Use of organosilane, and polyolefin resin and preparation method thereof

Abstract

Provided are use of organosilane, and polyolefin resin and preparation method thereof. The method of preparing the polyolefin resin comprises: conducting olefin polymerization of olefin monomers in the presence of a catalyst, and adding organosilane to a polymerization system before the olefin polymerization and/or during the olefin polymerization, wherein the organosilane is represented by a general formula of R.sup.1.sub.mSiX.sub.n(OR.sup.2).sub.k, wherein R.sup.1 is a C.sub.2-C.sub.20 alkyl, and a terminal of R.sup.1 has an -olefin double bond, a norbornene group, a cycloalkene group, or a dicyclopentadiene group; X is a halogen element; R.sup.2 is a C.sub.1-C.sub.20 straight chain, a C.sub.1-C.sub.20 branched chain, or an isomerized alkyl group; m is an integer from 1-3; n is an integer from 1-3; k is an integer from 0-2; and m, n, and k satisfy the following condition: m+n+k=4. The polyolefin resin obtained by the above method has higher melt strength and mechanical strength.

Claims

1. A method of preparing a polyolefin resin comprising: conducting an olefin polymerization reaction of olefin monomers in the presence of a catalyst, and adding an organosilane during the olefin polymerization reaction, wherein the organosilane is represented by a general formula R.sup.1.sub.mSiX.sub.n(OR.sup.2).sub.k, wherein R.sup.1 is a C.sub.2-C.sub.20 alkyl group and a terminal of R.sup.1 has an -olefin double bond, a norbornene group, a cycloolefin group, or a dicyclopentadiene group, X is a halogen element, R.sup.2 is a C.sub.1-C.sub.20 linear chain, branched chain or isomerized alkyl group, m is an integer within a range of 1-3, n is an integer within a range of 1-3, k is an integer within a range of 0-2, and m+n+k=4, wherein the catalyst is a metallocene catalyst, the organosilane is at least one of 2-(5-ethylidene-2-norbornenyl)ethyl trichlorosilane, 2-(3-cyclohexenyl)ethyl trichlorosilane, 4-(2,7-cyclooctathenyl)butyl trichlorosilane, and 2-(dicyclopentathenyl)ethylidene trichlorosilane, which is represented by the following Formula (3): ##STR00003## and in relation to 100 pbw olefin monomers, the dose of the organosilane is 0.0005-1 pbw.

2. The method according to claim 1, wherein in relation to 100 pbw olefin monomers, the dose of the organosilane is 0.0001-0.5 pbw.

3. The method according to claim 1 further comprising: washing the product obtained from the olefin polymerization reaction with water and/or alcohol at 20-120 C., after the olefin polymerization reaction is finished.

4. The method according to claim 3, wherein the -olefin is at least one of propylene, 1-butylene, 1-pentene, 1-hexylene, and 1-octylene.

5. The method according to claim 1, wherein the olefin monomer is ethylene and/or -olefin.

6. A polyolefin resin prepared by the method according to claim 1.

Description

(1) The present invention hereunder will be detailed in examples.

(2) In the following examples and reference examples, the gel content in the polyolefin resin is measured with the following method.

(3) The polyolefin resin is dried in an vacuum drying oven at 50 C. till the weight doesn't change any more, the dry polymer is weighed and the weight is denoted as W.sub.1, then the dried polyolefin resin is dissolved in dimethyl benzene at 135 C. while the solution is oscillated till the in-reactor polyolefin alloy is dissolved extensively, the solution is filtered through a 200-mesh stainless steel screen, the undissolved polymer left on the stainless steel screen is collected, and then dried in a vacuum drying oven at 100 C. for 4 h, then the dry polymer is weighed and the weight is denoted as W.sub.2; then the gel content in the polyolefin resin is calculated with the following formula:
Gel content (wt. %)=(W.sub.2/W.sub.1)100 (wt. %).

EXAMPLE 1

(4) This example is provided to describe the method of preparing the polyolefin resin provided in the present invention.

