WO2008031992A2

WO2008031992A2 - Composition of polymers exhibiting enhanced conductivity and enhanced antistatic properties

Info

Publication number: WO2008031992A2
Application number: PCT/FR2007/051918
Authority: WO
Inventors: Alexander Korzhenko; Dominique Jousset
Original assignee: Arkema France
Priority date: 2006-09-13
Filing date: 2007-09-12
Publication date: 2008-03-20
Also published as: WO2008031992A3

Abstract

The invention provides a composition comprising at least one polymer (A) and at least one non-(A) copolymer (B) containing polyamide blocks and polyether blocks, the composition being characterized in that it comprises an inherently conductive polymer such as polyaniline (PANI). Polymer (A) is selected from polyolefins, polyamides, fluoropolymers, saturated polyesters, polycarbonate, styrenic resins, PMMA, thermoplastic polyurethanes (TPU), PVC, copolymers of ethylene and vinyl acetate (EVA), copolymers of ethylene and an alkyl (meth)acrylate, ABS, SAN, polyacetal, polyketones and blends thereof.

Description

POLYMER COMPOSITION WITH IMPROVED ANTISTATIC CONDUCTIVITY AND PROPERTIES

The present invention relates to a polymer composition having improved conductivity and antistatic properties. It is more specifically a polymer composition comprising an intrinsically conductive polymer such as polyaniline and a copolymer with polyamide blocks and polyether blocks.

The formation and retention of static charges on the surface of most plastics are known. The presence of static electricity on thermoplastic films leads, for example, these films to stick on each other making their separation difficult. The presence of static electricity on packaging films can cause the accumulation of dust on the objects to be packaged and thus hinder their use. It can also damage microprocessors or components of electronic circuits or even cause the combustion or explosion of flammable materials such as, for example, expandable polystyrene beads which contain pentane.

The object of EP 1046675 is to provide permanent antistatic properties to a thermosensitive polymer (A) by using a copolymer (B) with polyamide blocks and polyether blocks (abbreviated PEBA).

The Applicant Company has now surprisingly discovered that it is possible to significantly improve the conductivity of a polymer (A) by mixing it with PEBA and an intrinsically conductive polymer such as polyaniline (abbreviated as PANI) in its form doped with an organic acid and thus provide permanent antistatic properties to said polymer (A).

As regards the polymer (A), mention may be made of polyolefins, polyamides, fluorinated polymers, saturated polyesters, polycarbonate, styrenic resins, PMMA, thermoplastic polyurethanes (TPUs), PVC, copolymers of polyesters, ethylene and vinyl acetate (EVA), copolymers of ethylene and an alkyl (meth) acrylate, ABS, SAN, polyacetal and polyketones. Polyolefins within the meaning of the invention also denote copolymers of ethylene and an alpha olefin. It would not depart from the scope of the invention using a mixture of two or more polymers (A). The copolymer comprising polyamide blocks and polyether blocks has the general formula (I)

- [PA - PE] _n - in which - PA represents a polyamide block;

PE represents a polyether block; and n represents the number of units -PA-PE- of said copolymer, n is 1, in particular at least 5, more preferably at least 6, and up to an average of 60, preferably up to an average of 30, more preferably up to an average of 25.

As regards the polyamide block copolymers (PA) and polyether blocks (PE) or PEBA copolymer, they result from the copolycondensation of polyamide sequences with reactive ends with polyether sequences with reactive ends, such as, inter alia,:

(1) diamine chain-end polyamide blocks with polyoxyalkylene blocks having dicarboxylic chain ends or diisocyanate;

(2) polyamide sequences having dicarboxylic chain ends with polyoxyalkylene sequences having diamine chain ends obtained by cyanoethylation and hydrogenation of aliphatic dihydroxy aliphatic polyoxyalkylene aliphatic sequences known as polyetherdiols;

(3) Polyamide sequences with dicarboxylic chain ends with polyetherdiols, the products obtained being, in this particular case, polyetheresteramides.

