EP0306834A1 - Multilayer joint covering, manufacturing method and use - Google Patents

Abstract

Joint covering which consists of at least two thermosetting resin layers (5, 7) on the two parts to be covered and between which a covering layer made of thermoplastics or elastomers (6) is incorporated, manufacturing method and use. <IMAGE>

Description

In construction engineering, expansion joints and connection joints are required for many construction types. Such interruptions in buildings are intended to compensate for the changes in length of the materials, both in the manufacture of the building and in the event of later influence from temperature fluctuations. The joints are either created by recesses in the manufacture of the surface or they are created when prefabricated parts are joined together. Such an example is e.g. the laying of pipes.

In general, such joints are filled with sealants at the end of the work in order to prevent the penetration of undesirable substances such as dirt, water, etc. It is essential that such sealants participate in the compensating movements of the joints. In general, these are plastic or elastic materials such as bitumen, silicone rubber or others. In some cases, press-in foam strips made of different materials are often used, often in combination with the above-mentioned materials. It is also known to use sealing tapes made of flexible plastics such as polyisobutylene, soft PVC, high-pressure polyethylene, etc.

In many cases, these known systems have disadvantages. The sealing compounds lose their elasticity over time due to aging processes, they lose their adhesion to the joint flanks or tear in themselves. Media from outside can penetrate and destroy the connection even further.

Joint tapes of the conventional type can be attacked, for example, by weather influences and micro-cracked by depolymerizing influences on the surface will. The consequence is also increased permeability or sometimes spontaneous tearing of the tape in the joint. Often there is no tightness to the investment material due to the lack of liability. In addition, there is no satisfactory solution for joints that collide or intersect at angles.

So far there is no satisfactory solution for particularly high demands on sealing effectiveness, chemical resistance and weather stability. Such a case is e.g. when coating collecting trays and collecting rooms made of concrete with expansion joints. Especially when it comes to the storage of chlorinated hydrocarbons, only a few plastics are durable enough to meet all requirements.

It is known that a crack-bridging multilayer system based on various hardening plastics can be used to carry out highly chemical-resistant coatings. This coating system has been approved with the test mark PA-VI 211.019 from March 12, 1987 by the Institut für Bautechnik, Berlin, for sealing drip pans and collecting rooms made of reinforced concrete for the storage of the following liquids: dichloromethane, trichloromethane, carbon tetrachloride and chlorinated hydrocarbons with C ≧ 2, unless they can be assigned to hazard class AI, A II and B according to the Ordinance on Flammable Liquids. It is also suitable for aqueous solutions of organic acids up to 10% acidity.

The system is structured as follows:

A solvent-free 2-component system from one is used to seal the concrete surface Epoxy resin and an amine hardener. A rubber-elastic polyurethane layer consisting of a polyol and an isocyanate hardener is applied to this layer, which is followed by the application of the actual chemical-resistant surface layer. This surface layer consists of a modified phenol-formaldehyde resin with an acidic hardener, which can be applied together with a glass fiber insert as a laminate layer.

With this coating system, too, the problem of bridging expansion joints has not yet been satisfactorily solved. Although a screwed-on fluoroelastomer film anchored in the concrete with expansion anchors was approved as part of the test mark, which is complex and expensive, it was desirable to find a universally applicable option, for example, for the renovation of old drip pans with expansion joints. A solution had to be found, particularly with regard to joints that meet or intersect at angles.

The present invention has for its object to provide a liquid-tight, chemical-resistant, flexible expansion joint bridging in combination with a suitable connection compound, which does not have the disadvantages mentioned.

