SEBS hydrogenation degree prediction and accurate control method

Abstract

The invention relates to the field of SEBS (Styrene-Ethylene-Butylene-Styrene) preparation, in particular to a SEBS hydrogenation degree prediction method, which comprises the following steps of: performing calculation according to formulas 1-9 by utilizing design values of the use amount m of a main catalyst, the molar ratio n of lithium to the main catalyst and the molar ratio X of a cocatalyst to the main catalyst in a selective hydrogenation process of an active lithium anion polymerized SBS glue solution and the main catalyst and the cocatalyst; predicting the hydrogenation degree Y of the prepared SEBS; the formula 1: Y = 0.12 + 0.88 * X, the formula 2: Y = 0.19 + 0.81 * X, the formula 3: Y = 0.25 + 0.75 * X, the formula 4: Y = 0.17 + 0.83 * X, the formula 5: Y = 0.25 + 0.75 * X, the formula 6: Y = 0.31 + 0.69 * X, the formula 7: Y = 0.2 + 0.8 * X, the formula 8: Y = 0.32 + 0.68 * X, and the formula 9: Y = 0.4 + 0.6 * X. The invention also comprises a synthesis method for knowing precise control of the hydrogenation degree of SEBS by using the prediction method. According to the process provided by the invention, the hydrogenation degree of SEBS can be predicted with high precision.

Description

Technical Field

[0001] The invention belongs to the technical field of styrene-based thermoplastic elastomer synthesis, and particularly relates to a method for predicting the hydrogenation degree of SEBS selective hydrogenation and controlling the synthesis method. Background Art

[0002] SEBS is a linear triblock copolymer with polystyrene as the terminal block and hydrogenated polybutadiene as the middle elastic block. This type of polymer does not contain unsaturated double bonds and has good light aging resistance and stability. It can be blended with filler oil, polypropylene, additives and inorganic fillers and is widely used in the coating of tool handles, shoe materials, headphone cables, wires and cables, medical infusion equipment, etc.

[0003] Usually, the degree of hydrogenation of SEBS is ≥97%. This type of product has good aging resistance, but because it contains less double bonds and insufficient polarity, it does not adhere firmly to polar materials. For example, if it is used to coat nylon, epoxy resin and other materials, if a part of the double bonds are added, the purpose of improving the adhesion between the polar materials by chemical bonding can be achieved. In addition, SEBS containing a certain amount of double bonds is used in the foaming field, and the products have the characteristics of high resilience, fast vulcanization speed, and long half-life. For example, Asahi Kasei P1083, Zhongli 5583 and 5083, which are widely used in the foaming midsoles of existing sports shoes, have a degree of hydrogenation of about 80%; partial double bond vulcanization cross-linking can also be used to improve the tear strength of the product. For example, patent CN101668805A uses a vinyl aromatic hydrocarbon-conjugated diene copolymer with a hydrogenation degree of 30%-80% as a key component in the tire formula to balance the rolling resistance and wet grip performance; patent CN103848948A involves And partially hydrogenated terpolymers and preparation methods and applications. In the terpolymer, the degree of hydrogenation of the structural unit derived from butadiene is 5-90%, among which the degree of hydrogenation of the structural unit formed by butadiene in 1,2 polymerization is 60-95%, and the degree of hydrogenation of the structural unit formed by butadiene in 1,4 polymerization is 2-20%; the degree of hydrogenation of the structural unit derived from isoprene is 5-90%, the degree of hydrogenation of the structural unit formed by isoprene in 3,4 polymerization is 10-40%, and the degree of hydrogenation of the structural unit formed by isoprene in 1,4 polymerization is 2-30%. The copolymer of the invention has a good balance between high anti-slip properties, low rolling resistance and high wear resistance. Therefore, partially hydrogenated grades should have a wide range of application scenarios, but neither of the above two patents mentions the accurate control method of partial hydrogenation of butadiene segments. CN106317350B provides a method for preparing a partially hydrogenated polystyrene-b-random copolymerized conjugated diene / styrene copolymer and its application in asphalt modification, wherein the preparation method comprises first homopolymerizing a styrene monomer, and then randomly copolymerizing the styrene, conjugated diene and divinylbenzene mixed monomers, and then hydrogenating the copolymerized product to obtain the partially hydrogenated polystyrene-b-random copolymerized conjugated diene / styrene copolymer. The partially hydrogenated polystyrene-b-random copolymerized conjugated diene / styrene copolymer prepared by the method has high strength, good heat resistance and processing performance, and is used for modified asphalt to prepare a modified asphalt having excellent cold resistance, heat resistance, weather resistance, ozone resistance and UV resistance, and having high elasticity and strength, and can improve the adhesion and bonding strength between asphalt and concrete stone pavement. The partial hydrogenation method in this patent is based on the principle that the polybutadiene chain segment can be hydrogenated by a titanocene catalyst, but the polyisoprene chain segment cannot be hydrogenated. The degree of hydrogenation is accurately controlled by adding amounts of styrene, butadiene and isoprene. Since isoprene is added to the soft segment, the influence of the reactivity ratio of butadiene and isoprene needs to be considered during the polymerization synthesis process. The control requirements are high, the operation is difficult, and the product quality performance is difficult to stabilize.

[0004] Although some selective hydrogenation methods have been reported in the prior art, the prior art still lacks an accurate prediction method for the hydrogenation degree of SEBS, and it is difficult to obtain SEBS that meets the design requirements simply and with high precision. Summary of the invention

[0005] In view of the problem that the prior art lacks advance prediction of SEBS, the first object of the present invention is to provide a method for predicting the degree of hydrogenation of SEBS, aiming to provide a method for accurately calculating and predicting the degree of hydrogenation of selective hydrogenation.

[0006] The second object of the present invention is to provide a preparation method for accurately controlling the hydrogenation degree of SEBS, so as to facilitate the calculation of key parameter values ​​by the prediction method, and then to obtain SEBS that meets the design requirements of hydrogenation degree with high purpose and high precision.