The polyamide sequences with dicarboxylic chain ends come for example from the condensation of polyamide precursors in the presence of a chain-control dicarboxylic acid.

The polyamide blocks with diamine chain ends come for example from the condensation of polyamide precursors in the presence of a chain-regulating diamine.

The polyamide block and polyether block polymers may also comprise randomly distributed units. Said polymers can be prepared by the simultaneous reaction of the polyether and the precursors of the polyamide blocks. For example, polyetherdiol, polyamide precursors, and a chain-regulating diacid can be reacted or polyetherdiamine, polyamide precursors, and a chain-regulating diacid can be reacted. A polymer having essentially polyether blocks is obtained, polyamide blocks of very variable length depending on the moment in which the chain regulator intervenes during the formation of the PA block, but also the various reagents reacted randomly which are distributed in a Random (statistical) along the polymer chain.

There are advantageously two types of polyamide blocks in the PEBA copolymers according to the invention. The polyamide block may consist of a "homopolyamide" structure [polymerization of a single monomer, ie a single lactam, a single amino acid or a single pair (diacid, diamine)] or else of a "copolyamide" type structure with the polymerization of a mixture of at least two monomers taken from the three types mentioned in the previous case. The polyamide blocks are obtained in the presence of a diacid or a chain-control diamine depending on whether polyamide blocks with acid or amine ends are desired. If the precursors already comprise a diacid or a diamine, it suffices, for example, to use it in excess, but it is also possible to use another diacid or another diamine taken from the dicarboxylic acid and diamine groups defined below.

The PA blocks are in particular carboxylic ends so that the bonds between the PA and PE blocks are ester bonds.

The PA blocks having carboxylic end groups may be the condensation product of a lactam, in particular a lactam C ₄ -C _4, of a particular amino acid with an amino acid C ₄ -C ₄ or a combination of both with a dicarboxylic acid, in particular a C ₄ -C ₂ O dicarboxylic acid,

Examples of lactams include caprolactam, oenantholactam and lauryllactam. Examples of amino acids that may be mentioned include aminocaproic acid, amino-7-heptanoic acid, amino-11-undecanoic acid and amino-12-dodecanoic acid.

Examples of dicarboxylic acids that may be mentioned include 1,4-cyclohexyldicarboxylic acid, butanedioic, adipic, azelaic, suberic, sebacic, dodecanedicarboxylic and terephthalic and isophthalic acids, but also dimerized fatty acids. The carboxyl-terminated PA blocks may also be the condensation product of a dicarboxylic acid such as a C ₄ -C ₂ ₄ alkyl dicarboxylic acid and a diamine, in particular a C ₂ -C diamine. ₂ 0-

Examples of dicarboxylic acids have been indicated above. Examples of diamines that may be mentioned include hexamethylenediamine, dodecamethylenediamine, trimethylhexamethylenediamine, isomers of bis- (4-aminocyclohexyl) methane (BACM), bis (3-methyl-4-aminocyclohexyl) methane (BMACM), and 2-2-bis- (3-methyl-4-aminocyclohexyl) -propane (BMACP), and para-aminodicyclohexylmethane (PACM), and isophoronediamine (IPDA), 2,6-bis (aminomethyl) norbornane (BAMN) and piperazine.

In particular, the PA blocks can be chosen from the blocks PA 6, PA 11, PA 12, PA 6.6, PA 6.9, PA 6.10, PA 6.12, PA 6.14, PA 6.18, PA Pip.10 and PA 9.6.

The PE blocks may be PEG blocks consisting of ethylene ether glycol units, PPG blocks consisting of propylene ether glycol units, PTMG blocks consisting of tetramethylene ether glycol units, blocks obtained by oxyethylation of bisphenols, such as, for example, bisphenol A. , PO3G blocks consisting of trimethylene ether glycol units, polyhexamethylene ether glycol blocks and copolymers of tetrahydrofuran (THF) and 3-alkyl tetrahydrofuran (3MeTHF). It is also possible to envisage a PE block of "copolyether" type containing a series of PE blocks of the types mentioned above. The chain ends of the copolyethers can be diOH, diNH 2, diisocyanate or diacid according to their synthesis process.

