KR20200127676A - Ethylene/alpha-olefin copolymer and method for preparing the same - Google Patents

Abstract

The present invention relates to a method for preparing a high flow ethylene/alpha-olefin copolymer having a melt index of 15 or higher with an excellent conversion rate. The present invention comprises a step of polymerizing ethylene and alpha-olefin monomers in the presence of a catalyst composition including transition metal compounds represented by chemical formulas 1 and 2.

Description

Ethylene/alpha-olefin copolymer and method for preparing the same}

The present invention relates to a method for preparing a high flow ethylene/alpha-olefin copolymer having a melt index of 15 or higher with excellent conversion.

The olefin polymerization catalyst system can be classified into a Ziegler Natta and a metallocene catalyst system, and these two highly active catalyst systems have been developed according to their respective characteristics. Ziegler Natta catalysts have been widely applied to conventional commercial processes since their invention in the 1950s, but since they are multi-site catalysts with multiple active points, they are characterized by a wide molecular weight distribution of polymers. There is a problem in that there is a limit to securing desired physical properties because the composition distribution of is not uniform.

On the other hand, the metallocene catalyst is composed of a combination of a main catalyst composed of a transition metal compound and a cocatalyst composed of an organometallic compound composed mainly of aluminum, and such a catalyst is a homogeneous complex catalyst and is a single site catalyst. A polymer having a narrow molecular weight distribution and a uniform composition distribution of a comonomer is obtained according to the single active point characteristics, and the stereoregularity of the polymer, copolymerization characteristics, molecular weight, and the like depending on the modification of the ligand structure of the catalyst and the change of polymerization conditions, It has properties that can change crystallinity and the like.

On the other hand, linear low-density polyethylene is a resin prepared by copolymerizing ethylene and alpha olefin at low pressure using a polymerization catalyst, and thus has a narrow molecular weight distribution, short chain branches of a constant length, and no long chain branches. Linear low-density polyethylene film has high breaking strength and elongation in addition to the properties of general polyethylene, and has excellent tear strength and drop impact strength, so it is increasingly used for stretch films and overlap films that are difficult to apply to existing low-density polyethylene or high-density polyethylene. Are doing.

However, linear low-density polyethylene using 1-butene or 1-hexene as a comonomer is mostly produced in a single gas phase reactor or a single loop slurry reactor, and has higher productivity compared to the process using 1-octene comonomer, but these products are also used. Due to the limitations of catalyst technology and process technology, physical properties are significantly inferior to when using 1-octene comonomer, and the molecular weight distribution is narrow, resulting in poor processability.

Against this background, there is a constant demand for the production of better products with a balance between physical properties and processability, and in particular, the need for an ethylene/alpha-olefin copolymer having excellent processability is further required.

Korean Patent Publication 2018-0071592

It is an object of the present invention to provide a method for producing a high flow ethylene/alpha-olefin copolymer having a melt index of 15 or more with excellent conversion.

An embodiment of the present invention comprises the step of polymerizing ethylene and alpha-olefin monomers in the presence of a catalyst composition comprising a transition metal compound represented by the following Chemical Formulas 1 and 2, wherein Chemical Formulas 1 and 2 The mixing ratio of the transition metal compound represented by is 3:7 to 7:3 based on the number of moles, providing a method of preparing an ethylene/alpha-olefin copolymer:

[Formula 1]

In Formula 1,

R ₁ is the same as or different from each other, and each independently of a group 4 metal substituted with hydrogen, alkyl having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, aryl, silyl, alkylaryl, arylalkyl, or hydrocarbyl It is a metalloid radical, and the two R ₁ may be linked to each other by an alkylidine radical including an alkyl having 1 to 20 carbon atoms or an aryl radical having 6 to 20 carbon atoms to form a ring;

R ₂ are the same as or different from each other, and each independently hydrogen; halogen; Alkyl of 1 to 20 carbon atoms; Aryl; Alkoxy; Aryloxy; An amido radical, and two or more of R ₂ may be linked to each other to form an aliphatic ring or an aromatic ring;

R ₃ is the same as or different from each other, and each independently hydrogen; halogen; Alkyl of 1 to 20 carbon atoms; Or a nitrogen-containing aliphatic or aromatic ring substituted or unsubstituted with an aryl radical, and when the number of substituents is plural, two or more substituents among the substituents may be connected to each other to form an aliphatic or aromatic ring;

M ₁ is a Group 4 transition metal;

Q ₁ and Q ₂ are each independently halogen; Alkyl of 1 to 20 carbon atoms; Alkenyl; Aryl; Alkylaryl; Arylalkyl; Alkyl amido having 1 to 20 carbon atoms; Aryl amido; Or an alkylidene radical having 1 to 20 carbon atoms;

[Formula 2]

In Chemical Formula 2,

R ₄ to R ₉ are each independently hydrogen; Alkyl of 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Alkylaryl having 7 to 20 carbon atoms; Or arylalkyl having 7 to 20 carbon atoms,

R ₁₀ and R ₁₁ are each independently hydrogen; Alkyl of 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Alkylaryl having 6 to 20 carbon atoms; Arylalkyl having 7 to 20 carbon atoms; Alkyl amido having 1 to 20 carbon atoms; Aryl amido having 6 to 20 carbon atoms; Or alkylidene having 1 to 20 carbon atoms,

R ₁₂ is hydrogen; Alkyl of 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Alkoxy having 1 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Arylalkoxy having 7 to 20 carbon atoms; Alkylaryl having 7 to 20 carbon atoms; Or arylalkyl having 7 to 20 carbon atoms,

Two or more adjacent to each other among the R ₄ to R ₁₂ may be connected to each other to form a ring,

R ₁₃ and R ₁₄ are each independently hydrogen, halogen, alkyl having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, alkylaryl having 7 to 20 carbon atoms, arylalkyl having 7 to 20 carbon atoms , C 1 to C 20 alkylamino, C 6 to C 20 arylamino or C 1 to C 20 alkylidene,

Q is Si, C, N, P or S,

M is a Group 4 transition metal.

