Structural adhesive cured by polycarbonate

Abstract

A material suitable for curing and / or foaming comprising (i) one or more epoxy resins, (ii) at least one polycarbonate, and (iii) at least one catalyst, preferably a transesterification catalyst for catalyzing the reaction of said polycarbonate.

Description

[0001] Priority Statement

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 453,311, filed March 20, 2023, the contents of which are incorporated herein by reference in their entirety and for all purposes. Technical Field

[0003] This teaching generally relates to adhesives, preferably structural adhesives, that are cured via transesterification of polycarbonate. Background Technology

[0004] Structural adhesives are widely used in various industries, including automotive, aerospace, wind energy, marine, and other industrial sectors. These adhesives offer alternatives to mechanical fastening, enabling more flexible product design and the use of new materials for lightweighting and sustainability. One-component, heat-activated adhesives contain a potential curing agent that can be activated by heat to initiate the polymerization process and subsequently polymerize or crosslink. Common potential curing agents include dicyandiamide, urea, hydrazides, boron trifluoride amine complexes, acid anhydrides, and other related compounds. When adhesives cure at high temperatures, nitrogen-containing curing agents often generate ammonia or amine byproducts with a strong odor.

[0005] The United Nations Economic Commission for Europe has been promoting its guidelines on automotive interior air quality standards aimed at reducing unpleasant odors in vehicles. Other organizations are also interested in addressing the odor problem, particularly in Asia, where complaints about unpleasant odors or harmful emissions from car interiors appear to be especially prevalent. As more and more automakers in Europe and Asia adopt automotive interior air quality regulations, there is a demand for materials that meet these requirements, which is particularly challenging for reactive chemical systems such as adhesives and sealants.

[0006] In the automotive industry, thermally activated foam sealants with reduced odor during the reaction process have been developed by introducing foaming agents that produce minimal ammonia byproducts. Similarly, structural adhesives with nitrogen-containing curing agents face the same challenge and may require alternatives to comply with automotive interior air quality regulations. Therefore, a different curing mechanism that does not generate odor byproducts is needed.

[0007] Polycarbonate (PC) has been found to react with other materials, including epoxides and hydroxyl / phenolic compounds, via a transesterification mechanism. Therefore, this teaching aims to provide a structural adhesive that cures via a hypothetical polycarbonate transesterification process in the absence of common heat-activated curing agents, including dicyandiamide, hydrazides, acid anhydrides, and boron trifluoride amine complexes. Furthermore, the PC transesterification curing mechanism may yield properties unattainable through conventional curing reactions. Summary of the Invention

[0008] The teachings herein relate to a material comprising: one or more epoxy resins, at least one polycarbonate, and at least one catalyst for the reaction between the one or more epoxy resins and the at least one polycarbonate. The material is an adhesive, preferably a one-component adhesive.

[0009] The adhesive may contain polyols and / or phenols.

[0010] The adhesive may contain moisture scavengers, toughening agents, and / or polymer core-shell particles.

[0011] When cured at 140 to 200°C for at least 30 minutes, the adhesive can have an expansion (volume expansion) of 0% to 100%.

[0012] The adhesive can be in the form of a pumpable material, tape, and / or injection moldable adhesive.

[0013] By using polycarbonate ester exchange curing, products with a wide range of desired physical properties can be produced.

[0014] High-modulus adhesives can be produced that, when cured at 162.8°C for 30 minutes, have an lap shear strength greater than 30 MPa as measured according to ASTM D5868 at a crosshead speed of 50.4 mm / min and a bond line of 0.25 mm, and a tensile modulus greater than 1100 MPa as measured according to ASTM D638 at a crosshead speed of 5 mm / min.

[0015] Elastomer adhesives can be produced that exhibit greater than 50% failure strain when cured at 162.8°C for 30 minutes (measured according to ASTM D638 at a crosshead speed of 5 mm / min).

[0016] It is possible to produce non-expanding adhesives that, when cured at 162.8°C for 30 minutes, have a T-peel strength of at least 5 N / mm when measured at a crosshead speed of 254 mm / min and a bond line of 0.25 mm, and an lap shear strength of at least 30 MPa when measured according to ASTM D5868 at a crosshead speed of 50.4 mm / min and a bond line of 0.25 mm.

[0017] It is possible to produce expandable adhesives that, when cured at 140°C to 200°C for at least 30 minutes, have a T-peel strength of at least 4 N / mm as measured at a crosshead speed of 254 mm / min and a bond line of 0.25 mm, and an lap shear strength of at least 14 MPa as measured according to ASTM D5868 at a crosshead speed of 50.4 mm / min and a bond line of 0.25 mm.

[0018] The adhesive may contain polycarbonate in the range of about 5% to about 60% by weight based on the total weight of the adhesive.

[0019] The adhesive may contain a catalyst ranging from about 0.01% by weight to about 10% by weight based on the total weight of the adhesive.

[0020] The adhesive may contain a moisture remover ranging from about 0% to about 40% by weight based on the total weight of the adhesive.

[0021] The adhesive may contain toughening agents ranging from about 0% to about 40% by weight based on the total weight of the adhesive.

[0022] The adhesive may contain polymer particles ranging from about 0% to about 30% by weight based on the total weight of the adhesive.

[0023] Polycarbonate resins can have a melt index (300°C, 1.2 kg load) ranging from about 2 g / 10 min to about 60 g / 10 min and a molecular weight ranging from about 5,000 Daltons to about 300,000 Daltons.

[0024] Polyols can be aliphatic or aromatic polyesters, polyethers, or polycarbonate polyols.

[0025] Phenols may include hydroquinone, resorcinol, catechol, various diphenols (including bisphenol A, bisphenol F, bisphenol E, bisphenol AP, bisphenol Z, bisphenol M, bisphenol P, bisphenol G, bisphenol BP), phenolic var. lacquers, or any combination thereof.

