DE19705998A1 - Thermoplastic polyamide moulding composition used for e.g. fibres and films - Google Patents

Abstract

Thermoplastic moulding composition comprises: (A) 10-98 wt.% polyamide containing at least 5% units derived from lactam monomers; (B) 1-20 wt.% red phosphorus; (C) 0.1-15 wt.% delaminated film silicate (phyllosilicate); and (D) 0-70 wt.% additives and aids. Also claimed are moulded articles obtained from the above composition. Preferably the composition contains 5-40 wt.% fibrous reinforcer. (A) is polyamide 6, polyamide 12, polyamide 6/66, polyamide 6/61 and/or polyamide 6/6T, preferably 5-95 wt.% polyamide 6 and 5-95 wt.% other polyamide. (C) is montmorillonite, smectite, illite, sepiolite, palygorskite, muscovite, allevardite, amesite, hectorite, talcum, fluorohectorite, saponite, beidellite, nontronite, stevensite, bentonite, mica, vermiculite, halloysite and/or fluorine containing mica.

Description

The invention relates to thermoplastic molding compositions containing

• A) 10 to 98 wt .-% of a polyamide, which at least 5 wt .-%, based on 100 wt .-% A), contains units, wel che derived from lactam monomers.
• B) 1 to 20% by weight of red phosphorus
• C) 0.1 to 15% by weight of a delaminated layered silicate (Phyllosilicates)
• D) 0 to 70% by weight of conventional additives and processing aids medium,

where the sum of the percentages by weight of components A) to D) 100% results.

Furthermore, the invention relates to the use of the Invention contemporary thermoplastic molding compositions for the production of fibers, Films and moldings of any kind as well as those available here Chen molded body.

Mixing polyamides with red phosphorus for flame protection equipment has long been known, e.g. B. from DE-A 19 31 387 and DE-A 19 67 354.

For polyamide 6 or its blends with other polyamides or Copolyamides, which are derived in particular from caprolactam Units contain, however, difficulties often arise with the Processing - especially for products containing glass fibers - on.

During processing and / or long hot storage (a measure of the amount of the possible continuous use temperature z. B. in electrical and electronic parts) becomes caprolactam or caprolactam dimer (by partial cleavage of the polyamide), which in the Form a covering is formed and the mechanical as well as flame protective properties u. a. ver by molecular weight reduction worse. When using molded parts as a switch leads this deposit formation z. B. wrong switching. This is not only true  for polyamides made of caprolactam, but for lac tam monomers built up polyamides in general.

From DE-A 44 02 917 it is known the caprolactam monomers and / or dimers and oligomers to reduce, powder shaped aluminosilicates added during compounding the.

This procedure does reduce the Oligomer or monomer content achieved, however, in the Minerals partially embedded or adsorbed on the surface oligomers bound only physically (not chemically); d. H. the oligomers remain extractable. The mechani properties such as elongation at break and impact strength unsatisfactory as well as the heat resistance (HDT).

The present invention was therefore based on the object, flaming protected polyamide molding compositions made from lactam monomers To make available which is less in processing Show blooming and allow a higher continuous use temperature with acceptable mechanical and flame protection characteristics.

Accordingly, the molding compositions defined at the outset were found. Preferred embodiments can be found in the subclaims men.

Surprisingly, the combination of red phosphorus carries along delaminated layered silicates, especially in the case of polyamide 6 PA molding compounds with a very low tendency to bleed processing and reduced build-up of deposits by caprolactam or caprolactam dimers or oligomers higher continuous service temperature of the molded parts.

The molding compositions 10 according to the invention contain component A) up to 98, preferably 20 to 97 and in particular 30 to 95% by weight a polyamide which contains at least 5, preferably 10% by weight, based on 100 wt .-% A), contains units which differ from Derive lactam monomers.

The polyamides of the molding compositions according to the invention generally have mean a viscosity number of 90 to 350, preferably 110 to 240 ml / g to determined in a 0.5 wt .-% solution in 96% by weight sulfuric acid at 25 ° C according to ISO 307.

Suitable lactam monomers have 7 to 13 ring members.  

Preferred polyamides contain units which are preferred of laurolactam, caprylic lactam, ε-caprolactam and butyrolactam derive, whereby polyamide 6 and polyamide 12 and copolyamides 6/66 and copolyamides from caprolactam and terephthalic acid / isophthal acid (e.g. PA 6 / 6T, PA 6 / 6I) are preferred.