(5) Slurry polymerization: In a vacuum state, 450 g gaseous propylene monomer is charged into a reactor, then 50 mL hexane, 3 mL heptane solution that contains 5.5 mmol triethyl aluminum, 0.1 mL 7-octenyl trichlorosilane, and 20 mg olefin polymerization catalyst (MgCl.sub.2/TiCl.sub.4/BMMF, wherein, BMMF is an internal electron donor 9,9-dimethoxy fluorene, and the mass ratio of MgCl.sub.2 to TiCl.sub.4 to BMMF is 80:12:8) are added into the reactor in sequence, and the pressure in the reactor is controlled at 5.0 atm, the reaction temperature is controlled at 60 C., and the mixture in the reactor is held under those conditions for 0.5 h for polymerization reaction; after the polymerization is finished, acidified ethanol is added to terminate the polymerization reaction, and then the product is washed with 60 C. deionized water and 50 C. ethanol for 3 times respectively, and finally the product is vacuum-dried at 60 C.; thus, 20.0 g homopolymerized polypropylene resin is obtained. Measured in a detection process, the concentration of 7-octenyl trichlorosilane in the homopolymerized polypropylene resin is 5,000 ppm, the homopolymerized polypropylene resin has a branched or crosslinked structure, and the gel content in the homopolymerized polypropylene resin is 20 wt. %.

EXAMPLE 2

(6) This example is provided to describe the method of preparing the polyolefin resin provided in the present invention.

(7) Bulk polymerization: In a vacuum state, 450 g liquid propylene is loaded into a reactor, then 0.25 mol triethyl aluminum, 0.005 g hydrogen, 0.02 mL 7-octenyl trichlorosilane and 18 mg olefin polymerization catalyst (MgCl.sub.2/TiCl.sub.4/BMMF, wherein, the mass ratio of MgCl.sub.2 to TiCl.sub.4 to BMMF is 80:12:8) are added into the reactor in sequence, the reaction temperature is controlled at 70 C., and the mixture in the reactor is held at the temperature for 30 min for polymerization reaction; after the polymerization is finished, the gas in the reactor is vented, and the product in the reactor is discharged; then, the obtained product is washed with hot water (90 C.), and is vacuum-dried at 60 C.; thus, a homopolymerized polypropylene resin is obtained. Measured in a detection process, the concentration of 7-octenyl trichlorosilane in the homopolymerized polypropylene resin is 57 ppm, the homopolymerized polypropylene resin has a branched or crosslinked structure, and the gel content in the homopolymerized polypropylene resin is 1.1 wt. %.

EXAMPLE 3

(8) This example is provided to describe the method of preparing the polyolefin resin provided in the present invention.

(9) The polyolefin resin is prepared by the method described in Example 2, but the 7-octenyl trichlorosilane is replaced with 7-octenyl dimethoxy chlorosilane in the same volume; thus, a homopolymerized polypropylene resin is obtained. Measured in a detection process, the concentration of 7-octenyl dimethoxy trichlorosilane in the homopolymerized polypropylene resin is 250 ppm, the homopolymerized polypropylene resin has a branched or crosslinked structure, and the gel content in the homopolymerized polypropylene resin is 1 wt. %.

COMPARATIVE EXAMPLE 1

(10) This comparative example is provided to describe the method of preparing a reference polyolefin resin.

(11) The polyolefin resin is prepared by the method described in Example 2, but no 7-octenyl trichlorosilane is added; thus, a reference homopolymerized polypropylene resin is obtained.

COMPARATIVE EXAMPLE 2

(12) This comparative example is provided to describe the method of preparing a reference polyolefin resin.

(13) The polyolefin resin is prepared by the method described in Example 2, but the 7-octenyl trichlorosilane is replaced with tetrachlorosilane in the same volume; thus, a reference homopolymerized polypropylene resin is obtained.

COMPARATIVE EXAMPLE 3

(14) This comparative example is provided to describe the method of preparing a reference polyolefin resin.

(15) The polyolefin resin is prepared by the method described in Example 2, but the 7-octenyl trichlorosilane is replaced with tetramethoxysilane in the same volume; thus, a reference homopolymerized polypropylene resin is obtained.

EXAMPLE 4

(16) This example is provided to describe the method of preparing the polyolefin resin provided in the present invention.