[0026] Catalysts for the reaction between one or more epoxy resins and at least one polycarbonate may include quaternary ammonium salts, quaternary phosphonium salts, Lewis acids, metal oxides, phosphine, solid strong acids, or any combination thereof. Moisture scavengers may include calcium oxide, molecular sieves, vinyltrimethoxysilanes, zeolites, oxazolidines, or any combination thereof.

[0027] Toughening agents (or toughening agents in the form of adducts with epoxy resins) may be selected from phenol-terminated urethanes, aliphatic dimer acid / epoxy resin adducts, and polyetheramines (e.g., available from Huntsman). Products) / epoxy resin adducts, Epoxonic 328 (e.g., dicarboxylic acid functional modifier) ​​(available from Epoxonic GmbH) or any combination thereof.

[0028] The polymer particles may include a core modifier for polybutadiene, a core modifier for styrene-butadiene rubber, or a combination thereof. The polymer particles may include core / shell rubber particles with an average size of about 100 nm to 200 nm, and may not contain agglomerated particles.

[0029] The adhesive may include one or more microparticle and / or fiber components, which may be selected from silica, diatomaceous earth, glass, clay (e.g., including nanoclay), glass beads or microbubbles, glass fibers, carbon fibers or ceramic fibers, nylon, aramid fibers or polyamide fibers (e.g., Kevlar), pyrophyllite, zinc montmorillonite, soapstone, chlorite, wollastonite, montmorillonite, or any combination thereof.

[0030] The adhesive may include silica-based and / or calcium-based reinforcing components. The adhesive may also include a silica-based rheology modifier comprising fumed silica. Attached Figure Description

[0031] Figure 1 This paper demonstrates how polycarbonate ester exchange can be characterized by measuring the peak shift of carbonate in FTIR spectra. Detailed Implementation

[0032] The explanations and descriptions presented herein are intended to familiarize those skilled in the art with the teachings, their principles, and their practical applications. The specific embodiments of the teachings described are not intended to be exhaustive or limiting. The scope of the teachings should be determined by reference to the appended claims and the full scope of their equivalents. All disclosures in articles and references (including patent applications and publications) are incorporated herein by reference for all purposes. Other combinations are also possible as may be learned from the appended claims, and these are also incorporated herein by reference.

[0033] Unless otherwise stated, percentages in this document refer to weight percentages.

[0034] Unless otherwise expressly stated, the terms "material" and "adhesive" are used interchangeably. Therefore, the material according to the invention is the adhesive according to the invention.

[0035] Unless otherwise expressly stated, the terms "epoxy resin" and "epoxy" are used interchangeably.

[0036] Unless otherwise expressly stated, the terms "polycarbonate resin" and "polycarbonate" are used interchangeably.

[0037] Unless otherwise explicitly stated, the molecular weight of polymeric substances is preferably expressed as weight-average molecular weight (Mw), and is preferably determined by GPC.

[0038] Unless otherwise expressly stated, all references to standards such as ASTM preferably refer to the version that is in force on January 1, 2024.

[0039] Melt index is preferably determined according to ASTM D1238.

[0040] T-peel strength is preferably determined according to ASTM D1876.

[0041] The material taught in this study can be applied to a variety of articles of manufacture to increase the structural integrity of parts or components of those articles. Examples of such articles of manufacture include, but are not limited to, household or industrial appliances, furniture, storage containers, buildings, structures, etc. The material can be applied to various parts of vehicles of transport, including ships, trucks, trains, airplanes, and motor vehicles. The material can be used in motor vehicles, such as for body or frame components (e.g., vehicle frame longitudinal beams).

[0042] This teaching aims to cure thermally activated compositions, including structural adhesives, using transesterification reactions in the absence of common nitrogen-containing curing agents such as dicyandiamide, hydrazides, and boron trifluoride amine complexes. Excluding these curing agents allows for the preparation of structural adhesives with minimal odor before, during, and after curing. Examples of transesterification include the thermal activation reaction of polycarbonate with epoxides and / or hydroxyl / phenols in the presence of a catalyst (which may be a transesterification catalyst).

[0043] Polycarbonates (e.g., polycarbonate resins) are a class of thermoplastic polymers characterized by high failure strain combined with high strength, high stiffness, and high impact resistance. They have not traditionally been used in thermosetting compositions. Their chemical structure contains carbonate groups, which are known to react with epoxy resins, polyols, and phenols via transesterification. This transesterification can be catalyzed by suitable catalysts.

[0044] This teaching aims to demonstrate the use of these reactions as a crosslinking mechanism for epoxy-based thermally activated structural adhesives, which can be single-component epoxy-based thermally activated structural adhesives. This teaching also aims to reveal the key factors that alter adhesive properties (i.e., lap shear strength, peel strength, failure strain, and foaming percentage, if any) when polycarbonate is used as a curing agent.

[0045] The material may comprise at least one type of polycarbonate resin having a melt index ranging from about 3 g / 10 min to about 35 g / 10 min (300 °C, 1.2 kg load) and a molecular weight ranging from about 10,000 Daltons to about 100,000 Daltons. A non-limiting example of a polycarbonate resin that may be used is Lexan from Saudi Basic Industries Corporation (Sabic). TM Hylex from Ravago Manufacturing Americas TM CALIBRE from Trinseo TM and TRIREX from Samyang Corporation TM Polycarbonate may be included in the total weight of the material at a maximum of about 50% by weight.

