DE19917260A1 - Use of polyoxymethylene molding compounds - Google Patents

Abstract

Use of thermoplastic polyoxymethylene molding compounds containing as essential components DOLLAR AA) 10 to 98% by weight of a polyoxymethylene homo- or copolymer, DOLLAR AB) 0.005 to 2% by weight of a sterically hindered phenol, DOLLAR AC) 0.001 to 2% by weight % of a polyamide, DOLLAR AD) 0.002 to 2% by weight of an alkaline earth metal silicate or an alkaline earth metal glycerophosphate, DOLLAR AE) 0 to 5% by weight of at least one ester or amide of saturated or unsaturated aliphatic carboxylic acids with 10 to 40 carbon atoms with polyols or aliphatic saturated alcohols or amines with 2 to 40 carbon atoms or an ether derived from alcohols and ethylene oxide, DOLLAR AF) 0.01 to 5 wt .-% of a melamine-formaldehyde condensate, DOLLAR AG) 0 to 50 wt .-% of an impact-modifying polymer, DOLLAR AH) 0 to 30% by weight of further additives, the sum of the percentages by weight of components A) to H) in each case being 100%, DOLLAR A for the production of moldings by blow molding, profile extrusion and / or pipe extrusion.

Description

The invention relates to the use of thermoplastic poly oxymethylene molding compositions containing as essential components

• A) 10 to 98% by weight of a polyoxymethylene homo- or copoly merisats,
• B) 0.005 to 2% by weight of a sterically hindered phenol,
• C) 0.001 to 2% by weight of a polyamide,
• D) 0.002 to 2% by weight of an alkaline earth silicate or one Alkaline earth glycerophosphates,
• E) 0 to 5% by weight of at least one ester or amide seeded saturated or unsaturated aliphatic carboxylic acids with 10 to 40 carbon atoms sown with polyols or aliphatic saturated alcohols or amines with 2 to 40 carbon atoms or an ether that is different from alcohols and ethylene oxide directs,
• F) 0.01 to 5% by weight of a melamine-formaldehyde condensate,
• G) 0 to 50% by weight of an impact-modifying polymer,
• H) 0 to 30% by weight of further additives, the sum the percentages by weight of components A) to H), respectively 100% results,

for the production of moldings by blow molding, profile extrusion and / or pipe extrusion.

The invention also relates to the form obtainable here body of any kind.

Due to their high crystallinity, polyacetals have a good one Resistance to numerous chemicals, with the high one Resistance to all common solvents and fuels (also containing methanol and rapeseed oil methyl ester), fats, oils, Brake and cooling fluids and also especially against hot water ers is to be emphasized. POM parts hardly swell in this environment and thus have a high degree of dimensional stability. This is the reason, why polyacetals are always used in automotive engineering where a Contact with solvents and fuels is expected.

However, POM has the disadvantage that it is relatively hard and is inflexible, so that it is for line systems, especially fle flexible pipes or hoses, can only be used to a limited extent (e.g. Tubes for Bowden cables and actuating elements).

For pipes e.g. B. in the automotive sector - both for gas -, as well as for liquid transport - are mainly polyamides used (PA 6, PA 66, PA 11, PA 12). These products have the The advantage that they are very tough and flexible due to the absorption of the medium but not dimensionally stable due to the swelling caused in this way are what z. B. can lead to leaks on fasteners. In addition, polyamides contain from the polycondensation process still small proportions of monomers or oligomers, which over long longer periods of time can diffuse into the medium, which is what Engstel oils or nozzles lead to deposits and thus to blockages can.

The present invention had the object of polyoxy to provide methylene molding compounds, which are in the Use for the production of blow moldings, pipe and / or Profile extrudates continuously and regardless of the type of Process raw materials and have a low tendency to creep and have good stability. At the same time, such Moldings have sufficient flexibility for pipe systems especially when processing into so-called Wellroh ren, with which even closer when connecting the line systems Radii can be realized. Corrugated pipes are understood to mean generally flexible tubes, which have an undulating longitudinal have cut.

According to the invention, this object is achieved through the use of poly Oxymethylene molding compositions according to claim 1 dissolved. Preferred execution Forms of information can be found in the subclaims.

Contain as component A) the form used according to the invention masses 10 to 98, preferably 30 to 98 wt .-% and in particular 40 to 98% by weight of a polyoxymethylene homo- or copolymer.

Such polymers are known per se to the person skilled in the art and are described in described in the literature.

Quite generally, these polymers have at least 50 mol% of recurring —CH ₂ O— units in the main polymer chain.

The homopolymers are generally made by polymerizing Formaldehyde or trioxane produced, preferably in the counter waiting for suitable catalysts.

In the context of the invention, polyoxymethylene copolymers are preferred as component A, in particular those which, in addition to the recurring units -CH ₂ O-, also contain up to 50, preferably 0.1 to 20, in particular 0.3 to 10 mol% and very particularly preferably 2 to 6 mol% of recurring units

where R ¹ to R ⁴ independently of one another are a hydrogen atom, a C _{1 to} C ₄ alkyl group or a halogen-substituted alkyl group with 1 to 4 carbon atoms and R ^{5 is} a -CH ₂ -, -CH ₂ O-, a C ₁ - to C ₄ -alkyl or C ₁ - to C ₄ -haloalkyl substituted methylene group or a corresponding oxymethylene group and n has a value in the range from 0 to 3. These groups can advantageously be introduced into the copolymers by ring opening of cyclic ethers. Preferred cyclic ethers are those of the formula

where R ¹ to R ⁵ and n have the meaning given above. Ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide, 1,3-butylene oxide, 1,3-dioxane, 1,3-dioxolane and 1,3-dioxepane may be mentioned as cyclic ethers, as well as linear oligo- or Polyformals such as polydioxolane or polydioxepane are called comonomers.

