A hydrogenated styrene-conjugated diene-styrene triblock copolymer, and a method for preparing and using the same

Abstract

The application discloses a hydrogenated styrene-conjugated diene-styrene triblock copolymer and a preparation method and application thereof. The hydrogenated styrene-conjugated diene-styrene triblock copolymer is obtained through three-stage anionic polymerization, has a narrow distribution of molecular mass, a high degree of randomness and a high content of short branches such as ethyl, isopropyl and methyl in the middle block, and has the characteristics of high oil filling, low deformation, high cohesion and high tensile strength, and in particular, the hot melt pressure sheet glue thereof has excellent dry and wet skid resistance, and the comprehensive physical properties are superior to those of existing SEBS, so that the hydrogenated styrene-conjugated diene-styrene triblock copolymer is a relatively ideal material for a high-end shoe sole.

Description

Technical Field

[0001] This invention relates to a hydrogenated styrene-conjugated diene copolymer, particularly to a hydrogenated styrene-conjugated diene-styrene triblock copolymer, and also to its preparation method and application as a shoe outsole material, belonging to the field of functional polymer synthesis technology. Background Technology

[0002] Traditional commercially available styrene-conjugated diene copolymers include latex styrene-butadiene rubber (ESBR) with low vinyl content, anionic styrene-butadiene rubber (SSBR and SBS), and solid-state rubber (SIBR), with polymer sequence distributions including random copolymerization and block copolymerization. For example, ESBR and SSBR used in tire tread rubber have random distributions. However, SSBR used in vulcanizable footwear materials, such as the 1205 and 2003 types, has a partially block linear structure, and the content of conjugated diene side chain groups (such as vinyl or 3,4-addition groups) in the polymer molecule does not exceed 20%, resulting in poor anti-slip performance of vulcanized shoe soles. In addition, the abrasion resistance, flexural resistance, and aging resistance of shoe soles made of thermoplastic styrene-butadiene elastomer (SBS) are inferior to those of vulcanized rubber. At the same time, their wet grip is also lower. Existing SBS hydrides (SEBS), such as commercially available products produced by the Synthetic Rubber Plant of Sinopec Baling Petrochemical Company, such as YH-501, YH-502, YH-503, YH-602, YH-603, and YH-604, which are used as outsole materials, have slightly better wet grip than polyvinyl acetate polymers (EVA). However, they still cannot meet people's requirements for safe and high-quality footwear soles.

[0003] Chinese patents (CN111718453A and CN111718454A) disclose a partially hydrogenated styrene-b-conjugated diene / divinylbenzene random copolymer, its preparation method, and its applications. This polymer possesses advantages such as vulcanizable double bonds, long-chain branching, and a wide molecular weight distribution, making it particularly suitable for outdoor window sealing materials. In the aforementioned two patents, divinylbenzene is used solely to provide branching density, broaden the polymer's molecular weight distribution, improve the polymer's powder absorption and roller coating properties during mixing with inorganic powders, and enhance the processing performance of the composite material. The polymer is a biblock copolymer and does not exhibit thermoplastic elastomer behavior, belonging to the technical field of synthetic rubber or vulcanized rubber. Chinese patent (CN112011017A) discloses a solution method for preparing bimodal star-branched butyl rubber. This method uses solution-based anionic polymerization to prepare bimodal star-branched butyl rubber, synthesizing a poly(styrene-conjugated diene) block polymer, which is then coupled with silicon tetrachloride to obtain a four-armed star-block polymer. Kraton has filed a patent application in China (CN107057260B) disclosing high-flow, hydrogenated styrene-butadiene-styrene block copolymers and their applications. The patent relates to novel, high-melt-flow, low-viscosity, selectively hydrogenated styrene-butadiene-styrene (hSBS) or selectively hydrogenated controlled-distribution styrene-butadiene / styrene-styrene (hSBSS) block copolymers, wherein the melt flow rate of the block copolymer is at least 100 g / 10 min (230°C / 2.16 kg). These block copolymers exhibit very high melt flow rates while also possessing high strength and elasticity, as styrene is a block copolymer, and applications with typically low melt flow rates are impossible. This invention also includes various applications, such as glass fiber hSBS or hSBSS reinforced mats, low-viscosity hSBS or hSBSS coatings for industrial use, hot melt adhesives prepared from hSBS or hSBSS blended with polyalphaolefins, and elastic films, fibers; nonwoven structures using hSBS or hSBSS, and melt-sprayed elastic nonwoven fabrics. The paper "Advances in Styrene-Based Thermoplastic Elastomer Technology," Gansu Petroleum and Chemical Industry, 2007, Issue 3, reviews the progress of SBC in polarization modification, selective hydrogenation of SBS, and coupling agent technology through a survey of published patents from major domestic and international styrene-based thermoplastic elastomer (SBC) manufacturers (such as Kraton Polymer Research Co., Ltd. and Taiwan Synthetic Rubber Co., Ltd.). In addition, Kunshan Duowei Sports Goods Co., Ltd. in China has conducted extensive research on high-end sports shoes. In particular, it has achieved good results in preparing marathon running shoes and sneakers with anti-fatigue and anti-slip properties by combining high vinyl content styrene-butadiene random copolymer (SSBR) with polar rubber (brominated butyl rubber).