• a) gegebenenfalls einer Versiegelungsschicht,
• b) gegebenenfalls einer gummielastischen Schicht
• c) zwei Schichten aus Duroplastharzen
• d) einer Schicht aus thermoplastischen oder elastomeren Kunststoffen und gegebenenfalls e) einer mit Duroplastharz getränkten Abdeckschicht,

wobei die Schicht d) zwischen die beiden Duroplastharzschichten c) eingelagert ist mit der Maßgabe, daß nur die Ränder der Schicht d) mit dem mehrschichtigen Material der Schichten a) bis c) in Kontakt kommen und der Mittelteil sich über dem zu überbrückenden Übergang befindet.The invention relates to a multi-layer joint bridging material consisting of

• a) optionally a sealing layer,
• b) optionally a rubber-elastic layer
• c) two layers of thermosetting resins
• d) a layer of thermoplastic or elastomeric plastics and optionally e) a cover layer impregnated with thermosetting resin,

with layer d) between the two Thermosetting resin layers c) is embedded with the proviso that only the edges of layer d) come into contact with the multilayer material of layers a) to c) and the middle part is located above the transition to be bridged.

• a) gegebenenfalls eine Versiegelungsschicht,
• b) gegebenenfalls eine gummielastische Schicht,
• c₁) eine Duroplastharzschicht aufgebracht wird, anschließend
• d) eine den Übergang und den Schichtaufbau a) bis c₁) vollständig überdeckende Schicht aus einem thermoplastischen oder elastomeren Kunststoff gelegt wird, die ihrerseits an den Rändern mit
• c₂) einer zweiten Duroplastharzschicht und gegebenenfalls
• e) einer ebenso getränkten Abdeckschicht beschichtet wird.

Another object is a method for its manufacture, in which first of all on the edges of a transition (joint) one after the other

• a) optionally a sealing layer,
• b) optionally a rubber-elastic layer,
• c₁) a thermosetting resin layer is applied, then
• d) a transition and the layer structure a) to c₁) completely covering layer made of a thermoplastic or elastomeric plastic is placed, which in turn with the edges
• c₂) a second thermosetting resin layer and optionally
• e) an equally impregnated cover layer is coated.

Even if fluoroplastics are often mentioned in the following, this does not mean that no other plastic can be used for less aggressive chemical effects or potential effects, such as are present when storing and handling chemicals. The letters a) to e) result from the order of the coating steps.

• 1. Vorgefertigte und vorbereitete Kunststoff-Teile und Bänder (Kompensatoren),
• 2. Verbund der Teile untereinander,
• 3. Verbund der Kompensatoren mit der Anschluß-Beschichtungsmasse.

The system on which the invention is based is divided into three parts:

• 1. Prefabricated and prepared plastic parts and strips (compensators),
• 2. interconnection of the parts with each other,
• 3. Compound of the expansion joints with the connection coating compound.

1) For the expansion joint tape, films of 0.2 to 5.0, preferably 0.7 to 1.5, in particular approximately 1 mm thick and approximately 240 mm wide are generally used. However, the width of the tapes can vary depending on the purpose and type of use, e.g. widths of 100 to 500 mm are suitable. With flexible material, the preforming of a middle loop may not be necessary. The loop is then created manually during embedding. In the case of stiffer foils, a continuous bead of, for example, 20 mm wide and 20 mm deep with bevelled side surfaces is produced in the manufacture of the tape by conventional manufacturing methods for thermoplastics or elastomers.

For joints that meet or intersect at an angle, prefabricated shaped pieces are required which generally have the same dimensions in terms of thickness and width as the foils used for the joint tape. This can be T-shaped and cross-shaped parts or transitions from floor to wall joint, d. H. angular. The production takes place with appropriate tools, e.g. by deep drawing; Injection molding is also possible. Parts made of elastomers can be manufactured using the usual methods of rubber processing. The free ends in the longitudinal direction are connected with joint tape to further bridge the joints.

The individual parts should be made at least in such a size that the free-standing ends ensure a perfect connection with the joint tapes.

All plastic parts and tapes generally have recesses, for example, peripheral perforations of at least 10 mm in diameter, so that a good anchoring in the connecting mass is guaranteed.

