EP0714964B1 - Multiple glazing with plastic joints - Google Patents

Description

The invention relates to techniques for manufacturing insulating glazing which include transparent plates assembled with a gasket plastic material.

It is known to produce insulating glazing, particularly double glazing by depositing using a extruder or extruder the periphery of a glass plate a bead of a material which adheres to the glass and remains plastic and acts as a moisture barrier. This cord often includes among its components a desiccant which allows to dry the atmosphere of the glazing. Furthermore, a second subject is often deposited next to the first, it is intended to constitute a elastomer bead which strengthens the mechanical strength of the glazing while also participating in sealing. The invention relates more especially the first cord.

In addition to its adhesion and sealing function, this first bead also plays a temporary role, before the polymerization of the elastomer constituting the second barrier: it allows all the handling of the assembled glazing before the elastomer of the second bead can play its role without the deformations, in particular, the crushing of the first bead does not cause deviations in the tolerances of the insulating glass (overall thickness, sliding of one glass in relation to the other) which would be unacceptable.

In the current state of the art, the characteristics of the first cord are such that they guarantee good quality glazing as long as two conditions are met: the thickness of the blade gas between the plates remains limited (for example at most around 12 mm) and also, the polymerization of the elastomer of the second bead is performed at the place of manufacture, before packaging and shipping and in general, before it is possible to handle the assembly without pity. We want to be able to free ourselves from these constraints without necessarily harm other qualities of the product.

The task of the invention is to provide a material which allows the production of insulating glazing with an internal gas space greater than 12 mm and preferably of the order of 16 or 18 mm or even more.

Is also part of the mission of the invention the fact of being able handle insulating glass and even be able to pack it before the second elastomer bead is polymerized.

These aims must be achieved by the invention without deterioration of the performance of insulating glass, i.e. without delamination or loss waterproof during normal aging (well over 10 years) and without departing from the usually accepted dimensional tolerances.

The invention provides a product intended to constitute the first cord insulating glass without metal interlayer, the second bead being produced by polymerization of an elastomer, its composition comprises in particular polyisobutylene and butyl rubber, and the weight proportion of butyl rubber is less than 6%, the composition comprising a polymer hot-melt in a weight proportion of 1.5 to 4%. This polymer hot melt has a melting temperature range above 90 ° C and it essentially composed of copolymers based on ethylene, acrylic acid, derivatives of acrylic acid and ionomers.

Preferably, the weight proportion of polyisobutylene is included between 40 and 70% with a polyisobutylene fraction of molecular weight less than 1000 between 10 and 20%. In addition, the product of the invention comprises a weight proportion of colloidal silica included between 0 and 20%, carbon black from 10 to 40% and molecular sieve from 0 to 5%.

The invention also relates to the application of the product to the production insulating glazing whose plates are separated by spaces included between 11 and 20 mm and the production of insulating glazing which is packaged before polymerization of the elastomer constituting the second bead. Of preferably, this is carried out at room temperature.

• extrusion d'un premier cordon plastique,
• assemblage des vitrages,
• dépôt à la périphérie du vitrage d'une matière polymérisable en élastomère

dans lequel on donne à la partie du début et à celle de la fin du premier cordon des formes telles qu'au moment de l'assemblage, elles se rejoignent de manière étanche.The invention also proposes a method for manufacturing insulating glazing without metallic interlayer comprising the following phases:

• extrusion of a first plastic bead,
• glazing assembly,
• deposit on the periphery of the glazing of a polymerizable elastomer material

in which one gives to the part of the beginning and that of the end of the first bead shapes such that at the time of assembly, they meet in a sealed manner.

Preferably, the shapes of the parts of the beginning and the end of the first cord are complementary bevels, thinning one compensating for the thickening of the other. Advantageously, the junction of the beginning and end of the first bead is performed on a straight edge of the glazing.

• polyisobutylène, de 40 à 70 %,
• caoutchouc butyl, de 5 à 17,5 %
• noir de carbone, de 10 à 40 %
• silice colloïdale, de 0 à 20 % et enfin,
• tamis moléculaire, de 0 à 5 %.