Copolyamides 6/66 are particularly preferred, the proportion of Caprolactam units preferably 5 to 95 wt .-%, in particular 10 to 90 wt .-%, based on the copolyamide. Self ver Mixtures of such polyamides can of course also be used will.

Also preferred are polyamides A, which consist of a mixture (so-called blends, based on 100% by weight A)

• A1) 5 to 95 wt .-%, preferably from 10 to 90 wt .-% of one Lactam monomers available polyamide, preferably poly amide 6, with
• A2) 5 to 95 wt .-%, preferably from 10 to 90 wt .-% of one of A1) various polyamides

consist.

Semi-crystalline or amorphous resins are suitable as component A2) with a molecular weight (weight average) of at least 5,000, such as B. in the American patent specifications 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 this are polyamides, which are produced by the implementation of Dicarboxylic acids can be obtained with diamines.

As dicarboxylic acids are alkanedicarboxylic acids with 6 to 12 ins special 6 to 10 carbon atoms and aromatic dicarbon acids can be used. Here are only adipic acid, azelaic acid, Sebacic acid, dodecanedioic acid and terephthalic and / or isophthalic acid called as acids.

Particularly suitable diamines are alkane diamines with 6 to 12 ins special 6 to 8 carbon atoms and m-xylylenediamine, Di- (4-aminophenyl) methane, di- (4-aminocyclohexyl) methane, 2,2-di- (4-aminophenyl) propane or 2,2-di- (4-aminocyclo hexyl) propane.  

Preferred polyamides are polyhexamethylene adipamide and Polyhexamethylene sebacic acid amide.

In addition, polyamides should also be mentioned, which, for. B. by Condensation of 1,4-diaminobutane with adipic acid with increased Temperature are available (polyamide 4.6). production method for polyamides of this structure, e.g. B. in EP-A 38 094, EP-A 38 582 and EP-A 39 524.

The molding compositions 1 according to the invention contain component B) up to 20, preferably 2 to 15 and in particular 3 to 10% by weight red phosphorus.

The average particle size (d ₅₀ ) of the phosphor particles distributed in the molding compositions is usually in the range up to 2 mm, preferably 0.0001 to 0.5 mm.

As a rule, the phosphorus can easily be powdered into the Molding compositions according to the invention are incorporated, the Phosphorus is usually present as desensitized phosphorus (see EP-A 176 836, EP-A 384 232 and DE-A 196 48 503). Also are Concentrates of phlegmatized phosphorus e.g. B. in a polyamide or an elastomer suitable, which phosphorus contents up to Can have 60 wt .-%.

The molding compositions according to the invention contain 0.1 as component C) up to 15, preferably 1 to 10 and in particular 2 to 9% by weight a delaminated layered silicate (phyllosilicate).

Layered silicate is generally understood to mean silicates in which the SiO ₄ tetrahedra are connected in two-dimensional infinite networks. (The empirical formula for the anion is (Si ₂ O ₅ ^2- ) _n ). The individual layers are connected to one another by the cations lying between them, with Na, K, Mg, Al and / or Ca mostly being present as cations in the naturally occurring layered silicates.

The layer thicknesses of such silicates before delamination usually carry from 5 to 100 Å, preferably 5 to 50 and especially 8 to 20 Å.

As examples of synthetic and natural layered silicates (Phyllosilicates) are montmorillonite, smectite, illite, sepiolite, Palygorskite, Muscovite, Allevardite, Amesite, Hectorite, Fluorhecto rit, saponite, beidellite, talc, nontronite, stevensite, bentonite,  Contain mica, vermiculite, fluor vermiculite, halloysite and fluorine called synthetic mica types.

Under a delaminated layered silicate in the sense of the invention Layered silicates are to be understood, in which by Um settlement with so-called water repellents and given if subsequent monomer addition (so-called swelling e.g. with ε-caprolactam) the layer spacings are initially increased.

Subsequent polycondensation or mixing z. B. by Packaging of the hydrophobic and optionally swollen Layered silicates with polyamides are delaminated Layers which preferably form a layer in the molded body was at least 40 Å, preferably at least 50 Å.

To increase the layer spacing (hydrophobization) Layered silicates (before the production of the form according to the invention mass) with so-called hydrophobizing agents, which often referred to as onium ions or onium salts.

The cations of the layered silicates are replaced by organic hydro Phobierungsmittel replaced, being by the nature of the organic The desired layer spacing can be set, which depend on the type of the respective monomer or polymer, in which layer silicate is to be installed.

