POLYAMIDE-METAL LAMINATES

Abstract

Novel polyamide-metal laminates with desirable hydrolysis resistance are provided. The laminates comprise (A) a metal, (B) a bonding layer, and (C) a polyamide composition. The bonding layer is formed from a composition containing (B1) a polymer containing a comonomer having at least two adjacent carboxylic acid groups and (B2) an aminosilane containing a primary amine and at least one hydroxyl group.

Description

POLYAMIDE-METAL LAMINATES FIELD OF INVENTION This description mentions several patents and publications to provide a more complete description of the prior art to which the present invention belongs. The full description of each of these patents and publications is incorporated herein by reference. This document describes novel polyamide-metal laminates that have desirable hydrolysis resistance and comprise novel bonding layers for the adhesion of the polyamide composition to the metal surface. It also describes suitable compositions for forming bonding layers on metals, metal parts having bonding layers, articles comprising the polyamide-metal laminates, and processes for preparing these polyamide-metal laminates. BACKGROUND OF THE INVENTION Polyamide-based compositions typically possess desirable properties such as chemical resistance, processability, and heat resistance. This makes them particularly suitable for demanding, high-performance automotive and electrical / electronic applications, such as zczann / zznz / E / YiAi Ref. 333841 as vehicle radiators and heater hoses. There is a current and general desire in the automotive field for the continuous reduction of the weight of the various components that make up automobiles. U.S. Patent Application Publication No. 2003 / 0116269 describes aqueous primer compositions comprising organosilanes for use on metallic surfaces to bond primarily two metals together. U.S. Patent Application Publication No. 2003 / 0180552 describes a method of treating a metallic surface with a silane composition to enhance the adhesion of a polymer to the metallic surface. U.S. Patent Application Publication No. 2007 / 0056469 describes a method of treating a metallic surface with a silane composition to enhance the adhesion of a polymer to the metallic surface. The silane composition comprises a silane coating composition containing at least one water-soluble or water-dispersible silane and a polymeric resin. The polymeric resin is water-insoluble and is used as a dCUOSd dispersion. However, there remains a need for even lighter-weight components for under-the-hood applications in vehicles, components that are less numerous and easier to manufacture than currently available automotive components. Direct bonding of aluminum or other light metals to polyamides would eliminate parts and yield lighter articles. However, such direct bonding must be able to withstand the high temperatures found in under-the-hood areas of automobiles, especially when the article is exposed to high-temperature aqueous ethylene glycol solutions. BRIEF DESCRIPTION OF THE FIGURES Fig. 1 shows a schematic diagram of an expected chemical structure of metal (A), a bonding layer (B) and a polyamide (C) for the polyamide-aluminum laminate. Fig. 2 shows a schematic diagram of an expected chemical structure after the bonding layer (B) forms on the aluminum (A). Fig. 3 shows a schematic diagram of another expected chemical structure after the bonding layer (B) forms on the aluminum (A). Fig. 4 shows a schematic diagram of an expected chemical structure when the amino-silane (B2) is not included in the bonding layer (B) (Comparison). Fig. 5 shows a schematic diagram of an expected chemical structure when the carboxylic acid-containing polymer (B1) is not included in the bonding layer (B) (Comparison). Fig. 6 shows a cross-sectional side view of a polyamide cap test specimen. zczann / zznz / E / YiAi Fig. 7 shows a cross-sectional side view of a polyamide cap test specimen in a rolling apparatus for rolling a metal layer through a bonding layer to form a polyamide-metal laminate with a bonding layer. Fig. 8 shows a cross-sectional side view of a polyamide-metal laminate with a bonding layer in an apparatus for determining the bond strength between the polyamide cap test specimen and the metal layer. Fig. 9 shows a perspective view of a test specimen for the determination of adhesion strength according to ISO-19095-3. DETAILED DESCRIPTION OF THE INVENTION Abbreviations The claims and description in this document shall be interpreted using the abbreviations and definitions set forth below. h refers to hours. % refers to the term percentage. % in moles refers to percentage in moles. % in p refers to the percentage by weight. parts refers to parts by weight. g refers to grams. Definitions As used herein, the article un / a zczann / zznz / E / YiAi refers to one as well as more than one, and does not necessarily limit its noun of reference to the grammatical category of singular number. As used herein, the term "item" refers to a product, thing, structure, object, element, device, etc., that is in a form, shape, or configuration suitable for a particular use or purpose without further processing of the whole or a portion thereof. An item may comprise one or more elements or subassemblies that are partially completed and awaiting further processing or assembly with other elements or subassemblies to form a finished item. Additionally, as used herein, the term "item" may refer to a system or configuration of items. As used herein, the term solution refers to aqueous mixtures of ingredients in which the ingredients can be dissolved, suspended, or dispersed in water, alcohol, another suitable liquid, or a combination of two or more suitable liquids. As used herein, the term pure aluminum refers to aluminum metal comprising at least 99% by weight of aluminum, based on the total weight of pure aluminum. As used herein, the term aluminum alloy refers to aluminum metal comprising less than 99% by weight of aluminum, based on the total weight of the alloy, and comprising one or more different metals and, optionally, one or more non-metallic elements. As used herein, the term bonding layer refers to a composition that bonds metal compositions to polyamide without the need for mechanical bonding, although additional mechanical bonding is optional. The bonding layer forms an interleaved structure, with the metal forming the middle layer directly bonded to the bonding layer and the polyamide composition forming the other outer layer directly bonded to the bonding layer. Alternatively, the metal layer is bonded directly to one face of the bonding layer, and the polyamide composition is bonded directly to the opposite face of the bonding layer. Preferred intervals and variations Any range stated herein expressly includes its extremes, unless explicitly stated otherwise. The statement of a quantity, concentration, or other value or parameter in range form specifically describes all possible ranges formed between any possible upper range limit and any possible lower range limit, regardless of whether such pairs of upper and lower range limits are expressly described herein. The compounds, processes, and articles described herein are not limited to the specific values ​​described in the range definition of the description. The description herein of any variation in terms of materials, chemical entities, methods, steps, values, and / or ranges, etc., whether identified as preferred or not, of the processes, compounds, and articles described herein is specifically intended to include any possible combination of that variation with any other material, method, step, value, range, etc., described herein. Any described combination of features is a preferred variant of the processes, compounds, and articles described herein. Generalities This document describes polyamide-metal laminates comprising a polyamide composition bonded to the metal using a bonding layer of a specific composition. Preferably, the polyamide-metal laminates exhibit desirable hydrolysis resistance when exposed to an ethylene glycol / water solution at 130 °C for 1,000 hours, compared to the initial bond strength before exposure to the ethylene glycol / water solution. This document also describes zczann / zznz / E / YiAi bonding layers used to improve the bonding of metal-to-polyamide compositions and processes for preparing these bonding layers. Furthermore, preferably, the polyamide-metal laminates comprise (A) a metal, (B) a bonding layer formed on the surface of the metal, and (C) a polyamide formed on the surface of the bonding layer, wherein the bonding layer comprises: Bl) a polymer comprising carboxylic acid groups; and B2) an amino-silane comprising a primary amine and at least one hydroxyl group; wherein at least two carboxylic acid groups in the polymer (B1) are adjacent to each other and the molar ratio of the two adjacent carboxylic acid groups in (B1) with respect to the primary amine groups in (B2) is from 1:0.8 to 1:14. This document also describes compositions comprising the (B1) and (B2) described above, metal parts having bonding layers (B), processes for preparing polyamide-metal laminates, and articles