[0007] A method for predicting the hydrogenation degree of SEBS, using the amount m of the main catalyst, the lithium / main catalyst molar ratio n, and the co-catalyst / main catalyst molar ratio X in the process of selective hydrogenation of SBS gel polymerized by active lithium anions to calculate formulas 1 to 9, and predicting the hydrogenation degree Y of the prepared SEBS;

[0008] Formula 1: Y=0.12+0.88*X

[0009] Formula 2: Y=0.19+0.81*X

[0010] Formula 3: Y=0.25+0.75*X

[0011] Formula 4: Y=0.17+0.83*X

[0012] Formula 5: Y=0.25+0.75*X

[0013] Formula 6: Y=0.31+0.69*X

[0014] Formula 7: Y=0.2+0.8*X

[0015] Formula 8: Y=0.32+0.68*X

[0016] Formula 9: Y=0.4+0.6*X

[0017] The m is the ratio of the molar amount of the main catalyst to the weight of butadiene forming the SBS glue (in mmol / 100g); the n is the molar ratio of lithium ions and the main catalyst in the starting system of selective hydrogenation;

[0018] When the designed range of m is 0.14 - 0.16 mmol / 100 g and the designed range of 7 ≤ n ≤ 9, substitute X into Formula 1 to calculate the hydrogenation degree Y; when 9 < n ≤ 11, substitute X into Formula 2 to calculate the hydrogenation degree Y; when 11 < n ≤ 13, substitute X into Formula 3 to calculate the hydrogenation degree Y.

[0019] When the designed range of m is 0.17 - 0.19 mmol / 100 g and the designed range of 7 ≤ n ≤ 9, substitute X into Formula 4 to calculate the hydrogenation degree Y; when 9 < n ≤ 11, substitute X into Formula 5 to calculate the hydrogenation degree Y; when 11 < n ≤ 13, substitute X into Formula 6 to calculate the hydrogenation degree Y.

[0020] When the designed range of m is 0.19 - 0.21 mmol / 100 g and the designed range of 7 ≤ n ≤ 9, substitute X into Formula 7 to calculate the hydrogenation degree Y; when 9 < n ≤ 11, substitute X into Formula 8 to calculate the hydrogenation degree Y; when 11 < n ≤ 13, substitute X into Formula 9 to calculate the hydrogenation degree Y.

[0021] The present invention innovatively uses m, n, and X as key factors and innovatively uses the said Formulas 1 - 9 for calculation, so that the hydrogenation degree can be predicted with high precision. It is found that through the prediction calculation method of the present invention, the error between the predicted value and the actually verified hydrogenation degree can be controlled within 1%, showing excellent prediction accuracy.

[0022] In the present invention, the said Formulas 1 - 9 can be located and selected through the two parameters m and n, and then X is calculated innovatively based on the selected formula, thus unexpectedly improving the accuracy of hydrogenation degree calculation.

[0023] In the present invention, n is the molar ratio of lithium ions to the main catalyst in the starting system for selective hydrogenation; the lithium ions can be completely introduced by the active lithium initiator or can be artificially regulated.

[0024] A typical embodiment (Embodiment A) of the present invention: when the designed range of m is 0.145 - 0.155 mmol / 100 g, preferably 0.15 mmol / 100 g, and the designed range of n is 7.5 - 8.5, preferably 7.9 - 8.1, and further preferably 8, Formula 1 is used for calculation;

[0025] Preferably, when the designed range of m is 0.145 - 0.155 mmol / 100 g, preferably 0.15 mmol / 100 g, and the designed range of n is 9.5 - 10.5, preferably 9.9 - 10.1, and further preferably 10, Formula 2 is used for calculation;

[0026] Preferably, when the design range of m is 0.145 to 0.155 mmol / 100 g, preferably 0.15 mmol / 100 g, and the design range of n is 11.5 to 12.5, preferably 11.9 to 12.1, and more preferably 12, Formula 3 is used for calculation.

[0027] Another typical embodiment of the present invention (method B): when the design range of m is 0.175 to 0.185 mmol / 100 g, preferably 0.18 mmol / 100 g, and the design range of n is 7.5 to 8.5, preferably 7.9 to 8.1, and more preferably 8, formula 4 is used for calculation;

[0028] Preferably, when the design range of m is 0.175 to 0.185 mmol / 100 g, preferably 0.18 mmol / 100 g, and the design range of n is 9.5 to 10.5, preferably 9.9 to 10.1, and more preferably 10, the calculation is performed using Formula 5;

[0029] Preferably, when the design range of m is 0.175 to 0.185 mmol / 100 g, preferably 0.18 mmol / 100 g, and the design range of n is 11.5 to 12.5, preferably 11.9 to 12.1, and more preferably 12, formula 6 is used for calculation.

[0030] Another typical embodiment of the present invention (method C): when the design range of m is 0.195 to 0.205 mmol / 100 g, preferably 0.2 mmol / 100 g, and the design range of n is 7.5 to 8.5, preferably 7.9 to 8.1, and more preferably 8, formula 7 is used for calculation;

[0031] Preferably, when the design range of m is 0.195 to 0.205 mmol / 100 g, preferably 0.2 mmol / 100 g, and the design range of n is 9.5 to 10.5, preferably 9.9 to 10.1, and more preferably 10, the calculation is performed using Formula 8;

[0032] Preferably, when the design range of m is 0.195 to 0.205 mmol / 100 g, preferably 0.2 mmol / 100 g, and the design range of n is 11.5 to 12.5, preferably 11.9 to 12.1, and more preferably 12, formula 9 is used for calculation.

[0033] In the present invention, there is no particular requirement for the operation period of X, and it can usually be 0.05 to 1, taking into account the reaction conditions in the field of selective hydrogenation.

[0034] In the present invention, the prediction method can be applied to any SBS gel obtained by conventional active lithium anion polymerization.

