SE457960B - SET FOR MANUFACTURE OF A MULTILAYERED POLYMER MATERIAL OF SILAN CONTAINING OLEPHINE COPY POLYMER - Google Patents

Description

457 960 10 15 20 25 30 35 2 layer. By thin layer is meant in the present context a thickness corresponding to film and foil, i.e. up to about 2 mm, preferably at most about 1 mm, more preferably goat no more than about 0.6 mm.

In production by, for example, extrusion of a multilayer material, in which at least a layer is crosslinked, it is important that the crosslinking takes place only after the mixture has left the extruder, because premature crosslinking or hardening ("precu- ring ") in the extruder means that can be maintained and that it an even production does not not obtained the product exhibits satisfactory quality. One beginning crosslinking or hardening already in the extruder (or other equivalent equipment) causes gelation and adhesion of polymer gel to the surfaces of the equipment with risk of clogging as a result. To counteract this equipment must be cleaned from adherence polymer gel, and at each cleaning must the equipment is switched off with the consequent case.

Another disadvantage is that the gel lumps that form and which do not get caught in the manufacturing equipment and clogs it, discharges and is found in the product as disfiguring and unwanted lumps. In thin layers, such as films and foils, such lumps are unacceptable and usually renders the product unusable.

The unwanted hardening can be counteracted by incorporate into the polymer composition substances which counteract hardening, so-called hardening retarders. In the case of polymers, whose crosslinking is dependent on moisture, such as those silanes, such hardening computers can be constituted of desiccant. Addition of hardening retarders however, involves the introduction of an additional component in the polymer composition, which makes it more expensive and in addition may be less desirable e.g. in contact with food. On the addition of such additional components as pre-curing agents computers can be avoided, this is consequently an advantage. 10 15 20 25 30 35 457 960 3 The present invention has for its object to provide seek to eliminate the above-mentioned disadvantages of position of crosslinked, silane-containing polymer products products, more specifically silane copolymer material of polyolefins, which are crosslinked by means of hydro- lysable silane compounds.

According to the invention there is provided a method of position of a crosslinked polymeric product, which includes at least one catalyst-crosslinked polymer layer, characterized in that a multilayer polymeric material, such as a film, which comprises the least wet layer of one silane group-containing olefin copolymer which is crosslinked by the action of water and a silanol condensate catalyst, and at least one other, from the cross-linking bare silane free layer, which includes silanol condensation catalyst, is produced by co-extrusion of the layers, and introducing the silanol condensation catalyst into the material to the catalyst-containing layer before extrusion. and that crosslinking of the silane group containing the layer is provided by the multilayer polymer the material is exposed to the action of water and by the silanol condensation catalyst is caused to diffuse into the silane group-containing layer.

Additional features of the invention will become apparent of the following description and claims.

As mentioned above, it is crosslinkable the polymeric material in the invention of a silane content copolymer, by which is meant an olefin polymer, preferably an ethylene homopolymer or copolymer, which contains crosslinkable silane groups, which have been arranged in the polymer by copolymerization. That's the way they are crosslinkable silane groups attached to the polymer chain are thus of importance, and for example unsaturated silane compounds are copolymerized with oleic, aminosilane compounds can react with acrylate esters, while inventions however, does not include graft polymers in which silyl peroxide is decomposed and grafted onto the finished product the polymer by direct reaction with the polymer chain. 457 960 10 15 20 25 30 35 4 Preferably, the silane-containing polymer has obtained by copolymerization of an olefin, suitably ethylene, and an unsaturated silane compound, which through the formula RsiR'nY3_n where R is an ethylenically unsaturated hydrocarbyl or hydro- carbyloxy group, R 'is an aliphatic, saturated hydrocarbyl group, Y is a hydrolyzable organic group, and n is 0, 1 or 2. If there is more than one Y group, need these are not identical, Special examples of the unsaturated silane compound are those wherein R is vinyl, allyl, isopropenyl, butenyl, cyclohexenyl or gamma- (meth) acryloxypropyl, Y is meth oxy, ethoxy, formyloxy, acetoxy, propionyloxy or a alkyl or arylamino group, and R 'is a methyl, ethyl, propyl, decyl or phenyl group.

