The polyacrylic catalyst composition of preparation high fusion index, preparation method and purposes
Technical field
The invention belongs to material preparation and catalytic applications technical field, particularly, the present invention relates to a kind ofly be used to prepare the polyacrylic catalyst composition of high fusion index, adopt described catalyst composition to prepare the purposes of polyacrylic method of high fusion index and described catalyst composition.
Background technology
Polypropylene (PP) cost performance height is widely used.When production technique such as polypropylene is used for injection moulding, extrudes, blowing,, need to improve polyacrylic melting index usually and satisfy processing request in order to improve working (machining) efficiency and can to prepare large-scale Injection moulded part.The general MgCl that adopts
2The polymerization that the Ziegler-Natta catalyst of load carries out propylene prepares polypropylene, and adds hydrogen as molecular weight regulator when propylene polymerization.Hydrogen can reduce polyacrylic molecular weight, increases polyacrylic melting index, yet after amounts of hydrogen increased to a certain degree, the degree that melting index increases reduced, and catalytic activity descends, and influences catalytic efficiency.Therefore, the add-on of hydrogen is subjected to the restriction of polymerization technique.In addition, industrial in order to obtain the high fusion index polypropylene, after polypropylene is produced, add a certain amount of superoxide and impel degradation of polypropylene to increase polyacrylic melting index usually.The high fusion index polypropylene color of this method preparation is turned to be yellow easily, and has certain smell, the outward appearance of impact polypropylene product.
At present, the catalyzer of industrial production polypropylene use is mainly the MgCl that contains the diester internal electron donor
2The loading type Ziegler-Natta catalyst, such catalyzer need be equipped with external electron donor when polymerization.The main effect of external electron donor is to regulate polyacrylic degree of isotacticity and the catalyzer susceptibility to hydrogen, and the copolymerization performance of catalyst activity, polyacrylic apparent density and propylene and ethene etc. is also had to a certain degree influence.The external electron donor that uses mainly is the silicane electron donor now, contains 1 to 4 alkoxyl group, and the most frequently used is dialkyl group dimethoxy silane.The structure difference of external electron donor is to the hydrogen susceptibility of polyacrylic degree of isotacticity, catalyzer and active different influences arranged.According to different demands, can select for use different external electron donors to produce the polypropylene product of the different trades mark.
US5652303 and US5844046 report can be regulated polyacrylic molecular weight distribution and melting index with dialkoxy silicane and trialkoxy silane combination.Diether and siloxanes combination also can reach the purpose (US5869418) of regulation and control polypropylene degree of isotacticity, molecular weight distribution and melting index (MFR), but its effect is not so good as the obvious of two kinds of silane combinations.US6087459 can regulate and control polyacrylic melting index (MFR) with dicyclo amyl group dimethoxy silane and propyl-triethoxysilicane combination in very wide scope, particularly can obtain the polypropylene of high MFR.The polypropylene degree of isotacticity that tetraethoxysilane produces is low, but has high melting index, the PP of dicyclo amyl group dimethoxy silane preparation has high degree of isotacticity and low melting index, Exxson company (US6111039) is in two sections polymerizations, first section is used tetraethoxysilane as electron donor, second section is used tetraethoxysilane/dicyclo amyl group dimethoxy silane mixture electron donor, has obtained the PP of rigidity height, medium molecular weight distributions and medium melting index.The US7183234 report can be regulated and control polyacrylic MFR and molecular weight distribution with two Decahydroisoquinolinpreparation dimethoxy silane/propyl-triethoxysilicane combination in the scope of broad.Chinese patent application CN99805994.3 has reported use dicyclo amyl group dimethoxy silane and propyl-triethoxysilicane combined preparation impact polypropylene.
Utilize the combination external electron donor to cooperate, can prepare the polypropylene of high fusion index with the Ziegler-Natta catalyst that contains diester.The technical problem that this patent will solve is to provide a kind of better external electron donor combination, prepares the high fusion index polypropylene with the efficient of higher catalytic activity and Geng Gao.
