HK1130242B - Insulated glass unit with sealant composition having reduced permeability to gas - Google Patents

Description

Insulated glass unit with sealant composition having low gas permeability

Technical Field

The present invention relates generally to insulating structures, and more particularly, to a high thermal efficiency, insulated glass unit structure sealed with a room temperature cured composition that exhibits low permeability to gases or mixtures of gases.

Background

Room Temperature Curable (RTC) compositions are well known for use as sealants. In the manufacture of Insulating Glass Units (IGUs), glass sheets are placed parallel to each other and sealed at the periphery so that the space between the sheets, or the interior space, is completely enclosed. The interior space is typically filled with air. Energy transfer is reduced through this typical construction of the insulating glass unit as compared to a single glass panel due to the inclusion of an air insulating layer within the interior space. Energy transfer can be further reduced by increasing the separation distance (separation) between the panels in order to increase the thermal blanket (blanket) of air. There is a limit to the maximum separation distance beyond which convection in the air between the panels may increase energy transfer. The energy transfer can be further reduced by adding more insulating layers in the form of other inner spaces and closing the glass panels. For example, three parallel spaced glass panels are separated by two interior spaces and sealed at their peripheries. In this way, the separation of the panels is kept below the maximum limit in space for the effect of convection, yet the overall energy transfer can be further reduced. If further reduction in energy transfer is desired, additional interior space may be added.

In addition, the energy transfer of the sealed insulating glass unit can be reduced by replacing the air within the sealed insulating glass window with a denser, lower conductivity gas. Suitable gases should be colorless, non-toxic, non-corrosive, non-flammable, unaffected by ultraviolet radiation, and denser than air and less conductive than air. Argon, krypton, xenon, and sulfur hexafluoride are examples of gases commonly used in insulating glass windows to replace air to reduce energy transfer.

Various types of sealants are currently used in the manufacture of insulating glass units, including both cured and non-cured systems. Liquid polysulphides, polyurethanes and silicones represent the commonly used curing systems, whereas polybutylene-polyisoprene copolymer rubber based hot melt sealants are the commonly used non-curing systems.

Liquid polysulfides and polyurethanes are typically two-component systems comprising a base and a curing agent, which are mixed prior to their application to glass. Silicones can be one-component as well as two-component systems. The two-component system requires a set mixing ratio, a two-part mixing device and a curing time before the insulating glass unit can be moved to the next manufacturing stage.

However, current RTC silicone sealant compositions, while effective to some extent, still have only a limited ability to prevent the loss of low thermal conductivity gases (e.g., argon) from the interior space of the IGU. As a result of this permeability, the reduced energy transfer maintained by the gas between the glass panels is lost over time.

Therefore, there is a need for an IGU containing RTC composition having reduced gas permeability compared to known RTC compositions. When used as a sealant for an IGU, an RTC composition with reduced gas permeability will retain the insulating gas within the panel of the IGU for a longer period of time than a more gas permeable RTC composition, thus prolonging the insulating properties of the IGU for a longer period of time.

Summary of The Invention

The present invention relates to an insulated glazing unit with increased insulation stability. In particular, the present invention relates to an insulated glass unit comprising at least two spaced apart sheets of glass or other functionally equivalent material (glass panes) in spaced apart relation to one another, a low thermal conductivity gas therebetween, and a gas sealant element comprising a cured sealant composition resulting from the curing of a moisture-curable silylated resin-containing composition comprising:

a) a moisture-curable silylated resin that, when cured, provides a cured resin exhibiting gas permeability; and

b) at least one other polymer having a gas permeability less than that of the cured resin (a); and optionally

c) At least one further component selected from the group consisting of catalysts, adhesion promoters, fillers, surfactants, UV stabilizers, antioxidants, curing accelerators, thixotropic agents, moisture scavengers, pigments, dyes, solvents and biocides.

When used as a component of a gas sealing member of an IGU, the above cured sealant composition reduces the loss of gas from the IGU, thereby extending its effective service life.

Brief Description of Drawings

FIG. 1 is a cross-sectional side view of a double-glazed Insulated Glass Unit (IGU) having a gas sealing element comprising a cured sealant composition of the present invention.

Detailed Description

The present invention provides an insulated glass unit comprising at least two spaced apart glass sheets in spaced apart relation to one another, an insulating gas or gas mixture having low thermal conductivity therebetween, and a gas sealant element comprising a cured (i.e., crosslinked or vulcanized) sealant composition resulting from the curing of a moisture-curable silylated resin-containing composition comprising: a) a moisture-curable silylated resin that, when cured, provides a cured resin exhibiting gas permeability; and b) at least one other polymer having a gas permeability less than that of the cured resin (a); and optionally c) at least one further component selected from the group consisting of fillers, adhesion promoters, catalysts, surfactants, UV stabilizers, antioxidants, curing accelerators, thixotropic agents, moisture scavengers, pigments, dyes, solvents and biocides.

