阅读说明：本技术 丁二烯-异戊二烯共聚物及其制备方法 (Butadiene-isoprene copolymer and preparation method thereof ) 是由 唐正伟 赵姜维 徐林 李建成 邵明波 孙伟 于 2019-08-21 设计创作，主要内容包括：本发明涉及丁二烯-异戊二烯共聚物的制备领域,具体地,涉及丁二烯-异戊二烯共聚物及其制备方法。该丁二烯-异戊二烯共聚物的制备方法包括：(1)制备均相稀土催化剂包括：在第一有机溶剂中,将第一物料和第五物料进行混合,而后静置处理；再引入第四物料和第二物料进行混合,然后引入第三物料进行陈化；(2)在第二有机溶剂中,在均相稀土催化剂存在下,将丁二烯和异戊二烯进行聚合反应；A：式(1)所示的膦酸钕类化合物；B：烷基铝类化合物；C：卤代化合物；D：共轭二烯烃；E：式(2)所示的化合物。本发明的制备方法中所采用的均相稀土催化剂具有较高的活性,能够在较低的催化剂用量下仍然表现出较高的活性。(The invention relates to the field of preparation of butadiene-isoprene copolymers, in particular to a butadiene-isoprene copolymer and a preparation method thereof. The preparation method of the butadiene-isoprene copolymer comprises the following steps: (1) the preparation of the homogeneous rare earth catalyst comprises the following steps: mixing the first material and the fifth material in a first organic solvent, and then standing; then introducing a fourth material and a second material for mixing, and then introducing a third material for aging; (2) in a second organic solvent, carrying out polymerization reaction on butadiene and isoprene in the presence of a homogeneous rare earth catalyst; a: a neodymium phosphonate compound represented by formula (1); b: an alkylaluminum-based compound; c: a halogenated compound; d: a conjugated diene; e: a compound represented by the formula (2). The homogeneous phase rare earth catalyst adopted in the preparation method has higher activityAnd the catalyst still shows higher activity at lower catalyst dosage.)

1. A method for producing a butadiene-isoprene copolymer, the method comprising:

(1) preparing a homogeneous rare earth catalyst comprising: in a first organic solvent, carrying out first mixing on a first material and a fifth material, and then carrying out standing treatment; introducing a fourth material and a second material for second mixing, and introducing a third material for aging; wherein the standing treatment time is more than 1 h; wherein the molar ratio of the first material to the second material to the fifth material is 1: 12-30: 0.2-0.4;

a first material: a neodymium phosphonate compound represented by formula (1);

formula (1)R^a1、R^a2、R^b1、R^b2、R^c1And R^c2Each independently is hydrogen, hydroxy, C₁-C₂₀Alkyl or C₁-C₂₀Alkoxy group of (a);

a second material: an aluminum alkyl-based compound selected from one or more of trialkylaluminums and dialkylaluminum hydrides;

a third material: a halogenated compound selected from one or more of an aluminum alkyl halide, a halosilane, and an aluminum alkyl sesquihalide;

and a fourth material: a conjugated diene;

and (5) fifth material: a compound represented by the formula (2);

formula (2)

Wherein R is^d1、R^d2And R^d3Each independently is hydrogen, hydroxy, C₁-C₂₀Alkyl or C₁-C₂₀Alkoxy group of (a);

(2) and (2) carrying out polymerization reaction on butadiene and isoprene in a second organic solvent in the presence of the homogeneous rare earth catalyst prepared in the step (1).

2. The method according to claim 1, wherein the standing treatment time is 1-60h, preferably 5-50h, more preferably 5-36 h;

preferably, the conditions of the first mixing include: the temperature is 10-40 deg.C, and the time is 10-200 min;

preferably, the conditions of the second mixing include: the temperature is 10-50 deg.C, and the time is 10-200 min;

preferably, the aging conditions include: the temperature is 40-80 deg.C, and the time is 30-300 min.

