Lining hose for the restoration of fluid conveying pipe systems

Abstract

The present invention relates to a liner tube for the rehabilitation of a fluid conduction system, comprising at least one tubular layer made of fiber bundles saturated with a curable acrylate resin, silicate resin, unsaturated polyester resin or vinyl ester resin and at least one further tubular layer made of fiber bundles saturated with a photochemically curable epoxy resin, the further tubular layer being in indirect or direct contact with the first tubular layer, the liner tube being based on thermoplastic and having an inner tubular layer in contact with the fluid medium in the mounted state.

Description

[Technical field]

[0001] The present invention relates to a lining hose for restoration of a fluid transport system.

[0002] Lining hoses for the rehabilitation of fluid conveying systems are known and described in the literature, which comprise at least one tubular layer of fiber bundles soaked in a curable resin. Unsaturated polyester resins, vinyl ester resins or epoxy resins are used as the resin.

[0003] The lining hose according to Patent Document 1 typically comprises an opaque outer protective membrane, an inner membrane that is transparent to a specific range of electromagnetic radiation wavelengths, and at least one fiber bundle soaked in a polymeric resin, disposed between the inner and outer membranes.

[0004] The outer membrane hose is intended to prevent the resin used for dipping from leaking out of the textile hose and into the environment, which requires a good seal and bonding of the outer membrane hose to the resin soaked textile hose.

[0005] From Patent Document 2, a lining hose is known which comprises an inner membrane hose, a resin-impregnated fiber bundle, and an outer membrane hose laminated with a nonwoven fabric on its inner side (ie, on the side of the resin-impregnated fiber bundle).

[0006] From US Pat. No. 5,399,513 a short liner with an integrated hat profile for restoring a branched channel is known, the hat profile consisting of at least one layer and the short liner consisting of several layers, which have at least one depression at the same location and at least one flange of the hat profile extends between at least two layers of the short liner, the several layers of the short liner may be superimposed on top of each other, one layer being immersed in polyester resin and another layer being immersed in epoxy resin.

[0007] Often, such lining hoses are made by spirally winding and overlapping a resin soaked fiber bundle onto an inner membrane hose, which is then further spirally wound and overlapped around the resin soaked fiber hose.

[0008] The inner hose itself is wound around a mandrel for ease of manufacture. Alternatively, for example, US Pat. No. 5,399,433 discloses that a pre-manufactured inner membrane hose can be inflated to act as the mandrel itself. Such a pre-manufactured inner membrane hose is made from a bundle of membranes whose edges are joined together by welding or gluing to form the inner membrane hose. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] International Publication No. 9504646 [Patent Document 2] International Publication No. 0073692 [Patent Document 3] German Patent Publication No. 102014112600

[0010] The lining hoses described in the prior art for the rehabilitation of the above mentioned fluid conveying systems do not meet all requirements well.

[0011] It was therefore an object of the present invention to provide a lining hose which can be used to rehabilitate fluid conveying systems and which has improved properties.

[0012] The object of the invention is achieved by a lining hose according to claim 1.

[0013] Preferred embodiments of the invention can be found in the dependent claims and the following detailed description.

[0014] Furthermore, the invention relates to the use of a lining hose according to the invention for the rehabilitation of a fluid conveying system.

[0015] The lining hose according to the invention for the rehabilitation of fluid conveying systems comprises at least a first tubular layer made from fiber bundles impregnated with a curable unsaturated polyester or vinyl ester resin and at least one further tubular layer made from fiber bundles impregnated with a photochemically curable epoxy resin, the further tubular layer being in direct or indirect contact with the first tubular layer, the lining hose further comprising a tubular layer based on a thermoplastic material which comes into contact with the fluid medium when installed.

[0016] The term "fluid conveying system" in the context of the present invention should be understood as any type of system for conveying liquid or gaseous media. Examples include pipelines of any kind, visible above ground as well as underground or hidden, piping systems for conveying gaseous or liquid (fluid) media in chemical plants and manufacturing facilities, pressurized water pipes, drinking water pipes or wastewater systems. There are no particular limitations regarding the design, diameter or material of the system to be restored.

[0017] The choice of material depends on the fluid (gaseous or liquid) medium to be transported in the system, whose properties also ultimately determine the service life of such a system and the restoration needs that can be performed with the lining hose according to the invention.

[0018] The lining hose according to the invention for the rehabilitation of fluid conveying systems comprises at least one tubular layer made of fiber bundles soaked in a curable acrylate, silicate, unsaturated polyester, or vinyl ester resin.

[0019] As the fiber bundle to be soaked in the resin, any product known to those skilled in the art in the form of a fabric, knit, scrim, mat, or nonwoven fabric that may contain fibers in the form of long continuous fibers or short fibers can generally be used in the lining hose of the present invention.

