DE102011002440A1 - Process for crosslinking moisture-crosslinkable polymers with a water-dispensing system - Google Patents

Abstract

The invention relates to a process in which a composition comprising the components (A) is a moisture-crosslinkable polymer (P) - [- (S)] s, in which (P) - is the rest of a polymer, - (S) for silane groups and s represents an integer of at least 1, and (B) a water dispenser (W) comprising a cyclic carboxylic anhydride (W1) in which the anhydride group is part of a ring system and a primary amine (W2), or a primary product ( W12) obtainable from (W1) and (W2), (i) thermoplastic processing of the composition at a temperature T1 above the melting range of the polymer used (P) - [- (S)] s, i.e. H. Above temperature T0, which defines the upper limit temperature of the endothermic heat flow during the melting process of the polymer used (P) - [- (S)] s, determined by thermal analysis, (ii) shaping, (iii) water release and crosslinking at a temperature T2 without destroying the mold produced in step (ii), by carrying out this step at a temperature T2 below the temperature T1, so that the relationship T1> T2 has.

Description

The present invention relates to a process in which moisture-crosslinkable polymers are provided with a water-dispensing system for latent water, the polymer is thermoplastically processed, shaped and crosslinked in the finished form.

Moisture-crosslinkable polymers require a stoichiometric amount of water for the reaction that forms the network points. This water can not simply be added during processing as this would lead to premature cross-linking. Premature crosslinking means that crosslinking takes place before shaping in the thermoplastic state. A precrosslinked polymer is no longer or only to a limited extent thermoplastically formable. In addition, the processing of many polymers requires temperatures above 100 ° C, so that directly added water at normal pressure would lead to foaming.

According to the prior art, the water required for the crosslinking is supplied after shaping, for example by. Outsourcing of the finished molding in atmospheric air or under artificial humidification in water baths or steam chambers. As a rule, crosslinking is accelerated by using elevated temperatures. However, the melting point of the corresponding uncrosslinked polymer sets an upper limit on the applicable temperature, since the molding would lose its desired shape if the temperature is too high. Crosslinking takes place from the surface where the water enters, progressing inwards. If the diffusion of water into the moisture-crosslinkable polymer is slower than the network-forming molecular crosslinking reaction, the rate of crosslinking is limited by the diffusion of water and can not be increased by more active catalysts or by more reactive crosslinking systems. Furthermore, the depth of crosslinking is limited by the penetration depth of the water. The water access occurs mainly in hydrophobic systems, such as in moisture-crosslinkable polyolefins, very slowly and thick layers are therefore not or only by water exposure over a very long time crosslinkable. This makes the process more expensive. For example, crosslinking times of one day (24 hours) with hot water aging (90-120 ° C.) are typical for moisture-crosslinkable polyolefins with a layer thickness of about 3 mm. Larger layer thicknesses require significantly longer removal times, which is uneconomical for most applications.

If, therefore, the moisture crosslinking is to be effected quickly and to the depth of thick shaped bodies, then the required water must be introduced into the system in latent, masked form-in the form of a water dispenser. Before and during the thermoplastic shaping, the water dispenser may not deliver the water or only in small quantities. After shaping, the water dispenser should deliver water as efficiently as possible in a simple, inexpensive and robust process. The water should be distributed as finely as possible in order to avoid droplets and foaming. This places special demands on the water dispenser, because the thermoplastic shaping must take place in the melt, ie at a particularly high temperature, without the water dispenser emitting significant amounts of water, while the subsequent release of water and moisture crosslinking in the solid, ie at a lower temperature - below the Polymer melting point - should be done. In other words, the water dispenser may not give off any water at high temperature during molding and should release water as efficiently as possible later at a lower temperature. Various systems have been described in the literature which have attempted to meet these requirements. Most of these systems split off water during compounding, ie in the molten state. Classic examples are thermoplastic vulcanizates (TPV), see for example US2006 / 0258796A1 , In this case, a non-crosslinked first polymer is mixed with a crosslinked second polymer (rubber). In the TPV systems, it does not interfere with cross-linking of the second polymer (gum) during compounding because the overall blend remains moldable by the presence of the first (uncrosslinked) polymer. The TPV technology, which typically results in gel contents of less than 50% of the total mixture (see US2006 / 0258796A1 ), is therefore not transferable to systems in which the total mixture should be as completely as possible durchvernetzbar. So z. B. the Standard DIN EN ISO 15875-2 for pipes of silane-crosslinked poly (ethene) a gel content of at least 65%.

The writings EP149782 and WO85 / 03080 describe in principle crosslinkable materials which can be thermoplastically processed (eg extruded and molded) with the addition of hydrated zeolites or salts containing water of crystallization without too much precrosslinking. Subsequently, the release of water is triggered by microwave irradiation: The microwave energy coupled with good selectivity to the - compared to the polymer - polar water donors, so that they are stimulated to release water, while the surrounding polymer does not melt, since it hardly by the microwave radiation is stimulated. As a result, however, the water is released very inhomogeneously, which leads to blemishes causing defects in the polymer.

Other documents describe water release from organic compounds, for example by condensation or elimination reactions. However, the described systems release the water under the conditions of thermoplastic processing, ie at high temperature, and not after the physical solidification of the polymer. Physical solidification means solidification through crystallization processes. The writings WO2009 / 012069A1 and WO2009 / 058545A2 point out the need, if the process steps (i) thermoplastic processing above the polymer melting point, (ii) shaping and (iii) water release and crosslinking below the polymer melt point to proceed in this order, the water dispenser may only be active in step (iii). However, both documents do not show with any of the examples shown that the particular composition according to the invention fulfills this requirement. This is done in Scripture WO2009 / 058545A2 the thermoplastic processing at 125 ° C and the crosslinking at 120-182 ° C, in the Scriptures WO2009 / 012069A1 processing at 112-128 ° C and crosslinking at 140 ° C. This shows that the blends and processes set forth in both documents are not suitable for solving the problem of carrying out the thermoplastic processing (step (i)) at a significantly higher temperature than the water release and crosslinking (step (iii)).

