Polyamide composition

Abstract

The present invention relates to polyamide compositions that exhibit reduced release of substances in hot water and increased resistance to oxidizing agents, and are therefore suitable for hot water applications, particularly hot drinking water applications.

Description

[Technical Field]

[0001] The present invention relates to polyamide compositions that reduce the release of substances in hot water and increase resistance to oxidizing agents, and are therefore suitable for hot water applications, particularly hot drinking water applications. [Background technology]

[0002] Polyamides are synthetic polymers that are widely used to manufacture a variety of articles, including those that come into contact with hot water, such as pipes, hoses, fittings, seals and tanks.

[0003] In these fields of use, it is important that organic materials that come into contact with water, in particular potable water (i.e. water intended for human consumption), do not release substances in concentrations exceeding limits considered unavoidable according to generally accepted technical standards, do not directly or indirectly affect the level of protection for human health, or alter the odour or flavour of the water. This issue is relevant for cold water applications as well, but is even more pronounced in hot water applications.

[0004] Oxidizing agents, such as halogen-containing oxidizing agents, such as diatomic halogens, halogen radicals, halogen oxides, halogen amines, and / or halogen oxoanion salts or their precursors, are widely used in water purification, disinfection, and bleaching. Thus, water containing such dissolved chemicals may be present in drinking water purified with chlorine-containing chemicals, swimming pool water, disinfectant water in health care facilities, and water to / from bleaching processes in the textile and paper industries. Summary of the Invention [Problem to be solved by the invention]

[0005] Polyamides have poor resistance to oxidizing agents: for example, after several hours of contact with sodium hypochlorite solution, the strength decreases and significant deterioration of the surface appearance occurs at the surface of articles made from polyamide.

[0006] Polyamide-based compositions are raw materials that can be converted into plastic products and parts, but it is difficult to find formulations, especially those based on conventional polyamides, that have low release of substances in hot water, given the elevated temperatures involved in hot water applications, and it is also difficult to find formulations based on conventional polyamides that have good resistance to oxidizing agents, allowing them to meet the specifications for this application. [Means for solving the problem]

[0007] The inventors have now found that the use of polyolefin and / or phenyl ether polymers in polyamide-based compositions, where the polyamide is an aliphatic, cycloaliphatic or semi-aromatic polyamide having a total C / CONH ratio of more than 6 (>6), makes it possible to reduce the release of substances in hot water and to increase the resistance to oxidizing agents.

[0008] Therefore, the present invention provides i) aliphatic, cycloaliphatic or semi-aromatic polyamides having an overall C / CONH ratio greater than 6; ii) 5% to 30% by weight of a polyolefin and / or a phenyl ether polymer; iii) at least 1% by weight of a compatibilizer; iv) at least 0.05% by weight of a heat stabilizer, and v) More than 30% to 70% by mass of filler (each of the above based on the total weight of the composition).

[0009] The present invention also relates to a method for reducing release of substances in hot water from a composition comprising an aliphatic, cycloaliphatic or semi-aromatic polyamide having a total C / CONH ratio greater than 6 and / or increasing the resistance of the composition to oxidizing agents, the method comprising the step of blending the polyamide with a polyolefin and / or a phenyl ether polymer, preferably in the presence of a compatibilizer, more preferably in the presence of a compatibilizer and a filler.

[0010] In a further embodiment, the present invention relates to a method of using polyolefin and / or phenyl ether polymers to reduce the release of substances in hot water from a composition comprising an aliphatic, cycloaliphatic, or semi-aromatic polyamide having a total C / CONH ratio greater than 6 and / or to increase the resistance of the composition to oxidizing agents.

[0011] In a further embodiment, the present invention provides a method for reducing the release of substances from an article in hot water and / or increasing the resistance of the article to oxidizing agents, comprising: i) aliphatic, cycloaliphatic or semi-aromatic polyamides having an overall C / CONH ratio greater than 6, and ii) polyolefin and / or phenyl ether polymers; The present invention relates to a method of using a polyamide comprising the steps of:

[0012] In a further embodiment, the present invention provides a method for producing a hot water purifier, for hot water applications, preferably hot drinking water applications, comprising: i) aliphatic, cycloaliphatic or semi-aromatic polyamides having an overall C / CONH ratio greater than 6, and ii) polyolefin and / or phenyl ether polymers; The present invention relates to a method of using an article comprising a polyamide composition comprising:

[0013] Finally, the present invention relates to an article comprising the polyamide composition defined above. DETAILED DESCRIPTION OF THE INVENTION

[0014] In the description of the present invention, when an element or composition is said to be included in and / or selected from an explicitly stated list of elements or components, it is to be understood that in the relevant embodiments expressly contemplated herein, the element or component can also be any one of the individually stated elements or components, or can be selected from a group consisting of any two or more of the explicitly listed elements or components.

[0015] The term "comprising" includes "consisting essentially of" and "consisting of."

[0016] The symbol "%" or "% by weight" means "percent by weight" unless otherwise specified.

[0017] Any recitation herein of a range of values ​​for a variable defined by a lower limit or upper limit, or a lower limit and an upper limit, also includes embodiments in which the variable is selected within the range of values, excluding the lower limit, or excluding the upper limit, or excluding the lower limit and upper limit, respectively.

[0018] Where an element or composition is referred to herein as being included in and / or selected from a list of explicitly stated elements or components, it is to be understood that in the relevant embodiments expressly contemplated herein, that element or component can also be any one of the individually stated elements or components, or can be selected from a group consisting of any two or more of the explicitly stated elements or components.

