Composition with marble effect and the production method thereof

Abstract

A polyamide-based composition with marble effect, comprising a component A providing the background color and one or more components B providing the contrast colors, wherein the component A and the component B are based on different polyamide composition, exhibiting high levels of mechanical strength, excellent scratch resistance, excellent temperature resistance, excellent chemical resistance, and high surface gloss, a process for producing same and their use.

Description

Composition with marble effect and the production method thereof

[0001] The present invention relates to a composition with marble effect, the production method thereof, and its use. In detail, the present invention relates to a polyamide-based composition with marble effect, a polymer system with marble effect, a method for producing the polymer system with marble effect, as well as its use in a wide variety of applications.

[0002] In recent years, molders and their customers have started to ask for aesthetic beyond what a single block color can deliver. Furthermore, the plastic market has begun to require effects that highlight the fact that molded articles are made of recycled plastic. Specialist material suppliers to the plastic industry have responded by developing molded plastics giving the appearance of stone or marble. Marble effect means a colored background surface showing surface effects such as colored shading, stripes, lines and structures. In detail, the shading, tripes, lines or structures are of a different color (contrast color) than the background color.

[0003] Articles with marble effect can cover the scratches on the surface of the items, and therefore its application has been largely expanded in automotive industries, household appliances, kitchen utensils, office appliances, constructions, architectures, and other fields. For example, such articles can be used in automotive interiors such as trims (e.g., pillar trim, trunk side trim, center console trims), panels (e.g., instrument panel, switching panel, decoration panel, indicator panel), grip handle, door module, trunk board, covers or gear shift knob as well as automotive exteriors such as mirror caps, base door, cradle plate, B post cover upper, C post cover upper, trunk lining, rear trunk panel, belt covers, wheel caps, bumpers, grilles, etc. Furthermore, such articles can also be used in packaging, especially cosmetics packaging, toys, gifts, stationeries, garden furniture, electronic products, sport articles, etc.

[0004] A natural appearance for the articles with marble effect can be achieved in an injection molding process by using a compound providing the background color of the articles and one or more compounds providing the contrast colors which are different from the background color and are visible on the surface of the finished articles.

[0005] The compounds that provide the contrast colors, whilst extremely effective visually, can introduce a further level of variability into a process with controllable parameters compared to other techniques. In other words, producing a satisfactory and controllable uniformity of the effect has often failed, either because the marble effect could not be uniformly distributed or because the color of the additives / particles was diffused. Diffusion of the color is mainly due to lack of mechanical and thermal stability of the compounds that providing the contrast colors during the processing of the plastic.

[0006] Several techniques are involved to obtain a marble effect, including careful selection of polymers and formulation combination, the particle size of particles / additives. Other techniques are based on machine design and involve plunger type injection molding machine. The plunger injection molding machine uses the plunger to push the plastic in the barrel forward, make it pass through the diverter shuttle, and then inject it into the mold through the nozzle. However, they are nowadays very rare.

[0007] There are many similar inventions where a marble effect is obtained with polypropylene (PP) using compounds that provide the contrast colors. The compounds that provide the contrast colors are often based on a non-compatible polymer like polyamide to obtain a marble effect.

[0008] For example, CN 102617933 B discloses the use of a colored compound which is mixed to polypropylene (PP) to achieve a marble effect. The colored compound is apolyolefin I thermoplastic polyamide (PA) resin compound, which is added to the polypropylene. Poor resin dispersion and diffusion can produce uneven visual effects, i.e. , marble effect.

[0009] Similar to CN 102617933 B, CN 102993568 A, CN 109135061 B and CN 108976602 A also disclose modifying polypropylene (PP) using a compound based on polyamide (PA) which provide the contrast color.

[0010] However, one of the disadvantages of these systems is that polypropylene (PP) is used as background-colored compound. Compared with some other thermoplastic polymers, polypropylene (PP) is less durable and less resistant to abrasion, making it not an ideal choice for some applications like automotive interiors, household appliances, kitchen utensils, constructions, and architectures, etc. In addition, the use of polyamide (PA) / polyolefin blends in polypropylene (PP) show some issues which need to be adequately addressed, such as the incompatibility between the two components. As a result, mechanical properties of the systems are reduced. This is usually overcome by using suitable compatibilizers, typically based on functionalized polyolefins. But this makes the products and the production process more complicated and expensive.

[0011] CN 101392082 B and CN 1557870 A disclose modifying a background polypropylene (PP) matrix with engineering polymers like polyesters or polycarbonates. The disadvantages are similar to the ones using PP / PA mixtures, i.e., the use of a polypropylene (PP) matrix as background-colored compound limits its applications in certain field. In addition, mixing of incompatible (immiscible) polymers reduces the mechanical properties of the molded parts.

[0012] Other techniques involve modified injection molding equipment and are therefore more complicated and more expensive. For example, WO 2021 / 074148 A1discloses the production of a marble effect system achieved by using an injection mold comprising at least one hot runner, a cavity, an inlet opening into the injection mold and an inlet opening into the cavity, wherein the hot runner has at least two channels. The at least two channels are connected at a first end of each channel to an inlet opening into the cavity and at a second end of each channel to an inlet opening into the injection mold, wherein at least two channels each at least partially form a helix and the at least two channels are delimited by a single piece component.