The techniques for manufacturing insulating glazing without the use of metallic interlayer are described in several documents. Thus, patent FR-B-2 294 313 proposes a method of placing an intermediate bead at the periphery of a transparent or translucent sheet with a view to producing multiple glazing in which one extrudes, onto said sheet , a composition which has, after eight minutes and at 40 ° C, a viscosity greater than 115 ° Mooney, and in which, the placement of said material is carried out in such a way that the axis of the nozzle extrusion forms with said sheet an angle between 15 and 45 ° and preferably between 25 and 35 °. The material to be extruded comprises a mixture of polyisobutylene and butyl, the weight ratio of the first to the second being between 4 and 8. In the same document, a first bead is proposed, the composition of which is:

• polyisobutylene, from 40 to 70%,
• butyl rubber, 5 to 17.5%
• carbon black, 10 to 40%
• colloidal silica, from 0 to 20% and finally,
• molecular sieve, from 0 to 5%.

Using to make insulating glass with the previous material the technique described for example in document FR-B-2 211 413 or in one of the documents EP-B2-0 171 309 or EP-B-0 176 388, one obtains, in the recommended production conditions, excellent results and particularly long-life insulating glass, that is to say where finds no detachment of the seal, or rise in the dew point for lifetimes much longer than that of the warranty (generally ten years).

The conditions that must be respected concern the thickness of the gas slide and the conditions of polymerization of the bead in elastomer. The latter usually consists of polysulfide. The conditions for its polymerization are either rapid polymerization (of a duration of about an hour) in an oven where the temperature is around of 50 ° C or, for a much longer duration at temperature ordinary. Industrially, it is the first solution which is retained, it is necessary therefore provide an appropriate oven and staff on the production lines to make it work. We want to be able to delete this step which loads the cost of the product. But on the other hand, we wish not to lengthen unnecessarily the duration of storage of the product on the production lines. The solution would be to be able to immediately package the product, as soon as the coating of the polysulfide is finished. With mechanical characteristics of the first cord as it was before the invention, it is impossible, the pressures and vibrations exerted on the product during manipulations to pack it in the box or on the easel then at the time loading and during transport and unloading are not bearable by the glazing, it deforms, undergoes variations in thickness, crushing in some places compensated by thickening in others, and sliding of one glass in relation to the other (or to the others). To can do without the steaming phase, it is essential to improve the mechanical performance of the product constituting the first bead.

La figure 1 représente une coupe du joint du vitrage selon l'invention,

La figure 2 présente un dispositif d'essai,

la figure 3 montre un type de raccord réalisé grâce au matériau de l'invention avant l'assemblage et,

la figure 4 le même raccord après pose du deuxième verre et pressage de l'ensemble, avant enduction du deuxième cordon,

et la figure 5 montre en coupe un autre type de raccord.

The figures and the description will make it possible to understand the operation of the invention and to appreciate the advantages thereof.

FIG. 1 represents a section of the glazing seal according to the invention,

Figure 2 shows a test device,

FIG. 3 shows a type of connection made using the material of the invention before assembly and,

FIG. 4 the same fitting after fitting the second glass and pressing the assembly, before coating the second bead,

and Figure 5 shows in section another type of fitting.

• un premier mastic (3), déposé par extrusion continue. Ce mastic (3) assure les rôles d'espacement des deux verres pendant la phase de fabrication, de barrière étanche à la vapeur d'eau et de «containeur» aux déshydratants nécessaires à la déshydratation de la lame d'air puis à son maintien sec.

The glazings of the type of the invention are shown in FIG. 1 , they consist of at least two sheets of glass (1, 2) separated by a peripheral seal itself composed of two sealants:

• a first sealant (3), deposited by continuous extrusion. This mastic (3) fulfills the roles of spacing the two glasses during the manufacturing phase, of a watertight barrier against water vapor and of a "container" for the desiccants necessary for dehydrating the air space and then for maintaining it. dry.

A second elastomeric sealant (4) is deposited by coating, in the state pasty then gradually hardens. This sealant (4) seals the two glasses and protects the first sealant (3) against liquid water.

The innovation described below relates to an improvement of the first putty (3).