[0019] For example, in embodiments where a selection of elements from a group of elements is recited, the following elements are also expressly recited: - a selection of two or more elements from this group, - A selection of elements from a sub-set of elements consisting of a set of elements from which one or more elements have been deleted.

[0020] As used herein, the use of the singular form "a" or "one" includes the plural unless specifically stated otherwise.

[0021] Furthermore, when the term "about" is used before a quantitative value, the present teachings also include the specific quantitative value itself unless otherwise specified. As used herein, the term "about" refers to a ±10% variation from the nominal value unless otherwise specified.

[0022] The term "and / or" includes the meaning of "and", "or" and all other possible combinations of the elements connected to this term.

[0023] The present invention provides i) aliphatic, cycloaliphatic or semi-aromatic polyamides having an overall C / CONH ratio greater than 6; ii) 5% to 30% by weight of a polyolefin and / or a phenyl ether polymer; iii) at least 1% by weight of a compatibilizer; iv) at least 0.05% by weight of a heat stabilizer, and v) More than 30% to 70% by mass of filler (each of the above based on the total weight of the composition).

[0024] The polyamides that can be used according to the invention include semi-crystalline or amorphous (co)polyamides, i.e. polyamides or copolyamides, and more generally linear polyamides obtained by polycondensation of aliphatic, cycloaliphatic or aromatic diacids with aliphatic or cycloaliphatic primary diamines, polyamides obtained by condensation of lactams or amino acids, or linear polyamides obtained by condensation of mixtures of these various monomers.

[0025] Therefore, this polyamide - below, at least one aliphatic, cycloaliphatic or aromatic diacid and at least one aliphatic, cycloaliphatic or aromatic diamine, at least one amino acid per se (this amino acid is preferably an omega amino acid produced by lactam ring opening); or a polyamide obtained by polycondensation of copolyamides obtained by polycondensation of said combinations of diacids, diamines and / or amino acids may be selected from the group consisting of:

[0026] At least one of the diacid, diamine and / or amino acid monomers used in the polycondensation may contain from 4 to 40 carbon atoms.

[0027] Suitable diamines are, for example, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,9-diaminononane, 1,10-diaminodecane, 1,5-methylpentamethylenediamine (MPMD), isophoronediamine (IPD), and 4,4-diaminodicyclohexylmethane (PACM).

[0028] Suitable diacids are, for example, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, octadecanedioic acid, C36 dimerized fatty acids or C36 dimer acids such as UNIDYME or CRODA products, terephthalic acid (T), and isophthalic acid (I).

[0029] Suitable lactams and amino acids are, for example, aminocaproic acid (epsilon-caprolactam), 12-aminododecanoic acid (laurolactam), 11-aminoundecanoic acid, and 10-aminodecanoic acid.

[0030] The polyamide is preferably selected from the group consisting of the following (co)polyamides: polyamide 10, polyamide 11, polyamide 12, polyamide 6.9, polyamide 4.10, polyamide 5.10, polyamide 6.10, polyamide 6.12, polyamide 6.14, polyamide 10.10, polyamide 10.12, polyamide 10.14, polyamide 10.18, polyamide 12.12, polyamide 6.18, polyamide 6.36, polyamide 9.T, polyamide 6.6 / 6.T, polyamide 6.T, polyamide 6.I, polyamide 10.T, polyamide PACM.6, polyamide MPMD.10 (MPMD = methylpentamethylenediamine, MPMD.6 / MPMD.T), polyamide IPD.6 (IPD = isophoronediamine), and blends and copolymers based on these polyamides.

[0031] The compositions of the invention may also comprise copolyamides derived in particular from the above polyamides, or blends of these polyamides or copolyamides.

[0032] Preferred polyamides are polyamide 11, polyamide 12, polyamide 6.10, polyamide 6.12, polyamide 4.10, polyamide 6.6 / 6.T, polyamide 10.10, polyamide 6.18, and mixtures thereof. Polyamide 6.10 is particularly preferred.

[0033] The polyamide in the composition of the present invention has a total C / CONH ratio greater than 6, preferably greater than 7. Preferably, the C / CONH ratio is at most 12. The C / CONH ratio is defined as the total number of carbon atoms in the polyamide divided by the number of CONH moieties in the polyamide, where the "total" number of carbon atoms is defined as the number of carbon atoms including the carbon atoms of the CONH moieties. For example, polyamide 6 has a total of 6 carbon atoms per each CONH moiety. Therefore, the total C / CONH ratio of polyamide 6 is 6. As a result, polyamide 6 is not suitable as a polyamide for the composition of the present invention.

[0034] The amount of polyamide in the polyamide composition of the present invention is not particularly limited. Preferably, the composition contains more polyamide than the sum of a) polyolefin and / or phenyl ether polymer and b) compatibilizer. Thus, the weight ratio of 1.) polyamide to 2.) (polyolefin and / or phenyl ether polymer and compatibilizer) is greater than 1, preferably greater than about 1.2, more preferably greater than about 1.4, and even more preferably greater than about 1.6.

[0035] For example, the polyamide composition may contain from greater than 5% by mass to about 80% by mass of polyamide, preferably from about 10% by mass to about 70% by mass of polyamide, more preferably from about 20% by mass to about 65% by mass of polyamide, and most preferably from 23.95% by mass to less than 63.95% by mass of polyamide, each based on the total mass of the composition.