[0035] For example, the steps for obtaining SBS glue are as follows: in an anionic polymerization solution system, a solvent, a styrene monomer, an active lithium activator and an initiator are added to initiate and carry out a first-stage polymerization reaction; after the first-stage polymerization is completed, a structure regulator is added, and at the same time, butadiene monomer is continuously and evenly added to carry out a second-stage polymerization reaction; after the second-stage polymerization reaction is completed, a styrene monomer is added to carry out a third-stage polymerization reaction, and after the third-stage polymerization reaction is completed, SBS glue is obtained.

[0036] The concentration of the monomer is 10-15%.

[0037] The solvent is one of cyclohexane, n-hexane and cyclopentane.

[0038] The structure regulator includes at least one of ethylene glycol dimethyl ether, ditetrahydrofurfuryl propane, ethylene glycol diethyl ether, tetrahydrofurfuryl alcohol ethyl ether, tetramethylethylenediamine, and hexamethylphosphoric triamide.

[0039] The total time for continuously and uniformly adding the butadiene monomer is 40 to 60 minutes.

[0040] The initial temperature of the two-stage polymerization reaction is controlled at 62-65° C., the maximum temperature is controlled at 70-85° C., and the total reaction time is controlled at 30-80 minutes.

[0041] The activating agent includes tetrahydrofuran.

[0042] The active lithium initiator includes at least one of n-butyl lithium, sec-butyl lithium and isobutyl lithium.

[0043] The temperature of the first and third stage polymerization reactions is 50° C. to 70° C., and the reaction time is 20 to 50 minutes.

[0044] In the present invention, the prediction method can be applied to any selective hydrogenation conditions known in the industry.

[0045] In the present invention, the main catalyst is a titanocene catalyst, which includes at least one of bis(cyclopentadienyl)titanium dichloride, bis(cyclopentadienyl)titanium dibromide, bis(cyclopentadienyl)titanium diiodide, bis(cyclopentadienyl)titanium difluoride, bis(cyclopentadienyl)titanium dicarbonyl, bis(cyclopentadienyl)titanium dimethyl, bis(cyclopentadienyl)titanium diethyl, and bis(cyclopentadienyl)titanium dibutyl;

[0046] Preferably, the co-catalyst is a carboxylic acid ester containing a benzene ring, preferably at least one of C1-C5 alkyl benzoate and C1-C5 alkyl phthalate;

[0047] More preferably, the molar ratio of the main catalyst to the co-catalyst is 1 to 20:1.

[0048] In the present invention, during the selective hydrogenation process, the starting temperature is 72-80°C, the hydrogen pressure is 1.2-1.4 MPa, and after the reaction reaches the highest temperature (80-130°C), the hydrogen valve is closed and the pressure in the reactor is released to 0.05 MPa to discharge the hydrogen.

[0049] The present invention also provides a preparation method for accurately controlling the hydrogenation degree of SEBS. Based on the SEBS hydrogenation degree prediction method of the present invention, m, n and X in the selective hydrogenation stage are calculated, and a selective hydrogenation reaction is performed based on the calculated m, n and X as conditions to accurately prepare SEBS with a hydrogenation degree that meets the design requirements.

[0050] Beneficial Effects

[0051] The present invention innovatively uses m, n, and X as key factors, and innovatively uses the above formulas 1 to 9 for calculation, so that the degree of hydrogenation can be predicted with high accuracy. Studies have found that the error between the predicted calculation method of the present invention and the actually verified degree of hydrogenation can be controlled within 1%, which has excellent prediction accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is the H-NMR spectrum of the SBS base glue prepared in Example 1.

[0053] Figure 2 This is the H NMR spectrum of the partially hydrogenated SEBS prepared in Example 1. DETAILED DESCRIPTION

[0054] The following examples are intended to further illustrate the present invention in detail and are not intended to limit the scope of protection or implementation of the present invention.

[0055] The present invention provides an operation formula for selecting X adaptation through two factors, namely, the main catalyst dosage (m) and the Li / main catalyst ratio (n) in the selective hydrogenation stage, and further cooperates with the formula control of formulas 1 to 9, so that the SEBS selective hydrogenation degree can be unexpectedly predicted with high accuracy.

[0056] The prediction method of the present invention is applicable to the prediction of the hydrogenation degree of any selective hydrogenation method of SBS glue formed by polymerization of any active lithium anions. The lithium ions in the SBS glue can be introduced by active lithium initiators or artificially controlled.

[0057] As a typical example, the preparation method of the SBS glue is as follows:

[0058] In the present invention, a solvent, a styrene monomer, an activator and an initiator are added to an anionic polymerization solution system to initiate and carry out a first stage polymerization reaction; after the first stage polymerization is completed, a structure regulator is added, and a butadiene monomer is continuously and uniformly added to carry out a second stage polymerization reaction; after the second stage polymerization is completed, a styrene monomer is added to carry out a third stage polymerization reaction, and after the third stage polymerization is completed, an SBS glue solution is obtained. The concentration of the monomer is 10-15%. The solvent is one of cyclohexane, n-hexane and cyclopentane. The structure regulator includes at least one of ethylene glycol dimethyl ether, ditetrahydrofurfuryl propane, ethylene glycol diethyl ether, tetrahydrofurfuryl alcohol ethyl ether, tetramethylethylenediamine and hexamethylphosphoric triamide. The total time for the continuous and uniform addition of the butadiene monomer is 40 to 60 minutes. The initial temperature of the second stage polymerization reaction is controlled at 62 to 65° C., the maximum temperature is 70 to 85° C., and the total reaction time is within the range of 30 to 80 minutes. The activator includes tetrahydrofuran. The active lithium initiator includes at least one of n-butyl lithium, sec-butyl lithium and isobutyl lithium. The temperature of the first and third stage polymerization reactions is 50° C. to 70° C., and the time is 20 to 50 minutes.

