DE19853306A1 - Polyoxymethylene composition useful for molded articles and film contains additive prepared from crosslinking agent, (meth)acrylate, (meth)acrylamide or dialkylaminoalkyl(meth)acrylate - Google Patents

Abstract

A polyoxymethylene molding composition contains an additive prepared by radical polymerization of a crosslinking agent, an acrylate and/or methacrylate, an acrylamide, methacrylamide, dialkylaminoalkylacrylate and/or dialkylaminoalkylmethacrylate. A polyoxymethylene molding composition (I) comprises (II) a polyoxymethylene homo- and/or copolymer, (III) a conventional additive and (IV) 0.01-2 pts.wt. of a polymeric material (wrt II+III) as an additive to simultaneously act as a nucleation agent and to improve thermal stability. (IV) is prepared by polymerization of a mixture of (A1) 0.1-100 pts. of a crosslinking agent having at least 2 polymerizable carbon-carbon double bonds, (A2) 0-99.9 pts.wt. of an acrylate and/or methacrylate, (B) 0-99.9 pts.wt. of an acrylamide, methacrylamide, dialkylaminoalkylacrylate and/or dialkylaminoalkylmethacrylate. (C) 10 pts.wt. of a mol. wt. regulator (w.r.t.. 100 pts.wt (A1)+(A2)+(B)) and (D) upto 5 pts.wt. of a radical polymerization initiator (w.r.t. 100 pts.wt. (A1)+(A2)+(B)). Independent claims are included for (i) a process to produce a molded article or a film by melting and mixing the components of (I) optionally with reinforcing filler in an extruder at 150-260 deg C with processing to form a molded article or film; (ii) the resulting molded article, semi-finished product or film.

Description

The invention relates to nucleated polyoxymethylene Molding compounds that are reinforced or unreinforced can, with improved discoloration stability, as well Shaped body from this by using certain non-yellowing additives that are nucleating at the same time and have a stabilizing effect in polyoxymethylene.

In particular, the invention relates to reinforced or unreinforced polyoxymethylene molding compositions

• a) at least one polyoxymethylene homo- and / or Copolymer,
• b) at least one common additive and
• c) at least one polymeric plastic material.

Polyoxymethylene (POM, polyacetal) is an excellent Material from which, in particular by injection molding have a wide variety of everyday objects manufactured. Chemical resistance is particularly advantageous compared to many organic solvents and bases. Since the market launch of polyacetals have been diverse Attempts have been made to improve the properties of polyoxymethylene to improve specifically so that its technical The range of applications could be broadened further.

Polyoxymethylene homo- and / or are particularly suitable Copolymers for the production of reinforced or unreinforced molding compounds. In order to process them, mechanical properties and thermal stability too improve, the polyoxymethylene homo- and / or Copolymers with conventional additives and at least  an additive to improve thermal stability and mixed at least one additive for nucleation.

It is known that polyacetals (Polyoxymethylene, POM) as semi-crystalline materials have a pronounced inclination possess for crystallization. The degree of crystallization depends among other things on the comonomer content and amounts to between 50 to 80% (Ullmanns Encyclopedia of Industrial Chemistry, Vol. A21, 1992, VCH Publishers, Inc.). Already with slight hypothermia of a polyoxymethylene melt rapid growth of spherulites is observed are usually larger than the light wavelength and the material give a strong opacity. Also arise as Consequence of the crystallization process inside and on the Surface of the material numerous microscopic Cracks and internal tension. Through these cracks and inner ones The mechanical properties of stresses Shaped bodies, e.g. B. injection molded parts made of polyoxymethylene adversely affected. The defects described are The larger the individual, the more pronounced Are spherulites.

The size and number of spherulites in polyoxymethylene and so their mechanical properties depend crucially on the type and number of crystallization nuclei. Nucleating agents act as crystallization agents or Crystallization accelerators and increase the number of Spherulites while reducing and Standardization of spherulite size. The resulting one Spherolite structure of nucleated polyoxymethylene much finer and more even than that of not nucleated polyoxymethylenes, which is evident in reflects improved mechanical properties (H. Domininghaus: The plastics and their properties, 3rd edition, VDI-Verlag, Düsseldorf, 1988, 307-336; H. Cherdron et al .: Makromol. Chem. Suppl. 1975, 1, 621-636). Spiked with nucleating agents Polyoxymethylenes also solidify significantly faster and  thus enable a shorter cycle time when Injection molding. To improve the mechanical Properties and cycle time of polyoxymethylenes it is therefore necessary to reduce the spherulite size and to unify. This is done by using Nucleating agents reached. As a nucleating agent for Polyoxymethylenes become inorganic and organic Materials suggested. This includes talc (DE 12 47 645), boron nitride (US 3 767 610), branched or cross-linked polyoxymethylene (DE 21 01 817), trioxane Block copolymers (DE 21 42 091) or special melamine Formaldehyde polycondensates (DE 25 40 207).

Of the nucleating agents listed above, the last-mentioned melamine-formaldehyde polycondensates due to their excellent nucleating effect By far greatest commercial importance than Nucleating agents are obtained in polyoxymethylene therefore in large quantities in commercial polyoxymethylenes used. Compared to all other known ones Nucleating agents for polyoxymethylene show that mentioned melamine-formaldehyde condensates also one considerable improvement in the thermal stability of Polyoxymethylene. This is another reason for the wide Spread of these melamine-formaldehyde condensates as nucleating and stabilizing additive in Polyoxymethylenes. The advantage of melamine formaldehyde Condensates versus inorganic nucleating agents or branched or cross-linked polyoxymethylenes thus in the combination of nucleating agent and Heat stabilizer in a single substance.

Nucleating agents, the nucleating and stabilizing Combining properties also makes it easier Production, handling and dosing of the for Polyoxymethylene to be added and stabilized and Nucleation mandatory additive mixture, the at least from an antioxidant, a nucleating agent  and a heat stabilizer; other additives, such as B. pigments, lubricants, formaldehyde scavengers or Light stabilizers can optionally be added to this mixture will. The fewer components of this Basic stabilizing composition, consisting of a Antioxidant, a nucleating agent and one Heat stabilizer contains, the lower the risk a partial or complete segregation of the individual components of this additive mixture in its Manufacturing, conveying and dosing as they are typically with solid mixtures due to Density differences, differences in the Grain size distribution and different bulk densities of the individual components contained therein occur. It comes from the dosage described in the above Components existing basic stabilization mixture for Polyoxymethylene melt to the separation described of the individual components, the Polyoxymethylene intended optimal concentration of the individual stabilizers and the nucleating agent in the Polyoxymethylene from the actual concentration in the Polyoxymethylene more or less strongly, with the result that the properties, especially the stability and the mechanical properties of polyoxymethylene, disadvantageous to be influenced.

It is therefore desirable to have the number of individual components in the additive mixture as low as possible to avoid the danger the separation of the individual components during handling to minimize the reaction mixture and thus always one constant and optimal concentration of Stabilizers and nucleating agents in polyoxymethylene too achieve. The melamine already described above Formaldehyde condensate helps reduce the number of Individual components because, as I said, at the same time the function of a heat stabilizer and Nucleating agent takes over.  

However, melamine-formaldehyde condensates have the disadvantage increase the yellowing of polyoxymethylenes, especially after heat storage. For most by far However, applications will be as yellowing-free as possible Polyoxymethylene required. Less yellowing or even non-yellowing additives like melamine-formaldehyde Nucleating and simultaneously stabilizing condensates Polyoxymethylenes have not yet been effective suggested. There are low-yellowing or non-yellowing nucleating agents, but they have no thermostabilizing effect. When using only nucleating additives in polyoxymethylene must therefore have at least one additional additive for Heat stabilization are added, with the disadvantage that when dosing to the above-mentioned segregation can come.

In view of the state indicated and set forth herein the technology was therefore the object of the invention, amplified or unreinforced polyoxymethylene molding compounds for the to provide technical production that meets the previous POM molding compounds used in practice are superior. In particular, the new POM molding compositions should have a have less tendency to discolour than previously known POM molding compounds. Finally, the aim is also that Nucleation and heat stabilization with one Additive to achieve, which is also easy and inexpensive should be producible.

These and other unspecified issues will be resolved Tasks through a polyoxymethylene molding compound of the beginning Specified genus with the characteristics of the characteristic Part of claim 1. Advantageous refinements are Subject of the subclaims referring back to claim 1. With regard to the procedural aspects, the in Claim 21 reproduced technical teaching the problems the invention. Appropriate uses are in the Claims 22 and 23 placed under protection.  

Claims 24 and 25 relate to moldings and semi-finished products or Films made from the molding compositions according to the invention, directed.

