Thermoplastic composite material made of a semi-crystalline polyamide and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-10377898-B2
Application number	US-201715667211-A
Country	US
Kind code	B2
Filing date	Aug 2, 2017
Priority date	Oct 23, 2012
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

A composition for a thermoplastic composite material having a thermoplastic matrix made of a semi-crystalline polyamide having a specific composition that includes at least two amide units, A, 55-95 mol %, and B, 5-45 mol %. A corresponds to x.T, wherein x is a C9-C18 linear aliphatic diamine and B corresponds to x′.T, wherein x′ can be B1): a specific branched x-dependent aliphatic diamine, B2): MXD or B3): a linear x-dependent aliphatic diamine, said polyamide having a glass transition temperature Tg of at least 90° C. and a melting point no higher than 280° C. Also, a method for manufacturing the composite material, the semi-crystalline polyamide polymer, the use of the composition and of the polymer for parts made of composite material, as well as the material and the resulting composite part.

First claim

The invention claimed is:

1. A composition for a thermoplastic composite material, said thermoplastic composite material comprising reinforcing fibers or a fibrous reinforcement, and a thermoplastic matrix which impregnates said reinforcing fibers or said fibrous reinforcement,
said composition comprises:
reinforcing fibers or a fibrous reinforcement; and
a reactive composition comprising one or more reactive polyamide prepolymers, said composition being a composition which is a precursor of a polyamide polymer of said thermoplastic matrix,

wherein said one or more reactive polyamide prepolymers comprise different amide units A and B and, optionally, amide units C and D, selected as follows:
A: is a major amide unit present at a molar content ranging from 55% to 95%, chosen from x.T units, where x is a C 9 to C 18 , linear aliphatic diamine, and where T is terephthalic acid,
B: is an amide unit different than A, said unit B being present at a molar content ranging from 5% to 45%, according to the Tm of the polyamide based on unit A and said amide unit B being chosen from x′.T units, where x′ is chosen from:
B1) a branched aliphatic diamine bearing a single methyl or ethyl branching and having a main chain length which is different by at least two carbon atoms compared with the main chain length of the diamine x of said associated unit A,
B2) m-xylylenediamine (MXD) or
B3) a C 4 to C 18 linear aliphatic diamine when, in the unit A, said diamine x is a C 11 to C 18 linear aliphatic diamine and x′ is a C 9 to C 18 diamine when, in the unit A, said diamine x is a C 9 or C 10 diamine,

C: optional amide unit different than A and than B, chosen from amide units based on a cycloaliphatic and/or aromatic structure or based on x′T as defined above for B but with x′ being different than x′ for the unit B, and
D: optional amide unit different than A, than B and than C when C is present, and chosen from the aliphatic amide units derived from:
amino acids or lactams which are C 6 to C 12 , r mixtures thereof, the reaction of a C 6 to C 18 linear aliphatic diacid and of a C 6 to C 18 linear aliphatic diamine, or mixtures thereof,

and under the condition that the sum of the molar contents of A+B+C+D is equal to 100%,
wherein one or more reactive polyamide prepolymers is a precursor of a semi-crystalline polyamide polymer with a glass transition temperature Tg of at least 90° C. and with a melting temperature Tm below or equal to 280° C.,
and
wherein said reactive composition further comprises:
a1) at least one reactive polyamide prepolymer of said thermoplastic composite material, bearing n end reactive functions X, chosen from: —NH 2 , —CO 2 H and —OH, with n being 2; and
a2) at least one chain extender Y-A′-Y, with A′ being a hydrocarbon-based diradical of nonpolymeric structure, bearing 2 identical end reactive functions Y, which are reactive, by polyaddition, with at least one function X of said reactive polyamide prepolymer a1), a2) having a molecular weight of less than 500, wherein Y is selected from the group consisting of maleimide, optionally blocked isocyanate, oxazinone and oxazolinone.

2. The composition of claim 1 , wherein said amide unit C is present and partially replaces B at a molar content ranging up to 25% relative to said unit B.

3. The composition of claim 1 , wherein said unit D is present and partially replaces B at a molar content ranging up to 70%, relative to said unit B.

