WO2025201399A1

WO2025201399A1 - Sustainable AABB Polyamide for flame-retardant applications

Info

Publication number: WO2025201399A1
Application number: PCT/CN2025/085013
Authority: WO
Inventors: Philippe Desbois; Lin Chen; Hang Lu
Original assignee: BASF Advanced Chemicals Co Ltd; BASF SE
Current assignee: BASF Advanced Chemicals Co Ltd; BASF SE
Priority date: 2024-03-27
Filing date: 2025-03-26
Publication date: 2025-10-02
Anticipated expiration: 2026-09-27

Abstract

A thermoplastic molding composition comprising at least one thermoplastic polyamide, as com-ponent A; red phosphorous, as component B; at least one fibrous and/or particulate filler, as component C; and wherein component A comprises at least one polyamide of A1) units derived from 1, 5-pentanediamine as component A1; A2) units derived from at least one aliphatic dicarboxylic acid, preferably selected from the group consisting of adipic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecanedioic acid, as component A2; A3) units derived from at least one aromatic dicarboxylic acid, preferably selected from the group consisting of terephthalic acid, isophthalic acid, and phthalic acid, as component A3; wherein the molar ratio of component A1 to the sum of components A2 and A3 is 1-1.05 to 0.95; a process for preparing of the inventive thermoplastic molding composition; the use of the in-ventive thermoplastic molding composition for producing fibers, foils or moldings; and fibers, foils or moldings comprising the inventive thermoplastic molding composition.

Description

Sustainable AABB Polyamide for flame-retardant applications

Description

The present invention relates to a thermoplastic molding composition comprising at least one thermoplastic polyamide, as component A; red phosphorous, as component B; at least one fi-brous and/or particulate filler, as component C;

wherein

component A comprises at least one polyamide derived from

A1) units derived from 1, 5-pentanediamine or a combination of 1, 5-pentanediamine with at least one further diamine, as component A1;

A2) units derived from at least one aliphatic dicarboxylic acid, preferably selected from the group consisting of adipic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedi-oic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, and octade-canedioic acid, as component A2;

A3) units derived from at least one aromatic dicarboxylic acid, preferably selected from the group consisting of terephthalic acid, isophthalic acid, and phthalic acid, as component A3; wherein the molar ratio of component A1 to the sum of components A2 and A3 is 1-1.05 to 0.95.

In an ever-increasing number of applications, polymers are required to stop burning after removal of an applied flame or even to resist the spread of a fire. Nonflammable plastics which decompose or char at high temperatures without melting and do not continue to burn of their own accord, are for example phenolic and amino resins. Flammable plastics which extinguish after removal of the flame are, for example, polyvinyl chloride, polyvinyl carbazole and polycarbonate.

Molding compositions based on nylon 6 (PA6) and nylon 6, 6 (PA66) have a different burning behavior. They extinguish on removal of the applied flame after the burning melt has dripped from the solid portion of the material. If these low-viscosity polyamides are reinforced with glass fibers, they show yet another burning behavior. They continue to burn on removal of the flame in a way similar to that of polyolefins, probably due to the glass fibers acting as wicks.

Thus flame-proofing is just as desirable in the case of glass-fiber-reinforced polyamides as it is in the case of other non-self-extinguishing polymers.

US3778407 A relates to self extinguishing glass-fiber-reinforced nylon 6, 6 polyamide molding compositions. The fire retardancy is achieved by incorporating into the glass-fiber-reinforced ny-lon 6, 6 polyamide molding composition red phosphorus in quantities ranging from 0.5 to 15%by weight with reference to the total mixture.

EP303031 A1 relates to flame-proofed reinforced polyamide molding compositions comprising red phosphorus, which, in addition to improved flame resistance, also exhibit improved mechani-cal properties overall. The flame-retardant thermoplastic molding compositions contain A) 5-92%by weight of a polyamide, B) 5-60%by weight of a reinforcing filler and, as a flame retardant combination, C) 2-15%by weight of red phosphorus and D) 1-30%by weight of an olefin polymer. EP384232 A1 relates to readily accessible flame-proofed thermoplastic polyamide or polyester molding compositions which combine good low-flammability characteristics with good mechani-cal characteristics. In addition, the thermal stability of the flameproofing phosphorus combina-tion used should also be adequate. The flame-proofed thermoplastic molding compositions con-tain (A) 10-99%by weight of a thermoplastic polyamide or polyester or polyphenylene ether or a mixture thereof, (B) 1-50%by weight of red phosphorus having a particle size of up to 2 mm which contains per 100 parts by weight from 0.05 to 5 parts by weight of a polyurethane or poly-ester-polyurethane as phlegmatizer, (C) 0-60%by weight of a fibrous or particulate filler or a mixture thereof and (D) 0-20%by weight of an elastomeric polymer.

WO2014170148 A1 relates to thermoplastic molding compositions comprising impact-modified polyamides which have a halogen-free flame-retardancy system and at the same time have good fire-protection properties, and in particular have glow-wire resistance. The thermoplastic molding compositions comprise A) from 10 to 97%by weight of a thermoplastic polyamide, B) from 1 to 10%by weight of red phosphorus, C) from 0.15 to 6%by weight of a dialkylphosphinic salt, where the ratio of B) to C) is from 6: 1 to 6: 4, D) from 1 to 10%by weight of an ethylene co-polymer as impact modifier, comprising as component D) a copolymer of D1 ) from 40 to 98%by weight of ethylene, D2 ) from 2 to 40%by weight of a (meth) acrylate having from 1 to 18 car-bon atoms, or/and D3 ) from 0 to 20%by weight of functional monomers selected from the group of the ethylenically unsaturated mono-or dicarboxylic acids or of the carboxylic anhy-drides or epoxide groups, or a mixture of these, or an ethylene- (meth) acrylic acid copolymer neutralized with zinc up to an extent of 72%, E) from 0 to 5%by weight of talc powder with a median particle size (d50 value) below 7.5 μm, F) from 0 to 60%by weight of further additional substances, where the sum of the percentages by weight of components A) to F) is 100%.

Recently, renewable polymers from biomass have attracted significant attention. These bio-based polymers can reduce dependence on nonrenewable petrochemical resources and de-crease greenhouse gas emissions. Nylon 6, 6 (PA66) is a versatile thermoplastic with a wide range of applications, including engineering plastics, fibers, and films, because of its good phys-ical and mechanical properties. To date, it is still difficult to produce bio-based PA66 without bio-sourced monomers, 1, 6-hexamethylene diamine. The commercialized 1, 5-pentanediamine, ob-tained via lysine fermentation, can be combined with adipic acid to fabricate a partly bio-based polyamide-PA56. Due to the fact that PA56 has a similar structure and properties to that of PA66, PA56 is considered a promising bio-based alternative to PA66. Also the burning behavior of PA56 is mainly similar to that of PA66, described above.

EP4282920 A1 relates to a flame-retardant polyamide glass fiber composition comprising 40-65 parts by mass of a polyamide resin, 25-40 parts by mass of glass fibers, 0-20 parts by mass of a flame retardant, 0.2-1 part by mass of an antioxidant and 0.1-2 parts by mass of other auxilia-ries;

raw materials prepared the polyamide resin comprise pentanediamine and a diacid; the diacid comprises an aliphatic diacid and an aromatic diacid; and the molar ratio of pentanediamine to the diacid is 1-1.05: 1. The flame retardant is selected from one or more of a phosphorus-con-taining flame retardant, a halogen flame retardant, a nitrogen-based flame retardant and an in-organic flame retardant.

It is an object of the invention to provide a self-extinguishing glass-fiber-reinforced polyamide molding composition, which polyamide contains 1, 5-pentanediamine monomer units and aliphatic dicarboxylic acid monomer units, especially a glass-fiber-reinforced PA56 molding composition.

In particular, it is an object of the invention to flameproof a glass-fiber-reinforced PA56 (nylon 5, 6) polyamide.

These objects are achieved by a thermoplastic molding composition comprising

A) from 35 to 98.5%by weight, preferably 40 to 88%by weight, more preferably 45 to 75% by weight of at least one thermoplastic polyamide, as component A;

B) from 0.5 to 15%by weight, preferably 1 to 8%by weight, more preferably 2 to 7%by weight of red phosphorous, as component B;

C) from 1 to 50%by weight, preferably 10 to 45%by weight, more preferably 20 to 40%by weight of at least one fibrous and/or particulate filler, as component C;

D) from 0 to 20%by weight, preferably 1 to 15%by weight, more preferably 3 to 10%by weight of at least one impact modifier, as component D;

E) from 0 to 50%by weight of further additional substances, as component E;

wherein the sum of the percentages by weight of components A to E is 100%by weight, and wherein component A comprises at least one polyamide of

A2) units derived from at least one aliphatic dicarboxylic acid, preferably selected from the group consisting of adipic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecanedioic acid, as component A2;

A3) units derived from at least one aromatic dicarboxylic acid, preferably selected from the group consisting of terephthalic acid, isophthalic acid, and phthalic acid, as component A3;

wherein the molar ratio of component A1 to the sum of components A2 and A3 is 1-1.05 to 0.95.

