FR2864097A1 - Thermoplastic composition useful for making shaped articles comprises a flame retardant system comprising a phosphinate salt, a melamine phosphate and a melamine condensation product - Google Patents

Abstract

Thermoplastic composition comprises a thermoplastic matrix and a flame retardant system comprising a phosphinate salt (I), a compound (II) which is a reaction product of phosphoric acid and melamine or a melamine condensation product, and a melamine condensation product (III). The composition comprises at least 13 wt.% of (I) and (II). Thermoplastic composition comprises a thermoplastic matrix and a flame retardant system comprising a phosphinate salt of formula (I), a compound (II) which is a reaction product of phosphoric acid and melamine or a melamine condensation product, and a melamine condensation product (III). The composition comprises at least 13 wt.% of (I) and (II). [ R1>, R2>1-6C alkyl or aryl; M : Ca, Mg, Al or Zn; z : 2 or 3. An independent claim is also included for an article obtained by shaping the composition. [Image].

Description

i 2864097 Fire retardant composition based on thermoplastic matrix

  The present invention relates to a flame-retarded thermoplastic composition comprising a particular flame retardant system based on phosphinic acid salt and melamine derivatives. This composition is particularly useful for the production of articles used in the field of electrical or electronic connectivity.

  The compositions based on thermoplastic resins are used for the production of articles by different shaping processes. These articles are used in many technical fields, such as for the production of parts of electrical or electronic systems. These parts must have high mechanical properties but also properties of chemical resistance, electrical insulation, and good fireproofing when these parts come into combustion. One of the important aspects is that these parts must not go into combustion, that is to say do not produce flames; or then go into combustion but at the highest possible temperatures.

  Fireproofing of compositions based on thermoplastic matrix has been studied for a very long time. Thus, the main flame retardants used are red phosphorus, halogenated compounds such as polybrominated diphenyls, polybrominated diphenoxides, brominated polystyrenes, organic nitrogen compounds belonging to the triazine class such as melamine or its derivatives such as melamine cyanurate and more recently phosphates, polyphosphates and pyrophosphates of melamine, organophosphorous acids and their salts.

  Flame retardants with consistently higher flame retardancy properties are constantly being sought. Moreover, flame retardants, generally used in large quantities lead to problems of forming parts. In addition, some flame retardants containing halogens or red phosphorus can generate toxic gases or vapors during the combustion of the polyamide composition. In addition, flame retardants are known to be unstable at elevated temperatures. Thus, some of the flame retardants degrade during the manufacturing process of the plastic article, thereby decreasing their flame retardancy.

  There is thus a need for thermoplastic matrix-based compositions for producing articles having satisfactory mechanical properties and good flame retardancy, while avoiding the disadvantages mentioned above. The present invention firstly relates to a composition based on a thermoplastic matrix comprising a flame retardant system comprising at least: a compound (F1) of formula (I): ## STR1 ##

_ _ Z

  in which: R 1 and R 2 are identical or different and represent a linear or branched alkyl chain comprising from 1 to 6 carbon atoms, preferably from 1 to 3 carbon atoms, and / or an aryl radical; M represents a calcium, magnesium, aluminum and / or zinc ion, preferentially a magnesium and / or aluminum ion; Z represents 2 or 3, preferentially 3; a compound (F2) which is a reaction product between phosphoric acid and melamine and / or a reaction product between phosphoric acid and a condensation derivative of melamine; and a compound (F3) which is a condensation derivative of melamine; said composition preferably comprises at least 13% by weight of compounds F1 and F2, more preferably at least 15%, relative to the total weight of the composition.

  The Applicant has discovered, quite surprisingly, that the compounds of this particular flame retardant system according to the invention act synergistically in the composition based on thermoplastic matrix and make it possible to obtain articles which, in addition to a low propagation of flame, good mechanical properties and good thermal stability, capacity

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  high to not generate flames, when they come into contact with incandescent bodies or propagating flames.