Referring to fig. 1, an insulated glass unit 10 of known and conventional construction includes glass sheets 1 and 2 held in spaced relation by a gas-tight member having a primary gas-tight member 4, a continuous spacer member 5, and a low-permeability sealant composition 7 (prepared as described below), the space 6 between glass sheets 1 and 2 being filled with an insulating gas or gas mixture (e.g., argon). Glazing beads (8) known in the art are placed between the glass sheets 1 and 2 and the window frame 9. The panes 1 and 2 can be made of any of a variety of materials, for example, glass, such as clear float glass, annealed glass, tempered glass, solar glass, colored glass, such as low energy glass, and the like, acrylic resins, polycarbonate resins, and the like.

The inclusion of the cured sealant composition 7 in the above gas sealant unit provides improved gas barrier and moisture leakage characteristics relative to known and conventional gas sealants. As a result, the cured sealant composition 7 provides longer-life service performance for insulated glass units of all configurations, including those specifically described above.

The primary sealant member 4 of the insulated glazing unit can comprise a polymeric material known in the art, such as a rubber-like material, e.g., polyisobutylene, butyl rubber, polythioether, EPDM rubber, nitrile rubber, and the like. Other useful materials include polyisobutylene/polyisoprene copolymers, polyisobutylene polymers, brominated olefin polymers, copolymers of polyisobutylene and para-methylstyrene, copolymers of polyisobutylene and brominated para-methylstyrene, butyl rubber copolymers of isobutylene and isoprene, ethylene-propylene polymers, polysulfide polymers, polyurethane polymers, styrene butadiene polymers, and the like.

As described above, the main gas seal element 4 can be made of a material having very good sealing properties (e.g., polyisobutylene). Glazing beads 8 are sealants sometimes referred to as glazing bedding and may be in the form of silicone or butyl rubber. A desiccant may be included in the continuous spacer 5 to remove moisture from the insulating gas occupying the space between the panes 1 and 2. Useful desiccants are those that do not absorb the insulating gas/gas mixture that fills the interior of the insulated glass unit.

Suitable low thermal conductivity gases and mixtures of such gases for use in insulated glass units are well known and include transparent gases such as air, carbon dioxide, sulfur hexafluoride, nitrogen, argon, krypton, xenon, and the like, and mixtures thereof.

Moisture-curable silylated resins (a) useful in the present invention are known materials and are generally prepared by the following process: (i) the isocyanate-terminated Polyurethane (PUR) prepolymer is reacted with a suitable silane, such as a silane having hydrolyzable functionality (e.g., alkoxy groups, etc.) and active hydrogen-containing functionality (e.g., thiol, primary and secondary amines (the latter being preferred), etc.), or (ii) the hydroxyl-terminated PUR prepolymer is reacted with a suitable isocyanate-terminated silane (e.g., a silane having 1 to 3 alkoxy groups). Details of these reactions and of the preparation of isocyanate-terminated and hydroxyl-terminated PUR prepolymers can be found in the following documents: U.S. Pat. Nos. 4,985,491, 5,919,888, 6,207,794, 6,303,731, 6,359,101 and 6,515,164 and published U.S. Pat. Nos. 2004/0122253 and 2005/0020706 (isocyanate-terminated PUR prepolymers); U.S. Pat. Nos. 3,786,081 and 4,481,367 (hydroxyl terminated PUR prepolymers); U.S. Pat. nos. 3,627,722, 3,632,557, 3,971,751, 5,623,044, 5,852,137, 6,197,912 and 6,310,170 (moisture curable SPUR derived from the reaction of isocyanate-terminated PUR prepolymers with reactive silanes such as aminoalkoxysilanes); and U.S. Pat. nos. 4,345,053, 4,625,012, 6,833,423 and published U.S. patent application 2002/0198352 (moisture curable SPUR derived from the reaction of hydroxyl terminated PUR prepolymer with isocyanatosilane). The entire contents of the above U.S. patent documents are incorporated by reference into this application.

Moisture-curable silylated resin (a) of the present invention can also be prepared by the direct reaction of (iii) isocyanatosilane with a polyol.

(a) Moisture curable SPUR resins from isocyanate terminated PUR prepolymers

Isocyanate-terminated PUR prepolymers are prepared by reacting one or more polyols, preferably diols, with one or more polyisocyanates, preferably diisocyanates, in proportions such that the resulting prepolymers are isocyanate-terminated. In the case of the reaction of the diol with the diisocyanate, a molar excess of diisocyanate is used.

Included among the polyols that may be used in the preparation of the isocyanate-terminated PUR prepolymer are polyether polyols, polyester polyols such as hydroxyl-terminated polycaprolactones, polyetherester polyols such as those derived from the reaction of polyether polyols with epsilon-caprolactone, polyesterether polyols such as those derived from the reaction of hydroxyl-terminated polycaprolactones with one or more alkylene oxides such as ethylene oxide and propylene oxide, hydroxyl-terminated polybutadienes, and the like.

Specific suitable polyols include polyether diols, specifically poly (oxyethylene) diols, poly (oxypropylene) diols and poly (oxyethylene-oxypropylene) diols, polyoxyalkylene triols, polytetramethylene glycols, polyacetals, polyhydroxy polyacrylates, polyhydroxy polyester amides and polyhydroxy polythioethers, polycaprolactone diols and triols, and the like. In one embodiment of the present invention, the polyol used to prepare the isocyanate-terminated PUR prepolymer is a poly (oxyethylene) diol having an equivalent weight of about 500-25,000. In another embodiment of the present invention, the polyol used to prepare the isocyanate-terminated PUR prepolymer is a poly (oxypropylene) diol having an equivalent weight of about 1,000-20,000. Mixtures of polyols of various structures, molecular weights and/or functionalities may also be used.