[0036] The composition of the present invention further comprises a polyolefin and / or a phenyl ether polymer. Thus, the composition may comprise a polyolefin, a phenyl ether polymer, or a mixture thereof. The composition comprises 5% to 30% by weight of a polyolefin, 5% to 30% by weight of a phenyl ether polymer, or a total amount of a polyolefin and a phenyl ether polymer of 5% to 30% by weight.

[0037] Suitable polyolefins are, for example, thermoplastic polyolefins such as polyethylene, polypropylene, polymethylpentene and polybutene-1. Preferred polyolefins are polyethylene and polypropylene, in particular linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and polypropylene (PP).

[0038] Suitable phenyl ether polymers are polymers obtainable by oxidative polymerization of phenolic compounds. Specific examples of phenolic compounds include phenol, o-, m-, or p-cresol, 2,6-, 2,5-, 2,4-, or 3,5-dimethylphenol, 2-methyl-6-phenylphenol, 2,6-diphenylphenol, 2,6-diethylphenol, 2-methyl-6-ethylphenol, and 2,3,5-, 2,3,6-, or 2,4,6-trimethylphenol. These phenolic compounds may also be used as mixtures thereof. Preferred phenyl ether polymers are polyphenyl ether (PPE) and polyphenylene oxide (PPO). The polyphenylene ether family may include those having C1-C4 alkyl substituents at two positions perpendicular to the oxygen ether atom. Exemplary members of this class are: poly(2,6-dimethyl-1,4-phenylene) ether; poly(2,6-diethyl-1,4-phenylene) ether; poly(2-methyl-6-ethyl-1,4-phenylene) ether; poly(2,6-dipropyl-1,4-phenylene) ether; poly(2-ethyl-6-propyl-1,4-phenylene) ether, and the like; most preferably poly(2,6-dimethyl-1,4-phenylene) ether.

[0039] In a preferred embodiment, at least one of the polyolefin / phenyl ether polymers is a semi-crystalline polymer. More preferably, the composition comprises at least one semi-crystalline polyolefin, especially HDPE.

[0040] Compatibilizers are used in the preparation of compositions. As used herein and in the appended claims, the term "compatibilizer" is meant to refer to multifunctional, non-rubber-like compounds and / or polymers that interact with polyolefins or polyphenylene ethers, polyamides, or both chemically, e.g., by grafting, or physically, e.g., by modifying the surface properties of the dispersed phase and / or enhancing its dispersion, to improve the compatibility of the resin mixture.

[0041] As a compatibilizer, the composition of the present invention may contain an ionomer, i.e., a polymer composed of both electrically neutral repeating units and ionizable units covalently bonded to the polymer backbone. The ionizable units may be carboxylic acid groups. Such polymers may be prepared by grafting or copolymerizing carboxyl- or carboxylic anhydride-containing compounds onto the polymer, such as metal-neutralized maleic anhydride-grafted ethylene / α-olefin polymers. Preferred metal cations for these carboxylates include Zn, Li, Mg, and Mn. These polymers are disclosed as "tougheners" in WO 2009 / 073429 A1, the contents of which are hereby incorporated by reference.

[0042] Common examples of ionomers may include polystyrene sulfonate, Nafion®, and Hycar®. Preferred ionomers are copolymers of ethylene and ethylenically unsaturated acids, more preferably copolymers of ethylene and methacrylic acid, especially the ionomer resins available from DuPont under the trade name Surlyn®.

[0043] Examples of various compatibilizers that can be used in phenyl ether polymer-polyamide blends include: a) A polyfunctional compound having in its molecule both (A) at least one carbon-carbon double bond (a) and at least one carboxylic acid, acid halide, anhydride, acid halide anhydride, acid amide, acid ester, imide, amino, or hydroxyl group (b); or (B) both a group (a) represented by the formula -(-OR) (where R is hydrogen or an alkyl, aryl, acyl, or carbonyldioxy group) and at least two groups (b) selected from carboxylic acids, acid halides, acid anhydrides, acid halide anhydrides, acid esters, acid amides, imides, amino, and salts thereof (each of which may be the same or different). Preferred examples of such compounds from the (A) type are maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, and maleimide. Preferred examples of compounds from the (B) type are citric acid, malic acid, and agaric acid, including their various commercially available forms, such as anhydrous and hydrated acids. Illustrative acid esters useful herein include, for example, acetyl citrate, and mono- and / or distearyl citrate; or b) The second class of modifier resins is derived from vinyl aromatic monomers. These include, for example, modified and unmodified polystyrene. A particularly preferred class of polymer resins derived from vinyl aromatic monomers is block copolymers containing monoalkenyl arene blocks and hydrogenated, partially hydrogenated, and unhydrogenated conjugated diene blocks, represented as AB and ABA block copolymers. Typical examples of AB block copolymers include polystyrene-polybutadiene (SBR), polystyrene-polyisoprene, and poly(alpha-methylstyrene)-polybutadiene. Typical examples of triblock copolymers include polystyrene-polybutadiene-polystyrene (SBS), polystyrene-polyisoprene-polystyrene (SIS), poly(alpha-methylstyrene)-polybutadiene-poly(alpha-methylstyrene), and poly(alpha-methylstyrene)-polyisoprene-poly(alpha-methylstyrene). A particularly preferred class of such triblock copolymers is available commercially from Shell as CARIFLEX®, KRATON D® and KRATONG®.

[0044] As a particular category, suitable compatibilizers are resins from vinyl aromatic monomers of type b) copolymerized or grafted with polyfunctional compounds of type a), which may include styrene-maleic anhydride copolymers (SMA), maleic anhydride-grafted SBS block copolymers, and their hydrogenated derivatives, such as SEBS-g-MA.