  The composition according to the invention may comprise from 1 to 50% by weight of the flame retardant system according to the invention comprising at least compounds F1, F2 and F3, preferably from 5 to 40%, even more preferably from 10 to 30%. , particularly from 15 to 30%, relative to the total weight of the composition. The composition according to the invention may comprise from 1 to 30% by weight of compound F1, preferably from 1 to 20% by weight, more preferably from 5 to 15% by weight.

  The composition according to the invention may comprise from 1 to 20% by weight of compound F2, preferably from 2 to 10% by weight.

  The composition according to the invention may comprise from 0.1 to 20% by weight of compound F3, preferably from 1 to 10% by weight.

  Preferably, the weight ratio of the compounds F1 and F2 is respectively between 1: 1 and 4: 1, preferably around 2: 1 and 3: 2.

  R1 and R2 of the compound F1 of formula (I) may be identical or different and represent a methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl and / or aryl such as a phenyl for example. M is preferably an aluminum ion. The phosphinic acid of the compound F1 can be chosen for example from the group comprising: dimethyl phosphinic acid, ethylmethyl phosphinic acid, diethyl phosphinic acid, methyl-n-propyl phosphinic acid, and / or their mixture. Different phosphinic acids can be used in combination. The compounds FI are in particular described in the patent US6255371.

  The phosphinic acid salts according to the invention may be prepared according to the usual methods well known to those skilled in the art, such as, for example, that described in patent EP 0699708. The phosphinic acid salts according to the invention may be used in different forms depending on the nature of the polymer and the desired properties. For example, to obtain a good dispersion in the polymer, a phosphinic acid salt may be in the form of fine particles.

  Compound F2 is a reaction product between phosphoric acid and melamine and / or a reaction product between phosphoric acid and a melamine condensation derivative. Different F2 compounds can be used in combination. The condensed derivatives of melamine are for example melam, melem and melon. Even more condensed compounds can be used. Preferably, the compound F2 may be chosen for example from the group comprising the following reaction products: melamine polyphosphate, melam polyphosphate, and melem polyphosphate, and / or their mixture. It is particularly preferable to use a melamine polyphosphate having chains of a length greater than 2, and in particular greater than 10. These compounds are described in particular in the patent WO 9839306 and US6255371. The compounds F2 can also be obtained. by methods other than those based on the direct reaction with a phosphoric acid. For example, melamine polyphosphate can be prepared by reaction of melamine with polyphosphoric acid (see WO9845364), but also by condensation of melamine phosphate and melamine pyrophosphate (see WO9808898).

  The compound F3 is, for example, melam, melem and / or melon. Even more condensed compounds can be used. Different F3 compounds can be used in combination. Preferentially, melem is used which is a compound of formula C6H6N10, which can be represented with the following formula: ## STR2 ## In a very preferred manner, the flame-retarding system of the present invention comprises a compound F1 of formula (I) wherein R1 = R2 = ethyl, M = aluminum and Z = 3; a compound F2: melamine polyphosphate; and a compound F3 which is melem. The weight ratio of the compounds F1 and F2 can be, for example, respectively 2: 1.

  The present invention relates to a thermoplastic matrix-based composition selected from the group consisting of: (co) polyamides; mono- or diolefin (co) polymers, such as polypropylene, polyisobutylene, polybutylene, polybutadiene, polyethylene; ethylene-propylene copolymers, optionally grafted styrene copolymer, such as polystyrene, poly (p-methylstyrene, poly- (α-methylstyrene), styrene or α-methylstyrene copolymer with dienes or with acrylics, such as styrene-butadiene, styrene-acrylonitrile, anhydrous maleic styrene, polyurethanes, polymers comprising halogens, such as polychloropropene, polymers derived from α, β-unsaturated acids, such as polyacrylate, polymethacrylate polyacrylonitrile, polyacrylamide, unsaturated polymers derived from alcohols and amines, such as polyvinyl alcohol, vinyl polymers and their copolymers such as polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride; polyacetals such as polyoxymethylene, polyphenylene oxide, polyphenylene ether, polyphenylene sulphide, polyurea, polyketone, polyimide, polyester such as polyethylene terephthalate, polybutylene terephthalate, polycarbonates, polyester carbonates, polysulfones, polyether sulfones, their derivatives and / or mixtures thereof.

