FR3101080A1 - Polyamide compositions comprising reinforcing fibers and exhibiting high modulus stability and uses thereof - Google Patents

Abstract

The present invention relates to the use of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide in which said at least one semi-crystalline aliphatic polyamide is obtained by polycondensation: of at least one amino acid C6 to C18, preferably C10 to C18, more preferably C10 to C12, or at least one lactam C6 to C18, preferably C10 to C18, more preferably C10 to C12, or at least one diamine Ca in C4-C36, preferentially C5-C18, preferentially C5-C12, more preferentially C10-C12, with at least one Cb in C4-C36 dicarboxylic acid, preferentially C6-C18, preferentially C6-C12, more preferentially C10-C12 ,; to prepare a semi-crystalline composition whose modulus does not vary by more than 25% in the temperature range of 10 ° C to 40 ° C.

Description

Polyamide compositions comprising reinforcing fibers and exhibiting high modulus stability and uses thereof

The present patent application relates to the use of mixtures of semi-crystalline aliphatic and amorphous polyamides 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.

Many applications in the E / E field require the use of high modulus polymer materials, for example for televisions, digital cameras, digital games, telephone parts, digital tablets, drones, printers or computer parts. The modulus of the material is indeed a crucial factor in allowing a reduction in weight, since it allows a reduction in the thickness of the parts while maintaining high 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 stiffness 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 to ensure easy assembly of parts when it is carried out in places where the temperature and / or humidity may be high.

Thus, polyamide compositions 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 should be stable at a temperature ranging from 10 ° 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 can vary from 0 to 100%, or in liquid water)

Furthermore, the polyamide compositions 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 in rigidity when the temperature increases, in particular when these polyamides have been packaged in a humid atmosphere beforehand because they contain a certain quantity of water.

We know from application WO 2018/073536 the use of a semi-aromatic polyamide, in particular an MXDZ polyamide in a mixture of aliphatic polyamide, in particular semi-crystalline, comprising glass fibers with a circular section, to limit 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 implementation, 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 μeq / g, an end-of-chain content acid less than or equal to 100 µeq / g, and a non-reactive end-of-chain content greater than or equal to 20 µeq / 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 / 10T units characterized in that it has 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 GPa determined. 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 polyamide-based formulation combining a stable modulus over a wide temperature range, even when the composition is saturated with water, and good suitability for injection molding.

The aim of the invention is therefore to provide mixtures of semi-crystalline and amorphous polyamides for the manufacture of compositions exhibiting high modulus stability under the effect of temperature and humidity.

Also, according to a first aspect, the invention relates to the use of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide in which said semi-crystalline aliphatic polyamide is obtained by polycondensation. :

at least one C ₆ to C ₁₈ , preferably C ₁₀ to C ₁₈ , more preferably C ₁₀ to C ₁₂ amino acid, or

at least one C ₆ to C ₁₈ , preferably C ₁₀ to C ₁₈ , more preferably C ₁₀ to C ₁₂ lactam, or

of at least one C ₄ -C ₃₆ aliphatic Ca diamine, preferably C ₅ -C ₁₈ , preferably C ₅ -C ₁₂ , more preferably C ₁₀ -C ₁₂ , with at least one Cb C ₄ -C aliphatic dicarboxylic acid ₃₆ , preferably C ₆ -C ₁₈ , preferably C ₆ -C ₁₂ , more preferably C ₁₀ -C _12,;

to prepare a semi-crystalline composition whose modulus does not vary by more than 25% in the temperature range from 10 ° C to 40 ° C, in particular in the temperature range from 0 ° C to 40 ° C , especially in the temperature range from -10 ° C to 40 ° C.

Advantageously, the Tg of said semi-crystalline composition, determined by DMA according to ISO 6721-11: 2019, exhibits an increase greater than or equal to 5 ° C, preferably greater than or equal to 10 ° C, more preferably greater than or equal to 15 ° C. relative to the initial Tg of said semi-crystalline polyamide before mixing.

The Tg of said semi-crystalline composition above is determined under a dry or humid atmosphere, advantageously under an atmosphere saturated in water at 65 ° C.

Advantageously, the Tg of said semi-crystalline composition, determined by DMA, is from 5 ° C to 120 ° C, advantageously from 10 ° C to 120 ° C, more advantageously from 15 ° C to 120 ° C.

The Tg is determined by dynamic mechanical analysis (DMA) according to ISO 6721-11: 2019.

The inventors have unexpectedly found that the selection of a mixture of semi-crystalline aliphatic polyamide and of at least one amorphous polyamide, in a very precise proportion, made it possible to prepare a composition whose modulus not only exhibits stability under l. effect of temperature and humidity, and does not vary by more than 25% in the temperature range from 10 ° 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, more preferably less than 80 ° C, and by a short cycle time during its implementation, in particular less than or equal to 50 s.