[0013] As described above, the systems with marble effect according to the state of the art are disadvantageous with respect to its mechanical properties, its durability and resistance to abrasion and / or compatibility with the background-color medium. What is more, the production of a marble effect system achieved by using a modified injection molding equipment is complicated and expensive, which further restricts the popularization of the marble pattern plastic products.

[0014] Thus, there continues to be a demand for systems having marble effect with improved mechanical properties and scratch resistance performance. Furthermore, there is also a need for a simple, fast, and inexpensive production process for producing molded articles having a marble effect.

[0015] In view of the foregoing problems, an object of the present invention is to provide a composition with marble effect which can achieve high levels of mechanical strength, excellent scratch resistance, excellent temperature resistance, excellent chemical resistance, as well as high surface gloss. A further object of the present invention is to design a simple, fast, and inexpensive production process for producing the articles having a marble esthetic effect.

[0016] To solve the problems of state of the art, the present invention is directed to apolymer system with natural marble effect which can be produced by a standard injection molding machine.

[0017] In detail, the present invention relates to polymer formulations with marble effect comprising a component A providing the background color and the one or more components B providing the contrast color, wherein the component A and component B are based on different polyamide (PA) based formulations. The invention further relates to a simple and low-cost process for producing marbled moldings, wherein a first molding compound (component A) and at least one further molding compound (component B) are molded by an injection molding process.

[0018] In detail, the present invention relates to a polyamide-based composition, comprising a component A and one or more components B, wherein the component A and the component B are based on different polyamide compositions that comprise coloring agent.

[0019] The present invention further relates to the above-mentioned polyamide-based composition, wherein the component A and the component B have different colors.

[0020] The present invention further relates to the above-mentioned polyamide-based composition, wherein the component B, which provides the contrast color for a polymer system produced by molding the component A and one or more components B, is based on polyamide or polyamide mixtures having a melting temperature which is at least 20 °C, preferably 25 °C, particularly preferably 30 °C higher than that of the component A, which provides the background color for the polymer system.

[0021] The present invention further relates to the above-mentioned polyamide-basedcomposition, wherein the component A and / or the component B comprise coloring agents which are selected from at least one type of inorganic and organic pigments, inorganic and organic dyes, wherein the inorganic pigments can be selected from metallic pigments, pearlescent pigments, interference pigments, liquid crystal pigments, and mixtures thereof, wherein the organic pigments and dyes are stable under the preparation conditions for a polymer system produced by molding the component A and one or more components B.

[0022] The present invention further relates to the above-mentioned polyamide-based composition, wherein the component A is PA 11 , PA 12, PA 6, PA 612, and mixtures thereof; and / or the component B is PA 66 or PA 46, aromatic polyamides or Polyphthalamide, and mixtures thereof.

[0023] The present invention further relates to the above-mentioned polyamide-based composition, wherein the component A and / or the component B contains one or more additives comprising impact modifiers, stabilizers, flame retardants, compatibilizers, and bonding agents.

[0024] The present invention further relates to the above-mentioned polyamide-based composition, wherein the modifiers are selected from grafted-maleic anhydride elastomers, terpolymers, and / or chain extenders. Chain extenders are multifunctional reactive systems. Chain extenders increase the molecular weight of poly-condensates by re-coupling their degraded chains while their synthesis, processing, re-processing or recycling is taking place. Chain extenders can be reactive epoxy-based oligomers or polymers or other reactive systems.

[0025] The present invention further relates to a polymer system, produced by molding the above-mentioned component A and one or more components B.

[0026] The present invention further relates to a method for preparing the above- mentioned polymer system, wherein the component A and one or more components B are molded in an injection molding process.

[0027] The present invention further relates to use of the above-mentioned polymer system in automotive interiors, automotive exteriors, household appliances, kitchen utensils, garden furniture, office appliances, stationeries, electronic products, sport articles, cosmetics packaging, toys, gifts, constructions, architectures, and other fields.

[0028] The composition with marble effect of the present invention shows excellent compatibility between the component A which provides the background color and the component B which provides the contrast color since they are based on the same family of polymer, i.e., polyamide (PA), resulting in good mechanical properties. In addition, there is no need for further polymer modification like grafting to improve compatibility, therefore the production process is less complicated and inexpensive. The present invention provides a marble effect based on polyamide (PA). Compared to polyolefins, polyamide (PA) has advantages of high surface gloss, good scratch resistance, excellent chemical resistance, and can withstand higher temperatures. One of the main differences between polypropylene and polyamide is the mechanical strength. Polyamides (PA) are generally stronger and more durable than polypropylene (PP), making them a better choice for applications that require high levels of mechanical strength. In other words, the polymer system of the present invention can be used in a wide variety of applications including automotive interiors, automotive exteriors, household appliances, kitchen utensils, garden furniture, office appliances, stationeries, electronic products, sport articles, packaging, especially cosmetics packaging, toys, gifts, constructions, architectures, etc., due to its high durability and strength.

[0029] Moreover, the polymer system of the present invention can be produced by molding the component A which provides the background color and one or more components B which provide the contrast colors using a standard injection molding machine by only slightly modifying process parameters. In other words, there is no need to modify the injection molding machine, but it can be achieved by only adjusting the process parameters. Therefore, the production procedure is simple and easy to operate, and the cost for manufacturing is lowered.

[0030] Hereinafter, the present invention will be explained in more detail together with the preparing method.

