WO2013017674A1

WO2013017674A1 - Polyamide composition

Info

Publication number: WO2013017674A1
Application number: PCT/EP2012/065195
Authority: WO
Inventors: Nancy J. Singletary; Corinne Bushelman
Original assignee: Solvay Specialty Polymers Usa, Llc
Priority date: 2011-08-04
Filing date: 2012-08-02
Publication date: 2013-02-07

Abstract

The invention pertains to a composition made from an aromatic polyamide comprising recurring units derived from at least one naphthalene dicarboxylic acid and a diamine component comprising at least one aliphatic alkylene-diamine wherein said polyamide comprises at least one end capping agent and in an overall amount of 2.7 to 6 % moles. The invention further relates to the use of such composition for manufacturing shaped articles, including lighting apparatus, including LED, and more particularly power LEDs.

Description

Polyamide composition

This application claims priority to U.S. provisional application No. 61/515017 filed August 04, 2011 and to European application No. 11183498.2 filed on September 30, 2011, the whole content of each of these applications being incorporated herein by reference for all purposes.

Technical Field

The invention pertains to an aromatic polyamide comprising at least one polyamide having recurring units derived from at least one naphthalene dicarboxylic acid and at least one diamine, to a composition comprising the same in combination with a reinforcing filler and a white pigment, to the use of this latter for manufacturing shaped articles, and to shaped articles there from, including components of light emitting apparatuses, e.g. LED assemblies.

Background Art

Light emitting diode (LED) components, such as housings, reflectors, reflector cups, heatsink slugs, require an especially demanding combination of excellent colour and improved physical properties, so as to ensure good opacity and outstanding reflective properties both after high temperature processing and soldering conditions (during LED assembly manufacture) and after prolonged exposure to heat and radiation, such as those of continuous LED operations. This is particularly true for LED assemblies of new generations, adapted to higher conductive power dissipations, necessitating, notably, the use of a central heat-conducting slug in packages. While ceramics might be used for manufacturing above mentioned components, their inherent cost and highly demanding processing technologies have called for alternative materials. Therefore, plastics have been extensively studied and developed to this aim.

Aromatic polyamide-based compositions comprising appropriate reinforcing and pigment ingredients, generally titanium dioxide, are thus attracting great attention as useful raw materials for such LED components, exhibiting superior properties for moulding, providing moulded parts having thermal stability, including dimensional stability and retention of mechanical properties, during fabrication and end use, and suitably retaining whiteness and reflectivity during processing and end use. Among said aromatic polyamides, those comprising recurring units derived from at least one naphthalene dicarboxylic acid (NDA) and at least one diamine are considered as promising candidates.

On the other side, compounds based on said NDA-containing polyamides and comprising certain additives and pigments are known in the art.

Thus,

US

4012365

TEIJIN LTD 19770315

discloses transparent amorphous co-polyamide prepared by polycondensation reaction of:
(A) 2,7-naphthalene dicarboxylic acid (NDA) (or derivative thereof);
(B) a straight chain aliphatic diamine comprising 4 to 13 carbon atoms;
(C) a copolymer component derived from at least one of (i) an acid different from NDA and (ii) diamine components different from (B). Said co-polyamide might be added of pigments, such as titanium dioxide.

US

5362846

ELF ATOCHEM 19941108

discloses certain copolyamides comprising recurring units derived from terephthalic acid and naphthalene dicarboxylic acid in combination with an aliphatic diamine having 4 to 20 carbon atoms. Said copolyamides might be added of conventional additives, such as notably colouring agents, optical brighteners, and the like; further, they may be used in compositions comprising fillers, preferably glass fibers.

JP

2005170964

NAT INST OF ADV IND & TECHNOL 20050630

discloses a polyamide copolymer comprising recurring units derived from terephthalic acid in combination with recurring units derived from a naphthalene dicarboxylic acid, and recurring units derived from an aliphatic diamine (typically hexamethylene diamine). The above mentioned copolyamide is used in a composition further comprising, inter alia, a reinforcing filler (typically glass fibers) and other auxiliaries intended for fire resistance.

Finally,

WO

WO 2010/139369

EMS PATENT AG 20101209

discloses reinforced polyamide moulding compositions comprising a semi-crystalline polyamide comprising recurring units derived from terephthalic acid (TA) and from a diamine and a filling and reinforcing agent. The TA can be replaced by using a diacid different from TA; among said diacids, NDA is mentioned. Reinforcing filler can be under the form of fibres or particulates; fibrous fillers being preferably glass fibres, in particular those with non-circular section; particulate fillers being preferably based on titanium dioxide or wollastonite. Fibrous fillers and particulate fillers can be used in admixture. Compositions as above described are taught as suitable for the manufacture of LED housing components.

Nevertheless, there is a continuous need for polymer compositions suitable to be used for manufacturing LED components, possessing improved performances, including, notably, higher reflectance of light (in general, of visible light), higher whiteness, both initial and after thermal aging, while maintaining good processability (e.g. good moldability), high dimensional stability (notably low coefficient of linear expansion), high mechanical strength, high heat deflection temperature and high heat resistance (low discoloration and low loss of reflectance when exposed to a high temperature e.g. by means of soldering and the like).

Summary of invention

The Applicant has now found that certain polyamides comprising recurring units derived from at least one naphthalene dicarboxylic acid and at least one diamine and having well-defined amount of monocarboxylic acid end capping units are particularly advantageous when compounded with specific ingredients to provide polymer compounds particularly effective in fulfilling above mentioned requirements.

The invention thus pertains to an aromatic polyamide composition [composition (C)] comprising:
(i) at least one polyamide [polyamide (A)] comprising recurring units derived from:
(i-1) a dicarboxylic acid component [acid component (AA)], wherein said acid component (AA) comprises at least one naphthalene dicarboxylic acid or derivative thereof [acid (NDA)] and, optionally, at least one acid comprising only one reactive carboxylic acid group [acid (MA)]; and
(i-2) a diamine component [amine component (NN)] comprising at least one aliphatic alkylene-diamine and, optionally, at least one amine comprising only one reactive amine group [agent (MN)],
wherein said polyamide (A) comprises at least one end capping agent [agent (M)] selected from the group of said acid (MA) and said amine (MN) in at least one of said acid component (AA) and amine component (NN), and wherein the and wherein the overall amount of agent (M) in the polyamide (A), computed as:

is of 2.7 to 6 % moles.;
(ii) at least one pigment selected from the group consisting of titanium dioxide (TiO₂), zinc disulfide (ZnS₂), zinc oxide (ZnO) and barium sulfate (BaSO₄) [pigment (P)]; and
(iii) at least one reinforcing filler [filler (F)], different from pigment (P).