[0046] The polycarbonate resin content, based on the total weight of the material, can be at least about 2% by weight, more typically at least about 10% by weight, and more typically at least about 20% by weight. Based on the total weight of the material, this content can be about 50% by weight or less, more typically about 40% by weight or less, more typically about 30% by weight or less, and even more typically 25% by weight or less. To enhance the composability of the adhesive, it is preferable to combine the polycarbonate resin with other compositional components as a solution. While any solvent can be used to lower the incorporation temperature during mixing, low molecular weight epoxy resin is particularly preferred as a solvent, allowing the solvent to react and enter the adhesive composition upon activation.

[0047] The materials described herein may include epoxy resins, polymer matrices formed by transesterification with polycarbonate to create adhesives. Liquid and solid epoxy resins may be used in combination to adjust the viscosity of the material. Exemplary epoxy resins may be DER 331 from Olin Corporation or Epotec available from Aditya Birla Group. TM YDF 172LV (DGEBF) and DER 664 from Olin Chemical. Epoxy resins can also be added to this material to enhance its adhesive properties and flexibility. Silane-modified epoxy resins can help improve adhesion to non-ferrous metals (such as aluminum) and improve adhesion after environmental exposure (i.e., moisture, salt spray). Silane-modified epoxy resins can be the product of a reaction between at least one epoxy resin and a silane compound. An example of a suitable silane-modified epoxy resin is Epokukdo, available from Kukdo Chemical. TMKSR-177 (a bifunctional silane-modified epoxy resin). Suitable flexible epoxy resins include Epiol from Kukdo Finechem Co., Ltd. TM DE202 and DER 732 from Olin Corporation. Various mixtures of several different epoxy resins can be used to achieve the desired properties for the intended purpose.

[0048] The epoxy resin content, based on the total weight of the material, can be at least about 20% by weight, more typically at least about 30% by weight, and more typically at least about 40% by weight. Based on the total weight of the material, the content can be about 80% by weight or less, more typically about 70% by weight or less, more typically about 60% by weight or less, and even more typically 50% by weight or less.

[0049] The material may include a bifunctional or polyfunctional polyol or phenol, which reacts with both epoxy resin and polycarbonate at high temperature in the presence of a catalyst; the reaction may be an transesterification reaction.

[0050] Bifunctional phenols act as chain extenders for epoxy resins, increasing chain length and making it more likely to obtain compositions capable of plastic deformation. Studies have found that longer-chain oligomers contribute to improved peel resistance of adhesives because they reduce crosslinking density. Although polyols and phenols are not essential for the preparation of crosslinked epoxy resins, they can be used as bridging molecules to link epoxy resins to polycarbonates due to their reactivity with both epoxy resins and polycarbonates, thereby increasing crosslinking density and glass transition temperature. Examples of polyols include aliphatic and aromatic polyesters, polyether and polycarbonate polyols, such as those from Bakelike... TM Resonance aliphatic and aromatic polyols and Eternacoll from UBE Industries Ltd. TM Polyols. Example phenols include hydroquinone, resorcinol, catechol, bisphenol A, bisphenol F, bisphenol E, bisphenol AP, bisphenol Z, bisphenol M, bisphenol P, bisphenol G, bisphenol BP, and other related compounds. Polyphenols with a functionality greater than 2 can also be used to increase the crosslinking density to achieve high-temperature performance. Exemplary polyphenols include tannic acid, ellagic acid, theaflavin-3-gallate, and phenolic resins.

[0051] The content of polyols and phenols, based on the total weight of the material, may be at least about 1% by weight, more typically at least about 5% by weight, and more typically at least about 10% by weight. Based on the total weight of the material, this content may be about 30% by weight or less, more typically about 25% by weight or less, more typically about 20% by weight or less, and even more typically 15% by weight or less.

[0052] Catalysts can be used to activate the transesterification of polycarbonate to facilitate full crosslinking. The reaction partners in the transesterification reaction with polycarbonate can be one or more epoxy resins and / or optionally one or more polyols and / or phenols. Quaternary ammonium salts, quaternary phosphonium salts, phosphine, Lewis acids, metal oxides, and solid strong acids can be suitable catalysts for this reaction.

[0053] Examples of quaternary ammonium salts and quaternary phosphonium salts include tetraethylammonium bromide, tetrabutylammonium bromide, tetramethylammonium chloride, tetraethylphosphonium chloride, tetrabutylphosphonium chloride, and other related compounds. Catalysts can also be quaternary ammonium-functionalized fillers (such as BYK's Garamite-treated nanoclay products) and quaternary ammonium-functionalized ion exchange resins (such as Dowex, available from DuPont). TM Strong base resins. The catalyst can also be phosphine, such as triphenylphosphine, trinaphthylphosphine, or trimethylbenzylphosphine. Examples of Lewis acid catalysts include SnCl4, Si(OEt)3(CH2)2SnCl3, TiCl4, TiCl3, Ti(O-isopropyl)4, Cp2TiCl2, SmI2, VOCl3, AlCl3, dimethyltin dimercaptoacetate, dibutyltin dilaurate, dioctyltin dimercaptoacetate, and related materials. Available metal oxides include TiO2, TiO2 / SiO2, PbO, PbO / MgO, PbO / SiO2, PbO-r-Al2O3, PbO / TiO2, MoO3, MoO3 / Al2O3, MoO3 / CaO, MgO, and Mg6Fe(OH). 16 CO3, Mg-Al-hydrotalcite, and / or SnO2. Solid strong acids that can be included are sulfonated inorganic fillers or ion exchange resins, including Amberlyst available from DuPont. TM and Amberlite TM Materials and Dowex from Lenntech TM product.

[0054] The catalyst may be present in an amount of at least about 0.02% by weight, more typically at least about 0.1% by weight, and more typically at least about 0.2% by weight, based on the total weight of the material. The amount may be about 10% by weight or less, more typically about 5% by weight or less, and even more typically about 2% by weight or less, based on the total weight of the material.