An especially preferred, unsaturated silane compound represented by the formula 'cH2 = cHsi (oA) 3 where A is a hydrocarbyl group having 1-8 carbon atoms, approximately 1-4 carbon atoms.

The most preferred compounds are vinyltrimethoxy- silane, vinylbismethoxyethoxysilane, vinyltriethoxysilane, gamma- (meth) acryloxypropylsilane, and vinyltriacetoxysilane.

The copolymerization of the olefin (ethylene) and the unsaturated silane compound can be carried out under which preferably suitable conditions, which entail copolymerization of the two monomers.

In addition, the copolymerization can be carried out in the presence of one or more other comonomers, which are co- polymerizable with the two monomers. Examples of such comonomers are: (a) vinyl carboxylate esters, such as vinyl acetate and vinyl pivalate, (b) (meth) acrylates, such as methyl (meth) acrylate, ethyl (meth) acrylate and butyl (meth) acrylate, (c) olefinically unsaturated carboxylic acids, such as (meth) acrylic acids acid, maleic acid and fumaric acid, (d) (meth) acrylic acid derivatives, such as (mct) acrylonitrile and (meth) acrylamide, and (e) vinyl 10 15 20 25 30 457 960 5 ethers such as vinyl methyl ether and vinyl phenyl ether. Of these comonomers, vinyl esters of monocarboxylic acid are preferred. acids having 1-4 carbon atoms, such as vinyl acetate, and (meth) - acrylates of alcohols having 1-4 carbon atoms, such as methyl (meth) ~ acrylate. An especially preferred comonomer is butyl acrylate. Two or more such, olefinically unsaturated compounds can be used in combination. Use this the term "(meth) acrylic acid" is intended to include both acrylic acid and methacrylic acid. The comonomer content in sampoly ~ may amount to about 40% by weight, preferably about 0.5-35% by weight, most preferably about 1-25% by weight of the copolymer. lakes. in The silane-containing polymer of the invention contains the silane compound in a content of 0.001-15% by weight, preferably 0.01-5% by weight, particularly preferably 0.1-3 weight%.

The crosslinking of the polymer takes place by so-called moisture curing. by the action of water the silane group hydrolyzed during the decomposition of alcohol and formation of silanol. The silanol groups are then crosslinked below effect of a so-called silano1 condensation catalyst by a condensation reaction during decomposition of water.

In general, all are silanol condensation catalysts useful in the invention, and more particularly selected those among carboxylates of metals such as tin, zinc, iron, lead and cobalt, organic bases, inorganic acids and organic acids.

Particular examples of silanol condensation catalyst are dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, stannous acetate, stannous caprylate, lead naphthenate, zinc caprylate, cobalt naphthenate, ethylamines, dibutylamine, hexylamines, pyridine, inorganic acids, such as sulfuric acid and hydrochloric acid, and organic acids, such as toluenesulfonic acid, acetic acid, stearic acid and maleic acid. Particularly preferred catalyst compounds are the tin carboxylates. 457 960 10 15 20 25 30 35 6 The amount of silanol condensation catalyst which used is generally of the order of 0.001-10% by weight, preferably o, o1-s folded, in particular o, o3-3 fold, relative to the amount of silane-containing polymer in the sitionen.

The crosslinkable polymer can, as usual is the case with polymer compositions, contain different additives. Examples of such additives are miscible thermoplastics, stabilizers, lubricants agents, fillers, colorants, and foaming agents.

Among additives in the form of miscible thermoplastics Mention may be made of miscible polyolefins, such as polyethylene with low density, medium density and high density, polypropylene, chlorinated polyethylene, and various copolymers including ethylene and one or more other monomers (eg vinyl acetate, methyl acrylate, propylene, butene, hexene and similar). The above polyolefin can be used alone or as a mixture of several polyolefins.

