Multilayer film and method for preparing the same

Abstract

The present invention discloses a multilayer film, comprising a first layer, a second layer and a third layer. The first layer comprises at least one aromatic polyester and has a loss modulus of at least 70 MPa at 1 Hz and 25° C. The second layer is thermoplastic and has a loss modulus of less than or equal to 60 MPa at 1 Hz and 25° C., and comprises a thermoplastic elastomer and a polyamide. The third layer contacts the second layer and is opposite to the first layer, and has a loss modulus of at least 70 MPa at 1 Hz and 25° C. The second layer is sandwiched between the first layer and the third layer. The present invention also discloses a method for preparing the multilayer film by coextrusion.

Description

Technical Field

[0001] The present disclosure relates broadly to multilayer films and methods of making the same. Background Art

[0002] Thermoplastic protective films are used in a variety of applications, including, for example, as window protective films, vehicle paint protective films, temporary access carpets, and electronic display protective parts. In some of these applications, an adhesive layer is applied to one major surface of the thermoplastic protective film.

[0003] For some applications, thermoplastic protective films are thermoformed to provide a specific shape. Thermoforming is a widely used technique in which a plastic film is typically heated and vacuumed into a mold. Exemplary thermoformed films include protective packaging films (e.g., blister packs) used to protect merchandise, dental aligners, battery protection, and smartphone covers.

[0004] For these and other applications, there continues to be a need for thermoplastic films having excellent clarity, low haze, and excellent toughness (eg, with respect to puncture and tear). Summary of the invention

[0005] In the case of multilayer protective films, separation between adjacent layers during use may result in aesthetically and / or mechanically undesirable changes in the film. Advantageously, multilayer films according to the present disclosure can be fine-tuned for clarity, low haze, and toughness (e.g., with respect to punctures and tears) as required for specific applications, and are resistant to interlayer delamination during use.

[0006] In a first aspect, the present disclosure provides a multilayer film comprising:

[0007] a first layer, wherein the first layer is thermoplastic, comprises at least one aromatic polyester, and has a loss modulus of at least 70 MPa at 1 Hz and 25°C;

[0008] A second layer, the second layer contacting the first layer, wherein the second layer is thermoplastic and has a loss modulus less than or equal to 60 MPa at 1 Hz and 25° C., and comprises:

[0009] Thermoplastic elastomers; and

[0010] A polyamide resin, the polyamide resin being the reaction product of:

[0011] (i) a dicarboxylic acid, wherein the dicarboxylic acid comprises a non-aromatic dicarboxylic dimer acid, and the mole fraction of the non-aromatic dicarboxylic dimer acid is between 0.10 and 1.00 based on the total moles of the dicarboxylic acid used to form the polyamide resin; and

[0012] (ii) a diamine, and wherein the polyamide resin is amine terminated and comprises amine end groups; and

[0013] a third layer, the third layer contacting the second layer, wherein the third layer is thermoplastic, comprises at least one aromatic polyester, and has a loss modulus of at least 70 MPa at 1 Hz and 25°C; and

[0014] The second layer is sandwiched between the first layer and the third layer.

[0015] In a second aspect, the present disclosure provides a method of preparing a multilayer film, the method comprising coextruding a first layer, a second layer, and a third layer, wherein:

[0016] The first layer is thermoplastic, comprises at least one aromatic polyester, and has a loss modulus of at least 70 MPa at 1 Hz and 25°C;

[0017] The second layer contacts the first layer, and wherein the second layer is thermoplastic and has a loss modulus less than or equal to 60 MPa at 1 Hz and 25° C., and comprises:

[0018] Thermoplastic elastomers; and

[0019] A polyamide resin, the polyamide resin being the reaction product of:

[0020] (i) a dicarboxylic acid, wherein the dicarboxylic acid comprises a non-aromatic dicarboxylic dimer acid, and the mole fraction of the non-aromatic dicarboxylic dimer acid is between 0.10 and 1.00 based on the total moles of the dicarboxylic acid used to form the polyamide resin; and

[0021] (ii) a diamine, and wherein the polyamide resin is amine terminated and comprises amine end groups; and

[0022] The third layer is thermoplastic, has a loss modulus of at least 70 MPa at 1 Hz and 25° C., and comprises at least one aromatic polyester; and

[0023] The second layer is sandwiched between the first layer and the third layer.

[0024] As used herein, the term "elastomer" refers to an elastic polymer.

[0025] As used herein, the term "polymer" encompasses copolymers (eg, polyester encompasses copolyesters).

[0026] The loss modulus values ​​referred to herein may be determined in accordance with ASTM test method D5026-15 (2015), entitled "Standard Test Method for Plastics: Dynamic Mechanical Properties: In Tension."

[0027]

[0026] A further understanding of the features and advantages of the present disclosure will be achieved upon consideration of the detailed description and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic side view of an exemplary multilayer film 100 according to the present disclosure.

[0029] Reference symbols used repeatedly in the specification and drawings are intended to represent the same or similar features or elements of the present disclosure. It should be understood that those skilled in the art can design many other modifications and embodiments that fall within the scope and essence of the principles of the present disclosure. The drawings may not be drawn to scale. DETAILED DESCRIPTION

[0030] Reference now Figure 1 , the exemplary multilayer film 100 includes a first layer, a second layer, and a third layer (110, 120, and 130, respectively). The second layer 120 is sandwiched between the first layer 110 and the third layer 130. The optional fourth layer 140 is sandwiched between the third layer 130 and the fifth layer 150. The optional sixth layer 160 is sandwiched between the optional fifth layer 150 and the optional seventh layer 170. Although not required, in some preferred embodiments, the even-numbered layers (e.g., layers 120, 140, and 160) have the same composition, and the odd-numbered layers (e.g., layers 110, 130, 150, and 170) all have the same composition.

