JP7100628B2 - Multilayer stretched film with high adhesive strength and its method - Google Patents

Description

The embodiments of the present disclosure generally relate to a multilayer stretched film, and more specifically to a multilayer stretched film having high adhesive strength.

Multilayer films are often used for packaging and can wrap a variety of items, from large amounts of farm materials such as grass and hay to items in small grocery stores such as meat and vegetables. For all of these items, the film is generally sturdy and stretchable, with a sufficient level of tack or stickiness so that the film can be detachably adhered to the film itself and / or the article wrapped in the film. It is desirable to have a film.

Adhesiveness is one of the important performance requirements of stretched films. Additives can be incorporated into the adhesive layer to improve the tack of the adhesive layer in order to achieve the desired level of adhesiveness. However, films containing such additives can be costly compared to the base resin and can have a significant impact on the overall cost of the stretched film. In addition, films containing such additives are 1) overly noisy when unraveling from film rolls when used on high speed packaging machines, 2) additives move to the surface of the film during the aging period. One that needs to be aged for a certain period of time (ie, blooms), 3) contaminates the processing equipment, and 4) causes sticking on both sides when one-sided sticking is desired. It may have the above drawbacks. Moreover, such additives can cause excessive handling problems when the additive is in liquid form and excessively drips from the processing apparatus.

Multilayer films can also incorporate high levels of ethylene / alpha-olefin elastomers to achieve higher levels of tack or tackiness, but ethylene / alpha-olefin elastomers can make multilayer films very expensive.

Therefore, it is desirable that the alternative multilayer film has improved properties such as high adhesiveness, while being cost-effective and / or relatively easy to make using cast film technology. Can be done.

In the embodiments of the present specification, the multilayer cast film is disclosed. The multilayer cast film has an adhesive layer, a core layer, and a release layer, and the adhesive layer contains a unit derived from at least 60% by weight of propylene and a unit derived from 1 to 40% by weight of ethylene. Including the polymer, the propylene interpolymer has a density of 0.840 g / cm ³ to 0.900 g / cm ³ , a maximum DSC melting peak temperature of 50.0 ° C to 120.0 ° C, 230 ° C and 2.16 kg according to ASM D1238. It has a melt flow rate of MFR2 of 1-100 g / 10 min when measured under load, as well as a molecular weight distribution (MWD) of less than 4.0, with a core layer of ethylene and optionally one or more alpha olefin comonomer. The core layer polyethylene composition containing the reaction product of (a) 2.5 to 12.0 g / 10 minutes melt index I2, (b) 0.910 to One of a density of 0.925 g / cc, (c) a melt flow ratio of 6.0 to 7.6, I10 / I2, and (d) a molecular weight distribution of 2.25 to 4.0 (Mw / Mn). It features one or more.

Also disclosed are methods of making multilayer films in embodiments herein. The method comprises co-extruding the pressure-sensitive adhesive layer composition, the core layer composition, and the release layer composition to form a multilayer cast film, wherein the pressure-sensitive adhesive layer composition is derived from at least 60% by weight of propylene. It contains a propylene interpolymer containing units derived from 1-40% by weight of ethylene, and the propylene interpolymer has a density of 0.840 g / cm ³ to 0.900 g / cm ³ and a density of 50.0 ° C to 120.0 ° C. Highest DSC melting peak temperature of 1-100 g / 10 min melt flow rate MFR2 when measured at 230 ° C. and 2.16 kg load according to ASTM D1238, and a core with a molecular weight distribution of less than 4.0 (MWD). The layer composition comprises a core layer polyethylene composition containing a reaction product of ethylene and optionally one or more alpha olefin comonomers, and the core layer polyethylene composition has the following properties: (a) 2.5 to 1.2.0 g / 10 min melt index I2, (b) density of 0.910 to 0.925 g / cc, (c) melt flow ratio I10 / I2 of 6.0 to 7.6, and (d) 2. Characterized by one or more of a molecular weight distribution (Mw / Mn) of 25-4.0, the release layer composition comprises a direct product containing a reaction product of ethylene and optionally one or more alpha olefin comonomers. The release layer polyethylene composition contains the chain low density polyethylene or the release layer polyethylene composition, and the release layer polyethylene composition has the following characteristics: (a) 2.5 to 12.0 g / 10 minutes melt index I2, (b) 0.910 to One of a density of 0.925 g / cc, (c) a melt flow ratio of 6.0 to 7.6, I10 / I2, and (d) a molecular weight distribution of 2.25 to 4.0 (Mw / Mn). Characterized by one or more.

Additional features and advantages of embodiments are described in embodiments for carrying out the invention below, some of which are readily apparent to those of skill in the art from the description, or embodiments for carrying out the invention below. Recognized by practicing the embodiments described herein, including the scope of the claims. It should be understood that both the above and the following description are intended to illustrate the various embodiments and provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. This description serves to explain the principles and behavior of the claimed subject matter.

Embodiments of multilayer cast films and materials used to make such films will be described in detail. "Multilayer cast film" and "multilayer film" may be used interchangeably herein to refer to the multilayer cast film described herein. Multilayer cast films can be used in stretched adhesive applications. However, it should be noted that this is only an exemplary practice of the embodiments disclosed herein. The embodiments are also applicable to other techniques that are susceptible to problems similar to those described above. For example, the multilayer cast films described herein can be used as surface protective films, agricultural films such as silage wraps, or shrink films, durable transport bags, liners, bags, stand-up pouches, detergent pouches, sachets, etc. It can be used in other flexible packaging applications, all of which are within the scope of this embodiment.

In the embodiments described herein, the multilayer cast film comprises an adhesive layer, a core layer, and a release layer. Optionally, one or more intermediate layers may be located between the adhesive layer and the core layer and / or between the core layer and the delamination layer. The adhesive layer is an outer layer of the multilayer cast film having sufficient adhesive tack such that the adhesive layer of the multilayer cast film can form a peelable bond when it comes into contact with a surface such as the surface of an article or the surface of a release layer. be. The release layer is an outer layer of a multilayer cast film that exhibits low adhesiveness to the adhesive layer. The release layer allows the interface between the adhesive layer / release layer on the roll to separate so that the multilayer cast film can be unwound from the spool without applying excessive force or tearing the film. do.

The thickness of the adhesive layer, the core layer, and the release layer can vary over a wide range. In some embodiments, the adhesive layer has a thickness that is 5 to 50 percent of the total thickness of the film, 5 to 30 percent of the total thickness of the film, or even 5 to 20 percent of the total thickness of the film. obtain. The core layer has a thickness that is 20 to 90 percent of the total thickness of the film, 30 to 90 percent of the total thickness of the film, 50 to 90 percent of the total thickness of the film, or 60 to 90 percent of the total thickness of the film. Can be. The release layer can have a thickness of 5 to 50 percent of the total thickness of the film, 5 to 30 percent of the total thickness of the film, or even 5 to 20 percent of the total thickness of the film. The thickness ratio between the adhesive layer, the peeling layer, and the core layer can be any ratio that provides the desired properties such as adhesiveness, peelability, and the like. In some embodiments, the multilayer cast film may have an adhesive layer thickness, a core layer thickness, and a release layer thickness in a ratio of 1: 8: 1 to 3: 4: 3.

Adhesive layer The adhesive layer may contain a propylene interpolymer. As used herein, "polymer" means a polymer compound prepared by polymerizing a monomer, whether of the same or different type. The general term "interpolymer" includes "homomopolymer", "copolymer", "terpolymer", as well as "interpolymer". "Interpolymer" refers to a polymer prepared by the polymerization of at least two different types of monomers. The general term "interpolymer" includes the term "copolymer" (usually used to refer to a polymer prepared from two different monomers) and the term "terpolymer" (usually three different types). (Used to refer to polymers prepared from the monomers of). It also includes polymers made by polymerizing four or more types of monomers.

Propylene interpolymer generally refers to polymers containing propylene and α-olefins having two or more carbon atoms. In embodiments herein, the propylene interpolymer comprises at least 60% by weight of propylene-derived units and 1-40% by weight of ethylene-derived units (based on the total amount of polymerizable monomers). All individual values and partial ranges of units derived from at least 60% by weight propylene and units derived from 1-40% by weight ethylene are included and disclosed herein. For example, in some embodiments, the propylene interpolymer is (a) at least 65% by weight, at least 70% by weight, at least 75% by weight, at least 80% by weight, at least 82% by weight, at least 85% by weight, at least 87% by weight. %, At least 90% by weight, at least 92% by weight, at least 95% by weight, at least 97% by weight, 60 to 99% by weight, 60 to 99% by weight, 65 to 99% by weight, 70 to 99% by weight, 75 to 99% by weight. %, 80-99% by weight, 82-99% by weight, 84-99% by weight, 85-99% by weight, 88-99% by weight, 80-97% by weight, 82-97% by weight, 85-97% by weight, Derived from 88-95.5% by weight, 80-95.5% by weight, 82-95.5% by weight, 84-95.5% by weight, 85-95.5% by weight, or 88-95.5% by weight of propylene Units to be used, and (b) 1-40% by weight, for example 1-35% by weight, 1-30% by weight, 1-25% by weight, 1-20% by weight, 1-18% by weight%, 1-16% by weight. 1 to 15%, 1 to 12%, 3 to 20%, 3 to 18%, 3 to 16%, 3 to 15%, 3 to 12%, 4.5 to 20%, 4.5 to 18%, Includes units derived from 4.5-16%, 4.5-15% by weight, or 4.5-12% by weight of ethylene. The comonomer content is described in US Pat. No. 7,498,282, which is incorporated herein by reference, using any suitable technique, such as techniques based on nuclear magnetic resonance (“NMR”) spectroscopy. It can be measured by such 13C NMR analysis.