  Mention may be made, for example, of linear semi-crystalline or amorphous polyamides, such as aliphatic polyamides, semiaromatic polyamides and, more generally, polyamides obtained by polycondensation between an aliphatic or aromatic saturated diacid, and a saturated aromatic or aliphatic primary diamine. polyamides obtained by condensation of a lactam and / or an amino acid, or polyamides obtained by condensation of a mixture of these different monomers. These copolyamides may be, for example, hexamethylene polyadipamide, polyphthalamides obtained from terephthalic and / or isophthalic acid, copolyamides obtained from caprolactam, and one or more monomers generally used for the manufacture of polyamides, such as adipic acid, terephthalic acid, and / or hexamethylenediamine.

  The polyamide is preferably chosen from semicrystalline polyamides, for example polymers obtained by the polycondensation action of saturated aliphatic diacids having 6 to 12 carbon atoms, such as, for example, adipic acid, azelaic acid or sebacic acid. dodecanoic acid or a mixture thereof with linear or branched saturated aliphatic diamines preferably having from 4 to 12 carbon atoms such as, for example, hexamethylenediamine, trimethylhexamethylenediamine, tetramethylenediamine, xylene diamine or a mixture thereof; the polyamides obtained either by direct homopolycondensation of coaminoalkanoic acid having a hydrocarbon chain having from 4 to 12 carbon atoms, or by hydrolytic opening and polymerization of lactams derived from these acids; the copolyamides obtained from the starting monomers of the abovementioned polyamides, the acid component of these copolyamides possibly being partly terephthalic acid and / or isophthalic acid; and mixtures of these polyamides or their copolymers.

  By way of illustration of the polyamides obtained by polycondensation of diacids and diamines, mention may be made, for example, of polyamide 6,6 (tetramethylenediamine and adipic acid polymer), polyamide 6,6 (hexamethylenediamine polymer and adipic acid), polyamide 6,9 (hexamethylenediamine and azelaic acid polymer), polyamide 6,10 (hexamethylenediamine and sebacic acid polymer), polyamide 6,12 (hexamethylenediamine polymer and dodecanedioic acid).

  By way of illustration of the polyamides obtained by homopolycondensation which may be suitable, mention may be made of: polyamide 4 (4-aminobutanoic acid or γ-butyrolactam polymer), polyamide 5 (amino-5-pentanoic acid polymer or amylolactam), polyamide 6 (caprolactam polymer), polyamide 7 (7-amino-heptanoic acid polymer), polyamide 8 (capryllactam polymer), polyamide 9 (9-amino-nonanoic acid polymer), polyamide 10 (amino-decanoic acid polymer), polyamide 11 (amino-11 undecanoic acid polymer), polyamide 12 (amino-12-dodecanoic acid or laurylactam polymer).

  By way of illustration of the copolyamides, mention may be made, for example, of polyamide 6,6 / 6,10 (copolymer of hexamethylenediamine, of adipic acid and of sebacic acid), polyamide 6,6 / 6 (copolymer of hexamethylenediamine, adipic acid and caprolactam), polyamide 6112, polyamide 6/11, polyamide 6 / 6,36.

  Mention may also be made of polyamide 6 (T) which is a polyamide obtained by polycondensation of terephthalic acid and hexamethylenediamine; polyamide 9 (T) which is a polyamide obtained by polycondensation of terephthalic acid and a diamine comprising 9 carbon atoms; polyamide 6 (1) which is a polyamide obtained by polycondensation of isophthalic acid and hexamethylenediamine; and polyamide MXD6 which is a polyamide obtained by polycondensation of adipic acid and metaxylylene diamine.

  The (co) polyamide matrix according to the invention generally comprises at least one (co) polyamide chosen from the group comprising: (co) polyamide 6; 4; 11; 12, 4.6; 6.6; 6.9; 6.10; 6.12; 6.18; 6.36; 6 (T); 9 (T); 6 (1); MXD6; their copolymers and / or mixtures.