Characterized in that in polyoxymethylene molding compositions

• a) at least one polyoxymethylene homo- and / or Copolymer and
• b) at least one common additive

a copolymer is used as additive (iii) to simultaneously improve the tendency to nucleation and thermostability, which is obtained by polymerization in solution or substance of a mixture of

• a) 0.1-100 parts of one or more crosslinkers at least two polymerizable carbon Carbon double bonds
• b) 0-99.9 parts of one or more acrylates and / or methacrylates
• c) 0-99.9 parts of one or more acrylamides and / or methacrylamides and / or Dialkylaminoalkyl acrylates and / or Dialkylaminoalkyl methacrylates
• d) based on 100 parts A1) + A2) + B) 0 to 10 parts molecular weight regulator and
• e) based on 100 parts A1) + A2) + B) up to 5 parts radical polymerization initiators,

is available
and that

• a) in an amount of 0.01 to 2 parts based on the Sum of (i) + (ii)

is contained in the molding compound,
1 where all amounts relate to parts by weight (wt / wt) and A1), A2) and B) together have to give 100 parts, the problems on which the invention is based are solved in an unpredictable manner. In particular, it was found, completely surprisingly, that the polymeric additives (iii) according to the invention, in addition to a heat-stabilizing effect with less tendency to discolouration, also have a nucleating effect in polyoxymethylenes.

So the invention offers reinforced or unreinforced Molding compound based on polyoxymethylene compared to POM molding compositions known from the prior art, especially compared to those from DE-PS 25 40 207 known masses, u. a. the advantage of one clearly cause less yellowing in polyoxymethylenes.

Component (i)

An essential part of the invention Molding compound is component (i). This is it to polyoxymethylene homo- and / or copolymers, wherein in Within the scope of the invention, this includes both a homopolymer alone, several homopolymers in a mixture with one another, one copolymer alone, several copolymers in Mixture with one another and mixtures are understood the one or more homopolymers together with one or have several copolymers.

The main component (i) of the invention Molding compounds forming polyoxymethylenes can be homopolymers of formaldehyde or trioxane or copolymers of Trioxane. They can have a linear structure, however also be branched or networked. You can individually or can be used as a mixture.

Among homopolymers of formaldehyde or trioxane are understood to be those polymers whose semi-acetal hydroxyl groups chemically, for example by esterification or etherification, against degradation are stabilized. Among copolymers of trioxane  Copolymers of trioxane and at least one with trioxane understood copolymerizable compound.

The homopolymers have i. d. R. thermally stable End groups such as ester or ether groups. The copolymers of formaldehyde or trioxane advantageously more than 50%, in particular more than 75%, oxymethylene groups. Have proven particularly successful Copolymers in which at least 0.1% by weight of groups of the copolymer are contained, at least two have adjacent carbon atoms in the chain. Special Polyoxymethylenes which have 1 contain up to 10 wt .-% comonomers.

In the context of the invention, polyoxymethylene copolymers are preferred as component (i) which, in addition to the repeating units -CH ₂ O-, also up to 50, preferably 0.1 to 20 and in particular 0.3 to 10 mol% of repeating 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 having 1 to 4 C atoms and R ^{5 'is} a -CH ₂ -, -CH ₂ O- represent 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. Compounds of the formula in particular are suitable as comonomers

suitable in which R is a hydrogen atom, an alkyl radical 1 to 6, preferably 1, 2 or 3 carbon atoms, the with 1, 2 or 3 halogen atoms, preferably chlorine atoms, can be substituted, an alkoxymethyl radical with 2 to 6, preferably 2, 3 or 4 carbon atoms, one Phenyl radical or a phenoxymethyl radical, x denotes a integer from 1 to 3, where y is zero, y is one integer from 1 to 3, where x is zero and z is 2 and z is an integer from 3 to 6, preferably 3 or 4, where x is zero and y is 1.

Particularly suitable cyclic ethers are epoxides, e.g. B. Ethylene oxide, styrene oxide, propylene oxide or epichlorohydrin, and glycidyl ether of mono- or polyhydric alcohols or phenols.

Suitable cyclic acetals are, above all, cyclic formals of aliphatic or cycloaliphatic α, ω-diols having 2 to 8, preferably 2, 3 or 4, carbon atoms, the carbon chain of which can be interrupted by an oxygen atom at intervals of 2 carbon atoms, e.g. B .:
Glycol formal (1,3-dioxolane),
Propanediol formal (1,3-dioxane)
Butanediol formal (1,3-dioxepane) and diglycol formal (1,3,6-trioxocane) as well
4-chloromethyl-1,3-dioxoxolane,
Hexanediol formal (1,3-dioxonane) and
Butenediol formal (1,3-dioxacyclohepten-5).

Both linear or. Are suitable as linear polyacetals Copolymers of the cyclic acetals defined above as well as linear condensates from aliphatic or cycloaliphatic α, ω-diols with aliphatic aldehydes or thioaldehydes, preferably formaldehyde. In particular become homopolymers of cyclic formals of aliphatic α, ω-diols with 2 to 8, preferably 2, 3 or 4 Carbon atoms used, e.g. B. poly (1,3-dioxolane), Poly (1,3-dioxane) and poly (1,3-dioxepane).

The values for the viscosity number of the polyoxymethylenes used according to the invention (measured on a solution of the polymer in hexafluoroisopropanol, which is adjusted to pH 8 to 9 with methanolic sodium hydroxide solution, at 25 ° C. in a concentration of 0.3 g / 100 ml) should generally be at least 160 (ml / g). The crystallite melting points of the polyoxymethylenes are in the range from 140 to 180 ° C., preferably 150 to 170 ° C., their densities are 1.38 to 1.45 g × ml ^-1 , preferably 1.40 to 1.43 g × ml ^-1 (measured according to DIN 53 479). As a rule, the polyoxymethylenes used have a number-average molecular weight M _n of 2,000 to 200,000, preferably 10,000 to 100,000, and a volume flow index (melt volume rate, MVR) at 190 ° C. and a contact force of 2.16 kg according to DIN ISO 1133 of 0.5 to 200 cm ^3/10 min. preferably from 1 to 70 cm ^3/10 min.

The preferably binary or used according to the invention ternary trioxane copolymers are known in the art by polymerizing the monomers cationically in the presence effective catalysts at temperatures between 0 and 150 ° C, preferably between 70 and 140 ° C, produced (see e.g. DE-AS 14 20 283). A1 s catalysts here, for example, Lewis acids, such as boron trifluoride or Antimony pentafluoride, and complex compounds of such Lewis acids, preferably etherates, e.g. B. boron trifluoride diethyl etherate or boron trifluoride di-tert-butyl etherate, used. Protonic acids, e.g. B.  Perchloric acid, as well as salt-like compounds, e.g. B. Triphenylmethylhexafluorophosphate or Triethyloxonium tetrafluoroborate, acetyl perchlorate or Esters of perchloric acid, e.g. B. methoxymethyl perchlorate or tert-butyl perchlorate. For regulating the molecular weight All substances known to be used can be used is that they are considered in the polymerization of trioxane Chain carriers work. The polymerization can be carried out according to the known for trioxane homo- and copolymerization Bulk or continuous process, Suspension or solution take place. To remove more unstable The copolymers can be a thermal or hydrolytic controlled, partial degradation up to primary alcohol end groups (see e.g. DE-AS 14 45 273 and 14 45 294).

The homopolymers of the invention used Formaldehyde or trioxane are also in known manner by catalytically polymerizing the Monomers prepared (cf. e.g. DE-AS 10 37 705 and 11 37 215).

Polymers, which have become particularly important from trioxane and 1 to 10 wt .-% ethylene oxide, 1,3-dioxolane or butanediol formal. As an additional Comonomers for trioxane can preferably still compounds with several polymerizable groups in the molecule, e.g. B. Alkylglycidyl formal, polyglycol diglycidyl ether, Alkanediol diglycidyl ether, e.g. B. 1,4-butanediol diglycidyl ether or bis (alkanetriol) - triformale can be used. But are also suitable especially for the production of terpolymers of Trioxans, Diformals, e.g. B. Diglycerol diformal.

They are usually used in an amount of 0.05 to 5 wt .-%, preferably 0.1 to 2 wt .-%, based on the Total amount of monomer applied.  

In the molding composition according to the invention, component (i) in an amount of 40 to 99, 99, advantageously 70 to 99, 99 and in particular 95 to 99.9% by weight, based on the weight of components (i), (ii) and (iii). The invention is particularly advantageous Molding composition from components (i), (ii) and (iii).

Component (ii)

Another essential component of the invention reinforced or unreinforced polyoxymethylene molding compound is component (ii). This is a Additive, but several additives can also be used can be used simultaneously.

Depending on how the advantageous property profile of the molding compound according to the invention is to be varied further, one or more additives (ii) are used.

The additives (ii) can be very different Connection classes come from and the most varied cause technical effects. Coming as additives (ii) all those additives into consideration which usually for use in reinforced or unreinforced polyoxymethylene molding compounds are provided.

Examples of suitable additives (ii) are Costabilizers, reinforcing fillers such as inorganic fibers such as B. carbon fibers or glass fibers, organic polymer fibers such as B. aramid fibers (Nomex®, Kevlar) or polyacrylonitrile fibers, wollastonites as well Chalk, talc, carbon black and potassium titanates, nucleating agents, Antistatic, light and flame retardants, lubricants and Lubricants, plasticizers, antioxidants, pigments, Dyes, optical brighteners, internal release agents, Impact modifiers such as polyurethane rubbers or Graft rubbers based on polymerized (Meth) acrylic acid esters, copolymerized  (Meth) acrylonitrile and / or copolymerized butadiene as well as polymers such as polyalkylene terephthalates.

