METHOD FOR SYNTHESISING A BLOCK COPOLYMER ALLOY HAVING IMPROVED ANTISTATIC PROPERTIES

• US 20120108694A1
• Filed: 02/02/2010
• Published: 05/03/2012
• Est. Priority Date: 02/02/2009
• Status: Active Grant

• Current Assignee: Arkema France (Arkema)
• Original Assignee: Arkema France (Arkema)
• Inventors: Malet, Frederic, Gamache, Eric, Werth, Michael, Babin, Perrine, Andre, Benoit
• Granted Patent: US 9,914,804 B2
• Time in Patent Office: Days
• US Class Current: 521/183
• CPC Class Codes: C08G 69/40 Polyamides containing oxygen in the form of ether groups C08G69/12, C08G69/32 take precedence
• CPC Class Codes: C08K 5/0075 Antistatics
• CPC Class Codes: C08L 101/00 Compositions of unspecified macromolecular compounds
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 77/12 Polyester-amides
• CPC Class Codes: C08L 87/005 Block or graft polymers not provided for in groups C08L1/00 - C08L85/04

Abstract

The invention relates to a method for synthesising a block copolymer alloy including at least one rigid polyamide block PA, including the steps of: a) producing said block copolymer; b) adding, during step a) and to at least a portion of said block copolymer, 0.1 to 30 wt % of at least one organic salt in the molten state relative to the total weight of the alloy, so that the alloy thus obtained has improved antistatic properties and identical mechanical properties when compared to the same polymer produced without adding an organic salt. The invention also relates to a block copolymer alloy having improved antistatic properties and obtained by said method, to the use thereof in a polymer matrix, and to a composition containing same.

Claims

1. A process for synthesizing an alloy based on a block copolymer comprising at least one rigid polyamide block PA, comprising the following steps:

I—

production of at least one polyamide block PA;

II—

polycondensation of at least one soft block SB having a glass transition temperature Tg below 15°

C., with said at least one polyamide block PA so as to obtain a block copolymer; and

III—

recovery of said block copolymer alloy,

and comprising the addition to the block copolymer, during step III, of 0.1% to 30% by weight of at least one organic salt in the molten state, relative to the total weight of alloy;

such that the alloy obtained has improved antistatic properties and identical mechanical properties compared with the same copolymer produced without adding an organic salt.

2. The process as claimed in claim 1, in which step III comprises the following substeps:

III-1—

adjustment of the viscosity of the copolymer alloy,

III-2—

extrusion of the copolymer alloy, and optionally;

III-3—

stoving of the alloy.

3. The process as claimed in claim 1, in which the organic salt is added by means of an impregnation liquid containing the organic salt pure or diluted in a solvent.

4. The process as claimed in claim 1, in which the organic salt is added to the block copolymer during step III-1, III-2 and/or III-3.

5. The process as claimed in claim 1, in which said at least one organic salt comprises at least one cation comprising at least one of the following molecules:

ammonium, sulfonium, pyridinium, pyrrolidinium, imidazolium, imidazolinium, phosphonium, lithium, guanidinium, piperidinium, thiazolium, triazolium, oxazolium, pyrazolium, and mixtures thereof.

6. The process as claimed in claim 1, in which said at least one organic salt comprises at least one anion comprising at least one of the following molecules:

imides, in particular bis(trifluoromethanesulfonyl)imide;

borates, in particular tetrafluoroborate;

phosphates, in particular hexafluorophosphate;

phosphinates and phosphonates, in particular alkyl phosphonates;

amides, in particular dicyanamide;

aluminates, in particular tetrachloroaluminate;

halides, such as bromide, chloride or iodide anions;

cyanates;

acetates, in particular trifluoroacetate;

sulfonates, in particular methanesulfonate, trifluoromethanesulfonate;

sulfates, in particular ethyl sulfate;

hydrogen sulfate; and

mixtures thereof.

7. The process as claimed in claim 1, in which said step I comprises the polycondensation of polyamide precursors in the presence of a chain regulator.

8. The process as claimed in claim 1, in which steps I and II are carried out simultaneously.

9. The process as claimed in claim 1, also comprising the addition of agents which improve surface conductivity, during step I, II and/or III, said agents being chosen from:

hygroscopic agents;

fatty acids;

lubricants;

metals;

metal film coatings;

metal powders;

metal nanopowders;

aluminosilicates;

amines, such as quaternary amines;

esters;

fibers;

carbon black;

carbon fibers;

carbon nanotubes;

polyethylene glycol;

intrinsically conductive polymers, such as derivatives of polyanaline, of polythiophene or of polypyrrole;

masterbatches; and

mixtures thereof.

10. The process as claimed in claim 1, also comprising the addition of additives and/or adjuvants during step I, II and/or III, said additives and/or adjuvants being chosen from:

organic or inorganic fillers, reinforcing agents, plasticizers, stabilizers, antioxidants, anti-UV agents, flame retardants, carbon black, carbon nanotubes;

mineral or organic dyes, pigments, dyes, demolding agents, lubricants, foaming agents, anti-impact agents, shrink-proofing agents, fire-retardants, nucleating agents, and mixtures thereof.

