CA2152776C - Liquid adhesive thermoset composition - Google Patents
Liquid adhesive thermoset compositionInfo
- Publication number
- CA2152776C CA2152776C CA002152776A CA2152776A CA2152776C CA 2152776 C CA2152776 C CA 2152776C CA 002152776 A CA002152776 A CA 002152776A CA 2152776 A CA2152776 A CA 2152776A CA 2152776 C CA2152776 C CA 2152776C
- Authority
- CA
- Canada
- Prior art keywords
- composition
- film
- liquid
- dispersion
- thermoset
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J163/00—Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J201/00—Adhesives based on unspecified macromolecular compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2666/00—Composition of polymers characterized by a further compound in the blend, being organic macromolecular compounds, natural resins, waxes or and bituminous materials, non-macromolecular organic substances, inorganic substances or characterized by their function in the composition
- C08L2666/02—Organic macromolecular compounds, natural resins, waxes or and bituminous materials
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2666/00—Composition of polymers characterized by a further compound in the blend, being organic macromolecular compounds, natural resins, waxes or and bituminous materials, non-macromolecular organic substances, inorganic substances or characterized by their function in the composition
- C08L2666/02—Organic macromolecular compounds, natural resins, waxes or and bituminous materials
- C08L2666/04—Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
Abstract
A liquid adhesive dispersion comprises of a powdered thermosetting adhesive composition comprising thermoset and curing agent and having a particle size of about 25 microns or less. The composition may also comprises a film-forming polymer composition, and a liquid vehicle, wherein the dispersion remains storage stable at ambient temperatures and after application the adhesive forms a physically stable intermediate film.
Description
WO 94/16027 , ~ ~ ~ PCTlUS93/04679 LIQUID ADHESIVE THERMOSET COMPOSITION
Field of the Invention The invention generally relates to liquid, film-forming, thermosetting adhesive compositions. More specifically, the invention relates to adhesive compositions that can form an adhesive film which cures to a rigid bond.
Background of the Invention Thermoset compositions are well-known within the coating, adhesive, composite, and plastics industry.
Recently, powdered thermosets have become desirable due to their long-term storage stability and ease of handling. However, difficult problems arise when applying powdered compositions in various applications.
For instance, in applications where the powder is applied directly to a substrate, the substrate must be held stationary until the powdered thermoset is cured.
Exposure of the powder-laden substrate to movement, vibration, air flow or other environmental stresses may result in the removal of the powdered.thermoset from the substrate. Moreover, simply applying the powdered thermoset from a solvent such as water or ethanol often does not provide the means necessary to maintain the powder on the intended surface as these solvents may evaporate leaving the powdered thermoset free to fall from the intended surface.
Certain solvents may not allow for the long term storage of the adhesive composition in the liquid state.
Also, once the thermoset composition is applied onto or into a carrier to form a preimpregnated composite or deposited film, the system may require refrigeration to ensure that the composite will remain reactive and capable of curing once applied to the desired application. In fact, even when refrigerated the shelf life of certain composite materials may often be measured in terms of days or weeks instead of months.
Furthermore, certain methods of applying powders such as electrostatic applications are limited by factors such as the particle size of the powdered thermoset composition or the geometry of the area of application. These methods may not allow for the most uniform application of particles into narrow or tight areas due to electrical forces created by the surfaces of application. Overall, present methods of applying powdered thermoset compositions do not accurately control particle concentration over the surface of application, or the size of the particle domaine for each individual particle. As a result, present compositions and processes of application may result in a bond having variable uniformity and strength.
Accordingly, there is a need for a powdered thermoset composition which has extended stability at room temperature and preferably avoids stability and toxicity problems as well as providing for a method of application which results in a bond having a higher degree of uniform strength than those found in the prior art.