[0031] The odd-numbered (i.e., first, third, fifth, and seventh) layers, which may be the same or different, are thermoplastic, have a loss modulus of at least 70 megapascals (MPa) at 1 Hz and 25° C. (e.g., at least 75 MPa, at least 80 MPa, at least 85 MPa, at least 90 MPa, at least 95 MPa, at least 100 MPa, at least 110 MPa, at least 120 MPa, at least 130 MPa, at least 140 MPa, at least 150 MPa, at least 160 MPa, at least 170 MPa, or at least 180 MPa), and each independently comprises at least one aromatic polyester. Exemplary suitable aromatic polyesters include polyethylene terephthalate (PET), polyethylene naphthalate (PEN) (e.g., 2,6-polyethylene naphthalate), and glycol-modified polyethylene terephthalate (PETG).

[0032] PET and PEN are widely available from commercial suppliers. PETG is a polyethylene terephthalate copolyester modified by polymerizing a trace amount of cyclohexanediol or other glycols with ethylene glycol. Other glycols include propylene glycol, diethylene glycol or any other linear low molecular weight except ethylene glycol. PETG is generally an amorphous polyester of terephthalic acid esterified with a mixture of mainly ethylene glycol and a small amount of 1,4-cyclohexanedimethanol. PETG is commercially available from various commercial manufacturers and suppliers, including commercially available from Eastman Chemical Company (EastmanChemical Company) under the trade name "EASTAR". Particularly useful commercially available PETG polymers include EASTAR 6763 and GN071 purchased from Eastman Chemical Company (Eastman Chemical, Kingsport, Tennessee) in Kingsport, Tennessee, USA. The amount of the component derived from 1,4-cyclohexanedimethanol or other diols is about 0.5 to about 20 parts by weight, and preferably about 1 to about 5 parts by weight, based on the total 100 parts by weight of PETG.

[0033] In many preferred embodiments, blends of PETG and PET, or blends of PETG and PEN are used. In some preferred embodiments, blends of PET or PEN with glycol-modified polyethylene terephthalate in respective weight ratios of 4:1 to 9:1 are used.

[0034] The even-numbered (i.e., second, fourth, and sixth) layers are thermoplastic, have a loss modulus of less than or equal to 60 MPa (e.g., less than or equal to 55 MPa, less than or equal to 50 MPa, less than or equal to 45 MPa, less than or equal to 40 MPa, less than or equal to 35 MPa, or less than or equal to 30 MPa) at 1 Hz and 25°C, and each independently comprises a thermoplastic elastomer and a polyamide resin, the polyamide resin being the reaction product of: (i) a dicarboxylic acid, wherein the dicarboxylic acid comprises a non-aromatic dicarboxylic dimer acid, and the mole fraction of the non-aromatic dicarboxylic dimer acid is between 0.10 and 1.00, based on the total moles of the dicarboxylic acid used to form the polyamide resin; and (ii) a diamine, and wherein the polyamide resin is amine-terminated and comprises amine end groups.

[0035] Exemplary suitable elastomers include at least one of a thermoplastic ionomeric elastomer, a thermoplastic polyurethane elastomer, a thermoplastic polyester elastomer, a thermoplastic polyolefin elastomer (TPO), an EP-diene rubber (EPDM), a thermoplastic copolyester elastomer, a thermoplastic polyether block amide elastomer, a styrene block copolymer elastomer, an elastomeric copolymer of ethylene and propylene (EPR), or an ethylene-vinyl acetate (EVA) elastomer. Elastomers of the above types are widely available from commercial suppliers in a variety of grades.

[0036] In some preferred embodiments, the thermoplastic elastomer includes a styrene block copolymer elastomer, such as, for example, styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS), styrene-(ethylene-butylene)-styrene (SEBS), styrene-(ethylene-propylene)-styrene (SEPS). Typically, these elastomers contain 10% to 70% by weight or more of non-styrene monomers. Such polymers are widely available from commercial manufacturers, such as, for example, from Kraton Corp., Houston, Texas, USA, under the trade name KRATON.

[0037] The polyamide resin of the present disclosure is the reaction product of: (i) a dicarboxylic acid, wherein the dicarboxylic acid includes a dicarboxy dimer acid, and the mole fraction of the dicarboxy dimer acid is between 0.10 and 1.00 based on the total moles of the dicarboxylic acid used to form the polyamide resin; and (ii) a diamine; and wherein the polyamide resin is amine-terminated and includes amine end groups. In some embodiments, the polyamide resin of the present disclosure is the reaction product of: (i) a dicarboxylic acid, wherein the dicarboxylic acid includes a non-aromatic dicarboxy dimer acid, and the mole fraction of the non-aromatic dicarboxy dimer acid is between 0.10 and 1.00 based on the total moles of the dicarboxylic acid used to form the polyamide resin; and (ii) a diamine; and wherein the polyamide resin is amine-terminated and includes amine end groups. The use of at least 10 mol % (i.e., a mole fraction of 0.1) dimer acid (e.g., non-aromatic dimer acid) imparts unique properties to the resulting polyamide resin. Dimer acid destroys the structural regularity of polyamide, thereby significantly reducing or eliminating crystallinity, while maintaining H-bond interactions in the resulting polyamide resin. Surprisingly, the polyamide resin of the present disclosure includes amine end-capping, which is used as a toughening agent and curing agent for the curable composition of the present disclosure. Although not wishing to be bound by theory, it is believed that once cured in the curable composition of the present disclosure, the reduction and / or elimination of the crystallinity of the polyamide resin imparts enhanced toughening and flexibility characteristics.

