SE431098B - IN THE PRESENCE OF THE WATER, ASTADKOMMA MAKES A ADMINISTRATION WITH THE USE OF A CASTLE PLASTIC ADMINISTRATION AND KIT FOR USE IN THE SET - Google Patents

Description

7904265-1 When an open cell carrier material is compressed, the size of the gap passages is reduced, whereby the mobility of the adhesive inside them is also reduced. By suitable adjustment of the viscosity and the curing speed of the adhesive to the porosity of the carrier, a cured bond can be achieved without any significant disturbance of the adhesive under the applied pressure. Adhesive compounds made using the impregnated foam carrier can be used to clog punctured substrates, the method comprising applying the impregnated carrier to the substrate around the hole and pressing the impregnated carrier into the hole.

Furthermore, adhesive compounds made by using the impregnated foam carrier material can be used to apply an overlying layer, e.g. a repair or structural attachment, to the substrate, which method comprises applying the plastic impregnated foam carrier material to either the substrate or the overlying layer and compressing the two to compress the carrier material therebetween. This method is useful for in situ repairing damaged hulls, underwater structures or pressure vessels, due to the compression of the plastic-impregnated foam by the hydrostatic or internal pressure trapping adhesive inside the foam and helps to reduce the tendency of said pressure to upset the glue. However, this method has a wider range of applications due to the ease with which large quantities of plastic can be handled for bonds over large surface areas and / or when thick plastic layers are required. A further advantage is that bindings can be produced by means of the method according to the invention with a relatively small air enclosure, which enclosure, in particular at the plastic interface, can reduce the bond strength considerably.

The main use of the invention lies in the manufacture of underwater connections to ship hulls, pipelines, drilling platforms, etc.

For these uses, the open cell carrier material is impregnated with an adhesive that can displace, absorb or otherwise eliminate the water from the substrate to which a bond is to be formed, after which the adhesive can be cured to form a strong bond therewith.

Preferably, this adhesive is a two-component mixture, the first part of which comprises a diglycidyl ether of bisphenol 'A' and the second part comprises a hardener, based on either a cycloaliphatic polyamine or a 4,4'-diaminodiphenylmethane ( DDM). It has been found that these adhesives easily wet a surface to which they are physically applied, regardless of whether the water is present, but a non-ionic surfactant may be incorporated into the adhesive to modify it so that it preferably wets the substrate. An epoxide-functional silane can also be incorporated to chemically stabilize the adhesive / substrate bond in the interface.

Preferably, the open cell carrier material comprises a resilient polyester-based polyurethane foam having a porosity of between 30 and 45 pores per 25.4 mm. This material is readily available in a number of different degrees of porosity and has the necessary resilience and inactivity for glue formation.

While the substrate should preferably be cleaned and polished before bonding to achieve maximum bond strength, the method of the invention can produce acceptable bonds with uneven or coated surfaces. Furthermore, relatively large adhesive thicknesses in a layer can be used thanks to the support provided by the carrier material.

According to another aspect of the invention, there is provided a repair kit for use in the method described above, which kit comprises a thermoset adhesive and a resilient synthetic foam carrier material having an open cell structure.

According to the invention, the components of the kit are preferably contained in separate compartments in a plastic bag, whereby for use the partitions between the compartments can be broken or otherwise removed so that the components can be mixed.

The adhesive is thus arranged in two parts for admixture before use, the first part comprising a diglycidyl ether of bisphenol 'A' and the second part comprising a harder one based on either a cycloaliphatic polyamine or 4,4'-diamino-diphenylmethane. Preferably, the open cell carrier material is a resilient polyester-based polyurethane foam having a porosity of between 30 and 45 pores per 25.4 mm.

The repair kit can be delivered in the form of a simple package in a plastic bag with separate compartments for each of the components. In use, the partitions between the glue compartments can be destroyed or otherwise removed so that the compo- V _ ------ _ "HV -» .-- -w - «. ~. - __.-__..- ......... v ..._-..__.._.._._ .. f 7904265-1 nents can be mixed.

The bonding method of the invention and the repair kit can be used on a wide variety of substrates including glass fiber reinforced plastic (GRP), steel and concrete. It may be necessary to vary the adhesive composition for certain special applications.

The method according to the invention will now be described with the aid of the following examples in connection with the accompanying drawings, in which Figs. 1A, 1B and 1C show a backfill repair on a glass fiber reinforced plastic substrate, Fig. 2 illustrates a patch repair and Fig. 3 illustrates a repair of a pipe flange weld.

