CN113584717B - Preparation method of non-woven fabric with strength and flexible touch feeling - Google Patents

Abstract

The application relates to a preparation method of a non-woven fabric with both strength and flexible touch feeling. The homopolymerization propylene resin is prepared by catalyzing and preparing special lanthanum N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide monochloride, neodymium N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide monochloride, samarium N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide monochloride or yttrium N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide monochloride in advance, and the molecular weight of the homopolymerization propylene resin is ensured to be between 180000 and 200000; the molecular weight distribution is between 1.3 and 1.5; the melt index is between 18 and 22g/10 min; the residual stress ratio is not higher than 0.03%. Furthermore, the melt-blown non-woven fabric is prepared by a melt-blown method, so that the non-woven fabric with both strength and flexible touch can be obtained.

Description

Preparation method of non-woven fabric with strength and flexible touch feeling

Technical Field

The application belongs to the technical field of non-woven fabric manufacturing, and particularly relates to a preparation method of a non-woven fabric with strength and flexible touch feeling.

Background

A nonwoven fabric is a fabric that is made of oriented or random fibers that have been mechanically and chemically treated without weaving to have an appearance similar to that of a conventional woven fabric. The fibers used to make the nonwoven fabric are typically synthetic fibers of polymeric materials such as polypropylene, chitosan, cellulose, and the like.

The polyolefin resin synthetic fiber is the most common non-woven fabric fiber, has good flexibility and air permeability, and is widely applied to the fields of medical treatment and health, clothing, automobiles, buildings and the like. Among them, the properties of polyolefin resin directly determine the properties of the polyolefin nonwoven fabric obtained.

Improved flexibility can be obtained by using conventional ziegler-natta catalysts to synthesize homopolyolefin resins, and in particular by ziegler-natta catalysts to catalyze the bicomponent copolymerization of polypropylene and polyethylene. However, the resin fiber obtained by this method is not suitable for producing a high-strength nonwoven fabric due to deterioration of strength.

By preparing a homopolypropylene resin using a metallocene catalyst, an acrylic resin having a narrow molecular weight distribution can be obtained, which in turn enables the production of fine and uniform fibers and is used to prepare a high-strength nonwoven fabric. However, such a high-strength nonwoven fabric has poor soft touch and is not suitable for use in the fields of clothing, sanitary goods, and the like.

Therefore, the application aims to provide a preparation method of the non-woven fabric which is particularly suitable for being applied to the fields of clothes, hygienic products and the like and has both strength and flexible touch feeling.

Disclosure of Invention

Aiming at the defects in the related art, the application provides a preparation method of a non-woven fabric with both strength and flexible touch.

In order to realize the application, as one aspect of the application, firstly, a homopolymerized propylene resin prepared by catalysis of a rare earth organic catalyst is provided, wherein the rare earth organic catalyst is a rare earth organic compound shown as a formula (I);

（I）

wherein M is selected from one of La, Nd, Sm and Y;

the molecular weight of the obtained homopolymerized propylene resin is between 180000 and 200000; the molecular weight distribution is between 1.3 and 1.5; the melt index is between 18 and 22g/10 min; the residual stress ratio is not higher than 0.03%.

In order to achieve the present application, as another aspect of the present application, there is provided a method for preparing a rare earth organic compound represented by formula (I).

In the preparation method, the raw materials used comprise: n, N-dichloro-p-toluenesulfonamide, 2-ethyl-7-phenyl-1H-indene, benzene, toluene, cyclohexane, tetrahydrofuran, N-butyl lithium, lanthanum trichloride, neodymium trichloride, samarium trichloride and yttrium trichloride. Wherein, the structural formulas of the N, N-dichloro-p-toluenesulfonamide and the 2-ethyl-7-phenyl-1H-indene are respectively shown as the following formulas (II) and (III).