[0045] In one embodiment, the composition of the present invention comprises a blend of a polyamide and a phenyl ether polymer, wherein the compatibilizer is acetic acid.

[0046] The compositions of the present invention may use one compatibilizer or a mixture of two or more compatibilizers.

[0047] The composition of the present invention contains at least 1% by weight of a compatibilizer. The upper limit of the amount of the compatibilizer is not particularly limited, but generally does not exceed about 20% by weight, preferably about 15% by weight, and more preferably about 10% by weight, based on the total weight of the composition.

[0048] The composition of the present invention further comprises a heat stabilizer. One heat stabilizer or a mixture of two or more heat stabilizers can be employed.

[0049] Heat stabilizers well known in the art for heat stabilization of polyamides can be used effectively.

[0050] The stabilizers used in the compositions are generally selected from the group consisting of copper-containing stabilizers, hindered amine compounds, hindered phenol compounds, and phosphorus compounds.

[0051] Copper-containing stabilizers The stabilizer preferably comprises at least one copper-containing stabilizer, which can be used alone in the composition or in combination with one or more of the other stabilizers described above.

[0052] Copper-containing stabilizers useful in the practice of the present invention may be characterized as comprising a copper compound [Compound (Cu)] and an alkali metal halide [Halide (M)]. More specifically, the copper-containing stabilizer consists essentially of a copper compound [Compound (Cu)] selected from the group consisting of copper(I) oxide, copper(II) oxide, copper(I) salts such as cuprous acetate, cuprous stearate, copper zinc organic complex compounds such as copper acetylacetonate, and cuprous halide; and an alkali metal halide [Halide (M)]. According to certain preferred embodiments, the copper-containing stabilizer consists essentially of a copper halide selected from copper iodide and copper bromide, and an alkali metal halide, preferably selected from the iodides and bromides of lithium, sodium, and potassium.

[0053] A particularly preferred combination is CuI with KI. Another very advantageous combination is a mixture of Cu2O and KBr.

[0054] Preferably, the copper-containing stabilizer consists of a copper compound [compound (Cu)], preferably in the oxidation state +I, and an alkali metal halide [halide (M)], where the atomic weight ratio of Cu:halide, i.e., the mass ratio of the total copper content of compound (Cu) to the total halogen content of halide (M) and, optionally, compound (Cu) (if the latter contains halogen), is between 1:99 and 30:70, preferably between 5:95 and 20:80. A Cu:halide mass ratio of about 0.15 (i.e., equivalent to about 13:87) has proven particularly effective.

[0055] The total amount of the compound (Cu) and the halide (M) in the composition, i.e., the amount of the copper-containing stabilizer, is about 0.05 to about 3 mass %, preferably about 0.05 to about 2.5 mass %, and more preferably about 0.1 to about 1.5 mass %, based on the total mass of the composition.

[0056] The amount of compound (Cu) in the copper-containing stabilizer is generally sufficient to provide a level of copper in the composition of from about 25 to about 1000 ppm, preferably from about 50 to about 500 ppm, and more preferably from about 75 to about 150 ppm. The amount of alkali metal halide (halide (M)) associated with the copper-containing stabilizer is generally sufficient to provide a level of copper in the composition of from about 100 to 4000 ppm, preferably from about 300 to about 2000 ppm, and more preferably from about 500 to about 1500 ppm.

[0057] Hindered Amine Compounds The expression "hindered amine compound" is used according to its conventional meaning in the art and is generally intended to denote derivatives of 2,2,6,6-tetramethylpiperidine, which are well known in the art (see, for example, Plastics Additives Handbook, 5th Edition, Hanser, 2001). The hindered amine compounds of the compositions according to the invention may be of either low or high molecular weight.

[0058] Low molecular weight hindered amine compounds typically have a molecular weight of at most 900 g / mol, preferably at most 800 g / mol, more preferably at most 700 g / mol, even more preferably at most 600 g / mol, and most preferably at most 500 g / mol.

[0059] High molecular weight hindered amine compounds are typically polymeric and typically have a molecular weight of at least 1000 g / mol, preferably at least 1100 g / mol, more preferably at least 1200 g / mol, even more preferably at least 1300 g / mol, and most preferably at least 1400 g / mol.

[0060] If used, the hindered amine compound is typically present in an amount advantageously of at least 0.05 wt. %, more preferably at least 0.07 wt. %, and even more preferably at least 0.1 wt. %, based on the total weight of the composition.

[0061] Similarly, when present, the hindered amine compound is also typically present in an amount advantageously up to 1% by weight, based on the total weight of the composition.

[0062] Hindered phenol compounds The expression "hindered phenol compound" is used in accordance with its conventional meaning in the art and is intended to generally refer to derivatives of ortho-substituted phenols well known in the art, particularly (but not limited to) di-tert-butyl-phenol derivatives.

[0063] If used, the hindered phenol compound is typically present in an amount advantageously of at least 0.05 wt. %, more preferably at least 0.07 wt. %, and even more preferably at least 0.1 wt. %, based on the total weight of the composition.

[0064] Similarly, when present, the hindered phenol compound is also typically present in an amount advantageously up to 1% by weight, based on the total weight of the composition.

[0065] phosphorus compounds The stabilizer may be at least one phosphorus compound selected from the group consisting of alkali or alkaline earth metal hypophosphites, phosphites, phosphonites, and mixtures thereof.