• (A) ein feuchtevernetzbares Polymer (P)-[-(S)]s, in dem (P)- der Rest eines Polymers ist, -(S) für Silangruppen und s für eine ganze Zahl von mindestens 1 steht, und
• (B) einen Wasserspender (W), umfassend ein cyclisches Carbonsäureanhydrid (W1), in dem die Anhydridgruppe Teil eines Ringsystems ist, und ein primäres Amin (W2), oder ein Primärprodukt (W12) erhältlich aus (W1) und (W2), einem Prozess unterworfen wird, der die Schritte (i) thermoplastische Verarbeitung der Zusammensetzung bei einer Temperatur T1 oberhalb des Schmelzbereichs des eingesetzten Polymers (P)-[-(S)]s, d. h. oberhalb Temperatur T0, welche die obere Grenztemperatur des endothermen Wärmeflusses beim Schmelzvorgang des eingesetzten Polymers (P)-[-(S)]s, bestimmt durch thermische Analyse, definiert, (ii) Formgebung, (iii) Wasserfreisetzung und Vernetzung bei einer Temperatur T2 ohne Zerstörung der in Schritt (ii) hergestellten Form, indem dieser Schritt bei einer Temperatur T2 unterhalb der Temperatur T1 ausgeführt wird, so dass die Beziehung T1 > T2 gilt, aufweist.

The invention relates to a method in which a composition comprising the components

• (A) a moisture crosslinkable polymer (P) - [- (S)] s in which (P) - is the radical of a polymer, - (S) represents silane groups and s is an integer of at least 1, and
• (B) a water dispenser (W) comprising a cyclic carboxylic acid anhydride (W1) in which the anhydride group is part of a ring system, and a primary amine (W2), or a primary product (W12) obtainable from (W1) and (W2), is subjected to a process comprising the steps of (i) thermoplastic processing of the composition at a temperature T1 above the melting range of the polymer (P) - [- (S)] s used, ie above temperature T0, which is the upper limit temperature of the endothermic heat flow at Melting process of the polymer (P) - [- (S)] s as determined by thermal analysis, (ii) shaping, (iii) release of water and cross-linking at a temperature T2 without destroying the mold produced in step (ii) by this step is carried out at a temperature T2 below the temperature T1, so that the relationship T1> T2 applies.

In determining the melting range of polymer (P) - [- (S)] s by thermal analysis, Differential Scanning Calorimetry, hereinafter referred to as DSC, is used. The peak of the endothermic melting process is considered by DSC. This range is characterized by the onset of melting, the lower limit temperature of the endothermic peak, the actual peak, the temperature at which maximum endothermic heat flux is observed and the end of the melting process, the upper limit temperature of the endothermic peak. This upper limit temperature is defined as temperature T0.

In the process, water is split off from the water dispenser (W) in the moisture-crosslinkable polymer (P) - [- (S)] s. In step (iii) the release of water and crosslinking takes place below the temperature T1, into deep layers of the shaped body, without destroying the mold produced in step (ii).

Examples of thermal destruction of the finished form are softening-related change or melting of the mold. Another destruction is, for example, droplet or blistering.

(P) - is preferably the radical of a polymer having a weight average molecular weight Mw of at least 1000 g / mol or number average Mn of at least 1000 g / mol, preferably Mw of at least 3000 g / mol or Mn of at least 2000 g / mol, particularly preferably Mw at least 5000 g / mol or Mn at least 3000 g / mol.

(P) - is preferably the radical of a polymer having a weight-average molecular weight Mw of at most 5000 kg / mol or number-average Mn of at most 2000 kg / mol, preferably Mw of not more than 1000 kg / mol or Mn of not more than 400 kg / mol Mw at most 250 kg / mol or Mn at most 100 kg / mol.

(P) - is preferably the radical of an inorganic or organic polymer whose units are wholly or partly of the monomers dimethylsiloxane or of olefinically unsaturated monomers or of dicarboxylic acids or carbonic acid and diols or diamines or of lactones or lactams or cyclic carbonic esters or cyclic ethers or derive from alkene oxides.

(P) - is preferably the residue of an organic polymer whose units are derived from monomers selected from optionally substituted olefins such as ethene, propene, but-1-ene, 2-methylpropene, pent-1-ene, hex-1 or vinyl esters such as vinyl acetate, vinyl laurate, vinyl pivalate, vinyl versatate, or of vinyl ethers such butyl ether, or from unsaturated silanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (2-methoxyethoxy) silane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, allyltrimethoxysilane, oct-7-enyltrimethoxysilan, (methacryloxymethyl) trimethoxysilane, (methacryloxymethyl) triethoxysilane, (methacryloxymethyl) dimethoxymethylsilane, (methacryloxymethyl) diethoxymethylsilane , or from allyl compounds such as allyl esters, allylamides, or from unsaturated carboxylic acids or carboxylic acid derivative such as, for example, acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, undecenoic acid, the abovementioned carboxylic acid derivatives including esters thereof, for example methyl, ethyl or butyl esters, their optionally N-substituted amides, their anhydrides and their nitriles, or dicarboxylic acids, such as Terephthalic acid, phthalic acid, isophthalic acid, carbonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid and diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, bisphenol A, or diamines such as 1,2-ethanediamine, 1,6-hexanediamine, or from lactones such as γ-butyrolactone or ε-caprolactone, or from lactams such as γ-butyrolactam or ε-caprolactam, or from cyclic ethers such as tetrahydrofuran or tetrahydropyran, or of alkene oxides such as ethene oxide or propene oxide.