Enjoy special preference among additives (ii) thermoplastic polyurethane (TPU).

Suitable TPUs can be produced, for example, by reacting

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

The following applies to the starting materials (a) to (c), catalysts (d), auxiliaries and additives (e) which can be used for this:

• a) As organic diisocyanates (a) come for example aliphatic, cycloaliphatic and preferably aromatic diisocyanates into consideration. In detail Examples include: aliphatic diisocyanates, such as hexamethylene diisocyanate, cycloaliphatic Diisocyanates, such as isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 1-methyl-2,4- and -2,6-cyclohexane diisocyanate and the corresponding Mixtures of isomers, 4,4'-, 2,4'- and 2,2'-dicyclohexylmethane diisocyanate and the corresponding mixtures of isomers and preferably aromatic diisocyanates, such as 2,4-tolylene diisocyanate, Mixtures of 2,4- and 2,6-tolylene 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'-diisocyanato diphenylethane (1,2) and 1,5-naphthylene diisocyanate. Hexamethylene diisocyanate is preferably used, Isophorone diisocyanate, 1,5-naphthylene diisocyanate, Diphenylmethane diisocyanate isomer mixtures with one 4,4'Diphenylmethane diisocyanate content greater than 96% by weight and in particular 4,4'-diphenylmethane diisocyanate.
• b) Polyetherols and polyesterols are preferably suitable as higher molecular weight polyhydroxyl compounds (b) with molecular weights of 500 to 8000. However, hydroxyl-containing polymers are also suitable, for example polyacetals, such as polyoxymethylenes and, above all, water-insoluble formals, e.g. B. polybutanediol formal and polyhexanediol formal, and polycarbonates, especially those made of diphenyl carbonate and 1,6-hexanediol, produced by transesterification, with the above-mentioned molecular weights. The polyhydroxyl compounds have to be at least predominantly linear, ie they 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 such. 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 in succession or as a mixture. Examples of suitable starter molecules 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-butanediol and 1,6-hexanediol. Possibly. Mixtures of starter molecules can also be used. Suitable polyetherols are also the hydroxyl-containing polymerization products of tetrahydrofuran (polyoxytetramethylene glycols).
  Polyetherols of propylene oxide-1,2 and ethylene oxide are preferably used 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; e.g. B. in particular polyoxytetramethylene glycols.
  Such polyetherols can be obtained by e.g. B. first polymerized the propylene oxide-1,2 and then the ethylene oxide onto the starter molecule, or first copolymerized all of the propylene oxide-1,2 in a mixture with part of the ethylene oxide and then polymerized the rest of the ethylene oxide or gradually a part 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 both individually and in the form of mixtures with one another.
  Suitable polyesterols can be prepared, for example, from dicarboxylic acids having 2 to 30 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. 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 having 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 having 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-decanediol, 2,2- 1,3-dimethylpropanediol, 1,3-propanediol and dipropylene glycol. Depending on the desired properties, the polyhydric alcohols can be used alone or, if necessary, 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-hydroxycaproic acid and preferably polymerization products of lactones, for example optionally substituted ω -Caprolactones.
  Dialkylene glycol polyadipates with 2 to 6 carbon atoms in the ATkylenrest, such as. B. ethanediol polyadipate, 1,4-butanediol polyadipate, ethanediol butanediol-1,4-polyadipate, 1,6-hexanediol neopentylglycol polyadipate, polycaprolactones and in particular 1,6-hexanediol-1,4-butanediol polyadipate.
  The polyesterols have molecular weights from 500 to 6000, preferably from 800 to 3500. c) Suitable chain extenders (c) with molecular weights from 60 to 400, preferably 60 to 300, are preferably aliphatic diols having 2 to 30 carbon atoms, preferably 2, 4 or 6 Carbon atoms, such as B. ethanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol and in particular 1,4-butanediol. However, diesters of terephthalic acid with glycols having 2 to 4 carbon atoms, such as. B. terephthalic acid bis ethylene glycol or 1,4-butanediol, hydroxyalkylene ether 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-propylene-diamine, N-methyl propylene- diamine-1,3, N, N'-dimethyl-ethylenediamine and aromatic diamines such as e.g. B. 2,4- and 2,6-tolylene diamine, 3,5-diethyl-2,4- and -2,6-toluenediamine and primary ortho-di-, tri- and / or tetraalkyl-substituted 4, 4 ' -Diamino-diphenylmethane.
  To set the hardness and melting point of the TPU, the structural components (b) and (c) can be varied in relatively wide molar ratios. Molar ratios of polyhydroxyl compounds (b) to chain extenders (c) from 1: 1 to 1:12, in particular from 1: 1.8 to 1: 6.4, have proven useful, the hardness and melting point of the TPU increasing with the content Diols increases.
  To prepare the TPU, the components (a), (b) and (c) are reacted in the presence of any catalysts (d), auxiliaries and / or additives (e) in amounts such that the equivalence ratio of NCO groups the 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 is up to 1.02.
• c) 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, they are according to the prior art known and customary tertiary amines, such as. B. Triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N, N'-dimethylpiperazine, 2- (dimethyl aminoethoxy) ethanol, diazabicyclo (2,2,2) octane and similar and in particular organic Metal compounds such as titanium acid esters, Iron compounds such as B. iron (III) acetylacetonate, Tin compounds, e.g. B. tin diacetate, tin dioctoate, Tin dilaurate or tin dialkyl salts more aliphatic Carboxylic acids such as dibutyltin diacetate, Dibutyltin dilaurate or the like. The catalysts are usually used in amounts of 0.001 to 0.1 parts used per 100 parts of polyhydroxy compound (b).

In addition to catalysts, structural components (a) to (c) auxiliaries and / or additives (e) are also incorporated will. Lubricants may be mentioned, for example, Inhibitors, stabilizers against hydrolysis, light, heat or discoloration and plasticizers.

More information on the above-mentioned auxiliary and Additives are in the specialist literature, for example the Monograph by J. H. Saunders and K.C. Fresh "high Polymers ", Volume XVI, Polyurethane, Parts 1 and 2, Publisher Interscience Publishers 1962 or 1964 or the DE-OS 29 01 774 can be found.  

Preferred components (ii) in the invention Molding compounds are also made by elastomers Emulsion polymerization were prepared and z. B. at Blackley in the monograph "Emulsion Polymerization" are described. The emulsifiers and Catalysts are known per se. Basically you can homogeneous elastomers or those with a Shell structure are used, so-called core-shell Polymers. The shell-like structure is made possible by the Order of addition of the individual monomers determined; also the morphology of the polymers is determined by this The order of addition is affected.

Only representative here are as monomers for the Production of the rubber part of the elastomers such as acrylates e.g. B. n-butyl acrylate and 2-ethylhexyl acrylate, corresponding Methacrylates, butadiene and isoprene and mixtures thereof called. These monomers can be combined with other monomers such as e.g. B. styrene, acrylonitrile, vinyl ethers and others Acrylates or methacrylates such as methyl methacrylate, Methyl acrylate, ethyl acrylate and propyl acrylate be copolymerized.

The soft or rubber phase (with a glass temperature of below 0 ° C) the elastomer can form the core, the outer Shell or a medium shell (for elastomers with more as a double-shell structure); for multi-layer Elastomers can also have multiple shells from one Rubber phase exist.

Are one or more in addition to the rubber phase Hard components (with glass transition temperatures of more than 20 ° C) involved in the construction of the elastomer, so these generally by polymerizing styrene, Acrylonitrile, methacrylonitrile, α-methylstyrene, p-methylstyrene, acrylic acid esters and methacrylic acid esters such as methyl acrylate, ethyl acrylate and methyl methacrylate as Major monomers produced. Besides that, here too  lower proportions of other comonomers used will.

In some cases it has proven 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 by the use of monomers of the general formula

can be introduced, where the substituents can have the following meanings:
R ^{1 '' is} hydrogen or a C ₁ to C ₄ alkyl group
R ^{2 ″ is} hydrogen, a C ₁ - to C ₈ -alkyl group or an aryl group, in particular phenyl
R ^{3 "} hydrogen, a C ₁ to C ₁₀ alkyl, a C ₆ to C ₁₂ aryl group or -OR ^4"
R ^{4 ″ 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 to C ₁₂ arylene group or

Y OZ- or NH-Z and
Z is a C ₁ to C ₁₀ alkylene or C ₆ to C ₁₂ arylene group. The graft monomers described in EP-A 208 187 are also suitable for introducing reactive groups on the surface.

Acrylamide and methacrylamide are further examples 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 methacrylate and (N, N-Diethylamino) called ethyl acrylate.

Furthermore, the particles of the rubber phase can also to be connected. Monomers which act as crosslinkers for example buta-1,3-diene, divinylbenzene, diallyl phthalate and dihydrodicyclopentadienyl acrylate as well as those in the Compounds described in EP-A 50 265.