The polyether polyol may have a functionality of up to about 8, but preferably has a functionality of about 2-4, and more preferably 2 (i.e., diols). Particularly suitable are polyether polyols prepared in the presence of Double Metal Cyanide (DMC) catalysts, alkali metal hydroxide catalysts or alkali metal alkoxide catalysts; see, for example, U.S. Pat. nos. 3,829,505, 3,941,849, 4,242,490, 4,335,188, 4,687,851, 4,985,491, 5,096,993, 5,100,997, 5,106,874, 5,116,931, 5,136,010, 5,185,420, and 5,266,681, the entire contents of which are incorporated by reference into this application. Polyether polyols prepared in the presence of these catalysts tend to have high molecular weights and low levels of unsaturation, which properties are believed to be responsible for the improved performance of the retroreflective articles of the present invention. Preferably, the polyether polyols have a number average molecular weight of from about 1,000 to about 25,000, more preferably from about 2,000 to about 20,000, and even more preferably from about 4,000 to about 18,000. Preferably, the polyether polyol has an end group unsaturation of no greater than about 0.04 milliequivalents per gram of polyol. More preferably, the polyether polyol has an end group unsaturation of no greater than about 0.02 milliequivalents per gram of polyol. Examples of commercially available diols suitable for use in preparing the isocyanate-terminated PUR prepolymer include ARCOL R-1819 (number average molecular weight of 8,000), E-2204 (number average molecular weight of 4,000) and ARCOL E-2211 (number average molecular weight of 11,000).

Any of a number of polyisocyanates (preferably diisocyanates) and mixtures thereof may be used to prepare the isocyanate-terminated PUR prepolymers. In one embodiment, the polyisocyanate may be diphenylmethane diisocyanate ("MDI"), polymethylene polyphenyl isocyanates ("PMDI"), p-phenylene diisocyanate, naphthylene diisocyanate, liquid carbodiimide modified MDI and derivatives thereof, isophorone diisocyanate, dicyclohexylmethane-4, 4' -diisocyanate, toluene diisocyanate ("TDI"), particularly the 2, 6-TDI isomer, as well as various other aliphatic and aromatic polyisocyanates well-established in the art, and combinations thereof.

The silylation reactants reacted with the isocyanate-terminated PUR prepolymers described above must contain functional groups reactive with isocyanate and at least one group that is readily hydrolyzable and subsequently crosslinkable (e.g., alkoxy). In particular, useful silylating reactants are aminosilanes, particularly those having the general formula:

wherein R is¹Is hydrogen, alkyl or cycloalkyl having up to 8 carbon atoms or aryl having up to 8 carbon atoms, R²Is alkylene having up to 12 carbon atoms, optionally containing one or more heteroatoms, each R³Are identical or different alkyl or aryl radicals having up to 8 carbon atoms, each R⁴Are identical or different alkyl radicals having up to 6 carbon atoms and x is 0,1 or 2. In a kind of implementationIn the scheme, R¹Is hydrogen or methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, cyclohexyl or phenyl, R²Having 1 to 4 carbon atoms, each R⁴Are identical or different methyl, ethyl, propyl or isopropyl radicals, and x is 0.

Specific aminosilanes for use herein include, for example, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, aminobutyltriethoxysilane, N- (2-aminoethyl-3-aminopropyl) triethoxysilane, aminoundecyltrimethoxysilane and aminopropylmethyldiethoxysilane. Other suitable aminosilanes include, but are not limited to, phenylaminopropyltrimethoxysilane, methylaminopropyltrimethoxysilane, N-butylaminopropyltrimethoxysilane, t-butylaminopropyltrimethoxysilane, cyclohexylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane, dibutylacetalsubstituted 4-amino-3, 3-dimethylbutyltrimethoxysilane, N-methyl-3-amino-2-methylpropyltrimethoxysilane, N-ethyl-3-amino-2-methylpropyldiethoxysilane, N-ethyl-3-amino-2-methylpropyltriethoxysilane, N-tert-butylaminopropyltrimethoxysilane, N-2-, N-ethyl-3-amino-2-methylpropylmethyldimethoxysilane, N-butyl-3-amino-2-methylpropyltrimethoxysilane, 3- (N-methyl-3-amino-1-methyl-1-ethoxy) propyltrimethoxysilane, N-ethyl-4-amino-3, 3-dimethylbutyldimethoxymethylsilane, and N-ethyl-4-amino-3, 3-dimethylbutyltrimethoxysilane.

Catalysts are commonly used to prepare isocyanate-terminated PUR prepolymers. Condensation catalysts are preferably used, as they also catalyze the curing (hydrolysis followed by crosslinking) of the SPUR resin component of the curable compositions of the invention. Suitable condensation catalysts include dialkyltin dicarboxylates such as dibutyltin dilaurate and dibutyltin diacetate, tertiary amines, stannous salts of carboxylic acids such as stannous octoate and stannous acetate, and the like. In one embodiment of the present invention, dibutyltin dilaurate catalyst is used in the preparation of the PUR prepolymer. Other useful catalysts include zirconium complexes (KAT XC6212, K-KA)TXC-A209, available from King Industries, Inc., aluminum chelate: (Class, available from dupont company; and KRs from Kenrich Petrochemical, Inc.) and other organometallics (e.g., Zn, Co, Ni, Fe, etc.).

