solvent-based laminating adhesive

Abstract

A crystalline polycarbonate-based two-component solvent-based polyurethane adhesive composition for producing adhesive laminate structures, comprising: (a) at least one isocyanate component; and (b) at least one isocyanate-reactive component comprising the reaction product of (i) at least one crystalline polycarbonate diol compound, (ii) at least one acrylic polymer compound, and (iii) at least one solvent, as well as a process for preparing the adhesive composition.

Description

Technical Field

[0001] The present invention relates to a solvent-based laminated adhesive composition and a process for preparing such a laminated adhesive composition.

Background Art

[0002] Laminated adhesives are used to bond different substrates together. A common use of such bonded substrates is in flexible food packaging applications. Laminated adhesives are typically applied to the surfaces of two polymer substrate layers to form a bonding layer between the two substrate layers. The adhesive forms a bonding layer between the substrate layers, providing a strong bond between the two substrate layers. The substrate structure bonded with the adhesive helps to keep the packaging structure intact and keeps the food inside the packaging structure safe and secure. The increasing demand in the flexible food packaging industry relates to laminated adhesives having good gas barrier properties such as reducing oxygen permeability through the layered structure of flexible food packaging. Laminated adhesives used to produce a layered food packaging structure exhibiting reduced oxygen permeability can potentially simplify the packaging structure, reduce costs during use, and make food packaging recyclable. Therefore, it is desirable to provide a laminated adhesive having improved oxygen barrier performance, such as an adhesive showing lower oxygen permeability compared to standard adhesives. In particular, it is desirable to provide a laminated adhesive based on a crystalline polycarbonate compound such that the adhesive has a gas barrier effect / property.

Summary of the Invention

[0003] An object of the present invention is to provide a laminated adhesive useful for flexible packaging applications, which has enhanced oxygen barrier performance compared to standard adhesives, and a process for producing such a laminated adhesive.

[0004] In one embodiment, the present invention relates to a two-component solvent-based polyurethane laminate adhesive composition, the adhesive composition being based on crystalline polycarbonate, and the adhesive composition being useful for producing multilayer laminate structures. The adhesive composition comprises, for example, (a) at least one isocyanate component, (b) at least one isocyanate-reactive component comprising (bi) at least one crystalline polycarbonate diol compound, (bii) at least one flow modifier such as an acrylic polymer compound, (biii) optionally, a reaction product of an optional additive, and (c) at least one solvent.

[0005] In another embodiment, the present invention relates to a process for preparing the above-mentioned adhesive composition.

[0006] In another embodiment, the present invention relates to a multilayer laminate product comprising (A) at least a first layer, (B) at least a second layer, and (C) at least one layer of the adhesive composition disposed between the first layer and the second layer, wherein the adhesive composition is cured to bond the first layer to the second layer.

[0007] In yet another embodiment, the present invention relates to a process for manufacturing the above-described multilayer laminate product.

[0008] In yet another embodiment, the present invention relates to packaging products manufactured using the above-described multilayer laminate product. [Modes for carrying out the invention]

[0009] When used throughout this specification, the following abbreviations have the following meanings unless otherwise explicitly indicated by the context: "<" means "less than", ">" means "greater than", "≦" means "less than or equal to", "≧" means "greater than or equal to", and "@" means "at", μm = micrometer, g = gram, mg = milligram, L = liter, g / cc = grams per cubic centimeter, mL = milliliter, g / mL = grams per milliliter, g / mol = grams per mole, g / m 2 = grams per square meter, ppm = parts per million, ppmw = parts per million weight, rpm = revolutions per minute, m = meter, mm = millimeter, cm = centimeter, cm / min = centimeters per minute, min = minute, s = second, hr = hour, °C = Celsius temperature, N = Newton, mmHg = millimeters of mercury, psig = pounds per square inch, ccO2 / m 2 / day = cubic centimeters of oxygen per square meter per day, N / 15mm = Newtons per 15 millimeters, kPa = kilopascals, % = percent, volume% = volume percent, and weight% = weight percent.

[0010] Unless otherwise specified, all quantities such as percentages, parts, and ratios are defined by weight. For example, all percentages mentioned herein are weight percentages (weight %) unless otherwise indicated.