Propylene interpolymers can be made by any process and include random copolymers, block copolymers, and graft copolymers. In some embodiments, the propylene interpolymer has a random composition. These include Ziegler-Natta, CGC (constrained geometric catalysts), metallocenes, and interpolymers made with non-metallocene, metal-centered heteroaryl ligand catalysts. Additional suitable metal complexes include compounds corresponding to the following formulas, including

R ²⁰ is an aromatic or inert substituted aromatic group containing 5 to 20 atoms free of hydrogen, or a polyvalent derivative thereof.
T ³ is a hydrocarbylene or silane group having 1 to 20 atoms free of hydrogen, or an inert substituted derivative thereof.
M ³ is a Group 4 metal, preferably zirconium or hafnium.
G is an anionic, neutral or dianionic coordinating group, preferably a halide, hydrocarbyl, or dihydrocarbylamide group having up to 20 hydrogen-free atoms.
g is a number from 1 to 5 indicating the number of such G groups.
Covalent and electron donating interactions are represented by lines and arrows, respectively.

In some embodiments, such complexes correspond to the following equations,

T ³ is a hydrogen-free, divalent cross-linking group of 2 to 20 atoms, preferably a substituted or unsubstituted C _3-6 alkylene group.
Ar ² is an arylene or alkyl or aryl substituted arylene group of 6 to 20 atoms, each independently containing no hydrogen.
M ³ is a Group 4 metal, preferably hafnium or zirconium,
G is an independent, neutral or dianionic coordinating group, respectively.
g is a number from 1 to 5 indicating the number of such X groups.
Electron-donating interactions are represented by arrows.

Examples of the metal complex of the above formula include the following compounds.

In the formula, M ³ is Hf or Zr and
Ar ⁴ is C _6-20aryl or its Inactive Substituted Derivatives, in particular 3,5-di (isopropyl) phenyl, carbazole, 3,5-di (isobutyl) phenyl, dibenzo-1H-pyrrole-1-yl, or. Anthracene-5-Il,
Each T ^{4 independently contains} a C _3-6 alkylene group, a C _3-6 cycloalkylene group, or an inert substituted derivative thereof.
R ²¹ is independently hydrogen, halo, hydrocarbyl, trihydrocarbylsilyl, or trihydrocarbylsilylhydrocarbyl of 50 or less atoms without hydrogen.
G is independently the hydrocarbyl or trihydrocarbylsilyl group of 20 or less atoms, each existence free of halo or hydrogen, or the hydrocarbyl or the above hydrocarbyl or the combination of two G groups. It is a divalent derivative of the trihydrocarbylsilyl group.

Without limiting the scope of the present invention, one means for producing the propylene interpolymer described herein is as follows. The monomer to be polymerized is continuously introduced into the stirring tank reactor with any solvent or diluent, and in some embodiments the solvent is an alkane hydrocarbon solvent such as ISPAR ™ E. The reactor comprises a liquid phase consisting substantially of the monomer and any solvent or diluent and dissolved polymer. The catalyst, along with the co-catalyst and optionally the chain transfer agent, is introduced continuously or intermittently into the reactor liquid phase or any reused portion thereof. The temperature of the reactor can be controlled by adjusting the solvent / monomer ratio, the rate of catalyst addition, and by using cooling and / or heating coils, jackets, or both. The polymerization rate is controlled by the catalyst addition rate. The pressure is controlled by the flow rate of the monomer and the partial pressure of the volatile components. The propylene content in the polymer product is determined by the ratio of propylene to comonomer in the reactor, which is controlled by manipulating the rate of supply of each of these components to the reactor. The molecular weight of the polymer product is optionally controlled by controlling other polymerization variables such as temperature, monomer concentration, or the flow rate of the chain transfer agent described above. After leaving the reactor, the effluent is contacted with a catalytic terminator such as water, steam, or alcohol. The polymer solution is optionally heated and the polymer product evaporates the unreacted gaseous monomer and residual solvent or diluent under reduced pressure for further volatilization in equipment such as a devolatilization extruder as needed. Recovered by running. In a continuous process, the average residence time of the catalyst and polymer in the reactor is generally 5 minutes to 8 hours, and in some embodiments 10 minutes to 6 hours.

While not limiting the scope of the invention in any way, alternative means for producing the propylene interpolymer as described herein are: Continuous solution polymerization may be performed in a computer controlled autoclave reactor equipped with an internal stirrer. Purified and mixed alkane solvents (ISOPAR ™ E available from the ExxonMobile Chemical Company), ethylene, propylene, and hydrogen are continuously fed into a 3.8 L reactor with a temperature control jacket and an internal thermocouple. May be. The amount of solvent supplied to the reactor may be measured by a mass flow controller. A variable speed diaphragm pump controls the flow rate of the solvent and the pressure on the reactor. At the time of pump discharge, side currents are taken to supply the flush flow to the catalyst and co-catalyst injection lines as well as the reactor agitator. These flow rates can be measured by a mass flow meter and controlled by a control valve or by manual adjustment of the needle valve. The remaining solvent is mixed with the monomer and hydrogen and supplied to the reactor. Hydrogen is supplied to the reactor using a mass flow controller as needed. The temperature of the solvent / monomer solution is controlled by using a heat exchanger before entering the reactor. This stream enters the bottom of the reactor.

A solution of the catalyst and co-catalyst components may be weighed using a pump and mass flow meter, combined with a catalytic flash solvent and introduced into the bottom of the reactor. The catalyst may be a metal complex as described above. In some embodiments, the catalyst is bis ((2-oxoyl-3- (dibenzo-1H-pyrrole-1-yl) -5- (methyl) phenyl) -2-phenoxymethyl) as outlined above. ) -Methylenetrans-1,2-cyclohexanediylhafnium (IV) dimethyl may be used. The cocatalyst used was methyldi (octadecyl) ammonium tetrakis in combination with the tertiary component tri (isobutyl) aluminum-modified metaalmoxane (MMAO), which contained a molar ratio of about 1/3 i-butyl / methyl group. It may be a long-chain alkylammonium borate of near stoichiometry, equal to (pentafluorophenyl) borate (MDB). The catalyst / co-catalyst may have a molar ratio based on Hf of 1.0 / 1 to 1.5 / 1 and MMAO (ratio of 25/1 to 35/1, Al / Hf). The reactor may be driven to full liquid at 500 to 525 psig (3.45 to 3.62 MPa) with vigorous stirring. The reactor temperature may be in the range of 125 ° C to 165 ° C and the propylene conversion may be about 80%. The reactor is operated at a polymer concentration of about 15-20 wt%. Propylene conversion in the reactor may be maintained by controlling the catalyst injection rate. The reaction temperature may be maintained by controlling the water temperature over the shell side of the heat exchanger. The polymer molecular weight may be maintained by controlling the hydrogen flow.

The product is removed through the outlet line at the top of the reactor. All outlet lines from the reactor are steam traced and insulated. Polymerization may be stopped by adding a small amount of water to the outlet line with any stabilizer or other additive and passing the mixture through a static mixer. The product stream may then be heated by passing through a heat exchanger prior to volatilization. The polymer product may be recovered by extrusion using a volatile removal extruder and a water-cooled pelletizer.

Exemplary propylene interpolymers include VISTAMAXX® polymers from the ExxonMobile Chemical Company and VERSIFY® polymers from The Dow Chemical Company.

In embodiments herein, the propylene interpolymer has a density of 0.840 g / cm ³ to 0.900 g / cm ³ as measured by ASTM D-792. All individual values and subranges of 0.840 g / cm ³ to 0.900 g / cm ³ are included and disclosed herein. For example, in some embodiments, the propylene interpolymer is 0.850 g / cm ³ to 0.890 g / cm ³ , 0.850 g / cm ³ to 0.880 g / cm ³ , or 0.850 g / cm ³ to. It has a density of 0.870 g / cm ³ .

In embodiments herein, the propylene interpolymer has a differential scanning calorimetry (“DSC”) melting peak temperature of 50.0 ° C to 120.0 ° C. All individual values and subranges from 50.0 ° C to 120.0 ° C are included and disclosed herein. For example, in some embodiments, the propylene interpolymer is 50.0 ° C to 115.0 ° C, 50.0 ° C to 110.0 ° C, 50.0 ° C to 100.0 ° C, or 50.0 ° C to. It has a maximum DSC melting peak temperature of 105.0 ° C.

In addition to density and DSC melting peak temperature, the propylene interpolymer has a melt flow rate of 1-100 g / 10 min as measured according to ASTM D-1238 (2.16 kg, 230 ° C.). All individual values and subranges from 1 to 100 g / 10 min are included and disclosed herein. For example, in some embodiments, the propylene interpolymer has a melt flow rate of 1-50 g / 10 min, or 1-30 g / 10 min.

In addition to density, maximum DSC melting peak temperature, and melt flow rate, the propylene interpolymer further has a molecular weight distribution (MWD) of less than 4.0. The molecular weight distribution (MWD) is a ratio of weight average molecular weight logarithmic mean molecular weight (Mw / Mn). The molecular weight may be determined by gel permeation chromatography. All individual values and subranges less than 4.0 are included and disclosed herein. For example, in some embodiments, the propylene interpolymer is 2.0-4.0, 2.0-3.7, 2.0-3.5, 2.0-3.2, 2.0-. It has a molecular weight distribution of 3.0 or 2.0 to 2.8.

In addition to density, DSC melting peak temperature, melt flow rate, and MWD, the propylene interpolymer may have a weight average molecular weight (Mw) of at least 50,000 g / mol. All individual values and subranges of at least 50,000 g / mol are included and disclosed herein. For example, in some embodiments, the propylene interpolymer is 50,000 to 1,000,000 g / mol, 50,000 to 500,000 g / mol, 50,000 to 400,000 g / mol, or 50,000. It may have a weight average molecular weight (Mw) of ~ 300,000 g / mol.