3. The method of claim 1 or 2, wherein R^a1、R^a2、R^b1、R^b2、R^c1And R^c2Each independently is C₁-C₂₀Alkyl or C₁-C₂₀Alkoxy of (3), preferably C₄-C₁₂Alkyl or C₄-C₁₂More preferably n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-methylpentyl, 2-ethylpentyl, n-hexyl, 2-methylhexyl, 2-ethylhexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, 2-methylpentoxy, 2-ethylpentoxy, n-hexoxy, 2-methylhexoxy, 2-ethylhexoxy, n-heptoxy, n-octoxy, n-nonoxy, n-decoxy, n-undecyloxy or n-dodecoxy;

R^d1、R^d2and R^d3Each independently is hydroxy, C₄-C₁₂Alkyl or C₄-C₁₂Alkoxy group of (a); more preferably, R^d1Is hydroxy, R^d2And R^d3Each independently is n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-methylpentyl, 2-ethylpentyl, n-hexyl, 2-methylhexyl, 2-ethylhexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, 2-methylpentoxy, 2-ethylpentoxy, n-hexoxy, 2-methylhexoxy, 2-ethylhexoxy, n-heptoxy, n-octoxy, n-nonoxy, n-decoxy, n-undecyloxy or n-dodecoxy.

4. The process according to any one of claims 1 to 3, wherein the trialkylaluminum is represented by the formula Al (R)₃Said dialkylaluminum hydride is represented by the formula AlH (R)₂Each R is independently selected from C₁-C₆Alkyl groups of (a);

preferably, the aluminum alkyl compound is one or more of trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, tripentylaluminum, trihexylaluminum, triisobutylaluminum, diethylaluminum hydride, dipropylaluminum hydride, dibutylaluminum hydride and diisobutylaluminum hydride.

5. The method of any one of claims 1-4, wherein the molar ratio of the first material to the third material is 1: 2-5;

preferably, the haloalkylaluminum is represented by the formula Al (R)¹)₂X, said halosilane being of the formula Si (R)¹)_4-nX_nSaid sesquihaloalkylaluminum is represented by the formula Al₂(R¹)₃X₃Wherein each R is¹Each independently selected from C₁-C₆Each X is independently selected from halogen, n is an integer from 1 to 4;

more preferably, the halogenated compound is one or more of diethylaluminum chloride, diisobutylaluminum chloride, ethylaluminum sesquichloride, isobutylaluminum chloride, monochlorosilane, dichlorosilane, trichlorosilane, and silicon tetrachloride.

6. The method of any one of claims 1-5, wherein the molar ratio of the first material to the fourth material is 1: 10-80 parts;

preferably, the conjugated diene is one or more of 1, 3-butadiene, isoprene, piperylene and 2, 4-hexadiene.

7. The method of any one of claims 1-6, wherein the homogeneous rare earth catalyst is used in an amount such that the first mass is used in an amount of 10-200 μmol with respect to 1mol of the total amount of butadiene and isoprene.

8. The method according to any one of claims 1 to 7, wherein the method is such that the weight average molecular weight of the resulting butadiene-isoprene copolymer is 2.3 x 10⁵-3.5×10⁵g/mol, the content of cis-1, 4-polymeric structure is more than 97 mol%, the molecular weight distribution index is less than 2.3, and the Mooney viscosity ML of raw rubber₍₁₊₄₎35-65 ℃ at 100 ℃.

9. The process according to any one of claims 1 to 8, wherein butadiene and isoprene are used in a molar ratio of 1: 0.1 to 10;

preferably, the polymerization conditions include: the temperature is 10-90 ℃ and the time is 1-5 h.

10. A butadiene-isoprene copolymer produced by the method of any one of claims 1 to 9.

Technical Field

The invention relates to the field of preparation of butadiene-isoprene copolymers, in particular to a butadiene-isoprene copolymer and a preparation method thereof.

Background

High cis butadiene (Bd) -isoprene (Ip) copolymer rubber refers to Bd-Ip copolymers having a cis-1, 4-structure mole fraction greater than 90 wt%. The high cis Bd-Ip copolymer rubber has excellent low temperature resistance and wear resistance, better wet skid resistance and lower rolling resistance, has better processing behavior than butadiene rubber, has better comprehensive physical and mechanical properties of vulcanized rubber, and is applied to industrial products such as high-performance tires, damping materials and the like. The catalyst for preparing Bd-Ip copolymer mainly comprises lithium, transition metal (cobalt, nickel, titanium and chromium) and a rare earth catalytic system, wherein only the rare earth catalytic system can enable Bd and Ip chain links in the copolymer to have high cis-1, 4-structures simultaneously, so that research on synthesizing high cis Bd-Ip copolymer rubber is concentrated on the rare earth catalytic system at present.

