Thermoplastic compositions for metal plating

Abstract

A thermoplastic composition for metal plating and a method of metal plating using the thermoplastic composition are described herein. The thermoplastic composition includes a copolymer in an amount of 30% to 80% by weight of the composition. The copolymer includes polymerized units derived from a vinyl aromatic monomer and a vinyl nitrile monomer. The thermoplastic composition further includes a rubber-modified polymer in an amount of 18% to 50% by weight of the composition and a styrene-maleic anhydride (SMA) copolymer in an amount of 2% to 15% by weight of the composition. The SMA copolymer includes a maleic anhydride content in an amount of 10% to 30% by weight of the SMA copolymer, and the SMA copolymer has a weight average molecular weight of 5,000 g / mol to 30,000 g / mol.

Description

Detailed Description of the Invention

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of the priority and filing date of European Patent Application No. 22211168.4, filed December 2, 2022, which is incorporated herein by reference in its entirety.

[0002] [Technical Field] FIELD OF THE DISCLOSURE The present disclosure relates to thermoplastic compositions for metal plating and methods of metal plating thermoplastic compositions.

[0003] [Technical background] Polymeric plastic parts prepared from thermoplastic compositions such as acrylonitrile-butadiene-styrene (ABS) polymers are often metallized when used for certain applications, such as automotive applications. The thermoplastic composition serves as a polymeric substrate onto which a metallic coating can be deposited. For example, polymeric plastic parts prepared from ABS polymers can be coated with a metal layer to impart a mirror-finish appearance, resembling metal parts, while retaining the distinct advantage of being lightweight. In addition, the metal coating can improve the mechanical strength, thermal stability, and chemical resistance of the underlying polymeric substrate onto which the metal is coated. In this regard, ABS polymers are particularly useful in automotive and other industrial applications due to their desirable impact properties and other useful characteristics.

[0004] However, there are several problems with the use of metal coatings on polymeric plastic parts. Metal coatings do not readily bond or adhere to most polymeric substrates unless the surface of such substrates is first chemically treated. Traditionally, the surface of a polymeric substrate can be chemically etched with oxidizing agents such as hexavalent chromium trioxide, a mixture of chromic acid and sulfuric acid, or a mixture of chromic acid, sulfuric acid, and phosphoric acid. These strong oxidizing agents can micro-roughen and chemically modify the surface of a polymeric substrate by forming polar organic functional groups such as R-COOH, R-OH, R-SO3, and R-CH=O on the surface of the substrate. The presence of these polar groups can promote the adsorption of plating catalysts from aqueous solutions, allowing subsequent metal deposition to occur during the plating process. After the etching process, the surface of the polymeric substrate can be metal-plated. One suitable indicator for measuring the success of the bond between a metal layer and a polymeric substrate is peel strength, with greater peel strength correlating with better adhesion of the metal to the polymeric substrate.

[0005] However, the use of hexavalent chromium compounds such as chromium trioxide (1) health risks (because such compounds are carcinogenic); (2) effective treatment of waste liquids generated from etching processes (which make such etching processes not only environmentally harmful but also expensive); (3) Purification of etched plastic parts to remove any residual chromium trioxide that may be present as an impurity (because such impurities adversely affect the metal plating process); and / or (4) The use of highly oxidizing acid solutions can often damage the polymer substrate itself or render the polymer substrate structurally weak for metal plating; poses certain risks and challenges, such as:

[0006] In an effort to avoid these problems, many alternative processes to chromic acid etching have been investigated. For example, dry plasma etching processes have been proposed as an alternative to wet etching processes. However, the application of this method is limited to flat polymeric parts. Alternatively, etching reagents such as potassium permanganate have been used in attempts to replace chromic acid. The use of heated alkaline permanganate solutions has met with limited commercial success due to their slower oxidation rate compared to chromic acid, but the applicability of permanganate solutions is largely limited. It is commercially desirable to obtain as strong a bond as possible between the surface of a thermoplastic article and the electroless metal deposited thereon to enable easy electroplating.

[0007] 〔overview〕 An exemplary embodiment of the present disclosure is directed to a thermoplastic composition for metal plating. The thermoplastic composition includes a first copolymer in an amount of 30% to 80% by weight of the composition. The first copolymer includes polymerized units derived from a vinyl aromatic monomer and a vinyl nitrile monomer. The thermoplastic composition further includes a rubber-modified polymer in an amount of 18% to 50% by weight of the composition and a styrene-maleic anhydride (SMA) copolymer in an amount of 2% to 15% by weight of the composition. The SMA copolymer includes a maleic anhydride content in an amount of 10% to 30% by weight of the SMA copolymer, and the SMA copolymer has a weight average molecular weight of 5,000 g / mol to 30,000 g / mol.

[0008] In some embodiments, the vinyl aromatic monomer comprises at least one of styrene, α-methylstyrene, dibromostyrene, vinyltoluene, vinylxylene, butylstyrene, p-hydroxystyrene, and methoxystyrene (preferably the vinyl aromatic monomer is styrene), and the vinyl nitrile monomer comprises at least one of acrylonitrile, chloroacrylonitrile, methacrylonitrile, and ethacrylonitrile (preferably the vinyl nitrile monomer is acrylonitrile).