[0011] Temperatures are expressed in degrees Celsius (°C), and "ambient temperature" and / or "room temperature" refer to temperatures between 20°C and 25°C unless otherwise specified.

[0012] The present invention relates to a novel two-component solvent-based polyurethane adhesive composition, the adhesive composition being based on crystalline polycarbonate, and the adhesive composition being useful for producing adhesive laminate structures. The adhesive composition comprises, for example, (a) at least one isocyanate component; and (b) at least one isocyanate-reactive component comprising (bi) at least one crystalline polycarbonate diol compound, (bii) at least one acrylic polymer compound, and (biii) at least one solvent reaction product.

[0013] Generally, preparing a two-component lamination adhesive composition involves providing a first portion, component (a), which contains an isocyanate component; providing a second portion, component (b), which contains an isocyanate-reactive component, such as a polyol component; and then combining or mixing components (a) and (b) together to form a two-component adhesive system or composition.

[0014] The isocyanate component (a) of the present invention may include one or more isocyanate compounds. For example, the isocyanate compound may include aliphatic isocyanates, aromatic isocyanates, and mixtures thereof. "Aliphatic polyisocyanate" is an isocyanate that does not contain an aromatic ring. Examples of suitable aliphatic isocyanates useful in the present invention include hexamethylene diisocyanate (HDI) and diisocyanatodicyclohexylmethane (H 12 Examples include, but are not limited to, MDI, xylylene diisocyanate (XDI), 1,4- or 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI), tetramethylxylylene diisocyanate, two or more dimers, trimers, derivatives, and mixtures thereof.

[0015] Examples of aromatic isocyanates useful in the present invention include, but are not limited to, 1,3- and 1,4-phenylenediisocyanates, 1,5-naphthylenediisocyanate, 2,6-toluenediisocyanate (2,6-TDI), 2,4-toluenediisocyanate (2,4-TDI), 2,4'-diphenylmethanediisocyanate (2,4'-MDI), 4,4'-diphenylmethanediisocyanate (4,4'-MDI), polymer isocyanates, and one or more polyisocyanate compounds, including but not limited to mixtures of two or more of these.

[0016] In one preferred embodiment, the isocyanate components useful in the present invention may be XDI-based polyisocyanates, HDI-based polyisocyanates, MDI-based polyisocyanates, TDI-based polyisocyanates, and mixtures thereof.

[0017] Some examples of commercially available isocyanate components useful in the present invention include TAKENATE® D-110N and TAKENATE® D-120N (both available from Mitsui Chemicals), DESMODUR® N 3300, DESMODUR® Quix 175, and DESMODUR® E 2200 / 76 (all available from The Covestro Company), as well as ISONATE® 125M, ADCOTE® L76-204, COREACTANT CT, and CATALYST F (all available from The Dow Chemical Company), and mixtures thereof.

[0018] Isocyanates have an average functional value of more than two isocyanate groups / molecules. In one embodiment, for example, an isocyanate may have an average functional value of 2.1 to 4.0.

[0019] Compounds having an isocyanate group, such as component (a) of the present invention, can also be characterized by the weight percentage of isocyanate groups (NCO) based on the total weight of the compound. The weight percentage of isocyanate groups is referred to as "NCO%" and is measured according to ASTM D2572-97. In one embodiment, the NCO content of component (a) is 7% or more, and in another embodiment, it is 10% or more. In yet another embodiment, the NCO content of component (a) is 30% or less, and in yet another embodiment, it is 25% or less.

[0020] The amount of isocyanate component used in the process of the present invention is, for example, 2% to 40% by weight in one embodiment, 3% to 30% by weight in another embodiment, and 4% to 20% by weight in yet another embodiment.

[0021] The isocyanate-reactive component, which is component (b) (or component B) of the present invention, comprises an isocyanate-reactive composition which is the reaction product of (bi) a predetermined amount of at least one crystalline polycarbonate diol compound, (bii) a predetermined amount of at least one acrylic polymer compound, and (biii) a predetermined amount of at least one solvent. A blend or mixture of the above three components (bi) to (biii) forms an isocyanate-reactive component (b) which is mixed with the isocyanate component (a). A polyurethane adhesive composition based on crystalline polycarbonate for producing an adhesive laminate structure is formed by mixing component (a) with component (b).

