EP1843895A2

EP1843895A2 - Method of applying an anti-freeze film to a transparent substrate

Info

Publication number: EP1843895A2
Application number: EP06709457A
Authority: EP
Inventors: Hélène GRUSSAUTE-NGHIEM; Marie-Isabelle Watchi; Yves Demars; Gilles Lonchampt
Original assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Current assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Priority date: 2005-01-31
Filing date: 2006-01-30
Publication date: 2007-10-17
Also published as: CA2595977A1; CN101111369A; KR101364233B1; FR2881422B1; JP5160900B2; KR20070102692A; KR20120128170A; KR101364041B1; FR2881422A1; WO2006079763A2; CA2595977C; BRPI0607050A2; US20080138603A1; JP2008528329A; MX2007008994A; KR101362793B1; US8057615B2; US20100116416A1; WO2006079763A3; KR20120140259A

Abstract

The invention relates to: a method of adhering a flexible film to a substrate, in which a sufficient quantity of a liquid is disposed between the film and the substrate such that no bubbles are trapped therebetween once the film has been applied to the substrate with the aid of a scraper, said method being characterised in that the liquid does not freeze at a substrate temperature of less than 0 °C; the mutually-adhered substrate and flexible film which is characterised by the continued absence of frost in the event of the substrate and film being moved into an atmosphere in which the temperature thereof is less than 0 °C, from an atmosphere having a temperature that is at least equal to 0 °C and residual moisture of at least 25 %; glazing comprising same; and the applications of said glazing, including for example exposure to temperatures of less than 0 °C.

Description

APPLICATION OF ANTI-FREEZING FILM ON TRANSPARENT SUBSTRATE

The present invention relates to substrates which are, occasionally or permanently, at temperatures below 0 ^° C., especially transparent.

Various functionalities are likely to be given to such substrates: anti-ice for preserving transparency, hydrophobic, hydrophilic, antifouling-self-cleaning (photocatalytic), reflecting light or heat radiation, colored at least in part, electroconductive-heating, semi -conductor, antistatic, electroluminescent

Several of these functions can be associated on the substrate, for example in the form of a coating. In this case, the coating formation process is adapted to ensure the desired adhesion and mechanical strength and, in particular, as little scratchability as possible or self-healing ability of the coating scratches, when the substrate is transparent. . Of course, the coating is regenerated when necessary.

On the other hand, one or more functions can be provided by an adhesive film, having the advantage of the ease of its replacement by an identical film or carrying different functions.

We then obviously try to obtain a quality of perfect adhesion of the film on the substrate, avoiding in particular the imprisonment of air bubbles between the two. To do this, a method may consist in interposing a sufficient quantity of a liquid, in particular water mixed with a surfactant, to allow all the bubbles to be expelled by applying pressure to the film, for example its central part. towards its periphery, by means of a squeegee.

This method does not, however, give satisfaction for substrates which are occasionally or permanently at temperatures below 0 ^° C. In fact for these, the fraction of liquid which remains between the substrate and the film after they have been assembled, is likely to crystallize forming frost. Thus, when the functional adhesive film is applied to an inner face of a transparent refrigerated enclosure door, the temperature of which may be, for example, between -28 and 0 ^° C., the frost is formed in such a way that we can no longer see through the door. Due to the permeability of the film and the relative dryness of the chilled atmosphere, the frost is likely to disappear, at least four days to more than a week after its formation. Such discomfort prohibits use as a vertical door of refrigerated storehouse large area, whose frequency of opening by customers or for replenishment results in the permanence of the gel, while maintaining a perfect transparency is indispensable in the field of mass distribution.

The object of the invention is therefore to provide a method of assembling a flexible film to a substrate that guarantees a perfect interface between the two and, in particular, the absence of trapped air bubbles and the formation of frosted.