comprising polyamide-metal laminates. Polyamide-metal laminates Polyamide-metal laminates, as described herein, can be used to prepare articles of any shape, such as a polyamide hose (polyamide (C)) bonded to a metal radiator (metal (A)) using a bonding layer (B). The bonding layers (B) described herein can be applied or coated onto metal (A) to provide bonding / metal laminates. These bonding / metal laminates can then be bonded to a polyamide composition to prepare polyamide-metal laminates. Metal layer (A) The metal (A) can be any metal capable of forming a bond with the hydroxyl group of the amino-silane (B2). Examples of metal (A) include carbon steel, galvanized steel, stainless steel, cast steel, aluminum, titanium, and alloys thereof. Metal (A) is preferably a light metal, such as aluminum or titanium, preferably aluminum. The metal can be a pure metal or a metal alloy. The metal alloy can comprise a mixture of metals. Alternatively, one or more metals can be combined with one or more non-metallic elements, such as carbon or silicon, to form the alloy. When the metal is aluminum, the aluminum content of the aluminum alloy must be at least approximately 70 percent by weight of aluminum, preferably at least approximately 80 percent by weight of aluminum, and more preferably at least 90 percent by weight of aluminum. zczann / zznz / E / YiAi Cleaning metal surfaces Before forming the bonding layer (B) on the metal (A), it may or may not be necessary to clean the metal surface. When cleaning the metal surface is required, methods typically used in the art to remove contaminants and oxidation from the metal surface may be employed. Cleaning metal surfaces includes both chemical treatments and mechanical methods, as well as combinations of two or more suitable cleaning methods. Examples of such cleaning methods include, but are not limited to, polishing; abrasion with abrasive material, such as sandpaper; atmospheric plasma treatment; corona discharge treatment; shot blasting; washing with a cleaning solution, detergent solution, solvent, or deionized water; and chemical etching. A solution comprising an abrasive material may be used when polishing metals.Non-limiting examples of abrasive materials include calcium carbonate, sodium bicarbonate, calcium sulfate, magnesium sulfate, and combinations thereof. The solution may also include alcohols, such as ethyl alcohol, methyl alcohol, and isopropyl alcohol. The cleaning solution preferably contains cationic, anionic, or nonionic surfactants, or a combination of two or more surfactants. The detergent solution may be any detergent or surfactant solution capable of removing contaminants from the metal surface. Examples of suitable cleaning solutions are well known in the art. When the metal is aluminum or aluminum alloys, the aluminum must be cleaned so that it can react with the aminosilane (B2). Any cleaning method can be used. The preferred methods for cleaning aluminum or aluminum alloys are polishing the surface of the aluminum or aluminum alloy by abrasion, such as with wet sandpaper, or shot blasting. While not strictly theoretical, it is generally considered that the aluminum surface needs to be cleaned and, optionally, activated to achieve sufficient hydrolysis resistance to form the polyamide-metal laminates. One example of analyzing the aluminum surface is X-ray photoelectron spectroscopy (XPS). Typically, the aluminum or aluminum alloy surface is oxidized or contaminated with oil; therefore, the signals from carbon and oxygen atoms are observed, in addition to the aluminum signal.To achieve sufficient hydrolysis resistance for forming polyamide-metal laminates, an aluminum signal analyzed by XPS must be 15% or higher, preferably 20% or higher. The percentage of the aluminum signal is based on the total moles of elements present on the aluminum surface. Alternatively, the percentage is an atomic percent based on the total number of zczann / zznz / E / YiAi atoms detected in the analysis, after applying relative sensitivity factors and properly integrating the peak areas of the XPS spectrum. Another example of analyzing the aluminum surface is time-of-flight secondary ion mass spectrometry (TOF-SIMS). Again, without being bound by theory, it is considered that one or more hydroxyl groups must be present on the aluminum surface to achieve sufficient hydrolysis resistance for polyamide-metal laminates.The number of hydroxyl groups is analyzed as an aluminum hydroxide signal (Al(OH)3 or A1O(OH)-nH2O) using TOF-SIMS. Bonding layer (B) The bonding layer (B) that can be used to prepare the polyamide-metal laminates described herein comprises polymer (B1) and an amino-silane (B2). Polymer (B1) comprises carboxylic acid groups. The amino-silane (B2) comprises a primary amine group and at least one hydroxyl group in the amino-silane molecule. The bonding layer (B) can be a mixture of polymer (B1) and amino-silane (B2) or a reaction product of polymer (B1) and amino-silane (B2). When the bonding layer (B) is a reaction product, the carboxylic acid groups of polymer (B1) react with the amino group of amino-silane (B2). In some preferred bonding layers, this reaction forms a cyclic imide with a silane group attached to the nitrogen of the imide.It is believed that the reaction between the carboxylic acid groups of the polymer (B1) and the amino group of the amino-silane (B2) will occur upon heating, for example, to a temperature of 220 degrees C or more. Polymer (Bl) The polymer (Bl) used to prepare the bonding layer (B) comprises carboxylic acid groups. The carboxylic acid groups may be derived from carboxylic acid groups, such as, without limitation, carboxylic acid salts, alkyl esters, including monoesters and diesters, or a carboxylic acid anhydride. At least two carboxylic acid groups in (Bl) must be adjacent to each other. Preferably, the adjacent carboxylic acid groups are derived from anhydride groups, such as copolymerized maleic anhydride units, since anhydride groups provide two adjacent carboxylic acid groups when they are hydrolyzed. The adjacent carboxylic acid groups contribute to forming a cyclic imide structure with the nitrogen atom of the amino group, as described below. Typically, the polymer (Bl) can be prepared by copolymerization from one or more monomers having an ethylenically unsaturated group (Bl-a) and one or more monomers having an ethylenically unsaturated group and at least two adjacent carboxylic acid groups or a derivative thereof (Bl-b). As used herein, the expression "adjacent carboxylic acid groups" refers to a molecule in which at least two carbon atoms are directly bonded to each other by a single or double bond, and each of these at least two carbon atoms is substituted by a carboxylic acid group. The monomer (Bl-a) may also have a carboxylic acid group.Monomers having an ethylenically unsaturated group (Bl-a) include, without limitation, unsaturated aliphatic hydrocarbons such as ethylene, propylene, butene, octene, and isopropylene; aromatic monomers such as styrene and 4-methylstyrene; acrylic acid; methacrylic acid; acrylates such as salts or esters of acrylic acid; methacrylates such as salts or esters of methacrylic acid; and combinations of two or more of these. Preferred monomers having dicarboxylic acid groups or derivatives thereof (Bl-b) include, without limitation, maleic acid, fumaric acid, itaconic acid, citraconic acid, and derivatives such as acid anhydrides, salts, diesters, and monoesters of these acids. Maleic anhydride and alkyl monoesters of maleic acid are preferred.In the copolymer of the monomer (Bl-a) and the monomer (Bl-b), the preferred molar content of residues of the monomer (Bl-b) is 10 mol% or more, more preferably 20 mol% or more, furthermore, more preferably 40 mol% or more, based on the total number of copolymerized moles of (Bl-a) and (Bl-b). zczann / zznz / E / YiAi The content of the two adjacent carboxylic acid groups in the polymer (Bl) may be 2 wt% or more, preferably 5 wt% or more, based on the total wt% of the polymer (Bl). The remaining copolymerized units of Polymer Bl may consist or consist essentially of up to 90 mol% or more, preferably up to 80 mol% or more, of (Bl-a). The polymer (Bl) can be prepared by direct polymerization from monomers having dicarboxylic acid groups or derivatives thereof (Bl-b), such as maleic acid, fumaric acid and derivatives thereof. The polymer (Bl) can also be prepared by grafting maleic anhydride onto the polymer backbone (Bl) and hydrolyzing the anhydride to form two carboxylic acid groups Examples of suitable polymers (Bl) include, for example, poly(butadiene-maleic acid) copolymers, propylene-maleic acid copolymers, ethylene-maleic acid copolymers, ethylene-maleic anhydride copolymers, propylene-maleic anhydride copolymers, polymaleic acid, poly(isobutylene-maleic acid) or its hydrolysate, ethylene-maleic anhydride copolymers or those hydrolysates, and combinations of two or more of these polymers. Examples of suitable polymers (Bl) in which carboxylic acid groups are grafted onto the main chain zczann / zznz / E / YiAi of the polymer (Bl) include, for example, maleic anhydride grafted onto ethylenectene copolymers, ethylenebutene copolymers, ethylenepropylene