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

Abstract

To provide a copolymer for an adhesive that has excellent adhesive strength at room temperature and low temperature using an ethylene / alpha-olefin copolymer having a continuous sequence having a small number of ethylene repeat units in the molecular structure thereof.SOLUTION: There is provided an ethylene / alpha-olefin copolymer that satisfies an ERI (Ethylene-unit Repeatness Index) value defined by the following Equation 1 of 1.20 or less. In the Equation 1, [EE](ethylene-ethylene), [EO](ethylene-alpha-olefin), and [OO](alpha-olefin-alpha-olefin) are diad fractions of the ethylene / alpha-olefin copolymer measured by 13C-NMR; and CE / CO is a ratio of a number of ethylene moles (CE) to a number of alpha-olefin moles (CO) in a liquid phase.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an ethylene / alpha-olefin copolymer and a method for producing the same.

Background Art

[0002] Hot melt adhesives are adhesives obtained from blends of resins such as polyolefin elastomers, polypropylene-based polymers, and amorphous polyolefins. Hot melt adhesives have a very fast adhesion force compared to other adhesives and are increasingly used as adhesives that are friendly to solvent-free environments. They are widely used in paper, woodworking, construction, packaging, sanitary products, the electronics field, etc.

[0003]

[0004] ​However, in the case of conventional amorphous polypropylene that has been used in hot melt adhesives, due to insufficient stereoregularity, there were many deficiencies when used in combination with many types of plasticizers, waxes, filler substances, tackifiers, etc. Subsequently, APAO (amorphous poly alpha olefin) with improved physical properties, copolymers and terpolymers produced using Ziegler-Natta catalysts (for example, Vestoplast of Evonik, Rextac of REXtac, Eastoflex of Eastman Chemical, etc.) were proposed, and in recent years, polyolefins with even more sophisticated and excellent properties have been produced using metallocene catalysts. In particular, each catalyst system capable of producing ethylene- or propylene-based copolymers (for example, Affinity, Engage, Versify of DOW Chemical, Vistamaxx of ExxonMobil, etc.) using each comonomer of 1-butene and 1-octene has been developed.

[0005] In recent years, during the production of paper or films, the demand for hot melt adhesives that can exhibit a certain level of adhesive strength with a small amount of adhesive has been increasing. In particular, the development of hot melt adhesives that are excellent in low-temperature adhesiveness and coating properties and exhibit satisfactory adhesive strength over a wide temperature range is urgently required.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention aims to provide a copolymer for adhesives having excellent adhesive strength at normal temperature and low temperature by using an ethylene / alpha olefin copolymer having a low ethylene repeating unit continuous sequence in its molecular structure.

Means for Solving the Problem

[0008] One embodiment provides an ethylene / alpha-olefin copolymer that satisfies an ERI (Ethylene-unit Repeatness Index) value defined by the following Mathematical Formula 1 of 1.20 or less.

[0009]

Number

[0010] In the Mathematical Formula 1, [EE] (ethylene-ethylene), [EO] (ethylene-alpha-olefin), and [OO] (alpha-olefin-alpha-olefin) are 13 the diad fractions of the ethylene / alpha-olefin copolymer measured by C-NMR, C E / C O is the ratio of the number of moles of ethylene (C O ) to the number of moles of alpha-olefin (C E ) in the liquid phase.

[0011] The ratio of the number of moles of ethylene to the number of moles of alpha-olefin (C E / C O ) can be from 6.0 to 11.0.

[0012] The [EE] can be from 0.75 to 0.85, the [EO] can be from 0.15 to 0.25, and the [OO] can be from 0.001 to 0.05.

[0013] The alpha-olefin can be any one or more selected from the group consisting of 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, and 1-octene.

[0014] The molecular weight distribution (Mw / Mn, PDI) of the ethylene / alpha-olefin copolymer can be from 1.97 to 2.5.

[0015] The number average molecular weight (Mn) of the ethylene / alpha-olefin copolymer can be from 10,000 g / mol to 25,000 g / mol, and the weight average molecular weight (Mw) can be from 25,000 g / mol to 50,000 g / mol.

[0016] The Brookfield viscosity of the ethylene / alpha-olefin copolymer at 190 °C can be from 4,000 cps to 15,000 cps.

[0017] The melting temperature (T m ) of the ethylene / alpha-olefin copolymer can be from 50 °C to 90 °C, the crystallization temperature (T c ) can be from 45 °C to 80 °C, and the glass transition temperature (T g ) can be from -70 °C to -40 °C.

[0018] Another embodiment provides a method for producing an ethylene / alpha-olefin copolymer, comprising the steps of: polymerizing a feed stream supplied in the presence of a catalyst containing one or more of a transition metal catalyst and a cocatalyst to produce a reaction product; and obtaining an ethylene / alpha-olefin copolymer from the reaction product, wherein the ethylene / alpha-olefin copolymer satisfies an ERI (Ethylene-unit Repeatness Index) value defined by the following Mathematical Formula 1 of 1.20 or less.