The Applicant has surprisingly found that the composition (C), thanks to the presence of the particular NDA-containing polyamide, possessing mentioned end capping agent content, when combined with above detailed ingredients, possesses outstanding light reflectance capabilities, both initial and, more importantly, after thermal aging, while maintaining good processability (e.g. good moldability), including the possibility of being processed in relatively smooth conditions (moderated temperatures), as well as all other desirable properties typical of aromatic polyamide compositions.

Brief description of drawings

Figure 1 is a top view LED comprising one or more component made from the composition of the invention.

Figure 2 is a power LED comprising one or more component made from the composition of the invention.

Description of embodiments

The expression ‘derivative thereof' when used in combination with the expression ‘carboxylic acid’ is intended to denote whichever derivative which is susceptible of reacting in polycondensation conditions to yield an amide bond. Examples of amide-forming derivatives include a mono- or di-alkyl ester, such as a mono- or di-methyl, ethyl or propyl ester, of such carboxylic acid; a mono- or di-aryl ester thereof; a mono- or di-acid halide thereof; and a mono-or di-acid amide thereof, a mono- or di-carboxylate salt.

The acid component (AA) and the amine component (NN) are generally comprised in substantially equimolecular amount in the polyamide (A); this means that the molar ratio between the overall number of –COOH groups of the acid component (AA) and the overall number of –NH₂ groups of the amine component (NN) is of 1.1:1 to 0.9:1, preferably of 1.075:1 to 1:0.925.

The acid component (AA) comprises at least one acid (NDA); acid (NDA) comprises two reactive carboxylic acid groups; any of the isomers of acid (NDA) can be advantageously used, including those wherein the two carboxylic acid groups are bound to the same aromatic ring or wherein each of the carboxylic acid groups are bound to each of the naphthalene dicarboxylic acid groups. Also, isomers of naphthalene dicarboxylic acids can be used in admixture.

Non limitative examples of acids (NDA) are notably the 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid,1,4-naphthalene dicarboxylic acid, 1,8-naphthalene dicarboxylic acid.

More particularly, 2,6-naphthalene dicarboxylic acid and 2,7-naphthalene dicarboxylic acid are particularly preferred. A acid (NDA) which has been found to provide particularly good result is 2,6-naphthalene dicarboxylic acid.

The acid component (AA) comprises said at least one acid (NDA) in an amount of at least 20, preferably of at least 25, more preferably of at least 30, still more preferably of at least 35, yet more preferably of at least 40 and most preferably of at least 45 % moles, based on the all components of the acid component (AA).

The acid component (AA) comprises said at least one acid (NDA) in an amount of at most 95, preferably of at most 90, more preferably of at most 85, still more preferably of at most 80, yet more preferably of at most 75, even more preferably of at most 70 and most preferably of at most 65 % moles, based on the all components of the acid component (AA).

The acid component (AA) generally further comprises at least one additional acid component comprising two reactive carboxylic acid groups or derivatives thereof [acid (DA)] different from acid (NDA).

Said acid (DA) different from acid (NDA) can be an aromatic dicarboxylic acid comprising two reactive carboxylic acid groups [acid (AR)] or an aliphatic dicarboxylic acid comprising two reactive carboxylic acid groups [acid (AL)] .

For the purpose of the present invention, a dicarboxylic acid is considered “aromatic” when it comprises one or more than one aromatic group.

Non limitative examples of acids (AR) are notably phthalic acids, including isophthalic acid (IA), and terephthalic acid (TA), 2,5-pyridinedicarboxylic acid, 2,4‑pyridinedicarboxylic acid, 3,5-pyridinedicarboxylic acid, 2,2‑bis(4‑carboxyphenyl)propane, bis(4-carboxyphenyl)methane, 2,2‑bis(4‑carboxyphenyl)hexafluoropropane, 2,2-bis(4-carboxyphenyl)ketone, 4,4’‑bis(4-carboxyphenyl)sulfone, 2,2-bis(3-carboxyphenyl)propane, bis(3‑carboxyphenyl)methane, 2,2-bis(3-carboxyphenyl)hexafluoropropane, 2,2‑bis(3-carboxyphenyl)ketone, bis(3-carboxyphenoxy)benzene.

Among acids (AL), mention can be notably made of oxalic acid (HOOC-COOH), malonic acid (HOOC‑CH₂-COOH), succinic acid [HOOC‑(CH₂)₂-COOH], glutaric acid [HOOC-(CH₂)₃-COOH], 2,2‑dimethyl‑glutaric acid [HOOC‑C(CH₃)₂‑(CH₂)₂‑COOH], adipic acid [HOOC-(CH₂)₄-COOH], 2,4,4‑trimethyl-adipic acid [HOOC‑CH(CH₃)‑CH₂‑C(CH₃)₂– CH₂–COOH], pimelic acid [HOOC‑(CH₂)_5‑COOH], suberic acid [HOOC-(CH₂)₆-COOH], azelaic acid [HOOC-(CH₂)₇-COOH], sebacic acid [HOOC-(CH₂)₈-COOH], undecanedioic acid [HOOC-(CH₂)₉-COOH], dodecandioic acid [HOOC‑(CH₂)₁₀‑COOH], tetradecandioic acid [HOOC-(CH₂)₁₁-COOH].

According to preferred embodiments of the present invention, the acid component (AA) further comprises advantageously at least one phthalic acid selected from the group consisting of isophthalic acid (IA), and terephthalic acid (TA). Isophthalic acid and terephthalic acid can be used alone or in combination. The phthalic acid is preferably terephthalic acid, optionally in combination with isophthalic acid.

The acid component according to this preferred embodiment comprises said phthalic acid in an amount of at least 35 %, preferably at least 50 % moles, based on the all components of the acid component (AA).

The diamine component [amine component (NN)] comprises at least one aliphatic alkylene-diamine.

Said aliphatic alkylene-diamine is typically an aliphatic alkylene diamine having 2 to18 carbon atoms.

Said aliphatic alkylene diamine is advantageously selected from the group consisting of 1,2‑diaminoethane, 1,2-diaminopropane, propylene-1,3-diamine, 1,3‑diaminobutane, 1,4-diaminobutane, 1,5-diaminopentane, 1,4-diamino-1,1-dimethylbutane, 1,4-diamino-1-ethylbutane, 1,4-diamino-1,2-dimethylbutane, 1,4-diamino-1,3-dimethylbutane, 1,4-diamino-1,4-dimethylbutane, 1,4-diamino-2,3-dimethylbutane, 1,2-diamino-1-butylethane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diamino-octane, 1,6-diamino-2,5-dimethylhexane, 1,6-diamino-2,4-dimethylhexane, 1,6-diamino-3,3-dimethylhexane, 1,6-diamino-2,2-dimethylhexane, 1,9-diaminononane, 1,6-diamino-2,2,4-trimethylhexane, 1,6-diamino-2,4,4-trimethylhexane, 1,7-diamino-2,3-dimethylheptane, 1,7-diamino-2,4-dimethylheptane, 1,7-diamino-2,5-dimethylheptane, 1,7-diamino-2,2-dimethylheptane, 1,10-diaminodecane, 1.8-diamino-1,3-dimethyloctane, 1,8-diamino-1,4-dimethyloctane, 1.8-diamino-2,4-dimethyloctane, 1,8-diamino-3,4-dimethyloctane, 1.8-diamino-4,5-dimethyloctane, 1.8-diamino-2,2-dimethyloctane, 1.8-diamino-3,3-dimethyloctane, 1,8-diamino-4,4-dimethyloctane, 1,6-diamino-2,4-diethylhexane, 1,9-diamino-5-methylnonane, 1,11-diaminoundecane and 1,12-diaminododecane.

