FR2820139A1 - Antistatic polymer composition comprises a styrene polymer, a polyamide-polyoxyethylene block copolymer and a compatibilizing styrene/methyl methacrylate block copolymer - Google Patents

Abstract

New composition comprises (wt.%): (I) a styrene polymer (A) (60-99); and (II) a combination of a polyamide/polyoxyethylene block copolymer (B) and a styrene/ethylene oxide block copolymer (C) (1-40). (B) and (C) are in a weight ratio (B):(C) of 2-10. Independent claims are also included for: (i) objects made using the composition; and (ii) use of the objects for contacting electronic components.

Description

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1 COMPOSITIONS OF ANTISTATIC STYRENIC POLYMERS
The invention relates to antistatic styrene polymer compositions and more specifically to a composition comprising a styrenic polymer (A), a copolymer (B) with polyamide blocks and polyether blocks essentially comprising ethylene oxide (C2H4-O) units and a compatibilizer (C).

 This is to give the styrene polymer (A) antistatic properties. 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. Styrene resins such as for example polystyrene or ABS are used to make computer housings, telephones, televisions, photocopiers and many objects. Static electricity causes the accumulation of dust but above all can also damage the microprocessors or the constituents of the electronic circuits contained in these objects. For these applications, it is generally sought compositions based on styrenic resin having a surface resistivity measured according to IEC93 less than 5. 1013 nID or a volume resistivity measured according to IEC93 less than 5. 1016 Q. cm (we choose the type of resistivity depending on the application, it being understood that these two types of resistivity evolve anyway in the same direction). It is considered that such resistivities provide sufficient antistatic properties for certain applications in the field of polymer materials in contact with electronic components.

 The prior art has described antistatic agents such as ionic surfactants of the ethoxylated amine or sulfonate type which are added to polymers. However, the antistatic properties of polymers depend on ambient humidity and are not permanent since these agents migrate to the surface of the polymers and disappear. It was then proposed as antistatic agents of polyamide block copolymers and hydrophilic polyether blocks, these agents have the advantage of not migrating and

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 therefore to give permanent antistatic properties and more independent of the ambient humidity.

 Japanese Patent Application JP 60 170 646 A published September 4, 1985 discloses compositions consisting of 0.01 to 50 parts of polyether block amide and 100 parts of polystyrene, they are useful for making sliding parts and parts resistant to wear. Antistatic properties are not mentioned.

 The patent application EP 167 824 published January 15, 1986 describes compositions similar to the preceding and in one form of the invention the polystyrene can be mixed with a polystyrene functionalized with an unsaturated carboxylic anhydride. These compositions are useful for making injected parts. Antistatic properties are not mentioned.

 Japanese Patent Application JP 60 023 435 A published February 6, 1985 discloses antistatic compositions comprising 5 to 80% of polyetheresteramide and 95 to 20% of a thermoplastic resin selected among others from polystyrene, LABS and PMMA, this resin being functionalized with acrylic acid or maleic anhydride. The amount of polyetheresteramide in the examples is 30% by weight of the compositions.

 EP 242 158 discloses antistatic compositions comprising 1 to 40% polyetheresteramide and 99 to 60% of a thermoplastic resin selected from styrene resins, PPO and polycarbonate. According to a preferred form, the compositions also comprise a vinylic polymer functionalized with a carboxylic acid which may be, for example, a polystyrene modified with methacrylic acid.

 International Patent Application PCT / FROO / 02140 teaches the use of copolymers of styrene and an unsaturated carboxylic acid anhydride, copolymers of ethylene and an unsaturated carboxylic acid anhydride, copolymers of ethylene and unsaturated epoxide, SBS or SIS block copolymers grafted with a carboxylic acid or an unsaturated carboxylic acid anhydride as a compatibilizer between a styrenic resin and a polyamide block copolymer and polyether blocks.

As documents of the prior art, mention may also be made of: EP 927727, J. Polym. Sci, Part C: Polym. Lett. (1989), 27 (12), 481 - J. Polym. Sci, Part B, Polym. Phys. (1996), 34 (7), 1289
JAPS, (1995), 58 (4), 753 JP 04370156

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JP 04239045 JP 02014232
JP 11060855
JP 11060856
JP 09249780
JP 08239530 JP08143780
The prior art shows either mixtures (i) of styrene resin and polyetheresteramide without compatibilizer, or mixtures (ii) of polyetheresteramide and functionalized styrene resin or mixtures (iii) of polyetheresteramide, non-functionalized styrenic resin and functionalized styrene resin.