Although available polybutadiene-isoprene rubber materials are obtained by the existing rare earth catalysts, the problems that the activity of the catalysts is low and the consumption of the catalysts is high exist. This makes the material cost high, has restricted extensive development and use.

Disclosure of Invention

The present invention aims to provide a butadiene-isoprene copolymer having a high cis-content and a method for producing the same, which can be produced with a low catalyst consumption.

In order to achieve the above object, a first aspect of the present invention provides a method for preparing a butadiene-isoprene copolymer, the method comprising:

(1) preparing a homogeneous rare earth catalyst comprising: in a first organic solvent, carrying out first mixing on a first material and a fifth material, and then carrying out standing treatment; introducing a fourth material and a second material for second mixing, and introducing a third material for aging; wherein the standing treatment time is more than 1 h; wherein the molar ratio of the first material to the second material to the fifth material is 1: 12-30: 0.2-0.4;

a first material: a neodymium phosphonate compound represented by formula (1);

formula (1)R^a1、R^a2、R^b1、R^b2、R^c1And R^c2Each independently is hydrogen, hydroxy, C₁-C₂₀Alkyl or C₁-C₂₀Alkoxy group of (a);

a second material: an aluminum alkyl-based compound selected from one or more of trialkylaluminums and dialkylaluminum hydrides;

a third material: a halogenated compound selected from one or more of an aluminum alkyl halide, a halosilane, and an aluminum alkyl sesquihalide;

and a fourth material: a conjugated diene;

and (5) fifth material: a compound represented by the formula (2);

formula (2)

Wherein R is^d1、R^d2And R^d3Each independently is hydrogen, hydroxy, C₁-C₂₀Alkyl or C₁-C₂₀Alkoxy group of (a);

(2) and (2) carrying out polymerization reaction on butadiene and isoprene in a second organic solvent in the presence of the homogeneous rare earth catalyst prepared in the step (1).

In a second aspect, the present invention provides a butadiene-isoprene copolymer produced by the above-described method.

The homogeneous rare earth catalyst adopted in the preparation method can prepare the butadiene-isoprene copolymer required by the invention at a lower dosage, shows higher activity, and the obtained butadiene-isoprene copolymer has proper molecular weight and high cis-structure content.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The first aspect of the present invention provides a method for preparing a butadiene-isoprene copolymer, the method comprising:

(1) preparing a homogeneous rare earth catalyst comprising: in a first organic solvent, carrying out first mixing on a first material and a fifth material, and then carrying out standing treatment; introducing a fourth material and a second material for second mixing, and introducing a third material for aging; wherein the standing treatment time is more than 1 h; wherein the molar ratio of the first material to the second material to the fifth material is 1: 12-30: 0.2-0.4;

a first material: a neodymium phosphonate compound represented by formula (1);

formula (1)R^a1、R^a2、R^b1、R^b2、R^c1And R^c2Each independently is hydrogen, hydroxy, C₁-C₂₀Alkyl or C₁-C₂₀Alkoxy group of (a);

a second material: an aluminum alkyl-based compound selected from one or more of trialkylaluminums and dialkylaluminum hydrides;

a third material: a halogenated compound selected from one or more of an aluminum alkyl halide, a halosilane, and an aluminum alkyl sesquihalide;

and a fourth material: a conjugated diene;

and (5) fifth material: a compound represented by the formula (2);

formula (2)

Wherein R is^d1、R^d2And R^d3Each independently is hydrogen, hydroxy, C₁-C₂₀Alkyl or C₁-C₂₀Alkoxy group of (a);

(2) and (2) carrying out polymerization reaction on butadiene and isoprene in a second organic solvent in the presence of the homogeneous rare earth catalyst prepared in the step (1).

According to the present invention, the preparation by step (1) of the process of the present invention will allow the rare earth catalyst to be obtained in a homogeneous state, and it is understood that the homogeneous rare earth catalyst of the present invention is a homogeneous solution containing the above-mentioned first material, B, C, D and E.