The amine component (NN) preferably comprises at least one diamine selected from the group consisting of 1,6-diaminohexane, 1,8-diamino-octane, 1,10-diaminodecane, 1,12-diaminododecane and mixtures thereof. More preferably, the amine component (NN) comprises at least one diamine selected from the group consisting of 1,6-diaminohexane, 1,10-diaminodecane and mixtures thereof.

In addition to the at least one aliphatic alkylene-diamine, the amine component (NN) can further comprise at least one diamine different from said aliphatic alkylene-diamine.

Said additional diamine can be notably an aromatic diamine, preferably selected from the group consisting of meta-phenylene diamine, meta-xylylene diamine and para-xylylene diamine.

As said, the polyamide (A) comprises an end capping agent [agent (M)] selected from the group consisting of an acid comprising only one reactive carboxylic acid group [acid (MA)] and an amine comprising only one reactive amine group [agent (MN)].

The expression ‘acid comprising only one reactive carboxylic acid group’ is intended to encompass not only mono-carboxylic acids but also acids comprising more than one carboxylic acid group or derivative thereof, but wherein only one of said carboxylic acid group has reactivity in polycondensation reaction with component (NN).

Among acids comprising more than one carboxylic acid group or derivative thereof wherein only one of said carboxylic acid group has reactivity in polycondensation reaction mention can be notably made of aromatic dicarboxylic acids wherein the carboxylic acid groups are in ortho-position with respect to each other on the same aromatic ring.

It is nevertheless generally preferred that said acid (MA) comprises only one carboxylic acid group.

Thus, acid (MA) is preferably selected from the group consisting of acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, stearic acid, cyclohexanecarboxylic acid, benzoic acid, preferably from acetic acid and benzoic acid.

Similarly, the expression ‘amine comprising only one reactive amine group’ is intended to encompass not only mono-amine but also amines comprising more than one amine group or derivative thereof, but wherein only one of said amine group has reactivity in polycondensation reaction with component (AA).

It is nevertheless generally preferred that said amine (MN) comprises only one amine group.

Thus, amine (MN) is preferably selected from the group consisting of methylamine, ethylamine, butylamine, octylamine, aniline, toluidine.

As said, the overall amount of agent (M) in polymer (A), computed as

is comprised between 2.7 and 6 % moles, being understood that the agent (M) might advantageously be agent (MA) alone, agent (MN) alone or a combination thereof. In other words, in above mentioned formula, the amount of agent (MA) with respect to the total moles of acid component (AA) can be from 0 to 6 % moles, the amount of agent (MN) with respect to the total moles of amine component (NN) can be from 0 to 6 % moles, with the additional provisions that at least one of these amounts is not null, and their sum is of 2.7 to 6 % moles.

The Applicant has surprisingly found that the particular amount of agent (M) used in the NDA-containing polyamide (A) is particularly important for providing a composition (C) by appropriate compounding of the same with suitable ingredients having outstanding whiteness and retaining this property, even after thermal treatment.

Comparative examples have shown that when the agent (M) is not present in said claimed amount in the polyamide (A), the composition (C) fails to provide suitable optical behaviour so that it cannot be advantageously used for LED applications.

The amount of agent (M), as above described, is of at most 6 % moles, preferably at most 5.5 % moles, more preferably at most 5 % moles.

The amount of agent (M), as above described, is of at least 2.7 % moles, preferably at least 2.75 % moles.

According to a preferred embodiment the polyamide (A) comprises recurring units derived from:
(i-1) a dicarboxylic acid component [acid component (AA)], wherein said acid component (AA) comprises at least one naphthalene dicarboxylic acid or derivative thereof [acid (NDA)] and at least one acid comprising only one reactive carboxylic acid group or derivative thereof [acid (MA)], the amount of said acid (MA) in polymer (A) being comprised between 2.7 and 6 % moles, based on the all components of the acid component (AA) ; and
(i-2) a diamine component [amine component (NN)] comprising at least one aliphatic alkylene-diamine.

In this embodiment, the acid component (AA) comprises said at least one acid (MA), in an amount comprised between 2.7 and 6 % moles, based on the all components of the acid component (AA).

The acid component (AA) comprises said at least one acid (MA), in an amount of at most 6 % moles, preferably at most 5.5 % moles, more preferably at most 5 % moles, based on the all components of the acid component (AA).

The acid component (AA) comprises said at least one acid (MA), in an amount of at least 2.7 % moles, preferably at least 2.75 % moles, based on the all components of the acid component (AA).

A first group of preferred polyamides (A) of the present invention are those consisting essentially of recurring units formed by the polycondensation reaction between terephthalic acid, 2,6-naphthalenedicarboxylic acid, benzoic acid and 1,6-diaminohexane, and, optionally isophthalic acid.

A second group of preferred polyamides (A) of the present invention are those consisting essentially of recurring units formed by the polycondensation reaction between terephthalic acid, 2,6-naphthalenedicarboxylic acid, benzoic acid, 1,10‑diaminodecane and 1,6-diaminohexane, and optionally isophthalic acid.

A third group of preferred polyamides (A) suitable for being used in the composition (C) of the present invention are those consisting essentially of recurring units formed by the polycondensation reaction between terephthalic acid, 2,6-naphthalenedicarboxylic acid, benzoic acid,1,10‑diaminodecane, and optionally isophthalic acid.

In certain embodiments, terephthalic acid and isophthalic acid (when present) are advantageously present in an overall amount of about 35-65 mol. %, preferably in about 40‑60 mol. %, and most preferably in about 45-56.25 mol. %, 2,6-naphthalenedicarboxylic acid is advantageously present in about 29-62 mol. %, preferably in about 34.5-56.5 mol. % and most preferably in about 40-50 mol. %, and benzoic acid is present in an amount of 3-6 mol %, preferably of 3.5-5.5 mol %, and most preferably in an amount of 3.75 to 5 mol %, based on al acid components, being understood that when isophthalic acid is present, the ratio terephthalic acid/isophthalic acid is generally comprised from 5:1 to 1:1, preferably 3:1 to 1:1, more preferably 2.5:1 to 1:1.