[0022] Component (a) can be mixed with component (b) in a weight ratio of 4:100 to 30:100 in one embodiment, 5:100 to 25:100 in another embodiment, and 6:100 to 20:100 in yet another embodiment.

[0023] Crystalline polycarbonate diol is a compound having a structure of carbonate units and hydroxyl end groups, and is solid over a temperature range including the range of 10°C to 40°C. Examples of suitable crystalline polycarbonate diols useful in the present invention include, but are not limited to, poly(hexanediol-carbonate), poly(butanediol-carbonate), and mixtures of two or more of these.

[0024] In one preferred embodiment, the crystalline polycarbonate diol has a melting temperature of 35°C to 60°C and a molecular weight of 500 g / mol to 3,500 g / mol.

[0025] Some examples of commercially available crystalline polycarbonate diol compounds useful in the present invention include, for example, ETERNACOLL® UH-100, ETERNACOLL® UH-200, and ETERNACOLL® UH-300 available from UBE Industries, Inc.

[0026] The amount of the crystalline polycarbonate diol compound used to prepare the isocyanate-reactive co-reactant, which is component (b) of the process of the present invention, is, for example, 10 wt% to 50 wt% in one embodiment, 15 wt% to 15 wt% in another embodiment, and 20 wt% to 40 wt% in yet another embodiment.

[0027] At least one acrylic polymer compound, which is component (ii) useful in the present invention, is a flow modifier or flow control agent typically used in powder coatings to control cratering and reduce orange peel characteristics. The flow regulator helps control the interfacial tension and surface tension of the adhesive.

[0028] Useful flow modifiers in the present invention include one or more common flow modifiers, such as low glass transition temperature acrylic resins, such as polylauryl acrylate, polybutyl acrylate, poly(2-ethylhexyl) acrylate, poly(ethyl acrylate-2-ethylhexyl acrylate), polylauryl methacrylate, acrylic copolymers made from two or more monomers (including methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, methyl methacrylate, acrylic acid, methacrylic acid, styrene, vinyl acetate, butadiene, etc.), and mixtures thereof. Other useful flow modifiers include silicon-containing polymers and fluorinated polymers, such as esters of polyethylene glycol or polypropylene glycol, and fluorinated fatty acids.

[0029] The amount of acrylic polymer used to produce the isocyanate-reactive coreactate, which is component (b) of the process of the present invention, is, for example, 0.05% to 4% by weight in one embodiment, 0.1% to 3% by weight in another embodiment, and 0.2% to 2% by weight in yet another embodiment.

[0030] The at least one solvent compound that is component (c) of the present invention may comprise one or more compounds, including any conventional carrier solvent such as ethyl acetate, methyl ethyl ketone, dioxolane, propyl acetate, toluene, and mixtures thereof. In one preferred embodiment, the solvent compounds useful in the present invention may be ethyl acetate, methyl ethyl ketone, and mixtures thereof.

[0031] The amount of solvent compound used to produce the isocyanate-reactive coreactate, which is component (b) of the process of the present invention, is, for example, 10% to 90% by weight in one embodiment, 30% to 85% by weight in another embodiment, and 50% to 80% by weight in yet another embodiment.

[0032] In some embodiments, the adhesive composition of the present invention may include, but is not limited to, one or more optional additives, including, tackifiers, catalytic plasticizers, rheology modifiers, adhesion promoters, antioxidants, fillers, colorants, surfactants, solvents, and combinations of two or more thereof.

[0033] The amount of any optional component useful in the adhesive composition may be, for example, 0% to 3% by weight in one embodiment, 0% to 2% by weight in another embodiment, and 0.01% to 1% by weight in yet another embodiment.

[0034] Generally, the process for preparing a laminated adhesive composition includes: (I) melting a crystalline polycarbonate diol at a temperature of 50°C to 70°C; (II) pouring the molten diol into a reactor, wherein the reactor is preheated to a temperature of 50°C to 60°C; (II) loading the reactor with a solvent and any other optional additives; (IV) mixing all the components in the reactor by stirring until a uniformly mixed, completely clear solution is formed; and (V) removing the resulting completely clear solution from the reactor.