The content of polyolefin in the composition can be up to 70% by weight, based on the sum of the amounts thereof polyolefin and the silane-containing polymer.

Examples of fillers include inorganic fillers, such as silicates, such as kaolin, talc, morillonite, zeolite, mica, silica, calcium silicate, asbestos, glass powder, fiberglass, calcium carbonate, gypsum, magnesium carbonate, magnesium hydroxide, carbon black, titanium oxide and the like. The content of this inorganic filler may be up to 60% by weight, based on the sum of the the weights of the agent and the silane-containing polymer.

It should be noted that the above refers to the composition of the preferred crosslinkable polymer of the multilayer polymeric material of the invention.

The multilayer polymeric material of the invention includes at least one crosslinkable layer, preferably of this preferred polymer, and at least one layer 10 15 20 25 30 457 960 7 of other material. Such other materials are those that commonly used, for example in laminate films or foils, together with polyolefins, and as an example can mention is made of saturated polyesters, polyamides, saponified products of ethylene-vinyl acetate copolymers, polyol- veneers, polystyrenes, polyvinyl chlorides, polyvinylidene chlorides, and acrylic resins, paper, fabrics, and similar. The multilayer polymeric material at cellophane, the invention may further comprise a film or foil of metal, such as aluminum, iron and copper; The preparation of the multilayer polymer material The material of the invention is carried out by coextrusion.

If necessary, the adhesion between the layers can increased by arranging an anchoring layer between the layers.

As stated previously, the invention relates generally to grips least a multilayer polymeric material which includes a catalyst-crosslinked silane containing polymer layers. This latter layer is thin, ie has a thickness of not more than about 2 mm, preferably generally no more than approx. 1 mm. The invention is particular useful in co-extruded multilayer structures, such as film, extrusion coating and bottles. Up- The findings will be described in more detail below with reference to extrusion coatings and movies.

In the drawings, Fig. 1 shows a cross section of a three-layer polymer film.

Fig. 1 shows a three-layer film 1. Of course that the invention is not limited to just three-layer films without laminate with everything from two layers up to in principle an infinite number of layers are covered by the invention. provided that at least one of the layers is a silane meshable layer. The catalyst content the holding layer can in principle be arranged anywhere 457 960 10 20 25 30 8 in the film structure and it is not necessary that arranged so as to be adjacent to the silane (s) crosslinkable layers. A prerequisite, however, is that any intermediate layers between the catalyst the layer containing the filter and the silane network the absorbable layer does not absorb, react with or acts as a barrier against the catalyst. It showed the three-layer film consists of three layers.2, 3 and 4, which on the figure is shown to have the same thickness, but as in practice may have different thicknesses. Polymer layers 2 'and 4 are silane crosslinkable and consist of the former described, silane-modified polyolefin, preferably an ethylene vinyl alkoxysilane copolymer, a silane modified ethylene polymer or an ethylene / butyl acrylate / vinyl alkoxysilane terpolymer, which is crosslinkable under the influence of moisture in the presence of a silanol condensation catalyst, such as dibutyltin dilaurate, dibutyltin diacetate or dioctyltin dilaurate. The middle layer 3 consists of a non crosslinkable polymer, such as, for example, polyethylene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, polyamide, polyethylene terephthalate, ethylene vinyl acetate, polypropylene, etc.

In conventional manufacturing of a crosslinked film as above, single film is extruded from a additional composition, which contains all the components, ie also catalyst. In such a manufacture there the catalyst is involved in the polymer composite from the outset the risk that the networking is already initiated in the extruder, resulting in gel formation with the accompanying problems and disadvantages described above digare.