In addition to density, maximum DSC melting peak temperature, melt flow rate, MWD, and weight average molecular weight, the propylene interpolymer has a DSC-determined percentage of crystallinity in the range of 0.5% to 45%. May be good. All individual values and subranges from 0.5% to 45% are included and disclosed herein. For example, in some embodiments, the propylene interpolymer may have a percent crystallinity determined by DSC in the range of 2% to 42%.

In embodiments herein, the pressure-sensitive adhesive layer comprises 3% to 30% by weight of propylene interpolymer. All individual values and subranges of 3% to 30% by weight are included and disclosed herein. For example, in some embodiments, the pressure-sensitive adhesive layer comprises 3% by weight to 25% by weight, or 3% by weight to 20% by weight, or 3% by weight to 15% by weight, by weight of the pressure-sensitive adhesive layer of the propylene interpolymer. ..

Optionally, the pressure-sensitive adhesive layer can include one or more additives such as pigments, inorganic fillers, UV stabilizers, antioxidants and / or additional polymers. For example, in some embodiments, the adhesive layer is dry-blended or melt-blended in 70% to 95% by weight or 85% to 95% by weight of the linear low density polyethylene or adhesive layer polyethylene composition. Adhesive layer blends can be formed. The adhesive layer polyethylene composition contains a reaction product of ethylene and optionally one or more alpha olefin comonomer, and the adhesive layer polyethylene composition has the following characteristics: (a) 2.5 to 12.0 g / 10 Minutes or melt index I2 of 2.5 to 8.0, (b) density of 0.910 to 0.925 g / cc or 0.912 to 0.920 g / cc, (c) 6.0 to 7.6 or It is characterized by one or more of a melt flow ratio of 6.4 to 7.4, I10 / I2, and (d) a molecular weight distribution of 2.25 to 4.0 or 2.6 to 3.5 (Mw / Mn). And. The linear low density polyethylene may have a density in the range of 0.912 to 0.940 g / cm ³ and a melt index in the range of 0.5 to 30 g / 10 min. The pressure-sensitive polyethylene composition is formed via solution polymerization in the presence of a catalytic composition comprising a multi-element metal procatalyst. In a further embodiment, the pressure-sensitive polyethylene composition may have less than 60% or 40% -60% CDBI. An exemplary LLDPE for use in the release layer of a multilayer film is commercially available from The Dow Chemical Company under the trade names ELITE ™, TUFLIN ™, and DOWLEX ™. A method of dry blending the resin can be found in US Pat. No. 3,318,538 (Needham), the entire patent of which is incorporated herein by reference. A method of melt-blending the resin can be found in US Pat. No. 6,111,019 (Arjunan et al.), The entire patent of which is incorporated herein by reference.

Core Layer The core layer comprises a core layer polyethylene composition comprising a reaction product of ethylene and optionally one or more alpha olefin comonomer. The core polyethylene composition comprises units derived from more than 50% by weight ethylene and less than 30% by weight derived from one or more alpha-olefin comonomer. In some embodiments, the core layer polyethylene composition is (a) 55% or higher, eg 60% or higher, 65% or higher, 70% or higher, 75% or higher, 80% or higher, 85% or higher, 90% or higher, 92% or more, 95% or more, 97% or more, 98% or more, 99% or more, 99.5% or more, 50% to 99%, 50% to 97%, 50% to 94%, 50% or more -90%, 70% -99.5%, 70% -99%, 70% -97%, 70% -94%, 80% -99.5%, 80% -99%, 80% -97%, 80% -94%, 80% -90%, 85% -99.5%, 85% -99%, 85% -97%, 88% -99.9%, 88% -99.7%, 88% -99.5%, 88% -99%, 88% -98%, 88% -97%, 88% -95%, 88% -94%, 90% -99.9%, 90% -99.5 %, 90% -99%, 90% -97%, 90% -95%, 93% -99.9%, 93% -99.5%, 93% -99%, or 93% -97% (weight) ), Derived from ethylene; and (b) optionally, less than 30%, eg less than 25%, or less than 20%, less than 18%, less than 15%, less than 12%, less than 10%, 8%. Less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, 0.1-20%, 0.1-15%, 0.1-12%, 0.1-10%, 0.1-8%, 0.1-5%, 0.1-3%, 0.1-2%, 0.5-12%, 0.5-10%, 0.5-8%, 0 .5-5%, 0.5-3%, 0.5-2.5%, 1-10%, 1-8%, 1-5%, 1-3%, 2-10%, 2-8 % 2-5%, 3.5-12%, 3.5-10%, 3.5-8%, 3.5% -7%, or 4-12%, 4-10%, 4-8 %, Or 4-7% (weight), containing units derived from one or more a-olefin commonomers. The comonomer content is described in US Pat. No. 7,498,282, which is incorporated herein by reference, using any suitable technique, such as techniques based on nuclear magnetic resonance (“NMR”) spectroscopy. It can be measured by such 13C NMR analysis.

Suitable comonomeres may typically include alpha-olefin comonomer with 20 or less carbon atoms. The one or more alpha-olefins may be selected from the group consisting of C3-C20 acetylene unsaturated monomers and C4-C18 diolefins. It will be appreciated by those skilled in the art that the monomer selected is preferably a monomer that does not destroy the conventional Ziegler-Natta catalyst. For example, an alpha-olefin comonomer can have 3-10 carbon atoms or 3-8 carbon atoms. Exemplary alpha-olefin comonomers include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and 4-methyl-1-pentene. However, it is not limited to them. One or more alpha-olefin comonomer can be selected from the group consisting of, for example, propylene, 1-butene, 1-hexene, and 1-octene, or in alternatives 1-butene, 1-hexene, and 1-. It can be selected from the group consisting of octene. In some embodiments, the core layer polyethylene composition comprises units derived from one or more of the octene, hexene, or butenkomonomers in excess of 0% by weight and less than 30% by weight.

In some embodiments, the core layer polyethylene composition of the core layer is formed via solution polymerization in the presence of a catalytic composition comprising a multi-element metal procatalyst. The multi-element metal procatalyst used to produce the reaction product is at least a ternary metal, but may also contain four or more transition metals and is therefore more comprehensively defined as a multi-element metal in one embodiment. obtain. These three or more transition metals are selected prior to the production of the catalyst. In certain embodiments, the multi-element metal catalyst comprises titanium as one element.

Preparation of the catalyst composition may begin with the preparation of a prepared magnesium halide-based carrier. Preparation of the prepared magnesium halide-based carrier begins with the selection of an organic magnesium compound or a complex containing an organic magnesium compound. Such compounds or complexes are preferably soluble in inert hydrocarbon diluents. The concentration of the components is preferably from about 0.005 to about 0.25 mol with respect to magnesium when the magnesium complex is combined with an active halide such as a metal halide or a non-metal halide. The concentration is such that it becomes (mol / liter). Examples of suitable inert organic diluents are liquefied ethane, propane, isobutane, n-butane, n-hexane, various isomer hexanes, isooctanes, alkane paraffin mixtures with 5-10 carbon atoms, cyclohexane. , Methylcyclopentane, dimethylcyclohexane, dodecane, industrial solvents composed of saturated or aromatic hydrocarbons such as kerosene, naphtha, and combinations thereof, especially when free of any olefin compounds and other impurities. Examples thereof include those having a boiling point in the range of 50 ° C. to about 200 ° C. Ethylbenzene, cumene, decalin and combinations thereof are also included as suitable inert diluents.

Suitable organic magnesium compounds and complexes may include, for example, magnesium C2-C8 alkyl and aryl, magnesium alkoxide and aryl oxide, carboxylated magnesium alkoxide, and carboxylated magnesium aryl oxide. Preferred sources of magnesium moieties may include magnesium C2-C8 alkyl and C1-C4 alkoxide. Such organic magnesium compounds or complexes are reacted with metal or non-metal halide sources such as chlorides, bromides, iodides, or fluorides to make magnesium halide compounds under suitable conditions. Can be done. Such conditions may include temperatures in the range of −25 ° C. to 100 ° C., 0 ° C. to 50 ° C. as an alternative; time in the range of 1 to 12 hours, time in the range of 4 to 6 hours as an alternative; or both. .. As a result, a magnesium halide-based carrier is obtained.

Then, under conditions suitable for forming the adjusted magnesium halide carrier, the magnesium halide carrier is selected to contain an element selected from the group consisting of boron, aluminum, gallium, indium and tellurium. React with the compound. The compound and the magnesium halide carrier are then contacted under conditions sufficient to provide a conditioned magnesium halide carrier. Such conditions may include temperatures ranging from 0 ° C to 50 ° C, or 25 ° C to 35 ° C as an alternative; 4 to 24 hours, and / or 6 to 12 hours as an alternative. good. The conditioning compound has a specific molar ratio composition, which is considered to be an important feature in ensuring desirable catalytic performance. Specifically, the procatalyst preferably exhibits a molar ratio of magnesium to adjusted compounds in the range 3: 1 to 6: 1. Although not bound by any theory of mechanism, it is suggested that this aging helps promote or enhance the adsorption of additional metals on the carrier.

Once the prepared carrier has been prepared and properly aged, it is contacted with a titanium compound that can be added individually or as a mixture with a "second metal". In certain preferred embodiments, titanium halide or titanium alkoxide, or a combination thereof, may be selected. Conditions may include temperatures in the range of 0 ° C. to 50 ° C., 25 ° C. to 35 ° C. for alternatives; 3 hours to 24 hours, 6 hours to 12 hours for alternatives; or both. As a result of this step, at least a part of the titanium compound is adsorbed on the prepared magnesium halide carrier.

Finally, one or two additional metals, referred to herein as "second metal" and "third metal" for convenience, will also be adsorbed on the magnesium-based carrier. The "second metal" and "third metal" are zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo). , And tungsten (W) are selected independently. These metals can be incorporated by any of the various methods known to those of skill in the art, but are generally used to form what may be referred to here as a "procatalyst", which is a multi-element metal procatalyst. Contact between the adjusted magnesium halide carrier containing titanium and the selected second and third metals in a liquid phase, such as a suitable hydrocarbon solution, is the deposition of additional metal. Would be suitable for ensuring.

