HOT MELT SINGLE-COMPONENT PRIMARY SEALANT

Abstract

1) Hot-melt single component sealant composition, comprising from 70% to 99 weight % of polyisobutylene based on the total weight of the composition. 2) Use as a primary sealant in a manufacturing process of Insulating Glass units.

Claims

1-13. (canceled)

14. A hot-melt single component sealant composition comprising from 70 weight % to 99 weight % of polyisobutylene, based on the total weight of the composition.

15. The hot-melt single component sealant composition according to claim 14, further comprising a thermoplastic polymer selected from the group consisting of polyalkylenes, poly-alpha-olefin polymers, poly(alkylene oxides), poly(phenylenediamine terephthalamide), polyesters, polyacrylates, polymethacrylates, polyacrylamides, polyacrylonitriles, copolymers of acrylonitrile, polyimides, polyamides, copolymers of vinyl alcohol and ethylenically unsaturated monomers, polyvinyl acetate, polyvinyl alcohol, vinyl chloride homopolymers and copolymers, terpolymers of ethylene, carbon monoxide and acrylic acid ester or vinyl monomer, polysiloxanes, polyurethanes, and polystyrene.

16. The hot-melt single component sealant composition according to claim 15, wherein the thermoplastic polymer is a copolymer of ethylene and vinyl acetate.

17. The hot-melt single component sealant composition according to claim 15, wherein it comprises from 0.5 weight % to 10 weight %, of the thermoplastic polymer, based on the total weight of the sealant composition.

18. The hot-melt single component sealant composition according to claim 14, wherein it further comprises a transparent tackifying resin selected from the group consisting of the following classes: (a) natural and modified rosins; (b) glycerol and pentaerythritol esters of natural and modified rosins; (c) polyterpene resins; (d) phenolic-modified terpene resins; (e) aliphatic petroleum hydrocarbon resins (C.sub.5) having a Ring and Ball softening point of from about 60° C. to 140° C., said resins resulting from the polymerization of C.sub.5-hydrocarbon monomers; and the corresponding hydrogenated derivatives resulting from a subsequent total or partial hydrogenation thereof; (f) aromatic petroleum hydrocarbons resins (C.sub.9) having Ring and Ball softening point of from about 60° C. to 140° C., said resins resulting from the polymerization of C.sub.9-hydrocarbon monomers; and the corresponding hydrogenated derivatives resulting from a subsequent total or partial hydrogenation thereof; and (g) aliphatic and/or aromatic petroleum resins (C.sub.5/C.sub.9) having a Ring and Ball softening point of from about 60° C. to 140° C., said resins resulting from the polymerization of C.sub.5/C.sub.9-hydrocarbon monomers; and the corresponding hydrogenated derivatives resulting from a subsequent total or partial hydrogenation thereof.

19. The hot-melt single component sealant composition according to claim 18, wherein it comprises from 5 weight % to 50 weight % of the tackifying resin, based on the total weight of the sealant composition.

20. The hot-melt single component sealant composition according to claim 14, wherein it further comprises an antioxidant stabilizer, in an amount of from 0.05 weight % to 3 weight % based on the total weight of the sealant composition.

21. The hot-melt single component sealant composition according to claim 14, wherein it further comprises an adhesion promoter selected from an epoxy-based silane and an amino-based silane, in an amount of from 0.1 weight % to 2 weight %, based on the total weight of the sealant composition.

22. The hot-melt single component sealant composition according to claim 14, wherein it comprises: from 90 weight % to 99 weight % of polyisobutylene; and from 1 weight % to 10 weight % of a copolymer of ethylene and vinyl acetate; based on the total weight of the sealant composition.

23. The hot-melt single component sealant composition according to claim 18, wherein it comprises: from 70 weight % to 80 weight % of polyisobutylene; and from 20 weight % to 30 weight %, of the tackifying resin; based on the total weight of the sealant composition.

24. An insulating glass unit comprising: a first pane of glass, a second pane of glass, a spacer positioned between a first inner surface of the first pane of glass and a second inner surface of the second pane of glass, and a sealant system for adhering the first and second inner surfaces of the first and second glass panes to the spacer, wherein the sealant system comprises a primary sealant located in first and second side regions of the spacer and a secondary sealant located in an outer region of the spacer, wherein the primary sealant comprises the hot-melt single component sealant composition of claim 14.