[0031] The present invention is a polyamide-based composition of a component A providing the background color and one or more components B providing the contrast color which is different from the background color. One or more components B can be used, resulting in numerous contrast colors that create the marble effect with the background color. More important, the component A and the component B are based on different polyamide composition, that are critical to obtain the desired marble effect.

[0032] The correct choice of the component B is vital to the aspect of the colored plastic part. In detail, the component B must be extremely robust with respect to the mechanical resistance (shear) and the heat resistance. As a result, low resin dispersion of the component B can be achieved which results in a marble effect. In other words, the colorant present in the component B is not distributed uniformly, resulting in colored structures resembling natural marble.

[0033] Component A and component B may contain all type of coloring agents, for example, inorganic and organic pigments, inorganic and organic dyes, wherein the inorganic pigments can be selected from metallic pigments, pearlescent pigments,interference pigments, liquid crystal pigments, and mixtures thereof, wherein the organic pigments and dyes are stable under the preparation conditions for molding a polymer system, especially with respect to the preparation temperature. Pearl luster pigments offer many design possibilities to improve the appearance of the colored plastic part. Glittery as well as silky matte effect are possible to be combined with a marble effect. Pigment combinations can be used as well.

[0034] In detail:Inorganic and organic pigments:Inorganic pigments are not based on carbon chains and rings. Instead, they comprise dry ground minerals, usually metals and metallic salts. They can be based on iron oxide, zinc white, titanium oxide, chromium or cadmium for example. Black pigments can also be used. Organic pigments are based on carbon chains and rings. While some contain inorganic elements such as stabilizers, organic pigments are defined primarily by this factor. Examples are azo, phthalocyanine, alizarin or quinacridone pigments. For the present invention, suitable organic pigments should be stable under the preparation conditions for molding a polymer system, especially with respect to the preparation temperature.

[0035] Metallic pigments:Metal effect pigments can be based on aluminium, including conventional leafing and non-leafing aluminium pigments (cornflakes), silver dollar aluminium pigments and thin and brilliant foil pigments (vacuum-metallized pigments - VMPs). Other metallic pigments include but are not limited to leafing and non-leafing gold bronze pigments, copper and lamellar zinc pigments, including alloys.

[0036] Pearl luster pigments:Pearlescent pigments comprise transparent flakes of high refractive index and exhibit a characteristic pearlescence due to multiple reflection in the case of parallelorientation. Pearlescent pigments of this type which additionally exhibit interference colors are known as interference pigments.

[0037] Classical pearlescent pigments, such as TiC>2 flakes, basic lead carbonate, BiOCI pigments or nacreous pigments, are naturally suitable for the present invention. Nevertheless, the effect pigments employed for the purposes of the invention are preferably flake-form interference pigments or metal-effect pigments, which have at least one coating of a metal, metal oxide, metal oxide hydrate or mixtures thereof, a metal mixed oxide, metal suboxide, metal oxynitride, metal fluoride or a polymer on a flakeform substrate.

[0038] The flake-form substrate preferably comprises natural or synthetic mica, kaolin or another phyllosilicate, glass, calcium aluminium borosilicate, SiC>2, TiC>2, AI2O3, Fe2Oa, polymer flakes, graphite flakes or metal flakes, such as aluminium, titanium, bronze, silver, copper, gold, steel or diverse metal alloys. Particular preference is the flake-form substrates comprising natural mica, synthetic mica, glass, calcium aluminium borosilicate, graphite, SiC>2, AI2O3, Fe2Os or aluminium.

[0039] The size of the flake-form substrates is not crucial per se. The substrates generally have a thickness of between 0.01 and 5 pm, preferably between 0.05 and 4.5 pm and particularly preferably from 0.1 to 1 pm. The length or width dimension is usually from 5 to 250 pm, preferably from 5 to 200 pm and particularly preferably from 5 to 125 pm. They generally have an aspect ratio of at least 2:1 , preferably of from 3:1 to 500:1 and particularly preferably from 6:1 to 250:1 , wherein the aspect ratio is defined as the ratio of the mean diameter to mean thickness of the particle.

[0040] Examples for the effect pigments which can be employed are Iriodin®, Colorstream®, Xirallic®, Miraval®, Pyrisma® from Merck KGaA, KC® from FujianKuncai Material Technology Co. Ltd. , Reflex® from CQV Co., Ltd., Clareium®, Iridesium®, Nacreium® from Pritty Pearlescent Pigments Co., Ltd., SunMICA®, SunGEM® , and Mearlin® from Sun Chemical Group Codperatief U.A., metal-effect pigments from Eckart GmbH or Schlenk Metallic Pigments GmbH and optically variable effect pigments, such as Variochrom® from Sun Chemical Group Codperatief U.A..

[0041] Examples of pearlescent or metallic pigments are listed as follows:- Sun Chemical Group Codperatief U.A.:■ SunGEM® XST: natural mineral mica coated with optical layers of titanium dioxide and / or iron oxide■ SunMICA®: synthetic mineral mica coated with optical layers of titanium dioxide and / or iron oxide■ SunGEM®: glass platelets coated with titanium dioxide■ Variochrom®- Fujian Kuncai Material Technology Co. Ltd.:■ KC Pearls: natural Mica base■ Crystal, Chameleon: synthetic Mica base■ DinaStar: borosilicate base- CQV Co., Ltd.:■ Kromax™: natural Mica base■ Reflex™, Chaos®, Ferrius®: synthetic Mica base■ Axion®: borosilicate base■ Adamas®: Alumina base- Schlenk Metallic Pigments GmbH (aluminum pigments)■ Constant® 1500

[0042] The pigments described above may be present individually or as a mixture of two or more in the pigmented compounds employed in accordance with the present invention.