The composition (C) may comprise one or more than one polyamide (A) as above detailed.

The weight percent of the polyamide (A) in the composition (C) is generally of at least 30 wt. %, preferably of at least 40 wt. %, more preferably of at least 45 wt. %, still more preferably of at least 50 wt. %, and most preferably of at least 55 wt. %, based on the total weight of the composition (C). It is further understood that the weight percent of the polyamide (A) in the composition (C) will generally be of at most 90 wt. %, preferably of at most 80 wt. % and most preferably of at most 60 wt. %, based on the total weight of the composition (C).

Excellent results were obtained when the composition (C) comprised the polyamide (A) in an amount of 40-70 wt. %, preferably of 50-60 wt. %, based on the total weight of the composition (C).

Reinforcing fillers [fillers (F)] which are suitable to be used in the composition (C) of the invention are well known by the skilled in the art.

Having regards to its morphology, the filler (F) of the composition (C) is generally selected from the group consisting of fibrous fillers and particulate fillers.

Typically, the filler (F) is selected from the group consisting of mineral fillers (such as talc, mica, kaolin, calcium carbonate, calcium silicate, magnesium carbonate), glass fibers, carbon fibers, synthetic polymeric fibers, aramid fibers, aluminum fibers, titanium fibers, magnesium fibers, boron carbide fibers, rock wool fibers, steel fibers, wollastonite, inorganic whiskers. Still more preferably, it is selected from mica, kaolin, calcium silicate, magnesium carbonate, inorganic whiskers, glass fiber and wollastonite.

A particular class of fibrous fillers which are advantageously usable in the composition (C) consists of whiskers, i.e. single crystal fibers made from various raw materials, such as Al₂O₃, SiC, BC, Fe and Ni.

According to certain preferred embodiments, the filler (F) is selected from the group consisting of fibrous fillers. Among fibrous fillers, glass fibers are preferred; non limitative examples of glass fibers include notably chopped strand A-, E-, C-, D-, S- and R-glass fibers, as described in chapter 5.2.3, p. 43-48 of Additives for Plastics Handbook, 2nd edition, John Murphy, the whole content of which is herein incorporated by reference. Glass fibers fillers useful in composition (C) may have a round cross-section or a non-circular cross-section.

In a preferred embodiment of the present invention, the filler (F) is selected from the group consisting of wollastonite fillers and glass fiber fillers. Excellent results were obtained when wollastonite and/or glass fibers were used.

The weight percent of the filler (F) in the composition (C) is generally of at least 5 wt. %, preferably of at least 10 wt. %, more preferably of at least 15 wt. % and most preferably of at least 20 wt. %, based on the total weight of composition (C). The weight percent of the filler (F) is generally of at most 50 wt. %, preferably of at most 40 wt. % and most preferably of at most 30 wt. %, based on the total weight of the composition (C).

Excellent results were obtained when the filler (F) was used in an amount of 10-40 wt. %, preferably of 20-30 wt. %, based on the total weight of the composition (C).

Above mentioned fillers are typically known as white pigments, in that they absorb limited incident visible radiation and scatter most of said incident visible radiation. Otherwise stated, the pigments (P) used in the composition (C) generally absorb essentially no light in the visible region (wavelength 400 - 800 nm), but disperse incident radiation in this region as completely as possible.

The pigment (P) is selected from the group consisting of titanium dioxide (TiO₂), zinc disulfide (ZnS₂), zinc oxide (ZnO) and barium sulfate (BaSO₄).

The pigment (P) is advantageously present in the composition (C) under the form of particles having an average particle size (APS) of generally less than 250 µm, preferably less than 100 µm, more preferably of less than 5 µm. Larger sizes may deleteriously affect the properties of the composition.

While pigments (P) having larger APS can be used, these pigments (P) are less advantageous, in that they might impair other relevant properties (e.g. mechanical properties) of the composition (C).

Preferably, the APS of the pigment (P) is of below 1 µm. While lower boundaries for APS of pigment (P) are not particularly critical, it is generally understood that pigment (P) will have an APS of at least 0.1 µm.

The shape of the particles is not particularly limited; they may be notably round, flaky, flat and so on.

The pigment (P) is preferably titanium dioxide.

The nature of the titanium dioxide pigment is not particularly limited, and a variety of crystalline forms such as the anatase form, the rutile form and the monoclinic type can be advantageously used. However, the rutile form is generally preferred due its higher refraction index and its superior light stability. Titanium dioxide pigment may be treated on its surface with at least one treatment agent, even if embodiments wherein titanium dioxide pigments have no surface treatment are also suitable. Preferably the APS of the titanium oxide pigment is in the range of 0.15 µm to 0.35 µm.

The weight percent of the pigment (P) in the composition (C) is generally of at least 1 wt. %, preferably of at least 6 wt. %, more preferably of at least 8 wt. % and most preferably of at least 15 wt. %, based on the total weight of the composition (C). Besides, the weight percent of the pigment (P) is generally of at most 50 wt. %, preferably of at most 40 wt. %, more preferably of at most 30 wt. % and most preferably of at most 30 wt. %, based on the total weight of the composition (C).

Excellent results were obtained when the pigment (P) was used in an amount of 10-30 wt. %, preferably of 15-25 wt. %, based on the total weight of the composition (C).

Optional ingredients

The composition (C) can optionally comprise additional components such as stabilizing additive, notably mould release agents, plasticizers, lubricants, thermal stabilizers, light stabilizers and antioxidants etc.

The composition (C) advantageously further comprises at least a stabilizing additive. The stabilizing additive may be present in an amount of 1 to 10 wt. %, based on the total weight of the composition (C).

The levels of these optional additives will be determined for the particular use envisioned, with generally up to 20 wt. %, preferably up to 10 wt. %, more preferably up to 5 wt. % and still more preferably up to 2 wt. % (based on the total weight of the polymer composition) of such additional additives considered to be within the range of ordinary practice in the extrusion art.