  The composition according to the invention may also comprise reinforcing fillers that are well known to those skilled in the art and chosen, for example, from the group comprising glass, carbon, mineral, ceramic, heat-resistant organic fibers such as polyphthalamide fibers, and mineral fillers such as wollastonite, kaolin, clay, silica and mica, and mineral nanofillers such as montmorillonite and a-ZrP; and / or their mixtures. Glass fibers are particularly preferred according to the invention. The glass fibers that are preferably used are glass fibers for polyamide, having, for example, a mean diameter of between 5 and 20 μm, preferably between 10 and 14 μm, such as, for example, CS123D-10C glass fibers (Owens Corning). Fiberglass), CS1103 (Owens Corning Fiberglass) and CS983 (Vetrotex) and CS99B (Vetrotex). The reinforcing fillers may represent from 0 to 80%, preferably from 5 to 55%, even more preferably from 10 to 40% by weight relative to the total weight of the composition.

  The composition according to the invention may also comprise one or more additives usually used by a person skilled in the art in compositions used for the manufacture of molded articles. Examples of additives that may be mentioned include thermal stabilizers, molding agents such as calcium stearate, UV stabilizers, antioxidants, lubricants, abrasion reducing agents, pigments, dyes, plasticizers, laser marking promoters or resilience modifying agents. For example, antioxidants and heat stabilizers are, for example, alkali halides, copper halides, sterically hindered phenolics, organic phosphites, and aromatic amines.

  The composition according to the invention may also furthermore comprise various other flame retardant compounds or synergistic agents with the fireproofing system, such as thermal stabilizers. There may be mentioned, for example, ceramic powder, magnesium hydroxide, hydrotalcites, magnesium carbonates and other alkaline earth carbonates, zinc oxide, zinc stannate, zinc hydroxystannate , zinc phosphate, zinc borate, zinc sulphide, aluminum hydroxide, aluminum phosphate and red phosphorus, the nitrogenous organic compounds belonging to the class of triazines such as melamine and / or its derivatives such as melamine cyanurate. The compounds based on zinc, such as zinc borate, may be present in proportions of between 0.01 and 5% by weight, preferably between 0.1 and 5% by weight, relative to the total weight of the composition. .

  The present invention also relates to a process for the production of a fireproof composition according to the invention in which at least one thermoplastic matrix and at least one flame retardant system are mixed, for example by extrusion in a molten or dry manner. as previously described.

  Mixing can be carried out in the molten state, for example in a single or twin screw extruder, or by mixing without going into the molten state, for example in a mechanical mixer. The compounds can be introduced simultaneously or successively. Any means known to those skilled in the art relating to the introduction of the various compounds of a thermoplastic composition may be used. An extrusion device is generally used in which the material is heated, subjected to shear force, and conveyed. Such devices are well known to those skilled in the art. The composition according to the invention, when prepared using an extrusion device can be packaged in granular form or used directly for shaping an article.

  The present invention also relates to an article obtained by shaping a composition according to the invention in particular by a method chosen from the group comprising an extrusion process, such as the extrusion of sheets and films, molding, such as as compression molding, injection molding, such as injection molding, and spinning. Such articles can be used in the field of automotive, electrical or electronic connectors such as circuit breakers, switches, connectors or the like.

  Other details or advantages of the invention will emerge more clearly in the light of the examples given below solely for information purposes.

  The compounds used in the examples below are the following: PA 66: PA 66 having a viscosity number of 140 ml / g (ISO 307, formic acid), and an Mn of 17600 g / mol (measured by GPC); - F1 compound of formula (VI) wherein R6 = R7 = ethyl, M = aluminum and Z = 3; - Compound F2: melamine polyphosphate.

  - Compound F3: melem (2,6,10-triamine symmetric-heptazine) Delacal 450 (Delamin); - FV: Glass fibers CS99B (Vetrotex); - SC: Calcium stearate.

  BZ: Zinc Borate: Firebrake ZB (US Borax) EXAMPLE 1 Preparation of Compositions The compositions are prepared by mixing the components in proportions indicated in Table 1 of Example 2, on a Werner & Pfleiderer twin-screw extruder. ZSK 40, having a screw speed of 200 rpm and an output of 35 kg / h, at a temperature of 270 C. The glass fibers are added to the mixture at the throat of the extruder. The granules are dried and melted on an Arburg 320 M500-210 injection molding machine at a temperature of 270-280 ° C. and then molded at 80 ° C. in the form of test specimens.

