EP3941968A1

EP3941968A1 - Copolyamide compositions comprising reinforcing fibers and having high modulus stability and uses thereof

Info

Publication number: EP3941968A1
Application number: EP20726194.2A
Authority: EP
Inventors: Mathieu SABARD; Benoît BRULE; Marie POMMIER DE SANTI; Stefania Cassiano Gaspar; Damien Vitry; Rui MAO
Original assignee: Arkema France SA
Current assignee: Arkema France SA
Priority date: 2019-03-21
Filing date: 2020-03-13
Publication date: 2022-01-26
Also published as: WO2020188203A1; KR20210141625A; US20220153998A1; JP2022526097A; FR3094010B1; CN113785018A; FR3094010A1

Abstract

The present invention relates to the use of a copolyamide comprising at least two distinct units A and X ₁ Y of formula A/X ₁ Y, wherein: - A is a repeating unit obtained by polycondensation of: at least one C ₉ to C ₁₈, preferably C ₁₀ to C ₁₈, more preferably C ₁₀ to C ₁₂ amino acid, or at least one C ₉ to C ₁₈, preferably C ₁₀ to C ₁₈, more preferably C ₁₀ to C ₁₂ lactam, or at least one C ₄-C ₃₆, preferably C ₆-C ₁₈, preferably C ₆-C ₁₂, more preferably C ₁₀-C ₁₂ diamine Ca, with at least one C ₄-C ₃₆, preferably C ₆-C ₁₈, preferably C ₆-C ₁₂, more preferably C ₁₀-C ₁₂ dicarboxylic acid Cb; - X ₁ Y is a repeating unit obtained from the polycondensation of at least one C ₉ to C ₁₈, preferably C ₁₀ to C ₁₈, more preferably C ₁₀ to C ₁₂ linear aliphatic diamine (X ₁), and at least one aromatic dicarboxylic acid (Y), to prepare a composition comprising between 35 and 65%, and preferably between 50 and 65% by weight of reinforcing fibers, relative to the total weight of the composition, and for which the flexural modulus or tensile modulus, measured after an identical conditioning, does not vary by more than 20% in the temperature range from 20°C to 40°C, in particular in the temperature range from 0°C to 40°C, more particularly in the temperature range from -10°C to 40°C.

Description

DESCRIPTION

TITLE: Compositions of copolyamides comprising reinforcing fibers and exhibiting high modulus stability and their uses

[Technical area]

The present patent application relates to the use of semi-aromatic copolyamides for the manufacture of compositions exhibiting a high modulus stability under the effect of temperature and humidity, their manufacturing process as well as said compositions.

[Prior art]

Many applications in the E / E field require the use of high modulus polymeric materials, for example for televisions, digital cameras, digital games, phone parts, digital tablets, drones, printers or computer parts. The modulus of the material is in fact a crucial factor in enabling a reduction in weight, since it allows a reduction in the thickness of the parts while maintaining great rigidity. There are different moduli (for example tensile modulus, flexural modulus, etc.). These modules can be impacted by temperature and by the humidity level contained in the sample.

It is also important that the rigidity is little affected by changes in temperature or by the water content in the material. Indeed, the stability of the module is also an important factor for subsequent use or for ensuring easy assembly of the parts when this is carried out in places where the temperature and / or humidity may be high.

Thus, polymers are sought whose modulus remains stable in the temperature and / or humidity range to which they are exposed, in particular during the assembly of the parts and the subsequent operation of the devices. Preferably, the modulus would be stable at a temperature ranging from 20 ° C to 40 ° C, especially in the temperature range from 0 ° C to 40 ° C, in particular in the temperature range from -10 ° C to 40 ° C for compositions having variable water contents (caused by conditioning the compositions in an atmosphere where the humidity could vary from 0 to 100%, or in liquid water)

Furthermore, the polymer formulations must exhibit moderate molding temperatures and crystallize sufficiently quickly to allow a transformation time, in particular a cycle time, suitable for an industrial process.

Now, aliphatic polyamides generally exhibit a significant loss of rigidity when the temperature increases, in particular when these polyamides have been packaged in a humid atmosphere beforehand because they contain a certain amount of water.

The use of a semi-aromatic polyamide, in particular an MXDZ polyamide in a mixture of aliphatic polyamide, in particular semi-aromatic polyamide, is known from application WO 2018/073536. crystalline, comprising glass fibers with a circular section, to limit the warping of the composition obtained.

International application WO 2018/073537 also knows the use of glass fibers with a circular section in a mixture comprising at least one MXDZ polyamide and at least one aliphatic polyamide, in particular semi-crystalline, to improve the mechanical properties of said composition. , in particular the elongation at break, after its processing, in particular by injection or compression molding.

Furthermore, document WO 10/015785 describes copolyamides comprising at least two distinct A / XT units characterized in that said copolyamide has an amine end-of-chain content greater than or equal to 20 peq / g, an end-of-chain content acid less than or equal to 100 peq / g, and a non-reactive chain end content greater than or equal to 20 peq / g. The copolyamide can comprise additives, in particular reinforcing fibers, said reinforcing fibers possibly being glass fibers.

Document WO 10/015786 describes copolyamides comprising at least two A / 10.T units characterized in that it exhibits a polymolecularity index, denoted Ip less than or equal to 3.5, measured by gel permeation chromatography.

International application WO 2014/195226 describes compositions for an electronic mobile device comprising at least 20% of at least one polymer and at least 20% of glass fibers having a non-circular section and an elastic modulus of at least 76 determined GPa. according to ASTM C1557-03.

None of these documents of the prior art mentions the stability of the modulus as a function of the temperature and of the prior conditioning of the compositions.

There therefore remains the problem of providing a formulation based on polyamides combining a high modulus which is stable over a wide temperature range, even when the composition is saturated with water, and good suitability for injection molding.

[Summary of the invention]

The aim of the invention is therefore to provide semi-aromatic copolyamides for the manufacture of compositions exhibiting a high modulus stability under the effect of temperature and humidity.

Also, according to a first aspect, a subject of the invention is the use of a copolyamide comprising at least two distinct units A and XiY of formula A / XiY, in which:

- A is a repeating unit obtained by polycondensation:

at least one C8 to Cis amino acid, preferably Cio to Cis, more preferably Cio to C, or at least one C8 to Cis lactam, preferably Cio to Cis, more preferably Cio to C12, or

of at least one C4-C36 diamine Ca, preferably C6-C18, preferably C6-C12, more preferably C10-C12, with at least one Cb C4-C36 dicarboxylic acid, preferentially C6-C18, preferentially C6-C12, more preferably _C10-C12;

- XiY is a repeating unit obtained from the polycondensation of at least one linear aliphatic diamine (Xi) in Cg to Cis, preferably from Cio to Cis, more preferably from Cio to C ₁₂ , and at least one acid aromatic dicarboxylic (Y),

to prepare a composition whose modulus does not vary by more than 20% in the temperature range from 20 ° C to 40 ° C, in particular in the temperature range from 0 ° C to 40 ° C, in particular in the temperature range from -10 ° C to 40 ° C.