(P) - is particularly preferably a polyester such as polyether terephthalate, or a polyvinyl compound such as polyethene, polypropene, polybut-1-ene, polyisobutene, polyisoprene, polybutadiene, ethene-propene copolymer, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, ethene-vinyl acetate copolymer, Ethene-vinyltrimethoxysilane copolymer, polyvinyl acetate, vinyl acetate-vinyl laurate copolymer, polymethyl methacrylate, ethene-methacrylate copolymer, ethene-acrylate copolymer, or a polyether such as polyethylene glycol, polypropylene glycol or polyethylene glycol / polypropylene glycol copolymers, especially a polyolefin such as polyethene, polypropene, Ethene-propene copolymer, ethene-hexene copolymer, ethene-octene copolymer, polyisobutene.

(P) - may be the residue of a linear or branched polymer or a unimodal, bimodal or multimodal dispersed polymer. (P) - may be the residue of a homopolymer or copolymer or graft polymer.

- (S) preferably represents a silane group -R ² -SiX _n R ¹ _3-n in which X is a hydrolyzable group or a hydroxy group and R ^{1 is} a nonhydrolyzable group and n is 0, 1, 2 or 3 and -R ² - represents a divalent group or a divalent atom or a bond, where the individual silane groups - (S) can independently assume different substitution patterns, with the proviso that the average number of groups X per unit (P) - [- (S)] s is greater than or equal to 2, ie the product n × s must be at least equal to 2 in the arithmetic mean.

Polymers (P) - [- (S)] s are obtainable for example by copolymerization of olefinically unsaturated monomers with unsaturated silanes such as the aforementioned unsaturated silanes, or by radical grafting of polymers (P) -H with unsaturated silanes such as the aforementioned unsaturated Silanes, or by grafting of unsaturated polymers with mercapto-functional silanes such as of polyisobutene with (3-mercaptopropyl) trimethoxysilane, or by hydrosilylation of unsaturated polymers such as of polyisobutene with trimethoxysilane or with triethoxysilane, or by grafting of epoxy-containing polymers with silanes, the Amino or mercapto groups, or by grafting of chlorinated polymers with silanes having amino groups, or by grafting polymers having carboxylic anhydride groups, with silanes having amino or mercapto groups.

The polymer (P) - [- (S)] s is preferable
an ethene-vinyltrimethoxysilane copolymer,
an ethene-vinyl acetate-vinyltrimethoxysilane copolymer,
a polyethene-vinyltrimethoxysilane graft polymer,
a polypropene-vinyltrimethoxysilane graft polymer,
a polybutene-1-vinyltrimethoxysilane graft polymer or a vinyltrimethoxysilane graft polymer of an ethene-alpha-olefin copolymer such as a vinyltrimethoxysilane graft polymer of an ethene-propene copolymer, an ethene-but-1-ene copolymer, an ethene Propene-but-1-ene copolymer, an ethene-pent-1-ene copolymer, an ethene-hex-1-ene copolymer, an ethene-oct-1-ene copolymer, or an ethene-vinyl acetate copolymer.

The polymer (P) - [- (S)] s is preferred
an ethene-vinyltrimethoxysilane copolymer,
a polyethene-vinyltrimethoxysilane graft polymer,
a polypropene-vinyltrimethoxysilane graft polymer,
a polybutene-1-vinyltrimethoxysilane graft polymer or a vinyltrimethoxysilane graft polymer of an ethene-propene copolymer, an ethene-but-1-ene copolymer, an ethene-propene-but-1-ene copolymer, an ethene-pentene 1-ene copolymer, an ethene-hex-1-ene copolymer or an ethene-oct-1-ene copolymer.

The polymer (P) - [- (S)] s is particularly preferably an ethene-vinyltrimethoxysilane copolymer or a polyethene-vinyltrimethoxysilane graft polymer, or a vinyltrimethoxysilane graft polymer of an ethene-propene copolymer, an ethen-1-butene Copolymer, an ethene-hex-1-ene copolymer or an ethene-oct-1-ene copolymer, especially an ethene-vinyltrimethoxysilane copolymer or a polyethene-vinyltrimethoxysilane graft polymer.

The groups R ¹ are preferably substituted or unsubstituted C ₁ -C ₂₀ hydrocarbon groups or R ³ -substituted Si ₁ -Si ₂₀ silane groups or siloxane groups. If the radicals R ^{1 are} C ₁ -C ₂₀ hydrocarbon groups, these are preferably selected from methyl, ethyl, propyl, butyl or phenyl, in particular methyl.

The units -R ² - are preferably a bond or a divalent, optionally substituted or heterocyclic interrupted hydrocarbon group, preferably a bond or groups selected from -CH ₂ -, -CH ₂ -CH ₂ -, -CH (CH ₃ ) -, -CH ₂ -CH ₂ -CH ₂ -, -CH (CH ₃ ) -CH ₂ -.

R ³ is preferably C ₁ -C ₂₀ hydrocarbonoxy groups, C ₁ -C ₂₀ hydrocarbon groups or hydroxy groups, preferably methoxy, ethoxy or methyl.

X is preferably C ₁ -C ₂₀ hydrocarbonoxy groups or hydroxy groups, preferably methoxy, ethoxy or 2-methoxyethoxy, more preferably methoxy.

s is, based on a single macromolecule (P) - [- (S)] s, preferably an integer from 1 to 100, preferably 1 to 10, particularly preferably 1 to 5.

s, based on the mean value of all macromolecules (P) - [- (S)] s, preferably represents a number from 1 to 20, preferably 1 to 10, particularly preferably 1.5 to 5.

n is preferably an integer from 1-3, preferably 2 or 3.