• polyisobutylène : de 40 à 70 %
• butyl : de 5 à 17,5 %
• noir de carbone : de 10 à 40 %
• silice colloïdale : de 0 à 20 %
• et tamis moléculaire : de 0 à 5 %,

des charges inertes pouvant compléter la composition.The composition of this first sealant, used for many years for the production of the first seal is as follows (% by weight):

• polyisobutylene: 40 to 70%
• butyl: 5 to 17.5%
• carbon black: 10 to 40%
• colloidal silica: 0 to 20%
• and molecular sieve: from 0 to 5%,

inert fillers which can complete the composition.

This composition has the advantage of allowing the manufacture of a 6 or 10 mm thick seal, very waterproof and sufficiently adherent to insulating glass panes. Insulating glass without metal interlayer assembled with this composition, very largely satisfy the requirements of standards and directives concerning the durability of insulating glass: in particular 56 day high humidity test at 55 ° C / 95% relative humidity and the test described in NF P 78-451 and in the UEATC directive of October 1985 for approval of insulating glass. In addition, this sealant can be made from inexpensive and can be extruded and applied to glass at a temperature from 80 to 120 ° C and at high speed, up to 50 cm / s.

However, due to its plasto-elastic nature, this putty has the disadvantage of being easily deformable which prohibits the manufacture of very reliable and very reproducible way of insulating glass without interlayer metallic over 12 mm air gap thickness, within tolerance required ± 0.5 mm from nominal thickness.

a - elles sont en relation, lorsque le vitrage est sur la ligne d'assemblage, avec le comportement du mastic du premier cordon pendant son refroidissement, depuis le poste d'extrusion (à 80-120°C) jusqu'à la sortie de la ligne (environ 25°C). Les écarts d'épaisseur constatés sur un même vitrage ou d'un vitrage à un autre sont dus au fait qu'immédiatement après extrusion, le mastic du premier cordon (3) a tendance à légèrement regonfler (relaxation après libération des pressions mises en oeuvre pour l'extrusion)Ces variations se produisent même lorsque les opérations de production sont entièrement effectuées automatiquement, sans intervention humaine, elles sont liées à la nature du produit constituant le premier cordon (3).

b - une autre source de déformations a pour origine les manipulations effectuées à la sortie de la ligne, l'enduction et la mise sur chariot. Les déformations sont dans ce cas relativement aléatoires dans la mesure où elles sont le fait d'efforts plus ou moins ponctuels agissant sur le joint. Ces efforts agissent essentiellement en compression. Un mastic un peu moins plastique et plus résistant à la compression résistera mieux à ces efforts et sera donc moins déformé.

c - une troisième source de déformation trouve son origine dans la phase de polymérisation du mastic élastomère constituant le deuxième cordon (4). Lorsque ce deuxième joint (4) est complètement durci, le vitrage se trouve à l'abri de déformations ; mais pendant la phase transitoire de durcissement, ses propriétés mécaniques ne sont pas alors suffisantes pour supporter les efforts liés à l'emballage ou au stockage des vitrages.

The deformations of the joint (3) at the origin of the thickness differences observed have several origins:

a - they are related, when the glazing is on the assembly line, with the behavior of the putty of the first bead during its cooling, from the extrusion station (at 80-120 ° C) to the exit of the line (around 25 ° C). The thickness differences observed on the same glazing or from one glazing to another are due to the fact that immediately after extrusion, the putty of the first bead (3) tends to slightly swell (relaxation after release of the pressures used These variations occur even when the production operations are entirely carried out automatically, without human intervention, they are linked to the nature of the product constituting the first bead (3).

b - another source of deformation comes from the manipulations carried out at the end of the line, the coating and the placing on a trolley. The deformations are in this case relatively random insofar as they are the result of more or less punctual forces acting on the joint. These efforts act essentially in compression. A slightly less plastic sealant that is more resistant to compression will resist these efforts better and will therefore be less deformed.

c - a third source of deformation has its origin in the polymerization phase of the elastomeric sealant constituting the second bead (4). When this second seal (4) is completely hardened, the glazing is protected from deformations; but during the transitional curing phase, its mechanical properties are not then sufficient to withstand the forces associated with the packaging or storage of the glazing.