[0043] Suitable plastics for the component A and component B are based on polyamides. The polyamides are compatible and provide compatibility to the polymer system produced thereof. On the other hand, the properties i.e., viscosity and melting points of the component A and component B must be different enough to provide incomplete mixing and the desired marble effect.

[0044] It was found that suitable polyamide for the component A which provides the background color can be PA 11 , PA 12, PA 6, PA 612, or combinations of them.

[0045] In a similar way, it was found that suitable polyamide for the component B which provides the contrast color can be PA 66 or PA 46, semi-aromatic (formally named as polyphthlamide) or aromatic polyamides, or combinations of them.

[0046] In detail, polyamides are classified into two categories: Aliphatic polyamides, known as nylons, and aromatic polyamides, known as aramids. Semi-aromatic polyamides are those that have different monomers (aliphatic and aromatic) in their polymer chains. An example is PA6T (PA 6T = hexamethylenediamine + terephthalic acid). Another example is PA 6T / 6I (diamine + terephthalic and isophthalic acid). Semiaromatic polyamides are formally named as polyphthlamide and are part of the polyamide family. They are defined as polyamides where 55% or more moles of the carboxylic acid portion of the repeating unit in the polymer chain is composed of a combination of terephthalic (TPA) and isophthalic (IPA) acids. The copolymerization with diamine makes them processable using plastic processing technologies (by decreasing the melting point). The substitution of aliphatic diacids by aromatic diacids in the polymer backbone increases the melting point, glass transition temperature, chemical resistance and stiffness.

[0047] The principle of producing the marble pattern is that the component A which provides the background color and the component B which provides the contrast color have different melting points and viscosities. When they are co-injected during molding processing, the streaks and corrugations are then produced due to uneven dispersion and processing flow traces, therefore present a marble pattern. Thus, the viscosity and melting points of the component A and component B must be different enough so as to provide the desired marble effect. It was found that using the following polyamide combination was needed to get the best marble effect.

[0048] As to the melting point, the present invention is characterized in that the component B which provides the contrast color is based on polyamide or polyamide mixtures having a melting point of at least 20 °C, preferably 25 °C, particularly preferably 30 °C higher than that of the polyamide of the component A which provides the background color. The maximum melting point for the component B is 350 °C.

[0049] If the melting point difference between the contrast and the background polyamide is not larger than 20 °C, it is possible to use the difference in viscosity between the polyamide materials. The component B which provides the contrast color has a higher viscosity than that of the component A which provides the background color. The viscosity can be measured in according to different methods. MVR according to ISO 1133 can be used for the purpose of choosing the correct polyamide combination. Component A has a MVR (275 °C / 5 kg) of at least 10 cm3 / 10 min, preferably 15 cm3 / 10 min, particularly preferably 20 cm3 / 10 min higher than that of component B. The minimum MVR (275 °C / 5 kg) for component B is 0.1 cm3 / 10 min.

[0050] The component A and / or the component B in the present invention may contain one or more additives including impact modifiers, stabilizers, flame retardants, compatibilizers, bonding agents, etc.Component B can be modified using highly reactive chain extender (reactive additives) to increase the molecular weight of the polyamide. Chain extenders are multifunctional reactive systems. Chain extenders increase the molecular weight of polycondensates by re-coupling their degraded chains while their synthesis, processing, reprocessing or recycling is taking place. Chain extenders are generally functionalized and block or graft oligomers / polymers. Illustrative polyamide chain extenders that can be used for this purpose are reactive epoxy-based oligomers / polymers or other reactive systems. Examples of the multi-functional reactive polymer are Joncryl® ADR or BRUGGOLEN® M (chain modifier for polyamides).

[0051] Properties like compatibility between polymers or UV-resistance may be needed and are therefore addressed by the formulations in the present invention. The component B can be designed in such a way that it also contains impact modifiers or bonding agents.

[0052] In detail, the polyamides can be impact modified. Illustrative polyamide modifiers that can be used for this purpose are grafted-maleic anhydride elastomers or terpolymers where the content of maleic anhydride is usually less than 5% and typically in the range of 0.8 to 2%. Examples from the class of maleic-anhydride grafted elastomers are thermoplastic olefins (TPO) , also named reactor TPOs, rubber copolymers produced in a reactor from ethylene and propylene (EPR), or rubber terpolymers of ethylene, propylene and diene-modifier (EPDM), plastomers of ethylene with an alpha-olefin, etc., all grafted with maleic anhydride off-line and random terpolymers of ethylene, acrylic ester and maleic anhydride with typical maleic anhydride contents in the range of 1-5%. In the case of EPDM, typically dienes currently used in the manufacture of EPDM rubbers are dicyclopentadiene (DCPD), ethylidene norbomene (ENB), and vinyl norbornene (VNB) used at a 1-12% level. Other examples include maleic-anhydride grafted olefinic thermoplastic elastomers (TPE) produced from copolymers of monomers like butadiene, isoprene, propylene, ethylene, butene and octene, which behave like elastomers in performance but process like thermoplastics. Styrenic type modifiers such as linear tri-block copolymer of styrene, ethylene andbutylene with grafted maleic-anhydride groups are also sometimes used. Another example of an impact modifier is a terpolymer like an ethylene-acrylate ester-maleic anhydride terpolymer, where the acrylate ester is a methyl, propyl, butyl and other acrylate esters. It is well known to one skilled in the art that these elastomeric materials without the compatibilizing functional maleic anhydride group are not able to provide impact strength improvement to the compound, because in such a case the nylon and the elastomeric phase in the toughener have limited or no interaction and stress cannot be transferred from the rigid polyamide phase to the elastomeric phase which can withstand the impact energy. The use of these maleic-grafted elastomers to impart impact resistance to polyamides has been in commercial use for several decades.