The object is further achieved by a process for producing the inventive thermoplastic molding composition comprising the step of mixing the components A) , B) , C) and optionally D) and op-tionally E) ; and the use of the inventive thermoplastic molding composition or the thermoplastic molding composition obtained by the inventive process for producing fibers, foils or moldings, preferably connectors and conjunction boxes; and fibers, foils or moldings, preferably connectors and conjunction boxes comprising the inventive thermoplastic molding composition or the ther-moplastic molding composition obtained by the inventive process for producing fibers, foils or moldings, preferably connectors and conjunction boxes.

It has been found that by incorporating into the glass-fiber reinforced molding composition com-prising a polyamide comprising monomer units derived from 1, 5-pentanediamine and aliphatic dicarboxylic acid monomer units, especially a glass-fiber-reinforced PA56 molding composition red phosphorus in quantities ranging from 0.5 to 15%by weight with reference to the total mixture and aromatic dicarboxylic acid monomer units as second kind of dicarboxylic acid monomers in the polyamide, the fire retardance (FR) performance of the polyamide composition can be strongly improved in comparison to standard polyamide composed of 1, 6-hexamethylene diamine mono-mer units and aliphatic dicarboxylic acid units, especially PA66, but also to polyamide composed of 1, 5-pentamethylene diamine monomer units and aliphatic dicarboxylic acid units, especially neat PA 56.

It has further been found by the inventors of the present invention that the inventive thermo-plastic composition comprising red phosphorus fulfills the required properties in terms of tough-ness and fire-protection properties.

It is known that the addition of red phosphorus to glass-fiber-reinforced thermoplastic and ther-mosetting synthetic materials produces a flame-proofing effect. But it is highly surprising to find that glass-fiber-reinforced polyamides, which normally continue to burn when the part is thin enough or when the concentration of red phosphorus is not sufficient, become self-extinguishing when aromatic dicarboxylic acid comonomers are incorporated therein, although the same addi-tion to polyamides not reinforced with glass fibers does not suppress burning or even promotes combustion.

It is further surprising that glass-fiber-reinforced polyamide composed of 1, 5-pentanediamine monomer units and aliphatic dicarboxylic acid monomer units, especially a glass-fiber-reinforced PA56 is rendered self-extinguishing when red phosphorus is added in quantities as low as, from 0.5 to 15%, preferably from 1 to 8%.

The term 1, 5-pentanediamine used in this application is synonymous with the terms pentanedia-mine, pentamethylenediamine; pentane-1, 5-diamine; animal coniine; cadaverine; 1, 5-diamin-opentane; H2N (CH2) 5NH2; cadaverin; 1, 5-pentamethylenediamine.

The term hexamethylenediamine used in this application is synonymous with the terms 1, 6-hex-anediamine, hexanediamine, HMD, HMDA; 1, 6-Diamino-n-Hexane; 1, 6-Diaminohexane; 1, 6-Hexylenediamine; H2N (CH2) 6NH2; 1, 6-Hexamethylenediamine; NCI-C61405; UN 2280; Hexylenediamine; NSC 9257.

Component A

The inventive thermoplastic composition comprises from 35 to 98.5%by weight, preferably 40 to 88%by weight, more preferably 45 to 75%by weight of at least one thermoplastic polyamide, as component A, wherein the sum of the percentages by weight of components A, B, C, option-ally D and optionally E is 100%by weight.

Component A comprises at least one polyamide consisting of

A1) units derived from 1, 5-pentanediamine;

Component A may exclusively comprise component AI or may be a blend of component AI with at least one further polyamide AII. Preferably, component A exclusively comprises (consists of) component AI.

Preferably, component A comprises

i) 10 to 100 wt%, preferably 30 to 100 wt%, more preferably 55 to 100 wt%of at least one polyamide consisting of units derived from components A1, A2 and A3, as component AI;

ii) 0 to 90 wt%, preferably 0 to 70 wt%, more preferably 0 to 45 wt%of at least one polyam-ide different from component AI as component AII.

Component AII may generally be any known polyamide. Preferably, component AII is selected from PA 46, PA 66, PA 69, PA 610, PA 612, PA 613, PA 1212, PA 1313, PA 6T, PA MXD6, PA 6I, PA 6-3-T, PA 6/6.36, PA 6/6T, PA66/6T, PA 6/66, PA 6/12, PA 66/6/610, PA 6I/6T, PA PACM 12, PA 6I/6T/PACM, PA 12/MACMI, PA 12/MACMT, PA PDA-T, PA 4, PA 6, PA 7, PA 8, PA 9, PA 11 and mixtures thereof, more preferably selected from PA 6, PA 66, PA 46, PA 6/66, PA 66/6, PA 6/636, PA 6T/6, PA66/6T, PA 6T/6I, PA 6T/6I/66, PA 9T, PA 6T/66 and mixtures thereof, most preferably selected from PA66/6T, PA 6, PA 66, PA 6/66 and PA 66/6, PA 6/636 and mixtures thereof, further most preferably PA66/6T, PA 6, PA 66 or mixtures thereof.

The polyamides AII mentioned above are known by a person skilled in the art and commercially available or prepared by known processes.

The polyamides AI mentioned above are either known by a person skilled in the art and com-mercially available or prepared in analogy known processes.

The units A1 are derived from 1, 5-pentanediamine as component A1.

Preferably, the 1, 5-pentanediamine is be prepared from a bio-based feedstock, more preferably by fermentation or enzymatic conversion. The preparation of 1, 5-pentanediamine from a bio-based feedstock is known in the art.

Component A1 is preferably prepared from a bio-based feedstock, more preferably by fermen-tation or enzymatic conversion. Component A2 is preferably adipic acid. Component A3 is pref-erably terephthalic acid. More preferably, component A1 is 1, 5-pentanediamine, component A2 is adipic acid and component A3 is terephthalic acid. The polyamide A is therefore most prefer-ably polyamide PA56/5T.

PA56/5T is generally a random copolymer of n units A1, A2 and m units A1, A3:

Preferably, the molar ratio of component A2, more preferably adipic acid, and A3, more prefera-bly terephthalic acid, is 1 to 0.1-1.5, more preferably 1 to 0.2-1.3, most preferably 1 to 0.3-0.7.

The relative viscosity of the component A in 96%concentrated sulfuric acid at 25℃ is prefera-bly 2 to 4, and more preferably 2.2 to 2.9.

The relative viscosity is measured in accordance with ISO 307: 2019 (1%in 96%sulfuric Acid) .

Preferably, component A has a melting point of 200 to 350℃, more preferably 250 to 300℃, most preferably 260 to 278℃. The melting temperature is determined by ISO 11357-1/-3 (10℃/min) .

The moisture content of component A is preferably 0 to 5000 ppm, more preferably 50 to 3000 ppm, most preferably 100 ppm to 2000 ppm.

The moisture content is measured in accordance with ISO 15512: 2019.

The amino terminal group content of component A is preferably 20 to 90 mmol/kg, more prefer-ably 30 to 80 mmol/kg, most preferably 40 to 70 mmol/kg.

The amino end group (ATG) content was determined by a potentiometric titration method. The quantity of 2 grams of polyamide is added to about 70 ml of phenol 90%wt. The mixture is kept under agitation and temperature of 40℃ until complete dissolution of the polyamide. The solu-tion is then titrated by 0.1N HC1 at about 25℃. The result is reported as mmol/kg.

The number average molecular weight of component A is preferably 10000 to 50000 g/mol, more preferably 15000 to 35000 g/mol.

The number average molecular weight is determined by gel permeation chromatography (GPC) using ASTM D5296-19 with polystyrene standards.

Component A is commercially available or can be prepared by known processes.

One preparation method for component A preferably comprises the following steps:

(1) raising the temperature of a reaction device preferably to 30℃ to 95℃, more preferably to 40℃ to 80℃, such as 45℃, 50℃, 60℃, 65℃, 70℃, 75℃ and 80℃, and mixing wa-ter, components A1 (1, 5-pentanediamine) , A2 and A3 in an inert gas atmosphere to pre-pare a polyamide salt solution, preferably with a concentration of 10 to 80 wt%, more preferably 30-70 wt%, e.g. 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%or 75 wt%;

(2) transferring the aqueous polyamide salt solution into a polymerization device, heating under inert gas atmosphere, increasing the temperature in the device preferably to 180℃ to 380℃, preferably to 230 to 310℃, preferably increasing the pressure in the polymerization device, more preferably to 0.5 to 4 MPa, most preferably to 0.7 to 2.5 MPa, and maintaining preferably for 10 to 360 min, more preferably 60 to 180 min; then preferably in 10 to 240 min, more preferably in 30 to120 minutes, exhausting the gas and depressurizing to normal pressure, and at the same time, increasing the tempera-ture in the polymerization device preferably to 220℃ to 420℃, more preferably to 260 to 340℃; evacuating and depressurizing in the polymerization apparatus preferably to -0.03 to -0.1 MPa, more preferably to -0.02 to -0.08 MPa and maintaining preferably for 10 to 240 minutes, more preferably for 30 to120 minutes to obtain the polyamide resin.