[0038] The dicarboxylic acid that can be used to synthesize the polyamide resin disclosed herein is not particularly limited, except that the dicarboxylic acid includes dicarboxyl dimer acid, and based on the total mole number of dicarboxylic acids used to form the polyamide resin, the mole fraction of dicarboxyl dimer acid is between 0.10 and 1.00. The dicarboxylic acid may include at least one alkyl group or alkenyl group, and may contain 3 to 30 carbon atoms, and is characterized in that it has two carboxylic acid groups. The alkyl group or alkenyl group may be branched. The alkyl group may be cyclic. Available dicarboxylic acids may include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecane dioic acid, dodecanedioic acid, hexadecanedioic acid, (Z)-butenedioic acid, (E)-butenedioic acid, pentane-2-enedioic acid, dodecanedioic acid, (2Z)-2-methylbut-2-enedioic acid, (2E, 4E)-hexane-2,4-dienedioic acid. Aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid and 2,6-naphthalene dicarboxylic acid can be used. However, due to their aromatic structure, aromatic dicarboxylic acids can reduce the flexibility of polyamide resins, which may limit their practicality in some applications. In some embodiments, the dicarboxylic acid contains between 0% and 30%, between 0% and 20%, between 0% and 10%, between 0% and 5%, or even between 0% and 2% aromatic dicarboxylic acids based on the total moles of dicarboxylic acids used to form the polyamide resin. Aromatic dicarboxylic acids are defined as dicarboxylic acids in which the ratio R of the number of carbon atoms in one or more aromatic groups to the total number of carbon atoms in the dicarboxylic acid is 0. c is at least 0.25, at least 0.33, at least 0.37, at least 0.42, at least 0.5, at least 0.6, or even higher. For example, terephthalic acid has a total of 8 carbon atoms, 6 of which are in the aromatic group. Thus, the ratio R c will be equal to 0.75. Mixtures of two or more dicarboxylic acids may be used and may be preferred because mixtures of different dicarboxylic acids will help to disrupt the structural regularity of the polyamide, thereby significantly reducing or eliminating the crystallinity of the resulting polyamide resin.

[0039] The dicarboxyl dimer acid that can be used to synthesize the polyamide resin disclosed herein is not particularly limited. The dicarboxyl dimer acid can include at least one alkyl group or alkenyl group, and can contain 12 to 100 carbon atoms, 16 to 100 carbon atoms or even 18 to 100 carbon atoms, and is characterized in that it has two carboxylic acid groups. The dimer acid can be saturated or unsaturated. In some embodiments, the dimer acid can be a dimer of a fatty acid. As used herein, the phrase "fatty acid" means an organic compound consisting of an alkyl group or alkenyl group containing 5 to 22 carbon atoms, and is characterized in that it has a terminal carboxylic acid group. Available fatty acids are disclosed in "Fatty Acids in Industry:Processes,Properties,Derivatives,Applications (Fatty Acids in Industry: Methods, Characteristics, Derivatives, Applications)", Chapter 7, Pages 153 to 175, Marcel Dekker, Inc., 1989. In some embodiments, the dimer acid can be formed by dimerization of unsaturated fatty acids with 18 carbon atoms, such as oleic acid or tall oil fatty acids. Dimer acids are typically at least partially unsaturated and typically contain 36 carbon atoms. Dimer acids can have a relatively high molecular weight and are composed of a mixture of various large or relatively high molecular weight substituted cyclohexene carboxylic acids (mainly 36-carbon dicarboxyl dimer acids) comprising various ratios. The component structures can be acyclic, cyclic (monocyclic or dicyclic) or aromatic, as shown below. Note that the dimer acid structures below that contain aromatic rings will be considered non-aromatic dicarboxylic acids because R c will be 0.167.

[0040]

[0041]

[0042] Dimer acids can be prepared by condensing unsaturated monofunctional carboxylic acids such as oleic acid, linoleic acid, soy acid, or tall oil acid through their ethylenically unsaturated groups in the presence of a catalyst such as an acidic clay. 36The distribution of various structures in dicarboxylic acid (dicarboxylic acid) depends on the unsaturated acid used in its manufacture. Typically, oleic acid produces dicarboxylic dimer acids containing about 38% acyclic compounds, about 56% monocyclic and dicyclic compounds, and about 6% aromatic compounds. Soybean acid produces dicarboxylic dimer acids containing about 24% acyclic compounds, about 58% monocyclic and dicyclic compounds, and about 18% aromatic compounds. Tall oil acid produces dicarboxylic dimer acids containing about 13% acyclic compounds, about 75% monocyclic and dicyclic compounds, and about 12% aromatic compounds. The dimerization process also produces trimer acids. Commercial dimer acid products are usually purified by distillation to produce a range of dicarboxylic acid contents. Available dimer acids contain at least 80% dicarboxylic acids, more preferably 90% dicarboxylic acid content, and even more preferably at least 95% dicarboxylic acid content. For some applications, it may be advantageous to further purify the dimer acid by color reduction techniques (including hydrogenation of unsaturated groups), as disclosed in U.S. Pat. No. 3,595,887 (Kulkarni et al.). Hydrogenated dimer acid can also provide enhanced oxidative stability at elevated temperatures. Other available dimer acids are disclosed in Kirk-Othmer Encyclopedia of Chemical Technology, Organic Chemicals: Dimer Acids (ISBN 9780471238966) Copyright 1999-2014, John Wiley and Sons, Inc. Available dimer acids contain at least 80% dicarboxylic acid, more preferably 90% dicarboxylic acid content, even more preferably at least 95% dicarboxylic acid content. For some applications, it may be advantageous to further purify the dimer acid by color reduction techniques (including hydrogenation of unsaturated groups), as disclosed in U.S. Pat. No. 3,595,887 (Kulkarni et al.). Hydrogenated dimer acid can also provide enhanced oxidative stability at elevated temperatures. Other available dimer acids are also disclosed in Kirk-Othmer Encyclopedia of Chemical Technology, Organic Chemicals: Dimer Acids (ISBN 9780471238966) Copyright 1999-2014, John Wiley and Sons, Inc.Commercially available dicarboxy dimer acids are, for example, available under the trade names EMPOL 1008 and EMPOL 1061 from BASF, Florham Park, New Jersey, and under the trade names PRIPOL 1006, PRIPOL 1009, PRIPOL 1013, PRIPOL 1017, and PRIPOL 1025 from Coroda Inc., Edison, New Jersey.