[0019]

Number

[0020] In the Mathematical Formula 1, [EE] (ethylene-ethylene), [EO] (ethylene-alpha-olefin), and [OO] (alpha-olefin-alpha-olefin) are 13 the binary fractions of the ethylene and alpha-olefin copolymer measured by C-NMR, C E / C O is the number of moles of alpha-olefin in the liquid phase (C OThe molar number of ethylene relative to (C E ), which is a ratio.

[0021] The feed stream contains monomers and comonomers. The monomer contains ethylene, and the comonomer can contain any one or more selected from the group consisting of 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, and 1-octene.

[0022] In the polymerization reaction, the monomer is supplied at 50 g / hr to 350 g / hr, the comonomer is supplied at 50 g / hr to 250 g / hr, and the flow rate ratio of the monomer to the flow rate of the comonomer can be 0.1 to 2.

[0023] In the polymerization reaction, hydrogen can be supplied at 0.01 g / hr to 0.3 g / hr.

[0024] The polymerization reaction can be carried out under the conditions of a temperature of 70°C to 140°C and a pressure of 30 bar to 100 bar.

[0025] The transition metal catalyst can be any one or more selected from the group consisting of Chemical Formula 1 and Chemical Formula 2.

[0026]

Chemical formula

[0027]

Chemical formula

[0028] In each of Chemical Formula 1 and Chemical Formula 2, M is titanium, zirconium, or hafnium, B is an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, a dialkyl silicone group having 1 to 20 carbon atoms, a dialkyl germanium group having 1 to 20 carbon atoms, an alkyl phosphine group having 1 to 20 carbon atoms, or an alkyl amine group having 1 to 20 carbon atoms, X1 and X2 are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, an arylalkyl group having 7 to 40 carbon atoms, an alkylamide group having 1 to 20 carbon atoms, an arylamide group having 6 to 20 carbon atoms, an alkylidene group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, R1 to R7 can each independently be hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, a cycloalkyl group having 5 to 60 carbon atoms, a heterocyclic group having 4 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, a heteroaryl group having 6 to 20 carbon atoms or a silyl group having 6 to 20 carbon atoms.

[0029] The cocatalyst can include an activator compound containing a boron compound and a co-activator compound containing an organoaluminum compound.

[0030] The boron compound is any one or more selected from the group consisting of triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylcyclohexylammonium tetrakis(pentafluorophenyl)borate, N,N-dimethylbenzylammonium tetrakis(pentafluorophenyl)borate, and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, and the organoaluminum compound may be any one or more selected from the group consisting of alkylaluminums such as dimethylaluminum, dimethylethylaluminum, trimethylaluminum, triethylaluminum, tributylaluminum, trihexylaluminum, trioctylaluminum, triisopropylaluminum, and triisobutylaluminum; alkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, dimethylaluminum fluoride, and ethylaluminum sesquichloride; dialkylaluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride, methylaluminoxane, and modified methylaluminoxane.

[0031] In the polymerization reaction, the transition metal catalyst can be supplied at 0.001 μmol / min to 0.040 μmol / min, and the cocatalyst can be supplied at 0.01 μmol / min to 0.2 μmol / min.

[0032] Yet another embodiment provides an ethylene / alpha-olefin copolymer produced by the method for producing an ethylene / alpha-olefin copolymer described above.

[0033] Yet another embodiment provides a composition for a hot melt adhesive containing the ethylene / alpha-olefin copolymer described above.

Advantages of the Invention

[0034] The present invention provides a copolymer for adhesives having excellent adhesive strength at normal temperature and low temperature by using an ethylene / alpha-olefin copolymer having a low ethylene repeat unit continuous sequence in its molecular structure. The ethylene / alpha-olefin copolymer according to the present invention can make the distribution of ethylene repeat units and short-chain branches in the main chain uniform by having a low ethylene repeat unit continuous sequence in its molecular structure. The ethylene / alpha-olefin copolymer of the present invention is applicable to hot melt adhesives, and the hot melt adhesives have excellent adhesive strength in a wide temperature range even when applied in a small amount.

Embodiments for Carrying Out the Invention

[0035] The terms and words used in the description and claims of the present invention should not be construed as limited to ordinary or dictionary meanings. Based on the principle that the inventor can appropriately define the concept of terms in order to explain his invention in the best way, they should be construed in meanings and concepts that conform to the technical idea of the present invention.

[0036] In the present invention, the term "stream" can mean the flow of a fluid in a process, and can also mean the fluid itself flowing in a pipe. Specifically, the "stream" can simultaneously mean the fluid itself flowing in the pipe connecting each device and the flow of the fluid. Further, the fluid can mean a gas or a liquid, and does not exclude those in which a solid component is contained in the fluid.

