NO750689L - - Google Patents

Description

"Reinforced and cased lanes &v blan-

things of bitumen and ethylene copolymers"

This invention relates to webs of mixtures of ethylene copolymers and bit urn sora on one side coated with a pals of fibres, and which optionally contain common fillers and additives.

Sheets of mixtures of bitumen and ethylene copolymers have for some years been used for sealing building structures against water and moisture. This material is very stretchy; can be well welded and if necessary it can be glued with hot bitumen* due to its excellent weather and aging resistance it is mainly used for sealing roofs, foundations, canals, tunnels, earth basins etc.

Sealing webs of mixtures of bitumen and ethylene copolymers are produced, normally by extrusion. During the extrusion and withdrawal of the web, stresses are normally generated and frozen, which can be released again when the web is heated, i.e. for example by sticking with hot bitumen or by long-term intensive solar radiation on d<8 loosely placed welded webs, which can lead to shrinkage of the track. This shrinkage is avoided by one-sided casing or the application of furs, which must be sufficiently stiff and strong to absorb the shrinkage stresses. Suitable furs consist, for example, of glass, polyester, polyaroid, treu11, asbestos. Such paths have previously been described, for example in the German usage pattern hr. 6,915,274.

Although the fur prevents shrinkage to a large extent, it generally does not make any particular contribution to increasing the firmness when it comes to tensile forces. In many applications, the paths of bitumen/ethylene copolymer are subjected to tensile stresses close to the limit of what they can withstand (tensile limit, tensile stress). This can, for example, be the case when coating large flat surfaces and the material must be straightened by stretching. In addition, the firmness of the bitumen/ethylene copolymer mixtures decreases with increasing temperature.

The basis for the invention was therefore the task of providing webs of ethylene copolymer/bitumen mixtures which, on the one hand, are provided with a coat of fibres, which webs exhibit an improved firmness and tensile stress at the temperatures relevant for the application up to 80° C, without the web's ability to absorb shrinkage stresses thereby becoming worse and without necessarily making the production significantly more expensive.

It was now found that this task can be solved by inserting at least one special, reinforcing insert of a weave, wire mesh or net in a specific way into the fur-coated ethylene copolymer/bitumen track.

The object of the invention is thus a web which is coated on one side with a coat of fibres, which web consists of a substance mixture containing an ethylene copolymer of 50-97% by weight ethylene and 3-50% by weight of a polymerised ethylenically unsaturated co-monomer and bitumen 1 weight ratio ltlO to lOtl, as well as any usual fillers and additives. The track is characterized by the fact that between the bitumen/ethylene copolymer mixture and the fur, at least one reinforcing insert of a weave, wire mesh or net has been incorporated, where the wire-free surface is 5-98% of the total surface.

Mixtures of bitumen and ethylene copolymers that are suitable for the production of the webs according to the invention are known, for example, from DT-AS 1 298 282. Suitable ethylene copolymers are produced in particular according to high-pressure polymerization methods by copolymerization of ethylene and other ethylenically unsaturated monomers, such as acrylic acid esters, methacrylic acid esters, fumaric acid esters, maleic acid esters, itaconic acid esters, mesaconic acid esters, crotonic acid esters, acrylic acid, methacrylic acid in itaconic acid, mesaconic acid, crotonic acid, furnaric acid, maleic acid, propylene and isobutylene. Such ethylene copolymers which contain acrylic acid or methacrylic acid ethers as comonomers polymerized in are preferred. Vinyl esters of unsaturated carboxylic acids with 2-10 carbon atoms, preferably vinyl acetate and vinyl propionate, also come into consideration. Also suitable are ethylene copolymers which polymerized contain two or more of the aforementioned comonomers, for example copolymers of ethylene, acrylic acid and vinyl acetate or ethylene, acrylic acid and n-butyl acrylate or t-butyl acrylate. Likewise, it is possible to use several ethylene copolymers. Suitable ethylene copolymers melt indices are between 0.01 and 100 g/10 minutes, determined according to ASTM D 1238-65T at a temperature of 190°C under a weight load of 2.16 kg. The ethylene copolymer salts contain 3-50% by weight of one or more of the aforementioned ethylenically unsaturated comonomers.

By bitumen is meant the bituroinous materials described in H. Abraham "Asphalts and Allied Substances", volume I, chapter 2, page 52 et seq., 6th edition, D. van Nostrand company inc. N.Y., 1960. Suitable for example distillation residues obtained from petroleum distillation, natural asphalt, pitch and tar. In addition, high vacuum bitumen, blown bitumen, cracking bitumen, albino bitumen, sulphate pitch, propane bitumen and bitumen varieties where the maltenes or asphaltenes have been enriched or removed are also taken into account. It is also possible to use pure asphalt or asphalt as a bitumen component. In particular, bitumen with a penetration according to DIN 1995-*J3 is used. 1-300 VlO mm and a softening point (Ring and Kugel) according to DIN 1995-U4 of 25-140°C.