Certain stabilizers such as hindered amine light stabilizers (HALS) may be present in the composition. For example one or more of the group of hindered amines selected from the group bis(2,2,6,6- tetramethylpiperidin-4-yl)sebacate, bis(l,2,2,6,6-pentamethyl piperidin-4-yl)sebacate, di(l,2,2,6,6‑pentamethylpiperidin-4-yl) (3,5-di-tert- butyl-4-hydroxybenzyl)butylmalonate, the polycondensation product of l‑(2‑hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, the polycondensation product of 2,4‑dichloro-6-tert-octylamino-s-triazine and 4,4'- hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine), N,N',N",N'"- tetrakis[(4,6-bis(butyl-(1,2,2,6,6-pentamethylpiperidin-4-y- l)amino)-s-triazine- 2-yl]- 1, 10-diamino-4,7-diazadecane, di-(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl)sebacate, di-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)succinate, l-octyloxy-2,2,6,6-tetramethyl-4-hydroxy-piperidine, poly-{[6-tert-octylamino-s-triazin-2,4-diyl][2-(1 -cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)imino-hexamethylene-[4-(l-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)imino], or 2,4,6-tris[N-(l-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)-n-butylamino]-s-triazine may be present in the composition according to the present invention.

The composition (C) can additionally contain one or more other UV absorbers selected from the group consisting of s-triazines, oxanilides, hydroxybenzophenones, benzoates and α-cyanoacrylates.

Thermal stabilizers may also be included in the composition (C). The thermal stabilizers commonly used in polyamide compositions are well known in the art. They can typically be one or more selected from, 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, pentaerythritol tetrakis (3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 3,3'-bis (3,5-di-tert-butyl-4-hydroxyphenyl)-N,N'-hexamethylenedipropionamide, 1,3,5-tris(3,5-di-(tert)-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-triazine-2,4,6(1H,3H,5H)-trione,1,3,5-tris[[4-(1,1 -dimethylethyl)-3-hydroxy-2,6-dimethylphenyl]methyl], benzenepropanoic acid,3-(1,1-dimethylethyl)-b-[3-(1,1-dimethylethyl)-4-hydroxyphenyl]-4-hydroxy-b-methyl-, 1,1'-(1,2-ethanediyl)ester, bis(1,2,2,6,6-pentamethyl-4 -piperidyl) [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl] butylmalonate, 2-(4,6-diphenyl-1,3,5-triazin-2-yl-)-5-((hexyl)oxyl-phenol, 2,4,8,10-tetraoxa-3,9-diphodphaspiro[5,5]undecane,3,9-bis[2,6-bis-1,1-dimethylethyl]-4-methylphenoxy], 12H dibenzo[d,g][1,3,2]dioxaphosphocin, 2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy], 2,4,8,10-tetraoxa -3,9-diphosphaspiro[5.5]undecane,3,9-bis[2,4-bis(1-methyl-1-phenylethyl)phenoxy], tris(2,4-di-(tert)-butylphenyl)phosphate, bis-2,4-di-tert- butylphenyl) pentaerythritol diphosphite, 2,4,8,10-tetraoxa-3,9- diphosphaspiro[5.5]undecane,3,9-bis(octadecyloxy), 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane,3,9-bis[2,4-bis(1-methyl-1-phenylethyl)phenoxy], 2-(tert-Butyl)-6-methyl-4-(3-((2,4,8,10-tetrakis (tert-butyl)dibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy)propyl)phenol and bis[4-(2-phenyl-2-propyl)phenyl]amine.

In a particular embodiment the composition does not contain any hindered amine light stabilizer, does not contain any thermal stabilizer, or does not contain any of a hindered amine light stabilizer and a thermal stabilizer.

The article

An aspect of the present invention also provides an article comprising at least one component comprising the polyamide composition (C), as above detailed, which provides various advantages over prior art parts and articles, in particular an increased resistance to concurrent exposure to heat and radiation (both visible and UV) while maintaining all their other properties at a high level. Preferably, the article or part of the article consists of the composition (C) as above detailed.

In a particular embodiment, the article is a light emission apparatus.

Non limitative examples of light emission apparatuses are keyless entry systems of an automobile, lightings in a refrigerator, liquid crystal display apparatuses, automobile front panel lighting apparatuses, desk lamps, headlights, household electrical appliance indicators and outdoor display apparatuses such as traffic signs, and optoelectronic devices comprising at least one semi-conductor chip that emits and/or transmits electromagnetic radiation commonly known as Light Emitting Diodes devices (LEDs). Preferably, the light emission apparatus is a Light Emitting Diode device (LED).

LEDs are preferably chosen from the group of top view LEDs, side view LEDs and power LEDs. Top view and side view LEDs comprise usually a basic housing, which, in general, acts as reflector; besides, top view and side view LEDs usually do not comprise any heatsink slug. On the other hand, power LEDs comprise usually a heatsink slug, which, in general, acts as reflector; power LEDs usually further comprise a basic housing, which is a part distinct from the heatsink slug.

The top view LEDs are notably used in automotive lighting applications such as instrumental panel displays, stop lights and turn signals. The side view LEDs are notably used for mobile appliance applications such as, for example, cell phones and PDAs. The power LEDs are notably used in flashlights, automotive day light running lights, signs and as backlight for LCD displays and TVs.

The LED according to the present invention comprises at least one part comprising the composition (C) as above described. The part is preferably selected from the group consisting of basic housings and heatsink slugs. The part made from the composition (C), as above detailed, is generally intended to act as reflector.

Preferably at least 50 wt. % and more preferably more than 80 wt. % of the part comprises the composition (C), being understood that the part may possibly further contain other materials, e.g. a metal; for example, for certain end uses, the surface of certain parts made from the composition (C), as above detailed, and acting as reflector, may be metal plated. More preferably, more than 90 wt. % of the part comprises the composition (C). Still more preferably, the part consists essentially of the composition (C). The most preferably, the part consists of the composition (C).

An exemplary embodiment of a top view LED is provided in Figure 1, which illustrates a sectional view of said embodiment. The top view LED 1 comprises a basic housing 2 comprising, and preferably consisting of, the composition (C) as above detailed. As will be detailed hereafter, the basic housing 2 acts also as reflector cup. No heatsink slug is present. Usually, the LED 1 further comprises a prefabricated electrical lead frame 3. Lead frame 3 can be advantageously encapsulated by injection moulding with the composition (C) included in the basic housing 2.

The basic housing 2 has a cavity 6. A semiconductor chip 4 that emits electromagnetic radiations, such as a LED chip, is mounted inside such cavity. The semiconductor chip 4 is generally bonded and electrically contact-connected on one of the lead frame terminals by means of a bonding wire 5.

A transparent or translucent potting compound (e.g. an epoxy, a polycarbonate or a silicone resin, not shown in Figure 1) is generally built into the cavity in order to protect the LED chip. It is customary, for the purpose of increasing the external efficiency of the LED chip, to shape the cavity of the basic housing with non perpendicular inner areas in such a way that the cavity acquires a form opening towards the front side (the sectional view of the inner wall of the cavity may have, for instance, the form of an oblique straight line, as in the exemplary embodiment in accordance with Figure 1, or that of a parabola).

Thus, the inner walls 7 of the cavity serve as reflector cup for the radiation which is emitted laterally by the semiconductor chip, notably reflecting this radiation towards the front side of the basic housing.