Also suitable as component A) are oxymethylene terpolymerizates which, for example, are obtained by reacting trioxane, one of the cyclic ethers described above, with a third monomer, preferably bifunctional compounds of the formula

and or

where Z is a chemical bond, -O-, -ORO- (R = C ₁ - to C ₈ -alkylene or C ₂ - to C ₈ -cycloalkylene).

Preferred monomers of this type are ethylene diglycid and diglycidyl ethers and diethers from glycidyls and formaldehyde, dioxane or Trioxane in a molar ratio of 2: 1 and diether from 2 mol glycidyl compound and 1 mol of an aliphatic diol with 2 to 8 carbon atoms men such as the diglycidyl ethers of ethylene glycol, 1,4-butanediol, 1,3-butanediol, cyclobutane-1,3-diol, 1,2-propanediol and cyclohexane-1,4-diol, to name just a few examples.

Process for the preparation of the above-described homo- and Copolymers are known to the person skilled in the art and are in the literature so that further details are not required here.

The preferred polyoxymethylene copolymers have melting points of at least 150 ° C. and molecular weights (weight _{average) M W} in the range from 5000 to 200,000, preferably from 7000 to 150,000. Particularly preferred polyoxymethylene homo- or copolymers have an MVR (190 ° C. / 2.16 kg) according to ISO 1133 / B from 1 to 45, preferably from 2 to 25 ml / 10 min.

End group-stabilized polyoxymethylene polymers which are attached to the Chain ends having C-C bonds are particularly preferred.

In principle, all are suitable as sterically hindered phenols B) Compounds with a phenolic structure attached to the phenolic ring have at least one sterically demanding group.

Preferably come z. B. Compounds of the formula

into consideration, in which mean:
R ¹ and R ^{2 are} an alkyl group, a substituted alkyl group or a substituted triazole group, where the radicals R ¹ and R ^{2 can be} identical or different and R ^{3 is} an alkyl group, a substituted alkyl group, an alkoxy group or a substituted amino group.

Antioxidants of the type mentioned are for example in the DE-A 27 02 661 (US-A 4,360,617).

Another group of preferred sterically hindered phenols is lei ten from substituted benzenecarboxylic acids, in particular of substituted benzene propionic acids.

Particularly preferred compounds from this class are compounds of the formula

where R ⁴ , R ⁵ , R ⁷ and R ^8, independently of one another, represent C ₁ -C ₈ -alkyl groups, which in turn may be substituted (at least one of which is a sterically demanding group) and R ^{6 is} a divalent aliphatic radical having 1 to 10 C -Atoms means that can also have CO bonds in the main chain.

Preferred compounds corresponding to these forms are

(Irganox® 245 from Ciba Specialty Chemicals GmbH)

(Irganox® 259 from Ciba Specialty Chemicals GmbH)

The following are examples of sterically hindered phenols:
2,2'-methylene-bis (4-methyl-6-tert-butylphenol), 1,6-hexanediol bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate ], Pentaerythril tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], distearyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 2,6 , 7-Trioxa-1-phosphabicyclo- [2.2.2] oct-4-yl-methyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate, 3,5-di-tert-butyl-4- hydroxy phenyl-3,5-distearyl-thiotriazylamine, 2- (2'-hydroxy-3'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 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'-methylene bis- (2,6-di-tert-butylphenol), 3,5-di-tert-butyl-4-hydroxybenzyl-dimethylamine and N, N'-hexamethylene-bis-3,5-di-tert. -butyl-4-hydroxyhydro cinnamide.

Have proven to be particularly effective and therefore preferred 2,2'-methylenebis (4-methyl-6-tert.-butylphe) are used nyl), 1,6-hexanediol bis (3,5-di-tert-butyl-4-hydroxy phenyl] propionate (Irganox® 259), pentaerythrityl tetra kis- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and the Irganox® 245 described above from Ciba Spezialitä tenchemie GmbH, which is particularly suitable.

The antioxidants (B) used individually or as mixtures are in an amount of 0.005 to 2 wt .-%, preferably from 0.05 to 2% by weight, in particular 0.1 to 1 % By weight, based on the total weight of the molding compounds A) to H) contain.

In some cases, sterically hindered phenols have become involved no more than one sterically hindered group in ortho-stel ment to the phenolic hydroxyl group as particularly advantageous grasslands; especially when assessing color stability Storage in diffuse light for long periods of time.

The polyamides which can be used as components C) are per se knows. Semicrystalline or amorphous resins, such as those used e.g. B. in the Encyclopedia of Polymer Science and Engineering, Vol. 11, p. 315 to 489, John Wiley & Sons, Inc., 1988, can nen are used, the melting point of the polyamide is preferably below 225 ° C, preferably below 215 ° C.

Examples are polyhexamethylene azelaic acid amide, poly hexamethylene sebacic acid amide, polyhexamethylene dodecanedioic acid amide, Poly-11-aminoundecanoic acid amide and bis- (p-aminocyclohexyl) methane dodecanoic acid diamide or the ring opening of lactams, e.g. B. or polylaurolactam obtained products. Also polyamides on the Based on terephthalic or isophthalic acid as the acid component and / or trimethylhexamethylenediamine or bis- (p-aminocyclohe xyl) propane as a diamine component and polyamide base resins, the by copolymerizing two or more of the aforementioned Po polymers or their components have been produced suitable.