[0020] Corresponding products are well known to those skilled in the art and are commercially available in a variety of versions from various manufacturers.

[0021] Fabrics are generally understood to be flat textile products made from at least two intersecting yarn systems that cross each other at an angle in the surface pattern of the fabric. This angle is preferably about or exactly 90°. The two yarn systems are referred to as warp and weft yarns, the warp yarns often running parallel or nearly parallel to the longitudinal edges of the fabric. However, systems in which the warp yarns run at any angle to the longitudinal edges of the fabric and the weft yarns run at nearly perpendicular angles to them are also conceivable. Within the scope of the present invention, "nearly perpendicular" is understood to mean an angle between the warp and weft yarns in the range of 60 to 120°.

[0022] Knitted fabrics are generally understood to be textile products that are made by forming loops.

[0023] A fiber scrim is a processing variation in which the fibers are not woven, but are aligned parallel to one another, embedded in a chemical transport material (matrix), and typically held in place by top and bottom coatings, and sometimes by stitching threads or adhesives. Because of the parallel fiber alignment, fiber scrims exhibit significant strength anisotropy in and across the direction of orientation, which can be advantageous for certain applications.

[0024] Nonwoven fabrics consist of loosely assembled fibers that are not bonded together. The strength of a nonwoven fabric depends only on the natural contact of the fibers, but can be affected by further processing. To enable processing and use of nonwoven fabrics, they are typically consolidated and various methods can be applied.

[0025] Nonwoven fabrics differ from woven or knitted fabrics, which are characterized by a specific arrangement of individual fibers or threads determined by the manufacturing process. In contrast, nonwoven fabrics consist of fibers in an arrangement that can only be explained using statistical methods. The fibers are randomly present in nonwoven materials. The English term "nonwoven" (not woven) clearly distinguishes them from woven fabrics. Nonwoven fabrics are differentiated based on the fiber material (e.g., polymers in synthetic fibers), the bonding method, the fiber type (staple or continuous fibers), the fineness of the fibers, and the fiber orientation. The fibers can be laid in a defined preferred direction or oriented completely randomly, as in randomly aligned nonwoven fabrics.

[0026] A fabric is said to be isotropic if the fibers have no preferred direction in their orientation, and anisotropic if the fibers are arranged more frequently in one direction than in another.

[0027] Within the scope of the present invention, felt should also be understood as a fiber bundle in the sense of the present invention. Felt is a flat structure made from random and difficult to separate fiber material. In essence, felt is a non-woven textile. Felts made from synthetic vegetable fibers are typically produced by dry needling (so-called needle felting) or by integration with water jets coming out of a nozzle bar under high pressure. The individual fibers in the felt are random and entangled together.

[0028] Needle felt is usually made mechanically with multiple barbed needles, which are arranged in the opposite direction to the barbs of a harpoon. In this process, the fibers are forced into the felt, and the needles can be easily withdrawn. By repeated needling, the fibers become entangled and can subsequently be post-treated chemically or with steam.

[0029] Like nonwovens, felts can be made from virtually all natural or synthetic fibers. In addition to, or as a complement to, needling, the fibers can also be entangled by pulsed water jets or by binders. These latter methods are particularly suitable for fibers without a scale-like structure, such as polyester or polyamide fibers.

[0030] Felt has good temperature resistance and is usually moisture resistant, which can be particularly advantageous when used in liquid delivery systems.

[0031] For the lining hose according to the invention, a fiberglass cloth or a fiberglass scrim is preferably used.

[0032] According to a preferred embodiment, the lining hose according to the invention comprises at least two different fiber bundles soaked in a curable acrylate, silicate, unsaturated polyester or vinyl ester resin and radially wound around one another.

[0033] The at least two different fiber bundles may differ with respect to at least one of the following parameters: fiber embedment, fiber orientation, fiber length, or fiber type.

[0034] Within the scope of the present invention, fibre embedment refers to the way in which fibres are incorporated into the carrier material.

[0035] The fiber bundles used are selected such that, on the one hand, the lining hose has a characteristic profile optimized for the specific application and, on the other hand, can be most easily manufactured using existing equipment for producing such lining hoses.

[0036] By using a combination of several different fiber bundles, which are structured differently in terms of fiber type, fiber length, fiber embedment or fiber orientation, the characteristic profile can be individually adjusted to a specific application without requiring significant changes to the equipment used for production. By selecting the sequence in which these at least two different fiber bundles are wound, the radial and longitudinal profiles of the lining hose according to the invention can be individually designed and optimally adapted to a specific application.

[0037] The length of the fibers used is not subject to any particular limitations, meaning that both so-called long fibers and short fibers or fiber fragments can be used. The properties of the corresponding fiber bundles can also be adjusted and controlled over a wide range based on the length of the fibers used.