[0009] In some embodiments, the rubber-modified polymer comprises a polymer rubber with polymerized units derived from a conjugated diene, and the rubber-modified polymer also comprises a graft thermoplastic copolymer grafted onto the polymer rubber.

[0010] In some embodiments, the rubber-modified polymer comprises a polymer rubber with polymerized units derived from a conjugated diene. The conjugated diene comprises at least one of 1,3-butadiene, isoprene, 1,3-heptadiene, methyl-1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-pentadiene, 1,3-hexadiene, and 2,4-hexadiene (preferably 1,3-butadiene). The rubber-modified polymer also comprises a graft thermoplastic copolymer grafted onto the polymer rubber. The graft thermoplastic copolymer comprises polymerized units derived from a vinyl aromatic monomer (preferably styrene) and a vinyl nitrile monomer (preferably acrylonitrile).

[0011] In some embodiments, the first copolymer comprises a styrene-acrylonitrile copolymer (SAN) and the rubber-modified polymer comprises a SAN-grafted butadiene rubber.

[0012] In some embodiments, the thermoplastic composition further comprises an ethylene-acrylic acid (EAA) copolymer in an amount of 2% to 10% by weight of the composition, the EAA copolymer having an acrylic acid content in an amount of 1% to 10% by weight of the EAA copolymer, preferably 5% to 7% by weight of the EAA copolymer.

[0013] In some embodiments, the thermoplastic composition further comprises one or more additional components in an amount of 0% to 5% by weight of the composition.

[0014] In some embodiments, the one or more additional components in the thermoplastic composition are selected from the group consisting of impact modifiers, flow modifiers, reinforcing agents, antioxidants, heat stabilizers, light stabilizers, UV stabilizers, UV absorbing additives, plasticizers, lubricants, mold release agents, antistatic agents, melt processing additives, and any combination thereof.

[0015] In some embodiments, the one or more additional ingredients include at least one of magnesium oxide (MgO), silicone fluid, ethylene bisstearamide (EBX) wax, and magnesium stearate.

[0016] In some embodiments, the thermoplastic composition has a thermal conductivity of 3.0 kJ / m as measured in accordance with ISO 180 / 1A. 2 ~30.0kJ / m 2 , preferably 4.0 kJ / m 2 ~25.0kJ / m 2 , more preferably 5.0 kJ / m 2 ~20.0kJ / m 2 It has a notched Izod impact strength of

[0017] Various embodiments of the present disclosure are directed to an electroplating process that includes molding a thermoplastic composition to form a molded article, and then depositing a metal on the molded article to produce a metal-plated molded article with high peel strength and good impact properties. (i) molding the thermoplastic composition into a molded article; (ii) optionally washing and / or rinsing the article; (iii) contacting the surface of the molded article with a chemical agent to form a surface-treated article; and, (iv) subjecting the surface-treated article to conditions suitable for depositing one or more metal layers on at least a portion of the surface of the surface-treated article to produce a metal-plated article; Includes.

[0018] In some embodiments, the chemicals include a suspension of colloidal manganese oxide particles in a mineral acid mixture that includes sulfuric acid and / or phosphoric acid.

[0019] In some embodiments, the one or more metal layers are selected from the group consisting of copper, nickel, and chromium (preferably nickel).

[0020] In some embodiments, the metal plated molded article has a peel strength determined in accordance with ASTM B533-85 of greater than 0.4 N / mm.

[0021] Further embodiments of the present disclosure are directed to thermoplastic compositions used to prepare metal-plated articles suitable for various industrial applications where it is desirable for the material to have excellent impact strength. Also, in one aspect, the thermoplastic compositions of the present disclosure can be coated with metal without the use of chemical etching processes that rely on oxidizing reagents such as hexavalent chromium trioxide or mixtures of chromic acid / sulfuric acid or chromic acid / sulfuric acid / phosphoric acid.

[0022] An exemplary embodiment of the present disclosure is also directed to a metal-plated article comprising a metal layer and a thermoplastic article. The metal layer is deposited on at least a portion of the surface of the thermoplastic article. The thermoplastic article comprises a copolymer in an amount of 30% to 80% by weight of the composition. The copolymer comprises polymerized units derived from a vinyl aromatic monomer and a vinyl nitrile monomer. The thermoplastic composition further comprises a rubber-modified polymer in an amount of 18% to 50% by weight of the composition and a styrene-maleic anhydride (SMA) copolymer in an amount of 2% to 15% by weight of the composition. The SMA copolymer comprises a maleic anhydride content in an amount of 10% to 30% by weight of the SMA copolymer and has a weight average molecular weight of 5,000 g / mol to 30,000 g / mol.

[0023] In some embodiments, the metal plated article is an automotive part or an electrical part.

[0024] BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects, and advantages of the present disclosure will be better understood from the following detailed description of the disclosure when read in conjunction with the accompanying drawings, in which: FIG. 1 shows a plot of peel force (in N / mm) versus peel length (in mm) for Examples E2 and E6, and Comparative Example CE1, according to various embodiments of the present disclosure.