[0059] The prediction method described in the present invention can be applied to any selective hydrogenation process. For example, as a typical example, the selective catalyst can be a titanocene catalyst. The SBS glue is regulated to add a titanocene catalyst, and hydrogenation treatment is carried out by hydrogen. The degree of hydrogenation is calculated by the ratio of lithium ions to the titanocene catalyst and the amount of the catalyst involved. The hydrogenation catalyst is a catalyst for selective hydrogenation of olefin double bonds, wherein the main catalyst can be a titanocene catalyst, and further can be a titanocene-benzoate composite catalyst system, which includes at least one of bis(cyclopentadienyl) titanium dichloride, bis(cyclopentadienyl) titanium dibromide, bis(cyclopentadienyl) titanium diiodide, bis(cyclopentadienyl) titanium difluoride, bis(cyclopentadienyl) titanium dicarbonyl, bis(cyclopentadienyl) dimethyl titanium, bis(cyclopentadienyl) diethyl titanium, and bis(cyclopentadienyl) dibutyl titanium. The co-catalyst can be at least one of C1-C5 alkyl benzoate and C1-C5 alkyl phthalate; more preferably, the molar ratio of the main catalyst to the co-catalyst is 1-20:1. The m is the ratio of the molar amount of the main catalyst to the weight of the SBS butadiene formed. The conditions of the selective hydrogenation reaction are: using a titanocene-benzoate composite catalyst system, a starting temperature of 72-80°C, a hydrogen pressure of 1.2-1.4MPa, and after the reaction reaches the highest temperature, closing the hydrogen valve and releasing the pressure in the reactor to 0.05MPa to discharge the hydrogen.

[0060] In the present invention, typical prediction calculation methods are shown in Table 1:

[0061] As shown in Table 1:

[0062]

[0063]

[0064] In the formula described in the present invention, the * refers to a multiplication sign.

[0065] The present invention is particularly suitable for a concentration of the glue solution of 10-15%, and a number average molecular weight (Mn) of SEBS controlled between 10,000 and 300,000.

[0066] In the present invention, linear mapping can be performed according to the prediction formula, and according to the subsequent hydrogenation degree design requirements, a suitable formula can be adapted to obtain more suitable m / n and X preparation parameters, and based on the reverse predicted preparation parameters, SEBS with a hydrogenation degree that meets the design requirements can be prepared more accurately and efficiently.

[0067] It should be noted that: in the following examples, gel permeation chromatography (mobile phase is tetrahydrofuran) is used to test the number average molecular weight (Mn) of the gel solution; H-NMR nuclear magnetic spectrum is used to analyze the degree of hydrogenation of partially hydrogenated SEBS. Figure 1 This is a typical SBS polymerized basic colloid NMR spectrum. The peaks with a displacement of 5.3-5.6ppm are the hydrogen peaks on the double bonds of the 1,4 structure of polybutadiene and the single hydrogen peaks on the double bonds of the 1,2 structure side chains, with a peak area of ​​A. The peaks with a displacement of around 4.96ppm are the two hydrogen peaks on the double bonds of the 1,2 structure side chains of polybutadiene, with a peak area of ​​B. The molar weight of butadiene is (2A+B) / 4; after partial hydrogenation, the attached Figure 2 The peak displacement of 5.3-5.6ppm is the hydrogen peak on the double bond of 1,4 structure and the single hydrogen peak on the double bond of 1,2 structure side chain of polybutadiene, and the peak area is C. The peak displacement of 4.96ppm is the two hydrogen peaks on the double bond of 1,2 structure side chain of polybutadiene, and the peak area is D. The molar amount of butadiene is (2C+D) / 4; the degree of hydrogenation = {1-(2C+D) /

[0068] (2A+B)}*100%.

[0069] Example 1

[0070] The designed m is 0.15 mmol / 100 g butadiene, n is 8, and X=0.1 is substituted into Formula 1 in Table 1 for calculation. The calculated hydrogenation degree Y under this condition is 20.8%;

[0071] Experimental verification of prediction results:

[0072] The SEBS with a number average molecular weight (Mn) of 6±10,000 is prepared by an anionic polymerization method known in the industry, wherein the amount of titanocene catalyst / 100g butadiene = 0.15mmol, the molar ratio of lithium ion / titanocene catalyst = 8, and the molar ratio of co-catalyst to titanocene catalyst (also known as main catalyst) is 0.1.

[0073] Into a polymerization kettle replaced with dry protective gas (such as nitrogen), 40 kg of cyclohexane, 12 g of tetrahydrofuran, 3.74 g of tetramethylethylenediamine and 66 mmol of butyl lithium were added. The temperature of the polymerization kettle was maintained at 65°C and the pressure was 0.3 MPa. 600 g of styrene monomer was first added for a first-stage reaction for 30 min. After the reaction, the polymerization temperature was lowered to 63°C. Then, 2800 g of butadiene monomer was continuously added within 40 min. After reaching the high temperature, the reaction was carried out for 10 min. In the third-stage reaction, 600 g of styrene monomer was added for a reaction for 30 min. 32.4 mmol of methanol was added to terminate part of the butyl lithium. The prepared polymerized glue was poured into a hydrogenation kettle, and 4.2 mmol of dicyclopentadiene titanium dichloride and 0.42 mmol of methyl benzoate were added. The initial reaction temperature was controlled at 75°C, and hydrogen was introduced to make the pressure in the kettle 1.2 MPa. The reaction temperature reached 82°C, and the introduction of hydrogen was immediately stopped. The pressure in the kettle was vented to 0.05 MPa. The glue was dried and the degree of hydrogenation was tested to be 20.5%, which was close to the result of 20.8% obtained by applying formula ① in Table 1.

[0074] Example 2

[0075] The designed m is 0.15 mmol / 100 g butadiene, n is 10, and X=0.3 is substituted into Formula 2 in Table 1 for calculation. The calculated hydrogenation degree Y under this condition is 43.3%;

[0076] Experimental verification of prediction results:

[0077] The SEBS with a number average molecular weight (Mn) of 100,000±10,000 is prepared by an anionic polymerization method known in the industry, wherein the amount of titanocene catalyst / 100g butadiene = 0.15mmol, the molar ratio of lithium ion / titanocene catalyst = 10, and the molar ratio of co-catalyst to titanocene catalyst is 0.3.