[0004] The article "Synthetic Rubber Industry, 2010-11-15, Synthesis of Tin-Coupled Oil-Extended Styrene-Isoprene-Butadiene Terpolymer [SIBR]" describes the polymerization of styrene-isoprene-butadiene in cyclohexane with an asymmetric ether as a regulator, initiated by butyllithium, followed by coupling with tin tetrachloride. The results did not describe the 1,2-addition and 3,4-addition units of the polymer, which exhibited a narrow bimodal distribution. Low Green's strength led to poor roll wrapping performance during processing, and low inter-chain entanglement resulted in a small decrease in viscosity due to shear thinning. DMA analysis showed that the SIBR vulcanizate exhibited better wet-slip properties than general-purpose styrene-butadiene rubbers such as SSBR2305 and ESBR1502. Similarly, in the article "(Elastomers, 2012-2-25, Research on the Basic Properties of Domestic Integrated Rubber SIBR)," it was introduced that the anti-slip performance of tread rubber made of polystyrene-butadiene-isoprene rubber is 2.5 times that of latex styrene-butadiene rubber, but the microstructure of this SIBR was not described, nor was there any description of the application of this material in sports shoes.

[0005] In summary, existing polystyrene-conjugated diene hydrides are obtained by selective hydrogenation of polystyrene-butadiene diblock coupling or triblock linear copolymers (SBS) with a vinyl unit distribution of 38-42% by mass. They exhibit the behavior of thermoplastic elastomers and are mainly used in tool handles, elastic oil-filled products, and toys. However, when used to prepare shoe outsole materials, they exhibit poor dry and wet slip resistance. In contrast, existing styrene-isoprene-butadiene terpolymer (SIBR) compounded and vulcanized films exhibit excellent dry and wet slip resistance, but they are non-thermoplastic elastomers. Summary of the Invention

[0006] As is well known, during the polymerization of the polybutadiene segment in the synthesis of existing SEBS raw rubber SBS, the polymerization of butadiene is a strongly exothermic reaction. Even with forced heat removal in the second stage of polymerization, the 1,2-addition of butadiene decreases with increasing temperature due to factors such as local overheating or limited mass and heat transfer in the polymerization environment. The 1,4-addition mainly occurs, and the hydrogenated 1,4-addition units produce polyethylene long chains and crystallization. The hot melt extruded sheet of polymer exhibits poor dry and wet slip resistance. In addition, existing SSBR and SIBR are non-thermoplastic elastomers and cannot be injection molded.

[0007] The first objective of this invention is to provide a hydrogenated styrene-conjugated diene-styrene triblock copolymer with a narrow molecular weight distribution, and a high degree of randomness in the intermediate blocks, with high content of short-chain components such as ethyl, isopropyl, and methyl. This copolymer has the characteristics of high oil fillability, low deformation, high cohesion, and high tensile strength. In particular, its hot melt adhesive exhibits excellent dry and wet slip resistance, and its overall physical properties are superior to existing SEBS, making it an ideal material for mid-to-high-end shoe outsoles.