In other words, the present invention relates to the use of a copolyamide comprising at least two distinct units A and XiY of formula A / XiY, as defined above, to prepare a composition whose modulus does not vary. not more than 20% in the temperature range from 20 ° C to 40 ° C, especially in the temperature range from 0 ° C to 40 ° C, in particular in the temperature range from - 10 ° C to 40 ° C in comparison with the variation of the modulus of an aliphatic homopolyamide measured under the same conditions.

Or in other words, the present invention relates to the use of a copolyamide comprising at least two distinct units A and XiY of formula A / XiY, as defined above, to prepare a composition whose modulus does not vary by more than 20% in the temperature range from 20 ° C to 40 ° C, in particular in the temperature range from 0 ° C to 40 ° C, in particular in the temperature range from from -10 ° C to 40 ° C in comparison with the variation of the modulus of an aliphatic homopolyamide having the same unit A, measured under the same conditions.

Or in other words, the present invention relates to the use of a composition comprising a copolyamide comprising at least two distinct units A and XiY of formula A / XiY as defined above, to limit the variation of the modulus in the '' temperature range from 20 ° C to 40 ° C, in particular in the temperature range from 0 ° C to 40 ° C, in particular in the temperature range from -10 ° C to 40 ° C, said modulus not varying by more than 20% compared to the variation in modulus of said composition measured under the same conditions in which an aliphatic homopolyamide is used instead of said copolyamide.

Or in other words, the present invention relates to the use of a composition comprising a copolyamide comprising at least two distinct units A and XiY of formula A / XiY as defined above, to limit the variation of the modulus in the '' temperature range from 20 ° C to 40 ° C, especially in the temperature range from 0 ° C to 40 ° C, in particular in the temperature range ranging from -10 ° C to 40 ° C, said modulus not varying by more than 20% compared to the variation in the modulus of said composition measured under the same conditions in which an aliphatic homopolyamide having the same unit A, is used instead of said copolyamide.

The inventors have unexpectedly found that the selection of a semi-aromatic copolyamide comprising a repeating unit A and a repeating unit XiY based on an aromatic diacid, made it possible to prepare a composition of which not only the modulus exhibits stability under l effect of temperature and humidity, and does not vary by more than 20% in the temperature range from 20 ° C to 40 ° C, especially in the temperature range from 0 ° C to 40 ° C, in particular in the temperature range from -10 ° C to 40 ° C, but also the implementation of which is facilitated by a low molding temperature, in particular less than 100 ° C, preferably less than 90 ° C, and by a short cycle time during its implementation.

The nomenclature used to define polyamides is described in standard ISO 1874-1: 2011 "Plastics - Polyamide materials (PA) for molding and extrusion - Part 1: Designation", in particular on page 3 (tables 1 and 2) and is indeed known to those skilled in the art.

When the repeating unit A said copolyamide is obtained from the polycondensation of at least one lactam, at least one lactam may be chosen from a lactam C₆-Cis, preferably in the Cio to Cis, more preferably in Cio to C ₁₂ . A C10 to C ₁₂ lactam is in particular decanolactam, undecanolactam, and lauryllactam.

Said unit A is obtained from the polycondensation of at least one lactam and can therefore comprise a single lactam or several lactams.

Advantageously, said unit A is obtained from the polycondensation of a single lactam and said lactam is lauryllactam.

When the repeating unit A of said copolyamide is obtained from the polycondensation of at least one amino acid, said at least one amino acid can be chosen from a C 8 to Cis amino acid, preferably Cio to Cis, more preferably Cio to C12.

A Cg to C12 amino acid is in particular 9-aminononanoic acid, 10-aminodecanoic acid, 10-aminoundecanoic acid, 12-aminododecanoic acid and 11-aminoundecanoic acid as well as its derivatives, in particular acid N-heptyl-11-aminoundecanoic.

Said unit A is obtained from the polycondensation of at least one amino acid and can therefore comprise a single amino acid or several amino acids.

Advantageously, said unit A is obtained from the polycondensation of a single amino acid and said amino acid is 11-aminoundecanoic acid.

When the repeating unit A of said copolyamide is obtained from the polycondensation of at least one C4-C36, preferably C6-C18, preferably C6-C12 diamine Ca, more preferably C10-C12, with at least one diacid Cb in C4-C36, preferentially C6-C18, preferentially C6-C12, more preferentially C10-C12, then said at least one diamine in Ca is a linear or branched aliphatic diamine, in particular linear and said at least one Cb diacid is a linear or branched aliphatic diacid, in particular a linear diacid.

Advantageously, said at least one diamine is linear aliphatic and said at least one diacid is aliphatic and linear.

Said at least one C4-C36 diamine Ca can be in particular chosen from 1,4-butanediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine, 1,13-tridecamethylenediamine, 1,14-tetradecamethylenediamine, 1,16-hexadecamethylenediamine and 1, 18- octadecamethylenediamine, octadecenediamine, eicosanediamine, docosanediamine and diamines obtained from fatty acids.

Advantageously, said at least one Ca diamine is C6-C18 and chosen from 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine, 1,13-tridecamethylenediamine, 1,14-tetradecamethylenediamine, 1,16-hexadecamethylenediamine and 1,18-octadecamethylenediamine.

Advantageously, said at least one C ₆ to C ₁₂ diamine Ca is in particular chosen from 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10 -decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine.

Advantageously, the Ca diamine used is C10 to C12, in particular chosen from 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine.

Said at least one Cb C ₄ to C36 dicarboxylic acid may be chosen from succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid , dodecanedioic acid, brassylic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, octadecenediamine, eicosanediamine, docosanediamine and diamines obtained from acids fat.

Advantageously, said at least one Cb dicarboxylic acid is C ₆ to Cis and is chosen from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid. Advantageously, said at least one Cb dicarboxylic acid is C6 to C12 and is chosen from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid and dodecanedioic acid.

Advantageously, said at least one Cb dicarboxylic acid is C10 to C12 and is chosen from sebacic acid, undecanedioic acid and dodecanedioic acid.

Said unit A is obtained from the polycondensation of at least one diamine Ca with at least one dicarboxylic acid Cb and can therefore comprise a single diamine or several diamines and a single dicarboxylic acid or several dicarboxylic acids.

Advantageously, said unit A is obtained from the polycondensation of a single diamine Ca with a single dicarboxylic acid Cb.

Said XiY unit is a repeating unit obtained from the polycondensation of at least one linear C9 to Cis aliphatic diamine (Xi), preferably Cio to Cis, more preferably Cio to C12, and at least one dicarboxylic acid aromatic (Y).

Said linear aliphatic diamine (Xi) is as defined for said linear aliphatic diamine Ca.

Said linear aliphatic diamine (Xi) can be identical to or different from the aliphatic and linear diamine Ca.