copolymers, and combinations of two or more of these polymers. Commercially available copolymers that can be used as the polymer (Bl) of the invention include ZeMac™ E60, E400 and Solution S67025, available from Vertellus, and ISOBAM™ 104, available from Kuraray co., ltd. Amino-Silane (B2) The amino-silane (B2) comprises a primary amine group and at least one hydroxyl group in the amino-silane molecule. The amino-silanes (B2) used in the bonding layer (B) are represented by Formula (I): OR2 R1O — Si — (CH2)XNR4R5(I) OR3 In Formula (I), R1, R2, and R3 are independently selected from H, linear, branched, or cyclic alkyl groups having from 1 to 6 carbon atoms. R4 is H; R5 is independently selected from H and -(CH2) and -NH2; yx and y are independently selected integers from 1 to 6, inclusive. At least one of R1, R2, and R3 is H. Preferably, zczann / zznz / E / YiAi R1, R2, R3, R4 and R5 are H, which is represented by Formula (II) · OH HO — Si — (CH2)xNH2(II) OH In Formula (II), x varies from 1 to 6. Non-limiting examples of suitable amino-silanes (B2) include 3-aminopropyltrimethoxysilane, 2-aminoethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminoethyltriethoxysilane and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and combinations of two or more of these amino-silanes. The amino-silane can be hydrolyzed in water and converted into an oligomer. Such an oligomer can be used in the invention. Composition As mentioned above, the bonding layer (B) can be a reaction product of the polymer (B1) and the aminosilane (B2) or an unreacted mixture of these materials. During the preparation of the bonding layer (B), a composition is used comprising (B1) a polymer comprising carboxylic acid groups and (B2) an aminosilane comprising a primary amine and at least one hydroxyl group. Suitable polymers (B1) and aminosilanes (B2) have been described in detail above. The carboxylic acid groups of the polymer (B1) can be present as salts, such as ammonium salts or alkali metal salts, for example. The composition can further comprise a solvent, such as, but not limited to, water or an alcohol / water mixture to form a solvent mixture. The composition can be an emulsion or dispersion comprising an aminosilane material and a polymer, or the composition can be a solution. The total concentration of the combination of at least one amino-silane (B2) and at least one polymer (Bl) in the composition may vary from approximately 0.5 to 20 percent by weight, preferably from 1 to 15 percent by weight and more preferably from 1 to 10 percent by weight of the total concentration of polymer (Bl) and amino-silane (B2), based on the total weight of the composition. The composition may also include a pH adjuster. Examples of pH adjusters include, for instance, ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, and 1,8-diazabicyclo[5.4.0]undec-7-ene, the salts of these materials, and mixtures of these materials with their salts. When the composition is a solution, the pH of the solution is preferably from 5 to 14, more preferably from 7 to 12, and most preferably from 8 to 11. Without being bound to theory, the carboxylic acid groups of polymer (B1) zczann / zznz / E / YiAi are considered to dissociate electrolytically in alkaline solution; therefore, polymer (B1) is stable in alkaline solution. At the same time, the amino group of aminosilane (B2) ionizes in alkaline solution. These two groups are considered to interact with each other in alkaline solution. Therefore, the solution is stable when the solution is alkaline.When the solution is in the weak acid range (pH 5 to 7), some of the carboxylic acid groups of the polymer (Bl) dissociate electrolytically; therefore, the solution is also stable for the same reason described above. Bonding Layer B may further comprise one or more additional components. Suitable additional components include, without limitation, reinforcing agents such as carbon black or glass fibers, as described below with respect to Polyamide Composition C; other polymers such as polyacrylates or ethylene-acrylate copolymers; heat stabilizers, as described below with respect to Polyamide Composition C; and optional additives, as described below with respect to Polyamide Composition C. When a solvent or one or more additional components are present in Bonding Layer B, they are preferably present at a level of 50 wt% or more, or 20 wt% or more, or 15 wt% or more, or 10 wt% or more, based on the total weight of the composition. Additionally, the amount of Polymer B1 and Aminosilane B2 in the composition is 50 wt% or less, or 80 wt% or less, or 85 wt% or less, or 90 wt% or less, based on the total weight of the composition. The sum of the weight percentages of all components in the composition is 100 wt%. Alternatively, when an optional component is also suitable for use in Polymer Composition C, it may be present in the same amount as is suitable for use in Polyamide Composition C. Bonding layer preparation (B) Formation of the bonding layer (B) on the metal (A) With reference now to the figures, where the same reference numbers indicate the corresponding structure along the views and with reference, in particular, to Fig. 3, these compositions can be applied to the metal (A) 11 by any known method, such as spraying, roller coating, or immersion, and then the solvent, if present, is evaporated (i.e., removed) to form a bonding layer (B) 21 on the metal (A) 11. The evaporation of the solvent can be carried out under any suitable known condition, such as at room temperature or with heating and at atmospheric pressure or decompression.Without being tied to the theory, it is believed that the amino-silane hydroxyl group interacts with the zczann / zznz / E / YiAi hydroxyl group on the metal surface when the composition is applied to the metal (A) 11 and then the amino-silane would bond to the metal surface (A) 11 by dehydration when the solvent is removed, as shown in Fig. 3. With reference to Fig. 2, the bonding layer (B) 21 can optionally be heated after being applied to the metal (A) 11, for example, from 100 to 300 degrees C for 1 to 120 minutes. While not strictly theoretical, it is believed that when the bonding layer (B) 21 is heated, the two adjacent carboxylic acid groups of the polymer (B1) react chemically with the primary amine group of the aminosilane (B2) to form cyclic imide groups that covalently link the aminosilane molecule to the polymer molecule. Therefore, if the heating step is added, the bonding layer (B) 21 is believed to be a reaction product of the polymer (B1) and the amino-silane (B2), as shown in Fig. 2. However, the step can be omitted because the bonding layer (B) 21 is heated during the polyamide lamination step (C), as described below. The molar ratio of the two adjacent carboxylic acid groups in the polymer (B1) with respect to the primary amine groups in the amino-silane (B2) (acid:amine) is 1:0.8 to 1:12, preferably 1:0.9 to 1:6, more preferably 1:0.9 to 1:5, still more preferably 1:1 to 1:4, and still more preferably 1:1.3 to 1:4. The molar ratios described herein are based on the fact that one anhydride group provides two carboxylic acid groups when hydrolyzed. After forming layer (B) 21 on the metal (A) 11, the metal can be used as a stable metal part. The metal part with the bonding layer (B) can be stored, distributed, and used as a component ready for lamination with polyamide (C). Polyamide composition (C) The polyamide composition (C) can have any form, such as a sheet or plate, a tube or hose, or a box. When the polyamide composition (C) is a tube or hose, the end of the tube or hose can be made of a bonding layer (B) on the metal (A). In other words, polyamide-metal laminates are not limited to sheet or plate structures, but can be, for example, a polyamide hose bonded to a metal bonding layer / part. Any article having a metal (A) bonded to a polyamide composition (C) through a bonding layer (B) is within the scope of the present invention, regardless of the conformation of the metal (A), the bonding layer (B) or the polyamide composition (C), provided that some part of the article has the structure of metal (A) / bonding layer (B) / polyamide composition (C), wherein (A), (B) and (C) are contiguous layers.More preferably, the metal (A) is in direct contact with the bonding layer (B), the bonding layer (B) is in direct contact with the polyamide composition (C), and the metal (A) and the polyamide composition (C) are in direct contact with opposite faces of the bonding layer (B). Polyamide resin (Cl) The polyamide resin (Cl) that can be used to prepare the polyamide-metal laminates described herein is not limited and may preferably be any polyamide having a melting point above approximately 170 °C, preferably above approximately 180 °C. Polyamides are condensation products of one or more dicarboxylic acids and one or more diamines and / or one or more aminocarboxylic acids and / or ring-opening polymerization products of one or more cyclic lactams. Suitable cyclic lactams are caprolactam and laurolactam. Polyamides may be fully aliphatic or semiaromatic. Los ejemplos de polyamides que se pueden usar en los laminados de polyamide-metal include poly(tetramethylene