HK1216181B - Phosphorylated polymers - Google Patents

Description

Phosphate polymer

describe

The invention relates to a process for preparing phosphorus-containing organic polymers, the phosphorus-containing organic polymers obtainable by this process, their use for flame-retardant modification of combustible solids or for modification of inorganic oxide solids, and corresponding modified thermoplastic molding compositions.

The flame-retardant modification of thermoplastic molding compositions by phosphorus-containing compounds such as DEPAL and red phosphorus is known per se. Furthermore, WO 2012/152805 describes the use of cyclic phenoxyphosphazenes and (di)phosphinates as flame-retardant components in thermoplastic molding compositions.

Other materials of interest as well as low molecular weight phosphorus-containing flame retardants are phosphorylated polymers that can be used in flame retardant applications.

The synthesis of compounds having carbon-phosphorus bonds is known per se and is described in US Pat. No. 2,957,931.

Furthermore, the connection between dialkyl phosphonates and ethylenically unsaturated compounds is described in J. Am. Chem. Soc. 81, (1959) pp. 6275-6277.

J. Polymer Science, Polymer Chemistry Edition, Vol. 15 (1977), pp. 547-560, describes the free radical addition of dimethyl phosphite to polypentene.

Phosphation reactions generally have low yields. For example, polypentene is reacted with a 20-fold excess of dimethyl phosphite, where the amount of dimethyl phosphonate bonded to the polymer chain is less than 10 mol %.

When a monomer is phosphorylated, the resulting phosphorylated monomer must be polymerized, which is often technically impossible.

There is therefore still a need for phosphating polymers which are suitable for the flame-retardant modification of combustible solids and which can be prepared in an uncomplicated manner.

This object is achieved by the process according to the invention for preparing phosphorus-containing organic polymers, wherein a dialkyl phosphite is reacted with an organic polymer containing carbon-carbon double bonds in the presence of an organic compound which forms free radicals under the reaction conditions, wherein the phosphorus atom of the dialkyl phosphite is covalently bonded to a carbon atom of the organic polymer.

This object is also achieved by the phosphorus-containing organic polymers obtainable by the process.

The object is also achieved by the use of such phosphorus-containing organic polymers for the flame-retardant modification of combustible solids or for the modification of inorganic oxide solids.

This object is also achieved by a thermoplastic molding composition, which contains: a) as component A, 30 to 95% by weight of at least one phosphorus-free thermoplastic polymer; b) as component B, 1 to 30% by weight of at least one phosphorus-containing organic polymer of the above-mentioned type; c) as component C, 0 to 15% by weight of further flame retardant auxiliary agents; d) as component D, 0 to 20% by weight of at least one impact-modifying polymer; e) as component E, 0 to 50% by weight of glass fibers; f) as component F, 0 to 30% by weight of further additives, the total amount of components A to F being 100% by weight.

In the process of the present invention, an organic polymer containing carbon-carbon double bonds is reacted or phosphylated with a dialkyl phosphite in the presence of an organic compound capable of forming free radicals under the reaction conditions.

It has been found in the present invention that when the affinity of the dialkyl phosphite for the organic polymer is sufficiently high, the phosphorylation reaction of the organic polymer can be successfully carried out in high yield.

This can be ensured by using an organic polymer with sufficient polarity. In the present invention, an organic polymer with sufficient polarity can be used, or a non-polar or insufficiently polar organic polymer can be rendered more polar by introducing polar groups into the polymer.

For example, organic polymers having more than 65% by weight of vinyl aromatic units, based on the organic polymer, are generally sufficiently polar to be phosphorylated. In this case, the introduction of ionic groups is not necessary.

The polarity of the organic polymer can be increased, for example, by introducing polar groups, such as (meth)acrylic acid or its esters, hydroxy (meth)acrylates such as hydroxyethylhexyl acrylate, (meth)acrylamide, acrylonitrile, and the like.

Alternatively or in addition, maleic anhydride can act on the carbon-carbon double bonds of the organic polymer to introduce succinic anhydride groups. Preferably, up to 20%, in particular up to 10%, of the allyl groups or carbon-carbon double bonds are grafted in this manner.

Furthermore, polar groups may be introduced by hydroboration/oxidation, chloromethylation or bromomethylation/hydrolysis, or sulfonation.The polar groups may be in the form of terminal groups in the polymer chain or may be present within the polymer chain.

In the present invention, it is preferred to use an organic polymer for the reaction which has, based on the monomer units of the organic polymer, 0.01 to 50 mol %, in particular 0.5 to 20 mol %, especially 1 to 10 mol % of ionic groups, which may be present completely or partially in salt form. Therefore, the ionic groups may be present partially or completely in deprotonated form.

Preferably, the ionic groups are selected from carboxyl, sulfinate, sulfonate and/or sulfate groups.

The presence of the ionic groups makes the polarity of the organic polymer used in the present invention match the polarity of the dialkyl phosphite, thus realizing sufficient affinity between the two components.Through this method, the rapid reaction of the dialkyl phosphite and the carbon-carbon double bond can be realized with a high graft yield, while the rise of crosslinking or molar mass can be basically prevented.

For example, the organic polymer used in the reaction may have been sulfonated.

For sulfonation, it is advantageous for the organic polymer to have aromatic groups, since sulfonation of aromatic groups is possible under non-aggressive conditions without attacking the carbon-carbon double bond or the allyl group generated by the sulfonation.

Therefore, it is preferred that the organic polymer contains 10-70% by weight, preferably 20-60% by weight, in particular 30-50% by weight of monomer units containing aromatic groups, based on the total amount of the organic polymer. Examples of suitable monomers having aromatic groups are vinyl aromatic monomers, such as styrene or methylstyrene.