[0035] A multilayer laminate product can be formed comprising layers of the solvent-based polyurethane adhesive composition based on the crystalline polycarbonate of the present invention. Any number of layers can be used to form the laminate product. In one preferred embodiment, the laminate is formed by the steps of: applying the adhesive composition to at least one of two substrate layers (for example, the substrates may be made from the same or different materials); combining the substrates together such that the adhesive composition is positioned as a layer between the surfaces of the two substrates; and then curing the adhesive composition to form a bonding layer between the two substrates. Generally, each of the two substrates may include, for example, two separate polymer films. As used herein, “film” is any layer structure in which one dimension of the layer structure is 0.5 mm or less and the other two dimensions of the layer structure are both 1 cm or more. “Polymer film” is a film made from a polymer or a mixture of polymers. The composition of a polymer film is typically 80 weight percent or more of one or more polymers.

[0036] Suitable substrates used to form a laminated structure include films such as paper, woven and nonwoven fabrics, polymer films, metal-coated (metallized) polymer films, and combinations thereof. The substrates are layered using an adhesive composition according to the present invention to bond one or more of the substrates together to form a laminated structure.

[0037] In a preferred embodiment, a multilayer laminate product prepared using the adhesive composition of the present invention comprises (A) at least a first layer, (B) at least a second layer, and (C) at least one layer of the adhesive composition disposed between the first layer and the second layer, wherein the adhesive is cured to bond the first layer to the second layer.

[0038] In one common embodiment, a multilayer laminate product may be two or more film substrates or film layers joined together using an adhesive composition. In some embodiments, a laminate film structure is disclosed that includes a first film layer, a second film layer, and a barrier adhesive layer positioned between the first and second film layers. For example, in a preferred embodiment, a multilayer laminate product may be made of three layers, including a first film layer (or outer layer), a second film layer (or inner layer), and a bonding layer containing an adhesive composition positioned between the first and second layers.

[0039] The three-layer laminate product of the present invention may have an A / B / A layered structure, where A represents the first and second layers of the same material, and B represents the bonding layer of the adhesive composition. Although the three-layer laminate film product is referred to herein, the present invention includes multilayer laminate members having any number of film layers, provided that at least one layer of the multilayer film member is the bonding layer of the adhesive composition, and the bonding layer has appropriate gas barrier properties. As described above, the structure of the multilayer film member may be A / B / A, where both layers represented by A are made from the same polymer material, or the structure of the multilayer film member may be A / B / C, where C represents a film layer made from a different material than layer A, or the structure of the multilayer film member may be any combination of layers A, B, and C, as will be apparent to those skilled in the art who manufacture laminates.

[0040] The first layer of the laminate product of the present invention may be made from one or more materials, including, for example, polyethylene, polypropylene, polyethylene terephthalate, polyamide, polystyrene, cycloolefin copolymer, polyvinyl chloride, styrene butadiene, and the like. In one preferred embodiment, the material of the first layer useful in the present invention may be polypropylene, polyethylene, and combinations thereof. Some examples of commercially available materials useful in the first layer of the present invention include, for example, biaxially oriented polypropylene (available from FILMTECH, INC.) and polyethylene (available from Berry Plastics), and mixtures thereof. In another preferred embodiment, the first film layer may be made from polypropylene having a density of, for example, 0.89 g / cc to 0.92 g / cc.

[0041] The thickness of the first layer used in the laminated product of the present invention is, for example, 10 μm to 200 μm in one embodiment, 15 μm to 150 μm in another embodiment, and 20 μm to 125 μm in yet another embodiment.

[0042] As described above, the second layer of the laminate product of the present invention can be made from the same material as the first layer, which has the advantage of being more easily recyclable. In another embodiment, the second layer can be made from one or more materials different from the first layer.

[0043] If the second layer of the laminated product is made from a polymer different from the first layer, the second layer may include, for example, polyethylene, polypropylene, polyethylene terephthalate, polyamide, polystyrene, cycloolefin copolymer, polyvinyl chloride, styrene butadiene, and mixtures thereof. In one preferred embodiment, the materials for the second layer useful in the present invention may be polyethylene, polypropylene, and mixtures thereof. Some examples of commercially available materials useful in the second layer of the present invention include, for example, polyethylene (available from Berry Plastics) and biaxially oriented polypropylene (available from FILMTECH, INC.), and mixtures thereof. In another preferred embodiment, if the second film layer is different from the first layer, it may be made from polyethylene having a density of, for example, 0.915 g / cc to 0.967 g / cc.