[0078] Into a polymerization kettle replaced with dry protective gas (such as nitrogen), 40 kg of cyclohexane, 12 g of tetrahydrofuran, 2.8 g of ethylene glycol dimethyl ether and 40 mmol of sec-butyl lithium were added, the temperature of the polymerization kettle was maintained at 64°C and the pressure was maintained at 0.3 MPa. 400 g of styrene monomer was first added for a first-stage reaction for 30 min. After the reaction, the polymerization temperature was lowered to 63°C. Then, 3200 g of butadiene monomer was continuously added within 40 min. After reaching the high temperature, the reaction was carried out for 10 min. In the third-stage reaction, 400 g of styrene monomer was added for a reaction for 30 min. 8 mmol of sec-butyl lithium was added. The prepared polymerized glue was poured into a hydrogenation kettle, and 4.8 mmol of dicyclopentadiene titanium dichloride and 1.44 mmol of ethyl benzoate were added. The initial reaction temperature was controlled at 74°C, and hydrogen was introduced to make the pressure in the kettle 1.3 MPa. The reaction reached a high temperature of 91°C, and the introduction of hydrogen was immediately stopped. The pressure in the kettle was vented to 0.05 MPa. The glue was dried and the degree of hydrogenation was tested to be 43.9%, which was close to the result of 43.3% using formula ② in Table 1.

[0079] Example 3

[0080] The designed m is 0.15 mmol / 100 g butadiene, n is 12, and X=0.7 is substituted into Formula 3 in Table 1 for calculation. The calculated hydrogenation degree Y under this condition is 77.5%;

[0081] Experimental verification of prediction results:

[0082] The SEBS with a number average molecular weight (Mn) of 200,000±10,000 is prepared by an anionic polymerization method known in the industry, wherein the amount of titanocene catalyst / 100g butadiene = 0.15mmol, the molar ratio of lithium ion / titanocene catalyst = 12, and the molar ratio of co-catalyst to titanocene catalyst is 0.7.

[0083] Into a polymerization kettle replaced with dry protective gas (such as nitrogen), 40 kg of cyclohexane, 12 g of tetrahydrofuran, 4 g of tetrahydrofurfuryl alcohol ethyl ether and 40 mmol of isobutyl lithium were added, the temperature of the polymerization kettle was maintained at 64°C and the pressure was 0.3 MPa, 200 g of styrene monomer was first added, and a first-stage reaction was carried out for 30 min. After the reaction, the polymerization temperature was lowered to 63°C, and then 3600 g of butadiene monomer was continuously added within 40 min. After reaching the high temperature, the reaction was carried out for 10 min. In the third-stage reaction, 200 g of styrene monomer was added, and the reaction was carried out for 30 min. 37.6 mmol of sec-butyl lithium was added. The prepared polymerized glue was poured into a hydrogenation kettle, and 4.8 mmol of dicyclopentadiene titanium dichloride and 3.36 mmol of ethyl benzoate were added. The initial reaction temperature was controlled at 74°C, and hydrogen was introduced to make the pressure in the kettle 1.4 MPa. The reaction reached a high temperature of 103°C, and the introduction of hydrogen was immediately stopped. The pressure in the kettle was vented to 0.05 MPa. The glue was dried and the degree of hydrogenation was tested to be 77.8%, which was close to the result of 77.5% using formula ③ in Table 1.

[0084] Example 4

[0085] The designed m is 0.18 mmol / 100 g butadiene, n is 8, and X=0.2 is substituted into Formula 4 in Table 1 for calculation. The calculated hydrogenation degree Y under this condition is 33.6%;

[0086] Experimental verification of prediction results:

[0087] The SEBS with a number average molecular weight (Mn) of 6±10,000 is prepared by an anionic polymerization method known in the industry, wherein the amount of titanocene catalyst / 100g butadiene = 0.18mmol, the molar ratio of lithium ion / titanocene catalyst = 8, and the molar ratio of co-catalyst to titanocene catalyst is 0.2.

[0088] Into a polymerization kettle replaced with dry protective gas (such as nitrogen), 40 kg of cyclohexane, 12 g of tetrahydrofuran, 3.6 g of tetrahydrofurfuryl alcohol ethyl ether and 66.7 mmol of butyl lithium were added. The temperature of the polymerization kettle was maintained at 64°C and the pressure was 0.3 MPa. 600 g of styrene monomer was first added for a first-stage reaction for 30 min. After the reaction, the polymerization temperature was lowered to 63°C. Then, 2800 g of butadiene monomer was continuously added within 40 min. After reaching the high temperature, the reaction was carried out for 10 min. In the third-stage reaction, 600 g of styrene monomer was added for 30 min. 26.3 mmol of methanol was added to terminate part of the butyl lithium. The prepared polymerized glue was poured into a hydrogenation kettle, and 5.04 mmol of dicyclopentadiene titanium dichloride and 1.08 mmol of methyl benzoate were added. The initial reaction temperature was controlled at 75°C, and hydrogen was introduced to make the pressure in the kettle 1.2 MPa. The reaction reached a high temperature of 87°C, and the introduction of hydrogen was immediately stopped. The pressure in the kettle was vented to 0.05 MPa. The glue was dried and the degree of hydrogenation was tested to be 34.4%, which was close to the result of 33.6% using formula ④ in Table 1.