[0038] There is no restriction on the type of fiber used. By way of example only, these may include synthetic fibers such as glass fibers, carbon fibers, or aramid fibers, fibers made from thermoplastics such as polyesters, polyamides, or polyolefins (e.g., polypropylene), or combinations of these fiber types, all of which, together with their properties, are known to those skilled in the art and are commercially available in a wide variety. For economic reasons, glass fibers are usually preferred, but where special heat resistance is important, aramid or carbon fibers can be used, which may offer advantages over glass fibers in terms of strength at higher temperatures.

[0039] In some cases, it has proven advantageous for the first resin-impregnated fiber bundle to be selected from fabrics, knits, scrims, mats, felts or nonwovens with a fiber length chosen for the desired application. For example, the first resin-impregnated fiber bundle can be a fiber scrim made of parallel-oriented continuous fibers, preferably parallel-oriented continuous glass fibers. Advantageously, the continuous fibers are essentially oriented perpendicular to the longitudinal direction of the resin-impregnated fiber bundle. Such a first fiber bundle can be preferably combined with a second fiber bundle, the fibers of which are randomly arranged in a random fiber mat. The first fiber bundle gives the lining hose a very good longitudinal strength, which is advantageous when it is installed in the system to be restored. The second fiber bundle with randomly oriented fibers in the form of a random fiber mat stabilizes the inner surface through a high resin absorption, avoiding voids on the inner surface that can lead to damage during prolonged contact with aggressive media. On the other hand, the use of an oriented fiber scrim reduces the risk that the fiber mat will pull apart during soaking, leading to uneven soaking, and the static requirements of the liner also favor this design.

[0040] In the first wound resin-impregnated fiber bundle, the fiber scrim according to an embodiment of the present invention can be needled or stitched into the already random fiber mat, meaning that the first and the subsequent wound fiber bundles can also have a multi-layer structure. In some cases, it has proven advantageous for at least one of the fiber bundles wound on the first fiber bundle to have a multi-layer structure, so that between two layers of randomly oriented fibers, an intermediate layer is included, which comprises fibers that are preferably cut parallel to the longitudinal direction of the fiber bundle and have a length in the range of 2 to 60 cm, preferably 3 to 30 cm.

[0041] According to another embodiment, the lining hose according to the invention comprises a resin-impregnated fiber hose made by winding at least one fiber bundle with fibers oriented essentially perpendicular to the longitudinal direction of the fiber bundle and at least one other fiber bundle with fibers oriented parallel to the longitudinal direction of the fiber bundle.

[0042] According to another embodiment, nonwoven fabrics are used as at least one first resin-impregnated fiber bundle, which may be combined with any other fiber of the above-mentioned type. Examples include glass nonwoven fabrics, polyolefin nonwoven fabrics such as polyethylene or polypropylene nonwoven fabrics, polyester nonwoven fabrics such as polyethylene terephthalate nonwoven fabrics (PET nonwoven fabrics), or polyacrylonitrile nonwoven fabrics (PAN nonwoven fabrics). Basically, any nonwoven fabric is suitable. In some cases, plastic nonwoven fabrics have proven to be advantageous.

[0043] Finally, according to another embodiment, one of the fibre bundles used is a felt of the above-mentioned type, which may then be combined with at least one other fibre bundle of the above-mentioned type.

[0044] In principle, any type of fiber bundle can be combined to best achieve the desired property profile for the intended application. For example, fiber bundles with the same type of fiber embedment (e.g. two fiber scrims or two fiber fabrics) with different chemical composition, different orientation, or different length can be used. For example, short fibers in one fiber bundle can be combined with long fibers in at least one other fiber bundle wound on top of it, or a fabric can be combined with a nonwoven, mat, or knitted fabric. Two fiber fabrics with the same type of embedment and the same orientation and length, but with fibers of different chemical composition, can also be used. This gives a wide range of variations that allow the specialist to adjust the properties of the lining hose to the individual application.

[0045] Starting from the desired property profile, the expert can use his knowledge of the properties of different types of fibers to select suitable fiber bundles for the lining hose according to the invention, thereby providing a product that is optimally adapted to the individual application case.

[0046] The resin used to soak the fiber bundles of the first tubular layer is a curable acrylate, silicate, unsaturated polyester (UP) or vinyl ester resin, which is soluble in styrene and / or (meth)acrylate esters. Suitable resins are usually known to the expert and are commercially available in various forms.

[0047] Silicate resins are essentially inorganic resins consisting of the elements silicon and oxygen spatially cross-linked through a crystalline framework.

[0048] Silicate materials are still soluble in water but contain Si-OH groups instead of Si-O-Si bonds to varying degrees and are frequently referred to as water glass.