Summary of the invention
At above-mentioned technical problem, one object of the present invention is to provide a kind of polyacrylic catalyst composition of high fusion index that is used to prepare.
Another object of the present invention is to provide the polyacrylic method of described preparation of compositions high fusion index that adopts.
A further object of the present invention is to provide the purposes of described composition.
To achieve these goals, the technical scheme taked of the present invention is as follows:
On the one hand, the invention provides a kind of polyacrylic catalyst composition of high fusion index that is used to prepare, described catalyst composition comprises following component:
(a) comprise the MgCl of diester internal electron donor
2The TiCl of load
4The type Ziegler-Natta catalyst;
(b) trialkyl aluminium compound;
(c) a kind of in isobutyl-sec.-propyl dimethoxy silane, the isobutyl-cyclohexyl dimethoxy silane or two kinds; And
(d) a kind of in n-propyl Trimethoxy silane, the n-propyl triethoxyl silane or two kinds.
Wherein, described component (a) comprises the MgCl of diester internal electron donor
2The TiCl of load
4In the type Ziegler-Natta catalyst, the content of Ti is 1.5-3.5wt%;
And in the described component (a), the diester internal electron donor is adjacent this dicarboxylate compound; Preferably, described diester internal electron donor is selected from one or more in diisobutyl phthalate, n-butyl phthalate, the n-propyl phthalate.
In addition, described component (b) trialkyl aluminium compound is selected from one or more in trimethyl aluminium, triethyl aluminum, the triisobutyl aluminium.
Preferably, in described catalyst composition, the mol ratio of the middle Ti of Al and component (a) is 10-1000 in the component (b), is preferably 100-600, more preferably 100-400.Component (c) and (d) summation be 1-100 in the mol ratio of Ti in Si and the component (a), be preferably 10-60, more preferably 10-40.Al and component (c) and (d) summation are 5-100 in the mol ratio of Si in the component (b), are preferably 10-50, more preferably 10-30.
And the molar percentage between component (c) and the component (d) is 2.5-15: 85-97.5; Preferably, described molar percentage is 2.5-10: 90-97.5, further preferred 3.0-10: 90-97.
On the other hand, the invention provides a kind of polyacrylic method of high fusion index that is used to prepare, described method comprises: adopt as each described catalyst composition among the claim 1-5, catalyzing propone polymerization in the presence of hydrogen;
Preferably, described propylene polymerization in the propylene body, carry out or gas-phase propene in carry out.
Preferably, the temperature of reaction of described propylene polymerization is 50-90 ℃.Further preferably, described temperature of reaction is 60-80 ℃.In aforesaid method, the polyacrylic melting index that described method makes is 5-60 gram/10 minutes.
Another aspect the invention provides the purposes of above-mentioned catalyst composition in the preparation polypropylene.
Below will describe the present invention.
The invention provides the polyacrylic method of a kind of preparation high fusion index, it is characterized by the MgCl that use (a) contains the diester internal electron donor
2The TiCl of load
4Type Ziegler-Natta catalyst solid ingredient, (b) trialkyl aluminium compound, (c) a kind of in isobutyl-sec.-propyl dimethoxy silane, the isobutyl-cyclohexyl dimethoxy silane or two kinds and (d) a kind of in n-propyl Trimethoxy silane, the n-propyl triethoxyl silane or two kinds, form catalyst system, in the presence of hydrogen, the polypropylene of high fusion index is prepared in the catalyzing propone polymerization.
The polyacrylic melting index of described high fusion index is between 5-60g/10min.Diester internal electron donor in the catalyst solid constituent (a) is the Bisphthalate compound, takes from diisobutyl phthalate, n-butyl phthalate, one or more in the n-propyl phthalate.The component of catalyst system (b) trialkylaluminium is taken from trimethyl aluminium, triethyl aluminum, one or more in the triisobutyl aluminium.(c) component and (d) molar percentage of component be 2.5-15: 97.5-85.Propylene polymerization in the propylene body, carry out or gas-phase propene in carry out.