So-called graft-crosslinking monomers can also be used (graftlinking monomers) are used, d. H. Monomers with two or more polymerizable Double bonds in the polymerization with react at different speeds. Preferably such connections are used in which at least a reactive group at about the same speed as the remaining monomers polymerized while the other reactive group (or reactive groups) e.g. B. clearly polymerizes more slowly (polymerize). The bring different polymerization rates a certain proportion of unsaturated double bonds in the Rubber with itself. Will then on such Another phase grafted on rubber, so they react at least double bonds present in the rubber partially with the graft monomer to form chemical bonds, d. H. is the grafted phase at least in part through chemical bonds with the Graft base linked.

Examples of such graft-crosslinking monomers are Monomers containing allyl groups, in particular allyl esters of ethylenically unsaturated carboxylic acids such as Allyl acrylate, allyl methacrylate, diallyl maleate, Diallyl fumarate, diallylitavonate or the corresponding  Monoallyl compounds of these dicarboxylic acids. Besides there there are a variety of other graft-crosslinking monomers; For More details here, for example, on U.S. Patent 4,148,846. In general, the Proportion of these crosslinking monomers up to 5% by weight, preferably not more than 3% by weight, based on the Elastomer or emulsion polymer.

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

Instead of graft polymers with a multi-layer Structure can also be homogeneous, i.e. H. single-shell elastomers from buta-1,3-diene, isoprene and n-butyl acrylate or their Copolymers are used. These products can too by using crosslinking monomers or Monomers with reactive groups can be prepared. The The elastomers described can also be made according to other conventional methods Process, e.g. B. by suspension polymerization, getting produced.

Preferred components (ii) in the invention Molding compounds are also called ethylene propylene (EPM) or Ethylene propylene diene (EPDM) rubbers.

EPM rubbers generally have practically none Double bonds more, while EPDM rubbers 1 to 20 Can have double bonds / 100 carbon atoms.  

Examples of diene monomers for EPDM rubbers are conjugated dienes like isoprene and butadiene, not conjugated dienes with 5 to 25 carbon atoms such as penta-1,4-diene, Hexa-1,4-diene, hexa-1,5-diene, 2,5-dimethylhexa-1,5-diene and Octa-1,4-diene, cyclic dienes such as cyclopentadiene, Cyclohexadienes, cyclooctadienes and dicyclopentadiene as well Alkenyl norbornenes such as 5-ethylidene-2-norbornene, 5-butylidene 2-norbornene, 2-methallyl-5-norbornene, 2-isopropenyl-5- norbornene and tricyclodienes such as 3-methyl tricyclo (5.2.1.0.2.6) -3,8-decadiene or mixtures thereof called. Hexa-1,5-diene-5-ethylidene are preferred norbornene and dicyclopentadiene. The diene content of the EPDM Rubbers are preferably 0.5 to 50, in particular 1 up to 8 wt .-%, based on the total weight of the rubber.

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

Further preferred components (ii) in the Molding compositions according to the invention are for intercepting Formaldehyde (formaldehyde scavenger) suitable compounds, Plasticizers, lubricants, antioxidants, adhesion promoters, Light stabilizers and pigments.

Lubricants, individually or as a mixture can be added to the most varied Belong to substance classes, such as B. metal stearates (such e.g. Calcium stearate), waxes, fatty acid amides (such as e.g. Stearic acid amide, bis-stearoyl-ethylenediamide), Hydroxycarboxamides, fatty acids, fatty acid esters, Montanic acid esters, paraffin waxes, synthetic paraffins, low molecular weight or oligomeric polyolefin waxes (such as Polyethylene waxes), polar modified by grafting Polyolefin waxes, alcohols (such as palmityl alcohol, Stearyl alcohol, tallow fatty alcohol), ketones (such as Stearone), silicones (such as polydimethylsiloxane), Silicone oils, polysiloxanes, acrylic-modified polysiloxanes,  Polytetrafluoroethylene (PTFE), polyalkylene glycols, special Fatty acid esters as described in DE 41 17 655.

Esters of polyhydric alcohols are particularly preferred (such as ethylene glycol, diethylene glycol, butanediol, Glycerin, diglycerin, pentaerythritol, sorbitol) with long-chain fatty acids (e.g. stearic acid, behenic acid, Palmitic acid, capric acid, lauric acid, linoleic acid, Erucic acid), which are used individually or as a mixture can. The hydroxyl groups of the alcohol component in the Carboxylic acid esters can either be completely esterified or only partially esterified. Are particularly preferred Glycerol esters based on saturated fatty acids, in which not all hydroxyl groups are esterified.

More information about the above sliding and Lubricants are described in Ullmann 's encyclopedia Technical Chemistry, Volume 15, Verlag Chemie, 4th edition (1978) 268-270, Additives for Plastics Handbook, J. Murphy, Elsevier Advanced Technology (1996) 239-255 or polymers Materials, Volume 2, H. Batzer, Thieme-Verlag (1984) 328-337 called.

In principle, any person skilled in the art can use them as light stabilizers substances suitable for this purpose. they can be used individually or as a mixture. As Light stabilizers have been found to be particularly advantageous Based on benzotriazole derivatives (such as 2- (2'-hydroxy- 3 ', 5'-di (1,1-dimethylbenzyl) phenyl) benzotriazole), Benzophenone derivatives (such as 2-hydroxy-4- methoxybenzophenone or 2,2'-dihydroxy-4,4'- dimethoxybenzophenone), aromatic benzoate derivatives (such as e.g. B. p-octylphenyl salicylate), phenyltriazines, Cyanocinnamic acid amides or cyanocinnamic acid esters (such as described in WO 9713749), or sterically hindered Amine compounds (HALS), for example derivatives of 2,2,6,6-tetramethylpiperidine (such as one Dimethyl succinate polymer with 4-hydroxy-2,2,6,6-tetramethyl  1-piperidineethanol). Have been particularly suitable benzotriazole derivatives, which are found under the Name Tinuvin® (registered trademark of Ciba-Geigy AG) are commercially available. Especially Tinuvin® 234: 2- (2'-hydroxy-3 ', 5'-di (1,1- Dimethylbenzyl) phenyl) benzotriazole. Particularly suitable are also derivatives of 2,2,6,6-tetramethylpiperidine, which under the name Tinuviri or Chimasorb® (registered trademark of Ciba-Geigy AG) in Are available commercially. Tinuvin are particularly preferred 622 LD from Ciba-Geigy AG: dimethyl succinate polymer with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol and Tinuvin® 770 LD from Ciba-Geigy AG: bis (2,2,6,6- tetramethyl-4-piperidyl) sebazate.

Find more information about suitable light stabilizers in the monograph by J.F. Rabek, Photostabilization of polymers; Principles and Applications, Elsevier Applied Science, NY, 1990.

Polyamides which can also be used as additives are in themselves known. Semicrystalline or amorphous resins such as z. B. in the Encyclopedia of Polymer Science and Engineering, Vol. 11, pp. 315 to 489, John Wiley & Sons, Inc. 1988 can be used, the Melting point of the polyamide, preferably below 225 ° C., is preferably below 215 ° C.

Examples include polyhexamethylene azelaic acid amine, Polyhexamethylene sebacic acid amide, Polyhexamethylene dodecanedioic acid amide, poly-11- aminoundecanoic acid amide and bis (p-aminocyclohexyl) methane dodecanoic acid diamide or by ring opening of lactams, e.g. B. or polylaurine lactam products obtained. Also Polyamides based on terephthalic or isophthalic acid as an acid component and / or trimethylhexamethylene diamine or bis (p-aminocyclohexyl) propane as the diamine component and polyamide base resins, which are obtained by copolymerizing two  or more of the aforementioned polymers or their Components that have been manufactured are suitable.

Mixed polyamides are particularly suitable polyamides based on caprolactam, hexamethylenediamine, called p, p'-diamino-dicyclohexylmethane and adipic acid. An example of this is under the label Ultramid® 1 C marketed by BASF Aktiengesellschaft Product.

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

The production of these polyamides is also in the described above. The ratio of terminal amino groups to terminal acid groups by varying the molar ratio of the Output connections can be controlled.

The proportion of the polyamide in the molding composition according to the invention is preferably 0.005 to 1.99% by weight, in particular 0.01 to 1.5% by weight.

By using a polycondensation product 2,2-di- (4-hydroxyphenyl) propane (bisphenol A) and In some cases, epichlorohydrin can increase dispersibility of the polyamides used can be improved.

Such condensation products from epichlorohydrin and Bisphenol A are commercially available. Process for their Production are also known to the person skilled in the art. Trade names of the polycondensates are Phenoxy® (the Union Carbide Corporation) or Epikote® (Shell). The molecular weight of the polycondensates can vary widely Limits vary; in principle they are in the trade available types are all suitable.