[0053] The component A provides the background coIor and the component B provides the contrast color as described above are used in an injection molding process to make parts with a marble effect.

[0054] The processing conditions of the marble composition depends on the type of the used injection molding machine as well as the mold. The processing conditions have an influence on the final marble effect. To achieve the desired marble effect, optimized parameters need to be selected for each machine and each mode. It includes:- Temperature control: The temperature must be kept to a minimum to ensure minimum mixing of the component A and the component B (see examples). In the Examples listed below, the component A which provides the background color is based on PA6. Normal melt temperature range for PA6 is 240-270°C. Therefore the minimum temperatures of 240°C for injection molding are recommended. To produce a marble effect, the component B which provides the contrast color is added and the temperature range should be high enough to melt the component B but kept to a minimum to avoid mixing with the component A. For the machine and mold used, a temperature range of 240 to 290 °C, preferably 240 to 260°C are recommended. The temperature range might change by using a different injection molding machine and molds.- Back pressure control: the function of back-pressure is to maintain the speed atwhich the guide screw does not retreat from the reaction force. If the back pressure is too high, and the screw back time is prolonged, the shear force of the material is also increased and the mixing of the component A and the component B would be too high. The back pressure should be kept to a minimum to ensure optimal marble effect (see examples). In the Examples listed below, the back pressure of 10 bars is used. In general, a back pressure from 0 to 50 bars can be used, but it should be kept minimum to reduce mixing during injection molding.- Screw speed control: the screw speed should be kept maximum for optimal marble effect (see examples). In the Examples listed below, the screw speed of 250 rpm is used. In general, a screw speed from 150 to 250 rpm can be used, but it should be kept as high as possible. The screw speed range might change depending on the injection molding machine and molds used.- Cooling time control: the cooling time should be kept as short as possible to decrease the time the material is staying in the barrel at elevated temperatures (see examples). In the Examples listed below, the cooling time of 12 seconds is used. In general, a cooling time of less than 20 seconds can be used, but it should be kept to be the minimum, so that the material is not staying long in the cylinder (less mixing). The cooling time clearly depends on the size of the plastic part, especially the thickness thereof.

[0055] The polymer system with marble effect in accordance with the present invention can be used in all areas where thermoplastic polyamide has been employed to. For example, moldings of the plastic according to the present invention can be used in the electrical, electronics and motor vehicle industries. The plastic system according to the present invention can also be employed in packaging. Furthermore, the polymer system according to the invention can be used in the area of construction and architecture, as well as sport and leisure. Further embodiments according to the present invention are revealed by the examples and the claims.Examples

[0056] Hereinafter, the present invention will be described in more detail by reference to the Examples and Comparative Examples, which, however, are not intended to limit the present invention.

[0057] Compounds are concentrated solid mixtures of pigments and / or additives that are manufactured by twin screw extrusion of a carrier matrix.

[0058] The component A and component B are both colored as desired and can contains other additives like stabilizers, flame retardants, but also compatibilizers or impact modifiers.

[0059] For PA66 impact modification, GRAFTABOND EP-MAH 00110 IM or GRAFTABOND LPO-MAH 00110 IM are recommended. GRAFTABOND EP-MAH 00110 IM (Graft Polymer pic) gives good properties for PA 66 due to its relatively high level of high functionality.For PA66 chain extension, Joncryl ADR-4368C or Bruggolen M1251 are recommended. Joncryl ADR-4368C increases melt viscosity for PA 66 due to its relatively high level of high functionality and reactivity (reactive extrusion).

[0060] In the foregoing and in the examples, all temperatures are set forth in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.

[0061] Example 1 : Component APellets of Ultramid® B3K (BASF), color and additives are compounded using a 16 mm co-rotating twin screw extruder (LTE16-40 from LabTech). The Ultramid® B3K, color are fed together using single masterbatch for the color (10% of a 4% carbon blackmasterbatch). UV-Stabiliser additives are fed via a side feeder in an amount to provide a final blend having about 0,3% Irganox® B1171 , 0,4% Chimassorb® 2020 and 0,3% Tinuvin® 312.The temperature profile is as follows: zone 1 is 250°C, zone 2 is 250°C, zones 3-9 are 270°C and the die is 270°C. The screw speed is 250 RPM with a feed rate of 3 kg / hr. The extruded material is chopped into pellets for use in molding.In detail, Ultramid® B3K (BASF) is PA6 with a melting point of 220°C and a MVR (275°C / 5kg) of 160 cm3 / 10min, mainly used for injection molding.