[0025] Detailed Description An exemplary embodiment of the present disclosure is directed to a thermoplastic composition. The thermoplastic composition includes a first copolymer in an amount of 30% to 80% by weight of the composition. The copolymer includes polymerized units derived from a vinyl aromatic monomer and a vinyl nitrile monomer. The thermoplastic composition further includes a rubber-modified polymer in an amount of 18% to 50% by weight of the composition and a styrene-maleic anhydride (SMA) copolymer in an amount of 2% to 15% by weight of the composition. The SMA copolymer includes a maleic anhydride content in an amount of 10% to 30% by weight of the SMA copolymer, and the SMA copolymer has a weight average molecular weight of 5,000 g / mol to 30,000 g / mol. While not intending to be bound by theory, the inventors believe that the incorporation of SMA into ABS leads to the presence of polar anchor groups on the surface of a molded article (including the thermoplastic composition of the present disclosure). The presence of maleic anhydride groups in SMA increases the surface energy and surface polarity at the surface of the molded article. These increases lead to better interfacial adhesion between the ABS and metals bonded to the surface of the molded article, thereby allowing for easier metallization. Details of various embodiments are provided below.

[0026] <Thermoplastic composition> The thermoplastic composition described herein comprises a first copolymer in an amount of 30% to 80% by weight of the composition, preferably 45% to 75% by weight of the composition. The first copolymer comprises polymerized units derived from a vinyl aromatic monomer and a vinyl nitrile monomer. The thermoplastic composition also comprises a rubber-modified polymer in an amount of 18% to 50% by weight of the composition, preferably 30% to 45% by weight of the composition. The thermoplastic composition also comprises a styrene-maleic anhydride (SMA) copolymer in an amount of 2% to 15% by weight of the composition. The SMA copolymer comprises a maleic anhydride content in an amount of 10% to 30% by weight of the SMA copolymer, preferably 12% to 25% by weight of the SMA copolymer, and more preferably 15% to 20% by weight of the SMA copolymer. The SMA copolymer has a weight average molecular weight of 5000 g / mol to 30000 g / mol, preferably 10000 g / mol to 25000 g / mol, more preferably 15000 g / mol to 20000 g / mol.

[0027] The thermoplastic compositions can be molded or formed into polymeric articles that can have the appropriate impact properties required for specific applications, including door handles, holders, lamp bodies, corporate logos, and other decorative parts used in the automotive industry, home appliances, electronic devices, furniture, sanitary fittings, etc. For example, the polymeric articles can have an impact strength of 3.0 kJ / m when measured in accordance with ISO 180 / 1A. 2 or more, preferably 4.0 kJ / m 2 ~25.0kJ / m 2 , more preferably 5.0 kJ / m 2 ~20.0kJ / m 2 The notched Izod impact strength may be

[0028] <Copolymer (A)> The thermoplastic compositions described herein include a copolymer including polymerized units derived from a vinyl aromatic monomer and a vinyl nitrile monomer. Based on the total weight of the thermoplastic composition, the first copolymer may be present in an amount of 30% to 80% by weight of the thermoplastic composition, preferably 45% to 75% by weight of the thermoplastic composition, or any range or value therebetween.

[0029] Non-limiting examples of vinyl aromatic monomers include styrene, α-methylstyrene, dibromostyrene, vinyltoluene, vinylxylene, butylstyrene, p-hydroxystyrene, methoxystyrene, or any combination thereof. Non-limiting examples of vinyl nitrile monomers include acrylonitrile, α-chloroacrylonitrile, methacrylonitrile, ethacrylonitrile, or any combination thereof. In one embodiment, the vinyl aromatic monomer is styrene, and the vinyl nitrile monomer is acrylonitrile. Preferably, the copolymer is a styrene-acrylonitrile (SAN) copolymer. In a preferred embodiment of the present disclosure, the copolymer may be a styrene-acrylonitrile copolymer having 30.0 wt.% or more and 35.0 wt.% or less of polymerized units derived from acrylonitrile.

[0030] In some embodiments of the present disclosure, the copolymer may be a terpolymer containing polymerized units derived from (i) a vinyl aromatic monomer, (ii) a vinyl nitrile monomer, and (iii) a (meth)acrylic monomer. The vinyl aromatic monomer and the vinyl nitrile monomer may be selected from the monomers defined above. Non-limiting examples of the (meth)acrylic monomer may include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl methacrylate, and decyl methacrylate. Preferably, the (meth)acrylic monomer may be methyl methacrylate (MMA). Thus, the copolymer may be a terpolymer containing polymerized units derived from styrene / acrylonitrile / methyl methacrylate or α-methylstyrene / acrylonitrile / methyl methacrylate.

[0031] The copolymer may have a suitable molecular weight and melt flow rate, and the weight average molecular weight (Mw) of the copolymer may be 50,000 g / mol to 100,000 g / mol, or any range or value therebetween, as determined by gel permeation chromatography according to ASTM D5296-11 using a polystyrene-based calibration in tetrahydrofuran (THF) as the solvent.

