KR20100092905A - Flexible laminate for cryogenic sealing barrier, this barrier comprising this laminate bonded to a subjacent laminate and process for assembling same - Google Patents

Abstract

PURPOSE: A flexible laminate for a cryogenic sealing barrier is provided to improve the reliability of an assembly unit while preventing the exfoliation in time passing. CONSTITUTION: A flexible laminate(9) forms a cover strip of a hermetic sealing barrier and is guided to the combining unit of a synthetic panel. Two laminates include aluminum foil which is inserted into two glass fabric sheets which are dipped in a binder. An adhesion assembly is manufactured by spraying adhesive on the flexible laminate through a hot melt adhesive(208).

Description

FLEXIBLE LAMINATE FOR CRYOGENIC SEALING BARRIER, THIS BARRIER COMPRISING THIS LAMINATE BONDED TO A SUBJACENT LAMINATE AND PROCESS FOR ASSEMBLING SAME}

The present invention includes, for example, a flexible composite laminate that forms a cover strip of a cryogenic sealing barrier for a tank containing liquid methane at -162 ° C, a strip of flexible laminate bonded to a joint of a composite panel covered with other laminates. A secondary barrier, and a method for assembling this secondary barrier by adhesion.

Currently, the secondary sealing barrier in tanks of methane tankers designed according to the "Mark III" or "CS1" developed by the French company GTT is known as "Triplex" and is parallel to the wall of the tank. It is based on a laminate designed to function as a barrier against the leakage of liquid methane in the event of damage or breakage of the primary barrier in direct contact with cryogenic liquids. This triplex is c. Therefore, this secondary barrier must not pass liquefied gas over the entire service life of the methane tanker, and must withstand many mechanical and thermal stresses exerted by the ship or tank during its operating time. This secondary barrier is disposed between each of the two primary insulating layers and the secondary insulating layer, the preparation of which is usually made according to the following steps performed with reference to FIGS. 1 to 4 attached hereto.

First, a composite panel is produced in a dedicated factory for this operation, and between these panels, which consist of two primary and secondary insulating layers, a "triplex" laminate which does not penetrate liquefied gas is bonded. Various of these panels are adjacent to each other and are adhesively and mechanically attached to the wall of the tank. As shown in FIG. 1, these panels 1 attached to the shell 2 of the methane tanker through the resin 4 attached to the fastening member 3 and the shell 2 may have adequate flexibility, rigidity or half A laminated panel 7 having rigidity, each comprising insulating foams 5a and 6a in contact with sheets of wood 5b and 6b, wherein the two insulating layers 5 and 6 described above adhered therebetween. Is done.

As can be seen in FIG. 2, a stack of "triplex", called "flexible" 9, is then interposed between these composite panels 1 by coating with adhesive 8, usually in the form of polyurethane or epoxy. Is bonded to the laminate 7 so that the bonding with the laminate 7 is achieved. In a known manner, these "triplex" laminates 7 consist of aluminum foil sandwiched between two glass woven sheets impregnated with an elastomeric binder. The adhesion formed between the strips of the flexible laminate 9 and the lower laminate 7 ensures an overall sealing of the entire secondary barrier.

In order to effect this adhesion, the flexible laminate 9 is unrolled from the roll and the flexible laminate is applied to the joints between the sheets formed by the laminate 7 coated with the adhesive 8 and then applied. This flexible laminate 9 is heated in the pressurized state for the time necessary for good curing of the adhesive 8 (typically during several hours of heating in the pressurized state). As shown in Fig. 3, it is possible to carry out the pressurization and heating by means of a heating " air bag "

Once bonding is performed, the primary insulating sheet 12 on which the plywood sheet (also known as the upper bridge pad, seen in the cross-sectional view of FIG. 2) is placed at the junction between the composite panels 1 is next. A primary sealing barrier (not shown) is attached to this stack. In this way, two sealing barriers alternately arranged with the two insulating barriers are finally obtained, and the object installed in the tank can never penetrate the liquefied gas in order to maintain the liquefied gas at a temperature of about -162 ° C. There will be no.

