A styrene butadiene resin composition, a method for preparing the same, and use thereof

Abstract

The present application relates to a kind of styrene-butadiene resin composition and its preparation method and application, the styrene-butadiene resin composition includes first styrene-butadiene block copolymer and second styrene-butadiene block copolymer;The structural formula of the first styrene-butadiene block copolymer is as follows: A m -X1;The structural formula of the second styrene-butadiene block copolymer is as follows: A n -X2;Wherein, A is styrene-butadiene block copolymer, m, n are integers, m≥3, n≥2, X1 is the residue of first coupling agent, its functionality≥3, X2 is the residue of second coupling agent, its functionality≥2.The styrene-butadiene resin composition of the present application has excellent hardness and notched izod impact strength, and has environmental stress resistance and processing performance.

Description

Technical Field

[0001] This invention relates to the field of styrene-butadiene resin technology, and more particularly to a styrene-butadiene resin composition, its preparation method, and its application. Background Technology

[0002] The environmental stress resistance and processing properties of styrene-butadiene resin are crucial.

[0003] CN101456938A discloses a star-shaped comb-like butadiene / styrene block copolymer. The disclosed polymer has the following structure: An-C, where A is the butadiene / styrene block copolymer, C is a star-shaped seed tree coupling agent residue, the star-shaped seed tree coupling agent is an epoxidized liquid star polymer, n is the degree of branching, n is greater than or equal to 3, and the number-average molecular weight of the star-shaped comb-like block copolymer An-C is 5 × 10⁻⁶. 4 ~50×10 4 The number-average molecular weight of block copolymer A is 1×10⁻⁶. 4 ~15×10 4 The styrene content is 55% to 85% (mass percentage, the same below), the butadiene content is 15% to 45%, and the 1,2-structure content in polybutadiene is less than 30% (mass percentage, based on 100% of the total amount of monomer butadiene).

[0004] CN111205416A discloses a method for preparing a styrene-butadiene-styrene block copolymer, which solves the technical problems of low vinyl content, high block ratio, and easy molecular chain breakage in commercially available butadiene-styrene copolymers. The steps are as follows: the temperature is 60℃~130℃, the pressure is 1.2Mpa~1.7Mpa, an inert protective gas is introduced into the reaction vessel, an organic solvent is added, butadiene is introduced into the organic solvent, an organic lithium catalyst is added, and then styrene, a composite structure regulator, and a coupling agent are added to carry out a heated and pressurized polymerization reaction; an antioxidant is added to the polymerization reaction liquid obtained in step (1), the polymerization reaction liquid is poured into a crystallizing agent to crystallize and precipitate, washed, granulated, and dried at 60~80℃ to obtain a styrene-butadiene-styrene block copolymer.

[0005] In the prior art, it is difficult for styrene-butadiene resin compositions to achieve both excellent impact resistance and processability. Therefore, it is crucial to develop a styrene-butadiene resin composition that combines environmental stress resistance and processing performance. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide a styrene-butadiene resin composition, its preparation method and application, wherein the styrene-butadiene resin composition has excellent hardness and notched cantilever beam impact strength, and also has environmental stress resistance and processing performance.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a styrene-butadiene resin composition, the styrene-butadiene resin composition comprising a first styrene-butadiene block copolymer and a second styrene-butadiene block copolymer;

[0009] The structural formula of the first styrene-butadiene block copolymer is as follows: A m -X1;

[0010] The structural formula of the second styrene-butadiene block copolymer is as follows: A n -X2;

[0011] Wherein, A is a styrene-butadiene block copolymer, m and n are integers, m≥3, n≥2, X1 is the residue of the first coupling agent with a functionality ≥3, and X2 is the residue of the second coupling agent with a functionality ≥2.

[0012] A is prepared by reacting styrene, butadiene, an initiator, and a first coupling agent.

[0013] In this invention, A is a styrene-butadiene block copolymer, which has high hardness and impact resistance. A, through coupling with a first coupling agent and a second coupling agent, forms a macromolecular block copolymer comprising a first styrene-butadiene block copolymer and a second styrene-butadiene block copolymer, which enables the styrene-butadiene resin composition to have excellent hardness and impact resistance. The second coupling agent is beneficial to improving the molecular weight distribution of the styrene-butadiene resin composition and improving processing performance. The first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer work together synergistically, and the resulting styrene-butadiene resin composition has excellent hardness and notched cantilever beam impact strength, and also has environmental stress resistance and processing performance.

[0014] Preferably, in the first and second styrene-butadiene block copolymers, the mass percentage of styrene structural units is 60%-80% (e.g., 65%, 67%, 69%, 70%, 72%, 74%, 76%, 78%, or 80%), and the mass percentage of butadiene structural units is 20%-40% (e.g., 20%, 22%, 24%, 26%, 28%, 30%, 32%, 35%, 37%, or 40%).

[0015] In this invention, the mass percentage of styrene structural units in the first and second styrene-butadiene block copolymers is controlled within the range of 60%-80%. This is because the mass ratio of styrene structural units to butadiene structural units affects impact resistance and hardness. A higher mass percentage of styrene structural units leads to higher hardness and poor impact resistance, while a lower mass percentage of styrene structural units leads to lower hardness, resulting in softer products with insufficient rigidity.