Summary of the Invention The present invention comprises a liquid adhesive dispersion which can cure to a thermoset bond, comprising an effective amount of film forming agent; and comprising in solid phase: an effective amount of a powdered thermosetting resin or composition having a particle size of 1 to 5 microns;
and in a liquid phase: a liquid vehicle; wherein said dispersion remains storage stable at ambient temperatures, and after application, said dispersion forms a physically stable intermediate film.
Preferably the thermosetting resin or composition is selected from the group of polymeric material consisting of an epoxy, a polyurethane, a polyester, a bis-maleimide, an acrylic, mixtures thereof and hybrids thereof.
Preferably the film forming agent comprises a theromplastic polymer composed of one or more monomers selected from the group consisting of vinyl acetate, ethylene, - 2a -acrylic acid, methacrylic acid, crotonic acid, itaconic acid, esters of acrylic acid, esters of methacrylic acid, stylene, butadiene, vinyl chloride, vinyllidene chloride, isoprene, chlorprene, polyvinyl alcohol, and malefic anhydride.
Preferably the film-forming agent comprises a polymer selected from the group consisting of cellulose polymers, ether cellulose polymers, derivatized cellulosic and ether cellulosic polymers, starch, starch grafted copolymers, guar gum, karaya gum, and dextrine.
Preferably the dispersion comprises a dispersant selected from the group consisting of silicates, polyphosphate salts, colloidal proteins, surfactants, cellulosic polymers, starch compositions and fatty acid soups.
A further aspect of the present invention is a method of using this liquid adhesive dispersion comprising the steps of applying the liquid adhesive dispersion composition to a substrate and forming a physically stable intermediate film capable of curing to a thermoset bond. Optionally the method may include forming a workpiece by placing a second substrate onto said intermediate film and curing tha thermosetting resin or composition contained within said intermediate film to create an adhesive bond.
The method may additionally comprising the steps of:-placing a plurality of said thermosetting film laden carriers together in series; and heat curing said thermosetting f~.lm laden carrier to produce a composite laminate structure.
An additional aspect of the invention. is an article of manufacture or a workpiece comprising a substrate coated with a physically stable adhesive dispersion which can cure to a thermoset bond, the liquid adhesive disper3ion comprising an effective amount of a film farming agent; in a solid phase: an effective amount of a thermosetting resin or composition having a particle size of 1-5 microns; and in a liquid. phase: a liquid vehicle; wherein said film dispersion remains storage stable at ambient temperatures and after application said dispersion forms a physically stable intermediate phase. The article may optionally include a second substrate or a series of substrates to forth a composite matrix.
Prior to deposition, the dispersion composition of the present invention is storage stable. storage stability in accordance with the present invention means that the level of particle separation or the degree of particle dispersion present after storage of the dispersion for the desired period of~~time remains substantially constant and will. not prevent the formation ~of an effective bond. Moreover, the dispersion composition of the present invention remains substantially unreacted and the solid phase remains partially, if not wholly, undissolved in the solvsnt over the intended storage period.
After deposition on a substrate but prior to curing, the composition of the present invention forms an intermediate film. The intermediate film results from the evaporation of the liquid vehicle from the composition which, in turn, tends to congeal the film-forming polymer composition. The particulate thermoset adhesive becomes cast within the resulting film.
. .r ~i . -3$-Prior to curing, the film formed by .the present composition provides a high degree of physical stability holding the powdered thermoset material on thQ surface where it was deposited. This stabilizing character is effective against mechan~.cal stresses which arise in the environment of use such as vibration, water or air flow, horizontal or inclined movement, and prolonged exposure of the adhesive to ambient atmospheric conditions among other factors.
Upon curing, the resulting film may become an integral element of the crosslinked bond or the film-forming polymer may be fugitive (i.e. may leave or be removed from the bond site).
Brief Description of the Figure Figure 1 is a graphical depiction of lap shear strengths plotted against compositional particle size.