Patent Literature 1 and Patent Literature 2 coat the flexible laminates with a hot-melt adhesive at an adhesion-diffusion temperature of 120 ° C., whereby each flexible laminate is continuously bonded to the (semi) rigid laminate. Taught. 90-100 ° C. was taught as to the temperature for placing the flexible laminate on the rigid laminate.

One major drawback of the known assembly method is that there is a risk of unsatisfactory adhesion of each flexible laminate to the lower laminate, which may damage the overall sealing of the secondary barrier formed by the adhesion, and after a certain time, The flexible laminate may separate, causing severe leakage of liquefied gas. In practice, these flexible laminates, therefore, are produced at the center during operation, over time, with high mechanical stresses due to the movement of the ship and especially for liquefied gases loading and unloading at temperatures of -162 ° C in tanks. Many thermal shocks can not withstand all the time.

In particular, since the assembly is subjected to high shear stress (all of these shear stresses are roughly indicated by reference C in FIG. 4), the assembly between the adhesive 8 and the rigid laminate 7 to which the adhesive is applied is vulnerable. It is found through experiments that there is an arrow F in FIG. 5. In addition, the fine leakage of liquefied gas is likely to propagate in the inner surface of the laminate / adhesive of the glass woven yarn applying the adhesive forming the outer surface of the flexible laminate and / or adjacent laminates, and thus the potential important mentioned above. As a result, there is a risk of eventually propagating across the secondary sealing barrier.

(1) France (FR) Patent A1-2 822 814 publication

(2) France (FR) Patent A1-2 822 815

One object of the present invention is to solve the above-mentioned problems, and to provide a flexible synthetic laminate which forms a cover strip of a secondary sealing barrier for a tank containing methane, which is a different synthetic laminate (hereinafter, Intended to adhere to the joints of adjacent composite panels covered by " lower laminates " in the adhesive assembly, these two laminates each comprising a metal foil sandwiched between two fabrics impregnated with a binder.

In order to achieve the above object, the flexible laminate according to the invention can be cured by the input heat applied at the softening point of the outer fabric of each bottom laminate and its fabric intended to cover at least one peripheral edge of the flexible laminate. By pre-coating the adhesive using a heat dissolving adhesive, there is provided an adhesive assembly which is subsequently obtained through pressurization of the adhesive in contact with the lower laminate and curing by heating, in particular by the known method described above (ie with epoxy adhesive). Compared to the bonded assembly, it prevents microleakage of cryogenic liquids (through adhesion defects that may be at these interfaces) at the position of the rim and improves mechanical strength.

The expression "peripheral rim" of the flexible laminate herein means all or part of the laminate rim including simultaneously the rim of two fabrics and metal insert foils across the laminate.

Therefore, the adhesive according to the invention is preferably a glass impregnated with an elastomeric mixture that forms the entire surface of the flexible laminate fabric or the inner fabric (“flexible triplex”) that, after assembled by coating, is flipped over to the lower laminate. Woven fabrics, etc.), and that the fabric and elastomer binder each provide a satisfactory mechanical strength and satisfactory flexibility to the assembly, while the inner metal foil (eg, made of aluminum) is designed to have a sealing function. It should be noted.

It should be noted that due to the control in which the adhesive is applied by the process described above, it is possible to greatly improve the reliability of the durability against mechanical stress of the adhesive assembly forming the peeling and secondary barrier.

This improved mechanical strength and improved protection against leakage are obtained by high temperature adhesion with the low viscosity adhesives of the present invention directly impregnated into the inner fabric of the flexible laminate and the outer fabric of the lower laminate.

 Therefore, flexible laminates pre-applied with adhesives at the factory are easily placed directly on the lower laminates with simple activation of the adhesives through the input heat under pressure in contact with the lower laminates, thus ensuring the installation performance while ensuring the resulting adhesive performance. It should be noted that this can be greatly facilitated.

Preferably, the adhesive according to the invention is also applied to the outer fabric of the flexible laminate, at least in the peripheral region of this fabric extending the pre-coated adhesive rim.