To eliminate these disadvantages, one proceeds in the invention so that the catalyst for the crosslinking layer 2 and 4 are not mixed into the polymer the composition of these layers before extrusion, but instead the composition is applied to the layer 3. 10 20 25 30 35 457 960 9 Thus, during extrusion, the catalyst will present in the layer 3 so that it is then diffused sion can migrate over to layers 2 and 4 and initiate crosslinking in these layers. By the networking of the polymers in layers 2 and 4 are not initiated until after extrusion, the problems encountered are avoided the prior art. Layer 3 consists of a non crosslinkable polymer composition, i.e. a polymeric position not affected by the catalytic con satorn, as this could otherwise lead to pre-curing with the formation of gel lumps and thus cause just the problems one is trying to avoid for them both other layers 2 and 4. When in this context indicated that the layer 3 is not "crosslinkable" is meant that it is not networked with the help of the person involved the catalyst. Polymer layers 3, which are crosslinkable in other ways, which are not affected by the person involved the catalyst, can in this context be equated with non-crosslinkable polymer compositions.

While the crosslinkable layers 2 and 4 at the invention consists of the previously stated silane holding the polyolefin, layer 3 can be selected substantially free among other polymers, cellulose, fabric and the like material into which the catalyst can be introduced. Example pà such materials have been mentioned previously.

When the catalyst after the extrusion of three layers the film 1 diffused from the layer 3 to the crosslinked interlaceable layers 2 and 4, the crosslinking can be initiated by the action of water in liquid or vapor form.

The crosslinking is conveniently carried out at a temperature of the order of 20 ~ 200 ° C, usually about 20-130 ° C for a time of the order of about 10 s to l week, usually about l min to l day. The networking can be performed at atmospheric pressure or at elevated print. 457 960 10 15 20 25 10 To further facilitate the understanding of the invention, it will be elucidated below by some examples which are not intended to limit the the finding.

In the examples, the materials used, test method the conversion equipment, the extrusion mesh and the design as set out below.

USE MATERIAL = SILAN 1 Ethylene-butyl acrylate-vinyltrimethoxysilane terpolymer with 20% butyl acrylate and 2.3% vinyltrimethoxysilane. Melt index 4.5, ñ (w) 2 132000 SILAN 2 Ethylene-vinyltrimethoxysilane copolymer with 1.7% vinyltrimethoxysilane. Melt index 4.5, ñ (w) = 124ooo SILAN 3 Ethylene-methacryloxypropyltrimethoxysilane compound polymer with 1.5% methacryloxypropyltrimethoxy- silan. Melt index 2.5, Ü (w) à_l20000 CAT.OCTYL CAT.BUTYL LDPE 1 1% Dioctyl tin dilaurate in LDPE l 1% Dibutyl tin dilaurate in LDPE 2 High pressure polyethylene with: Melt index 4.0 g / 10 min Density 922 kg / m3 ü High pressure polyethylene with: Melt index 4.5 g / 10 min 919 kg / m3 202000 LDPE 2 Density fi (w) 10 20 25 30 35 457 960 ll Ethylene-vinyl acetate copolymer Melt index 1.6 g / 10 min Vinyl acetate 4% ñ Ethylene-butyl acrylate copolymer Melt index 7.0 g / 10 min Butyl acrylate content 17% 171m) 09500 TEST METHODS: ' l.Crosslinking degree: The film sample is ground and sieved so that it is used EVA EBA the part that goes through a 30 mesh net, but stops left on a 60 mesh net. The sample is placed in a 100 mesh net and a 500 ml glass flask, which is filled with xylene and add 1% antioxidant (2,2-methylene-bis-4- -methyl-tert-butylphenol). The sample is boiled for 6 hours during reflux. Then it is dried at 140 ° C for 1 hour, cooled in desiccator and weighed.