For this purpose, the subject of the invention is a process for adhesion of a flexible film to a substrate, comprising the interposition between film and substrate of a sufficient quantity of a liquid, so that no bubbles trapped between the film and the substrate after the film has been applied to the substrate by means of a squeegee, characterized in that the liquid does not freeze at a substrate temperature below 0 ^° C., especially at most -5 ⁰ C and in particular at most -1O ⁰ C, and also at least -25 ⁰ C, occasionally or permanently.

Advantageously, the substrate is freed from any particles that are adhered to, cleaned and wiped, prior to the interposition of a sufficient amount of a liquid between film and substrate.

Preferably, the face of the flexible film to be adhered to the substrate is wetted with said sufficient amount of a liquid. Any suitable liquid deposition techniques such as flow coating, spraying, spray or the like may be employed. On the other hand, it is not excluded to wet the face of the substrate on which the film is to adhere to said sufficient quantity of a liquid, or to wet both said faces of the film and the substrate.

According to another preferred characteristic of the process of the invention, the face of the flexible film to be adhered to the substrate comprises an adhesive layer optionally provided with a protective film to be removed before the setting adhesion on the substrate. Alternatively, an adhesive can be integrated with the liquid interposed between film and substrate.

The adhesives can be chosen from:

- The so-called "hot melt" adhesives: heated thermoplastic polymers to obtain a liquid having the appropriate viscosity to be deposited and then cooled to obtain a solid (polyethylene, ethylene-vinyl acetate copolymer, polyamide, polyester, etc.);

adhesives in solution or aqueous or organic dispersion, the solvent of which is evaporated after deposition to obtain a solid: in aqueous solution: phenolic, poly (vinyl methyl ether), poly

(vinyl alcohol), dextrin, natural product such as casein, blood-based glue (albumin and serum globulin), fish glue (derived from collagen); in organic solution: natural rubber, acrylic, polyurethane, polyamide, polyvinyl acetal, phenoxy; in dispersion: polyurethane, epoxy, silicone, certain elastomers (nitrile rubber, etc.);

adhesives in the form of ready-to-use films: epoxy, phenolic, nitrile rubber, polyamide, polyvinyl butyral, polyvinyl chloride, ethylene-carboxylic acid copolymer;

adhesives involving in situ polymerization reactions: cyanoacrylates, certain reactive acrylics;

- pressure-sensitive adhesives: do not change their physical state before and after application, remain permanently deformable and have a certain stickiness at ambient temperature: tackified elastomers (natural rubber - latex), ethylene-acetate copolymer vinyl, thermoplastic elastomer (polyurethane ...), styrene - diene block copolymer (styrene - butadiene - styrene, styrene - isoprene - styrene), polyaryl arylate), silicones;

- elastomers: natural rubber, styrene - butadiene rubber, polychloroprene, neoprene, nitrile rubber, butyl rubber;

Inorganic adhesives: soluble silicates with different silica - alkali proportions. According to preferred embodiments of the method of the invention:

the face of the flexible film opposite that to be adhered to the substrate, is wetted with an effective amount of liquid so that the squeegee slides easily on the film during the operation of applying the film to the substrate;

the face of the flexible film opposite to that to be adhered to the substrate is provided with a protective film to be removed after adhesion of the flexible film to the substrate; this protective film is particularly likely to be wet to facilitate the sliding of the squeegee as indicated above;

the liquid interposed between the film and the substrate comprises an effective amount of an antifreeze compound lowering the crystallization temperature such as a salt, in particular KCl, NaCl or equivalent in solution and / or alcohol and / or a polymer, copolymer, prepolymer or hydrophilic oligomer suitable, optionally in water, and optionally one or more surfactants.

As alcohols are particularly used ethanol, isopropanol.