Ethylene copolymers and bitumen are present in the fuel mixtures in the weight ratio of It10 to 10*1. The material mixtures of ethylene copolymer and bitumen may possibly contain common additives, for example chalk, ternoxide red, shale flour, soot, coal dust, talc, glass fibres, stone or slag fibres, wood dust, guromi meal, silt clay, limestone flour, klselgur, tungspar, asbestos, clay soil, bauxite, in fact and bentonite. The filling materials are used in amounts of 0.5-90% by weight, preferably 10-60% by weight, calculated on the weight of the ethylene copolymer/bitumen mixture. As common additive materials, dyes, pigments, antioxidants, protective agents against ageing, flame retardants and anti-static agents can also be used in such quantities as such are usually used in connection with synthetic resins. Polyethylene with a density of 0.918-0.965 g/cm 3 , polypropylene, polyisobutylene or styrene polyurethanes can also be used as additives. These polymers can be used in quantities of up to 50% by weight, calculated on ethylene grain polymer and bitumen.

The fur used for casing is known as such and can be made from very different materials. The fur fibers can for example consist of glass, polyester, polyamide, wood wool, asbestos, metals, cellulose, polypropylene, polyethylene, polyacrylonitrile, melt-extruded stone or slag materials and other organic or inorganic fibrous substances. The fibers used in the production of the fur suitably have a diameter of 0.001-0.2 mm. The pallets themselves have a thickness of approximately 0.05-1 mm and are mostly attached to each other by means of adhesive* and finishing agents or by direct connection of the individual © fibers (opening3-welding or slnring). The fur's glue content is almost always below 35% by weight.

In order for the fleece to be suitable for the purpose, it is essential that it has sufficient compressive strength in the plane of the fleece, thereby the fleece will be able to absorb the shrinking forces that are released by heating the bitumen/ethylene copolymer layer, so that the web does not undergo dimensional changes, <p>elos which, when heated to 80°C, undergo dimensional changes of more than 2% in the longitudinal or transverse direction of the web, are unsuitable for ■ most applications. Suitable furs keep the webs from shrinking in the heat underneath

As the furs, for reasons of flexibility, cannot be overly thick, they cannot, as a rule, be stressed very strongly;

the furs therefore do not make any significant contribution to increasing the tensile stress, with the reinforcing Insertion of woven fabric, thread floats or nets, the tensile stress on the web can, on the other hand, be significantly increased.

According to the invention, this reinforcing insert is placed between the bitumen/ethylene copolymer layer and the pile. As reinforcing inserts, you can use weaves, wire inserts, braiding, netting, tulle and the like » A corresponding definition can be found in the island is S. Siebel, Eand-buch der PrUfung von Textillen, Spinger-Verlag, volume 5 (1960)^ aide 313-317 . Essential for these inserts to be suitable for the purpose, in addition to the mechanical strength, is also the size of the thread-free surface. As thread-free surface is considered the proportional, eamled© part of.,

the total area of the fabric that is covered by the threads corresponding definition can be found in Lueger, "Lexiken der Technik", binfi 4, oide 505 (keyword "Freio Siobflache"), DeutQcho Verlags-Anstalt GrøBB, Stuttgart (1962). The thread-free surface is a prerequisite for a good connection between the bitufaan/ethylene copolymer mixture and the coat, which can only be achieved by a sufficient permeability of the reinforcing inlay, for example of the fabric etc; the threaded surface must be 5-98?£, preferably 25-90%, of the total surface.. Also the non-drying of the holes in the fabric etc. is important for the application according to the invention, because the bonding is improved bit varas n/ethylene copor1vrcer- mixture and the fur lying on the other side of the fabric can be obtained via these openings. The holes can, for the aforementioned purpose, generally have

A size between 0.1 and 2000 mnT5, preferably between 4 and 100

The thickness of the threads in the weave, braid etc. is determined by the intended use of the webs according to the invention and therefore cannot be specified in general terms.