[0016] Preferably, the structural formula of the first styrene-butadiene block copolymer includes (St1-Li-X1-Li-St2-Bd1 / St3-Bd2 / St4-Bd3). m -X1, where St1 and St2 are polystyrene segments, Bd3 is a polybutadiene segment, and Bd1 / St3 and Bd2 / St4 are segments of butadiene and styrene random blocks.

[0017] Preferably, the structural formula of the second styrene-butadiene block copolymer includes: (St1-Li-X1-Li-St2-Bd1 / St3-Bd2 / St4-Bd3) n -X2, where St1 and St2 are polystyrene segments, Bd3 is a polybutadiene segment, and Bd1 / St3 and Bd2 / St4 are segments of butadiene and styrene random blocks.

[0018] Preferably, the styrene-butadiene resin composition further includes (St1). m -X1, where St1 is a polystyrene segment.

[0019] Preferably, the number average molecular weight of the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is 50,000-350,000 g / mol, such as 50,000 g / mol, 80,000 g / mol, 100,000 g / mol, 120,000 g / mol, 150,000 g / mol, 180,000 g / mol, 200,000 g / mol, 250,000 g / mol, 300,000 g / mol, 320,000 g / mol, or 350,000 g / mol.

[0020] In this invention, the number-average molecular weight of the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is controlled within the range of 50,000-350,000 g / mol. If the number-average molecular weight is too high, it will result in high hardness and difficult processing; if the number-average molecular weight is too low, it will result in low resin hardness and insufficient toughness, and poor impact resistance.

[0021] Preferably, the first coupling agent comprises any one or a combination of at least two of silicon tetrachloride, tin tetrachloride, or tetramethoxysilane.

[0022] Preferably, the second coupling agent comprises silicon dichloride and / or dimethoxydichlorosilane.

[0023] Preferably, the styrene-butadiene resin composition further includes additives.

[0024] Preferably, the additives include antioxidants and lubricants.

[0025] Preferably, the lubricant comprises microcrystalline wax and / or zinc stearate.

[0026] Preferably, the antioxidant includes phenolic antioxidants and / or phosphite antioxidants. For example, the antioxidant includes, but is not limited to, any one or a combination of at least two of antioxidants 1076, 1010, or 168. Typical but non-limiting combinations include: a combination of antioxidants 1076 and 168, a combination of antioxidants 1010 and 168, or a combination of antioxidants 1010, 1076, and 168, etc.

[0027] In a second aspect, the present invention provides a method for preparing the styrene-butadiene resin composition as described in the first aspect, the method comprising the following steps:

[0028] (1) Styrene, butadiene, initiator and part of the first coupling agent are mixed and reacted to obtain styrene-butadiene block copolymer.

[0029] (2) The styrene-butadiene block copolymer obtained in step (1), the remaining first coupling agent and the second coupling agent are mixed, reacted, and a terminator is added to obtain the styrene-butadiene resin composition.

[0030] Preferably, step (1) includes the following steps:

[0031] (S1) The solvent, regulator, part of styrene and part of the initiator are mixed and reacted to obtain product a.

[0032] (S2) The product a obtained in step (S1), a portion of the first coupling agent, the remaining initiator and a portion of styrene are mixed and reacted to obtain product b.

[0033] (S3) Mix the product b obtained in step (S2), a portion of butadiene and a portion of styrene, and react to obtain product c.

[0034] (S4) The product c obtained in step (S3), a portion of the butadiene and the remaining styrene are mixed and reacted to obtain product d.

[0035] (S5) The product d obtained in step (S4) is mixed with the remaining butadiene and reacted to obtain the styrene-butadiene block copolymer.

[0036] In this invention, steps (S1) and (S2) involve mixing a solvent, a modifier, a portion of styrene, and a portion of an initiator, reacting the mixture, and adding a portion of a first coupling agent to increase the molecular weight of the polystyrene, thereby preparing branched high molecular weight polystyrene with high hardness. This results in the styrene-butadiene resin composition prepared based on this polystyrene having excellent hardness.

[0037] Preferably, the solvent includes any one or a combination of at least two of cyclohexane, n-hexane, or toluene.

[0038] Preferably, the regulator comprises any one or a combination of at least two of tetrahydrofuran, tetramethylethylenediamine, or diethanol dimethyl ether.

[0039] Preferably, the initiator comprises n-butyllithium.

[0040] Preferably, the molar ratio of the first coupling agent in step (S2) to the initiator in step (S1) is 0.05 to 0.1:1, for example, 0.05:1, 0.055:1, 0.06:1, 0.065:1, 0.07:1, 0.075:1, 0.08:1, 0.085:1, 0.09:1, 0.095:1, or 0.1:1, etc.