Said aromatic dicarboxylic acid (Y) may be C6 to Cis, C6 to Cis, preferably Cs to Cis, more preferably Cs to C12.

Advantageously, it is chosen from terepthalic acid (T), isophthalic acid (I), naphthalene dicarboxylic acid (N).

In an advantageous embodiment, said aromatic dicarboxylic acid (Y) is terepthalic acid.

The modulus of a composition changes as a function of the temperature and in general, the modulus decreases with the increase in temperature.

The expression "the modulus does not vary by more than 20% in the temperature range from 20 ° C to 40 ° C" means that in this temperature range from 20 ° C to 40 ° C, the modulus of the same composition, whether it is the flexural modulus or the tensile modulus measured after identical conditioning (dry or humid atmosphere), does not change by more than 20%.

The expression “conditioning in a humid atmosphere” means after saturation in liquid water at 65 ° C.

The same is obviously true for the other temperature intervals.

In other words, let M20 be the modulus measured at 20 ° C and M _{T be} the modulus measured at a temperature T for a composition conditioned under the same dry or humid atmosphere conditions, then: ((M ₂₀ - M _T ) / M _2O ) x 100 <20, with T varying from 20 to 40 ° C.

Advantageously, the modulus does not vary by more than 20% in the temperature range going from 0 ° C to 40 ° C and therefore ((Mo - M _T ) / Mo) x 100 <20, with T varying from 0 at 40 ° C for a composition packaged under the same dry or humid atmosphere conditions.

More advantageously, the modulus does not vary by more than 20% in the temperature range going from -10 ° C to 40 ° C and therefore ((M-io - M _T ) / M-io) x 100 <20, with T varying from -10 to 40 ° C for a composition packaged under the same conditions of a dry or humid atmosphere.

Advantageously, the modulus does not vary by more than 15% in the temperature range going from 0 ° C to 40 ° C and therefore ((Mo - M _T ) / Mo) x 100 <15, with T varying from 0 at 40 ° C for a composition packaged under the same humid atmosphere conditions.

More advantageously, the modulus does not vary by more than 15% in the temperature range going from -10 ° C to 40 ° C and therefore ((M-io - M _T ) / M-io) x 100 <15, with T varying from -10 to 40 ° C for a composition packaged under the same humid atmosphere conditions.

Advantageously, the modulus does not vary by more than 5% in the temperature range going from 0 ° C to 40 ° C and therefore ((Mo - M _T ) / Mo) x 100 <5, with T varying from 0 at 40 ° C for a composition packaged under the same dry atmosphere conditions.

More advantageously, the modulus does not vary by more than 5% in the temperature range going from -10 ° C to 40 ° C and therefore ((M-io - M _T ) / M-io) x 100 <5, with T varying from -10 to 40 ° C for a composition packaged under the same dry atmosphere conditions.

In one embodiment, the modulus is measured as defined above according to the ISO 178: 2010 standard and corresponds to the flexural modulus.

In another embodiment, the modulus is measured as defined above according to the ISO 527-1 and 2: 2012 standard and corresponds to the tensile modulus.

In another embodiment, the modulus corresponds to both the flexural modulus and the tensile modulus, both being measured as defined above.

Advantageously, the ratio of the flexural modulus, measured at 20 ° C on a sample saturated in water at 65 ° C, on the flexural modulus, measured at 20 ° C on a dry sample, is less than 10%, in particular less than 7%, both measurements being carried out according to ISO 178: 2010.

In one embodiment, said XiY unit of said copolyamide defined above is a repeating unit obtained by polycondensation of at least one C10 to Cis aliphatic diamine (Xi), more preferably Cio to C12, and at least one aromatic dicarboxylic acid (Y).

Examples of XiY units are 101, 10T, ION, 121, 12T, 12N, 141, 14T, 14N.

Advantageously, said copolyamide is of formula A / XiT Advantageously, said XiY unit of said copolyamide defined above is a repeating unit obtained by polycondensation of at least one C10 to C12 aliphatic diamine (Xi), and of at least one aromatic dicarboxylic acid (Y).

Examples of XiY units are 101, 10T, 10N, 121, 12T, 12N,

Advantageously, XiY is chosen from 10T, 12T.

Advantageously, said copolyamide is of formula A / 10T or A / 12T, preferentially A / 10T. In another embodiment, said unit A of said copolyamide defined above is an amino acid or a lactam as defined above.

Advantageously, said copolyamide is of formula A / XiY in which A is an amino acid or a lactam as defined above and XiY is as defined above.

Advantageously, said copolyamide is of formula A / XiT in which A is an amino acid or a lactam as defined above.

Advantageously, said copolyamide is of formula A / 10T or A / 12T, preferably A / 10T in which A is an amino acid or a lactam as defined above.

In another embodiment, said unit A of said copolyamide defined above is an amino acid or a Cn or C ₁₂ lactam respectively.

Advantageously, said copolyamide is of formula A / XiY in which A is an amino acid or a Cn or C12 lactam and XiY is as defined above.

In yet another embodiment, said copolyamide defined above is semi-crystalline.

A semi-crystalline copolyamide, within the meaning of the invention, denotes a copolyamide which has a melting point (Tm) in DSC according to standard ISO 11357-3: 2013, and an enthalpy of crystallization during the cooling step at a speed of 20K / min in DSC measured according to standard ISO 11357-3 of 2013 greater than 30 J / g, preferably greater than 35 J / g.

Advantageously, the Tm of said copolyamide is <280 ° C, in particular <270 ° C, in particular <265 ° C. Consequently, in this embodiment, the molar ratio of the units A and XiY in the copolyamide of the invention is adapted according to the different units so that said copolyamide is semi-crystalline.

In another embodiment, said copolyamide of formula A / XiY consists only of units A and XiY as defined above.

Consequently, in this embodiment, the copolyamide has only one or more unit (s) A and one or more unit (s) XiY nevertheless, A is a repeating unit obtained by polycondensation of at least one amino acid or at least one lactam or at least one diamine in Ca with at least one dicarboxylic acid in Cb, as defined above, and XiY is a repeating unit obtained from the polycondensation of at least one diamine linear aliphatic (Xi) as defined above, and at least one aromatic dicarboxylic acid (Y) as defined above. In another embodiment, said copolyamide of formula A / XiY consists only of an A unit and a XiY unit as defined above.

Therefore, in this embodiment, the copolyamide has only one unit A and only one unit XiY and A is a repeating unit obtained by polycondensation of an amino acid or of a lactam or of a diamine in Ca with a Cb dicarboxylic acid as defined above, and XiY is a repeating unit obtained from the polycondensation of a linear aliphatic diamine (Xi) as defined above, and of an aromatic dicarboxylic acid (Y) as defined above.