Detailed Description of the Preferred Embodiment The composition of the present invention comprises a dispersion having at least two phases containing a thermosetting composition, a film-forming polymer, and a liquid vehicle. The first phase comprises a solid powdered thermosetting composition and may additionally comprise any of a variety of curing agents, fillers, or added functional elements as needed. The second phase of the present composition is a liquid vehicle, a film-forming agents being provided in the liquid or solid phase. While the film-forming polymer has been preferably included in the liquid phase it should be understood that the film-forming agents may be dissolved in the liquid vehicle or, alternatively, dispersed in the liquid vehicle as either a liquid a solid. The liquid vehicle may be aqueous, organic in nature, or a combination thereof. Optionally, as desired, the liquid phase of the present composition may also comprise dispersing agents, thixotropes, wetting agents, or any other variety or constituents depending on the intended application.
Solid Phase The first phase of the present invention comprises a powdered solid composition. The solid powdered phase, in turn, comprises at least the powdered thermosetting resin and any needed curing agent in each discrete particle.
Optionally, the solid phase may also comprise fillers or the functional material, such as, conductive particles depending on the intended application.
Thermosetting Composition The thermosetting composition functions to promote adhesion to the substrate and to form a cohesively stable bonding mass after curing. The thermoset composition also functions together with the film-forming phase of the present invention as a carrier for any particulate substance included in the composition such as, for example fillers, electrically conductive particle or constituents which may add flexibility, high temperature resistance or any number of other pre-cured physical characteristics to the liquid adhesive once the film is formed.
Thermosetting coating powders, with some exceptions, are based on resins that are cured by addition reactions rather than condensation reactions. Thermosets are synthetic resins which solidify or set upon heating and cannot be remelted.
Generally, thermosetting compositions useful in the present composition are those thermosetting compositions which can be powdered and which remain stable once combined with the chosen film-forming polymer and solvent in the liquid pre-application state.
In sharp contrast, prior art compositions using thermoset powders having particle sizes in excess of 150 microns may fail to effectively deposit onto or into the intended surface especially when applied by methods such as electrostatic deposition.
The thermoset composition useful in the present invention are partially or wholly insoluble in the liquid vehicle comprising a solid phase within the dispersion composition. Thermosetting compositions useful in the present invention are also those which provide chemical and physical storage stability upon film deposition given evaporation of the liquid vehicle under elevated heat and prolonged stability over time in the intermediate film state.
Generally, any well known thermosetting composition can be used in the present invention. Thermosetting compositions useful in the present invention include those selected from the group of polymeric materials consisting of an epoxy, a polyurethane, a polyester, a bis-maleimide, an acrylic, mixtures thereof and hybrides thereof among a large number of other compositions. Also useful in the present invention are bis-maleimides such as the partial reaction product of the bis maleimide of methylene dianaline with methylene dianaline.
Examplary thermosetting compositions useful in the present invention include the reaction product of orthotolybiguanide known as Casmine and commercially available from SES Chemicals Inc. and bisphenol A-epichlorohydein available from Ciba-Geigy Corporation under the commerical name Araldite* GT 7013 triglycidyl isocyanurate thermosetting compositions; bisphenol A-epichlorohydrin cured with phenolic crosslinking agents, the epoxy composition being available from Ciba-Geigy Corporation Araldite GT 7013 and the phenolic curing agent being available from Cow Chemical Company under the brand name DEH 84; aliphatic urethane thermosetting compositions such as an unblocked isophorone diisocyanate-Epcaprolactam available from Ruco Polymer Corporation under the commercial name NI2 which may be used with Rucote HBF
which is a hydroxyl terminated polyester resin also available from Ruco Chemicals; BTDA thermosetting compositions which are generally the reaction product of 3,3,4,4-benzophenone tetracarboxylic dianhydride and a disphenol A-epichlorohydrin;
hybrid thermosetting compositions which are the reaction product of a carboxylated *Trademark ..~~i~2~'~6 WO 94116027 ~ ' PCT/US93/04679 saturated polyester curing agent such as Arakote 3001 available from Ciba-Geigy Corporation and a bisphenol A-epichlorohydrin; standard bisphenol A-epichlorohydrin thermosets such as those which are cured with 2-methyl imidazole; and standard bisphenol A-epichlorohydrin thermosets which are cured with 2-methyl imidazole and dicyandiamide.