Copolyamides are particularly suitable polyamides on the Based on caprolactam, hexamethylenediamine, p, p'-diaminodi called cyclohexylmethane and adipic acid. An example of this is under the name Ultramid® 1 C from BASF Public company distributed product.

Other suitable polyamides are available from Du Pont under the name Elvamide®.

The production of these polyamides is also mentioned in the above th font described. The ratio of terminal amino groups to terminal acid groups can be changed by varying the Molar ratio of the starting compounds can be controlled.

The proportion of the polyamide in the molding composition according to the invention is from 0.001 to 2% by weight, preferably from 0.005 to 1.99% by weight, preferably 0.01 to 0.08% by weight.

By using a polycondensation product 2,2-di- (4-hydroxyphenyl) propane (bisphenol A) and epichlorohydrin can in some cases reduce the dispersibility of the used Polyamides are improved.

Such condensation products from epichlorohydrin and bis phenol A are commercially available. Process for their manufacture treatment are also known to the person skilled in the art. Trade names of the polycondensates are Phenoxy® (from Union Carbide Corporation) or Epikote® (from Shell). The molecular weight of the poly condensate can vary within wide limits; in principle they are commercially available types are all suitable.

The polyoxymethylene molding compositions which can be used according to the invention contain, as component D), 0.002 to 2.0% by weight, preferably 0.005 to 0.5% by weight and in particular 0.01 to 0.3% by weight, based on the total weight the molding compositions of one or more of the alkaline earth silicates and / or alkaline earth glycerophosphates. As alkaline earth metals for the formation of the silicates and glycerophosphates, calcium and especially magnesium have proven to be excellent. Calcium glycerophosphate and preferably magnesium glycerophosphate and / or calcium silicate and preferably magnesium silicate are expediently used, the alkaline earth metal silicates particularly preferred being those represented by the formula

Me. xSiO ₂ . nH ₂ O

be described in the mean
Me an alkaline earth metal, preferably calcium or especially magnesium,
x is a number from 1.4 to 10, preferably 1.4 to 6 and
n is a number equal to or greater than 0, preferably 0 to 8.

The compound D) are advantageously finely ground Form used. Products with an average particle size smaller than 100 µm, preferably smaller than 50 µm are particularly suitable.

Calcium and magnesium silicates and / or calcium and magnesium glycerine phosphates can, for example can be specified in more detail by the following characteristics:

Calcium or magnesium silicate

Content of CaO or MgO: 4 to 32% by weight, preferably 8 to 30% by weight and in particular 12 to 25% by weight,
SiO _{2 ratio}

: CaO or SiO ₂

: MgO (mol / mol): 1.4 to 10, preferably 1.4 to 6 and in particular 1.5 to 4,
Bulk density: 10 to 80 g / 100 ml, preferably 10 to 40 g / 100 ml and average parameter: less than 100 μm, preferably less than 50 μm and

Calcium and magnesium glycerophosphates

Content of CaO or MgO: greater than 70% by weight, preferably greater than 80% by weight
Residue on ignition: 45 to 65% by weight
Melting point: greater than 300 ° C and
average grain size: smaller than 100 µm, preferably smaller than 50 µm.

The form which can be used according to the invention can be used as component E) masses from 0 to 5, preferably from 0.01 to 5, preferably from 0.09 to 2 and in particular 0.1 to 0.7 of at least one ester or amide ge saturated or unsaturated aliphatic carboxylic acids with 10 up to 40 carbon atoms, preferably 16 to 22 carbon atoms with polyols or aliphatic saturated alcohols or amines with 2 to 40 C- Atoms preferably 2 to 6 carbon atoms or an ether, which is different from Alcohols and ethylene oxide derived contain.

The carboxylic acids can be monovalent or divalent. As examples be pelargonic acid, palmitic acid, lauric acid, margaric acid, Dodecanedioic acid, behenic acid and particularly preferably stearic acid, Capric acid and montanic acid (mixture of fatty acids with 30 to 40 carbon atoms).

The aliphatic alcohols can be monohydric to tetrahydric. Examples for alcohols are n-butanol, n-octanol, stearyl alcohol, ethylene glycol, propylene glycol, neopentyl glycol, pentaerythritol, where Glycerin and pentaerythritol are preferred.

The aliphatic amines can be 1- to 3-valent. Examples these are stearylamine, ethylenediamine, propylenediamine, hexa methylenediamine, di (6-aminohexyl) amine, with ethylenediamine and Hexamethylenediamine are particularly preferred. Preferred esters or amides are correspondingly glycerol distearate, glycerol tristea rat, ethylenediamine distearate, glycerine monopalmitate, glycerine tri laurate, glycerol monobehenate and pentaerythritol tetrastearate.

Mixtures of different esters or amides or Esters with amides can be used in combination, with the Mi ratio is arbitrary.

Polyether polyols or polyester polyols are also suitable, those with mono- or polybasic carboxylic acids, preferably Fatty acids are esterified or etherified. Suitable products are commercially for example as Loxiol® EP 728 from Henkel KGaA available.

Preferred ethers, which are derived from alcohols and ethylene oxide, have the general formula

RO (CH ₂ CH ₂ O) _n H

in which R is an alkyl group having 6 to 40 carbon atoms and n is an integer greater than or equal to 1.

_{A saturated C 16} to C ₁₈ fatty alcohol with n ≈ 50, which is commercially available as Lutensol® AT 50 from BASF, is particularly preferred for R.