The average number of groups X per unit (P) - [- (S)] s is preferably at least 2, particularly preferably at least 2.1, in particular at least 2.5 and preferably at most 100, particularly preferably at most 20, in particular at most 10.

auf, wobei m ganzzahlige Werte von mindestens 1 annehmen kann und R⁴ und R⁵ unabhängig voneinander für Wasserstoff, Kohlenwasserstoffreste, Heteroatome oder heteroatomhaltige Gruppen stehen kann.(W1) preferably has the structure of general formula (I)

in which m can assume integer values of at least 1 and R ⁴ and R ⁵ independently of one another can stand for hydrogen, hydrocarbon radicals, heteroatoms or heteroatom-containing groups.

The term heteroatom in the present invention includes all elements except hydrogen and carbon and is preferably oxygen, nitrogen, phosphorus, sulfur, fluorine, chlorine, bromine or iodine, preferably oxygen, nitrogen, fluorine or chlorine.

m preferably assumes values of 1 to 10, preferably 2 to 4, preferably 2 or 3, in particular 2.

R ⁴ and R ⁵ independently of one another preferably represent hydrogen, C ₁ -C ₂₀ hydrocarbon radical or the radical of a polymer, preferably hydrogen or C ₁ -C ₂₀ n-alkyl radical or the radical of a polyolefin or of an olefin copolymer, in particular of a polyethene or polypropene. For example, R ⁴ and R ⁵ may be selected such that the formula (I) is succinic anhydride, glutaric anhydride, phthalic anhydride, a polyolefin-maleic anhydride graft polymer such as a polyethene-maleic anhydride graft polymer or a polypropene maleic anhydride graft polymer, or an olefin Maleic anhydride copolymer such as ethylene-maleic anhydride copolymer.

(W2) preferably has the structure of general formula (II) H ₂ NR ⁶ (II) in which R ^{6 may be} hydrogen, a hydrocarbon radical, the radical of a polymer, a heteroatom or heteroatom-containing groups.

Preferably, R ^{6 is} hydrogen, a hydroxy group, an amino group or an optionally substituted and optionally further NH ₂ groups having C ₁ -C ₄₀ hydrocarbon radical, preferably an unsubstituted or substituted with further NH ₂ groups C ₁ -C ₄₀ hydrocarbon radical, more preferably for an unsubstituted or substituted with further NH ₂ groups C ₄ -C ₃₀ hydrocarbon radical, in particular a C ₆ -C ₂₀ hydrocarbon radical.

Examples of radicals R ⁴ , R ⁵ and R ⁶ are hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, (1-ethylpentyl), n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, benzyl, 2-naphthyl, 3-naphthyl.

A primary product (W12) obtainable from (W1) and (W2) preferably has the structure of general formula (III) R ⁶ -N (H) -C (= O) - [C (R ⁴ ) (R ⁵ )) _m -C (= O) OH (III) in which R ⁴ , R ⁵ , R ⁶ and m can assume the meanings defined above.

In general, (W1) and (W2) form on contact spontaneously the primary product (W12), the rate of formation may depend upon the conditions and the choice of the substituents R ^4, R ^5, R ⁶ and by the choice of m. For the process according to the invention optionally (W1) and (W2) can be added separately or (W12) can be preformed and added as such. If (W1) several anhydride groups or (W2) more amino groups per molecule or on, then the corresponding reactions to primary products (W12) for each - for one or more - amino or anhydride group per molecule take place.

In a preferred embodiment of the process according to the invention, it is ensured that (W12) has a solubility in the polymer (P) - [- (S)] s in that the radicals R ⁴ , R ⁵ in (W1) or in (W12) and R ⁶ in (W2) or in (W12) are chosen so that they have a total of at least 1 carbon atom. Preferably, R ⁴ , R ⁵ and R ^{6 have} a total of at least 2, preferably at least 4, more preferably at least 6, in particular at least 8 carbon atoms. Provided that R ⁴ , R ⁵ and R ^{6 are} not radicals of a polymer, R ⁴ , R ⁵ and R ⁶ preferably have a total of at most 100, preferably at most 70, particularly preferably at most 40, carbon atoms.

In a particularly preferred embodiment (W1) is selected from succinic anhydride or a maleic anhydride graft polymer or a maleic anhydride copolymer and component (W2) of a primary amine having a C ₄ -C ₃₀ hydrocarbon group, said hydrocarbon group being zero or one more NH ₂ Or the primary product (W12) obtainable by reaction of these selections for (W1) or (W2) is used.

The primary product obtainable from (W1) and (W2) is capable of splitting off water, usually according to the reaction:

Surprisingly, it has been found that this reaction can be controlled by a suitable choice of starting materials and temperature profiles such that the splitting off kinetics of the water and the resulting crosslinking of the polymer (P) - [- (S)] s allow the process according to the invention to be carried out. The crosslinking is preferably carried out into deep layers.

The process step (iii) according to the invention is carried out at selected temperatures T1, T2 and T3, respectively, wherein T1 is relative to the melting range of the crosslinkable polymer being processed, i. H. relative to temperature T0, T2 relative to T1 and T3 relative to T2.

The difference between T1 and T0 is preferably at least 5 K, preferably at least 10 K, particularly preferably at least 15 K. The difference between T1 and T2 is preferably at least 10 K, preferably at least 20 K, particularly preferably at least 30 K. The temperature T2 becomes after process step (ii) preferably at least 1 minute, preferably at least 10 minutes, more preferably at least 30 minutes applied, and preferably at most 48 hours, preferably at most 12 hours, more preferably at most 4 hours long.

The temperature T2 can be applied immediately after the process step (ii) or at a time interval, wherein the process product can be stored in the meantime at a temperature below T2.