The crosslinking in the film was measured in three different stages. 1. Immediately after running the film (1-6 hours after running) 2. After storage in a conditioned room (approx. 14 days at 23 ° C and 50% relative humidity) on unrolled roll After 1 day in 60 ° C water šrêysëêëërësëi the vinylsilane films were measured at (160 ° C, 180 ° C, 200 ° C) and (0.1 s, 0.2 s and 0.5 s), the weld Weldability for three different temperatures three different contact times tested according to tensile strength test. â; 9맧_ë§92 ASTM D 1709 êrêšëïäëxäëë ISO R 1184 CONVERSION EQUIPMENT YEAR: ...._._......__._.___-__....._______.___.....___......._. 4 ...___.__ ..___._ 4 ... 1st extruder: - Screw diameter 70 mm ~ Combined LDPE / LLDPE screw, length 25 D with UCC mixing zone and 3 D long mixer unit 457 960 12 Zzdra extruder: - Screw diameter 50 mm HDPE screw, length 20 D, with 5 D long mixer unit 3rd extruder: - Screw diameter 50 mm 5 - Polyamide screw, length 23 D 3 layers rotating nozzle with diameter 200 mm and gap 1 mm šlâsleit dual slot 'fi yêslsiktsutraëëaieršër_s§§§2§s§¿a9§: ëslëssaias - 10 Screw diameters 4 1/2 ”. LDPE screws with a length of 24 D Nozzle: Dual slot, 2 x 850 mm long with 2 x 0.75 mm split Å- EXTRUCTION CONDITIONS: MOVING: The Extrusion Temperature Setting l5 for layers containing SILAN l or SlLAN.2 was below experiments from feed zone to filter: 130 ° C, 140 ° C, 10 ° C. The temperature of the filter was maintained at 150 ° C, as well the temperature in the adapter. When driving with LDPE 1, LDPE 2, EVA, CAT.0CTYL, CAT.BUTYL and mixtures thereof The corresponding temperature was: 140 ° C, 150 ° C, 160 ° C. Tempe- The temperature in the filter and adapter was 160 ° C- The temperature in the nozzle was maintained at 160 ° C.

The film was run with an inflation ratio of 3 and with a frost line of 750 mm. The total production rate was maintained at 60 kg film / hour.

Layer thicknesses for LDPE 1, LDPE 2, CAT.OCTYL, CAT.BUTYL and the mixtures of these were kept constant at 10 μm.

For SILAN 1, SILAN 2, SILAN 3, EVA, EBA As well 30 mixtures of these used 20 μm layer thicknesses.

Thus, the total film thickness in all samples was 50 μm.

EXTRUITION COATING: The temperature setting was the same for all layers and materials. From input zone to filter: 200 ° C, 240 ° C, 280 ° C, 280 ° C, 280 ° C. Tem- Temperature in filter and adapter 280 ° C. Track speed 100 m / min.

For SILAN 2, 40 μm layers were extruded, while for LD? E l as well as the CAT.BUTYL layer was 10 pm. 10 20 25 30 ku UI 457 960 13 PERFORMANCE: FILM BLOWING: Extruder and nozzle temperatures was set with LDPE 1 in the film blowing line. When constant conditions were achieved, silane more in the selected layer or layers. When the silane polymer respectively - the polymers displaced LDPE 1 were catalyzed satorn in the remaining layers. This allowed a flawless film without gel formation is produced. If, on the other hand, polymer and catalyst charged in the same extruder are crosslinked the silane polymer already in the extruder and there is a great risk for a very gel film and total crosslinking in the extrusion which in that case must be cleaned.

EXTRUCTION COATING: The extruders were started with LDPE 1 and when constant conditions were reached were invested the silane polymer in the desired extruder. When the silane polymer displaced LDPE 1, the catalyst was charged into the extruder for the remaining layers. A flawless coating without gel formation was obtained. If, on the other hand, the silane polymer and the catalyst was charged in the same extruder at the extrusion coating temperature, there was a great risk that the extruder got stuck due to crosslinking of the silane polymer in the extruder.

This is especially risky with extrusion coating where high temperatures are used and thus the risk is increased for hardening.