The molecular weight of the organic polymer used in the reaction is not critical. Preferably, the number average molecular weight (Mn) is in the range of 1000 to 1,000,000, particularly 2000 to 300,000, especially 5000 to 200,000.

The organic polymer used in the reaction may be a homopolymer or a copolymer, preferably a random copolymer, a diblock copolymer or a multiblock copolymer.

Here, the carbon-carbon double bond may be present in the polymer main chain or in the side chain. Preferably, the carbon-carbon double bond is present in the polymer main chain.

The organic polymers used in the present invention may be derived from any desired suitable monomeric units. Examples of suitable polymers can be found in Hadjichristidis, "Block copolymers," Wiley, 2003, pp. 4-173, and Hsieh and Quirk, "Anionic Polymerization," Decker, 1996, pp. 261-394.

The polymers can be prepared by any polymerization method, such as anionic polymerization, cationic polymerization, free radical polymerization or ring-opening metathesis polymerization. Free radical polymerization methods also include controlled radical polymerization methods, such as using TEMPO and similar compounds.

Suitable AB diblock copolymers can be prepared, for example, by anionic polymerization of styrene with isoprene, butadiene, cyclohexadiene, methyl methacrylate, butyl methacrylate, butyl acrylate, 2,3-glycidyl methacrylate, stearyl methacrylate, 2-vinylpyridine, 4-vinylpyridine, ethylene oxide, caprolactone, hexamethylcyclotrisiloxane, ferrophenyldimethylsilane or hexyl isocyanate; they can also be prepared from the anionic polymerization of α-methylstyrene with isoprene, the anionic polymerization of isoprene with 2-vinylpyridine, ethylene oxide, hexamethylcyclotrisiloxane, the anionic polymerization of butadiene with caprolactone or ethylene oxide, the anionic polymerization of methyl methacrylate with butyl methacrylate, and the anionic polymerization of 2-vinylpyridine with butyl methacrylate, caprolactone or ethylene oxide.

ABA triblock copolymers can be prepared, for example, by anionic polymerization of the following monomers: styrene/butadiene, styrene/isoprene, p-methylstyrene/butadiene, α-methylstyrene/isoprene, tert-butylstyrene/butadiene, 4-vinylpyridine/butadiene, ethylene oxide/isoprene, isoprene/tert-butyl acrylate, tert-butyl methacrylate/isoprene, methyl methacrylate/butadiene, methyl methacrylate/octyl acrylate, glycidyl methacrylate/butadiene, isobornyl methacrylate/butadiene, ethylene oxide/butadiene.

Chemical modification of the polymers can optionally be carried out as described above, for example by hydrogenation, hydrolysis, quaternization, sulfonation, hydroboration/oxidation, epoxidation, chloro/bromomethylation or hydrosilylation.

As further functionalized monomers, compounds customarily used as regulators, such as monocarboxylic acids and dicarboxylic acids, can also be used. Reference is made in this respect to DE-A-4413177.

Non-linear block copolymers, such as radial block copolymers, or graft copolymers, or other complex copolymer structures can also be used. Unsaturated block copolymers can also be obtained by ring-opening metathesis polymerization.

Ring-opening metathesis polymerization (ROMP) can use any suitable monomer, such as oxanorbornenes.

Preferred in the present invention are vinyl aromatic-diene copolymers having a total butadiene content of up to 30% by weight. Under the conditions described below for the free-radical phosphonylation process, these can be directly phosphonylated with yields exceeding 50%, based on the double bonds in the polymer. Such polymers can have a random structure or be in the form of linear block polymers with block sequences such as S-B, S-B-S, (S-B)n, B-S-B, (S-B)nS, or B-(S-B)n; or have a star structure, for example, according to the following formulae: (S-B)n-x, (B-S)n-x, (S-B-S)n-x, (B–S-B)n-x, where x is an n-functional coupling agent or an initiator molecule with a functionality greater than 1. S represents polymer blocks composed of styrene and/or other vinyl aromatic compounds, with identical or varying block lengths and a narrow, broad, or multimodal block length distribution. B represents a diene-containing polymer block, which may be composed entirely of diene units, such as butadiene, isoprene, other dienes, and mixtures thereof, but may also be a random copolymer of such dienes with vinyl aromatic compounds, such as styrene and butadiene, wherein the diene/vinyl aromatic monomer ratio may range from 99/1 to 1/99, preferably from 90/10 to 10/90. Within this block, the monomer composition may be constant or may exhibit a gradient. The transitions between the individual blocks may be sharp or tapered, and if the transition is sharp, it indicates an abrupt change in composition; if the transition is tapered, it indicates a polymer segment with a monomer gradient.

Vinyl aromatic/diene copolymers having a total butadiene content of greater than 30% by weight are also within the scope of the present invention.To achieve phosphorylation levels of greater than 50%, polar groups, especially ionic groups, are preferably introduced.

The material that can also be advantageously used in the present invention is a graft polymer, in which a vinyl monomer is grafted onto an ethylenically unsaturated polymer. The graft base can be a polydiene, which is based on monomers such as butadiene, isoprene, and other alkyl butadienes, or their mixtures, or mixtures thereof with vinyl aromatic monomers such as styrene, such as SBR, especially solution SBR, or mixtures thereof with other vinyl monomers such as acrylonitrile, acrylate and methacrylate. Other materials that are also suitable for use as graft bases are polymers obtained from ring-opening metathesis polymerization, such as polypentene, polyoctenes, polynorbornene, polyoxy norbornene, and other monomers suitable for ring-opening metathesis polymerization. Also suitable for use as a graft base material is the vinyl aromatic compound-diene block copolymer described above. Preferably, the graft base is dissolved in the monomer, or dissolved in a monomer mixture, and it is used by grafting in the form of a graft chain. Grafting can optionally be carried out in the presence of a solvent and a free radical initiator. Suitable monomers are vinyl aromatic monomers, such as styrene, other vinyl monomers, such as acrylonitrile, acrylate, methacrylate, and their mixtures. The molar mass of the grafted chains can be controlled by the polymerization temperature and optionally by adding a conditioning agent. A wide range of phosphorus contents can be obtained according to the needs of the application, which is achieved by the molar mass of the grafted base and the number and molar mass of the grafted chains. The molar mass range is from the oligomer region (Mw>500) and extends to two million.