[0062] Example 2: Component BPellets of Ultramid® A3K (BASF), impact modifier, color and additives are compounded using an 18 mm co-rotating twin screw extruder (LTE16-40 from LabTech). The Ultramid® A3K, impact modifier GRAFTABOND EP-MAH 00110 IM (Graft Polymer (UK) Pic) and stabilizers are fed together using single masterbatch for the stabilizers (10% of a masterbatch containing 3% Irganox® B1171 , 4% Chimassorb® 2020 and 3% Tinuvin® 312). The pigments are fed via a side feeder in an amount to provide a final blend having about 10% Colorstream® T10-04 Lapis Sunlight and 0,04% carbon black.The temperature profile is as follows: zone 1 is 280°C, zone 2 is 280°C, zones 3-9 are 300°C and the die is 300°C. The screw speed is 250 RPM with a feed rate of 3 kg / hr. The extruded material is chopped into pellets for use in molding.In detail, Ultramid® A3K (BASF) is PA66 with a melting point of 260°C and a MVR (275°C / 5kg) of 120 cm3 / 10min, mainly used for injection molding. GRAFTABOND™ EP-MAH 00110 IM is an impact modifier for polyamides blends based on EPDM. It contains 1-2% Maleic anhydride and has a MFI (230°C / 5kg) of 1 ,5 cm3 / 10min.

[0063] Example 3: Component BPellets of Ultramid® A34 (BASF), impact modifier, color and additives are compounded using an 18 mm co-rotating twin screw extruder (LTE16-40 from LabTech). The Ultramid® A34 and stabilizers are fed together using single masterbatch for thestabilizers (10% of a masterbatch containing 3% Irganox® B1171 , 4% Chimassorb® 2020 and 3% Tinuvin® 312). The pigments are fed via a side feeder in an amount to provide a final blend having about 10% Iriodin® 7225 Ultra Rutile Blue Pearl, 1 % Pigment Violet PV. 15 and 0,3% TiO2Kronos® 2220.The temperature profile is as follows: zone 1 is 280°C, zone 2 is 280°C, zones 3-9 are 300°C and the die is 300°C. The screw speed is 250 RPM with a feed rate of 3 kg / hr. The extruded material is chopped into pellets for use in molding.In detail, Ultramid® A34 (BASF) is PA66 for film or filament extrusion. PA66 has a melting point of 260°C and a MVR (275°C / 5kg) of at least 20 cm3 / 10min lower than that of Ultramid® B3K (BASF).

[0064] Example 4: Component BPellets of Amodel® AT-1002 HS (Solvay), impact modifier, color and additives are compounded using a 18 mm co-rotating twin screw extruder (LTE16-40 from LabTech). The Amodel® AT-1002 HS and stabilizers are fed together using single masterbatch for the stabilizers (10% of a masterbatch containing 3% Irganox® B1171 , 4% Chimassorb® 2020 and 3% Tinuvin® 312). The pigments are fed via a side feeder in an amount to provide a final blend having about 10% Iriodin® 7225 Ultra Rutile Blue Pearl, 1% Pigment Violet PV. 15 and 0,3% TiO2Kronos® 2220.The temperature profile is as follows: zone 1 is 300°C, zone 2 is 300°C, zones 3-9 are 320°C and the die is 320°C. The screw speed is 250 RPM with a feed rate of 3 kg / hr. The extruded material is chopped into pellets for use in molding.In detail, Amodel® AT-1002 HS (Solvay) is PPA (Polyphthlamide) with a melting point of 315°C, mainly used for injection molding. Its MVR is definitely lower than that of Ultramid® A3K, since it is an extrusion grade.

[0065] Example 5: Component BPellets of Stanyl® TW341 B-MB (DSM), impact modifier, coIor and additives are compounded using an 18 mm co-rotating twin screw extruder (LTE16-40 from LabTech). The Stanyl® TW341 B-MB and stabilizers are fed together using single masterbatch forthe stabilizers (10% of a masterbatch containing 3% Irganox® B1171 , 4% Chimassorb® 2020 and 3% Tinuvin® 312). The pigments are fed via a side feeder in an amount to provide a final blend having about 10% Iriodin® 7225 Ultra Rutile Blue Pearl, 1 % Pigment Violet PV. 15 and 0,3% TiO2Kronos® 2220.The temperature profile is as follows: zone 1 is 300°C, zone 2 is 300°C, zones 3-9 are 320°C and the die is 320°C. The screw speed is 250 RPM with a feed rate of 3 kg / hr. The extruded material is chopped into pellets for use in molding.In detail, Stanyl® TW341 B-MB (DSM) is PA46 (Stanyl), a high-performance aliphatic polyamide with a high melting temperature due to its high crystallinity. Its melting point is 295°C. Its MVR is definitely lower than that of Ultramid® A3K, since it is an extrusion grade. It is more viscous than Ultramid® B3K and its MVR (275°C / 5kg) is at least 20 cm3 / 10min lower than that of Ultramid® B3K (BASF).