When the method for producing ethylene/alpha-olefin according to the present invention is used, there is an advantage in that a melt index of 15 or more and an ethylene/alpha-olefin copolymer exhibiting excellent fluidity can be produced with high efficiency.

Hereinafter, the present invention will be described in more detail to aid understanding of the present invention. The terms or words used in this specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventor may appropriately define the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

The terms used in the present specification are only used to describe exemplary embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

The present invention will be described in detail below and exemplify specific embodiments, as various changes can be made and various forms can be obtained. However, this is not intended to limit the present invention to a specific form disclosed, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

Hereinafter, the method for preparing the ethylene/alpha-olefin copolymer of the present invention will be described in detail.

The method for preparing an ethylene/alpha-olefin copolymer according to an embodiment of the present invention is to polymerize ethylene and alpha-olefin monomers in the presence of a catalyst composition including a transition metal compound represented by the following Chemical Formulas 1 and 2. Step; Including, and the mixing ratio of the transition metal compound represented by the formula (1) and (2) is characterized in that 3:7 to 7:3 based on the number of moles:

[Formula 1]

In Formula 1,

R ₁ is the same as or different from each other, and each independently of a group 4 metal substituted with hydrogen, alkyl having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, aryl, silyl, alkylaryl, arylalkyl, or hydrocarbyl It is a metalloid radical, and the two R ₁ may be linked to each other by an alkylidine radical including an alkyl having 1 to 20 carbon atoms or an aryl radical having 6 to 20 carbon atoms to form a ring;

R ₂ are the same as or different from each other, and each independently hydrogen; halogen; Alkyl of 1 to 20 carbon atoms; Aryl; Alkoxy; Aryloxy; An amido radical, and two or more of R ₂ may be linked to each other to form an aliphatic ring or an aromatic ring;

R ₃ is the same as or different from each other, and each independently hydrogen; halogen; Alkyl of 1 to 20 carbon atoms; Or a nitrogen-containing aliphatic or aromatic ring substituted or unsubstituted with an aryl radical, and when the number of substituents is plural, two or more substituents among the substituents may be connected to each other to form an aliphatic or aromatic ring;

M ₁ is a Group 4 transition metal;

Q ₁ and Q ₂ are each independently halogen; Alkyl of 1 to 20 carbon atoms; Alkenyl; Aryl; Alkylaryl; Arylalkyl; Alkyl amido having 1 to 20 carbon atoms; Aryl amido; Or an alkylidene radical having 1 to 20 carbon atoms;

[Formula 2]

In Chemical Formula 2,

R ₄ to R ₉ are each independently hydrogen; Alkyl of 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Alkylaryl having 7 to 20 carbon atoms; Or arylalkyl having 7 to 20 carbon atoms,

R ₁₀ and R ₁₁ are each independently hydrogen; Alkyl of 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Alkylaryl having 6 to 20 carbon atoms; Arylalkyl having 7 to 20 carbon atoms; Alkyl amido having 1 to 20 carbon atoms; Aryl amido having 6 to 20 carbon atoms; Or alkylidene having 1 to 20 carbon atoms,

R ₁₂ is hydrogen; Alkyl of 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Alkoxy having 1 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Arylalkoxy having 7 to 20 carbon atoms; Alkylaryl having 7 to 20 carbon atoms; Or arylalkyl having 7 to 20 carbon atoms,

Two or more adjacent to each other among the R ₄ to R ₁₂ may be connected to each other to form a ring,

R ₁₃ and R ₁₄ are each independently hydrogen, halogen, alkyl having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, alkylaryl having 7 to 20 carbon atoms, arylalkyl having 7 to 20 carbon atoms , C 1 to C 20 alkylamino, C 6 to C 20 arylamino or C 1 to C 20 alkylidene,

Q is Si, C, N, P or S,

M is a Group 4 transition metal.

Specifically, in Formula 1, R ₁ and R ₂ are the same as or different from each other, and each independently hydrogen; Alkyl of 1 to 20 carbon atoms; Aryl; Or it may be silyl,

R ₃ is the same as or different from each other, and alkyl having 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Aryl; Alkylaryl; Arylalkyl; Alkoxy having 1 to 20 carbon atoms; Aryloxy; Or may be amido; Two or more adjacent R ₃ of R ₃ may be linked to each other to form an aliphatic or aromatic ring;

Q ₁ and Q ₂ are the same as or different from each other, and each independently halogen; Alkyl of 1 to 20 carbon atoms; Alkylamidos having 1 to 20 carbon atoms; May be an arylamido,

M ₁ may be a Group 4 transition metal.

Further, in Formula 2, R ₄ to R ₉ are each independently hydrogen; Alkyl of 1 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Alkylaryl having 7 to 20 carbon atoms; Or arylalkyl having 7 to 20 carbon atoms,

R ₁₀ and R ₁₁ are each independently hydrogen; Alkyl of 1 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Or alkylaryl having 6 to 20 carbon atoms,

R ₁₂ is hydrogen; Alkyl of 1 to 20 carbon atoms; Alkoxy having 1 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Arylalkoxy having 7 to 20 carbon atoms; Alkylaryl having 7 to 20 carbon atoms; Or arylalkyl having 7 to 20 carbon atoms,

Two or more adjacent to each other among the R ₄ to R ₁₂ may be connected to each other to form an aliphatic ring having 5 to 20 carbon atoms or an aromatic ring having 6 to 20 carbon atoms; The aliphatic ring or aromatic ring may be substituted with halogen, alkyl having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, or aryl having 6 to 20 carbon atoms,

Q can be Si, C, N, or P.