(b) Moisture curable SPUR resins from hydroxyl terminated PUR prepolymers

As previously described, moisture-curable SPUR resins can be prepared by reacting hydroxyl-terminated PUR prepolymers with isocyanatosilanes. Hydroxyl-terminated PUR prepolymers can be prepared in substantially the same manner using substantially the same materials described above for the preparation of isocyanate-terminated PUR prepolymers, i.e., polyol, polyisocyanate and optionally catalyst (preferably a condensation catalyst), one major difference being that the ratio of polyol to polyisocyanate is such that the resulting prepolymer is hydroxyl-terminated. Thus, for example, in the case of a diol reacted with a diisocyanate, a molar excess of the diol is used, thereby obtaining a hydroxyl-terminated PUR prepolymer.

Useful silylation reactants for hydroxyl-terminated SPUR resins are those containing isocyanate-terminated and readily hydrolyzable functional groups (e.g., 1-3 alkoxy groups). Suitable silylation reactants are isocyanatosilanes having the general formula:

wherein R is⁵Is alkylene having up to 12 carbon atoms, optionally containing one or more heteroatoms, each R⁶Are identical or different alkyl or aryl radicals having up to 8 carbon atoms, each R⁷Are identical or different alkyl radicals having up to 6 carbon atoms and y is 0,1 or 2. In one embodiment, R⁵Having 1 to 4 carbon atoms, each R⁷Are identical or different methyl, ethyl, propyl or isopropyl radicals and y is 0.

Specific isocyanatosilanes useful herein for reacting with the aforementioned hydroxyl-terminated PUR prepolymers to obtain moisture-curable SPUR resins include isocyanatopropyltrimethoxysilane, isocyanatoisopropyltrimethoxysilane, isocyanaton-butyltrimethoxysilane, isocyanatot-butyltrimethoxysilane, isocyanatopropyltriethoxysilane, isocyanatoisopropylisocyanatotriethoxysilane, isocyanaton-butyltriethoxysilane, isocyanatot-butyltriethoxysilane, and the like.

c) Moisture curable SPUR resins derived from reacting isocyanatosilane directly with polyol

The moisture-curable SPUR resins of the present invention can be obtained from the direct reaction of one or more polyols (preferably diols) with isocyanatosilanes without prior formation of a polyurethane prepolymer.

The various materials that can be used in this process to make moisture-curable SPUR resins, namely polyols and silanes (e.g., those having both hydrolyzable and isocyanato functionality) are described above. Thus, suitable polyols include hydroxyl-terminated polyols having a molecular weight of about 4,000-20,000. However, mixtures of polyols of various structures, molecular weights and/or functionalities may also be used. Suitable isocyanatosilanes for reaction with the foregoing polyols to provide moisture-curable SPUR resins are described above.

The synthesis of the urethane prepolymer and the subsequent silylation reaction and the direct reaction of the polyol with the isocyanatosilane are carried out under anhydrous conditions and preferably under an inert atmosphere (e.g., under a nitrogen blanket) to prevent premature hydrolysis of the alkoxysilyl groups. Typical temperatures for both reaction steps range from 0 ℃ to 150 ℃, more preferably from 60 ℃ to 90 ℃. Typically, the total reaction time for the silylated polyurethane synthesis is from 4 to 8 hours.

The synthesis was monitored using standard titration techniques (ASTM2572-87) or infrared analysis. The silylation reaction of the urethane prepolymer is considered complete when no residual-NCO can be detected by either technique.

The curable sealant composition of the present invention includes at least one other polymer (b) that exhibits a gas permeability to a gas or gas mixture that is less than the gas permeability of the cured resin (a). Suitable polymers include polyethylenes such as Low Density Polyethylene (LDPE), Very Low Density Polyethylene (VLDPE), Linear Low Density Polyethylene (LLDPE) and High Density Polyethylene (HDPE); polypropylene (PP); polyisobutylene (PIB), polyvinyl acetate (PVAc), polyvinyl alcohol (PVOH), polystyrene, polycarbonate, polyester, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), glycol-modified polyethylene terephthalate (PETG); polyvinyl chloride (PVC), polyvinylidene chloride, polyvinylidene fluoride, Thermoplastic Polyurethane (TPU), acrylonitrile-butadiene-styrene copolymer (ABS), polymethyl methacrylate (PMMA), polyvinyl fluoride (PVF), polyamide (nylon), polymethylpentene, Polyimide (PI), Polyetherimide (PEI), Polyetheretherketone (PEEK), polysulfone, polyethersulfone, ethylene-chlorotrifluoroethylene copolymer, Polytetrafluoroethylene (PTFE), cellulose acetate butyrate, plasticized polyvinyl chloride, ionomer (Surtyn), polyphenylene sulfide (PPS), styrene-maleic anhydride copolymer, modified polyphenylene oxide (PPO), and the like, and mixtures thereof.