25. The insulating glass unit according to claim 25, wherein the spacer has a substantially rectangular cross-section.

Description

BRIEF DESCRIPTION OF THE FIGURE

[0076] FIG. 1 is a cross-section of an elevational view of a portion of an edge assembly of an IG unit having a primary sealant according to the invention.

[0077] In reference to FIG. 1, the IG unit (1) has a first pane (11) having an inner surface (21) and an outer surface (31). The first pane (11) is spaced from a second pane (12) which also has an inner surface (22) and an outer surface (32). The two panes (11) and (12) may be of any transparent material conventionally used in the IG unit art, for instance clear float glass.

[0078] The inner surface (21) of the first pane (11) faces the inner surface (22) of the second pane (12), and the inner surfaces (21) and (22) are spaced apart by a spacer (3) which is attached, ie adhesively bonded, to the two panes (11) and (12) by a sealant system (5).

[0079] The spacer (3) may be any of the type used in the IG unit art, such as a conventional rigid spacer, with an essentially rectangular cross-section. In the illustrative embodiment shown in FIG. 1 but not to be considered as limiting to the invention, the spacer (3) is depicted as having a base (31) with a first side (32) and a second side (33) extending from the base (31). Each side (32), (33) includes an outer surface (42), (43) facing the inner surfaces (21), (22) of the respective adjacent panes (11), (12).

[0080] The two panes (11) and (12) and the spacer (3) define a chamber (4) or “dead space” between the two panes (11) and (12). The chamber (4) can be filled with an insulating atmosphere, such as air or argon or krypton gas.

[0081] Preferably, the spacer (3) comprised in the IG unit according to the invention has a substantially rectangular cross-section.

[0082] The sealant composition according to the invention is used in a dual seal system (5) having two separate or distinct regions: an outer or secondary sealant (52) and an inner or primary sealant (51), wherein the sealant composition according to the invention is used to form the primary sealant (51).

[0083] The primary sealant (51) is located mainly in the side regions of the spacer (3), namely the majority of the sealant is located between the outer surfaces (42), (43) of each side (32), (33) and the inner surfaces (21), (22) of the respective adjacent panes (11), (12).

[0084] The secondary sealant (52) preferably extends across the width of the outside of the spacer (3) (outer region), e.g. extends across the perimeter groove formed by the outer surface of the base (31) of the spacer (3) and the outer marginal edges of the inner surfaces (21) and (22) of the panes (11) and (12).

[0085] The sealants (51), (52) may be of any suitable dimensions to adhere the panes (11), (12) to the spacer (3).

[0086] According to a preferred embodiment, the secondary sealant (52) is a conventional edge sealant, such as a conventional thermoset sealant material. For example, the secondary sealant (52) can comprise one or more conventional silicone, polyurethane, polysulfide or butyl rubber based edge sealant materials as are known in the art.

[0087] The sealant composition according to the invention may be applied, as a primary sealant, to the surface of the panes of glass by hot melt pumps and linear extruders at a temperature from 140 to 250° C., preferably at a temperature of from 170 to 200° C., and more preferably at a temperature from 180 to 195° C., for instance by using any suitable applicator including a hand held glue gun, extruder, linear extruder, other forms of extruder beads, automated application equipment, and combinations thereof.

[0088] The following examples are given purely by way of illustration of the invention and should not, under any circumstances, be interpreted as limiting the scope thereof.

[0089] The test procedures used in the examples are the following:

[0090] Moisture Vapor Transmission Rate (MVTR):

[0091] The MVTR was determined according to ASTM E96-90. The test was conducted at 23° C. and 92% relative humidity on a sealant film having a thickness of 2 mm. Said film was sealed to the open mouth of a test dish containing a desiccant. The assembly was placed in the controlled atmosphere. Periodic weighings determined the rate of moisture vapour movement through the sealant film into the desiccant.