[0089] Example 5

[0090] The designed m is 0.18 mmol / 100 g butadiene, n is 10, and X=0.5 is substituted into Formula 5 in Table 1 for calculation. The calculated hydrogenation degree Y under this condition is 62.5%;

[0091] Experimental verification of prediction results:

[0092] The SEBS with a number average molecular weight (Mn) of 10±10,000 is prepared by an anionic polymerization method known in the industry, wherein the amount of titanocene catalyst / 100g butadiene=0.18mmol, the molar ratio of lithium ion / titanocene catalyst=10, and the molar ratio of cocatalyst to titanocene catalyst is 0.5. 40Kg of cyclohexane, 12g of tetrahydrofuran, 2.8g of hexamethylphosphoric triamide and 48mmol of butyl lithium are added to a polymerization kettle replaced with dry protective gas (such as nitrogen), the temperature of the polymerization kettle is maintained at 66°C, the pressure is 0.3MPa, 800g of styrene monomer is added first, a first reaction is carried out, the reaction time is 30min, and after the reaction time is completed, the polymerization temperature is lowered to 63°C, and then 3200g of butadiene monomer is continuously added within 40min, and the reaction time is 10min after reaching high temperature, 800g of styrene monomer is added in the third reaction, the reaction time is 30min, and 9.6mmol of butyl lithium is added. The prepared polymerized glue was poured into a hydrogenation kettle, and 5.76 mmol of dicyclopentadiene titanium dichloride and 2.88 mmol of ethyl benzoate were added. The initial reaction temperature was controlled at 75°C, and hydrogen was introduced to make the pressure in the kettle 1.3 MPa. The reaction reached a high temperature of 97°C, and the introduction of hydrogen was immediately stopped. The pressure in the kettle was vented to 0.05 MPa. The glue was dried and the degree of hydrogenation was tested to be 63.1%, which was close to the result of 62.5% using formula ⑤ in Table 1.

[0093] Example 6

[0094] The designed m is 0.18 mmol / 100 g butadiene, n is 12, and X=0.9 is substituted into Formula 6 in Table 1 for calculation. The calculated hydrogenation degree Y under this condition is 93.1%;

[0095] Experimental verification of prediction results:

[0096] The SEBS with a number average molecular weight (Mn) of 20±10,000 is prepared by an anionic polymerization method known in the industry, wherein the amount of titanocene catalyst / 100g butadiene=0.18mmol, the molar ratio of lithium ion / titanocene catalyst=12, and the molar ratio of cocatalyst to titanocene catalyst is 0.9. 40Kg of cyclohexane, 12g of tetrahydrofuran, 2.4g of tetrahydrofurfuryl alcohol ethyl ether and 28mmol of isobutyl lithium are added to a polymerization kettle replaced with dry protective gas (such as nitrogen), the temperature of the polymerization kettle is maintained at 64°C, the pressure is 0.3MPa, 1000g of styrene monomer is added first, a first-stage reaction is carried out, the reaction is carried out for 30min, and the polymerization temperature is lowered to 63°C after the reaction is completed, and then 3600g of butadiene monomer is continuously added within 40min, and the reaction is carried out for 10min after reaching high temperature, 1000g of styrene monomer is added in the third-stage reaction, the reaction is carried out for 30min, and 49.76mmol of isobutyl lithium is added. The prepared polymerized glue was poured into a hydrogenation kettle, and 6.48 mmol of dicyclopentadiene titanium dichloride and 5.83 mmol of ethyl benzoate were added. The initial reaction temperature was controlled at 74°C, and hydrogen was introduced to make the pressure in the kettle 1.4 MPa. The reaction reached a high temperature of 122°C, and the introduction of hydrogen was immediately stopped. The pressure in the kettle was vented to 0.05 MPa. The glue was dried and the degree of hydrogenation was tested to be 93.8%, which was close to the result of 93.1% using formula ⑥ in Table 1.

[0097] Example 7

[0098] The designed m is 0.2 mmol / 100 g butadiene, n is 8, and X=0.2 is substituted into Formula 7 in Table 1 for calculation. The calculated hydrogenation degree Y under this condition is 36%;

[0099] Experimental verification of prediction results:

[0100] The SEBS with a number average molecular weight (Mn) of 6±10,000 is prepared by an anionic polymerization method known in the industry, wherein the amount of titanocene catalyst / 100g butadiene=0.2mmol, the molar ratio of lithium ion / titanocene catalyst=8, and the molar ratio of cocatalyst to titanocene catalyst is 0.2. 40Kg of cyclohexane, 12g of tetrahydrofuran, 3.6g of tetrahydrofurfuryl alcohol ethyl ether and 66.7mmol of butyl lithium are added to a polymerization kettle replaced with dry protective gas (such as nitrogen), the temperature of the polymerization kettle is maintained at 64°C, the pressure is 0.3MPa, 600g of styrene monomer is added first, and a first-stage reaction is carried out for 30min. After the reaction is completed, the polymerization temperature is lowered to 63°C, and then 2800g of butadiene monomer is continuously added within 40min, and the reaction is carried out for 10min after reaching high temperature. 600g of styrene monomer is added in the third-stage reaction for 30min, and 21.9mmol of methanol is added to terminate part of the butyl lithium. The prepared polymerized glue was poured into a hydrogenation kettle, and 5.6 mmol of dicyclopentadiene titanium dichloride and 1.12 mmol of methyl benzoate were added. The initial reaction temperature was controlled at 75°C, and hydrogen was introduced to make the pressure in the kettle 1.2 MPa. The reaction reached a high temperature of 89°C, and the introduction of hydrogen was immediately stopped. The pressure in the kettle was vented to 0.05 MPa. The glue was dried and tested for a degree of hydrogenation of 35.4%, which was close to the result of 36% using formula ⑦ in Table 1.