[0041] In this invention, the molar ratio of the first coupling agent in step (S2) to the initiator in step (S1) is 0.05 to 0.1:1. If the molar ratio is too large, it will affect the subsequent polymerization reaction, resulting in a smaller block distribution, higher hardness, and lower processing performance of the obtained styrene-butadiene block copolymer. If the molar ratio is too small, the proportion of branched polystyrene formed will be too low, and the hardness will be too low.

[0042] Preferably, based on the total mass of styrene as 100%, in step (S1), the mass percentage of styrene in the portion is 50% to 70%, for example, 50%, 52%, 55%, 58%, 60%, 62%, 64%, 66%, 68%, or 70%.

[0043] Preferably, based on the total mass of the initiator being 100%, in step (S1), the mass percentage of the initiator in the portion is 20% to 75%, for example, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or 75%.

[0044] Preferably, based on the total mass of styrene as 100%, in step (S2), the mass percentage of styrene in the portion is 15% to 40%, for example, 15%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, or 40%.

[0045] Preferably, based on the total mass of butadiene as 100%, in step (S3), the mass percentage of butadiene in the portion is 10-30%, for example, 10%, 12%, 15%, 17%, 20%, 22%, 25%, 27%, 29%, or 30%.

[0046] Preferably, based on the total mass of styrene as 100%, in step (S3), the mass percentage of styrene in the portion is 5% to 15%, for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 15%, or 15%.

[0047] Preferably, based on the total mass of butadiene as 100%, in step (S4), the mass percentage of butadiene in the portion is 10% to 30%, for example, 10%, 12%, 15%, 17%, 20%, 22%, 25%, 27%, 29%, or 30%.

[0048] Preferably, the reactions described in steps (S1) and (S2) are each independently carried out to a conversion rate ≥99%, such as 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, or 99.9%.

[0049] Preferably, in steps (S1), (S3), (S4), and (S5), the temperature of each reaction is independently 50-95°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, or 95°C, and the temperature of the second reaction in step (S2) is 50-95°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, or 95°C, etc.

[0050] Preferably, in steps (S1), (S2), (S3), (S4), and (S5), the reaction time is independently 20-40 min, for example, 20 min, 22 min, 25 min, 28 min, 30 min, 32 min, 35 min, 36 min, 38 min, 39 min, or 40 min, etc., and the second reaction time in step (S2) is 20-40 min, for example, 20 min, 22 min, 25 min, 28 min, 30 min, 32 min, 35 min, 36 min, 38 min, 39 min, or 40 min, etc.

[0051] Preferably, the ratio of the total molar amount of the remaining first coupling agent and the second coupling agent in step (2) to the molar amount of the initiator in step (1) is 0.15 to 0.5:1, for example, 0.15:1, 0.17:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1 or 0.5:1, etc.

[0052] Preferably, in step (2), with the total molar amount of the remaining first coupling agent and the second coupling agent being 100%, the mass percentage of the molar amount of the remaining first coupling agent is 50-70%, for example, 50°C, 52°C, 57°C, 58°C, 60°C, 62°C, 64°C, 66°C, 68°C, or 70°C.

[0053] Preferably, the terminating agent comprises any one or a combination of at least two of methanol, carbonic acid, or water.

[0054] Preferably, the addition of the terminator further includes the addition of an auxiliary agent to the system.

[0055] Thirdly, the present invention provides the use of the styrene-butadiene resin composition as described in the first aspect in impact-resistant articles.

[0056] Preferably, the impact-resistant product is a transparent impact-resistant product.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] (1) The styrene-butadiene resin composition of the present invention has excellent hardness and notched cantilever beam impact strength, and also has environmental stress resistance and processing performance.

[0059] (2) The hardness of the styrene-butadiene resin composition of the present invention is between 65 and 84A, and the notched cantilever beam impact strength is ≥4.20 kJ / m. 2 Preferably, the styrene-butadiene resin composition has a hardness between 70 and 77A and a notched cantilever beam impact strength ≥ 6.4 kJ / m. 2 . Detailed Implementation

[0060] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0061] Example 1

[0062] This embodiment provides a styrene-butadiene resin composition, which includes a first styrene-butadiene block copolymer, a second styrene-butadiene block copolymer, an antioxidant, and zinc stearate;

[0063] The structural formula of the first styrene-butadiene block copolymer is as follows: A m -X1;

[0064] The structural formula of the second styrene-butadiene block copolymer is as follows: A n -X2;

[0065] Wherein, A is a styrene-butadiene block copolymer, m=4, n=2, X1 is a silicon tetrachloride residue with a functionality of 4, and X2 is a dichlorodimethylsilane residue with a functionality of 2.

[0066] The molar ratio of the first styrene-butadiene block copolymer to the second styrene-butadiene block copolymer is 3:1.

