FR2800087A1 - Bonding different polymers comprises using compatible material, used for silicon chip cards in mobile phones, as intermediate layer between one polymer and adhesive layer applied to the other polymer - Google Patents

Abstract

Bonding different polymers comprises using a compatible material as an intermediate layer between one polymer and the adhesive layer applied to the other polymer to give good adhesion. Bonding different polymers using a cyanoacrylate or heat-activated adhesive comprises using a compatible material as an intermediate layer between one polymer and the adhesive layer applied to the other polymer. Independent claims are included for a compatible material for improving the counter adhesion of two different plastic materials as above, an integrated circuit module comprising a dielectric film of polymer material and integrated circuit fixed using the material and a silicon chip card comprising the module fixed using a cyanoacrylate or heat-activated adhesive.

Description

The present invention relates to the bonding of polymeric materials to each other, in particular for an application in the field of electronic cards more commonly known as smart cards, with contacts. flush and / or contactless.

Although it generally relates to the bonding between them of materials as envisaged below, the present invention will be described below, for simplicity, with reference to its application in the sector of smart cards.

For the manufacture of chip cards with micromodule, a dielectric material is used as support for the micromodule which, provided with at least one integrated circuit chip and its connections with communication interfaces, is inserted in a card body.

This dielectric support is implemented in the form of a film from which the micromodules to be transferred are then cut out from a card body.

The polymeric materials which are used today for the manufacture of the film are a polyamide, such as for example the polyamide commercially known as Kapton, and epoxy glass. These materials are coated with an adhesive to be laminated with a copper film, cut mechanically or chemically and on which the ISO contacts of the smart card are created.

Their opposite face is used for the application, after cutting in the format of a micromodule, of an adhesive of cyanoacrylate type or of thermoactivable type (also called "hot melt"? For the insertion of said micromodule. It should be noted that here understood by "thermoactivable" a heat activated adhesive, which includes adhesives more commonly known as hot melt and also included in the concept of hot melt adhesives.

However, a polyimide such as Kapton is not suitable for bonding with heat-activated adhesives, because its surface is very smooth and has a low bonding power. On the other hand, it adheres well with cyanoacrylate adhesives.

Untreated epoxy glass sticks well with cyanoacrylate type adhesives, but sandblasting of the epoxy glass is necessary for bonding with a heat-activated adhesive.

Since the aforementioned materials are expensive, it has therefore been envisaged to replace them with less expensive materials, such as, for example, a polyethyleneterephthalate (PET) or a polyethylenenaphthenate (PEN). However, despite the high resistance of surface treatments available on the market, these alternative materials do not offer a universal surface which can be treated with an adhesive both of cyanoacrylate type and of heat-activated type.

The invention provides a method and means for making a lamination of different polymer materials, both by bonding with a cyanoacrylate and by bonding of the heat-activated type, said method and said means using a compatibilization material intended to constitute an intermediate layer between the one of the polymer materials concerned and an adhesive of cyanoacrylate type or of thermoactivable type applied to the other polymer material.

The first object of the invention is thus such a method, comprising the intercalation, between two different polymeric materials to be laminated, of a compatibilization material constituting an intermediate layer between a first polymeric material and an adhesive material of cyanoacrylate type or of type thermoactivable applied on a second polymeric material for the lamination to the first.

In one embodiment, the invention relates to a process as mentioned above for the lamination of two different polymer materials, one of which can be bonded with an adhesive of cyanoacrylate type or with a heat-activated adhesive, while the other does not adhere well to the same adhesive.

According to the invention, said compatibilization material is preferably applied preferably by coating on the face of the first polymer material to be adhered to the second, while the adhesive of the chosen type is applied to the face to be laminated with the second plastic material or, alternatively, on said coating layer. The coating operation can be carried out by any suitable means known to those skilled in the art.

The compatibilization material used in this process aims to increase the adhesiveness of a material with low surface energy, constituting one of the materials to be laminated. To this end, it is advantageous that it provides both mechanical anchoring sites and active sites chosen in particular from the groups -C = O, -COOR, = NH and -NH2.

By the expression "capable of providing mechanical anchoring sites" is meant the ability to increase the roughness of the material thus coated. Such sites are present in a compatibilization material whose physical structure comprises at the molecular level ramifications conferring on the macroscopic scale a three-dimensional deployment with indentations, giving a layer of compatibilization material thus constituted a roughness and / or a power interpenetration facilitating its anchoring with an adjacent material. By the expression "capable of providing active sites", cry means the ability to increase the surface energy of the material thus coated, by increasing the number of active sites constituting bridging sites.