[0032] The copolymer may have a melt flow rate of 7.0 g / 10 min to 40.0 g / 10 min, or any value or range therebetween, as determined in accordance with ASTM D1238 at 230° C. under a 3.8 kg load. Copolymer melt flow rates above these rates may adversely affect the overall impact properties of the thermoplastic composition, while copolymer melt flow rates below these rates may not provide the desired flow characteristics of the thermoplastic polymer, affecting the melt processability of the thermoplastic polymer.

[0033] <Rubber-modified polymer (B)> The thermoplastic compositions described herein comprise a rubber-modified polymer in an amount of 18% to 50% by weight of the composition, or any range or value therebetween. The rubber-modified polymer may be referred to as high rubber graft, or "HRG." The thermoplastic composition may comprise at least 26.0% by weight of the rubber-modified polymer. In some embodiments, the thermoplastic composition may comprise a rubber-modified polymer present in an amount of 20.0% to 50.0% by weight, or any range or value therebetween, based on the total weight of the thermoplastic composition.

[0034] The rubber-modified polymer may contain a suitable amount of polymer rubber, preferably 55.0 to 75.0 wt % based on the total weight of the rubber-modified polymer. The polymer rubber may contain polymerized units derived from a conjugated diene. Non-limiting examples of conjugated dienes include 1,3-butadiene, isoprene, 1,3-heptadiene, methyl-1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-pentadiene, 1,3-hexadiene, 2,4-hexadiene, and any combination thereof. Preferably, the conjugated diene is 1,3-butadiene, and the polymer rubber may be polybutadiene.

[0035] In a preferred embodiment of the present disclosure, the rubber-modified polymer comprises a polymer rubber containing polymerized units derived from 1,3-butadiene and a graft thermoplastic copolymer grafted onto the polymer rubber. The graft thermoplastic copolymer contains polymerized units derived from a vinyl aromatic monomer, preferably styrene, and a vinyl nitrile monomer, preferably acrylonitrile. Most preferably, the rubber-modified polymer is acrylonitrile-butadiene-styrene (ABS).

[0036] <Styrene-maleic anhydride copolymer, SMA(C)> The thermoplastic compositions described herein comprise a styrene-maleic anhydride (SMA) copolymer in an amount of 2% to 15% by weight of the composition, preferably 5% to 20% by weight of the composition, and more preferably 10% to 15% by weight of the composition. The SMA copolymer comprises styrene and maleic anhydride monomers. The SMA copolymer comprises a maleic anhydride content in an amount of 10% to 30% by weight of the SMA copolymer, preferably 12% to 25% by weight of the SMA copolymer, and more preferably 15% to 20% by weight of the SMA copolymer. In various embodiments, the SMA copolymer has a weight average molecular weight of 5,000 g / mol to 30,000 g / mol, preferably 10,000 g / mol to 25,000 g / mol, and more preferably 15,000 g / mol to 20,000 g / mol.

[0037] Generally, SMA is produced by reacting maleic anhydride with styrene at elevated temperatures in the presence of a peroxide catalyst, as shown, for example, in U.S. Pat. Nos. 2,866,771, 2,971,939, and the references cited therein. Copolymers may also be used in place of styrene, such as methylstyrene, 2,4-dimethylstyrene, chlorostyrene, and other substituted styrenes. The weight-average molecular weight of the SMA copolymer may vary over a wide range, for example, from about 5,000 g / mol to 30,000 g / mol, preferably from 10,000 g / mol to 25,000 g / mol, and more preferably from 15,000 g / mol to 20,000 g / mol. A representative structure of SMA is shown in Scheme IA.

[0038] The thermoplastic composition may further comprise 2 to 10 weight percent ethylene-acrylic acid (EAA) copolymer. The EAA copolymer may comprise 1 to 10 weight percent, preferably 5 to 7 weight percent, of acrylic acid, based on the total weight of the EAA copolymer. A representative structure of EAA is shown in Scheme I(B), where x=160 to 800 and y=4.8 to 35.

[0039] [ka]

[0040] <Additional Ingredient (D)> The thermoplastic compositions described herein may include one or more additional components depending on the application and use. For example, the thermoplastic composition may include 0% to 5% by weight, preferably 0% to 3% by weight, of additional component(s) based on the total weight of the thermoplastic composition.

[0041] Non-limiting examples of the one or more additional components that can be used include an impact modifier, a flow modifier, a reinforcing agent, an antioxidant, a heat stabilizer, a light stabilizer, a UV stabilizer, a UV absorbing additive, a plasticizer, a lubricant, a mold release agent, an antistatic agent, a melt processing additive, or any combination thereof.

[0042] The additional components preferably include at least one melt-processing additive. The melt-processing additive may include magnesium oxide (MgO), silicone oil, ethylene bis(stearamide) wax (EBS wax), magnesium stearate, and combinations thereof. The melt-processing additive(s) may be present in an amount of 0% to 5% by weight, preferably 1% to 3% by weight, based on the total weight of the thermoplastic composition.

[0043] <Thermoplastic composition> The combination of specific types and amounts of materials that make up the thermoplastic compositions described herein results in advantageous property profiles of impact performance and peel strength. The examples and comparative examples disclosed herein provide those skilled in the art with materials that fall within and outside the scope of the present disclosure, thereby forming a basis for the development of further embodiments according to the present disclosure.