The polymer (b) may also be elastomeric in nature, examples including, but not limited to, ethylene propylene rubber (EPDM), polybutadiene, polychloroprene, polyisoprene, polyurethane (TPU), styrene-butadiene-styrene copolymer (SBS), styrene-ethylene-butadiene-styrene copolymer (SEEBS), polymethylphenylsiloxane (PMPS), and the like.

These polymers may be blended individually or in combination or in the form of copolymers, such as polycarbonate-ABS blends, polycarbonate polyester blends, graft polymers, such as silane-grafted polyethylene and silane-grafted polyurethane.

In one embodiment of the invention, polymer (b) is selected from: low Density Polyethylene (LDPE), Very Low Density Polyethylene (VLDPE), Linear Low Density Polyethylene (LLDPE), High Density Polyethylene (HDPE), and mixtures thereof. In another embodiment of the present invention, polymer (b) is selected from: low Density Polyethylene (LDPE), Very Low Density Polyethylene (VLDPE), Linear Low Density Polyethylene (LLDPE), and mixtures thereof. In yet another embodiment of the present invention, polymer (b) is a Linear Low Density Polyethylene (LLDPE).

Optionally, the curable sealant compositions herein can also include one or more fillers, such as calcium carbonate including ground, precipitated and colloidal calcium carbonate treated with compounds such as stearates or stearic acid; reinforcing silicas such as fumed silica, precipitated silica, silica gel and hydrophobicized silica and silica gel; crushed and ground quartz, alumina, aluminum hydroxide, titanium hydroxide, diatomaceous earth, iron oxide, carbon black, graphite, talc, mica, and the like, and mixtures thereof.

In one aspect of the invention, the filler component of the curable composition is calcium carbonate, silica or mixtures thereof. The type and amount of filler added depends on the desired physical properties of the cured silicone composition. Thus, the filler may be a single species or a mixture of two or more species.

Other useful fillers may be nanoclays having a unique morphology with dimensions in one direction in the nanometer range. Nanoclays can form chemical complexes with intercalants ionically associated with the surfaces between the layers making up the clay particles. This association of the intercalant and clay particles results in a material that is compatible with many different types of matrix resins, thereby allowing the clay filler to be dispersed therein

When describing the organo nanoclay filler of the present invention, the following terms have the following meanings, unless otherwise indicated.

The term "exfoliation" as used herein describes a process in which small packets of nanoclay platelets are separated from each other in a polymer matrix. During exfoliation, the platelets at the outermost region of each packet cleave, exposing more platelets for separation.

The term "gallery" as used herein describes the space between parallel layers of clay platelets. The gallery space varies depending on the nature of the molecule or polymer occupying the space. The interlayer spacing between each nanoclay platelet also varies depending on the type of molecule occupying that space.

The term "intercalant" as used herein includes any inorganic or organic compound that is capable of entering the clay gallery and bonding to its surface.

The term "intercalate" as used herein refers to a clay-chemical complex in which the clay gallery space is increased due to a surface modification process. Under appropriate temperature and shear conditions, the insert can flake off in the resin matrix.

The expression "modified clay" as used herein refers to a clay material treated with any inorganic or organic compound capable of undergoing ion exchange reactions with cations present at the interlayer surfaces of the clay.

The term "organoclay" as used herein refers to a clay or other layered material that has been treated with organic molecules (also referred to as "exfoliants", "surface modifiers" or "intercalants") that are capable of undergoing ion exchange reactions with cations present at the interlayer surfaces of the clay.

The expression "organic nanoclay" as used herein describes a nanoclay treated or modified with an organic or semi-organic intercalant, such as a diorganopolysiloxane ionically bonded to the surfaces between the layers making up the clay particles.

Useful nanoclays for providing the organic nanoclay filler component of the present composition include natural or synthetic phyllosilicates, particularly smectite clays such as montmorillonite, sodium montmorillonite, calcium montmorillonite, magnesium montmorillonite, nontronite, beidellite, volkonskoite, laponite, hectorite, saponite, sauconite, NaSiO₁₃(OH)₃.3H₂O (magadite), kenyaite, sobockite, svindordite, stevensite, talc, mica, kaoliniteVermiculite, halloysite, aluminate oxides or hydrotalcite, and the like and mixtures thereof. In another embodiment, useful nanoclays include micaceous minerals such as illite and mixed layered illite/smectite minerals such as rectorite, tarosovite, ledikite and mixtures of illite with one or more of the clay minerals described above. Any swellable layered material that sufficiently adsorbs organic molecules to increase the interlayer spacing between adjacent phyllosilicate platelets to at least about 5 angstroms, or at least about 10 angstroms (when the phyllosilicate is measured dry), may be used in the preparation of the filler component to provide the curable sealant composition of the invention.

Nanoclays can be natural or synthetic materials. This characteristic can affect particle size, and for purposes of the present invention, the particles should have a lateral dimension of from about 0.01 μm to about 5 μm, preferably from about 0.05 μm to about 2 μm, and more preferably from about 0.1 μm to about 1 μm. The thickness or longitudinal dimension of the particles may generally vary from about 0.5nm to about 10nm, and preferably from about 1nm to about 5 nm.