[0008] Another object of the present invention is to provide a simple and low-cost method for preparing the hydrogenated styrene-conjugated diene-styrene triblock copolymer.

[0009] The third objective of this invention is to provide an application of a hydrogenated styrene-conjugated diene-styrene triblock copolymer, which has the characteristics of high oil filling capacity, low deformation, high cohesion and high tensile strength. The hot melt adhesive exhibits excellent anti-dry and anti-wet slip properties and can be widely used as a mid-to-high-end shoe outsole material.

[0010] To achieve the above technical objectives, the present invention provides a hydrogenated styrene-conjugated diene-styrene triblock copolymer (abbreviated as SIEBS, its unhydrogenated raw rubber is abbreviated as SIBS), which has the expression in Formula 1:

[0011] S-(I x E y B z ) n -S

[0012] Formula 1

[0013] in,

[0014] S represents a polystyrene block;

[0015] I x It is a hydrogenated polyisoprene microblock (including hydrogenated 1,4-addition polyisoprene units and hydrogenated 3,4-addition polyisoprene units);

[0016] E y For hydrogenated 1,4-addition polybutadiene microblocks;

[0017] B z For hydrogenated 1,2-addition polybutadiene microblocks;

[0018] (I x E y B z ) n It is a random copolymer block of hydrogenated butadiene-isoprene;

[0019] n, x, y, and z are all polymer degrees, and x, y, and z are all ≤3 (generally, x, y, and z are all 1, 2, or 3).

[0020] The hydrogenated styrene-conjugated diene-styrene triblock copolymer of the present invention is characterized by the fact that the intermediate block is a random copolymer block of hydrogenated isoprene and butadiene with a high degree of randomness. The degree of polymerization of the hydrogenated 1,4-addition polybutadiene microblock contained therein does not exceed 3, which avoids the defects of crystallization or physical nodes of long polyethylene chain segments, resulting in decreased resilience and increased deformation. At the same time, the hydrogenated 1,2-addition polybutadiene microblock and hydrogenated polyisoprene microblock can provide a large number of short branches such as methyl, ethyl, and isopropyl, which can also reduce the crystallinity of the polymer chain.

[0021] As a preferred embodiment, the mass ratio of the polystyrene block to the random copolymer block of hydrogenated butadiene and isoprene is (40-50) / (60-50).

[0022] As a preferred embodiment, the mass ratio of hydrogenated isoprene units to hydrogenated butadiene units in the random copolymer block of hydrogenated butadiene and isoprene is (5-90) / (95-10); more preferably (10-20) / (90-80). A small amount of hydrogenated isoprene units is beneficial for modifying isopropyl side groups on the polymer backbone, such as SIBR (integrated rubber), which has good dry and wet slip resistance. However, if the proportion of hydrogenated isoprene units is too high, and if dicyclopentadiene titanium dichloride is used as a conventional hydrogenation catalyst, the hydrogenation of its double bonds is difficult to occur due to the greater steric hindrance of the isoprene addition chain compared to butadiene, resulting in an excessively high iodine value of the hydrogenated polymer and a decrease in the strength and anti-aging properties of the hydride.

[0023] As a preferred embodiment, the total mass of the 3,4-addition units of the hydrogenated isoprene unit and the 1,2-addition units of the hydrogenated butadiene unit in the random copolymer block of hydrogenated butadiene and isoprene accounts for 45-55%. If the proportion of 1,4-addition units in the hydrogenated butadiene unit is too high, it is easy to form polyethylene long chains with good crystallinity, which will reduce the dry and wet slip resistance of the polymer vulcanizate. When the total mass of the 3,4-addition units of the hydrogenated isoprene unit and the 1,2-addition units of the hydrogenated butadiene unit is controlled to be 45-55%, and a higher proportion of side groups such as methyl, ethyl, and isopropyl can be obtained, the crystallinity of the polymer can be significantly reduced, and the resilience can be increased.