(17) Bulk polymerization: In a vacuum state, 450 g liquid propylene is loaded into a reactor, then 0.25 mol triethyl aluminum, 0.025 mL methyl cyclohexyl dimethoxy silicane, 0.05 mL 7-octenyl trichlorosilane, and 18 mg olefin polymerization catalyst (MgCl.sub.2/TiCl.sub.4/DIBP, wherein, DIBP is internal electron donor diisobutyl o-phthalate, the mass ratio of MgCl.sub.2 to TiCl.sub.4 to DIBP is 85:8:7) are added into the reactor in sequence, the reaction temperature is controlled at 70 C., and the mixture in the reactor is held at the temperature for 30 min for polymerization reaction; after the polymerization is finished, the gas in the reactor is vented, and the product in the reactor is discharged; thus, 300 g homopolymerized polypropylene resin is obtained. Measured in a detection process, the concentration of 7-octenyl trichlorosilane in the homopolymerized polypropylene resin is 167 ppm, the homopolymerized polypropylene resin has a branched or crosslinked structure, and the gel content in the homopolymerized polypropylene resin is 0.2 wt. %.

EXAMPLE 5

(18) This example is provided to describe the method of preparing the polyolefin resin provided in the present invention.

(19) Bulk polymerization: In a vacuum state, 450 g liquid propylene is loaded into a reactor, then 0.25 mol methylaluminoxane, 0.02 mL 7-octenyl trichlorosilane, and 0.0025 g transitional metal compound rac-Me.sub.2Si(2-Me-4-PhInd).sub.2ZrCl.sub.2 (wherein, rac-represents racemized, Me is methyl, Ph is phenyl, and Ind is indentyl) are added into the reactor in sequence, the reaction temperature is controlled at 70 C., the mixture in the reactor is held at the temperature for 30 min for polymerization reaction; after the polymerization is finished, the gas in the reactor is vented, and the product is discharged from the reactor; thus, 300 g homopolymerized polypropylene resin is obtained. Measured in a detection process, the concentration of 7-octenyl trichlorosilane in the homopolymerized polypropylene resin is 67 ppm, the homopolymerized polypropylene resin has a branched or crosslinked structure, and the gel content in the homopolymerized polypropylene resin is 15.2 wt. %.

EXAMPLE 6

(20) This example is provided to describe the method of preparing the polyolefin resin provided in the present invention.

(21) Bulk polymerization: In a vacuum state, 450 g liquid propylene is loaded into a reactor, then 0.25 mol alkylaluminoxane, 0.01 mL 7-octenyl trichlorosilane, and 0.0025 g transitional metal compound Me.sub.2C(Cp)(Flu)ZrCl.sub.2 (wherein, Me is methyl, Cp is cyclopentadienyl, and Flu is fluorenyl) are added into the reactor in sequence, the reaction temperature is controlled at 70 C., the mixture in the reactor is held at the temperature for 30 min for polymerization reaction; after the polymerization is finished, the gas in the reactor is vented, and the product is discharged from the reactor; thus, 360 g homopolymerized polypropylene resin is obtained. Measured in a detection process, the concentration of 7-octenyl trichlorosilane in the homopolymerized polypropylene resin is 28 ppm, the homopolymerized polypropylene resin has a branched or crosslinked structure, and the gel content in the homopolymerized polypropylene resin is 12.0 wt. %.

EXAMPLE 7

(22) This example is provided to describe the method of preparing the polyolefin resin provided in the present invention.

(23) The polyolefin resin is prepared by the method described in Example 6, but the 7-octenyl trichlorosilane is replaced with 2-(5-ethylidene-2-norbornene) ethyl trichlorosilane in the same volume; thus, a homopolymerized polypropylene resin is obtained. Measured in a detection process, the concentration of 2-(5-ethylidene-2-norbornene) ethyl trichlorosilane in the homopolymerized polypropylene resin is 150 ppm, the homopolymerized polypropylene resin has a branched or crosslinked structure, and the gel content in the homopolymerized polypropylene resin is 8.5 wt. %.

EXAMPLE 8

(24) This example is provided to describe the method of preparing the polyolefin resin provided in the present invention.

(25) The polyolefin resin is prepared by the method described in Example 6, but the 7-octenyl trichlorosilane is replaced with 2-(3-cyclohexenyl) ethyl trichlorosilane in the same volume; thus, a homopolymerized polypropylene resin is obtained. Measured in a detection process, the concentration of 2-(3-cyclohexenyl) ethyl trichlorosilane in the homopolymerized polypropylene resin is 60 ppm, the homopolymerized polypropylene resin has a branched or crosslinked structure, and the gel content in the homopolymerized polypropylene resin is 5.2 wt. %.