The hydrophilic polymers, copolymers, prepolymers or oligomers constituting the interposed liquid are especially based on polyvinylpyrrolidone of the poly (n-vinyl-2-pyrrolidone) or poly (1-vinylpyrrolidone) type, polyvinylpyrridine of the poly (n-vinyl-2 pyridine) type. ), poly type

(n-vinyl-3-pyridine), of the poly (n-vinyl-4-pyridine) type, polyacrylate of the poly type

(2-hydroxyethylacrylate), poly (N ', N-hydroxyacrylamide) polyacrylamide, polyvinylacetate, polyacrylonitrile, polyvinylalcohol, polyacrolein, polyethylene glycol, polypropylene glycol, polyoxyethylene. In particular, the copolymers are based on at least one of the monomers constituting these polymers.

As surfactants there may be mentioned compounds comprising a lipophilic part Y, which may be a linear, branched or unsaturated aliphatic chain or an aromatic or alkylaromatic chain, and an ionic hydrophilic head or not.

Examples are:

anionic surfactants: Y - CO ₂ M ⁺ ; Y - OSO ₃ M ⁺ ; Y - SO ₃ M ⁺ ; dodecylbenzene sulfonate; alkyl sufonate; fatty acid and sulphonated fatty acid ester; alkylarylsulfonate; cationic surfactants: Y - (R) _n NH ⁺ ( _4-n ), X ^" ; Y - R ₄ N ⁺ , X ^" ; alkyltrimethylammonium; alkylbenzyldimethylammonium; imidazolinium salts; amine salts;

- zwitterionic: Y - N ⁺ CO ₂ ^" ; Y - N ⁺ SO ₃ ^" ; betaines; sulfobetaines; imidazolium salts;

- nonionic: Y - OR; Y - OH; Y - CO ₂ R; Y - CONHR; Y - (CH ₂ CH ₂ ^~ - O) _n -; polyol; alcohol; acid; ester; polyethoxylated fatty alcohol.

Another object of the invention is constituted by a substrate and flexible film in mutual adhesion obtained with the interposition of a sufficient quantity of a liquid in the absence of any imprisoned bubble, characterized by the persistent absence of frost in case of displacement of the substrate and the film in an atmosphere where their temperature will be below 0 ^° C., respectively at most -5 ^° C. and -10 ^° C., from an atmosphere with a temperature at least equal to 0, preferably between 10 and 35, in particular 15 and 30 and in particular 23 and 27 ⁰ C and residual moisture of at least 25%.

According to a preferred feature, the substrate and flexible film form a transparent assembly. The substrate is made of glass or a plastic material such as polycarbonate, polypropylene, poly (methyl methacrylate), ethylene / vinyl acetate copolymer, polyethylene terephthalate, polybutylene terephthalate, polyurethane, polyvinyl butyral , cycloolefinic copolymer such as ethylene / norbornene or ethylene / cyclopentadiene, polycarbonate / polyester copolymer, ionomer resin such as ethylene / polyamine-neutralized (meth) acrylic acid copolymer and the like, alone or in mixtures. According to other advantageous features of the substrate and flexible film of the invention:

the film is anti-freeze and / or hydrophobic and / or hydrophilic and / or antifouling-self-cleaning (photocatalytic) and / or reflecting light or heat radiation, antisolar, low-emissive, and / or colored at least in part and / or electroconductive-heating and / or semiconductor and / or antistatic and / or electroluminescent;