[0049] Two Si-OH groups can form a bond by releasing water, a reaction that can be accelerated by a suitable catalyst.

[0050] Schematically, this reaction can be represented as follows:

[0051] [ka]

[0052] In principle, the corresponding reaction is possible for all Si-OH groups in the water glass, and large insoluble molecules form from the individual soluble water glass molecules (the product hardens). This results in a solid silicate material similar to glass, which is why the term "silicate resin" was chosen for such systems.

[0053] Glass is known to be relatively brittle and can only be deformed to a limited extent. To improve deformability, additional components are mixed with the waterglass, resulting in a formulation. Examples of suitable formulation components include polyurethane / polyurea systems that can be cured using diisocyanates.

[0054] By way of example only, silicate-isocyanate based three-component systems consisting of resin, hardener and catalyst are commercially available from several suppliers. The processing time of such resin systems is adjusted according to the type and amount of catalyst and hardener used. Such systems are, for example, sold by RS Technik GmbH under the name MaxPatch and are known to provide good soaking of fiber mats or nonwoven fabrics.

[0055] Acrylate resins typically consist of (meth)acrylic monomers as the main component and can be modified, for example, with styrene. Photoinitiated curing acrylates are one-component reactive resins, the radical polymerization of which occurs with UV or visible light. Acrylate resins that can be cured using thermal energy or a combination of thermal energy and electromagnetic radiation are also suitable.

[0056] Unsaturated polyester (UP) resins are made by esterifying polyunsaturated magnetic carboxylic acids with diols to give low molecular weight products which upon curing typically polymerize with vinyl compounds (especially styrene) as comonomers to form high molecular weight three-dimensional networks.

[0057] Mixtures of saturated and unsaturated difunctional carboxylic acids or their anhydrides can be used as the acid component of the UP resin. Acid components such as adipic acid, glutaric acid, phthalic acid, isophthalic acid, and terephthalic acid and their reactive derivatives can be employed. Examples of preferred unsaturated acids include maleic acid or its anhydride, fumaric acid, and the Diels-Alder adduct of maleic anhydride with cyclopentadiene. Diols preferably used for crosslinking the UP resin include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, 2,2-dimethyl-1,2-propanediol, 1,4-butanediol, 2,2,4-trimethyl-1,3-pentanediol, or bisphenol A. Comonomers required for crosslinking the UP resin can also simultaneously function as a solvent for low molecular weight oligomers, for example, styrene is commonly used in many UP resins. Other examples of suitable comonomers include methylstyrene, vinyltoluene, or methylmethacrylate.

[0058] Difunctional monomers such as diallyl phthalate or divinylbenzene may also be added.

[0059] Other components of UP resins, such as hardeners, polymerization initiators, accelerators, plasticizers, etc., are known to those skilled in the art and described in the literature and do not require further elaboration.

[0060] Vinyl ester resins (also called VE resins), another group suitable for soaking the fiber tape of at least one first tubular layer, are obtained by first preparing an epoxy oligomer in a first stage. This oligomer contains terminal vinyl ester groups such as acrylate or methacrylate groups, thereby carrying reactive double bonds. In a second step, crosslinking occurs, typically utilizing styrene as a solvent and crosslinking agent. The crosslink density of VE resins is generally lower compared to UP resins due to the presence of fewer reactive double bonds.

[0061] In the VE resins, the oligomeric backbone preferably comprises aromatic glycidyl ethers of phenols or epoxidized novolaks, which are preferably terminally esterified with (meth)acrylic acid.

[0062] The reactive resins used for impregnating the fiber tapes can be cured thermally (usually by peroxide catalysis) or, together with a photoinitiator, by radiation, for example UV light, as described, for example, in EP-A-0023623. It is also possible to carry out a combined curing with a peroxide initiator used in thermal curing in combination with a photoinitiator, which has proven to be advantageous, in particular for the large wall thicknesses of lining hoses, as described, for example, in EP-A-1262708. Such a combined curing method is described, for example, in EP-A-1262708.

[0063] After dipping, the resin can be brought to a convenient thickness, for example as described in WO2006061129. This increases the viscosity of the resin, improving handling and winding of the fiber tape used.

[0064] In addition to at least one first tubular layer of fiber tape impregnated with an acrylate, silicate, unsaturated polyester or vinyl ester resin, the lining hose according to the invention contains at least one further tubular layer of fiber tape impregnated with a photochemically curable epoxy resin, the further tubular layer being in direct or indirect contact with the at least one first tubular layer.

[0065] In the context of the present invention, indirect contact means that contact can also be established via additional intermediate elements which are themselves bonded to the resin-impregnated fibrous tape or tapes.