The transition metal compound represented by Formula 1 has a narrow Cp-MN angle structurally because the metal sites are linked by a cyclopentadienyl ligand into which tetrahydroquinoline is introduced, and the monomer approaches Q ₁ -MQ ₂ (Q ₃ -MQ ₄ ) The angle has the feature of keeping it wide. In addition, Cp, tetrahydroquinoline, nitrogen and metal sites are sequentially connected by a cyclic bond to form a more stable and rigid pentagonal ring structure. Therefore, when these compounds are activated by reacting with a cocatalyst such as methylaluminoxane or B(C ₆ F ₅ ) ₃ and then applied to olefin polymerization, characteristics such as high activity, high molecular weight and high co-polymerization are achieved even at high polymerization temperatures It is possible to polymerize the possessed olefin-based polymer. However, in the case of the compound represented by Formula 1, there is a limit to manufacturing a high-flow product having a melt index (MI) of 15 or more.

In the case of the transition metal compound represented by Formula 2, the conversion rate is low, and when used alone as a catalyst, the melt index of the prepared ethylene/alpha-olefin copolymer exceeds 50 and tends to appear too high. This may be advantageous in terms of productivity because of its good flowability, but it has a disadvantage that it cannot be properly applied commercially because its mechanical properties are deteriorated because of its very low molecular weight.

Thus, the present invention prepares an ethylene/alpha-olefin copolymer having a target melt index of 15 to 50 by mixing the transition metal compound represented by Formula 1 and the transition metal compound represented by Formula 2, while maintaining a high conversion rate. As a result, it is characterized by securing the efficiency and economy of the polymerization reaction.

Specifically, according to the production method of the present invention, the alpha-olefin conversion rate of the polymerization reaction between ethylene and alpha-olefin may be 25% or more, 29% or more, or 30% or more. Through this, since the input raw material is converted to a polymer at a high rate, there is an advantage of reducing the manufacturing cost.

The catalyst composition used in the method for preparing the ethylene/alpha-olefin copolymer of the present invention includes a mixture ratio of 3:7 to 7:3 based on the number of moles of the transition metal compound represented by Chemical Formulas 1 and 2, specifically 3: It is characterized in that it comprises 7 to 6: 4, 4: 6 to 6: 4, 3.5: 6.5 to 5: 5.

According to another embodiment of the present invention, the compound of Formula 1 may be at least one selected from the group consisting of the following Formulas 1-1 to 1-2.

[Formula 1-1]

[Formula 1-2]

In addition, it may be a compound having various structures within the range defined in Chemical Formula 1.

The transition metal compound of Formula 1 may be prepared by the following method as an example.

[Scheme 1]

According to another embodiment of the present invention, the compound of Formula 2 may be at least one selected from the group consisting of the following Formulas 2-1 to 2-3.

[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

The transition metal compound of Formula 2 may be prepared by the following method as an example.

[Scheme 2]

In addition, the method for preparing the ethylene/alpha-olefin copolymer according to an embodiment of the present invention, the alpha-olefin monomer as a comonomer may be an olefin monomer having 4 to 20 carbon atoms. Specific examples include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetra Decene, 1-hexadecene, 1-eicosene, and the like, and one of them alone or a mixture of two or more may be used.

Among these, the alpha-olefin monomer may be 1-butene, 1-hexene, or 1-octene, and most preferably 1-octene when considering the remarkable improvement effect when applied to a hot melt adhesive composition.

In addition, in the method for producing the ethylene/alpha-olefin copolymer, the content of the alpha-olefin as the comonomer may be appropriately selected within a range that satisfies the above-described physical property requirements, and specifically, more than 0 99 mol% Or less, or may be 10 to 50 mol%.

Meanwhile, in the preparation of the ethylene/alpha-olefin copolymer according to an embodiment of the present invention, a cocatalyst may be additionally used to activate the transition metal compound of Formula 1 and/or Formula 2.

The cocatalyst is an organometallic compound containing a Group 13 metal, and specifically, may include at least one of a compound of the following formula 3, a compound of the following formula 4, and a compound of the following formula 5.

[Formula 3]

R ₄₁ -[Al(R ₄₂ )-O] _n -R ₄₃

In Chemical Formula 3,

R ₄₁ , R ₄₂ and R ₄₃ are each independently hydrogen, halogen, a hydrocarbyl group having 1 to 20 carbon atoms and a hydrocarbyl group having 1 to 20 carbon atoms substituted with a halogen,

n is an integer of 2 or more,

[Formula 4]

D(R ₄₄ ) ₃

In Formula 4, D is aluminum or boron,

R ₄₄ is each independently any one of halogen, a C 1 to C 20 hydrocarbyl group, and a halogen substituted C 1 to C 20 hydrocarbyl group,

[Formula 5]

^{[LH] + [Z (A} ) 4] - or ^{[L] + [Z (A} ) 4] -

In Chemical Formula 5,

L is a neutral or cationic Lewis base, H is a hydrogen atom,

Z is a Group 13 element, and A is each independently a hydrocarbyl group having 1 to 20 carbon atoms; Hydrocarbyloxy group having 1 to 20 carbon atoms; And at least one hydrogen atom of these substituents is any one of a substituent substituted with at least one of halogen, a C1-C20 hydrocarbyloxy group, and a C1-C20 hydrocarbylsilyl group.

More specifically, the compound of Formula 3 may be an alkylaluminoxane-based compound in which a repeating unit is bonded in a linear, circular or network type, and specific examples are methylaluminoxane (MAO), ethylaluminoxane, isobutylaluminoxane, or tert-butylaluminoxane, and the like.