The exchange of the metal ions can be complete or partial respectively. A complete exchange of the metal is preferred ions. The amount of exchangeable metal ions is becoming more common in milliequivalents (meq) per 100 g layered silicate ben and called ion exchange capacity.

Layered silicates with a cation exchange capacity are preferred activity of at least 50, preferably 80 to 130 meq / 100 g.

Suitable organic water repellents are derived from Oxo nium, ammonium, phosphonium and sulfonium ions, which can carry one or more organic residues.

Suitable hydrophobicizing agents are those of the general formula I and / or II:

where the substituents have the following meaning:
R ¹ , R ² , R ³ , R ⁴ independently of one another are hydrogen, a straight-chain, branched, saturated or unsaturated hydrocarbon radical having 6 to 40, preferably 6 to 20, carbon atoms, which can optionally carry at least one functional group or 2 of the Residues are connected to one another, in particular to form a heterocyclic residue with 5 to 10 carbon atoms,
X for phosphorus or nitrogen,
Y for oxygen or sulfur,
n for an integer from 1 to 5, preferably 1 to 3 and
Z for an anion
stands.

Suitable functional groups are hydroxyl, nitro or sulfo groups, with carboxyl groups being particularly preferred because such functional groups an improved connection to the End groups of the polyamide takes place.

Suitable anions Z are derived from proton-producing acids, especially mineral acids, with halogens such as chlorine, bromine, Fluorine, iodine, sulfate, sulfonate, phosphate, phosphonate, phosphite and Carboxylate, especially acetate, are preferred.

The layered silicates used as starting materials are in the Usually implemented in the form of a suspension. The preferred Suspen diermittel is water, optionally in a mixture with alcohols, especially lower alcohols with 1 to 3 carbon atoms. It can be advantageous together with the aqueous medium Use hydrocarbon, for example heptane, because the  hydrophobic layered silicates with hydrocarbons are more tolerable than with water.

Other suitable examples of suspending agents are ketones and Hydrocarbons. Usually one becomes miscible with water Preferred solvent. When adding the water repellent with Due to the layered silicate, an ion exchange occurs, which means that Layered silicate usually becomes more hydrophobic and from solution fails. The resulting as a by-product of ion exchange Metal salt is preferably water-soluble, so that the hydro phobicized layered silicate as a crystalline solid by e.g. B. Filtering can be separated.

The ion exchange is largely dependent on the reaction temperature independently. The temperature is preferably above the crystal point of the medium and below its boiling point. At aqueous systems the temperature is between 0 and 100 ° C, preferably between 40 and 80 ° C.

Alkylammonium ions are preferred for polyamides, which ins especially by reacting suitable ω-aminocarboxylic acids such as ω-aminododecanoic acid, ω-aminoundecanoic acid, ω-aminobutyric acid, ω-aminocaprylic acid or ω-aminocaproic acid with usual mineral acids, for example hydrochloric acid, sulfuric acid or phosphorus acid or methylating agents such as methyl iodide are available.

Other preferred alkylammonium ions are laurylammonium, myri stylammonium, palmitylammonium, stearylammonium, pyridinium, Octadecylammonium, monomethyloctadecylammonium and dimethyloc tadecylammonium ions.

Examples of suitable phosphonium ions are docosyl trimes thylphosphonium, hexatriacontyltricyclohexylphosphonium, octade cyltriethylphosphonium, dicosyltriisobutylphosphonium, methyltri nonylphosphonium, ethyltrihexadecylphosphonium, dimethyldidecyl phosphonium, diethyldioctadecylphosphonium, octadecyldiethylal lylphosphonium, trioctylvinylbenzylphosphonium, dioctydecylethyl hydroxyethylphosphonium, docosyldiethyldichlorobenzylphosphonium, Octylnonyldecylpropargylphosphonium triisobutylperfluorodecyl phosphonium, eicosyltrihydroxymethylphosphonium, triacontyltris cyanethylphosphonium and bis-trioctylethylene diphosphonium ge called.

Other suitable water repellents include. a. in the WO 93/4117, EP-A 398 551 and DF-A 36 32 865.  

After the hydrophobization, the layered silicates have one Layer spacing of 10 to 40 Å, preferably from 13 to 20 Å. The layer spacing usually means the distance from the Lower layer edge of the upper layer to the upper layer edge of the lower layer. The length of the leaflets is usually up to 2000 Å, preferably up to 1500 Å.

The layered silicate hydrophobicized in the above manner can then in suspension or as a solid with the polyamide Monomers or prepolymers mixed and the polycondensation in be carried out in the usual way.