Multi-metal procatalysts have a particular molar ratio composition, which is believed to be an important feature in ensuring desirable polymer properties that may result from catalysts made from procatalysts. Specifically, the procatalyst is preferably a magnesium-to-titanium in the range of 30: 1-5: 1 with the second and third metals under conditions sufficient to form a multi-element metal procatalyst. The molar ratio of the combination is shown. Therefore, the total molar ratio of magnesium to titanium is in the range of 8: 1-80: 1.

Once a procatalyst is formed, it can be at least such as alkyl or haloalkyl of aluminum, alkylaluminum halides, Grinard reagents, alkali metal aluminum hydrides, alkali metal hydrides, alkali metal hydrides, alkaline earth metal hydrides, etc. It can be used to form a final catalyst when combined with a co-catalyst consisting of one organic metal compound. The formation of the final catalyst from the reaction of the procatalyst with the organometallic co-catalyst can be carried out in situ or just before entering the polymerization reactor. Therefore, combinations of cocatalysts and procatalysts can occur under a wide variety of conditions. Such conditions include contacting them under an inert atmosphere, such as nitrogen, argon or other inert gas, at temperatures in the range 0 ° C to 250 ° C, preferably in the range 15 ° C to 200 ° C. May include letting. In the preparation of catalytic reaction products, it is not necessary to separate the hydrocarbon soluble component from the hydrocarbon insoluble component. The contact time between the procatalyst and the cocatalyst may be preferably in the range of, for example, 0 to 240 seconds, preferably 5 to 120 seconds. Various combinations of these conditions can be adopted.

In the embodiments described herein, the core layered polyethylene composition may have at least one part of the metal catalyst residue in total weight of at least ternary metal residue per million parts of the polyethylene polymer, at least 3 yuan. The metal residue is selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, and combinations thereof, and at least each of the ternary metal residues is 0.2 ppm or more, for example, 0. It is present in the range of 2-5 ppm. All individual values and subranges from 0.2 ppm and above are included herein and disclosed herein. For example, the core layer polyethylene composition may further contain at least 2 parts by weight of at least 3 elemental metal residues remaining from the multielement metal polymerization catalyst per 1 million parts of the core layer polyethylene composition.

In some embodiments, the core polyethylene composition comprises at least 0.75 ppm V (vanadium). All individual values and subranges from V at least 0.75 ppm are included and disclosed herein. For example, the lower limit of V in the core layer polyethylene composition may be 0.75, 1, 1.1, 1.2, 1.3 or 1.4 ppm, and the lower limit of V in the core layer polyethylene composition may be 0.75, 1, 1.1, 1.2, 1.3 or 1.4 ppm. The upper limit may be 5, 4, 3, 2, 1.9, 1.8, 1.7, 1.6, 1.5, or 1 ppm. The vanadium-catalyzed metal residual concentration of the core layer polyethylene composition can be measured using the metal neutron activation method described below.

In some embodiments, the core layer polyethylene composition comprises at least 0.3 ppm Zr (zirconium). All individual values and subranges of Zr at least 0.3 ppm are included and disclosed herein. For example, the lower limit of Zr in the core layer polyethylene composition may be 0.3, 0.4, 0.5, 0.6 or 0.7 ppm. In yet another embodiment, the upper limit of Zr in the core layer polyethylene composition may be 5, 4, 3, 2, 1, 0.9, 0.8 or 0.7 ppm. The residual concentration of the zirconium-catalyzed metal in the core layer polyethylene composition can be measured using the metal neutron activation method described below.

In the embodiments described herein, the core layer polyethylene composition may have a density of 0.910 g / cc to 0.925 g / cc. All individual values and subranges of at least 0.910 g / cc to 0.925 g / cc are included and disclosed herein. For example, in some embodiments, polyethylene has a density of 0.910 to 0.923 g / cc, 0.912 to 0.923 g / cc, or 0.912 to 0.920 g / cc. Density may be measured according to ASTM D792.

In addition to the density, the core layer polyethylene composition may have a melt index I2 of 2.5 g / 10 min to 12.0 g / 10 min. All individual values and subranges from 2.5 g / 10 min to 12.0 g / 10 min are included and disclosed herein. For example, in some embodiments, the core layer polyethylene composition is 2.5 g / 10 min to 10.0 g / 10 min, 2.5 g / 10 min to 8.0 g / 10 min, or 2.5 g / 10 min. It may have a melt index I2 of min to 5.0 g / 10 min. Melt index I2 may be measured according to ASTM D1238 (190 ° C. and 2.16 kg).

In addition to the density and melt index I2, the core layer polyethylene composition may have a melt flow ratio I10 / I2 of 6.0-7.6. All individual values and subranges from 6.0 to 7.6 are included and disclosed herein. For example, in some embodiments, the core layer polyethylene composition is 7.6, 7.5, 7.3, 7.1 from the lower limit of 6.0, 6.2, 6.3, or 6.5. , Or may have a melt flow ratio I10 / I2 in the range up to the upper limit of 7.0. In other embodiments, the core layer polyethylene composition may have a melt flow ratio of I10 / I2 of 6.0-7.4 or 6.4-7.4. Melt index I10 may be measured according to ASTM D1238 (190 ° C. and 10.0 kg).

In addition to the density, melt index I2, and melt flow ratio I10 / I2, the core polyethylene composition may have a molecular weight distribution (Mw / Mn) of 2.25 to 4.0. All individual values and subranges from 2.25 to 4.0 are included and disclosed herein. For example, polyethylene compositions have a lower limit of 2.5, 2.6, 2.7, or 2.8 to 4.0, 3.9, 3.7, 3.5, 3.2, or 3.0. It may have a Mw / Mn ratio up to the upper limit of. In some embodiments, the core layer polyethylene composition may have a Mw / Mn ratio of 2.5-3.5, 2.6-3.5, or 2.6-3.2. The molecular weight distribution can be described as the ratio of the weight average molecular weight (M _w ) to the number average molecular weight (M _n ) (ie, M _w / M _n ) and can be measured by gel permeation chromatography.

In addition to density, melt index I2, melt flow ratio I10 / I2, and molecular weight distribution (Mw / Mn), the core layer polyethylene composition has a number average molecular weight Mn (g / mol) of 30,000 to 50,000 g / mol. ) May have. All individual values and subranges from 30,000 g / mol to 50,000 g / mol are included and disclosed herein. For example, the core layer polyethylene composition may have Mn of 33,000 to 50,000 g / mol, 33,000 to 45,000 g / mol, or 33,000 to 40,000 g / mol.

In addition to density, melt index I2, melt flow ratio I10 / I2, molecular weight distribution (Mw / Mn), and number average molecular weight, the core layer polyethylene composition has a weight average molecular weight Mw of 60,000 to 110,000 g / mol. It may have (g / mol). All individual values and subranges from 60,000 g / mol to 110,000 g / mol are included and disclosed herein. For example, the core layer polyethylene composition may have Mw of 65,000 to 105,000 g / mol, 75,000 to 100,000 g / mol, or 85,000 to 100,000 g / mol.

In addition to density, melt index I2, melt flow ratio I10 / I2, molecular weight distribution (Mw / Mn), number average molecular weight, and weight average molecular weight, the core layer polyethylene composition is 200,000-325,000 g / mol. It may have a z average molecular weight Mz (g / mol). All individual values and subranges from 200,000 g / mol to 325,000 g / mol are included and disclosed herein. For example, the polyethylene composition may have Mz of 240,000 to 325,000, 240,000 to 315,000 g / mol, or 240,000 to 300,000 g / mol.

In addition to density, melt index I2, melt flow ratio I10 / I2, molecular weight distribution (Mw / Mn), number average molecular weight, weight average molecular weight, and z average molecular weight, the core layer polyethylene composition has a viscosity ratio of 2-6. It may have (viscosity at 0.1 rad / s / viscosity at 100 rad / s, both measured at 190 ° C.). All individual values and subranges from 2 to 6 are included and disclosed herein. For example, the core layer polyethylene composition may have a viscosity ratio of 2-4, 2.0-2.9, or 2.5-3.5.

In addition to density, melt index I2, melt flow ratio I10 / I2, molecular weight distribution (Mw / Mn), number average molecular weight, weight average molecular weight, z average molecular weight, and viscosity ratio, the core layer polyethylene composition is at 190 ° C. It may have a tan delta of 15-40 at the measured 0.1 rad / s. All individual values and subranges of 15-40 are included and disclosed herein. For example, the core layer polyethylene composition may have a tan delta of 20-40 or 25-40 at 0.1 rad / s measured at 190 ° C.

In addition to density, melt index I2, melt flow ratio I10 / I2, molecular weight distribution (Mw / Mn), number average molecular weight, weight average molecular weight, z average molecular weight, viscosity ratio, and tandelta, the core layer polyethylene composition is 60. It may have a composition distribution width index CDBI of less than%. All individual values and subranges less than 60% are included and disclosed herein. For example, in some embodiments, the core layer polyethylene composition may have a CDBI of 37% -60% or 40% -60%.

CDBI can be defined as the weight percent of a polymer molecule having a comonomer content within 50 percent of the comonomer content per average total mole. The CDBI of linear polyethylene containing no comonomer is specified to be 100%. The CDBI of the copolymer is easily calculated from the data obtained from the crystallization elution fraction (“CEF”) as described below. Unless otherwise stated, terms such as "comonomer content" and "average comonomer content" refer to the bulk comonomer content of the indicated interpolymer blends, blend components, or molar-based fractions.

In embodiments herein, the core layer comprises 60% to 100% by weight of a core layer polyethylene composition. All individual values and subranges from 60% to 100% by weight are included and disclosed herein. For example, in some embodiments, the core layer is 70% by weight to 100% by weight, 80% by weight to 100% by weight, 90% by weight to 100% by weight, or 95 by weight of the polymer present in the core layer. Includes a core layer polyethylene composition from% to 100% by weight.