[0024] As a preferred option, the number-average molecular weight Mn of the hydrogenated styrene-conjugated diene-styrene triblock copolymer is 6 × 10⁻⁶. 4 ~15×10 4 Molecular weight distribution index M W / M n =1.03~1.05.

[0025] As a preferred option, the iodine value of the hydrogenated styrene-conjugated diene-styrene triblock copolymer is 30-50 g / 100 g.

[0026] This invention also provides a method for preparing hydrogenated styrene-conjugated diene-styrene triblock copolymer, wherein an initiator and styrene monomer are added to an anionic polymerization solution system to initiate a first-stage polymerization reaction, followed by the continuous and uniform addition of a mixed monomer of isoprene and butadiene to carry out a second-stage polymerization reaction, and then the addition of styrene monomer to carry out a third-stage polymerization reaction to obtain a SIBS adhesive solution, which is then subjected to a hydrogenation reaction to obtain the final product.

[0027] As a preferred embodiment, the anionic polymerization solution system comprises cyclohexane and / or n-hexane solvents. The cyclohexane and n-hexane used in the anionic polymerization solution system of this invention are solvents well known to those skilled in the art.

[0028] As a preferred embodiment, the anionic polymerization solution system contains at least one activator selected from tetrahydrofurfuryl propane, tetrahydrofurfuryl ethyl ether, and tetrahydrofurfuryl ethyl ether; the amount of the activator is 50-60 mg / kg solvent. Using an activator can effectively control the total mass of the 1,2-addition units of butadiene and the 3,4-addition units of isoprene in SIBS to be 45-55% of the total mass of butadiene and isoprene units. As a preferred embodiment, the conditions for the single-stage polymerization reaction are: temperature 55℃-60℃, time 20-30 min.

[0029] As a preferred embodiment, the conditions for the two-stage polymerization reaction are as follows: the continuous feeding time of the isoprene and butadiene mixed monomers is 15–20 min, the temperature is 55°C–75°C, and the reaction continues for another 15–25 min after the feeding is completed. It is worth further clarifying that the reason for the continuous feeding copolymerization of the mixed dienes in the two-stage copolymerization is to increase the randomness of the isoprene-butadiene copolymerization. Because the polymerization rate of isoprene is lower than that of butadiene, continuous feeding can prevent the butadiene from homopolymerizing.

[0030] As a preferred embodiment, the conditions for the three-stage polymerization reaction are: a temperature of 60℃~70℃ and a time of not less than 25 minutes.

[0031] As a preferred embodiment, the hydrogenation reaction process is as follows: first, an initiator is added to the SIBS solution, and the solution is activated for 10 to 30 minutes at a temperature of 40 to 75°C and a hydrogen pressure of 6 to 13 bar. Then, a co-catalyst is added and activated for 10 to 20 minutes. Finally, the main catalyst is added, and the solution is catalytically hydrogenated for more than 120 minutes at a temperature of 70 to 105°C and a hydrogen pressure of 13 to 18 bar.

[0032] As a preferred embodiment, the main catalyst is dicyclopentadiene titanium dichloride, and its dosage is 0.035-0.050 g / 100 g relative to the dry basis mass of SIBS adhesive; the co-catalyst is dimethyl phthalate, and its molar ratio to the main catalyst is 0.3-0.5:1.

[0033] The preparation method of SIBS of the present invention is as follows: In a closed environment containing solvent, a set amount of activator, n-butyllithium (NBL), and styrene are added, and a homopolymerization reaction is initiated and carried out at a temperature of 55°C to 60°C for 20 to 30 minutes. Then, a set amount of isoprene and butadiene mixed monomers are added. The isoprene and butadiene mixed monomers are added continuously over a period of 15 to 20 minutes at a reaction temperature of 55°C to 75°C. After the addition is complete, the reaction continues for another 15 to 25 minutes. Finally, the remaining amount of styrene is added, and the reaction is carried out at a temperature of 60°C to 70°C for at least 25 minutes to obtain the SIBS solution. The number-average molecular weight Mn of SIBS is 6 × 10⁻⁶. 4 ~15×10 4 (Preferred in Mn=7×10) 4 ~10×10 4 Within the range), the molecular weight distribution index M of SIBS W / M n =1.03~1.05.