hexanodiamida) (PA46), poly(ε-caprolactam) (PA 6), poly(hexamethylene hexanodiamida / (ε-caprolactam) (PA 66 / 6), poly(hexamethylene hexanodiamida) (PA 66), poly(hexamethylene hexanodiamida / hexamethylene decanodiamida) (PA66 / 610), zczann / zznz / E / YiAi poly(hexamethylene hexanodiamida / hexamethylene dodecanodiamida) (PA66 / 612), poly(hexamethylene hexanodiamida / decamethylene decanodiamida) (PA66 / 1010), poly(hexamethylene dodecanodiamida) (PA610), poly(hexamethylene dodecanodiamida) (PA612) tetradecanodiamida) (PA614), poly(tetramethylene hexanodiamida / 2-metilpentamethylene hexanediamide) (PA46 / D6), poly(tetramethylene hexanediamide / tetramethylene terephthalamide) (PA46 / 4T), poly(tetramethylene hexanediamide / hexamethylene terephthalamide) (PA46 / 6T), poly(tetramethylene hexanediamide / 2methylpentamethylene hexanediamide / decamethylene terephthalamide) (PA46 / D6 / 10T),poly(hexamethylene hexanediamide / hexamethylene terephthalamide) (PA66 / 6T), poly(hexamethylene hexanediamide / hexamethylene isophthalamide / hexamethylene terephthalamide PA66 / 6I / 6T, poly(hexamethylene hexanediamide / 2methylpentamethylene hexanediamide / hexamethylene terephthalamide (PA66 / D6 / 6T), poly(tetramethylene terephthalamide / hexamethylene hexanediamide) (PA4T / 66), poly(tetramethylene terephthalamide / caprolactam) (PA4T / 6), poly(tetramethylene terephthalamide / hexamethylene dodecanediamide) (PA4T / 612), poly(tetramethylene terephthalamide / 2-methylpentamethylene hexanediamide / hexamethylene hexanediamide) (PA4T / D6 / 66), poly(hexamethylene terephthalamide / 2-methylpentamethylene terephthalamide / hexamethylene hexanediamide) (PA6T / DT / 66), poly(hexamethylene terephthalamida / hexametilen hexanodiamida) zczann / zznz / E / YiAi, PA6T / 66, poly(hexamethylene terephthalamide / hexamethylene decanediamide) (PA6T / 610), poly(hexamethylene terephthalamide / hexamethylene dodecanediamide) (PA6T / 612), poly(hexamethylene terephthalamide / hexamethylene tetradecanediamide) (PA6T / 614), poly(hexamethylene terephthalamide / isophorone diamine terephthalamide) (PA6T / IPDT), poly(nonamethylene terephthalamide / nonamethylene decanediamide) (PA9T / 910), poly(nonamethylene terephthalamide / nonamethylene dodecanediamide) (PA9T / 912), poly(nonamethylene terephthalamide / ll-aminoundecanamide) (PA9T / 11), poly(nonamethylene terephthalamide / 12-aminododecanamide) (PA9T / 12), poly(decamethylene terephthalamide / 11aminoundecanamide) (PA 10T / 11), poly(decamethylene terephthalamide / 12-aminododecanamide) (PA1OT / 12) poly(decamethylene terephthalamide / decamethylene decanediamide) (PA10T / 1010), poly(decamethylene terephthalamide / decamethylene dodecanediamide) (PA10T / 1012), poly(decamethylene terephthalamide / tetramethylene hexanediamide) (PA10T / 46), poly(decamethylene terephthalamide / ε-caprolactam) (PA10T / 6),poly(decamethylene terephthalamide / hexamethylene hexanodiamide) (PA10T / 66), poly(dodecamethylene terephthalamide / dodecamethylene dodecanodiamide) (PA12T / 1212), poly(dodecamethylene terephthalamide / ε-caprolactam) (PA1 / 6) and poly(dodecamethylene) terephthalamide / hexamethylene hexanodiamide) (PA12T / 66)., Preferred polyamides described in this zczann / zznz / E / YiAi document include PA6T / DT, PA66, PA612, PA610, PA6T / 610, PA6T / 612, PA6T / IPDT, PA6, ΡΑΙΟ and mixtures thereof. The amount of polyamide (Cl) in the polyamide (C) composition is complementary to the amounts of the other components in the polyamide (C) composition. Alternatively, the sum of the weight percentages of all components in the polyamide (C) composition is 100% by weight. Therefore, for example, if the polyamide (C) composition comprises 70% by weight of a reinforcing agent and 5% by weight of a heat stabilizer, the amount of polyamide (Cl) is 25% by weight, based on the total weight of the polyamide (C) composition. Reinforcing agent (C2) The polyamide (C) compositions described herein may comprise one or more reinforcing agents (C2). The reinforcing agent is preferably selected from the group consisting of calcium carbonate, glass fibers with circular and non-circular cross-sections, glass flakes, glass beads, carbon fibers, aramid fibers, talc, mica, wollastonite, calcined clay, kaolin, diatomite, magnesium sulfate, magnesium silicate, barium sulfate, titanium dioxide, sodium aluminum carbonate, barium ferrite, potassium titanate, and mixtures of two or more suitable reinforcing agents (C2). In preferred embodiments, the reinforcing agent is selected from the group consisting of glass fibers having a circular cross-section, glass fibers with a non-circular cross-section, and aramid fibers.The reinforcing agent may have sizing or coupling agents, organic or inorganic materials that improve the bond between the reinforcing agent and the polyamide resin. The polyamide (C) composition described herein may comprise from 0 to 70, preferably from 10 to 70 and more preferably from 20 to 70 percent by weight of one or more reinforcing agents, based on the total weight percent of all ingredients in the polyamide (C) composition. Thermal stabilizer (C3) The polyamide composition (C) may include a heat stabilizer (C3). Organic heat stabilizers are preferred because inorganic heat stabilizers typically provide halogen ions and / or copper ions, which affect the corrosion of the metal (A). Organic heat stabilizers, also called antioxidants, as described herein, include hindered phenol compounds, amine-based heat stabilizers, and phosphorus-based heat stabilizers. Examples of hindered phenol compounds include tetrakis(methylene(3,5-di-(tere)-butyl-4-hydroxyhydrocinnamate))methane, commercially available as Irganox™ 1010 from CIBA Specialty Chemicals, Tarrytown, NY, and N,N'-hexamethylene bis(3,5-di-(tere)butyl-hydroxyhydrocinnamamide), also available from GIBA Specialty Chemicals as Irganox™ 1098. Other suitable hindered phenols include 1,3,5-trimethyl-2,4,6-tris(3,5-di-(tere)-butyl-4-hydroxybenzyl)benzene and 1,6-hexamethylene bis(3,5-di(tere)butyl-4-hydroxyhydrocinnamate), both available from GIBA Specialty Chemicals as Irganox™ 1330 and 259. respectively. Examples of amine-based heat stabilizers include hindered amine light stabilizers (HALS). Preferably, the HALS is a compound derived from a substituted piperidine compound, in particular, any compound derived from an alkyl-substituted piperidyl, piperidinyl, or piperazinone compound and substituted alkoxypiperidinyl compounds. Examples of such compounds are: 2,2,6,6-tetramethyl-4-piperidone; 2,2,6,6-tetramethyl-4-piperidinol; bis(1,2,2,6,6-pentamethylpiperidyl)-(3',5'-di-tere-butyl-4'-hydroxybenzyl) butylmalonate; di-(2,2,6,6-tetramethyl-4-piperidyl) sebacate (Tinuvin® 770, MW 481); N-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol and succinic acid oligomer (Tinuvin® 622); cyanuric acid and N,Ndi-(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine oligomer; bis-(2,2,6,6-tetramethyl-4-piperidinyl) succinate ; sebacate zczann / zznz / E / YiAi of bis-(l-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) (Tinuvin® 123); bis-(1,2,2,6,6-pentamethyl-4piperidinyl) sebacate (Tinuvin® 765); Tinuvin® 144; Tinuvin® XT850; tetraquis-(2,2,6,6-tetramethyl-4piperidyl)-1,2,3,4-butane tetracarboxylate; N,N'-bis-(2,2,6,6-tetramethyl-4piperidyl)-hexane-1,6-diamine (Chimasorb® T5); N-butyl2,2,6,6-tetramethyl-4-piperidynamine; 2,2'- [ (2,2,6,6tetramethyl-piperidinyl)-imino]-bis-[ethanol] ; poly( (6morpholine-S-triazin-2,4-diyl)(2,2,6,6-tetramethyl-4piperidinyl)-iminohexamethylene-(2,2,6,6-tetramethyl-4piperidinyl)-imino) (Cyasorb® UV 3346); 5-(2,2,6,6-tetramethyl4-piperidinyl)-2-cyclo-undecyl-oxazole) (Hostavin® N20); 1,1'(1,2-ethane-di-yl)-bis-(3,3',5,5'-tetramethyl-piperazinone); 8acetyl-3-dotecyl-7,7,9,9-tetramethyl-l,3,8triazaspiro(4,5)decane-2,4-dione; polymethylpropyl-3-oxy[4(2,2,6,6-tetramethyl)-piperidinyl]siloxane (Uvasil® 299);1,2,3-tris(1,2,2,6,6-pentamethyl-4-piperidinyl)-4-tridecyl ester of 1,2,3,4-butanetetracarboxylic acid; copolymer of alpha-methylstyrene-N-(2,2,6,6-tetramethyl-4-piperidinyl)maleimide and N-stearyl maleimide; 1,2,3,4-butanetetracarboxylic acid, polymer with beta,beta,beta',beta'tetramethyl-2,4,8,1O-tetraoxaespiro[5.5]undecane-3,9-diethanol, 1,2,2,6,6-pentamethyl-4-piperidinyl ester (Mark® LA63); 2,4,8,1O-tetraoxaspiro[5.5]undecane-3,9diethanol,beta,beta,beta',beta'-tetramethyl-polymer with acid zczann / zznz / E / YiAi; 1,2,3,4-butanotetracarboxilico, 2,2,6,6-tetrametil-4piperidinyl ester (Mark® LA68); D-glucitol, 1,3:2,4-bis-O(2,2,6,6-tetrametil-4-piperidiniliden)-(HALS 7); oligómero de 7-oxa-3,2 0-diazadiespiro[5.1.11.2]-heneicosan-2l-ona-2,2,4,4tetrametil-20-(oxiranilmetil) (Hostavin® N30); ácido propanodioico, [ (4-methoxyphenyl)methylene]-,bis(1,2,2, 6,6pentametil-4-piperidinil) ester (Sanduvor® PR 31); formamide, N,N'-1,6-hexanediylbis[N-(2,2,6,6-tetramethyl-4-piperidinyl (Uvinul® 4050H); 1,3,5-triazine-2,4,6-triamine, N,N'-[1,2ethanediylbis [[[ 4,6-bis [butyl(1,2,2,6,6-pentamethyl-4piperidinyl)amino]-1,3,5-triazin-2-yl] imino]-3,1propanediyl]]-bis[N', N-dibutyl-N',N-bis(1,2,2,6,6pentamethyl-4-piperidinyl) (Chimassorb® 119 PM 2286); poly[[6[ (1,1,3,33-tetramethylbutyl) amino]-1,3,5-triazine-2,4diyl] [(2,2, 