[0066] The materials mentioned above for the fiber tapes of the at least one first tubular layer can be used as materials for the fiber tapes in the at least one further tubular layer, for further details please refer to the corresponding preceding description to avoid repetition.

[0067] The fibrous tape of at least one further tubular layer is immersed in a curable epoxy resin.

[0068] Preferably, photochemically curable epoxy resins, particularly preferably cationically curable epoxy resins, are used.

[0069] Photochemical cationic curing is based on the principle that salts of certain photosensitive compounds can photochemically trigger cationic polymerization. Cationically polymerizable monomers range from vinyl to ring-opening polymerizable heterocyclic monomers, and in principle, any cationically polymerizable monomer can be photoinitiated, cationic polymerized when a suitable initiator is used.

[0070] Photochemically induced cationic polymerization overcomes the lack of sustained spontaneous cationic polymerization, which significantly precludes the production of stable spontaneously cationic curable products during storage. The use of photochemical initiation allows for the continuous in situ generation of active species upon irradiation, resulting in rapid and uniform cure in the desired time.

[0071] The active initiating species in cationic polymerization is a cation, usually a proton or a strongly electrophilic carbocation. Examples of suitable cations include, for example, Lewis acids or Bronsted acids.

[0072] For the photochemically initiated cationic polymerization of epoxides, various initiators are known, of which only aryldiazonium salts, aryliodonium salts, diaryliodonium salts, diarylchloronium salts, diarylbromonium salts, triarylsulfonium salts, dialkylphenylacylsulfonium salts, phosphonium salts, N-alkoxypyridinium salts, pyridinium salts, pyrylium salts, and thiapyrylium salts are mentioned by way of example.

[0073] [ka]

[0074] The anions of these photocatalytic initiator compounds must exhibit as little nucleophilicity as possible to avoid interference with the curing process. Typically, the cure rate, extent of polymerization, and achievable conversion follow the following hierarchy:

[0075] SbF6 - >AsF6 - >PF6 - >>BF4 - >>CF3SO3 - ~ClO4 - >Cl - ~Br

[0076] In practice, hexafluoroantimonate, hexafluorophosphate, tetrafluoroborate, and hexafluoroarsenate have proven to be the most effective, the first two being particularly preferred.

[0077] Since the cation is an absorbing component, the absorption maximum of the cation determines the wavelength required for radiation. The sensitivity to the wavelength used for radiation determines the extent to which initiating species are formed and therefore the cure. Ideally, effective initiating species are formed in high yield at the lowest possible irradiance. Therefore, the initiator used must show a strong absorption band within the range of wavelengths used for radiation.

[0078] Particularly preferred as initiator is onium salt, which is commercially available.Among diarylhalonium salts, diaryliodonium salts are preferred because they are easier to prepare and generally more thermally stable than corresponding chloronium or bromonium salts.Suitable aryliodonium salts are described, for example, in WO 9613538, to which reference is made for further details.

[0079] Other preferred photoinitiators include aryl diazonium and arylsulfonium salts, as described, for example, in EP-A-0 770 608, to which reference is made herein in this regard.

[0080] Arylsulfonium salts usually show slightly better absorption in the wavelength range above 300 nm than aryliodonium salts. In addition, they are very thermally stable and easy to synthesize. However, their photosensitizing ability is usually lower than that of aryliodonium salts.

[0081] Another group of potentially suitable initiators includes the benzothiazolium compounds, as described in the paper entitled "Benzothiazolium Salts as Photoinitiators for Cationic Epoxide Polymerization" by Dr. Verena Goertz (University of Mainz, 2005), to which reference is made herein for further details of these compounds.

[0082] Essentially, it is also possible to bind initiators to polymers. They can then behave as latent cationic macroinitiators. Since initiators are usually ionic compounds, it is preferable to use ionic polymers for this purpose. Such systems can provide advantages in terms of the solubility of the initiator in the system to be cured, which can be desirable in some applications.

[0083] Ionic polymers are basically differentiated into polyelectrolytes (which have ionic structures in each repeating unit), ionomers (which do not have ionic structures in each repeating unit) and macroions which only have a few ionic groups. Examples of such polymers are known to those skilled in the art and therefore a detailed description is not necessary here.

[0084] The abovementioned initiators typically have absorption maxima at wavelengths ranging from 200 to 350 nm. Therefore, electromagnetic radiation within this wavelength range must be used for radiation curing. However, UV radiation is associated with certain risks due to its high energy content. Moreover, since epoxy resins or their monomers themselves have strong partial absorption within this range, the radiation ends up being absorbed by the much more abundant monomer molecules, which may result in insufficient formation of the necessary cations during application.

[0085] In some cases, it is desirable to use light for radiation curing at wavelengths above 350 nm, especially in the range of 360-800 nm, preferably 380-700 nm. However, the absorption of the above-mentioned initiators in this wavelength range is sometimes insufficient to generate the cations required for cationic curing. In these cases, a combination of initiator and so-called sensitizer can be used.