[0037] Hereinafter, each embodiment will be described in detail so that those skilled in the art can easily implement it. However, each embodiment can be implemented in various different forms and is not limited to the embodiments described here.

[0038] <Ethylene / alpha-olefin copolymer>

[0039] The ethylene / alpha-olefin copolymer according to an embodiment satisfies an ERI (Ethylene-unit Repeatness Index) value defined by the following Mathematical Formula 1 of 1.20 or less.

[0040] [Number]

[0041] In the above Mathematical Formula 1, [EE] (ethylene-ethylene), [EO] (ethylene-alpha-olefin), and [OO] (alpha-olefin-alpha-olefin) are 13 the binary fractions of the ethylene / alpha-olefin copolymer measured by C-NMR, C E / C O is the ratio of the number of moles of ethylene (C O ) to the number of moles of alpha-olefin (C E ) in the liquid phase.

[0042] The ethylene / alpha-olefin copolymer according to the present invention has a low ethylene repeat unit continuous sequence in the molecular structure, and the ERI (Ethylene-unit Repeatness Index) value can be 1.20 or less, for example, 1.15 or less. When the ERI value satisfies the above-described range, a molecular structure in which the distribution of ethylene repeat units and short-chain branches in the main chain of the ethylene / alpha-olefin copolymer is uniform can be realized, and excellent adhesive strength can be provided in a wide temperature range from normal temperature to low temperature even when a small amount thereof is applied.

[0043] [EE] may be from 0.75 to 0.85, [EO] may be from 0.15 to 0.25, and [OO] may be from 0.001 to 0.05. When [EE], [EO], and [OO] are in the above-described ranges, excellent adhesive strength can be provided in a wide temperature range from normal temperature to low temperature even when a small amount of the ethylene / alpha-olefin copolymer is applied.

[0044] The alpha-olefin can be any one or more selected from the group consisting of 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, and 1-octene.

[0045] The molecular weight distribution (Mw / Mn, PDI) of the ethylene / alpha-olefin copolymer can be from 1.97 to 2.5. When Mw / Mn exceeds the above-mentioned range, the productivity of the target product may decrease.

[0046] The number average molecular weight (Mn) of the ethylene / alpha-olefin copolymer can be from 10,000 g / mol to 25,000 g / mol, and the weight average molecular weight (Mw) can be from 25,000 g / mol to 50,000 g / mol. When the number average molecular weight and the weight average molecular weight are less than the above-mentioned range, the viscosity and cohesion are very low, so the adhesive strength of the hot melt adhesive may decrease. On the other hand, when the number average molecular weight and the weight average molecular weight exceed the above-mentioned range, the viscosity of the hot melt adhesive is very high, making it difficult to apply.

[0047] The Brookfield viscosity of the ethylene / alpha-olefin copolymer at 190 °C can be from 4,000 cps to 15,000 cps. When the Brookfield viscosity is less than the above-mentioned range, the molecular weight and cohesion are very low, so the adhesive strength of the hot melt adhesive may decrease. On the other hand, when the Brookfield viscosity exceeds the above-mentioned range, the molecular weight of the hot melt adhesive is very high, making it difficult to apply.

[0048] The melting temperature (T m ) of the ethylene / alpha-olefin copolymer is from 50 °C to 90 °C, the crystallization temperature (T c ) is from 45 °C to 80 °C, and the glass transition temperature (T g) can be from -70°C to -40°C. When the melting temperature and the crystallization temperature are less than the above-mentioned range, the thermal stability may decrease. On the other hand, when the melting temperature and the crystallization temperature exceed the above-mentioned range, the viscosity of the adhesive composition containing this may deviate from the target viscosity, or the related mechanical properties and processability may decrease. When the glass transition temperature is less than the above-mentioned range, the heat resistance may decrease. On the other hand, when the glass transition temperature exceeds the above-mentioned range, the stickiness of the hot melt adhesive increases and the cold resistance may decrease.

[0049] <Method for Producing Ethylene / α-Olefin Copolymer>

[0050] A method for producing an ethylene / α-olefin copolymer according to an embodiment includes polymerizing a feed stream supplied in the presence of a catalyst containing one or more of a transition metal catalyst and a cocatalyst to produce a reaction product; and obtaining an ethylene / α-olefin copolymer from the reaction product. The ethylene / α-olefin copolymer produced by the production method satisfies that the ERI (Ethylene-unit Repeatness Index) value defined by the following Mathematical Formula 1 is 1.20 or less.

[0051] [Number]

[0052] In the above Mathematical Formula 1, [EE] (ethylene-ethylene), [EO] (ethylene-α-olefin), and [OO] (α-olefin-α-olefin) are 13 the binary fractions of the ethylene and α-olefin copolymer measured by C-NMR, C E / C O is the ratio of the number of moles of ethylene (C O ) to the number of moles of α-olefin (C E ) in the liquid phase.