In addition, specific examples of the compound of Formula 4 include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tripropyl aluminum, tributyl aluminum, dimethyl chloro aluminum, triisopropyl aluminum, tri-s-butyl aluminum, tricyclo Pentyl aluminum, tripentyl aluminum, triisopentyl aluminum, trihexyl aluminum, trioctyl aluminum, ethyl dimethyl aluminum, methyl diethyl aluminum, triphenyl aluminum, tri-p-tolyl aluminum, dimethyl aluminum methoxide, dimethyl aluminum ethoxide , Trimethyl boron, triethyl boron, triisobutyl boron, tripropyl boron or tributyl boron, and the like, and may be particularly selected from trimethyl aluminum, triethyl aluminum or triisobutyl aluminum.

In addition, examples of the compound of Formula 5 include a trisubstituted ammonium salt, a dialkyl ammonium salt, or a trisubstituted phosphonium salt type borate compound. More specific examples include trimetalammonium tetraphenylborate, methyldioctadecylammonium tetraphenylborate, triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tri(n-butyl)ammonium tetraphenylborate, methyltetradecyclo Octadecylammonium tetraphenylborate, N,N-dimethylaninium tetraphenylborate, N,N-diethylaninium tetraphenylborate, N,N-dimethyl(2,4,6-trimethylaninium)tetraphenylborate, Trimethylammonium tetrakis(pentafluorophenyl)borate, methylditetradecylammonium tetrakis(pentaphenyl)borate, methyldioctadecylammonium tetrakis(pentafluorophenyl)borate, triethylammonium, tetrakis(pentafluoro Phenyl) borate, tripropylammonium tetrakis (pentafluorophenyl) borate, tri (n-butyl) ammonium tetrakis (pentafluorophenyl) borate, tri (secondary-butyl) ammonium tetrakis (pentafluorophenyl) ) Borate, N,N-dimethylaninium tetrakis (pentafluorophenyl) borate, N,N-diethylaninium tetrakis (pentafluorophenyl) borate, N,N-dimethyl (2,4,6- Trimethylaninium) tetrakis (pentafluorophenyl) borate, trimethylammonium tetrakis (2,3,4,6-tetrafluorophenyl) borate, triethylammonium tetrakis (2,3,4,6-tetrafluoro) Rophenyl) borate, tripropylammonium tetrakis (2,3,4,6-tetrafluorophenyl) borate, tri(n-butyl) ammonium tetrakis (2,3,4,6-, tetrafluorophenyl) Borate, dimethyl (t-butyl) ammonium tetrakis (2,3,4,6-tetrafluorophenyl) borate, N,N-dimethylaninium tetrakis (2,3,4,6-tetrafluorophenyl) Borate, N,N-diethylaninium tetrakis(2,3,4,6-tetrafluorophenyl)borate or N,N-dimethyl-(2,4,6-trimethylaninium)tetrakis-(2 A borate-based compound in the form of a trisubstituted ammonium salt such as ,3,4,6-tetrafluorophenyl)borate; A borate type of dialkyl ammonium salt such as dioctadecyl ammonium tetrakis (pentafluorophenyl) borate, ditetradecyl ammonium tetrakis (pentafluorophenyl) borate or dicyclohexyl ammonium tetrakis (pentafluorophenyl) borate compound; Or triphenylphosphonium tetrakis(pentafluorophenyl)borate, methyldioctadecylphosphonium tetrakis(pentafluorophenyl)borate or tri(2,6-, dimethylphenyl)phosphonium tetrakis(pentafluorophenyl) ) Borate compounds in the form of trisubstituted phosphonium salts such as borate.

By using such a cocatalyst, the molecular weight distribution of the finally produced ethylene/alpha-olefin copolymer becomes more uniform, and polymerization activity may be improved.

The cocatalyst may be used in an appropriate amount so that the activation of the transition metal compound of Formula 1 and/or Formula 2 can sufficiently proceed.

The transition metal compound of Formula 1 and/or Formula 2 may be used in a form supported on a carrier.

When the transition metal compound of Formula 1 and/or Formula 2 is supported on a carrier, the weight ratio of the transition metal compound to the carrier may be 1:10 to 1:1,000, more specifically 1:10 to 1:500. When the carrier and the transition metal compound are included in the weight ratio within the above range, the optimum shape may be exhibited. In addition, when the cocatalyst is supported on the carrier together, the weight ratio of the cocatalyst to the carrier may be 1:1 to 1:100, more specifically 1:1 to 1:50. When the cocatalyst and the carrier are included in the weight ratio, it is possible to improve the catalytic activity and optimize the microstructure of the polymer to be produced.

Meanwhile, silica, alumina, magnesia, or a mixture thereof may be used as the carrier, or by drying these materials at a high temperature to remove moisture from the surface, the surface contains a highly reactive hydroxyl group or a siloxane group. It can also be used. In addition, the high-temperature dried carriers may further include oxides, carbonates, sulfates, or nitrate components such as Na ₂ O, K ₂ CO ₃ , BaSO ₄ and Mg(NO ₃ ) ₂ .

The drying temperature of the carrier is preferably 200 to 800°C, more preferably 300 to 600°C, and most preferably 300 to 400°C. When the drying temperature of the carrier is less than 200°C, there is too much moisture so that the moisture on the surface and the cocatalyst react, and when it exceeds 800°C, the pores on the surface of the carrier are combined and the surface area decreases, and there are many hydroxyl groups on the surface. It is not preferable because it disappears and only siloxane groups remain, and the reaction site with the cocatalyst decreases.

In addition, the amount of hydroxy groups on the surface of the carrier is preferably 0.1 to 10 mmol/g, more preferably 0.5 to 5 mmol/g. The amount of hydroxy groups on the surface of the carrier can be controlled by a method and conditions for preparing the carrier or drying conditions such as temperature, time, vacuum or spray drying.

The polymerization reaction of the ethylene/alpha-olefin copolymer of the present invention can be carried out by continuously polymerizing ethylene and alpha-olefin-based monomers by continuously adding hydrogen in the presence of a catalyst.