They also found that this selection of a mixture of semi-crystalline aliphatic polyamide and at least one amorphous polyamide, in a very precise proportion, made it possible to increase the Tg of the composition relative to that of the semi-crystalline polyamide. aliphatic alone while keeping the semi-crystalline character of the composition.

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.

A semi-crystalline polyamide, within the meaning of the invention, denotes a polyamide which exhibits a glass transition temperature determined by dynamic mechanical analysis (DMA) according to standard ISO 6721-11: 2019 and a melting point (Tm) determined according to the ISO 11357-3: 2013 standard, and an enthalpy of crystallization during the cooling step at a speed of 20K / min in DSC measured according to the ISO 11357-3 standard of 2013 greater than 30 J / g, preferably greater at 35 J / g.

An amorphous polyamide within the meaning of the invention denotes a polyamide which exhibits only a glass transition temperature (no melting point (Tm)), or a very poorly crystalline polyamide having a glass transition temperature and a melting point. such that the enthalpy of crystallization during the cooling step at a speed of 20K / min measured according to standard ISO 11357-3: 2013 is less than 30 J / g, in particular less than 20 J / g, preferably less at 15 J / g.

In one embodiment, the semi-crystalline aliphatic polyamide is linear.

In one embodiment, the semi-crystalline aliphatic polyamide is a homopolyamide, in particular a semi-crystalline linear aliphatic homopolyamide.

Advantageously, the amorphous polyamide used in the invention has a Tg of 100 to 200 ° C, in particular of 120 to 190 ° C.

When said at least one semi-crystalline aliphatic polyamide is obtained from the polycondensation of at least one lactam, said at least one lactam can be chosen from a C ₆ to C ₁₈ lactam, preferably C ₁₀ to C ₁₈ , more preferably in C ₁₀ to C ₁₂ . _{A C 6} to C ₁₂ lactam is in particular caprolactam, decanolactam, undecanolactam, and lauryllactam.

When said at least one semi-crystalline aliphatic polyamide is obtained from the polycondensation of at least one lactam, it can therefore comprise a single lactam or several lactams.

Advantageously, said at least one semi-crystalline aliphatic polyamide is obtained from the polycondensation of a single lactam and said lactam is chosen from lauryllactam and unecanolactam, advantageously lauryllactam.

When said at least one semi-crystalline aliphatic polyamide is obtained from the polycondensation of at least one amino acid, said at least one amino acid can be chosen from a C ₆ to C ₁₈ amino acid, preferably C ₁₀ to C ₁₈ , more preferably in C ₁₀ to C ₁₂ .

A C ₆ to C ₁₂ amino acid is in particular 6-aminohexanoic acid, 9-aminononanoic acid, 10-aminodecanoic acid, 10-aminoundecanoic acid, 12-aminododecanoic acid and 11-aminoundecanoic acid. as well as its derivatives, in particular N-heptyl-11-aminoundecanoic acid.

When said at least one semi-crystalline aliphatic polyamide is obtained from the polycondensation of at least one amino acid, it can therefore comprise a single amino acid or several amino acids.

Advantageously, said semi-crystalline aliphatic polyamide is obtained from the polycondensation of a single amino acid and said amino acid is chosen from 11-aminoundecanoic acid and 12-aminododecanoic acid, advantageously 11-aminoundecanoic acid.

When said at least one semi-crystalline aliphatic polyamide is obtained from the polycondensation of at least one C ₄ -C ₃₆ diamine Ca, preferably C ₅ -C ₁₈ , preferably C ₅ -C _{1 2} , more preferably C ₁₀ -C _{1 2} , with at least one diacid Cb in C ₄ -C ₃₆ , preferentially C ₆ -C ₁₈ , preferentially C ₆ -C _{1 2} , more preferentially C ₁₀ -C _{1 2 ,} then said at least one diamine in Ca is an aliphatic diamine and said at least one Cb diacid is an aliphatic diacid.

The diamine can be linear or branched. Advantageously, it is linear.

Said at least one diamine Ca in C₄-VS₃₆ may in particular be chosen from 1,4-butanediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1, 10-decamethylèdiamine, 1,11-undecamethylèdiamine, 1,12-dodecamethylèdiamine, 1,13-tridecamethylèdiamine, 1,14-tetradecamethylèdiamine, 1,16-hexadecamethylèdiamine and 1,18-octadecamethylèdiamine, octadecenediamine, l 'eicosanediamine, docosanediamine and diamines obtained from fatty acids.

Advantageously, said at least one Ca diamine is C ₅ -C ₁₈ and chosen from 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9- nonamethylèdiamine, 1,10-decamethylèdiamine, 1,11-undécamethylèdiamine, 1,12-dodecamethylèdiamine, 1,13-tridecamethylèdiamine, 1,14-tetradecamethylèdiamine, 1,16-hexadecamethylèdiamine and 1,18-octadecamethylèdiamine.