According to the invention, the homogeneous rare earth catalyst adopted in the preparation method can be used for preparing the butadiene-isoprene copolymer required by the invention at a lower dosage, the butadiene-isoprene copolymer has higher activity, and the obtained butadiene-isoprene copolymer has proper molecular weight and high cis-structure content. The method is mainly realized by regulating and controlling the catalyst preparation method, wherein in the invention, the dosage of the fifth material can be reduced to the molar ratio of the first material to the fifth material of 1: 0.2-0.4. Preferably, the molar ratio of the first material to the fifth material is 0.25-0.35. The rare earth homogeneous catalyst can be prepared from the fifth material with a relatively low dosage under the condition that the first material and the fifth material are controlled to be subjected to standing treatment for a long time after being mixed for the first time, so that the performance of the obtained catalyst can still be maintained under the condition that the addition amount of the fifth material in the prepared catalyst is small.

According to the invention, the standing treatment is preferably carried out for a period of time of from 1 to 60 hours, preferably from 5 to 50 hours, more preferably from 5 to 36 hours (for example from 5 to 12 hours or from 5 to 8 hours). Preferably, the temperature of the standing treatment is 10 to 40 ℃.

In the present invention, preferably, R^a1、R^a2、R^b1、R^b2、R^c1And R^c2Each independently is C₁-C₂₀Alkyl or C₁-C₂₀Alkoxy of (3), preferably C₄-C₁₂Alkyl or C₄-C₁₂More preferably n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-methylpentyl, 2-ethylpentyl, n-hexyl, 2-methylhexyl, 2-ethylhexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, 2-methylpentoxy, 2-ethylpentoxy, n-hexoxy, 2-methylhexoxy, 2-ethylhexoxy, n-heptoxy, n-octoxy, n-nonoxy, n-decoxy, n-undecyloxy or n-dodecoxy.

Specific examples of the neodymium phosphonate-based compound may be, for example, one or more compounds selected from the group consisting of compounds represented by the following formulae:

formula (1-1): in the formula (1), R^a1、R^a2、R^b1、R^b2、R^c1And R^c2Are all 2-ethylhexyloxy (i.e. di (2-ethylhexyl) phosphonate neodymium);

formula (1-2): in the formula (1), R^a1、R^a2、R^b1、R^b2、R^c1And R^c2Are both 2-methylhexyloxy (i.e. di (2-methylhexyl) phosphonate neodymium);

formula (1-3): in the formula (1), R^a1、R^a2、R^b1、R^b2、R^c1And R^c2Both are n-hexyloxy (i.e., neodymium di (n-hexyl) phosphonate).

The neodymium phosphonate compound can be obtained by a conventional method in the art, and for example, can be a commercially available product or can be prepared by a conventional method in the art, and the invention is not particularly limited thereto.

According to the invention, preferably, said trialkylaluminium is represented by the formula Al (R)₃Said dialkylaluminum hydride is represented by the formula AlH (R)₂Each R is independently selected from C₁-C₆Alkyl group of (1). More preferably, the aluminum alkyl compound is one or more of trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, tripentylaluminum, trihexylaluminum, triisobutylaluminum, diethylaluminum hydride, dipropylaluminum hydride, dibutylaluminum hydride and diisobutylaluminum hydride.

According to the invention, preferably R^d1、R^d2And R^d3Each independently is hydroxy, C₄-C₁₂Alkyl or C₄-C₁₂Alkoxy group of (a); more preferably, R^d1Is hydroxy, R^d2And R^d3Each independently is n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-methylpentyl, 2-ethylpentyl, n-hexyl, 2-methylhexyl, 2-ethylhexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, 2-methylpentoxy, 2-ethylpentoxy, n-hexoxy, 2-methylhexoxy, 2-ethylhexoxy, n-heptoxy, n-octoxy, n-nonoxy, n-decoxy, n-undecyloxy or n-dodecoxy.

Among them, specific examples of the compound represented by formula (2) may be, for example, one or more selected from compounds represented by the following formulae:

formula (2-1): in the formula (2), R^d1Is hydroxy, R^d2And R^d3Are all 2-ethylhexyloxy (i.e., di (2-ethylhexyl) phosphonate);

formula (2-2): in the formula (2), R^d1Is hydroxy, R^d2And R^d3Are all 2-methylhexyloxy (i.e. di (2-methylhexyl) phosphonate);

formula (2-3): in the formula (2), R^d1Is hydroxy, R^d2And R^d3Are both n-hexyloxy (i.e., di (n-hexyl) phosphonate).