At this time, the hydrogen gas serves to suppress the rapid reaction of the transition metal compound in the initial stage of polymerization and terminate the polymerization reaction. Accordingly, by controlling the use and amount of hydrogen gas, an ethylene/alpha-olefin copolymer having a narrow molecular weight distribution with an ultra-low molecular weight can be effectively prepared.

The hydrogen gas may be added at 45 to 100 cc/min, more specifically 50 to 95 cc/min. When introduced under the above-described conditions, the ethylene/alpha-olefin polymer to be produced may realize the physical properties in the present invention. If the content of hydrogen gas is less than 45 cc/min, termination of the polymerization reaction does not occur uniformly, making it difficult to prepare an ethylene/alpha-olefin copolymer having desired physical properties, and it may exceed 100 cc/min. In this case, there is a concern that a termination reaction occurs too quickly, resulting in an ethylene/alpha-olefin copolymer having an excessively low molecular weight.

In addition, the polymerization reaction may be carried out at 80 to 200°C, but the number of unsaturated functional groups in the ethylene/alpha-olefin copolymer can be more easily controlled by controlling the polymerization temperature together with the amount of hydrogen added. Accordingly, in detail, the polymerization reaction may be performed at 100 to 200°C, 120 to 180°C, 130 to 170°C, and 140 to 160°C.

In addition, during the polymerization reaction, an organoaluminum compound for removing moisture in the reactor is further added, and the polymerization reaction may proceed in the presence thereof. Specific examples of such an organoaluminum compound include trialkyl aluminum, dialkyl aluminum halide, alkyl aluminum dihalide, aluminum dialkyl hydride or alkyl aluminum sesqui halide, and more specific examples thereof, Al(C ₂ H ₅ ) ₃ , Al(C ₂ H ₅ ) ₂ H, Al(C ₃ H ₇ ) ₃ , Al(C ₃ H ₇ ) ₂ H, Al(iC ₄ H ₉ ) ₂ H, Al(C ₈ H ₁₇ ) ₃ , Al(C ₁₂ H ₂₅ ) ₃ , Al(C ₂ H ₅ )(C ₁₂ H ₂₅ ) ₂ , Al(iC ₄ H ₉ )(C ₁₂ H ₂₅ ) ₂ , Al(iC ₄ H ₉ ) ₂ H, Al(iC ₄ H ₉ ) ₃ , (C ₂ H ₅ ) ₂ AlCl, (iC ₃ H ₉ ) ₂ AlCl, or (C ₂ H ₅ ) ₃ A _l2 Cl ₃ , and the like. These organoaluminum compounds may be continuously introduced into the reactor, and may be added in a ratio of about 0.1 to 10 moles per 1 kg of the reaction medium introduced into the reactor for proper moisture removal.

In addition, the polymerization pressure may be about 1 to about 100 Kgf/cm ² , preferably about 1 to about 50 Kgf/cm ² , more preferably about 5 to about 30 Kgf/cm ² .

In addition, when a transition metal compound is used in the form supported on a carrier, the transition metal compound is an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, such as pentane, hexane, heptane, nonane, decane, and isomers thereof and toluene, benzene. It may be dissolved or diluted in an aromatic hydrocarbon solvent such as, dichloromethane, or a hydrocarbon solvent substituted with a chlorine atom such as chlorobenzene. The solvent used here is preferably used after removing a small amount of water or air, which acts as a catalyst poison, by treating a small amount of alkyl aluminum, and it is possible to further use a cocatalyst.

In addition, the present invention provides a hot melt adhesive composition comprising the ethylene/alpha-olefin copolymer. The hot melt adhesive composition may be prepared and used according to a conventional method, except that the ethylene/alpha-olefin copolymer is included as a main component.

Example

Hereinafter, the present invention will be described in more detail by examples. However, the following examples are for illustrative purposes only, and the scope of the present invention is not limited thereto.

Preparation Example 1: Preparation of transition metal compound 1

(1) Ligand compound 1 (8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline (8-(2,3, Preparation of 4,5-Tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline))

(i) Preparation of lithium carbamate

1,2,3,4-tetrahydroquinoline (13.08 g, 98.24 mmol) and diethyl ether (150 mL) were added to a Schlenk flask. The Schlenk flask was immersed in a -78°C low temperature bath made of dry ice and acetone and stirred for 30 minutes. Then, n-BuLi (39.3 mL, 2.5 M, 98.24 mmol) was injected into a syringe under a nitrogen atmosphere, and a pale yellow slurry was formed. Then, after the flask was stirred for 2 hours, the temperature of the flask was raised to room temperature while removing the generated butane gas. The flask was again immersed in a -78°C low temperature bath to lower the temperature, and then CO ₂ gas was added. As the carbon dioxide gas was added, the slurry disappeared, resulting in a transparent solution. The flask was connected to a bubbler and the temperature was raised to room temperature while removing carbon dioxide gas. After that, excess CO ₂ gas and solvent were removed under vacuum. After moving the flask to a dry box, pentane was added, stirred vigorously, and filtered to obtain a white solid compound, lithium carbamate. The white solid compound is coordinated with diethyl ether. At this time, the yield is 100%.