[0043] In some embodiments, the number average molecular weight of the dicarboxy dimer acid (e.g., non-aromatic dicarboxy dimer acid) can be between 300 g / mol and 1400 g / mol, between 300 g / mol and 1200 g / mol, between 300 g / mol and 1000 g / mol, or even between 300 g / mol and 800 g / mol. In some embodiments, the number of carbon atoms in the dicarboxy dimer acid (e.g., non-aromatic dicarboxy dimer acid) can be between 12 and 100, between 20 and 100, between 30 and 100, between 12 and 80, between 20 and 80, between 30 and 80, between 12 and 60, between 20 and 60, or even between 30 and 60. The mole fraction of the dicarboxylic acid dimer acid (e.g., non-aromatic dicarboxylic acid dimer acid) included as the dicarboxylic acid is between 0.10 and 1.00, based on the total moles of the dicarboxylic acid used to form the polyamide resin. In some embodiments, the mole fraction of the dicarboxylic acid dimer acid (e.g., non-aromatic dicarboxylic acid dimer acid) included as the dicarboxylic acid is between 0.10 and 1.00, between 0.30 and 1.00, between 0.50 and 1.00, between 0.70 and 1.00, between 0.80 and 1.00, between 0.90 and 1.00, between 0.10 and 0.95, between 0.30 and 0.95, between 0.50 and 0.95, between 0.70 and 0.95, between 0.80 and 0.95, or even between 0.90 and 0.95, based on the total moles of the dicarboxylic acid used to form the polyamide resin. In some embodiments, the mole fraction of the dicarboxylic dimer acid (eg, non-aromatic dicarboxylic dimer acid) included as the dicarboxylic acid is 1.00 based on the total moles of dicarboxylic acids used to form the polyamide resin. A mixture of two or more dimer acids may be used.

[0044] The diamines that can be used to synthesize the polyamide resin disclosed herein are not particularly limited. The diamines are generally alkylenediamines or heteroalkylenediamines. The previously disclosed diamines of the oxazine resins can be used to synthesize the polyamide resins. The preferred diamines have the formula H 2 NR n NH 2 , where R n It can be a straight chain or branched aliphatic, alicyclic or aromatic group. n It can also be a polyether bond, so that the diamine belongs to the diamine family sold under the trade name "JEFFAMINE" and purchased from Huntsman Corp, Salt Lake City, Utah, USA. The diamine can also be an amine-terminated butadiene or butadiene-acrylonitrile, such as butadiene or butadiene-acrylonitrile sold under the trade name "HYPRO" and purchased from CVC Thermoset Specialties, a division of Emerald Performance Materials, Moorestown, New Jersey, USA. The diamine can also be a dimer diamine, such as a dimer diamine sold under the trade name "PRIAMINE" and purchased from Croda, Inc., New Castle, Delaware. Mixtures of diamines can be used. Aromatic diamines can also be used. However, in some embodiments, the diamine does not contain an aromatic moiety, that is, the diamine does not contain an aromatic moiety. The diamine can be a low molecular weight molecule, an oligomeric molecule, or even a low molecular weight polymer molecule. The diamine can be an amine-terminated polymer, such as at least one of an amine-terminated polyethylene glycol and an amine-terminated polypropylene glycol. In some embodiments, the diamine has the following structure: 2 NR 1 NH 2 , where R 1 is at least one of an aliphatic, alicyclic, and aromatic hydrocarbon having 2 to 20 carbon atoms. In some embodiments, the diamine has the following structure: 2 NR 1 NR 1 H, where R 1 is at least one of an aliphatic, alicyclic, and aromatic hydrocarbon having 2 to 20 carbon atoms. In some embodiments, the diamine has the following structure: HR 4 NR 4 NR 4 H, where R 4 is at least one of an aliphatic, alicyclic, and aromatic hydrocarbon having 2 to 20 carbon atoms. 4The group may be cyclized as with piperazine. Other examples include, but are not limited to, aminoethylpiperazine (mixed primary and secondary diamines); 4,4'-(1,3-propanediyl)bispiperidine; 1,3-di-4-piperidinylpropane, which can be purchased from Vertellus Industrial Specialties, Indianapolis, Indiana, USA under the trade name "DIPIP"; alicyclic bis(secondary amines) purchased from Huntsman International, LLC, Salt Lake City, Utah, USA under the trade name "JEFFLINK 754 DIAMINE" and aliphatic secondary diamines purchased from Dorf Ketal, Houston, Texas, USA under the trade name "CLEARLINK 1000". Combinations of two or more of the various diamines may also be used. In some embodiments, secondary diamines can be used alone or in combination with primary diamines. Secondary amines can help reduce the density of the H-bond network, which can help improve toughening. By changing the ratio of primary diamines to secondary diamines, the mechanical properties of the cured curable composition, such as modulus, can be changed.