[0086] Under the influence of actinic radiation (with wavelengths in the range of 360-800 nm), the sensitizer decomposes into radicals which, through electron transfer from the initiator or redox reactions, generate the required cations, typically Lewis or Bronsted acids.

[0087] The effectiveness of an initiator system consisting of an initiator and a sensitizer depends on the initiator's ability to accept the electrons released by the sensitizer. Compounds with relatively high reduction potentials (such as iodonium salts) have shown a more significant increase in effectiveness when combined with a sensitizer compared to initiators with relatively low reduction potentials such as arylsulfonium salts. Therefore, the choice of initiator-sensitizer combination will be considered by the expert depending on these influencing factors.

[0088] Suitable sensitizers are generally known to the person skilled in the art and described in the literature. Generally, sensitizers used for the cationic hardening of materials for dental applications are suitable.

[0089] Preferred sensitizers include alpha-dicarbonyl compounds (WO 9613538), alpha-hydroxyketones (U.S. Pat. No. 6,245,827), acylphosphine oxides and diacylphosphine oxides (WO 0144873), and polycyclic aromatic hydrocarbons and aromatic amines (DE-A-2 639 395).

[0090] A group of preferred alpha-dicarbonyl compounds are those of the structure A(CO)(CO)B, where A and B can be the same or different and can be hydrogen atoms or optionally substituted aryl, alkyl, alkaryl, or aralkyl groups, or A and B together can form a substituted or unsubstituted alicyclic, aromatic, or heteroaromatic ring. For specific examples, reference is made to WO 9613538, especially pages 14 and 15.

[0091] Preferred acylphosphine oxides as sensitizers are described in WO 0144873. Preferred compounds include diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide available under the trade name Lucirin TPO® (BASF SE) or bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, also available commercially. Other preferred acylphosphine oxides have the general structure Ar-CO-P(=O)(Ar)2, where Ar represents an aromatic group (whether the same or different).

[0092] The addition of a sensitizer allows the cure to be carried out with lower intensity light, which in turn allows for deeper light penetration.

[0093] The weight ratio of initiator to sensitizer is usually within the range of 30:70 to 70:30, and preferably within the range of 40:60 to 60:40.

[0094] The resin preferably contains 0.02 to 10, particularly 0.05 to 5, wt % of an initiator or initiator system based on the total weight of the monomer components.

[0095] Such resins can be obtained from epoxy compounds having an average of more than one epoxy group per molecule, optionally with other monomers containing hydroxyl groups. Furthermore, preferred epoxy compounds include those that contain hydroxyl groups in addition to the epoxy groups in the molecule.

[0096] Suitable epoxides include compounds containing cyclohexane oxide groups, such as epoxycyclohexanecarboxylates, as detailed in, for example, US Pat. No. 3,117,099, to which specific reference is made herein.

[0097] Another preferred group of epoxides are the glycidyl ether derivatives, for example obtained by reacting phenol derivatives having multiple hydroxyl groups with epichlorohydrin. These include, in particular, the diglycidyl ethers of 2,2-dimethyl-2,2-di-(4-hydroxyphenyl)-propane (bisphenol A) or 2,2-di(4-hydroxyphenyl)-propane (bisphenol F). Aliphatic epoxy compounds are also suitable, such as, for example, epoxidized fatty acid derivatives.

[0098] Specifically, example compounds include octadecylene oxide, styrene oxide, cyclohexene oxide, vinylcyclohexene oxide, limonene dioxide, 1,omega-bis(3,4-epoxycyclohexylmethyloxy)alkanes, glycidol, glycidyl methacrylate, vinylcyclohexene dioxide, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methyl-cyclohexene carboxylate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexene carboxylate, bis-(3,4-epoxy-6-methylcyclohexylmethyl)adipate, bis-(3,4-epoxy-4-methylcyclohexanecarboxylic acid) hexyl diester, 1,3-bis(3,4-epoxycyclohexylethyl)tetramethyldisiloxane, and bis-(2,3-epoxycyclopentyl)ether, some of which are shown below.

[0099] [ka]

[0100] During polymerization, the active cation opens the epoxy ring and initiates further polymerization with chain growth.

[0101] The corresponding products have been described in different variations in the literature and are commercially available.

[0102] In order to tailor the properties of epoxy resins to specific desired applications, it has proven effective to use epoxy compounds with more than one epoxy group per molecule in combination with compounds containing more than one hydroxyl group per molecule. These mixtures result in better cured products due to chain transfer reactions. Therefore, the hydroxy compounds in such mixtures are often referred to as hardeners.