In the embodiments described herein, the core layer may further comprise linear low density polyethylene (LLDPE), low density polyethylene (LDPE), or a blend thereof. In some embodiments, the core layer is 1% to 40% by weight, 1% to 30% by weight, 1% to 25% by weight, 5% by weight to 25% by weight, or by weight of the core layer. Further may include LLDPE, LDPE, or a blend thereof in an amount ranging from 5% to 20% by weight. LLDPE may have a density in the range of 0.912 to 0.940 g / cm ³ and a melt index in the range of 0.5 to 30 g / 10 min. LDPE may have a density in the range of 0.910 to 0.935 g / cm ³ and a melt index in the range of 0.2 to 20 g / 10 min. The core layer may further contain one or more additives such as pigments, inorganic fillers, UV stabilizers, antioxidants and the like.

Peeling layer The peeling layer may have LDPE, LLDPE, or the following properties: (a) 2.5-12.0 g / 10 min or 2.5-8.0 g / 10 min melt index I2, (b) 0.910. Densities of ~ 0.925 g / cc or 0.912 to 0.920 g / cc, melt flow ratios I10 / I2 of (c) 6.0-7.6 or 6.4-7.4, and (d) 2. Includes one or more of the stripped layer polyethylene compositions characterized by a molecular weight distribution (Mw / Mn) of .25 to 4.0 or 2.6 to 3.5. The release layer polyethylene composition is formed via solution polymerization in the presence of a catalytic composition comprising a multi-element metal procatalyst. In a further embodiment, the release layer polyethylene composition may have less than 60% or 40% -60% CDBI. LLDPE can have a density in the range of 0.912 to 0.940 grams / cm ³ and a melt index in the range of 0.5 to 30 grams / 10 minutes. An exemplary LLDPE for use in the release layer of a multilayer film is commercially available from The Dow Chemical Company under the trade names ELITE ™, TUFLIN ™, and DOWLEX ™.

In some embodiments, the release layer is an amount of 0-100 percent, 50-100 percent, 75-100 percent, 85-100 percent, or 95-100 percent by weight of the polymer present in the release layer. Includes LLDPE. In other embodiments, the release layer is an amount of 0-100 percent, 50-100 percent, 75-100 percent, 85-100 percent, or 95-100 percent release by weight of the polymer present in the release layer. Includes layered polyethylene composition. In a further embodiment, the release layer may contain LLDPE and the release layer polyethylene composition in a weight ratio in the range of 1: 4 to 4: 1 or 1: 3 to 3: 4. The release layer may further contain one or more additives such as pigments, inorganic fillers, UV stabilizers, and antioxidants.

The multilayer films described herein can be made by a variety of techniques, such as cast film techniques, including uniaxial and biaxial orientations, as is commonly known in the art. The multilayer films described herein may also be advantageous to stretch at least 50%, preferably 100% in the longitudinal and / or transverse directions. In some embodiments, the multilayer cast film can be made by coextruding the adhesive layer composition, the core layer composition, and the release layer composition to form a multilayer cast film. The pressure-sensitive adhesive layer composition may include a propylene interpolymer as described above herein, and may optionally include a pressure-sensitive adhesive layer polyethylene composition as described herein above. The core layer composition comprises a core layer polyethylene composition as described above herein. The release layer composition also includes a linear low density polyethylene or a release layer polyethylene composition as described above. The core layer polyethylene composition, the adhesive layer polyethylene composition, and the release layer polyethylene composition used for the multilayer cast film may be independently the same or different from each other.

Here, embodiments of the multilayer film will be further described in the following exemplary examples.

Test Method Density Density can be measured according to ASTM D-792 and is reported in grams / cubic centimeters (g / cc or g / cm ³ ).

Melt Index / Melt Flow Rate The melt index (I2) of an ethylene polymer is measured according to ASTM D1238-10, conditions, 190 ° C./2.16 kg and reported in grams elution every 10 minutes. The melt index (I10) of the ethylene polymer is measured according to ASTM D1238-10, conditions, 190 ° C./10 kg and is reported in grams eluting every 10 minutes. The melt flow rate (MFR2) of the propylene-based polymer is measured according to ASTM D1238-10, conditions, 230 ° C./2.16 kg and reported in grams elution every 10 minutes. The melt flow rate (MFR10) of the propylene-based polymer is measured according to ASTM D1238-10, conditions, 230 ° C./10 kg and is reported in grams eluting every 10 minutes.

High temperature gel permeation chromatography (HT-GPC)
The propylene interpolymer polymer is a gel permeation chromatography on a Polymer Laboratories PL-GPC-220 high temperature chromatography unit with three linear mixed bed columns 300 x 7.5 mm (Polymer Laboratories PLgel Mixed B (10 micron particle size)). Analyzed by GPC). The oven temperature is 160 ° C., the autosampler hot zone is 160 ° C. and the warm zone is 145 ° C. The polymer is 200 ppm 2,6-di-t-butyl-4. -1,2,4-trichlorobenzene containing methylphenol (BHT). Flow rate is 1.0 ml / min and injection size is 100 microliters. 0.15 wt% solution of sample. Dissolve the sample in nitrogen-purged 1,2,4-trichlorobenzene containing 200 ppm 2,6-di-t-butyl-4-methylphenol at 160 ° C. for 2.5 hours with gentle mixing. Prepared for injection by.

Molecular weight determination is inferred by using 10 narrow molecular weight distribution polystyrene standards (Polymer Laboratories, EasiCal PS1 in the range of 580-7,500,000 g / mol) in combination with their elution amounts. .. BHT is used as a relative flow marker and each chromatograph is referenced back to the narrow polystyrene standard calibration curve.

Equivalent polypropylene molecular weights are those of polypropylene, which are incorporated herein by reference: Th.G.Scholte, NLJ. (As described in 3763-3782 (1984)), and polystyrene (incorporated herein by reference, EP Otokka, RJ Rowe, NY Hellman, PM Muglia, Determined by using the appropriate Mark-Houwink coefficients for (as described in Polymercules, 4 507 (1971)) in the Mark-Houwink equation (equation 1), which associates the original viscosity with the molecular weight. The instantaneous molecular weight (M _(PP) ) at each chromatographic point is determined by equation 2 using universal calibration and the Mark-Houwink coefficient defined in equation 1. The number average, weight average, and z-average molecular weight moments, Mn, Mw, and Mz are calculated according to equation 3, equation 4, and equation 5, respectively, where RI is each chromatographic point (i). ) Is the refractometer signal height subtracted from the baseline of the polymer elution peak.

K _{pp =} 1.90E-04, a _{pp =} 0.725, and K _{ps =} 1.26E-04 _, a _{ps =} 0.702.

A PolymerChar (Valencia, Spain) high temperature gel permeation chromatography system consisting of an ethylene polymer infrared concentration detector (IR-5) is used for MW and MWD determination. The solvent delivery pump, online solvent degassing device, autosampler, and column oven are made by Agilent. The column compartment and detector compartment operate at 150 ° C. The column is a three PLgel 10 μm mixed B, Agilent. The carrier solvent was 1,2,4-trichlorobenzene (TCB) and the flow rate was 1.0 mL / min. Both the chromatographic and sample preparation solvent sources contain 250 ppm butylated hydroxytoluene (BHT) and are nitrogen sprayed. A polyethylene sample is prepared at a target polymer concentration of 2 mg / mL by dissolving in TCB at 160 ° C. for 3 hours immediately prior to injection. The injection volume is 200 μL.

Calibration of the GPC column is performed using 21 narrow molecular weight distribution polystyrene standards. The molecular weight of the standard is in the range of 580-8,400,000 g / mol and is placed in 6 "cocktail" mixtures with at least an order of magnitude between the individual molecular weights. Polystyrene standard peak molecular weight is converted to polyethylene molecular weight using the following equation (Williams and Ward, J. Polymer. Sci., Polymer. Let., 6, 621 (1968)):
M _polyethylene = A (M _polystyrene ) ^B (1)

Here, B has a value of 1.0, and the experimentally determined value of A is about 0.42.

A cubic polynomial is used to fit each polyethylene equivalent calibration point obtained from equation (1) to their observed elution amount. The actual polynomial fit is obtained to correlate the logarithm of the polyethylene equivalent molecular weight to the observed elution amount (and associated force) of each polystyrene standard.

The number average molecular weight, the weight average molecular weight, and the z average molecular weight are calculated according to the following equations.

In the formula, Wf _i is the weight fraction of the _i -th component, and Mi is the molecular weight of the i-th component. MWD is expressed as a ratio of weight average molecular weight (Mw) to logarithmic average molecular weight (Mn).

The exact A value is the A value of equation (1), the weight average molecular weight calculated using equation (3) and the corresponding holding capacity polynomial, the known weight average molecular weight is 120,000 g / mol. Determined by adjusting until consistent with an independently determined value of Mw obtained according to the linear homopolymer reference.

Neutron Activation of Metals Two sets of replicative samples are prepared by transferring approximately 3.5 grams of pellets into pre-washed 2-drum polyethylene vials. For each metal tested, a standard is prepared in a 2-drum polyethylene vial from NIST traceable standard solution (Certi.pure from SPEX). Dilute them to 6 ml with Milli-Q pure water and heat seal the vials. The Mark I TRIGA reactor is then used to analyze samples and standards for these elements. The reactions and experimental conditions used for these elements are summarized in the table below. Transfer the sample to a non-irradiated vial before performing gamma spectroscopy. Elemental concentrations are calculated using CANBERRA software and standard comparison techniques. Table 1 shows the measurement parameters for metal determination.