Thermoplastic materials and elastomers are generally used as the material for the production of the joint tapes and the prefabricated individual parts. Examples of these are polyethylene, polypropylene, polystyrene, polyester, polyamides, poly (meth) acrylates, polyvinylidene fluoride, polyvinyl chloride, polytetrafluoroethylene, fluoropolymers, elastomers such as natural or synthetic rubber types or fluoroelastomers. However, woven or non-woven material made from these materials can also be used in the form of laminates, with metal mesh also serving as an insert in the latter. In many cases it is a prerequisite when using such substances that, like the resins used for the lamination, they have sufficient resistance to chemicals and weathering.

The curable plastics which are used as the connection (coating) composition can generally be cured using the hardener substances known for curing at room temperature, for example polyamines, inorganic and organic acids, polyisocyanates and organic peroxide compounds. most of the plastics that can be used do not result in an adhesive and tight connection to the connecting compound, which can consist, for example, of thermosets such as phenoplasts, aminoplasts, polyurethanes, epoxy and unsaturated polyester resins, but also of the thermoplastic or elastic plastics already mentioned above. A special pretreatment, ie an etching of the plastic parts and tapes is therefore necessary. In the case of fluorothermoplastics or fluoroelastomers, for example, it is advantageous to generally carry out this pretreatment either with a solution of metallic sodium in tetrahydrofuran and naphthalene or in liquid ammonia in which the metallic sodium is dissolved is to be carried out. After thorough washing and drying, the treated parts are protected from contact by packaging.

2) The prefabricated joint parts are generally connected with tapes of different lengths depending on the local conditions. This can be done, for example, by welding, gluing or, in the case of elastomers, by vulcanization.

Welding such strips with a profile is usually problematic. It was found here that the welding by means of flat electrically conductive strips (metal mesh), as described in the German patent application P 37 15 377.3 and to which reference is hereby made, works very well.

If the composite is to be produced by means of adhesive, it can often be carried out with the same reactive resin that is used for the connection coating. The installation of a thin glass fiber fleece is advisable because of the better flexibility of the glue point.

During the connection process, it is convenient to fix the parts under pressure.

3) The prefabricated, prepared and connected plastic parts and webs are now embedded in the connection coating composition, which consists of the above-mentioned substances.

The system of epoxy resin, polyurethane and phenolic resin already mentioned can also be used advantageously according to the invention with the plastic parts and strips. For example, an unmodified liquid epoxy resin with an epoxy equivalent of 175-185 is used as the epoxy component. Polyamines, for example 4,4′-diamino, can be used as hardeners diphenylmethane, bis-cyclohexylaminomethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane can be used, the mixing ratio being 1-3: 1, preferably 2: 1 parts by weight.

The rubber-elastic layer consists of compounds bearing hydroxyl groups, e.g. a polyol such as "Poly BD" from Sartomer, Westchester, PA, USA and a polyisocyanate hardener, for example tolylene-2,4-, toluene-2,6-, cyclohexylene-1,4-, isophorone or diphenylmethane diisocyanate and Xylylene diisocyanates. The two components are generally used in a mixing ratio of 1-5: 1, preferably 2-4: 1 parts by weight. Phenol resols, for example, can be used as modified phenol-formaldehyde resins. Such a medium viscosity and a molar ratio of phenol: formaldehyde of 1: 1.75 is preferred. Organic sulfonic acids such as benzenesulfonic acid, p-toluenesulfonic acid and others. can be used as a hardener for the phenol-formaldehyde resins in conventional amounts. In the following description, the hardeners used are generally no longer mentioned in the resins to be used.