the film is anti-icing and, when at a temperature of at most -1 ^{0 °} C., respectively -15 ^° C. and -20 ^° C., it is placed in an atmosphere at a temperature of at least 0, preferably between 10 and 35, in particular 15 and 30 and in particular 23 and 27 ^° C. and at least 25% residual moisture, no frost is formed for at least 12 s, preferably at least 1 min, in particular at least 2 min, or even as long as 3 min at least; the film is based on a support made of polyamide, polyester, polyolefin such as polyethylene, polypropylene, cellulose, polystyrene, ethylene / vinyl acetate copolymer, polyvinyl alcohol, polyvinyl chloride, poly (terephthalate), ethylene), poly (methyl methacrylate), polycarbonate, polyvinylburyral, polyurethane, polyvinylpyrrolidone, polyvinylpyrridine, poly-2-hydroxyethylacrylate polyacrylate), polyacrylamide, polyvinyl acetate, polyacrylonitrile, polyacrolein, polyethylene glycol, polyoxyethylene; it may also be a copolymer or a mixture based on at least one of the polymers mentioned above; - The film is anti-icing in that it comprises an antifreeze compound lowering the crystallization temperature and optionally has a hydrophobic character on a portion of its surface. As the antifreeze compound, the same as described above can be used for said interposed liquid. However, it is sought a durability of the anti-frost function of the film, which may require improving the mechanical strength of the layer incorporating the antifreeze compound, particularly when it is likely to be subjected to occasional mechanical contact, or For this purpose, the antifreeze compound may be crosslinked and / or combined with at least one compound that is physically interacting with it and / or dispersed in a solid, inorganic, for example, or mixed matrix of the ORMOCER (Organically Modified Ceramics) type. ).

By physical interaction, here is meant a hydrogen bond, a polar interaction of the Van der WaIs type or a hydrophobic interaction capable of achieving a mechanical reinforcement comparable to a crosslinking.

The anti-icing function can be integrated in the film itself or in a coating formed on the support of the film.

The invention furthermore relates to a glazing unit comprising a substrate and flexible film as described above, as well as possibly other transparent sheets to which they are connected via adhesive layer (s) interlayer (s) or gas blade (s). From this glazing, said flexible film advantageously constitutes an outer face, thus functionalized.

The glazing consists in particular of a monolithic glazing, laminated, multiple, insulating, vacuum.

Such multiple glazing, insulating, comprises for example two or three sheets of monolithic or laminated glass, separated two by two by a gas blade. The interest may be the thermal insulation of a refrigerated chamber vis-à-vis the outside atmosphere (a store ....). This thermal insulation is obtained alternately by a vacuum glazing comprising at least two sheets of monolithic or laminated glass separated by a vacuum or a gas blade at reduced pressure. These two sheets may be associated with a third of which they are separated by a gas strip at reduced pressure or not. Such structures may comprise one or more low-emissive layers reflecting the heat radiated from outside the refrigerated enclosure.

According to an advantageous characteristic of this glazing, the thermal conductivity of its barrier, that is to say all the elements through which the various sheets of monolithic or laminated glass constituent are held together and spaced two by two, is at most 1, 46 W / mK

Finally, the subject of the invention is the application of such a glazing unit

- as refrigerated enclosure door;

- for the building, street furniture or billboards, road mirrors, refrigerated enclosure elements other than the door, such as shelves ...;

- for a land, air or water transport vehicle (windshield, side glazing, rear window, roof part, rearview mirror, lighthouse);

- for a vision element (glasses, helmet). The invention is indeed particularly used in products subjected, at least occasionally, to temperatures below 0 ^° C, and has an increased interest in outdoor applications in severe climate. The invention will be better understood in the light of the following example. EXAMPLE

We repeat the first example of the application WO 00/71481 except that

- triple insulation glazing is used instead of vacuum insulating glazing, and that

the polycarbonate film is provided with an adhesive layer oriented towards the insulating glazing unit, to which the film is fixed with the interposition of a liquid specified below.

The polycarbonate film is coated, on the side opposite to that of the adhesive layer, with an anti-ice adsorbent layer forming a three-dimensional polymeric network based on polyvinylpyrrolidone and polyurethane. The thickness of the anti-icing layer is equal to 14.5 μm.

Tests are carried out on doors installed on refrigerated sales cabinets in which a temperature of -25.5 ^° C is maintained. The temperature measured on the inside of the door is -22 ^° C. The furniture is placed in an atmosphere at a temperature of 25 ^° C. and 60% residual humidity.

The procedure is as follows.

The cabinet door is opened 10 min before the film is laid to prevent frosting on the glass.