Staying on the problem of the conservation of the thickness, two phenomena are to be taken into account. The first relates to the trend of elastomeric sealants of the second bead (4) to show a slight shrinkage which results in a thickness reduction of 0.1 to 0.2 mm. The second is a function conditions for the polymerization of the elastomer. The polymerization of some sealants can be significantly accelerated by temperature: for example, a polysulfide typically requires 6 hours to cure at 20 ° C and only 1 hour 30 in an oven at 50 ° C. But at 50 ° C the pressure increases in the blade air from the glazing which can cause some deformation of the first seal (3) in the upper part, the glazing being held vertically. For these reasons, polymerization at 20 ° C will be preferred, but for this to be possible it is necessary that the composition of the first bead (3) allows it. That means that if the drying phase disappears, we must be able to do without storage medium at room temperature and therefore proceed to the packaging of glazing immediately, before polymerization of the second bead (4).

1 - résistance à la compression supérieure à celle du mastic existant. Nous mesurons ce paramètre par un essai d'écrasement (figure 2) qui consiste à mesurer la variation de hauteur d'une éprouvette de hauteur nominale 12 mm; de largeur nominale 5 mm, de longueur 100 mm, maintenue sous charge de 0,8 kg/cm² pendant 6 heures à 20°C. Le cordon de 12 mm est obtenu par extrusion d'un cordon à 14 mm, calibré entre deux feuilles de verre à 12 mm préablement à la mise sous charge.

2 - extrusion équivalente à celle de l'ancien mastic. Nous mesurons ce paramètre par un essai d'extrusion à 85°C à travers un orifice calibré (buse de 14 mm) et sous une pression constante.

3 - durabilité du vitrage isolant assemblé avec le mastic, supérieure ou égale à celle d'un vitrage conventionnel. Cela comprend : étanchéité à la vapeur d'eau et aux gaz, adhésion sur le verre, tenue aux essais, pouvoir deshydratant efficace.

The sealant improvement (3) must meet the following requirements:

1 - higher compressive strength than existing putty. We measure this parameter by a crushing test ( figure 2 ) which consists in measuring the variation in height of a test piece with nominal height 12 mm; nominal width 5 mm, length 100 mm, kept under load of 0.8 kg / cm ² for 6 hours at 20 ° C. The 12 mm bead is obtained by extruding a 14 mm bead, calibrated between two sheets of 12 mm glass prior to loading.

2 - extrusion equivalent to that of the old putty. We measure this parameter by an extrusion test at 85 ° C through a calibrated orifice (14 mm nozzle) and under constant pressure.

3 - durability of insulating glazing assembled with putty, greater than or equal to that of conventional glazing. This includes: water vapor and gas tightness, adhesion to glass, resistance to tests, effective dehydrating power.

The inventors to solve the problem have thought of reducing substantially the amount of butyl rubber introduced into the composition. Whereas in the most common variant of the first bead putty this proportion was 10% they reduced it to 5% and even in one case to 2%.

It would have been logical, in compensation for the decrease in the proportion of this elastic component, replace it with an increase in the component plastic, polyisobutylene, usually about 50% of the composition and, especially of a high molecular weight element capable of increasing the elasticity module. The tests made in this sense are shown quite disappointing.

Quite surprisingly, it is the introduction of a polyisobutylene (PIB) with a molecular weight less than 1000, therefore liquid, in a significant proportion (10 to 20%) with reduction in mass GDP molecular of the order of 8000 or higher and the addition of a low amount (2 to 3%) of a hot-melt polymer which provided the solution.

The butyl rubber used was a commercial composition consisting of a copolymer of isoprene and isobutylene in a proportion about 5-95%, GDP was also a trade product with molecular weights between 8,000 and 15,000 for solid GDP and 800 for the newly introduced liquid GDP, for the polymer hot melt, it was a copolymer composition based on ethylene, acrylic acid, derivatives of the same acid and ionomers.

The following two examples show two compositions with the results of the crushing, extrusion and durability tests in comparison with the putty of traditional composition.