（II）；

（III）。

The preparation method of the rare earth organic compound shown in the formula (I) comprises the following steps:

(1) preparing a toluene/tetrahydrofuran mixed solvent according to a volume ratio of 7:3, dissolving 11 g of 2-ethyl-7-phenyl-1H-indene in 100 ml of the toluene/tetrahydrofuran mixed solvent to obtain a solution A,

(2) dripping 10 ml of 2mol/L cyclohexane solution of n-butyllithium into the solution A, and stirring for 3-12 hours;

(3) slowly dropwise adding 100 ml of benzene solution of N, N-dichloro-p-toluenesulfonamide with the concentration of 60g/L into the solution obtained in the step (2) at the environment below-20 ℃, stirring for 5 minutes, continuously stirring at room temperature for 12-24 hours, and obtaining an intermediate product N, N-bis (2-ethyl-7-phenyl-1H-indenyl) benzenesulfonamide after the reaction is finished;

(4) adding 100 ml of 0.025mol/L lanthanum trichloride tetrahydrofuran solution, neodymium trichloride tetrahydrofuran solution, samarium trichloride tetrahydrofuran solution or yttrium trichloride tetrahydrofuran solution into the solution obtained in the step (3) at the temperature of below-20 ℃, stirring for 20 minutes, continuously stirring for 20-40 hours at room temperature, and obtaining the rare earth organic compound shown in the formula (I) after the reaction is finished;

(5) removing the solvent in the reaction solution under reduced pressure, and then dissolving again and recrystallizing with toluene solvent to obtain high-purity N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide lanthanum monochloride, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide neodymium monochloride, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide samarium monochloride or N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide yttrium monochloride.

To achieve the present application, as yet another aspect of the present application, there is provided a method for preparing a homopolypropylene resin catalyzed by a rare earth organic catalyst, comprising the steps of:

(1) loading a rare earth organic compound shown in a formula (I) on the surface of alumina or silica particles to obtain a solid particle-loaded rare earth organic catalyst;

(2) the rare earth organic catalyst loaded by solid particles is used for catalyzing the preparation of homopolymerization propylene resin, and the polymerization temperature is 15-40 ℃.

Finally, in order to realize the present application, there is provided a method for preparing a nonwoven fabric having both strength and a soft touch, comprising the steps of:

(1) the homopolymerized propylene resin prepared by the catalysis of the rare earth organic catalyst and the electret master batch are mixed in a mixer according to the weight ratio of (95-99) to (1-5), the rotating speed of the mixer is 90-180rpm, and the mixing time is 10-15 min;

(2) melting and mixing the mixed raw materials through a double-screw extrusion further machine, and extruding and granulating to obtain melt-blown master batches, wherein the melting temperature of the double-screw extrusion machine is 215-235 ℃, and the rotating speed of a screw is 120-180 rpm;

(3) and (3) carrying out melt-blown spinning on the melt-blown master batches prepared in the step (2) through a screw extruder, cooling and solidifying the melt-blown master batches into fiber filaments through surrounding cold air media, laying the fiber filaments on a receiving device to form a web, and forming a multi-layer composite fiber web, wherein the air pressure is 0.3-0.5MPa and the receiving distance is 11-15cm in the melt-blowing process.

(4) And carrying out hot rolling reinforcement treatment on the multilayer composite fiber web to obtain the non-woven fabric, wherein the temperature of the hot rolling reinforcement treatment is 170 ℃, the pressure is 5MPa, and the hot rolling time is 15 s.

Has the advantages that:

the inventor finds in practice that polyolefin resins prepared by catalysis of existing Ziegler-Natta catalysts or metallocene catalysts have the defects of insufficient strength or poor soft touch. According to the scheme of the application, the homopolymerized propylene resin is prepared by using the specific rare earth organic catalyst for catalysis, the molecular weight distribution, the melt index, the residual stress ratio, the flexible touch feeling and other properties of the obtained homopolymerized propylene resin are in more excellent levels, and then the non-woven fabric with both strength and flexible touch feeling can be prepared.

Detailed Description

The present application is further described in detail with reference to the following specific examples, and the content of the present application is not limited to the following examples. Variations that may occur to those skilled in the art are included in this application without departing from the scope of the inventive concept.

The inventor finds in practice that the polyolefin resin prepared by the existing Ziegler-Natta catalyst has the defect of insufficient strength, and the polyolefin resin prepared by the existing metallocene catalyst has the defect of poor flexible touch. Therefore, the inventors found in the course of research for improving the above problems that the molecular weight of the homopolypropylene resin prepared by using the rare earth organic compound with a specific structure as the catalyst is 180000-200000, the molecular weight distribution is 1.3-1.5, the melt index is 18-22g/10min, and the ratio of the residual stress is not higher than 0.03%. Wherein the molecular weight, molecular weight distribution, melt index and residual stress ratio are optimized to 180000-.