It is possible to further increase the spacing between layers by coating the layer silicate with polyamide monomers or prepolymers at temperatures from 25 to 300, preferably from 100 to 280 and in particular from 200 to 260 ° C. over a residence time of 5 to 120 minutes. preferably from 10 to 60 minutes (so-called swelling). Depending on the duration of the residence time and the type of monomer chosen, the layer spacing is additionally increased by 10 to 150 Å, preferably by 20 to 50 Å. Subsequently, the poly condensation is carried out in the usual way. The polycondensation is carried out particularly advantageously with simultaneous shear, preferably with shear stresses in accordance with DIN 11 443 of 10 to 10 ⁵ Pa, in particular 10 ² to 10 ⁴ Pa.

The additives D) can be added to the monomers or Prepolymer melt (degassing extruder) are added.

As a further preferred production of the mold according to the invention be the mixing of the individual components A) to D) by means of conventional devices such. B. called extruders. After extrusion, the extrudate is cooled and crushed.

The polyamide molding compounds can then be subjected to a further thermal Treatment, d. H. a post-condensation in the solid phase fen. In tempering units such as B. a tumbler mixer or continuously and discontinuously operated tempering tubes one anneals the one present in the respective processing form Molding compound until the desired viscosity number VZ or relative Viscosity ηrel of the polyamide is reached. The temperature range the tempering depends on the melting point of the pure component A). Preferred temperature ranges are 5 to 50, preferably 20 to 30 ° C below the respective melting point of the pure components ten A). The process is preferably carried out in an inert gas atmosphere, where nitrogen and superheated steam are considered Inert gases are preferred.  

The residence times are generally from 0.5 to 50, preferably from 4 to 20 hours. Then the Molding compounds are produced using conventional devices.

The molding compositions 0 to 70, in particular up to 50% by weight of further additives and ver tools included.

Usual additives are, for example, in amounts of up to 40. preferably up to 30% by weight of rubber-elastic polymers (often also as impact modifiers, elastomers or rubbers designated).

In general, these are copolymers before are composed of at least two of the following monomers: Ethylene, propylene, butadiene, isobutene, isoprene, chloroprene, Vinyl acetate, styrene, acrylonitrile and acrylic or methacrylic acid esters with 1 to 18 carbon atoms in the alcohol component.

Such polymers are e.g. B. in Houben-Weyl, methods of organization African Chemistry, vol. 14/1 (Georg-Thieme-Verlag, Stuttgart, 1961). Pages 392 to 406 and in the monograph by C.B. Bucknall, "Toughened Plastics" (Applied Science Publishers, London, 1977) described.

The following are some preferred types of such elastomers presented.

Preferred types of such elastomers are the so-called ethylene Propylene (EPM) or ethylene-propylene-diene (EPDM) rubbers.

EPM rubbers generally have practically no doubles bonds more, while EPDM rubbers 1 to 20 double bonds gen / 100 carbon atoms can have.

For example, konju may be used as diene monomers for EPDM rubbers gated dienes such as isoprene and butadiene, non-conjugated dienes with 5 to 25 carbon atoms such as penta-1,4-diene, hexa-1,4-diene, Hexa-1,5-diene, 2,5-dimethylhexa-1,5-diene and octa-1,4-diene, cyclic dienes such as cyclopentadiene, cyclohexadienes, cycloocta dienes and dicyclopentadiene and alkenylnorbornenes such as 5-ethyl iden-2-norbornene, 5-butylidene-2-norbornene, 2-methallyl-5-norbornene nen, 2-isopropenyl-5-norbornene and tricyclodienes such as 3-methyl tricyclo (5.2.1.0.2.6) -3,8-decadiene or mixtures thereof. Hexa-1,5-diene-5-ethylidene-norbornene and dicyclo are preferred pentadiene. The diene content of EPDM rubbers is preferred  as 0.5 to 50, in particular 1 to 8 wt .-%, based on the Total weight of the rubber.

EPM or EPDM rubbers can preferably also be reactive Carboxylic acids or their derivatives may be grafted. Here are z. B. Acrylic acid, methacrylic acid and their derivatives, e.g. B. Gly cidyl (meth) acrylate, as well as maleic anhydride.