[0053] [Feed Stream]

[0054] The feed stream contains monomers and comonomers. The monomer contains ethylene, and the comonomer can contain an alpha-olefin monomer having 2 to 20 carbon atoms, for example, an aliphatic alpha-olefin monomer having 6 to 20 carbon atoms. As the comonomer, linear alpha-olefins such as propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene; branched alpha-olefins such as 3-methyl-1-pentene, 4-methyl-1-pentene; or mixtures thereof can be used alone or in combination, and isomers thereof can also be used. For example, the comonomer can contain any one or more selected from the group consisting of 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, and 1-octene.

[0055] In the polymerization reaction, the monomer is supplied at 50 g / hr to 350 g / hr, the comonomer is supplied at 50 g / hr to 250 g / hr, and the flow rate ratio of the monomer to the flow rate of the comonomer can be 0.1 to 2. When the supply rates of the monomer and the comonomer are less than the above-described ranges, the relative amount of catalyst injection increases, resulting in a decrease in quality such as color change due to excessive catalyst, or a decrease in productivity due to a very small amount of polymerization product. When the flow rate ratio of the monomer to the flow rate of the comonomer deviates from the above-described range, the molecular weight and viscosity of the product can deviate from the target molecular weight and viscosity.

[0056] In the polymerization reaction, hydrogen can be supplied at 0.01 g / hr to 0.3 g / hr. When the supply rate of hydrogen exceeds the above-described range, a chain transfer reaction occurs in the direction of decreasing molecular weight rather than a chain propagation reaction in which the molecular weight of the ethylene / alpha-olefin copolymer increases, and the molecular weight and viscosity of the product can deviate from the target molecular weight and viscosity.

[0057] In the polymerization reaction, the polymerization temperature and pressure can vary depending on reactants, reaction conditions, etc. Generally, it can be carried out in the presence of an inert gas such as argon or nitrogen under the conditions of a temperature of 70°C to 140°C and a pressure of 30 bar to 100 bar. When the temperature is below the above-mentioned range, the chain growth reaction proceeds better than the chain transfer reaction that occurs in the direction of decreasing the molecular weight of the ethylene / alpha-olefin copolymer. As a result, a copolymer with high molecular weight and high viscosity is formed, and the molecular weight and viscosity of the product may deviate from the target molecular weight and viscosity. On the other hand, when the temperature exceeds the above-mentioned range, the thermal stability of the catalyst decreases, and the catalytic activity may decrease. When the pressure is below the above-mentioned range, the solubility of the monomer in the solvent decreases, the polymerization activity decreases, or the fluctuations during the reaction of hydrogen become intense and the reaction cannot be stabilized. On the other hand, when the pressure exceeds the above-mentioned range, there is no benefit, and a large amount of energy is used during operation, so the operation efficiency may decrease.

[0058] The polymerization reaction can be carried out in a liquid phase, slurry phase, bulk phase, or gas phase polymerization in a hydrocarbon solvent. As the hydrocarbon solvent, aliphatic hydrocarbon solvents having 5 to 20 carbon atoms, such as pentane, hexane, heptane, nonane, decane, etc. and aliphatic hydrocarbon solvents in their isomeric forms; aromatic hydrocarbon solvents such as toluene, benzene, xylene; hydrocarbon solvents containing halogen atoms such as chlorobenzene can be used alone or in combination. The polymerization reaction can be carried out as a batch, semi-continuous, or continuous reaction in a reactor in a single or combined form such as a batch reactor or a loop reactor.

[0059] [Catalyst]

[0060] The catalyst contains one or more of a transition metal catalyst and a co-catalyst.

[0061] [Transition Metal Catalyst]

[0062] The transition metal catalyst is an organometallic compound containing two ligands linked to each other by a bridge group. The transition metal catalyst can be any one or more selected from the group consisting of the following Chemical Formula 1 and the following Chemical Formula 2.

[0063] [Chemical Formula]

[0064] [Chemical Formula]

[0065] In each of Chemical Formula 1 and Chemical Formula 2, M is titanium, zirconium, or hafnium, B is an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, a dialkyl silicone group having 1 to 20 carbon atoms, a dialkyl germanium group having 1 to 20 carbon atoms, an alkyl phosphine group having 1 to 20 carbon atoms, or an alkyl amine group having 1 to 20 carbon atoms, X1 and X2 are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, an arylalkyl group having 7 to 40 carbon atoms, an alkylamide group having 1 to 20 carbon atoms, an arylamide group having 6 to 20 carbon atoms, an alkylidene group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms, R1 to R7 can each independently be hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, a cycloalkyl group having 5 to 60 carbon atoms, a heterocyclic group having 4 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, a heteroaryl group having 6 to 20 carbon atoms, or a silyl group having 6 to 20 carbon atoms.

[0066] [Co-catalyst]

[0067] The cocatalyst can include an activator compound, a co-activator compound, or a mixture thereof.