[0103] Particularly preferred representatives of compounds having more than one hydroxyl group per molecule are aliphatic alkylene glycols and polyoxyalkylene glycols. Examples of suitable hydroxy compounds can be found in WO 9613538, to which reference is made for this purpose.

[0104] When a combination of an epoxide having more than one epoxy group per molecule and a compound having more than one hydroxyl group per molecule is used, the equivalent ratio of epoxy groups to hydroxyl groups is usually in the range of 0.1:10 to 10:0.1, preferably 0.5:5 to 5:0.5, in particular 0.7:1 to 1:0.7, with mixtures in which the equivalent ratio is in the range of 0.9:1 to 1.1:1 being particularly preferred. A slight excess of hydroxyl groups has proven to be particularly advantageous.

[0105] Instead of a mixture of two different compounds, a compound containing both an epoxy group and a hydroxyl group in the same molecule can also be used. Such compounds are known to those skilled in the art and therefore no further details are necessary here.

[0106] The epoxy resin in the lining tube of the present invention may contain fillers such as glass powder, aluminum hydroxide, or silicon dioxide to improve the mechanical properties of the cured liner, which must be transparent to the light used for irradiation.

[0107] In some cases, it may be advantageous for the resin to contain a small amount of organic peroxide capable of initiating radical polymerization. This can aid in curing in areas not reached by radiation. Suitable peroxides are described in EP 1 262 708, to which reference is made for details. However, the advantage of photochemically initiated cationic polymerization is that once the reaction has started, it continues even if radiation is interrupted or stopped. This allows curing in areas of the tube that are not directly reached by the light from the radiation source. The cations generated are long-lived enough to sustain chain propagation without continued radiation. Nevertheless, it is advantageous to maintain radiation until complete cure is achieved, as the desired cure is achieved in a shorter time.

[0108] At least one additional tubular layer of fiber tape impregnated with a curable epoxy resin may be disposed on a side of the first tubular layer opposite the side in the mounted state that faces the flowing fluid medium, or may be disposed on the side that faces the flowing fluid medium in the mounted state.

[0109] The lining tube of the present invention may have more than one tubular layer containing a fibrous tape impregnated with an acrylic, silicate, unsaturated polyester, or vinyl ester resin, and an additional tubular layer containing a fibrous tape impregnated with an epoxy resin may also be placed between two layers impregnated with an acrylic, unsaturated polyester, or vinyl ester resin.

[0110] The specialists will select the appropriate arrangement based on their expertise and taking into account the current requirements.

[0111] The width of the fiber tape is usually not subject to any particular limitation: fiber tapes with widths of 20 to 150, preferably 30 to 100, in particular 30 to 90 cm have proven suitable for various applications.

[0112] The thickness of the fiber tape in the lining tube of the present invention is not subject to any particular limitation and is determined by the thickness of the lining required for the desired application. A fiber tape thickness in the range of 0.01-1, particularly 0.05-0.7 mm, has proven to be effective in practice.

[0113] The lining tube of the present invention has an inner tubular layer, such as a potentially reinforced inner membrane tube made of a thermoplastic material, which is in contact with the fluid when installed and can be removed after installation of the lining tube or left behind in the pipeline system to be restored, and which can contain 0.01 to 40 wt. % of nanoparticles relative to the total weight of the inner membrane tube.

[0114] Suitable thermoplastic materials for the inner tubular layer include any polymer that can be processed into a membrane or membrane tube of the thickness or strength required for each application. Furthermore, if the curing is carried out photochemically, care must be taken that the product has sufficient transparency for the wavelength or range of wavelengths of the radiation used for curing. If the inner tubular layer is intended to be left in the recovery system after curing, it must also have sufficient strength for the fluids to be conveyed and for the resin of the textile tube. However, in most cases, the inner tubular layer is removed after curing. In principle, taking these indicators into account, polyolefins such as polyethylene or polypropylene, polyamides, polyesters such as polybutylene terephthalate, polyethylene terephthalate or polyethylene naphthalate, polyvinyl chloride, polyacrylonitrile or thermoplastic polyurethanes or mixtures of these polymers are suitable. Thermoplastic elastomers are also usually suitable. Thermoplastic elastomers are materials in which elastic polymer chains are incorporated into the thermoplastic material. Despite the lack of vulcanization required for conventional elastomers, thermoplastic elastomers exhibit rubber-like elastic properties, which can be advantageous in some applications. Examples include polyolefin elastomers or polyamide elastomers. Detailed information is not necessary since the corresponding products are described in the literature and are commercially available from various manufacturers.

[0115] Depending on the application, thermoplastic polyurethanes, polyamides, silicones, and oleic polymers, or combinations of these thermoplastic materials have proven to be materials for the inner tubular layer.