EXAMPLE 1 Using the above materials, equipment and methods were prepared by coextrusion multilayer films with the general configuration Silane Polymer more / Catalyst-containing layers / Silane polymer and was compared to a single layer film of silane polymer and catalyst. More specifically, the multilayer films the following composition: SILAN 1/25% KPUIHBUTYL + 75% LDPE Z / SILAN l SILAN 1/503; KAÜHBUTYL + 50% LDPE Z / SILAN l 50% SILAN 1 + 50% EB / '1/25% CAT.BUTYL + 75% LDPE 2/50% SILAN 1 + 50% EBA STLAN 2/25% KFUIHBIJTYL + 75% LDPE Z / SILAN 2 Example 1.1: Example 1.2: Example 1.3: Example 1.4: 457 960 10 15 20 25 30 35 14 Example 1.5: SILAN 3/25% CAT.BUTYL + 75% LDPE 2 / SILAN 3 Example 1.6: SILAN 2 / LDPE 2 / SILAN 2 Example 1.7: SILAN 2/20% CAT.OCTYL + 80% LDPE 1 / SILAN 2 Example 1.8: SILAN 1/20% Cat.0CTYL + 80% LDPE 1 / SILAN 1.

The one used for comparison single layer film had the following composition: Example 0: 80% SILAN 1 + 20% (25% CAT.BUTYL + 75% LDPE 2) Table l has test results for the different films compiled. In Table 1 and in the following tables have the abbreviations A-E have the following meaning: ' A = Crosslinking immediately after extrusion (%) B ä Crosslinking after 14 days (%) C = Crosslinking after storage in 60 ° C water (%) D = Dart drop immediately after film blowing (g) E à_Dart drop after 14 days (g) Ieäål1_1 A B C D E (%) (%) (%) (9) (Q) Example 0 20 63 82 230 300 Example 1.2 2 S2 78 343 859 Example 1.2 10 57 76 351 1287 Example 1.3 1 29 51 246 470 Examples 1-4 6 34 57 102 104 Example 1.5 8 41 62 105 107 Example 1.6 0 0 0 94 85 Example 1.7 0 20 52 84 94 Examples 1-8 0 51 73 161 940 Example 0 was extremely difficult to drive compared to the coextruded films of Examples 1-1.8. The film appearance was extremely poor with large gels contaminating caused hose breakage in production. The pressure in the cylinder was high compared to silane polymer without catalyst and the risk of total crosslinking in the extruder was bar. 10 , _: UI 20 25 30 457 960 15 Examples 1.1, 1.2 and 1.3 gave a lightly extruded, gel-free film even at high production speeds. On due to the smooth and gel-free film, darts are improved drop ~ properties significantly after crosslinking of the film (compare the dart drop properties for example 0 with other examples in Table 1). The dart drop properties increases sharply with the degree of crosslinking for the extruded the film. The total catalyst concentration does not affect the final degree of binder binding there is a catalyst, but only the crosslinking the speed (examples 1.1 and 1.2). The film's total degree of crosslinking thus depends solely on the vinyl silane the content of the film as there is catalyst in the film (examples 1.3 and l.l).

Examples 1.4-1.5 show the effect during use of various silane-containing polyolefins. Of the examples one can also see that copolymers of ethylene and various hydrolyzable silanes are crosslinked in the same way as the terpolymer in Examples 1.1-1.3, but the degree of crosslinking is lower and the improvement in dart drop is less.

The effect of omitting catalyst is clear of example l.6. The dart drop value should be compared with Dart drop ~ values for the other SILAN 1-containing the films, i.e. examples 1.1-1.3 and 1.8.

Examples 1.7 and 1.8 show the effect of use of higher molecular weight catalyst, and should be compared with examples l.l-1.3 in table 1. Catalyst with higher molecular weight does not affect mechanical tc results.