The compatibilization material used according to the invention is preferably chosen from polymers or copolymers of which at least one monomer has a functionality strictly greater than 2. The polymers or copolymers thus formed have free functions, and / or protected and releasable functions, able to intervene in the crosslinking of the polymer chains forming such a compatibilization material.

Without wishing to be bound by any theory, it is believed that the compatibilization materials have the role of increasing the adhesiveness of a material with low surface energy, by increasing this surface energy of said polymer material, so as to make it more wettable. In itself, this could lead to the use of any adhesive, for which the material concerned would have an affinity, alone or via a specific primer for said material. However, it has been found that the thermoplastic or cross-linked compatibilization materials would generate a tacky state (in English "tackle") during a rise in temperature. thermosetting compatibilization materials are therefore preferred, and among them preferably thermosettable and / or photocrosslinkable materials.

In practice, said compatibilization material can be chosen in particular, but not limited to, from amide-type resins, phenolic resins, epoxy resins, which are heat-crosslinkable, and acrylamide, acrylate and polymethylmethacrylate type resins, which are photo- crosslinkable alone or in the presence of UV activator, crosslinked phenolic resins, and acrylonitrile-butadiene-styrene (ABS) compositions in solvent phase, as well as their mixtures.

As a variant, it is possible to combine with another compatibilization material of the aforementioned type one or more other materials having other functions, such as for example ABS in the solvent phase, allowing good compatibility with a card body which would be ABS itself.

The quantity or the proportion of compatibilization material to be used is not critical and depends on each concrete application case. It can be determined by a person skilled in the art by means of preliminary tests, carried out according to known methodologies and making it possible to define an effective range and advantageous ranges, both in terms of efficiency and in terms of cost. It is recommended that the layer of compatibilization material applied according to the invention has a thickness of approximately 1 to 5 gym, preferably a thickness of approximately 1 gym, in the illustrative application considered here.

In a preferred embodiment, said compatibilization material is crosslinked. This avoids possible adhesion problems, in particular during the various assembly operations of the electronics of the smart cards, which for the most part require a temperature setting of the assembly. This crosslinking can be carried out in a known manner, either by thermal activation, or by photonic activation, for example by means of UV or other radiation. Such activation induces a chemical bridging between several polymer chains, by condensation or complexation involving the groups present on the aforementioned active sites.

In an alternative embodiment, the compatibilization material can be applied to the two faces to be laminated, in non-crosslinked form on one, and in non-crosslinked form or preferably crosslinked on the other, while the adhesive of the chosen type is then applied to one of the surfaces thus treated. As a variant, it is also possible to use such a non-crosslinkable material, but having no tackiness or stickiness at the temperatures at which the assembly process for laminating is carried out.

In an advantageous embodiment, that of plastic materials which is intended to directly receive the compatibilization material can be subjected to a treatment by corona effect before its coating with said material. This further improves the adhesion of said material on the plastic material concerned, which allows for example to treat according to the invention surfaces more difficult to subject to the envisaged lamination, such as untreated PET.

According to another variant, the surface intended to receive the compatibilization material according to the invention can be subjected to a chemical attack.

In a preferred embodiment of the method according to the invention, said coating of the compatibilization material is carried out in coordination with a coating as mentioned above on the other face of said material.

The invention also makes it possible to keep a polyamide-type material, such as the product called Kapton, for the base film to be bonded to another plastic material. In the application envisaged by way of illustration, said polyamide, or alternatively an epoxy glass, is in practice the material of a dielectric film intended to constitute the support of a module to be inserted by gluing on a smart card body which , it can be ABS, PVC, ABS-PVC composites, polycarbonate, ABS-polycarbonate composites, or others. If a technique in accordance with the invention had been envisaged, it could reasonably have been expected to result in additional cost and technical constraints making the whole process less economical.

On the contrary, it turned out that the addition of compatibilization material according to the invention makes its own contribution to this set and allows a reduction in the thickness of the base film. This reduction in thickness of one of the polymer materials can be compensated for by the layer of compatibilization material, and this makes it possible to achieve a substantial saving on said polymer material, which in this case is an expensive material.

The technique according to the invention thus provides an economical solution for laminating two different plastic materials, at least one of which has a low surface energy, respectively with an adhesive of cyanoacrylate type or with an adhesive of heat-activated type. More particularly, as regards the application to smart cards with micromodule, it is thus possible according to the invention to obtain a surface of the module support which can be correctly bonded both with a cyanoacrylate liquid adhesive and with a heat-activated adhesive. . Even more advantageously, the invention makes it possible to achieve an unusual efficiency and quality of bonding, with such an inexpensive treatment and even with materials, in particular support materials for the chip card module, inexpensive.