As component F) contain those which can be used according to the invention Molding compositions from 0.001 to 5% by weight, preferably from 0.01 to 3% by weight and in particular 0.05 to 1% by weight of a melamine-formaldehyde condensate sates. This is preferably a fine precipitation condensate part form, which is cross-linked and insoluble in water. The mole ratio of formaldehyde to melamine is preferably 1.2: 1 to 10: 1, in particular 1.2: 1 to 2: 1. Structure and method for Hers Position of such condensates can be found in DE-A 25 40 207 men.

As further additives (G), in amounts of up to 50, are preferred wise 0 to 40 wt .-%, in particular 1 to 45 wt .-%, impact resistant modifying polymers (hereinafter also referred to as rubber called elastic polymers or elastomers).

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

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

As diene monomers for EPDM rubbers, for example, conju 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, cy clic dienes such as cyclopentadiene, cyclohexadienes, cyclooctadienes and dicyclopentadiene and alkenyl norbornenes such as 5-ethylidene-2-norbornene, 5-butylidene-2-norbornene, 2-meth allyl-5-norbornene, 2-isopropenyl-5-norbornene and tricyclodienes such as 3-methyl-tricyclo (5.2.1.0.2.6) -3,8-decadiene or their Called mixtures. Hexa-1,5-diene-5-ethylidene is preferred norbornene and dicyclo-pentadiene. The diene content of the EPDM chew Tschuke is preferably 0.5 to 50, in particular 1 to 8 % By weight, based on the total weight of the rubber.

The EPDM rubbers can also be grafted with other monomers be e.g. B. with glycidyl (meth) acrylates, (meth) acrylic acid esters and (meth) acrylamides.

Another group of preferred rubbers are copolymers of ethylene with esters of (meth) acrylic acid. In addition, the rubbers can also contain monomers containing epoxy groups. These epoxy group-containing monomers are preferably incorporated into the rubber by adding epoxy group-containing monomers of the general formula I or II to the monomer mixture

where R ⁶ -R ^{10 represent} hydrogen or alkyl groups with 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 ⁶ to R ^{8 are} preferably hydrogen, m being 0 or 1 and g being 1. The corresponding compounds are allyl glycidyl ether and vinyl glycidyl ether.

Preferred compounds of the formula II contain epoxy groups tending esters of acrylic acid and / or methacrylic acid, such as glycidyl acrylate and glycidyl methacrylate.

The copolymers advantageously consist of 50 to 98% by weight Ethylene, 0 to 20 wt .-% epoxy group-containing monomers so like the remaining amount of (meth) acrylic acid esters.

Copolymers made from are particularly preferred
50 to 98, in particular 55 to 95% by weight of ethylene, in particular 0.3 to 20% by weight of glycidyl acrylate and / or
0 to 40, in particular 0.1 to 20% by weight of glycidyl methacrylate, and
1 to 50, 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 produced, preferably by random copolymerization under high pressure and elevated Temperature. Corresponding processes are generally known.

Preferred elastomers are also emulsion polymers, their Manufacture e.g. B. Blackley in the monograph "Emulsion Polymerization ". The emulsifiers that can be used and catalysts are known per se.

In principle, homogeneously structured elastomers or sol surface can be used with a shell structure. The shell-like The structure is determined by the order in which the individual monomers are added certainly; the morphology of the polymers is also influenced by this Order of addition influenced.

The monomers for the production are only representative here of the rubber part of the elastomers acrylates such. B. n-butyl acryl lat and 2-ethylhexyl acrylate, corresponding methacrylates, butadiene and isoprene and mixtures thereof. These monomers can NEN with other monomers such. B. styrene, acrylonitrile, vinyl ethers and other acrylates or methacrylates such as methyl meth acrylate, methyl acrylate, ethyl acrylate and propyl acrylate copoly be merized.

The soft or rubber phase (with a glass transition temperature below 0 ° C) the elastomers can be the core, the outer shell or a middle shell (for elastomers with more than two shell structure); in the case of multi-shell elastomers, Several shells can also consist of one rubber phase.

In addition to the rubber phase, there are also one or more hard ones components (with glass transition temperatures of more than 20 ° C) am Structure of the elastomer involved, so these are generally through polymerization of styrene, acrylonitrile, methacrylonitrile, α-methylstyrene, p-methylstyrene, acrylic acid esters and methacrylic acid esters such as methyl acrylate, ethyl acrylate and methyl methacrylate produced as the main monomers. In addition, you can also curdle here more proportions of other comonomers are used.

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

can be introduced,
where the substituents can have the following meanings:
R ^{15 is} hydrogen or a C ₁ - to C ₄ -alkyl group,
R ^{16 is} hydrogen, a C ₁ - to C ₈ -alkyl group or an aryl group, in particular phenyl,
R ^{17 is} hydrogen, a C ₁ - to C ₁₀ -alkyl, a C ₆ - to C ₁₂ -aryl group or -OR ₁₈
R ^{18 is} a C ₁ - to C ₈ -alkyl or C ₆ - to C ₁₂ -aryl group, which may optionally be substituted with O- or N-containing groups,
X is a chemical bond, a C ₁ - to C ₁₀ -alkylene or C ₆ -C ₁₂ -arylene group or

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

Further examples are 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 acrylate.

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

Furthermore, so-called graft-crosslinking monomers (graft linking monomers) can be used, d. H. Monomers with two or more polymerizable double bonds that occur in the polymer react at different speeds. Preferably, those compounds are used in which min at least one reactive group with about the same speed polymerizes like the other monomers, while the other reacts tive group (or reactive groups) e.g. B. significantly slower polymerized (polymerize). The different Polymerisa tion speeds add a certain amount unsaturated double bonds in rubber. Will then a further phase on such a rubber grafted, the double bin present in the rubber react applications at least partially with the graft monomers with training formation of chemical bonds, d. H. is the grafted phase at least partially through chemical bonds with the graft base location linked.