The percentage by weight of PA blocks in the PEBA copolymer is at least

10%, more preferably at least 15%, and preferably up to 90%, more preferably between 40 and 60%.

The PA blocks have in particular a number-average molecular mass of at least 300, preferably at least 600, and preferably ranging up to 10,000, more preferably up to 5000, and even more preferably up to at 3000.

The PE blocks in particular have a number-average molecular weight of at least 250, more preferably at least 1000, and even more preferably at least 1500, and preferably up to 5000, more preferably up to 4000 and even more preferably up to 2000. Regarding their preparation, the copolymers of the invention may be prepared by any means for hanging polyamide blocks and polyether blocks. In practice, essentially two methods are used, one said in two steps, the other in one step. In the two-step process, the polyamide blocks are first manufactured and then, in a second step, the polyamide blocks and the polyether blocks are bonded. In the one-step process, the polyamide precursors, the chain regulator (or the dicarboxylic acid or stoichiometric excess diamine) and the polyether are mixed; a polymer having essentially polyether blocks, polyamide blocks of very variable length, but also the various reagents reacted in a random manner which are distributed randomly (statistically) along the polymer chain.

Whether in one or two stages, it is advantageous to operate in the presence of a catalyst. The catalysts described in US Pat. Nos. 4,331,786, 4,145,475, 4,195,155, 4,839,441, 4,884,014, 4,230,838 and 4,332,920 can be used.

It is also possible to use a process for which the polyether diol is first converted into polyether diamine, diacid or diisocyanate, then reacted with the diacid or diamine PA block.

With regard to the intrinsically conductive polymer, it is a polymer whose resistivity may be less than typically 10 ⁶ ohm cm without addition of conductive metal charges. The best known are polyaniline (PANI), polyacetylene, poly-p-phenylene, polypyrrole or polythiophenes. Their good conductive properties are generally achieved or improved by the addition of dopants (electron donors or acceptors). For PANI, we mean polymers of aniline or its derivatives doped with one or more protic acid compounds. The aniline units in the polyaniline are linked together by the carbon in the para position on the aromatic ring with respect to the nitrogen atom, as for example in emeraldine. The most commonly used acidic dopants are the sulfonic derivatives, for example dodecylbenzene sulfonic acid. The doped polyaniline may be formulated in the form of a complex with metal oxides (PANI complex), in particular zinc oxide, copper, calcium and / or magnesium, to neutralize the possible excess of acid and promote dispersion in the polymer by plasticizing the complex. The document EP0582919 describes the PANI and materials incorporating it which represents PANI doped with an organic acid and in the form of complex with metal oxides (PANI complex). The polyaniline content in the complex can typically be from 5 to 20% by weight.

These include such commercial grades of PANI complex PANIPOL ^® CXH or PANIPOL CXM ^® produced by PANIPOL Ltd. PANI is used in preference to other intrinsically conductive polymers because of its good performance / cost ratio.

The percentage by weight of intrinsically conductive polymer is from 5 to

40%, preferably 10 to 20%, in the intrinsically conductive polymer (B) + polymer mixture. The weight percentage of the intrinsically conductive polymer (B) + polymer blend in the final composition is 10 to 70%, preferably 20 to 40%.

In a preferred embodiment of the invention, the weight percentage of complex PANI in the PEBA + PANI complex mixture is 5 to 40%, preferably 10 to 20%. The weight percentage of the mixture (PEBA + PANI complex) in the final composition is 10 to 70%, preferably 20 to 40%.

The composition according to the invention can be used in particular to limit the risks of electrostatic discharge or electromagnetic interference, and for all technical applications that require effective permanent electrical dissipation or electrical resistance between 10 ⁵ and 10 ¹⁰ ohm cm. It is used in all applications of antistatic polymer materials. Such materials can be shaped by any method of shaping or thermal transformation, such as extrusion, injection, thermoforming, extrusion blow molding, overmolding.