Thus, according to a first embodiment according to the present application, there is provided a rare earth organic catalyst for catalyzing the preparation of homopolypropylene resins having the above-mentioned excellent properties. The rare earth organic catalyst has a structural formula shown in a formula (I),

（I）

wherein M is selected from one of La, Nd, Sm and Y.

Example 1

Preparation of N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide lanthanum monochloride

The preparation method comprises the following specific steps:

(1) preparing a toluene/tetrahydrofuran mixed solvent according to a volume ratio of 7:3, dissolving 11 g of 2-ethyl-7-phenyl-1H-indene in 100 ml of the toluene/tetrahydrofuran mixed solvent to obtain a solution A,

(2) dripping 10 ml of 2mol/L cyclohexane solution of n-butyllithium into the solution A, and stirring for 10 hours;

(3) slowly dropwise adding 100 ml of benzene solution of N, N-dichloro-p-toluenesulfonamide with the concentration of 60g/L into the solution obtained in the step (2) at the environment below-20 ℃, stirring for 5 minutes, continuously stirring at room temperature for 16 hours, and obtaining an intermediate product N, N-bis (2-ethyl-7-phenyl-1H-indenyl) benzenesulfonamide after the reaction is finished;

(4) adding 100 ml of tetrahydrofuran solution of lanthanum trichloride with the concentration of 0.025mol/L into the solution obtained in the step (3) at the temperature of below 20 ℃ below zero, stirring for 20 minutes, continuously stirring for 24 hours at room temperature, and obtaining the preparation of N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide lanthanum monochloride after the reaction is finished;

(5) the solvent in the reaction solution was removed under reduced pressure, and then re-dissolved and recrystallized in toluene solvent to obtain high-purity N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide lanthanum monochloride.

Example 2

Preparation of neodymium N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide monochloride

The preparation method comprises the following specific steps:

(1) preparing a toluene/tetrahydrofuran mixed solvent according to a volume ratio of 7:3, dissolving 11 g of 2-ethyl-7-phenyl-1H-indene in 100 ml of the toluene/tetrahydrofuran mixed solvent to obtain a solution A,

(2) dripping 10 ml of 2mol/L cyclohexane solution of n-butyllithium into the solution A, and stirring for 10 hours;

(3) slowly dropwise adding 100 ml of benzene solution of N, N-dichloro-p-toluenesulfonamide with the concentration of 60g/L into the solution obtained in the step (2) at the environment below-20 ℃, stirring for 5 minutes, continuously stirring at room temperature for 24 hours, and obtaining an intermediate product N, N-bis (2-ethyl-7-phenyl-1H-indenyl) benzenesulfonamide after the reaction is finished;

(4) adding 100 ml of tetrahydrofuran solution of neodymium trichloride with the concentration of 0.025mol/L into the solution obtained in the step (3) at the temperature of below 20 ℃ below zero, stirring for 20 minutes, continuously stirring for 40 hours at room temperature, and obtaining the preparation of the neodymium N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide monochloride after the reaction is finished;

(5) removing the solvent in the reaction solution under reduced pressure, and then dissolving and recrystallizing with toluene solvent again to obtain high-purity N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide neodymium monochloride

Example 3

Preparation of N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide samarium monochloride

The preparation method comprises the following specific steps:

(1) preparing a toluene/tetrahydrofuran mixed solvent according to a volume ratio of 7:3, dissolving 11 g of 2-ethyl-7-phenyl-1H-indene in 100 ml of the toluene/tetrahydrofuran mixed solvent to obtain a solution A,

(2) dripping 10 ml of 2mol/L cyclohexane solution of n-butyllithium into the solution A, and stirring for 10 hours;

(3) slowly dropwise adding 100 ml of benzene solution of N, N-dichloro-p-toluenesulfonamide with the concentration of 60g/L into the solution obtained in the step (2) at the environment below-20 ℃, stirring for 5 minutes, continuously stirring at room temperature for 12 hours, and obtaining an intermediate product N, N-bis (2-ethyl-7-phenyl-1H-indenyl) benzenesulfonamide after the reaction is finished;

(4) adding 100 ml of tetrahydrofuran solution of samarium trichloride with the concentration of 0.025mol/L into the solution obtained in the step (3) at the temperature of below-20 ℃, stirring for 20 minutes, continuously stirring for 24 hours at room temperature, and obtaining the preparation of N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide-samarium chloride after the reaction is finished;

(5) the solvent in the reaction solution was removed under reduced pressure, and then re-dissolved and recrystallized in a toluene solvent to obtain high-purity N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide-samarium chloride.