In general, the structure of the bridging according to the invention is carried out as follows, it being understood that the resin components and the reinforcing insert, that is to say the connecting layer, are only applied to the edges of the substrates to be bridged and the compensators effect the actual bridging of the joints: the epoxy resin the sealing layer to be applied first. This is followed by the crack-bridging rubber-elastic layer made of polyurethane. Both functionally have only barrier and crack-bridging properties and are not always necessary. This is followed by a mat layer impregnated with phenolic resin, for example made of glass fiber fleece, whereupon the Plastic expansion joints are placed on the edge and covered with a second soaked mat layer and, if necessary, a cover fleece so that 60 - 80 mm expansion joint edge is laminated. The edge perforation in the mats ensures that the somewhat rigid mat layers can approach from above and below in the area of the perforations in such a way that an additional anchoring takes place through the hardened resin.

The entire system offers the following advantages after curing:
- The movements at the expansion joint or at the connection joint are absorbed by the flexible material
- The bond between the compensators and the connection layer is liquid-tight - also against solvents
- When using suitable materials, they show excellent resistance to aggressive liquids and gases.

Of course, the embedding is not limited to laminate systems. The expansion joints can also be installed in chemical-resistant bricks, for example in production boilers, laboratory buildings, etc.

The possible areas of application are: coating drip pans with expansion joint bridging, bridging transitions when pipes are laid, creating tight transitions in brickwork (eg washing towers, chimneys) to connecting pieces, high-quality facade seals, etc. It does not matter, which materials are to be bridged, eg concrete, stone, metal, plastic etc. it is essential that the side parts of the thermoplastic or elastomeric layer are firmly and tightly embedded in the surrounding thermosetting resin.

For the examples described below, a coating system consisting of a liquid epoxy resin (EA 175-185) and 4,4'-diaminodiphenylmethane, mixing ratio 2: 1 / "Poly BD" and diphenylmethane diisocyanate, mixing ratio 4: 1 / a medium-viscosity phenoresol with a Molar ratio of phenol: formaldehyde of 1.75, which contained an organic sulfonic acid as a hardener.

The epoxy resin was applied to the substrate in a thickness of approx. 0.5 mm (a). After approx. 24 hours, (b) followed, the application of the polyol (approx. 2 mm) and after a further 24 hours (c) the phenolic resin and the expansion joints in the following order: 1) glass fiber mat impregnated with phenolic resin (weight per unit area 450 g / m²) , 2) compensators, 3) like 1), 4) cover fleece made of glass fiber (basis weight 30 g / m²), also impregnated with phenolic resin (total layer thickness (c) approx. 3 mm).

A thermoplastic, processable, terpolymeric fluoroplastic in film form made of tetrafluoroethylene and partially fluorinated cocomponents, which had previously been perforated and etched, served as the compensator material. The etching was carried out with liquid ammonia in which metallic sodium was dissolved.

The test for the stability of the bridging systems was carried out in accordance with the "Construction and test principles for coatings for concrete, plaster and screed surfaces of collecting basins and collecting rooms for water-polluting liquids" from the Institute for Building Technology, Berlin.

Examples

1) A reinforced concrete slab (1) with the dimensions 230 x 200 x 40 mm was coated on one side with epoxy resin (2) and polyol (3) in such a way that a circular place (approx. 30 mm diameter) concrete (4) remained free. A hole of the same size was previously punched into the textile glass mats to be applied subsequently. After the first, the lower mat layer (5), impregnated with phenolic resin, was applied, a prepared film made of fluoroplastic (6) was placed. This film had a size of 150 x 150 x 1 mm. 12 holes were punched evenly distributed on a circular arc with r = 45 mm. The diameter of the holes was 10 mm. The film was previously etched. Then came the second, the upper textile glass mat soaked with phenolic resin (7).
After a storage period of 28 days at room temperature, the sample was loaded in a bending testing machine in such a way that a crack (8) of 0.2 mm in width was produced across the entire plate. After unloading, the remaining crack width should be at least 0.05 mm. Then a cylinder with an inner diameter of 100 mm (9) was placed on the site to be tested. The cylinder was filled with about 500 ml of colored dichloromethane (10) and pressurized (1 bar). After 42 days at 1 bar, the test arrangement was disassembled and checked for leaks.