[0067] The styrene-butadiene resin composition is obtained by the following preparation method, which includes the following steps:

[0068] (1) Replace the 5L stainless steel polymerization reactor with purified nitrogen. In a nitrogen atmosphere, add 2500g cyclohexane, 0.25g diethanol dimethyl ether, and 348g styrene to the reactor. Add 6.3mL of a mixture of n-butyllithium and cyclohexane, where the mass percentage of n-butyllithium in the mixture is 20%. Initiate the polymerization reaction at 53°C. After 25 minutes of reaction, add 4.2mL of a mixture of silicon tetrachloride and cyclohexane, where the mass percentage of silicon tetrachloride in the mixture is 5%. React for 15 minutes, then add 3.5mL of... A mixture of n-butyllithium and cyclohexane, with n-butyllithium comprising 20% ​​by mass, was reacted with 192g of styrene at 53°C for 20 minutes. Then, 45g of butadiene and 60g of styrene were added, and the reaction was completed at 53°C for 30 minutes. Next, 48g of butadiene and 67g of styrene were added, and the reaction was completed at 53°C for 30 minutes. Finally, 73g of butadiene was added, and the reaction was completed at 60°C for 30 minutes, yielding a styrene-butadiene block copolymer.

[0069] (2) Add 12.8 mL of a mixture of silicon tetrachloride and cyclohexane to the styrene-butadiene block copolymer obtained in step (1), wherein the mass percentage of silicon tetrachloride in the mixture is 5%, add 4.2 mL of a mixture of dichlorodimethylsilane and cyclohexane, wherein the mass percentage of dichlorodimethylsilane in the mixture is 5%, and after 20 minutes, add 0.2 g of methanol, then add 3.2 g of antioxidant (antioxidant 1076 and antioxidant 1010 in a mass ratio of 1:1) and 0.5 g of zinc stearate. After the resulting adhesive is devolatilized and granulated, a styrene-butadiene resin composition comprising the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is obtained, wherein the number average molecular weight of the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is 184000 g / mol.

[0070] Example 2

[0071] This embodiment provides a styrene-butadiene resin composition, which includes a first styrene-butadiene block copolymer, a second styrene-butadiene block copolymer, and an antioxidant.

[0072] The structural formula of the first styrene-butadiene block copolymer is as follows: Am -X1;

[0073] The structural formula of the second styrene-butadiene block copolymer is as follows: A n -X2;

[0074] Wherein, A is a styrene-butadiene block copolymer, m=4, n=2, X1 is a tin tetrachloride residue with a functionality of 4, and X2 is a dichlorodimethylsilane residue with a functionality of 2.

[0075] The molar ratio of the first styrene-butadiene block copolymer to the second styrene-butadiene block copolymer is 1.1:1.

[0076] The styrene-butadiene resin composition is obtained by the following preparation method, which includes the following steps:

[0077] (1) Purge a 5L stainless steel polymerization reactor with purified nitrogen. In a nitrogen atmosphere, add 2500g of n-hexane, 0.25g of tetramethylethylenediamine, and 298g of styrene. Add 5.2mL of a mixture of n-butyllithium and n-hexane, where the mass percentage of n-butyllithium in the mixture is 20%. Initiate the polymerization reaction at 55°C. After 25 minutes of reaction, add 8mL of a mixture of tin tetrachloride and cyclohexane, where the mass percentage of tin tetrachloride in the mixture is 5%. React for 15 minutes, then immediately add 17.4mL of n-butyllithium... A mixture of butyllithium and n-hexane, with butyllithium comprising 20% ​​by mass, was reacted with 98g of styrene at 55°C for 20 minutes. Then, 90g of butadiene and 50g of styrene were added, and the reaction was completed at 55°C for 30 minutes. Next, 100g of butadiene and 52g of styrene were added, and the reaction was completed at 55°C for 30 minutes. Finally, 145g of butadiene was added, and the reaction was completed at 62°C for 30 minutes, yielding a styrene-butadiene block copolymer.

[0078] (2) Add 50 mL of a mixture of tin tetrachloride and n-hexane to the styrene-butadiene block copolymer obtained in step (1) and mix. The mass percentage of tin tetrachloride in the mixture is 5%. Add 25.1 mL of a mixture of dichlorodimethylsilane and n-hexane and mix. The mass percentage of dichlorodimethylsilane in the mixture is 5%. After 20 minutes, add 5 g of water and then add 3.2 g of antioxidant (antioxidant 1076 and antioxidant 1010 in a mass ratio of 1:1). After the resulting adhesive is devolatilized and granulated, a styrene-butadiene resin composition including the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is obtained. The number average molecular weight of the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is 50000 g / mol.

[0079] Example 3

[0080] This embodiment provides a styrene-butadiene resin composition, which includes a first styrene-butadiene block copolymer, a second styrene-butadiene block copolymer, and an antioxidant.

[0081] The structural formula of the first styrene-butadiene block copolymer is as follows: A m -X1;

[0082] The structural formula of the second styrene-butadiene block copolymer is as follows: A n -X2;

[0083] Wherein, A is a styrene-butadiene block copolymer, m=4, n=2, X1 is a tetramethoxysilane residue with a functionality of 4, and X2 is a dichlorodimethylsilane residue with a functionality of 2.

[0084] The molar ratio of the first styrene-butadiene block copolymer to the second styrene-butadiene block copolymer is 2.6:1.