The invention also relates to these antistatic polymer materials comprising a composition of the invention.

We will now give examples of the invention.

A mixture of PEBA doped with PANI is mixed in an extruder at 165 ° C for 10 minutes. This mixture constitutes Comparative 2. This mixture is then introduced into a polyolefin matrix by the same method according to the proportions defined in Table 1 to give the compositions of Examples 1 and 2. These compositions recovered at the exit of the extruder are then injected to form bars of 10x50x2mm. The volume resistance values of these bars are measured and grouped in Table 1 below and can determine whether the compositions are rather resistant or not.

The percentages are% expressed as total weight of the composition unless otherwise indicated.

Table 1

(1) PPC 5660 (2) Clearflex® FFDO

(3) Pebax® MV 1074SA01

(4) Pebax® MV 1074SA01 + 15% PANIPOL® CXH,% expressed relative to PEBA + complex PANI mixture

(5) PANIPOL® CXH

There is a clear and surprising improvement in the conductivity of the compositions according to Examples 1 and 2 compared to Comparatives 4 and 5. The PEBA of Comparative 3 has a specific resistance of the order of 10 ⁹ ohms cm. Introduced into an insulating polymer matrix such as PP, it gives Comparative 4 which is an antistatic composition with an improved electrical electrical resistance of 10 ¹⁰ ohm cm.

Claims

1. Composition comprising at least one polymer (A) and at least one copolymer (B) with polyamide blocks and polyether blocks, different from (A), characterized in that it comprises an intrinsically conductive polymer chosen from polyaniline (PANI). ), polyacetylene, poly-p-phenylene, polypyrrole or polythiophenes.

2. Composition according to the preceding claim, characterized in that the intrinsically conductive polymer used is polyaniline (PANI), doped with an organic acid and in the form of complex with metal oxides (PANI complex).

3. Composition according to one of the preceding claims, characterized in that the polymer (A) is selected from polyolefins, polyamides, fluoropolymers, saturated polyesters, polycarbonate, styrenic resins, PMMA, thermoplastic polyurethanes (TPU), PVC, copolymers of ethylene and vinyl acetate (EVA), copolymers of ethylene and an alkyl (meth) acrylate, ABS, SAN, polyacetal, polyketones and mixtures thereof.

4. Composition according to one of the preceding claims, characterized in that the PA blocks are chosen from the blocks PA 6, PA 1 1, PA 12, PA 6.6, PA 6.9, PA 6.10, PA 6.12, PA 6.14, PA 6.18 , PA Pip.10 and PA 9.6.

5. Composition according to one of the preceding claims, characterized in that the PE blocks are chosen from PEG blocks consisting of ethylene ether glycol units, PPG blocks consisting of propylene ether glycol units, PTMG blocks consisting of tetramethylene ether glycol units. , blocks obtained by oxyethylation of bisphenols, PO3G blocks consisting of trimethylene ether glycol units, polyhexamethylene ether glycol blocks and copolymers of tetrahydrofuran (THF) and 3-alkyl tetrahydrofuran (3MeTHF).

6. Composition according to one of the preceding claims, characterized in that the copolymer (B) and the complex PANI represent 10 to 70%, preferably 20 to 40% by weight of the total composition.

7. Composition according to one of the preceding claims, characterized in that the PANI complex is 5 to 40%, preferably 10 to 20% by weight of the copolymer (B) + PANI complex.

8. Use of a composition according to one of the preceding claims, to limit the risk of electrostatic discharge or electromagnetic interference, and for all technical applications that require effective permanent electrical dissipation or a resistivity between 10 ⁵ and 10 ¹⁰ Ohms cm.

9. antistatic polymer material comprising a composition according to one of claims 1 to 7, and obtainable by any method of shaping or thermal transformation, such as extrusion, injection, thermoforming, extrusion blow molding, overmolding .