A preferred preparation method for component A is for example disclosed in EP 4828920 A1.

Typical reaction devices and polymerization devices are known in the art. The reaction device is for example a salt-forming kettle and the polymerization device is for example a polymerization kettle.

Preferably, the pH in step (1) is controlled, more preferably to 7 to 10, most preferably to 7.5 to 9.0.

The inert gas preferably comprises nitrogen, argon or helium.

Component B

As component B 0.5 to 15 %by weight, preferably 1 to 8 %by weight, more preferably 2 to 7 %by weight of red phosphorus (P) are present in the inventive molding compositions, wherein the sum of the percentages by weight of components A, B, C, optionally D and optionally E is 100%by weight.

The amount of component B is in each case calculated on P.

Generally, elemental red phosphorus can be employed as component B in the inventive mold-ing compositions, in particular in combination with glassfiber-reinforced molding compositions, it can be used in untreated form.

However, the phosphorus may be surface-coated with low-molecular-weight liquid substances, such as silicone oil, paraffin oil, or esters of phthalic acid (in particular dioctyl phthalate, see EP 176 836) or adipic acid, or with polymeric or oligomeric compounds, e.g. with phenolic resins or amino plastics, or else with polyurethanes (see EP-A 384 232, DE-A 19648 503) . The amounts comprised of these “phlegmatizing agents” are generally from 0.05 to 5%by weight, based on 100%by weight of B) .

The red phosphorous is in one embodiment employed in form of a masterbatch (concentrate) of red phosphorous, e.g. in a polyamide or elastomer (olefin copolymer) .

Also in said masterbatches the red phosphorous is preferably used in untreated form. Particu-larly suitable concentrate polymers are polyolefin homopolymers and polyolefin copolymers.

The weight%amount of component B is in each case calculated on red phosphorous.

Preferred masterbatch (concentrate) compositions are

B₁) from 30 to 90%by weight, preferably from 45 to 70%by weight, of a polyamide, e.g. poly-amide A, or an elastomer (e.g. polyolefin homopolymers and polyolefin copolymers) , and

B₂) from 10 to 70%by weight, preferably from 30 to 55%by weight, of red phosphorus.

Suitable elastomers B1) are the impact modifiers (elastomers) mentioned as component D be-low, e.g. polyolefin homopolymers and polyolefin copolymers which may be grafted for example with maleic anhydride.

Suitable polyamides B1) are mentioned above (see component A) . The polyamide B1) used for the concentrate (masterbatch) can differ from component A or can preferably be identical with component A, in order that no adverse effect on the molding composition results from any in-compatibility or melting-point differences.

The average particle size (d₅₀) of the phosphorus particles dispersed in the molding composi-tions is preferably in the range from 0.0001 to 0.5 mm; in particular from 0.001 to 0.2 mm, deter-mined by laser diffraction according to ISO 13320: 2009.

Component C

The thermoplastic molding compositions of the invention comprise, as component C, from 1 to 50%by weight, preferably 10 to 45%by weight, more preferably 20 to 40%by weight of at least one fibrous and/or particulate filler, wherein the sum of the percentages by weight of compo-nents A, B, C, optionally D and optionally E is 100%by weight.

Preferably, component C is selected from the group consisting of glass fibers, carbon fibers, glass beads, e.g. solid or hollow glass beads, ground glass, amorphous quartz glass, aluminum borosilicate glass having an alkali content of about 1%, amorphous silica, quartz flour, alkaline earth metal silicate, especially calcium silicate, calcium metasilicate, magnesium carbonate, ka-olin, calcined kaolin, chalk, kyanite, powdered or milled quartz, mica, phlogopite, barium sulfate, feldspar, wollastonite, montmorillonite, boehmite, bentonite, vermiculite, hectorite, laponite, pseudoboehmite of formula AIO (OH) , magnesium carbonate, talc, aramid fibers, potassium ti-tanate fibers, barium carbonate, metallic fibers, ceramic fibers, basalt fibers, cellulose, nanocel-lulose, plaster, clay, silica-alumina, sericite, diatomite, silica stone, glassy hollow microspheres, lamellar or acicular nanofillers and mixtures thereof.

Preferred fillers C are glass fibers, preferably the glass fibers are selected from the group con-sisting of E-glass fibers, S-glass fibers, D-glass fibers, C-glass fibers, L-glass fibers, M-glass fi-bers and mixtures thereof, more preferably the glass fibers are E-glass fibers.

The types of glass fibers mentioned above are known in the art. E-glass fibers are for example generally made of glass having low alkali content, usually alumino-borosilicate glass with less than 1%w/w alkali oxides.

These can be used in the form of e.g. rovings or chopped glass, generally in all forms available commercially.

More preferred glass fibres to be used as component C are chopped long glass fibers having an average starting length to be determined by laser diffraction-particle size analysis (laser granu-lometry/laser diffractometry) according to ISO 13320: 2009 in the range from 1 to 50 mm, more preferably in the range from 3 to 10 mm, most preferably in the range from 3.5 to 8 mm. Most preferred glass fibers for use as component C have an average fiber diameter to be determined by laser diffractometry according to ISO 13320: 2009 in the range from 3 to 15 μm, more prefer-ably in the range from 4 to 12 μm.

An example are standard chopped glass fibers (i.e. E glass fibers) for polyamides, length=4.5 mm, diameter=10 μm.

The glass fibers to be used with preference as component C, as a result of the processing to give the thermoplastic moulding composition, may be shorter in the composition than the glass fibers originally used. Thus, the arithmetic average of the glass fiber length after processing, to be determined by high-resolution X-ray computed tomography, is frequently only in the range from <10 mm, preferably 0.2 to 1 mm, more preferably 250 μm to 500 μm.

In order to improve compatibility with the thermoplastics, the fillers, especially the glass fibers, can be surface-pretreated with a silane compound.

Suitable silane compounds are those of the general formula

in which the definitions of the substituents are as follows:

n is an integer from 2 to 10, preferably from 3 to 4,

m is an integer from 1 to 5, preferably from 1 to 2,

k is an integer from 1 to 3, preferably 1.

Preferred silane compounds are aminopropyltrimethoxysilane, aminobutyltrimethoxysilane, ami-nopropyltriethoxysilane, aminobutyltriethoxysilane, and also the corresponding silanes which comprise a glycidyl group as substituent X.

The amounts of the silane compounds generally used for surface treatment are from 0.01 to 2%by weight, preferably from 0.025 to 1.0%by weight, and in particular from 0.05 to 0.5%by weight (based on the total weight of the fibrous filler) .

Acicular mineral fillers are also suitable.

For the purposes of the invention, acicular mineral fillers are mineral fillers with strongly devel-oped acicular character. An example is acicular wollastonite. The mineral preferably has an L/D (length to diameter) ratio of from 8: 1 to 35: 1, preferably from 8: 1 to 11: 1. The mineral filler may, if appropriate, have been pretreated with the abovementioned silane compounds, but the pre-treatment is not essential.

Other fillers which may be mentioned are kaolin, calcined kaolin, wollastonite, talc and chalk, and also lamellar or acicular nanofillers. Materials preferred for this purpose are boehmite, ben-tonite, montmorillonite, vermiculite, hectorite, and laponite. The lamellar nanofillers are organi-cally modified by prior-art methods, to give them good compatibility with the polyamide. Addition of the lamellar or acicular nanofillers to the inventive molding compositions gives a further in-crease in mechanical strength.

Component D

The thermoplastic molding compositions of the invention comprise, as component D, from 0 to 20%by weight, preferably 1 to 15%by weight, more preferably 3 to 10%by weight of at least one impact modifier, wherein the sum of the percentages by weight of components A, B, C, op-tionally D and optionally E is 100%by weight.

If component D is present, the maximum amount of component A is decreased by the minimum amount of component D, so that the total amount of components A to E is still 100 wt%.

The “impact modifier” is often also termed elastomeric polymer, elastomer, or rubber.

Preferably component D is selected from

D1) copolymers of ethylene with at least one comonomer selected from C_3-12-olefins, C_1-12-al-kyl (meth) acrylates, (meth) acrylic acid, maleic anhydride, vinyl acetate and acrylonitrile, as component D1,

and

D2) polyethylene or polypropylene as component D2,

wherein components D1 and D2 may also be additionally grafted with maleic anhydride.