 The mixtures (i) are antistatic if the polyetheresteramide is well chosen but have poor mechanical properties, in particular the elongation at break is much lower than that of the styrene resin alone. As for mixtures (ii) and (iii) it is necessary to have a functionalized styrene resin which is complicated and expensive. The object of the invention is to render antistatic the ordinary styrene resins used to make the objects mentioned above, these resins not being functionalized. It has now been found that by using particular compatibilizers styrene resin compositions comprising a styrenic resin and a polyamide block and polyether block copolymer having excellent elongation at break, excellent tensile strength and excellent impact resistance (notched charpy), compared to the same composition without compatibilizer.

 The present invention relates to a composition comprising per 100 parts by weight: 99 to 60 parts by weight of a styrenic polymer (A), 1 to 40 parts by weight of (B) + (C), (B) being a polyamide block copolymer and polyether block comprising essentially ethylene oxide units (C 2 H 4 O) -, (C) being a compatibilizer selected from block copolymers comprising at least one polymerized block comprising styrene and at least one polymerized block comprising ethylene oxide units.

 In the polymerized block comprising ethylene oxide units, the repeating unit is -O-CH 2 -CH 2 -. This block can also be called PEG block (which means polyethylene glycol).

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The composition according to the invention may not comprise polyphenylene oxide (PPO).

éthylène-propylene), l'EPDM (abréviation d'éthylène-propylene-diène rubber ou élastomère éthylène-propylene-diène), le polybutadiène, le copolymère acrylonitrile-butadiène, le polyisoprène, le copolymère isoprène-acrylonitrile. By way of example of styrene polymer (A), mention may be made of polystyrene, polystyrene modified with elastomers, random or block copolymers of styrene and dienes such as butadiene, copolymers of styrene and acrylonitrile (SAN ), the SAN modified by elastomers, in particular ABS which is obtained for example by grafting (graft-polymerization) of styrene and acrylonitrile on a truncated polybutadiene or butadiene-acrylonitrile copolymer, mixtures of SAN and ABS. The elastomers mentioned above can be for example EPR (abbreviation of ethylene-propylene-rubber or elastomer

ethylene-propylene), EPDM (abbreviation of ethylene-propylene-diene rubber or ethylene-propylene-diene elastomer), polybutadiene, acrylonitrile-butadiene copolymer, polyisoprene, isoprene-acrylonitrile copolymer.

In particular, A may be a high impact polystyrene comprising a polystyrene matrix surrounding rubber nodules generally comprising polybutadiene.

 In the polymers (A) which have just been mentioned, part of the styrene may be replaced by unsaturated monomers copolymerizable with styrene, for example mention may be made of alpha-methylstyrene and (meth) acrylic esters. In this case, A may comprise a styrene copolymer of which mention may be made of styrene-alpha-methylstyrene copolymers, styrene-chlorostyrene copolymers, styrene-propylene copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers and styrene copolymers. vinyl chloride, styrene-vinyl acetate copolymers, styrene-alkyl acrylate copolymers (methyl, ethyl, butyl, octyl, phenyl acrylate), styrene methacrylate copolymers (methacrylate), methyl, ethyl, butyl, phenyl), styrene-chloroacrylate copolymers and styrene-acrylonitrile-alkyl acrylate copolymers. In these copolymers, the comonomer content is generally up to 20% by weight. The present invention also relates to high melting metallocene polystyrenes.

 It would not depart from the scope of the invention if (A) was a mixture of two or more of the foregoing polymers.

 The styrenic polymer A preferably comprises more than 50% by weight of styrene. For the case where the styrene polymer is SAN, it preferably contains more than 75% by weight of styrene.

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Polymers (B) with polyamide blocks and polyether blocks result from the copolycondensation of polyamide sequences with reactive ends with polyether sequences with reactive ends, such as, inter alia:
1) Polyamide sequences with diamine chain ends with polyoxyalkylene sequences with dicarboxylic chain ends.

 2) Polyamide sequences with dicarboxylic chain ends with polyoxyalkylene sequences having diamine chain ends obtained by cyanoethylation and hydrogenation of aliphatic alpha-omega-dihydroxylated polyoxyalkylene sequences known as polyetherdiols.

 3) Polyamide sequences with dicarboxylic chain ends with polyetherdiols, the products obtained being, in this particular case, polyetheresteramides. The copolymers (8) are advantageously of this type.

 The polyamide sequences with dicarboxylic chain ends result, for example, from the condensation of alpha-omega-aminocarboxylic acids, lactams or dicarboxylic and diamine diacids in the presence of a dicarboxylic acid chain-limiting agent.

 The molar mass in number Mn of the polyamide sequences is between 300 and 15,000 and preferably between 600 and 5,000. The mass Mn of the polyether blocks is between 100 and 6,000 and preferably between 200 and 3,000.