It is understood that the number of chips which can be mounted in the cavity of the basic housing, as well as the number of cavities which can be formed inside a basic housing, is not restricted to one.

An exemplary embodiment of a power LED is provided in Figure 2, which illustrates a sectional view of said embodiment. The power LED 8 comprises advantageously an aspherical lens 1 and a basic housing 2 comprising, and preferably consisting of, the composition (C), as above detailed. As in the previous embodiment, the LED 8 further comprises a prefabricated electrical lead frame 3.

The power LED 8 also comprises a carrier body or heatsink slug 9 which may comprise, or consist of, the composition (C) as above detailed. A cavity 6 is realized in the upper portion of the heatsink slug 9. A semiconductor LED chip 4 that emits electromagnetic radiations is mounted on the bottom area of cavity 6 and it is generally fixed by means of a chip carrier substrate or solder connection 10 to the heatsink slug 9. The solder connection 10 is generally an epoxy resin or another equivalent adhesive material. The LED chip is generally conductively connected to the electric terminals of the lead frame 3 via the bonding wires 5.

The inner walls 7 of the cavity 6 run generally from the bottom area of the cavity to the front side so as to form a reflector cup increasing the external efficiency of the LED chip. The inner walls 7 of the reflector cup may be, for example, straight and oblique or concavely curved (like in the exemplary embodiment in accordance with Figure 2).

The lead frame 3 and the heatsink slug 9 are generally encapsulated within the basic housing 2. In order to protect the LED chip 4, the cavity is generally completely filled, likewise in the first exemplary embodiment of Figure 1, with a radiation- transmissive, for example transparent, encapsulation compound (the encapsulant is not shown in Figure 2). The composition (C) as above detailed is particularly suitable for making basic housings and/or heatsink slugs as above described, because, besides having excellent thermal conductivity thus allowing the heat produced by the optoelectronic device to be easily dissipated, it has also good mechanical properties, high heat deflection temperature, good plateability, good adhesion to lead frame, excellent optical properties, notably excellent initial whiteness and high retention of reflectance, even after prolonged exposure to heat and radiation.

Should the disclosure of any patents, patent applications, and publications which are incorporated herein by reference conflict with the description of the present application to the extent that it may render a term unclear, the present description shall take precedence.

The invention will now be described in more details with reference to the following examples whose purpose is merely illustrative and not intended to limit the scope of the present invention.

EXAMPLES

Measurement of end capping agent amount in polyamide
Proton nuclear magnetic resonance spectroscopy (NMR) spectroscopy was used to determine the amount of benzamide or acetamide end capping agent in exemplified polyamides. Solutions for NMR analysis were prepared by dissolving the samples in trifluoroacetic acid or trifluoroacetic acid optionally with a few drops of hexafluoroisopropanol. Solution spectra were collected using an Oxford (Varian) magnet with a Tecmag Apollo console and either a Varian BB or ID probe operating at a frequency of 400 MHz. Routine acquisitions at room temperature employed a 1.4 s acquisition time, a 90° flip angle of 17.8 usec or 9 usec depending on the probe and a 6 s recycle delay. Data points were collected using a sweep width of 6000 Hz. The 8K data points were zero- filled to 16K data points using 0.5 Hz exponential apodization.
The molar concentration of benzamide end cap was obtained as ratio among area of signals as detailed in below formula:

Similarly, the molar concentration of acetamide end cap was obtained as ratio among area of signals as detailed in below formula:

In both cases the area of the terephthalamide singlet at 7.94 ppm is corrected for the benzamide 2H doublet and the naphthalene dicarboxylic doublet 2H doublet that also appear at about 7.9 ppm. If both isophthalic acid and napthalenedicarboxylic acid are present, the areas at 8.06 ppm and 8.44 ppm, respectively, are calculated by first computing the fraction of isophthalic acid from the area at 8.15 to 8.05 ppm minus the area at 8.35 to 8.45 ppm.

Preparative Example 1 - Preparation of the polyamide (A-1) – PA 6T/6,NDA 50/50 – Acid (MA): charged: 4.88 % moles, found in polyamide: 3.90 % moles
A stirred batch vessel was charged with 25,088 g distilled water, a diamine component consisting of 20,081 g 1,6-hexamethylenediamine (172.8 mol) and with a dicarboxylic acid component consisting of 12,958 g of terephthalic acid (78.0 mol) and 16,863 g of 2,6-naphthalenedicarboxylic acid (78.0 mol). The reactor was also charged with 58.2 g sodium hypophosphite and 977 g benzoic acid (8.00 mol). A salt solution was obtained by heating the above described mixture at 138°C. The contents were pumped continuously to a reactor zone maintained at about 185 psig and 224°C, then to a zone maintained at about 308°C and 1800 psig, then through a tubular reactor at 100 psig and heated with oil at 349°C and into a vented Werner and Pfleiderer Corporation ZSK-30^® twin-screw extruder equipped with a forward vacuum vent. Die temperature was set at 333°C. The finished polymer was extruded through a strand die into a water bath at a through-put rate of about 5.5-6.5 kg/hr and then chopped into pellets. The melting point of the obtained polyamide was 328°C. Proton NMR analysis in trifluoroacetic acid solution showed a benzamide end cap content of 3.90 % moles.

Preparative Example 2 - Preparation of the polyamide (A-2) - PA6T/6,NDA 50/50 - Acid (MA): charged: 3.92 % moles, found in polyamide: 2.77 % moles
A stirred batch vessel was charged with 24,976 g distilled water, a diamine component consisting of 19,895 g 1,6-hexamethylenediamine (171.2 mol) and with a dicarboxylic acid component consisting of 13,025 g of terephthalic acid (78.4 mol) and 16,949 g of 2,6-naphthalenedicarboxylic acid (78.4 mol). The reactor was also charged with 58.2 g sodium hypophosphite and 782 g benzoic acid (6.40 mol). The polymerization conditions of E3 were the same as for E2. The melting point of the obtained polyamide was 332°C. Proton NMR analysis in trifluoroacetic acid solution with a few drops of hexafluoroisopropanol showed a benzamide end cap content of 2.77 % moles.

Preparative Example 3 - Preparation of the polyamide (C-1) - PA6T/6I 70/30 – free from NDA, Acid (MA): charged: 5.35 % moles, found in polyamide: 3.70 % moles
A stirred batch vessel was charged with 20,572 g distilled water, a diamine component consisting of 17,906 g 1,6-hexamethylenediamine (154.1 mol) and with a dicarboxylic acid component consisting of 16,285 g of terephthalic acid (98.0 mol) and 6,979 g of isophthalic acid (42.0 mol). The reactor was also charged with 47.1 g sodium hypophosphite, 75.0 g sodium phenylphosphinate and 476 g acetic acid (7.92 mol). A salt solution was obtained by heating the above described mixture at 127°C. The contents were pumped continuously to a reactor zone maintained at about 165 psig and 221°C, then to a zone maintained at about 296°C and 1800 psig, then through a tubular reactor at 100 psig and heated with oil at 349°C and then pumped through the extruder. Die temperature was set at 326°C. The melting point of the obtained polyamide was 323°C. Proton NMR analysis in trifluoroacetic acid solution showed an acetamide end cap content of 3.70 % moles.