1H NMR(C ₆ D ₆ , C ₅ D ₅ N): δ 1.90 (t, J = 7.2 Hz, 6H, ether), 1.50 (br s, 2H, quin-CH ₂ ), 2.34 (br s, 2H, quin-CH ₂ ), 3.25 (q, J = 7.2 Hz, 4H, ether), 3.87 (br, s, 2H, quin-CH ₂ ), 6.76 (br d, J = 5.6 Hz, 1H, quin-CH) ppm

13C NMR (C ₆ D ₆ ): δ 24.24, 28.54, 45.37, 65.95, 121.17, 125.34, 125.57, 142.04, 163.09 (C=O) ppm

(ii) Preparation of 8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline

The lithium carbamate compound (8.47 g, 42.60 mmol) prepared in step (i) was added to a Schlenk flask. Then, tetrahydrofuran (4.6 g, 63.9 mmol) and 45 mL of diethyl ether were sequentially added. After immersing the Schlenk flask in a -20°C low temperature bath made of acetone and a small amount of dry ice and stirring for 30 minutes, t-BuLi (25.1 mL, 1.7 M, 42.60 mmol) was added. At this time, the color of the reaction mixture turned red. The mixture was stirred for 6 hours while maintaining -20°C. CeCl3·2LiCl solution (129 mL, 0.33 M, 42.60 mmol) dissolved in tetrahydrofuran and tetramethylcyclopentinone (5.89 g, 42.60 mmol) were mixed in a syringe, and then introduced into a flask under a nitrogen atmosphere. The temperature of the flask was slowly raised to room temperature, and after 1 hour, the thermostat was removed and the temperature was maintained at room temperature. Then, after adding water (15 mL) to the flask, ethyl acetate was added thereto, followed by filtration to obtain a filtrate. After transferring the filtrate to a separatory funnel, hydrochloric acid (2 N, 80 mL) was added and shaken for 12 minutes. Then, a saturated aqueous sodium hydrogen carbonate solution (160 mL) was added to neutralize and the organic layer was extracted. Anhydrous magnesium sulfate was added to the organic layer to remove moisture and filtered. The filtrate was taken and the solvent was removed. The obtained filtrate was purified by column chromatography using hexane and ethyl acetate (v/v, 10:1) solvent to obtain a yellow oil. The yield was 40%.

1H NMR(C ₆ D ₆ ): δ 1.00 (br d, 3H, Cp-CH ₃ ), 1.63-1.73 (m, 2H, quin-CH ₂ ), 1.80 (s, 3H, Cp-CH ₃ ), 1.81 (s, 3H, Cp-CH ₃ ), 1.85 (s, 3H, Cp-CH ₃ ), 2.64 (t, J = 6.0 Hz, 2H, quin-CH ₂ ), 2.84-2.90 (br, 2H, quin- CH ₂ ), 3.06 (br s, 1H, Cp-H), 3.76 (br s, 1H, NH), 6.77 (t, J = 7.2 Hz, 1H, quin-CH), 6.92 (d, J = 2.4 Hz , 1H, quin-CH), 6.94 (d, J = 2.4 Hz, 1H, quin-CH) ppm

(2) Preparation of transition metal compound 1

(i) [(1,2,3,4-tetrahydroquinolin-8-yl)tetramethylcyclopentadienyl-η5, κ-N] Preparation of dilithium compound

8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline (8.07 g) prepared through step (1) in a dry box , 32.0 mmol) and 140 mL of diethyl ether were added to a round flask, and the temperature was lowered to -30°C, and n-BuLi (17.7 g, 2.5 M, 64.0 mmol) was slowly added while stirring. It was reacted for 6 hours while raising the temperature to room temperature. After that, it was filtered while washing several times with diethyl ether, and the solid was obtained. Vacuum was applied to remove the remaining solvent to obtain a yellow solid dilithium compound (9.83 g). The yield was 95%.

1H NMR(C ₆ D ₆ , C ₅ D ₅ N): δ 2.38 (br s, 2H, quin-CH ₂ ), 2.53 (br s, 12H, Cp-CH ₃ ), 3.48 (br s, 2H, quin -CH ₂ ), 4.19 (br s, 2H, quin-CH ₂ ), 6.77 (t, J = 6.8 Hz, 2H, quin-CH), 7.28 (br s, 1H, quin-CH), 7.75 (brs, 1H, quin-CH) ppm

(ii) Preparation of (1,2,3,4-tetrahydroquinolin-8-yl)tetramethylcyclopentadienyl-η5, κ-N] titanium dimethyl

In a dry box, TiCl4·DME (4.41 g, 15.76 mmol) and diethyl ether (150 mL) were placed in a round flask, and MeLi (21.7 mL, 31.52 mmol, 1.4 M) was slowly added while stirring at -30°C. After stirring for 15 minutes, [(1,2,3,4-tetrahydroquinolin-8-yl)tetramethylcyclopentadienyl-ηη5, κ-N]dilithium compound (5.30) prepared in step (i) g, 15.76 mmol) was added to the flask. The mixture was stirred for 3 hours while raising the temperature to room temperature. After the reaction was completed, vacuum was applied to remove the solvent, dissolved in pentane, and filtered to obtain a filtrate. When pentane was removed by applying vacuum, a dark brown compound (3.70 g) was obtained. The yield was 71.3%.

¹ H NMR(C ₆ D ₆ ): δ 0.59 (s, 6H, Ti-CH ₃ ), 1.66 (s, 6H, Cp-CH ₃ ), 1.69 (br t, J = 6.4 Hz, 2H, quin-CH ₂ ), 2.05 (s, 6H, Cp-CH ₃ ), 2.47 (t, J = 6.0 Hz, 2H, quin-CH ₂ ), 4.53 (m, 2H, quin-CH ₂ ), 6.84 (t, J = 7.2 Hz, 1H, quin-CH), 6.93 (d, J = 7.6 Hz, quin-CH), 7.01 (d, J = 6.8 Hz, quin-CH) ppm

¹³ C NMR (C ₆ D ₆ ): δ 12.12, 23.08, 27.30, 48.84, 51.01, 119.70, 119.96, 120.95, 126.99, 128.73, 131.67, 136.21 ppm

Preparation Example 2: Preparation of transition metal compound 2

(1) Preparation of ligand compound 2 (N-tert-butyl-1-(2,3-dimethyl-1H-benzo[b]cyclopenta[d]thiophen-1-yl)-1,1-dimethylsilanamine)

After quantifying and adding 330 mg (0.12 mmol) of the compound of Formula 3 to a 100 ml Schlenk flask, 20 ml of hexane was added thereto. After tBuNH ₂ (4eq, 0.47 ml) was added at room temperature, it was reacted at room temperature for 3 days. After the reaction, it was filtered. After drying the solvent, the title compound represented by the following formula 2-1 as an orange liquid was obtained in a yield of 345 mg (93%).