According to another feature of the invention, the adhesive may be, in a cured state, essentially the reaction product of the following first and second reactants:

The first reactant is an isocyanate which is physically and / or chemically separated from the second reactant such as polyol, polyester or polyether, said second reactant forming a matrix for the adhesive;

The second reactant involves heating of the adhesive at a predetermined limit temperature, which is preferably a single component adhesive, for example in the form of polyurethane or polyester-urethane.

Preferably, the adhesive has a softening point between 55 ° C. and 65 ° C. and a curing temperature of 100 ° C. to 150 ° C. for its application in a liquid state where no reaction occurs.

There is a gap of at least about 35 ° C. between the treatment temperature of the adhesive during preapplying the adhesive on the flexible laminate and the curing temperature of the adhesive during application of the adhesive on the lower laminate, which gap is passed through the instant installation flexible laminate. It should be understood that it is very suitable for manufacturing the assembly.

In addition, the adhesives usable in accordance with the present invention may belong to a chemical group other than polyurethane or polyester-urethane, which adhesives are subjected to mechanical stresses sufficient to meet the specification of secondary barriers for tanks for methane tankers. It has mechanical properties to withstand and can be cured by input heat (and not by moisture from the air, to prevent any hardening during the period from factory pre-spread to installation at the shipyard). Understand that there is.

According to another feature of the invention, this thermosetting heat soluble adhesive can be applied to the flexible laminate at an application rate of 50 g / m 2 to 800 g / m 2, preferably using a doctor blade, roller or powder coater.

Advantageously, the adhesive has its degree of cure resulting through a predetermined color or color brightness, for example, indicating an inadequate initiation of adhesive cure prior to manufacturing the assembly or insufficient curing during the heating performed to obtain the assembly. It may include a visualization means designed to represent.

These visualization means can include the following choices:

a) in the case of the aforementioned at least physical separation between the first and second reactants,

Present in the capsule containing the matrix or the first reactant, and selectively react with the first reactant or this matrix, respectively, immediately after rupture of the capsule to provide a reaction product that is identifiable by its color in the adhesive. Compound capable of;

Present in an auxiliary capsule other than the capsule containing the first reactant and designed to rupture simultaneously with the capsule, and selectively react with the first reactant or the matrix immediately after rupture of the capsule of the first reactant and these auxiliary capsules A compound capable of providing a reaction product that can be identified by its color in the adhesive; or

A dye present in the capsule containing the first reactant or in the auxiliary capsule designed to rupture simultaneously with the first reactant and which can diffuse into the adhesive immediately after rupture of the capsule of the first reactant or the entire first reactant and the auxiliary capsule; And

b) in the case of the other aforementioned chemical separation between the first and second reactants,

Selectively reacts with the first reactant or the matrix immediately after reaching the limit temperature during heating to provide a reaction product which is identifiable by its color in the adhesive in the case of the compound or in the case of the dye A compound capable of diffusing into this adhesive; or

A dye which is designed to rupture immediately after said limit temperature during heating, and which can subsequently diffuse into the adhesive.

Secondary sealing barriers for tanks containing liquid methane according to the present invention comprise strips of flexible laminates bonded at the joints of adjacent composite panels, each covered with a different synthetic laminate or bottom laminate, these two laminates being binders. Each comprising a metal foil sandwiched between two fabrics impregnated with the barrier, the barrier being obtained by introduction at a high temperature under pressure, preferably at a temperature of from 100 ° C. to 150 ° C., the adhesive flexible laminate according to the invention Each pre-coated strip is in contact with an adjacent laminate optionally coated with the thermosetting heat soluble adhesive.

The method of assembling the secondary cryogenic sealing barrier according to the invention by adhesion is essentially

a) pre-applying each production strip of the flexible laminate at the softening point thereof, preferably using a thermosetting heat soluble adhesive applied at a temperature of 55 ° C. to 65 ° C .;

b) optionally applying at the factory each strip of the lower laminate covering the composite panel using the same adhesive;

c) In the shipyard for assembling the barrier to the tank wall of the methane tanker, each strip of flexible laminate is placed underneath at a high temperature under pressure, preferably for a time ranging from 30 to 5 minutes at a curing temperature of from 100 ° C. to 150 ° C. Contacting the panel covered with the laminate (eg, for a minimum elapsed time of 3 minutes, at a temperature of 135 ° C.).