Preparative Example 4 - Preparation of the polyamide (C-2) - PA6T/6,NDA 50/50 – Acid (MA): charged: 2.96 % moles, found in polyamide: 2.57 % moles
A stirred batch vessel was charged with 22,441 g distilled water, a diamine component consisting of 17,906 g 1,6-hexamethylenediamine (154.1 mol) and with a dicarboxylic acid component consisting of 11,782 g of terephthalic acid (70.9 mol) and 15,332 g of 2,6-naphthalenedicarboxylic acid (70.9 mol). The reactor was also charged with 15.6 g phosphorous acid and 528 g benzoic acid (4.32 mol). A salt solution was obtained by heating the above described mixture at 138°C. The contents were pumped continuously to a reactor zone maintained at about 185 psig and 226°C, then to a zone maintained at about 308°C and 1800 psig, then through a tubular reactor at 100 psig and heated with oil at 349°C and then pumped through the extruder. Die temperature was set at 326°C. The melting point of the obtained polyamide was 328°C. Proton NMR analysis in trifluoroacetic acid solution with a few drops of hexafluoroisopropanol showed a benzamide end cap content of 2.57 % moles.

Preparative Example 5 - Preparation of the polyamide (C-3) - PA6T/6I/6,NDA 62/13/25 - Acid (MA): charged: 1.98 % moles, found in polyamide: 1.50 % moles
A stirred batch vessel was charged with 21,626 g distilled water, a diamine component consisting of 18,073 g 1,6-hexamethylenediamine (155.5 mol) and with a dicarboxylic acid component consisting of 14,684 g of terephthalic acid (88.4 mol), 3,079 g isophthalic acid (18.5 mol) and 7,705 g of 2,6-naphthalenedicarboxylic acid (35.6 mol). The reactor was also charged with 14.8 g phosphorous acid and 352 g benzoic acid (2.88 mol). A salt solution was obtained by heating the above described mixture at 133°C. The contents were pumped continuously to a reactor zone maintained at about 165 psig and 222°C, then to a zone maintained at about 307°C and 1800 psig, then through a tubular reactor at 100 psig and heated with oil at 349°C and then pumped through the extruder. Die temperature was set at 316°C. The melting point of the obtained polyamide was 311°C. Proton NMR analysis in trifluoroacetic acid solution showed a benzamide end cap content of 1.50 % moles

The table herein below summarizes composition of the acid component (AA) in each of above detailed polyamides (A-1), (A-2) (according to the invention) and (C-1), (C-2) and (C-3) (of comparison):

Table 1

polyamide	(A-1)	(A-2)	(C-1)	(C-2)	(C-3)
Component	% moles in acid component (AA)
Acid (NDA)	47.56	48.04	0	48.52	24.49
Acid (DA)	47.56	48.04	94.65	48.52	76.53
Acid (MA) charged in polymerization	4.88	3.92	5.35	2.96	1.98
Acid (MA) found in polyamide	3.90	2.77	3.70	1.57	1.50

The polyamides (A-1), (A-2), (C-1), (C-2) and (C-3), as above detailed have been compounded with the ingredients detailed in the following table using the following commercially available materials in the amounts specified below:
Reinforcing filler :
Woll-1: Vansil^®HR-1500 available from RT Vanderbilt – 9 µ median particle size – 14:1 aspect ratio (as specified by supplier)
Glass-1: CHOPVANTAGE^® HP 3540 glass fibers from PPG Industries
Titanium Dioxide:
Pig-1 : Tipaque PC-3 available from Ishihara Sangyo Kaisha, Ltd - rutile TiO₂ manufactured by chloride process, treated with silica and alumina.
Pig-2 : Ti-Pure^® R-105 available from DuPont Titanium Technologies – rutile TiO₂ manufactured by chloride process, treated with silica and alumina;
Stabilizers:
Stab-1: Irganox^® 1010 stabilizer is a hindered phenol available from Ciba.
Stab-2: NYLOSTAB® SEED stabilizer is a hindered amine available from Clariant Corp.
Stab-3: ULTRANOX^® 626 stabilizer is (2,4-di-t-butylphenyl)pentaerythritol diphosphite commercially available from Chemtura.
Brightener:
Brig-1: EASTOBRITE^® OB-3 brightener is a fluorescent whitening agent commercially available from Eastman Chemical Company.
Polymer additive:
LLDPE-1: LLDPE GRSN-9820 NT 7 commercially available from DOW.

Each one of the polyamides were used to prepare discs of about 50 mm diameter with a thickness of about 1.6 mm. Percentage retention of reflectivity at a wavelength of 450 nm with discs as moulded and when disc were heated in air at 260°C for 10 min is also given in following table.

Table 2

Run	E1	E2	E3	E4	CE1	CE2	CE3	CE4
Polyamide component (% wt)
(A-1)	58	58	-	-	-	-	-	-
(A-2)	-	-	58	58	-	-	-	-
(C-1)	-	-	-	-	58	58	-	-
(C-2)	-	-	-	-	-	-	55	-
(C-3)	-	-	-	-	-	-	-	55
Other ingredients (% wt)
Woll-1	22	22	22	22	22	22	-	-
Glass-1	-	-	-	-	-	-	22	22
Pig-1	-	20	-	20	-	20	-	-
Pig-2	20	-	20	-	20	-	20	20
Stab-1	-	-	-	-	-	-	0.6	0.6
Stab-2	-	-	-	-	-	-	0.3	0.3
Stab-3	-	-	-	-	-	-	1.3	1.3
Brig-1	-	-	-	-	-	-	0.015	0.015
LLDPE-1	-	-	-	-	-	-	0.75	0.75
Optical Properties on sample as moulded
Reflectance	90.2	89.5	89.2	88.6	91.1	90.0	85.0	84.1
Optical Properties on sample after thermal treatment (10 min at 260°C)
Reflectance	75.4	75.1	75.0	73.1	64.4	69.1	67.1	61.4

The data summarized in Table herein above well demonstrate that only with the polyamides of the present invention, comprising recurring units derived from NDA and a well-defined amount of acid (MA) (i.e. of end-capping agent) it is advantageously possible to achieve outstanding optical properties both on the moulded article as such and after thermal treatment, intended to mimic conditions which the materials might be exposed during processing for e.g. manufacturing elements to be incorporated in LED apparatuses.