[0055] The materials described herein may further include moisture scavengers. In addition to improving the moisture resistance of the green state (uncured), the moisture scavengers of this teaching also prevent moisture from participating in the polycarbonate decomposition pathway via hot hydrolysis and / or ammonolysis. Since primary and secondary amines are lacking in the materials of this teaching, which are known initiators of polycarbonate decomposition, polycarbonate is expected to decompose primarily via hot hydrolysis. Carbon dioxide is one of the products of this decomposition reaction, which can cause the material to foam upon thermal activation. For applications where foaming is not desired, moisture scavengers can be added to minimize foaming or porosity of the material. Examples of suitable moisture scavengers include calcium oxide, molecular sieves, vinyltrimethoxysilanes, zeolites, and oxazolidines.

[0056] To minimize foaming, the moisture scavenger may be included in an amount of at least about 1% by weight, more typically at least about 7% by weight, and even more typically at least about 15% by weight, based on the total weight of the material. This content may be about 30% by weight or less, more typically about 25% by weight or less, more typically about 20% by weight or less, or even more typically 15% by weight or less, based on the total weight of the material. For applications where crossing gaps is important, the moisture scavenger may be excluded to ensure high volume expansion, as the presence of water in the composition will act as a foaming agent to increase volume expansion.

[0057] The material may include toughening agents to improve properties such as failure strain and peel resistance. The term toughening agent can refer to a single toughening agent or a combination of several different toughening agents. While other toughening agents may be used, preferred toughening agents include epoxy-modified polymers, urethane-modified polymers, or any combination thereof. It is believed that when polyurethane toughening agents are included, the material can reduce stiffness, increase failure strain, and substantially maintain impact strength (e.g., impact resistance) at low temperatures, while minimizing the decrease in glass transition temperature (Tg) (e.g., compared to other toughening agents). Examples of preferred toughening agents may be phenol-terminated urethane-based toughening agents. EP 1820 (available from Innovative Resin Systems) and DY965 from Huntsman.

[0058] Other preferred toughening agents include epoxy-terminated polyethers or amine precursors used to produce epoxide-terminated polyethers, such as JEFFAMINE. TM The M or SD series (polyetheramine / epoxy adducts) are commercially available from Huntsman Corporation. Toughening agents based on cashew nutshell liquid (such as epoxidized liquid Cardolite) TM NC-514 and Cardolite TMLite2513HP is also a useful plasticizer. Another example of a toughening agent is Epoxonic. TM 328 (e.g., dicarboxylic acid functional modifiers) adducts with epoxy resins. Unless otherwise stated, all individual toughening agents discussed herein may be used alone or in combination with each other in the materials of the present invention. Other examples of preferred toughening agents are HyPox, available from Emerald Performance Materials. TM DA323 (DGEBA and dimer fatty acid adduct) and Epokukdo from Guodu Chemical Co., Ltd. TM YD-172.

[0059] Typically, the toughening agent content is less than 50% by weight of the total weight of the material, more typically less than 35% by weight, and possibly even less than 20% by weight, although higher and lower values ​​are also possible (unless otherwise stated).

[0060] Typically, preferably, the material comprises at least one type of polymer particles. Such polymer particles can be used to improve fracture toughness (G). 1C ), peel resistance and impact resistance. As used herein, the term "polymer particles" is defined as particles comprising polymer material. Like any other component of this teaching, the term "polymer particles" can include one or more polymer particles. Various polymer particles can be used in the practice of this invention and generally include one or more elastomers.

[0061] Typically, preferably, the polymer particles are at least 2% by weight of the material, more typically at least 3% by weight, even more typically at least 6% by weight, even more typically at least 10% by weight, even more typically at least 20% by weight, and preferably, the polymer particles are less than 90% by weight of the material, more typically less than 40% by weight, even more typically less than 30% by weight, although higher or lower amounts may be used in certain embodiments.

[0062] Examples of useful polymer particles include, but are not limited to, those sold under the following trade names: Kane Ace, commercially available from Kaneka Americas Holding, Inc. TM Clearstrength from Arkema TM Paraaloid from Dow TM Kane Ace, a premium grade. TM Sold under the names MX-134 and MX-267. The average size of the polymer particles is likely to be no less than 50 nm and no greater than 300 nm.

[0063] The epoxy-functionalized elastomer may be present in the range of about 1% to about 40% by weight, based on the total weight of the material. The elastomer is typically a product of an epoxy resin and an elastomer selected from carboxyl-terminated butadiene-acrylonitrile (CTBN), amine-terminated butadiene-acrylonitrile (ATBN), carboxylated nitrile butadiene rubber (XNBR), and polysulfides, or any combination thereof.

[0064] The material may include one or more components (e.g., discrete components) that are discrete from the remaining polymer matrix and do not melt during normal compounding or processing. Discrete components are organic or inorganic additives different from the polymer matrix to improve adhesive properties, alter thixotropic properties, improve moisture resistance, and / or reduce cost. These may include: silicates (such as those marketed under the trade name Garamite). TM and Satintone TM The clay sold, mica, talc, clay, product name Nyglos TM Vansil TM and Wollastocoat TM Wollastonite, calcium carbonate, calcium oxide, calcium sulfate, trade name Aerosil TM and Cab-o-sil TM Fumed silica, hollow glass and polymer spheres, carbon black, barium sulfate and graphite.

[0065] Depending on the requirements, the material may also include other additives, reagents, or performance modifiers, including but not limited to UV stabilizers, flame retardants, heat stabilizers, colorants, processing aids, lubricants, etc.

[0066] The idea is that virtually any additional chemical, material, or other substance can be added to the material, assuming they are suitable for the material and its selected application, without impairing the latency of the single-component material.