Preferably, the thermosetting composition used in the present invention are those selected from the group consisting of polymerized triglycidyl isocyanurate, aliphatic urethane thermosets, BTDA cured bisphenol A-epichlorohydrin thermosets, polyester-bisphenol A-epichlorohydrin thermoset complexes, 2-methylimidazole cured bisphenol A-epichlorohydrin thermosets, and orthotolylbiguanide cured bisphenol A-epichlorohydrin thermosets. These compositions, as can be seen in Table I, provide maximum storage stability in the liquid state when used in the preferred mode with an aqueous carrier.
Generally, the concentration of the powdered thermoset may be varied from 5 wt-~ to 95 wt-~ of the adhesive dispersion, preferably 20 wt-~ to 80 wt-~ of the adhesive dispersion and most preferably 40 wt-~ to 60 wt-~ of the adhesive dispersion. The concentration of powdered thermoset in the resulting film will range from about 30 wt-~ to 95 wt-$, preferably 60 wt-~ to 95 wt-$ and most preferably 80 wt-~ to 95 wt-$ depending on the specific application. The concentration of thermoset may range as a percentage of either the liquid composition or the resulting film outside the range as provided above depending on the application.
Increasing the concentration of the powdered thermoset will tend to increase the viscosity of the aqueous liquid composition depending on the relative particle size of the powdered thermoset used. A higher viscosity may be desirable to develop a compositional consistency of a caulk or putty which may be used as an _8_ adhesive sealing agent for any variety of applications.
Moreover, the use of an increased concentration of powdered thermoset may be desirable to promote an increased spreading or wetting of the surface of application once the thermoset adhesive is heated.
In contrast, reducing the relative concentration of the powdered thermoset within the composition of the present invention may reduce the degree of relative bonding strength in the resulting composition. Moreover, reducing the relative concentration of the powdered thermoset may potentially allow for a thinner more uniform film as deposited across the surface of application.
The present invention allows for varying the concentration of the thermoset composition within the dispersion and as a result varying the domain size of each powdered thermoset particle. The present invention also allows for the deposition of very fine particle thermoset powders of 1 to 5 microns. The ability to vary particle concentration and, in turn, particle domain size combined with the use of very fine particle size thermosets allows the resulting adhesive composition to have a higher relative adhesion than higher particle size thermosets which are applied in a less uniform manner.
The powdered thermoset may be combined with a curing agent commonly used to promote cross-linking within the powdered thermoset. Curing agents commonly known to the art include melamine such as dialkylmelamine; amides such as dicyandiamide, adipamide, and isophthalyl diamide; ureas such as ethylene thiourea or guyanylurea; azides such as thiosemicarbazide, or adipyl dihydrazide, and isophthalyl dihydrazide; azoles such as guanazole, or 3 amino-1,2,4 triazole; and anilines such as diethylaniline.
-g-The curing agents generally useful in the composition of the present invention are subject to the same stability limitations as the powdered thermoset resin. Specifically, the curing agent may be partially or wholly insoluble in the liquid vehicle. However, the curing agent must have an effective degree of chemical stability so that the required amount of cross-linking takes place at the intended point of curing. Accordingly, the curing agent may be solubilized in the liquid vehicle or remain in powder form with the powdered thermoset. Crosslinking mechanisms may be additionally retarded by intentionally including a crosslinking agent which will be solubilized within the liquid vehicle while retaining the powdered themoset in the powdered form as a separate solid phase.
When present, the curing mechanism may be a single curing agent or any combination of curing agents having a concentration between about 0.1 wt-o and 50 wt-% of the initial solid phase, preferably between about 1 wt-% and 30 wt-°s of the initial solid phase, and most preferably about 5 wt-% and 25 wt-% of the initial solid phase.