Advantageously, the copolyamide is chosen from PA11 / 10T, PA11 / 12T, PA12 / 10T, PA12 / 12T, PA610 / 10T, PA610 / 12T, PA612 / 10T, PA612 / 12T, PA1010 / 10T, PA1012 / 10T, PA1010 / 12T ,

PA1012 / 12T, PA1210 / 10T, PA1212 / 10T, PA1210 / 12T, PA1212 / 12T, in particular PA11 / 10T.

In another embodiment, said copolyamide comprises at least a third Z unit, distinct from the A and XiY units, and corresponds to the general formulation A / XiY / Z

in which :

the A and XiT units are as defined above,

Z is chosen from a unit obtained from an amino acid, a unit obtained from a lactam and a unit corresponding to the formula (Ce diamine). (Cd diacid), with c representing the number of carbon atoms of the diamine and d representing the number of carbon atoms of the diacid, c and d each being between 4 and 36, advantageously between 9 and 18,

with the proviso that caprolactam or aminohexanoic acid are excluded from the definition of lactam and amino acid of Z and that when the Ce diamine is a C6 diamine, then terepthalic acid is excluded from the definition of diacid in Cd.

It is obvious that when said copolyamide of formula A / XiY consists only of units A and XiY as defined above or that said copolyamide of formula A / XiY consists only of a unit A and of a unit XiY as defined above, there can be no third Z motif.

However, in this embodiment where at least one third Z unit distinct from A and XiY is present, the copolyamide of the invention can comprise one or more A unit (s) and one or more XiY unit (s) and at least a Z pattern.

The term “distinct” means that even if there are several A and / or XiY units, the Z unit when it is present is different from the A and XiY units present in the copolyamide but that it can however also be of the same type. than for A, namely a repeating unit obtained from the polycondensation of a lactam, or of an amino acid or of a diamine in Ca with a dicarboxylic acid in Cb, or of the same type as XiY, namely a unit repetitive obtained from polycondensation of at least one linear C 8 to C 18 aliphatic diamine (Xi), and of at least one aromatic dicarboxylic acid (Y).

When Z represents a unit obtained from an amino acid, it can be chosen from 9-aminononanoic acid, 10-aminodecanoic acid, 10-aminoundecanoic acid, 12-aminododecanoic acid and 11-acid. -aminoundecanoic acid as well as its derivatives, in particular N-heptyl-ll-aminoundecanoic acid.

When Z represents a unit obtained from a lactam, it can be chosen from pyrrolidinone, 2-piperidinone, caprolactam, enantholactam, caprolactam, pelargolactam, decanolactam, undecanolactam, and lauryllactam.

When the Z unit is a unit corresponding to the formula (diamine in Ce). (Cd-diacid), the (Cd-diamine) unit is chosen from aliphatic, linear or branched diamines, cycloaliphatic diamines and arylaliphatic diamines.

When the diamine is aliphatic and linear, it is chosen from butanediamine, pentanediamine, hexanediamine, heptanediamine, octanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, hexadecanediamine, octadecanediamine, octadecenediamine, eicosanediamine, docosanediamine and diamines obtained from fatty acids.

When the diamine is aliphatic and branched, it may contain one or more methyl or ethyl substituents on the main chain. For example, the C-diamine can advantageously be chosen from 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 1,3-diaminopentane, 2-methyl-l, 5-pentanediamine, 2-methyl-l, 8-octanediamine.

When the C6 diamine is cycloaliphatic, it is chosen from bis (3,5-dialkyl-4-aminocyclohexyl) methane, bis (3,5-dialkyl-4-aminocyclohexyl) ethane, bis (3,5-dialkyl) -4- aminocyclo-hexyl) propane, bis (3,5-dialkyl-4-aminocyclo-hexyl) butane, bis- (3-methyl-4-aminocyclohexyl) -methane (BMACM or MACM), p-bis (aminocyclohexyl) -methane (PACM) and isopropylidenedi (cyclohexylamine) (PACP), 1,3-bis (aminomethyl) cyclohexyl (1,3 BAC), 1,4-bis (aminomethyl) cyclohexyl (1,4 BAC) and a mixture of these. It can also include the following carbon skeletons: norbornyl methane, cyclohexylmethane, dicyclohexylpropane, di (methylcyclohexyl), di (methylcyclohexyl) propane. A non-exhaustive list of these cycloaliphatic diamines is given in the publication "Cycloaliphatic Amines" (Encyclopaedia of Chemical Technology, Kirk-Othmer, 4th Edition (1992), pp. 386-405).

When the C6 diamine is arylaliphatic, it is chosen from 1,3-xylylenediamine and 1,4-xylylenediamine.

The Cd dicarboxylic acid is chosen from aliphatic, linear or branched diacids, cycloaliphatic diacids and aromatic diacids. When the Cd-diacid is aliphatic and linear, it is chosen from succinic acid, glutaric acid, adipic acid, heptanedioic acid, octanedioic acid, azelaic acid, sebacic acid, l 'undecanedioic acid, dodecanedioic acid, brassylic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, octadecenedioic acid, eicosanedioic acid, docosanedioic acid and fatty acid dimers containing 36 carbons.

The dimers of fatty acids mentioned above are dimerized fatty acids obtained by oligomerization or polymerization of long-chain hydrocarbon unsaturated monobasic fatty acids (such as linoleic acid and oleic acid), as described in particular in the document EP 0 471 566.

When the diacid is cycloaliphatic, it may contain the following carbon skeletons: norbornyl methane, cyclohexylmethane, dicyclohexylmethane, dicyclohexylpropane, di (methylcyclohexyl), di (methylcyclohexyl) propane.

When the diacid is aromatic, it is chosen from terephthalic acid (denoted T), isophthalic (denoted I) and naphthalenic diacids (denoted N).

Caprolactam or aminohexanoic acid are excluded from the definition of lactam and amino acid of Z which means that compounds of formula 6 / A / XiY in which A and XiY are as defined above are excluded.

When the Ce diamine is a C6 diamine, then terepthalic acid is excluded from the definition of Cd diacid means that the compounds of formula 6T / A / X ₁ Y in which A and XiY are as defined above are excluded.

In one embodiment, said copolyamide consists only of three units of formula A / XiY / Z.

All three grounds are as defined above and the exclusions also apply.

In this embodiment, there are therefore only the three distinct units A, XiY and Z, nevertheless one or more unit (s) A, one or more unit (s) XiY and one or more unit (s) Z may be present. In another embodiment, a said copolyamide consists of only three units of formula A / XiY / Z and a single unit A, a single unit XiY and a single unit Z are present in the formula A / XiY / Z.

In yet another embodiment, the present invention relates to the use of a copolyamide as defined above for preparing a composition as defined above, said composition comprising up to 70% by weight of reinforcing fibers, in particular from 30 to 70% by weight of reinforcing fibers.

According to one embodiment, the composition comprises between 35 and 65%, and preferably between 50 and 65% by weight of reinforcing fibers, relative to the total weight of the composition. Throughout the description, the expression “between ... and” means limits included.

The composition according to the invention may comprise short reinforcing fibers or short fibrous reinforcement.