As additives (ii), the polyoxymethylene molding compositions according to the invention can contain up 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 contain the molding compositions of one or more alkaline earth metal silicates and / or alkaline earth metal glycerophosphates. Calcium and in particular magnesium have proven to be excellent as alkaline earth metals for the formation of the silicates and glycerophosphates. Calcium glycerophosphate and preferably magnesium glycerophosphate and / or calcium silicate and preferably magnesium silicate are expediently used, alkaline-earth silicates, in particular those which are preferred by the formula, being particularly preferred

Me.x SiO ₂ .n H ₂ O

are 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 connections are advantageously in finely ground form used. Products with one average particle size of less than 100 µm, preferably less than 50 µm are particularly good suitable.

Calcium and magnesium silicates and / or calcium and magnesium glycerophosphates are preferably used. These can be specified, for example, by the following key data:
Calcium or magnesium silicate: CaO or MgO content: 4 to 32% by weight, preferably 8 to 30% by weight and in particular 12 to 25% by weight, SiO ₂ : CaO or SiO ₂ ratio: 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: smaller than 100 microns, preferably less than 50 microns and
Calcium or magnesium glycerophosphates:
CaO or MgO content: 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: less than 100 µm,
preferably less than 50 microns.

Ambosol®, has proven to be particularly suitable synthetic magnesium silicate from Societe Nobel, Bozel, Puteaux.

The molding compositions according to the invention can be used as additives also amounts of a fibrous or particulate filler or contain mixtures thereof.

Examples of reinforcing fillers are inorganic fibers such as potassium titanate whiskers, carbon and preferably called glass fibers, the glass fibers e.g. B. in the form of glass fabrics, mats, nonwovens and / or Glass silk rovings or cut glass silk low-alkali e-glass with a diameter of 5 to 200 µm, preferably 8 to 50 microns can be used, the fibrous Fillers preferably one after incorporation average length of 0.05 to 1 mm, in particular 0.1 to 0.5 mm.

Other suitable reinforcing fillers are e.g. B. organic polymer fibers such as B. aramid fibers (Nomex®, Kevlar®) or polyacrylonitrile fibers.

Other suitable additional fillers are, for example Wollastonite, calcium carbonate, glass balls, quartz powder, Silicon and boron nitride or mixtures of these fillers.  

Preferred combinations of fillers are: wollastonite with glass fibers, mixing ratios of 5: 1 to 1: 5 are preferred.

Also antioxidants, individually or as a mixture can be used can be used. As Antioxidants are, for example, sterically hindered Phenols. Suitable as sterically hindered phenols in principle all compounds with phenolic Structure attached to the phenolic ring at least one steric have a demanding group.

Preferably come e.g. B. Compounds of formula

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 may be the} same 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 described, for example, in DE-A 27 02 661 (US-A 4 360 617).

Another group of preferred sterically hindered phenols is derived from substituted benzene carboxylic acids, in particular from 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 can be substituted (at least one of them is a sterically demanding group) and R ^{6 is} a divalent aliphatic radical with 1 to 10 C. -Atoms means that the main chain can also have CO bonds.

Examples include 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 ], Pentaerythritol 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-hydroxyphenyl - 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- (2nd , 6-di-tert-butylphenol), 3,5-di-tert-butyl-4-hydroxybenzyl-dimethylamine, N, N'-hexamethylene-bis-3,5-di-tert-butyl-4- hydroxyhydrocinnamide (Irganox 1098 from Ciba-Geigy), 3- (3-tert-butyl-4-hydroxy-5-methylphenyl) -N- (6- (3- (3-tert-butyl-4-hydroxy -5-methylphenyl) propionylamino) hexyl) propionamide and N, N'-bis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propi onyl) hydrazine (Irganox MD 1024 from Ciba-Geigy).

Have proven to be particularly effective and therefore 2,2'-methylene-bis- (4-methyl- 6-tert-butylphenyl), 1,6-hexanediol-bis- [3,5-di-tert.- butyl-4-hydroxyphenyl) propionate (Irganox® 259 from the company Ciba-Geigy), pentaerythritol tetrakis [3- (3,5-di-tert-butyl- 4-hydroxyphenyl) propionate] (Irganox® 1010 from Ciba Geigy), diethylene glycol bis- [3- [3- (tert-butyl) -4-hydroxy- 5-methylphenyl] propionate], or triethylene glycol bis- [3- (3- (tert-butyl) -4-hydroxy-5-methylphenyl] propionatil (Irganox © 245 from Ciba-Geigy), which is particularly good suitable is.

In addition to sterically hindered phenols, too Antioxidants with a lactone structure can be used. Examples of this are those described in DE-PS-44 32 732 3-arylbenzofuranones or those described in EP 644190 Benzofuran-2-one. One is particularly advantageous Combination of the sterically hindered described above Phenols such as e.g. B. Triethylene glycol bis- [3- (3- (tert.- butyl) -4-hydroxy-5-methylphenyl] propionate] (Irganox® 245 from Ciba-Geigy) and one or more 3- Arylbenzofuranones, such as. B. 3- (3,4-Dimethylphenyl) -5,7- di-tert-butyl-3H-benzofuran-2-one.

The antioxidants, individually or as mixtures can usually be used in an amount up to 2% by weight, preferably from 0.005 to 2% by weight, in particular 0.1 to 1 wt .-%, based on the Total weight of the molding compounds included.

In some cases, sterically hindered phenols with no more than one sterically hindered group in ortho position to the phenolic hydroxy group as special proven advantageous; especially when assessing the Color stability when stored in diffuse light for long periods Periods.  

These additives can be used in the invention Molding compounds are available in a wide variety of quantities, where in each case the relevant amount of each used additive (ii) depends on which special useful technical effect wants to achieve. The additives are expedient (ii) in the molding composition according to the invention in the from the stand up to 60% by weight of conventional amounts known in the art used, with amounts of 0.01 to 50 wt .-%, based on the weight of components (i), (ii) and (iii), especially are advantageous.

Component (iii)

The essential part of the invention of the reinforced or unreinforced according to the invention Polyoxymethylene molding compounds is an additive to Nucleation and to improve thermal stability polymeric plastic material used (iii). The Component (iii) is therefore an essential component. The polymeric plastic material (iii) lies in the Molding composition according to the invention in an amount of 0.01 to 2 parts based on 100 parts of (i) + (ii). Here it is generally not advisable to increase the proportion of the polymeric material (iii) in the invention Molding compound over 2 parts, based on 100 parts (i) + (ii), increase because of the benefits that this brings can be achieved, the higher consumption of polymer No longer justify material (iii). Besides, it can segregation of the polymer under certain circumstances Materials (iii) and the molding composition according to the invention come. In contrast, the amount of polymeric material (iii) in the Molding compound according to the invention not 0.01 parts fall below, because otherwise the polymer Material (iii) evoked advantageous technical Effects do not always meet the demands of practice in full Scope can meet. Accordingly, it is  the range of 0.01 to 2 parts around an optimum, within the proportion of the polymeric material (iii) in the Molding composition according to the invention varies and each used other essential components of the Molding composition according to the invention can be adapted. Within this preferred area is a narrower window particularly useful, so that the invention Molding composition in a particularly preferred embodiment indicates that (iii) in an amount of 0.02 to 1 part, based on the sum (i) + (ii) calculated as 100 parts, is contained in the molding compound. Within this particularly expedient range within which the invention Molding compound is particularly advantageous and is excellent is suitable for the production of moldings and foils the range from 0.05 to 0.5 parts, again based on the sum (i) + (ii), which is calculated as 100 parts, to be emphasized because of such a proportion of polymer Plastic material (iii) an excellent application-related property profile of the concerned Molding composition according to the invention results. This means that the amount of polymeric plastic material (iii) as Low yellowing additive for nucleation and improvement the thermal stability of reinforced or unreinforced Polyoxymethylene molding compositions with regard to The cost of materials on the one hand and the one achieved thereby advantageous technical effect on the other hand excellently balanced and therefore entirely according to the invention is particularly preferred.

Basically, the polyoxymethylene molding composition can be according to the Invention comprising components (i), (ii) and (iii), which should stand for the fact that more are not in the Description of the constituents mentioned in the polyoxymethylene Molding composition can be included. Particularly preferred Embodiment, however, the molding compound consists of the three mentioned components (i), (ii) and (iii).  

As already stated, (iii) is a copolymer, which by polymerization in solution or polymerization is available in bulk (bulk polymerization). Under Solution polymerization becomes a polymerization process understood, after the monomers in a solvent the methods known for solution polymerizations, such as e.g. B. in Ullmann's Encyclopedia of Industrial Chemistry, 4th edition, Verlag Chemie, vol. 19, p. 112, be polymerized continuously or batchwise. Under bulk polymerization is a Understanding polymerization process in which monomers without Solvents are polymerized so that the Bulk or bulk polymerization reaction takes place.

Components A1) and A2) of the polymer (iii)

Component A1) is a connection, which have at least two polymerizable C = C double bonds possess in the molecule. Component A1) can consist of one or several such connections exist.

Therefore, in a particular variant of the invention (iii) is a copolymer which can be obtained by solution polymerization or bulk polymerization of a mixture in which

• 1. from 0.1-100 parts with one or more crosslinkers at least two polymerizable carbon-carbon There are double bonds.