The solid phase may also contain other constituents including dispersing agents, fillers or any other element which is insoluble in the liquid phase, remains effectively dispersed in the composition and provides the intended functional characteristic to the composition.
Preferably, the solid phase of the invention will comprise a powdered composition of minimal particle size which comprises both thermoset and curing agent within each individual powdered particle. Individual particles may be formed by melt mixing and extruding thermoset and curing agents below curing temperatures.
The resulting extrudate, in the form of, for example, a rope, a sheet, etc., may then be particlized. Particle sizes range from about 5 microns to 1 micron.
As will be reflected in the working examples, and as can be seen in Figure 1, smaller particle size compositions are ._ believed to provide more uniform domains and as such result in higher lap shear strengths.
Liquid Phase The liquid phase of the present invention generally comprises the film-forming polymer, a solvent and optionally solubilized dispersing agents, thixotropes, or hardeners among other potential constituents, which.-may be wholly or partially dissolved in the liquid phase Of the~present invEmtion.
Film-Forminq Agent The function of the.film-forming agent is to carry the thermoset and deposit it on the surface. After liquid vehicle removal the film holds the powdered thermosettinq_ composition on the surface of application. Specifically, the film-forming polymer may form a liquid solution or an insolub7.e dispersion in the liquid vehicle (i.e. the film former may be a part of the dispersed solid phase or in solution as part of the liquid phase) .
Preferably, the film-forming polymer should not impair the reactivity of the powdered thermosetting composition. Once the film-forming polymer is either dispersed or dissolved, the liquid is applied through any variety of means. The liquid vehicle may be evaporated from the surface of application and the powdered thermosetting composition is retained or encapsulated on the surface by the film-forming polymer. The film-forming polymer may also be used to provide added functional character to the pre-cured or post-cured composition such as, for instance, pre- cured tack, solubil.it:y, adhesion, or wettability as well as post-cured hardness, or water-resistance.
Generally, compounds useful in the present invention are organic or inorganic film-forming agent which impart the intended character to the resulting film.
Generally, thermoplastic resins are preferred film-forming agents as they soften or melt at a given temperature, and when cooled, recover the physical and chemical properties of the original resin.
Generally, the physical and chemical properties of the original resin as well as any resulting films formed from the thermoplastic include a variable degree of plasticized flexibility, easy solubilization and emulsification in various liquid aqueous and organic vehicles, variable surface stability and stability against mechanical forces such as vibration, and horizontal or inclined movement, various degrees of stability when subjected to environmental forces such as heat, wind, or any other number of environmental forces which might impinge upon the composition within the area of use or application, various degrees of pre-application thickness or viscosity depending upon the choice of liquid vehicle.
At a minimum, any thermoplastic film-forming agent may be used which encapsulates the powdered thermosetting composition and does not adversely detract from the functioning of the thermoset once it is applied to the intended surface. Compounds and polymers which may function as film formers include plasticizers, wetting agents, tackifiers, elastomers, thixotropes, as well as coalescing agents used alone or with inert fillers .
Exemplary polymeric film-forming dispersions or solutions can be made from polymerizing one or more of the following monomers in a solvent medium, such as, vinyl acetate, ethylene, acrylic acid, methacrylic acid, crotonic acid, or itaconic acid; esters of acrylic and methacrylic acid including methyl esters, ethyl esters, butyl and 2-ethylhexyl esters; as well as styrene, butadiene, vinyl chloride, vinylidene chloride, isoprene, and chloroprene.
Synthetic polymers resulting from polymerization of many of the preceding monomers which are useful as film-forming elements of the present composition include generally, polyvinyl alcohol (with varying degrees of hydrolysis), ethylene/acrylic acid copolymers, ethylene/maleic anhydride copolymers, and styrene/maleic anhydride copolymers among others.