 Polymers with polyamide blocks and polyether blocks may also comprise randomly distributed units. These polymers can be prepared by the simultaneous reaction of the polyether and the precursors of the polyamide blocks.

 For example, polyetherdiol, a lactam (or an alpha-omega amino acid) and a chain-limiting diacid can be reacted in the presence of a little water. A polymer having essentially polyether blocks, polyamide blocks of very variable length, but also the various reagents reacted randomly are obtained which are distributed statistically along the polymer chain.

 These polymers with polyamide blocks and polyether blocks, whether they come from the copolycondensation of previously prepared polyamide and polyether blocks or from a one-step reaction, have, for example, Shore D durations which can be between 20 and 75 and advantageously between 30 and 75. and 70 and intrinsic viscosity between 0.8 and 2.5 measured in metacresol at 250 C for an initial concentration of 0.8

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g/100 ml. Les MFI peuvent être compris entre 5 et 50 (235OC sous une charge de 1 kg)
Les blocs polyétherdiols sont soit utilisés tels quels et copolycondensés avec des blocs polyamides à extrémités carboxyliques, soit ils sont aminés pour être transformés en polyéther diamines et condensés avec des blocs polyamides à extrémités carboxyliques. Ils peuvent être aussi mélangés avec des précurseurs de polyamide et un limiteur de chaîne pour faire les polymères à blocs polyamides et blocs polyéthers ayant des motifs répartis de façon statistique.

g / 100 ml. The MFI can be between 5 and 50 (235OC under a load of 1 kg)
The polyetherdiol blocks are either used as such and copolycondensed with polyamide blocks having carboxylic ends, or they are aminated to be converted into polyether diamines and condensed with polyamide blocks having carboxylic ends. They can also be mixed with polyamide precursors and a chain limiter to make the polyamide block and polyether block polymers having statistically distributed patterns.

 Polymers with polyamide blocks and polyethers are described in US Pat. Nos. 4,331,786, 4,155,415, 4,195,155, 4,839,441, 4,884,014, 4,230,838 and 4,332,920.

 According to a first form of the invention, the polyamide sequences containing dicarboxylic chain ends come, for example, from the condensation of alpha-omega-aminocarboxylic acids, lactams or dicarboxylic and diamine diacids in the presence of a dicarboxylic acid chain-limiting agent. . By way of example of alpha omega-aminocarboxylic acids mention may be made of aminoundecanoic acid, by way of example of lactam, caprolactam and lauryllactam may be mentioned, by way of example of a dicarboxylic acid, mention may be made of adipic acid. decanedioic acid and dodecanedioic acid, as an example of a diamine mention may be made of hexamethylene diamine. Advantageously, the polyamide blocks are made of polyamide 12 or polyamide 6. The melting temperature of these polyamide blocks, which is also that of the copolymer (B), is in general 10 to 15 C below that of PA 12 or PA 6.

 Depending on the nature of (A) it may be useful to use a copolymer (B) having a lower melting temperature so as not to degrade (A) during the incorporation of (B), which is what makes the object of the second and third form of the invention below.

 According to a second form of the invention, the polyamide sequences result from the condensation of one or more alpha omega-aminocarboxylic acids and / or one or more lactams having from 6 to 12 carbon atoms in the presence of a dicarboxylic acid having from 4 to 12 carbon atoms and are of low mass, that is to say Mn of 400 to 1000. Examples of alpha omega aminocarboxylic acid include aminoundecanoic acid and aminododecanoic acid. By way of example of a dicarboxylic acid, mention may be made of adipic acid, sebacic acid, isophthalic acid, butanedioic acid and 1,4-cyclohexyldicarboxylic acid.

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 terephthalic acid, sodium or lithium salt of sulphoisophthalic acid, dimerized fatty acids (these dimerized fatty acids have a dimer content of at least 98% and are preferably hydrogenated) and dodecanedioic acid HOOC - (CH 2) 10 -COOH.

 By way of example of lactam, mention may be made of caprolactam and lauryllactam.

 Caprolactam will be avoided unless the polyamide is purified from the caprolactam monomer which remains dissolved therein.

 Polyamide sequences obtained by condensation of lauryllactam in the presence of adipic acid or dodecanedioic acid and mass Mn 750 have a melting temperature of 127-130oC.

 According to a third form of the invention, the polyamide sequences result from the condensation of at least one alpha omega aminocarboxylic acid (or a lactam), at least one diamine and at least one dicarboxylic acid. The alpha omega-aminocarboxylic acid, the lactam and the dicarboxylic acid can be chosen from those mentioned above.