Another group of preferred rubbers are copolymers of ethylene with acrylic acid and / or methacrylic acid and / or the esters of these acids. In addition, the rubbers can still Di carboxylic acids such as maleic acid and fumaric acid or derivatives of these acids, e.g. B. esters and anhydrides, and / or epoxy groups containing monomers. These dicarboxylic acid derivatives or monomers containing epoxy groups are preferably incorporated into the rubber by adding dicarboxylic acid or epoxy group-containing monomers of the general formulas I or II or III or IV to the monomer mixture:

where R ¹ to R ^{9 represent} hydrogen or alkyl groups having 1 to 6 carbon atoms and m is an integer from 0 to 20, g is an integer from 0 to 10 and p is an integer from 0 to 5.

The radicals R ¹ to R ^{9 are} preferably hydrogen, where m is 0 or 1 and g is 1. The corresponding compounds are maleic acid, fumaric acid, maleic anhydride, allyl glycidyl ether and vinyl glycidyl ether.

Preferred compounds of the formulas I, II and IV are maleic acid, maleic anhydride and epoxy group-containing esters of Acrylic acid and / or methacrylic acid, such as glycidyl acrylate, Glycidyl methacrylate and the esters with tertiary alcohols, such as t-butyl acrylate. The latter do not have any free carboxyl groups but come close in their behavior to the free acids and are therefore used as monomers with latent carboxyl groups designated.

The copolymers advantageously consist of 50 to 98% by weight Ethylene, monomers containing 0.1 to 20% by weight of epoxy groups and / or contain methacrylic acid and / or acid anhydride groups the monomers and the remaining amount of (meth) acrylic acid esters.

Copolymers of are particularly preferred
50 to 98, in particular 55 to 95% by weight of ethylene,
0.1 to 40, in particular 0.3 to 20% by weight of glycidyl acrylate and / or glycidyl methacrylate, (meth) acrylic acid and / or maleic anhydride, and
1 to 45, in particular 10 to 40% by weight of n-butyl acrylate and / or 2-ethylhexyl acrylate.

Further preferred esters of acrylic and / or methacrylic acid are the methyl, ethyl, propyl and i- or t-butyl esters.

In addition, vinyl esters and vinyl ethers can also be used as comonomers be set.

The ethylene copolymers described above can according to known processes are prepared, preferably by statistical copolymerization under high pressure and elevated tem temperature. Appropriate methods are generally known.

Preferred elastomers are also emulsion polymers whose origin position z. B. Blackley in the monograph "Emulsion Polymeri zation ". The usable emulsifiers and kata lystors are known per se.

In principle, homogeneous elastomers or those with a shell structure can be used. The schalenar The structure is determined by the order of addition of the individual mono  determined; the morphology of the polymers is also influenced by this order of addition is affected.

Representative here are as monomers for the production the rubber part of the elastomers acrylates such. B. n-butyl acrylate and 2-ethylhexyl acrylate, corresponding methacrylates, Butadiene and isoprene and their mixtures called. This mono mer can with other monomers such. B. styrene, acrylonitrile, Vinyl ethers and other acrylates or methacrylates such as methyl methacrylate, methyl acrylate, ethyl acrylate and propyl acrylate copo be lymerized.

The soft or rubber phase (with a glass transition temperature of below 0 ° C) the elastomer can form the core, the outer shell or a medium shell (for elastomers with more than two shells structure); with multi-layer elastomers also several shells consist of a rubber phase.

In addition to the rubber phase, there are one or more hard compos components (with glass transition temperatures of more than 20 ° C) on the body of the elastomer involved, these are generally by Polymerization of styrene, acrylonitrile, methacrylonitrile, α- Methyl styrene, p-methyl styrene, acrylic acid esters and methacrylic acid esters such as methyl acrylate, ethyl acrylate and methyl methacrylate produced as main monomers. In addition, ge lower proportions of other comonomers are used.

In some cases it has proven to be advantageous to use emulsion polymers which have reactive groups on the surface. Such groups are e.g. B. epoxy, carboxyl, latent carboxyl, amino or amide groups and functional groups by the use of monomers of the general formula

can be introduced
where the substituents can have the following meanings:
R ^{10 is} hydrogen or a C ₁ to C ₄ alkyl group,
R ^{11 is} hydrogen, a C ₁ to C ₈ alkyl group or an aryl group, in particular phenyl,
R ^{12 is} hydrogen, a C ₁ to C ₁₀ alkyl group, a C ₆ to C ₁₂ aryl group or -OR ¹³
R ^{13 is} a C ₁ - to C ₈ -alkyl or C ₆ - to C ₁₀ -aryl group which can optionally be substituted by O- or N-containing groups,
X is a chemical bond, a C ₁ to C ₁₀ alkylene or C _{6 to} C ₁₂ arylene group or

Y OZ or NH-Z and
Z is a C ₁ to C ₁₀ alkylene or C ₆ to C ₁₂ arylene group.