6, 6-tetramethyl-4-piperidinyl)-imino]-1,6-hexanediyl [(2,2,6,6-tetramethyl-4-piperidinyl)imino]] (Chimassorb® 944 PM 2000-3000);1,5-dioxaespiro (5,5) undecane 3,3-dicarboxylic acid, bis (2,2,6,6-tetramethyl-4peridinyl) ester (Cyasorb® UV-500); 1,5-dioxaespiro (5,5) undecane 3,3-dicarboxylic acid, bis (1,2,2,6,6-pentamethyl-4peridinyl) ester (Cyasorb® UV-516); N-2,2,6,6-tetramethyl-4piperidinyl-N-amino-oxamida; 4-acryloyloxy-1,2,2,6,6-pentamethyl-4-piperidine, 1,5,8,12-tetraquis [2',4' bis(1, 2,2, 6, 6-pentamethyl-4-piperidinyl (butyl)amino)1',3',5'-triazin-6'-yl]-1,5,8,12-tetraazadodecane; HALS PB-41 zczann / zznz / E / YiAi (Clariant Huningue SA); Nylostab® S-EED (Clariant Huningue SA); 3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidin-2,5-diona; Uvasorb® HA88; l,l'-(l,2-ethane-di-yl)bis-(3,3',5,5'-tetra-methyl-piperazinona) (Good-rite® 3034); 1,1'1-(1,3,5-triazin-2,4,6-triyltris((cyclohexilimino)-2,1-ethanediyl)tris(3,3,5,5-tetramethylpiperazinone) (Good-rite® 3150) and 1,1',1-(1,3,5-triazin-2,4,6-triyltris((cyclohexilimino)-2,1-ethanediyl)tris(3,3,4,5,5-tetramethylpiperazinone) (Good-rite® 3159). (Tinuvin® and Chimassorb® materials are available from Ciba Specialty Chemicals; Cyasorb® materials are available from Cytec Technology Corp.; Uvasil® materials are available from Great Lakes Chemical Corp.; Saduvor®, Hostavin®, and Nylostab® materials are available from Clariant Corp.; Uvinul® materials are available from BASF; Uvasorb® is available at Partecipazioni Industriali; and Good-rite® materials are available at BF Goodrich Co. Mark® materials are available at Asahi Denka Co.) Other specific HALS are selected from the group consisting of di-(2,2,6,6-tetramethyl-4-piperidyl) sebacate (Tinuvin® 770, PM 481) Nylostab® S-EED (Clariant Huningue S. TO.); 1,3,5-triazin-2,4,6-triamine, N,N'-[l,Ιοί anodi i Ibis [[[4,6-bis[butyl(1,2,2,6,6-pentamethyl-4piperidinyl)amino]-1,3,5-triazin-2-yl]imino]-3,1propanediyl] ]-bis[Ν',N-dibutyl-N',N-bis (1,2,2,6,6 zczann / zznz / E / YiAi pentamethyl-4-piperidinyl) (Chimassorb® 119 PM 2286); and poly[[6—[(1,1,3,33-tetramethylbutyl)amino]-1,3,5-triazin-2,4diyl][(2,2,6,6-tetramethyl-4-peperidinyl)-imino]-1,6hexanediyl[ (2,2,6,6-tetramethyl-4-piperidinyl)imino]] (Chimassorb® 944 PM 2000-3000). The concentration of the optional heat stabilizer in the polyamide (C) composition, when present, ranges from approximately 0.01 to 5, preferably from 0.1 to 4 and more preferably from 0.1 to 2 percent by weight, based on the total weight of all ingredients in the polyamide (C) composition. Additives Optional additives that can be added to the polyamide (C) composition include, for example, waxes, UV stabilizers, colorants, lubricants, and mixtures thereof. Optional additives may also include materials that, when added to the polyamide (C) composition described herein, result in a polyamide (C) composition with a coefficient of linear thermal expansion similar to that of the metal used. In the case of aluminum, an example of such an additive is aramid fibers, such as DuPont™ Kevlar® aramid fibers. The concentration of additives in the polyamide (C) composition, when present, ranges from approximately 0.01 to 25, preferably from 0.1 to 20 percent by weight, based on the total weight of all ingredients in the polyamide (C) composition. Preparation of polyamide-metal laminates Generally, the polyamide-metal laminates described in this document can be prepared by the following steps: a) form a bonding layer on a metal to provide a metal laminate / bonding layer; b) bonding the metal laminate / bonding layer from Step a) to a polyamide composition to provide a polyamide-metal laminate. Step a) is the same as that described above for the formation of the bonding layer (B) on the metal (A). As mentioned, the heating step of the bonding layer (B) is optional. While not strictly theoretical, it is believed that the carboxylic acid groups or carboxylic acid dyads of the polymer (B1) react with the aminosilane (B2) when the bonding layer (B) is heated. Several practical methods exist for Step (b). One suitable method involves preparing a pre-formed polyamide and then bonding it to the surface of the bonding layer prepared in Step (a). This method is also called the welding method. Specifically, the polyamide-metal laminates zczann / zznz / E / YiAi can be prepared using the following procedure. The polyamide (C) composition can be shaped using any process, such as molding, extrusion, or compression, to provide the polyamide (C) composition in the desired shape, such as a tube or hose. The shaped polyamide (C) composition is brought into contact with a metal-bonding laminate, as described herein. The polyamide (C) composition and the metal-bonding laminate, while in contact with each other, are heated, preferably under pressure, to a temperature of 200 to 350 °C for a period of time sufficient to melt the polyamide (Cl) resin and allow the reaction of the polyamide amine groups with the acid groups of the bonding layer (B). Any welding method can be used, for example, using heating equipment such as a furnace or hot plate, laser welding, ultrasonic welding, and hot gas welding.For example, the hot pressing process uses a temperature of 220 to 320 degrees Celsius for 1 to 120 seconds at 0.1 MPa or higher. If this is used, the pressure is then released to obtain an article comprising a polyamide-metal laminate. A second suitable method involves feeding a polyamide composition comprising polyamide (Cl) and, optionally, a reinforcing agent (C2) and a thermal stabilizer (C3) into an injection molding machine, mixing it in the molten state to form the polyamide composition (C), and then molding the polyamide composition (C) directly onto the surface of the bonding metal laminate, preferably by injection molding. Without wishing to adhere strictly to theory, it is assumed that the polyamide (Cl) melts during the injection of the polyamide composition (C). It is further assumed, therefore, that the temperature of the bonding metal laminate and the injected polyamide composition (C) are sufficiently high to cause the amine groups of the polyamide (Cl) to react with the acid groups of the bonding layer (B). When the bonding layer (B) is used to bond the polyamide composition (C) to the metal (A), the resulting polyamide-metal laminates exhibit a combination of desirable bond strength between the polyamide composition (C) and the metal (A), as well as excellent resistance to hydrolysis. While not yet fully understood, it is believed that the terminal amine groups of the polyamide bond to the carboxylic acid groups of the polymer to provide imide groups that chemically connect or bond the polyamide molecule to the bonding layer. Polyamide-metal laminates The polyamide-metal laminate obtained by bonding with the specific bonding layer exhibits a desirable bond strength (zczann / zznz / E / YiAi) and excellent hydrolysis resistance, greater than a laminate using a conventional surface treatment (aminopropylsilane). Specifically, the polyamide-metal laminate using the bonding layer of the invention exhibits desirable hydrolysis resistance when exposed to an ethylene glycol / water solution at 130 °C for 1,000 hours, compared to the initial bond strength before exposure to the ethylene glycol / water solution. The expected structure for the polyamide-metal laminate of the invention is shown in Figure 1.Without wishing to be bound by theory, it is believed that the silanol group of bonding layer 21 reacts with the hydroxyl group of the metal (e.g., aluminum) 11, while two carboxylic acid groups of bonding layer 21 form a cyclic imide structure with the nitrogen atom of the amino group of the polyamide composition 31. Therefore, the aluminum 11 and the polyamide composition 31 are strongly bonded via bonding layer 21. On the other hand, when a conventional surface treatment, such as aminopropylsilane, is used, as shown in Fig. 5, the interaction between the carboxylic acid group of the polyamide composition 31 and the amino group of the aminosilane is weak, especially in the presence of water (hydrolysis). Fig. 4 shows another comparative model when aminosilane is not included in the bonding layer.Although the zczann / zznz / E / YiAi polyamide 31 composition can be bonded to polymer 23, the interaction between the carboxylic acid of polymer 23 and the hydroxyl group of aluminum 11 is weak, therefore, the desired bonding strength between aluminum 11 and the polyamide 31 composition can be obtained. Articles The invention comprises the polyamide-metal laminate described above. The articles can be used in any technology requiring the direct bonding of metals to polyamides. Examples of such technologies include the automotive, electronics, and construction industries. Specifically, the articles are useful for automotive technologies such as tubing, hoses, water pump housings, oil filter housings, and transmission housings. The following examples are provided to describe the invention in more detail. These examples, which illustrate a currently contemplated preferred embodiment of the invention, are intended to illustrate, not limit, the invention. EXAMPLES Articles that are Examples of the invention are identified