[0067] It is possible that specific combinations and relative amounts of one or more materials described herein can contribute to providing improved values ​​for one or more of the T-peel strength or lap shear strength. For example, a combination of polyetheramine / epoxy adduct, core-shell particles, and urethane toughening agents is useful for high T-peel strength. At the optimal ratio of these three components, a T-peel strength of approximately 9 N / mm can be achieved when measured at a crosshead speed of 254 mm / min and a bond line of 0.25 mm. The synergistic effect of these components can be explained by a combination of phase separation toughening, matrix flexibility, localized plastic deformation capacity, and reduced internal strength. For example, core-shell particles and urethane toughening agents can form phase-separated or separating domains for toughening, while the polyetheramine / epoxy adduct improves the flexibility and localized deformation of the adhesive matrix.

[0068] When measured according to ASTM D638 Type IV test method at a crosshead speed of 5 mm / min, certain adhesive materials formed according to this teaching exhibit failure strain greater than about 2%, greater than about 10%, and possibly even greater than about 100%. Failure strain is measured by recording deformation using an extensometer, and then the deformation is used to calculate the material strain.

[0069] When measured according to ASTM D5868 at a crosshead speed of 50.4 mm / min and an adhesive line of 0.25 mm, certain adhesive materials formed according to this teaching exhibit lap shear strengths greater than about 10 MPa, greater than about 30 MPa, and possibly even greater than 40 MPa.

[0070] When measured at a crosshead speed of 254 mm / min and an adhesion line of 0.25 mm, some materials formed according to this teaching have exhibited T-peel strengths greater than about 5 N / mm, greater than about 7 N / mm, and possibly even greater than 8.5 N / mm.

[0071] When measured according to ASTM D7028-07, certain adhesive materials formed according to this teaching have exhibited glass transition temperatures (Tg) greater than 20°C, greater than 70°C, and even greater than 90°C. The glass transition temperature determined by this test method (referred to as Dynamic Mechanical Analysis Tg or "DMA Tg") may differ from the glass transition temperature reported on the same test specimen by other measurement techniques (i.e., tanδ peak). This test method is commonly used to determine the maximum service temperature of composite materials.

[0072] For illustrative purposes, Table A below is prepared to illustrate six exemplary formulations for forming one-component thermally activated adhesives that cure via an ester exchange curing mechanism.

[0073] Table A

[0074]

[0075]

[0076] 1.0.030″EG60, test speed: 254mm / min, adhesive line 0.25mm;

[0077] 2.0.060″EG60, test speed: 50.4mm / min, adhesive line 0.25mm;

[0078] 3. ASTM D638 Type IV test method, crosshead speed is 5 mm / min;

[0079] 4. ASTM D7028-07. Curing schedule: 162.8℃, 30 minutes.

[0080] The materials shown in Table A are single-component, heat-activated adhesives with a wide range of properties. Sample 1 is an example of a high-strength structural adhesive cured via transesterification between polycarbonate and epoxy resin. Sample 1 exhibits an lap shear strength greater than 30 MPa and a T-peel strength greater than 5 N / mm. Samples 2 through 6 demonstrate how adhesive properties can be tuned by incorporating other components or manipulating their ratios. For example, Jeffamine... TM The epoxy resin adduct increased the T-peel strength (>8 N / mm) and failure strain (>14%) of samples 2 and 4, respectively. The added bisphenol A helped achieve a higher Tg (i.e., 80 °C) for sample 3. Reducing the polycarbonate to epoxy ratio resulted in an elastomeric adhesive with a failure strain exceeding 290% (i.e., sample 5). Sample 6, without the moisture scavenger (CaO), was a foaming adhesive with a volume expansion of approximately 100%. These results demonstrate the feasibility of transesterification as a curing mechanism for various structural adhesives.

[0081] Notably, Sample 5 exhibits both a tensile modulus exceeding 200 MPa and a failure strain of 290%. This adhesive demonstrates a significantly higher modulus compared to typical dicyandiamide-cured adhesives with the same failure strain. Typically, to achieve an epoxy adhesive with a failure strain of 290%, the tensile modulus would be below 5 MPa. Failure strain and tensile modulus are generally inversely proportional, with an increase in one corresponding to a decrease in the other. Therefore, simultaneously providing high failure strain and high elastic modulus is a significant challenge. This result reveals a significant benefit of using PC transesterification curing for adhesives that achieve high failure strain, relatively high modulus, and consequently excellent toughness.

[0082] It has been found that different components play a significant role in influencing adhesive and mechanical properties. The comparative examples shown below illustrate the changes in physical properties resulting from the inclusion / removal of certain components in the materials disclosed herein.

[0083] Table B

[0084]

[0085]

[0086] 1.0.030″EG60, test speed: 254mm / min, adhesive line 0.25mm;

[0087] 2.0.060″EG60, test speed: 50.4mm / min, adhesive line 0.25mm;

[0088] 3. ASTM D638 Type IV test method, crosshead speed is 5 mm / min;

[0089] 4. ASTM D7028-07. Curing schedule: 162.8℃, 30 minutes.

[0090] Sample 2 was used as a control to show how excluding each component affects the properties of the corresponding composition. A comparison of Sample 7 with Sample 2 demonstrates that polycarbonate is a key component necessary for the formation of a highly cross-linked network. Removing polycarbonate from Sample 2 caused the lap shear strength of Sample 7 to decrease from over 40 MPa to 2.3 MPa. Essentially, removing polycarbonate renders the composition no longer a structural binder. Analysis of the T-peel strength results for Samples 8 through 11 revealed the presence of core-shell particles, urethane toughening agents, and Jeffamine. TM The epoxy resin adduct and bisphenol A have a synergistic effect on the peel resistance of the material. Excluding any of these components from Sample 2 results in a decrease in T-peel strength, although they can still be considered adhesives. This can be explained by the synergistic effect of the adhesive's plastic properties, phase separation toughening agents, and matrix flexibility on the structural adhesive's toughness. Sample 6, without the moisture scavenger CaO, foams to 94% due to the hydrolytic decomposition of polycarbonate into carbon dioxide in the presence of a catalyst, which explains the decrease in lap shear strength and T-peel strength. For high-strength applications, a moisture scavenger is preferred to minimize foaming. However, foaming is desirable when crossing gaps between substrates. CaO can be excluded or reduced to promote foaming and prepare high-performance foamed adhesives.

