Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
  • C07F7/02—Silicon compounds
  • C07F7/21—Cyclic compounds having at least one ring containing silicon, but no carbon in the ring
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C25/00—Surface treatment of fibres or filaments made from glass, minerals or slags
  • C03C25/10—Coating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
  • B05D3/02—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by baking
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B9/00—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
  • B32B9/04—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00 comprising such particular substance as the main or only constituent of a layer, which is next to another layer of the same or of a different material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
  • C07B2200/00—Indexing scheme relating to specific properties of organic compounds
  • C07B2200/11—Compounds covalently bound to a solid support

Definitions

• This invention relates generally to nanoreinforced coatings with improved hydrophobicity, thermal stability, hardness and durability.
• Polymers in particular utilize a wide variety of inorganic materials as fillers to impart desirable electrical, thermal, mechanical and other physical properties in the final composition.
• the hydrocarbon composition of polymers often renders them incompatible with the inorganic composition of most filler systems.
• Polymers include aliphatics, olefininic, aromatic, and heterofunctional systems (representative examples include polyethylene, polypropylene, polybutadiene, polyethers, polyimides, epoxides, acrylics, styrenics, polysulfides, polysulfones, polycarbonadtes, polyesters, polyamindes).
• compositions for example glasses, semicrystalline, crystalline and elastomers.
• Representative fillers include fillers such as layered silicates, clay, calcium carbonate, talc, Wollanstonite, diatomacious earth Kaloin, ATH (aluminum trihydrate),vermiculite, baryte, glass, metal, metal oxides, and wood.
• ATH aluminum trihydrate
• Mineral and synthetic silicates include bentonite, hectorite, montmorillonite.
• the goal of such surface interior and exterior surface modification has been to expand the spacing between adjacient silicate sheets and to compatabilize their interior surfaces to polymers and thereby improve both their dispersion and reinforcement characteristics.
• the present invention describes the use of nanostructured hybrid "organic-inorganic” chemicals as interior and exterior surface treatments and exfoliants for macroscopic fillers.
• Prior art with nanostructured polyhedral oligomeric silsesquioxanes (POSS and spherosiloxanes) reports their utility as corrosion resistant materials but makes no mention of their application and utility in composite, nanocomposite or filler technologies in which their nanoscopic size, hybrid compostion and interfacial compatabilizing properties are utilized to improved physical properties. See U.S. Patent No. 5,888,544.
• Nanoreinforced coatings with improved hydrophobicity, thermal stability, hardness, and durability have been developed from polyhedral oligomeric silsesquioxane (POSS) reagents and resins.
• POSS reagents bearing silanols are particularily useful for coating fillers derived from minerals, metals, glasses, and polymeric materials.
• the nanoscopic dimensions and hybrid (organic/inorganic) composition of POSS reagents are highly effective at improving the compatability of macroscopic and nanoscopic particulate fillers with a wide range of dissimilar materials including polymeric, biological, hydrocarbon and aqueous systems.
• the preferred coating agents utilize POSS-silanols, POSS-alkoxides, POSS-chlorides, and POSS-salts.
• POSS nanostructures containing functionalized heteroleptic compositions corresponding to formula [(RSiO 1 ,.X 1 (RXSiO 10 )J ⁇ # (m, n, # even and odd integers 1-
• the preferred processes for coating include solventless spraying, flame spraying, melt flowing, and vapor deposition. These processes are advantagous because they do not produce nor utilize volatile organic chemicals and hence are emission free. Alternatively, traditional solvent based methods of application can be utilized and include spin coating, dipping, painting, and spraying.
• POSS reagent and resin systems are also desirably utilized in the exfoliation of layered silicates and in the compatabilization of fillers including, clay, calcium carbonate, talc, Wollanstonite, diatomacious earth Kaloin, ATH (aluminum trihydrate), vermiculite, Baryte, glass, metal, metal oxides, and wood.
• the resulting POSS-modified fillers exhibit improved hydrophobicity, improved dispersion and rheological properties, fire retardancy, and refractive index.
• the present invention teaches the use of nanostructured POSS chemicals as surface treatments for the introduction of nanoscopic surface features onto macroscopic and nanoscopic fillers and surfaces.
• the nanoscopic surface features provided by the POSS agents further serve to compatabilize these fillers with the nanoscopic length scales present in polymer systems to provide multi-scale levels of reinforcement in polymeric coatings, composities and nanocomposites.
• the POSS-surface modification agents can be applied using all conventional coating techniques including slurry, spin-coating, painting spraying, flowing and vapor deposition. POSS-surface modification agents are readily available from commercial silane feedstocks.
• R hydrocarbon, silane or siloxy groups
• X OH, Cl, OR
• Figure 1 shows the anatomy of a POSS nanostructured chemical.