The inner face of the door is wetted with a sprayer filled with a washing composition (soapy water).

The glass is scraped off with a scraper to remove any particles that are stuck, then with a rubber squeegee to wipe off the water. There must be no more frost on the door. If necessary wipe the edges with a cloth.

The protective film of the adhesive is removed from the polycarbonate film and the liquid indicated in the table below is sprayed onto the adhesive.

We put the adhesive side of the film on the glass. The other side of the film is wetted by spraying the same liquid as the adhesive, so that the rubber squeegee slides easily onto the film.

Using the rubber squeegee, the liquid between the glass and the film is removed. For a perfect evacuation of the liquid, the center of the glazing is scraped outwards. If necessary, cut the film so as to leave a game of a few mm between the amounts of the door and the film to promote the evacuation of the liquid.

We repeat the scraping operation, and we close the door of the furniture.

The table below shows the presence or absence of frost at different times after closing the door, as well as bubbles between the glass and the film.

BOARD

The percentages are indicated in mass.

Mir is a detergent composition marketed by Henkel.

Triton X is a mixture of polyethoxylated octylphenols (nonionic surfactant) marketed by Union Carbide.

PEG 200 is a polyethylene glycol marketed by Merck (Art 807483).

This table illustrates the possibility of reducing the formation of frost to prevent it, and thus obtain a permanent absence of frost.

Claims

A method of adhering a flexible film to a substrate, comprising interposing a sufficient amount of liquid between the film and the substrate so that no bubbles are trapped between the film and the substrate after the film was applied to the substrate using a squeegee, characterized in that the liquid does not freeze at a substrate temperature below 0 ^° C.

2. Method according to claim 1, characterized in that the liquid does not freeze at a substrate temperature of at most -5 ⁰ C.

3. Method according to claim 2, characterized in that the liquid does not freeze at a substrate temperature of at most -1O ⁰ C.

4. Method according to one of claims 1 to 3, characterized in that prior to the interposition between film and substrate of a sufficient amount of a liquid, the substrate is freed from any particles which are adhered to, cleaned and wiped.

5. Method according to one of claims 1 or 4, characterized in that the face of the flexible film to be adhered to the substrate is wetted with said sufficient amount of a liquid.

6. Method according to one of claims 1 to 5, characterized in that the face of the flexible film to be adhered to the substrate comprises an adhesive layer optionally provided with a protective film to be removed before adhesion to the substrate .

7. Method according to one of claims 1 to 6, characterized in that the face of the flexible film opposite to that to be adhered to the substrate, is wet with an effective amount of liquid so that the squeegee slides easily on the film during the operation of applying the film to the substrate.

8. Method according to one of claims 1 to 7, characterized in that the face of the flexible film opposite to that to be adhered to the substrate is provided with a protective film to be removed after adhesion of the flexible film on the substrate.

9. Method according to one of claims 1 to 8, characterized in that the liquid interposed between film and substrate comprises an effective amount of an antifreeze compound lowering the crystallization temperature such as a salt, in particular KCl, NaCl or equivalent in solution and / or alcohol, and / or a suitable hydrophilic polymer, copolymer, prepolymer or oligomer, optionally in water, and optionally one or more surfactants.

10. Substrate and flexible film in mutual adhesion obtained with interposition of a sufficient quantity of a liquid in the absence of any trapped bubble, characterized by the persistent absence of frost in case of displacement of the substrate and the film in an atmosphere where their temperature will be lower than 0 ^° C, from an atmosphere with a temperature of at least 0 ^° C and residual moisture of at least 25%.

11. Substrate and flexible film according to claim 10, characterized by the persistent absence of frost in case of displacement of the substrate and the film in an atmosphere where their temperature will be at most -5 ^° C., from an atmosphere at a temperature of at least 0 ^° C and residual moisture of at least 25%.