[0066] Example 6: Component BPellets of Ultramid® A3K (BASF), impact modifier, color and additives are compounded using an 18 mm co-rotating twin screw extruder (LTE16-40 from LabTech). The Ultramid® A3K and stabilizers are fed together using single masterbatch for the stabilizers (10% of a masterbatch containing 3% Irganox® B1171 , 4% Chimassorb® 2020 and 3% Tinuvin® 312). The pigments are fed via a side feeder in an amount to provide a final blend having about 10% Chameleon® Pearl pigment P12S1 (Pritty) and 0,05% carbon black.The temperature profile is as follows: zone 1 is 280°C, zone 2 is 280°C, zones 3-9 are 300°C and the die is 300°C. The screw speed is 250 RPM with a feed rate of 3 kg / hr. The extruded material is chopped into pellets for use in molding.

[0067] Example 7: Component BPellets of Ultramid® A3K (BASF), impact modifier, color and additives are compounded using an 18 mm co-rotating twin screw extruder (LTE16-40 from LabTech). The Ultramid® A3K and stabilizers are fed together using single masterbatch for the stabilizers (10% of a masterbatch containing 3% Irganox® B1171 , 4% Chimassorb®2020 and 3% Tinuvin® 312). The pigments are fed via a side feeder in an amount to provide a final blend having about 2% Constant® 1500 Aluminium pigment (Schlenk).The temperature profile is as follows: zone 1 is 280°C, zone 2 is 280°C, zones 3-9 are 300°C and the die is 300°C. The screw speed is 250 RPM with a feed rate of 3 kg / hr. The extruded material is chopped into pellets for use in molding.Example 8: Component BPellets of Ultramid® A3K (BASF), color and additives are compounded using an 18 mm co-rotating twin screw extruder (LTE16-40 from LabTech). The Ultramid® A3K, and stabilizers are fed together using single masterbatch for the stabilizers (10% of a masterbatch containing 3% Irganox® B1171 , 4% Chimassorb® 2020 and 3% Tinuvin® 312). The pigments are fed via a side feeder in an amount to provide a final blend having about 10% Colorstream® T10-04 Lapis Sunlight and 0,04% carbon black.The temperature profile is as follows: zone 1 is 280°C, zone 2 is 280°C, zones 3-9 are 300°C and the die is 300°C. The screw speed is 250 RPM with a feed rate of 3 kg / hr. The extruded material is chopped into pellets for use in molding.In detail, Ultramid® A3K (BASF) is PA66 with a melting point of 260°C and a MVR (275°C / 5kg) of 120 cm3 / 10min, mainly used for injection molding.Example 9: Component BPellets of Ultramid® A3K (BASF), chain extender, color and additives are compounded using an 18 mm co-rotating twin screw extruder (LTE16-40 from LabTech). The Ultramid® A3K, chain extender Joncryl ADR-4368C and stabilizers are fed together using single masterbatch for the stabilizers (10% of a masterbatch containing 3% Irganox® B1171 , 4% Chimassorb® 2020 and 3% Tinuvin® 312). The pigments are fed via a side feeder in an amount to provide a final blend having about 10% Colorstream® T10-04 Lapis Sunlight and 0,04% carbon black.The temperature profile is as follows: zone 1 is 280°C, zone 2 is 280°C, zones 3-9 are 300°C and the die is 300°C. The screw speed is 250 RPM with a feed rate of 3 kg / hr. The extruded material is chopped into pellets for use in molding.In detail, Ultramid® A3K (BASF) is PA66 with a melting point of 260°C and a MVR (275°C / 5kg) of 120 cm3 / 10min, mainly used for injection molding. Joncryl ADR-4368C is a chain extender based on a multi-functional reactive polymer system. It contains epoxy functionalities.Example 10: Component BPellets of Ultramid® A3K (BASF), chain extender, color and additives are compounded using an 18 mm co-rotating twin screw extruder (LTE16-40 from LabTech). The Ultramid® A3K, chain extender Bruggolen M1251 and stabilizers are fed together using single masterbatch for the stabilizers (10% of a masterbatch containing 3% Irganox® B1171 , 4% Chimassorb® 2020 and 3% Tinuvin® 312). The pigments are fed via a side feeder in an amount to provide a final blend having about 10% Colorstream® T10-04 Lapis Sunlight and 0,04% carbon black.The temperature profile is as follows: zone 1 is 280°C, zone 2 is 280°C, zones 3-9 are 300°C and the die is 300°C. The screw speed is 250 RPM with a feed rate of 3 kg / hr. The extruded material is chopped into pellets for use in molding.In detail, Ultramid® A3K (BASF) is PA66 with a melting point of 260°C and a MVR (275°C / 5kg) of 120 cm3 / 10min, mainly used for injection molding. Bruggolen M1251 is a highly reactive chain extender based on a modified polyamide in granule form.

[0068] Comparative example 1 :Pellets of Ultramid® B3K (BASF), impact modifier, color and additives are compounded using an 18 mm co-rotating twin screw extruder (LTE16-40 from LabTech). The Ultramid® B3K, impact modifier GRAFTABOND EP-MAH 00110 IM (Graft Polymer (UK) Pic) and stabilizers are fed together using single masterbatch for the stabilizers (10% of a masterbatch containing 3% Irganox® B1171 , 4% Chimassorb® 2020 and 3% Tinuvin® 312). The pigments are fed via a side feeder in an amount to provide a final blend having about 10% Colorstream® T10-04 Lapis Sunlight and 0,04% carbon black.The temperature profile is as follows: zone 1 is 250°C, zone 2 is 250°C, zones 3-9 are 270°C and the die is 270°C. The screw speed is 250 RPM with a feed rate of 3 kg / hr. The extruded material is chopped into pellets for use in molding.