• Figure 2 shows physical size relationships of a traditional silane applied to a surface as a monolayer (left) and nanostructured coupling agents applied as monolayers.
• Figure 3 shows multi-length scale reinforcement (nano-macro) provided through POSS-surface modification of macroscopic surfaces.
• Figure 4 shows structural representations; for POSS silanol coupling agents R can be a functionalized group suitable for coupling to a polymer.
• Figure 5 shows examples of nanostructured surface modification agents that include POSS-mono, di-, and tri- silanols; POSS-siloxides; halides; and POSS-resins.
• Figure 6 shows representative intercalation/exfoliation of two silicate sheets by POSS.
• Figure 7 shows selected X-ray diffraction maxima for potassium montmorillonite (MMT) and MMT exfoliated with POSS silanols.
• R organic substituent (H, siloxy, cyclic or linear aliphatic, aromatic, or siloxide groups that may additionally contain reactive functionalities such as alcohols, esters, amines, ketones, olefins, ethers or halides).
• X includes but is not limited to OH, Cl, Br, I, alkoxide (OR), acetate (OOCR), peroxide (OOR), amine (NR 2 ) isocyanate
• Nanostructured chemicals are defined by the following features. They are single molecules and not compositionally fluxional assemblies of molecules. They possess polyhedral geometries with well-defined three-dimensional shapes. Clusters are good examples whereas planar hydrocarbons, dendrimers and particulates are not. They have a Nanoscopic Size that ranges from approximately 0.7 nm to 5.0 nm. Hence, they are larger than small molecules but smaller than macromolecules. They have systematic chemistries that enable control over stereochemistry, reactivity and their physical properties.
• a strucutural representation for nanostructured chemicals based on the class of chemicals known as polyhedral oligomeric silsesquioxanes (POSS) is shown in Figure 1.
• inorganic skeleton coupled with the peripheral groups combine to form chemically precise cubic like building blocks that when applied to a surface provide a regular and well defined surface topology.
• a particularly advantageous feature provided by nanostructured surface modification agents is that a single molecule is capable of providing five times the surface area coverage relative to that provided by comparable silane coupling agents applied in a hypothetical monolayer fashion.
• POSS chemicals When applied to both macroscopic surfaces (fibers, fillers, particulates, etc) or to nanoscopic surfaces (nanoparticles, fillers), POSS chemicals provide a surface topology that is truly nanoscopic. Depending upon the number of surface bonding sites the POSS cages assemble themselves on the surface in a regular pattern to provide a regular pattern of nano building blocks.
• POSS-silanols are the most cost effective and affordable entities to be utilized as surface modifiers. POSS-silanols are also preferable as they readily react with other polar surface groups (e.g. Si-OH ) to form thermally stable silicon-oxygen linkages to the surface. The assembly of POSS-mercaptos and POSS-Silanes on various surfaces has been reported.
• POSS-silanols as surface modifiers is derived from the fact that they are emission free.
• the nanoscopic size of POSS-silanols renders them nonvolatile as comparied to traditional silane and organic-based surfactants.
• the inherent stability of POSS-silanols is unique and thus eliminates the in situ production and release of volatile organic components such as alcohols or acid as is necessary to occur prior to the bonding and adhesion of a traditional silane coupling agent to a surface. Consequently POSS-silanols are also less flammable due to their lower volatility and the emissionless processing advantages.
• POSS-silanols are also capable of chemically coupling two dissimilar material types together through the incorporation of reactive groups (such as vinyl, amino, epoxy, methacrylic etc.) directly onto the cage ( Figure 4). This capability is analogous to the widely known capability offered by silane coupling agents.
• Nanostructured chemicals are part of a global nanotechnology trend (smaller, cheaper, and molecular control) that is directly impacting all aspects of business and business products.
• a simple and cost-effective approach to the modification of fibers and mineral particulates is the application of nanostructured chemicals to the surfaces of these macroscopic reinforcements.
• This approach is analogous to the coating of surfaces with organosilanes, coupling agents, ammonium salts, or other surface modifiers.
• Surface modification with nanostructured chemicals can be more effective at promoting compatibility, retarding moisture and in controlling coating structure which ultimately improves coating durability and reliability.
• POSS surface modification agents can be applied to minerals, glass, metal, ceramic, and polymeric surfaces via solution processing, melt spraying, or vapor deposition.
• the polar groups (e.g. silanol, silane, alkoxy, etc.) on each POSS system provide a chemical point of attachment to the filler surface while the remaining organic groups on the nanostructure render the surface hydrophobic and provide compatibility between the filler and the polymer matrix (see Figures 2 and 3).
• the surface of such treated fillers is now suitable to interact with a polymer matrix at the nanoscopic level and thus provides nanoscopic, as well as macroscopic, reinforcement of polymer chains.