[0101] Example 8

[0102] The designed m is 0.2 mmol / 100 g butadiene, n is 10, and X=0.6 is substituted into Formula 8 in Table 1 for calculation. The calculated hydrogenation degree Y under this condition is 72.8%;

[0103] Experimental verification of prediction results:

[0104] The SEBS with a number average molecular weight (Mn) of 10±10,000 is prepared by an anionic polymerization method known in the industry, wherein the amount of titanocene catalyst / 100g butadiene=0.18mmol, the molar ratio of lithium ion / titanocene catalyst=10, and the molar ratio of cocatalyst to titanocene catalyst is 0.6. 40Kg of cyclohexane, 12g of tetrahydrofuran, 3g of hexamethylphosphoric triamide and 48mmol of butyl lithium are added to a polymerization kettle replaced with dry protective gas (such as nitrogen), the temperature of the polymerization kettle is maintained at 66°C, the pressure is 0.3MPa, 800g of styrene monomer is added first, a first reaction is carried out, the reaction time is 30min, and the polymerization temperature is lowered to 63°C after the reaction, and then 3200g of butadiene monomer is continuously added within 40min, the reaction time is 10min after reaching high temperature, 800g of styrene monomer is added in the third reaction, the reaction time is 30min, and 9.6mmol of butyl lithium is added. The prepared polymerized glue was poured into a hydrogenation kettle, and 6.4 mmol of dicyclopentadiene titanium dichloride and 3.84 mmol of ethyl benzoate were added. The initial reaction temperature was controlled at 75°C, and hydrogen was introduced to make the pressure in the kettle 1.4 MPa. The reaction reached a high temperature of 106°C, and the introduction of hydrogen was immediately stopped. The pressure in the kettle was vented to 0.05 MPa. The glue was dried and the degree of hydrogenation was tested to be 73.1%, which was close to the result of 72.8% using formula ⑧ in Table 1.

[0105] Example 9

[0106] The designed m is 0.2 mmol / 100 g butadiene, n is 12, and X=0.8 is substituted into Formula 9 in Table 1 for calculation. The calculated hydrogenation degree Y under this condition is 88%;

[0107] Experimental verification of prediction results:

[0108] The SEBS with a number average molecular weight (Mn) of 20±10,000 is prepared by an anionic polymerization method known in the industry, wherein the amount of titanocene catalyst / 100g butadiene=0.2mmol, the molar ratio of lithium ion / titanocene catalyst=12, and the molar ratio of cocatalyst to titanocene catalyst is 0.8. 40Kg of cyclohexane, 12g of tetrahydrofuran, 2.8g of tetrahydrofurfuryl alcohol ethyl ether and 28mmol of isobutyl lithium are added to a polymerization kettle replaced with dry protective gas (such as nitrogen), the polymerization kettle temperature is maintained at 64°C, the pressure is 0.3MPa, 1000g of styrene monomer is added first, a first reaction is carried out, the reaction time is 30min, and the polymerization temperature is lowered to 63°C after the reaction, and then 3600g of butadiene monomer is continuously added within 40min, and the reaction time is 10min after reaching high temperature, 1000g of styrene monomer is added in the third reaction, the reaction time is 30min, and 49.76mmol of isobutyl lithium is added. The prepared polymerized glue was poured into a hydrogenation kettle, and 7.2 mmol of dicyclopentadiene titanium dichloride and 5.76 mmol of ethyl benzoate were added. The initial reaction temperature was controlled at 74°C, and hydrogen was introduced to make the pressure in the kettle 1.3 MPa. The reaction reached a high temperature of 124°C, and the introduction of hydrogen was immediately stopped. The pressure in the kettle was vented to 0.05 MPa. The glue was dried and tested for a degree of hydrogenation of 87.6%, which was close to the result of 88% using formula ⑨ in Table 1.

[0109] It can be seen from Examples 1 to 9 that the prediction method described in the present invention can accurately predict the hydrogenation results, and based on the prediction results, a more accurate hydrogenation method can be developed.

Claims

1. A method for predicting SEBS degree of hydrogenation, characterized in that: The amounts m of the main catalyst, the molar ratio n of lithium to the main catalyst, and the molar ratio X of the cocatalyst to the main catalyst in the selective hydrogenation process of the SBS solution and the main catalyst using living lithium anionic polymerization are used to calculate Formulas 1 to 9 to predict the hydrogenation degree Y of the prepared SEBS; Formula 1: Y = 0.12 + 0.88 * X Formula 2: Y = 0.19 + 0.81 * X Formula 3: Y = 0.25 + 0.75 * X Formula 4: Y = 0.17 + 0.83 * X Formula 5: Y = 0.25 + 0.75 * X Formula 6: Y = 0.31 + 0.69 * X Formula 7: Y = 0.2 + 0.8 * X Formula 8: Y = 0.32 + 0.68 * X Formula 9: Y = 0.4 + 0.6 * X The m described is the proportion of the molar amount of the main catalyst relative to the weight of butadiene forming the SBS solution, with the unit of mmol / 100 g; the n described is the molar ratio of lithium ions to the main catalyst in the initial system of selective hydrogenation; When the design range of m is 0.14 - 0.16 mmol / 100 g and 7 ≤ the design range of n ≤ 9, substitute X into Formula 1 to calculate the hydrogenation degree Y; when 9 < n ≤ 11, substitute X into Formula 2 to calculate the hydrogenation degree Y; when 11 < n ≤ 13, substitute X into Formula 3 to calculate the hydrogenation degree Y; When the design range of m is 0.17 - 0.19 mmol / 100 g and 7 ≤ the design range of n ≤ 9, substitute X into Formula 4 to calculate the hydrogenation degree Y; when 9 < n ≤ 11, substitute X into Formula 5 to calculate the hydrogenation degree Y; when 11 < n ≤ 13, substitute X into Formula 6 to calculate the hydrogenation degree Y; When the design range of m is 0.19 - 0.21 mmol / 100 g and 7 ≤ the design range of n ≤ 9, substitute X into Formula 7 to calculate the hydrogenation degree Y; when 9 < n ≤ 11, substitute X into Formula 8 to calculate the hydrogenation degree Y; when 11 < n ≤ 13, substitute X into Formula 9 to calculate the hydrogenation degree Y.