[0044] The thickness of the second layer used in the film of the present invention is, for example, 10 μm to 200 μm in one embodiment, 15 μm to 150 μm in another embodiment, and 20 μm to 125 μm in yet another embodiment.

[0045] In a typical embodiment, one process for manufacturing a multilayer laminated product is, for example, (I) The step of applying the adhesive composition of the present invention to at least a portion of the surface of the first layer and / or the second layer, (II) The step of bringing the first layer and the second layer into contact so that the adhesive is placed between the first layer and the second layer, (III) The step of curing the adhesive to form a multilayer laminate product including a first layer bonded to a second layer via the cured adhesive.

[0046] The laminated film structure of the present invention includes a film made from polymers bonded together using a barrier adhesive composition instead of a standard adhesive composition, but the laminated film structure of the present invention still achieves similar or enhanced barrier properties. One of the advantageous properties exhibited by laminated products made by the above process of the present invention is, for example, that the laminate may have an improved (i.e., reduced) oxygen permeability (OTR). In some embodiments, the laminated film structure is "ccO2 / m² 2 Abbreviated as " / day," it has an OTR of 750 cubic centimeters or less per square meter [square meters / day], as measured according to ASTM method D3985.

[0047] Since laminated film structures can be designed with various layer materials, number of layers, film thickness, and other properties, the OTR of a particular laminated structure will depend, for example, on the various properties of the first and second layers. Exemplarily, but not limited thereto, the OTR of the laminated structures of the present invention is generally 15% lower than that of a laminate using a standard adhesive composition in one embodiment, 25% lower in another embodiment, and 50% lower in yet another embodiment. In yet another embodiment, the OTR of the laminated structures of the present invention is 10% to 90% lower than that of a laminate using a standard adhesive composition.

[0048] Laminates prepared as described above can be used, for example, in flexible packaging applications, as well as in household and personal care applications. In one preferred embodiment, the laminate is used to produce multilayer laminated products or articles, such as packages, pouches, or containers for packaging food. In a preferred embodiment, the laminate is made from two layers of polymer film, with an adhesive layer placed between two film layers that bond the two polymer films together. The process of producing articles such as food packaging articles can be carried out by those skilled in the art of food packaging manufacturing.

[0049] As described above, by using the barrier adhesive layer of the present invention instead of a standard adhesive, there is a reduction in oxygen permeability through the laminate structure, and therefore articles made using the above laminate will have the same advantageous gas barrier properties, such as the improved (i.e., reduced) OTR, as shown by the above laminate.

[0050] Furthermore, multilayer laminates having an ABA structure can be advantageously simple and easy to manufacture, and can be beneficially renewable, making food packaging made from these laminates environmentally friendly. [Examples]

[0051] The following embodiments are provided to illustrate the present invention in further detail, but should not be construed as limiting the scope of the claims. Unless otherwise indicated, all parts and percentages are by weight.

[0052] The various raw materials or components used in the embodiments (Inv.Ex.) and comparative examples (Comp.Ex.) of the invention are described below. MOR-FREE® C33 is an aliphatic isocyanate available from The Dow Chemical Company (Dow). ADCOTE(trademark) 577 is an isocyanate-terminated compound available from Dow. ADCOTE(trademark) 577B is a hydroxyl-terminated compound available from Dow. ETERNACOLL® UH-100 is a 1,6-hexanediol-based crystalline polycarbonate diol with a molecular weight (Mw) of 1,000 and a melting point of approximately 45°C, and is available from UBE Industries Company (UBE). ETERNACOLL® UH-200 is a 1,6-hexanediol-based crystalline polycarbonate diol with a wattage of 2,000 and a melting point of approximately 50°C, and is available from UBE. ETERNACOLL® PH-100 is an amorphous copolymer diol with a Mw of 1,000, in which 1,4-cyclohexanedimethanol and 1,6-hexanediol are applied as copolymer diol components, and is available from UBE. MODAFLOW® resin is an acrylic copolymer and is available from Allnex Inc. "BOPP" stands for biaxially oriented polypropylene. BOPP is a film with a thickness of 20 μm and is available from Filmtech Inc.