Examination of these results shows a marked improvement in crushing without appreciable degradation of the ease of extrusion (and even, improvement for example 1) and satisfactory durability. The performance of this new product allow higher extrusion temperature and in general, greater control of the viscosity.

It was also found that the product's "memory" was less important. This is the characteristic of a product that has just been extruded, which deforms by swelling to regain the state it was in before it under enormous pressure in the extruder and in the nozzle.

This memory, which had to be accommodated, prevented a mastery complete with the final shape of the cord. This new sealant allows previously impossible achievements.

In Figure 3 we see a new way to achieve the junction between the beginning and the end of the first extruded bead on the glass 5. The arrows 6 indicate the direction of extrusion. The nozzle which deposits the bead 7 is designed so as to be able to start by depositing a bevel-shaped bead 8. After the relative nozzle-glass movement has made it possible to deposit the bead 7 over the entire periphery of the glass, the final part 9 of the bead is deposited thanks to the design of the nozzle, with a complementary bevel shape. After assembly with the second glass, at the time of calendering or passing through the press, or during the mixed operation bringing together these two production phases, the crushing undergone by the cord 7 brings the two parts 8, 9 closer to the bevel and ensures sealing ( Figure 4 ).

This technique described here with the sealant of the invention can obviously be used with any sealant which allows control of the extruded form. A sealant, like that of the invention which has little "memory" meets this definition but any system which allows this memory effect to be taken into account to obtain the desired shape is also compatible with this form of connection. The bevel itself is not essential. It suffices to have between the start and the end of the extrusion a space, a slot, sufficiently narrow and / or a putty sufficiently malleable and sticky so that at the time of pressing, the plugging of the slot is guaranteed. FIG. 5 shows such an example without a bevel with the ends 11 and 12 of the adjacent convex cord 3 which have merged.

Before the development of the putty of the invention, with reduced memory, the only solution to practice the connection between the beginning and the end of the cord extruded was to start and end the extrusion in a corner and do perform the junction, after assembly, by an operator equipped with a tool adapted. The new design of the start-end junction of the cord allows to save this operation.

Claims (11)

1. Product intended to form the first bead (3) of an insulating glazing without metallic spacer, the second bead (4) being produced by the polymerization of an elastomer, and whose composition in particular includes polyisobutylene and butyl rubber, characterized in that the weight proportion of the butyl rubber is below 6% and in that the composition incorporates heat-fusible polymer in a weight proportion of 1.5 to 4%.
2. Product according to claim 1, characterized in that the heat-fusible polymer has a melting temperature range above 90°C.
3. Product according to claim 2, characterized in that the heat-fusible polymer is essentially constituted by copolymers based on ethylene, acrylic acid, derivatives of acrylic acid and ionomers.
4. Product according to any one of the preceding claims, characterized in that the polyisobutylene weight proportion is between 40 and 70% with between 10 and 20% polyisobutylene with a molecular weight below 1000.
5. Product according to any one of the preceding claims, characterized in that it comprises a weight proportion of colloidal silica between 0 and 20%, carbon black between 10 and 40% and molecular sieve between 0 and 5%.
6. Application of the product according to any one of the preceding claims to the production of insulating glazings, whose plates (1, 2) are separated by spaces between 11 and 20 mm.
7. Application of the product according to one of the claims 1 to 5 to the production of insulating glazings packed prior to the polymerization of the elastomer constituting the second bead (4).
8. Application according to claim 6 or 7 to the production of insulating glazings, where polymerization of the elastomer takes place at ambient temperature.
9. Process for the production of an insulating glazing without a metallic spacer and having the following phases:

   extrusion of a first plastic bead (3) according to one of the claims 1 to 5,

   assembly of the glazings,

   deposition on the periphery of the glazing of a polymerizable elastomer material (4),

   characterized in that shapes are given to the starting part and the end part of the first bead (3) such that at the time of assembly they are tightly rejoined.
10. Process according to claim 9, characterized in that the shapes of the start and end parts of the first bead (3) are complimentary bevels (8, 9), the thinning of one compensating the thickening of the other.
11. Process according to claim 9 or 10, characterized in that the junction of the start and end of the first bead (3) is on a rectilinear edge of the glazing.

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