The optional laminate included in the in-house prespread and insulation panels of each flexible laminate can facilitate the installation operation of the flexible laminate to obtain an adhesive assembly, and its performance against the risk of delamination over time. It should be noted that by ensuring the reliability, the reliability of the assembly can be improved.

It should also be noted that the pre-applying of the adhesive has the following advantages:

Due to the fact that it is easier to avoid contamination of the surface in the production zone than in the installation zone, quality control of the surface to precoat the adhesive;

By means of the adhesive, the optimum humidity of the surface to precoat the adhesive and the penetration of the adhesive into the fabric of the flexible laminate;

Improved control of the deposited adhesive thickness compared to the pre-applying of the adhesive carried out in the installation zone.

Other features, advantages, and details of the invention are given by way of example and not by way of limitation, and will be understood by reading several of the following exemplary embodiments, which are made with reference to the accompanying drawings.

1 is a schematic vertical cross-sectional view showing two adjacent composite panels in a process fabricated for a tank of a methane tanker according to the prior art, the panel being a bottom laminate intended to form a secondary sealing barrier by adhering to a flexible laminate Covered with.
FIG. 2 is a schematic vertical cross-sectional view of the panel shown in FIG. 1 wherein the lower laminate is covered by adhesion with a flexible laminate according to the prior art.
FIG. 3 is a schematic vertical cross-sectional view showing an example according to the prior art to obtain the adhesion under pressure from FIG. 2.
FIG. 4 is a schematic vertical cross-sectional view showing mechanical shear stress in operation on a flexible laminate bonded to the lower laminate from FIGS. 2 and 3 according to the prior art.
5 is a vertical sectional view showing in detail the weak area of the bonded assembly according to the prior art with reference to FIGS.
6 is a vertical cross-sectional view detailing the application area of the adhesive for each flexible laminate bonded to the lower laminate in accordance with another exemplary embodiment of the present invention.
FIG. 7 is a vertical cross-sectional view detailing the application area of the adhesive for each flexible laminate bonded to the lower laminate, in a variation of FIG. 6, in accordance with another exemplary embodiment of the present invention. FIG.
8 is a schematic vertical cross-sectional view showing an optional step in the process of assembling a secondary barrier in accordance with the present invention, with reference to FIG. 1, wherein the lower laminate included in the insulation panel is an example of an adhesive using the adhesive of the present invention; Apply.
9 is a schematic vertical cross-sectional view partially showing an automatic machine for gluing by heating in a pressurized state that can be used to carry out the assembly process of the present invention.
10 and 11 are two schematic perspective views showing an example of adhesive application according to the present invention by coating the adhesive onto each flexible laminate using a doctor plate, before and during the adhesive application operation, respectively.
12 is a schematic vertical cross-sectional view showing a coating area of each flexible laminate obtained with the doctor blade used in FIGS. 10 and 11 as an example according to the present invention.
13 is a schematic diagram showing a means for visualizing the degree of cure of an adhesive, included in an adhesive, in accordance with an embodiment of the present invention.
14 is a schematic view showing these visualization means in a variant included in the adhesive, in accordance with an embodiment of the present invention.

Adhesive 108 usable in accordance with the present invention for pre-spreading of each flexible laminate 9 (such as a flexible “triplex”) and additionally a laminate comprising an insulating panel 7. Representatively, is a heat soluble adhesive that can be specially cured through input heat. This adhesive 108 may consist primarily of isolated isocyanate capsules embedded in a polyol matrix. As mentioned above, even without such capsules inserted into this matrix, the adhesive can be pre-applied to each flexible laminate 9 at the manufacturing plant and then any other form of adhesive that can be cured by heating at the shipyard. You can also use

The process of pre-gluing the adhesive onto each flexible laminate 9 involves the application of a thermally soluble adhesive 108 in the form of polyurethane or polyester-urethane, such as a single component adhesive sold by Collano under the name "HCM 555" to around 60 ° C. Is executed at the first softening point. In practice, the matrix of adhesive 108 is liquid at this temperature, but is not sufficient to release the isocyanate to prevent premature curing of the adhesive 108. Once applied on the flexible laminate 9, the adhesive is cooled to ambient temperature to form a layer of continuous and compact adhesive 108 on the surface of the flexible laminate 9.