The crosslinking speed decreases slightly, which is due to a lower migration rate. »Iv l .q 457 960 10 15 20 25 30 16 EXAMPLE 2 In a similar manner as in Example 1 was prepared a multilayer film with the general configuration Silane polymer / Silane polymer / Catalyst-containing layer. More specifically, the multilayer film had the following composition Example 2: SILAN 1 / SILAN l / 25% CAT.BUTYL + 75% LDPE 2.

The test result of the film is shown in Table 2.

Table 2.

A B D -E (%) (%) (q) (g) Example 2 582 904 901 It can be seen that the layer thickness of the silane polymer or the location of the catalyst layer does not significantly affect the crosslinking process or the mechanical values.

EXAMPLE 3 In a manner similar to that of Examples 1 and 2, was a multilayer film with the general configuration Silane polymer / Polyolefin / Catalyst-containing layers.

More specifically, the multilayer film had the following setting: Example 3.1: -SILAN 1 / EVA / 25% CAT.BUTYL + 75% LDPE 2.

In addition, another multilayer film was produced without catalyst with the composition: Example 3.2: SILAN 1 / EVA / LDPE 2.

The test results for the films are shown in Table 3.

Table 3 A B D E (%) (%) (9) (9) Example 3.1 0 34 255 585 Example 3.2 O 0 260 245 10 15 20 25 30 35 457 969 17 It is clear that it is not necessary that the catalyst-containing layer adjoins the crosslinked the silane polymer layer. This means that the catalyst-containing layer can be arranged anywhere preferably in the multilayer film structure under the that any intermediate layers do not absorbs, reacts with or acts as a barrier against the catalyst.

EXAMPLE 4 ' Using the previously described coating extrusion technology was coated paper. Fölšande attempts were made:.

Paper / ma (zsæ xA fl iußufr-yr + 75% LDPE 2) + 80% SILAN 2 Example 4.0: Example 4.1: Paper / 25% CAT.BUTYL + 75% LDPE 2 / SILAN 2 Example 4.2: Paper / LDPE 2 / SILAN 2.

Example 4.0 with mixture of catalyst and silane-containing polymer could not be run because the mixture was crosslinked in the extruder and the screw ran but so that production must be stopped. When driving with the silane-containing polymer and the catalyst in different layers (Example 4.1) there was no tendency to crosslink in the extruder and a gel-free film could coated on the paper web. Test results with respect to on the degree of crosslinking is shown in Table 4.

Table 4 A B (%) (%) Example 4.0 65 Example 4.1 0 35 Example 4.2 EXAMPLE 5 In this example, the weldability of SILAN 1 was tested and SILAN 2. The test results are shown in Table 5, which indicates the strength of the weld in N / cm weld. 457 960 18 Table S shows that weldability deteriorates for SILAN l as a function of the degree of crosslinking.

After 14 days, however, the film can be welded, although the strength becomes slightly lower. 5 entered for SILAN 2.

However, a deterioration does not Table 5 immediately after extrusion 0.1 s 0.2 s 0.5 s - SILAN l: Welded 10 Å 0.2 5.0 5.6 16o ° c 2.3 5.6 5.8 1so ° c _ 5.7 5.8 5.8 20 ° C Welded 14 days after extrusion 0.1 s 0.2 s 0.5 s 1.2 3.6 4.2 l60 ° C 1.5 4.0 4.1 180 ° C 2.0 4.0_ 4.0 200 ° C SILAN 2: Welded immediately after extrusion 0.1 s 0.2 s 0.5 s 3.0 6.3 160 ° C 0 5.7 6.2 180 ° C 0 6.1 6.3 '200 ° C Welded 14 days after extrusion 0.1 s 0.2 s 0.5 s 0.2 0.2 6.6 160 ° C O 6.4 6.5 l80 ° C 0 6.4 6.6 200 ° C From the previous description it appears, among other things The following advantages of the present invention: 1. No risk of crosslinking of material in the extruder, despite the use of temperatures as usual cases would partially crosslink the material and complicate a film production 35 2. Possible to manufacture a gel-free product (none crosslinking reaction during the extrusion phase).