Example 4

Preparation of yttrium N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide monochloride

The preparation method comprises the following specific steps:

(1) preparing a toluene/tetrahydrofuran mixed solvent according to a volume ratio of 7:3, dissolving 11 g of 2-ethyl-7-phenyl-1H-indene in 100 ml of the toluene/tetrahydrofuran mixed solvent to obtain a solution A,

(2) dripping 10 ml of 2mol/L cyclohexane solution of n-butyllithium into the solution A, and stirring for 10 hours;

(3) slowly dropwise adding 100 ml of benzene solution of N, N-dichloro-p-toluenesulfonamide with the concentration of 60g/L into the solution obtained in the step (2) at the environment below-20 ℃, stirring for 5 minutes, continuously stirring at room temperature for 20 hours, and obtaining an intermediate product N, N-bis (2-ethyl-7-phenyl-1H-indenyl) benzenesulfonamide after the reaction is finished;

(4) adding 100 ml of tetrahydrofuran solution of yttrium trichloride with the concentration of 0.025mol/L into the solution obtained in the step (3) at the temperature of below 20 ℃ below zero, stirring for 20 minutes, continuously stirring for 20 hours at room temperature, and obtaining the preparation of the yttrium chloride of the N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide after the reaction is finished;

(5) the solvent in the reaction solution was removed under reduced pressure, and then redissolved and recrystallized in toluene solvent to obtain high-purity N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide yttrium monochloride.

In order to compare the difference in effect between the rare earth metal organic compound and the transition metal organic compound, comparative example 1 was provided.

Comparative example 1

Preparation of N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide zirconium dichloride

The preparation method comprises the following specific steps:

(1) preparing a toluene/tetrahydrofuran mixed solvent according to a volume ratio of 7:3, dissolving 11 g of 2-ethyl-7-phenyl-1H-indene in 100 ml of the toluene/tetrahydrofuran mixed solvent to obtain a solution A,

(2) dripping 10 ml of 2mol/L cyclohexane solution of n-butyllithium into the solution A, and stirring for 10 hours;

(3) slowly dropwise adding 100 ml of benzene solution of N, N-dichloro-p-toluenesulfonamide with the concentration of 60g/L into the solution obtained in the step (2) at the environment below-20 ℃, stirring for 5 minutes, continuously stirring at room temperature for 16 hours, and obtaining an intermediate product N, N-bis (2-ethyl-7-phenyl-1H-indenyl) benzenesulfonamide after the reaction is finished;

(4) adding 100 ml of tetrahydrofuran solution of zirconium tetrachloride with the concentration of 0.025mol/L into the solution obtained in the step (3) at the temperature of below 20 ℃ below zero, stirring for 20 minutes, continuously stirring at room temperature for 24 hours, and obtaining the preparation of the N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide zirconium dichloride after the reaction is finished;

(5) the solvent in the reaction solution was removed under reduced pressure, and then redissolved and recrystallized in toluene solvent to obtain high-purity N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide zirconium dichloride.

According to a second embodiment of the present application, there is provided a homopolypropylene resin. In order to correspond to examples 1 to 4 and comparative example 1 in the first embodiment, examples 5 to 8 and comparative example 2 were provided. The preparation method of the homopolymerized propylene resin comprises the following steps:

(1) respectively loading the final products prepared in examples 1-4 and comparative example 1 on the surfaces of silica particles to obtain corresponding solid particle-loaded metal organic catalysts;

(2) the 5 kinds of solid particle-supported metal organic catalysts obtained in (1) were used for the preparation of a homopolypropylene resin catalyzed at a polymerization temperature of 25 ℃, and the homopolypropylene resins obtained were labeled as examples 5 to 8 and comparative example 2, respectively.