As can be seen in FIGS. 6 and 7, the adhesives 108, 208 are in accordance with the present invention the entire fabric 9a of the flexible laminate 9 intended to cover the visible fabric of each lower laminate 7. As well as on the surface, as a variant of FIG. 7, in the embodiment from FIG. 6, a flexible laminate extending over the peripheral edge 115 of this flexible laminate 9 and to this edge 115 covered with adhesive 208 ( 9) is applied over the opposing fabric surface 9b.

As shown in these FIGS. 6 and 7, the application of the adhesives 108, 208 avoids the presence of vulnerabilities at the junction of the flexible laminate 9 to the lower laminate 7, which can be received during operation. The laminate is more resistant to mechanical stress, has a longer life and substantially less chance of rupture. In addition, by covering the ends of the flexible laminate with adhesives 108 and 208 and / or penetrating into the glass woven fibers of the lower laminate, any fine along the yarns that make up the important fabric of the flexible laminate 9 Leakage cannot propagate.

In addition to preapplying the adhesive to the flexible laminate 9, parallel to preapply the same adhesive 108 to the outer surface of each lower laminate included in the insulating panel 7, as shown in FIG. 8. Can be selectively made available.

FIG. 9 schematically shows the use of an automatic machine 120 for installing each strip of flexible laminate 9 on the lower laminate 7 for purposes of illustration, the automatic machine being (eg, by means of infrared radiation). And / or through the hot plate), and at least the adhesives 108 and 208 previously deposited on the flexible laminate 9 can be pressed. The automatic machine 120 moving in the direction of the arrow A comprises, in particular, a roller 121 for unwinding the flexible laminate 9 pre-coated with an adhesive on the base support 5 of the panel 1. In the example of an “HCM 555” adhesive for 3-4 minutes at a heating temperature of 135 ° C., for example, under a pressure of 0.05 MPa, after contact of the laminates 7 and 9 it is possible to cure this adhesive, finally Cured adhesives 108 and 208 exhibit all of their properties, in particular their strength and sealing properties.

As mentioned above, the method of assembling the secondary sealing barrier has several advantages in particular compared to the prior art:

Pre-applying the adhesive to the flexible laminate 9, saving a lot of time by using automatic equipment, in the case of this laminate 9 which is achieved in a few minutes by curing the adhesives 108, 208 under pressure;

Adhesion is more reliable, more robust, and better withstands the many stresses encountered during operation.

10 to 12 use an adhesive technique to each flexible laminate 9 using a coating technique by a doctor blade 131 placed on a conveyor 132 that is wider than the strip of laminate 9 to be coated, according to an example of the invention. By showing the device 130 for pre-application, the adhesive 108 is applied to the surface 9a of the laminate 9 (ie, at the top in FIG. 12) intended to form an adhesive interface with the lower laminate 7. And is deposited on the peripheral edge 115 of the laminate 9. It should be noted that this method allows precise control of the thickness of the adhesive 108 deposited on these two surfaces 9a and 115.

13 and 14 illustrate the possibility of accidental hardening initiation of this adhesive, for example, by carrying it over a long time during transport of the adhesive, through a predetermined color or brightness of the color, for example, before carrying out assembly. ), Or high mechanical pressure applied to the adhesive that may result in premature rupture of the capsule, or to indicate its correct or insufficient curing during heating for adhesion. An example is shown which includes visualization means designed to indicate the degree of cure In practice, although it is impossible to apply a temperature of 120 ° C. during the transport of a product, a temperature of 60 ° C. may be accidentally applied for several hours over a day and several days Also, if the adhesives 108 ', 108 "begin to harden before their completion, this can make the completion difficult and the material to be bonded For lack of adhesion, it can result in insufficient bonding strength, or lack of adhesive sealing.