The graft monomers described in EP-A 208 187 are also suitable for the introduction of reactive groups on the surface.

Acrylamide, methacrylamide and substituted esters of acrylic acid or methacrylic acid such as (N-t- Butylamino) ethyl methacrylate, (N, N-dimethylamino) ethyl acrylate, (N, N-dimethylamino) methyl acrylate and (N, N-diethylamino) ethyl called crylate.

The particles of the rubber phase can also be crosslinked be. Monomers acting as crosslinkers are, for example, Bu ta-1,3-diene, divinylbenzene, diallyl phthalate and dihydrodicyclo pentadienyl acrylate and those described in EP-A 50 265 Links.

So-called graft-crosslinking monomers (graft linking monomers) are used, d. H. Monomers with two or more polymerizable double bonds, which in the polymer sation react at different speeds. Before preferably such connections are used in which min least a reactive group at about the same speed as the remaining monomers polymerized while the other was reactive Group (or reactive groups) e.g. B. significantly slower polymeri siert (polymerize). The different polymerization speeds bring a certain proportion of unsaturated Double bonds in rubber with it. Then on such a rubber grafted on another phase, so  at least the double bonds present in the rubber react partly with the graft monomers to form chemical Bonds, d. H. the grafted phase is at least partially linked to the graft base via chemical bonds.

Examples of such graft-crosslinking monomers are allyl groups containing monomers, especially allyl esters of ethylenically un saturated carboxylic acids such as allyl acrylate, allyl methacrylate, Diallyl maleate, diallyl fumarate, diallyl itaconate or the ent speaking monoallyl compounds of these dicarboxylic acids. Besides there are a variety of other suitable graft-crosslinking Mo. nomer; for more details, see here, for example U.S. Patent 4,148,846.

In general, the proportion of these crosslinking monomers is up to 5% by weight of the impact-modifying polymer preferably not more than 3% by weight, based on the impact strength modifying polymers.

Some preferred emulsion polymers are listed below. First of all, graft polymers with a core and at least one outer shell are to be mentioned, which have the following structure:

Instead of graft polymers with a multi-layer structure can also be homogeneous, d. H. single-shell elastomers Bu-ta-1,3-diene, tsoprene and n-butyl acrylate or their copolymers be used. These products can also be used of crosslinking monomers or monomers with reactive groups getting produced.

Examples of preferred emulsion polymers are n-butyl acrylate / (meth) acrylic acid copolymers, n-butyl acrylate / glycidyl acrylate or n-butyl acrylate / glycidyl methacrylate copolymers, Graft polymers with an inner core made of n-butyl acrylate or based on butadiene and an outer shell of the above mentioned copolymers and copolymers of ethylene with comonomers, that provide reactive groups.

The elastomers described can also be made according to other conventional ones Process, e.g. B. produced by suspension polymerization will.

Silicone rubbers, as in DE-A 37 25 576, EP-A 235 690, DE-A 38 00 603 and EP-A 319 290 are just described if preferred.

Of course, mixtures of the above can also be used rubber types are used.

Furthermore, the thermoplastic form according to the invention mass stabilizers, antioxidants, anti-heat agents decomposition and decomposition by ultraviolet light, sliding and Mold release agents, colorants such as dyes and pigments, germs contain educational agents, plasticizers, etc.

As examples of oxidation retarders and heat stabilizers are sterically hindered phenols, hydroquinones, copper ver bindings aromatic secondary amines such as diphenylamines, ver different substituted representatives of these groups and their Mixtures in concentrations up to 1 wt .-%, based on the Weight of the thermoplastic molding compositions called.

As UV stabilizers, generally in amounts up to 2% by weight, based on the molding composition, are used various substituted resorcinols, salicylates, benzotriazoles and Called benzophenones.  

Inorganic pigments such as titanium dioxide, ultramarine blue, Iron oxide and carbon black, as well as organic pigments such as phthalo cyanines, quinacridones, perylenes and dyes such as nigrosine and anthraquinones can be added as colorants.

Sodium phenylphosphinate, aluminum can be used as nucleating agents oxide or silicon dioxide can be used.