Naturally derivativized and naturally occurring polymers such as casein compositions, natural gum compositions including karaya gum and guar gum, cellulosic and ether cellulosic compositions, starch, protein compositions, and starch-grafted copolymers are also useful as a film-forming polymer of the present invention. Inorganic compounds such as sodium silicate may also be useful as the film-forming agent in the present invention. Those skilled in the art will realize that the preceding compounds and polymers are only exemplary of compounds and polymers which may be used as film-forming agents in the composition of the present invention and this list should not be viewed as limiting.
The concentration of the film-forming polymer used in the composition of the present invention will generally range from about 1 to 99 wt-~, preferably range from about 2 to 50 wt-$, and most preferably range from about 4 to 7 wt-~ depending on the characteristics to be imparted to the resulting film and the physical and chemical characteristic of the powdered thermoset adhesive. As a percentage of the resulting film, the film- forming polymer may again generally range from about 1 to 99 wt-~, preferably range from about 4 to 75 wt-~, and most preferably range from about 8 to 14 wt-~
again depending upon the character and quantity of powdered thermoset adhesive to be encapsulated within ~I ~~'~~'6 the film and the desired character which the film is intended to have in either the pre-cured or post-cured state.
Generally, the film-forming ability of the polymer depends on the film's ability to support the powdered thermoset. However, diminishing or increasing the concentration of film-forming agent within the composition of the present invention may limit or increase, respectively, the thermoplastic character of the film former and the ability of the film-former to retain the powdered thermoset on the surface of application. Moreover, pre-cure and post-cure film characteristics may be increased or diminished by the use of, for instance, thixotropes which can be used to affect changes in the viscosity and flowability of the composition of the present invention.
Liauid Vehicle The liquid phase of the present composition also principally contains a liquid vehicle. The liquid vehicle facilitates transport and deposition of the adhesive used in the composition of the present invention. Use of the liquid vehicle may also allow reduction of the concentration of the film-forming component.
Generally, the liquid vehicle may be aqueous, organic or a mixture thereof. While the liquid vehicle preferably does not interact with the thermoset, the liquid vehicle may generally be used to modify the effect of the thermoset by enhancing or reducing adhesion.
Organic liquid vehicles useful in the present invention are limited to those which maintain the dispersed character of the thermoset within the liquid phase of the present invention without reacting and destabilizing either the thermoset or any curing agent which may be present in the system. Organic liquid vehicles which function accordingly may partially or wholly displace any aqueous solvent used in the composition.
Organic liquid vehicles useful in the present invention include but~are not limited to low molecular weight (600-650 m.w.) fatty acid polymers including dimer and trimer acid compositions resulting from the polymerization of long chain (CV24-C40) aliphatic dibasic acids with long chain (C50-C60) aliphatic tribasic acids polymers such as those fatty acid polymers available from Emery under_,the Empol brand name; liquid curing agents including dicyanamide; liquid epoxy compositions including liquid bisphenol A-epichlorohydrin low molecular weight epoxies such as the Epon* brand epoxies available from Shell Chemical Company; mineral solvents; naptha; and liquid polyamides such as N-ethyl 0. P-toluene sulfanamide available from Monsanto Corporation as Saniticizer 8.
Alternatively, the liquid vehicle may be aqueous or an aqueous-organic solvent mixture. Such a liquid vehicle is useful in minimizing environmental and safety hazards often prevalent with the use of volatile organic. Also, a mixture of aqueous and organic liquid vehicles may be useful in maintaining, for example, a curing agent and resin in separate phases and thus increasing the chemical stability and storage life of the present composition prior to application. Such a system will comprise a liquid vehicle or combination of liquid vehicles which may completely solubilize the curing agent yet retain the thermoset resin in solid undissolved form.