[0034] The method for preparing SIEBS by hydrogenation of SIBS adhesive solution according to the present invention is as follows:

[0035] A measured amount of n-butyllithium is added to a hydrogenation reactor containing the SIBS solution prepared above. The mixture is then stirred and activated for 10–30 min at 40–75 °C and 6–13 bar hydrogen pressure. A measured amount of co-catalyst is then added for further activation for 10–20 min. At this point, the main catalyst is added and hydrogenated at 13–18 bar and 70–105 °C for at least 120 min until the iodine value (30–50 g / 100 g) of the polymer meets the requirements. Hydrogenation is then stopped. Finally, after the hydrogenation of the solution is terminated, 3‰ of antioxidants 1076 and 168 are added and stirred evenly. The solution is then coagulated, dehydrated, and dried to obtain granular SIEBS elastomer.

[0036] The preferred main catalyst of this invention is dicyclopentadiene titanium dichloride, which is well known to those skilled in the art, and its dosage is 0.035 to 0.050 g / 100 g relative to the total amount of polymerizable monomers; the co-catalyst is dimethyl phthalate, and the molar ratio of the co-catalyst dosage to the main catalyst is 0.3 to 0.5:1.

[0037] The present invention also provides an application of hydrogenated styrene-conjugated diene-styrene triblock copolymer in shoe outsole materials.

[0038] The SIEBS of the present invention can be processed and molded in the same way as existing general-purpose SEBS elastomers.

[0039] The formula (parts by weight) for the shoe outsole composite material of the present invention is as follows: SIEBS, 100 parts; carbon black N330, 15-25 parts; light calcium carbonate, 45-55 parts; naphthenic oil 4010, 55-65 parts; antioxidant 1076, 2-4 parts.

[0040] The preparation method of the shoe outsole of the present invention is as follows: the materials in the above-mentioned formula are mixed, and then melted, extruded and granulated in a screw extruder at 190-200°C. Then, the granules are fed into an injection molding machine and the melt is injected into a shoe mold at 190-200°C to obtain the shoe outsole.

[0041] The physical properties of the SIEBS outsole composite hot melt adhesive preferred in this invention are as follows: 300% tensile stress (MPa) > 8.0; tensile strength (MPa) > 18; elongation at break (%) > 300; Shore A hardness 70-80; permanent deformation at break (%) < 50; dry slip resistance coefficient > 0.9; wet slip resistance coefficient 0.45.

[0042] Compared with existing technologies, the beneficial technical effects of the present invention are as follows:

[0043] Compared to existing SBS with an iodine value of 300-400g / 100g, existing SEBS and shoe outsole materials made from it have poor dry and wet slip resistance, and existing SIBR and SSBR require long-processing such as mixing and vulcanization.

[0044] The SIEBS molecules of this invention have an iodine value of only 30-50 g / 100g. The SIEBS molecules not only have a low content of unsaturated double bonds, but also possess the anti-aging and high-strength physical behaviors of existing SEBS, as well as low shrinkage, good elasticity, and, most importantly, excellent dry and wet slip resistance, with dry and wet slip resistance coefficients greater than 0.90 and 0.45, respectively. It is suitable for foam shoes and is a superior material for mid-to-high-end sports shoes. SIEBS is incomparable to existing thermoplastic elastic materials such as SBS, SEBS, EVA, and polyurethane, and also overcomes the shortcomings of existing SIBR and SSBR in the footwear industry, which involve long manufacturing processes.

[0045] The SIEBS of this invention is simple to prepare, can be synthesized using existing mature processes, and is easy to control and industrialize. Attached Figure Description

[0046] Figure 1 H of the SIEBS raw rubber prepared in Example 1 1 -NMR.