Preferably, the fibers are short and of length between 2 and 13 mm, preferably from 3 to 8 mm, before use of the compositions.

These short reinforcing fibers can be chosen from:

- natural fibers

- mineral fibers, these having high melting temperatures Tf 'and greater than the melting point Tf of said semi-crystalline copolyamide of the invention and higher than the polymerization and / or processing temperature.

- Polymeric or polymer fibers having a melting point Tf 'or in the absence of Tf', a glass transition temperature Tg ', higher than the polymerization temperature or higher than the melting temperature Tf of said semi-crystalline copolyamide constituting said matrix of the thermoplastic material and greater than the processing temperature.

- or mixtures of the fibers mentioned above.

As mineral fibers suitable for the invention, mention may be made of carbon fibers, which includes fibers of carbon nanotubes or nanotubes (CNTs), carbon nanofibers or graphenes; silica fibers such as glass fibers, in particular of type E, R, S2 or T; boron fibers; ceramic fibers, in particular silicon carbide fibers, boron carbide fibers, boron carbonitride fibers, silicon nitride fibers, boron nitride fibers, basalt fibers or basalt-based fibers; fibers or filaments based on metals and / or their alloys; fibers of metal oxides, in particular of alumina (Al203); metallized fibers such as metallized glass fibers and metallized carbon fibers or mixtures of the aforementioned fibers. More particularly, these fibers can be chosen as follows:

- the mineral fibers can be chosen from: carbon fibers, fibers of carbon nanotubes, glass fibers, in particular of type E, R, S2, or T, boron fibers, ceramic fibers, in particular silicon carbide fibers , boron carbide fibers, boron carbonitride fibers, silicon nitride fibers, boron nitride fibers, basalt fibers or the basalt based fibers; fibers or filaments based on metals and / or their alloys, fibers based on metal oxides such as AI203, metallized fibers such as metallized glass fibers and metallized carbon fibers or mixtures of the aforementioned fibers, and

- the polymer or polymer fibers, under the aforementioned condition, are chosen from:

- fibers of thermosetting polymers and more particularly chosen from: unsaturated polyesters, epoxy resins, vinyl esters, phenolic resins, polyurethanes, cyanoacrylates and polyimides, such as bis-maleimide resins, aminoplasts resulting from the reaction of an amine such as melamine with an aldehyde such as glyoxal or formaldehyde,

- fibers of thermoplastic polymers and more particularly chosen from: polyethylene terephthalate (PET), polybutylene terephthalate (PBT),

- polyamide fibers,

- aramid fibers (such as Kevlar ^® ) and aromatic polyamides such as those corresponding to one of the formulas: PPD.T, MPD.I, PAA and PPA, with PPD and MPD being respectively p- and m- phenylene diamine, PAA being polyarylamides and PPA being polyphthalamides,

- fibers of polyamide block copolymers such as polyamide / polyether, fibers of polyarylether ketones (PAEK) such as polyetherether ketone (PEEK), polyetherketone ketone (PEKK), polyetherketoneetherketone ketone (PEKEKK).

Preferred short reinforcing fibers are short fibers chosen among: carbon fibers, including metallic, glass fibers, including metallized type E, R, S2, T fibers or aramid (such as Kevlar ^®) or of aromatic polyamides, polyarylether ketone (PAEK) fibers, such as polyetherether ketone (PEEK), polyetherketone ketone (PEKK) fibers, polyetherketoneetherketone ketone (PEKEKK) fibers, or mixtures thereof.

More particularly, the natural fibers are chosen from fibers of flax, castor, wood, sisal, kenaf, coconut, hemp and jute.

Advantageously, the weight ratio of reinforcing fibers / copolyamide does not exceed 1.75, in particular 1.6.

By glass fiber within the meaning of the invention is meant any glass fiber, in particular as described by Frederick T. Wallenberger, James C. Watson and Hong Li, PPG industries Inc. (ASM Handbook, Vol 21: composites (# 06781G), 2001 ASM International).

The reinforcing fiber can be:

- Or with a circular section with a diameter of 4 μm and 25 μm, preferably 4 to 15 μm.

- either with a non-circular section with an L / D ratio (L representing the largest dimension of the cross section of the fiber and D the smallest dimension of the cross section of said fiber) ranging from 2 to 8, in particular 2 to 4. L and D can be measured by scanning electron microscopy (SEM).

Advantageously, the reinforcing fibers are chosen from glass fibers, carbon fibers, and a mixture thereof.

Advantageously, the reinforcing fiber is chosen from a glass fiber with a non-circular cross section, a glass fiber with a circular section, a carbon fiber and a mixture of these. Advantageously, the reinforcing fiber is chosen from a glass fiber with a non-circular cross section, a glass fiber with a circular section and a mixture of these. Advantageously, the reinforcing fiber is a glass fiber with a non-circular cross section. Advantageously, the reinforcing fiber is a glass fiber with a non-circular cross section and having an elastic modulus of less than 76 GPa as measured according to ASTM C1557-03.

In one embodiment, said composition is devoid of at least one of the constituents chosen from polyphenylene ether (PPE), an anti-drip agent, a PA46, a PA66, a PA6, a polyamide based on a unit obtained by polycondensation of caprolactam , a free radical inhibitor, in particular inorganic, a flame retardant, nigrosine, elemental iron, a polyhydric alcohol, a metal oxide chosen from magnesium oxide, zinc oxide, calcium oxide or a mixture thereof, an amino acid heat stabilizer, an amino acid heat stabilizer with at least one hydroxy group and an amorphous polyamide.

In one embodiment, if said composition comprises a titanium oxide then it is devoid of a metal oxide selected from magnesium oxide, zinc oxide, calcium oxide or a mixture thereof.

In another embodiment, said composition further comprises copolyamide and reinforcing fibers:

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

- 0 to less than 2%, preferably 0.5 to less than 2% by weight of additives,

the sum of copolyamide, reinforcing fibers, an impact modifier, filler, fluidifying agent and additives being equal to 100%.

In this last embodiment, advantageously, said composition is devoid of at least one of the constituents excluded above defined.

In one embodiment, the present invention therefore relates to the use of a copolyamide comprising at least two distinct units A and XiY of formula A / XiY as defined above, to prepare a composition comprising:

- 35 to 70%, in particular 35 to 50, and more particularly 38 to 50% by weight of at least one copolyamide as defined above, - from 30 to 70% by weight of reinforcing fibers,

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

- 0 to less than 2%, preferably 0.5 to less than 2% by weight of additives,

the sum of copolyamide, reinforcing fibers, impact modifier, filler, fluidifying agent and additives being equal to 100%, and whose modulus does not vary by more than 20% in the temperature range from 20 ° C to 40 ° C, in particular in the temperature range from 0 ° C to 40 ° C, in particular in the temperature range from -10 ° C to 40 ° C as defined above.