The component of above-mentioned catalyst system (a) comprises MgCl
2, TiCl
4With a kind of diester internal electron donor.This solid ingredient can be taked the several different methods preparation, as Chinese patent application CN 00109216.2, CN02122750.0, CN 02136543.1, CN 200310101833.9, CN 200380106197.X, and CN 200410017269.7, CN 87101423, CN 90104123.8, and CN 93102795.0, CN94102813.5, CN 94103454, the method described in the CN 97112005.6.The diester internal electron donor is the Bisphthalate compound, takes from diisobutyl phthalate, n-butyl phthalate, one or more in the n-propyl phthalate.
When catalyst component (c) is external electron donor separately, have high isotactic directional property and low hydrogen response, when catalyst component (d) is external electron donor separately, generally have low isotactic directional property and high hydrogen response.The effect of an external electron donor part is and the aluminum alkyls complexing, reduce the reducing power of aluminum alkyls, another part is and the complexing of Ziegler-Natta catalyst active centre that the isotactic directional property in the high active centre of isotactic directional property is further improved in the active centre of inhibition isotactic directional property difference.Different electron donors are different with the action intensity in Ziegler-Natta catalyst active centre.Component (c) can alternative compositions (d) in the complexing in active centre.During with component (c) and component (d) mixing use, when the content of component (c) was less than 2.5 moles of %, the isotactic directional property of catalyzer was poor, when the content of component (c) during greater than 15 moles of %, the hydrogen regulation performance of catalyzer is identical when separately using component (c), can not obtain height and melt the finger polypropylene.Component (c) and component (d) are mixed when using, and under suitable ratio, can effectively strengthen the hydrogen regulation performance of catalyzer, prepare high isotactic, height melts the finger polypropylene.
Compared with prior art, the invention provides a kind of novel polyacrylic catalyst composition of preparation high fusion index, when in the presence of hydrogen, when this catalyst composition is used for propylene polymerization, can obtain to have the polypropylene of high fusion index, this melting index even can help to satisfy in the present industrial application for the polyacrylic demand of high fusion index up to nearly 60g/ minute.
Embodiment
Below in conjunction with specific embodiment, and comparable data describes in further detail the present invention.Should be understood that these embodiment just in order to demonstrate the invention, but not limit scope of invention by any way.
In following embodiment, various processes of Xiang Ximiaoshuing and method are not ordinary methods as known in the art.
The propylene that adopts among the embodiment is a polymerization-grade propylene, and catalyst component (a) is Yingkou CS-I catalyzer that catalyst plant produces that faces south, and wherein contained internal electron donor is a diisobutyl phthalate.
The polypropylene that makes among the following embodiment has been carried out the test of degree of isotacticity and melting index, and described method is as follows:
Polyacrylic degree of isotacticity uses the heptane extraction process to measure, and 2g left and right sides polypropylene is placed Soxhlet extractor, with boiling heptane extracting 6 hours, residual polymer is dried to constant weight, is degree of isotacticity with residual polymer and the first part by weight that adds polymkeric substance.
Polyacrylic melting index is measured according to elastomerics melting index testing standard ASTM D1238, and experiment condition is 2.16Kg, 230 ℃.
Embodiment 1
The heating of 5L autoclave is vacuumized, and excluding air and water are used nitrogen replacement, three times repeatedly, then add MgCl
2The TiCl of load
4Catalyst solid constituent 20mg, the content of Ti is 2.36wt% in the solid ingredient, the triethyl aluminum add-on is Al/Ti (mole)=600, add 30mmol hydrogen, isobutyl-sec.-propyl dimethoxy silane (IBIPDMS), n-propyl Trimethoxy silane (NPTMS), the molar percentage of the two is 5: 95, two kinds of total add-ons of silane are calculated as Al/Si (mole)=20 by silicon, then add hydrogen and 1.2 kilograms of propylene, and hydrogen and propylene mol ratio are 2.94mmol/mol.The off-response still, with still temperature rise to 70 ℃, the beginning polymerization, react after 2 hours, discharge unreacting propylene, obtain polypropylene GRANULES 830g, calculating catalytic activity is the 41.5KgPP/g catalyzer, and polyacrylic melting index is 10.7gPP/10min, and polyacrylic degree of isotacticity is 98.2%.