Lubricants and mold release agents, which are usually in amounts up to 1% by weight are preferably long-chain fat acids (e.g. stearic acid or behenic acid), their salts (e.g. Ca or Zn stearate) and amide derivatives (e.g. ethylene bis stearylamide) or montan waxes (mixtures of straight-chain, ge saturated carboxylic acids with chain lengths of 28 to 32 carbon atoms) as well as low molecular weight polyethylene or polypropylene waxes.

The molding compositions 0 to 50, preferably 5 to 40 and in particular 10 to 30% by weight of one contain fibrous or particulate filler.

The preferred fibrous fillers are carbon fibers, Aramid fibers and potassium titanate fibers called glass fibers are particularly preferred as E-glass. These can be used as rovings or cut glass can be used in the commercially available forms.

The fibrous fillers can be better tolerated superficial with the thermoplastic with a silane compound be pretreated.

Suitable silane compounds are those of the general formula III

(X- (CH ₂ ) _n ) _K -Si- (OC _m H _{2m + 1} ) _4-K III

in which the substituents have the following meaning:

n is an integer from 2 to 10, preferably 3 to 4
m is an integer from 1 to 5, preferably 1 to 2
k is an integer from 1 to 3, preferably 1.

Preferred silane compounds are aminopropyltrimethoxysilane, Aminobutyltrimethoxysilane, aminopropyltriethoxysilane, aminobutyl triethoxysilane and the corresponding silanes, which as sub stituent X contain a glycidyl group.

The silane compounds are generally used in amounts of 0.05 up to 5, preferably 0.5 to 1.5 and in particular 0.8 to 1% by weight (based on C) used for surface coating.

Fibrous fillers with a medium arith are preferred metallic fiber length of 70 to 200 microns, preferably 80 to 180 microns and in particular 100 to 150 µm. The average diameter is generally from 3 to 30 microns, preferably from 8 to 20 microns and ins special 10 to 14 µm.

The desired fiber length can e.g. B. by grinding in a ball mill be adjusted, ent a fiber length distribution ent stands.

The reduction in fiber length results when the middle fiber length is <200 µm to a free-flowing bulk material that looks like a Powder can be mixed into the polymer. Due to the ge wrinkle fiber length occurs only a little when incorporated further shortening the fiber length.

The fiber content is usually determined after the polymer has been incinerated. To determine the fiber length distribution, the ash residue is generally taken up in silicone oil and photographed at 20x magnification of the microscope. The length of at least 500 fibers can be measured on the images and the arithmetic mean (d ₅₀ ) can be calculated from them.

Acicular mineral fillers are also suitable, under which mineral fillers with pronounced needle-like character should be understood. As an an example be called needle-shaped wollastonite. Preferably that Mineral an L / D (length diameter) ratio of 8: 1 to 35: 1, preferably from 8: 1 to 11: 1. The mineral fill Substance can optionally with the above Silanver bindings are pretreated; however, the pretreatment is not absolutely necessary.

Suitable particulate fillers are amorphous silica, Magnesium carbonate (chalk), kaolin (especially calcined Kaolin), powdered quartz, mica, talc, feldspar and especially calcium silicates such as wollastonite.  

The molding compositions according to the invention are notable for good Processability (low mold coverage). Shaped body of Molding compositions according to the invention show a higher continuous use temperature with reduced monomer formation at the same time good mechanical and flame retardant properties.

They are therefore suitable for the production of moldings, ins especially for the electrical and electronics sector, with application as lamp parts (e.g. lamp holders and holders), Plugs, power strips, coil formers, housing of capacitors, Fuse switches, relay housings and reflectors in particular are preferred.

Examples I. Preparation of component C

1 kg of purified montmorillonite were placed in a reaction kettle as a 2 wt .-% aqueous solution with an ion exchange capacity of 120 meq / 100 g with 40 g (2.5 mol) ω-aminoundecanoic acid as well 1 1 3-molar aqueous HCl at room temperature over a period of time of 30 minutes implemented.

The suspension was then filtered, the precipitate with Water cleaned and spray dried.

The layer spacing was 29.2 Å (determined by Wide X-ray scattering: λ = 0.15 418 nm).

II. The following components were used Component A / 1

Polyamide 6 with a viscosity number (VZ) of 150 ml / g (measured as a 0.5% by weight solution in 96% by weight H ₂ SO ₄ according to ISO 307).

Component B

Red phosphorus (containing 0.7% by weight of dioctyl phthalate as desensitizing agent) with an average particle size (d ₅₀ ) of 45 μm.

Component C

As described under I above.  