Examples of such graft-linking monomers are allyl groups containing monomers, especially allyl esters of ethylenic unsaturated carboxylic acids such as allyl acrylate, allyl methacrylate, Diallyl maleate, diallyl fumarate, diallyl itaconate or the corresponding corresponding monoallyl compounds of these dicarboxylic acids. Besides there there are a large number of other suitable graft-linking monomers ren; for more details, see, for example, the See U.S. Patent 4,148,846.

In general, the proportion of these crosslinking monomers is of component G) up to 5 wt .-%, preferably not more than 3% by weight, based on G).

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

Particularly preferred graft polymers are for Use according to the invention those with a polybutadiene core and a shell made of (methyl) methacrylate / styrene in the ratio 90:10 to 50:50.

Instead of graft polymers with a multi-shell structure can also be homogeneous, i.e. H. single-shell elastomers 1,3-butadiene, isoprene and n-butyl acrylate or their copolymers can be used. These products can also be used by using of crosslinking monomers or monomers with reactive groups getting produced.

The elastomers G) described can also be used according to other customary Procedure, e.g. B. by suspension polymerization, who produced the.

Other suitable elastomers are thermoplastic polyurethane known as supplementethane (TPU), for example in the EP-A 115 846 and EP-A 115 847 and EP-A 117 664 are described are.

Suitable TPU can be produced, for example, by reacting

• a) organic, preferably aromatic, diisocyanates,
• b) Polyhydroxyl compounds with molecular weights from 500 to 8000 and
• c) chain extenders with molecular weights from 60 to 400 in the presence of optionally
• d) catalysts,
• e) auxiliaries and / or additives.

We would like to explain the following to the starting materials (a) to (c), catalysts (d), auxiliaries and additives (e) that can be used for this purpose:

• a) Examples of organic diisocyanates (a) are aliphatic, cycloaliphatic and preferably aromatic Diisocyanates into consideration. In detail are exemplary ge called: aliphatic diisocyanates, such as hexamethylene diisocya nat, cycloaliphatic diisocyanates, such as isophorone diisocya nat, 1,4-cyclohexane diisocyanate, 1-methyl-2,4- and -2,6-cy clohexane diisocyanate and the corresponding isomers mixtures, 4,4'-, 2,4'- and 2,2'-dicyclohexylmethane-diisocya nat and the corresponding isomer mixtures and preferred wise aromatic diisocyanates, such as 2,4-toluene diisocyanate, Mixtures of 2,4- and 2,6-toluene-diisocyanate, 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate. Mixtures of 2,4'- and 4,4'-diphenylmethane diisocyanate, urethane modified liquid 4,4'- and / or 2,4'-diphenylmethane diisocyanate, 4,4'-diiso cyanato-diphenylethane (1,2) and 1,5-naphthylene diisocyanate. Preference is given to using hexamethylene diisocyanate, Iso phosphorone diisocyanate, 1,5-naphthylene diisocyanate, diphenylme Thane diisocyanate isomer mixtures with a 4,4'-diphenylme Thane diisocyanate content greater than 96% by weight and ins special 4,4'-diphenylmethane diisocyanate.
• b) As higher molecular weight polyhydroxyl compounds (b) with molecular weights of 500 to 8000 are preferably poly etherols and polyesterols. However, hydroxyl-containing polymers, for example polyacetals such as polyoxymethylenes and especially water-insoluble formals, e.g. B. polybutanediol formal and polyhexanediol formal, and poly carbonates, especially those made from diphenyl carbonate and 1,6-hexanediol, prepared by transesterification, with the molecular weights mentioned above. The polyhydroxyl compounds must be at least predominantly linear, ie have a difunctional structure in the sense of the isocyanate reaction. The polyhydroxyl compounds mentioned can be used as individual components or in the form of mixtures.
  Suitable polyetherols can be prepared by reacting one or more alkylene oxides having 2 to 4 carbon atoms in the alkylene radical with a starter molecule which contains two active hydrogen atoms bonded. As alkylene oxides are, for. B. called: ethylene oxide, 1,2-propylene oxide, 1,2- and 2,3-butylene oxide. Ethylene oxide and mixtures of 1,2-propylene oxide and ethylene oxide are preferably used. The alkylene oxides can be used individually, alternately one after the other or as a mixture. Examples of starter molecules that can be used are: water, amino alcohols, such as N-alkyl-diethanolamines, for example N-methyl-diethanolamine, and diols, such as ethylene glycol, 1,3-propylene glycol, 1,4-butane diol and 1,6-hexanediol. If appropriate, mixtures of starter molecules can also be used. Suitable polyetherols are also the hydroxyl-containing polymerization products of tetrahydrofuran (polyoxytetra methylene glycols).
  Preference is given to using polyetherols made from propylene oxide-1,2 and ethylene oxide in which more than 50%, preferably 60 to 80% of the OH groups are primary hydroxyl groups and in which at least part of the ethylene oxide is arranged as a terminal block; z. B. in particular polyoxy tetramethylene glycols.
  Such polyetherols can be obtained by e.g. B. on the starter molecule first the 1,2-propylene oxide and then the ethylene oxide is polymerized or initially all of the 1,2-propylene oxide is copolymerized in a mixture with a part of the ethylene oxide and the remainder of the ethylene oxide is then polymerized or, step by step, a portion of the ethylene oxide, then all of the 1,2-propylene oxide and then the remainder of the ethylene oxide, polymerized onto the starter molecule.
  The essentially linear polyetherols have molecular weights of 500 to 8000, preferably 600 to 6000 and in particular 800 to 3500. They can be used either individually or in the form of mixtures with one another.
  Suitable polyesterols can be prepared, for example, from dicarboxylic acids having 2 to 12 carbon atoms, preferably 4 to 8 carbon atoms, and polyhydric alcohols. Examples of suitable dicarboxylic acids are: aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid and sebacic acid and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can be used individually or as mixtures, e.g. B. be used in the form of a succinic, glutaric and adipic acid mixture. Mixtures of aromatic and aliphatic dicarboxylic acids can also be used. To prepare the polyesterols, it may be advantageous to use the corresponding dicarboxylic acid derivatives, such as dicarboxylic acid esters with 1 to 4 carbon atoms in the alcohol radical, dicarboxylic acid anhydrides or dicarboxylic acid chlorides instead of the dicarboxylic acids. Examples of polyhydric alcohols are glycols with 2 to 10, preferably 2 to 6 carbon atoms, such as ethylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10,2-decanediol, 2-dimethylpropanediol-1,3, propanediol-1,3 and dipropylene glycol. Depending on the properties desired, the polyhydric alcohols can be used alone or, if appropriate, in mixtures with one another.
  Also suitable are esters of carbonic acid with the diols mentioned, in particular those with 4 to 6 carbon atoms, such as 1,4-butanediol and / or 1,6-hexanediol, condensation products of ω-hydroxycarboxylic acids, for example ω-hydroxycaproic acid and preferably polymerization products of Lactones, for example optionally substituted ω-caprolactones.
  The polyesterols used are preferably dialkylene glycol polyadipates having 2 to 6 carbon atoms in the alkylene radical, such as. B. ethanediol polyadipate, 1,4-butanediol polyadipate, ethanediol-butanediol-1,4-polyadipate, 1,6-hexanediol-neopentyl glycol polyadipate, polycaprolactones and in particular 1,6-hexanediol-1,4-butanediol polyadipates.
  The polyesterols have molecular weights from 500 to 6000, preferably from 800 to 3500.
• c) As chain extenders (c) with molecular weights of 60 to 400, preferably 60 to 300, preferably aliphatic diols with 2 to 12 carbon atoms, preferably with 2.4 or 6 carbon atoms, such as. B. ethanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol and in particular 1,4-butanediol are suitable. However, diesters of terephthalic acid with glycols having 2 to 4 carbon atoms, such as. B. terephthalic acid-bis-ethylene glycol or -butanediol-1,4, hydroxyalkylene ethers of hydroquinone, such as. B. 1,4-di (β-hydroxyethyl) hydroquinone, (cyclo) aliphatic diamines, such as. B. 4,4'-diamino-dicyclohexylmethane, 3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane, isophorone-diamine, ethylenediamine, 1,2-, 1,3-propylenediamine, N-methyl-propylenediamine -1,3, N, N'-dimethyl-ethylenediamine and aromatic diamines, such as. B. 2,4- and 2,6-toluene-diamine, 3,5-diethyl-2,4- and -2,6-toluene-diamine and primary ort ho-di-, tri- and / or tetraalkyl-substituted 4, 4'-diamino diphenylmethane.
  To adjust the hardness and melting point of the TPU, the structural components (b) and (c) can be varied in relatively broad molar ratios. Molar ratios of polyhydroxyl compounds (b) to chain extenders (c) of 1: 1 to 1:12, in particular 1: 1.8 to 1: 6.4, have proven useful, the hardness and melting point of the TPU increasing with increasing Diol content increases.
  To prepare the TPU, the structural components (a), (b) and (c) are reacted in the presence of, if appropriate, catalysts (d), auxiliaries and / or additives (e) in such amounts that the equivalence ratio of NCO groups is Diisocyanates (a) to the sum of the hydroxyl groups or hydroxyl and amino groups of components (b) and (c) 1: 0.85 to 1.20, preferably 1: 0.95 to 1: 1.05 and in particular 1: 0 .98 to 1.02.
• d) Suitable catalysts, which in particular the reaction between the NCO groups of the diisocyanates (a) and the Hydroxyl groups of the structural components (b) and (c) accelerate gen, are those known in the prior art and usual tertiary amines, such as. B. triethylamine, dimethyl cyclohexylamine, N-methylmorpholine, N, N'-dimethylpiperazine, 2- (dimethylaminoethoxy) ethanol, diazabicyclo (2,2,2) octane and similar and especially organic metal compounds such as titanic acid esters, iron compounds such. B. Iron (III) acetyl acetonate, tin compounds, e.g. B. tin diacetate, tin dioctoate, tin dilaurate or the tin dialkyl salts aliphati shear carboxylic acids such as dibutyltin diacetate, dibutyltin dilaurate or similar. The catalysts are becoming more common wise in amounts from 0.001 to 0.1 part per 100 parts poly hydroxyl compound (b) used.

In addition to catalysts, the structural components (a) to (c) can also Aids and / or additives (e) are incorporated. Called are, for example, lubricants, inhibitors, stabilizers gene hydrolysis, light, heat or discoloration, dyes, pig ments, inorganic and / or organic fillers and plasticizers cher.

More detailed information about the above mentioned auxiliary means and additions substances are the technical literature, for example the monograph of J. H. Saunders and K. C. Frisch "High Polymers", Volume XVI, Polyure thane, part 1 and 2, Interscience Publishers 1962 resp. 1964 or DE-OS 29 01 774 can be found.