Embodiment 2
The heating of 5L autoclave is vacuumized, and excluding air and water are used nitrogen replacement, three times repeatedly, then add MgCl
2The TiCl of load
4Catalyst solid constituent 20mg, the content of Ti is 2.36wt% in the solid ingredient, the triethyl aluminum add-on is Al/Ti (mole)=600, add 30mmol hydrogen, isobutyl-cyclohexyl dimethoxy silane (IBCHDMS), n-propyl Trimethoxy silane (NPTMS), the molar percentage of the two is 5: 95, two kinds of total add-ons of silane are calculated as Al/Si (mole)=20 by silicon, then add hydrogen and 1.2 kilograms of propylene, and hydrogen and propylene mol ratio are 2.94mmol/mol.The off-response still, with still temperature rise to 70 ℃, the beginning polymerization, react after 2 hours, discharge unreacting propylene, obtain polypropylene GRANULES 810g, catalytic activity is the 40.5KgPP/g catalyzer, and polyacrylic melting index is 15.7gPP/10min, and polyacrylic degree of isotacticity is 98.1%.
Embodiment 3
The heating of 5L autoclave is vacuumized, and excluding air and water are used nitrogen replacement, three times repeatedly, then add MgCl
2The TiCl of load
4Catalyst solid constituent 20mg, the content of Ti is 2.36wt% in the solid ingredient, the triethyl aluminum add-on is Al/Ti (mole)=600, add 30mmol hydrogen, isobutyl-sec.-propyl dimethoxy silane (IBIPDMS), n-propyl triethoxyl silane (NPTES), the molar percentage of the two is 5: 95, two kinds of total add-ons of silane are calculated as Al/Si (mole)=20 by silicon, then add hydrogen and 1.2 kilograms of propylene, and hydrogen and propylene mol ratio are 2.94mmol/mol.The off-response still, with still temperature rise to 70 ℃, the beginning polymerization, react after 2 hours, discharge unreacting propylene, obtain polypropylene GRANULES 810g, catalytic activity is the 40.5KgPP/g catalyzer, and polyacrylic melting index is 16.2gPP/10min, and polyacrylic degree of isotacticity is 98.1%.
Embodiment 4
The heating of 5L autoclave is vacuumized, and excluding air and water are used nitrogen replacement, three times repeatedly, then add MgCl
2The TiCl of load
4Catalyst solid constituent 20mg, the content of Ti is 2.36wt% in the solid ingredient, the triethyl aluminum add-on is Al/Ti (mole)=600, add 30mmol hydrogen, isobutyl-cyclohexyl dimethoxy silane (IBCHDMS), n-propyl triethoxyl silane (NPTES), the molar percentage of the two is 5: 95, two kinds of total add-ons of silane are calculated as Al/Si (mole)=20 by silicon, then add hydrogen and 1.2 kilograms of propylene, and hydrogen and propylene mol ratio are 2.94mmol/mol.The off-response still, with still temperature rise to 70 ℃, the beginning polymerization, react after 2 hours, discharge unreacting propylene, obtain polypropylene GRANULES 790g, catalytic activity is the 39.5KgPP/g catalyzer, and polyacrylic melting index is 22.3gPP/10min, and polyacrylic degree of isotacticity is 97.9%.