As crosslinking increases, the thermal loadability that can be applied to the product without loss of shape increases due to crosslinking. Preferably, the temperature T2 is kept constant during the crosslinking or increased in one or more steps or continuously to a temperature T3, where: T3> T2. In this case, T3 may be larger, smaller or equal to T1. The temperature T3 is preferably used for at least 1 minute, preferably at least 10 minutes, more preferably at least 30 minutes, and preferably at most 48 hours, preferably at most 12 hours, more preferably at most 4 hours, at which times the duration of any intermediate temperature steps of T2 after T3 are already taken into account.

The method is carried out by suitable amounts of water dispensers (component (B)) and by choosing a suitable temperature profile in the crosslinking step (iii) so that products with a gel content (determination method DIN EN 579 ) of preferably> 50%, preferably> 65%, particularly preferably> 70%. The process is carried out by suitable amounts of water dispensers (component (B)) and by choosing a suitable temperature profile in process steps (i) and (ii) such that directly after process step (ii) and before process step (iii) products with a Gel content according to the method of determination DIN EN 579 of preferably <50%, preferably <45%, particularly preferably <40% are obtained. This means that during the execution of the method steps (i) or (ii) the composition has gel contents of preferably <50%, preferably <45%, particularly preferably <40%. The temperature profile defines the choice and duration of the applied temperatures T2 and the choice and duration of the optionally applied temperature T3 as well as the selection and duration of optional temperature intermediate steps from T2 to T3. The amounts of water dispenser and the appropriate temperature profile to be selected to achieve individually desired gel contents before and after process step (iii) can be readily determined by those skilled in the art using the method disclosed in the instant specification. If catalysts are present, catalyst effects as described below must be taken into account.

The molar ratio of (W1) to (W2) is, based on the particular amount of cyclic carboxylic anhydride or amino groups present, preferably in the range 10: 1 to 1:10 selected, preferably in the range 5: 1 to 1: 5, especially preferably in the range 2: 1 to 1: 2, in particular 1: 1. The amount of carboxylic acid anhydride or amino groups present in the deficit determines the Amount of releasable water from the forming primary product (W12) according to the water-generating reaction described above. The amount of releasable water is chosen to achieve the desired degree of crosslinking, those skilled in the art can readily determine the amount required by orienting experiments, see also the Examples. Preferably, the amount of releasable water is adjusted by selecting the amounts of (W1) and (W2) or (W12), respectively, so that at least 0.1 equivalents, at most 5 equivalents of water per silane group - (S) can be released preferably at least 0.2 equivalents, in particular at least 0.3 equivalents and particularly preferably at most 2 equivalents, in particular at most 1 equivalent. For the condensation of two silane groups - (S) to form a disiloxane unit, theoretically, 0.5 equivalents of water are required according to the underlying net reaction.

In addition to the water that can be released from the water dispenser system (component (B)), crosslinking by water access from the atmosphere or by artificial humidification is possible, but not essential. Especially when crosslinking thick moldings (usually> 2 mm), the water required for the crosslinking is preferably at least partially made available from the water dispenser system (component (B)), since the diffusion of corresponding amounts of water from the outside with a larger layer thickness of the durchzuvernetzenden molding increasingly long lasts.

The composition containing the components (A) and (B) may optionally be added with catalyst such as acids, bases or metal compounds. Examples of catalysts are alkylbenzenesulfonic acids, carboxylic acids, phosphoric acid mono- and dihydrocarbyl esters, amine, amidine or guanidine bases, carbonates or bicarbonates, compounds of titanium, bismuth or tin, such as titanium (IV) isopropylate or dibutyl or dioctyltin dilaurate or oxide. Preferably, the process is carried out with less than 0.1% by weight of added catalyst, preferably without added catalyst, in particular without tin-containing catalysts. Catalysts can be chosen to catalyze the crosslinking of the silane groups (S) and / or the release of water from the water delivery system. Experts can easily determine the effects of individual catalysts by preliminary experiments.

The invention can be further carried out with further optional additives, such as stabilizers (eg antioxidants), dyes, pigments, viscosity reducers (eg oils), addition of further polymers.

All the above symbols of the above formulas each have their meanings independently of each other.

In the following examples, unless otherwise indicated, all amounts and percentages are by weight, all pressures are 0.10 MPa (abs.) And all temperatures are 20 ° C.

Examples

Material 1: Polymer (P) - [- (S)] s.

As the polymer (P) - [- (S)] s, a polyethene grafted with vinyltrimethoxysilane was used. These are Eltex A4040 (Ineos), which is reacted with vinyltrimethoxysilane according to the method described in WO2009 / 033908A2 was grafted in there, referred to as "Example 9" rule (Amounts used: Eltex A4040, 98.9 wt%; Di-tert-butyl peroxide, 0.1% by weight; vinyltrimethoxysilane (GENIOSIL ^® XL 10 from Wacker Chemie AG). The graft product (polyethene-graft-vinyltrimethoxysilane) had a silicon content of 0.32 as measured by ICP / OES (inductively coupled plasma / optical emission spectroscopy) measurement % By weight, corresponding to a content of grafted vinyltrimethoxysilane (silane groups (S)) of 1.7% by weight (non-grafted silane was volatilized according to the cited specification), and a molar mass of the number average Mn 26 kg / mol and im Weight average Mw 212 kg / mol on (gel permeation chromatography, GPC) and a gel content of 0% (measurement by extraction according to DIN EN 579 ). The measured silane content of 1.7% by weight corresponds to a mean content of 3 units graft-vinyltrimethoxysilane per macromolecule or 9 hydrolyzable groups X (here: X = OMe) per macromolecule for a number-average molar mass of Mn = 26 kg / mol. Material 1 had a content of grafted vinyltrimethoxysilane units of 114.7 mmol / kg (calculated from 1.7% by weight). By differential scanning calorimetry (DSC, 10 K / min) was determined for the endothermic melting range, a lower limit of 59 ° C, a peak at 129 ° C and an upper limit of T0 = 142 ° C and a heat of fusion of 159 J / g ,

Component (B) containing water dispenser system (W1) and (W2)

Succinic anhydride (W1) or dodecylamine (W2) were added as component (B). The amounts are given in the respective example.