[0053] test 90°T peel test A 90°T peel test was performed on a laminated sample consisting of two films, i.e., a primary film and a secondary film bonded together with an adhesive. The laminated sample was cut into 15 mm wide strips, and each sample was pulled using a Thwing Albert® QC-3A peel tester equipped with a 50 N loading cell. The laminated sample was pulled on the 15 mm strip at a speed of 4 inches / min (10 cm / min) using the peel tester. The average force during tensile strength was recorded when the two films in the laminate separated (peeled). If one of the films stretched or broke, the maximum force or force at the time of breakage was recorded. The final values ​​for the laminated sample are the average values ​​of the three separate sample strips tested. The failure mode (FM) or mode of failure (MOF) was recorded as follows: AS (Adhesive Split) or cohesive failure, indicating that the adhesive was found on both the primary and secondary films.

[0054] Oxygen permeability (OTR) measurement The oxygen permeability (OTR) of the formed laminate was measured using a MOCON OXTRAN 2 / 21 under ASTM method D3985 ("Standard test method for oxygen gas permeability through plastic films and sheets using coulometric sensors"). OTR data is expressed in standard units "cc / m". 2It is reported as " / day". The conditions used in the tests to obtain the OTR measurements were 23°C and 85% relative humidity (RH).

[0055] Isocyanate co-reactants General procedure for preparing isocyanate co-reactants (CRs) The co-reactants (CR) listed in Table I are prepared using crystalline polycarbonate diol compounds or amorphous polycarbonate diol compounds. First, the polycarbonate diol is melted in an oven at 60°C, and then the molten crystalline or amorphous polycarbonate diol compound is mixed with ethyl acetate and an acrylic polymer at 60°C for 1 hour to form an isocyanate-reactive component composition.

[0056] [Table 1]

[0057] Adhesive formulations General procedure for preparing adhesive formulations The adhesive formulations listed in Table II are prepared by mixing the components listed in Table V under the following conditions.

[0058] Table II lists appropriate compounding components, isocyanate-reactive components, and isocyanate components for preparing adhesive formulations. As an example of preparing an adhesive formulation sample, approximately 2,541 g of isocyanate component (component B) and approximately 459 g of isocyanate component (component A) are loaded into a plastic container using the adhesive of Example 1 of the Invention. The materials are mixed using a mechanical mixer at room temperature (approximately 25°C) for 30 minutes to obtain the compounded adhesive of Example 1 of the Invention.

[0059] Table II lists the adhesive formulations of selected examples in which all adhesives have the same amount of excess isocyanate.

[0060] [Table 2]

[0061] Coated laminate General procedure for preparing coated laminates The polyurethane adhesive is prepared as described above using the general procedure for preparing adhesive formulations. The adhesive is first coated onto the primary substrate via a gravure cylinder. The coated film is then passed through a three-zone oven. The coated film is then nipped onto another substrate under heated steel rolls at a temperature of 90°C and a nip pressure set to 40 pounds per square inch (275.8 kPa). The laminated structure is passed through a final cooling roll at a cooling roll temperature of 17°C. The resulting laminate is then placed in a temperature-controlled chamber and cured at 23°C and 50% RH for 7 days.

[0062] Examples 4-6 The coated laminates were prepared using the polyurethane adhesive compositions of Examples 1 to 3 of the Invention described in Table II, and using the general procedure for preparing the coated laminates described above. Each of the resulting laminates of Examples 4 to 6 of the Invention had a viscosity of 3.5 g / m². 2 It had the weight of the adhesive coating.

[0063] Comparative example C The coated laminate was prepared using the polyurethane adhesive composition of Comparative Example A described in Table II, and using the general procedure for preparing the coated laminate. The resulting laminate of Comparative Example A had a viscosity of 3.5 g / m². 2 It had the weight of the adhesive coating.