[0085] The styrene-butadiene resin composition is obtained by the following preparation method, which includes the following steps:

[0086] (1) Purge a 5L stainless steel polymerization reactor with purified nitrogen. In a nitrogen atmosphere, add 2500g cyclohexane, 0.25g tetrahydrofuran, and 325g styrene to the reactor. Add 2.5mL of a mixture of n-butyllithium and cyclohexane, where the mass percentage of n-butyllithium in the mixture is 20%. Initiate the polymerization reaction at 50°C. After 25 minutes of reaction, add 1.2mL of a mixture of tetramethoxysilane and cyclohexane, where the mass percentage of tetramethoxysilane in the mixture is 5%. React for 15 minutes, then immediately add 2.4mL of... A mixture of n-butyllithium and cyclohexane, with n-butyllithium comprising 20% ​​by mass, was reacted with 116g of styrene at 50°C for 20 minutes. Then, 71g of butadiene and 69g of styrene were added, and the reaction was completed at 50°C for 30 minutes. Next, 71g of butadiene and 73g of styrene were added, and the reaction was completed at 50°C for 30 minutes. Finally, 108g of butadiene was added, and the reaction was completed at 70°C for 30 minutes, yielding a styrene-butadiene block copolymer. (2) Add 9 mL of a mixture of tetramethoxysilane and cyclohexane to the styrene-butadiene block copolymer prepared in (1) and mix. The mass percentage of tetramethoxysilane in the mixture is 5%. Add 3.2 mL of a mixture of dichlorodimethylsilane and cyclohexane and mix. The mass percentage of dichlorodimethylsilane in the mixture is 5%. After 20 minutes, add 6 g of carbonic acid and then add 3.2 g of antioxidant (antioxidant 1076 and antioxidant 168 in a mass ratio of 1:1). After the resulting adhesive is devolatilized and granulated, a styrene-butadiene resin composition including the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is obtained. The number average molecular weight of the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is 350,000 g / mol.

[0087] Example 4

[0088] This embodiment provides a styrene-butadiene resin composition, which differs from Example 1 in that the styrene-butadiene resin composition contains 95% styrene structural units by mass. To obtain the styrene-butadiene resin composition, the preparation method of A is adjusted as follows:

[0089] (1) Replace the 5L stainless steel polymerization reactor with purified nitrogen. In the nitrogen atmosphere, add 2500g cyclohexane, 0.25g diethanol dimethyl ether and 412g styrene to the reactor. Add 6.5mL of a mixture of n-butyllithium and cyclohexane, in which the mass percentage of n-butyllithium is 20%. The polymerization reaction is carried out at 53℃. After 25 minutes of reaction, add 4.2mL of a mixture of silicon tetrachloride and cyclohexane, in which the mass percentage of silicon tetrachloride is 5%. React for 15 minutes, and then add 3.3mL of the mixture of n-butyllithium and cyclohexane. The mixture contains 20% n-butyllithium by mass. 195g of styrene is added, and the reaction is completed after 20 minutes at 53°C to obtain a second polystyrene. Then, 23g of butadiene and 70g of styrene are added, and the reaction is completed after 30 minutes at 53°C to obtain a styrene-butadiene block copolymer. Then, 23g of butadiene and 70g of styrene are added, and the reaction is completed after 30 minutes at 53°C. Finally, 40g of butadiene is added, and the reaction is completed after 30 minutes at 60°C to obtain a styrene-butadiene block copolymer.

[0090] (2) Add 12.5 mL of a mixture of silicon tetrachloride and cyclohexane to the styrene-butadiene block copolymer prepared in (1), wherein the mass percentage of silicon tetrachloride in the mixture is 5%, add 4.2 mL of a mixture of dichlorodimethylsilane and cyclohexane, wherein the mass percentage of dichlorodimethylsilane in the mixture is 5%, and after 20 minutes, add 0.2 g of methanol, and then add 3.2 g of antioxidant (antioxidant 1076 and antioxidant 1010 in a mass ratio of 1:1). After the resulting adhesive is devolatilized and granulated, a styrene-butadiene resin composition comprising the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is obtained, wherein the number average molecular weight of the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is 184000 g / mol.

[0091] Everything else is the same as in Example 1.

[0092] Example 5

[0093] This embodiment provides a styrene-butadiene resin composition, which differs from Example 1 in that the styrene-butadiene resin composition contains 55% styrene structural units by mass. To obtain the styrene-butadiene resin composition, the preparation method of A is adjusted as follows:

[0094] (1) Replace the 5L stainless steel polymerization reactor with purified nitrogen. In a nitrogen atmosphere, add 2500g cyclohexane, 0.25g diethanol dimethyl ether, and 257g styrene to the reactor. Add 5.3mL of a mixture of n-butyllithium and cyclohexane, where the mass percentage of n-butyllithium in the mixture is 20%. Initiate the polymerization reaction at 53°C. After 25 minutes of reaction, add 3.8mL of a mixture of silicon tetrachloride and cyclohexane, where the mass percentage of silicon tetrachloride in the mixture is 5%. React for 15 minutes, then add 4.5mL of... A mixture of n-butyllithium and cyclohexane, with n-butyllithium comprising 20% ​​by mass, was reacted with 83g of styrene at 53°C for 20 minutes. Then, 98g of butadiene and 68g of styrene were added, and the reaction was completed at 53°C for 30 minutes. Next, 70g of butadiene and 55g of styrene were added, and the reaction was completed at 53°C for 30 minutes. Finally, 208g of butadiene was added, and the reaction was completed at 60°C for 30 minutes, yielding a styrene-butadiene block copolymer.