by E in the tables below, and Comparative Examples are identified in the tables below, C. zczann / zznz / E / YiAi Materials The following materials were used in the compounds, procedures, and articles illustrated in the tables below. All percentages are by weight unless otherwise stated. Metal layers (A) Metal 1: Aluminum comprising 1.2 to 0.8 percent by weight of magnesium, 0.7 percent by weight of iron, 0.4 to 0.8 percent by weight of silicon and up to 1.4 percent by weight of other metals and is available as JIS (Japanese Industrial Standards) A6061. Metal 2: Aluminum comprising 2.2 to 2.8 percent by weight of magnesium and up to 1.3 percent by weight of other metals and is available as JIS A5052. Metal 3: Aluminum comprising more than 99.5 percent by weight of aluminum and up to 0.5 percent by weight of other metals and is available as JIS A1050. Polymers (Bl) Polymer A: Ethylene-maleic anhydride copolymer available as ZeMac E60 from Vertellus Specialties Inc., indicated as a 1:1 alternative copolymer of ethylene and maleic anhydride. Polymer B: Polybutadiene-maleic acid copolymer available as poly(butadiene-maleic acid), with 42% zczann / zznz / E / YiAi solids in water, from Polysciences, Inc. Amino-silanes (B2) Silane A: an aqueous solution of 30 percent by weight of 3-aminopropyltrimethoxysilane hydrolysate and available from ShinEtsu Silicone as KBP-90. Silane B: an amino-silane coupling agent comprising N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and available from ShinEtsu Silicone as KBM-603. Silane C: an amino-silane coupling agent comprising 3-aminopropyltriethoxysilane and available from ShinEtsu Silicone as KBE-903. Silane D: a 30 percent by weight aqueous solution of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane hydrolysate from ShinEtsu Silicone as KBP-64. Polyamide compositions (C) Polyamide A (PA-A): a polyamide composition comprising 51% PA66, 13% PA6, 35 percent by weight of glass fibers and an organic heat stabilizer, PA66 having a melting point of 260 °C and PA6 having a melting point of 221 °C. Polyamide B (PA-B): a polyamide composition comprising 66% PA66, 33% glass fibers and no heat stabilizer, PA66 having a melting point of 260 °C. Polyamide C (PA-C): a polyamide composition comprising 66% PA612, 33% glass fibers and an organic heat stabilizer, PA612 having a melting point of 218 °C. Polyamide D (PA-D): a polyamide composition comprising 65% PA612, 33% glass fibers and no heat stabilizer, PA612 having a melting point of 218 °C. Polyamide E (PA-E): a polyamide composition comprising 63% PA6T / DT, 35% glass fibers and an organic heat stabilizer, PA6T / DT having a melting point of 300 °C. Thermal stabilizers (C3) HS2-A: an organic heat stabilizer comprising a mixture of Chimasorb 944FDL at 0.3%, Irganoxl098 at 0.75%, Ultranox626A at 0.3%, wherein the weights are based on the weight of the Polyamide C Composition. HS2-B: BASF organic heat stabilizer as Irganox® 1098. Before treating the aluminum with a metal treatment solution, as described herein, the aluminum surface can be cleaned using one of the following cleaning procedures: Cleaning procedures Procedure A: Exposure of the aluminum surface to isopropyl alcohol. zczann / zznz / E / YiAi Procedure B: Polishing the aluminum surface with an abrasive material (500 grit sandpaper) to provide a polished aluminum surface, followed by exposing the aluminum surface to a cleaning solution and subsequently rinsing the treated aluminum surface with a detergent solution to remove residues of the cleaning solution. Procedure C: Shot blasting of the aluminum surface with aluminum oxide particles (No. 240) at 0.2 MPa, using Baby-blast manufactured by Macoho Co., Ltd. Procedure D: irradiation by ultraviolet (254 nm) at 14 mW / cm2 at a distance of 5 cm, at room temperature (26 °C) for 1 hour. Welding A (hot press welding) With reference to Fig. 6, a polyamide 41 cap has a cylindrical cross-section in the horizontal plane perpendicular to the vertical plane through which the cross-section of the polyamide 41 cap is represented. This cylindrical section is the welding area 42 through which the polyamide 41 cap will be bonded to the metal layer A. With reference to Fig. 7, an aluminum test plate 43 (50 mm square and 6 mm thick) has a circular hole (25 mm) in its center. The aluminum test plate 43 was cleaned and then treated with a metal treatment solution, resulting in a bonding layer 44 on the metal surface. The polyamide 41 cap test specimen was brought into contact with and centered on the aluminum plate 43 such that the polyamide 41 cap covered the circular hole.The surface area 42 of the polyamide cap 41 in contact with the aluminum plate 43 was approximately 177 mm². The aluminum plate 43 and cap 41 were placed on the heated plate 46 by placing a metal cylinder 45 that transmitted pressure to the right over the weld area 42. The direction of the pressure is indicated by the arrow. This assembly was hot-pressed at 0.3 MPa at 240 to 315 degrees C for 1 minute and then cooled to a temperature below the melting point of the polyamide composition (C) at the same pressure. Welding B (direct injection molding) With reference to Fig. 9, an aluminum plate 50, 18 mm wide, 4.5 mm long, and 2.0 mm thick, was used as the aluminum test plate. The aluminum plate 50 was cleaned and then treated with a metal treatment solution that deposited a bonding layer B onto the aluminum plate 50. The aluminum plate 50 was placed in the molding tool, and a polyamide mold 51, 10 mm wide, 45 mm long, and 3 mm thick, was then formed onto the aluminum plate 50 by direct molding with an overlap area 52 of 10 x 5 mm. The set cylinder temperatures in the polyamide box are 280 to zczann / zznz / E / YiAi The Y-HeaT heating and cooling system from Yamashita Electric Co., Ltd. was used for direct injection molding. The heating temperature was 240°C and the cooling temperature was 180°C. The holding pressure was 40 MPa and the holding time was 6 seconds. Bond strength retention test Two specimens were prepared for each polyamide composition and surface treatment solution. One test specimen was exposed to an aqueous ethylene glycol solution heated to 130 °C for 1,000 hours (unless otherwise stated) to observe resistance to hydrolysis, and the second test specimen was not exposed to the solution. The bond strength of both test specimens was measured. After exposure to the heated aqueous ethylene glycol solution, the test specimens were analyzed to determine the bond strength of the shaped polyamide composition to the aluminum plate. Referring to Fig. 8, with respect to weld A, a shaped polyamide cap 41 was pushed in from the inside of the cap using a piston 48 that was 32 mm long and had an 8 mm shaft diameter. The arrow shows the direction of the applied force. The metal plate 47 was held in place with the metal cylinder 49 until the polyamide cap 41 was completely separated from the plate 47. With respect to weld B, a test specimen was held in a specimen retainer based on the retainer shown in Fig. 1 of ISO 19095-3, § 5.2.1.2. The measurements were performed with a crosshead speed of 10 mm / min until breakage.The shear strength (MPa) was calculated by dividing the breaking load (N) by the joint area (mm²). The maximum force required to separate the shaped polyamide composition from the aluminum plate is the bond strength of the test specimen. The bond strength of a test specimen that has not been exposed to an aqueous ethylene glycol solution is compared to the bond strength of a test specimen prepared by an identical process but exposed to an aqueous ethylene glycol solution. The difference between the bond strength of the test specimen after exposure to the aqueous ethylene glycol solution and the bond strength of the test specimen not exposed to the aqueous ethylene glycol solution represents the bond strength retention of the test specimen. Table 1 shows the ingredients of the polyamide layers used in the Examples and Comparative Examples. Table 2 shows the composition of the solvent solution used to apply the bonding layer (B) to the aluminum before bonding the aluminum to the polyamide layer. In Tables 1 and 2, the values ​​are weight percent, based on the total weight of the polyamide composition in Table 1 and the total weight of the metal treatment solution in Table 2. Bond strength retention values ​​for various test specimens are shown in Tables 3 and 4. Table 1 zczann / zznz / E / YiAi PA-A PA-B PA-C PA-D PA-E PA6 6 51.05 66.52 PA6 12.77 PA612 66.2 65.3 PA6T / DT 63.25 PA610 Glass 35 33 33 33 35 HS2-A 0.4 HS2-B 0.6 0.3 Talc 0.35 Lubricant 0.08 0.08 0.1 0.1 Colorant 0.5 0.4 0.4 1.6 1 Table 2 SS-1 SS-2 SS-3 SS-4 SS-5 SS-6 SS-7 SS-8 SS-9 SS-10 SS-11 Silane A 1.5 1 0.5 2.5 0.5 2.5 1.5 1.5 0 0 0 Silane B 0 0 0 0 0 0 0 0 0 2.25 0 Silane C 0 0 0 0 0 0 0 0 0 2.25 Polymer A 1.28 1.28 2.23 1.28 0.43 0.43 0 0 1.28 1.28 1.28 Polymer B 0 0 0 0 0 0 1.5 0 0 0 0 Ratio (2COOH / NH2) 2.76 4.15 14.44 1.66 2.79 0.56 2.43 0 - 0.98 0.79 Water 97.22 97.72 97.27 96.22 99.07 97.07 97 98.5 98.72 96.47 96.47 SS - solvent solution zczann / zznz / E / YiAi Table 3 E1 E2 E3 E4 E5 E7 Polyamide ABCDEE HS HS2-B none HS2-B none HS2-A HS2-B Metal 1 1 1 1 1 2 SS SS-1 SS-1 