In one embodiment of the invention, the organic and inorganic compounds used to treat or nanoclays and layered materials to provide the filler components herein include cationic surfactants such as ammonium, ammonium chloride, alkylammonium (primary, secondary, tertiary and quaternary), phosphonium or sulfonium derivatives of aliphatic or aromatic or arylaliphatic amines, phosphines or sulfides.

Other organic treating agents for nanoclays that may be used herein include amine compounds and/or quaternary ammonium compounds R⁶R⁷R⁸N⁺X^-，R⁶、R⁷And R⁸Each independently of the other being an alkoxysilyl, alkyl or alkenyl radical having up to 60 carbon atoms, X being an anion, e.g. Cl^-、F^-、SO₄ ^2-And the like.

The curable sealant composition may also include one or more alkoxysilanes as adhesion promoters. Useful adhesion promoters include N-2-aminoethyl-3-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, bis-gamma- (trimethoxysilylpropyl) amine, N-phenyl-gamma-aminopropyltrimethoxysilane, triamino-functional trimethoxysilane, gamma-aminopropylmethyldiethoxysilane, methacryloxypropyltrimethoxysilane, methylaminopropyltrimethoxysilane, gamma-glycidoxypropylethyldimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxyethyltrimethoxysilane, beta- (3, 4-epoxycyclohexyl) propyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxyethyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, beta- (3, 4-epoxycyclohexyl) propyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-, Beta- (3, 4-epoxycyclohexyl) ethylmethyldimethoxysilane, propylisocyanatotriethoxysilane, propylisocyanatomethyldimethoxysilane, beta-cyanoethyltrimethoxysilane, gamma-acryloyloxypropyltrimethoxysilane, gamma-methacryloyloxypropylmethyldimethoxysilane, 4-amino-3, 3-dimethylbutyltrimethoxysilane, and N-ethyl-3-trimethoxysilyl-2-methylpropylamine, and the like. In one embodiment, the adhesion promoter may be a combination of N-2-aminoethyl-3-aminopropyltrimethoxysilane and 1,3, 5-tris (trimethoxysilylpropyl) isocyanurate.

Catalysts commonly used in the preparation of the aforementioned urethane prepolymers and related Silylated Polyurethanes (SPUR) include those known to be useful in promoting crosslinking of silicone sealant compositions. The catalyst may include metal catalysts and non-metal catalysts. The metal portion of the metal condensation catalysts useful in the present invention include tin, titanium, zirconium, lead, iron, cobalt, antimony, manganese, bismuth and zinc compounds.

In one embodiment of the present invention, the tin compound used to facilitate crosslinking of the silicone sealant composition comprises: tin compounds such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dimethoxide, tin octylate, isobutyltin triscalate (isobutyltin triceroate), dibutyltin oxide, solubilized dibutyltin oxide, dibutyltin bis (isooctylphthalate), bis (tripropoxysilyldioctyl) tin, dibutyltin bisacetone, dibutyltin bisacetylate, dibutyltin silanate dioxide, carbomethoxyphenyl tin tris-uberate, isobutyltin triscalate (isobutyltin triceroate), dimethyltin dibutyrate, dimethyltin dineodecanoate, triethyltin tartrate, dibutyltin dibenzoate, tin oleate, tin naphthenate, butyltin tris-2-ethylhexylhexanoate, and tin butyrate, and the like. In another embodiment, the titanium compounds useful for promoting crosslinking of the silicone sealant composition are chelated titanium compounds, such as bis (ethylacetoacetate) 1, 3-propylenedioxytitanium; bis (ethylacetoacetate) diisopropoxytitanium; and tetraalkyl titanates such as tetra-n-butyl titanate and tetra-isopropyl titanate. In yet another embodiment of the present invention, diorganotin bis beta-diketonates are used to facilitate crosslinking of the silicone sealant composition.

In one aspect of the invention, the catalyst is a metal catalyst. In another aspect of the invention, the metal catalyst is selected from tin compounds, and in another aspect of the invention, the metal catalyst is dibutyltin dilaurate.

The compositions of the present invention may also include one or more nonionic surfactant compounds such as polyethylene glycol, polypropylene glycol, ethoxylated castor oil, oleic acid ethoxylate, alkylphenol ethoxylates, copolymers of Ethylene Oxide (EO) and Propylene Oxide (PO), copolymers of silicones and polyethers (silicone polyether copolymers), copolymers of silicones and copolymers of ethylene oxide and propylene oxide, and mixtures thereof.

The curable compositions of the present invention also include known and conventional amounts of other components conventionally used in RTC silicone-containing compositions, such as colorants, pigments, plasticizers, cure accelerators, thixotropic agents, moisture scavengers, dyes, solvents, antioxidants, UV stabilizers, biocides, and the like, provided that these components do not affect the desired properties of the cured composition.

The amounts of moisture-curable silylated resin (a), other polymer (b), and optional components such as filler, adhesion promoter, crosslinking catalyst and ionic surfactant disclosed herein can vary over a wide range and preferably can be selected from the ranges set forth in the following table.