4. The composition of claim 1 , wherein the difference Tm−Tc, between the melting temperature Tm and the crystallization temperature Tc of said semi-crystalline polyamide, does not exceed 50° C.

5. The composition of claim 1 , wherein the enthalpy of crystallization of said semi-crystalline polyamide, measured by differential scanning calorimetry (DSC) according to standard ISO 11357-3, is greater than 40 J/g.

6. The composition of claim 1 , wherein said amide unit A is present with a molar content ranging from 55% to 80%, relative to all the units of said polymer.

7. The composition of claim 1 , wherein said unit B corresponds to x′T with x′ being 2-methylpentamethylenediamine (MPMD).

8. The composition of claim 1 , wherein said unit B corresponds to x′T with x′ chosen according to option B2), x′ being MXD.

9. The composition of claim 1 , wherein said unit B corresponds to a linear aliphatic diamine according to option B3).

10. The composition of claim 1 , wherein the units A and B are selected as follows:
for the unit A being 9T, said unit B is selected from: 10T, 11T, 12T, 13T, 14T, 15T, 16T, 17T and 18T, 2-methylpentamethylenediamine (MPMD).T and MXD.T, with a molar content of B ranging from 30% to 45%,
for the unit A being 10T, said unit B is selected from: 9T, 11T, 12T, 13T, 14T, 15T, 16T, 17T and 18T, MPMD.T and MXD.T, with a molar content of B ranging from 25% to 45%,
for the unit A being 11T, said unit B is selected from: 9T, 10T, 12T, 13T, 14T, 15T, 16T, 17T and 18T, MPMD.T and MXD.T, with a molar content of B ranging from 20% to 45%, and
for the unit A being 12T, said unit B is selected from: 9T, 10T, 11T, 13T, 14T, 15T, 16T, 17T and 18T, MPMD.T and MXD.T, with a molar content of B ranging from 20% to 45%.

11. The composition of claim 7 , wherein a part of the unit B which is up to 70 mol %, relative to B, is replaced with a unit C and/or D.

12. The composition of claim 1 , wherein said reactive prepolymers of said reactive composition have a number-average molecular weight Mn ranging from 500 to 10 000.

13. The composition of claim 1 , wherein the composition comprises a fibrous reinforcement with long fibers with L/D>1000.

14. A process for manufacturing a thermoplastic composite material, having the composition of claim 1 , wherein the process comprises at least one step of polymerization of at least one reactive composition which is a precursor of said polyamide polymer of said matrix of the thermoplastic composite material.

15. The process of claim 14 , wherein the process comprises the following steps:
i) impregnation in the molten state of a fibrous reinforcement with the reactive composition, in an open or closed mold or outside the mold, in order to obtain the thermoplastic composite material,
ii) polymerization reaction by heating said composition of step i) with chain extension, as appropriate, by polycondensation reaction or by polyaddition reaction, in bulk in the molten state with, in the case of polycondensation, elimination under vacuum of the condensation products when a closed mold is involved, using a vacuum extraction system, otherwise with the polycondensation being carried out in an open mold or outside the mold, and
iii) processing by molding or by means of another processing system and simultaneously with the polymerization step ii).

16. A method for manufacturing mechanical or structural parts based on said composite material, comprising using a composition of claim 1 .

17. The method of claim 16 , wherein said mechanical or structural parts made of said composite material concern applications in the following fields: the motor vehicle industry, the railroad industry, the marine or maritime industry, wind power, photovoltaics, the solar industry, including solar panels and components for solar power stations, sports, aeronautics and space, road transport, the construction industry, civil engineering, panels, and leisure.

18. A thermoplastic composite material wherein the thermoplastic composite material results from the use of at least one composition for thermoplastic composite material of cl

Assignees

• Arkema France

Inventors

• Briffaud Thierry
• Hochstetter Gilles

Classifications

• C08L77/06 Primary

  Polyamides derived from polyamines and polycarboxylic acids (C08L77/10 takes precedence) · CPC title

• C08J5/04

  Reinforcing macromolecular compounds with loose or coherent fibrous material · CPC title

• B29C70/021

  Combinations of fibrous reinforcement and non-fibrous material · CPC title

• C08J5/24

  Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title