 The diamine may be an aliphatic diamine having from 6 to 12 atoms, it may be aryl and / or cyclic saturated.

 By way of examples, mention may be made of hexamethylenediamine, piperazine, 1'-aminoethylpiperazine, bisaminopropylpiperazine, tetramethylenediamine, octamethylene diamine, decamethylene diamine, dodecamethylenediamine, 1,5 diaminohexane and the like. 2,4-trimethyl-1,6-diamino-hexane, diamine polyols, isophoron diamine (IPD), methyl pentamethylenediamine (MPDM), bis (aminocyclohexyl) methane (BACM), bis (3-methyl4-aminocyclohexyl) methane (BMACM).

obtenir une température de fusion inférieure à 150OC et avantageusement comprise entre 90 et 135OC. Des copolyamides à basse température de fusion sont décrits dans les brevets US 4 483 975, DE 3 730 504, US 5 459 230. On reprend les mêmes proportions des constituants pour les blocs polyamides de (B). (B) peut être aussi les copolymères décrits dans US 5 489 667. In the second and third form of the invention, the various constituents of the polyamide block and their proportion are chosen for

obtain a melting point of less than 150 ° C. and advantageously of between 90 ° and 135 ° C. Copolyamides with a low melting point are described in US Pat. No. 4,483,975, DE 3,730,504 and US Pat. No. 5,459,230. The same proportions of constituents are used for the polyamide blocks of (B). (B) may also be the copolymers described in US 5,489,667.

 The polyether blocks can represent 5 to 85% by weight of (B).

The polyether blocks may contain other units than the ethylene oxide units such as, for example, propylene oxide or polytetrahydrofuran (which leads to the polytetramethylene glycol linkages). PEG blocks can also be used simultaneously, that is to say those

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 composed of ethylene oxide units, PPG blocks, ie those consisting of propylene oxide units and PTMG blocks, ie those consisting of tetramethylene glycol units also called polytetrahydrofuran units. PEG blocks or blocks obtained by oxyethylation of bisphenols, such as, for example, bisphenol A, are advantageously used. The latter products are described in patent EP 613 919. The amount of polyether blocks in (B) is advantageously from 10 to 50 % by weight of (B) and preferably from 35 to 50%.

 The copolymers of the invention may be prepared by any means for hanging the polyamide blocks and the polyether blocks. In practice, essentially two methods are used, one in 2 steps, the other in one step.

 The two-step process consists firstly in preparing the polyamide blocks with carboxylic ends by condensation of the polyamide precursors in the presence of a chain-limiting dicarboxylic acid and then in a second step in adding the polyether and a catalyst. If the polyamide precursors are only lactams or alpha omega aminocarboxylic acids, a dicarboxylic acid is added. If the precursors already comprise a dicarboxylic acid, it is used in excess relative to the stoichiometry of the diamines. The reaction is usually between 180 and 300 ° C., preferably 200 ° to 260 ° C., the pressure in the reactor is between 5 and 30 bar and is maintained for about 2 hours.

The pressure is slowly reduced by putting the reactor in the atmosphere and then the excess water is distilled, for example an hour or two.

 The polyamide with carboxylic acid ends having been prepared, the polyether and a catalyst are then added. The polyether can be added in one or more times, as can the catalyst. According to one advantageous form, the polyether is firstly added, the reaction of the OH ends of the polyether and the COOH ends of the polyamide begins with ester bond formation and water elimination; As much water as possible is removed from the reaction medium by distillation and then the catalyst is introduced to complete the bonding of the polyamide blocks and the polyether blocks. This second step is carried out with stirring preferably under a vacuum of at least 5 mmHg (650 Pa) at a temperature such that the reagents and copolymers obtained are in the molten state. For example, this temperature can be between 100 and 400oC and most often 200 and 300OC. The reaction is monitored by measuring the torque exerted by the molten polymer on the stirrer or by measuring the electrical power consumed by the stirrer. The end

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 of the reaction is determined by the value of the target torque or power. The catalyst is defined as any product that facilitates the bonding of polyamide blocks and polyether blocks by esterification. The catalyst is advantageously a derivative of a metal (M) chosen from the group formed by titanium, zirconium and hafnium.