The laminate, the connection to the film and the film had not passed any test medium.

2) The experimental setup was as described in Example 1. A well had previously been deep-drawn in the embedded film. Diameter 20 mm, depth 20 mm, with rounded bottom. Accordingly, there was a recess in the concrete base used been incorporated. Storage liquid was dichloromethane here too.

The laminate, the connection to the film, the film and the film in the thermally and mechanically stressed deep-drawn area of the well were sealed against the test medium.

3) Two etched pieces of film made of fluoroplastic were overlapped approx. 50 mm, glued with phenolic resin and provided with a 50 mm wide cover fleece for reinforcement. After 14 days of curing, this film was tested as described in Example 1. The test medium was dichloromethane. The glue point showed no penetration of test medium.

4) The bondability over an extended storage period was tested on an etched fluoroplastic film. Two etching processes were used for the tests: the method with liquid ammonia and metallic sodium, and secondly a solution of metallic sodium in tetrahydrofuran and naphthalene. After the etching, it was washed thoroughly with water and in the latter case also with acetone and dried.

A small segment was immediately coated with phenolic resin laminate on the surface pretreated in this way. Then the parts were stored at room temperature and exposure to light. After 4 days / 1 week / 2 weeks / 1 month / 2 months / 3 months, a section was coated again.

Peeling tests showed no decrease in liability.

Claims (13)

1. Multi-layer joint bridging material consisting of
a) optionally a sealing layer,
b) optionally a rubber-elastic layer
c) two layers of thermosetting resins
d) a layer of thermoplastic or elastomeric plastics and optionally e) a cover layer impregnated with thermosetting resin,
layer d) being embedded between the two thermosetting resin layers c) with the proviso that only the edges of layer d) come into contact with the multilayer material of layers a) to c) and the middle part is located above the transition to be bridged. 2. A process for producing a multilayer joint bridging material, characterized in that first of all on the edges of a transition (joint) one after the other a) optionally a sealing layer, b) optionally a rubber-elastic layer, c₁) a thermosetting resin layer is applied, then d) a transition and the layer structure a) to c₁) completely covering layer made of a thermoplastic or elastomeric plastic is placed, which in turn with the edges c₂) a second thermosetting resin layer and optionally e) an equally impregnated cover layer is coated. 3. Embodiment according to claim 1 or 2, characterized in that the layer d) represents prefabricated parts in the form of strips or shaped pieces. 4. Embodiment according to one or more of claims 1 to 3, characterized in that polyethylene, polypropylene, polyester, polytetrafluoroethylene, fluoropolymers, natural and synthetic rubbers or fluoroelastomers are used as layer d). 5. Embodiment according to one or more of claims 1 to 4, characterized in that the edges of the layer d) are provided with recesses, preferably an edge perforation. 6. Embodiment according to one or more of claims 1 to 5, characterized in that the layer c) consists of a thermosetting resin from the group of phenoplasts, aminoplasts, polyurethanes and unsaturated polyester resins. 7. Embodiment according to claim 7, characterized in that the thermosetting resin is a phenol-formaldehyde resin. 8. Embodiment according to one or more of claims 1 to 7, characterized in that the strips and shaped pieces of layer d) are provided with a central bead. 9. Embodiment according to one or more of claims 1 to 8, characterized in that the strips and molded parts of layer d) are etched. 10. Embodiment according to one or more of claims 1 to 9, characterized in that the sealing layer a) consists of a liquid epoxy resin hardened with a polyamine hardener. 11. Embodiment according to one or more of claims 1 to 10, characterized in that the rubber-elastic layer b) consists of a polyurethane made of a polyol and a polyisocyanate. 12. Use of the material according to claim 1 for the manufacture of permanent, tear-resistant, liquid-tight seals. 13. Use according to claim 12 as bridging expansion joints, transitions in laid pipes, bricks.

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