For component A2), which is also used to obtain the Polymer according to the invention (component (iii)) can be used, it is one or more (Meth) acrylates. Under the term "(meth) acrylates" basically esters of acrylic acid as well as esters of Understood methacrylic acid, which has a polymerizable C-C double bond in the molecule.  

Component A2) can consist of one or more Methacrylates exist. These can be optional or have several acrylates.

Therefore, in a particular variant of the invention (iii) is a copolymer which can be obtained by solution polymerization or bulk polymerization of a mixture in which

• 1. 0-99.9 parts of one or more methacrylates of the general formula I
  wherein R ^{1 represents} a linear, cyclic or branched alkyl radical having 1 to 30 carbon atoms or a linear or branched hydroxyalkyl radical having 1 to 30 carbon atoms or a linear or branched alkylene radical having 1 to 30 carbon atoms or a linear or branched epoxyalkyl radical having 1 to 30 Is carbon atoms or is a linear or branched alkylene glycol alkyl ether radical having 2 to 100 carbon atoms or is a linear or branched alkylene glycol alkyl radical having 2 to 100 carbon atoms or is an alkoxy radical or is a benzyl radical or is a furfuryl or tetrahydrofurfuryl radical,
  and or
  0-99.9 parts of one or more acrylates of the general formula II
  wherein R ^{2 represents} a cyclic or linear or branched alkyl radical having 1 to 30 carbon atoms or a linear or branched hydroxyalkyl radical having 1 to 30 carbon atoms or a linear or branched alkylene radical having 1 to 30 carbon atoms or a linear or branched epoxyalkyl radical having 1 to 30 Means carbon atoms or means a linear or branched alkylene glycol alkyl ether residue with 2 to 100 carbon atoms or means a linear or branched alkylene glycol residue with 2 to 100 carbon atoms or means a benzyl residue or means a furfuryl or tetrahydrofurfuryl residue,

is
where A1) and A2) together can result in 0.1-100 parts and the sum of parts A1), A2) and B) results in 100.

Among the compounds of the formula I, those in which R ^{1 is} methyl, ethyl and / or propyl, butyl, pentyl and / or hexyl are particularly preferred in the context of the invention. Mixtures of compounds in which, in the general formula II, methyl, ethyl, propyl, butyl, pentyl and / or hexyl are also particularly useful.

Among the crosslinking or crosslinking monomers A1) those skilled in the art understand the reason after all common connections that are used for networking in the polymerization can be used. Not in one Complete list includes u. a. Methacrylic anhydride, allyl methacrylate, Ethylene glycol dimethacrylate, ethylene glycol diacrylate, Diethylene glycol dimethacrylate, diethylene glycol diacrylate, Triethylene glycol dimethacrylate, triethylene glycol diacrylate, Tetraethylene glycol dimethacrylate, Polyethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol diacrylate, 1,4- Butanediol diacrylate, 1,6-hexanediol dimethacrylate, Hexanediol diacrylate, glycerol-1,3-dimethacrylate, Neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, Neopentyl glycol ethoxylate diacrylate, neopentyl glycol  ethoxylate dimethacrylate, diurethane dimethacrylate, Trimethylolpropane trimethacrylate, Trimethylolpropane triacrylate, pentaerythritol triacrylate, Pentaerythritol tetraacrylate, pentaerythritol trimethacrylate, Dipentaerythritol hexaacrylate dipentaerythritol pentaacrylate, Polyethylene oxide dimethacrylate, divinylbenzene, 1,5-hexadiene, 1,7-octadiene, 1,4-butylene dimethacrylate, 1,4- Butanediol diacrylate, bisphenol A dimethacrylate, Polybutanediol dimethacrylate, N, N'-methylene-bis- (acrylic acid amide), N, N'-methylene-bis- (methacrylic acid amide), Ethylene glycol divinyl ether, triethylene glycol divinyl ether, Tetraethylene glycol divinyl ether, butanediol divinyl ether, Hexanediol divinyl ether, polyethylene oxide divinyl ether or Trimethylolpropane trivinyl ether.

Component B) of the polymer (iii)

In the context of the invention as component B) (Meth) acrylamides to be used and / or Dialkylaminoalkyl acrylates and / or Dialkylaminoalkyl methacrylates are general to the person skilled in the art common. In a preferred embodiment of the molding compound according to the invention is used as component B) Acrylamide and / or methacrylamide and / or Dimethylaminoethyl methacrylate used. The amount of Component B) in the polymer (iii) is in the range of 0-99.9 parts, with A1), A2) and B) together 100 parts surrender.  

Component C) of the polymer (iii)

Another for the polymerization to generate the copolymers (iii) according to the invention can be used Component C) are 0 to 10 parts of molecular weight regulators based on 100 parts A1) + A2) + B). These include the Basically all compounds familiar to the person skilled in the art which for regulating the molecular weight in solution polymerization can be used. In an incomplete list include u. a. 4-methyl-2,4-diphenylpentene (1) (1,1'- (1,1-dimethyl-3-methlene-1,1-propenediyl) bisbenzene, α- Methylstyrene), or aliphatic mercapto compounds, such as e.g. B. ethyl mercaptoacetate, 2-ethylhexyl mercaptoacetate, Methyl 3-mercaptopropionate, 2-ethylhexyl mercaptopropionate, Trimethylolpropane trimercaptoacetate, glycol dimercaptoacetate, Pentaerythritol tetrakis mercaptoacetate, 1-propanethiol, 2-propanethiol, n-dodecyl mercaptan (1-dodecanethiol), tert-dodecyl mercaptan.

Of the aforementioned compounds, n-dodecyl mercaptan is particularly preferred. An advantage when using Molecular weight regulator is the generation of stable End groups in the copolymer, which have thermal stability of the copolymer (iii) compared to unregulated increase.

Component D) of the polymer (iii)

Another component based on up to 5 parts 100 parts A1) + A2) + B) should be present in the mixture which can be used to produce the copolymers of the invention (Component (iii)) used are radical Polymerization initiators. Although the Polymerization reaction basically to any dew specialist common way (e.g. by radiation or the like) can be triggered is an initiation with radical-forming polymerization initiators preferred. To usable connections belong in addition to the classic  Azo initiators such as azobisisobutyronitrile (AIBN) or 1,1-azobiscyclohexane carbonitrile, u. a. aliphatic Peroxy compounds, such as. B. tert-amyl peroxyneodecanoate, tert-amyl peroxypivalate, tert-butyl peroxy neodecanoate, tert-butyl peroxypivalate, tert-amyl peroxy-2-ethylhexanoate, tert-butylperoxy-2-ethylhexanoate, tert-amylperoxy-3,5,5, - trimethylhexanoate, ethyl 3,3-di (tert-amylperoxy) - butyrates, tert-butyl perbenzoate, tert-butyl hydroperoxide, Decanoyl peroxide, lauroyl peroxide, benzoyl peroxide and any mixtures of the compounds mentioned. Of the the aforementioned compounds are lauroyl peroxide, Azobisisobutyronitrile, tert-amyl peroxyneodecanoate and tert-butyl peroxypivalate is particularly preferred.

Azobisisobutyronitrile and lauroyl peroxide are whole particularly preferred.

With regard to the invention, a molding composition which comprises a copolymer (iii) which can be obtained by bulk polymerization or solution polymerization is very particularly preferred
30-90 parts A1),
0-60 parts A2),
10-50 parts B),
0.5 - 5 parts C) and
0.1-2 parts D),

contains, whereby A1) + A2) + B) result in 100 parts (wt / wt) have to.

Molding compositions in which are also extremely preferred A1) trimethylolpropane triacrylate, A2) methyl methacrylate, B) methacrylamide, C) n-dodecyl mercaptan and D) Azobis (isobutyronitrile) or A1) trimethylolpropane trimethacrylate, A2) methyl methacrylate, B) methacrylamide, C) n-dodecyl mercaptan and D) Azobis (isobutyronitrile) or A1) pentaerythritol tetraacrylate, A2) methyl methacrylate,  B) methacrylamide, C) n-dodecyl mercaptan and D) azobis (isobutyronitrile) or A1) dipentaerythritol penta- / hexa-acrylate, A2) methyl methacrylate, B) methacrylamide, C) n-dodecyl mercaptan and D) azobis (isobutyronitrile).

The proportions of component (iii) in an amount of 0.02-1 part, preferably 0.05-0.5 part, based on the sum (i) + (ii) calculated as 100 parts in the Molding compositions are also extremely preferred.

The invention also relates to a process for producing a shaped body or a film from a molding material

• 1. Melting and mixing the components of the Molding compound on an extruder at 150 to 260 ° C and
• 2. shaping processing of the resulting Molding compound for the molding in question or relevant slide,

using a molding compound which is a reinforced or unreinforced according to the invention Contains polyoxymethylene molding compound or which from a such molding compound.