The compound represented by formula (2) may be obtained by a method conventional in the art, and may be, for example, a commercially available product or a method conventional in the art.

According to the invention, preferably, the molar ratio of the first material to the third material is 1: 2-5. Preferably, the molar ratio of the first material to the fourth material is 1: 10-80, preferably 1: 40-60. By adopting the proportion in the molar ratio range, the high-activity homogeneous rare earth catalyst which is more suitable for preparing the butadiene-isoprene copolymer can be obtained.

According to the invention, preferably, the haloalkylaluminum is represented by the formula Al (R)¹)₂X, said halosilane being of the formula Si (R)¹)_4-nX_nSaid sesquihaloalkylaluminum is represented by the formula Al₂(R¹)₃X₃Wherein each R is¹Each independently selected from C₁-C₆Each X is independently selected from halogen (e.g., F, Cl, Br), and n is an integer from 1 to 4. More preferably, the halogenated compound is one or more of diethylaluminum chloride, diisobutylaluminum chloride, ethylaluminum sesquichloride, isobutylaluminum chloride, monochlorosilane, dichlorosilane, trichlorosilane, and silicon tetrachloride.

According to the invention, the conjugated diene in the homogeneous rare earth catalyst can stabilize the active center of the catalyst, generally refers to an olefin monomer with conjugated double bonds, and preferably, the conjugated diene is one or more of 1, 3-butadiene, isoprene, piperylene and 2, 4-hexadiene. It is to be understood that the conjugated diene and the butadiene and isoprene used hereinafter to form the butadiene-isoprene copolymer should be metered separately.

Wherein the first organic solvent may be one that can be suitably used for preparing the present hairSolvents for homogeneous solutions of the homogeneous rare earth catalysts of the invention, preferably C₅-C₁₀Alkane, C₅-C₁₀Cycloalkanes and C₆-C₁₂Preferably one or more of pentane, cyclopentane, hexane, cyclohexane, methylcyclohexane, heptane, octane, benzene, toluene, xylene, and cumene. The first solvent herein is understood to be a generic term for the solvents contained in the homogeneous rare earth catalyst produced, i.e., including the solvent added during the first mixing, and also including the solvent introduced during subsequent processing, including the solvent introduced in the form of a solution of the active component.

Wherein, the first material, the second material, the third material, the fourth material and the fifth material can be provided in the form of pure substances or in the form of solution, and when the first material, the second material, the third material, the fourth material and the fifth material are provided in the form of solution, the concentration of the solution of the first material, the second material, the third material, the fourth material and the fifth material can be 0.01-0.5 mol/L. The solvent may be selected from the first organic solvents employed in the homogeneous solutions described above.

The amount of solvent used may vary within wide limits and is preferably such that the concentration of the first material in the homogeneous solution is from 0.01 to 0.5mmol/mL, preferably from 0.01 to 0.1mmol/mL, more preferably from 0.01 to 0.02 mmol/mL.

According to the present invention, preferably, the conditions of the first mixing include: the temperature is 10-40 deg.C, and the time is 10-200 min.

According to the present invention, preferably, the conditions of the second mixing include: the temperature is 10-50 deg.C, and the time is 10-200 min.

According to the present invention, preferably, the aging conditions include: the temperature is 40-80 deg.C, and the time is 30-300 min.

According to the invention, the process of the invention preferably makes it possible to obtain a weight-average molecular weight of 2.3X 10⁵-3.5×10⁵g/mol, the content of cis 1, 4-polymeric structures is 97 mol%Above, a molecular weight distribution index of 2.3 or less, and a Mooney viscosity ML of the raw rubber₍₁₊₄₎For butadiene-isoprene copolymers having a temperature of from 35 to 65 ℃ at 100 ℃, the process of the invention is preferably such that the butadiene-isoprene copolymer obtained has a weight average molecular weight of 2.3X 10⁵-3.5×10⁵g/mol, the content of cis-1, 4-polymeric structure is more than 97 mol%, the molecular weight distribution index is less than 2.3, and the Mooney viscosity ML of raw rubber₍₁₊₄₎35-65 ℃ at 100 ℃.

Preferably, the homogeneous rare earth catalyst is used in an amount such that the first material is used in an amount of 10 to 200. mu. mol, preferably 20 to 100. mu. mol, and more preferably 30 to 60. mu. mol, relative to 1mol of the total amount of butadiene and isoprene.