2. The SEBS hydrogenation degree prediction method according to claim 1, characterized in that: When the design range of m is 0.145 - 0.155 mmol / 100 g, preferably 0.15 mmol / 100 g, and the design range of n is 7.5 - 8.5, preferably 7.9 - 8.1, and further preferably 8, use Formula 1 for calculation; Preferably, when the design range of m is 0.145 - 0.155 mmol / 100 g, preferably 0.15 mmol / 100 g, and the design range of n is 9.5 - 10.5, preferably 9.9 - 10.1, and further preferably 10, use Formula 2 for calculation; Preferably, when the design range of m is 0.145 - 0.155 mmol / 100 g, preferably 0.15 mmol / 100 g, and the design range of n is 11.5 - 12.5, preferably 11.9 - 12.1, and further preferably 12, use Formula 3 for calculation.

3. The SEBS hydrogenation degree prediction method according to claim 1, characterized in that: When the design range of m is 0.175 - 0.185 mmol / 100 g, preferably 0.18 mmol / 100 g, and the design range of n is 7.5 - 8.5, preferably 7.9 - 8.1, and further preferably 8, use Formula 4 for calculation; Preferably, when the design range of m is 0.175 to 0.185 mmol / 100 g, preferably 0.18 mmol / 100 g, and the design range of n is 9.5 to 10.5, preferably 9.9 to 10.1, and more preferably 10, the calculation is performed using Formula 5; Preferably, when the design range of m is 0.175 to 0.185 mmol / 100 g, preferably 0.18 mmol / 100 g, and the design range of n is 11.5 to 12.5, preferably 11.9 to 12.1, and more preferably 12, formula 6 is used for calculation.

4. The SEBS hydrogenation degree prediction method according to claim 1, characterized in that: When the design range of m is 0.195 to 0.205 mmol / 100 g, preferably 0.2 mmol / 100 g, and the design range of n is 7.5 to 8.5, preferably 7.9 to 8.1, and more preferably 8, formula 7 is used for calculation; Preferably, when the design range of m is 0.195 to 0.205 mmol / 100 g, preferably 0.2 mmol / 100 g, and the design range of n is 9.5 to 10.5, preferably 9.9 to 10.1, and more preferably 10, the calculation is performed using Formula 8; Preferably, when the design range of m is 0.195 to 0.205 mmol / 100 g, preferably 0.2 mmol / 100 g, and the design range of n is 11.5 to 12.5, preferably 11.9 to 12.1, and more preferably 12, formula 9 is used for calculation.

5. The method for predicting the degree of hydrogenation of SEBS according to any one of claims 1 to 4, characterized in that: The selection range of X is 0.05~1.

6. The method for predicting the degree of hydrogenation of SEBS according to any one of claims 1 to 5, characterized in that: SBS glue is a block polymer glue formed by active lithium anion polymerization; Preferably, the steps for obtaining the SBS glue solution are: adding a solvent, a styrene monomer, an active lithium activator and an initiator to an anionic polymerization solution system to initiate and carry out a first-stage polymerization reaction; after the first-stage polymerization is completed, adding a structure regulator, and simultaneously continuously and uniformly adding a butadiene monomer to carry out a second-stage polymerization reaction; after the second-stage polymerization is completed, adding a styrene monomer to carry out a third-stage polymerization reaction, and after the third-stage polymerization is completed, the SBS glue solution is obtained.

7. The method for predicting the degree of hydrogenation of SEBS according to claim 6, characterized in that: The concentration of the monomer is 10-15%; Preferably, the solvent is one of cyclohexane, n-hexane and cyclopentane; Preferably, the structure regulator includes at least one of ethylene glycol dimethyl ether, ditetrahydrofurfuryl propane, ethylene glycol diethyl ether, tetrahydrofurfuryl alcohol ethyl ether, tetramethylethylenediamine, and hexamethylphosphoric triamide; Preferably, the total time for continuous and uniform addition of the butadiene monomer is 40 to 60 minutes; Preferably, the initial temperature of the two-stage polymerization reaction is controlled at 62-65°C, the maximum temperature is 70-85°C, and the total reaction time is within the range of 30-80 min; Preferably, the activating agent comprises tetrahydrofuran; Preferably, the active lithium initiator includes at least one of n-butyl lithium, sec-butyl lithium and isobutyl lithium; Preferably, the temperature of the first and third stage polymerization reactions is 50° C. to 70° C., and the time is 20 to 50 min.

8. The method for predicting the degree of hydrogenation of SEBS according to claim 1, characterized in that: The main catalyst is a titanocene catalyst, which includes at least one of bis(cyclopentadienyl)titanium dichloride, bis(cyclopentadienyl)titanium dibromide, bis(cyclopentadienyl)titanium diiodide, bis(cyclopentadienyl)titanium difluoride, bis(cyclopentadienyl)titanium dicarbonyl, bis(cyclopentadienyl)titanium dimethyl, bis(cyclopentadienyl)titanium diethyl, and bis(cyclopentadienyl)titanium dibutyl; Preferably, the co-catalyst is a carboxylic acid ester containing a benzene ring, preferably at least one of C1-C5 alkyl benzoate and C1-C5 alkyl phthalate; More preferably, the molar ratio of the main catalyst to the co-catalyst is 1 to 20:

1.

9. The method for predicting the degree of hydrogenation of SEBS according to claim 8, characterized in that: During the selective hydrogenation process, the starting temperature is 72-80°C and the hydrogen pressure is 1.2-1.4 MPa. After the reaction reaches a high temperature of 80-130°C, the hydrogen valve is closed and the pressure in the reactor is released to 0.05 MPa to discharge the hydrogen.

10. A method for preparing SEBS by accurately controlling the degree of hydrogenation, characterized in that: According to the required hydrogenation degree, m, n and X in the selective hydrogenation stage are calculated based on the SEBS hydrogenation degree prediction method of claims 1 to 9, and a selective hydrogenation reaction is performed based on the calculated m, n and X as conditions to accurately produce SEBS with a hydrogenation degree that meets the design requirements.

Images