Furthermore, these polymers may contain other reactive groups, such as -OH, NCO, etc. These groups may be important for other subsequent reactions, for example during the coating of hot-dip galvanized steel sheets treated with the phosphonated polymers.

Particularly preferred in the present invention are elastomeric block copolymers composed of at least one hard block A composed of styrene monomers and at least one elastomeric block B/A composed of styrene monomers and diene monomers, as described in WO 97/40079. Preferred are elastomeric block copolymers composed of at least one block A, which forms a hard phase and contains copolymerized units derived from vinyl aromatic monomers, and at least one block (B/A), which forms a soft phase and contains copolymerized units of vinyl aromatic monomers and diene monomers, wherein the glass transition temperature (Tg) of block A is higher than 25°C, and the glass transition temperature (Tg) of block (B/A) is lower than 25°C, and the phase volume ratio of block A to block (B/A) is selected such that, based on the entire block copolymer, the proportion of the hard phase is 1 to 40% by volume, the weight proportion of diene is less than 50% by weight, and the relative content of 1,2-bonds of the polydiene is less than 15% based on all 1,2- and 1,4-cis/trans bonds.

Preferred organic polymers for use in the present invention contain copolymerized units of a vinyl aromatic monomer and a diene monomer.

Here, more than 65% by weight of vinylaromatic monomer units, based on the organic polymer used for the reaction, are present, and no ionic groups are present.

The organic polymers used for the reaction may also have, as copolymerized units, 10 to 70% by weight, preferably 20 to 60% by weight, in particular 30 to 50% by weight, based in each case on the polymer, of vinylaromatic units and 30 to 90% by weight, preferably 40 to 80% by weight, in particular 50 to 70% by weight, of diene units, and 0.5 to 5%, preferably 1 to 4%, in particular 2 to 3% of the aromatic units have been sulfonated.

The reaction of the dialkyl phosphite with the carbon-carbon double bond is carried out in the presence of free radicals. These free radicals can be derived, for example, from peroxides, hydroperoxides, unstable C-C compounds, or azo compounds. Suitable compounds should have a half-life of 20 seconds to 10 hours at the reaction temperature. Typical reaction temperatures are 50-150°C, preferably 60-120°C.

It may be advantageous to additionally use polymer stabilizers, such as sterically hindered phenols. These compounds reduce polymer crosslinking under the reaction conditions.

The molar excess of dialkyl phosphite is preferably 1 to 50, preferably 2 to 30, based on the carbon-carbon double bonds.

These components can be added in various ways. Preferably, a dialkyl phosphite is used together with a solvent as the initial charge. The polymer can then be metered into the system together with the free radical generator. The metering time is preferably 1 hour to 7 days, particularly preferably 8-48 hours.

The correct choice of solvent can be advantageous. The solvent should have moderate polarity, and a dielectric constant greater than 5 is advantageous in many cases. Dioxane, dimethoxyethane, diethylene glycol dimethyl ether and diethylene glycol diethyl ether are preferred.

The addition of alkaline components with a pH > 8 can be advantageous, preferably amines (primary, secondary, tertiary), preferably in a small excess based on the deprotonatable groups in the polymer. Furthermore, organic salts acting as soaps and nonionic surfactants can be used, which can advantageously also serve as phase transfer catalysts, in amounts of less than 10% by weight, based on the polymer used.

Dialkyl phosphites which can be used are any desired suitable dialkyl phosphites having identical or different alkyl moieties. Preference is given to using di-C ₁ -C ₆ alkyl phosphites, in particular di-C ₁ -C ₃ alkyl phosphites, especially dimethyl phosphite or diethyl phosphite.

The obtained phosphorus-containing organic polymer has a high degree of phosphorylation and can be used for flame retardant modification of polymers and, after hydrolysis, for bonding on polar surfaces and dispersing inorganic fillers on oxide surfaces.

Preferably, the degree of phosphorylation is 10 to 100 mol %, in particular 40 to 100 mol %, and especially 60 to 100 mol %, based on the carbon-carbon double bonds present in the organic polymer used for the reaction.

This reaction may advantageously be carried out in the presence of a free-radical scavenger, in order to inhibit any cross-linking reactions.

After phosphating, the phosphorus-containing organic polymer can be hydrolyzed to form phosphonic acid groups. This is particularly advantageous in the modification of inorganic oxide solids, while the flame retardant modification of combustible solids, preferably those made of plastics, wood or natural fibers, uses unhydrolyzed phosphorus-containing organic polymers.

The phosphorus-containing organic polymers obtainable in the present invention are preferably used for flame retardant modification of combustible solids or for modification of inorganic oxide solids, which are preferably made of plastic, wood, or natural fibers. The plastic may be bulk plastic, plastic foam, elastomer, dispersion, or coating material. The inorganic oxide solid is preferably derived from aluminum, silicon, titanium, zinc, or magnesium, or from inorganic substances containing these elements. Furthermore, polymers and color pigments can also be modified.

Sulfonated and phosphonylated organic polymers are preferably used in the present invention.