According to the invention, the amounts of butadiene and isoprene may vary within wide limits, preferably the molar ratio between the amounts of butadiene and isoprene is 1: 0.1-10.

According to the invention, the second organic solvent may be any hydrocarbon solvent inert to the polymerization reaction, and may be, for example, C₅-C₁₀Alkane, C₅-C₁₀Cycloalkanes and C₆-C₁₂Preferably one or more of hexane, cyclohexane, heptane, pentane, isopentane, octane, methylcyclohexane, benzene, toluene, xylene and cumene. Wherein the amount of the second organic solvent may vary within wide ranges, preferably from 300 to 1000 parts by weight, relative to 100 parts by weight of the total amount of butadiene and isoprene.

According to the present invention, preferably, the polymerization conditions include: the temperature is 10-90 ℃ and the time is 1-5 h. More preferably, the polymerization conditions include: the temperature is 60-80 ℃ and the time is 1.5-3 h.

According to the invention, the polymerization can be carried out in an inert atmosphere in order to overcome the destruction of the active centers of the catalyst by oxygen. The inert atmosphere may be maintained by evacuating the reaction vessel and introducing a gas selected from nitrogen, argon, helium, and the like.

The preparation method of the butadiene-isoprene copolymer provided by the invention still has the following advantages under the condition of less E component consumption:

(1) the catalyst consumption is low, and is below 130mgNd/kg Bd-Ip (the amount of Nd required for producing 1kg of butadiene-isoprene copolymer);

(2) the obtained butadiene-isoprene copolymer had a suitable molecular weight, that is, the weight average molecular weight of the obtained butadiene-isoprene copolymer was 2.3X 10⁵-3.5×10⁵g/mol, Mooney viscosity ML of crude rubber₍₁₊₄₎38-55 ℃ at 100 ℃;

(3) the obtained butadiene-isoprene copolymer has a narrow molecular weight distribution, namely the molecular weight distribution index of the obtained butadiene-isoprene copolymer is less than 2.3;

(4) the butadiene-isoprene copolymer obtained is a high-cis butadiene-isoprene copolymer having a cis 1, 4-polymerization structure content of 97 mol% or more (based on the molar amount of the total structural units of the butadiene-isoprene copolymer).

In a second aspect, the present invention provides a butadiene-isoprene copolymer produced by the above-described method.

According to the present invention, preferably, the butadiene-isoprene copolymer has a weight average molecular weight of 2.3 × 10⁵-3.5×10⁵g/mol, the content of cis-1, 4-polymeric structure is more than 97 mol%, the molecular weight distribution index is less than 2.3, and the Mooney viscosity ML of raw rubber₍₁₊₄₎35-65 ℃ at 100 ℃. Preferably, the above method is such that the weight average molecular weight of the resulting butadiene-isoprene copolymer is 2.3X 10⁵-3.2×10⁵g/mol, the content of cis-1, 4-polymeric structure is 97.5-100 mol%, the molecular weight distribution index is 1.9-2.2, and the Mooney viscosity ML of the raw rubber₍₁₊₄₎38-55 ℃ at 100 ℃.

The present invention will be described in detail below by way of examples.

In the following examples, the Mooney viscosity was measured using a Mooney viscometer without a rotor, model SMV-201SK-160, manufactured by Shimadzu corporation, Japan, in which the preheating time was 1min, the rotation time was 4min, and the measuring temperature was 100 ℃.

The molecular weight and molecular weight distribution were determined by HLC-8320 Gel Permeation Chromatography (GPC) from Tosoh, Japan, and 2 TSKgelSuperMultipolypore HZ-M analytical columns were prepared, with THF as mobile phase, narrow-distribution polystyrene as standard sample, and temperature of 40 deg.C.

The cis 1, 4-polymeric structure content was determined by means of an infrared spectrometer in Bruker Tensor 27, Germany.

Preparation example 1

30mL of hydrochloric acid (concentration 12mol/L) was added to 0.05mol of Nd₂O₃Then heated to boiling and stirred for 30min to obtain NdCl₃The aqueous solution was pale purple and transparent. 0.3mol of acetone solution of di (2-ethylhexyl) phosphonate (180mL of acetone) was added to 450mL of aqueous sodium hydroxide solution (sodium hydroxide content: 0.3mol), and mixed well to obtain a pale yellow solution, followed by addition of the above NdCl₃And stirring and mixing the aqueous solution to obtain a suspension containing fine white granular precipitates, filtering, washing a filter cake for 3 times by using a proper amount of distilled water and acetone respectively, and drying in an oven at 60 ℃ for 72 hours to obtain the di (2-ethylhexyl) phosphonate neodymium.