  The final compositions comprise 30% glass fiber, 0.5% calcium stearate and 0.5% zinc borate.

  Example 2: Measurement of properties The properties are determined on test pieces, according to the following methods: The flame resistance is measured according to the UL-94 test ("Underwriters Laboratories"). This test is carried out with test pieces with a thickness of 0.8 mm, after conditioning for 48 hours at 50% RH (relative humidity) and 168 hours at 70 C. The result is coded as follows: N.0: not classified ( weak fireproofing). V2: the average burning time is less than 25 seconds, the maximum burning time is less than 30 seconds (self-extinguishing); polyamide drop igniting the cotton. V-1: average combustion time is less than 25 seconds, the maximum combustion time is less than 30 seconds (self-extinguishing); no inflammation of the cotton by the gout. V-0: average combustion time is less than 5 seconds, the maximum combustion time is less than 10 seconds (self-extinguishing); no inflammation of the cotton.

  - GWFT: The flame extinguishing capacity caused by the application of an incandescent wire according to IEC 60695-2-12 is measured on specimens with a thickness of 1.0 mm and a surface area of 80 * 80 mm, at a temperature of 960 C. It is noted that the composition passes the test successfully when there is ignition during the application of the incandescent wire but self-extinguishing within 30 seconds after removal of said incandescent wire. It is noted that the composition fails the test when there is ignition during the application of the incandescent wire and not self-extinguishing within 30 seconds after removal of said incandescent wire. The test is passed successfully when the three different test pieces successively confirm the same temperature.

  - GWIT: Measurement of the ability not to form a flame following the application of an incandescent wire according to the standard IEC 60695-2-13 on specimens of thickness 1.0 mm, at a temperature of 750 C The standard provides that when the sample successfully passes the test at 750 C, 25 C is added at that temperature, and the sample is therefore classified with a GWIT of 775 C. It is noted that the composition successfully passes the test. test when there is no ignition during the application of the incandescent wire. It is noted that the composition fails the test when there is ignition during the application of the incandescent wire, that is to say production of flames having a permanence of more than 5 seconds. The test is passed successfully when the three different test pieces successively confirm the same temperature.

  - CHARPY impact resistance according to ISO 179 \ 1 eA and ISO 17911 eU.

  - CTI: according to the IEC 112. The CTI resistance is the voltage for which a material does not undergo flame in its area. For this test, it is applied 50 times, and every thirty seconds, currents at the same point, through a saline solution of ammonium chloride which falls within a fixed interval between two electrodes. If it does not happen flames and until the end of the 50 applications, the test is passed successfully.

  The properties of the previously made compositions are summarized in Table 1 (the percentages are by weight).

Table 1

  A 1 2 3 PA 66 (%) 51.5 46.5 50 47 F1 (%) 11.5 11.5 12.5 10 F2 (%) 6 6 6, 5 5 F3 (%) - 5 1 7 GWIT Fail Pass Pass Pass (775 C) GWFT Pass Pass Pass Pass (960 C) UL 94 V-0 V-0 V-0 V-0 CHARPY 59, 6 49.9 53.3 49.1 (KJIm2) CTI (volt ) 600 600 600 575 The compositions according to the invention make it possible to obtain articles having a very satisfactory mechanical behavior as well as a low inflammation and a good flame retardancy, compared with articles obtained from compositions of the prior art not comprising no melem.