[0069] Injection molding tests:For all injection moulding tests, an injection-moulding machine of the Kraus- Maffei CX-130-380 type is used.

[0070] The resulting compounded material is injection molded to form standard test plaques having dimensions as follows: 10.5 cm x 10.5 cm x 0.20 cm).

[0071] Obtained plastic systems:Example 11 :The pellets from Example 1 and Example 2 are mixed in a ratio 90:10. The process parameters must be optimized for every mold and machine. In a nutshell, the main parameters are:- Temperature: 240-260°C.- Back pressure: 10 bars.- Screw speed: 250 rpm.- Cooling time: 12 seconds.After the cooling operation and the opening of the injection mold, a plastic plate is obtained whose surface has an intensely colored marble effect (black background with a metallic dark green contrast color).

[0072] The preceding example 6 can be repeated with similar success by substituting the Polyamide used for the compound B. This is shown in Examples 12-19.

[0073] Example 12:The pellets from Example 1 and Example 3 are mixed in a ratio 90:10. The process parameters are similar to the parameters from example 6.Here again a strong marble effect can be observed.

[0074] Example 13:The pellets from Example 1 and Example 4 are mixed in a ratio 90:10. The process parameters are similar to the parameters from example 6.Here again a strong marble effect can be observed.

[0075] Example 14:The pellets from Example 1 and Example 5 are mixed in a ratio 90:10. The process parameters are similar to the parameters from example 6.Here again a strong marble effect can be observed.

[0076] Example 15:The pellets from Example 1 and Example 6 are mixed in a ratio 90:10. The process parameters are similar to the parameters from example 6.Here again a strong marble effect can be observed.

[0077] Example 16:The pellets from Example 1 and Example 7 are mixed in a ratio 90:10. The process parameters are similar to the parameters from example 6.Here again a strong marble effect can be observed.Example 17:The pellets from Example 1 and Example 8 are mixed in a ratio 90:10. The process parameters are similar to the parameters from example 6.Here again a strong marble effect can be observed.Example 18:The pellets from Example 1 and Example 9 are mixed in a ratio 90:10. Theprocess parameters are similar to the parameters from example 6.Here again a strong marble effect can be observed.Example 19:The pellets from Example 1 and Example 10 are mixed in a ratio 90:10. The process parameters are similar to the parameters from example 6.Here again a strong marble effect can be observed.

[0078] Comparative example 2:The pellets from Example 1 and Comparative Example 1 are mixed in a ratio 90:10. The process parameters are similar to the parameters from example 6.After the cooling operation and the opening of the injection mold, a plastic plate is obtained whose surface does not have a colored marble effect. The contrast color is mixed with the background color resulting in a homogeneous black plate with some greenish aspect. This demonstrates that the wrong choice of polyamide combination is not leading to the desired effect.

[0079] Without further elaboration, one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific examples are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.[Industrial Applicability]

[0080] The polymer system with marble effect of the present invention shows high levels of mechanical strength, excellent scratch resistance, excellent temperature resistance, excellent chemical resistance, as well as high surface gloss. Therefore, it can be used in automotive interiors, automotive exteriors, household appliances, kitchen utensils, garden furniture, office appliances, stationeries, electronic products, sport articles, cosmetics packaging, toys, gifts, constructions, architectures, and other fields.

Claims

Patent Claims1. A polyamide-based composition, comprising a component A and one or more components B, wherein the component A and the component B are different polyamide compositions that comprise coloring agents.

2. The polyamide-based composition according to claim 1 , wherein the component A and the component B have different colors.

3. The polyamide-based composition according to claim 1 or 2, wherein the component B is a polyamide or polyamide mixture having a melting point which is at least 20 °C higher than that of the component A.

4. The polyamide-based composition according to any one of the preceding claims, wherein the component A and / or the component B comprise coloring agents which are selected from at least one type of inorganic and organic pigments or inorganic and organic dyes, wherein the organic pigments and dyes are stable under the preparation conditions for a polymer system produced by molding the component A and one or more components B.

5. The polyamide-based composition according to any one of the preceding claims, wherein the inorganic pigments are selected from metallic pigments, pearlescent pigments, interference pigments, liquid crystal pigments, and mixtures thereof.

6. The polyamide-based composition according to any one of the preceding claims, wherein the component A is selected from PA 11 , PA 12, PA 6, PA 612, or mixtures thereof; and / or the component B is selected from PA 66 or PA 46, polyphthlamide or aromatic polyamides, and mixtures thereof.

7. The polyamide-based composition according to any one of the preceding claims, wherein the component A and / or the component B contains one or more additivescomprising modifiers, stabilizers, flame retardants, compatibilizers, and bonding agents.

8. The polyamide-based composition according to claim 7, wherein the modifiers are selected from grafted-maleic anhydride elastomers, terpolymers, and / or chain extenders.

9. A polymer system, produced by molding the component A and one or more components B according to any one of the preceding claims.

10. Method for preparing the polymer system according to claim 9, wherein the component A and one or more components B are molded in an injection molding process.

11. Use of the polymer system according to according to claim 9 in automotive interiors, automotive exteriors, household appliances, kitchen utensils, garden furniture, office appliances, stationeries, electronic products, sport articles, cosmetics packaging, toys, gifts, constructions, architectures, and other fields.