. Possible to use silane-containing polymer as O 4. 457 960 19 a weldable layer in a structure of otherwise heat- stable layers (usually not weldable) so that the whole the structure withstands elevated operating temperature.

Possible to combine one or more cross-linked layer to an otherwise non-crosslinked structure of functional layers in a work phase.

Possible to weld the silane-containing polymer layer before crosslinking took place. After crosslinking welds are obtained which are resistant to surfactants, solvents and aggressive substances. This is of interest in the pharmaceutical industry, the food industry and the chemical industry.

Silane crosslinked product can be welded peroxide- or radiation-crosslinked product. in contrast to The production of silane crosslinked product requires no large investments in peripherals in contrast to peroxide or radiation crosslinked product.

Claims (9)

457 960 10,.: (JI 20 25 30 20 PATENTKRAV 1. A process for preparing a crosslinked polymeric product comprising at least one catalyst-crosslinked polymer layer, characterized in that a multilayer polymeric material, such as a film (1), comprising at least one layer (2, 4) of a silane group-containing olefin copolymer, which is crosslinkable by the action of water and a silanol condensation catalyst, and at least one other, from the crosslinkable silane free layer (3), which includes silanol condensation catalyst, is prepared by coextrusion of the layers, and silanolate condensation is introduced in the material of the catalyst-containing layer (3) before the extrusion, and that crosslinking of the silane group-containing layer (2, 4) is effected by subjecting the multilayer polymeric material to the action of water and by causing the silanol condensation catalyst to diffuse into the silane group content ( 2, 4). 2. A process according to claim 1, characterized in that the silane group-containing olefin copolymer layer which is crosslinked consists of a copolymer of (a) ethylene, (b) ethylenically unsaturated silane compound, and optionally (C) one or more further, with these monomers copolymerizable monomers. 3. A process according to claim 2, characterized in that the silane group-containing olefin copolymer layer which is crosslinked consists of a copolymer of (a) ethylene, (b) an unsaturated silane compound of the formula RSiR 'Y n 3-n where R is an ethylenic unsaturated hydrocarbyl or hydrocarbyl is an aliphatic, saturated hydrocarbylcarbyloxy group, R 'group, Y is a hydrolyzable organic group, and n is 0, 1 or 2, and optionally (c) one or more several further monomers copolymerizable with these monomers. 4. A method according to claim 3, characterized in that the silane group-containing olefin copolymer layer which is crosslinked consists of a copolymer of (a) (b) an unsaturated silane compound of the formula ethylene, CH = CHSi (OA) 3 2 where A is a hydrocarbyl group having 1-8 carbon atoms, preferably 1-4 carbon atoms, and optionally (c) one or more additional monomers copolymerizable with these monomers. A method according to any one of claims 1-4, characterized in that the silane-containing one or more outer core-olein copolymer layer contains lighter monomers (c) selected from vinyl esters of monocarboxylic acids having 1-4 carbon atoms and acrylate or methacrylate of alcohols with 1-4 carbon atoms. 6. A method according to any one of claims 1-5, wherein the silane group-containing characteristic olefin copolymer is crosslinked by the action of silanol condensation catalyst, which consists of a tin salt of a carboxylic acid, preferably dibutyltin dilaurate, dibutylteniothylate dibutyltenoate. 7. A method according to any one of claims 1-6, characterized in that the silane group-containing olefin copolymer layer has a thickness of at most 2 mm. 8. A process according to any one of claims 2-7, characterized in that the monomer (b) constitutes 0.001-15% by weight of the silane group-containing olefin copolymer. »F-J fl y 457 960 22 9. A method according to any one of the preceding claims, characterized in that the catalyst is introduced in a layer (3) adjacent to the layer (2, 4) to be crosslinked.