The weave, the braid, the thread insert or the net can remain

of the most diverse materials, for example glass, asbestos, steel or other metals, cellulose, jute, hemp, wood wool, polypropylene, polyethylene, polyamide, polyester, polyacrylonitrile. essential for the choice of material is a good tensile stress and sufficient resistance to heat and ageing. These materials must have properties corresponding to the purpose that, during the processing and use of the web, they must serve as a supporting layer for this within the relevant teroperatur areas. It is advantageous for the weave, the braid, to eat. consists of a material that softens at higher temperatures than the bitumen/ethylene copolymer mixture. The fabric etc. can be fixed with binders, finishing etc. to achieve a uniform surface. In many cases it is advantageous that the threads in the fabric etc. are monofilament and have a ribbon-like structure. Such a tape weave etc. has the advantage that it lays flat, and especially at the cuts" this is particularly important for lanes with a relatively thin bitumen/ethylene copolymer layer, as there is then a danger that the contours of too strongly profiled reinforcing inlays of tissue, wicker teat. penetrates too deeply into the bitumen/ethylene copolymer layer. For the same reason, weaves, braids etc. of thicker monofilament threads with a round cross-section should only be used for lanes with a correspondingly thicker bitumen/ethylene copolymer layer. You can also use other reinforcing inserts of fabric, fabric etc. on top of each other between the bitumen/ethylene copolymer layer and the fur. As far as possible, wide-masked weaves are used so that they are laid diagonally over each other. These webs stretch less when diagonally stretched than webs with a single weave insert.

The tracks can also be lined on the other side with a double layer of reinforcing inserts and fur »Blike baner" can, for example, be used for the protection of buildings as a sealing intermediate layer, which can be made adhesive on both aiders using va.rm-b in the urn. In a known manner, the webs can also be coated on the still free bitumen/ethylene copolymer side with metal or plastic foils or against paper or fur. The uncoated webs can, for example, serve as a vapor barrier layer on roofs, or webs coated with colored polyethylene can be used for lining swimming pools.

The webs according to the invention can, for example, be produced in one work step using an extruder with a wide slot nozzle,

a cooled rolling device and a winding device. Such a facility is shown schematically in fig. 1. In an extruder 1, a granule of bitumen/ethylene copolymer mixture is melted, which is pressed out through a heated slot-shaped nozzle 2. The extruded melt of ethylene copolymer A) itumen mixture 3 is fed into the lower slot 5 of a three-cooled roller 4 smooth facilities provided. The gap 5 in this system is adjusted so that the web gets the desired thickness. The relationship between extruding heat and drawing speed is set so that the forge 3 forms a bead 6 in front of the roll gap 5. The fur 7 and the reinforcing insert 3 of a weave, braid, wire insert or

night is unwound from the supply rolls 9 and 10 and passed over the smoothing plate 4 to the bitumen/ethylene copolymer paste 3. due to the bead 6 or the roller gap S, a pressure occurs in the gap S which pushes the paste 3 through the openings in it as a reinforcing insert 3 serving tissue etc. and into the fur 7. on the way over the middle and upper roller 4, the web is cooled enough that it can be pulled over a runway 11. Here it is further cooled in the air and then runs over the take-off roller 12 to the winding device 13, where dan is rolled up.

The structure of the web according to the invention enables the just-described, simple manufacturing method in a continuous workflow. Compared to a fur-lined track without weaving, with this three most illiterate additional costs are incurred only for the weaving or the like, but not for machinery or working time.

Bn qualitatively similar web where* the défc reinforcing tissue insert lies in the interior of the bitunten/ethylancopolyrøar s jikt requires either an additional work stage or a more complicated fabrication facility. In the first case, in the first work step, a bitumen/ethylene copolymer web is produced with a tissue coating on one side, after which the web in the second work step on the web side is provided with an additional layer of bitumen/ethylene copolymer and the peel coating, in the in the second case, the tissue etc.

coated on both sides in one operation using two extruders and two wide-blade nozzles and covered with fur from the outside. The manufacture of such a web is in any case significantly more expensive than the web according to the invention. One could also think of coating the bituaao/ethylene copolymer web in a simple way with tissue etc. on one side and imao palfi on the other side. This ban©, which can be produced without major costs for machines and labour, is not, however, in question for

most applications, because the reinforcing layer will then lie on top and will be exposed to the external climatic conditions, mechanical damage if you walk on it, etc. Added to this are difficulties when welding such tracks.

For most applications, webs that are lined with fur are laid over la pp-s ve icet t the web lies down, the lined side on the flat sow is to be sealed, while the unlined side faces out. As the casing in most cases interferes with this method of welding, one of the edge zones of the web is left uncoated in a width of approx. 3-5 era. The second edge zone of the pitch is completely covered.