The phosphonated polymer can be reacted with HCl gas as described by Azuma to give a polymer having free phosphonic acid groups. Alternatively, successful cleavage of the ester bonds is achieved by adding preferably a 1-10% aqueous solution of phosphonic acid to a solution of the polymer in the above-mentioned ether and subsequently heating for 2-4 hours, preferably to 100-150° C., optionally in an autoclave.

Phosphonic acid groups help to disperse fillers in polymers or solvents. Therefore, they can also be used in detergents.

The higher the molar mass of the diene block to be phosphorylated, the more difficult it is to overcome the phase transfer problem between the nonpolar polydiene or diene-rich styrene-diene polymer and the polar alkyl phosphonate. This results in a lower degree of phosphorylation, accompanied by an increasing degree of molar mass and gelation due to crosslinking. The effect of remote ionic groups located at the chain ends, such as those introduced by reacting the living polymer chain with sulfur dioxide to produce sulfinic acid, is generally insufficient. This problem is preferably solved by introducing additional polar, preferably ionic, groups into the diene chain using suitable monomers. This can be achieved, for example, by maleation of some diene units. In a preferred embodiment, styrene units are introduced at intervals of 10-20 diene units and then sulfonated, for example by reacting a (sub)stoichiometric amount of a sulfonating agent such as chlorosulfonic acid or an acetylsulfonate, preferably in a chlorinated hydrocarbon such as 1,2-dichloroethane, preferably at a temperature of 0-25°C. This reaction should be carried out under particularly mild conditions to avoid sulfonation of the polydiene, which would subsequently decompose and produce a black coloration. This process is particularly interesting when the polymers used consist primarily of dienes and have a molar mass of more than 2000 g/mol, in particular more than 5000 g/mol. This increases the degree of phosphorylation of dialkyl and diaryl phosphonates. Such polyphosphonates are suitable, for example, as flame retardants in thermoplastics, foams, dispersions, and reactive plastics.

They are preferably used for the modification of thermoplastic molding compositions containing a) as component A 30 to 95% by weight of at least one phosphorus-free thermoplastic polymer, b) as component B 1 to 30% by weight of at least one phosphorus-containing organic polymer according to the invention, c) as component C 0 to 15% by weight of further flame retardant auxiliary agents, d) as component D 0 to 20% by weight of at least one impact-modifying polymer, e) as component E 0 to 50% by weight of glass fibers, f) as component F 0 to 30% by weight of further additives, the total amount of components A to F being 100% by weight.

Component A can be selected from any desired suitable polymers, including, for example, polyamides, polyesters, polycarbonates, polyethers, polyurethanes, polysulfones, polyolefins, or polymer blends formed from two or more of these polymers.

It is particularly preferred that component A comprises polyamide.

The polyamides preferably used in the present invention are prepared by reacting starting monomers, which are selected, for example, from dicarboxylic acids and diamines, or from salts of dicarboxylic acids and diamines, aminocarboxylic acids, aminonitriles, lactams, and mixtures thereof. Any desired aliphatic polyamide starting monomers may be included herein. The polyamides may be amorphous, crystalline, or semicrystalline. In addition, the polyamides may have any desired suitable viscosity or molecular weight. Particularly suitable polyamides have any type of aliphatic, semicrystalline, or semiaromatic structure, or are amorphous.

The intrinsic viscosity of these polyamides is generally from 90 to 350 ml/g, preferably from 110 to 240 ml/g, measured in a 0.5% by weight solution in 96% by weight sulfuric acid at 25° C. in accordance with ISO 307.

Semicrystalline or amorphous resins having a molecular weight (weight average molecular weight) of at least 5000 are preferred, and these are described, for example, in the following U.S. Patents: 2 071 250, 2 071 251, 2 130 523, 2 130 948, 2 241 322, 2 312 966, 2 512 606 and 3 393 210. Examples of these are polyamides derived from lactams having 7 to 11 ring members, such as polycaprolactam and polycapryllactam, and polyamides obtained by reaction of dicarboxylic acids with diamines.

Dicarboxylic acids which can be used are alkanedicarboxylic acids having 6 to 12, in particular 6 to 10, carbon atoms, and aromatic dicarboxylic acids. Mention may be made here of the following acids: adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid (=decanedicarboxylic acid).

Particularly suitable diamines are alkanediamines having 2 to 12, in particular 6 to 8, carbon atoms, and also di(4-aminocyclohexyl)methane or 2,2′-bis(4-aminocyclohexyl)propane.

Preferred polyamides are polyhexamethylene adipamide (PA 66) and polydecamethylene adipamide (PA 610), polycaprolactam (PA 6), and nylon 6/6,6 copolyamides, especially with a proportion of 5 to 95% by weight of caprolactam units. Particular preference is given to PA 6, PA 66, and nylon 6/6,6 copolyamides.

Mention may also be made of polyamides obtainable, for example, by condensing 1,4-diaminobutane with adipic acid at elevated temperatures (nylon-4,6). Processes for preparing polyamides of this structure are described, for example, in EP-A 38,094, EP-A 38,582 and EP-A 39,524.

Further examples are polyamides obtainable by copolymerization of two or more of the abovementioned monomers, and mixtures of a plurality of polyamides in any desired mixing ratios.