Embodiment 5
The heating of 5L autoclave is vacuumized, and excluding air and water are used nitrogen replacement, three times repeatedly, then add MgCl
2The TiCl of load
4Catalyst solid constituent 20mg, the content of Ti is 2.36wt% in the solid ingredient, the triethyl aluminum add-on is Al/Ti (mole)=600, add 30mmol hydrogen, isobutyl-sec.-propyl dimethoxy silane (IBIPDMS), n-propyl Trimethoxy silane (NPTMS), the molar percentage of the two is 5: 95, two kinds of total add-ons of silane are calculated as Al/Si (mole)=20 by silicon, then add hydrogen and 1.2 kilograms of propylene, and hydrogen and propylene mol ratio are 6.83mmol/mol.The off-response still, with still temperature rise to 70 ℃, the beginning polymerization, react after 2 hours, discharge unreacting propylene, obtain polypropylene GRANULES 790g, catalytic activity is the 39.0KgPP/g catalyzer, and polyacrylic melting index is 50.4gPP/10min, and polyacrylic degree of isotacticity is 97.6%.
Embodiment 6
The heating of 5L autoclave is vacuumized, and excluding air and water are used nitrogen replacement, three times repeatedly, then add MgCl
2The TiCl of load
4Catalyst solid constituent 20mg, the content of Ti is 2.36wt% in the solid ingredient, the triethyl aluminum add-on is Al/Ti (mole)=600, add 30mmol hydrogen, isobutyl-cyclohexyl dimethoxy silane (IBCHDMS), n-propyl Trimethoxy silane (NPTMS), the molar percentage of the two is 5: 95, two kinds of total add-ons of silane are calculated as Al/Si (mole)=20 by silicon, then add hydrogen and 1.2 kilograms of propylene, and hydrogen and propylene mol ratio are 6.83mmol/mol.The off-response still, with still temperature rise to 70 ℃, the beginning polymerization, react after 2 hours, discharge unreacting propylene, obtain polypropylene GRANULES 760g, catalytic activity is the 38.0KgPP/g catalyzer, and polyacrylic melting index is 56.4gPP/10min, and polyacrylic degree of isotacticity is 97.6%.
Embodiment 7
The heating of 5L autoclave is vacuumized, and excluding air and water are used nitrogen replacement, three times repeatedly, then add MgCl
2The TiCl of load
4Catalyst solid constituent 20mg, the content of Ti is 2.36wt% in the solid ingredient, the triethyl aluminum add-on is Al/Ti (mole)=600, add 30mmol hydrogen, isobutyl-cyclohexyl dimethoxy silane (IBCHDMS), n-propyl triethoxyl silane (NPTES), the molar percentage of the two is 3: 97, two kinds of total add-ons of silane are calculated as Al/Si (mole)=20 by silicon, then add hydrogen and 1.2 kilograms of propylene, and hydrogen and propylene mol ratio are 2.94mmol/mol.The off-response still, with still temperature rise to 70 ℃, the beginning polymerization, react after 2 hours, discharge unreacting propylene, obtain polypropylene GRANULES 750g, catalytic activity is the 37.5KgPP/g catalyzer, and polyacrylic melting index is 32.3gPP/10min, and polyacrylic degree of isotacticity is 97.3%.
For the effect of catalyst composition of the present invention is described more fully, provide the comparative example below.
The comparative example 1
The heating of 5L autoclave is vacuumized, and excluding air and water are used nitrogen replacement, three times repeatedly, then add MgCl
2The TiCl of load
4Catalyst solid constituent 20mg, the content of Ti is 2.36wt% in the solid ingredient, the triethyl aluminum add-on is Al/Ti (mole)=600, add 300mmol hydrogen, isobutyl-sec.-propyl dimethoxy silane, add-on is calculated as Al/Si (mole)=20 by silicon, then adds hydrogen and 1.2 kilograms of propylene, and hydrogen and propylene mol ratio are 2.94mmol/mol.The off-response still, with still temperature rise to 70 ℃, the beginning polymerization, react after 2 hours, discharge unreacting propylene, obtain polypropylene GRANULES 860g, catalytic activity is the 43.0KgPP/g catalyzer, and polyacrylic melting index is 2.7gPP/10min, and polyacrylic degree of isotacticity is 98.5%.