[0045] In some embodiments, the number average molecular weight of the diamine is between 60g / mol and 10000g / mol, between 60g / mol and 5000g / mol, between 60g / mol and 4000g / mol, between 60g / mol and 3000g / mol, between 100g / mol and 10000g / mol, between 100g / mol and 5000g / mol, between 100g / mol and 4000g / mol, between 100g / mol and 3000g / mol, between 200g / mol and 10000g / mol, between 200g / mol and 5000g / mol, between 200g / mol and 4000g / mol, or even between 200g / mol and 3000g / mol. The amine groups of the diamine can be at least one of a primary amine and a secondary amine. In some embodiments, the amine groups of the diamine can all be primary amines. In some embodiments, the amine groups of the diamine can all be secondary amines. In some embodiments, the amine groups of the diamine can be primary amines and secondary amines. A mixture of amines having two primary amines, two secondary amines, or one primary amine and one secondary amine can be used.

[0046] The polyamide resin of the present disclosure can be formed after a conventional condensation reaction between at least one dicarboxylic acid and at least one diamine. A mixture of at least two dicarboxylic acid types and at least one diamine, a mixture of at least two diamine types and at least one dicarboxylic acid type, or a mixture of at least two dicarboxylic acid types and at least two diamine types can be used. The polyamide resin of the present disclosure is amine terminated and includes amine end groups. Amine termination can be obtained by using an appropriate stoichiometric ratio of amine groups to acid groups (e.g., an appropriate stoichiometric ratio of diamines to dicarboxylic acids) during polyamide synthesis. In some embodiments, the molar ratio of diamine to dicarboxylic acid is between 1.01 / 1.00 and 2.00 / 1.00, between 1.01 / 1.00 and 1.90 / 1.00, between 1.01 / 1.00 and 1.80 / 1.00, between 1.01 / 1.00 and 1.70 / 1.00, between 1.01 / 1.00 and 1.60 / 1.00, between 1.01 / 1.00 and 1.50 / 1.00, between 1.01 / 1.00 and 1.40 / 1.00, between 1.05 / 1.00 and 2.00 / 1.00, between 1.05 / 1.00 and 1.90 / 1.00, between 1.05 / 1.00 and 1.80 / 1.00, between 1.01 / 1.00 and 1.70 / 1.00, between 1.01 / 1.00 and 1.80 / 1.00, between 1.01 / 1.00 and 1.9 ... 1.00, between 1.05 / 1.00 and 1.70 / 1.00, between 1.05 / 1.00 and 1.60 / 1.00, between 1.05 / 1.00 and 1.50 / 1.00, between 1.05 / 1.00 and 1.40 / 1.00, between 1.10 / 1.00 and 2.00 / 1.00, between 1.10 / 1.00 and 1.90 / 1.00, between 1.10 / 1.00 and 1.80 / 1.00, between 1.10 / 1.00 and 1.70 / 1.00, between 1.10 / 1.00 and 1.60 / 1.00, between 1.10 / 1.00 and 1.50 / 1.00, or even between 1.10 / 1.00 and 1.40 / 1.00.

[0047] In some embodiments, the amine end groups of the polyamide resin may contain between 1 mol % and 100 mol %, between 10 mol % and 100 mol %, between 20 mol % and 100 mol %, between 30 mol % and 100 mol %, between 40 mol % and 100 mol %, between 50 mol % and 100 mol %, between 60 mol % and 100 mol %, or even between 70 mol % and 100 mol % primary amine end groups.

[0048] In some embodiments, the amine amount of the polyamide resin may be between 1 mg KOH / g and 80 mg KOH / g, between 2 mg KOH / g and 22 mg KOH / g, or even between 5 mg KOH / g and 15 mg KOH / g.

[0049] The polyamide resins of the present disclosure are capable of curing the curable compositions of the present disclosure without the use of catalysts or other curing agents. In some embodiments, a secondary curing agent may be used.

[0050] Compared to polyamides that do not contain dicarboxylic dimer acid, polyamide resins of the present disclosure that contain dicarboxylic dimer acid at a mole fraction of at least 0.1 based on the total moles of dicarboxylic acid used to form the polyamide resin have unique properties. Polyamide resins are characterized by low or no crystallinity, low softening point, and generally low transition temperature range (melting temperature and low glass transition temperature). These characteristics are in contrast to highly crystalline nylon-based polyamides known in the art (which are generally highly crystalline and have high melting temperatures). In some embodiments, the polyamide resin is an amorphous polyamide resin. It has been found that when the polyamide resins of the present disclosure are used as benzoic acid Azine resins (e.g., bisphenol-A-benzo Oxazine and / or bisphenol-F-benzo When a curing agent such as oxazine is used, the resulting cured composition has a surprisingly high glass transition temperature, above 220°C, 230°C, or even above 240°C, and improved flexibility and toughness. The resulting properties make the curable composition suitable for a variety of applications (e.g., use as a high temperature protective coating for metals. In some embodiments, the polyamide resin is a liquid at room temperature. In some embodiments, the polyamide resin is a solid (e.g., a powder or pellet) at room temperature.

[0051] Useful commercially available polyamide resins include those available under the trade name MACROMELT (e.g., MACROMELT OM 633, MACROMELT OM 641, MACROMELT OM 652, MACROMELT OM 673, MACROMELT OM 6208, MACROMELT 7001, MACROMELT 7002, MACROMELT 7003) from Henkel Corp., Rocky Hill, Connecticut, USA; polyamide resins available under the trade name UNI-REZ (e.g., UNI-REZ 2600, UNI-REZ 2620, UNI-REZ 2700, and UNI-REZ 2720) from Arizona Chemical LLC, Jacksonville, Florida, USA; and polyamide resins available under the trade name VERSAMID (e.g., VERSAMID VERSAMID 100 and VERSAMID 115×70) are polyamide resins available from Gabriel Performance Chemicals, Ashtabula, Ohio, U.S. Other useful polyamide resins are disclosed in U.S. Pat. Nos. 3,377,303 (Peerman et al.); 3,242,141 (Vertnik et al.); and 3,483,237 (Vertnik et al.).