[0047] Figure 2 H of SIEBS prepared in Example 1 1 -NMR. Detailed Implementation

[0048] The following examples are intended to further illustrate and describe the content of the present invention, and do not constitute a limitation on the scope of protection of the claims of the present invention.

[0049] In the following examples, the number-average molecular weight and molecular weight distribution index of the polymers were determined using gel permeation chromatography (GPC); H2 was used. 1 - The microstructure of the polymer was quantitatively determined by NMR spectroscopy; the mechanical properties of the tablet adhesive were tested according to GB / T36089-2018; the anti-slip coefficient of the tablet adhesive was tested according to DW-09BL-312.

[0050] Example 1

[0051] Under nitrogen protection, 3000 mL of cyclohexane and 132 mg of tetrahydrofurfuryl ethyl ether (ETE) were added to a 5 L polymerization reactor. Stirring was started and the material temperature was raised to 55 °C. At this time, 5.7 mL of 0.7 mol / L NBL and 66.5 mL of styrene were added to the polymerization reactor to initiate polymerization for 25 min. Then, a mixed monomer consisting of 30 mL of isoprene and 230 mL of butadiene was continuously and uniformly added to the polymerization reactor over 17 min, controlling the maximum polymerization temperature not to exceed 75 °C. After the mixed monomer was added, polymerization continued for another 20 min. Then, 66.5 mL of styrene was added to carry out the third stage of polymerization for 26 min, and the SIBS solution was obtained.

[0052] The gel solution was pressurized into a hydrogenation reactor under nitrogen pressure, and 6 mL of NBL was added. The temperature was raised to 70°C, and the mixture was stirred and activated at 10 bar hydrogen pressure for 20 min to convert butyllithium to lithium hydride. Then, 8 mL of a 0.02 mol / L dimethyl phthalate cyclohexane solution (co-catalyst) was added, and the mixture was activated for another 15 min. At this point, 0.18 g of dicyclopentadiene titanium dichloride was added, and the mixture was stirred at 16 bar hydrogen pressure for 130 min, controlling the maximum temperature not to exceed 95°C. During this period, the iodine value of the polymer was measured, and hydrogenation was stopped when it reached 43.6 g / 100 g. After the hydrogenation of the gel solution was terminated with water, 8.0 g each of antioxidant 1076 and antioxidant 168 were added and stirred evenly. The gel solution was then coagulated, dehydrated, and dried to obtain 306 g of granular SIEBS elastomer, labeled as SIEBS1#. The original polymer gel SIEBS gel solution and SIEBS1#H were also discussed. 1 -NMR spectra are attached. Figure 1 and Figure 2 The molecular weight and molecular behavior of the raw gum are shown in Table 1.

[0053] Example 2

[0054] The relevant process conditions in Example 1 were kept unchanged, except that the amount of styrene added in the first and third stages was 80 mL, the amount of isoprene added in the second stage was 40 mL, and the amount of ETE added was 120 mg.

[0055] The resulting hydrogenated gel was labeled as SIEBS2#, and the molecular weight and molecular behavior of the original gel are shown in Table 1.

[0056] Example 3

[0057] The relevant process conditions in Example 1 were kept unchanged, except that the amount of styrene added in the first and third stages was 66 mL, the amount of isoprene added in the second stage was 53 mL, and the amount of ETE added was 138 mg.

[0058] The resulting hydrogenated gum was labeled as SIEBS3#, and the molecular weight and molecular behavior of the original gum are shown in Table 1.

[0059] Example 4

[0060] The relevant process conditions in Example 1 were kept unchanged, except that 5.2 mL of NBL was added during polymerization.

[0061] The resulting hydrogenated gel was labeled as SIEBS4#, and the molecular weight and molecular behavior of the original gel are shown in Table 1.

[0062] Example 5

[0063] The relevant process conditions in Example 1 were kept unchanged, except that 145 mg of ETE and 6.2 mL of NBL were added during polymerization.