Polymers of this type are described, for example, in Houben-Weyl, Methoden der organischen Chemie, vol. 14/1 (Georg-Thieme-Verlag, Stuttgart, Germany, 1961) , pages 392 to 406, and in the monograph by C.B. Bucknall, Toughened Plastics (Applied Science Publishers, London, UK, 1977) .

Examples for C_3-12-olefins are propylene, butadiene, isobutene, isoprene, octane, chloroprene, styrene and mixtures thereof.

Examples for C_1-12-alkyl (meth) acrylates are methyl, ethyl, propyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, octyl and decyl acrylates and methacrylates. Of these, n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferred.

The impact modifiers D1 are very generally copolymers preferably composed of ethylene and at least one of the following monomers: propylene, butadiene, isobutene, isoprene, chloroprene, vinyl acetate, styrene, acrylonitrile and acrylates and/or methacrylates having from 1 to 12 car-bon atoms in the alcohol component.

Preferably component D1 is selected from ethylene-propylene rubbers (EPM) , ethylene-propyl-ene-diene-rubbers (EPDM) , ethylene-butyl acrylate copolymers, copolymers of ethylene and/or propylene and maleic anhydride and mixtures thereof. More preferred types of such elastomers D1 are those known as ethylene-propylene (EPM) and ethylene-propylene-diene (EPDM) rub-bers.

EPM rubbers generally have practically no residual double bonds, whereas EPDM rubbers may have from 1 to 20 double bonds per 100 carbon atoms.

Examples which may be mentioned of diene monomers for EPDM rubbers are conjugated dienes, such as isoprene and butadiene, non-conjugated dienes having from 5 to 25 carbon at-oms, such as 1, 4-pentadiene, 1, 4-hexadiene, 1, 5-hexadiene, 2, 5-dimethyl-l, 5-hexadiene and 1, 4-octadiene, cyclic dienes, such as cyclopentadiene, cyclohexadienes, cyclooctadienes and dicyclopentadiene, and also alkenylnorbornenes, such as 5-ethylidene-2-norbornene, 5-butyli-dene-2-norbornene, 2-methallyl-5-norbornene and 2-isopropenyl-5-norbornene, and tric clodienes, such as 3-methyltricyclo- [5.2.1.02’6] -3, 8-decadiene, and mixtures of these. Prefer-ence is given to 1, 5-hexadiene, 5-ethylidenenorbornene and dicyclopentadiene.

The diene content of the EPDM rubbers is preferably from 0.5 to 50%by weight, in particular from 1 to 8%by weight, based on the total weight of the rubber.

EPM rubbers and EPDM rubbers may preferably also have been grafted with reactive carbox-ylic acids or with derivatives of these. Examples of these are acrylic acid, methacrylic acid and derivatives thereof, e.g. glycidyl (meth) acrylate, and also maleic anhydride.

Copolymers of ethylene with acrylic acid and/or methacrylic acid and/or with the esters of these acids are another group of preferred rubbers. The rubbers may also comprise dicarboxylic aids, such as maleic acid and fumaric acid, or derivatives of these acids, e.g. esters and anhydrides, and/or monomers comprising epoxy groups. These monomers comprising dicarboxylic acid de-rivatives or comprising epoxy groups are preferably incorporated into the rubber by adding to the monomer mixture monomers comprising dicarboxylic acid groups and/or epoxy groups and having the general formulae I or II or III or IV

where R¹ to R⁹ are hydrogen or alkyl groups having from 1 to 6 carbon atoms, and m is a whole number from 0 to 20, g is a whole number from 0 to 10 and p is a whole number from 0 to 5.

The radicals R¹ to R⁹ 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 formulae I, II and IV are maleic acid, maleic anhydride and (meth) acrylates comprising epoxy groups, such as glycidyl acrylate and glycidyl methacrylate, and the esters with tertiary alcohols, such as tert-butyl acrylate. Although the latter have no free carboxy groups, their behavior approximates to that of the free acids and they are therefore termed monomers with latent carboxy groups.

The copolymers are advantageously composed of from 50 to 98%by weight of ethylene, from 0.1 to 20%by weight of monomers comprising epoxy groups and/or methacrylic acid and/or monomers comprising anhydride groups, the remaining amount being (meth) acrylates.

Particular preference is given to copolymers composed of from 50 to 98%by weight, in particular from 55 to 95%by weight, of ethylene, from 0.1 to 40%by weight, in particular from 0.3 to 20%by weight, of glycidyl acrylate and/or glycidyl methacrylate, (meth) acrylic acid and/or maleic anhydride, and from 1 to 45%by weight, in particular from 5 to 40%by weight, of n-butyl acrylate and/or 2-ethylhexyl acrylate.

Other preferred (meth) acrylates are the methyl, ethyl, propyl, isobutyl and tert-butyl esters.

Comonomers which may be used alongside these are vinyl esters and vinyl ethers.

The ethylene copolymers described above may be prepared by processes known per se, pref-erably by random copolymerization at high pressure and elevated temperature. Appropriate pro-cesses are well-known.

Other preferred elastomers are emulsion polymers whose preparation is described, for exam-ple, by Blackley in the monograph “Emulsion Polymerization” . The emulsifiers and catalysts which can be used are known per se.

In principle it is possible to use homogeneously structured elastomers or else those with a shell structure. The shell-type structure is determined by the sequence of addition of the individual monomers. The morphology of the polymers is also affected by this sequence of addition.

Monomers which may be mentioned here, merely as examples, for the preparation of the rubber fraction of the elastomers are acrylates, such as n-butyl acrylate and 2-ethylhexyl acrylate, cor-responding methacrylates, butadiene and isoprene, and also mixtures of these. These mono-mers may be copolymerized with other monomers, such as styrene, acrylonitrile, vinyl ethers and with other acrylates or methacrylates, such as methyl methacrylate, methyl acrylate, ethyl acrylate or propyl acrylate.

The soft or rubber phase (with a glass transition temperature of below 0℃) of the elastomers may be the core, the outer envelope or an intermediate shell (in the case of elastomers whose structure has more than two shells) . Elastomers having more than one shell may also have more than one shell composed of a rubber phase.

If one or more hard components (with glass transition temperatures above 20℃) are involved, besides the rubber phase, in the structure of the elastomer, these are generally prepared by polymerizing, as principal monomers, styrene, acrylonitrile, methacrylonitrile, α-methylstyrene, p-methylstyrene, or acrylates or methacrylates, such as methyl acrylate, ethyl acrylate or methyl methacrylate. Besides these, it is also possible to use relatively small proportions of other comonomers.

It has proven advantageous in some cases to use emulsion polymers which have reactive groups at their surfaces. Examples of groups of this type are epoxy, carboxy, latent carboxy, amino and amide groups, and also functional groups which may be introduced by concomitant use of monomers of the general formula

where the substituents can be defined as follows:

R¹⁰ is hydrogen or a C₁-C₄-alkyl group,

R¹¹ is hydrogen, a C₁-C₈-alkyl group or an aryl group, in particular phenyl,

R¹² is hydrogen, a C₁-C₁₀-alkyl group, a C₆-C₁₂-aryl group, or -OR¹³,

R¹³ is a C₁-C₈-alkyl group or a C₆-C₁₂-aryl group, which can optionally have substitution by groups that comprise O or by groups that comprise N,

X is a chemical bond, a (C₁-C₁₀-alkylene group, or a C₆-C₁₂-arylene group, or

Y is O-Z or NH-Z, and

Z is a C₁-C₁₀-alkylene or C₆-C₁₂-arylene group.

The graft monomers described in EP-A208 187 are also suitable for introducing reactive groups at the surface.

Other examples which may be mentioned are acrylamide, methacrylamide and substituted acry-lates or methacrylates, such as (N-tert-butylamino) ethyl methacrylate, (N, N-dimethylamino) ethyl acrylate, (N, N-dimethylamino) methyl acrylate and (N, N-diethylamino) ethyl acrylate.

The particles of the rubber phase may also have been crosslinked. Examples of crosslinking monomers are 1, 3-butadiene, divinylbenzene, diallyl phthalate and dihydrodicyclopentadi-enylacrylate, and also the compounds described in EP-A50 265.

It is also possible to use the monomers known as graft-linking monomers, i.e. monomers having two or more polymerizable double bonds which react at different rates during the polymeriza-tion. Preference is given to the use of compounds of this type in which at least one reactive group polymerizes at about the same rate as the other monomers, while the other reactive group (or reactive groups) , for example, polymerize (s) significantly more slowly. The different polymerization rates give rise to a certain proportion of unsaturated double bonds in the rubber. If another phase is then grafted onto a rubber of this type, at least some of the double bonds present in the rubber react with the graft monomers to form chemical bonds, i.e. the phase grafted on has at least some degree of chemical bonding to the graft base.