Referring first to the backfill repair illustrated in Figs. 1A, 1B and 1C, the substrate is a sheet 1 of fiberglass reinforced plastic (GRP) with a long crack 2.

The crack 2 is intended to be a damage of the type that can be expected in e.g. plastic boats. To create a realistic environment in the laboratory, the damaged sheet 1 was included as one of the walls in a metal box, for immersion in water. A rubber vent pipe, which opened into the surrounding air, was attached to the box and the box was lowered into a water tank.

The repair was carried out under water using the hands only using the two-component plastic system described below and is referred to as type I plastic composition UW43. 7904265-1 Type I plastic composition UW43 Ingredient Function or description Weight parts Shell Epikote 828 plastic: diglycidyl ether of 100 bisphenyl 'A' (epoxide equivalent Ca 185) Union Carbide A187 epoxide-functional silane 2.0 part A Ciba-Geigy White color paste 0.5 Aerosil 200 filler: to give the adhesive 8,0 thixotropic properties and / or to adjust the mixing proportions Ancamine MCA cycloaliphatic polyamine part B hardener Epophen ED-1Z polysulfide plasticizer / - 50 hardener Ciba-Geígy Black color paste 0, 2 Aerosil 200 filler: to give the adhesive 13 thixotropic properties and / or to adjust the mixing proportions Equal parts based on the weight of the two parts of the plastic composition designated UW43 were taken and mixed properly. A piece of an open-celled, flexible, low-density, suitable-sized polyurethane foam was then saturated with the freshly mixed plastic, taken underwater, and placed over the crack 2 through which water had previously passed. The impregnated foam piece was then worked by hand to press it into and completely fill in the crack 2. When the piece was worked in completely in place, the outer and inner sides of the panel 1 had an appearance as shown in Figs. 1B and 1C, respectively. From this it appears that the piece 3 completely covers the outer surface of the sheet 1 in the area of the crack and in fact to a large extent penetrated the crack 2 to the inner surface of the sheet. The tin box was lowered while the plastic was still uncured to the bottom of a 3 m deep water tank, so that it was exposed to the highest hydrostatic pressure achieved at existing GRP hulls. When the box was taken up after a period of 24 hours at this depth, the interior of the box was found to be substantially free of water, which shows that the repair was successful.

To indicate the strength of the GRP plastic bond, foam pads impregnated with the above adhesive composition have been used to bond overlapping water-saturated sheets of GRP. Subsequent tests on GRP sheets, which were joined underwater in this way, showed a tensile strength for the repair of approximately 7.0 MN / m2, with breakage occurring in the plastic. Epoxy-based adhesives are preferred for underwater applications due to the ease with which they can be cured, their good adhesion and their convenience in general. An alternative epoxy-based adhesive for use underwater is called type I, composition UW3l. This composition is similar to that for UW43 except that in part A 4.0 parts by weight Sylodex 24 replaces Aerosil 200 as filler and 2.0 parts by weight Colorol Aquasorb is included as non-ionic surfactant, and with the exception that in part B 5.0 parts by weight Sylodex 24 replaces Aerosil 200 as a filler.

Another plastic system suitable for underwater use is called type II composition UW27 and is described below. 7904265-1 7 Type II Plastic composition UW27 Ingredient Function or description Weight parts Part A Araldite GY250 plastic: diglycidyl ether of bisphenol 'A' 100 Union Carbide A187 epoxy-functional silane 15 Barite fillers: for imparting thixotropic properties and / or for adjusting -. ; ~ / ~ />. d _, \ / mixture proportions 75 Sylodex 24 3.0 Part B Araldite HY850 hardener: diamine-diphenylmethane in a liquid-transferable form 64 7 Orgol tar plasticizer 40 Barites (fillers: for imparting) of thixotropic properties) and / or for adjusting the blend proportions 86) Sylodex 24) The 2.0 UW43 composition has been used to provide satisfactory underwater bonds to GRP, when used with the open cell foam described above. Although it is not currently intended that such a method be used to effect permanent repairs, bindings thus prepared have withstood a complete immersion for one year at room temperature with no sign of decomposition.