[0091] Table C

[0092]

[0093]

[0094] 1.0.030″EG60, test speed: 254mm / min, adhesive line 0.25mm;

[0095] 2.0.060″EG60, test speed: 50.4mm / min, adhesive line 0.25mm;

[0096] 3. ASTM D638 Type IV test method, crosshead speed is 5 mm / min;

[0097] 4. ASTM D7028-07. Curing schedule: 162.8℃, 30 minutes.

[0098] Different types of phenols and catalysts have been used as alternatives to bisphenol A and quaternary ammonium salts for the preparation of adhesives cured via polycarbonate transesterification. Quaternary phosphonium salts and phosphine have been shown to be effective in catalyzing transesterification reactions. Resonance PM92-500, a highly functional (i.e., f = 2.6) phenol, further increases the Tg to approximately 100 °C compared to the use of bisphenol A, confirming the hypothesis that phenols contribute to crosslinking networks.

[0099] Table D

[0100]

[0101]

[0102] 1.0.030″EG60, test speed: 254mm / min, adhesive line 0.25mm;

[0103] 2.0.060″EG60, test speed: 50.4mm / min, adhesive line 0.25mm;

[0104] 3. ASTM D638 Type IV test method, crosshead speed is 5 mm / min;

[0105] 4. ASTM D7028-07. Curing schedule: 162.8℃, 30 minutes.

[0106] The examples shown in Table D demonstrate how the volume expansion of the material can be tuned by varying the percentage of the moisture scavenger. Samples 16 and 6, with low or no CaO, exhibit expansion suitable for gap-skipping applications. Sample 16, a low-expansion adhesive (i.e., 23% expansion), exhibits typical properties of a high-performance structural adhesive (i.e., 34.5 MPa lap shear strength and 7.3 N / mm T-peel strength). Sample 6, a high-expansion adhesive (i.e., 94% expansion), exhibits an lap shear strength of 14.7 MPa, exceeding the strength of structural adhesives (i.e., 7 MPa). These results demonstrate the feasibility of using polycarbonate transesterification as a curing mechanism to prepare expandable structural adhesives.

[0107] CaO is an excellent moisture scavenger because it reacts with water to form calcium hydroxide. Therefore, CaO may lose its defoaming function as it transforms into calcium hydroxide and loses its reactivity with moisture. To determine whether foaming occurs under moisture exposure, sample 2 was exposed to 85% humidity at 25°C. Under these conditions, the adhesive showed no swelling for up to 5 months.

[0108] For any potential curing agent, it is important to have high reactivity at the adhesive curing temperature and low reactivity at ambient temperature for storage and transport. Polycarbonate transesterification occurs only in the presence of a suitable catalyst. The catalytic reactivity at 325℉ and ambient temperature (i.e., 23℃ and 43℃) determines the curing and aging of adhesives cured by polycarbonate transesterification. An ideal catalyst is expected to activate transesterification at 325℉ for curing but not exhibit catalytic activity at 23℃ and 43℃ to maintain a suitable shelf life. Figure 1 As shown, polycarbonate transesterification can be characterized by a shift in the carbonate peak in the FTIR spectrum. Due to the chemical structural change from aromatic to aliphatic carbonates, transesterification shifts the carbonate peak in the epoxy resin to a higher wavenumber. Therefore, the catalyst reactivity at 325℉ can be calibrated from 0 to 2 based on the degree of carbonate peak shift. In contrast, catalyst reactivity at ambient temperature is measured by the increase in binder viscosity, which is a more sensitive response to lower reactivity levels than the IR peak shift.

[0109] Table E

[0110]

[0111] TEABr, tetraethylammonium bromide;

[0112] TBPBr, tetrabutylphosphonium bromide;

[0113] IATPPBr, isopentyltriphenylphosphonium bromide;

[0114] TpTP, Tris(p-tolyl)phosphine

[0115] The reactivity of these catalysts was investigated using an adhesive formulation consisting of 15% polycarbonate, 85% YDF-170 (i.e., bisphenol F type epoxy resin), and various catalysts. The adhesive was cured at 325℉ for 30 minutes. Aging studies of the uncured adhesive were performed at 23℃ and 43℃. As shown in Table E, catalyst reactivity at 325℉ decreased in the order of TBPBr (high), TEABr and IATPPBr (medium), and TpTP (low). Surprisingly, TpTP also caused the most significant aging at both 23℃ and 43℃. While low concentrations (i.e., 0.1 phr) of TBPBr showed very little aging only at 23℃, 0.2 phr of TEABr and 0.1 phr of IATPPBr both caused very little aging at both 23℃ and 43℃. For DICY-cured adhesives, viscosity typically increased by 70% to 100% after aging at 43℃ for 3 days. Analysis of the results in Table E reveals that when 0.2 phr TEABr and 0.1 phr IATPPBr are used as catalysts, the aging of adhesives cured by polycarbonate ester exchange is comparable to or reduced.

[0116] As shown in Table A, epoxy-based structural adhesives are typically composed of various components to positively influence properties including toughness, environmental exposure resistance, and elongation. To ensure minimal adhesive aging, it is equally important that components are incorporated in a manner compatible with polycarbonate curing, such that these components do not activate the polycarbonate transesterification reaction before it is required. Table F shows the viscosity increases caused by different components in 15% polycarbonate and 85% YDF-170. Clearly, none of these components activate polycarbonate transesterification, as indicated by the lack of a significant increase in viscosity.