The form which can be used according to the invention can be used as component H) masses 0 to 1 wt .-%, preferably 0.001 to 0.8 wt .-% and ins particularly 0.01 to 0.3% by weight of a nucleating agent which different from B) to F).

All known compounds can be used as nucleating agents Question, for example melamine cyanurate, boron compounds such as boron nitride, silica, pigments such as B. Heliogenblau® (copper ph talocyanine pigment; registered trademark of BASF Aktiengesellschaft) or branched polyoxymethylenes, which in these small amounts show a nucleating effect.

In particular, talc is used as the nucleating agent, which is a hydrated magnesium silicate of the composition Mg ₃ [(OH) ₂ / Si ₄ O ₁₀ ] or MgO. 4 SiO ₂ . H ₂ O is. These so-called three-layer phyllosilicates have a triclinic, monoclinic or rhombic crystal structure with a lamellar appearance. Mn, Ti, Cr, Ni, Na, and K can be present in other trace elements, and the OH group can be partially replaced by fluoride.

It is particularly preferred to use talc whose particle size is 100% <20 μm. The particle size distribution is usually determined by sedimentation analysis and is preferably:

<20 µm 100% by weight <10 µm 99% by weight <5 µm 85% by weight <3 µm 60% by weight <2 µm 43% by weight

Such products are commercially available as Micro-Talc I. T. extra (Fa. Norwegian Talc Minerals).

As fillers (which are different from B) to G) in quantities up to 50% by weight, preferably 5 to 40% by weight, are examples wise potassium titanate whiskers, carbon and preferably glass called fibers, the glass fibers z. B. in the form of glass woven, mats, fleeces and / or glass silk rovings or ge cut glass fiber made of low-alkali E-glass with an average knife from 5 to 200 µm, preferably 8 to 50 µm who is used den can, the fibrous fillers according to their Einar processing preferably an average length of 0.05 to 1 µm, ins particularly 0.1 to 0.5 µm.

Other suitable fillers are, for example, calcium carbonate or glass spheres, preferably in ground form or mixtures these fillers.

The molding compositions used in accordance with the invention can also contain further ones Contains common additives and processing aids. Just Examples are additives for scavenging formaldehyde (Formaldehyde scavenger), plasticizers, adhesion promoters and pigments called. The proportion of such additives is generally in the Be rich from 0.001 to 5% by weight.

The production of the thermoplastic mold according to the invention mass takes place by mixing the components in a known manner Way, which is why detailed information is not required here. Advantage The components are mixed in an extruder.

Process for the production of blow moldings or profile and / or pipe extrudates are generally known to the person skilled in the art, why no further information is required here.

The molding compositions which can be used according to the invention are preferred Gas and liquid lines, in particular in the form of corrugated pipes ren, easy to manufacture. The moldings show an excellent distinguished stability, low tendency to creep and a substantial improved flexibility.

The moldings are therefore suitable for the following applications:

• - fuel supply lines
• - Lubricant feed lines
• - Feed lines for oils, brake fluids
• - cooling water pipes
• - Washer fluid lines for windscreen washers and headlights cleaning systems
• - Lines for hydraulic fluids (e.g. power steering)
• - Lines for ventilation (e.g. crankcase ventilation)
• - Lines / pipes in air conditioning systems
• - compressed air lines
• - vacuum lines
• - Coupling pieces
• - connecting elements for pipes
• - valve body

Examples

The following components were used:

Component A)

• 1. A / 1 polyoxymethylene copolymer composed of 97.3% by weight of trioxane and 2.7 wt% butanediol formal. The product contained approximately 3% by weight of unconverted trioxane and 5% by weight of thermal in stable proportions. After removal of the thermally unstable components the copolymer had an MVR of 7.5 ml / 10 min (190 ° C, 2.16 kg, according to ISO 1133 / B)
• 2. A / 2 polyoxymethylene copolymer composed of 97.3% by weight of trioxane and 2.7 wt% butanediol formal. The product contained approximately 3% by weight of unconverted trioxane and 5% by weight of thermal in stable proportions. After removal of the thermally unstable components the copolymer had an MVR of 2.2 ml / 10 min (190 ° C, 2.16 kg. according to ISO 1133 / B)
• 3. A / 3 polyoxymethylene copolymer composed of 96.3% by weight of trioxane and 3.7 wt% butanediol formal. The product contained approximately 3% by weight of unconverted trioxane and 5% by weight of thermal in stable proportions. After removal of the thermally unstable components the copolymer had an MVR of 2.2 ml / 10 min (190 ° C, 2.16 kg. according to ISO 1133 / B)
• 4. A / 4 polyoxymethylene copolymer composed of 95% by weight of trioxane and 5 wt% butanediol formal. The product contained approximately 3% by weight of unconverted trioxane and 5% by weight of thermal in stable proportions. After removal of the thermally unstable components the copolymer had an MVR of 25 ml / 10 min (190 ° C, 2.16 kg, according to ISO 1133 / B)

Component B)

Irganox® 245 from Ciba Specialty Chemicals GmbH

Component C)

Polyamide oligomer with a molecular weight of about 3000, made from caprolactam, hexamethylenediamine, adipic acid and Propionic acid (as a molecular weight regulator) based on the Examples 5-4 of US-A 3,960,984 ("PA-dicapped").

Component D)

Synthetic Mg-silicate (Ambosol® company Societe Nobel, Puteaux) with the following properties:
MgO content: ≧ 14.8% by weight
SiO ₂ content: ≧ 59% by weight
SiO ₂ : MgO ratio: 2.7 mol / mol
Bulk density 20 to 30 g / 100 m
Loss on ignition <25% by weight

Component E)

Loxiol® VPG 1206 from Henkel KGaA (glycerol distearate)

Component F)

A melamine-formaldehyde condensate according to Example 1 of DE-A 25 40 207.