As noted above, the adhesives 108 ', 108 "are in the cured state, at least one reactant Rl, such as isocyanate, contained in the capsule 108a, and other reactants, containing these capsules 108a and containing polyols ( A reaction product of the matrix 108b based on at least one of R2), which may occur immediately after rupture of the capsule 108a which occurs for a sufficiently long time at a sufficiently high temperature. Encapsulation makes it possible to isolate each reactant R1 from each reactant R2 prior to curing of the adhesives 108 ', 108 ".

Means for visualizing the curing or non-curing of the adhesives 108 ', 108 "are optionally in the present embodiment showing the physical separation between the reactants R1 and R2 through these capsules 108a. Can include:

With reference to FIG. 13: Compound C1 present in the matrix 108b or Compound C2 present in the capsule 108a, each reacting rapidly with the reactants R1 or R2 after rupture of the capsule 108a, respectively. A compound capable of providing a reaction product that is identifiable by its color within the adhesive 108 '(in addition to the reaction between R1 and R2);

With reference to FIG. 14: present in an auxiliary capsule 108c other than the capsule 108a containing the reactant R1 and designed to rupture simultaneously with this capsule, R1 after simultaneous rupture of the capsules 108a and 108c. Or compound (C3) capable of reacting rapidly with R2 to provide a reaction product which is identifiable by its color within the adhesive 108 "(in addition to the reaction between R1 and R2); or

With reference to FIGS. 13 or 14: capsules that can diffuse into the adhesives 108 ′, 108 ″ together with the reactants R1 in the capsule 108a or, as the case may be, immediately after rupture of the capsules 108a or 108a and 108c. Dye alone in 108c (not shown).

In particular, in the case of FIG. 14 with two types of capsules 108a and 108c, if the adhesive 108 " overheats over a sufficiently long time, the capsule must be accurately measured in order to simultaneously rupture it accurately. You have to understand.

1: panel 5: insulation layer
7: bottom laminate 9: flexible laminate
108, 108 ', 108 ", 208: Adhesive 115: Border
131: doctor blade 132: conveyor

Claims (13)