The following non-limiting list includes the polyamides mentioned, as well as other polyamides useful in the present invention (monomers are identified in parentheses):

PA 26 (ethylenediamine, adipic acid)

PA 210 (ethylenediamine, sebacic acid)

PA 46 (tetramethylenediamine, adipic acid)

PA 66 (hexamethylenediamine, adipic acid)

PA 69 (hexamethylenediamine, azelaic acid)

PA 610 (hexamethylenediamine, sebacic acid)

PA 612 (hexamethylenediamine, decanedicarboxylic acid)

PA 613 (hexamethylenediamine, undecanedicarboxylic acid)

PA 1212 (1,12-dodecanediamine, decanedicarboxylic acid)

PA 1313 (1,13-diaminotridecane, undecanedicarboxylic acid)

PA 4 (pyrrolidone)

PA 6 (ε-caprolactam)

PA 7 (ethanol lactam)

PA 8 (capryllactam)

PA 9 (9-aminononanoic acid)

PA 11 (11-aminoundecanoic acid)

PA 12 (laurolactam).

These polyamides and their preparation methods are well known. For details of their preparation methods, the person skilled in the art can refer to Ullmanns Enzyklopadie der Technischen Chemie [Ullmanns Encyclopedia of Industrial Chemistry], 4th edition, volume 19, pages 39-54, Verlag Chemie Weinmann 1980, and Ullmanns Encyclopedia of Industrial Chemistry, volume A21, pages 179-206, VCH Verlag, Weinmann 1992, and Stoeckhert, Kunststofflexikon [Plastics Encyclopedia], pages 425-428, Hanser Verlag, Munich 1992 (keyword "Polyamide").

Particular preference is given to using nylon 6 or nylon 6,6.

Furthermore, the present invention can provide functional compounds in the polyamide, wherein they can be bonded to carboxyl or amino groups and, for example, have at least one carboxyl, hydroxyl or amino group. They are preferably:

Monomers with branching properties, wherein they have, for example, at least three carboxyl or amino groups;

Monomers capable of bonding to carboxyl or amino groups, for example via epoxy, hydroxyl, isocyanate, amino and/or carboxyl groups, and having a functional group selected from the group consisting of a hydroxyl group, an ether group, an ester group, an amide group, an imine group, an imide group, a halogen group, a cyano group, and a nitro group, a C-C double bond, or a C-C triple bond;

Or a polymer block capable of bonding to a carboxyl group or an amino group.

The use of functional compounds makes it possible to adjust the property profile of the resulting polyamides as desired within a wide range.

For example, triacetonediamine compounds can be used as functionalized monomers. These preferably include 4-amino-2,2,6,6-tetramethylpiperidine or 4-amino-1-alkyl-2,2,6,6-tetramethylpiperidine, in which the alkyl group has 1 to 18 carbon atoms or is substituted with a benzyl group. The triacetonediamine compound is preferably present in an amount of 0.03 to 0.8 mol %, particularly preferably 0.06 to 0.4 mol %, based in each case on 1 mol of amide groups in the polyamide. For further details, see DE-A-44 13 177.

The phosphorus-containing organic polymers can be used alone or together with other flame retardant substances and synergists as component C.

Other flame retardant substances may be, for example, red phosphorus, cyclic phenoxyphosphazenes having at least a phenoxyphosphazene unit, or (di)phosphinates.

Furthermore, it is also possible to use reaction products of melamine and phosphoric acid or metal borates.

Preferred reaction products of melamine and phosphoric acid are products obtained by reacting substantially equimolar amounts of melamine or a melamine condensation product with phosphoric acid, pyrophosphoric acid, or polyphosphoric acid by a suitable method. Particularly preferred are melamine polyphosphates, which can be obtained by condensing melamine phosphates by heating under nitrogen. The general formula of melamine polyphosphates is (C ₃ H ₆ N ₆ HPO ₃ ) _n .

The phosphorous acid component in melamine phosphate is, for example, orthophosphoric acid, phosphorous acid, phosphinic acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, or tetraphosphoric acid. Particularly preferred is melamine polyphosphate obtained by the condensation reaction of an adduct of orthophosphoric acid or pyrophosphoric acid with melamine. The degree of condensation of the melamine polyphosphate is preferably 5 or greater. Alternatively, the melamine polyphosphate may be an equimolar adduct salt of polyphosphoric acid and melamine. Cyclic polymetaphosphoric acid and non-cyclic polyphosphoric acid may also be used. The adduct salt of melamine polyphosphate is generally a powder obtained by reacting an aqueous slurry of a mixture of melamine and polyphosphoric acid and subsequently separating the mixture by filtering, washing, and drying. The particle size of the melamine polyphosphate can be adjusted within a wide range. For details, see paragraph [0026] of EP-A-2100919.

Suitable phosphinates have the general formula [R ¹ R ² P(═O)—O] ^- _m M ^m+ . Suitable (di)phosphinates have the general formula [OP(═O)R ¹ -OR ³ -OP(═O)R ² -O] ^2- _n M _x ^m+ , wherein R ¹ and R ² are each independently a linear or branched C _1-6 alkyl moiety or a C _6-10 aryl moiety, R ³ is a linear or branched C _1-10 alkylene moiety, a C _6-10 arylene moiety, a C _7-10 alkylarylene moiety or a C _7-10 arylalkylene moiety, M is Ca, Mg, Al or Zn, m is the valence of M, determined by 2n=mx, n is a value of 1 or 3, and x is 1 or 2. If m or n is 2 or greater, the moieties R ¹ to R ³ can be freely selected at each position.

Examples of suitable phosphinates are dimethylphosphinate, ethylmethylphosphinate, diethylphosphinate, methyl-n-propylphosphinate, methanedi(methylphosphinate), benzene-1,4-di(methylphosphinate), methylphenylphosphinate, and diphenylphosphinate. The metal component M is a calcium ion, a magnesium ion, an aluminum ion, or a zinc ion.

Examples of suitable phosphinates are calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, and zinc diphenylphosphinate.