12. Substrate and flexible film according to claim 11, characterized by the persistent absence of frost in case of displacement of the substrate and the film in an atmosphere where their temperature will be at most -1O ⁰ C, from an atmosphere. at a temperature of at least 0 ^° C and residual moisture of at least 25%.

13. Substrate and flexible film according to one of claims 10 to 12, characterized in that said atmosphere is at a temperature between 10 and 35, in particular 15 and 30 and in particular 23 and 27 ⁰ C.

14. Substrate and flexible film according to one of claims 10 to 13, characterized in that they form a transparent assembly.

15. Substrate and flexible film according to one of claims 10 to 14, characterized in that the film is anti-icing and / or hydrophobic and / or hydrophilic and / or anti-fouling-self-cleaning (photocatalytic) and / or reflecting light or radiation thermal, sunscreen, low-emissive and / or at least partly colored and / or electroconductive-heating and / or semiconductor and / or antistatic and / or electroluminescent.

16. Substrate and flexible film according to one of claims 10 to 15, characterized in that the film is anti-icing and that when at a temperature of at most -1O ⁰ C, it is placed in an atmosphere at least at temperature equal to At 0 ^° C and at least 25% residual moisture, no frost forms for at least 12 seconds.

17. Substrate and flexible film according to claim 16, characterized in that the film is anti-icing and that when at a temperature of at most -15 ^° C., it is placed in an atmosphere at a temperature of at least 0 ^° C. and at least

25% residual moisture, no frost forms for at least 12 seconds.

18. Substrate and flexible film according to claim 17, characterized in that the film is anti-icing and that when at a temperature of at most -2O ⁰ C, it is placed in an atmosphere at a temperature of at least 0 ^° C. and at least 25% residual moisture, no frost forms for at least 12 seconds.

19. Substrate and flexible film according to one of claims 16 to 18, characterized in that said atmosphere is at a temperature between 10 and 35, especially 15 and 30 and in particular 23 and 27 ⁰ C.

20. Substrate and flexible film according to one of claims 16 to 19, characterized in that no frost is formed for at least 1 min.

21. Substrate and flexible film according to claim 20, characterized in that no frost is formed for at least 2 min.

22. Substrate and flexible film according to claim 21, characterized in that no frost is formed for at least 3 minutes.

23. Substrate and flexible film according to one of claims 10 to 22, characterized in that the film is based on a support of polyamide, polyester, polyolefin such as polyethylene, polypropylene, cellulose, polystyrene, ethylene / acetate copolymer vinyl, polyvinyl alcohol, polyvinyl chloride, polyethylene terephthalate, poly (methyl methacrylate), polycarbonate, polyvinylbutyral, polyurethane, polyvinylpyrrolidone, polyvinylpyrridine, polyacrylate of the poly (2-hydroxyethylacrylate) type polyacrylamide, polyvinyl acetate, polyacrylonitrile, polyacrolein, polyethylene glycol, polyoxyethylene, copolymer or mixture of at least one of these polymers.

24. Substrate and flexible film according to one of claims 10 to 23, characterized in that the film is anti-icing in that it comprises an antifreeze compound lowering the crystallization temperature.

25. Glazing comprising a substrate and flexible film according to one of claims 10 to 24, and optionally other transparent sheets to which they are connected by means of adhesive layer (s) interlayer (s) or gas blade (s).

26. Glazing according to claim 25, wherein said flexible film constitutes an outer face.

27. Glazing according to claim 25 or 26, the thermal conductivity of the barrier is at most 1.46 W / m.K.

28. Application of a glazing according to one of claims 25 to 27 as a refrigerated enclosure door.

29. Application of a glazing according to one of claims 25 to 27 for the building, street furniture or billboards, road mirrors, refrigerated enclosure elements other than the door.

30. Application of a glazing according to one of claims 25 to 27 for a land, air or water transport vehicle.

31. Application of a glazing unit according to one of claims 25 to 27 for a vision element.