 (HT-2) is styrene-methyl methacrylate-maleic anhydride copolymer: the mass content of maleic anhydride in styrene-methyl methacrylate-maleic anhydride copolymer is 25%;

[0048] The above heat-resistant modifier 2 is prepared by the following preparation method:

[0049] S1, 0.1 parts by weight of diisopropylbenzene peroxide (DCP), 0.1 parts by weight of dodecyl mercaptan, 15 parts by weight of styrene, and 5 parts by weight of methyl methacrylate were stirred evenly and added into a reaction kettle, and polymerized at 100° C.;

[0050] S2. Dissolve 25 parts by weight of maleic anhydride in 45 parts by weight of styrene and 10 parts by weight of methyl methacrylate to form a mixed solution, then drop the mixed solution into the reactor in S1, and control the reaction degree to stop the reaction when the reactor becomes viscous, and obtain the product after washing, drying and crushing.

[0051] 10) Phase control agent 1 (X-1) is polystyrene, with a melt mass flow rate of 15 g / 10 min, a brand of G-32, and a manufacturer of Nippon Steel Chemical;

[0052] 11) Phase control agent 2 (X-2) is styrene-methyl methacrylate copolymer (SM-4), the mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer is 20%, the melt mass flow rate is 15g / 10min, the brand is KS-10, and the manufacturer is Nippon Steel Chemical.

[0053] 12) Haze control agent 1 (W-1) is polymethyl methacrylate, brand CM-207, manufacturer is Chimei;

[0054] 13) Haze control agent 2 (W-2) is styrene-methyl methacrylate copolymer (SM-5), the mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer is 60%, the melt mass flow rate is 1.5g / 10min, the brand is PM-600, and the manufacturer is Chimei.

[0055] The melt mass flow rates of the above styrene-butadiene copolymer, polystyrene and styrene-methyl methacrylate copolymer are all measured at 200° C. and 5 kg according to ISO 1133-1:2022 standard.

[0056] 2. Preparation method of styrene-butadiene copolymer composition of the present invention

[0057] The components are mixed uniformly according to the formula and then added into a twin-screw extruder for melt extrusion to obtain a styrene-butadiene copolymer composition; wherein the melt extrusion temperature is 160-250° C., and the screw speed of the twin-screw extruder is 200-800 rpm.

[0058] Table 1 Weight parts of each component of the styrene-butadiene copolymer composition in Examples 1 to 12

[0059]

[0060] In the above Table 1, X / SB refers to the mass ratio of the phase regulator to the styrene-butadiene copolymer, and W / HT refers to the mass ratio of the haze regulator to the heat-resistant modifier.

[0061] Table 2 Weight parts of each component of the styrene-butadiene copolymer composition in Comparative Examples 1 to 6

[0062]

[0063]

[0064] 3. Performance testing

[0065] (1) Light transmittance and haze: The samples were injection molded into 2.0 mm thick samples and tested according to ASTM D1003-2013.

[0066] (2) Heat deformation temperature: tested in accordance with ISO 75-2:2013 standard under a load of 0.45 MPa.

[0067] (3) Demolding force: The cavity demolding force test mold was used, and the injection molding was carried out at 200 °C with a cooling time of 20 s. The demolding force data was measured by the force sensor inside the test mold.

[0068] Table 3 Properties of the styrene-butadiene copolymer compositions in various examples and comparative examples

[0069]

[0070]

[0071] According to the data in Table 3, the light transmittance of the styrene-butadiene copolymer composition in Examples 1 to 12 is more than 85%, the haze is less than 10%, the heat deformation temperature is 87 to 92° C., and the demolding force is less than or equal to 625N, indicating that the styrene-butadiene copolymer composition of the present invention not only has high transparency, but also has good heat resistance and excellent demolding performance.

[0072] According to the data of Comparative Examples 1 and 2, it can be found that when the butadiene content in the styrene-butadiene copolymer is too low, the refractive index does not match the composition, which not only leads to a decrease in the transparency of the styrene-butadiene copolymer composition, but also causes its haze to increase significantly; and when the butadiene content in the styrene-butadiene copolymer is too high, while reducing the transparency of the styrene-butadiene copolymer composition, it also softens the surface of the composition, reduces its heat resistance and increases the difficulty of demolding.