Examples of suitable diphosphinates are calcium methanedi(methylphosphinate), magnesium methanedi(methylphosphinate), aluminum methanedi(methylphosphinate), zinc methanedi(methylphosphinate), calcium benzene-1,4-di(methylphosphinate), magnesium benzene-1,4-di(methylphosphinate), aluminum benzene-1,4-di(methylphosphinate), and zinc benzene-1,4-di(methylphosphinate).

Particular preference is given to using phosphinates, in particular aluminum ethylmethylphosphinate, aluminum diethylphosphinate and zinc diethylphosphinate. Particular preference is given to using aluminum diethylphosphinate.

The (di)phosphinates can be used in any desired suitable particle size, see EPA-2 100 919, paragraph [0032].

The thermoplastic molding compositions can contain, as component D, at least one impact-modifying polymer.

Used component D contains at least one impact-modified polymer of 0-20 % by weight, preferably 0-10 % by weight, especially 0-8 % by weight.If there is an impact-modified polymer, then its minimum amount is 0.1 % by weight, preferably 1 % by weight, especially 3 % by weight.The maximum possible amount of component A is correspondingly reduced so that the total amount of components A to F is 100 % by weight.It is not necessary to use component D simultaneously, but using component D can improve the impact resistance of the gained polyamide molding composition.Herein involved impact-modified polymer is those polymers that are generally used for the impact modification of component A polyamide.Preferably comprise elastomer, for example natural or synthetic rubber and other elastomers.

Synthetic rubbers that can be mentioned and can be used are ethylene-propylene-diene rubber (EPDM), styrene-butadiene rubber (SBR), butadiene rubber (BR), nitrile rubber (NBR), polyether rubber (ECO), and acrylic ester rubber (ASA). Silicone rubber, polyoxyalkylene rubber, and other rubbers can also be used.

The following can be used as thermoplastic elastomers: thermoplastic polyurethane (TPU), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), and styrene-ethylene-propylene-styrene block copolymer (SEPS).

Furthermore, a resin may be used as the blended polymer, such as a polyurethane resin, an acrylic resin, a fluororesin, a silicone resin, an imide resin, an amide-imide resin, an epoxy resin, a urea resin, an alkyd resin, or a melamine resin.

In addition, ethylene copolymers can be used as blend polymers, for example copolymers of ethylene and 1-octene, 1-butene or propylene, as described in WO 2008/074687. The molar mass of the above-mentioned ethylene/α-olefin copolymers is preferably 10,000 to 500,000 g/mol, preferably 15,000 to 400,000 g/mol (number average molar mass). Linear polyolefins, such as polyethylene or polypropylene, can also be used.

Suitable polyurethanes can be found in EP-B-1 984 438, DE-A-10 2006 045 869 and EP-A-2 223 904.

Other suitable thermoplastic resins are listed in paragraph [0028] of JP-A-2009-155436.

Further polymers suitable as component F can be found in EP-A-2 100 919, paragraph [0044].

Copolymers of ethylene and acrylic esters, acrylic acid and/or maleic anhydride are particularly preferably used as component F. Particular preference is given to using copolymers of ethylene, n-butyl acrylate, acrylic acid and maleic anhydride. Corresponding copolymers are available as KR1270 from BASF SE.

Component E

The thermoplastic molding composition contains, as component E, 0-50% by weight, or, if present, 1-50% by weight, preferably 10-35% by weight, in particular 20-30% by weight, for example, about 25% by weight, of glass fibers. Any desired suitable glass fibers can be used in the form of chopped strands or rovings. Preferably, the chopped strands have a diameter of about 10 microns. The glass fibers may be surface-treated, for example, by silanization. The use of glass fibers simultaneously is particularly advantageous.

Component F

The thermoplastic molding composition of the present invention may contain 0-30% by weight of other additives as component F. Such other additives may include other fillers, stabilizers, antioxidants, agents that provide protection against thermal and UV degradation, flame retardants, lubricants and mold release agents, colorants such as dyes and pigments, nucleating agents, plasticizers, etc. For a more detailed description of possible additives, see pages 31-37 of WO 2008/074687.

Preferably, 0.1 to 20% by weight of component F is present (the amount of component A is reduced accordingly), wherein component F contains a stabilizer and a lubricant. For example, zinc oxide can be used as a stabilizer and calcium stearate as a lubricant. Antioxidants conventionally used in polyamide molding compositions can be used, for example, as those sold under the trade name BASF SE.

Other fillers that may be used are carbon fibers, aramid fibers, and other fillers such as gypsum fibers, synthetic calcium silicate, kaolin, calcined kaolin, wollastonite, talc, and chalk.

It is also possible to use other flame retardants together with the flame retardants of components B to E, which are used as additives for component F, such as those based on triazines, metal hydrates and siloxanes. A typical flame retardant substance based on triazines is melamine cyanurate.

Other additional flame retardant substances may be metal compounds, such as magnesium hydroxide, aluminum hydroxide, zinc sulfate, iron oxide and boron oxide, as described in paragraphs [0046] to [0048] of EP-A-2 100 919.

Other flame retardant substances with synergistic effects are described, for example, in paragraphs [0064] to [0065] of US 2010/0261818.

The molding compositions of the invention are prepared by mixing components A to F. For this purpose, extruders, for example single-screw or twin-screw extruders, or other customary plasticizing apparatuses, for example Braybenz mixers or Banbury mixers, can advantageously be used.

The order in which the components are mixed can be freely selected.

The molding compositions of the invention are characterized by improved flame retardancy, combined with improved tensile strain at break and Charpy impact strength. They are suitable for producing moldings, fibers or foils.

The invention also provides corresponding moldings, fibers or foils produced from the above-described thermoplastic molding compositions.