TABLE A range of amounts (wt%) of the various components of the sealant composition 7 of the present invention

Components of the cured sealant composition First range Second range Third range

Moisture-curable silylated resins (a) 1-9910-5020-30

Other polymers (b) 1-995-5010-20

Fillers 0.1-8010-

Silane adhesion promoter 0.1-200.3-100.5-2

Catalyst 0.001-10.003-0.50.005-0.2

0-100.1-50.5-0.75 of ionic surfactant

The cured sealant compositions herein can be prepared by methods well known in the art, such as melt blending, extrusion blending, solution blending, dry blending, blending in a Banbury mixer, and the like, in the presence of moisture, to provide a substantially homogeneous mixture.

While the preferred embodiments of the invention have been illustrated and described in detail, various modifications, such as components, materials, and parameters, will be apparent to those skilled in the art, and it is intended to cover in the appended claims all such modifications and changes as fall within the scope of the invention.

Claims (29)

1. An insulated glass unit comprising at least two spaced apart sheets of glass or other functionally equivalent material in spaced relation to one another, a low thermal conductivity gas or gas mixture therebetween, and a gas sealant element comprising a cured sealant composition resulting from the curing of a moisture-curable silylated resin-containing composition comprising:

a) a moisture-curable silylated resin that, when cured, provides a cured resin exhibiting gas permeability prepared by reacting a hydroxyl-terminated polyurethane prepolymer prepared by reacting a molar excess of a polyether polyol selected from the group consisting of poly (oxyethylene) glycol, poly (oxypropylene) glycol, poly (oxyethylene-oxypropylene) glycol, polyoxyalkylene triol and polytetramethylene glycol, having a number average molecular weight of 4,000-18,000 g/mole and a terminal unsaturation of no greater than 0.04 milliequivalents per gram of polyol with an isocyanatosilane having the formula:

wherein R is⁵Is alkylene having up to 12 carbon atoms, R⁶Is an alkyl or aryl radical having up to 8 carbon atoms, R⁷Are identical or different alkyl radicals having up to 6 carbon atoms and y is 0,1 or 2; and

b) at least one other polymer having a gas permeability less than that of the cured resin a; and optionally

c) At least one further component selected from the group consisting of fillers, adhesion promoters, catalysts, surfactants, UV stabilizers, antioxidants, curing accelerators, thixotropic agents, moisture scavengers, pigments, dyes, solvents and biocides.

2. The insulated glass unit of claim 1 wherein moisture-curable silylated resin a is at least one member selected from the group consisting of: (i) a silylated resin derived from the reaction of an isocyanate-terminated polyurethane prepolymer with an active hydrogen-containing organofunctional silane; (ii) a silylated resin derived from the reaction of a hydroxyl-terminated polyurethane prepolymer with an isocyanatosilane; and (iii) a silylated polymer derived from the reaction of a polyol with an isocyanatosilane.

3. The insulated glass unit of claim 1 wherein moisture-curable silylated resin a ranges from 1 to 99 weight percent of the total composition.

4. The insulated glass unit of claim 1 wherein moisture-curable silylated resin a ranges from 10 to 50 weight percent of the total composition.

5. The insulated glass unit of claim 1 wherein moisture-curable silylated resin a ranges from 20 to 30 weight percent of the total composition.

6. The insulated glass unit of claim 1 wherein polymer b is selected from the group consisting of low density polyethylene, very low density polyethylene, high density polyethylene, polypropylene, polyisobutylene, polyvinyl acetate, polyvinyl alcohol, polystyrene, polycarbonate, polyester, polyvinyl chloride, polyvinylidene fluoride, acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyvinyl fluoride, polyamide, polymethylpentene, polyimide, polyetherimide, polyetheretherketone, polysulfone, polyethersulfone, ethylene-chlorotrifluoroethylene copolymer, polytetrafluoroethylene, cellulose acetate butyrate, plasticized polyvinyl chloride, ionomer, polyphenylene sulfide, styrene-maleic anhydride copolymer, modified polyphenylene ether, ethylene propylene rubber, polybutadiene, polychloroprene, polyisoprene, polyethylene terephthalate, polypropylene, polyethylene terephthalate, polyurethanes, styrene-butadiene-styrene copolymers, styrene-ethylene-butadiene-styrene copolymers, polymethylphenylsiloxanes, and mixtures thereof.

7. The insulated glass unit of claim 6 wherein the polyester is selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and glycol-modified polyethylene terephthalate.

8. The insulated glass unit of claim 6 wherein polymer b is selected from the group consisting of low density polyethylene, very low density polyethylene, high density polyethylene, and mixtures thereof.

9. The insulated glass unit of claim 8 wherein polymer b is selected from the group consisting of low density polyethylene, very low density polyethylene, and mixtures thereof.

10. The insulated glass unit of claim 1 wherein polymer b is 1 to 99 weight percent of the total composition.

11. The insulated glass unit of claim 1 wherein polymer b is 5 to 50 weight percent of the total composition.

12. The insulated glass unit of claim 1 wherein polymer b is 10 to 20 weight percent of the total composition.

13. The insulated glass unit of claim 1 wherein the filler is selected from the group consisting of calcium carbonate, calcium carbonate treated with compounds stearate or stearic acid, fumed silica, precipitated silica, silica gel, hydrophobized silica, crushed quartz, ground quartz, alumina, aluminum hydroxide, titanium hydroxide, clay, diatomaceous earth, iron oxide, carbon black and graphite, mica, talc, and mixtures thereof.