When welding the banana according to the invention, you proceed in an analogous way, but however the seam of the reinforcing insert 8

of weave etc. protrude further into the welding seam than the fur 7. For this purpose, the web is prepared so that the pre-reflective insert 8 of weave, braid etc. first begins, for example, at a distance of 1 cm from the edge of the web, while the fur lining 7 begins, for example, at 4 cm from can-ten? in the edge zone of the track, there will then be an approx. 1 cm strip that is without fur and tissue. This is joined by a 3 em wide fur-free but tissue-covered strip, and at a distance of approx. 4 cm from the edge of the web, the woven horizontal palecasing begins. At the other edge of the track, the webbing and pe1casing go right to the edge of the track.

Fig. 2 shows a section through a welding eye across the path direction and a suitable method of arrangement for such paths according to the invention. On the substrate 14, with the help of a hot-bite urn 15, a web of bitumen/ethylene copolymer mixture 3, which is lined with material p©l37 and provided with material reinforcing inlay 8 nv woven or braided etc., is affixed. also consists of layers of fur 7, reinforcing fabric inserts 8 and blturaen/ethylene copolymer blassnding 3, is, like the first, glued with varrabit to the urn 15, the welding edge, which extends from A to B, overlaps the edge of the first banana. The two webs are n" welded together with the help of a varrø air welding device which is equipped with a sn approx. 4 cm wide s field-cut nozzle. Below this, the seams of ps Isen 7 and the fabric 8 are welded in by the overlapping web with C and D respectively. Sam -early, the two-ply bituraen/ethylene polyreed layer 3 is welded together at Ej this outer part B of the weld seam ensures that the weld-eye seam becomes completely watertight. the seam so that it will withstand the mechanical stresses and temperatures that occur during use.

If the strips welded in this way are to be used as a tarpaulin, carpet or the like laid freely, then the gluing with the hot bitumen 13" is waived, then the unrolled strips are welded in a workshop on a large surface with the help of movable welding machines and rolls up the carpets or similar thus obtained for transport to the place of use or warehouses. Such carpets are, for example, used as roofing material in the building sector. Other areas of application for the reinforced and welded-together tracks according to the invention are, for example, the lining of fish ponds, earth basins for the collection of clean water or waste water, sealing of tunnels, control dams and waste storage facilities, where it is desired to prevent the inflow or outflow of water or the outflow of toxins.

Example

Sn finely dispersed mixture in the form of lentil granules with a grain diameter of 4 mm<p>g consists of equal parts by weight standard bitumen B 45 (according to DIN 1996) and an ethylene copolymer containing 73% by weight ethylene and 27% by weight ethyl acrylate, is processed in the extrusion plant described below (see fig. 1) into wide and 2 mm thick webs which are reinforced on one side with polypropylene web and covered with glass wool on the other side. The ethylene polyacetate in the mixture has an ame1te index of 0.9 g/10 minutes measured according to DIN 53 735 at 190°C with a load weight of 2.16 kg.

The granulate flows from a storage bunker to an extruder 1 with a 90 mm bore and a deep-cut, 2700 mm long screw that projects into the bore with a clearance of 0.1 mm. The extruder is heated in the first third of its length after product intake to >100°C, and the other two thirds, including the wide gap nozzle 2, is heated to 130°C, and the extruder's rotation speed is 80 revolutions per minute.

Under these conditions, a mass tampora trip of 14Q°C is established at the nozzle 2? 24d kg of product is ejected per hour.

The slow-flowing bitumen/ethylene copolymer mixture 3 leaves the exatruder 1 through the 1200 mm wide slot-shaped nozzle 2, where the slot is set to 2.0 mm. From here it is guided approximately horizontally

sontal direction into the lower roller gap 5 belonging to a smoothing device consisting of three cooled, rotating rollers 4. The distance between the nozzle outlet and the roller gap is 120 mm. The rollers 4 have a width of 1300 mm, a transverse dimension of 300 mm and are internally cooled with

circulating water. The temperature of the supplied water is +10°c.

The gap between the middle and respectively the Upper and lower rollers is set to 2.0 mm (gap 5) and 4 mm respectively. The middle and lower rollers rotate in opposite directions, so that the extruded material is pulled along in the direction of extrusion. The Upper roller rotates opposite to the middle roller and in the same direction as the lower one

the roller, the rotation speed of the rollers is set so that a bead 6 with a transverse dimension of approx. 20 mm/in front of the product intake at roller gap 5 between the lower and the middle roller 4.