[0066] Sodium hypophosphite and calcium hypophosphite are preferred alkali metal or alkaline earth metal hypophosphites.

[0067] Phosphites can be represented by the formula P(OR)3, and phosphonites can be represented by the formula P(OR)2R, where each R can be the same or different and is typically independently selected from the group consisting of a C1-20 alkyl, C3-22 alkenyl, C6-40 cycloalkyl, C7-40 cycloalkylene, aryl, alkaryl, or arylalkyl moiety.

[0068] When used in the composition, the phosphorus compound is preferably present in an amount of at least 0.05 wt. %, more preferably at least 0.07 wt. %, based on the total weight of the composition.

[0069] The phosphorus compound is also preferably present in an amount of at most 1 wt. %, more preferably at most 0.5 wt. %, and even more preferably at most 0.25 wt. %, based on the total weight of the composition.

[0070] In one embodiment, the polyamide composition according to the invention further comprises a filler. In the context of the present invention, the term "filler" includes "reinforcing materials" such as fibers.

[0071] The composition comprises from greater than 30% to 70% by weight, preferably from 31% (e.g., 32%, 33%, or 34%) to 70% by weight, more preferably from 35% to 70% by weight, and even more preferably from 40% to 70% by weight of filler, each based on the total weight of the composition.

[0072] The composition may contain one filler or a mixture of two or more fillers.

[0073] The filler may be any reinforcing agent, but is preferably selected from the group consisting of calcium carbonate, glass fiber, glass flake, glass beads, carbon fiber, talc, mica, wollastonite, calcined clay, kaolin, diatomaceous earth, magnesium sulfate, magnesium silicate, barium sulfate, titanium dioxide, sodium aluminum carbonate, barium ferrite, and potassium titanate.

[0074] Therefore, in terms of morphology, the filler can be selected from fibrous fillers and particulate fillers.

[0075] Preferably, the filler is selected from fibrous fillers. Among fibrous fillers, glass fibers are preferred. These include chopped strand A-, E-, C-, D-, S-, and R-glass fibers. Glass fibers with circular and noncircular cross sections can be used. In this specification, the expression "glass fiber with a noncircular cross section" is used in its usual sense, i.e., to refer to a glass fiber having a cross section with a major axis perpendicular to the longitudinal direction of the glass fiber and corresponding to the longest linear distance of the cross section, and a minor axis corresponding to the linear distance of the cross section perpendicular to the major axis. The noncircular cross section of the fiber may have various shapes, including cocoon-shaped, rectangular, elliptical, polygonal, and oval shapes; this list is not exhaustive. The ratio of the length of the major axis to the minor axis of the cross section is preferably between about 1.5:1 and about 6:1, more preferably between about 2:1 and about 5:1, and even more preferably between about 3:1 and about 4:1.

[0076] In a preferred embodiment, glass fibers, more particularly glass fibers of circular cross section, are used as fillers.

[0077] In one embodiment, the polyamide composition comprises the following, each of which is based on the total weight of the polyamide composition: i) 23.95% by mass to less than 63.95% by mass of polyamide; ii) 5% to 20% by weight of polyolefin and / or phenyl ether polymer; iii) 1% to 10% by weight of a compatibilizer; iv) 0.05% to 1% by weight of a heat stabilizer, and v) More than 30% to 70% by mass of filler Includes:

[0078] The composition may include other conventional additives commonly used in the art, including lubricants, plasticizers, colorants, pigments, antistatic agents, flame retardants, nucleating agents, catalysts, etc. When present, these components are present in amounts of up to 20% by weight, preferably up to 10% by weight, and more preferably up to 8% by weight, based on the total weight of the composition. Typical amounts will depend on the particular conventional additives selected for incorporation into the composition and will be selected according to common sense by one of ordinary skill in the art.

[0079] In one embodiment, the polyamide composition of the present invention does not contain any flame retardants.

[0080] The polyamide composition of the present invention may contain one or more other polymers, for example thermoplastic polymers, especially phenol-carbonyl condensates such as novolacs, ABS or polyesters.

[0081] The inventors have found that by mixing an aliphatic, cycloaliphatic or semi-aromatic polyamide having a total C / CONH ratio of more than 6 with a polyolefin and / or a phenyl ether polymer, the release of substances in hot water from the composition thus obtained is reduced. In this respect, hot water is considered to be water having a temperature of about 60° C., preferably 60±2° C. This water is preferably potable water, in particular water intended for human consumption.

[0082] "Reduced release of substances into hot water" is to be understood as a reduction in substances, especially organic substances, that migrate from the polyamide composition into water. The term "reduced" in this context should be understood so that the amount of substances, especially organic substances, that migrate into water from the polyamide composition of the present invention is reduced compared to the migration of the same substances into water from the same composition that does not contain polyolefin and / or phenyl ether polymer.

[0083] The amount of substances that migrate from a composition into water can be assessed according to the "Guideline for the Hygienic Assessment of Organic Substances in Contact with Drinking Water" (KTW Guideline), published by the German Federal Environment Agency (Umweltbundesamt) "For Man and the Environment" on October 7, 2008. Relevant substances refer specifically to organic substances. These can be measured by determining the total organic carbon (TOC) in a given water sample. TOC can be determined according to DIN EN 1484. According to the Guideline for the Hygienic Assessment of Organic Substances in Contact with Drinking Water (KTW Guideline), the TOC of a given polymer composition must be less than 0.5 mg / L to pass the test described in the guideline.