[0116] Particularly suitable and preferred thermoplastic materials include, for example, polyolefins and / or polyamides or silicones, and membrane tubes based on composite membranes of polyolefins and polyamides have proven advantageous in certain applications, since they show better barrier properties against styrenes or acrylates, which are commonly used as solvents for the resins used, compared to pure polyethylene membranes, thereby helping to better prevent the escape of these solvents / monomers inside the lining tube before curing.

[0117] According to one embodiment, the tubular layer, which is in contact with the fluid medium in the mounted state, comprises a barrier layer against monomers, gases and / or water vapor, for example silicones exhibit good barrier properties against water vapor.

[0118] According to one embodiment, the inner membrane tube may have a reinforcement material, which is selected to optimize the characteristic profile for each application, while also ensuring the simplest possible manufacture for the lining tube.

[0119] Preferably, the inner membrane tube has a fiber-based reinforcement, in particular based on fiber tapes or fleeces as described above.

[0120] The thickness of the reinforcing material such as fleece is advantageously in the range of 0.001 to 10 mm, particularly preferably in the range of 0.02 to 5 mm.

[0121] According to a particularly preferred embodiment, the fiber-based reinforcement is a fiberglass cloth or a fiberglass mat.

[0122] If curing occurs after insertion into the piping system being renovated by exposure to light, care must be taken that the material used for the inner membrane tube is sufficiently transparent to the light used for irradiation so as not to impair or prevent curing, which is not related to thermal curing.

[0123] According to another preferred embodiment, the lining tube of the invention has at least one outer membrane tube based on a thermoplastic material.

[0124] Suitable outer membrane tubes for use in the lining tube of the present invention are known and described in the literature, for example in US Pat. No. 5,399,623 and US Pat. No. 5,499,633, with the reinforced outer membrane tube described in US Pat. No. 5,499,623 representing a preferred embodiment. The lining tube of the present invention is suitable for salvaging any type of fluid transmission system while minimizing the downtime of the system when a shutdown is necessary. Downtime is reduced compared to replacement of damaged parts. The lining tube of the present invention can be used particularly advantageously for the rehabilitation of systems where traditional repair or salvage-related part replacement is difficult, either because these parts are components of the entire installation or because they are inaccessible, such as when they are buried underground. Examples include piping systems carrying water or wastewater, which are often buried underground in cities and municipalities, and often buried under roads and other traffic routes. When salvaging by replacement, these pipelines must first be exposed by appropriate trenching, which makes the traffic routes inaccessible to traffic for longer periods of time, causing significant disruptions, especially during periods of high traffic volume. In comparison, salvaging such piping systems with the lining tube of the present invention can be carried out in a few hours or days without extensive trenching.

Claims

1. A lining tube for the rehabilitation of a fluid conduction system, comprising at least a first tubular layer of textile tape impregnated with a curable acrylate, silicate, unsaturated polyester or vinyl ester resin and at least one additional tubular layer of textile tape impregnated with a curable epoxy resin, said additional tubular layer being in direct or indirect contact with said first tubular layer, said lining tube comprising an inner tubular layer based on a thermoplastic material which is in contact with the fluid medium when mounted.

2. The lining tube according to claim 1 , wherein the additional tubular layer is disposed on a surface of the first tubular layer opposite the surface facing the fluid medium when installed.

3. The lining tube according to claim 1 , wherein the additional tubular layer is disposed on a surface of the first tubular layer facing the fluid medium when installed.

4. 3. The lining tube according to claim 1 or 2, comprising at least two tubular layers of fibrous tape impregnated with a curable acrylate, unsaturated polyester or vinyl ester resin, the additional tubular layer of fibrous tape impregnated with a photochemically curable epoxy resin being disposed between the two tubular layers of fibrous tape impregnated with a curable acrylate, unsaturated polyester or vinyl ester resin.

5. 5. The lining tube according to claim 1, wherein the unsaturated polyester is obtained by esterification of a polyunsaturated carboxylic acid with a diol and a vinyl compound.

6. 6. The lining tube according to claim 1, wherein the vinyl ester resin is obtained by first producing an epoxy oligomer in a first step and then crosslinking it in a second step.

7. The lining tube according to any one of claims 1 to 6, characterized in that the inner tubular layer in contact with the fluid medium when installed is based on polyurethane, polyamide, silicone, olefin polymer, or a combination thereof.

8. The lining tube according to any one of claims 1 to 7, characterized in that the inner tubular layer comprises a barrier layer against monomers, gases or water vapor when in contact with the fluid medium during installation.

9. Use of a lining tube according to any one of claims 1 to 8 for the rehabilitation of a fluid conduction system.

10. 10. Use according to claim 9 for the rehabilitation of pipelines for water or wastewater or for the rehabilitation of pipelines in industrial manufacturing facilities.

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