[0064] Comparative example D In Comparative Example B, the same general procedure for preparing the coated laminate as described above was used, except that a polyurethane adhesive containing approximately 55% by weight of ADCOTE® 577, 4.9% by weight of ADCOTE® 577B, and 40.1% by weight of ethyl acetate was used. In Comparative Example B, the laminate structure was passed through a final cooling roll at a cooling roll temperature of 17°C, and then the laminate was placed in a temperature-controlled chamber and cured at 23°C and 50% RH for 7 days. The laminate was 3.5 g / m² 2 It had the weight of the adhesive coating.

[0065] Laminate / Adhesive Performance From the data in Table III below, it can be seen that the laminates of Examples 4, 5, and 6 of the Invention, which were coated with the adhesive formulations of Examples 1, 2, and 3, respectively, containing crystalline polycarbonate, showed improved OTR barrier performance compared to Comparative Examples C and D, which were coated with adhesive formulations containing amorphous polycarbonate main chains.

[0066] [Table 3]

Claims

1. A polyurethane adhesive composition based on crystalline polycarbonate for producing adhesive laminate structures, comprising: (a) at least one isocyanate component; (b) at least one isocyanate-reactive component, (bi) 15% to 45% by weight of at least one crystalline polycarbonate diol compound; (bii) 0.05% to 4% by weight of at least one acrylic polymer compound, and (biii) at least one isocyanate-reactive component, including at least one solvent; and Including, The polyurethane adhesive composition is used to form a laminate having an oxygen transmission rate (OTR) of less than 750 cubic centimeters per square meter per day.

2. 2. The adhesive composition of claim 1, wherein the weight ratio of component (a) to component (b) is from 4:100 to 30:

100.

3. 2. The adhesive composition of claim 1, wherein the at least one isocyanate component is selected from the group consisting of xylylene diisocyanate-based polyisocyanates, hexamethylene diisocyanate-based polyisocyanates, diphenylmethane diisocyanate-based polyisocyanates, toluene diisocyanate-based polyisocyanates, and mixtures thereof.

4. 2. The adhesive composition of claim 1, wherein the at least one crystalline polycarbonate diol compound comprises a compound having a structure of carbonate units and hydroxyl end groups, and being solid over a temperature range of 10°C to 40°C.

5. 10. The adhesive composition of claim 1, wherein the at least one crystalline polycarbonate diol compound comprises poly(hexanediol-carbonate), poly(butanediol-carbonate), and mixtures thereof.

6. 10. The adhesive composition of claim 1, wherein the at least one acrylic polymer compound comprises polylauryl acrylate, polybutyl acrylate, poly(2-ethylhexyl)acrylate, poly(ethyl acrylate-2-ethylhexyl acrylate), polylauryl methacrylate, acrylic copolymers made from two or more monomers including methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, methyl methacrylate, acrylic acid, methacrylic acid, styrene, vinyl acetate, butadiene, and mixtures thereof.

7. The adhesive composition of claim 1 , wherein the at least one solvent is ethyl acetate, methyl ethyl ketone, and mixtures thereof.

8. 1. A process for producing a polyurethane adhesive composition based on crystalline polycarbonate for producing an adhesive laminate structure, comprising: (a) at least one isocyanate component; (b) at least one isocyanate-reactive component, (bi) 15% to 45% by weight of at least one crystalline polycarbonate diol compound; (bii) 0.05% to 4% by weight of at least one acrylic polymer compound, and (biii) mixing at least one isocyanate-reactive component with a blend of at least one solvent; The process wherein the polyurethane adhesive composition is used to form a laminate having an oxygen transmission rate (OTR) of less than 750 cubic centimeters per square meter per day.

9. A multi-layer laminate product comprising: (A) at least a first layer; (B) at least a second layer; (C) at least one layer of the cured adhesive of claim 1 disposed between the first layer and the second layer, wherein the cured adhesive bonds the first layer to the second layer to provide a laminate having an oxygen transmission rate (OTR) of less than 750 cubic centimeters per square meter per day.

10. 1. A process for producing a multi-layer laminate product, comprising: (I) applying the adhesive of claim 1 to at least a portion of the surface of the first layer and / or the second layer; (II) contacting the first layer and the second layer such that the adhesive is disposed between the first layer and the second layer; (III) curing the adhesive to form a multi-layer laminate product comprising the first layer bonded to the second layer via the cured adhesive.

11. A packaging container item comprising the laminate described in claim 9.