[0044] For the avoidance of doubt, those skilled in the art will understand that the total weight of the composition adds up to 100% by weight and that any combination of materials not making up the total weight of 100% by weight is impractical and not in accordance with the present disclosure.

[0045] According to some embodiments of the present disclosure, the thermoplastic composition has a viscosity of 3.0 kJ / m 2 ~30.0kJ / m 2 , preferably 4.0 kJ / m 2 ~25.0kJ / m 2 , more preferably 5.0 kJ / m 2 ~20.0kJ / m 2 of notched Izod impact resistance, determined in accordance with ISO 180 / 1A at a temperature of 23°C.

[0046] Preferred ranges for the amounts of components and preferred ranges for the properties of the composition may, of course, be combined without restriction, provided they fall within the scope of the present disclosure as defined herein in its broadest form. In other words, preferred ranges for one or more of the amounts and / or types of components comprising the thermoplastic composition may be combined with preferred ranges for one or more of the properties of the thermoplastic composition, and all such combinations are considered to be disclosed herein.

[0047] The composition may be prepared by various methods known in the art. For example, the first copolymer, rubber-modified polymer, SMA, and other additives may be first blended in a high-speed mixer or by hand mixing. The blend is then fed into the throat of a twin-screw extruder via a hopper. Alternatively, at least one of the components may be incorporated into the composition by feeding it directly into the extruder at the throat and / or downstream via a side feeder, or by mixing it into a masterbatch with the desired polymer and feeding it into the extruder. For example, the composition may be prepared using a Krupp Werner & Pfleiderer ZSK2 co-rotating, intermeshing, 10-barrel twin-screw extruder with a diameter of 25 mm and an L / D ratio of 41. The temperature in the extruder may be 180°C to 265°C along the screw length. The extrudate may be immediately cooled in a water bath and pelletized. The pellets thus prepared may be 0.6 cm or less in length, if desired. Such pellets may be used for subsequent molding, shaping, or forming. The extruded form may be subjected to suitable conditions to produce a molded thermoplastic article. For example, the thermoplastic pellets of the present disclosure may be injection molded into bars, sheets, or foams.

[0048] <Electroplating process> A further subject of the present disclosure is the use of the polymer blend of the present invention for electroplating. A further embodiment of the present disclosure is a metal-plated molded article comprising the thermoplastic composition of the present invention as described above. The surface of the molded article is at least partially, or preferably entirely, coated with one or more metal layers (e.g., electroplated metal). The metal-plated molded article can be obtained by a conventional process for metal plating of thermoplastic compositions, such as (i) a conventional electroplating process or (ii) a direct plating process. Such processes have been previously described and are known in the art. The electroplating process according to the present disclosure comprises the following steps: i. molding a thermoplastic composition described herein into a molded article; ii. Optionally washing and / or rinsing the article; iii. contacting the surface of the molded article with a chemical agent to form a surface treated article; and, iv. subjecting the surface-treated article to conditions suitable for depositing one or more metal layers on at least a portion of the surface of the surface-treated article to produce a metal-plated article; may include:

[0049] In some embodiments of the present disclosure, molded articles prepared from the thermoplastic compositions of the present disclosure may be surface-treated. The surface treatment may involve contacting at least a portion of the thermoplastic composition of the present disclosure (e.g., a molded thermoplastic composition) with a chemical reagent for a sufficient time (e.g., 5.0 to 30.0 minutes, preferably 10.0 to 20.0 minutes) to form a surface-treated thermoplastic composition. The contact temperature may range from 60°C to 80°C, preferably 65.0 to 75.0°C. The surface-treated polymeric article may have appropriate surface polarity while retaining the desired impact strength. The surface polarity and impact strength attributes can be attributed to a tailored combination of the appropriate polymeric article, appropriate selection of chemical reagent, and appropriate process parameters of contact / exposure temperature and time.

[0050] Advantageously, in some embodiments, surface-treated articles can be produced without the use of hexavalent chromium compounds, thereby avoiding the drawbacks associated with conventional etching processes that use hexavalent chromium compounds. The article may be contacted with the chemical reagent for an appropriate time to ensure the desired surface roughness is incorporated. For example, contacting the article with the chemical reagent for too long (e.g., more than 30 minutes) may damage the surface of the article. Contacting the article with the chemical reagent for too short a time (e.g., less than 5 minutes) may not sufficiently modify the morphological features of the surface of the article to enable adhesion of the surface-treated article to the metal layer. The chemical reagent may be a suspension of sulfuric acid solution (70.0% by volume), colloidal manganese oxide particles suspended in a mineral acid mixture, potassium permanganate solution (6.5% by volume), or any combination thereof. In some embodiments, the chemical reagent may be a colloidal suspension comprising colloidal manganese oxide particles suspended in a mineral acid mixture of sulfuric acid and phosphoric acid. For example, for 1 liter of solution, the manganese oxide colloidal particles may be present in an amount of 50.0 g / L to 70.0 g / L, the phosphoric acid may be present in an amount of 210.0 ml / L to 230.0 ml / L, and the sulfuric acid may be present in an amount of 560.0 ml / L to 580.0 ml / L. The chemical reagent may include sulfuric acid (H2SO4) having a molar strength between 8.0 M and 14.0 M, and / or phosphoric acid having a molar strength between 2.0 M and 6.0 M. Surface-treated articles of exemplary embodiments of the present disclosure may retain advantageous impact properties even after surface treatment with the chemical reagent.