According to a third embodiment of the present application, a nonwoven fabric having both strength and a soft touch feeling is provided. In order to correspond to examples 5 to 8 and comparative example 2 in the second embodiment, examples 9 to 12 and comparative example 3 were provided. The preparation method of the non-woven fabric comprises the following steps:

(1) respectively putting the homopolymerized propylene resin of the examples 5-8 and the homopolymerized propylene resin of the comparative example 2 and the electret master batch into a mixer according to the weight ratio of 98:2 for mixing, wherein the rotating speed of the mixer is 120rpm, and the mixing time is 10 min;

(2) melting and mixing the mixed raw materials through a double-screw extrusion further machine, and extruding and granulating to obtain melt-blown master batches, wherein the melting temperature of the double-screw extrusion machine is 225 ℃, and the rotating speed of screws is 120 rpm;

(3) and (3) carrying out melt-blown spinning on the melt-blown master batches prepared in the step (2) through a screw extruder, cooling and solidifying the melt-blown master batches into fiber filaments through surrounding cold air media, laying the fiber filaments on a receiving device to form a web, and forming a multi-layer composite fiber web, wherein the air pressure in the melt-blowing process is 0.4MPa, and the receiving distance is 12 cm.

(4) The multi-layer composite web was subjected to hot-rolling consolidation at a temperature of 170 c under a pressure of 5MPa for a hot-rolling time of 15s to obtain five kinds of nonwoven fabrics, which were labeled as examples 9 to 12 and comparative example 3, respectively.

Testing of homopolypropylene resin and nonwoven Fabric

Test example 1

The evaluation of the properties of the homopolypropylene resin includes the following three aspects.

(1) Molecular Weight Distribution (MWD)

The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer were measured using gel permeation chromatography, and the Molecular Weight Distribution (MWD) was calculated by dividing the weight average molecular weight by the number average molecular weight.

(2) Melt index (g/10 min)

Measured at 230 ℃ under a load of 2.16Kg according to ASTM D1238 and expressed as the mass (g) of polymer melted and flowing out in 10 molecules.

(3) Ratio of residual stress

A strain of 200% was applied at 200 c, and then the change in residual stress after 10 seconds was measured. The sample was loaded between upper and lower plates having a diameter of 25mm using a DHR apparatus of watty science co, and then the gap was fixed to 5mm to measure residual stress data, and the residual stress ratio was calculated based on the measured residual stress data. The method for calculating the residual stress ratio comprises the following steps:

residual stress ratio = initial residual stress/residual stress after one minute

Wherein the initial residual stress is a residual stress at 0.1 second after applying 200% strain.

The results of evaluating the properties of the homopolypropylene resins of examples 5 to 8 and comparative example 2 are shown in Table 1.

TABLE 1

As can be seen from Table 1, the homopolypropylene resins of examples 5 to 8 had more optimized molecular weight distribution between 1.3 and 1.5 and also had more optimized melt index between 18 and 22g/10min and more optimized residual stress ratio of 0.03% or less. Compared with the homopolypropylene resin in the comparative example 2, the homopolypropylene resin prepared by the method has the potential of being more suitable for preparing non-woven fabrics with both strength and soft touch.

Test example 2

The evaluation of the properties of the nonwoven fabric includes the following three aspects.

(1) Strength of nonwoven fabric

The tensile strength of the nonwoven fabric in the machine direction and the transverse direction was measured by a 5 cm-wide cut strip method according to the cutting method of ASTM D-5035.

(2) Hand feeling of nonwoven fabric

The fabric hand feeling comfort degree tester with the model number of No.070 of Shanghai product Kui electromechanical technology Limited company is adopted for hand feeling test, the evaluation is respectively carried out from toughness, softness and smoothness, the grade of the toughness is 0-100, and the higher the grade is, the better the toughness is; the softness score is 0-100, and the higher the score is, the better the softness is; the slip score is 0-100, the higher the score, the better the slip.

(3) Coefficient of friction of nonwoven fabric

The friction coefficient of the nonwoven fabric was measured using a friction coefficient measuring device. Specifically, the measurement was carried out using an MXD-01 friction coefficient meter.