In another embodiment, the present invention therefore relates to the use of a copolyamide comprising at least two distinct units A and XiY of formula A / XiY as defined above, to prepare a composition comprising:

- 35 to 70%, in particular 35 to 50, and more particularly 38 to 50% by weight of at least one copolyamide as defined above,

- between 35 and 65%, and preferably between 50 and 65% by weight of reinforcing fibers,

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

- 0 to less than 2%, preferably 0.5 to less than 2% by weight of additives,

the sum of copolyamide, reinforcing fibers, impact modifier, filler, fluidifying agent and additives being equal to 100%, and the modulus of which does not vary by more than 20% in the temperature range going from 20 ° C to 40 ° C , in particular in the temperature range from 0 ° C to 40 ° C, in particular in the temperature range from -10 ° C to 40 ° C as defined above.

Advantageously, the present invention relates to the use of a copolyamide comprising at least two distinct units A and XiY of formula A / XiY as defined above, to prepare a composition comprising:

- from 35 to 65%, and preferably from 50 to 65% by weight of reinforcing fibers,

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

- 0 to less than 2%, preferably 0.5 to less than 2% by weight of additives,

More advantageously, the present invention relates to the use of a copolyamide comprising at least two distinct units A and XiY of formula A / XiY as defined above, to prepare a composition comprising: - 35 to 65%, in particular 35 to 50, and more particularly 38 to 50% by weight of at least one copolyamide as defined above,

- from 35 to 65%, and preferably from 50 to 65% by weight of reinforcing fibers, in particular from 50 to 62% by weight of reinforcing fibers,

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

- 0 to less than 2%, preferably 0.5 to less than 2% by weight of additives,

In yet another embodiment, said composition consists of copolyamide, reinforcing fibers, and:

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

- 0 to less than 2%, preferably 0.5 to less than 2% by weight of additives,

In this last embodiment, said composition therefore does not comprise said constituents defined above and excluded.

Advantageously, in this other embodiment, the present invention relates to the use of a copolyamide comprising at least two distinct units A and XiY of formula A / XiY as defined above, to prepare a composition consisting of:

- from 30 to 70% by weight of reinforcing fibers,

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

- 0 to less than 2%, preferably 0.5 to less than 2% by weight of additives,

the sum of copolyamide, reinforcing fibers, impact modifier, filler, fluidifying agent and additives being equal to 100%, and the modulus of which does not vary by more than 20% in the temperature range from from 20 ° C to 40 ° C, in particular in the temperature range from 0 ° C to 40 ° C, in particular in the temperature range from -10 ° C to 40 ° C as defined above .

Advantageously, in this other embodiment, the present invention therefore relates to the use of a copolyamide comprising at least two distinct units A and XiY of formula A / XiY as defined above, to prepare a composition consisting of:

- 35 to 65%, and preferably 50 to 65% by weight of reinforcing fibers,

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

- 0 to less than 2%, preferably 0.5 to less than 2% by weight of additives,

Advantageously, the present invention relates to the use of a copolyamide comprising at least two distinct units A and XiY of formula A / XiY as defined above, to prepare a composition consisting of:

- 35 to 65%, in particular 35 to 50, and more particularly 38 to 50% by weight of at least one copolyamide as defined above,

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

- 0 to less than 2%, preferably 0.5 to less than 2% by weight of additives,

By the expression “impact modifier” is meant a polyolefin-based polymer having a flexural modulus of less than 100 MPa measured according to the ISO 178: 2010 standard (23 ° C RH50) and of Tg less than 0 ° C (measured according to standard 11357-2: 2013 at the inflection point of the DSC thermogram), in particular a polyolefin. The impact modifier can also be a block polymer of PEBA (polyether-block-amide) type having a flexural modulus of <200 MPa.

The composition can also comprise one or more impact modifiers as defined above. The presence of an impact modifier makes it possible to impart greater ductility to the articles made. The polyolefin of the impact modifier can be functionalized or non-functionalized or comprise both as a mixture.

When the polyolefin is functionalized, some or all of the polyolefins bear a function chosen from carboxylic acid, carboxylic anhydride and epoxide functions. The function can in particular be chosen from a copolymer of ethylene and propylene with an elastomeric character (EPR), an ethylene-propylene-diene copolymer with an elastomeric character (EPDM) and an ethylene / (meth) acrylate copolymer, a ethylene-higher alkene copolymer, in particular ethylene-octene copolymer, ethylene-alkyl acrylate-maleic anhydride terpolymer.

Peba (polyether block amides) are copolymers comprising blocks with a polyamide pattern and blocks with a polyether pattern. They can also contain ester functions, in particular resulting from the condensation reaction of terminal carboxylic functions of the polyamide blocks with the hydroxyl functions of the polyether blocks. Peba are commercially available, in particular under the Pebax ^® brand by the company Arkema.

Advantageously, the impact modifier is selected from Fusabond ^® F493, the Tafmer MH5020, a Pebax ^®, particularly Pebax ^® 40R53 SP01, a Lotader ^®, the Exxelor ^® VA1803 or VA1801, the Orevac ^® IM800 or a mixture thereof -Here, in this case they are in a ratio ranging from 0.1 / 99.9 to 99.9 / 0.1. The impact modifier can also be a modifier of “core-shell” type, also designated “copolymer of core-shell type”. The "core-shell" type modifier is in the form of fine particles having an elastomeric core and at least one thermoplastic shell, the size of the particles is generally less than 1 μm and advantageously comprised from 150 to 500 nm. The “core-shell” core-shell modifier has an acrylic or butadiene base.

Several different impact modifiers may be present in the composition.

According to certain embodiments, the content of impact modifier relative to the total weight of the composition can vary from 0 to 10% by weight, advantageously from 1 to 10% by weight.

According to one embodiment, the composition comprises from 1 to 8%, and in particular from 2 to 5% by weight of impact modifier relative to the total weight of the composition.

In another embodiment, the impact modifier content in the composition can vary from 1 to 2% by weight; or from 2 to 3% by weight; or from 3 to 4% by weight; or from 4 to 5% by weight; or from 6 to 7% by weight; or from 7 to 8% by weight; or from 8 to 9% by weight; or from 9 to 10% by weight.

Regarding charges The composition can moreover also comprise fillers. The fillers envisaged include conventional mineral fillers, such as kaolin, magnesia, slag, carbon black, expanded or non-expanded graphite, wollastonite, nucleating agents such as silica, alumina, clay or talc, in particular talc, pigments such as titanium oxide and zinc sulphide, antistatic fillers.

The composition can moreover comprise thinning agents.

By the expression “fluidifying agent” is meant in particular prepolymers.

The prepolymer can be chosen from oligomers of aliphatic, linear or branched, cycloaliphatic, semi-aromatic or even aromatic polyamides. The prepolymer can also be a copolyamide oligomer or a mixture of polyamide and copolyamide oligomers. Preferably, the prepolymer has a number-average molar mass Mn ranging from 1000 to 10000 g / mol, in particular from 1000 to 5000 g / mol. It can in particular be monofunctional NFh if the chain limiter used is a monoamine for example. The molar mass in number (Mn) or the amine number is calculated according to the following formula: Mn = 100O / INFh], [NH2] being the concentration of amine functions in the copolyamide as determined for example by potentiometry.