Catalyst preparation example 1

Under the protection of nitrogen, 250mL of hexane, 6.2mmol of neodymium di (2-ethylhexyl) phosphonate, and 1.86mmol of neodymium di (2-ethylhexyl) phosphonate were mixed at 20 ℃ for 30min and then allowed to stand for 24 h. Adding 99mL of hexane solution of diisobutylaluminum hydride with the concentration of 1mol/L and 310mmol of butadiene at the temperature of 30 ℃, stirring and mixing for 30min, then heating to 60 ℃, adding 18.6mL of hexane solution of diethylaluminum chloride with the concentration of 1mol/L, and aging for 2h to obtain a catalyst in a homogeneous solution state, namely a homogeneous rare earth catalyst C1, wherein the content of Nd element is 0.0157 mmol/mL; the molar ratio of neodymium di (2-ethylhexyl) phosphonate, diisobutylaluminum hydride, diethylaluminum chloride, butadiene and di (2-ethylhexyl) phosphonate is 1: 16: 3: 50: 0.3.

catalyst preparation example 2

6.2mmol of neodymium di (2-ethylhexyl) phosphonate and 1.86mmol of di (2-ethylhexyl) phosphonate were mixed at 20 ℃ for 40min and then left to stand for 5 hours. Then adding 105mL of hexane solution of diethyl aluminum hydride with the concentration of 1mol/L and 248mmol of butadiene at the temperature of 30 ℃, stirring and mixing for 30min, then heating to 80 ℃, adding 18.6mL of hexane solution of diisobutyl aluminum chloride with the concentration of 1mol/L, and aging for 2h to obtain a catalyst in a homogeneous solution state, namely a homogeneous rare earth catalyst C2, wherein the content of Nd element is 0.0159 mmol/mL; the molar ratio of neodymium di (2-ethylhexyl) phosphonate, diethylaluminum hydride, diisobutylaluminum chloride, butadiene and di (2-ethylhexyl) phosphonate is 1: 17: 3: 40: 0.3.

catalyst preparation example 3

According to the method described in catalyst preparation example 1, except that the amount of butadiene was 496mmol, a catalyst in the form of a homogeneous solution, i.e., a homogeneous rare earth catalyst C3, in which the content of Nd element was 0.0151mmol/mL, was obtained; the molar ratio of neodymium di (2-ethylhexyl) phosphonate, diisobutylaluminum hydride, diethylaluminum chloride, butadiene and di (2-ethylhexyl) phosphonate is 1: 16: 3: 80: 0.3.

catalyst preparation example 4

According to the method described in catalyst preparation example 1, except that bis (2-ethylhexyl) phosphonate was used in an amount of 2.48mmol, a catalyst in a homogeneous solution state, i.e., a homogeneous rare earth catalyst C4, in which the content of Nd element was 0.0157mmol/mL, was obtained; the molar ratio of neodymium di (2-ethylhexyl) phosphonate, diisobutylaluminum hydride, diethylaluminum chloride, butadiene and di (2-ethylhexyl) phosphonate is 1: 16: 3: 50: 0.4.

catalyst preparation example 5

According to the method described in catalyst preparation example 1, except that bis (2-ethylhexyl) phosphonate was used in an amount of 1.24mmol, a catalyst in a homogeneous solution state, i.e., a homogeneous rare earth catalyst C5, in which the content of Nd element was 0.0157mmol/mL, was obtained; the molar ratio of neodymium di (2-ethylhexyl) phosphonate, diisobutylaluminum hydride, diethylaluminum chloride, butadiene and di (2-ethylhexyl) phosphonate is 1: 16: 3: 50: 0.2.

catalytic preparation example 6

According to the method described in catalyst preparation example 1, except that the amount of the hexane solution having a concentration of 1mol/L of diethylaluminum chloride was 21.7mL, the catalyst in a homogeneous solution state, i.e., the homogeneous rare earth catalyst C6, in which the content of Nd element was 0.0156mmol/mL was obtained; the molar ratio of neodymium di (2-ethylhexyl) phosphonate, diisobutylaluminum hydride, diethylaluminum chloride, butadiene and di (2-ethylhexyl) phosphonate is 1: 16: 3.5: 50: 0.3.