[0117] Table F

[0118]

[0119]

[0120] Table G

[0121]

[0122]

[0123] 1.0.030″EG60, test speed: 254mm / min, adhesive line 0.25mm;

[0124] 2.0.060″EG60, test speed: 50.4mm / min, adhesive line 0.25mm;

[0125] 3. ASTM D638 Type IV test method, crosshead speed is 5 mm / min;

[0126] 4. ASTM D7028-07. Curing schedule: 162.8℃, 30 minutes.

[0127] Table G shows the properties and aging of the formulated adhesives cured via polycarbonate transesterification. Samples 24 and 25 showed minimal aging. After 3 days at 43°C and 1 month at 23°C, the viscosity increase was equal to or less than 25%. Compared to sample 25, sample 26, an example excluding hexanediol glycidyl ether, showed a more significant viscosity increase at both 23°C and 43°C. This is likely a result of the higher polycarbonate to epoxide ratio. Indeed, adhesive aging is positively correlated with curing agent concentration. The examples shown in Table G demonstrate the feasibility of curing adhesives with minimal aging using polycarbonate transesterification. Catalyst concentration has been shown to play an important role in maintaining aging comparable to that of dicyandiamide-cured adhesives.

[0128] As used herein, unless otherwise stated, any member of the genus (list) of the teachings may be excluded from that genus; and / or any member of the Markush group may be excluded from that group.

[0129] Unless otherwise stated, the numerical values ​​described herein include all values ​​from lower to higher, in increments of one unit, provided that there is at least a two-unit interval between any lower and any higher value. As an example, if the quantity of a stated component, characteristic, or process variable (e.g., temperature, pressure, time, etc.) is, for example, from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, then it is intended that intermediate range values ​​(e.g., 15 to 85, 22 to 68, 43 to 51, 30 to 32, etc.) are within the teachings of this specification. Similarly, individual intermediate values ​​are also within the teachings. For values ​​less than 1, one unit is considered as 0.0001, 0.001, 0.01, or 0.1, as appropriate. These are merely embodiments of the specific intent, and all possible combinations of numerical values ​​between the listed minimum and maximum values ​​should be considered as expressly described in a similar manner in this application. It can be seen that the teachings of quantities expressed herein as "parts by weight" also contemplate the same range expressed as weight percentages. Therefore, the description of the resulting composition in the range of "at least x parts by weight" also envisions the teaching of the same enumerated range of "x" of the weight percentage of the resulting composition.

[0130] Unless otherwise stated, all ranges include both endpoints and all numbers between them. The use of “about” or “approximately” with respect to ranges applies to both ends of the range. Therefore, “about 20 to 30” is intended to cover “about 20 to about 30”, including at least the specified endpoints.

[0131] All publications and references (including patent applications and publications) are incorporated herein by reference for all purposes. The term “consistently of” used to describe a combination shall include the identified element, ingredient, component, or step, as well as any other such element, ingredient, component, or step that does not substantially affect the essential and novel features of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, ingredients, components, or steps herein also contemplates embodiments that consist of or are substantially composed of elements, ingredients, components, or steps.

[0132] Multiple elements, components, or steps may be provided by a single integrated element, component, component, or step. Alternatively, a single integrated element, component, component, or step may be divided into multiple separate elements, components, components, or steps. The disclosure of "one" or "an" describing an element, component, component, or step is not intended to exclude additional elements, components, components, or steps.

[0133] It should be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications, besides the examples provided, will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the invention should not be determined by reference to the foregoing description, but rather by reference to the appended claims and the full scope of their equivalents. All disclosures in articles and references (including patent applications and publications) are incorporated herein by reference for all purposes. The omission of any aspect of the subject matter disclosed herein in the appended claims is not a waiver of rights to that subject matter, nor should it be construed as the inventor considering that such subject matter is not part of the disclosed inventive subject matter.

Claims

1. A material comprising: (i) one or more epoxy resins; (ii) at least one polycarbonate; (iii) At least one catalyst, preferably an ester exchange catalyst.

2. The material according to claim 1, comprising one or more polyols and / or phenols.

3. The material according to claim 2, wherein the catalyst is capable of catalyzing the reaction of the at least one polycarbonate with the one or more epoxy resins and / or the one or more polyols and / or phenols.

4. The material according to any one of the preceding claims, comprising one or more toughening agents.

5. The material according to any one of the preceding claims, comprising one or more polymer core-shell particles.

6. The material according to any one of the preceding claims, wherein when cured at 162.8°C for 30 minutes, the material has a volume expansion of about 0% to about 100%.

7. The material according to any one of the preceding claims, wherein the material is a structural material, and when cured at 162.8°C for 30 minutes, the structural material has an lap shear strength greater than 30 MPa (as determined according to ASTM D5868) and a tensile modulus greater than 1100 MPa (as determined according to ASTM D638 at a crosshead speed of 5 mm / min).

8. The material according to any one of the preceding claims, wherein the material is an elastomer material having a failure strain greater than 50% (measured according to ASTM D638 at a crosshead speed of 5 mm / min) when cured at 162.8°C for 30 minutes.

9. The material according to any one of the preceding claims, wherein the material is a non-expanding material and, when cured at 162.8°C for 30 minutes, has a T-peel strength of at least 5 N / mm (as determined according to ISO 11339) and an lap shear strength of at least 30 MPa (as determined according to ASTM D5868).

10. The material according to any one of the preceding claims, wherein the material is an expandable material and, when cured at 162.8°C for 30 minutes, has a T-peel strength of at least 4 N / mm (as determined according to ISO 11339) and an lap shear strength of at least 14 MPa (as determined according to ASTM D5868).