According to certain embodiments, the content of thinning agent relative to the total weight of the composition can vary from 0 to 5% by weight, in particular from 1 to 5% by weight, in particular from 1 to 5%. According to one embodiment, the composition comprises from 1 to 4%, and in particular from 2 to 3% by weight of thinning agent relative to the total weight of the composition.

According to another embodiment, the content of thinning agent relative to the total weight of the composition is from 1 to 2% by weight; or from 2 to 3% by weight; or from 3 to 4% by weight; or from 4 to 5% by weight.

By the expression “additives” is meant dyes, stabilizers, surfactants, brighteners, antioxidants, lubricants, plasticizers, waxes as well as their mixtures.

Advantageously, it should be understood dyes, stabilizers, surfactants, brighteners, antioxidants, lubricants, waxes as well as their mixtures.

The stabilizers can be organic or inorganic stabilizers. The usual stabilizers used with polymers are, for example, phenols, phosphites, UV absorbers, stabilizers of the HALS (Hindered Amine Light Stabilizer) type, metal iodides. These include Irganox ^® 1010, 245, 1098 of BASF, Irgafos ^® 168, 126 from BASF, Tinuvin ^® 312, 770 from BASF, the Iodide P201 from Ciba, the Nylostab ^® S-EED from the company Clariant.

The lubricants can in particular be a stearate or a wax binder. The waxes can in particular be an amorphous wax such as beeswax, a silicone wax, a polyethylene wax, an oxidized polyethylene wax, an ethylene copolymer wax, a montane wax and a wax of. polyether.

Several different additives, of the same category or of different categories may be present in the composition.

The additive content is from 0 to less than 2% by weight relative to the total weight of the composition.

According to one embodiment, the composition comprises from 0.1 to less than 2%, and in particular from 0.5 to less than 2% by weight of additive relative to the total weight of the composition.

According to certain embodiments, the content of additive in the composition can vary from 0 to 0.5% by weight; or from 0.1 to 0.5% by weight, or from 0.5 to 1% by weight; or from 1 to 1.5% by weight; or from 1.5 to less than 2% by weight.

According to a second aspect, the invention relates to a composition, in particular useful for injection molding, comprising:

- 30 to 65, in particular 50 to 65, and more particularly 50 to 62% by weight of reinforcing fibers;

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

- 0 to less than 2%, preferably from 0.1 to less than 2%, in particular from 0.5 to less than 2% by weight of additives,

provided that the reinforcing fibers / copolyamide mass ratio does not exceed 1.75, in particular 1.6, when the reinforcing fibers have a non-circular section and have a cross-sectional area of from 1.5 to 5 , 0 ^c 10 ⁶ cm ² ;

the sum of the proportions of each constituent of said composition being equal to 100%.

The exclusion of said reinforcing fibers with a non-circular cross-section having a cross-sectional area of 1.5 to 5.0 ^c 10 ⁶ cm ² is therefore valid both for the ratio of 1.75 and for the ratio of 1 , 6.

In one embodiment, said composition useful in particular for injection molding, comprises:

- 0 to 10% by weight of at least one impact modifier; - 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

on condition that the reinforcing fibers / copolyamide mass ratio does not exceed 1.75, in particular 1.6, when the reinforcing fibers have a non-circular section;

The exclusion of said reinforcing fibers of non-circular section is therefore valid both for the ratio of 1.75 and for the ratio of 1.6.

In another embodiment, said composition useful in particular for injection molding, comprises:

- 0 to 10% by weight of at least one impact modifier;

0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

on condition that the weight ratio of reinforcing fibers / copolyamide does not exceed 1.75, in particular 1.6;

The reinforcing fibers, impact modifiers, fillers, thinning agents and additives are as defined above and all the concentration ranges relating to impact modifiers, thinning agents, fillers and additives, defined above, are also valid for said composition. as is.

The exclusions defined above for the preparation of the composition are also valid. Advantageously, said composition, in particular useful for injection molding, consists of:

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and - 0 to less than 2%, preferably from 0.1 to less than 2%, in particular from 0.5 to less than 2% by weight of additives,

In one embodiment, said composition, in particular useful for injection molding, consists of:

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

on condition that the reinforcing fibers / copolyamide mass ratio does not exceed 1.75, in particular 1.6 when the reinforcing fibers have a non-circular section;

In another embodiment, said composition useful in particular for injection molding, consists of:

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

- 0 to 5% by weight of at least one thinning agent; and

- 0 to less than 2%, preferably from 0.1 to less than 2%, in particular from 0.5 to less than 2% by weight of additives, on condition that the weight ratio of reinforcing fibers / copolyamide does not exceed 1.75, in particular 1.6;

Advantageously, said copolyamide of said composition is chosen from PA11 / 10T, PA11 / 12T, PA12 / 10T, PA12 / 12T, PA1010 / 10T, PA1012 / 10T, PA1010 / 12T, PA1012 / 12T, PA1210 / 10T,

PA1212 / 10T, PA1210 / 12T, PA1212 / 12T, in particular PA11 / 10T.

In one embodiment, the reinforcing fibers of said composition are chosen from glass fibers, carbon fibers, and a mixture thereof, in particular glass fibers.

Advantageously, the glass fibers of said composition are chosen from glass fibers with a non-circular cross section and glass fibers with a circular cross section, carbon fibers, and a mixture of these, in particular glass fibers with non-circular cross section and circular section glass fibers and a mixture thereof, including non-circular cross section glass fibers.

The glass fibers are as defined above.

According to a third aspect, the invention relates to a process for manufacturing the composition as defined above, in which the constituents of said composition are mixed by compounding, in particular in a twin-screw extruder, preferably co-rotating, a co-mixer, or an internal mixer.

Finally, according to a fourth aspect, the invention relates to a molded article capable of being obtained from the composition defined above, by injection molding.

Advantageously, said molded article is for electrical and electronics, and in particular chosen from the group consisting of televisions, digital cameras, digital games, telephone parts, digital tablets, drones, printers or computer parts.

[Examples]

The invention will be explained in more detail in the examples which follow.

Example 1: Synthesis of the copolyamides of the invention.

The various polyamides (comparative) and copolyamides of the invention were prepared according to the usual technique for the synthesis of polyamides and copolyamides.

Synthesis of CoPa 11 / 10T representative of the different copolyamides:

the monomers aminoundecanoic acid, decanediamine and terepthalic acid are loaded together into the reactor according to the desired mass ratio. The medium is first inerted in order to remove the oxygen which can generate yellowing or side reactions. Water can also be charged to improve heat exchange. Two stages of temperature and pressure rise are achieved. The temperature (T °) and pressure conditions are chosen to allow that the medium is in the molten state. After reaching the maintenance conditions, degassing takes place to allow the polycondensation reaction. The medium gradually becomes viscous and the water of reaction formed is entrained by flushing with nitrogen or placed under vacuum. When the stopping conditions are reached, in relation to the desired viscosity, the agitation is stopped and the extrusion and the granulation can start. The granules obtained will then be compounded with the glass fibers.