Differential scanning calorimetry (DSC)
Differential scanning calorimetry (DSC) is used to measure the melting and crystallization behavior of polymers over a wide range of temperatures. For example, a TA Instruments Q1000 DSC equipped with an RCS (refrigerating cooling system) and an autosampler is used to perform this analysis. During the test, a nitrogen purge gas flow of 50 ml / min is used. Each sample is melt-compressed into a thin film at about 175 ° C. and then the melted sample is air-cooled to room temperature (approximately 25 ° C.). The film sample is formed by pressing a "0.1-0.2 gram" sample at 175 ° C., 1,500 psi, and 30 seconds to form a "0.1-0.2 mil thick" film. To. A 3-10 mg, 6 mm diameter specimen is extracted from the cooled polymer, weighed, placed in a lightweight aluminum pan (about 50 mg), crimped and closed. An analysis is then performed to determine its thermal properties.

The thermal behavior of a sample is determined by creating a heat flow vs. temperature profile with a vertical gradient of the sample temperature. First, the sample is rapidly heated to 180 ° C. and kept isothermal for 5 minutes to remove its thermal history. The sample is then cooled to −40 ° C. at a cooling rate of 10 ° C./min and held isothermal to −40 ° C. for 5 minutes. The sample is then heated to 150 ° C. at a heating rate of 10 ° C./min (this is the "second heat" gradient). Record the cooling and second heating curves. The cooling curve is analyzed by setting a baseline end point from the start of crystallization to −20 ° C. The thermal curve is analyzed by setting the baseline end point from −20 ° C. to the melting end point. The determined values are peak melting temperature (T _m ), peak crystallization temperature (T _c ), starting crystallization temperature (Tc start), heat of fusion (H _f ) (grams per Joule), and PE crystallization. Degree = ((Hf) / (292J / g)) x 100 calculated for a polyethylene sample with% crystallinity, and PP crystallinity% = ((Hf) / 165J / g)) x 100 Is the crystallinity% of the polypropylene sample calculated using. The heat of fusion (H _f ) and peak melting temperature are reported from the second heat curve. The peak crystallization temperature and the start crystallization temperature are determined from the cooling curve.

Dynamic Mechanical Spectroscopy (DMS)
The resin is compression molded into a "3 mm thick x 1 inch" circular plaque at 350 ° F for 5 minutes under a pressure of 1500 psi in air. The sample is then removed from the compressor, placed on a counter and cooled.

A constant temperature frequency sweep is performed using the TA Instruments "Advanced Rheometric Expansion System (ARES)" with a 25 mm (diameter) parallel plate under nitrogen purge. Place the sample on a plate and melt at 190 ° C. for 5 minutes. The plate is then closed to a 2 mm spacing, the sample is trimmed (excessive sample extending beyond the circumference of the "25 mm diameter" plate), and then the test is started. This method incorporated an additional 5 minute delay to allow temperature equilibration. Experiments are performed at 190 ° C. over a frequency range of 0.1-100 rad / s. The strain amplitude is constant at 10%. Complex viscosity η *, tan (δ) or tan delta, viscosity at 0.1 rad / s (V0.1), viscosity at 100 rad / s (V100), and viscosity ratio (V0.1 / V100) are these. Calculated from the data.

Crystallization Elution Fractionation (CEF) Method The crystallization elution fraction (CEF) technique was described by Monrabal et al., Macromol. Symp. It is carried out according to 257, 71-79 (2007). The CEF machine comprises an IR-4 or IR-5 detector (eg, commercially available from PolymerChar, Spain) and a two-angle light scattering detector model 2040 (eg, commercially available from Precision Detectors). A 50 mm x 4.6 mm 10 micrometer guard column (eg, commercially available from PolymerLabs) is mounted in the detector oven in front of the IR-4 or IR-5 detector. Obtain orthodichlorobenzene (ODCB, 99% anhydrous grade) and 2,5-di-tert-butyl-4-methylphenol (BHT) (eg, commercially available from Sigma-Aldrich). Silica gel 40 (particle size 0.2-0.5 mm) (eg, commercially available from EMD Chemicals) is also available. Silica gel is dried in a vacuum oven at 160 ° C. for at least 2 hours before use. Prior to use, the ODCB is purged with dry nitrogen (N ₂ ) for 1 hour. Dry nitrogen is obtained by passing nitrogen through a molecular sieve of CaCO ₃ and 5 Å at <90 psig. ODCB is added by adding 5 grams of dry silica to 2 liters of ODCB, or by pumping at 0.1 ml / min to 1.0 ml / min through a column (s) filled with dry silica. Dry further. If no inert gas such as N ₂ is used to purge the sample vial, 800 milligrams of BHT is added to 2 liters of ODCB. Dry ODCB with or without BHT is hereinafter referred to as "ODCB-m". The sample solution is prepared by dissolving the polymer sample in ODCB-m at 4 mg / ml under shaking at 160 ° C. for 2 hours using an autosampler. Inject 300 μL of the sample solution into the column. The temperature profile of the CEF is as follows: crystallization from 110 ° C to 30 ° C at 3 ° C / min, thermal equilibrium at 30 ° C for 5 minutes (including soluble fraction elution time set to 2 minutes), and 30. Elute from ° C to 140 ° C at 3 ° C / min. The flow rate during crystallization is 0.052 ml / min. The flow rate during elution is 0.50 ml / min. IR-4 or IR-5 signal data is collected at 1 data point / sec.

Using a 1/8 inch stainless steel tube according to US No. 8,372,931, the CEF column is filled with 125 μm ± 6% glass beads (such as those commercially available from MO-SCI Specialty Products with pickling). do. The internal liquid volume of the CEF column is 2.1 ml to 2.3 ml. Temperature calibration is performed by using a mixture of NIST standard linear polyethylene 1475a (1.0 mg / ml) and Ecosane (2 mg / ml) in ODCB-m. Calibration consists of four steps: (1) calculating the delayed volume defined as the temperature offset between the measured peak elution temperatures of Eikosan minus 30.00 ° C., (2) the temperature offset of the elution temperature. (Note that this temperature offset is a function of experimental conditions such as elution temperature, elution flow rate, etc.), (3) NIST linear polyethylene 1475a at 101.00 ° C. Creating a calibration straight line that has a peak temperature and converts the elution temperature over the range of 30.00 ° C to 140.00 ° C so that Eikosan has a peak temperature of 30.00 ° C, (4) 30 ° C. It consists of linearly extrapolating the elution temperature by using an elution heating rate of 3 ° C./min for the soluble fraction measured at the same temperature. The reported elution peak temperature is obtained so that the observed comonomer content calibration curve is consistent with that previously reported in US Pat. No. 8,372,931.

Comonomer distribution width index (CDBI)
CDBI is calculated from the data obtained from the CEF using the method described in WO / 93/03093. CDBI is defined as the weight percent of a polymer molecule having a comonomer content within 50 percent of the comonomer content per average total mole. This represents a comparison between the comonomer distribution excluding the Bernoulli distribution and the comonomer distribution in the polymer.

CEF is used to measure the short chain branch distribution (SCBD) of polyolefins. CEF molar concentration comonomer content calibration, 24 standard materials with narrow SCBD (eg, polyethylene octene) with comonomer molar fractions ranging from 0 to 0.108 and Mw of 28,400 to 174,000 g / mol. Random copolymer and ethylene butene copolymer) are used. Obtain 1 / T (K) with respect to ln (mole fraction of ethylene), which is ln (mole fraction of comonomer). Here, T is the elution temperature of each standard substance in Kelvin. The comonomer distribution of the reference material is described, for example, in US Pat. No. 5,292,845 (Kawasaki et al.) And J. Mol. C. Randall's Rev. Macromol. Chem. Phys. , C29, 201-317, determined using 13C NMR analysis.

13C-NMR
Sample Preparation By adding approximately 2.7 g of a 50/50 mixture of tetrachloroethane-d2 / ortodichlorobenzene containing 0.025 M Cr (AcAc) 3 to a 0.25 g sample in a 10 mm NMR tube of Norell 1001-7. , Prepare the sample. The sample is melted and homogenized by heating the tube and its contents to 150 ° C. using a heating block and a vortex mixer. Visually inspect each sample to ensure homogeneity.

Data acquisition parameters Data is collected using a Bruker 400 MHz spectrometer equipped with a Bruker Dual DUL high temperature CryoProbe. Data is acquired at a sample temperature of 120 ° C. using 320 transient voltages per data file, 6 second pulse repetition delay, 90 degree flip angle, and decoupling with reverse gate. All measurements are made on non-rotating samples in lock mode. The sample is thermally equilibrated for 7 minutes prior to data acquisition. ¹³ C NMR chemical shifts internally refer to mmmm pentads at 21.90 ppm or EEE triads at 30.0 ppm.

Data analysis composition was described in S.I. Di Martino and M.D. Keclchtermans, "Determination of the Compression of Ethylene-Propyrene-Rubbers Using 13C-NMR Spectroscopic", Journal of Applied Polymer. Determined using the allocation from 56,1781-1787 (1995) and the integral C13 NMR spectrum, and solve the vector equation s = fM. In the equation, M is the allocation matrix, s is the row vector representation of the spectrum, and f is the mole fraction composition vector. It is assumed that the element of f is a triad of E and O with all sorts of E and O. The allocation matrix M is created with one row for each triad in f and each column of the integrated NMR signals. The elements of the matrix are integer values determined with reference to the assignments in reference 1. This equation is solved by the change in the element of f required to minimize the error function between s and the integrated C13 data of each sample. This is easily done in Microsoft Excel using the solver function.

Maximum Stretch The maximum stretch is tested on the Highlight Film Test System manufactured by Highlight Industries. Place the film roll on the unwinding part of the machine and pass the film through a set of rollers. The film is then unwound with increasing force until it reaches its maximum stretch point. The amount of force applied is measured by a load cell and calculations are made to measure the amount of stretch present in the film as a percentage. Three measurements are taken and averaged together to obtain the average maximum stretch value. The film width is 20 inches.