Examples of graft-linking monomers of this type are monomers comprising allyl groups, in par-ticular allyl esters of ethylenically unsaturated carboxylic acids, for example allyl acrylate, allyl methacrylate, diallyl maleate, diallyl fumarate and diallyl itaconate, and the corresponding mon-oallyl compounds of these dicarboxylic acids. Besides these there is a wide variety of other suit-able graft-linking monomers. For further details reference may be made here, for example, to U.S. Pat. No. 4,148,846.

The proportion of these crosslinking monomers in the impact-modifying polymer is generally up to 5%by weight, preferably not more than 3%by weight, based on the impact-modifying poly-mer.

Some preferred emulsion polymers are listed below. Mention may first be made here of graft polymers with a core and with at least one outer shell, and having the following structure:

Instead of graft polymers whose structure has more than one shell, it is also possible to use ho-mogeneous, i.e. single-shell, elastomers composed of 1, 3-butadiene, isoprene and n-butyl acry-late or of copolymers of these. These products, too, may be prepared by concomitant use of crosslinking monomers or of monomers having reactive groups.

Examples of preferred emulsion polymers are n-butyl acrylate- (meth) acrylic acid copolymers, n-butyl acrylateglycidyl acrylate or n-butyl acrylate-glycidyl methacrylate copolymers, graft poly-mers with an inner core composed of n-butyl acrylate or based on butadiene and with an outer envelope composed of the abovementioned copolymers, and copolymers of ethylene with comonomers which supply reactive groups.

The elastomers described may also be prepared by other conventional processes, e.g. by sus-pension polymerization.

Preference is also given to silicone rubbers, as described in DE-A 37 25 576, EP-A235 690, DE-A38 00 603 and EP-A 319 290.

Particularly preferred impact modifiers D are ethylene copolymers, as described above, which comprise functional monomers.

The proportion of the functional monomers is from 0.1 to 20%by weight, preferably from 0.2 to 10%by weight, and in particular from 0.3 to 3.5%by weight, based on 100%by weight of D.

Particularly preferably, component D1 is at least one copolymer composed of

i) 80 to 99.9%by weight, preferably 90 to 99.8%by weight, more preferably 96.5 to 99.7%by weight of ethylene, as component i) , and

ii) 0.1 to 20%by weight, preferably 0.2 to 10%by weight, more preferably 0.3 to 3.5%by weight of at least one functional monomer different from ethylene, as component ii) ,

wherein the sum of components i) and ii) is 100%by weight,

wherein the copolymer may also be additionally grafted with maleic anhydride.

The functional monomers are preferably selected from the group consisting of C_3-12-olefins, car-boxylic esters like C_1-18-alkyl (meth) acrylates, carboxylic acids like (meth) acrylic acid, carboxylic acid anhydrides like maleic anhydride, chloroprene, vinyl acetate, styrene, acrylonitrile, carbox-amides, carboximides, amino group comprising compounds, hydroxy group comprising com-pounds, epoxy group comprising compounds, and mixtures thereof.

The term “ (meth) acryl” means “methacryl or acryl” , e.g. “ (meth) acrylic acid” means “methacrylic acid or acrylic acid” .

Particularly preferred monomers are composed of an ethylenically unsaturated mono-or dicar-boxylic acid or of a functional derivative of this type of acid. In principle any of the primary, sec-ondary, and tertiary C₁-C₁₈-alkyl esters of (meth) acrylic acid is suitable, but preference is given to esters having from 1 to 12 carbon atoms, in particular having from 2 to 10 carbon atoms.

Examples of these are methyl, ethyl, propyl, n-butyl, isobutyl, and tert-butyl, 2-ethylhexyl, octyl, and decyl (meth) acrylates. Among these, particular preference is given to n-butyl acrylate and 2-ethylhexyl acrylate.

Instead of the esters or in addition to these, it is also possible that the olefin polymers comprise acid-functional and/or latent acid-functional monomers of ethylenically unsaturated mono-or di-carboxylic acids, or comprise monomers having epoxy groups.

Other examples that may be mentioned of monomers are (meth) acrylic acid, tertiary alkyl esters of said acids, in particular tert-butyl acrylate, and dicarboxylic acids, such as maleic acid and fumaric acid, and derivatives of said acids, and also monoesters of these.

Latent acid-functional monomers are compounds which form free acid groups under the polymerization conditions and, respectively, during incorporation of the olefin polymers into the molding compositions. Examples of these that may be mentioned are anhydrides of dicarboxylic acids having up to 20 carbon atoms, in particular maleic anhydride, and tertiary C₂-C₁₂-alkyl es-ters of the abovementioned acids, in particular tert-butyl acrylate and tert-butyl methacrylate.

The acid-functional or latent acid-functional monomers and the monomers comprising epoxy groups are preferably incorporated into the olefin polymers via addition of compounds of the general formulae I-IV to the monomer mixture.

The melt index of ethylene copolymers described above is generally in the range from 1 to 80 g/10 min (measured at 190℃ with 2.16 kg load) .

The molar mass of said ethylene copolymers is from 10 000 to 500 000 g/mol, preferably from 15 000 to 400 000 g/mol (Mn, determined by means of GPC in 1, 2, 4-trichlorobenzene with PS calibration) .

In one particular embodiment, ethylene-α-olefin copolymers are used which have been pro-duced by means of what are known as “single site catalysts” . Further details can be found in U.S. Pat. No. 5,272,236. In this case, the molecular weight distribution of the ethylene-α-olefin copolymers is narrow for polyolefins, being smaller than 4, preferably smaller than 3.5.

Further suitable impact modifiers are polyethylene or polypropylene (D2) , wherein D2 may also be additionally grafted with maleic anhydride.

The polyethylene and polypropylene may be low density or high density polyethylene or poly-propylene, preferably polyethylene, more preferably low density polyethylene, optionally grafted with maleic anhydride.

Further suitable impact modifiers are for example polyethylenes comprising a butyl acrylate comonomer, polyolefin elastomers like ethylene copolymers functionalized with maleic anhy-dride, ethylene (meth) acrylate copolymers grafted with maleic anhydride, polyolefin elastomers like ethylene copolymers grafted with maleic anhydride, ethylene (meth) acrylate copolymers, triblock copolymers based on styrene and ethylene/butylene grafted with maleic anhydride, and random terpolymers of ethylene, acrylic ester and maleic anhydride.

Preferably component D is selected from ethylene-propylene rubbers, ethylene-propylene-diene-rubbers, ethylene-butyl acrylate copolymers, copolymers of ethylene and/or propylene and maleic anhydride and mixtures thereof.

Examples of suitable commercial elastomers useful as impact modifiers are obtainable for ex-ample from Lyondellbasell under the designationsA2540D and A2540D is a low density polyethylene comprising a butyl acrylate comonomer. It has a density of 0.923 g/cm³ and a Vicat softening temperature of 85 ℃ and a melting temperature of 103 ℃ at a butyl acrylate proportion of 6.5%by weight. A2700M is a low density polyethylene likewise comprising a butyl acrylate comonomer. It has a density of 0.924 g/cm³, a Vicat softening temperature of 60 ℃ and a melting temperature of 95 ℃.

Further examples are copolymers of ethylene, n-butyl acrylate, acrylic acid and maleic anhy-dride. A corresponding copolymer is available from BASF SE under the name KR1270.

The polymer resin Exxelor^TM VA 1801 from ExxonMobil is a semicrystalline ethylene copolymer functionalized with maleic anhydride by reactive extrusion and having an intermediate viscosity. The polymer backbone is fully saturated. The density is 0.880 g/cm³ and the proportion of ma-leic anhydride is typically in the range from 0.5%to 1.0%by weight. Further suitable polymer resins are Exxelor^TM VA 1850 and VA 1803 from ExxonMobil.

The polymer resinA560 from Dow is a chemically modified ethylene acrylate copol-ymer, N493 from Dow is a maleic anhydride grafted low Tg ethylene copolymer, N416 from Dow is a chemically modified ethylene elastomer andfrom Dow are ionomers built from ethylene-methacrylic acid copolymers.

The polymer resinFG 1901 fromCorporation is a linear triblock copolymer based on styrene and ethylene/butylene with a polystyrene content of 30%. FG 1924 fromCorporation is a linear triblock copolymer based on styrene and ethylene/butylene with a polystyrene content of 13 wt. %. G 1567 fromCorporation is a linear triblock copolymer based on styrene and ethylene/butylene with a polystyrene content of 13 wt. %.

The polymer resins4503, 4700 and 4720 from Arkema are random terpolymers of ethylene, acrylic ester and maleic anhydride. The3, 5 and 8 series from Arkema are random terpolymers of ethylene, acrylic ester and maleic anhydride.