SS-1 SS-1 SS-1 SS-1 Cleanliness BBBBBB Weld AAAAAA Physical properties Weld strength (MPa) Initial 69.0 68.3 57.4 47.4 37.1 37.8 250 h 27.9 28.8 38.1 17.7 10.1 13.9 1,000 h 4.1 6.3 22.1 8.7 7.1 7.7 % RS retention 8.3 9.3 38.4 18.3 19.1 20.4 Table 3 shows that the bonding layer improves hydrolysis resistance between the shaped polyamide composition and the aluminum. See also the results obtained for the Comparative CIO Example below. Desirable bond strength retention is achieved when aliphatic polyamides are used. PA 66 or a mixture of PA66 and PA 6 are used in E1 and E2, respectively. PA612 is used in E3 and E4. E5 uses a semi-aromatic polyamide, PA6T / DT, and articles prepared from this polyamide using the bonding layers described herein also exhibit desirable bond strength retention properties. Table 3 also shows the effect of various heat stabilizers on the bond strength retention of polyamide compositions with aluminum. These examples (E1 - E7) show that the resulting bond strength retention between the shaped polyamide composition and aluminum after exposure of the article to an ethylene glycol / water solution at 130 °C for 1,000 hours is at least 7.1 percent. zczann / zznz / E / YiAi Table 4 E8 C8 E9 E10 C9 E11 C10 C11 C12 E12 Polyamide EEEEEEEEEE HS HS2-B HS2-B HS2-B HS2-B HS2-B HS2-B HS2-B HS2-B HS2-B HS2-B Metal 1 1 1 1 1 1 1 1 1 1 SS SS-2 SS-3 SS-4 SS-5 SS-6 SS-7 SS-8 SS-9 SS-10 SS-11 Cleaning BBBBBBBBBB Weld AAAAAAAAAA Physical properties Weld strength (MPa) Initial 40.6 43.7 43.4 41.2 10.8 42 22 38.3 27.8 40.2 250 h 15.4 17.1 15.8 17.0 0 14.4 0 0 0 13.6 1,000 h 7.8 0.1 8.1 6.7 - 7.1 - - - 7.1 % retention 19.1 0.2 18.7 16.3 - 17.0 - - - 17.7 Table 4 shows the effect of the amino-silane material-to-polymer ratio in the metal treatment solution on bond strength retention. In C8, the amino-silane material-to-polymer ratio is approximately 1 to 14.4, which is outside the desired range of 1 to 0.8 and 1 to 12, resulting in bond strength retention of less than 1 percent. Table 4 also shows how solvent solutions comprising various amino-silane materials and polymers are as effective as such metal treatment solutions in retaining the bond strength of conformal polyamide compositions with respect to aluminum. The Eli solvent solution comprises a polybutadiene-maleic acid copolymer. This solvent solution provides desirable retention of the bond strength between aluminum and a conformal polyamide composition, demonstrating that both acid- and anhydride-based copolymers can be used to prepare the solvent solutions described herein. The solvent solution used in CIO does not comprise a polymer. The solvent solution used in C11 does not comprise an amino-silane material. In both comparative examples, the desired bond strength retention is not achieved. C12 comprises N-2-(aminoethyl)-3-aminopropyltrimethoxysilane as the amino-silane material, and the resulting article does not exhibit the desired bond strength retention. Figure C9 shows the effect of the amino-silane to polymer ratio in the metal treatment solution on bond strength retention. In C9, the amino-silane to polymer ratio is approximately 5.8 to 1, which is outside the desired range of 3 to 0.8 to 8, resulting in less than one percent bond strength retention. zczann / zznz / E / YiAi Table 5 E13 E14 E15 C13 Polyamide AA EA A HS HS2-B HS2-B HS2-B HS2-B Metal 1 1 1 1 SS SS-1 SS-1 SS-1 SS-1 Cleaning c DBA Welding AABA Physical properties Weld strength (MPa) Initial 69.0 72.2 56.4 3.2 250 h 27.9 26.7 19.7 0 % RS retention 40 37 35 - Table 5 shows the effect of different cleaning methods and the welding process (direct injection molding). With reference to Examples 13, 14, and Comparative Example 13, Cleaning Procedure A does not achieve good bond strength. With reference to Example 15, the polyamide-metal laminate formed by direct injection molding (Welding B) shows excellent resistance to hydrolysis, as do the samples formed by hot-press molding (Welding A). Analysis of the surface of the aluminum plate The surface of the aluminum plate was analyzed using XPS or TOF-SIMS after the cleaning process. Procedure B or D, described above, was selected. The plate from Comparative Example 14 (C14) was cleaned with an oil-soaked cloth after surface cleaning using Procedure B. Following surface analysis, the polyamide was laminated as in Example 1. Bond strength and hydrolysis resistance were analyzed. XPS Measurement: QuanteraSXM from PHI co., Inc., X-ray source: Al(1,486.6 eV), detection area: 0100 micrometers, detection depth of 4~5 nm, measurement mode: wide scan: A12p, Oís, Cls, each element signal percentage was determined by peak area curve fitting. TOF-SIMS: Machine: TOF.SIMS5-300 from IONTOF GmbH, test conditions: primary ion: Bi, analytical area: 300 micrometers. Mass analyzer: time-of-flight mass spectrometer, each fragment mass was determined by comparison with a conventional sample of Al, A1(OH)3, A12O3 or AIO(OH)nH2O. zczann / zznz / E / YiAi zczann / zznz / E / YiAi Table 6 E16 C14 C15 C16 E17 Metal 1 3 3 3 3 Cleaning B B+ oil contamination - - D XPS Signals (%) Al 21.6 8.7 15 - - 0 49.5 22.2 45.1 - - C 27.7 67.4 30.9 - - TOF-SIMS Al(OH)3 (137 m / z) SS (after ethanol cleaning) NNN Al(OH)nH2O (103, 119 m / z) SS (after ethanol cleaning) NSS Al2O3 (102, 118 m / z) NNNSS Al(IO4) (199, 219, 245 m / z) NNSNN Strength OK NG NG NG OK Physical Properties Weld Strength Initial 69.3 37.9 0 0 65.8 250 h 27.6 0 0 0 24.3 Table 6 shows the effect of the aluminum surface condition. With reference to E16 and C14, oil contamination reduces bond strength even after surface cleaning B. With reference to C15 and E18, surface cleaning, such as polishing and UV / Ozone treatment, is necessary for good bond strength, and this effectiveness could be detected with a fragment of Al(OH)3 or a partially hydroxide aluminum compound, such as AlO(OH)nH2O, using TOF-SIMS. zczann / zznz / E / YiAi Table 7 SS-12 SS-13 SS-14 SS-15 SS-16 SS-17 SS-18 SS-19 SS-20 SS-21 Silane A 2 1.9 1.84 1.72 0.9 0.75 0.6 0.5 0.4 0 Silane D 0 0 0 0 0 0 0 0 0 1.5 Polymer A 0.78 0.88 0.94 1.06 1.88 2.03 2.18 2.28 2.30 1.28 Ratio (2COOH / NH2) 1.26 1.50 1.65 2.00 6.76 8.77 11.77 14.77 18.92 3.70 Water 97.22 97.22 97.22 97.22 97.22 97.22 97.22 97.22 97.3 97.22 All values ​​in weight percent SS - solvent solution Table 8 E18 E19 E20 E21 E22 E23 E24 E25 E26 E27 Polyamide AAAAAAAAAAA HS HS2-B HS2-B HS2-B HS2-B HS2-B HS2-B HS2-B HS2-B HS2-B HS2-B Metal 3 3 3 3 3 3 3 3 3 3 SS SS-12 SS-13 SS-14 SS-15 SS-16 SS-17 SS-18 SS-19 SS-20 SS-1 Cleaning BBBBBBBBBB Weld AAAAAAAAAA Physical properties Weld strength (MPa) Initial 50.6 63.8 68.9 67.7 63.0 68.3 67.6 68.5 66.1 66.6 250 h 13.8 20.8 24.7 27.8 20.9 24.0 21.8 13.8 10.3 27.0 % RS retention 27 33 36 41 33 35 32 20 16 41 For further clarification of the molar ratio of the amino-silane material and the polymers, the retention of bond strength after exposure of the article, which is prepared with shaped polyamide (PA66) and aluminum by hot press welding (Welding B), to an ethylene glycol / water solution at 130 °C for 250 hours, had been measured in various solvent solutions. Table 7 shows how the solvent solutions comprise various ratios of amino-silane materials and ethylene maleic copolymers. In E18-E27, the ratio of amino-silane material to polymer is approximately 1 to 19, resulting in a desired initial bonding strength of more than 50 MPa. Furthermore, in E19-E24, the amino-silane molar ratio with respect to the polymers is approximately 1:1.3 to 1:4 and shows excellent retention of bond strength after exposure of the article to an ethylene glycol / water solution at 130 °C for 250 hours, which is at least 20 MPa. Table 9 zczann / zznz / E / YiAi E28 E29 C17 Polyamide AAA HS HS2-B HS2-B HS2-B Metal 3 3 1 SS SS-21 ss-i SS-8 BBB Cleaning AAA Welding Physical Properties Weld Strength (MPa) After exposure to water up to 90 °C, 96 h 35.8 35.5 0 Hydrolysis Resistance OK OK NG Table 9 shows the weld strength after exposure to water at up to 90 °C for 96 hours. E28, using SS-21, which comprises Polymer D, the aminosilane diamine hydrolysate, and Polymer A, showed excellent bond strength, while C17, using SS-8, which consists only of aminosilane, showed 0 MPa after exposure. It can be observed that the aminosilane diamine type, which has a terminal -NH2 group, can also be effective in achieving good resistance to hydrolysis when hydrolyzed. Although certain preferred embodiments of the present invention have been specifically described and illustrated above, the invention is not intended to be limited to such embodiments. On the contrary, it is to be understood that, although the foregoing description has set forth numerous features and advantages of the present invention, along with details of its structure and function, the description is merely illustrative, and changes may be made to the details, particularly regarding the shape, size, and arrangement of the parts, within the principles of the invention to the fullest extent indicated by the broad general meaning of the terms in which the appended claims are expressed. It is hereby stated that, as of this date, the best method known to the applicant for putting the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