[0095] (2) Add 12.9 mL of a mixture of silicon tetrachloride and cyclohexane to the styrene-butadiene block copolymer prepared in (1), wherein the mass percentage of silicon tetrachloride in the mixture is 5%, add 4.3 mL of a mixture of dichlorodimethylsilane and cyclohexane, wherein the mass percentage of dichlorodimethylsilane in the mixture is 5%, and after 20 minutes, add 0.2 g of methanol, and then add 3.2 g of antioxidant (antioxidant 1076 and antioxidant 1010 in a mass ratio of 1:1). After the resulting adhesive is devolatilized and granulated, a styrene-butadiene resin composition comprising the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is obtained, wherein the number average molecular weight of the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is 184000 g / mol.

[0096] Everything else is the same as in Example 1.

[0097] Example 6

[0098] This embodiment provides a styrene-butadiene resin composition, which differs from Example 1 in that the number-average molecular weight of the styrene-butadiene resin composition is 440,000 g / mol. To obtain the styrene-butadiene resin composition, the preparation method is adjusted as follows:

[0099] (1) Purge a 5L stainless steel polymerization reactor with purified nitrogen. In a nitrogen atmosphere, add 2500g cyclohexane, 0.25g diethanol dimethyl ether, and 348g styrene to the reactor. Add 2.0mL of a mixture of n-butyllithium and cyclohexane, where the mass percentage of n-butyllithium in the mixture is 20%. Initiate the polymerization reaction at 53°C. After 25 minutes of reaction, add 1.0mL of a mixture of silicon tetrachloride and cyclohexane, where the mass percentage of silicon tetrachloride in the mixture is 5%. React for 15 minutes, then add 2.1mL of... A mixture of n-butyllithium and cyclohexane, wherein the mass percentage of n-butyllithium in the mixture is 20%, is added to 192g of styrene, and the reaction is completed after 20 minutes at 53°C. Then, 45g of butadiene and 60g of styrene are added, and the reaction is completed after 30 minutes at 53°C. Then, 48g of butadiene and 67g of styrene are added, and the reaction is completed after 30 minutes at 53°C. Finally, 73g of butadiene is added, and the reaction is completed after 30 minutes at 60°C, yielding a styrene-butadiene block copolymer.

[0100] (2) Add 8.6 mL of a mixture of silicon tetrachloride and cyclohexane to the mixture obtained in (1), wherein the mass percentage of silicon tetrachloride in the mixture is 5%, add 2.8 mL of a mixture of dichlorodimethylsilane and cyclohexane, wherein the mass percentage of dichlorodimethylsilane in the mixture is 5%, and after 20 minutes, add 0.2 g of methanol, and then add 3.2 g of antioxidant (antioxidant 1076 and antioxidant 1010 in a mass ratio of 1:1). After the resulting adhesive is devolatilized and granulated, a styrene-butadiene resin composition comprising the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is obtained, wherein the number average molecular weight of the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer is 440,000 g / mol.

[0101] Example 7

[0102] This embodiment provides a styrene-butadiene resin composition, which differs from Example 1 in that the preparation process of the styrene-butadiene resin composition is as follows: in step (1), the molar ratio of the first coupling agent (silicon tetrachloride) to part of the initiator is 0.15:1. In the preparation method of the styrene-butadiene resin composition, the amount of the mixture of silicon tetrachloride and cyclohexane added in step (1) is adjusted to 10 mL, and the rest is the same as in Example 1.

[0103] Example 8

[0104] This embodiment provides a styrene-butadiene resin composition, which differs from Example 1 in that the preparation process of the styrene-butadiene resin composition is as follows: in step (1), the molar ratio of the first coupling agent (silicon tetrachloride) to part of the initiator is 0.02:1. In the preparation method of the styrene-butadiene resin composition, the amount of the mixture of silicon tetrachloride and cyclohexane added in step (1) is adjusted to 1.5 mL, and the rest is the same as in Example 1.

[0105] Comparative Example 1

[0106] This comparative example provides a styrene-butadiene resin composition, which differs from Example 1 in that the styrene-butadiene resin composition does not include a first styrene-butadiene block copolymer. To obtain the styrene-butadiene resin composition, step (2) of the preparation method does not involve adding a mixture of silicon tetrachloride and cyclohexane; otherwise, it is the same as in Example 1.

[0107] Comparative Example 2

[0108] This comparative example provides a styrene-butadiene resin composition, which differs from Example 1 in that the styrene-butadiene resin composition does not include a second styrene-butadiene block copolymer. To obtain the styrene-butadiene resin composition, step (2) of the preparation method does not involve adding a mixture of dichlorodimethylsilane and cyclohexane; otherwise, it is the same as in Example 1.