The following examples are provided to further illustrate the present invention.

Synthesis Example

Provide styrene-butadiene (SB) block copolymer

The preparation of suitable SB block copolymers is described, for example, in EP 0 859 803 B1, where in particular Example 3 having the S-(S/B) 3 -S structure is used.

Example 1: Sulfonation of SB Block Copolymer

10.0 g of the SB block copolymer (35% Bu/65% S) from Example 3 of EP 0 859 803 B1 and 250 ml of anhydrous dichloroethane were initially charged in a nitrogen-inertized glass apparatus. Once the polymer had dissolved, the system was cooled to -10°C to -15°C, and 0.18 g of chlorosulfonic acid dissolved in 50 ml of anhydrous ethanol was metered into the system over 1 hour with stirring. After the reaction continued for 30 minutes, 0.56 g of tributylamine was added to neutralize the liberated HCl and sulfonic acid groups. For elemental analysis of S, the procedure was as follows: 10 ml of the reaction solution was precipitated in water, filtered, washed with ethanol, and dried at 50°C/20 mbar for 15 hours.

Elemental analysis for S: 0.59 g/100 g (theoretical value: 0.50 g/100 g, corresponding to 2.5% of phenyl units).

Example 2: Phosphorylation of Sulfonated SB Copolymer

300 ml of diethylene glycol diethyl ether (DEGDE) and 67.0 g of diethyl phosphite (15-fold excess, based on the olefinic double bonds) were initially charged to a glass apparatus. After heating to 120° C., 5.0 g of the sulfonated SB copolymer from Example 1 and 9.7 g of di-tert-butyl peroxide, each dissolved in 70 ml of DEGDE, were metered into the system over 24 hours, and the reaction was allowed to proceed for 8 hours. The phosphated polymer was precipitated in water, washed with water and ethanol, filtered, and dried at 70° C./20 mbar for 12 hours.

Elemental analysis for P: 6.6 g/100 g (theoretical value: 10.5 g/100 g; degree of phosphorylation = 63%).

Examples of flame retardant thermoplastic molding compositions

PA 6

Component A: Nylon-6, from BASF SE, B27,

Component B1: Ethylene-octene copolymer modified with maleic anhydride, MN493, DuPont,

Component B2: ethylene-acrylate copolymer, KR1270, BASF SE,

Component B3: Phosphated SB copolymer from Example 2

Component C: Glass fiber, 10 micron, OCF 1110, Dow Corning,

Component D1: aluminum diethylphosphinate flame retardant, OP 1230, Clariant,

Component D2: melamine polyphosphate flame retardant, M200, BASF SE,

Component E: zinc borate,

Component F: 30DF aluminum stearate, Barlocher AG,

Component G: 1098 antioxidant, BASF SE,

Table 1: Phosphorylated SB copolymers from the examples in reinforced PA6

Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 A 54.45 39.45 39.45 39.45 B1 15 B2 15 B3 15 C 25 25 25 25 D1 12.7 12.7 12.7 12.7 D2 6.3 6.3 6.3 6.3 E 1 1 1 1 F 0.2 0.2 0.2 0.2 G 0.35 0.35 0.35 0.35 Tensile modulus/MPa 8900 8800 8900 8900 Tensile stress at break/MPa 130 110 115 110 Tensile strain at break/% 3.2 3.5 3.5 3.6 70 90 95 95 UL 94, 0.8mm V-0 fail fail V-0

PA 66-flame retardant package based on aluminum diethylphosphinate

Component A: Nylon-6,6, B27, BASF SE,

Component B1: Ethylene-octene copolymer modified with maleic anhydride, MN493, DuPont,

Component B2: ethylene-acrylate copolymer, KR1270, BASF SE,

Component B3: Phosphorylated SB copolymer from Synthesis Example

Component C: Glass fiber, 10 micron, OCF 1110, Dow Corning,

Component D1: aluminum diethylphosphinate flame retardant, OP 1230, Clariant,

Component D2: melamine polyphosphate flame retardant, M200, BASF SE,

Component E: zinc borate,

Component F: 30DF aluminum stearate, Barlocher AG,

Component G: 1098 antioxidant, BASF SE,

Table 2: Phosphorylated SB copolymers from synthesis examples in reinforced PA66

Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 A 54.45 39.45 39.45 39.45 B1 15 B2 15 B3 15 C 25 25 25 25 D1 12.7 12.7 12.7 12.7 D2 6.3 6.3 6.3 6.3 E 1 1 1 1 F 0.2 0.2 0.2 0.2 G 0.35 0.35 0.35 0.35 Tensile modulus/MPa 9300 9200 9200 9200 Tensile stress at break/MPa 140 125 130 125 Tensile strain at break/% 3 3.5 3.5 3.5 60 90 85 85 UL 94, 0.8mm V-0 fail fail V-0

PA 66-Red Phosphorus-based flame retardant package

Component A: Nylon-6,6, B27, BASF SE,

Component B1: Ethylene-octene copolymer modified with maleic anhydride, MN493, DuPont,

Component B2: ethylene-acrylate copolymer, KR1270, BASF SE,

Component B3: Phosphorylated SB copolymer from Synthesis Example

Component C: Glass fiber, 10 micron, OCF 1110, Dow Corning,

Component D1: Masteret 21440 red phosphorus flame retardant, 40% red phosphorus in PA66 base, Italmatch,

Component E: Ultrabatch 190X stabilizer/lubricant, Great Lakes: 50% zinc oxide, 25% calcium stearate, 25% 98, BASF SE,

Component F: 170 lubricant, 50% stearyl stearate, 25% zinc stearate, 25% calcium stearate,