¹ H-NMR (in C ₆ D ₆ , 500 MHz):

7.82 (d, 1H), 7.69 (d, 1H), 7.27 (t, 1H), 7.03 (t, 1H), 3.39 (s, 1H), 2.03 (s, 3H), 1.99 (s, 3H), 1.04 (s, 9H), 0.07 (s, 3H), -0.11 (s, 3H).

(2) Preparation of transition metal compound 2

In a 20 ml Schlenk flask, the ligand compound represented by Chemical Formula 2-1 obtained in Synthesis Example 1 (260 mg, 0.80 mmol/1.0eq) and MTBE 6.0 ml (0.1M) were added and stirred first. Add n-BuLi (0.65 ml, 2.03 eq, 2.5M in hexane) at -40°C, and react at room temperature overnight. Then, MeMgBr (0.6 ml, 2.5 eq, 3.0M in diethyl ether) was slowly added dropwise at -40°C, and then TiCl ₄ (0.8 ml, 1.0 eq, 1.0M in toluene) was sequentially added and reacted overnight at room temperature. Thereafter, the reaction mixture was filtered through Celite using hexane. After drying the solvent, a transition metal compound represented by the following formula 1-1 as a brown solid was obtained in a yield of 170 mg (53%).

¹ H-NMR (in CDCl ₃ , 500 MHz):

7.99 (d, 1H), 7.47 (d, 1H), 7.10 (t, 1H), 6.97 (t, 1H), 2.12 (s, 3H), 1.89 (s, 3H), 1.46 (s, 9H), 0.67 (s, 3H), 0.59 (s, 3H), 0.51 (s, 3H), 0.10 (s, 3H).

Example 1

In a 1.5 L continuous process reactor, 7 kg of hexane solvent per hour and 1.03 kg of 1-octene per hour were added and preheated at 150°C. A mixture of a triisobutylaluminum compound (0.05 mmol/min), a transition metal compound 1 obtained in Preparation Example 1, and a transition metal compound 2 obtained in Preparation Example 2 at a molar ratio of 70:30 (0.5 μmol /min), and dimethylanilinium tetrakis (pentafluorophenyl) borate cocatalyst (1.5 μmol/min) were simultaneously introduced into the reactor. Subsequently, ethylene (0.87 kg/h) was introduced into the reactor and maintained at 170° C. for 60 minutes or more in a continuous process at a pressure of 89 bar to proceed with a copolymerization reaction to obtain a copolymer. After drying for 12 hours or more in a vacuum oven, the physical properties were measured.

Examples 2 to 6, Comparative Examples 1 to 7

The experiment was performed in the same manner as in Example 1, except that the contents and reaction conditions of the transition metal compounds 1 and 2 were changed as shown in Table 1.

Transition metal compound 1
(umol/min) Transition metal compound 2
(umol/min) Mixing ratio Ethylene
(kg/h) 1-octene
(kg/h) Hexane
(kg/h) Reaction temperature
(℃) Example 1 0.339 0.171 70:30 0.87 1.03 7.00 170 Example 2 0.370 0.200 65:35 0.87 1.03 7.00 170 Example 3 0.400 0.260 61:39 0.87 0.76 7.00 160 Example 4 0.285 0.285 50:50 0.87 1.03 7.00 170 Example 5 0.200 0.370 35:65 0.87 1.03 7.00 170 Example 6 0.171 0.399 30:70 0.87 1.03 7.00 170 Comparative Example 1 0.800 0.000 100:0 0.87 0.98 7.00 170 Comparative Example 2 0.570 0.000 100:0 0.87 1.03 7.00 170 Comparative Example 3 0.428 0.143 75:25 0.87 1.03 7.00 170 Comparative Example 4 0.143 0.428 25:75 0.87 1.03 7.00 170 Comparative Example 5 0.000 0.570 0:100 0.87 1.03 7.00 170 Comparative Example 6 0.800 0.000 100:0 0.87 0.76 7.00 160 Comparative Example 7 0.000 0.520 0:100 0.87 0.76 7.00 160

Experimental Example 1: Evaluation of physical properties of ethylene/alpha-olefin copolymer

The physical properties of the ethylene/alpha-olefin copolymer prepared in Examples and Comparative Examples were measured by the following method, and are shown in Table 2.

1) Density (Density, g/cm ³ ): It was measured according to ASTM D-792.

2) Melt Index (MI, dg/min): The melt index (MI) of the polymer was measured by ASTM D-1238 (Condition E, 190°C, 2.16 Kg load).

density Melt index yield C2 conv. 1-C8 conv. Polymerized 1-C8 (wt%) Example 1 0.874 15 745.0 56.9 24.2 33.5 Example 2 0.876 18 730.0 56.4 23.2 32.8 Example 3 0.877 17 1008.0 78.4 42.7 32.3 Example 4 0.880 24 721.0 57.4 21.4 30.7 Example 5 0.882 35 706.0 57.3 20.1 29.4 Example 6 0.883 47 696.0 56.8 19.5 29.0 Comparative Example 1 0.880 11 900.0 71.8 28.0 30.6 Comparative Example 2 0.871 6 780.0 58.9 25.9 34.3 Comparative Example 3 0.872 6 768.0 58.2 25.3 34.1 Comparative Example 4 0.886 55 672.0 56.7 17.3 26.6 Comparative Example 5 0.889 93 648.0 56.2 15.4 24.5 Comparative Example 6 0.869 6 1104.0 83.1 49.9 34.5 Comparative Example 7 0.884 89 912.0 75.4 33.6 28.1

Interpreting the results of Table 2 is as follows. In the case of Comparative Examples 1, 2 and 6 in which the ethylene/alpha-olefin copolymer was synthesized by using only the transition metal compound 1 without mixing the transition metal compound 2, the melt index was lower than 15, resulting in a high flow of desired physical properties. The copolymer could not be prepared, whereas in Comparative Examples 5 and 7 in which only the transition metal compound 2 was used without mixing the transition metal compound 1, it was found that the melt index was too high as 89 and 93. That is, in order to prepare a copolymer having an appropriate melt index of 15 to 50, it is preferable to prepare a copolymer by mixing transition metal compounds 1 and 2 as in the above example.