The results of evaluating the properties of the nonwoven fabrics of examples 9 to 12 and comparative example 3 are shown in Table 2.

TABLE 2

As can be seen from table 2, the nonwoven fabrics of examples 9 to 12 have more excellent tensile strength, hand and coefficient of friction, and are nonwoven fabrics having both higher strength and more excellent touch.

Claims (3)

1. A preparation method of a non-woven fabric with both strength and flexible touch comprises the following steps:

(1) the homopolymerized propylene resin and the electret master batch are mixed in a mixer according to the weight ratio of (95-99) to (1-5), the rotating speed of the mixer is 90-180rpm, and the mixing time is 10-15 min;

(2) further melting and mixing the mixed raw materials through a double-screw extruder, and extruding and granulating to obtain melt-blown master batches, wherein the melting temperature of the double-screw extruder is 215-235 ℃, and the screw rotating speed is 120-180 rpm;

(3) melt-blowing and spinning the melt-blown master batch prepared in the step (2) through a screw extruder, cooling and solidifying the melt-blown master batch into fiber filaments through surrounding cold air media, laying the fiber filaments on a receiving device to form a web, and forming a multilayer composite fiber web, wherein the air pressure is 0.3-0.5MPa and the receiving distance is 11-15cm in the melt-blowing process;

(4) carrying out hot rolling reinforcement treatment on the multilayer composite fiber web to obtain a non-woven fabric, wherein the temperature of the hot rolling reinforcement treatment is 170 ℃, the pressure is 5MPa, and the hot rolling time is 15 s;

characterized in that the molecular weight of the homopolymerized propylene resin is between 180000 and 200000; the molecular weight distribution is between 1.3 and 1.5; the melt index is between 18 and 22g/10 min; the residual stress ratio is not higher than 0.03%; the homopolymerization propylene resin is prepared by catalyzing a rare earth organic catalyst, wherein the rare earth organic catalyst is a rare earth organic compound shown in a formula (I);

（I）

wherein M is selected from one of La, Nd, Sm and Y.

2. The method of claim 1, wherein the method of preparing the rare earth organic compound represented by formula (I) comprises the steps of:

(1) preparing a toluene/tetrahydrofuran mixed solvent according to a volume ratio of 7:3, dissolving 11 g of 2-ethyl-7-phenyl-1H-indene in 100 ml of the toluene/tetrahydrofuran mixed solvent to obtain a solution A,

(2) dripping 10 ml of 2mol/L cyclohexane solution of n-butyllithium into the solution A, and stirring for 3-12 hours;

(3) slowly dropwise adding 100 ml of benzene solution of N, N-dichloro-p-toluenesulfonamide with the concentration of 60g/L into the solution obtained in the step (2) at the environment below-20 ℃, stirring for 5 minutes, continuously stirring at room temperature for 12-24 hours, and obtaining an intermediate product N, N-bis (2-ethyl-7-phenyl-1H-indenyl) benzenesulfonamide after the reaction is finished;

(4) adding 100 ml of 0.025mol/L lanthanum trichloride tetrahydrofuran solution, neodymium trichloride tetrahydrofuran solution, samarium trichloride tetrahydrofuran solution or yttrium trichloride tetrahydrofuran solution into the solution obtained in the step (3) at the temperature of below-20 ℃, stirring for 20 minutes, continuously stirring for 20-40 hours at room temperature, and obtaining the rare earth organic compound shown in the formula (I) after the reaction is finished;

(5) removing the solvent in the reaction solution under reduced pressure, and then dissolving again and recrystallizing with toluene solvent to obtain high-purity N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide lanthanum monochloride, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide neodymium monochloride, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide samarium monochloride or N, N-bis (2-ethyl-7-phenyl-1H-indenyl) p-toluenesulfonamide yttrium monochloride.

3. The method of claim 2, wherein the homopolypropylene resin is prepared by the steps of:

(1) loading a rare earth organic compound shown in a formula (I) on the surface of alumina or silica particles to obtain a solid particle-loaded rare earth organic catalyst;

(2) the rare earth organic catalyst loaded by solid particles is used for catalyzing the preparation of homopolymerization propylene resin, and the polymerization temperature is 15-40 ℃.