11. A block copolymer alloy having improved antistatic properties, comprising at least one rigid polyamide block and at least one soft block, which can be obtained by means of the synthesis process of claim 1, said alloy incorporating from 0.1% to 30% by weight of at least one organic salt, relative to the total weight of the alloy.

12. The copolymer alloy as claimed in claim 11, in which:

the proportion by weight of said at least one rigid polyamide block represents from 5% to 95%, preferably from 15% to 95%,

the proportion by weight of said at least one flexible block represents from 5% to 95%, preferably from 5% to 85%,

relative to the total mass of the copolymer.

13. The copolymer alloy as claimed in claim 11, in which said at least one rigid block and/or said at least one soft block are at least partially derived from renewable starting materials.

14. The alloy as claimed in claim 13, comprising a biocarbon content of at least 1%, which corresponds to a ¹⁴C/¹²C isotope ratio of at least 1.2×

10<sup>−

14</sup>.

15. The alloy as claimed in claim 14, comprising a biocarbon content of greater than 5%, preferably greater than 10%, preferably greater than 25%, preferably greater than 50%, preferably greater than 75%, preferably greater than 90%, preferably greater than 95%, preferably greater than 98%, preferably greater than 99%, advantageously substantially equal to 100%.

16. The copolymer alloy as claimed in claim 11, in which said at least one polyamide block comprises at least one of the following molecules:

PA12, PA11, PA10.10, PA6, PA6/12, a copolyamide comprising at least one of the following monomers;

11, 5.4, 5.9, 5.10, 5.12, 5.13, 5.14, 5.16, 5.18, 5.36, 6.4, 6.9, 6.10, 6.12, 6.13, 6.14, 6.16, 6.18, 6.36, 10.4, 10.9, 10.10, 10.12, 10.13, 10.14, 10.16, 10.18, 10.36, 10.T, 12.4, 12.9, 12.10, 12.12, 12.13, 12.14, 12.16, 12.18, 12.36, 12.T, and mixtures and copolymers thereof.

17. The copolymer alloy as claimed in claim 11, in which said at least one soft block is chosen from polyether blocks;

polyester blocks;

polysiloxane blocks, such as polydimethylsiloxane blocks;

polyolefin blocks;

polycarbonate blocks; and

mixtures thereof.

18. The copolymer alloy as claimed in claim 11, comprising at least one polyether block comprising at least 50% by weight of PEG, relative to the total weight of polyether block(s).

19. The copolymer alloy as claimed in claim 11, in which the total polyethylene glycol PEG content is at least 35% by weight, preferably at least 50% by weight, relative to the total weight of the alloy.

20. The alloy as claimed in claim 11, in which said copolymer comprises a PEBA.

21. The copolymer alloy as claimed in claim 20, in which said PEBA comprises PA12-PEG, PA6-PEG, PA6/12-PEG, PA11-PEG, PA12-PTMG, PA6-PTMG, PA6/12-PTMG, PA11-PTMG, PA12-PEG/PPG, PA6-PEG/PPG, PA6/12-PEG/PPG and/or PA11-PEG/PPG.

22. The copolymer alloy as claimed in claim 11, in which the copolymer is a segmented block copolymer comprising three different types of blocks, said copolymer being chosen from copolyetheresteramides and copolyetheramideurethanes in which:

the percentage by weight of rigid polyamide block is greater than 10%;

the percentage by weight of flexible block is greater than 20%;

relative to the total weight of copolymer.

23. A composition comprising a copolymer alloy as claimed claim 11, said alloy representing, by weight, from 5% to 100%, preferably from 5% to 70%, preferably from 5% to 30%, relative to the total mass of the composition.

24. In a thermoplastic polymer matrix comprising at least one thermoplastic polymer, the improvement comprising improving the antistatic properties of said matrix by incorporating a block copolymer alloy as claimed in claim 1.

25. The polymer matrix as claimed in claim 24, in which said polymer matrix comprises at least one thermoplastic polymer, which is a homopolymer or copolymer, chosen from:

polyolefins, polyamides, fluoropolymers, saturated polyesters, polycarbonate, styrene resins, PMMA, thermoplastic polyurethanes (TPUs), copolymers of ethylene and of vinyl acetate (EVA), copolymers comprising polyamide blocks and polyether blocks, copolymers comprising polyester blocks and polyether blocks, copolymers comprising polyamide blocks, comprising polyether blocks and comprising polyester blocks, copolymers of ethylene and an alkyl (meth)acrylate, copolymers of ethylene and of vinyl alcohol (EVOH), of ABS, of SAN, of ASA, of polyacetyl, polyketones, and mixtures thereof.

26. The composition as claimed in claim 23, comprising from 1% to 40% by weight of at least one block copolymer alloy as claimed claim 1 and from 60% to 99% by weight of a polymer matrix as defined in claim 24.

27. The process according to claim 1, whereby the use of an organic salt in the molten state synthesizing the alloy based on a block copolymer comprising at least one polyamide block PA, improves the kinetics of said synthesis.

28. The use process as claimed in claim 27, said organic salt being added during step II, and accelerating the kinetics of step II and of step III.