[0084] In one embodiment, the compositions of the present invention have a TOC according to DIN 1484 of less than 0.5 mg / l as described in the "Guidelines for the Hygienic Assessment of Organic Substances in Contact with Drinking Water" (KTW guidelines), edited and published October 7, 2008, by the German Federal Environment Agency (Umweltbundesamt) "For Man and the Environment."

[0085] A further aspect of the present invention relates to the problem that, given the temperatures encountered in hot water applications, it is difficult to find formulations, especially those based on conventional polyamides, that have good resistance to oxidizing agents naturally present in water, such as dissolved oxygen (O), or to oxidizing agents added to drinking water for the purpose of sterilizing microorganisms (e.g., Cl, NaOCl, HClO, ClO, HO, O, etc.). Surprisingly, the inventors have found that by blending an aliphatic, cycloaliphatic, or semi-aromatic polyamide having a total C / CONH ratio greater than 6 with a polyolefin and / or a phenyl ether polymer, the resistance of the composition to oxidizing agents, such as hydroxides, can be increased. The term "enhance" in this context is understood to mean that the resistance of the composition according to the invention to oxidizing agents is increased compared to the resistance of the same composition without the polyolefin and / or phenyl ether polymer to oxidizing agents.

[0086] Furthermore, the present invention therefore relates to a method for reducing the release of substances in hot water from a composition comprising an aliphatic, cycloaliphatic or semi-aromatic polyamide having an overall C / CONH ratio greater than 6 and / or for increasing the resistance of said composition to oxidizing agents, said method comprising the step of blending the polyamide with a polyolefin and / or a phenyl ether polymer.

[0087] As used herein, the term "oxidizing agent resistance" refers to the retention of mechanical properties and surface appearance of a polyamide composition after exposure to oxidizing agents, such as diatomic halogens, halogen radicals, halogen oxides, halogen amines and / or halogen oxoanion salts or their precursors, oxygen, oxygen radicals, peroxides, hydroperoxides and their radicals, ozone, etc. It also relates to resistance to dimensional changes due to erosion of material from the surface, water contamination from eroded products, increased surface roughness that affects flow properties and promotes bacterial growth, and discoloration. It also relates to improved retention of tensile strength of the polyamide composition.

[0088] Oxidizing agents refer to substances that have the ability to oxidize other substances, causing them to lose electrons. In the context of polyamides, oxidizing agents typically cause oxidation and breakage of polyamide chains, loss of mechanical properties, and significant deterioration of the surface appearance of polyamide articles.

[0089] A halogen-containing oxidizing agent refers to an oxidizing agent that contains at least one halogen atom.

[0090] Precursor is intended to mean a molecule which, when in contact with a polyamide, is capable of generating, inside or outside the polyamide matrix, diatomic halogens, halogen radicals, halogen oxides, halogen amines and / or halogen oxoanion salts, in particular by disproportionation reactions.

[0091] The halogen-containing oxidizing agent can be organic or inorganic.

[0092] Diatomic halogens are in particular I2, Br2 and Cl2. Precursors of diatomic halogens are in particular their ionic salts, such as NaCl, NaBr, NaI.

[0093] The halogen radical may be a fluorine radical, a chlorine radical, a bromine radical, or an iodine radical. The radical may also be a halogen oxide radical, such as FO * , CIO * , BrO * or IO * It may exist as a halide radical (ClO3 * , BrO3 or IO3 * ), or chlorine dioxide, bromine dioxide or iodine dioxide radicals.

[0094] Halogen oxides are in particular ClO2, BrO2, IO2, and I2O5. Precursors of halogen oxides are in particular hypohalogenites and the corresponding diatomic halogens.

[0095] The halogen oxoanion salts are in particular - Perhalogenates (oxidation state +7): e.g., perchlorate (ClO - 4), perbromate (BrO - 4), and periodate (IO - 4); - Halides (oxidation state +5): e.g., chlorate (ClO - 3), bromate (BrO - 3), and iodate (IO - 3) - Halogens (oxidation state +3): e.g., chlorite (ClO - 2), and bromite (BrO - 2) - Hypohalites (oxidation state +1): e.g., hypochlorite (ClO - ), and hypobromite (BrO - ) is selected from the group consisting of:

[0096] Preferably, the halogen oxoanion salt is an alkali metal halogen oxoanion salt, where the alkali metal is a chemical element found in Group 1 of the periodic table. Alkali metals include lithium, sodium, potassium, rubidium, cesium, and francium. The halogen oxoanion salt may also be an alkaline earth metal halogen oxoanion salt, where the alkaline earth metal is a chemical element found in Group 2 of the periodic table, such as calcium.

[0097] More preferably, the present invention aims to increase resistance to sodium hypochlorite and Cl2.

[0098] Precursors of halogen oxoanion salts are, in particular, diatomic halogens reacted with metal hydroxide solutions. Sodium hypochlorite may be formed from the decomposition of chloramines in aqueous media.

[0099] The halogen-containing oxidizing agent may also be selected from halogen amines such as monochloroamine, dichloroamine, trichloroamine or organic chloroamines such as N-chlorotosylamide (chloramine-T).

[0100] The halogen-containing oxidizing agent may in particular be a bleaching agent having cleaning and / or disinfecting properties.

[0101] Non-halogen-containing oxidizing agents may be, for example, oxygen (O2), peroxides, hydroperoxides, ozone, and radicals thereof.