[0109] Comparative Example 3

[0110] This comparative example provides a styrene-butadiene resin composition, which differs from Example 1 in that A is replaced with a styrene-butadiene block copolymer that does not contain residues of the first coupling agent. In order to obtain the styrene-butadiene resin composition, step (1) of the preparation method of the styrene-butadiene resin composition does not add a mixture of silicon tetrachloride and cyclohexane, and the rest is the same as in Example 1.

[0111] Performance testing

[0112] The styrene-butadiene resin compositions described in Examples 1-8 and Comparative Examples 1-3 were tested as follows:

[0113] (1) Hardness: Determined according to GB / T2411-2008 "Determination of indentation hardness (Shore hardness) of plastics and hard rubber using a hardness tester".

[0114] (2) Impact strength of notched cantilever beam: determined in accordance with GB / T 1843-2008 "Determination of impact strength of plastic cantilever beam".

[0115] (3) Melt flow index: determined according to GB / T 3682-2000 "Determination of melt mass flow rate and melt volume flow rate of thermoplastics" under test conditions of 200℃ and 5kg.

[0116] The test results are summarized in Table 1.

[0117] Table 1

[0118]

[0119]

[0120] Analysis of the data in Table 1 shows that the hardness of the styrene-butadiene resin compositions provided in Examples 1-8 is between 65 and 84 A, and the notched cantilever beam impact strength is ≥4.2 kJ / m. 2 The styrene-butadiene resin compositions provided in Examples 1-3 have a hardness between 70 and 77A and a notched cantilever beam impact strength ≥ 6.4 kJ / m. 2 The styrene-butadiene resin composition of the present invention has excellent hardness and notched cantilever beam impact strength, as well as resistance to environmental stress and processing performance.

[0121] Analysis of Comparative Examples 1-2 and Example 1 shows that the performance of Comparative Examples 1-2 is not as good as that of Example 1, proving that the styrene-butadiene resin composition formed by the synergistic combination of the first styrene-butadiene block copolymer and the second styrene-butadiene block copolymer of the present invention has better performance.

[0122] Analysis of Comparative Example 3 and Example 1 shows that the performance of Comparative Example 3 is not as good as that of Example 1, proving that the styrene-butadiene resin composition containing the A structure of the present invention has better performance.

[0123] Analysis of Examples 4-5 and Example 1 shows that if the mass percentage of styrene structural units in the styrene-butadiene resin composition is too high (Example 4), the impact strength of the notched cantilever beam is too low; if the mass percentage of styrene structural units in the styrene-butadiene resin composition is too low (Example 5), the hardness is too low. This proves that the performance of the styrene-butadiene resin composition is better when the mass percentage of styrene structural units is in the range of 60%-80%.

[0124] Analysis of Examples 6 and 1 shows that if the number-average molecular weight of the styrene-butadiene resin composition is too high (Example 6), the hardness is too high and the processing performance is too low, proving that the performance of the styrene-butadiene resin composition is better when the number-average molecular weight is in the range of 50,000-350,000 g / mol.

[0125] Analysis of Examples 7-8 and Example 1 shows that if the molar ratio of the first coupling agent to part of the initiator in step (1) is too large (Example 7), the hardness is too large and the processing performance is too low; if the molar ratio of the first coupling agent to part of the initiator in step (1) is too small (Example 8), the hardness is too small and the impact strength of the notched cantilever beam is too small. This proves that the performance is better when the molar ratio of the first coupling agent to part of the initiator in step (1) is in the range of 0.05 to 0.1:1.

[0126] The present invention has been illustrated with the above embodiments to explain the detailed method of the present invention. However, the present invention is not limited to the detailed method described above, that is, it does not mean that the present invention must rely on the detailed method described above to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A styrene-butadiene resin composition, characterized in that, The styrene-butadiene resin composition comprises a first styrene-butadiene block copolymer and a second styrene-butadiene block copolymer; The first styrene-butadiene block copolymer has the following structural formula: (St1-Li-X1-Li-St2-Bd1 / St3-Bd2 / St4-Bd3) m -X1, where St1 and St2 are polystyrene segments, Bd3 is a polybutadiene segment, and Bd1 / St3 and Bd2 / St4 are segments of butadiene and styrene random blocks; The second styrene-butadiene block copolymer has the following structural formula: (St1-Li-X1-Li-St2-Bd1 / St3-Bd2 / St4-Bd3) n -X2, where St1 and St2 are polystyrene segments, Bd3 is a polybutadiene segment, and Bd1 / St3 and Bd2 / St4 are segments of butadiene and styrene random blocks; Where m and n are integers, m≥4, n=2, X1 is the residue of the first coupling agent with a functionality ≥3, and X2 is the residue of the second coupling agent with a functionality ≥2.

2. The styrene-butadiene resin composition according to claim 1, characterized in that, In the first and second styrene-butadiene block copolymers, the mass percentage of styrene structural units is 60%-80%, and the mass percentage of butadiene structural units is 20%-40%.