• the resulting multi-scale reinforcement provides broader function and value for traditional macroscopic reinforcements.
• silane coupling agents e.g. RSiXs
• Traditional silane coupling agents typically possess one R group and
• Nanostructured coupling agents offer significant advantages over traditional "small molecule" technology.
• Figure 2 provides a comparison of the physical dimensions of a "silane monolayer” to those of a nanostructured coupling agent. It is clear from comparison of the area covered by each that the nanostructured coupling agents provide much greater hydrophobicity and increased surface coverage relative to a traditional silane monolayer. Additional benefits include the fact that a more regular surface coverage may be achievable given that the nanostructure has a well-defined polyhedral structure as opposed to the random structure produced by multiple layers of polyfunctional silanes.
• POSS nanostructures do not require activation through hydrolysis since POSS-silanols are air- stable, have indefinite shelf lives and can be reacted directly with the surface to be treated.
• Other desirable attributes obtained from the use of nanostructured POSS silane coupling agents include the ability to tailor the compatibilizing R-groups on the nanostructure to match the solubility characteristics of the resin matrix.
• POSS-silanol systems can be applied in solventless fashion and therefore are free from volatile organic components (VOCs), thus eliminating emissions and exposures to the VOCs present in traditional coupling agents.
• POSS-reagents and molecular silicas are also proficient at coating the interior surfaces of minerals, and in particular layered silicates. When applied as coatings to mineral or other porous materials the POSS-entity can effectively impart greater compatability of the mineral toward selective entry and exit of gases and other molecules such as solvents, monomer and polymers. In a similar capacity both POSS-silanols and the nonreactive molecular silicas can enter the internal galleries of layered silicates and simultaneously act as a spacer and compatabilizer of the galleries to impart such materials with a greater affinity for intercalation and exfoliation by polymerizable monomers and polymer chains (Figure 6).
• silanols are also present on the outer edges and surface of the montmorillonite sheets.
• POSS-silanols, molecular silicas and POSS-resins naturally exist as low and high melting solids and as oils. They also exhibit a high degree of solubility in wide range of common solvents which include aromatics, hydrocarbons, halogenated systems and a variety of organic monomers including styrene, acrylics, ring strained and unstrained olefins, glycidals, esters, alcohols, and ethers. Their ability to melt and dissolve thus enables them to be applied using all conventional coating techniques including slurry, spin-coating, painting spraying, flowing and vapor deposition.
• a typical solvent-assisted method of application involves dissolving the POSS entity in a desired solvent at a 0.1 wt% to 99 wt.% level and then placing this solution into contact with the material or surface desired to be coated. The solvent is then typically removed through evaporation and excess POSS can then be removed from the material or surface by physical wiping or by washing with additional solvent. The amount of material absorbed on the surface will vary by POSS composition, surface type and application method. Typical loadings for POSS-trisilanols on various material surfaces are shown below in Table 2.
• POSS-silanols Once applied to a material surface POSS-silanols have proven to exhibit excellent adhesion and durability properties. The adhesion however can be further enhanced through mild heating of the freshly treated material or surface. For example heating at temperatures as low as 12O 0 C enhance the bonding of POSS-silanols presumably through accelerating the bonding of polar surface groups with the reactive silicon-oxygen groups of POSS-silanols.
• Table 3 contains extraction data for selected materials coated with various POSS-silanols prior to and after heat treatment. Table 3. Typical loading level for various POSS-Silanols on various material surfaces.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Nanotechnology (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• General Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Ceramic Engineering (AREA)
• Physics & Mathematics (AREA)
• Composite Materials (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Geochemistry & Mineralogy (AREA)
• Crystallography & Structural Chemistry (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Pigments, Carbon Blacks, Or Wood Stains (AREA)
• Silicates, Zeolites, And Molecular Sieves (AREA)
• Silicon Polymers (AREA)
• Polymers With Sulfur, Phosphorus Or Metals In The Main Chain (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 2006
  • 2006-01-26 TW TW095103086A patent/TWI399297B/zh not_active IP Right Cessation
  • 2006-01-27 WO PCT/US2006/003120 patent/WO2006081512A2/en not_active Ceased
  • 2006-01-27 JP JP2007553305A patent/JP5086100B2/ja not_active Expired - Fee Related
  • 2006-01-27 EP EP06734021A patent/EP1841592A4/en not_active Withdrawn
  • 2006-01-27 KR KR1020077019457A patent/KR101288000B1/ko not_active Expired - Fee Related
  • 2006-01-27 CN CN2006800065349A patent/CN101203378B/zh not_active Expired - Fee Related
  • 2006-01-27 RU RU2007132158/04A patent/RU2425082C2/ru not_active IP Right Cessation

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