Advantageously, said at least one C ₅ to C ₁₂ diamine Ca is in particular chosen from 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1, 9-nonamethylèdiamine, 1,10-decamethylèdiamine, 1,11-undecamethylèdiamine, 1,12-dodecamethylèdiamine.

Advantageously, the diamine is used Ca C ₁₀ attached to C _{1 2,} in particular selected from 1,10-décaméthylèdiamine, 1,11-undécaméthylèdiamine, 1,12-dodécaméthylèdiamine.

Said at least one Cb in C ₄ to C ₃₆ dicarboxylic acid can be chosen from succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, acid undecanedioic acid, dodecanedioic acid, brassylic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, and diacids obtained from fatty acids.

The diacid can be linear or branched. Advantageously, it is linear.

Advantageously, said at least one Cb dicarboxylic acid is C ₆ to C ₁₈ 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 C ₆ to C ₁₂ 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 C ₁₀ to C ₁₂ and is chosen from sebacic acid, undecanedioic acid and dodecanedioic acid.

When said aliphatic semi-crystalline polyamide is obtained from the polycondensation of at least one Ca diamine with at least one Cb dicarboxylic acid, it can therefore comprise a single diamine or several diamines and a single dicarboxylic acid or several dicarboxylic acids.

Advantageously, said semi-crystalline aliphatic polyamide is obtained from the polycondensation of a single diamine Ca with a single dicarboxylic acid Cb.

When said at least one amorphous polyamide is a homopolyamide of formula XY or a copolyamide of formula A / XY, then XY is a repeating unit obtained by polycondensation of at least one cycloaliphatic diamine (X) and of at least one aliphatic dicarboxylic acid (Y) in C₄-VS₃₆, preferably C₆-VS₁₈, preferably C₆-VS₁₂, more preferably C₁₀-VS₁₂ or at least one aromatic dicarboxylic acid (Y) and A is a repeating unit obtained by polycondensation of at least one C amino acid₆to C₁₈, preferably in C₁₀to C₁₈, more preferably in C₁₀to C₁₂, or

at least one C ₆ to C ₁₈ , preferably C ₁₀ to C ₁₈ , more preferably C ₁₀ to C ₁₂ lactam, or

of at least one C ₄ -C ₃₆ diamine Ca, preferably C ₅ -C ₁₈ , preferably C ₅ -C ₁₂ , more preferably C ₁₀ -C ₁₂ , with at least one Cb C ₄ -C ₃₆ dicarboxylic acid, preferably C ₆ -C ₁₈ , preferably C ₆ -C ₁₂ , more preferably C ₁₀ -C ₁₂ .

The cycloaliphatic diamine (X) can be chosen from bis (3,5-dialkyl-4-aminocyclohexyl) -methane, bis (3,5-dialkyl-4-aminocyclohexyl) ethane, bis (3,5-dialkyl- 4-aminocyclohexyl) -propane, bis (3,5-dialkyl-4-aminocyclo-hexyl) -butane, bis- (3-methyl-4-aminocyclohexyl) -methane or 3,3'-dimethyl-4,4 '-diamino-dicyclohexyl-methane commonly referred to as (BMACM) or (MACM) (and denoted B below), bis (p-aminocyclohexyl) -methane commonly referred to as (PACM) (and denoted P below), in particular Dicykan®, isopropylidenedi (cyclohexylamine) commonly referred to as (PACP), isophorone-diamine (noted IPD below) and 2,6-bis (amino methyl) norbornane commonly referred to as (BAMN) and bis (aminomethyl ) cyclohexane (BAC), in particular 1,3-BAC or Ia, in particular 1,4-BAC.

Advantageously, it is chosen from bis- (3-methyl-4-aminocyclohexyl) -methane or 3,3'-dimethyl-4,4'-diamino-dicyclohexyl-methane commonly called (BMACM) or (MACM) (and noted B below), bis (p-aminocyclohexyl) -methane commonly known as (PACM) (and noted P below) and bis (aminomethyl) cyclohexane (BAC), in particular 1,3-BAC or 1a, in particular 1,4-BAC.

A, Ca and Cb are as defined above.

When (Y) is at least one C ₄ -C ₃₆ aliphatic dicarboxylic acid, preferably C ₆ -C ₁₈ , preferably C ₆ -C ₁₂ , more preferably C ₁₀ -C ₁₂ , it is as defined for Cb.

When (Y) is at least one aromatic dicarboxylic acid (Y), it is advantageously chosen from terephthalic acid (denoted T), isophthalic acid (denoted I) and 2,6 naphthalene dicarboxylic acid (denoted N) or their mixtures, in particular it is chosen from terephthalic acid (denoted T), isophthalic acid (denoted I) or their mixtures.

The modulus of a composition changes with temperature and generally, the modulus decreases with increasing temperature.