[0092] Melt Flow Index (MFI):

[0093] The MFI was determined according to ASTM D1238. The MFI is the weight of composition (placed beforehand in a vertical cylinder) which flows in 10 minutes through a die having a fixed diameter, under the effect of a pressure exerted by a loaded piston having a total weight of 2.16 kg.

[0094] Softening Point:

[0095] The softening point is determined by the Ring & Ball method according to ASTM D-36, using silicone oil as a medium, the principle of which is as follows. A brass ring about 2 cm in diameter is filled with the resin to be tested in the melt state. After cooling to room temperature, the ring and the solid resin are placed horizontally in a thermostatted glycerol bath, the temperature of which may vary by 5° C. per minute. A steel ball about 9.5 mm in diameter is centered on the solid resin disk. The softening temperature is, during the rise in temperature of the bath at a rate of 5° C. per minute, the temperature at which the resin disk flows by an amount of 25.4 mm under the weight of the ball.

[0096] The raw materials used in the examples are listed in Table 1:

Example A (Reference): PIB Based Sealant Composition Comprising an Inorganic Filler

[0097] The composition of example A in Table 1 is prepared as follows.

[0098] A part of PIB and antioxidant stabilizer are added in a mixing device, and are heated to a temperature comprised between 100° C. and 160° C. Then carbon black is added to the mixing device, the content of which is mixed under vacuum until the mixture is uniform before adding the remaining PIB, ground calcium carbonate and wax.

[0099] The mixture is maintained under vacuum during a period of time from about 30 min to 1 h, at the same temperature, until the ingredients are melted and uniformly blended.

[0100] This composition is opaque.

[0101] It is tested according to the Melt Flow Index, softening point and MVTR tests, as described above.

[0102] The results are given in Table 1.

Examples 1 to 3 (According to the Invention)

[0103] The composition of examples 1-3 in Table 1 are prepared as pointed out above.

[0104] They are found to be transparent.

[0105] They are tested according to the Melt Flow Index, softening point and MVTR tests, as described above.

[0106] The results are given in Table 1.

[0107] The values obtained for the softening point correspond to a significantly improved heat resistance with respect to example A.

TABLE-US-00001 TABLE 1 Ingredients Trade name Supplier Ex. A (ref.) Ex. 1 Ex. 2 Ex. 3 Polyisobutylene (PIB) OPPANOL ® B15N BASF 46.51 72.15 69.22 13.76 Polyisobutylene (PIB) OPPANOL ® B12 BASF 13.08 20.19 9.48 — Polyisobutylene (PIB) OPPANOL ® N50 BASF — 5 13.27 32.10 Polyisobutylene (PIB) GLISSOPAL ® V1500 BASF — — 4.74 — Polyisobutylene (PIB) GLISSOPAL ® V640 BASF — — — 28.67 Copolymer of ethylene and vinyl acetate EVATANE ® 28-420 ARKEMA — 2.50 — — Copolymer of ethylene and vinyl acetate EVATANE ® 28-25 ARKEMA — — 2.37 — Hydrogenated cycloaliphatic resin SUKOREZ ® SU-525 KOLON — — — 24.08 (R&B of about 125° C.) Pentaerythritol tetrakis(3,5-di-tert-butyl- Irganox ® 1010 BASF — 0.15 0.14 0.23 4-hydroxyhydrocinnamate) Butylated hydroxytoluene Topanol ® O VERTELLUS 0.01 0.01 0.02 0.02 3-Glycidoxypropyltrimethoxysilane Silquest ® A-187 MOMENTIVE — — 0.52 — Fumed silica Aerosil ® 300 EVONIK — — 0.24 1.14 Ground Calcium Carbonate PolCarb ® 29 IMERYS 33.43 — — — (d.sub.50 = 3.4 μm) Carbon black Continex ® N550 CONTINENTAL 4.98 — — — CARBON Wax Sasolwax ® H1 SASOL 1.99 — — — Aspect opaque transparent transparent transparent MVTR (g/m.sup.2) 0.05 0.06 0.06 0.05 Melt Flow Index (g/10 minutes) 55 45 25 17 Softening point (° C.) 102 104 119 148