Preferably, if minimal toxicity and flammability is desired the liquid vehicle is water. Generally, an aqueous or aqueous-organic may avoid or reduce toxicity and volatility problems which may be prevalent with certain organics, and is generally compatible with many known powdered thermoset adhesive compositions resulting in an unreacted composition having an extended *Trademxrk shelf life. Water provides a nonreactive environment together with the film-forming polymer which can be used to store the powdered adhesive for extended periods of time. Moreover, water may be readily vaporised to form the thermoset encapsulating stable intermediate film.
Generally, regardless of the aqueous or organic character of the liquid vehicle, concentrations of the liquid vehicle will range from about 1 to 99 wt-%_ of the :liquid dispersion composition of the present invention, preferably From about 25 to 75 wt-% and most preferably from about 45 to ~i5 ~wt-%.
Varying the concentration of the liquid vehicle promotes differing characteristics within the composition. For instance, reducing the concentration of liquid vehicle within the composition of the present invention may increase the viscosity of the composition and may provide for a material which has a physical character somewhat like a paste or a putty. Such a character is more applicable to environments which do not require a uniform coating.
In contrast, increasing the concentration of liquid vehicle within the composition of the present invention may result in a much less viscous composition. Such ~i formulation allows for the application of a thinner adhesive coat.
However, higher liquid vehicle concentrations may result in a settling of the thermoset powder making the composition inoperable as an adhesive dispersion. As a result, some thixotropic character is preferred within the composition in order to provide the proper level of dispersion necessary to provide an effective adhesive composition.
Dispersing' Agents Optionally, the composition of the present invention may also contain a dispersing agent dispersed as a element of the solid phase or dissolved or dispersed as an element of the liquid phase. The dispersing agent functions to efficiently disperse the powdered thermoset S
WO 94/16027 ~ PCT/US93104679 composition of the present invention when the film-forming agent alone is not adequate to keep the powdered thermoset dispersed within the solvent. The dispersing agent may also assist in forming the stable intermediate film used to hold the powdered thermoset on the surface of application prior to curing. Dispersing agents may also be used to lower surface tension and modify rheology within the system providing a thermoset composition which has a higher degree of wettability once applied to the intended surface.
Dispersing agents which can be used in the composition of the present invention generally include any physical or electrical dispersant which is not deleterious to the stability or curing ability of the thermoset. The dispersing agents preferably does not affect the chemical stability of the powdered thermoset adhesive by reducing shelf life either in the liquid state or in the solid film state prior to cure but after the composition is applied. To this end, the dispersants used in the composition of- the present invention may either be retained in the film once formed or vaporized upon evaporation of the liquid vehicle from the composition or upon curing of the powdered thermoset.
Solid and liquid dispersing agents which are exemplary of those useful in the present invention include those film-forming agents having a dispersing character disclosed as useful in the liquid phase of the present composition. Also useful as dispersants in the present invention are compounds such as complex phosphates such as sodium hexametaphosphate, sodium tetraphosphate, sodium tripolyphosphate, and tetrasodium pyrophosphate; colloidal compositions such as casein, soybean protein; cellulosic compositions such as carboxymethyl cellulose, carboxymethyl starch, and hydroxyethyl starch; silicates, such as sodium orthosilicate, sodium sesquasilicate, sodium 2 ~ 5 2 7 '~ 6 PCT/US93104679 methylsilicate, and sodium disilicate; various surface active agents including nonionic surfactants such as the condensation products of alkanols or ethylene oxide and the condensation products of fatty acids and ethylene oxide, anionic surfactants such as the alkali metal salts of alkyl or alkyl aryl sulfonic acid, and cationic surfactants such as alkyl and alkyl aryl quaternary ammonium salts; as well as miscellaneous other compositions such as polyacrylate polymers composed of monomers such as methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate or ethyl hexyl acrylate.
In the liquid state, prior to application of the composition of the present invention, the concentration of dispersant within the present invention may generally vary from 0 wt-$ to 5 wt-~, preferably from 0.5 to 4 wt-~ and most preferably from 1 to 3 wt-~.