In addition, for the implementation of the method according to the invention for the insertion of smart card modules with or without flush contacts, it is possible to use a coating line conventionally used for these products. In all cases, the coating of a compatibilization material according to the invention can be done at the same time as the possible conventional treatment of the other face of the material to which this material is applied, namely the coating of this material. other side with a non-crosslinked adhesive before lamination with a copper film in the case of the manufacture of smart card modules with flush contacts.

In the variant mentioned above implementing a treatment by corona effect, this corona treatment is fully taken advantage of, since it can be carried out immediately before the coating of compatibilization material and then allows the treatment of surfaces which are more difficult to treat. The surface treatment thus produced is stable over time, unlike the surface treatment by simple conventional corona effect, which is not and whose effect decreases over time.

The surface treatment before laminating according to the invention is economical, since it can be carried out online, as indicated above, unlike conventional treatments by sandblasting or with a plasma, which require a specific step and equipment. .

The subject of the invention is also a compatibilization material as defined above, to improve the lamination of two different plastic materials, consisting of a compatibilization material capable of forming an adherent intermediate layer between a first plastic material and an adhesive material of cyanoacrylate type or thermoactivable type applied to the second plastic material to adhere to the first.

According to a preferred embodiment, said compatibilization material is crosslinked so as not to have its own adhesion under the conditions of the assembly, olaae of the two plastic materials against each other. I-L crosslinking of this material can be done for example by thermal input or by UV radiation.

In the present description, it is envisaged to simplify two different materials to be laminated. It is however clear to a person skilled in the art that the case of more than two materials is also possible. It then suffices to apply the treatment according to the invention to one or more of the pairs of materials constituting such multiple materials.

The invention therefore also relates to an integrated circuit module comprising a dielectric film and an integrated circuit integral with the dielectric film, intended to be fixed by bonding with a polymer support, said module being provided with a layer of compatibilization material suitable to adhere to at least one adhesive chosen from an adhesive of cyanoacrylate type and an adhesive of thermoactivable type, while said compatibilization material is preferably as defined above.

In an advantageous embodiment of said module, said compatibilization material is crosslinked, so as not to have its own adhesion under the conditions of assembly against each other, by means of an adhesive , of the two polymer materials respectively of the module and of the polymer support forming the card body.

The invention further relates to a smart card comprising such an integrated circuit module, fixed by bonding by means of an adhesive of cyanoacrylate type or of thermoactivable type.

By way of illustration, smart cards have been produced by inserting an electronic module comprising a polyimide support with the commercial name Kapton, with an adhesive of cyanoacrylate and thermoac-ivable type respectively, in a body of thermostabilized PET card (product sold by the company Autotype under the name Autotex), using according to the invention a compatibilization material of photocrosslinkable acrylate type, over a thickness of approximately 1 gym. Very good results have been obtained both in cyanoacrylate type inserting (good kinetics and high tearing force) as in thermoactivable inserting.

The process according to the invention can also be applied with very good results on polymer materials of the polyetherimide (PEI), polybutylterephthalate (PBT), polyamide (PI), polyamide (PA), polyvinyl alcohol) (PVA) type, or else cyclo-olefin copolymers (COC, such as for example the product sold by the company Hoechst under the name Topas COC), among others.

The invention can be applied to smart cards with flush contacts, to cards with subscriber identification module for mobile phones, called SIM cards ("Subscriber Identity Module") and more commonly known as "plugs", as well than contactless cards or hybrid type cards.

Claims (27)