[0051] In one embodiment of the present disclosure, the surface-treated article of the present disclosure can be metal-plated by subjecting the article to conditions suitable for depositing one or more metal layers on at least a portion of the treated surface to form a metal-plated molded article. Metal plating can be performed by known metal plating techniques. For example, a combination of chemical plating and electroplating can be used herein. In one embodiment, the surface-treated article can be subjected to a chemical treatment to produce a metal-plated precursor material. The metal-plated precursor material can be contacted with a metal electrolyte solution at any applied current (e.g., 1.0 ampere or more and 4.0 amperes or less, and for a time period of 5 minutes or more and 30 minutes or less) to produce a metal-plated molded article.

[0052] The one or more metal layers are selected from the group consisting of copper, nickel, and chromium, preferably nickel. According to the present disclosure, at least a portion of the surface of the molded article is coated with one or more metal layers. The thickness of a single layer may be between 0.1 and 50 μm. The metal-plated molded article may have a peel strength, determined in accordance with ASTM B533-85, of greater than 0.4 N / mm, preferably 0.5 N / mm to 2.0 N / mm, more preferably 0.6 N / mm to 1.5 N / mm.

[0053] In some embodiments, the metal-plated moldings are incorporated into housing components of electrical or consumer electronic devices, or into bezels or reflectors for automobiles. They can also be used in door handles, holders, lamp bodies, corporate logos, and many other decorative components used in the automotive industry, home appliances, electronics, furniture, sanitary fittings, etc. In one aspect, the metal-plated moldings are used in automotive applications, and particularly in exterior applications such as automotive front grilles and wheel covers.

[0054] Metal-plated articles molded from the thermoplastic compositions of the present disclosure exhibit improved adhesion between the metal layer and the plastic material, as well as improved thermal cycling adhesion and excellent mechanical properties.

[0055] (Example) The present disclosure will now be described by way of the following non-limiting examples to demonstrate its practice and advantages, it being understood that the examples are given for illustrative purposes and are not intended to limit in any way the specific subject matter of the claims which follow.

[0056] <Preparation of Thermoplastic Composition of the Present Disclosure and Comparative Thermoplastic Composition> All formulations were prepared at a 4 kg scale. The ingredients of the compositions and their sources are listed in Table 1, and the formulation details are listed in Table 2.

[0057] [Table 1]

[0058] A mixture of SAN pellets (A) and SMA (C) was added through the main hopper / feeder, while a preblend of butadiene rubber (rubber-modified thermoplastic polymer (B)) was fed through a side feeder connected to the second barrel along with melt processing additives: EBX wax, magnesium stearate, magnesium oxide, and silicone fluid (see Table 3). Comparative Example CE1 was prepared by mixing equal amounts of both SAN1 and SAN2 (copolymer (A)) without any SMA. Comparative Examples CE2 and CE3, as well as the thermoplastic compositions of the examples of the present disclosure (E1 to E11), were prepared in a similar manner to the comparative samples, except that the mixture of SMA (C) pellets and SAN was premixed in a plastic container to produce homogeneously mixed pellets before loading into the main hopper. Similarly, a preblend in the form of a homogeneous powder was obtained by dry blending HRG and melt processing additives in a separate plastic container. Melt processing additives (MPA) were provided for all formulations in the following amounts: MgO (0.04%), silicone fluid (0.2%), EBX wax (1%), Mg stearate (0.3%).

[0059] [Table 2]

[0060] The physically mixed formulations were melt blended in a 10-barrel Coperion ZSK-26mm co-rotating twin-screw extruder with an L / D ratio of 40:1. Material throughput during extrusion was adjusted to maintain a specific mechanical energy (SME) between 0.172 and 0.185 while maintaining a screw speed of 250 revolutions per minute. Table 3 shows the temperature profile used during extrusion of the formulations of the present disclosure.

[0061] [Table 3]

[0062] Injection molding of test specimens such as ISO tensile bars, ISO impact bars, and 3 mm color plaques was carried out in an L&T Detech 100-ton molding machine equipped with a 32 mm diameter screw. Injection molding was carried out at a temperature of 240°C and the injection speed was maintained at 20 mm / s. The molded plaques were kept for conditioning at 23°C and 50% relative humidity (RH) for 72 hours.

[0063] Metal Plating of Molded Plaques of Comparative Thermoplastic Compositions and Thermoplastic Compositions of the Present Disclosure Chemical plating process: The surface of each molded plaque was chemically plated by placing the plaque in a plating bath. In the plating bath, the metal ions in the plating bath were reduced and bonded with the polar groups of the polymer plaque, forming a metal layer on the surface of the plaque. Prior to placing the plaque in the plating bath, all plaques (including the comparative and example thermoplastic compositions) were conventionally etched with hexachromic acid at 70°C for 10 minutes. All pretreated plaques were sensitized in a SnCl (10 g / L) / HCl (40 mL / L) solution and activated in a PdCl (0.25 g / L) / HCl (2.5 mL / L) solution. The chemical plating bath contained CuSO 5H O (15 g / L), NaKC H O 4H O (30 g / L), HCHO (100 mL / L), and NaOH (4 g / L). All samples were chemically plated for 15 minutes. The coated plaques were tested for their sheet resistance and electroplated using the process described below.