Material 2: Component (B) containing primary product (W12) - Production from (W1) and (W2)

• Succinic anhydride + C ₁₂ H ₂₃ -NH ₂ → C ₁₂ H ₂₃ -N (H) -C (= O) -CH ₂ CH ₂ -C (= O) OH [4- (dodecylamino) -4-oxobutanoic acid]

1.0 g (10 mmol) of succinic anhydride was suspended in 250 ml of toluene and 1 equivalent (10 mmol) of dodecylamine was added. The reaction mixture was heated at 80 ° C for 3 hours to give a clear solution. Upon cooling, a white solid precipitates slowly, which is filtered off and washed several times with toluene. The vacuum-dried solid (quantitative yield; identity: 4- (dodecylamino) -4-oxobutanoic acid, hereinafter referred to as "material 2") is characterized by NMR spectroscopy. ¹ H-NMR (300.13 MHz, d6-DMSO, 298 K): δ / ppm = 7.80 (m, ¹ H, CH ₂ -NHCO); 2.99 (m, 2H, NH-CH ₂ ); 2.40 (t, 2H, CH ₂ -CO-NH); 2.28 (t, 2H, CH ₂ -COOH); 1.30 (m, 2H, NH-CH ₂ -CH ₂ -); 1.24 (m, 18H, - (CH ₂ ) 9-CH ₃ ); 0.85 (t, 3H, CH _3).

Material 3: catalyst masterbatch.

As material 3, a masterbatch consisting of 1% by weight of dibutyltin dilaurate (DBTL) and 99% by weight of polyethene (Eltex A4040) was used.

Examples of crosslinking of shaped bodies of moderate layer thickness

Example 1 (Inventive) - Separate Dosage of (W1) and (W2). - Process steps (i) and (ii)

Mixing ratios: material 1 (99.3% by weight); Succinic anhydride (W1, 0.25% by weight); Dodecylamine (W2, 0.45% by weight). Process step (i) (Thermoplastic processing): All feeds were thoroughly mixed at room temperature. The mixture was dosed into a Brabender Mini Compounder KETSE 12/36 at 2 D (at 24 mm) (dosing screw: 15 rpm, extruder screws: 100 rpm, 5 heating zones, temperature profile: 150-155-160-165-170 ° C → nozzle, T1 = 170 ° C).

Process step (ii) (Shaping): The die was equipped with a round hole tool which produced cylindrical samples (strands) of 2.5 mm diameter.

The composition had a content of grafted vinyltrimethoxysilane units (Groups - (S)) of 114 mmol / kg, of succinic anhydride (W1) of 25 mmol / kg and of dodecylamine (W2) of 24.5 mmol / kg. The amount of water theoretically releasable from a condensation reaction of (W1) with (W2) to form the cyclic imide is thus 24.5 mmol / kg (approximately 0.2 equivalents based on the amount of groups of groups present - (S)) ,

Example 2 (Inventive) - Separate Dosage of (W1) and (W2). - Process steps (i) and (ii)

The following mixing ratios were selected: material 1 (98.6% by weight); Succinic anhydride (W1, 0.5% by weight); Dodecylamine (W2, 0.9% by weight). Carrying out process steps (i) and (ii) as in Example 1; T1 = 170 ° C. The composition had a content of grafted vinyltrimethoxysilane units (groups - (S)) of 113 mmol / kg, of succinic anhydride (W1) of 50 mmol / kg and of dodecylamine (W2) of 49 mmol / kg. The amount of water theoretically releasable from a condensation reaction of (W1) with (W2) to form the cyclic imide is thus 49 mmol / kg (around 0.4 equivalents based on the amount of group (- S) contained).

Example 3 (according to the invention) - Dosing of a primary product (W12). - Process steps (i) and (ii)

The following mixing ratios were selected: material 1 (99.3% by weight); Material 2 (W12, 0.7% by weight). Carrying out process steps (i) and (ii) as in Example 1; T1 = 170 ° C. The composition had a content of grafted vinyltrimethoxysilane units (groups - (S)) of 114 mmol / kg and material 2 (W12) of 24.7 mmol / kg. The amount of water, calculated from a condensation reaction of (W12) is releasable to the cyclic imide, is thus 24.7 mmol / kg (about 0.2 equivalents based on the amount of substance contained in groups - (S)).

Example 4 (noninventive comparative example) omission of W1.

The following mixing ratios were selected: material 1 (99.1% by weight); Dodecylamine (W2, 0.9% by weight). Carrying out analogous process steps (i) and (ii) as in Example 1; T1 = 170 ° C.

Example 5 (noninventive comparative example) Comparison product without water dispenser.

The following mixing ratios were selected: material 1 (95% by weight); Material 3 (5% by weight). Procedure analogous to process steps (i) and (ii) as in Example 1; T1 = 170 ° C.

Process step (iii) crosslinking at temperature T2 or at temperature profile T2, T3 (inventive examples) and analogous application of process step (iii) to comparative examples according to the invention:

The strands of Examples 1-5 were screwed into tubes in atmospheric air and heated in a heating block. Before swapping out (see Table 1, line a - corresponds to state after process step (ii) and before process step (iii)) and after defined swapping times at defined temperatures T2 (process step (iii)) samples were cut out of the strand center and subjected to a gel content determination; Furthermore, the dimensional stability was evaluated during the outsourcing (lines b-k). Further samples were subjected in analogous procedure to a stepwise temperature program T2, T3 (process step (iii) / alternative embodiment), the temperature steps are shown in Table 1 in their application order and duration, the dimensional stability was also evaluated (lines l-s).