 By way of example of a derivative, mention may be made of tetraalkoxides which correspond to the general formula M (OR) 4, in which M represents titanium, zirconium or hafnium, and R, which may be identical or different, denote linear alkyl radicals. or branched, having from 1 to 24 carbon atoms.

catalyseurs sont notamment Zr (OCH, Z (0-isoC3H/) , ZOCHg) , Zr (OC5Hn) 4, Zr (OC6H13) 4, Hf (OC2H5) 4, Hf (OC4Hg) 4, Hf (0-isoC3H7) 4. The C1 to C24 alkyl radicals chosen from among the R radicals of the tetraalkoxides used as catalysts in the process according to the invention are, for example, methyl, ethyl, propyl, isopropyl, butyl, ethylhexyl, decyl, dodecyl and hexadodecyl. The preferred catalysts are tetraalkoxides for which the radicals R, which may be identical or different, are C1-C4 alkyl radicals; at Cg. Examples of such

Catalysts are especially Zr (OCH, Z (O-isoC3H /), ZOCHg), Zr (OC5Hn) 4, Zr (OC6H13) 4, Hf (OC2H5) 4, Hf (OC4Hg) 4, Hf (O-isoC3H7) 4.

The catalyst used in this process according to the invention may consist solely of one or more of the tetraalkoxides of formula M (OR) 4 defined previously. It may also be formed by the combination of one or more of these tetraalkoxides with one or more alkali or alkaline-earth alkoxides of formula (R 1 O) pY in which R 1 denotes a hydrocarbon residue, advantageously a C 1 to C 24 alkyl residue. , and preferably C1 to C8, Y is an alkali or alkaline earth metal and p is the valence of Y. The amounts of alkali or alkaline earth alkoxide and tetraalkoxides of zirconium or hafnium which are associated for constituting the mixed catalyst can vary within wide limits. However, it is preferred to use amounts of alcoholate and tetraalkoxides such that the molar proportion of alkoxide is substantially equal to the molar proportion of tetraalkoxide.

 The proportion by weight of catalyst, that is to say of the tetraalkoxides or when the catalyst does not contain alkali or alkaline earth alkoxide or all of the tetraalkoxides and alkali or alkaline alkoxide or alcoholates when the catalyst is formed by the combination of these two types of compounds, advantageously varies from 0.01 to 5% of the weight of the mixture of the polyamide dicarboxylic with the

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 polyoxyalkylene glycol, and is preferably between 0.05 and 2% of this weight.

succinique, l'acide glutarique, l'acide adipique, l'acide maléique, l'acide fumarique, l'acide phtalique et l'acide crotonique. Les acides acétique et propionique sont particulièrement préférés. Avantageusement M est le zirconium. Ces sels peuvent s'appeler sels de zirconyle. La demanderesse sans être liée par cette explication pense que ces sels de zirconium et d'un acide organique ou les sels complexes cités plus haut libèrent ZrO++ au cours du procédé. On utilise le produit vendu sous le nom d'acétate de zirconyle. La quantité à utiliser est la même que pour les dérivés M (OR) 4. By way of example of other derivatives, mention may also be made of the salts of the metal (M), in particular the salts of (M) and of an organic acid and the complex salts between the oxide of (M) and / or (M) hydroxide and an organic acid. Advantageously, the organic acid may be formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauroyl acid, myristic, palmitic acid, stearic acid, oleic acid, linoleic acid, linoleic acid, cyclohexane carboxylic acid, phenylacetic acid, benzoic acid, salicylic acid, oxalic acid, malonic acid, acid

succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, phthalic acid and crotonic acid. Acetic and propionic acids are particularly preferred. Advantageously M is zirconium. These salts may be called zirconyl salts. Applicant without being bound by this explanation think that these salts of zirconium and an organic acid or complex salts mentioned above release ZrO ++ during the process. The product sold under the name of zirconyl acetate is used. The quantity to be used is the same as for the M (OR) 4 derivatives.

 This process and these catalysts are described in US Patents 4,332, 920, US 4,230,838, US 4,331,786, US 4,252,920, JP 07145368A, JP 06287547A, and EP 613919.

 As regards the one-step process, all the reagents used in the process are mixed in two stages, that is to say the polyamide precursors, the chain-limiting dicarboxylic acid, the polyether and the catalyst. These are the same reagents and the same catalyst as in the two-step process described above. If the polyamide precursors are only lactams it is advantageous to add a little water.

 The copolymer has essentially the same polyether blocks, the same polyamide blocks, but also a small portion of the various reagents reacted randomly that are randomly distributed along the polymer chain.

 The reactor is closed and heated with stirring as in the first step of the two-step process described above. The pressure is between 5 and 30 bar. When it no longer evolves, the reactor is reduced under reduced pressure while maintaining vigorous stirring of the molten reactants. The reaction is followed as above for the two-step process.

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 The catalyst used in the one-step process is preferably a salt of the metal (M) and an organic acid or a complex salt between the (M) oxide and / or the (M) hydroxide and an acid. organic.