[0064] Electroplating process: The electrodeposition experiments consisted of a copper deposition process and were performed using a MiniContactRS electroplating system. The electrolyte consisted of 75 g / L copper sulfate and 200 mL / L sulfuric acid. The applied current was 1.5 A and the temperature was 29°C. The plating time for both the comparative thermoplastic composition and the example thermoplastic compositions of the present disclosure was 30 minutes.

[0065] The process conditions for electroplating were optimized with respect to applied current and treatment time. Furthermore, a statistically significant trend was identified for metal growth on plaques of the formulated thermoplastic compositions of the present disclosure. Furthermore, when the treatment time was varied from 5 to 30 minutes, the thickness of the metal layer grown on the surface of the plaque appeared to increase.

[0066] To have finite control of the metal thickness during electroplating, different parameters (current and time) need to be considered. To compare the final peel strength of different samples, a constant metal thickness was required to ensure that the differences in peel strength were primarily caused by the different adhesion processes (i.e., chemical vs. mechanical). However, in these examples, the surface conductivity of all samples was different due to the chemical plating process. For this reason, all samples were cut to the same diameter to maintain the same surface area. Electroplating was performed on the same day, keeping the pH, electrolyte concentration, applied current, treatment time, and temperature unchanged.

[0067] <Peel Test of Comparative Thermoplastic Compositions and Examples of Thermoplastic Compositions of the Present Disclosure> Example thermoplastic compositions of the present disclosure (E1 to E11) and comparative examples (CE1 to CE3) were metallized and tested for peel adhesion. Figure 1 shows a plot of peel force (in N / mm) versus peel length (in mm) for CE, E2, and E6. The peel length and peel strength for the examples were found to be much higher than that of comparative example CE1. Table 4 shows the average peel strength measured in accordance with ASTM B533-85. Table 4 also shows the notched Izod impact (NII) strength of molded articles prepared using the thermoplastic compositions in accordance with ISO 180 / 1A.

[0068] From the results, it was determined that the tissues produced using the thermoplastic compositions of the present disclosure had better metal-plastic interlocking and better peel strength than comparative thermoplastic compositions that did not include the specific SMAs of the present disclosure.

[0069] [Table 4]

[0070] It will be understood that for purposes of this disclosure, "at least one of X, Y, and Z" can be interpreted as X only, Y only, Z only, or any combination of two or more items X, Y, and Z (e.g., XYZ, XY, XZ, YZ). It will further be understood that for purposes of this disclosure, "X, Y, and / or Z" can be interpreted as X only, Y only, Z only, or any combination of two or more items X, Y, and Z (e.g., XYZ, XY, XZ, YZ).

[0071] Furthermore, for purposes of this disclosure, unless otherwise stated in specific contexts, when a numerical range with upper and lower limits is referred to herein, it will be understood that the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the invention be limited to the specific values ​​recited when defining the range. Furthermore, when an amount, concentration, or other value or parameter is given as a range, one or more preferred ranges, or a list of upper and lower preferred values, this will be understood to specifically disclose all ranges formed from any pairing of the upper or upper preferred value of any range with the lower or lower preferred value of any range, regardless of whether such pairs are individually disclosed.

[0072] Although various embodiments of the present disclosure have been shown and described, modifications to the various embodiments may be made without departing from the spirit and teachings of the present disclosure. The embodiments and examples described herein are merely illustrative and are not intended to be limiting. Many variations and modifications of the present disclosure disclosed herein are possible and are within the scope of the present disclosure. Therefore, the scope of protection is not limited by the above-described specification, but only by the claims that follow, including all equivalents of the subject matter of the claims. Each claim is incorporated into the specification as an embodiment of the present disclosure. Thus, the claims are further explanation and are in addition to the detailed description of the present disclosure. The disclosures of all patents, patent applications, and publications cited herein are incorporated herein by reference. [Brief explanation of the drawings]

[0073] [Figure 1] 1 shows a plot of peel force (in N / mm) versus peel length (in mm) for Examples E2 and E6, and Comparative Example CE1, according to various embodiments of the present disclosure.