[0068] The activator compound forms an ionic compound by reacting with the transition metal catalyst and can include a boron compound. The boron compound can be any one or more selected from the group consisting of triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylcyclohexylammonium tetrakis(pentafluorophenyl)borate, N,N-dimethylbenzylammonium tetrakis(pentafluorophenyl)borate, and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate.

[0069] The mixing ratio (molar ratio) of the transition metal catalyst to the activator compound can be in the range of 10:1 to 1:100, for example, 2:1 to 1:10. When the mixing ratio of the activator compound to the transition metal catalyst is less than the above-described range, the activation of the transition metal catalyst is not complete, so that the control of the polymerization reaction may become difficult. On the other hand, when the mixing ratio of the activator compound to the transition metal catalyst exceeds the above-described range, the unactivated compound may cause side reactions, so that the control of the polymerization reaction may become difficult.

[0070] The auxiliary activator compound plays a role in assisting the activation of the catalyst and can include an organoaluminum compound. The organoaluminum compound can be any one or more selected from the group consisting of alkylaluminums such as dimethylaluminum, dimethylethylaluminum, trimethylaluminum, triethylaluminum, tributylaluminum, trihexylaluminum, trioctylaluminum, triisopropylaluminum, and triisobutylaluminum; alkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, dimethylaluminum fluoride, and ethylaluminum sesquichloride; dialkylaluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride, methylaluminoxane, and modified methylaluminoxane.

[0071] The mixing ratio (molar ratio) of the transition metal catalyst to the auxiliary activator compound can be in the range of 1:1 to 1:10,000, for example, 1:5 to 1:1,000. When the mixing ratio of the auxiliary activator compound to the transition metal catalyst is less than the above-mentioned range, since the amount of the auxiliary activator compound is small, there is a possibility that the alkylation of the catalyst compound may not be completely carried out. On the other hand, when the mixing ratio of the auxiliary activator compound to the transition metal catalyst exceeds the above-mentioned range, there is a possibility that the activation may not be completely carried out due to side reactions between the compounds.

[0072] Since the alpha-olefin monomer used in the present invention is sensitive to moisture, it is important to control the moisture contained for reasons such as catalyst poisons. In the polymerization reaction, in order to reduce the influence of moisture, it is preferable to use the auxiliary activator compound as a scavenger. The usage ratio (molar ratio) of the moisture to the auxiliary activator compound is in the range of 1:1 to 1:1,000, for example, 1:1 to 1:100. When the ratio of the auxiliary activator compound to moisture is less than the above-mentioned range, the role as a scavenger cannot be surely performed, so the polymerization activity of the catalyst activated by moisture may decrease. On the other hand, when the ratio of the auxiliary activator compound to moisture exceeds the above-mentioned range, it becomes more than the content required for scavenging or alkylation of the catalyst compound, and side reactions may occur or the polymerization reaction may be inhibited.

[0073] For the feed stream for forming the ethylene / alpha-olefin copolymer, 0.001 mol% to 1 mol%, for example, 0.001 mol% to 0.1 mol% of the catalyst can be used. When the content of the catalyst is less than the above-mentioned range, the polymerization reaction may not be sufficiently carried out. When the content of the catalyst exceeds the above-mentioned range, quality degradation such as discoloration due to an excess of the catalyst, difficulty in post-treatment, polymerization reaction control, and problems in the reactor may occur.

[0074] In the polymerization reaction, the transition metal catalyst can be supplied at 0.001 μmol / min to 0.040 μmol / min, and the cocatalyst can be supplied at 0.01 μmol / min to 0.2 μmol / min. When the supply rate of the transition metal catalyst is less than the above-mentioned range, the amount of catalyst input is very small compared to the monomer input amount, so the polymerization reaction cannot be surely carried out, and products with a higher molecular weight and higher polymers than the target may be produced. When the supply rate of the cocatalyst is less than the above-mentioned range, the activation of the transition metal catalyst is not completely carried out, so the control of the polymerization reaction may become difficult. On the other hand, when the supply rate of the cocatalyst exceeds the above-mentioned range, the unactivated compound may cause side reactions, so the control of the polymerization reaction may become difficult.

Example

[0075] Hereinafter, specific examples of the present invention will be presented. However, each of the following examples is merely for specifically exemplifying or explaining the present invention, and the present invention should not be limited thereby. Also, since the content not described herein can be sufficiently technically analogized by those skilled in this technical field, the description thereof is omitted.

[0076] [Synthesis Example 1: Synthesis of Transition Metal Catalyst A]

[0077] The transition metal catalyst A ([di-phenyl-silandiyl-bis(2-methyl-4-phenylindenyl)]-zirconium dimethyl) of Chemical Formula 1 was synthesized by the method described in Organometallics 1994, 13, 954-963 and J. Mol. Catal. A: chem. 1998, 130, 149-162. The bridged metallocene compound means a bridged metallocene compound obtained only as a racemic compound unless the ratio of the racemic isomer and the meso isomer is indicated.