Another aspect of the invention relates to the use of copolymers (iii), which by bulk polymerization or solution polymerization of a mixture of

• 1. 0.1-100 parts of one or more crosslinkers with at least two polymerizable carbon Carbon double bonds
• 2. 0-99.9 parts of one or more acrylates and / or methacrylates  
• 3. 0-99.9 parts of one or more acrylamides and / or methacrylamides and / or Dialkylaminoalkyl acrylates and / or Dialkylaminoalkyl methacrylates
• 4. based on 100 parts A) + B) <0.2 to 10 parts Molecular weight regulators and
• 5. based on 100 parts A) + B) up to 5 parts radical polymerization initiators, is available

where all amounts relate to parts by weight (wt / wt) and A1), A2) and B) must add up to 100 parts simultaneous stabilization and nucleation of Molding compositions which are polyoxymethylene homo- and / or Contain copolymers.

The use of copolymers (iii) in is preferred an amount of 0.01 to 2 parts based on 100 parts Molding compound, the 100 parts without the for nucleation and copolymers used for thermal stabilization are expected.

The invention further relates to films, moldings and Semi-finished products from molding compositions according to the invention.

The polymeric materials to be used according to the invention (iii) according to the usual and known methods of radical initiated substance polymerization or Solution polymerization continuously or batchwise produced.

Methodically, the preparation of the invention Molding compound no major peculiarities. Rather it will them according to the usual and known method of manufacture obtained from molding compounds. For this, the components (i), (ii) and (iii) of the molding composition according to the invention individually or in the form of one or more pre-made  Mixtures supplied to a suitable mixing device and be mixed there at temperatures from 0 to 260 ° C. It is advantageous here to use components (i), (ii) and (iii) the molding composition according to the invention at temperatures of 0 to 150 ° C, preferably from 0 to 50 ° C, intensely mix, the resulting prefabricated Mix in an extruder, preferably a multiple Shaft extruder, which if necessary with a Degassing device is equipped to introduce and at temperatures of 150 to 260 ° C, preferably 200 to Melt 250 ° C, the resulting melt degas and extrude and then from the discharge extruder concerned. That in this way Molding composition according to the invention obtained after cooling be granulated. The resulting granules can temporarily stored or directly for the production of foils or moldings are used, for which Production of the films and moldings from the Molding composition according to the invention the usual and known Blow molding and injection molding methods are considered come.

As the examples illustrate, the Molding compositions according to the invention compared to known Molding compounds in addition to good mechanical properties Improve temperature resistance and a significant less tendency to discolouration. The invention Molding compound is therefore ideal for the Manufacture of foils and moldings. The moldings are used with advantage in vehicle, Electrical appliances and electronics industry.

In the context of the invention, alkyl radicals denote linear or any branched alkyl groups, each of which have the specified number of carbons. It is indicated that the residues should also be disclosed, the Size between the carbon numbers specified lies. All conceivable constitutional isomers are among the  to subscribe the specified scope. The same applies to an alkyte group.

AC ₆ to C ₁₂ aryl group denotes an aromatic radical having 6 to 12 carbon atoms. These are preferably the phenyl and naphthyl radical. The same applies to an arylene group.

Halogen in the context of the invention is fluorine, chlorine, Bromine, iodine understood.

Examples

Examples of the present invention are as follows shown, but it goes without saying that the present invention is not limited to this.

The following examples serve to illustrate the subject matter of the invention.

• 1. First, the general implementation of a Solution polymerization and bulk polymerization for Production of usable according to the invention Copolymers described, it goes without saying is that the implementation of solution polymerization and bulk polymerization not to 1.1 to 1.3 described process steps and equipment is limited. The term "copolymers" includes for the entire description is a polymer which at least 2 different monomers has, in particular also terpolymers, etc. The for the preparation of the examples according to the invention required information about recipe, Process parameters and specifications are the See the tables below.  
• 2. Apparatus
  • 1. 500 mL HWS double jacket vessel with anchor stirrer, Pt 100 temperature measurement, reflux condenser and thermostat
  or
  • 1. Mold consisting of 2 glass plates, between which a plastic piping is inserted for sealing, the distance between the glass plates being controlled via the piping diameter and the piping comprising three sides of the mold and the fourth side remaining open or closed after filling with piping becomes. To prevent the polymer from adhering to the glass or the piping, the glass plates are covered with a release film (e.g. ®Hostaphan RV 36 / Putz). The shape is fixed on three sides with special clamps. The glass mold is heated to the desired polymerization temperature by introducing the glass mold into heated water baths or heated ovens of suitable size with temperature control.
• 3rd approach
  The type and concentration of the input materials can be found in the respective recipe.
  The reaction mixture consists of:
  Monomers, regulators, initiators and possibly solvents.
• 4. Implementation
  The polymerization is divided into 4 general steps A to D, the processing of which can vary depending on the specifications in the respective recipe.
  Step A:
  Monomers, regulators and any solvents are placed in the polymerization vessel and dissolved with stirring at room temperature or elevated temperature.
  Step B:
  The initiator is added and the solution is heated to 70 ° C using a thermostat. The temperatures of the heating jacket and, if applicable, of the reaction mixture are determined by means of a sensor and recorded on the temperature recorder.
  Step C:
  After the end of the polymerization, the contents of the reactor are brought to room temperature and the copolymer obtained is optionally separated from the supernatant solvent.
  Step D:
  Drying the polymer block or the viscous polymer solution or the precipitated polymer block and comminuting the polymeric material (iii) in a suitable Retsch impact cross mill SK 1 (6 mm sieve plate) and then in a Retsch Ultra centrifugal mill ZM 1 through a 0.25 mm sieve (cooled with liquid nitrogen). Some samples were additionally ground on an impact mill with pin disc inserts (from Bauermeister) and screened out fractionally.
• 5. Analytics
  The glass transition temperature of some polymers was determined by means of differential scanning calorimetry (DSC).

Essential data and results for copolymers (iii) are given in Table 1.  

• 1. Production and properties of the invention (Examples No. 1 to No. 30) and not according to the invention (comparative tests V1 to V3) Molding compounds:
• 2. General test instructions
  In Examples Nos. 1 to no. 30 and Comparison Examples C1 to C3, a thermally undegraded polyoxymethylene copolymer H ₂ O-00 or N20-00 (MVR = was in each case 1.8 to 4.0 ^cm3 / 10 minutes ; determined according to DIN ISO 1133 at 190 ° C and a contact force of 2.16 kg), which was made from a mixture of 97.3% by weight of trioxane and 2.7% by weight of butanediol formal and which was still approximately 5 % By weight of unreacted trioxane and approximately 3% by weight of thermally unstable formaldehyde adduct, mixed with different amounts of additives (B) and additives (C) for thermal stabilization in a dry mixer at a temperature of 23 ° C. The resulting prefabricated mixtures were introduced at a temperature of 23 ° C in a twin-screw extruder with a degassing device (type ZSK 28 from Werner and Pfleiderer, Stuttgart), homogenized at 180 to 230 ° C and degassed, after which the homogenized mixture through a nozzle as a strand was pressed out and granulated.
• 3. To test the thermal stability, the rate of solidification and the tendency to discolour the polyoxymethylene samples, the following were determined:
  GV (N ₂ 2 h): The weight loss in% by weight of a sample of 1.2 g of granules after heating for two hours at 222 ° C. under a nitrogen atmosphere;
  GV (air 2 h): weight loss in% by weight of a sample of 1.2 g of granules after heating for two hours at 222 ° C. in air;
  Isothermal crystallization time t ₂ : samples of 3.0 mg each are weighed into an Al crucible with a perforated lid and heated to 190 ° C at a heating rate of 40 K / min in the differential scanning calorimeter (type Mettler DSC 820), 5 min maintained at this temperature and then cooled to 149 ° C. at a cooling rate of 30 K / min and then kept at this temperature. Now the time until the maximum of the heat of crystallization released is reached, calculated from the time when reaching 149 ° C. This isothermal crystallization time is the time in s from reaching the crystallization temperature (149 ° C) to the maximum of the exothermic crystallization peak (= complete crystallization).
  CieLab values: Colorimetric determination of the color distances L *, a * and b * (CieLab color coordinates) of the granules after extrusion at the time 2 hours after storage in a circulating air dryer at 140 ° C according to DIN 6174 (ASTM E 1347). In addition, some of the samples pretreated in this way are then stored at 140 ° C. for 100 h and the CieLab color coordinates are determined again.

Table 2 gives an overview of the manufactured Molding compositions not according to the invention and according to the invention. The results of the above tests are reported in the Table 3 summarized.  