Compounding

The compositions were prepared by melt blending the polymer granules with the short fibers. This mixture was carried out by compounding on an MC26 type co-rotating twin-screw extruder with a temperature profile (T °) flat at 290 ° C. The screw speed is 250rpm and the flow rate is 20 kg / h.

The introduction of the glass fibers is carried out by lateral force-feeding.

The additives and charges are added during the compounding process in the main hopper.

The following compositions were prepared (E = Example of the invention CE = comparative example): [Table 1]

Irganox ^® 245 and irgafos ^® 168 are anti-oxidants CSX 451J circular section fiber and CSG 3PA820 non-circular section fiber (also known under the name flat fiber) are marketed by the company Nittobo

Injection

Plates of 100 * 100 * 1 mm ³ were prepared by injection of the different compositions: - Injection temperature: 300 ° C

- Mold temperature: 80 ° C

The cycle time is adjusted as a function of the compositions to allow injection of the compositions and is less than 50 seconds.

Example 2: Variation of flexural modulus after water sorption

In order to evaluate the impact of humidity on the flexural modulus, the flexural modulus of test pieces of the compositions obtained was measured on an Instron 5966 machine manufactured by the Instron company. The compositions are dried compositions and compositions saturated in water at 65 ° C beforehand.

The tests were carried out at different temperatures, from -10 ° C to 60 ° C.

In the injected plates, were cut, in the direction of injection, test specimens with dimensions according to the ISO 178 standard, but with a thickness = 1 mm.

The results are presented in Tables 2 to 8 below:

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

[Table 8] [Table 9]

[Table 10]

[Table 11]

Example 3: Variation of tensile modulus after water sorption

In order to assess the impact of humidity on the tensile modulus, the tensile modulus of test pieces of the compositions obtained was measured on an Instron 5966 machine manufactured by the company Instron dried compositions and compositions saturated in water at 65 ° C beforehand.

The tests were carried out at different temperatures, from -10 ° C to 60 ° C.

In the injected plates, in the direction of injection, test pieces were cut to dimensions according to the ISO 527 standard, but with a thickness of 1 mm.

The same tendencies as those observed in bending are found in traction.

Tables 2 to 8 and Example 3 show that the compositions of the invention exhibit a higher modulus stability than that of the comparative CEI and CE2 compositions, in flexion or in tension.

Claims

1. Use of a copolyamide comprising at least two distinct units A and XiY of formula A / XiY, in which:

- A is a repeating unit obtained by polycondensation:

at least one C8 to Cis amino acid, preferably C10 to Cis, more preferably C10 to C12, or

at least one C8 to Cis lactam, preferably Cio to Cis, more preferably Cio to C12, or

said at least one Ca diamine being a linear or branched aliphatic diamine, and said at least one Cb diacid being a linear or branched aliphatic diacid,

- XIY is a repeating unit obtained from the polycondensation of at least one linear aliphatic diamine (X) C₆-Cis, preferably in the Cio to Cis, more preferably in Cio to C ₁₂ and at least one dicarboxylic acid aromatic (Y),

to prepare a composition comprising between 35 and 65%, and preferably between 50 and 65% by weight of reinforcing fibers, relative to the total weight of the composition and of which the flexural modulus or the tensile modulus, measured after identical conditioning , does not vary by more than 20% in the temperature range from 20 ° C to 40 ° C, especially in the temperature range from 0 ° C to 40 ° C, especially in the temperature range ranging from -10 ° C to 40 ° C.

2. Use according to claim 1, wherein XiY is a repeating unit obtained by polycondensation of at least one Cio to Cis aliphatic diamine (X), more preferably Cio to C12, and at least one aromatic dicarboxylic acid ( Y).

3. Use according to one of claims 1 or 2, wherein Y is terepthalic acid.

4. Use according to one of claims 1 to 3, in which XiY is a unit chosen from the units 10T, 12T and one of their mixtures.

5. Use according to one of claims 1 to 4, wherein in the copolyamide of formula A / XiY, A is an amino acid or a lactam.

6. Use according to one of claims 1 to 5, in which in the copolyamide of formula A / XiY, A is an amino acid or a Cn or C ₁₂ lactam.

7. Use according to one of claims 1 to 6, wherein said copolyamide is semi-crystalline, in particular having an enthalpy of crystallization greater than 30 J / g.

8. Use according to one of claims 1 to 7, wherein said copolyamide consists only of units A and XiY of formula A / XiY.

9. Use according to one of claims 1 to 7, wherein said copolyamide comprises at least one third Z unit, distinct from the A and XiY units, and corresponds to the general formulation A / XiY / Z in which:

the units A and XiY are as defined in claim 1,

10. Use according to claim 9, wherein said copolyamide consists only of three units of formula A / XiY / Z.

11. Use according to claim 10, in which the reinforcing fibers are chosen from glass fibers and carbon fibers, or a mixture thereof, in particular glass fibers.

12. Composition, in particular useful for injection molding, comprising:

- 35 to 70%, in particular 35 to 50, and more particularly 38 to 50% by weight of at least one copolyamide as defined in one of claims 1 to 11,

- between 35 and 65%, and preferably between 50 and 65% by weight of reinforcing fibers;

- 0 to 10% by weight of at least one impact modifier;

- 0 to 20% by weight of at least one filler; and

13. Composition according to Claim 12, in which the copolyamide is chosen from PA11 / 10T, PA11 / 12T, PA12 / 10T, PA12 / 12T, PA1010 / 10T, PA1012 / 10T, PA1010 / 12T, PA1012 / 12T, PA1210 / 10T, PA1212 / 10T, PA1210 / 12T, PA1212 / 12T, in particular PA11 / 10T.

14. Composition according to Claim 12 or 13, in which the reinforcing fibers are chosen from glass fibers, carbon fibers, and a mixture thereof, in particular glass fibers.

15. The composition of claim 14, wherein the glass fibers are selected from glass fibers with a non-circular cross section and glass fibers with a circular section, carbon fibers, and a mixture thereof, in particular. glass fibers with a non-circular cross section and glass fibers with a circular cross section and a mixture thereof, in particular glass fibers with a non-circular cross section.

16. A method of manufacturing the composition as defined in claims 12 to 15, in which the constituents of said composition are mixed by compounding, in particular in a twin-screw extruder, a co-mixer, or an internal mixer.

17. A molded article obtainable from the composition according to one of claims 12 to 15, by injection molding.

18. A molded article according to claim 17, for electrical and electronic applications, and in particular selected from the group consisting of televisions, digital cameras, digital games, telephone parts, digital tablets, drones. , printers or computer parts.