The polymer resinsM series from Mitsui are acid modified α-olefin copolymer grades grafted with polar groups (MA 8510 and MA 9015, MH 7510, 7010, MD 715 and MH 7020, MH 5010, MH 5020, MH 5040) .

The polymer resinfrom NINGBO, CHINA is a polyolefin elastomer as resin with maleic ahhydride grafting.

The polymer resinfrom Shenyang Ketong Plastic Co., Ltd is a maleic anhydride grafted polyolefin elastomer.

The polymer resinsCMG5805 and CMG5805-L from Fine-Blend are polyolefine elastomers grafted with maleic anhydride.

It is also possible, of course, to use mixtures of the types of impact modifiers listed above.

Component E

The thermoplastic molding compositions of the invention comprise, as component E, from 0 to 50%preferably 0.01 to 20 %by weight, more preferably 0.1 to 10%by weight of further addi-tional substances, wherein the sum of the percentages by weight of components A, B, C, op-tionally component D and optionally component E is 100%by weight.

If component E is present, the maximum amount of component A is decreased by the minimum amount of component E, so that the total amount of components A to E is still 100 wt%.

Further additional substances are for example acid scavengers for the red phosphorus, and/or conventional processing aids, such as antioxidants, stabilizers, oxidation retarders, agents to counteract decomposition due to heat (heat stabilizers) and decomposition due to ultraviolet light (UV stabilizers) , lubricants, mold-release agents, colorants, such as dyes and pigments, nucleating agents, plasticizers, antistatic agents and flow enhancers.

The molding compositions of the invention can comprise acid scavengers for the red phospho-rus, as component E. If the acid scavengers for the red phosphorus are present, they are gener-ally present in an amount from 0.01 to 3%by weight, preferably from 0.1 to 2%by weight, and in particular from 0.1 to 1.5%by weight, based on the total amount of components A, B, C, op-tionally D and optionally E.

Suitable acid scavengers for the red phosphorous are metal oxides and/or metal salts, prefera-bly ZnO, Zn borate, Zn stannate, MgO, Mg (OH) _2j ZnCO₃, MgCO₃, CaCO₃ Mg Ca carbonates, AlOOH and mixtures thereof, particular preference being given here to ZnO, basic ZnCO₃, Mg(OH) _2; CaCO₃ and CuO/ZnO/Al₂O₃ mixed oxides and mixtures thereof; most preferred are CaCO₃ and/or ZnO.

Examples for suitable conventional processing aids are mentioned in the following in more de-tail:

The inventive molding compositions may comprise at least one lubricant. If the lubricant is pre-sent, it is generally present in an amount from 0.05 to 3%by weight, preferably from 0.1 to 1.5%by weight, and in particular from 0.1 to 1%by weight, based on the total amount of components A, B, C, optionally D and optionally E.

Preference is given to the salts of Al, of alkali metals, or of alkaline earth metals, or esters or amides of fatty acids having from 10 to 44 carbon atoms, preferably having from 12 to 44 car-bon atoms.

The metal ions are preferably alkaline earth metal, Zn and Al, particular preference being given to Ca or Mg. Preferred metal salts are Ca stearate and Ca montanate, and also Al stearate.

It is also possible to use a mixture of various salts, in any desired mixing ratio.

The carboxylic acids can be monobasic or dibasic. Examples which may be mentioned are pelaigonic acid, palmitic acid, lauric acid, margaric acid, dodecanedioic acid, behenic acid, and particularly preferably stearic acid, capric acid, and also montanic acid (amixture of fatty acids having from 30 to 40 carbon atoms) .

The aliphatic alcohols can be monohydric to tetrahydric. Examples of alcohols are n-butanol, n-octanol, stearyl alcohol, ethylene glycol, propylene glycol, neopentyl glycol, pentaerythritol, pref-erence being given to glycerol and pentaerythritol.

The aliphatic amines can be mono-to tribasic. Examples of these are stearylamine, ethylenedi-amine, propy-lenediamine, hexamethylenediamine, di (6-aminohexyl) amine, particular prefer-ence being given to ethylenediamine and hexamethylenediamine. Preferred esters or amides are correspondingly glycerol distearate, glycerol tristearate, ethylenediamine distearate, glycerol monopalmitate, glycerol trilaurate, glycerol monobehenate, and pentaerythritol tetrastearate.

It is also possible to use a mixture of various esters or amides, or of esters with amides in com-bination, in any desired mixing ratio.

The molding compositions of the invention can comprise at least one antioxidant, as component E. If the antioxidant is present, it is generally present in an amount from 0.05 to 3%by weight, preferably from 0.01 to 1.5%by weight, and in particular from 0.1 to 1%by weight, based on the total amount of components A, B, C, optionally D and optionally E.

Suitable antioxidants are sterically hindered phenols which are in principle all of the compounds which have a phenolic structure and which have at least one bulky group on the phenolic ring. Examples of compounds that can be used with preference are those of the formula

where:

R¹ and R² are an alkyl group, a substituted alkyl group, or a substituted triazole group, and where the radicals R¹ and R² may be identical or different, and R³ is an alkyl group, a substi-tuted alkyl group, an alkoxy group, or a substituted amino group.

Antioxidants of the abovementioned type are described by way of example inDE-A27 02 661 U.S. Pat. No. 4 360 617) .

Another group of preferred sterically hindered phenols is provided by those derived from substi-tuted benzenecarboxylic acids, in particular from substituted benzenepropionic acids. Particu-larly preferred compounds from this class are compounds of the formula

where R⁴, R⁵, R⁷, and R⁸, independently of one another, are C1-C8-alkyl groups which them-selves may have substitution (at least one of these substituents being a bulky group) , and R⁶ is a divalent aliphatic radical which has from 1 to 10 carbon atoms and whose main chain may also have C-O bonds. Preferred compounds corresponding to this formula are

All of the following should be mentioned as examples of sterically hindered phenols: 2, 2'-methylenebis (4-methyl-6-tert-butylphenol) , 1, 6-hexanediol bis [3- (3, 5-di-tert-butyl-4-hydroxy-phenyl) propionate] , pentaerythrityl tetrakis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate] , distearyl 3, 5-di-tert-butyl-4-hy-droxybenzylphosphonate, 2, 6, 7-trioxa-l-phosphabicyclo [2. 2.2] oct-4-ylmethyl 3, 5-di-tert-butyl-4-hydroxyhy drocinnamate, 3, 5 -di -tert-butyl -4 -hydrox-yphenyl-3, 5-distearylthiotriazylamine, 2- (2'-hydroxy-3'-hydroxy-3', 5'-di-tert-butylphenyl) -5-chlorobenzo triazole, 2, 6 -di -tert-butyl -4 -hydroxymethylphenol, 1, 3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4 hydroxybenzyl) benzene, 4, 4'-methylenebis (2, 6-di-tert-butylphenol) , 3, 5 -di -tert-butyl -4 -hydroxybenzy ldimethy lamine.

Compounds which have proven particularly effective and which are therefore used with prefer-ence are 2, 2'-methylenebis (4-methyl-6-tert-butylphenyl) , 1, 6-hexanediol bis (3, 5-di-tert-butyl-4-hydroxyphenyl] propionate (259) , pentaerythrityl tetrakis [3- (3, 5-di-tert-butyl-4-hydroxy-phenyl) propionate, and also N, N'-hexamethylenebis-3, 5-di-tert-butyl-4-hydroxyhydrocinnamide (1098) , and245 from BASF SE, which has particularly good suitability.

In some instances, sterically hindered phenols having not more than one sterically hindered group in ortho position with respect to the phenolic hydroxy group have proven particularly ad-vantageous, in particular when assessing colorfastness on storage in diffuse light over pro-longed periods.

Materials known as copper stabilizers provide another group of preferred antioxidants.

If present, the copper stabilizers are present in amounts of from 0 to 1%by weight, preferably from 0.05 to 0.5%by weight, based on the total amount of components A, B, C, optionally D and optionally E.

These copper stabilizers are generally composed of two components, namely of a mixture of copper compounds and of specific halide salts. The usual copper compounds are the copper (I) halides, and also copper salts such as copper acetate, copper sulfate, or copper stearate, and the copper complexes, for example copper acetylacetonate. In order that these compounds are effective as antioxidants, halogen compounds must be added in large excess. Those used here are in particular potassium iodide, and also potassium bromide. The amount used here is usu-ally selected in such a way that the molar ratio copper: halogen is 1 : from 5 to 15. The recom-mended amount added is generally from 30 to 200 ppm of copper. Preference is moreover given to copper complexes with the following complex ligands: triphenylphosphines, mercapto-benzimidazoles, acetylacetonates, and glycine. Particular preference is given to tri-phenylphosphines and mercaptobenzimidazoles .