14. The insulated glass unit of claim 13 wherein the filler is selected from the group consisting of montmorillonite, nontronite, beidellite, volkonskoite, laponite, hectorite, saponite, sauconite, magadite, kenyaite, sobockite, svindordite, stevensite, vermiculite, aluminate oxides, hydrotalcite, illite, rectorite, tarosovite, ledikite, kaolinite, and mixtures thereof.

15. The insulated glass unit of claim 14 wherein the filler is treated with at least one tertiary amine compound R³R⁴R⁵N and/or quaternary ammonium compounds R⁵R⁶R⁷R⁸N⁺X^-Modification of wherein R³、R⁴、R⁵、R⁶、R⁷And R⁸Each independently an alkyl, alkenyl or alkoxysilyl group having up to 60 carbon atoms, X^-Is an anion.

16. The insulated glass unit of claim 14 wherein the filler is modified with ammonium, primary alkylammonium, secondary alkylammonium, tertiary alkylammonium quaternary alkylammonium, phosphonium derivatives of aliphatic, aromatic or arylaliphatic amines, phosphines or sulfides or sulfonium derivatives of aliphatic, aromatic or arylaliphatic amines, phosphines or sulfides.

17. The insulated glass unit of claim 1 wherein the adhesion promoter is selected from the group consisting of N-2-aminoethyl-3-aminopropyltrimethoxysilane, 1,3, 5-tris (trimethoxysilylpropyl) isocyanurate, gamma-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, bis-gamma- (trimethoxysilylpropyl) amine, N-phenyl-gamma-aminopropyltrimethoxysilane, triamino-functional trimethoxysilane, gamma-aminopropylmethyldiethoxysilane, methacryloxypropyltrimethoxysilane, methylaminopropyltrimethoxysilane, gamma-glycidoxypropylethyldimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, di-, Gamma-glycidoxyethyltrimethoxysilane, beta- (3, 4-epoxycyclohexyl) propyltrimethoxysilane, beta- (3, 4-epoxycyclohexyl) ethylmethyldimethoxysilane, propylisocyanatotriethoxysilane, propylisocyanatomethyldimethoxysilane, beta-cyanoethyltrimethoxysilane, gamma-acryloyloxypropyltrimethoxysilane, gamma-methacryloyloxypropylmethyldimethoxysilane, 4-amino-3, 3-dimethylbutyltrimethoxysilane, n-ethyl-3-trimethoxysilyl-2-methylpropylamine, and mixtures thereof.

18. The insulated glass unit of claim 1 wherein the catalyst is a tin catalyst.

19. The insulated glass unit of claim 18 wherein the tin catalyst is selected from the group consisting of dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dimethoxide, tin octylate, isobutyltin tristannate, solubilized dibutyltin oxide, dibutyltin bis-diisooctylphthalate, bis-tripropoxysilyldioctyltin, dibutyltin bisacetoacetone, silylated dibutyltin dioxide, carbomethoxyphenyl tin tris-suberate, isobutyltin trisalicylate, dimethyltin dibutyrate, dimethyltin dineodecanoate, triethyltin tartrate, dibutyltin dibenzoate, tin oleate, tin naphthenate, butyltin tris-2-ethylhexyl hexanoate, tin butyrate, diorganotin bis- β -diketonates, and mixtures thereof.

20. The insulated glass unit of claim 1 wherein the surfactant is a nonionic surfactant selected from the group consisting of: polyethylene glycol, polypropylene glycol, ethoxylated castor oil, oleic acid ethoxylate, alkylphenol ethoxylates, copolymers of ethylene oxide and propylene oxide, copolymers of silicones and polyethers, copolymers of silicones and copolymers of ethylene oxide and propylene oxide, and mixtures thereof.

21. The insulated glass unit of claim 20 wherein the nonionic surfactant is selected from the group consisting of copolymers of ethylene oxide and propylene oxide, copolymers of silicones and polyethers, copolymers of silicones and copolymers of ethylene oxide and propylene oxide, and mixtures thereof.

22. The insulated glass unit of claim 1 wherein the insulating gas is selected from the group consisting of air, carbon dioxide, sulfur hexafluoride, nitrogen, argon, krypton, xenon, and mixtures thereof.

23. The insulated glass unit of claim 6,8 or 9 wherein the low density polyethylene is linear low density polyethylene.

24. The insulated glass unit of claim 6 wherein the polyurethane is a thermoplastic polyurethane.

25. The insulated glass unit of claim 13 wherein the calcium carbonate is selected from the group consisting of precipitated calcium carbonate and colloidal calcium carbonate.

26. The insulated glass unit of claim 13 wherein the silica gel is a hydrophilic silica gel.

27. The insulated glass unit of claim 13 wherein the clay is selected from the group consisting of kaolin, bentonite, and montmorillonite.

28. The insulated glass unit of claim 14 wherein the montmorillonite is selected from the group consisting of sodium montmorillonite, calcium montmorillonite, and magnesium montmorillonite.

29. The insulated glass unit of claim 14 wherein the kaolinite is halloysite.