Component D D / 1

An olefin polymer from
60% by weight ethylene
35% by weight of n-butyl acrylate
4.3% by weight acrylic acid
0.7% by weight maleic anhydride
with an MFI of 10 g / 10 min at 190 ° C and 1.16 kg load.

D / 2

Glass fibers with an average diameter of 10 µm.

D / 3

Zinc oxide.

D / 4

Copper-based heat stabilizer: Cu content: 0.76% by weight (Ultrabatch® 61 from BASF AG)

III. Production of molding compounds 1. Packaging (Example 1 and Comparative Example IV)

Components A / 1 to D) were on a twin-screw extruder (200 rpm, 50 kg / h) assembled at 270 ° C, extruded and in Chilled and granulated water bath. The granules were at 80 ° C in Vacuum dried and processed at 270 ° C on an injection molding machine works.

2. In-situ production (example 3)

500 g were added to 10 kg of a ε-caprolactam melt at 200 ° C., 5 bar Component C) added and stirred for 10 min. Then were 500 ml of water are added while maintaining pressure and the temperature is raised 270 ° C increased. After stirring for one hour (while maintaining pressure) the boiler ent to 1000 mbar over a period of 1 hour spanned and condensed for 2 hours at 700 mbar. The polyamide (Component A / 3, already containing 5% by weight of component C), based on the polyamide) had a VN of 140 ml / g. The addition the other components were carried out as described under III.1 by means of conventional assembly.  

3. Direct assembly (example 2 and 2V)

A polyamide prepolymer with a VZ of 80 ml / g was with the Components B) to D) on a degassing extruder at 270 ° C con packaged, chilled and granulated.

The granules were then placed in a fixed tempering tube (double-walled, glass tube heated from the outside with oil to temperature of 120 mm inside diameter and 1000 mm length, which with 120 l / min superheated steam was flowed through) at 180 ° C discontinuously annually tempered to a VZ of 150 ml / g (component A / 2). The Residence time was 12 hours.

Components A / 1 and A / 3 as well as the prepolymer of the component A / 2 were in each case before mixing with components B) to D) extracted with water.

For the fire test, rods were hosed down and used according to the usual con ditioning tested according to UL 94.

The residual extract (%) before hot storage was extracted of the granules (components A) to D)) with methanol (16 h) is true. After the extraction, the methanol was separated off and the Residual extract content (dimer, monomer and oligomer content) gravime determined. For the hot storage, granules were added for 24 hours Stored at 200 ° C under nitrogen and then with methanol for 16 h extracted. The methanol was then removed and gravime the residual extract content is determined.

The modulus of elasticity was according to ISO 527, the tensile strength according to ISO 527 certainly.

The composition of the molding compounds and the results of the Measurements are shown in Table 1.  

Table 1

Claims (8)

1. Thermoplastic molding compositions containing

• A) 10 to 98% by weight of a polyamide which contains at least 5% by weight of units, based on 100% by weight of A) which are derived from lactam monomers,
• B) 1 to 20% by weight of red phosphorus,
• C) 0.1 to 15% by weight of a delaminated layered silicate (phyllosilicate)
• D) 0 to 70% by weight of conventional additives and processing aids,

the sum of the percentages by weight of components A) to D) being 100%. 2. Thermoplastic molding compositions according to claim 1, containing 5 to 40% by weight of a fibrous reinforcing material D). 3. Thermoplastic molding compositions according to claims 1 or 2, in which component A) made of polyamide 6, polyamide 12, poly amide 6/66, polyamide 6 / 6T, polyamide 6/61 or mixtures thereof is constructed. 4. Thermoplastic molding compositions according to claims 1 or 2, in which the polyamide A) from a mixture of, based on 100 wt .-% A),

• A1) 5 to 95% by weight of polyamide 6
• A2) 5 to 95% by weight of a polyamide different from A1)

consists. 5. Thermoplastic molding compositions according to claims 1 to 4, ent holding as layered silicate C) montmorillonite, smectite, illite, Sepiolite, palygorskite, muscovite, allevardite, amesite, hecto rit, talc, fluorhectorite, saponite, beidellite, nontronite, Stevensite, bentonite, mica, vermiculite, fluorvermiculite, Halloysite, fluorine-containing synthetic micas or their Mixtures. 6. Use of the thermoplastic molding compositions according to Claims 1 to 5 for the production of fibers, films and Molded articles. 7. Moldings, obtainable from the thermoplastic molding compositions according to claims 1 to 5. 8. Shaped body according to claim 7, containing a delaminated Layered silicate with a layer spacing of at least 40 Å.