Claims

1. 1. A thermoplastic composition comprising: a first copolymer in an amount of 30% to 80% by weight of the composition, preferably 45% to 75% by weight of the composition, the first copolymer comprising polymerized units derived from a vinyl aromatic monomer and a vinyl nitrile monomer; a rubber-modified polymer in an amount of 18% to 50% by weight of the composition, preferably 30% to 45% by weight of the composition; a styrene-maleic anhydride (SMA) copolymer in an amount of 2% to 15% by weight of the composition, a maleic anhydride content in an amount of 10% to 30% by weight of the SMA copolymer, preferably 12% to 25% by weight of the SMA copolymer, more preferably 15% to 20% by weight of the SMA copolymer; and an SMA copolymer having a weight average molecular weight of 5,000 g / mol to 30,000 g / mol, preferably 10,000 g / mol to 25,000 g / mol, more preferably 15,000 g / mol to 20,000 g / mol; A thermoplastic composition comprising:

2. the vinyl aromatic monomer comprises at least one of styrene, α-methylstyrene, dibromostyrene, vinyltoluene, vinylxylene, butylstyrene, p-hydroxystyrene, and methoxystyrene, preferably the vinyl aromatic monomer is styrene; 10. The thermoplastic composition of claim 1, wherein the vinyl nitrile monomer comprises at least one of acrylonitrile, chloroacrylonitrile, methacrylonitrile, and ethacrylonitrile, and preferably the vinyl nitrile monomer is acrylonitrile.

3. The rubber-modified polymer is (i) A polymer rubber containing polymerized units derived from a conjugated diene, a polymer rubber, wherein the conjugated diene comprises at least one of 1,3-butadiene, isoprene, 1,3-heptadiene, methyl-1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-pentadiene, 1,3-hexadiene, and 2,4-hexadiene, preferably 1,3-butadiene; (ii) a graft thermoplastic copolymer grafted onto the polymer rubber, the graft thermoplastic copolymer comprising polymerized units derived from at least one of a vinyl aromatic monomer, preferably styrene, and a vinyl nitrile monomer, preferably acrylonitrile; The thermoplastic composition of claim 1 or 2, comprising:

4. the first copolymer comprises a styrene-acrylonitrile copolymer (SAN); The thermoplastic composition of any one of claims 1 to 3, wherein the rubber-modified polymer comprises a SAN-grafted butadiene rubber.

5. 5. The thermoplastic composition of any one of claims 1 to 4, further comprising an ethylene-acrylic acid (EAA) copolymer in an amount of 2% to 10% by weight of the composition, the EAA copolymer comprising an acrylic acid content in an amount of 1% to 10% by weight of the EAA copolymer, preferably 5% to 7% by weight of the EAA copolymer.

6. The thermoplastic composition of any one of claims 1 to 6, further comprising one or more additional components in an amount of from 0% to 5% by weight of the composition.

7. 7. The thermoplastic composition of claim 6, wherein the one or more additional components in the thermoplastic composition are selected from the group consisting of impact modifiers, flow modifiers, reinforcing agents, antioxidants, heat stabilizers, light stabilizers, UV stabilizers, UV absorbing additives, plasticizers, lubricants, mold release agents, antistatic agents, melt processing additives, and any combination thereof.

8. 7. The thermoplastic composition of claim 6, wherein the one or more additional components comprise at least one of magnesium oxide (MgO), silicone fluid, ethylene bisstearamide (EBX) wax, and magnesium stearate.

9. 3.0 kJ / m when measured in accordance with ISO 180 / 1A ２ ~30.0 kJ / m ２ , preferably 4.0 kJ / m ２ ~25.0 kJ / m ２ , more preferably 5.0 kJ / m ２ ~20.0 kJ / m ２ The thermoplastic composition of any one of claims 1 to 8, having a notched Izod impact strength of

10. forming the thermoplastic composition according to any one of claims 1 to 9 into a molded article; Optionally washing and / or rinsing the molded article; contacting the surface of the molded article with a chemical agent to form a surface treated article; and, subjecting the surface-treated article to conditions suitable for depositing one or more metal layers on at least a portion of a surface of the surface-treated article to produce a metal-plated article; Electroplating process including:

11. 11. The electroplating process of claim 10, wherein the chemicals comprise a suspension of colloidal manganese oxide particles in a mineral acid mixture comprising sulfuric acid and / or phosphoric acid.

12. 12. The electroplating process according to claim 10 or 11, wherein the one or more metal layers are selected from the group consisting of copper, nickel and chromium, preferably nickel.

13. 11. The metal-plated molded article of claim 10, having a peel strength determined in accordance with ASTM B533-85 of greater than 0.4 N / mm.

14. a metal layer; A thermoplastic article comprising: (i) the metal layer is deposited on at least a portion of the surface of the thermoplastic article; and, (ii) a first copolymer in an amount of 30% to 80% by weight of the composition, preferably 45% to 75% by weight of the composition, the first copolymer comprising polymerized units derived from a vinyl aromatic monomer and a vinyl nitrile monomer; a rubber-modified polymer in an amount of 18% to 50% by weight of the composition, preferably 30% to 45% by weight of the composition; a styrene-maleic anhydride (SMA) copolymer in an amount of 2% to 15% by weight of the composition, a maleic anhydride content in an amount of 10% to 30% by weight of the SMA copolymer, preferably 12% to 25% by weight of the SMA copolymer, more preferably 15% to 20% by weight of the SMA copolymer; and an SMA copolymer having a weight average molecular weight of 5,000 g / mol to 30,000 g / mol, preferably 10,000 g / mol to 25,000 g / mol, more preferably 15,000 g / mol to 20,000 g / mol; Includes; a thermoplastic article; A metal-plated article comprising:

15. 15. The metal plated article of claim 14 comprising an automotive or electrical part.

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