From the supply rolls 9 and 10, a 1 m wide web of a large-mesh polypropylene rotary fabric 8 and a 1 m wide glass wool web 7 are fed via the lower roller 4 and on to the bitumen/ethylene copolymer melt 3. Below this, the glass wool 7 lies immediately on the lower

roller 4, with the polypropylene fabric 6 on top. The polypropylene fabric 8 and the glass fleece 7 have the following data

Polypropylene rotation<n>float K/S , 24/24 Pd/10 cm consisting of polypropylene bands.

• ''Mesh width 3':,5 •» 3,5 mm . * ' '. Wireless phase \ 7256 •.'

Warps 2 threads* (ribbon)> each 0.06? g/m Weft» 1 thread (ribbon), 0.130 g/m vské

'■ • ■ weight» 63 g/ m2

Glass fur (standard values according to pm 52 141 - E) p

Because of the bead 6, a pressure arises in the roller gap 5 which pushes the bitumen/ethylene copolymer melt 3 through the polypropylene fabric 8 and into the glass fleece 7. The web of polypropylene fabric 8 is deposited against the glass fleece web 7 to produce a weld bead

in 30 ram width, so that the seam of the fabric 8 at one of the bitumen/

The two edge zones of the ethylene copolymer track lie 30 m inwards from the seam of the glass coat 7. Parallel to this glass-free, woven-shaped edge strip, a strip of uncoated bitumen/ethylene copolymer mixture 3, at least 15 mm wide, is laid, which forms the outermost edge of the track, wad the other edge of the track, the bitumen/ethylene copolymer mixture 3 is allowed to run at least to the seam of the polypropylene fabric 8.

The tissue-reinforced, glass-pillow-laid web thus obtained 1 the lower roller gap 5/ then runs on the middle roller through the upper roller gap and is pulled off in the extrusion direction over the upper roller. On these rollers 4, the web is cooled so much that the bitumen/ethylene copolymer mixture 3 goes from a thermoplastic state to an electrically solid state.

The web is then further cooled in the air on an 8 m long and 1.5 m wide runway 11 (roller diameter 6 cm*roller eye tooth 30 cm), passes two rubber exhaust valves 12 (diameter 200 ram), and from this the web is taken to a winding plant 13 provided with round knives. The circular knives serve to cut off protruding edge parts. They are set in such a way that a 10 mm wide strip of bare bitumen/ethylene copolymer mixture 3 is left as a weld edge at the casjarto underside, and connected to this is a 30 frame wide strip saw only or coated against tissue. The other edge of the track is trimmed so that the tissue and glass slats reach the outermost edge of the track. At plant 13, the web is wound up on rollers.

For comparison, a 2-room thick sheet of the same bitumen/ethylencopolymer mixture is produced in the same way without a tissue insert.

The mechanical strength of both webs is examined in a pull-out test according to DIN 53 455 at a pull-out speed of 200 mra/min. Test specimen no. 5 (according to DIM 53 455) is then used. In the case of the track with polypropylene woven inserts, it must be ensured that in each case there are 3 uncrossed woven threads running parallel to and parallel to the edge of the specimen. The results are shown in the following table.

It will be seen from the table that the tensile stress for webs equipped with woven inserts, in the temperature range from 20 to 80 c, is 2-4 times greater than for webs without woven inserts, and the first-mentioned webs are correspondingly better able to withstand mechanical stresses in the practical application. At 80°C, the web with tissue insert is approximately as strong as the web without tissue insert at 23°C. The elongation during tensile stress for webs with woven inserts is 3.5-8 times greater than for webs without woven inserts.

Claims (6)

1. Webs which are coated on one side with a coat and which consist of a material mixture containing an ethylene copolymer of 50-97% by weight ethylene and 3-50% by weight of an in <p>ol<y>merized ethylenically unsaturated copolymer and bitumen in the weight ratio lil0 to 10:1, ca characterized by the fact that a reinforcing insert is incorporated between the bitumen-ethylene copolymer mixture and the fur, whose thread-free surface is 5-98% of the total surface. 2. Track according to claim 1, characterized in that the reinforcing insert consists of a weave, wire insert, tulle or net. 3. Track according to claim 1 or 2, characterized in that the holes in the reinforcing insert have a size between 0.1 and 2000 mm. 4. Track according to claims 1-3, characterized in that the reinforcing insert consists of a material that softens at higher temperatures than the track's bitumen-ethylene copolymer mixture. 5. Track according to claims 1-4, characterized in that the reinforcing insert is coated with binders. 6. Track according to claims 1-5, characterized in that the reinforcing insert on one side and the fur on the other side are deposited against each other at the edge of the track in such a way that the outermost edge of the track consists of uncoated bitumen-ethylene copolymer mixture, and a connecting strip to this which is laid further to the middle of the track" is only coated with the reinforcing insert.