The expression "the modulus does not vary by more than 25% in the temperature range from 10 ° C to 40 ° C, in particular in the temperature range from 0 ° C to 40 ° C, in particular in the temperature range going from - 10 ° C to 40 ° C "means that in these different ranges from 10 ° C to 40 ° C, from 0 ° C to 40 ° C and from -10 ° 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 25%.

Advantageously, the modulus of said composition does not vary by more than 35% in the temperature range of -10 ° C to 50 ° C.

The expression "the modulus does not vary by more than 35% in the temperature range from - 10 ° C to 50 ° C" means that in the range from -10 ° C to 50 ° C, the modulus d '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 35%.

More advantageously, the modulus of said composition does not vary by more than 40% in the temperature range of -10 ° C to 60 ° C.

The expression "the modulus does not vary by more than 40% in the temperature range from - 10 ° C to 60 ° C" means that in the range from -10 ° C to 60 ° C, the modulus d '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 40%.

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

In other words, let M _{-1 0 be} the modulus measured at -10 ° C and M _T the modulus measured at a temperature T for a composition conditioned under the same dry or humid atmosphere conditions, then:

((M _{-1 0} - M _T ) / M _{-1 0} ) x 100 ≤ 25%, with T varying from -10 to 40 ° C.

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 variation in flexural modulus, measured at 20 ° C on a sample saturated in water at 65 ° C, and measured at 20 ° C on a dry sample, is less than or equal to 15%, in particular less than or equal at 7%, both measurements being carried out according to ISO 178: 2010.

In other words, (M _sec - M _sat ) x 100 / M _sec ≤ 15%.

In one embodiment, said at least one amorphous polyamide is a homopolyamide of formula XY or a copolyamide of formula A / XY, XY being a repeating unit obtained by polycondensation of at least one cycloaliphatic diamine (X) and at least an aliphatic (Y) dicarboxylic acid at C₄-VS₃₆, preferably C₆-VS₁₈, preferably C₆-VS₁₂, more preferably C₁₀-VS₁₂ or at least one aromatic dicarboxylic acid (Y) and A is a repeating unit obtained by polycondensation of at least one C amino acid₆to C₁₈, preferably in C₁₀to C₁₈, more preferably in C₁₀to C₁₂, or

at least one C ₆ to C ₁₈ , preferably C ₁₀ to C ₁₈ , more preferably C ₁₀ to C ₁₂ lactam, or

of at least one C ₄ -C ₃₆ diamine Ca, preferably C ₅ -C ₁₈ , preferably C ₅ -C ₁₂ , more preferably C ₁₀ -C ₁₂ , with at least one Cb C ₄ -C ₃₆ dicarboxylic acid, preferably C ₆ -C ₁₈ , preferably C ₆ -C ₁₂ , more preferably C ₁₀ -C ₁₂ .

In a first variant, said at least one amorphous polyamide is a copolyamide of formula A / XY, A being obtained by polycondensation of at least one amino acid or obtained by polycondensation of at least one lactam, X being chosen from B or P or BAC and Y being terepthalic and / or isophthalic acid.

Advantageously, in this first variant, A / XY is chosen from the patterns 11 / BI / BT, 12 / BI / BT, 11 / BACI / BACT, 12 / BACI / BACT, 11 / BACI, 12 / BACI, 11 / PI / PT, 12 / PI / PT and one of their mixtures.

In a second variant, said at least one amorphous polyamide is a copolyamide of formula A / XY, A being obtained by polycondensation of at least one amino acid or obtained by polycondensation of at least one lactam, X being chosen from B or P and Y being sebacic acid or dodecanedioic acid.

Advantageously, in this second variant, A / XY is chosen from the units 11 / B10, 11 / B12, 11 / P10, 11 / P12, 12 / B10, 12 / B12, 12 / P10, 12 / P12, and the one of their mixtures.

In a third variant, said at least one amorphous polyamide is a copolyamide of formula A / XY, A being obtained by polycondensation of at least one diamine Ca with at least one dicarboxylic acid Cb, X being chosen from B or P and Y being sebacic acid or dodecanedioic acid.

Advantageously, in this third variant, in which A / XY is chosen from the units 1010 / B10, 1010 / B12, 1010 / P10, 1010 / P12, 1012 / B10, 1012 / B12, 1012 / P10, 1012 / P12, 1210 / B10, 1210 / B12, 1210 / P10, 1210 / P12, 1212 / B10, 1212 / B12, 1212 / P10, 1212 / P12, and a mixture thereof.

In a fourth variant, said at least one amorphous polyamide is a homopolyamide of formula XY, X being chosen from B or P and Y being sebacic acid or dodecanedioic acid.

Advantageously, in this fourth variant, XY is chosen from the units B10, B12, P10, P12, and one of their mixtures.