 Ingredient (B) may also be a polyetheresteramide (B) having polyamide blocks comprising dicarboxylic acid sulfonates either as chain limiters of the polyamide block or associated with a diamine as one of the constituent monomers of the polyamide block and having polyether blocks consisting essentially of alkylene oxide units, as described in international application PCT / FROO / 02889.

 As regards compatibilizer C, it is a block copolymer comprising at least one polymerized block comprising styrene and at least one polymerized block comprising ethylene oxide units.

 The polymerized block comprising styrene is generally present in C at 60 to 99% by weight and preferably 60 to 98% by weight.

 The polymerized block comprising ethylene oxide units is generally present in C at 40 to 1% by weight and preferably 40 to 2% by weight.

 The polymerized block comprising styrene generally has a glass transition temperature of greater than 100 C and preferably comprises at least 50% by weight of styrene. The polymerized block comprising styrene may also comprise an unsaturated epoxide (obtained by copolymerization), the latter preferably being glycidyl methacrylate. The unsaturated epoxide may be present from 0.01% to 5% by weight in the polymerized block comprising styrene.

 The block copolymer comprising at least one polymerized block comprising styrene and at least one polymerized block comprising ethylene oxide units may also be grafted with an unsaturated epoxide, preferably glycidyl methacrylate.

- les esters et éthers de glycidyl alicycliques tels que le 2cyclohexène-1-glycidyléther, le cyclohexène-4, 5-diglycidyl carboxylate, le cyclohexène-4-glycidyl carboxylate, le 5-norbornène-2-méthyl-2-glycidyl carboxylate et l'endo cis-bicyclo (2, 2, 1)-5-heptène-2, 3-diglycidyl dicarboxylate. As examples of unsaturated epoxides, mention may be made of: aliphatic glycidyl esters and ethers such as allyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate and itaconate, glycidyl (meth) acrylate, and

alicyclic glycidyl esters and ethers such as 2-cyclohexene-1-glycidyl ether, cyclohexene-4,5-diglycidyl carboxylate, cyclohexene-4-glycidyl carboxylate, 5-norbornene-2-methyl-2-glycidyl carboxylate and endo cis-bicyclo (2, 2, 1) -5-heptene-2,3-diglycidyl dicarboxylate.

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 In the block comprising styrene, part of the styrene may be replaced by unsaturated monomers copolymerizable with styrene, for example mention may be made of alpha-methylstyrene and (meth) acrylic esters. In this case, the block comprising styrene is a copolymer of styrene, examples of which are styrene-alpha-methylstyrene copolymers, styrene-chlorostyrene copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers and styrene copolymers. vinyl chloride, styrene-vinyl acetate copolymers, styrene-alkyl acrylate copolymers (methyl, ethyl, butyl, octyl, phenyl acrylate), styrene methacrylate copolymers (methacrylate), methyl, ethyl, butyl, phenyl), styrene-chloroacrylate copolymers and styrene-acrylonitrile-alkyl acrylate copolymers.

 Preferably, the polymerized block comprising ethylene oxide units does not include a comonomer. This block generally ends with the function-OH from the ethylene glycol used as monomer to prepare it.

In particular, C may be: a diblock copolymer comprising a block of a styrene polymer and a block of a polymer of ethylene glycol (polyethylene glycol); a diblock copolymer comprising a homo polystyrene block and a block of a polymer of ethylene glycol (polyethylene glycol);
It would not be outside the scope of the invention using one or more compatibilizers C.

 Compatibilizer C may in particular be prepared by controlled radical polymerization techniques in the presence of a stable free radical (generally a nitroxide) based on the teaching principle of WO9411412 or WO 96/24260 or EP 927727.

 Antistaticism increases with the proportion of (B) and for equal amounts of (B) with the proportion of ethylene oxide units contained in (B).

 Depending on the application, it may be preferred to include a proportion of (B) sufficient to obtain at the final composition a surface resistivity measured according to IEC93 below 5. 1013Q / D.

Depending on the application, it may be preferred to include a proportion of (B) in a proportion sufficient for the final composition to have a volume resistivity measured according to IEC93 less than 5 1016 O. cm.

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 The amount of (B) + (C) is advantageously 5 to 30 parts for 95 to 70 parts of (A) and preferably 10 to 20 parts for 90 to 80 parts of (A). The ratio (B) / (C) is advantageously between 4 and 10. The amount of C in the composition can range from 0.5 to 5 parts by weight per 100 parts by weight of composition.

 We would not go beyond the scope of the invention by adding mineral fillers (talc, Ca3CO, kaolin ...), reinforcements (fiberglass, mineral fiber, carbon fiber, ...), stabilizers (thermal, UV), flame retardants and dyes.

 The compositions of the invention are prepared by the usual techniques of thermoplastics such as for example by extrusion or using twin-screw mixers.