[0073] It can be seen from the data of Comparative Examples 3 and 4 that the performance of the styrene-butadiene copolymer composition is not only related to the styrene-butadiene copolymer, but also affected by the styrene-methyl methacrylate copolymer. When the content of methyl methacrylate in the styrene-methyl methacrylate copolymer is too high or too low, it is difficult to effectively improve the transparency, heat resistance and demolding properties of the styrene-butadiene copolymer composition at the same time.

[0074] In addition, according to the data of Comparative Example 5, when styrene-methyl methacrylate copolymer B is used as a phase regulator, the difference in melt flow rate between it and styrene-methyl methacrylate copolymer A is too small to play the role of the phase regulator; according to the data of Comparative Example 6, it can be seen that when styrene-methyl methacrylate copolymer C is used as a haze regulator, its methyl methacrylate content is too low to play the effect of adjusting the haze, so that the transparency of the styrene-butadiene copolymer composition is significantly reduced.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution 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 the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A styrene-butadiene copolymer composition, characterized in that: The invention comprises the following components by weight: 40 to 65 parts of styrene-butadiene copolymer, 9 to 34 parts of styrene-methyl methacrylate copolymer A, 20 to 40 parts of heat-resistant modifier, 5 to 10 parts of phase regulator, and 0.5 to 5 parts of haze regulator; The mass content of butadiene in the styrene-butadiene copolymer is 25% to 30%; The mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer A is 20% to 30%; The heat-resistant modifier is at least one of styrene-maleic anhydride copolymer, styrene-acrylate-maleic anhydride copolymer, and styrene-acrylonitrile-maleic anhydride copolymer; The phase regulator is at least one of polystyrene and styrene-methyl methacrylate copolymer B, and the melt fluidity of the styrene-methyl methacrylate copolymer B is higher than that of the styrene-methyl methacrylate copolymer A; The haze control agent is at least one of polymethyl methacrylate and styrene-methyl methacrylate copolymer C; the mass content of methyl methacrylate in the styrene-methyl methacrylate copolymer C is ≥60%.

2. The styrene-butadiene copolymer composition according to claim 1, wherein The mass ratio of the phase regulator to the styrene-butadiene copolymer is 1:(5-10).

3. The styrene-butadiene copolymer composition according to claim 1, wherein The mass ratio of the haze control agent to the heat-resistant modifier is 1:(10-60).

4. The styrene-butadiene copolymer composition according to claim 1, wherein The mass content of maleic anhydride in the heat-resistant modifier is ≥20%.

5. The styrene-butadiene copolymer composition according to claim 1, characterized in that According to ISO 1133-1:2022 standard, at 200° C. and 5 kg, the difference in melt mass flow rate between the styrene-methyl methacrylate copolymer B and the styrene-methyl methacrylate copolymer A is ≥8 g / 10 min.

6. The styrene-butadiene copolymer composition according to claim 5, characterized in that According to ISO 1133-1:2022 standard, at 200° C. and 5 kg, the melt mass flow rate of the styrene-methyl methacrylate copolymer A is 2 to 4 g / 10 min, and the melt mass flow rate of the styrene-methyl methacrylate copolymer B is ≥12 g / 10 min.

7. The styrene-butadiene copolymer composition according to claim 1, wherein The components of the styrene-butadiene copolymer composition also include 0.2 to 5 parts by weight of a processing aid; the processing aid is at least one of an antioxidant, a weathering agent, and a colorant.

8. The styrene-butadiene copolymer composition according to claim 7, wherein Satisfy at least one of the following: (a) the antioxidant is at least one of a hindered phenol antioxidant, a phosphite antioxidant, and a thioether antioxidant; (b) the weathering agent is at least one of a benzophenone ultraviolet light absorber, a benzotriazole ultraviolet light absorber, and a hindered amine light stabilizer; (c) The colorant is at least one of a pigment colorant, a dye colorant, and a light diffusing agent.

9. The method for preparing the styrene-butadiene copolymer composition according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: mixing the components uniformly and then melting and extruding the components to obtain a styrene-butadiene copolymer composition.

10. Use of the styrene-butadiene copolymer composition according to any one of claims 1 to 8 in the preparation of parts for household appliances, consumer electronic products, automobiles or electronic and electrical products.

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