The dimensional stability was evaluated according to the following criteria:
Assessment "++": unchanged form.
Assessment "+": strand bends slightly, but form remains as a strand (curved cylinder shape).
Judgment "" 0 ": strand sinks together.
Assessment "-" strand shape is destroyed.

n. b.: nicht bestimmt
* erfindungsgemäßes Beispiel
** nicht-erfindungsgemäßes VergleichsbeispielGel contents were reduced by extraction DIN EN 579 measured. Table 1. Gel contents in% after application of the respectively specified outsourcing conditions.

nb: not determined
Inventive example
** non-inventive comparative example

The measurements in lines a-k show that with the non-inventive embodiments (Examples 4 and 5) a sufficient crosslinking (ie preferably> 50% gel content, preferably> 65%, more preferably>70%; DIN EN ISO 15875-2 : at least 65% gel content for pipe applications) is achieved only by destroying the mold (which would render useless for corresponding products / moldings), while adequate sufficient cross-linking with retention of shape is possible with the embodiments according to the invention (Examples 1, 2 and 3). The lines l-s show that the shape retention can be additionally improved by a suitable temperature program.

Non-inventive Example 5 (Comparative Example) shows that gel contents of 40% directly after extrusion for corresponding formulations without water dispenser are quite common, can be processed and therefore do not constitute a hindrance to the practice of the invention. The gel content already present before aging is caused by water which is present in the starting materials and / or enters during the process control.

Examples of crosslinking of shaped bodies of coarse layer thickness

The same mixtures were used as described in Examples 1-5 and processed in process step (i) at the same temperature T1 of 170 ° C, but the extruder was now equipped in step (ii) with a square hole tool, the strands with square cross section (Edge length of the cross-section square: 7 mm) generated. Table 2 gives the examples. Table 2. Preparation of Test Specimen with Large Film Thickness. Example no. Mixture (components (A) and (B) analogously to example no. Tool 6 * 1 square (7 mm edge length) 7 * 2 8th * 3 9 ** 4 10 ** 5 Inventive example
** non-inventive comparative example

Process step (iii) crosslinking at temperature T2 or at temperature profile T2, T3 (inventive examples) and analogous application of process step (iii) to comparative examples according to the invention:

The respective product was outsourced under different conditions. The crosslinking kinetics was measured as a function of the layer thickness: layer 1, surface up to 1 mm depth; Layer 2, 1 mm to 2 mm deep; Layer 3, complete core (2 mm to 3.5 mm depth).

Table 4 shows the temperatures used in step (iii) T2 and T2 and T3, z. T. with intermediate temperature steps, and the application times of the temperatures and the resulting results for the crosslinking. The strands of Examples 6-10 were bolted to atmospheric air in tubes and heated in a heating block. Before outsourcing and after defined aging times at defined temperatures, the layers described were stripped of the strands and subjected to a gel content determination; Furthermore, the dimensional stability was evaluated during the outsourcing (see Table 4). The dimensional stability was evaluated according to the same criteria as above. Table 4. Gel contents in% after application of the respectively specified outsourcing conditions. Example no. Gel content per layer 11 * Strand from Example 6 Layer 1 Layer 2 Layer 3 before outsourcing 34 33 36 120 ° C, 60 min 48 40 35 120 ° C, 180 min 62 52 53 140 ° C, 60 min 63 57 59 160 ° C, 60 min 77 71 71 dimensional stability ++ (all outsourcing conditions) 12 * Strand from Example 7 Layer 1 Layer 2 Layer 3 before outsourcing 44 43 46 120 ° C, 60 min 61 57 52 120 ° C, 180 min 68 67 70 140 ° C, 60 min 63 57 52 160 ° C, 60 min 79 76 73 120 ° C, 60 minutes; 140 ° C, 60 min 77 74 71 120 ° C, 60 minutes; 160 ° C, 60 min 81 79 79 120 ° C, 60 minutes; 140 ° C, 60 minutes; 160 ° C, 60 min 79 80 77 dimensional stability ++ (all outsourcing conditions) 13 * Strand from Example 8 Layer 1 Layer 2 Layer 3 before outsourcing 43 44 41 120 ° C, 60 min 58 50 50 120 ° C, 180 min 66 61 59 140 ° C, 60 min 64 60 60 160 ° C, 60 min 71 68 71 120 ° C, 60 minutes; 140 ° C, 60 min 67 65 65 120 ° C, 60 minutes; 160 ° C, 60 min 75 72 69 120 ° C, 60 minutes; 140 ° C, 60 minutes; 160 ° C, 60 min 77 74 71 dimensional stability ++ (all outsourcing conditions) 14 ** Strand from Example 9 Layer 1 Layer 2 Layer 3 before outsourcing 25 25 25 120 ° C, 60 min unchanged 120 ° C, 180 min 140 ° C, 60 min 160 ° C, 60 min 50 25 25 dimensional stability ++ (120 ° C) - (140 ° C, 160 ° C) 15 ** Strand from Example 10 Layer 1 Layer 2 Layer 3 before outsourcing 45 43 43 120 ° C, 60 min unchanged 120 ° C, 180 min 140 ° C, 180 min 55 43 43 160 ° C, 180 min 65 45 43 dimensional stability ++ (120 ° C) 0 (140 ° C, 160 ° C) Inventive example
** non-inventive comparative example

Examples 11, 12 and 13 according to the invention show how, with the aid of the method and composition described, crosslinking up to thick layers can be achieved without having to supply water from outside by diffusion. By contrast, Examples 14 and 15 (Comparative Examples), which are not in accordance with the invention, show that good accessibility is not achieved without water access and without internal water dispensers.