[0102] The mixing of at least one polyamide with at least one polyolefin and / or phenyl ether polymer may, for example, be carried out according to several methods, such as the following: - dry mixing, especially in a mechanical mixer, of at least one polyamide with at least one polyolefin and / or phenyl ether polymer, followed by melting the solid mixture, for example by an extrusion process; - mixing in the molten state at least one polyamide with at least one polyolefin and / or phenyl ether polymer, in particular by melt compounding during the process of extrusion of the polyamide. Other melt compounding methods can also be used, such as batch mixing in a bladenard machine or on a two-roll mill; - mixing at least one polyamide with at least one polyolefin and / or phenyl ether polymer in a solvent medium; - dry mixing at least one polyamide and at least one polyolefin and / or phenyl ether polymer in the form of fine powders and consolidating them into a single part by melt compression molding.

[0103] The polyamide composition according to the invention comprising polyolefin and / or phenyl ether polymer is used in particular as a matrix, in particular via granulation, calendering, injection, molding, injection moulding or pressing.

[0104] Thus, it is possible to prepare all spherical, flat or ovoid granules, chips, pellets, ingots, for example in the form of droplets, prisms, parallelepipeds, cylinders or pads.

[0105] In particular, when the material is in the form of substantially spherical or ellipsoidal pellets, they can be prepared by an underwater cutting process, as described, for example, in patents US 2918701 and US 3749539, or in patent application US 2005 / 0035483. This process uses a die head with holes to provide a molten thermoplastic matrix containing the filler and, optionally, one or more additives. The underwater die head is equipped with a rotating knife holder, the blades of which cut the molten material exiting the die holes, and the formed pellets can be rapidly cooled by a water bath in which the cutting head is immersed.

[0106] In a further embodiment, the present invention relates to the use of polyolefin and / or phenyl ether polymers to reduce the release of substances in hot water from and / or increase the resistance of compositions comprising aliphatic, cycloaliphatic, or semi-aromatic polyamides having a total C / CONH ratio greater than 6 to oxidizing agents.

[0107] In a further embodiment, the present invention provides a method for reducing the release of substances from an article in hot water and / or increasing resistance to oxidizing agents, comprising: i) aliphatic, cycloaliphatic or semi-aromatic polyamides having an overall C / CONH ratio greater than 6, and ii) polyolefin and / or phenyl ether polymers; The present invention relates to a method of using a polyamide comprising the steps of:

[0108] In this method of use, the polyamide composition is preferably as defined above.

[0109] The composition according to the invention can be used as a raw material in the field of plastics processing, for example, for the preparation of articles obtained by injection molding, injection / blow molding, extrusion molding, or extrusion / blow molding. According to a typical embodiment, the polyamide composition is extruded in the form of a rod, for example in a twin-screw extrusion device, and then cut into granules. Molded parts can be prepared by melting the granules produced above and feeding the molten composition into an injection molding device.

[0110] Thus, the present invention provides a method for hot water applications, preferably hot drinking water applications, comprising: i) aliphatic, cycloaliphatic or semi-aromatic polyamides having an overall C / CONH ratio greater than 6, and ii) polyolefin and / or phenyl ether polymers; The present invention also relates to a method of using an article comprising a polyamide composition comprising:

[0111] In this method of use, the polyamide composition is preferably as defined above.

[0112] Furthermore, the present invention relates to an article comprising the polyamide composition defined above. The article may have a shape that allows it to contain, store and / or transport a liquid, in particular water, such as drinking water. The article may be a semi-finished or finished product. The article may comprise or consist of the polyamide of the present invention. If the article comprises the polyamide composition, it may, for example, be coated with the polyamide composition, or part of the article may be made of the polyamide composition.

[0113] Articles according to the present invention include liquid metering devices, drums, pumps, pipes, plumbing joints / connectors, valves, containers, reservoirs, tanks, vessels, bottles, boxes, hoses, ducts and tubes, such as cooling tubes, cooling water housings, engine air guide hoses, oil circuit hoses, etc. The articles may be, for example, metering devices, drums, pumps, pipes, containers, reservoirs, tanks, vessels, bottles, boxes, hoses, ducts and tubes.

[0114] Preferably, these articles are made from the above compositions by injection molding, extrusion or blow molding.

[0115] The following examples are given by way of non-limiting illustration of the invention and variations thereof which are readily available to those skilled in the art. [Example]

[0116] Raw materials: Polyamide PA-6,10 (Solvay, Stabamid® 28CE2 or NEXIS T7005) Polyamide PA-6,6 (Solvay, Stabamid® 27AE1) - HDPE Rigidex HD 5218 EA-Y(INEOS) - Surlyn® 1652E (DuPont) - Glass fiber (PPG Industries, Grade HP3610) - Plasblak PE 2813 (CABOT) was used as the pigment - Heat stabilizer package: Lunanox 1098 (DKSH France), sodium hypophosphite monohydrate (Altichem) and aluminium stearate (FACI) in the ratios 55% / 18% / 27% by weight.

[0117] Sample preparation The compositions were melt-blended using a twin-screw extruder (Coperion, ZSK-26 MC+, 10 barrels, L / D 39). Glass fiber was added to the composition through the fourth barrel of the extruder. The rods exiting the extruder were cut and dried in an oven at 80°C under vacuum for 24 hours to obtain pellets. Table 1 shows the compositions of the tested formulations (% is by weight).

[0118] [Table 1]

[0119] The pellets were molded in an injection molding machine DEMAG® 50T at 250°C for the compounds based on PA6.10 and 290°C for the compounds based on PA6.6 at a mold temperature of 85°C to prepare standard 4 mm thick bars (tensile specimens ISO 527) and 2 mm thick plates with the following dimensions: 100 mm x 100 mm.