On the other hand, in the case of Comparative Example 3 in which the transition metal compounds 1 and 2 were mixed at 75:25, the melt index was still lower than 15, and the case of Comparative Example 4 in which the transition metal compounds 1 and 2 were mixed at 25:75 , It was confirmed that not only the melt index appeared too high as 55, but also the 1-octene conversion rate was lowered. It is possible to prepare an ethylene/alpha-olefin copolymer by mixing transition metal compounds 1 and 2 at 3:7 to 7:3, thereby producing a high flow copolymer having a melt index of 15 to 50 while exhibiting a high alpha-olefin conversion rate. It is to prove that there is.

Claims (8)

Including; polymerizing ethylene and alpha-olefin monomers in the presence of a catalyst composition comprising a transition metal compound represented by the following Formulas 1 and 2,
The mixing ratio of the transition metal compound represented by Chemical Formula 1 and Chemical Formula 2 is 3:7 to 7:3 based on the number of moles, and the method for preparing an ethylene/alpha-olefin copolymer:
[Formula 1]

In Formula 1,
R ₁ is the same as or different from each other, and each independently of a group 4 metal substituted with hydrogen, alkyl having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, aryl, silyl, alkylaryl, arylalkyl, or hydrocarbyl It is a metalloid radical, and the two R ₁ may be linked to each other by an alkylidine radical including an alkyl having 1 to 20 carbon atoms or an aryl radical having 6 to 20 carbon atoms to form a ring;
R ₂ are the same as or different from each other, and each independently hydrogen; halogen; Alkyl of 1 to 20 carbon atoms; Aryl; Alkoxy; Aryloxy; An amido radical, and two or more of R ₂ may be linked to each other to form an aliphatic ring or an aromatic ring;
R ₃ is the same as or different from each other, and each independently hydrogen; halogen; Alkyl of 1 to 20 carbon atoms; Or a nitrogen-containing aliphatic or aromatic ring substituted or unsubstituted with an aryl radical, and when the number of substituents is plural, two or more substituents among the substituents may be connected to each other to form an aliphatic or aromatic ring;
M ₁ is a Group 4 transition metal;
Q ₁ and Q ₂ are each independently halogen; Alkyl of 1 to 20 carbon atoms; Alkenyl; Aryl; Alkylaryl; Arylalkyl; Alkyl amido having 1 to 20 carbon atoms; Aryl amido; Or an alkylidene radical having 1 to 20 carbon atoms;
[Formula 2]

In Chemical Formula 2,
R ₄ to R ₉ are each independently hydrogen; Alkyl of 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Alkylaryl having 7 to 20 carbon atoms; Or arylalkyl having 7 to 20 carbon atoms,
R ₁₀ and R ₁₁ are each independently hydrogen; Alkyl of 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Alkylaryl having 6 to 20 carbon atoms; Arylalkyl having 7 to 20 carbon atoms; Alkyl amido having 1 to 20 carbon atoms; Aryl amido having 6 to 20 carbon atoms; Or alkylidene having 1 to 20 carbon atoms,
R ₁₂ is hydrogen; Alkyl of 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Alkoxy having 1 to 20 carbon atoms; Aryl of 6 to 20 carbon atoms; Arylalkoxy having 7 to 20 carbon atoms; Alkylaryl having 7 to 20 carbon atoms; Or arylalkyl having 7 to 20 carbon atoms,
Two or more adjacent to each other among the R ₄ to R ₁₂ may be connected to each other to form a ring,
R ₁₃ and R ₁₄ are each independently hydrogen, halogen, alkyl having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, alkylaryl having 7 to 20 carbon atoms, arylalkyl having 7 to 20 carbon atoms , C 1 to C 20 alkylamino, C 6 to C 20 arylamino or C 1 to C 20 alkylidene,
Q is Si, C, N, P or S,
M is a Group 4 transition metal.
The method according to claim 1,
The mixing ratio of the transition metal compound represented by Formula 1 and Formula 2 is 4:6 to 6:4 based on the number of moles, the method for producing an ethylene/alpha-olefin copolymer.
The method according to claim 1,
The ethylene/alpha-olefin copolymer prepared by the above method has a Melt Index (MI) of 15 to 50, and a method for producing an ethylene/alpha-olefin copolymer.
The method according to claim 1,
The conversion of the alpha-olefin in the polymerization step is 25% or more, an ethylene/alpha-olefin copolymer production method.
The method according to claim 1,
The alpha-olefin is propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1 -A method of producing an ethylene/alpha-olefin copolymer, which is at least one selected from the group consisting of tetradecene, 1-hexadecene and 1-eicosene.
The method according to claim 1,
The transition metal compound represented by Formula 1 is at least one selected from the group consisting of the following Formulas 1-1 and 1-2, wherein the method for producing an ethylene/alpha-olefin copolymer.
[Formula 1-1]

[Formula 1-2]

The method according to claim 1,
The transition metal compound represented by Chemical Formula 2 is at least one selected from the group consisting of the following Chemical Formulas 2-1 to 2-3, wherein the method for producing an ethylene/alpha-olefin copolymer.
[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

The method according to claim 1,
The polymerization is to be carried out at 100 to 200 ℃, ethylene / alpha-a method for producing an olefin copolymer.