EXAMPLE 9

(26) This example is provided to describe the method of preparing the polyolefin resin provided in the present invention.

(27) The polyolefin resin is prepared by the method described in Example 6, but the 7-octenyl trichlorosilane is replaced with 2-(dicyclopentadiene) ethylidene trichlorosilane in the same volume; thus, a homopolymerized polypropylene resin is obtained. Measured in a detection process, the concentration of 2-(dicyclopentadiene) ethylidene trichlorosilane in the homopolymerized polypropylene resin is 120 ppm, the homopolymerized polypropylene resin has a branched or crosslinked structure, and the gel content in the homopolymerized polypropylene resin is 6.0 wt. %.

(28) Test Cases

(29) The test cases are provided to describe the tests of the properties of the polyolefin resin.

(30) (1) Test of Melt Strength

(31) The experimental apparatus for determining melt strength consists of a single screw extrusion machine equipped with capillary tubes and a Gottfert Rheotens melt strength tester. First, melt mass of polyolefin resin of which the melt strength is to be tested is extruded through an outlet die of the extrusion machine, and then the obtained extruded melt beam sample is drawn by two rollers moving in opposite directions on an equalizing beam. The tensile force suffered by the melt beam when the melt beam is drawn is a function of roller speed and time. The rollers are accelerated and rotated at uniform acceleration, till the melt beam is broken. The tensile force suffered by the melt beam at the time the melt beam is broken is defined as melt strength. The obtained result is shown in Table 1.

(32) (2) Test of Mechanical Properties

(33) The impact strength is measured with the method specified in ASTM D256A, and the result is shown in Table 1.

(34) The tensile strength is measured with the method specified in ISO527-2-5A, and the result is shown in Table 1.

(35) The flexural modulus is measured with the method specified in ASTM 638-V, and the result is shown in Table 1.

(36) TABLE-US-00001 TABLE 1 Melt Impact Tensile Flexural strength, strength, strength, modulus, No. cN kJ/m.sup.2 MPa MPa Example 1 650 15.2 74.5 1600 Example 2 150 7.2 64.5 1460 Example 3 12.0 6.9 35.6 1260 Comparative 9.0 2.1 32.2 1200 Example 1 Comparative 8.9 1.8 32.5 1210 Example 2 Comparative 8.0 1.3 30.8 1090 Example 3 Example 4 27 5.4 40.2 1300 Example 5 520 10.8 59.0 1450 Example 6 480 11.5 46.0 1320 Example 7 75.0 15.0 44.2 1350 Example 8 48.0 10.0 41.2 1450 Example 9 50.0 13.6 44.0 1470

(37) It is seen from the above result that: the polyolefin resin obtained by the method provided in the present invention has higher melt strength and higher mechanical strength. It is seen from the comparison between Example 2 and Example 3 that, if the R.sup.1 in the organosilane is a C.sub.2-C.sub.18 alkyl group and a the terminal of R.sup.1 has an -olefin double bond, a norbornene group, a cycloolefin group, or a dicyclopentadiene group, X is a halogen element, R.sup.2 is a C.sub.1-C.sub.5 linear chain, branched chain or isomerized alkyl group, m is 1, n is 3, and k is 0, the obtained polyolefin resin has higher melt strength and higher mechanical strength. It is seen from the comparison between Example 3 and Comparative Example 2 and 3 that, the organosilane provided in the present invention behaves differently from silicon tetrahlaide and tetraalkoxysilane in the olefin polymerization reaction process, and the polyolefin resin obtained with the organosilane provided in the present invention has higher melt strength and higher mechanical strength.

(38) While some preferred embodiments of the present invention are described above, the present invention is not limited to the details in those embodiments. Those skilled in the art can make modifications and variations to the technical scheme of the present invention, without departing from the spirit of the present invention. However, all these modifications and variations shall be deemed as falling into the scope of protection of the present invention.

(39) In addition, it should be noted that the specific technical features described in the above embodiments can be combined in any appropriate form, provided that there is no conflict. To avoid unnecessary repetition, the possible combinations are not described specifically in the present invention.

(40) Moreover, the different embodiments of the present invention can be combined freely as required, as long as the combinations don't deviate from the ideal and spirit of the present invention. However, such combinations shall also be deemed as falling into the scope disclosed in the present invention.