3. The styrene-butadiene resin composition according to claim 1, characterized in that, The styrene-butadiene resin composition further includes (St1). m -X1, where St1 is a polystyrene segment.

4. The styrene-butadiene resin composition according to claim 1, characterized in that, The number-average molecular weights of the first and second styrene-butadiene block copolymers are 50,000-350,000 g / mol.

5. The styrene-butadiene resin composition according to claim 1, characterized in that, The first coupling agent includes any one or a combination of at least two of silicon tetrachloride, tin tetrachloride, or tetramethoxysilane.

6. The styrene-butadiene resin composition according to claim 1, characterized in that, The second coupling agent includes silicon dichloride and / or dimethoxydichlorosilane.

7. The styrene-butadiene resin composition according to claim 1, characterized in that, The styrene-butadiene resin composition also includes additives.

8. The styrene-butadiene resin composition according to claim 7, characterized in that, The additives include antioxidants and lubricants.

9. The styrene-butadiene resin composition according to claim 8, characterized in that, The lubricant includes microcrystalline wax and / or zinc stearate.

10. A method for preparing a styrene-butadiene resin composition according to any one of claims 1-9, characterized in that, The preparation method includes the following steps: (1) Styrene, butadiene, initiator and part of the first coupling agent are mixed and reacted to obtain styrene-butadiene block copolymer; (2) The styrene-butadiene block copolymer obtained in step (1), the remaining first coupling agent and the second coupling agent are mixed, reacted, and a terminator is added to obtain the styrene-butadiene resin composition. Step (1) includes the following steps: (S1) The solvent, regulator, part of styrene and part of the initiator are mixed and reacted to obtain product a; (S2) The product a obtained in step (S1) is mixed with a portion of the first coupling agent and reacted for the first time. The remaining initiator is mixed with a portion of styrene and reacted for the second time to obtain product b. (S3) Mix the product b obtained in step (S2), a portion of butadiene and a portion of styrene, and react to obtain product c; (S4) Mix the product c obtained in step (S3), a portion of the butadiene and the remaining styrene, and react to obtain product d; (S5) The product d obtained in step (S4) is mixed with the remaining butadiene and reacted to obtain the styrene-butadiene block copolymer; The molar ratio of the first coupling agent in step (S2) to the initiator in step (S1) is 0.05~0.1:

1.

11. The preparation method according to claim 10, characterized in that, The solvent includes any one or a combination of at least two of cyclohexane, n-hexane, or toluene.

12. The preparation method according to claim 10, characterized in that, The regulator includes any one or a combination of at least two of tetrahydrofuran, tetramethylethylenediamine, or diethanol dimethyl ether.

13. The preparation method according to claim 10, characterized in that, The initiator includes n-butyllithium.

14. The preparation method according to claim 10, characterized in that, Based on the total mass of styrene being 100%, in step (S1), the mass percentage of styrene in the aforementioned portion is 50-70%.

15. The preparation method according to claim 10, characterized in that, Based on the total mass of the initiator being 100%, in step (S1), the mass percentage of the initiator in the aforementioned portion is 20-75%.

16. The preparation method according to claim 10, characterized in that, Based on the total mass of styrene being 100%, in step (S2), the mass percentage of styrene in the aforementioned portion is 15-40%.

17. The preparation method according to claim 10, characterized in that, Based on the total mass of butadiene being 100%, in step (S3), the mass percentage of butadiene in the aforementioned portion is 10-30%.

18. The preparation method according to claim 10, characterized in that, Based on the total mass of styrene being 100%, in step (S3), the mass percentage of styrene in the aforementioned portion is 5-15%.

19. The preparation method according to claim 10, characterized in that, Based on the total mass of butadiene being 100%, in step (S4), the mass percentage of butadiene in the aforementioned portion is 10-30%.

20. The preparation method according to claim 10, characterized in that, The reactions described in steps (S1) and (S2) are carried out independently until the conversion rate is ≥99%.

21. The preparation method according to claim 10, characterized in that, In steps (S1), (S3), (S4) and (S5), the temperature of each reaction is independently 50-95°C, and the temperature of the second reaction in step (S2) is 50-95°C.

22. The preparation method according to claim 10, characterized in that, In steps (S1), (S3), (S4) and (S5), the reaction time is 20-40 min each independently, and the second reaction time in step (S2) is 20-40 min.

23. The preparation method according to claim 10, characterized in that, The ratio of the total molar amount of the remaining first coupling agent and the second coupling agent in step (2) to the molar amount of the initiator in step (1) is 0.15~0.5:

1.

24. The preparation method according to claim 10, characterized in that, In step (2), with the total molar amount of the remaining first coupling agent and the second coupling agent being 100%, the mass percentage of the molar amount of the remaining first coupling agent is 50-70%.

25. The preparation method according to claim 10, characterized in that, The terminating agent includes any one or a combination of at least two of methanol, carbonic acid, or water.

26. The preparation method according to claim 10, characterized in that, The addition of the terminator also includes the addition of auxiliary agents to the system.

27. The use of a styrene-butadiene resin composition according to any one of claims 1-9 in an impact-resistant article.

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