 The present invention also relates to objects made with the preceding compositions; these are for example films, tubes, plates, packaging, computer cases, fax or telephone.

 The following is a procedure for preparing a PS-b-PEG block copolymer.

- Azocarboxy : 4, 4'-azobis (cyanovaleric acid) :

Products used: - HO-TEMPO (or TEMPO-OH): 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy usually marketed under the name 4-hydroxy TEMPO;

Azocarboxy: 4, 4'-azobis (cyanovaleric acid):

(ce produit es commercialisé par ATOFINA sous le nom Azocarboxy ) - POE : poly (ethylene glycol) methyl éther :

(this product is marketed by ATOFINA under the name Azocarboxy) - POE: poly (ethylene glycol) methyl ether:

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- DMAP : Dimethylaminopyridine :

- DCC: Dicyclohexylcarbodiimide:

DMAP: Dimethylaminopyridine:

The synthesis is done in two steps:
1. Synthesis of AZO-PEG macroinitiator, then
2. Radical (controlled) polymerization of styrene.

1. Synthesis of AZO-PEG macroinitiator
For this synthesis the table below gathers the ingredients and the quantities used:

<Tb>
<tb> g <SEP> 2,832
<tb> AZO
<tb> Mol <SEP> 0.0101
<tb> q <SEP> 4475
<tb> OE-OH
<tb> Mol <SEP> 0.0224
<tb> g <SEP> 4.13
<tb> DCC
<tb> Mol <SEP> 0.0200
<tb> g <SEP> 0.145
<tb> DMAP
<tb> Mol <SEP> 0.0012
<tb> g <SEP> 141.5
<tb> CH2Cl2
<tb> Mol <SEP> 1,656
<tb> g <SEP> 86, <SEP> 5
<tb> Mol <SEP> 1,196
<Tb>

The solid compounds (POE-OH, Azocarboxy and DMAP) are weighed, mixed and introduced into a glass reactor of 11. Then the solvents are added (firstly dichloromethane to solubilize the POE-OH and then the

<Desc / Clms Page number 15>

THF pour solubiliser l'azocarboxy) et tempéré à 0 C. Le DCC est introduit à l'aide d'une seringue et d'une aiguille (il est en solution dans le dichlorométhane) à travers un septum. La réaction est faite à 0 C pendant une heure et est laissée à température ambiante pendant 20 heures (sous agitation mécanique). Ensuite le produit est filtré sur Büchner : le filtrat est récupéré et les solvants (THF et CH2Cl2) sont évaporés (évaporateur rotatif à température ambiante). Ensuite le résidu est solubilisé dans du CH2CI2, filtré sur Büchner. Le filtrat est évaporé à nouveau (évaporateur rotatif à température ambiante) et le produit est séché à l'étuve à température ambiante pendant 12 h (rendement 74 %).

THF to solubilize the azocarboxy) and tempered to 0 C. The DCC is introduced using a syringe and a needle (it is dissolved in dichloromethane) through a septum. The reaction is carried out at 0 ° C. for one hour and is left at room temperature for 20 hours (with mechanical stirring). Then the product is filtered on Buchner: the filtrate is recovered and the solvents (THF and CH2Cl2) are evaporated (rotary evaporator at room temperature). Then the residue is solubilized in CH2Cl2, filtered on Buchner. The filtrate is evaporated again (rotary evaporator at room temperature) and the product is oven-dried at room temperature for 12 hours (74% yield).

C13 NMR analysis:

<Tb>
<tb> Yield <SEP> Time
<tb> mass <SEP> (%) <SEP> (g / mol)
<tb> 74 <SEP> 16. <SEP> 2 <SEP> 83.8 <SEP> 0 <SEP> 1823 <SEP># 20h
<Tb>

These results are determined by C13 NMR analysis. The initiator contains 83.3% 4,4'-azobis (cyanovalericpolyethylene glycol ester) and 16.2% unreacted PEG-OH.

2. Controlled radical polymerization

<Tb>
<tb> STYRENE <SEP> TEMPO-OH
<tb> concentration <SEP> STARTER <SEP> (g)
<tb> (g) <SEP> Mass <SEP> (g) <SEP> (mol / L)
<tb> 802 <SEP> 1, <SEP> 381 <SEP> 0, <SEP> 0090816, <SEP> 98
<Tb>

The TEMPO-OH is solubilized in styrene and then introduced into a flask containing the initiator of step 1. The flask is degassed by bubbling nitrogen for about 20 minutes. Then the flask is placed in an oil bath previously heated to 140oC. The polymerization is conducted for 720 min and samples to monitor the kinetics are regularly taken. The time zero corresponds to obtaining a reaction medium temperature of 100oC. At the end of the synthesis, the product is precipitated in methanol, filtered and dried under vacuum at 50 ° C. for 12 hours.