In one embodiment, the proportion by weight of said amorphous polyamide is from 10 to 45%, preferably from 15 to 35% by weight, more preferably from 20 to 30% by weight relative to the sum by weight of said at least one semi-crystalline polyamide and said at least one amorphous polyamide.

In another embodiment, the present invention relates to the use of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide for preparing a semi-crystalline composition as defined above, said composition comprising from 35 to 75% by weight of reinforcing fibers, in particular from 35 to 65% by weight of reinforcing fibers.

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

Glass beads are excluded from the definition of reinforcing fibers.

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

These short reinforcing fibers can be chosen from:

- natural fibers

- mineral fibers, these having high melting temperatures Tf 'and above the melting temperature Tf of said semi-crystalline polyamide of the invention and above the processing temperature.

- Polymeric or polymer fibers having a melting point Tf 'or in the absence of Tf', a glass transition temperature Tg ', greater than the melting temperature Tf of said semi-crystalline polyamide constituting said matrix of 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 D, 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 (Al ₂ O ₃ ); 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 D, E, R, S2, or T, boron fibers, ceramic fibers, in particular carbide fibers silicon, 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 Al2O3, 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).

The preferred short reinforcing fibers are short fibers chosen from: carbon fibers, including metallized, glass fibers, including metallized type E, R, S2, or T aramid fibers (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.

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 circular section.

In another embodiment, said composition further comprises semi-crystalline aliphatic polyamide, amorphous polyamide 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 10% 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 semi-crystalline aliphatic polyamide, amorphous polyamide, reinforcing fibers, impact modifier, filler, fluidifying agent and additives being equal to 100%.

In yet another embodiment, said composition consists of semi-crystalline aliphatic polyamide, amorphous polyamide, 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 10% 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 semi-crystalline aliphatic polyamide, amorphous polyamide, reinforcing fibers, an impact modifier, filler, fluidifying agent and additives being equal to 100%.

The expression “ impact modifier ” should be understood to mean 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 <200 MPa.

The impact modifier can also be a polyolefin of SEBS type.

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 of manufacture.

The polyolefin of the impact modifier can be functionalized or non-functionalized or have 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 polyolefin 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 chosen from Fusabond® F493, Tafmer MH5020, a Pebax®, in particular Pebax® 40R53 SP01, a Lotader®, Exxelor® VA1803 or VA1801, Orevac® IM800 or a mixture of those - 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 “core-shell” type modifier, also designated “core-shell copolymer”. 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 one μm and advantageously between 150 and 500 nm. The “core-shell” type 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 content of the impact modifier 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 5 to 6% 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 glass beads, in particular solid or hollow, 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, flame retardant fillers, especially a halogen-free flame retardant, as described in US 2008/0274355 and in particular a phosphorus-based flame retardant, for example a metal salt chosen from a metal salt of phosphinic acid, in particular salts of dialkyl phosphinate, in particular diethylphosphinate aluminum salt or diethylphosphinate d aluminum, a metal salt of diphosphinic acid, a mixture of flame retardant based on aluminum phosphinate and a nitrogen synergist or a mixture of flame retardant based on aluminum phosphinate and a n phosphorus synergist, a polymer containing at least one metal salt of phosphinic acid, in particular on an ammonium base such as an ammonium polyphosphate, sulfamate or pentaborate, or on a melamine base such as melamine, melamine salts, melamine pyrophosphates and melamine cyanurates, or based on cyanuric acid, also a polymer containing at least one metal salt of diphosphinic acid or red phosphorus, an antimony oxide, a zinc oxide, an oxide of iron, magnesium oxide or metal borates such as zinc borate, or phosphazene, phospham or phosphoxynitride or a mixture thereof. Flame retardant fillers can also be halogenated flame retardants such as brominated or polybrominated polystyrene, brominated polycarbonate or brominated phenol.

It is understood that the glass beads are not reinforcing fibers.

The composition can also include fluidifying 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 NH ₂ 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 = 1000 / [NH ₂ ], [NH ₂ ] 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 10% by weight, in particular from 1 to 10% by weight, in particular from 5 to 10%.

According to one embodiment, the composition comprises from 1 to 5%, and in particular from 1 to 4%, 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.

The expression “ additives ” should be understood to mean colorants, 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. Mention may be made of Irganox® 1010, 245, 1098 from the company BASF, Irgafos® 168, 126 from the company BASF, Tinuvin® 312, 770 from the company BASF, Iodide P201 from the company Ciba, Nylostab® S-EED from Clariant.

The lubricants can in particular be a stearate or a wax binder.

The waxes can in particular be an amorphous wax such as a 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:

- 25 to 65%, in particular 35 to 65%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 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 10% 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;

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

All the characteristics defined above for the use of the mixture to prepare a composition are valid for the composition as such.

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.