[0078] [Synthesis Example 2: Synthesis of Transition Metal Catalyst B]

[0079] The transition metal catalyst B (1-(normal-butylcyclopentadienyl)-1-(2,7-di-tert-butylfluorenyl)-1,1-diphenylmethylidene zirconium dimethyl) of Chemical Formula 2 was synthesized by the method described in KR 10-1437509 and J. Mol. Catal. A: chem. 1998, 130, 149-162. The bridged metallocene compound means a bridged metallocene compound obtained only as a racemic compound unless the ratio of the racemic isomer and the meso isomer is indicated.

[0080] [Production Example: Production of Ethylene / alpha-Olefin Copolymer]

[0081] [Production Example 1]

[0082] 1 L of hexane was charged into a 1-L stainless steel autoclave continuous process reactor, and the internal temperature of the reactor was maintained at the polymerization temperature of 90°C. While injecting 2,000 g / hr of hexane, 120 g / hr of 1-octene, and 0.17 g / hr of hydrogen through LMFC and MFC, 0.0034 μmol / min of transition metal catalyst A, 0.014 μmol / min of cocatalyst 1 (dimethylanilinium tetrakis(pentafluorophenyl)borate), and 0.04 mmol / min of cocatalyst 2 (triisobutylaluminum) were simultaneously charged into the reactor to initiate the polymerization reaction. Subsequently, while maintaining the polymerization reaction pressure at 50 bar and the polymerization temperature at 90°C, the polymerization reaction was carried out while maintaining the conditions of 120 g / hr of ethylene and 0.017 g / hr of hydrogen. The polymerization was terminated with Irganox 1076, hexane, and isopropyl alcohol, and the residual solvent and raw materials were removed in a vacuum oven at 150°C for 6 hours or more to produce the ethylene / alpha-olefin copolymer of Production Example 1.

[0083] [Production of Production Examples 2 to 14]

[0084] The ethylene / alpha-olefin copolymers of each production example were produced in the same manner as in Production Example 1, except that the conditions shown in Table 1 below were followed.

[0085] [Table 1]

[0086] [Physical Property Measurement]

[0087] The physical properties of the ethylene / alpha-olefin copolymers of each production example and the ethylene / alpha-olefin copolymers of each comparative example were measured by the following method, and the results are shown in Tables 2 and 3 below. The ethylene / alpha-olefin copolymer of Comparative Example 1 is Affinity 1900 of DOW, and the ethylene / alpha-olefin copolymer of Comparative Example 2 is Affinity 1950 of DOW.

[0088] [Number-average molecular weight, weight-average molecular weight]

[0089] Measurement was carried out by the following method using Gel Permeation Chromatography-RI (GPC-RI; Polymer Laboratory Inc. 220 System) equipped with a Refractive Index Detector (RI Detector). Two Olexis and one Guard were used as separation columns, and the column temperature was maintained at 160 °C. Calibration was performed using a standard polystyrene set from Polymer Laboratory Inc. Trichlorobenzene containing 0.0125 wt% antioxidant (BHT) was used as the eluent. The sample concentration was 1.0 mg / ml, and measurement was carried out for 27 minutes under the conditions of an injection volume of 0.2 ml and a pump flow rate of 1.0 ml / min. After performing Universal Calibration using Easical A and Easical B (manufactured by Agilent), which are polystyrene standards, the number-average molecular weight (Mn) and weight-average molecular weight (Mw) were calculated by conversion to polyethylene.

[0090] [Viscosity]

[0091] Measurement was carried out as follows using a BROOKFIELD DV2T Viscometer. 10 g of the ethylene / alpha-olefin copolymer of each production example and comparative example was heated at 190 °C using a Thermo-cell, and after waiting until the sample completely melted, the viscometer device was lowered and the spindle (No. 27) was fixed. The rotational speed of the spindle (No. 27) was fixed at 0.5 rpm, and after confirming that the value was stabilized, the final value was recorded.

[0092] [Crystallization temperature (Tc), melting temperature (Tm), glass transition temperature (Tg)]

[0093] Using a differential scanning calorimeter (DSC, TA's Q2000), measurements were taken as follows. The temperature of the ethylene / alpha-olefin copolymer of each production example and comparative example was lowered to -80 °C and maintained for 1 minute. It was adjusted again to 40 °C / min, heated to 200 °C, maintained for 2 minutes, adjusted to 5 °C / min, the temperature was lowered to -80 °C and maintained for 2 minutes. Finally, it was adjusted to 10 °C / min and the temperature was raised to 200 °C. The measurement results confirmed by interval were defined as the crystallization temperature, melting temperature, and glass transition temperature.