[0052] Although Figure 1 A 7 layer multilayer film is shown, but it is contemplated that additional layers (e.g., 9, eleven, thirteen, or any other odd number of layers) may be included in the film by adding alternating layers having a relatively low loss modulus (e.g., as in the second layer) and a relatively high loss modulus (e.g., as in the third layer).

[0053] The multilayer film can have any thickness. In some embodiments, the thickness is in the range of 10 microns to 600 microns, more preferably 50 microns to 270 microns, more preferably 150 microns to 200 microns. Similarly, the individual layers constituting the multilayer film can have any desired thickness. For example, in some embodiments, the odd-numbered (first, third, etc.) layers are 20 microns to 30 microns, and the even-numbered (second, fourth, etc.) layers are 1.5 microns to 2.5 microns.

[0054] If desired, one or more layers in the multilayer film may include other ingredients, such as opacifying pigments, colorants, mineral fillers, stabilizers, lubricants, UV absorbers, processing aids and other additives as needed. Exemplary available UV absorbers include benzophenone, benzotriazole and triazine. Available fillers include clay, silicon dioxide, talc, mica, wollastonite, barium sulfate and calcium carbonate. If desired, available antioxidants may be used and include phenolic antioxidants, while available light stabilizers include organic phosphates and organotin mercaptides (thiolates). Available lubricants include metal stearates, paraffin and wax.

[0055] In some preferred embodiments, the multilayer film is uniaxially oriented or biaxially oriented, but this is not required. Orientation can affect properties such as tensile strength, toughness, thermal stability, tear resistance, and effectiveness as a gas barrier.

[0056] In some preferred embodiments, the multilayer film has a transparency of at least 90%, preferably at least 95%, more preferably at least 97%, even more preferably at least 99% if viewed parallel to the thickness of the multilayer film, but this is not required.

[0057] In some preferred embodiments, the multilayer film has a transmission haze of less than 5%, more preferably less than 4%, more preferably less than 3%, and even more preferably less than 1% if viewed parallel to the thickness of the multilayer film, but this is not required.

[0058] The multilayer film of the present patent application can be prepared using any known method.

[0059] Coextrusion is a known process for making films. For the present application, coextrusion means the simultaneous melt processing of multiple melt streams and the combining of such melt streams into a single integral structure or coextruded film, for example from a single extrusion die.

[0060] The process is usually carried out in the following manner: the feedstock is processed by a die head at or above the melting temperature of the feedstock to form a coextruded film. Coextruded film is usually a composite of all molten feedstocks present in the coextruded process. The resulting coextruded film is usually multilayer. In the molten state, these layers are in contact with each other. In certain embodiments, these layers are in contact during the entire extrusion process, for example, they are in contact in the die head.

[0061] Alternatively, the multilayer film can be prepared by continuous tandem extrusion, wherein one layer is extruded onto the laminated portion at a time, or can be prepared by a combination of coextrusion and tandem extrusion. The multilayer film can also be prepared by laminating the layers together, as is known in the art. In addition, the multilayer film can be prepared by any combination of coextrusion, tandem extrusion, and lamination.

[0062] The coextruded multilayer film may also be further processed, for example by orientation. An example of film orientation is biaxial orientation. Biaxial orientation involves stretching the film in two directions perpendicular to each other, typically in the downweb and crossweb directions. In a typical operation, the freshly extruded molten film is fed to chill rolls to produce a quenched amorphous film, which is briefly heated and stretched in the longitudinal direction of the web, and then stretched transversely by a tenter under moderate heating conditions. The longitudinal direction stretching of the web may be accomplished by transfer between two sets of rollers, the second set rotating at a higher speed than the first set. Biaxial orientation may be simultaneous or sequential.

[0063] Additional details regarding coextrusion can be found, for example, in US Pat. Nos. 3,565,985 (Schrenk et al.), 3,555,128 (Schrenk et al.), 3,448,183 (Chisholm et al.), and 4,405,547 (Koch et al.).

[0064] Objects and advantages of this disclosure are further illustrated by the following non-limiting examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this disclosure.

[0065] Example

[0066] Unless otherwise indicated, all parts, percentages, ratios, etc. in the examples and the rest of the specification are by weight.

[0067] In the examples, all loss modulus values ​​are at one Hertz and 25° C. according to ASTM test method D5026-15 unless otherwise indicated.

[0068] Table 1 below reports the materials used in the examples.

[0069] Table 1

[0070]

[0071]

[0072] Examples 1 to 6 and Comparative Examples A to E

[0073] Film cast sheets of the ABCBA structure were prepared using three extruders, all of which were purchased from Leistritz Extrusionstechnik GMBH, Nuremberg, Germany. Layer A used an 18 mm twin screw extruder with a temperature profile of: Zone 1: 260°C, Zone 2 and Zone 3: 265°C, Zone 4 to Zone 6: 268°C, Zone 7 and Zone 8: 271°C. Layer B was a 27 mm twin screw extruder with a temperature profile of: Zone 1: 121°C, Zone 2: 135°C, Zone 3: 149°C, Zone 4: 163°C, Zone 5: 190°C, Zone 6 to Zone 8: 204°C. For the samples with R4, the temperature profile of the layer B extruder was: Zone 1: 149°C, Zone 2: 163°C, Zone 3: 177°C, Zone 4: 190°C, Zone 5: 204°C, Zone 6: 218°C, Zone 7: 265°C, Zone 8: 282°C. Layer C was a 25 mm twin screw extruder with a temperature profile of: Zone 1: 232°C, Zone 2: 246°C, Zone 3: 254°C, Zone 4: 260°C, Zone 5: 265°C, Zone 6 to die: 271°C. All extrusion rates are provided in Table 2 in kg / hr. All thermoplastics in pellet form were fed into the twin screw extruder with a feeder (Model KCL24 / KQX4, purchased from Coperion K-Tron America, Pitman, New Jersey, USA). Table 2 below reports the description of the prepared film cast sheets, where A = skin layers (first and fifth layers), B = tie layers (second and fourth layers) and C = center layer (third layer).