Tear test on pallet This test uses the Bruceton staircase method to determine the maximum loading force that allows the film to pass over the test probe for three wraps without failure. Insert the test probe into the test bench with the desired protrusion distance. Place the film so that the test probe is aligned with the center of the film. Attach the film to the test stand and start the wrapper. When the wrapper reaches 250% pre-stretching, the film can pass through the probe for winding up to 3 times. If the film breaks during any of the windings, the load setting with that force is considered a failure. Depending on the performance of the film at the load setting (ie pass or fail), the load force is adjusted up and down and the test is repeated with the new load setting. This continues until you find the maximum force that will not fail. The table below shows the equipment and settings used in this way.

[table]

Stretching force, unwinding force, noise level:
Stretching force, unwinding force, and noise level are tested on a Highlight Film Test System manufactured by Highlight Industries. Place the film roll on the unwinding part of the machine and pass the film through a set of rollers. The film is then unwound with increasing force until it reaches its maximum stretch point. The load cell measures the magnitude of the force applied to stretching (stretching force) and the force required for unwinding (unwinding force). Noise levels are measured with a built-in sound level meter in decibels during this test. Three measurements are made for each test and the values of stretching force, unwinding force and noise level are averaged. The film width for these tests is 20 inches.

Puncture on pallet:
This test uses the Bruceton staircase method to determine the maximum loading force that allows the film to pass over the test probe for three windings without failure. Insert the test probe into the test bench with the desired protrusion distance. Place the film so that the test probe is aligned with the center of the film. Attach the film to the test stand and start the wrapper. When the wrapper reaches 250% pre-stretching, the film can pass through the probe for winding up to 3 times. If the film breaks during any of the windings, the load setting with that force is considered a failure. Depending on the performance of the film at the load setting (ie pass or fail), the load force is adjusted up and down and the test is repeated with the new load setting. This continues until you find the maximum force that will not fail. The table below shows the equipment and settings used in this way.

[table]

Adhesiveness (stretched adhesiveness) The stretched adhesiveness on the pallet can be measured by a Lantech SHS test device. The test consists of stretching the film 250% with a constant force of 12 pounds F2 during 5 windings while rotating the turntable at a speed of 10 rpm. The end of the film is then attached to a load cell that measures the force in grams required to strip from the drum.

The resins used for the multilayer cast film are shown in Tables 2, 3, and 5. The propylene interpolymer of the present invention is a propylene-ethylene copolymer and is prepared by the method described above in paragraphs [0018] to [0020]. Further properties of the propylene interpolymer are outlined in Table 3 below. The PE resin 1 is produced by the following method. Further properties of PE resin 1 and the comparative polyethylene composition are outlined in Table 5.

PE resin 1
The PE resin 1 is prepared as follows: a multi-metal catalyst is prepared (catalyst 1). Next, the PE resin 1 is prepared by solution polymerization using the catalyst 1.

Preparation of Catalyst 1 To about 109 kg of 0.20 M MgCl ₂ slurry was added 7.76 kg of EADC solution (15 wt% in heptane), followed by stirring for 8 hours. A mixture of TiCl ₄ / VOCl ₃ (85 mL and 146 mL, respectively) was then added, followed by a solution of Zr (TMHD) ₄ (0.320 kg of 0.30 M solution in Isopar E). These two additions were sequentially performed within 1 hour of each other. The obtained catalyst premix was aged with stirring for an additional 8 hours before use.

Production of Resin 1 PE resin 1 is prepared according to the following procedure: all raw materials (ethylene, 1-hexene) and process solvent (isoparaffin solvent under trade name ISPPAR E, commercially available from ExxonMobil Corporation). Purify with molecular sieves before introduction into the reaction environment. Hydrogen is supplied into the pressure cylinder as a high purity grade and is no longer purified. The reactor monomer feed (ethylene) stream is pressurized through a mechanical compressor to a pressure higher than the reaction pressure, eg 750 psig. The solvent and comonomer (1-hexene) feed are pressurized via a mechanical positive displacement pump to a pressure higher than the reaction pressure, eg 750 psig. The individual catalytic components are manually batch diluted with a purification solvent (ISOPAR E) to a specific component concentration and pressurized to a pressure higher than the reaction pressure, eg 750 psig. All reaction supply flows are measured with a mass flow meter and controlled independently by a computer automated valve control system.

The continuous solution polymerization reactor consists of a liquid-filled, non-adiabatic, isothermal, circulating loop. Independent control of all fresh solvents, monomers, comonomeres, hydrogens, and catalyst constituent feeds is possible. The combination of solvent, monomer, comonomer and hydrogen feed is temperature controlled somewhere between 5 ° C and 50 ° C, typically 40 ° C by passing the feed stream through a heat exchanger. The fresh comonomer feed to the polymerization reactor is aligned to add the comonomer to the recirculation solvent. The whole fresh feed to the polymerization reactor is injected into the reactor at two locations with approximately equal reactor volumes between each injection site. The fresh feed is typically controlled by each injector that receives half of the total fresh feed quantity flow rate. The catalyst component is injected into the polymerization reactor through a specially designed inlet and combined with one mixed catalyst / cocatalyst supply stream prior to injection into the reactor. The cocatalytic component is supplied to the procatalytic component based on the calculated specific molar ratio. Immediately after each fresh injection position (either the feed or the catalyst), the feed stream is mixed with the contents of the cyclic polymerization reactor with the Kenics static mixing element. The contents of the reactor are continuously circulated through a heat exchanger, which serves to remove most of the heat of reaction, and at a coolant-side temperature, which serves to maintain an isothermal reaction environment at a particular temperature. Circulation around the reactor loop is performed by a screw pump. The effluent from the polymerization reactor, including solvents, monomers, comonomer, hydrogen, catalytic components, and molten polymers, exits the reactor loop and is inactivated and associated with acid trapping agents (typically calcium stearate and accompanying. Enter the area in contact with water) to stop the reaction and remove hydrogen chloride. Further, at this point, various additives such as antioxidants can be added. The stream then passes through another set of Kenics static mixing elements to uniformly disperse the catalyst terminator and additives.

Following the addition of the additive, the effluent (including solvent, monomer, comonomer, hydrogen, catalytic component, and molten polymer) passes through the heat exchanger in preparation for separation of the polymer from other low boiling point reaction components. And raise the stream temperature. The stream then passes through a pressure drop control valve, which is responsible for keeping the reactor pressure at a particular target. The stream then enters a two-stage separation and devolatilization system, where the polymer is removed from the solvent, hydrogen, and unreacted and comonomer. Impurities are removed from the recirculation stream before re-entering the reactor. The separated and devolatile polymer melt is pumped through a die specially designed for underwater pelleting, cut into uniform solid pellets, dried and transferred to a hopper. After verification of the initial polymer properties, the solid polymer pellets are transferred to the storage device.

The portion removed in the devolatile step can be reused or destroyed. For example, most of the solvent is recirculated to the reactor after passing through the purification bed. The recirculated solvent can still have unreacted comonomer, which is fortified with fresh comonomer before re-entering the reactor. The recirculated solvent can still have some hydrogen, which is then fortified with fresh hydrogen. Table 4 summarizes the polymerization conditions of PE resin 1.

A 3-layer cast film was made using a Dolci 7-layer cast line with a 5-layer extruder. The adhesive layer has a layer ratio of 12%, the core layer has a layer ratio of 76%, and the release layer has a layer ratio of 12%. The extrusion melting temperature of the extruder 1 is 251 ° C, the extruder 2 is 197 ° C, the extruder 3 is 253 ° C, the extruder 4 is 235 ° C, the extruder 5 is 181 ° C, and the die temperature is 235 ° C. The output speed is 1,000 kg / hour. The chill roll temperature is 17 ° C. The air gap is 5 ml. The film thickness is 25 microns. The film structure and film properties are further outlined in Table 6 below.

As shown in Table 6, even when the amount of the pressure-sensitive adhesive is reduced from 18% of the comparative film 1 to 13% of the film 1 of the present invention, a higher pressure-sensitive adhesive value is achieved.

A three-layer cast film was made using a five-layer cast line with a four-layer extruder. The adhesive layer has a layer ratio of 10%, the core layer has a layer ratio of 80%, and the release layer has a layer ratio of 10%. The melting temperature of the extruder is in the range of 200 ° C to 250 ° C. The output speed is 860 kg / hour. The die temperature is 250 ° C. The air gap is 3 cm. The film 2 of the present invention was made using the following extruder pressures: 194/213/224/195 bar. Comparative film 2 was made using the following extruder pressure: 221/222/240/215 bar. The film thickness is 20 microns. The film structure and film properties are further outlined in Table 7 below.