Preferred copper complexes used are usually formed via reaction of copper (I) ions with the phosphine compounds or mercaptobenzimidazole compounds. By way of example, said com-plexes can be obtained via reaction of triphenylphosphine with a copper (I) halide suspended in chloroform (G. Kosta, E. ReisenhoferandL. Stafani, J. Inorg. Nucl. Chem. 27 (1965) 2581) . However, it is also possible to carry out a reductive reaction of copper (II) compounds with tri-phenylphosphine and thus obtain the copper (I) adducts (F.U. Jardine, L. Rule, A.G. Vohrei, J. Chem. Soc. (A) 238-241 (1970) ) .

Examples of suitable complexes can be represented by the following formulae:

[Cu (PPh₃) ₃X] , [Cu₂X₂ (PPh₃) ₃] , [Cu (PPh₃) X] ₄, and

[Cu (PPh₃) ₂) X] , where X is selected from Cl, Br,

I, CN, SCN, or 2-MBI.

Examples of oxidation retarders and heat stabilizers are sterically hindered phenols and/or phosphites, and amines (e.g. TAD) , hydroquinones, aromatic secondary amines, such as diphe-nylamines, various substituted members of these groups, and mixtures of these, if present, at concentrations of up to 1%by weight, based on the total amount of components A, B, C, option-ally D and optionally E.

UV stabilizers that may be mentioned, the amounts of which used are generally –if present -up to 2%by weight, based on the total amount of components A, B, C, optionally D and option-ally E, are various substituted resorcinols, salicylates, benzotriazoles, benzophenones and hy-droxyphenyltriazines.

Materials that can be added as colorants are inorganic pigments, such as titanium dioxide, ultra-marine blue, iron oxide, nigrosine and carbon black, and also organic pigments, such as phthal-ocyanines, quinacridones, perylenes, and also dyes, such as anthraquinones.

Materials that can be used as nucleating agents are sodium phenylphosphinate, talc powder, aluminum oxide, silicon dioxide.

The moulding compositions of the invention can comprise –if present -from 0.1 to 10%by weight, preferably 0.5 to 5 wt%, more preferably 1 to 4 wt%of at least one plasticizer, based on the total amount of components A, B, C, optionally D and optionally E.

Kunststoff-Handbuch, Band VI Polyamide, Carl Hanser Verlag München 1966, Section 3.4.2.1. b) on pages 238 and 239 in connection with Table 7 describes suitable plasticizers. They can be divided in aromatic hydroxy compounds, sulfonamides and further plasticizers like lactams, lactones, alcohols etc.

Suitable plasticizers are for example poly (trimethylene ether) glycol (PPD) , preferably poly (tri-methylene ether) glycol (PPD) having a number average molecular weight of 255 and poly (tri-methylene ether) glycol benzoate (PPDB) , N-butyl benzene sulfonamide (NBBS) , polyethylene glycol dibenzoate (M_n = 410) , poly (1, 2-propylene glycol) dibenzoate (M_n = 400) , monomeric am-ides, specifically sulfonamides, for example N-alkyl aryl sulfonamides, p-alkyl benzene sulfona-mides and guanidine-based compounds, a mixture of lactam compounds and polyethylene gly-col, an aromatic ester of poly (trimethylene ether) glycol with a number average molecular weight of 1000 or less or compounds of the general formula (1) .

R₁-O- (CH₂CH₂-O-) _nR₂ (1)

with n = 1 to 10

R₁, R₂ independently H, C_1-12-alkyl, phenyl or tolyl,

having a boiling point of more than 250 ℃.

A preferred plasticizer of general formula (1) is based on triethylene glycol, tetraethylene glycol, pentaethylene glycol or mixtures thereof. Most preferred is tetraethylene glycol. Therefore, n most preferably has a value of from 3.8 to 4.2, most preferably of 4.

Tetraethylene glycol is non-toxic and has a high plasticizing efficiency. When compared with sulfonamides and lactams, only half the amount of tetraethylene glycol is necessary to achieve the same plasticizing effect and the same decrease of the glass transition temperature. There-fore, in a preferred embodiment, the thermoplastic moulding composition comprises a com-pound of formula (1) as plasticizer, in the case that a plasticizer is present as component E.

The moulding compositions of the present invention can comprise –if present -0.1 to 3 wt%, preferably 0.2 to 2.5 wt%, based on the total amount of components A, B, C, optionally D and optionally E, of at least one flow enhancer.

Examples for suitable flow enhancers are branched, hyperbranched or dendritic components, usually macromolecules like polymers containing functional groups like –NH₂, –OH, -COOH, or -COOCH₃.

The macromolecules may be for example polyamide based polymers or polyesters.

Examples are CYD-701, CYD-C600, CYD-819, CYD-816A (all Weihai CY Dendrimer Technol-ogy Co, Ltd. ) , HyPer C100 (Wuhan HyPerBranched Polymers Science Technology Co., Ltd. ) , TER-PA9 from TER HELL &Co. GmbH and Bruggolen TP-P1507 and TP-P1810 from L. Brüg-gemann GmbH &Co. KG.

A dendrimer consists of two types of structural units: terminal units on the globular surface and dendritic units inside. As such, dendrimers are well defined in structure. On the other hand, a hyperbranched polymer has three types of structural units: dendritic units, linear units and termi-nal units. The terminal units are always located at the terminals, however, the dendritic units and linear units are randomly distributed within the macromolecular framework, resulting in ir-regular structures.

Compositions

The thermoplastic molding compositions according to the present invention are characterized by a good fire behavior and at the same time by good physical and mechanical properties. Further, the inventive molding compositions are bio-based.

The outstanding properties of the inventive thermoplastic molding compositions are achieved by the inventive combination of a polyamide based on 1, 5-pentanediamine, an aliphatic dicarbox-ylic acid and an aromatic dicarboxylic acid (component A) with red phosphorous (component B) and a filler (component C) .

The inventive thermoplastic moulding composition therefore comprises

E) from 0 to 50%by weight of further additional substances, as component E;

Suitable and preferred components A, B, C, D and E and amounts are described above and in the examples below.

The inventive thermoplastic molding composition is especially characterized by a V-0 classifica-tion in the UL 94-V test (0.8 mm, 2d/23℃/50%) concerning fire behavior. At the same time, the physical and mechanical properties are good.

The inventive thermoplastic molding composition comprises a viscosity number of 90 to 160 ml/g, preferably 100 to 150 ml/g, more preferably 110 to 140 ml/g, determined according to EN ISO 307: 2019 in sulfuric acid (0.5% [m/v] of polyamide in 96 wt. -% [m/m] sulfuric acid at 25 ℃) .

The melt temperature of the inventive thermoplastic moulding composition during compounding is preferably < 335℃, more preferably 250 to 330 ℃, most preferably 260 to 280 ℃.

The thermoplastic molding compositions of the invention can be produced by processes known per se, generally by mixing the starting components A, B, C, optionally D and optionally E.

Suitable mixing apparatus are conventional mixing apparatus, such as screw-based extruders, Brabender mixers, or Banbury mixers, and then extruding the same. The extrudate can be cooled and pelletized. It is also possible to premix individual components and then to add the remaining starting materials individually and/or likewise in the form of a mixture. The mixing temperatures are generally from 250 to 350 ℃.

The present invention therefore relates to a process for preparing of the inventive thermoplastic molding composition, comprising mixing components A, B, C and optionally D and E, preferably by kneading in a melt extruder, and more preferably by kneading in a twin-screw extruder.

Preferably, the process comprises: adding components A, B and optionally D and E into the mixing means, preferably a twin-screw extruder, and mixing to obtain a premix, then melt-mixing the premix at 15-40℃ higher than the melting point of component A, and adding component C into the premix, mixing, extruding and cooling to obtain thermoplastic molding composition.

Application

These materials are suitable for the production of fibers, films or moldings, preferably moldings. The present invention therefore further relates to the use of the inventive thermoplastic molding composition or the thermoplastic molding composition obtained by the inventive process for pro-ducing fibers, foils or moldings, preferably moldings; and fibers, foils or moldings, preferably moldings, comprising the inventive thermoplastic molding composition or the thermoplastic molding composition obtained by the inventive process.

The inventive thermoplastic molding compositions or semifinished products to be produced from the inventive thermoplastic molding compositions can be used by way of example in the motor vehicle industry, electrical industry, electronics industry, telecommunications industry, infor-mation technology industry, consumer electronics industry, or computer industry, in vehicles and other means of conveyance, in ships, in spacecraft, in the household, in office equipment, in sports, in medicine, and also generally in articles and parts of buildings which require in-creased fire protection.

The inventive thermoplastic molding compositions are for example especially useful in the elec-trical and electronic (E/E) applications, for example to produce plugs, plug parts, plug connect-ors, membrane switches, printed circuit board modules, microelectronic components, coils, I/O plug connectors, plugs for printed circuit boards (PCBs) , plugs for flexible printed circuits (FPCs) , plugs for flexible integrated circuits (FFCs) , high-speed plug connections, terminal strips, connector plugs, device connectors, cable-harness components, circuit mounts, circuit-mount components, three-dimensionally injection-moulded circuit mounts, electrical connection elements, and mechatronic components.