[0064] The resulting hydrogenated rubber was labeled as SIEBS5#, and the molecular weight and molecular behavior of the original rubber are shown in Table 1.

[0065] Comparative Example 1

[0066] The relevant process conditions in Example 1 were kept unchanged, except that 6.5 mL of NBL was added during polymerization.

[0067] The resulting hydrogenated gum was labeled SIEBST1, and the molecular weight and molecular behavior of the original gum are shown in Table 1.

[0068] Comparative Example 2

[0069] The relevant process conditions in Example 1 were kept unchanged, except that 85 mg of ETE was added during polymerization.

[0070] The resulting hydrogenated gum was labeled SIEBST2, and the molecular weight and molecular behavior of the original gum are shown in Table 1.

[0071] Comparative Example 3

[0072] The relevant process conditions in Example 1 were kept unchanged, except that 66 mL of styrene was added in the first and third stages, 80 mL of isoprene was added in the second stage, and 140 mL of butadiene was added. The resulting hydrogenated rubber was labeled SIEBST3. The molecular weight and molecular behavior of the original rubber are shown in Table 1.

[0073] Comparative Example 4

[0074] The relevant process conditions in Example 1 were kept unchanged, except that 66 mL of styrene was added in the first and third stages and 20 mL of isoprene was added in the second stage. The resulting hydrogenated gel was labeled SIEBST4, and the molecular weight and molecular behavior of the original gel are shown in Table 1.

[0075] Comparative Example 5

[0076] The relevant process conditions in Example 1 were kept unchanged, except that 4.5 mL of NBL was added during polymerization.

[0077] The resulting hydrogenated gum was labeled SIEBST5, and the molecular weight and molecular behavior of the original gum are shown in Table 1.

[0078] Comparative Example 6

[0079] The relevant process conditions in Example 1 were kept unchanged, except that the continuous and uniform feeding time of the mixed monomers in the second polymerization stage was 12 min.

[0080] The resulting hydrogenated gum was labeled SIEBST6, and the molecular weight and molecular behavior of the original gum are shown in Table 1.

[0081] Table 1. Molecular characteristics of the raw gum and hydrides in the examples.

[0082]

[0083] Note: Side groups refer to vinyl and isopropyl groups.

[0084] Example 6

[0085] The SIEBS and commercially available SEBS such as YH-502 prepared in Table 1 were granulated and hot-melt pressed into sheets, and the commercially available high-performance tire tread rubber solution polymerized styrene-butadiene rubber SSBR2557S was mixed and vulcanized according to national standards. The physical properties and behavior of the sheet rubber and vulcanized rubber are shown in Table 2.

[0086] Table 2 Physical properties and behavior of compressed rubber and vulcanized rubber

[0087]

[0088]

[0089] Note: 1) Vulcanizate formulation (parts by weight): SSBR2557S, 137.5 parts; N330, 68.75 parts; stearic acid, 1.0 part; zinc oxide, 3.0 parts; accelerator TBBS, 1.38 parts; sulfur, 1.75 parts; antioxidant RD, 1.0 part.

[0090] 2) Vulcanization conditions: 145℃×30min.

[0091] 3) The formulation (parts by weight) of the SIEBS and YH-502 hot melt adhesive of the present invention: SIEBS (or YH-502), 100 parts; carbon black N330, 20 parts; light calcium carbonate, 50 parts; naphthenic oil 4010, 60 parts; antioxidant 1076, 3 parts

[0092] 4) Tableting conditions: 175℃×10min.

[0093] As can be seen from Table 2, although the SIEBS of the present invention exhibits good physical properties like the existing general-purpose SEBS, it is still inferior to the SSBR used in high-performance tires in terms of dry and wet skid resistance. This is easy to understand. However, the SIEBS of the present invention exhibits excellent dry and wet skid resistance compared with general-purpose SEBS.