Results:
The analyzes are made in THF at room temperature.

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<Tb>
<tb> Time <SEP> (min) <SEP> Mw <SEP> (g / mol) <SEP> Mn <SEP> (g / mol) <SEP> Ip <SEP> Conversion <SEP> (%)
<tb> 186 <SEP> 29700 <SEP> 24400 <SEP> 1. <SEP> 2 <SEP> 22.07
<tb> 387 <SEP> 41500 <SEP> 33100 <SEP> 1. <SEP> 3 <SEP> 37.62
<tb> 480 <SEP> 47000 <SEP> 36450 <SEP> 1. <SEP> 3 <SEP> 46.54
<tb> 720 <SEP> (final) <SEP> 64700 <SEP> 50600 <SEP> 1. <SEP> 3 <SEP> 87.14
<Tb>

The samples were analyzed at 50 ° C. in chloroform-d by 1 H NMR: From the integration of the aromatic proton mass of the PS (by removing the contribution of styrene monomer), the integration of the lines of the CH 2 group Styrene monomer and the integration of the line of PEG ether groups, we have determined the mass ratio PS / PEG and the mass content of styrene monomer relative to the polymer.

In order to get an idea of the mass composition, we used the Mn determined by GPC and deduced a mass PS 1 mass PEG ratio assuming the PEG Mn equal to 2000 g / mol. The GPC and NMR results are in good agreement.

<Tb>
<Tb>

% <SEP> mass <SEP> PS-b-PEG
<tb> Ratio <SEP> PS / PEG <SEP> NMR <SEP> 97% / 3%
<tb> Ratio <SEP> PS / PEG <SEP> GPC <SEP> 96% / 4%
<Tb>

Claims (18)

CLAIMS aaaaa 1 composition comprising per 100 parts by weight: - 99 to 60 parts by weight of a styrene polymer (A), - 1 to 40 parts by weight of (B) + (C), (B) being a polyamide block copolymer and polyether blocks comprising essentially ethylene oxide units (C 2 H 4 O) -, (C) being a compatibilizer selected from block copolymers comprising at least one polymerized block comprising styrene and at least one polymerized block comprising oxide units ethylene, the mass ratio (B) / (C) being between 2 and 10.  2 Composition according to claim 1 wherein (B) is in sufficient proportion so that the final composition has a surface resistivity measured according to IEC93 less than 5. 1013Q / D.  3 Composition according to one of the preceding claims wherein (B) is in sufficient proportion for the final composition to have a volume resistivity measured according to IEC93 less than 5. 1016

 M cm.  4 Composition according to one of the preceding claims wherein the ratio (B) / (C) is between 4 and 10 Composition according to one of the preceding claims wherein (A) comprises more than 50% styrene.  6. Composition according to one of the preceding claims, characterized in that the amount of (C) ranges from 0.5 to 5 parts by weight in 100 parts by weight of composition.  Composition according to one of the preceding claims, characterized in that the polymerized block comprising styrene is present in C in a proportion of 60 to 99% by weight and in that the polymerized block comprising ethylene oxide units is present in C at a rate of 40 to 1% by weight.  8 Composition according to one of the preceding claims characterized in that the polymerized block comprising styrene is present in C at 60 to 98% by weight and in that the polymerized block comprising ethylene oxide units is present in C at a rate of 40 to 2% by weight.  9 Composition according to one of the preceding claims characterized in that the polymerized block comprising styrene comprises at least 50% by weight of styrene. <Desc / Clms Page number 18>  Composition according to one of the preceding claims, characterized in that the polymerized block comprising styrene comprises glycidyl methacrylate.  11. Composition according to one of the preceding claims, characterized in that the polymerized block comprising ethylene oxide units does not comprise a comonomer.  12 Composition according to one of the preceding claims characterized in that the block copolymer comprising at least one polymerized block comprising styrene and at least one polymerized block comprising ethylene oxide units is grafted with glycidyl methacrylate.  13 Composition according to one of the preceding claims characterized in that (A) is a styrene-butadiene copolymer.  Composition according to one of the preceding claims wherein the amount of (B) + (C) is from 5 to 30 parts per 95 to 70 parts of (A).  Composition according to the preceding claim wherein the amount of (B) + (C) is from 10 to 20 for 90 to 80 parts of (A).  Composition according to one of the preceding claims, characterized in that it does not comprise polyphenylene oxide.  Objects manufactured in a composition according to one of the preceding claims.  Use of the subject matter of the preceding claim for contacting electronic components.