[0094] [Sequence]

[0095] Using an Avance III 500 MHz, Bruker Biospin nuclear magnetic resonance apparatus, measurements were taken as follows. A sample tube was filled with a tetrachloroethane-d4 (Acros, 99.8 atom% D) solvent and 10 wt% of the ethylene / alpha-olefin copolymer of each production example and comparative example. Under the conditions of a pulse width of 45 μs, a pulse repetition time of 10 seconds, and 110 °C of the nuclear magnetic resonance apparatus 13 a 13C-NMR spectral spectrum was obtained to measure the contents of ethylene and alpha-olefin in the copolymer. Using the obtained 13 13C-NMR spectral spectrum, based on the calculation formulas in the literatures of J. Macromol. Sci. Part C: Polym. Rev. 1989, 29, 201 - 317, J. Polym. Sci. Part A: Polym. Chem. 1994, 32, 2979 - 2987, and RSC Adv. 2017, 7, 10175 - 10182, the triad fractions [EEE], [EEO + OEE], [EOE], [EOO + OOE], [OEO], [OOO], the dyad fractions [EE], [EO], [OO], and the number of moles of ethylene (C E ) and the number of moles of alpha-olefin (C O ) were derived.

[0096] [Kraft and BOPP Adhesion]

[0097] The ethylene / alpha-olefin copolymers of each production example and comparative example were melted at 180°C for 3 minutes. After preparing two Kraft films (14.8 cm wide and 10.5 cm long) each, they were coated on one side with five lines each at a thickness of 3.0 mm and a length of 2.0 cm. The remaining side was covered, and using a Heat Gradient Tester (Toyoseiki) equipment, it was pressed at a pressure of 2.8 kgf / cm² for an average of 5 seconds or until it melted. It was cut to a thickness of 1.0 cm wide, aged for 24 hours under constant temperature and humidity conditions, and then using a multi-axis fine adhesion measuring machine (YEONJIN S-Tech, TXA Multi-axis Precise Adhesion Testing Equipment), the Kraft adhesive strength was measured under the conditions of a width of 10.0 mm, a speed of 0.8334 mm / s, a test time of 70 seconds, and temperatures (room temperature, -20°C).

[0098] The BOPP (Bi-axially Oriented Polypropylene) adhesive strength was measured in the same manner as the Kraft adhesive strength measurement, except that a BOPP film (15.0 cm wide and 11.0 cm long) was used.

[0099]

Table 2

[0100]

Table 3

[0101] As shown in Tables 2 and 3 above, the ethylene / alpha-olefin copolymers of Production Examples 1-14 having ERI according to the present invention exhibited excellent adhesion at room temperature and low temperature. On the other hand, as a result of comparing the physical properties of ethylene / alpha-olefin copolymers within a similar viscosity range, the ethylene / alpha-olefin copolymer of Comparative Example 1 deviating from the ERI range according to the present invention showed inferior adhesion compared to the ethylene / alpha-olefin copolymers of Production Examples 1-5 according to the present invention, and the ethylene / alpha-olefin copolymer of Comparative Example 2 deviating from the ERI range according to the present invention showed inferior adhesion compared to the ethylene / alpha-olefin copolymers of Production Examples 6-14 according to the present invention.

Claims

1. An ethylene / alpha-olefin copolymer satisfying an ERI (Ethylene-unit Repeatness Index) value defined by the following Mathematical Formula 1 of 1.20 or less: 【Number 1】 In the Mathematical Formula 1, [EE] (ethylene-ethylene), [EO] (ethylene-alpha olefin) and [OO] (alpha olefin-alpha olefin) are １３ the dyad fractions of ethylene and alpha olefin copolymers measured by C-NMR C Ｅ / C Ｏ is the ratio of the number of moles of ethylene (C Ｏ ) to the number of moles of alpha-olefin in the liquid phase (C Ｅ ).

2. The ratio (C Ｅ / C Ｏ ) of the number of moles of ethylene to the number of moles of the alpha-olefin is from 6.0 to 11.

0. The ethylene / alpha-olefin copolymer according to claim 1.

3. The ethylene / alpha-olefin copolymer according to Claim 1, wherein [EE] is 0.75 to 0.85, [EO] is 0.15 to 0.25, and [OO] is 0.001 to 0.

05.

4. The ethylene / alpha-olefin copolymer according to Claim 1, wherein the alpha-olefin is any one or more selected from the group consisting of 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, and 1-octene.

5. The ethylene / alpha-olefin copolymer according to Claim 1, wherein the molecular weight distribution (Mw / Mn, PDI) of the ethylene / alpha-olefin copolymer is 1.97 to 2.

5.

6. The ethylene / alpha-olefin copolymer according to Claim 1, wherein the number average molecular weight (Mn) of the ethylene / alpha-olefin copolymer is 10,000 g / mol to 25,000 g / mol, and the weight average molecular weight (Mw) is 25,000 g / mol to 50,000 g / mol.

7. The ethylene / alpha-olefin copolymer according to Claim 1, wherein the Brookfield viscosity of the ethylene / alpha-olefin copolymer at 190°C is 4,000 cps to 15,000 cps.