1. A method for making a lamination of different polymer materials with an adhesive of cyanoacrylate type or of thermoactivable type, characterized in that a compatibilization material is used intended to constitute an intermediate layer between one of the polymer materials concerned and an adhesive cyanoacrylate type or thermoactivable type applied to the other polymeric material. 2. Method according to claim 1, characterized in that it comprises the intercalation, between two different polymeric materials to be laminated, of a compatibilization material constituting an intermediate layer between a first polymeric material and an adhesive material of cyanoacrylate type or thermoactivable type applied to a second polymeric material for laminating to the first. 3. Method according to one of claims 1 or 2, characterized in that it is used for the lamination of two different polymer materials, one of which can be bonded with an adhesive of cyanoacrylate type or with a heat-activated adhesive , while the other does not adhere well to the same adhesive. 4. Method according to any one of claims 1 to 3, characterized in that said compatibilization material is applied by coating on the face of the first polymeric material to be adhered to the second, while the adhesive of the chosen type is applied on the face to be laminated with the second polymer material. 5. Method according to any one of claims 1 to 3, characterized in that said compatibilization material is applied by coating on the face of the first polymeric material to be adhered to the second, while the adhesive of the chosen type is applied on this coating layer. 6. Method according to any one of claims 1 to 5, characterized in that a compatibilization material is used capable of providing both mechanical anchoring sites as active sites chosen from the groups -C = O, - COOR, = NH and -NH2, so as to increase the surface energy of the polymer material. 7. Method according to any one of claims 1 to 6, characterized in that the compatibilization material is chosen from polymers or copolymers of which at least one monomer has a functionality strictly greater than 2, so that the polymers or the copolymers thus formed have free functions, and / or protected and releasable functions, capable of intervening in the crosslinking of the polymer chains forming such a compatibilization material. 8. Method according to any one of claims 1 to 5, characterized in that the compatibilization material is chosen from amide type resins, phenolic resins, epoxy resins, acrylamide, acrylate and polymethylmethacrylate type resins, crosslinked phenolic resins and acrylonitrile-butadiene-styrene (ABS) compositions in solvent phase, as well as their mixtures. 9. Method according to claim 8, characterized in that said compatibilization material is combined with ABS in the solvent phase. 10. Method according to any one of claims 1 to 9, characterized in that the compatibilization material is applied in a thickness of about 1 gym. 11. Method according to any one of claims 1 to 9, characterized in that said compatibilization material is crosslinked. 12. Method according to claim 11, characterized in that said compatibilization material is heat-crosslinkable and / or photocrosslinkable. 13. Method according to any one of claims 1 to 10 and 12, characterized in that the compatibilization material is applied to the two faces to be laminated, in non-crosslinked form on one and in non-crosslinked form on the 'other, while the adhesive of the chosen type is then applied to one of the surfaces thus treated. 14. Method according to any one of claims 1 to 12, characterized in that the compatibilization material is applied to the two faces to be laminated, in non-crosslinked form on one and in crosslinked form on the other, while that the adhesive of the chosen type is then applied to one of the surfaces thus treated. 15. Method according to any one of claims 1 to 10, characterized in that a non-crosslinkable compatibilization material is used, but having no tackiness or tackiness at the temperatures at which the process of assembly for lamination. 16. Method according to any one of claims 1 to 10, characterized in that that of polymeric materials which is intended to directly receive the compatibilization material to a treatment by corona effect before its coating with said material. 17. Method according to any one of claims 1 or 10, characterized in that the surface intended to receive the compatibilization material is subjected to a chemical attack. 18. Method according to one of claims 4 or 5, characterized in that said coating of the compatibilization material is carried out in coordination with a coating of the other face of said material. 19. Method according to one of claims 1 or 2, characterized in that the first polymeric material is a dielectric film intended to constitute the support of an integrated circuit module to be inserted by gluing on a second material constituting the body of a smart card. 20. The method of claim 19, characterized in that the first polymeric material is polyimide or an epoxy glass. 21. The method of claim 19, characterized in that the second polymeric material is ABS, PVC, an ABS-PVC composite, polycarbonate or an ABS-polycarbonate composite. 22. Compatibility material to improve the lamination of two different plastic materials, characterized in that it is chosen from amide type resins, phenolic resins, epoxy resins, acrylamide, acrylate and polymethylmethacrylate type resins, resins crosslinked phenolics and acrylonitrile-butadiene-styrene (ABS) compositions in solvent phase, as well as their mixtures, and is capable of forming an adherent intermediate layer between a first polymeric material and an adhesive material of cyanocarylate type or of heat-activated type applied on a second polymeric material to adhere to the first. 23. compatibilization material according to claim 22, characterized in that said compatibilization material is crosslinked, so as not to have its own adhesion under the conditions of the assembly of the two polymeric materials against each other. 24. Integrated circuit module comprising a dielectric film composed of a polymer material and an integrated circuit integral with the dielectric film, intended to be fixed by bonding with a polymer support, characterized in that it is provided with a layer of material compatibilization capable of adhering to at least one adhesive chosen from an adhesive of the cyanoacrylate type and an adhesive of the heat-activated type. 25. Module according to claim 24, characterized in that it comprises a compatibilization material chosen from amide type resins, phenolic resins, epoxy resins, acrylamide, acrylate and polymethylmethacrylate type resins, crosslinked phenolic resins and acrylonitrile-butadiene-styrene (ABS) compositions in solvent phase, as well as their mixtures. 26. Module according to one of claims 24 or 25, characterized in that said compatibilization material is crosslinked, so as not to have its own adhesion under the conditions of assembly against each other, by by means of an adhesive, of the two polymer materials respectively of the module and of the polymer support forming the card body. 27. Chip card comprising a module according to any one of claims 24 to 26, fixed by bonding by means of an adhesive of cyanoacrylate type or of thermoactivable type.