11. The material according to any one of the preceding claims, wherein the polycarbonate is present in an amount of about 5% to about 60% by weight based on the total weight of the material.

12. The material according to any one of the preceding claims, wherein the at least one catalyst is present in an amount of about 0.01% by weight to about 10% by weight, based on the total weight of the material.

13. The material according to any one of the preceding claims, wherein the material comprises one or more moisture-removing agents in an amount of about 0% by weight to about 40% by weight based on the total weight of the material.

14. The material according to any one of the preceding claims, wherein the material comprises one or more toughening agents in an amount of about 2% by weight to about 40% by weight based on the total weight of the material.

15. The material according to any one of the preceding claims, wherein the material comprises one or more polymer particles in an amount of about 2% to about 30% by weight of the total weight of the material.

16. The material according to any one of the preceding claims, wherein the at least one polycarbonate has a melt index (300°C, 1.2 kg load) of about 2 g / 10 min to about 60 g / 10 min and a molecular weight of about 5,000 Daltons to about 300,000 Daltons.

17. The material according to any one of the preceding claims comprises one or more polyols, said one or more polyols being aliphatic or aromatic polyesters or polyethers or polycarbonate polyols.

18. The material according to any one of the preceding claims comprises one or more phenols selected from hydroquinone, resorcinol, catechol, bisphenol A, bisphenol F, bisphenol E, bisphenol AP, bisphenol Z, bisphenol M, bisphenol P, bisphenol G, bisphenol BP, and any combination thereof.

19. The material according to any one of the preceding claims, wherein the at least one catalyst is selected from quaternary ammonium salts, quaternary phosphorus salts, phosphine, Lewis acids, metal oxides, phosphine, solid strong acids, and any combination thereof.

20. The material according to any one of the preceding claims, comprising one or more moisture scavengers selected from calcium oxide, molecular sieves, vinyltrimethoxysilane, zeolite, oxazolidine, and any combination thereof.

21. The material according to any one of the preceding claims, comprising one or more toughening agents or toughening agents in the form of adducts with epoxy resins, said toughening agents or toughening agents in the form of adducts with epoxy resins selected from phenol-terminated urethanes, aliphatic dimer acid / epoxy resin adducts, polyetheramine / epoxy resin adducts, dicarboxylic acid functional modifiers, or any combination thereof.

22. The material according to any one of the preceding claims comprises one or more polymer particles selected from a core modifier of polybutadiene, a core modifier of styrene-butadiene rubber, or any combination thereof.

23. The material according to any one of the preceding claims, comprising one or more polymer particles, said one or more polymer particles comprising core / shell rubber particles with an average size of about 100 nm to about 200 nm.

24. The material according to any one of the preceding claims, comprising one or more polymer particles that are substantially free of agglomerated particles.

25. The material according to any one of the preceding claims, comprising one or more discrete components.

26. The material of claim 25, wherein the one or more discrete components are selected from silica, diatomaceous earth, glass, clay (e.g., including nanoclay), glass beads or microbubbles, glass fibers, carbon fibers or ceramic fibers, nylon, aramid fibers or polyamide fibers (e.g., Kevlar fibers), pyrophyllite, zinc montmorillonite, soapstone, chloroform, wollastonite, montmorillonite, or any combination thereof.

27. The material according to any one of the preceding claims, comprising discrete components based on silica and / or calcium.

28. The material according to any one of the preceding claims, comprising a silica-based discrete component including fumed silica.

29. The material according to any one of the preceding claims, wherein the material is substantially free of curing agent other than the polycarbonate.

30. The material according to any one of the preceding claims, wherein the material is substantially free of foaming agents other than the polycarbonate.

31. The material according to any one of the preceding claims, wherein the material is substantially free of any dicyandiamide.

32. The material according to any one of the preceding claims, wherein the material has a tensile modulus greater than 200 MPa (measured according to ASTM D638 at a crosshead speed of 5 mm / min) and a failure strain of at least 275% (measured according to ASTM D638 at a crosshead speed of 5 mm / min).

33. The material according to any one of the preceding claims, comprising one or more moisture scavenging agents.

34. The material according to any one of the preceding claims is an adhesive, preferably a structural adhesive, and more preferably a one-component adhesive.

35. An adhesive comprising at least (i) one or more epoxy resins; and (ii) at least one polycarbonate; The adhesive described herein has a tensile modulus greater than 200 MPa (measured according to ASTM D638 at a crosshead speed of 5 mm / min) and at least 275% failure strain (measured according to ASTM D638 at a crosshead speed of 5 mm / min).

36. The adhesive of claim 35, comprising a catalyst for reacting with the at least one polycarbonate, preferably an transesterification catalyst.

37. The adhesive according to claim 35 or 36, comprising: i) One or more polyols and / or phenols; ii) One or more moisture scavengers; iii) One or more toughening agents; iv) one or more polymer particles; and v) One or more discrete components; Or any combination thereof.

38. The adhesive according to any one of claims 35 to 37, wherein the catalyst is capable of catalyzing the reaction of the polycarbonate with the one or more epoxy resins and / or the one or more polyols and / or phenols.

39. The adhesive according to any one of claims 35 to 38, wherein the adhesive is substantially free of any curing agent other than the polycarbonate.

40. The adhesive according to any one of claims 35 to 39, wherein the adhesive is substantially free of any foaming agent other than the polycarbonate.

41. Use of the material or adhesive according to any one of the preceding claims for filling cavities in a transport vehicle.

42. Use of the material or adhesive according to any one of the preceding claims for reinforcing cavities in a transport vehicle.

43. Use of the material or adhesive according to any one of the preceding claims in building construction.

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