Claims (1)

12 2864097 Claims   1. Composition based on a thermoplastic matrix comprising a fireproofing system comprising at least: a compound (FI) of formula (I): ## STR2 ## Z   wherein: R 1 and R 2 are the same or different and represent a linear or branched alkyl chain comprising 1 to 6 carbon atoms, and / or an aryl radical; M represents a calcium, magnesium, aluminum and / or zinc ion; Z represents 2 or 3; a compound (F2) which is a reaction product between phosphoric acid and melamine and / or a reaction product between phosphoric acid and a condensation derivative of melamine; and a compound (F3) which is a condensation derivative of melamine; said composition comprising at least 13% by weight of compounds F1 and F2, preferably at least 15%, relative to the total weight of the composition.   2. Composition according to claim 1, characterized in that it comprises from 1 to 50% by weight of the flame retardant system comprising at least compounds F1, F2 and F3, relative to the total weight of the composition.   3. Composition according to claim 1 to 2, characterized in that it comprises from 1 to 30% by weight of compound FI.   4. Composition according to any one of claims 1 to 3, characterized in that it comprises from 1 to 20% by weight of compound F2.   5. Composition according to any one of claims 1 to 3, characterized in that it comprises from 0.1 to 20% by weight of compound F3.   6. Composition according to any one of claims 1 to 7, characterized in that the phosphinic acid of the compound F1 is chosen from the group comprising: dimethyl phosphinic acid, ethylmethyl phosphinic acid, diethyl phosphinic acid and methyl-n-propyl phosphinic acid, and / or their mixture.   7. Composition according to any one of claims 1 to 6, characterized in that the compound F2 is selected from the group comprising: melamine polyphosphate, melam polyphosphate, and melem polyphosphate, and / or their mixture.   8. Composition according to any one of claims 1 to 7, characterized in that the compound F3 is selected from the group comprising: melam, melem, melon, and / or their mixture.   9. Composition according to any one of claims 1 to 8, characterized in that the thermoplastic matrix is chosen from the group comprising: (co) polyamides; mono- or diolefin (co) polymers, such as polypropylene, polyisobutylene, polybutylene, polybutadiene, polyethylene; ethylene-propylene copolymers, optionally grafted styrene copolymer, such as polystyrene, poly (p-methylstyrene, poly- (α-methylstyrene), styrene or α-methylstyrene copolymer with dienes or with acrylics, such as styrene-butadiene, styrene-acrylonitrile, anhydrous maleic styrene, polyurethanes, polymers comprising halogens, such as polychloropropene, polymers derived from α, acides unsaturated acids, such as polyacrylate, polymethacrylate, polyacrylonitrile, polyacrylamide, unsaturated polymers derived from alcohols and amines, such as polyvinyl alcohol, vinyl polymers and their copolymers such as polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride; polyacetals such as polyoxymethylene, polyphenylenes oxide, polyphenylenes ether, polyphenylenesulphide, polyureas, polyketones, polyimides, polystyrene yesters, such as polyethylene terephthalate, polybutylene terephthalate, polycarbonates, polyester carbonates, polysulfones, polyether sulfones, their derivatives and / or mixtures thereof.   10. Composition according to claim 8, characterized in that matrix (co) polyamide comprises at least one (co) polyamide selected from the group comprising: (co) polyamide 6; 4; 11; 12, 4.6; 6.6; 6.9; 6.10; 6.12; 6. 18; 6.36. ; 6 (T); 9 (T); 6 (1); MXD6; their copolymers and / or mixtures.   11. The composition according to claim 1, wherein said composition comprises reinforcing fillers chosen from the group comprising: heat-resistant organic fibers; mineral fillers such as wollastonite, kaolin, clay, silica and mica, and mineral nanofillers such as montmorillonite and α-Zr phosphate, and / or mixtures thereof.   12. Composition according to any one of claims 1 to 11, characterized in that said composition comprises flame retardants or synergistic agents to the fireproofing system selected from the group comprising: ceramic powder, magnesium hydroxide, hydrotalcites, magnesium carbonates and other alkaline earth carbonates, zinc oxide, zinc stannate, zinc hydroxystannate, zinc phosphate, zinc borate, zinc sulfide, hydroxide aluminum, aluminum phosphate and red phosphorus, nitrogen-containing organic compounds belonging to the class of triazines such as melamine and / or its derivatives such as melamine cyanurate.   13. A method of manufacturing a composition according to any one of claims 1 to 12, wherein at least the thermoplastic matrix is mixed with the flame retardant system comprising at least compounds F1, F2 and F3.   14. Article obtained by shaping a composition according to any one of claims 1 to 12.