It is intended to form a cover strip of a secondary cryogenic sealing barrier for tanks containing liquid methane and to adhere to the joints of adjacent composite panels 1 each covered by another composite laminate 7 or a lower laminate, and these two In the flexible composite laminate 9, each laminate comprises an aluminum foil sandwiched between two glass woven sheets impregnated with a binder,
Thermally soluble adhesives 108, 108 ', which may be cured by the input heat applied at the softening point of the outer fabric of each bottom laminate and its fabric 9a intended to cover at least one peripheral edge 115 of this flexible laminate; 108 ", 208 to precoat the adhesive to the flexible laminate, thereby providing an adhesive assembly that is subsequently obtained through pressurization, heating and curing of the adhesive in contact with the lower laminate, and in particular improved mechanical strength. And a flexible laminate (9), characterized in that it prevents microleakage of cryogenic liquids. The outer fabric (9b) of the flexible laminate (9) of claim 1, wherein the adhesives (108, 108 ', 108 ", 208) are at least in the peripheral region of the fabric extending the pre-glued adhesive rim (115). Flexible laminate (9), characterized in that it is applied to optimize the mechanical strength of the assembly. The method of claim 1 or 2, wherein the adhesives 108, 108 ', 108 ", 208 are essentially reaction products of the first reactant (R1) and the second reactant (R2):
The first reactant (R1) is an isocyanate that is physically and / or chemically separated from the second reactant (R2), such as polyol, polyester or polyether, the second reactant forming a matrix 108b for the adhesive ;
The second reactant is accompanied by heating of the adhesive at a predetermined limit temperature, the adhesive being characterized in that it is a single component adhesive, for example in the form of a polyurethane or a polyester-urethane. 4. The adhesive (108), (108 '), (108), (208) of claim 3 has a softening point between 55 [deg.] C. and 65 [deg.] C., and a curing temperature between 100 [deg.] C. and 150 [deg.] C. for its application in a liquid state in which the reaction does not occur. Flexible laminate 9 characterized by having a temperature. 5. The adhesive according to claim 1, wherein the adhesives 108, 108 ′, 108 ″, 208 are preferably from 50 g / m 2 to 800 g / m using a doctor blade 131, roller or powder coater. The flexible laminate (9), which is applied to the flexible laminate at an application rate of m 2. 6. The adhesive according to any one of claims 1 to 5, wherein the adhesives 108 ', 108 "exhibit, for example, an inadequate initiation of adhesive curing prior to manufacturing the assembly or insufficient curing during the heating performed to obtain the assembly. Flexible laminate 9, characterized in that it comprises visualization means C1, C2, C3 designed to show the resulting degree of cure through a predetermined color or brightness of the color. 7. The capsule 108a according to claim 3 or 6, wherein the visualization means contains the matrix 108b or the first reactant R1 when the first and second reactants are at least physically separated from each other. ) Or a compound (C1 or) capable of selectively reacting with the first reactant or the matrix, respectively, immediately after rupture of the capsule, to provide a reaction product that is identifiable by its color in the adhesive 108 '. Flexible laminate (9), characterized in that it comprises C2). 7. The secondary capsule 108c according to claim 3 or 6, wherein the visualization means, other than the capsule 108a containing the first reactant R1, when the first and second reactants are at least physically separated from each other. ) And are designed to rupture simultaneously with the capsule, and selectively react with the first reactant R1 or the matrix 108b immediately after rupture of the capsule of the first reactant R1 and these auxiliary capsules 108c. Flexible laminate (9), characterized in that it comprises a compound (C3) which is capable of providing a reaction product which is identifiable by its color in the adhesive 108 ". 7. The method according to claim 3 or 6, wherein the visualization means comprises a capsule (108a) or a first reactant containing the first reactant (R1) when the first and second reactants are at least physically separated from each other. Present in the secondary capsule 108c designed to rupture at the same time and diffuse into the adhesive 108 ′ or 108 ″ immediately after rupture of the capsule 108a of the first reactant R1 or the entire first reactant and the secondary capsule 108c. Flexible laminate (9), characterized in that it comprises a dye which can be used. 7. The method according to claim 3 or 6, wherein the visualization means is selective with the first reactant or the matrix immediately after reaching the limit temperature during the heating, when the first and second reactants are chemically separated from each other. Reaction to provide a reaction product which can be identified by its color in the adhesive 108 in the case of the compound, or in the case of the dye comprises a compound which can diffuse into the adhesive. Flexible laminate (9). 7. The method of claim 3 or 6, wherein the visualization means is designed to rupture immediately after the limit temperature during the heating, when the first and second reactants are chemically separated from each other, followed by the rupture of the adhesive 108 Flexible laminate (9), characterized in that it comprises a dye capable of diffusing into). Comprising a strip of flexible laminate 9 bonded at the joints of adjacent composite panels 1, each covered with another synthetic laminate or a lower laminate 7, these two laminates being between two fabrics impregnated with a binder. In the secondary cryogenic sealing barrier for tanks containing liquid methane each containing a metal foil inserted in the
This barrier is obtained by introduction at high temperature under pressure, preferably at a temperature of from 100 ° C. to 150 ° C., wherein each strip pre-coated with an adhesive flexible laminate according to claim 1 is subjected to the thermosetting heat dissolution. Barrier in contact with an adjacent laminate optionally coated with adhesive (108, 108 ', 108 ", 208). In the method of assembling the secondary cryogenic sealing barrier according to claim 12 by adhesion,
a) at the softening point thereof, using a thermosetting heat soluble adhesive (108, 108 ', 108 ", 208) applied at a temperature of preferably 55 ° C to 65 ° C, pre-apply each production strip of the flexible laminate at the factory Steps;
b) optionally applying at the factory each strip of the lower laminate 7 covering the composite panel 1 using the same adhesive;
c) In the shipyard for assembling the barrier to the tank wall of the methane tanker, each strip of flexible laminate is placed underneath at a high temperature under pressure, preferably for a time ranging from 30 to 5 minutes at a curing temperature of from 100 ° C. to 150 ° C. Contacting a panel covered with a laminate (7).

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