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 65%, in particular 35 to 65%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 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 10% 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;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 64.9%, in particular 35 to 64.9%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 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 10% by weight of at least one thinning agent; and

- 0.1 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 64.5%, in particular 35 to 64.5%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 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;

- 0 to 10% by weight of at least one thinning agent; and

- 0.5 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 63.9%, in particular 35 to 63.9%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 to 65% by weight of reinforcing fibers;

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

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

- 0 to 10% by weight of at least one thinning agent; and

- 0.1 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 63.5%, in particular 35 to 63.5%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 to 65% by weight of reinforcing fibers;

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

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

- 0 to 10% by weight of at least one thinning agent; and

- 0.5 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 63.9%, in particular 35 to 63.9%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 to 65% by weight of reinforcing fibers;

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

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

- 0 to 10% by weight of at least one thinning agent; and

- 0.1 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 63.5%, in particular 35 to 63.5%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 to 65% by weight of reinforcing fibers;

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

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

- 0 to 10% by weight of at least one thinning agent; and

- 0.5 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 63.9%, in particular 35 to 63.9%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 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;

- 1 to 10% by weight of at least one thinning agent; and

- 0.1 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 63.5%, in particular 35 to 63.5%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 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;

- 1 to 10% by weight of at least one thinning agent; and

- 0.5 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 62.9%, in particular 35 to 62.9%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 to 65% by weight of reinforcing fibers;

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

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

- 1 to 10% by weight of at least one thinning agent; and

- 0.1 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 62.5%, in particular 35 to 62.5%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 to 65% by weight of reinforcing fibers;

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

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

- 1 to 10% by weight of at least one thinning agent; and

- 0.5 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 62.9%, in particular 35 to 62.9%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 to 65% by weight of reinforcing fibers;

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

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

- 1 to 10% by weight of at least one thinning agent; and

- 0.1 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 62.5%, in particular 35 to 62.5%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 to 65% by weight of reinforcing fibers;

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

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

- 1 to 10% by weight of at least one thinning agent; and

- 0.5 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 61.9%, in particular 35 to 61.9%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 to 65% by weight of reinforcing fibers;

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

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

- 1 to 10% by weight of at least one thinning agent; and

- 0.1 to less than 2% by weight of additives;

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

Advantageously, said composition, in particular useful for injection molding, consists of:

- 25 to 61.5%, in particular 35 to 61.5%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide as defined above,

- 35 to 75, in particular 35 to 65% by weight of reinforcing fibers;

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

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

- 1 to 10% by weight of at least one thinning agent; and

- 0.5 to less than 2% by weight of additives;

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

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 obtainable 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.

In another embodiment, said molded article is for sports, and in particular a ski boot or part of a ski boot or a rigid shoe with a stud, such as a soccer, rugby or American football boot. hockey or a game of hockey shoe, or a running shoe, a golf ball or a game of golf ball, or a lacrosse stick or a hockey article such as a helmet or sporting goods for the protection of the head, shoulders, elbows, hands, knees, back or shin, such as helmet, gloves, shoulder pads, elbow pads, knee pads or shin pads.

[Examples]

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

Example 1: Synthesis of (co) polyamides of the invention.

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

Synthesis of PA B10 representative of the different homopolyamides:

the bis- (3-methyl-4-aminocyclohexyl) -methane (B) and sebacic acid monomers are charged together in the reactor. The medium is first inerted in order to remove oxygen which can generate yellowing or side reactions. Water can also be charged to improve heat exchange and promote melting of the monomers. Two stages of temperature and pressure rise are carried out. The temperature (T °) and pressure conditions are chosen to allow the medium to be in a molten state. After reaching the maintenance conditions, degassing takes place to allow the polycondensation reaction. The medium gradually becomes viscous and the reaction water 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.

Synthesis of PA 11 / B10 representative of the different copolyamides:

the aminoundecanoic acid, bis- (3-methyl-4-aminocyclohexyl) -methane (B) and sebacic acid monomers are loaded together into the reactor according to the desired mass ratio. The medium is first inerted in order to remove oxygen which can generate yellowing or side reactions. Water can also be charged to improve heat exchange and promote melting of the monomers. Two stages of temperature and pressure rise are carried out. The temperature (T °) and pressure conditions are chosen to allow the medium to be in a molten state. After reaching the maintenance conditions, degassing takes place to allow the polycondensation reaction. The medium gradually becomes viscous and the reaction water 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 a co-rotating twin-screw extruder with a screw diameter of 26 mm 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 (co) polyamides, the additives and optionally the fillers are added during the compounding process in the main hopper.

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

Composition CE1 CE2 CE3 I1 I2 I3 I4 I5 I6 I7 I8 B10 7.89 7.89 PA1010 39.46 31.57 11 / B10 7.90 9.90 11.80 9.90 9.90 12 / B10 9.90 PA11 39.46 31.56 29.56 27.66 29.56 24.56 31.57 PA12 39.46 29.56 Prepolymer PA11
monoNH2 5.00 Antioxidant 0.24 0.24 0.24 0.24 0.24 0.24 0.24 0.24 0.24 0.24 0.24 Calcium stearate 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 Fiberglass CSX3J- 451 60.00 60.00 60.00 60.00 60.00 60.00 60.00 60.00 60.00 60.00 60.00

CSX3J-451 circular section fibers 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 depending on the compositions to allow injection of the compositions and is less than 50 seconds.