[0074]

[0075] The film cast sheets of Examples 1 to 11 were tested for tensile properties and Elmendorf tear resistance by the specified methods. Table 3 reports the mechanical properties obtained for these film cast sheets. The incorporation of the adhesion promoter increased the interlayer adhesion between the B layer and the surface (A) layer and between the B layer and the center (C) layer. It is difficult to quantify the level of adhesion, but the layers could not be separated with the aid of strong tape and rapid pulling, nor did they separate during thermoforming or stretching.

[0076]

[0077] The film cast sheets of Examples 1 to 6 and Comparative Examples A to E were also tested for haze and transmittance by the specified methods. All tests showed a transmittance close to 92%, and many showed a haze level below 2%. The results are reported in Table 4 below.

[0078] Table 4

[0079] Example Film thickness, mm Transmittance, % Haze, % A 0.39 92.6 3.4 1 0.40 92.2 1.8 B 0.40 91.9 2.9 2 0.39 91.7 50.0 C 0.45 92.4 1.5 3 0.39 92.2 1.7 4 0.34 92.5 1.6 5 0.35 92.3 1.8 D 0.36 92.5 2.4 6 0.37 92.0 35.8 E 0.41 92.3 6.1

[0080] Example 7

[0081] The film prepared from the cast sheet of Example 1 was thermoformed using a pressure molding machine for dental devices, BIOSTAR VI (Scheu-Dental GmbH, Iserlohn, Germany). The film cast sheet was then punched into 125 mm diameter discs. The discs were placed on the BIOSTAR and heated to 150° C. using an infrared heater and then thermoformed at a pressure of 91 psi (627 kPa) against a 3D printed mold aligned to the tray. The thermoformed tray was then trimmed using an ultrasonic cutter and manually removed from the 3D printed mold.

[0082] Examples 8 and 9

[0083] Film cast sheets of the ABCBA structure were prepared using three extruders, all of which were purchased from Leistritz Extrusionstechnik GMBH, Nuremberg, Germany. Layer A used an 18 mm twin screw extruder with a temperature profile of: Zone 1: 260°C, Zone 2 and Zone 3: 265°C, Zone 4 to Zone 6: 268°C, Zone 7 and Zone 8: 271°C. Layer B was a 27 mm twin screw extruder with a temperature profile of: Zone 1: 121°C, Zone 2: 135°C, Zone 3: 149°C, Zone 4: 163°C, Zone 5: 190°C, Zone 6 to Zone 8: 204°C. Layer C was a 25 mm twin screw extruder with a temperature profile of: Zone 1: 232°C, Zone 2: 246°C, Zone 3: 254°C, Zone 4: 260°C, Zone 5: 265°C, Zone 6 to die: 271°C. All extrusion rates are provided in Table 5 in kg / hr. All thermoplastics in pellet form were fed into the twin screw extruder with a feeder (Model KCL24 / KQX4, purchased from Coperion K-Tron America, Pitman, New Jersey). The final film cast sheet thickness ranged from 52 mils to 55 mils (1.32 mm to 1.40 mm). The following Table 5 reports the description of the film cast sheets produced, where A = skin layers (first and fifth layers), B = tie layers (second and fourth layers) and C = center layer (third layer).

[0084] Table 5

[0085]

[0086] Examples 10 to 19

[0087] A square of 100 mm × 100 mm was cut from the initial film casting sheet. The square was loaded and stretched using a laboratory biaxial film stretching machine (KAROIV, purchased from Bruckner Maschinenbau GmbH & Co. KG, Siegsdorf, Germany). Temperatures in the range of 95°C to 130°C were used as set points in all zones of the machine, as indicated in Table 6, and the fan speed setting was then set to 50%. The film casting sheet was biaxially stretched simultaneously at a speed of 10% / second. 45 seconds of preheating and 30 seconds of post-heating were used. During post-heating, the film was held and clamped at the maximum stretching reached during the cycle. The thickness of the finished stretched film was measured using a calliper. The following table 6 reports the process conditions for preparing the stretched (oriented) film.

[0088] Table 6

[0089] Example Film Thickness, Mil (Micron) Stretch ratio (longitudinal × transverse) Stretching temperature, °C 10 16.0(406) n / a n / a 11 14.0(355) n / a n / a 12 6.0(152) 2.5×2.5 110 13 6.5(165) 2.5×2.5 120 14 7.5(190) 2.5×2.5 95 15 6.0(152) 2.5×2.5 110 16 6.5(165) 2.5×2.5 120 17 7.0(178) 2.5×2.5 130 18 3.0(76) 4.0×4.0 120 19 1.7(43) 5.0×5.0 120

[0090] Examples 20 to 22

[0091] Thirteen-layer films were prepared using two twin-screw extruders, each with a separate gravity feeder. The first extruder (A layer) was a fixed 40 mm extruder purchased from Berstorff, Germany, with a K-tron twin-screw feeder purchased from Coperion GmbH, Stuttgart, Germany. The second extruder was a portable 25 mm extruder purchased from Berstorff, Germany, with a portable K-Tron compact gravity feeder purchased from Coperion GmbH. The extruder temperature profile was: Zone 1: 176.7°C, Zone 2: 204.4°C, Zone 3: 232.2°C, Zone 4: 260°C, Zones 5 to 8: 273.9°C. The feed head and die were maintained at 273.9°C. The film was withdrawn from the die at a rate of about 3.6 fpm and then lengthwise oriented (Killion Davis Standard, Hartford, CT) with rolls 1 and 3 set at 79.5°C, rolls 2 and 4 set at 82°C, and roll 5 set at 54.5°C. After lengthwise orientation, the film was oriented in the transverse direction via a tenter (Cellier / Bruckner, Germany) with Zone 1: 87.8°C, Zone 2: 93.3°C, Zone 3: 98.9°C, Zones 4 to 6: 107.2°C, and Zones 7 and 8: 121.1°C. The final film thickness after orientation ranged from 0.12 mm to 0.14 mm. Table 7 below provides a description of a thirteen layer film, where the layers alternate such that Layer A = odd layers, and Layer B = even layers.