1. A polyamide-metal laminate characterized in that it comprises (A) a metal, (B) a bonding layer formed on the surface of the metal and (C) a polyamide composition formed on the surface of the bonding layer, wherein the bonding layer comprises: B1) a polymer comprising carboxylic acid groups and B2) an amino-silane comprising a primary amine and at least one hydroxyl group; wherein at least two carboxylic acid groups in the polymer (B1) are adjacent to each other and the molar ratio of the two adjacent carboxylic acid groups in the polymer (B1) with respect to the primary amine group in the amino-silane (B2) is from 1:0.8 to 1:

12.

2. The polyamide-metal laminate according to claim 1, characterized in that the content of the two adjacent carboxylic acid groups in the polymer (Bl) is 2% by weight or more based on the total weight % of the polymer (Bl).

3. The polyamide-metal laminate according to claim 1 or 2, characterized in that the polymer (Bl) zczann / zznz / E / YiAi comprises one or more polymers selected from the group consisting of poly(butadiene-maleic acid) copolymers, propylene-maleic acid copolymers, ethylene-maleic acid copolymers, ethylene-maleic anhydride copolymers, propylene-maleic anhydride copolymers, ethylene-maleic anhydride copolymers, polymaleic acid(s), ethylenectene copolymers grafted with maleic anhydride, ethylenebutene copolymers grafted with maleic anhydride, and ethylenepropylene copolymers grafted with maleic anhydride.

4. The polyamide-metal laminate according to any of the preceding claims, characterized in that the amino-silane (B2) is represented by Formula (I): OR2 R2O Si (CH2)XNR4R5 (I) OR3 where R1, R2 and R3 are independently selected from H, linear, branched or cyclic C1 to C6 alkyl groups; R4 is H; R5 is independently selected from H and -(CH2)y-NH2; x and y vary independently from 1 to 6; and at least one of R1, R2 and R3 is H.

5. The polyamide-metal laminate according to any of the preceding claims, characterized in that the metal (A) is aluminum.

6. The polyamide-metal laminate according to claim 5, characterized in that the aluminum has hydroxyl groups on the aluminum surface.

7. A metal part characterized in that it has a bonding layer on the surface of the metal part, wherein the bonding layer comprises: B1) a polymer comprising carboxylic acid groups and B2) an amino-silane comprising a primary amine and at least one hydroxyl group; wherein at least two carboxylic acid groups in the polymer (B1) are adjacent to each other and the molar ratio of the carboxylic acid groups in (B1) with respect to the primary amine group in (B2) is from 1:0.8 to 1:

12.

8. A composition suitable for laminating a polyamide onto a metal surface, characterized in that it comprises: (b-1) a polymer comprising carboxylic acid groups, (b-2) an aminosilane comprising a primary amine and at least one hydroxyl group, and (b-3) water, wherein at least two carboxylic acid groups in polymer (b-1) are adjacent to each other and the molar ratio of the carboxylic acid groups in (b-1) to the primary amine group in (b-2) is from 1:0.8 to 1:

12. zczann / zznz / E / YiAi 9. The composition according to claim 8, characterized in that its pH is 5 or more.

10. A method for laminating a polyamide onto the surface of an aluminum, characterized in that it comprises the steps of: (i) preparing an aluminum in which the surface of the aluminum is cleaned, (ii) applying the composition according to claim 8 to form a bonding layer on the surface of the aluminum, then, (iii) laminating a polyamide composition onto the bonding layer with heating to at least the melting temperature of the polyamide.

11. An article characterized in that it comprises the polyamide-metal laminate in accordance with any of claims 1 to 6.

12. The article according to claim 11, characterized in that it is selected from the group consisting of a tube, a hose, a water pump housing, an oil filter housing, and a transmission housing.

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