Claims (25)

1. Having polyoxymethylene molding composition

• a) at least one polyoxymethylene homo- and / or copolymer,
• b) at least one common additive and
• c) at least one polymeric plastic material as an additive which simultaneously serves for nucleation and for improving the thermal stability,

characterized in that
component (iii) by polymerization in solution or substance from a mixture of

• 1. 0.1-100 parts of one or more crosslinkers with at least two polymerizable carbon-carbon double bonds
• 2. 0-99, 9 parts of one or more acrylates and / or methacrylates
• 3. 0-99, 9 parts of one or more acrylamides and / or methacrylamides and / or dialkylaminoalkyl acrylates and / or dialkylaminoalkyl methacrylates
• 4. based on 100 parts A1) + A2) + B) 0 to 10 parts molecular weight regulator and
• 5. based on 100 parts of A1) + A2) + B) up to 5 parts of free-radical polymerization initiators,

is available and that
(iii) in an amount of 0.01 to 2 parts based on the sum of (i) + (ii)
is contained in the molding compound,
where all quantities relate to parts by weight (wt / wt) and A1), A2) and B) together must result in 100 parts. 2. Molding compound consisting of (i), (ii) and (iii). 3. Molding composition according to claim 1 and / or 2, characterized in that
(iii) is a copolymer that can be obtained by solution polymerization or bulk polymerization of a mixture in which

• 1. consists of 0.1-100 parts of one or more crosslinkers with at least two polymerizable carbon-carbon double bonds,
• 2. from 0-99.9 parts of one or more methacrylates of the general formula I
  wherein R ^{1 represents} a cyclic or linear or branched alkyl radical having 1 to 30 carbon atoms or a linear or branched hydroxyalkyl radical having 1 to 30 carbon atoms or a linear or branched alkylene radical having 1 to 30 carbon atoms or a linear or branched epoxyalkyl radical having 1 to 30 Means carbon atoms or means a linear or branched alkylene glycol alkyl ether residue with 2 to 100 carbon atoms or means a linear or branched alkylene glycol residue with 2 to 100 carbon atoms or means a benzyl residue or means a furfuryl or tetrahydrofurfuryl residue,
  and or
  from 0-99.9 parts of one or more acrylates of the general formula II
  wherein R ^{2 represents} a cyclic or linear or branched alkyl radical having 1 to 30 carbon atoms or a linear or branched hydroxyalkyl radical having 1 to 30 carbon atoms or a linear or branched alkylene radical having 1 to 30 carbon atoms or a linear or branched epoxyalkyl radical having 1 to 30 Means carbon atoms or means a linear or branched alkylene glycol alkyl ether residue with 2 to 100 carbon atoms or means a linear or branched alkylene glycol residue with 2 to 100 carbon atoms or means a benzyl residue or means a furfuryl or tetrahydrofurfuryl residue,

consists,
where A1) and A2) together can give 1-100 parts and the sum of parts A1), A2) and B) results in 100. 4. Molding composition according to claim 3, characterized in that R1 is methyl, ethyl, propyl, butyl, pentyl and / or hexyl is.   5. Molding composition according to claim 3 or 4, characterized in that R ^{2 is} methyl, ethyl, propyl, butyl, pentyl and / or hexyl. 6. Molding composition according to one or more of the preceding Expectations, characterized in that A1) ethylene glycol dimethacrylate, ethylene glycol diacrylate, Diethylene glycol dimethacrylate, diethylene glycol diacrylate, Triethylene glycol dimethacrylate, Triethylene glycol diacrylate, Tetraethylene glycol dimethacrylate, Polyethylene glycol dimethacrylate, 1,3- Butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6- Hexanediol dimethacrylate, hexanediol diacrylate, glycerol 1,3-dimethacrylate, neopentyl glycol dimethacrylate, Neopentyl glycol diacrylate, neopentyl glycol ethoxylate diacrylate, neopentyl glycol ethoxylate dimethacrylate, Diurethane dimethacrylate, Trimethylolpropane trimethacrylate, Trimethylolpropane triacrylate, pentaerythritol triacrylate, Pentaerythritol tetraacrylate, pentaerythritol trimethacrylate, Dipentaerythritol hexaacrylate dipentaerythritol pentaacrylate, Polyethylene oxide dimethacrylate, divinylbenzene, 1,5- Hexadiene, 1,7-octadiene, 1,4-butylene dimethacrylate, 1,4- Butanediol diacrylate, bisphenol A dimethacrylate, Polybutanediol dimethacrylate, N, N'-methylene-bis- (acrylic acid amide), N, N'-methylene-bis- (methacrylic acid amide), ethylene glycol divinyl ether, Triethylene glycol divinyl ether, Tetraethylene glycol divinyl ether, butanediol divinyl ether, Hexanediol divinyl ether, polyethylene oxide divinyl ether and / or trimethylolpropane trivinyl ether.   7. Molding composition according to one or more of the preceding Expectations, characterized in that A1) butanediol dimethacrylate, Trimethylolpropane trimethacrylate, Trimethylolpropane triacrylate, pentaerythritol triacrylate, Pentaerythritol tetraacrylate, pentaerythritol trimethacrylate, Dipentaerythritol hexaacrylate Dipentaerythritol pentaacrylate and / or trimethylolpropane trivinyl ether. 8. Molding composition according to one or more of the preceding Expectations, characterized in that B) acrylamide and / or methyl acrylamide and / or Is dimethylaminomethyl methacrylate. 9. Molding composition according to one or more of the preceding Expectations, characterized in that C) is n-dodecyl mercaptan. 10. Molding composition according to one or more of the preceding Expectations, characterized in that D) lauryl peroxide and / or azobis (isobutyronitrile) and / or tert.-amylperoxyneodecanoate and / or tert.- Butyl peroxypivalate. 11. Molding composition according to one or more of claims 3-10, characterized in that (iii) is a copolymer which is obtainable by bulk polymerization or solution polymerization from
30-90 parts A1),
0-60 parts A2),
5-50 parts B),
0.5-5 parts C) and
0, 1-2 parts D),
where A1) + A2) + B) must result in 100 parts (wt / wt). 12. Molding composition according to claim 11, characterized in that A1) trimethylolpropane triacrylate, A2) methyl methacrylate, B) methacrylamide, C) n-dodecyl mercaptan and D) Azobis (isobutyronitrile). 13. Molding composition according to claim 11, characterized in that A1) trimethylolpropane trimethacrylate, A2) methyl methacrylate, B) methacrylamide, C) n-dodecyl mercaptan and D) azobis (isobutyronitrile) is. 14. Molding composition according to claim 11, characterized in that A1) pentaerythritol tetraacrylate, A2) methyl methacrylate, B) methacrylamide, C) n-dodecyl mercaptan and D) Azobis (isobutyronitrile). 15. Molding composition according to claim 11, characterized in that A1) dipentaerythritol penta- / hexa-acrylate, A2) methyl methacrylate, B) methacrylamide, C) n-dodecyl mercaptan and D) azobis (isobutyronitrile) is. 16. Molding composition according to claim 11, characterized in that A1) trimethylolpropane triacrylate, A2) methyl methacrylate, B) dimethylaminoethyl methacrylate, C) n-dodecyl mercaptan and D) is azobis (isobutyronitrile).   17. Molding composition according to claim 11, characterized in that A1) trimethylolpropane trimethacrylate, A2) methyl methacrylate, B) dimethylaminoethyl methacrylate, C) n-dodecyl mercaptan and D) is azobis (isobutyronitrile). 18. Molding composition according to claim 11, characterized in that A1) pentaerythritol tetraacrylate, A2) methyl methacrylate, B) dimethylaminoethyl methacrylate, C) n-dodecyl mercaptan and D) is azobis (isobutyronitrile). 19. Molding composition according to claim 11, characterized in that A1) dipentaerythritol penta- / hexa-acrylate, A2) methyl methacrylate, B) dimethylaminoethyl methacrylate, C) n-dodecyl mercaptan and D) is azobis (isobutyronitrile). 20. Molding composition according to one of the preceding claims, characterized in that (iii) in an amount of 0.02-1 part, preferably 0.05-0.5 parts, based on the sum (i) + (ii) calculated as 100 parts is contained in the molding compound. 21. Process for the production of a shaped body or a film from a molding material

• 1. Melt and mix the components of the molding compound in an extruder at 150 to 260 ° C.
  and
• 2. shaping processing of the resulting molding composition to give the molding or film in question,

characterized in that a molding composition is used which contains a reinforced or unreinforced polyoxymethylene molding composition according to one of Claims 1 to 20 or which consists of such a molding composition. 22. Use of copolymers which by bulk polymerization or solution polymerization of a mixture of

• 1. 0.1-100 parts of one or more crosslinkers with at least two polymerizable carbon-carbon double bonds
• 2. 0-99, 9 parts of one or more acrylates and / or methacrylates
• 3. 0-99, 9 parts of one or more acrylamides and / or methacrylamides and / or dialkylaminoalkyl acrylates and / or dialkylaminoalkyl methacrylates
• 4. based on 100 parts of A) + B) <0.2 to 10 parts of molecular weight regulator and
• 5. based on 100 parts of A) + B) up to 5 parts of free-radical polymerization initiators,

is available
where all amounts relate to parts by weight (wt / wt) and A1), A2) and B) must total 100 parts, for the simultaneous stabilization and nucleation of molding compositions which contain polyoxymethylene homo- and / or copolymers. 23. Use according to claim 22 of copolymers in an amount of 0.01 to 2 parts based on 100 parts Molding compound, the 100 parts without the nucleation  and thermal stabilizing copolymers are expected. 24. Shaped body and semi-finished product made of molding material according to Claims 1 to 20. 25. Film made of molding composition according to claims 1 to 20.