Referring to Fig. 2, a new, slightly oily steel plate 10 of mild carbon steel with a crack IIl was attached to a water pressure tank as a side. A water pressure of 131 kN / m2 7904265-1 8 was exerted on the interior of the tank, which gave rise to a strong jet of water from the crack ll. A cushion 12 of flexible open-cell polyurethane foam with the dimensions 250 x 160 x 25 mm was impregnated with a newly produced mixture of the plastic designated with type I composition UW43. The impregnated cushion was supported by a soft carbon steel plate 13 with the same area as the cushion 12 and the two were laid over the crack 11. The impregnated foam pad 12 was then compressed to a thickness of approximately 3 mm between the plate 13 and the broken plate 10 by means of G-staples (not shown) and a wooden beam 14. When the leak closed, the pressure on the beam 14 and the internal pressure was removed. which acted on the crack ll was increased to 200 k fi / m2 without any sign of leakage from the repair despite the plate 13 bending below the applied pressure.

In the repair shown in Fig. 3, a steel pipe 20 with an inner diameter of 50 mm was taken and provided with a flange 21 welded thereto and a 1 mm diameter hole was drilled through the weld 22. The pipe 20 was filled with water before repair took place according to following procedure. A cushion of an open-celled flexible polyurethane foam 23 measuring 75 x 25 x 25 mm was impregnated with a small amount of freshly blended plastic with the composition UW43. The impregnated cushion was then wound around the weld 22 and compressed thereon by means of an annular tool 24 held in place with a G-clamp not shown in the drawing.

After tool 24 was removed, the internal pressure was increased to 267 kN / m2 without any sign of leakage. After a period of 4 hours, the pressure was increased to 534 kN / m2, which was maintained over a weekend. Thereafter, the pressure was increased to 4.14 M / m2 without any sign of leakage.

For most applications, a repair kit consisting of the plastic parts and the open-cell foam that separate parts is satisfactory, but in some circumstances it may be advantageous to arrange the three components in a three-compartment container. For example, the kit can be enclosed in a simple plastic cover with dividers or holders that form three separate compartments in the cover. The plastic parts can then be mixed by removing the separating holders or breaking the partition and processing the cover. Thereafter, the open-cell foam can be impregnated by removing the remaining holder or breaking the remaining compartment. This type of cover is particularly well suited for underwater use.

As will be apparent to those skilled in the art, many variations in the method and kit of the invention are possible within the scope of the invention. The method can, for example, be used for many other substrates, including concrete, although the adhesive composition may need to be varied. Throughout the described experiments, a resilient polyurethane foam with a porosity of between 30 and 45 pores per 25.4 mm has been used.

Although the foam should be resilient, have open cells and be inactive in relation to the adhesive, its composition and porosity are not critical. In particular, the porosity can be selected to suit the viscosity and cure rate of the adhesive selected for the application in question.

As mentioned earlier, the method according to the invention is very well suited for use in many applications which require thick plastic layers or large coating areas, thanks to the ease with which the plastic-impregnated foam carrier can be applied. Furthermore, it has the advantage of minimal air entrapment.

Furthermore, the invention, although not limited to repair purposes or for use under or in the presence of water, can be advantageously used, for example, for the repair or reinforcement of existing underwater facilities, such as offshore platforms or as generators. real binding method.

Typical examples of the use of the invention in offshore repairs are described in the applicant's British Patents 1,598,433, 1,598,434, 2,026,123 and 1,598,435.

Claims (6)

w xo ND GN Un Patentkrav A method of providing an adhesive bond to a substrate using a thermoset adhesive, characterized in that the adhesive bond is provided in the presence of water and that the method comprises the steps of impregnating a resilient synthetic foam carrier having an open cell structure with the thermoset adhesive, applied by the impregnated the support material on the substrate, and compressing the impregnated support material against the substrate so that the plastic adhesive initially causes the present water to be displaced, absorbed or otherwise eliminated from the substrate to which bonding is to be effected, after which the plastic adhesive is immobilized inside the cavity of the carrier material and is cured to form a strong bond with the substrate. 2. A method according to claim 1, characterized in that the plastic adhesive consists of a two-component mixture, the first component of which comprises a diglycidyl ether of bisphenol 'A' and the second part comprises either a cycloaliphatic polyamine or an Ä, 4 '~ diaminodiphenylmethane. 3. A method according to claim 2, characterized in that the plastic adhesive comprises an epoxide-functional silane. Ä. 4. A method according to any one of the preceding claims, characterized in that the carrier material is a resilient polyester-based polyurethane foam with a porosity of between 30 and H5 pores per 25 mm. Kit for use in the method according to any one of claims 1 ~ M, characterized in that it comprises a core ~ of plastic glue and a resilient synthetic foam carrier material with an open cell structure. Kit according to claim 5, characterized in that the constituents of the kit are contained in separate compartments in a plastic bag, wherein for use the partitions between the compartments can be broken or otherwise removed so that the components can be mixed.