Example 16. Crosslinking with additional external water supply by diffusion (according to the invention). - Process step (iii)

The strand of Example 7 was aged in liquid water at a temperature T2 of 120 ° C (sealed pressure tube, self-adjusting pressure) for 60 minutes. The strand was dried. For the individual layers were subsequently measured for the following gel contents: layer 1, 71%; Layer 2, 71%; Layer 3, 71%. This example shows, in comparison to example 12, that the crosslinking can optionally be further accelerated by the introduction of water via diffusion.

In the first place, the examples show that with the process according to the invention, crosslinking is possible at a temperature below the polymer melting point and below the previously applied processing temperature by the described water-dispensing system, so that subsequent crosslinking is possible through retention of shape.

The examples further demonstrate to those skilled in the art how to drive desired levels of crosslinking by simple orienting experiments by varying the amount of water dispensers (component (B), compare Example 1 versus Example 2 or Example 6 versus Example 7) and the aging temperature.

The examples show that the appropriate choice of R ⁴ , R ⁵ and R ⁶ described above allows for better processing of the described composition with respect to the total number of carbon atoms contained in these radicals. This distinguishes the present invention from the Scriptures WO2009 / 012069A1 in which water dispensers are described without a particularly selected substitution pattern, resulting in poorer processability, so that a temperature profile in which thermoplastic processing takes place at a higher temperature than the subsequent crosslinking, in WO2009 / 012069A1 could not be realized. Furthermore, in the Scriptures WO2009 / 012069A1 described networking carried out in the presence of tin-containing catalysts, which inevitably the element-specific toxicity of the tin is its own. In contrast, the present invention is entirely without added catalyst.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2006/0258796 A1 [0004, 0004]
• EP 149782 [0005]
• WO 85/03080 [0005]
• WO 2009/012069 A1 [0006, 0006, 0077, 0077, 0077]
• WO 2009/058545 A2 [0006, 0006]
• WO 2009/033908 A2 [0054]

Cited non-patent literature

• Standard DIN EN ISO 15875-2 [0004]
• DIN EN 579 [0047]
• DIN EN 579 [0047]
• DIN EN 579 [0054]
• DIN EN 579 [0067]
• DIN EN ISO 15875-2 [0068]

Claims (10)

Method in which a composition containing the components (A) a moisture crosslinkable polymer (P) - [- (S)] s in which (P) - is the radical of a polymer, - (S) represents silane groups and s is an integer of at least 1, and (B) a water dispenser (W) comprising a cyclic carboxylic acid anhydride (W1) in which the anhydride group is part of a ring system, and a primary amine (W2), or a primary product (W12) obtainable from (W1) and (W2), is subjected to a process of taking the steps (i) thermoplastic processing of the composition at a temperature T1 above the melting range of the polymer (P) - [- (S)] s used, d. H. above temperature T0, which defines the upper limit temperature of the endothermic heat flux during the melting process of the polymer (P) - [- (S)] s, determined by thermal analysis, (ii) shaping, (iii) releasing water and crosslinking at a temperature T2 without destroying the mold produced in step (ii), by carrying out this step at a temperature T2 below the temperature T1, so that the relation T1> T2 holds, having. Process according to Claim 1, in which (P) - a radical of a polymer having a molar mass of weight average Mw is at least 1000 g / mol or the number average Mn is at least 1000 g / mol. A process as claimed in claim 1 or 2, wherein (P) - is the radical of an inorganic or organic polymer whose units are wholly or partly derived from the monomers dimethylsiloxane or from olefinically unsaturated monomers or from dicarboxylic acids or carbonic acid and diols or diamines or from lactones or Derive lactams or cyclic carbonic esters or cyclic ethers or alkene oxides. The process of claim 1 to 3, wherein - (S) is a silane group -R ² -SiX _n R ¹ _3-n wherein X is a hydrolyzable group or hydroxy group and R ^{1 is} a non-hydrolyzable group and n is 0 , 1, 2 or 3 and -R ² - represents a divalent group or a divalent atom or a bond, wherein the individual silane groups - (S) can independently assume different substitution patterns, provided that the average number of Groups X per unit (P) - [- (S)] s is greater than or equal to 2. The process of claims 1 to 4, wherein the polymer (P) - [- (S)] s is selected from ethene-vinyltrimethoxysilane copolymer, ethene-vinylacetate-vinyltrimethoxysilane copolymer, polyethene-vinyltrimethoxysilane graft polymer, polypropene-vinyltrimethoxysilane graft polymer , Polybut-1-ene-vinyltrimethoxysilane graft polymer and vinyltrimethoxysilane graft polymer of an ethene-alpha-olefin copolymer. Process according to Claims 1 to 5, in which (W1) the structure of the general formula (I)

where m can have integer values of at least 1 and R ⁴ and R ⁵ independently of one another can stand for hydrogen, hydrocarbon radicals, heteroatoms or heteroatom-containing groups. Process according to Claims 1 to 6, in which (W 2) the structure of the general formula (II) H ₂ NR ⁶ (II) wherein R ^{6 may be} hydrogen, a hydrocarbon radical, the radical of a polymer, a heteroatom or heteroatom-containing groups. Process according to Claims 1 to 7, in which the primary product (W12) obtainable from (W1) and (W2) has the structure of the general formula (III) R ⁶ -N (H) -C (= O) - [C (R ⁴ ) (R ⁵ )] _m -C (= O) OH (III) wherein R ⁴ , R ⁵ , R ⁶ and m may have the meanings defined in claims 6 and 7 above. Process according to claims 1 to 8, wherein in process step (iii) products with a gel content according to the determination method DIN EN 579 of> 50% are obtained. Process according to Claims 1 to 9, in which products having a gel content according to the determination method DIN EN 579 of <50% are obtained directly after process step (ii) and before process step (iii).