8. The melting temperature (T ｍ ) of the ethylene / alpha-olefin copolymer is from 50°C to 90°C, the crystallization temperature (T ｃ ) is from 45°C to 80°C, and the glass transition temperature (T ｇ ) is from -70°C to -40°C. The ethylene / alpha-olefin copolymer according to claim 1.

9. A step of subjecting a feed stream supplied in the presence of a catalyst containing one or more of a transition metal catalyst and a cocatalyst to a polymerization reaction to produce a reaction product; and A step of obtaining an ethylene / alpha-olefin copolymer from the reaction product, including A method for producing an ethylene / alpha-olefin copolymer, wherein the ethylene / alpha-olefin copolymer satisfies an ERI (Ethylene-unit Repeatness Index) value defined by the following Mathematical Formula 1 of 1.20 or less: 【Number 2】 In the Mathematical Formula 1, [EE] (ethylene-ethylene), [EO] (ethylene-alpha olefin) and [OO] (alpha olefin-alpha olefin) are １３ the binary fraction of ethylene and alpha olefin copolymer measured by C-NMR, C Ｅ / C Ｏ is the ratio of the number of moles of ethylene (C Ｏ ) to the number of moles of alpha-olefin in the liquid phase (C Ｅ ).

10. The feed stream contains a monomer and a comonomer, The monomer contains ethylene, The method for producing an ethylene / alpha-olefin copolymer according to Claim 9, wherein the comonomer contains any one or more selected from the group consisting of 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, and 1-octene.

11. In the polymerization reaction, the monomer is supplied at 50 g / hr to 350 g / hr, the comonomer is supplied at 50 g / hr to 250 g / hr, The method for producing an ethylene / alpha-olefin copolymer according to claim 10, wherein the flow rate ratio of the monomer to the flow rate of the comonomer is 0.1 to 2.

12. In the polymerization reaction, hydrogen is supplied at 0.01 g / hr to 0.3 g / hr. The method for producing an ethylene / alpha-olefin copolymer according to claim 9.

13. The polymerization reaction is carried out under the conditions of a temperature of 70°C to 140°C and a pressure of 30 bar to 100 bar. The method for producing an ethylene / alpha-olefin copolymer according to claim 9.

14. The transition metal catalyst is any one or more selected from the group consisting of Chemical Formula 1 and Chemical Formula 2. The method for producing an ethylene / alpha-olefin copolymer according to claim 9: 【Chemical 1】 [Chemical Formula 2] In each of Chemical Formula 1 and Chemical Formula 2, M is titanium, zirconium, or hafnium, B is an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, a dialkyl silicone group having 1 to 20 carbon atoms, a dialkyl germanium group having 1 to 20 carbon atoms, an alkyl phosphine group having 1 to 20 carbon atoms, or an alkyl amine group having 1 to 20 carbon atoms, X １ and X ２ each independently represents a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, an arylalkyl group having 7 to 40 carbon atoms, an alkylamide group having 1 to 20 carbon atoms, an arylamide group having 6 to 20 carbon atoms, an alkylidene group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, R １ to R ７ is each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, a cycloalkyl group having 5 to 60 carbon atoms, a heterocyclic group having 4 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, a heteroaryl group having 6 to 20 carbon atoms or a silyl group having 6 to 20 carbon atoms.

15. The cocatalyst includes an activator compound containing a boron compound and a co-activator compound containing an organoaluminum compound. The method for producing an ethylene / alpha-olefin copolymer according to claim 9.

16. The boron compound is any one or more selected from the group consisting of triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylcyclohexylammonium tetrakis(pentafluorophenyl)borate, N,N-dimethylbenzylammonium tetrakis(pentafluorophenyl)borate, and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate. The organoaluminum compound is any one or more selected from the group consisting of alkylaluminums such as dimethylaluminum, dimethylethylaluminum, trimethylaluminum, triethylaluminum, tributylaluminum, trihexylaluminum, trioctylaluminum, triisopropylaluminum, and triisobutylaluminum; alkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, dimethylaluminum fluoride, and ethylaluminum sesquichloride; dialkylaluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride; methylaluminoxane; and modified methylaluminoxane. The method for producing an ethylene / alpha-olefin copolymer according to claim 15.

17. In the polymerization reaction, the transition metal catalyst is supplied at 0.001 μmol / min to 0.040 μmol / min, and the cocatalyst is supplied at 0.01 μmol / min to 0.2 μmol / min. The method for producing an ethylene / alpha-olefin copolymer according to claim 9.

18. An ethylene / alpha-olefin copolymer produced by the method for producing an ethylene / alpha-olefin copolymer according to any one of claims 9 to 17.

19. A composition for a hot melt adhesive comprising an ethylene / alpha-olefin copolymer according to any one of claims 1 to 8.

20. A composition for a hot melt adhesive comprising an ethylene / alpha-olefin copolymer according to claim 18.

Images