catalytic preparation example 7

According to the method described in catalyst preparation example 1, except that the amount of the hexane solution having a concentration of 1mol/L of diethylaluminum chloride was 15.5mL, the catalyst in a homogeneous solution state, i.e., the homogeneous rare earth catalyst C7, in which the content of Nd element was 0.0158mmol/mL was obtained; the molar ratio of neodymium di (2-ethylhexyl) phosphonate, diisobutylaluminum hydride, diethylaluminum chloride, butadiene and di (2-ethylhexyl) phosphonate is 1: 16: 2.5: 50: 0.3.

catalyst preparation example 8

According to the method of catalyst preparation example 1, except that hexane, neodymium bis (2-ethylhexyl) phosphonate and bis (2-ethylhexyl) phosphonate are mixed and then are allowed to stand for 2 hours, namely the homogeneous rare earth catalyst C8.

Catalyst preparation example 9

According to the method described in catalyst preparation example 1, except that the standing time was 72 hours after mixing neodymium bis (2-ethylhexyl) phosphonate with bis (2-ethylhexyl) phosphonate, catalyst C9 was obtained in the form of a homogeneous solution.

Comparative example 1

According to the process described in catalyst preparation example 1, except that di (2-ethylhexyl) phosphonate was not used, catalyst DC1 was obtained, which contained a large amount of suspended solids.

Comparative example 2

According to the procedure described in catalyst preparation example 1, except that an equimolar amount of triphenylphosphine was used instead of di (2-ethylhexyl) phosphonate, catalyst DC2 was obtained, which contained a small amount of suspended solids.

Comparative example 3

According to the method described in catalyst preparation example 1, except that the standing was not performed after mixing of neodymium di (2-ethylhexyl) phosphonate with di (2-ethylhexyl) phosphonate, catalyst DC3 was obtained in a homogeneous solution state.

Polymerization examples 1 to 9

Under the protection of nitrogen, 900g of hexane, 40g of butadiene, 201g of isoprene and a certain amount of the catalyst C1-C9 (the amount and the type are shown in Table 1) are subjected to polymerization reaction for 2 hours at 60 ℃ to obtain the corresponding butadiene-isoprene copolymer, and the properties of the obtained butadiene-isoprene copolymer are shown in Table 1.

Polymerization example 10

Under the protection of nitrogen, 900g of hexane, 100g of butadiene, 126g of isoprene and a certain amount of the above catalyst C1 (the amount and the type are shown in Table 1) were subjected to polymerization reaction at 60 ℃ for 2h to obtain the corresponding butadiene-isoprene copolymer, and the properties of the obtained butadiene-isoprene copolymer are shown in Table 1.

Polymerization example 11

Under the protection of nitrogen, 900g of hexane, 160g of butadiene, 50g of isoprene and a certain amount of the above catalyst C1 (the amount and the type are shown in Table 1) were subjected to polymerization reaction at 60 ℃ for 2h to obtain the corresponding butadiene-isoprene copolymer, and the properties of the obtained butadiene-isoprene copolymer are shown in Table 1.

Polymerization comparative example 1

According to the method described in polymerization example 1, except that catalyst DC1 was used instead of catalyst C1, the corresponding butadiene-isoprene copolymer was obtained, and the properties of the obtained butadiene-isoprene copolymer are shown in Table 1.

Polymerization comparative example 2

According to the method described in polymerization example 1, except that catalyst DC2 was used instead of catalyst C1, the corresponding butadiene-isoprene copolymer was obtained, and the properties of the obtained butadiene-isoprene copolymer are shown in Table 1.

Polymerization comparative example 3

According to the method described in polymerization example 1, except that catalyst DC3 was used instead of catalyst C1, the corresponding butadiene-isoprene copolymer was obtained, and the properties of the obtained butadiene-isoprene copolymer are shown in Table 1.

TABLE 1

The results in table 1 show that the homogeneous rare earth catalyst used in the present invention has high activity, can still show high activity with low catalyst usage and E component usage, and the catalyst is a homogeneous system and has high industrial value.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.