[0120] Potable Hot Water Certification Test: The plates were tested according to the KTW guidelines for hot water (60°C). The plates were pretreated with tap water and test water and then subjected to seven transfer steps at 60°C. The final transfer water (seventh transfer) was used for the determination of total organic carbon (TOC) according to DIN EN 1484. To pass this test, the TOC must be less than or equal to 0.5 mg / l. The results are shown in Table 2.

[0121] [Table 2]

[0122] Table 2 shows that only Example 1 has a TOC value significantly below 0.5 mg / l.

[0123] Chlorine resistance test: Injection-molded tensile bars were exposed to a sodium hypochlorite solution containing 5 ppm chlorine at pH 7 and 50°C for 2500 hours. These measurements were performed on a test bench designed for chlorine aging. The specimens were immersed in a large tank through which chlorine water was circulating. The pH and chlorine content were constantly adjusted during aging. The specimens were recovered at 250, 500, 1500, and 2500 hours, rinsed smoothly with tap water, and left at 23°C (50% relative humidity) for 24 hours before being characterized. Table 3 summarizes all ISO 527 / 1A tensile results at 23°C and the mass change from the initial state.

[0124] [Table 3]

[0125] Table 3 shows that the composition of Example 1 of the present invention withstands degradation up to 2500 hours, while the comparative compositions experience degradation in tensile strain at break from 500 hours, or finally from 1500 hours for Comparative Example 2. Furthermore, the comparative compositions exhibit mass loss from 1500 hours, while the composition of Example 1 still has a positive mass change at 2500 hours.

Claims

1. 1. A polyamide composition, each of the following based on the total weight of the polyamide composition: i) from 23.95% by weight to less than 63.95% by weight of an aliphatic or semi-aromatic polyamide having a total C / CONH ratio greater than 6 selected from the group consisting of polyamide 11, polyamide 12, polyamide 6.10, polyamide 6.12, polyamide 4.10, polyamide 6.6 / 6.T, polyamide 10.10, polyamide 6.18, and mixtures thereof; ii) 5% to 20% by weight of a polyolefin; iii) 1% to 10% by weight of an ionomer as a compatibilizer; iv) 0.05% to 1% by weight of a heat stabilizer, and v) More than 30% to 70% by mass of filler 1. A polyamide composition comprising:

2. 2. The polyamide composition of claim 1, wherein the polyamide has an overall C / CONH ratio of 12 or less.

3. 3. The polyamide composition according to claim 1, wherein the filler is a fibrous filler.

4. 4. The polyamide composition according to any one of claims 1 to 3, wherein the polyolefin is selected from the group consisting of linear low density polyethylene (LLDPE), high density polyethylene (HDPE), polypropylene (PP), and mixtures thereof.

5. i) from 23.95% by weight to less than 63.95% by weight of an aliphatic or semi-aromatic polyamide having a total C / CONH ratio greater than 6 selected from the group consisting of polyamide 11, polyamide 12, polyamide 6.10, polyamide 6.12, polyamide 4.10, polyamide 6.6 / 6.T, polyamide 10.10, polyamide 6.18, and mixtures thereof; ii) 5% to 20% by weight of a polyolefin; iii) 1% to 10% by weight of an ionomer as a compatibilizer; iv) 0.05% to 1% by weight of a heat stabilizer, and v) A method for reducing release of substances in hot water having a temperature of about 60°C from a composition comprising greater than 30% to 70% by weight of a filler (each of the above based on the total weight of the composition) and / or increasing the resistance of the composition to oxidizing agents, the method comprising the step of blending the polyamide with a polyolefin.

6. i) from 23.95% by weight to less than 63.95% by weight of an aliphatic or semi-aromatic polyamide having a total C / CONH ratio greater than 6 selected from the group consisting of polyamide 11, polyamide 12, polyamide 6.10, polyamide 6.12, polyamide 4.10, polyamide 6.6 / 6.T, polyamide 10.10, polyamide 6.18, and mixtures thereof; ii) 5% to 20% by weight of a polyolefin; iii) 1% to 10% by weight of an ionomer as a compatibilizer; iv) 0.05% to 1% by weight of a heat stabilizer, and v) A method of using an article that comes into contact with hot water having a temperature of about 60°C, the article comprising a polyamide composition that includes more than 30% to 70% by weight of a filler, each of the above being based on the total weight of the composition.

7. 7. The use according to claim 6, wherein the polyamide composition is the polyamide composition according to any one of claims 2 to 4.

8. An article comprising the polyamide composition of any one of claims 1 to 4.

9. To prepare an article for contact with hot water having a temperature of about 60°C, i) aliphatic or semi-aromatic polyamides having a total C / CONH ratio greater than 6 selected from the group consisting of polyamide 11, polyamide 12, polyamide 6.10, polyamide 6.12, polyamide 4.10, polyamide 6.6 / 6.T, polyamide 10.10, polyamide 6.18, and mixtures thereof; ii) 5% to 30% by weight of a polyolefin; iii) 1% to 10% by weight of an ionomer as a compatibilizer; iv) 0.05% to 1% by weight of a heat stabilizer, and v) A method using a polyamide composition comprising greater than 30% to 70% by weight of a filler, each of the above being based on the total weight of the composition.

10. 10. The use according to claim 9, wherein the polyamide composition is the polyamide composition according to any one of claims 1 to 4.

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