Runs CE-1 and CE-2 provide evidence of the criticality of the presence of recurring units derived from NDA: polyamide (C-1), free from acid (NDA), even if comprising acid (MA) (as agent (M)) in an amount within the claimed range, is not effective in providing the outstanding optical properties obtained with polyamides (A-1) and (A-2) comprising acid (NDA) recurring units; actually despite high values of reflectance on moulded specimen as such, thermal treatment has a tremendous detrimental effect on said optical properties.

Runs CE3 and CE4, carried out starting from comparative polyamide (C-2) and (C-3), still comprising recurring units derived from NDA, but differing for the acid (MA) content (as agent (M)), have provided evidence that with such polyamides, even via addition of optical brightener, stabilizers and processing additive, optical properties are worse than what obtained in E1 to E4 runs, notwithstanding the fact that above mentioned additives are well known for improving reflectance and minimizing thermal degradation.

Claims

An aromatic polyamide composition [composition (C)] comprising:

(i) at least one polyamide [polyamide (A)] comprising recurring units derived from:

(i-1) a dicarboxylic acid component [acid component (AA)], wherein said acid component (AA) comprises at least one naphthalene dicarboxylic acid or derivative thereof [acid (NDA)] and, optionally, at least one acid comprising only one reactive carboxylic acid group [acid (MA)]; and

(i-2) a diamine component [amine component (NN)] comprising at least one aliphatic alkylene-diamine and, optionally, at least one amine comprising only one reactive amine group [agent (MN)],

wherein said polyamide (A) comprises at least one end capping agent [agent (M)] selected from the group of said acid (MA) and said amine (MN) in at least one of said acid component (AA) and amine component (NN), and wherein the and wherein the overall amount of agent (M) in the polyamide (A), computed as:

is of 2.7 to 6 % moles.;

(ii) at least one pigment selected from the group consisting of titanium dioxide (TiO₂), zinc disulfide (ZnS₂), zinc oxide (ZnO) and barium sulfate (BaSO₄) [pigment (P)]; and

(iii) at least one reinforcing filler [filler (F)], different from pigment (P).
The composition (C) of claim 1, wherein the acid component (AA) comprises at least one acid (NDA) selected from the group consisting of 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid,1,4-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid, and 1,8-naphthalene dicarboxylic acid.
The composition (C) of claim 2, wherein the acid component (AA) comprises 2,6-naphthalene dicarboxylic acid.
The composition (C) of anyone of the preceding claims, wherein the acid component (AA) comprises said at least one acid (NDA) in an amount of at least 20, preferably of at least 30, more preferably of at least 40 % moles, based on the all components of the acid component (AA).
The composition (C) of anyone of the preceding claims, wherein the acid component (AA) comprises said at least one acid (NDA) in an amount of at most 95, preferably of at most 80, more preferably of at most 75 % moles, based on the all components of the acid component (AA).
The composition (C) of anyone of the preceding claims, wherein said diamine component [amine component (NN)] comprises at least one aliphatic alkylene-diamine selected from the group consisting of 1,2‑diaminoethane, 1,2-diaminopropane, propylene-1,3-diamine, 1,3‑diaminobutane, 1,4-diaminobutane, 1,5-diaminopentane, 1,4-diamino-1,1-dimethylbutane, 1,4-diamino-1-ethylbutane, 1,4-diamino-1,2-dimethylbutane, 1,4-diamino-1,3-dimethylbutane, 1,4-diamino-1,4-dimethylbutane, 1,4-diamino-2,3-dimethylbutane, 1,2-diamino-1-butylethane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diamino-octane, 1,6-diamino-2,5-dimethylhexane, 1,6-diamino-2,4-dimethylhexane, 1,6-diamino-3,3-dimethylhexane, 1,6-diamino-2,2-dimethylhexane, 1,9-diaminononane, 1,6-diamino-2,2,4-trimethylhexane, 1,6-diamino-2,4,4-trimethylhexane, 1,7-diamino-2,3-dimethylheptane, 1,7-diamino-2,4-dimethylheptane, 1,7-diamino-2,5-dimethylheptane, 1,7-diamino-2,2-dimethylheptane, 1,10-diaminodecane, 1.8-diamino-1,3-dimethyloctane, 1,8-diamino-1,4-dimethyloctane, 1.8-diamino-2,4-dimethyloctane, 1,8-diamino-3,4-dimethyloctane, 1.8-diamino-4,5-dimethyloctane, 1.8-diamino-2,2-dimethyloctane, 1.8-diamino-3,3-dimethyloctane, 1,8-diamino-4,4-dimethyloctane, 1,6-diamino-2,4-diethylhexane, 1,9-diamino-5-methylnonane, 1,11-diaminoundecane and 1,12-diaminododecane.
The composition (C) of anyone of the preceding claims, wherein the acid component (AA) comprises said at least one acid (MA), in an amount of at most 5.5 % moles, more preferably at most 5 % moles, based on the all components of the acid component (AA).
The composition (C) of anyone of the preceding claims, wherein said acid (MA) is selected from the group consisting of acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, stearic acid, cyclohexanecarboxylic acid, benzoic acid, preferably from acetic acid and benzoic acid.
The composition (C) of anyone of the preceding claims, wherein the weight percent of the polyamide (A) in the composition (C) is of at least 30 wt. %, preferably of at least 40 wt. %, and more preferably of at least 50 wt. %, based on the total weight of the composition (C).
The composition (C) of anyone of the preceding claims, wherein the weight percent of the polyamide (A) in the composition (C) is of at most 90 wt. %, preferably of at most 80 wt. % and most preferably of at most 60 wt. %, based on the total weight of the composition (C).
The composition (C) of anyone of the preceding claims, wherein the filler (F) is selected from the group consisting of mineral fillers, glass fibers, carbon fibers, synthetic polymeric fibers, aramid fibers, aluminum fibers, titanium fibers, magnesium fibers, boron carbide fibers, rock wool fibers, steel fibers, wollastonite, inorganic whiskers.
The composition (C) according to claim 11, wherein the filler (F) is selected from mica, kaolin, calcium silicate, magnesium carbonate, inorganic whiskers, glass fiber and wollastonite.
An article comprising at least one component comprising the composition (C) according to anyone of the preceding claims.
The article of claim 13, said article being a light emission apparatus selected from the group consisting of keyless entry systems of an automobile, lightings in a refrigerator, liquid crystal display apparatuses, automobile front panel lighting apparatuses, desk lamps, headlights, household electrical appliance indicators and outdoor display apparatuses, and optoelectronic devices comprising at least one semi-conductor chip that emits and/or transmits electromagnetic radiation commonly known as Light Emitting Diodes devices (LEDs).