Although specific embodiments of the invention have been exemplified and described, it will be apparent to those skilled in the art that various other modifications and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended to cover all such changes and modifications within the scope of the present invention within the appended claims.
The present application also relates to the following aspects.
(1) A multilayer cast film including an adhesive layer, a core layer, and a release layer.
The pressure-sensitive adhesive layer contains a propylene interpolymer containing at least 60% by weight of propylene-derived units and 1 to 40% by weight of ethylene-derived units, and the propylene interpolymer is 0.840 g / cm ³ to 3. Density of 0.900 g / cm ³ , maximum DSC melting peak temperature of 50.0 ° C to 120.0 ° C, melt flow rate of 1 to 100 g / 10 min when measured at 230 ° C and 2.16 kg load according to ASTM D1238. It has MFR2, as well as a molecular weight distribution (MWD) of less than 4.0,
The core layer contains a core layer polyethylene composition containing a reaction product of ethylene and optionally one or more alpha olefin comonomer, and the core layer polyethylene composition has the following characteristics:
(A) Melt index I2 at 2.5 to 12.0 g / 10 minutes,
(B) Density of 0.910 to 0.925 g / cc,
(C) Melt flow ratios I10 / I2 from 6.0 to 7.6, and
(D) A multilayer cast film characterized by one or more of a molecular weight distribution (Mw / Mn) of 2.25 to 4.0.
(2) The film according to (1) above, wherein the propylene interpolymer has a crystallinity percentage in the range of 0.5% to 45%.
(3) The film according to (1) or (2) above, wherein the propylene interpolymer has a weight average molecular weight (Mw) of at least 50,000 grams / mol (g / mol).
(4) The pressure-sensitive adhesive layer further contains a pressure-sensitive adhesive layer polyethylene composition containing a reaction product of ethylene and optionally one or more alpha olefin comonomer, and the pressure-sensitive adhesive layer polyethylene composition has the following characteristics:
(A) Melt index I2 at 2.5 to 12.0 g / 10 minutes,
(B) Density of 0.910 to 0.925 g / cc,
(C) Melt flow ratios I10 / I2 from 6.0 to 7.6, and
(D) The film according to any one of (1) to (3) above, which comprises one or more of the molecular weight distributions (Mw / Mn) of 2.25 to 4.0.
(5) The release layer contains a linear low-density polyethylene or a release layer polyethylene composition containing a reaction product of ethylene and optionally one or more alpha olefin comonomer, and the release layer polyethylene composition is: The following characteristics:
(A) Melt index I2 at 2.5 to 12.0 g / 10 minutes,
(B) Density of 0.910 to 0.925 g / cc,
(C) Melt flow ratios I10 / I2 from 6.0 to 7.6, and
(D) The film according to any one of (1) to (4) above, which comprises one or more of the molecular weight distributions (Mw / Mn) of 2.25 to 4.0.
(6) The film according to (1) to (5) above, wherein the core layer polyethylene composition is formed in the presence of a catalyst composition containing a multi-element metal procatalyst via solution polymerization.
(7) The film according to any one of (1) to (6) above, wherein the core layer polyethylene composition has less than 60% or 40% to 60% CDBI.
(8) The film according to any one of (1) to (7) above, wherein the core layer polyethylene composition has a molecular weight distribution (Mw / Mn) of 2.6 to 3.5.
(9) The core layer polyethylene composition has a viscosity ratio of 2 to 6 or 2.0 to 2.9 (viscosity at 0.1 rad / s / viscosity at 100 rad / s, both of which are subjected to dynamic mechanical spectroscopy. The film according to any one of (1) to (8) above, which is used and measured at 190 ° C.).
(10) A method for producing a multilayer cast film.
Containing the coextrusion of an adhesive layer composition, a core layer composition, and a release layer composition to form a multilayer cast film.
The pressure-sensitive adhesive layer composition comprises a propylene interpolymer containing a unit derived from at least 60% by weight of propylene and a unit derived from 1 to 40% by weight of ethylene, and the propylene interpolymer is 0.840 g / cm. Density of ³ to 0.900 g / cm ³ , maximum DSC melting peak temperature of 50.0 ° C to 120.0 ° C, melt of 1 to 100 g / 10 min when measured at 230 ° C and 2.16 kg load according to ASTM D1238. It has a flow rate of MFR2, as well as a molecular weight distribution (MWD) of less than 4.0.
The core layer composition comprises a core layer polyethylene composition containing a reaction product of ethylene and optionally one or more alpha olefin comonomer, and the core layer polyethylene composition has the following characteristics:
(A) Melt index I2 at 2.5 to 12.0 g / 10 minutes,
(B) Density of 0.910 to 0.925 g / cc,
(C) Melt flow ratios I10 / I2 from 6.0 to 7.6, and
(D) Characterized by one or more of the molecular weight distributions (Mw / Mn) of 2.25 to 4.0.
The release layer composition comprises a linear low density polyethylene or a release layer polyethylene composition containing a reaction product of ethylene and optionally one or more alpha olefin comonomer, and the release layer polyethylene composition is described below. Characteristics:
(A) Melt index I2 at 2.5 to 12.0 g / 10 minutes,
(B) Density of 0.910 to 0.925 g / cc,
(C) Melt flow ratios I10 / I2 from 6.0 to 7.6, and
(D) A method comprising one or more of a molecular weight distribution (Mw / Mn) of 2.25 to 4.0.

The dimensions and values disclosed herein should not be understood as being strictly limited to the exact numerical values described. Instead, unless otherwise specified, each such dimension is intended to mean both the value described and the functionally equivalent range surrounding the value. For example, the dimension disclosed as "40 mm" is intended to mean "about 40 mm".

All documents listed herein, including any patents or applications that are mutually referenced or related, and any patent application or patent for which this application claims priority or interest, are express. Unless excluded or otherwise limited in its entirety, it is incorporated herein by reference in its entirety. Citation of any document is prior art for any invention disclosed or claimed herein, or such invention alone or in any combination with any other reference. Is not acknowledged to teach, suggest, or disclose. Moreover, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in the document incorporated by reference, the meaning or definition assigned to that term in this document It shall be prioritized.

Although specific embodiments of the invention have been exemplified and described, it will be apparent to those skilled in the art that various other modifications and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended to cover all such changes and modifications within the scope of the present invention within the appended claims.

Claims (10)

A multilayer cast film containing an adhesive layer, a core layer, and a release layer.
The pressure-sensitive adhesive layer contains a propylene interpolymer containing at least 60% by weight of propylene-derived units and 1 to 40% by weight of ethylene-derived units, and the propylene interpolymer is 0.840 g / cm ³ to 3. Density of 0.900 g / cm ³ , maximum DSC melting peak temperature of 50.0 ° C to 120.0 ° C, melt flow rate of 1 to 100 g / 10 min when measured at 230 ° C and 2.16 kg load according to ASTM D1238. It has MFR2, as well as a molecular weight distribution (MWD) of less than 4.0,
The core layer contains a core layer polyethylene composition containing a reaction product of ethylene and optionally one or more alpha olefin comonomer, and the core layer polyethylene composition has the following characteristics:
(A) Melt index I ₂ for 2.5 to 12.0 g / 10 minutes,
(B) Density of 0.910 to 0.925 g / cc,
(C) A melt flow ratio of 6.0 to 7.6, I10 / I2, and (d) a molecular weight distribution of 2.25 to 4.0 (Mw / Mn ).
A multi-layer cast film featuring . The film of claim 1, wherein the propylene interpolymer has a percentage of crystallinity in the range of 0.5% to 45%. The film of claim 1 or 2, wherein the propylene interpolymer has a weight average molecular weight (Mw) of at least 50,000 grams / mol (g / mol). The pressure-sensitive adhesive layer further comprises a pressure-sensitive adhesive layer polyethylene composition containing a reaction product of ethylene and optionally one or more alpha olefin comonomer, and the pressure-sensitive adhesive layer polyethylene composition has the following characteristics:
(A) Melt index I2 at 2.5 to 12.0 g / 10 minutes,
(B) Density of 0.910 to 0.925 g / cc,
Claims characterized by (c) one or more of a melt flow ratio I10 / I2 of 6.0-7.6 and (d) a molecular weight distribution (Mw / Mn) of 2.25-4.0. The film according to any one of Items 1 to 3. The release layer comprises a linear low density polyethylene or a release layer polyethylene composition containing a reaction product of ethylene and optionally one or more alpha olefin comonomer, and the release layer polyethylene composition has the following characteristics. :
(A) Melt index I2 at 2.5 to 12.0 g / 10 minutes,
(B) Density of 0.910 to 0.925 g / cc,
Claims characterized by (c) one or more of a melt flow ratio I10 / I2 of 6.0-7.6 and (d) a molecular weight distribution (Mw / Mn) of 2.25-4.0. The film according to any one of Items 1 to 4. The film according to claims 1 to 5, wherein the core layer polyethylene composition is formed through solution polymerization in the presence of a catalyst composition containing a multi-element metal procatalyst. The film according to any one of claims 1 to 6, wherein the core layer polyethylene composition has less than 60% or 40% to 60% CDBI. The film according to any one of claims 1 to 7, wherein the core layer polyethylene composition has a molecular weight distribution (Mw / Mn) of 2.6 to 3.5. The core layer polyethylene composition has a viscosity ratio of 2-6 or 2.0-2.9 (viscosity at 0.1 rad / s / viscosity at 100 rad / s, both using dynamic mechanical spectroscopy. The film according to any one of claims 1 to 8, which has (measured at 190 ° C.). It is a method of making a multilayer cast film.
Containing the coextrusion of an adhesive layer composition, a core layer composition, and a release layer composition to form a multilayer cast film.
The pressure-sensitive adhesive layer composition comprises a propylene interpolymer containing a unit derived from at least 60% by weight of propylene and a unit derived from 1 to 40% by weight of ethylene, and the propylene interpolymer is 0.840 g / cm. Density of ³ to 0.900 g / cm ³ , maximum DSC melting peak temperature of 50.0 ° C to 120.0 ° C, melt of 1 to 100 g / 10 min when measured at 230 ° C and 2.16 kg load according to ASTM D1238. It has a flow rate of MFR2, as well as a molecular weight distribution (MWD) of less than 4.0.
The core layer composition comprises a core layer polyethylene composition containing a reaction product of ethylene and optionally one or more alpha olefin comonomer, and the core layer polyethylene composition has the following characteristics:
(A) Melt index I2 at 2.5 to 12.0 g / 10 minutes,
(B) Density of 0.910 to 0.925 g / cc,
It is characterized by (c) a melt flow ratio of 6.0 to 7.6 of I10 / I2 and (d) a molecular weight distribution of 2.25 to 4.0 (Mw / Mn ) .
The release layer composition comprises a linear low density polyethylene or a release layer polyethylene composition containing a reaction product of ethylene and optionally one or more alpha olefin comonomer, and the release layer polyethylene composition is described below. Characteristics:
(A) Melt index I2 at 2.5 to 12.0 g / 10 minutes,
(B) Density of 0.910 to 0.925 g / cc,
A method comprising (c) one or more of a melt flow ratio I10 / I2 of 6.0-7.6 and (d) a molecular weight distribution (Mw / Mn) of 2.25-4.0. ..