Claims

1. A hydrogenated styrene-conjugated diene-styrene triblock copolymer, characterized in that: It has the expression of Equation 1: S-(I x E y B z ) n -S Formula 1 in, S represents a polystyrene block; I x It is a hydrogenated polyisoprene microblock; E y For hydrogenated 1,4-addition polybutadiene microblocks; B z For hydrogenated 1,2-addition polybutadiene microblocks; (I x E y B z ) n It is a random copolymer block of hydrogenated butadiene-isoprene; n, x, y, and z are all polymer degrees, and x, y, and z are all ≤3; The mass ratio of the polystyrene block to the random copolymer block of hydrogenated butadiene and isoprene is (40-50) / (60-50); The mass ratio of hydrogenated isoprene units to hydrogenated butadiene units in the random copolymer block of hydrogenated butadiene and isoprene is (10~20) / (90~80); The number-average molecular weight Mn of the hydrogenated styrene-conjugated diene-styrene triblock copolymer is 6 × 10⁻⁶. 4 ~15×10 4 Molecular weight distribution index M W / M n =1.03~1.

05.

2. The hydrogenated styrene-conjugated diene-styrene triblock copolymer according to claim 1, characterized in that: In the random copolymer block of hydrogenated butadiene and isoprene, the total mass of the 3,4-addition unit of the hydrogenated isoprene unit and the 1,2-addition unit of the hydrogenated butadiene unit accounts for 45-55%.

3. The hydrogenated styrene-conjugated diene-styrene triblock copolymer according to claim 1, characterized in that: The iodine value is 30~50g / 100g.

4. A method for preparing a hydrogenated styrene-conjugated diene-styrene triblock copolymer according to any one of claims 1 to 3, characterized in that: In an anionic polymerization solution system, an initiator and styrene monomer are added to initiate a first-stage polymerization reaction. Then, a mixture of isoprene and butadiene monomers is added continuously and uniformly to carry out a second-stage polymerization reaction. Finally, styrene monomer is added to carry out a third-stage polymerization reaction to obtain SIBS adhesive. The SIBS adhesive is then subjected to a hydrogenation reaction to obtain the final product.

5. The method for preparing a hydrogenated styrene-conjugated diene-styrene triblock copolymer according to claim 4, characterized in that: The anionic polymerization solution system contains cyclohexane and / or n-hexane solvents; The anionic polymerization solution system contains at least one activator selected from bis(tetrahydrofurfuryl propane), tetrahydrofurfuryl ethyl ether, and tetrahydrofurfuryl hexyl ether. The amount of the activator is 50~60 mg / kg solvent.

6. The method for preparing a hydrogenated styrene-conjugated diene-styrene triblock copolymer according to claim 4, characterized in that: The conditions for the polymerization reaction are: temperature 55℃~60℃, time 20~30min; The conditions for the two-stage polymerization reaction are as follows: the continuous feeding time of the mixed monomers of isoprene and butadiene is 15-20 min, the temperature is 55℃-75℃, and the reaction continues for another 15-25 min after the feeding is completed; The conditions for the three-stage polymerization reaction are: temperature of 60℃~70℃ and time of not less than 25min.

7. The method for preparing a hydrogenated styrene-conjugated diene-styrene triblock copolymer according to claim 4, characterized in that: The hydrogenation reaction process is as follows: first, an initiator is added to the SIBS solution, and it is activated for 10-30 minutes at a temperature of 40-75°C and a hydrogen pressure of 6-13 bar. Then, a co-catalyst is added and activated for 10-20 minutes. Finally, the main catalyst is added, and catalytic hydrogenation is carried out for more than 120 minutes at a temperature of 70-105°C and a hydrogen pressure of 13-18 bar.

8. The method for preparing a hydrogenated styrene-conjugated diene-styrene triblock copolymer according to claim 7, characterized in that: The main catalyst is dicyclopentadiene titanium dichloride, and its dosage is 0.035~0.050g / 100g relative to the dry basis mass of SIBS adhesive; the co-catalyst is dimethyl phthalate, and its molar ratio with the main catalyst is 0.3~0.5:

1.

9. The application of the hydrogenated styrene-conjugated diene-styrene triblock copolymer according to any one of claims 1 to 3, characterized in that: Used in shoe outsole materials.

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