[0092] Table 7

[0093]

[0094] Examples 20 to 22 were tested for tensile properties and Elmendorf tear resistance (Table 8) by the specified methods, and for transmittance and haze (Table 9).

[0095]

[0096] All references, patents, and patent applications cited in this application are incorporated by reference in a consistent manner. In the event of inconsistencies or conflicts between the incorporated references and this application, the information in this application shall prevail. The foregoing description given to enable one of ordinary skill in the art to practice the disclosure protected by the claims should not be construed as limiting the scope of the disclosure, which is defined by the claims and all equivalents thereof.

Claims

1. A multilayer film, comprising: a first layer, wherein the first layer is thermoplastic, comprises at least one aromatic polyester, and has a loss modulus of at least 70 MPa at 1 Hz and 25°C; a second layer, the second layer contacting the first layer, wherein the second layer is thermoplastic and has a loss modulus less than or equal to 60 MPa at 1 Hz and 25° C., and comprises: Thermoplastic elastomers; and A polyamide resin, wherein the polyamide resin is the reaction product of: (i) a dicarboxylic acid, wherein the dicarboxylic acid comprises a non-aromatic dicarboxylic dimer acid, and The mole fraction of the non-aromatic dicarboxylic dimer acid is between 0.10 and 1.00 based on the total moles of dicarboxylic acids used to form the polyamide resin; and (ii) a diamine, and wherein the polyamide resin is amine-terminated and comprises amine terminal groups; and a third layer, the third layer contacting the second layer, wherein the third layer is thermoplastic, comprises at least one aromatic polyester, and has a loss modulus of at least 70 MPa at 1 Hz and 25°C; and wherein the second layer is sandwiched between the first layer and the third layer, and wherein the loss modulus at 1 Hz and 25° C. is determined according to ASTM test method D5026-15 (2015).

2. The multilayer film of claim 1, wherein the multilayer film has a transparency of at least 90% when viewed parallel to the thickness of the multilayer film.

3. The multilayer film of claim 1, wherein the multilayer film has a transmission haze of less than 5 haze % when viewed parallel to the thickness of the multilayer film.

4. The multilayer film of claim 1, wherein the multilayer film is uniaxially oriented or biaxially oriented.

5. The multilayer film of claim 1, wherein the at least one aromatic polyester comprises polyethylene terephthalate.

6. The multilayer film of claim 1, wherein the at least one aromatic polyester comprises glycol-modified polyethylene terephthalate.

7. The multilayer film of claim 1, wherein the at least one aromatic polyester comprises a blend of polyethylene terephthalate and a glycol-modified polyethylene terephthalate in a respective weight ratio of 4:1 to 9:

1.

8. The multilayer film of claim 1, wherein the thermoplastic elastomer comprises at least one of an ionomer elastomer, a thermoplastic polyurethane elastomer, a thermoplastic polyester elastomer, a thermoplastic copolyester elastomer, a thermoplastic polyether block amide elastomer, a styrene block copolymer elastomer, an elastomeric copolymer of ethylene and propylene, or an ethylene vinyl acetate elastomer.

9. The multilayer film of claim 1, further comprising a fourth layer and a fifth layer, wherein the fourth layer is sandwiched between the third layer and the fifth layer, wherein the second layer and the fourth layer have the same composition, and wherein the first layer, the third layer, and the fifth layer have the same composition.

10. The multilayer film of claim 9, further comprising a sixth layer and a seventh layer, wherein the sixth layer is sandwiched between the fifth layer and the seventh layer, wherein the second layer, the fourth layer, and the sixth layer have the same composition, and wherein the first layer, the third layer, the fifth layer, and the seventh layer have the same composition.

11. The multilayer film of claim 1, wherein the number average molecular weight of the non-aromatic dicarboxy dimer acid is between 300 g / mol and 1400 g / mol.

12. The multilayer film of claim 1, wherein the number of carbon atoms in the non-aromatic dicarboxy dimer acid is between 12 and 100.

13. A method of preparing a multilayer film, the method comprising coextruding a first layer, a second layer and a third layer, wherein: The first layer is thermoplastic, comprises at least one aromatic polyester, and has a loss modulus of at least 70 MPa at 1 Hz and 25°C; The second layer contacts the first layer, and wherein the second layer is thermoplastic and has a loss modulus less than or equal to 60 MPa at 1 Hz and 25° C., and comprises: Thermoplastic elastomers; as well as A polyamide resin, wherein the polyamide resin is the reaction product of: (i) a dicarboxylic acid, wherein the dicarboxylic acid comprises a non-aromatic dicarboxylic dimer acid, and The mole fraction of the non-aromatic dicarboxylic dimer acid is between 0.10 and 1.00 based on the total moles of dicarboxylic acids used to form the polyamide resin; and (ii) a diamine, and wherein the polyamide resin is amine terminated and comprises amine terminal groups; and The third layer contacts the second layer and is thermoplastic, has a loss modulus of at least 70 MPa at 1 Hz and 25° C., and comprises at least one aromatic polyester; and wherein the second layer is sandwiched between the first layer and the third layer, and wherein the loss modulus at 1 Hz and 25° C. is determined according to ASTM test method D5026-15 (2015).

Images