Compositions I1 to I8 all exhibit a Tg relative to the comparative compositions CE1 to CE3 greater than 5 ° C.

The polyamide mixtures of compositions I1 to I8 of Table 1 all have crystallization enthalpies greater than 30 J / g.

Example 2 : Variation of the modulus of bending depending on temperature and humidity

In order to assess the impact of humidity and temperature on flexural modulus, the flexural modulus of test pieces of the obtained compositions 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, in the direction of injection, test pieces were cut to dimensions according to ISO 178, but with a thickness = 1mm.

The results are presented in the s board x 2 and 3 below :

modulus loss in saturated state (%) (M _-10 - M _T / M _-10 ) x 100 CE1 CE2 CE3 I1 I2 I3 I4 I5 I6 I7 I8 -10 0 0 0 0 0 0 0 0 0 0 0 0 4 3 3 1 1 1 1 1 1 2 3 10 11 9 10 3 3 3 3 3 3 5 6 20 22 20 21 6 5 4 5 5 4 9 10 30 32 31 33 10 8 8 9 8 8 15 17 40 40 39 39 17 13 11 14 14 12 24 25 50 45 43 45 23 20 17 21 21 18 30 31 60 47 45 48 30 28 24 28 28 24 37 38

Modulus variation between dry and saturated state (%) CE1 CE2 CE3 I1 I2 I3 I4 I5 I6 I7 I8 20 ° C 33 30 34 4 -2 -9 7 3 -1 15 15

Table 2 shows that the compositions of the invention exhibit a stability of the flexural modulus greater than that of the comparative composition CE1.

Example 3 : Variation of traction modulus depending on temperature and humidity

In order to assess the impact of humidity and temperature on tensile modulus, the tensile modulus of test pieces of the obtained compositions 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, in the direction of injection, test pieces were cut to dimensions according to ISO 527, but with a thickness of 1 mm.

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

Claims (22)