Examples

Following raw material have been used:

Polyamide 66 (A27E from BASF SE)

Polyamide 565T (E2260 from Cathay)

Polyamide 56 (E1273 from Cathay)

Polyamide 6 (B27 from BASF)

Glassfiber PA (GF OC995 fromSAS)

Zinkoxide (Z aktiv from Lanxess Deutschland GMbH)

Calciumstearate flakes (AV from Baerlocher GmbH)

30%Carbonblack 300 in Polyamide 6 (420 from BASF SE)

Carbonblack (300 or Speazial Black 4 from Orion Engineered Carbons GmbH Maleic Anhydride modified ethylene copolymer (N493 from Dow Europe GmbH) 52 %Red Phosphorus-Batch inKR127011452 from Italmatch) Phenolic antioxidant (1098 from BASF)

AH-Salt (Hexamethylenediamine adipate) from BASF

dentritic polymer from TER Chemicals

Maleic Anhydride modified ethylene /acrylate copolymer (KR 1270 from BASF SE)

Preparation of Polyamide compounds

The polymers listed below were compounded on a ZE25 twin-screw extruder under the process parameters listed below. The ZE25 can dose coldfeed and with two sidefeeds. The metering points vary depending on the configuration. The extruder has an L/D ratio of 40.

*Comparative example
**Inventive example

All raw materials have been added in the cold feed of the extruder, only the glass fibers have been introduced in zone 3 as well as flame retardant and impact modifier in zone 5.

Effect:

The examples show that when using component A according to the present invention, the fire retardance (FR) performance of the polyamide composition is strongly improved in comparison to standard polyamide compositions comprising PA66 but also to neat PA 56.

FR performance has been measured using UL94 test at different thickness (0.4 and 0.8 mm) . These tests show that V0 rating can be reached at lower thickness (especially important for ap-plication in E/E (electronic and electric) such as connector) form one side, or the use of such new resin can insure a V0 rating at lower concentration of FR additive (red P) .

Claims

A thermoplastic molding composition comprising

A) from 35 to 98.5%by weight, preferably 40 to 88%by weight, more preferably 45 to 75%by weight of at least one thermoplastic polyamide, as component A;

B) from 0.5 to 15%by weight, preferably 1 to 8%by weight, more preferably 2 to 7%by weight of red phosphorous, as component B;

C) from 1 to 50%by weight, preferably 10 to 45%by weight, more preferably 20 to 40%by weight of at least one fibrous and/or particulate filler, as component C;

D) from 0 to 20%by weight, preferably 1 to 15%by weight, more preferably 3 to 10%by weight of at least one impact modifier, as component D;

E) from 0 to 50%by weight of further additional substances, as component E;

wherein the sum of the percentages by weight of components A to E is 100%by weight, and wherein component A comprises at least one polyamide of

A1) units derived from 1, 5-pentanediamine as component A1;

A2) units derived from at least one aliphatic dicarboxylic acid, preferably selected from the group consisting of adipic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptade-canedioic acid, and octadecanedioic acid, as component A2;

A3) units derived from at least one aromatic dicarboxylic acid, preferably selected from the group consisting of terephthalic acid, isophthalic acid, and phthalic acid, as com-ponent A3;

wherein the molar ratio of component A1 to the sum of components A2 and A3 is 1-1.05 to 0.95.
The thermoplastic molding composition according to claim 1, wherein component A com-prises

i) 10 to 100 wt%of at least one polyamide of units derived from components A1, A2 and A3, as component AI;

ii) 0 to 90 wt%of at least one polyamide different from component AI as component AII; preferably selected from PA 46, PA 66, PA 69, PA 610, PA 612, PA 613, PA 1212, PA 1313, PA 6T, PA MXD6, PA 6I, PA 6-3-T, PA 6/6.36, PA 6/6T, PA66/6T, PA 6/66, PA 6/12, PA 66/6/610, PA 6I/6T, PA PACM 12, PA 6I/6T/PACM, PA 12/MACMI, PA 12/MACMT, PA PDA-T, PA 4, PA 6, PA 7, PA 8, PA 9, PA 11 and mixtures thereof, more preferably selected from PA 6, PA 66, PA 46, PA 6/66, PA 66/6, PA 6/636, PA 6T/6, PA66/6T, PA 6T/6I, PA 6T/6I/66, PA 9T, PA 6T/66 and mixtures thereof, most preferably selected from PA66/6T, PA 6, PA 66, PA 6/66 and PA 66/6, PA 6/636 and mixtures thereof, further most preferably PA66/6T, PA 6, PA 66 or mixtures thereof.
The thermoplastic molding composition according to claim 1 or 2, wherein the at least one further diamine is at least one aliphatic diamine and/or at least one aromatic diamine, pref-erably least one aliphatic diamine having from 6 to 12, in particular 6 to 8 carbon atoms, and/or m-xylylene diamine, di [4-aminophenyl] methane, di [4-aminocyclohexyl] methane, 2, 2-di [4-aminophenyl] propane, 2, 2-di [4-aminocyclohexyl] propane and 1, 5-diamino-2-methylpantane, more preferably least one aliphatic diamine selected from tetramethylene-diamine, hexamethylenediamine, most preferably hexamethylendiamine.
The thermoplastic molding composition according to any one of claims 1 to 3, wherein component A2 is adipic acid.
The thermoplastic molding composition according to any one of claims 1 to 4, wherein component A3 is terephthalic acid.
The thermoplastic molding composition according to any one of claims 1 to 5, wherein the molar ratio of component A2 to component A3 is 1 to 0.1-1.5.
The thermoplastic molding composition according to any one of claims 1 to 6, wherein the red phosphorous is employed in form of a masterbatch, preferably in form of a mas-terbatch in a polyamide or in an elastomer, wherein the weight%amount of component B is in each case calculated on red phosphorous.
The thermoplastic molding composition according to any one of claims 1 to 7, wherein component C are glass fibers, preferably the glass fibers are selected from the group con-sisting of E-Glass fibers, S-Glass fibers, D-Glass fibers, C-Glass fibers, L-Glass fibers, M-Glass fibers and mixtures thereof, more preferably the glass fibers are E-Glass fibers.
The thermoplastic molding composition according to claim 8, wherein the glass fibers are chopped long glass fibers, preferably having an average starting length to be determined by laser diffraction-particle size analysis (laser granulometry/laser diffractometry) accord-ing to ISO 13320: 2009 in the range from 1 to 50 mm, more preferably in the range from 2 to 10 mm, most preferably in the range from 3 to 8 mm.
The thermoplastic molding composition according to any one of claims 1 to 9, wherein component D is selected from

D1) copolymers of ethylene with at least one comonomer selected from C_3-12-olefins, C_1- ₁₂-alkyl (meth) acrylates, (meth) acrylic acid, maleic anhydride, vinyl acetate and acry-lonitrile, as component D1,

and

D2) polyethylene or polypropylene as component D2,

wherein components D1 and D2 may also be additionally grafted with maleic anhydride, preferably component D is selected from ethylene-propylene rubbers, ethylene-propylene-diene-rubbers, ethylene-butyl acrylate copolymers, copolymers of ethylene and/or propyl-ene and maleic anhydride and mixtures thereof.
The thermoplastic molding composition according to any one of claims 1 to 10, wherein component E is selected from at least one of acid scavengers for the red phosphorus and conventional processing aids, wherein the conventional processing aids are preferably se-lected from antioxidants, stabilizers, oxidation retarders, agents to counteract decomposi-tion due to heat and decomposition due to ultraviolet light, lubricants, mold-release agents, colorants, such as dyes and pigments, nucleating agents, plasticizers, and flow enhancers.
The thermoplastic molding composition according to any one of claims 1 to 11, wherein the thermoplastic molding composition has a V-0 classification in the UL 94-V test (0.8 mm, 2d/23℃/50%) concerning fire behavior.
A process for preparing of the thermoplastic molding composition according to any one of claims 1 to 12, comprising mixing components A, B, C and optionally D and E, preferably by kneading in a melt extruder, and more preferably by kneading in a twin-screw extruder; preferably, the process comprises: adding components A, B and optionally D and E into the stirrer, and mixing to obtain a premix, then melt-mixing the premix at 15-40℃ higher than the melting point of component A, and adding component C into the premix, mixing, extruding and cooling to obtain thermoplastic molding composition.
The use of the thermoplastic molding composition according to any one of claims 1 to 12 or obtained by the process according to claim 13 for producing fibers, foils or moldings.
Fibers, foils or moldings comprising the thermoplastic molding composition according to any one of claims 1 to 12 or obtained by the process according to claim 13.