Table 3: Phosphorylated SB copolymers from synthesis examples in reinforced PA66

Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 A 50.21 35.21 35.21 35.21 B1 15 B2 15 B3 15 C 26 26 26 26 D1 16.25 16.25 16.25 16.25 E 1.4 1.4 1.4 1.4 F 0.14 0.14 0.14 0.14 Tensile modulus/MPa 8500 6500 6500 6400 Tensile stress at break/MPa 120 110 105 115 Tensile strain at break/% 3.1 4 5.5 5 45 70 70 70 UL 94, 0.8mm V-0 fail fail V-0

PBT-polybutylene terephthalate

Component A: polybutylene terephthalate from BASF SE with an intrinsic viscosity of 107 ml/g (measured as a 0.5% (w/w) solution in a 1:1 phenol-dichlorobenzene mixture at 23° C.), B2550

Component B1: Ethylene-octene copolymer modified with maleic anhydride, MN493, DuPont,

Component B2: PTW ethylene-n-butyl acrylate-glycidyl methacrylate terpolymer, DuPont,

Component B3: Phosphorylated SB copolymer from Synthesis Example

Component C: PPG 3786 glass fiber, diameter 10 microns, standard fiber strength: 4.5 mm, PPG,

Component D1: aluminum diethylphosphinate flame retardant, OP 1240, Clariant,

Component D2: melamine polyphosphate flame retardant, M200, BASF SE,

Component D3: MC25 melamine cyanurate flame retardant, BASF SE,

Component E: OA5 polyethylene wax lubricant, BASF SE,

Table 4: Phosphorylated SB copolymers from synthesis examples in reinforced PBT

Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 A 52.2 37.2 37.2 37.2 B1 15 B2 15 B3 15 C 25 25 25 25 D1 15 15 15 15 D2 3.75 3.75 3.75 3.75 D3 3.75 3.75 3.75 3.75 E 0.3 0.3 0.3 0.3 Tensile modulus/MPa 10300 10000 9500 9500 Tensile stress at break/MPa 110 105 105 105 Tensile strain at break/% 2.3 3 3 3 45 80 85 85 UL 94, 0.8mm V-0 fail fail V-0

Processing

These components were extruded in a twin-screw extruder with an L/D ratio of 25. The compounding temperature during processing was 290°C for PA66 and 270°C for PA6 and PBT. The throughput was 25 kg/h. The screw speed was 350 rpm. The resulting polymer strands were pelletized and appropriately injection molded to produce experimental samples.

Flame retardant test

The flame retardancy test was conducted in accordance with UL94 (Underwriters Laboratory) using a test sample with a thickness of 0.8 mm.

Claims (15)

1. A method for preparing a phosphorus-containing organic polymer, wherein a dialkyl phosphite reacts with an organic polymer containing a carbon-carbon double bond in the presence of an organic compound capable of forming a free radical under reaction conditions, wherein the phosphorus atom of the dialkyl phosphite is covalently bonded to the carbon atom of the organic polymer, wherein the organic polymer used for the reaction has 0.01-50 mol% ionic groups based on the monomer units of the organic polymer, and wherein the organic polymer used for the reaction has a number average molecular weight (Mn) of 2000-300,000. 2. The method of claim 1, wherein the ionic group is present entirely or partially in the form of a salt. 3. The method according to claim 1, wherein the ionic group is selected from carboxylate, sulfinate, sulfonate and/or sulfate. 4. The method of claim 3, wherein the organic polymer used for the reaction has been sulfonated. 5. The method according to any one of claims 1-4, wherein the organic polymer used for the reaction is a random copolymer, a diblock copolymer, or a multiblock copolymer. 6. The method according to any one of claims 1-4, wherein the carbon-carbon double bond is present in the polymer backbone of the organic polymer used for the reaction. 7. The method of claim 6, wherein the organic polymer used for the reaction has polymerization units of vinyl aromatic monomers and diene monomers. 8. The method of claim 7, wherein in each case, based on the organic polymer used for the reaction, the organic polymer used for the reaction has 10-70% by weight of copolymer units of vinyl aromatic monomers and 30-90% by weight of copolymer units of diene monomers, and wherein 0.5-5% of the aromatic units have been sulfonated. 9. The method of claim 8, wherein in each case, based on the organic polymer used for the reaction, the organic polymer used for the reaction has 20-60% by weight of copolymer units of vinyl aromatic monomers and 40-80% by weight of copolymer units of diene monomers, and wherein 1-4% of the aromatic units have been sulfonated. 10. The method according to any one of claims 1-4, wherein the phosphorus-containing organic polymer is hydrolyzed to form phosphonic acid groups. 11. A phosphorus-containing organic polymer obtained by the method of any one of claims 1-10. 12. Use of the phosphorus-containing organic polymer according to claim 11 for flame retardant modification of flammable solids or for modification of inorganic oxide solids. 13. The use according to claim 12, wherein the combustible solid is plastic, wood, or natural fiber. 14. The use according to claim 12 or 13, wherein the phosphorus-containing organic polymer used for flame retardant modification does not hydrolyze to form phosphonic acid groups, and the phosphorus-containing organic polymer used for modifying inorganic oxide solids hydrolyzes to form phosphonic acid groups. 15. A thermoplastic molding composition comprising: a) As component A, 30-95% by weight of at least one phosphorus-free thermoplastic polymer. b) As component B, 1-30% by weight of at least one phosphorus-containing organic polymer according to claim 10, c) Other flame retardant additives, 0-15% by weight, as component C. d) As component D, 0-20% by weight of at least one impact-modified polymer, e) As component E, 0-50% by weight of glass fiber, f) Other additives, 0-30% by weight, as component F. The total amount of components A to F is 100% by weight.