Use of a mixture of at least one semi-crystalline aliphatic polyamide and at least one amorphous polyamide in which said at least one semi-crystalline aliphatic polyamide is obtained by polycondensation:
at least one C ₆ to C ₁₈ , preferably C ₁₀ to C ₁₈ , more preferably C ₁₀ to C ₁₂ amino acid, or
at least one C ₆ to C ₁₈ , preferably C ₁₀ to C ₁₈ , more preferably C ₁₀ to C ₁₂ lactam, or
of at least one C ₄ -C ₃₆ aliphatic Ca diamine, preferably C ₅ -C ₁₈ , preferably C ₅ -C ₁₂ , more preferably C ₁₀ -C ₁₂ , with at least one Cb C ₄ -C aliphatic dicarboxylic acid ₃₆ , preferably C ₆ -C ₁₈ , preferably C ₆ -C ₁₂ , more preferably C ₁₀ -C _12,;
to prepare a semi-crystalline composition whose tensile or flexural modulus does not vary by more than 25% in the temperature range from 10 ° C to 40 ° C, in particular in the temperature range from 0 ° C to 40 ° C, especially in the temperature range of -10 ° C to 40 ° C. Use according to claim 1, wherein the modulus does not vary by more than 35% in the temperature range of -10 ° C to 50 ° C. Use according to Claim 1 or 2, in which the Tg of said semi-crystalline composition, determined by DMA according to ISO 6721-11: 2019, exhibits an increase greater than or equal to 5 ° C, preferably greater than or equal to 10 ° C, more preferably greater than or equal to 15 ° C. relative to the initial Tg of said semi-crystalline polyamide before mixing. Use according to one of claims 1 to 3, in which said at least one amorphous polyamide is a homopolyamide of formula XY or a copolyamide of formula A / XY, XY being a repeating unit obtained by polycondensation of at least one cycloaliphatic diamine ( X) and at least one aliphatic (Y) dicarboxylic acid in C₄-VS₃₆, preferably C₆-VS₁₈, preferably C₆-VS₁₂, more preferably C₁₀-VS₁₂ or at least one aromatic dicarboxylic acid (Y) and A is a repeating unit obtained by polycondensation of at least one C amino acid₆to C₁₈, preferably in C₁₀to C₁₈, more preferably in C₁₀to C₁₂, or
at least one lactam in C₆to C₁₈, preferably in C₁₀to C₁₈, more preferably in C₁₀to C₁₂, or
of at least one Ca diamine in C₄-VS₃₆, preferably C₅-VS₁₈, preferably C₅-VS₁₂, more preferably C₁₀-VS₁₂, with at least one Cb to C dicarboxylic acid₄-VS₃₆, preferably C₆-VS₁₈, preferably C₆-VS₁₂, more preferably C₁₀-VS₁₂. Use according to Claim 4, in which said at least one amorphous polyamide is a copolyamide of formula A / XY, A being obtained by polycondensation of at least one amino acid or obtained by polycondensation of at least one lactam, X being chosen from among bis- (3-methyl-4-aminocyclohexyl) -methane (B) or bis (p-aminocyclohexyl) -methane (P) or bis (aminomethyl) cyclohexane (BAC) and Y being terepthalic and / or isophthalic acid . Use according to Claim 4 or 5, in which A / XY is chosen from the units 11 / BI / BT, 12 / BI / BT, 11 / BACI / BACT, 12 / BACI / BACT, 11 / BACI, 12 / BACI, 11 / PI / PT, 12 / PI / PT and one of their mixtures. Use according to Claim 4, in which said at least one amorphous polyamide is a copolyamide of formula A / XY, A being obtained by polycondensation of at least one amino acid or obtained by polycondensation of at least one lactam, X being chosen from among bis- (3-methyl-4-aminocyclohexyl) -methane (B) or bis (p-aminocyclohexyl) -methane (P) and Y being sebacic acid or dodecanedioic acid. Use according to Claim 4 or 7, in which A / XY is chosen from the units 11 / B10, 11 / B12, 11 / P10, 11 / P12, 12 / B10, 12 / B12, 12 / P10, 12 / P12, and one of their mixtures. Use according to Claim 4, in which said at least one amorphous polyamide is a copolyamide of formula A / XY, A being obtained by polycondensation of at least one diamine Ca with at least one Cb dicarboxylic acid, X being chosen from bis- (3-methyl-4-aminocyclohexyl) -methane (B) or bis (p-aminocyclohexyl) -methane (P) and Y being sebacic acid or dodecanedioic acid. Use according to Claim 4 or 9, in which A / XY is chosen from the units 1010 / B10, 1010 / B12, 1010 / P10, 1010 / P12, 1012 / B10, 1012 / B12, 1012 / P10, 1012 / P12, 1210 / B10, 1210 / B12, 1210 / P10, 1210 / P12, 1212 / B10, 1212 / B12, 1212 / P10, 1212 / P12, and a mixture thereof. Use according to claim 4, wherein said at least one amorphous polyamide is a homopolyamide of formula XY, X being selected from bis- (3-methyl-4-aminocyclohexyl) -methane (B) or bis (p-aminocyclohexyl) -methane (P) and Y being sebacic acid or dodecanedioic acid. Use according to claim 4 or 11, wherein XY is selected from the units B10, B12, P10, P12, and a mixture thereof. Use according to one of claims 1 to 12, wherein said semi-crystalline polyamide has an enthalpy of crystallization greater than 30 J / g. Use according to one of claims 1 to 13, in which the proportion by weight of said amorphous polyamide is from 10 to 45%, preferably from 15 to 35% by weight, more preferably from 20 to 30% by weight relative to the sum by weight of said at least one semi-crystalline polyamide and of said at least one amorphous polyamide. Use according to one of claims 1 to 14, wherein the composition comprises 35 to 75% by weight of reinforcing fibers, in particular 35 to 65% by weight of reinforcing fibers. Use according to Claim 15, in which the reinforcing fibers are chosen from glass fibers and carbon fibers, or a mixture thereof, in particular glass fibers. Use according to claim 16, wherein the glass fibers are selected from non-circular cross section glass fibers and circular cross section glass fibers, carbon fibers, and a mixture thereof, in particular fibers. glass having a non-circular cross section and glass fibers having a circular section and a mixture thereof, in particular glass fibers having a circular section. Composition, in particular useful for injection molding, comprising:
- 25 to 65%, in particular 35 to 65%, by weight of a mixture of at least one semi-crystalline aliphatic polyamide and of at least one amorphous polyamide as defined in one of claims 1 to 14,
- 35 to 75, in particular 35 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 10% 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;
the sum of the proportions of each constituent of said composition being equal to 100%. A method of manufacturing the composition as defined in claim 18, 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. A molded article obtainable from the composition of claim 18 by injection molding. A molded article according to claim 20, for electrical and electronic applications, and in particular selected from the group consisting of televisions, digital cameras, digital games, telephone parts, digital tablets, drones, devices. printers or computer parts. Molded article according to claim 20, for sports, and in particular a ski boot or part of a ski boot or a rigid shoe with a spike, such as a soccer, rugby or American football boot, a hockey boot or a part hockey shoe, or a running shoe, a golf ball or a game of golf ball, or a lacrosse stick or a hockey article such as a helmet or sports articles for the protection of head, shoulders, elbows, hands, knees, back or shin, such as helmet, gloves, shoulder pads, elbow pads, knee pads or shin guards.