Component G)

• 1. G / 1 A thermoplastic polyurethane (TPU) made up of
  41.4 wt% adipic acid
  33.8 wt% 1,4-butanediol
  24.8% by weight 4,4'-diphenylmethane diisocyanate (Elastollan® B 85 A from Elastogran)
  Shore hardness A: 83
• 2. G / 2 A TPU built from
  26.4 wt% adipic acid
  22.4% by weight 1,4-butanediol / 1,6-hexanediol (1: 1)
  17.2% by weight 4,4'-diphenylmethane diisocyanate
  34 wt% bis-butoxyethyl phthalate
  Shore hardness A: 62
• 3. G / 3 graft rubber made up of
  75% by weight of a graft base
  99% by weight 1,3-butadiene and
  1 wt .-% dodecyl mercaptan (regulator) and
  25% by weight of a graft shell
  60 wt .-% methyl methacrylate and
  40 wt% styrene

To produce the molding compositions, component A was mixed with the in the amounts of components B to F indicated in the table in one Dry mixer mixed at a temperature of 23 ° C. The so obtained mixture was in a twin screw extruder with Degassing device (ZKS 25 from Werner & Pfleiderer) brought, homogenized at 230 ° C with component G, degassed and the homogenized mixture is pressed out as a strand through a nozzle and granulated.

The manufacture of the corrugated pipes (dimensions: wall thickness: 1 mm; small largest diameter (inside): 3.8 cm, largest diameter (outside): 7 mm) was carried out by pipe extrusion on an extruder at one Melt temperature of 170 to 200 ° C for POM or 260-290 ° C for Polyamide. A heated corrugated pipe tool was connected downstream T = 120-150 ° C for POM or 150-250 ° C for PA.

The following thermoplastics were used as comparison components puts.

• 1. A / 1 V poly ε-caprolactam (PA6) with a viscosity number (VN) of 320 ml / g, determined in accordance with ISO 307 as a 0.5% by weight solution in 96% by weight H ₂ SO ₄ at 25 ° C (Ultramid® B 5W from BASF AG),
• 2. A / 2 V PA 66 with a VZ of 270 ml / g,
• 3. A / 3 V PA 11,
• 4. A / 4 V PA 12.

The following measurements were carried out:

The notched impact strength (a _k ) was measured according to ISO 179/1 eA.

The water and fuel uptake of the specimens was as carried out as follows:

To measure water or fuel uptake, 10-20 Test specimens (e.g. ISO tensile bars, the exact weight of which in the dry state was previously determined) in the respective medium at the specified temperature. The specimens must be completely from Medium.

At regular intervals (e.g. every day) a test specimen was removed, the adhering liquid with absorbent paper (e.g. filter paper) and dry it again weighed. This process was repeated until the Weight no longer changed.

The difference between the weight and the initial weight (in percent) is for the corresponding products listed in the table.

The compositions of the molding materials and the results of Measurements are shown in the table.

Claims (9)

1. Use of thermoplastic polyoxymethylene molding compositions containing as essential components

• A) 10 to 98% by weight of a polyoxymethylene homo- or copolymer,
• B) 0.005 to 2% by weight of a sterically hindered phenol,
• C) 0.001 to 2% by weight of a polyamide,
• D) 0.002 to 2% by weight of an alkaline earth silicate or an alkaline earth glycerophosphate,
• E) 0 to 5 wt .-% of at least one ester or amide saturated or unsaturated aliphatic carboxylic acids with 10 to 40 carbon atoms with polyols or aliphatic saturated alcohols or amines with 2 to 40 carbon atoms or an ether, which is from Derived from alcohols and ethylene oxide,
• F) 0.01 to 5% by weight of a melamine-formaldehyde condensate,
• G) 0 to 50% by weight of an impact-modifying polymer,
• H) 0 to 30% by weight of further additives, the sum of the percentages by weight of components A) to H) each being 100%,

for the production of moldings by blow molding, profile extrusion and / or pipe extrusion. 2. Use according to claim 1, wherein component A) is an MVR (190 ° C / 2.16 kg) according to ISO 1133 / B from 1 to 45 ml / 10 min shows. 3. Use according to claims 1 or 2, wherein the polyoxy methylene molding compounds contain 1 to 45% by weight of component G) th. 4. Use according to claims 1 to 3, wherein as Kompo nente B) a sterically hindered phenol with no more than a sterically hindered group in the ortho position to the phenolic hydroxyl group is used. 5. Use according to claims 1 to 4, wherein the compo nent F) from a finely divided, cross-linked, water-un soluble precipitation condensate from formaldehyde and melamine im Molar ratio 1.2: 1 to 10: 1 is built up. 6. Use according to claims 1 to 5, wherein the component E) of ethylenediamine distearate, glycerol distearate, poly ether polyol fatty acid esters, polyester polyol fatty acid esters or an ether of the general formula
RO (CH ₂ CH ₂ O) _n H
in which R is an alkyl group with 6 to 40 carbon atoms and n is a number greater than / equal to 1. 7. Blow moldings, profile extrudates, pipe extrudates available from the molding compositions which can be used according to claims 1 to 6. 8. Gas lines, liquid lines, couplings, conn application elements, valve bodies available from the according to An Proverbs 1 to 6 usable molding compounds. 9. Gas lines, liquid lines, couplings, conn connection elements, valve body according to claim 8, characterized records that this molded body has the shape of corrugated pipes point.