Generally, increasing the concentration of dispersant within the composition of the present invention tends to decrease the adhesive effect of the powdered thermoset. Accordingly, a dispersant may be used to regulate or reduce the bonding ability of the powdered thermoset adhesive. In sharp contrast, reducing the concentration of the dispersant may also result in a settling out of the thermoset powder in instances where the film-forming composition does not provide an adequate dispersing effect.
Concentration Ranges in Liquid Composition CONSTITUENT USEFUL WORKING PREFERRED
Thermoset 5-95 wt-% 20-80 wt-% 40-60 wt-Curing Agent 0.1-50 wt-% 1-30 wt-% 5-25 wt-%
(when present) Film-Forming 1-99 wt-% 2-50 wt-% 4-7 wt-%
Polymer Liquid Vehicle 1-99 wt-% 25-75 wt-% 45-55 wt-%
Dispersing Agent 0-5 wt-% 0.5-4 wt-% 1-3 wt-%
Particle Size 1-5E.sm 1-5,um 1-SE.sm Applications The liquid thermoset dispersion of the present invention may be incorporated into any number of products useful in a variety of applications.
The liquid thermoset dispersion of the present invention can easily be applied onto almost any surface. The liquid dispersion of the present invention may be cast into or onto an unidirectional, woven, or nonwoven carrier for a later application to a substrate or in the formation of a composite laminate. At the point of application the solvent may be flashed off or dried from the composition. If the surface is a unidirectional, woven or nonwoven carrier a film adhesion impregnate is formed. Generally, tack, drape or the ability to conform a material to a specific surface, and adhesion can be varied as desired by varying the concentration of film-forming agent, and liquid vehicle.
Multiple layers or different or similar materials can be applied to achieve desired characteristics. The unique advantage of this type of film adhesive or impregnated composition is the room temperature stability of the composition which does not require refrigeration of the material, specifically, once deposited on or in the carrier the powdered thermoset remains reactive and storage stable for extended periods of time.
Additionally, the liquid thermoset dispersion may be used as a film adhesive. In this case, the liquid dispersion may be cast onto a release liner where the intermediate film is formed. At a later time the film adhesive is applied to the intended substrate and the release liner removed. Furthermore, the liquid dispersion may be cast into or onto a unidirectional, woven, or nonwoven carrier and then combined with a release liner. In application the composite complete with the release liner is applied onto a substrate and the release liner is~then removed from the composite system.
The adhesive composition of the present invention can be loaded into or onto a woven or nonwoven carrier which could be used by itself or in a multiple layer composite system for the fabrication of a rigid composite laminate. Carrier systems commonly used in the formation of a composite include but are not limited to nonwoven carriers such as glass or polyester mats. Unidirectional or woven carriers include but are not limited to carbon, ceramic, thermoplastic, aramide, natural clothing fibers such as wool or cotton, synthetic clothing fibers, glass fibers and hybrids thereof .
The systems may be used in any number of applications by providing an adhesive with or without a carrier as well as including any number of additives in the adhesive composition. For instance, these systems could be used to replace sewing by heat sealing fabrics, the unused thermoset being washed out after the fusing processes are completed. This composition may be used to precoat metal against corrosion by forming the intermediate thermoset film on a substrate and then structurally bonding additional substrates to the ' surface of application by heat activating and curing the thermoset.
The easy application of the composition of the present invention allows the adhesive to be used as a primer for application to surfaces having a lower affinity for accepting a continuous adhesive layer. Intumescents or flame retardants may be used in the adhesive composition of the present invention which once applied may additionally function to protect the substrates carrying the adhesive layer.
Additionally, hydrophobic particulate elements may .be included within the composition of the present invention to define a resulting bond which is highly water resistant. These applications are only representative of the number of uses for the composition of the present invention.
Working Examples The Working Examples of the present invention were formulated first as solid phase premixes comprising dry thermoset compositions additionally containing curing agents, preservatives, defoamers, and fillers among other agents. The premixes were then used in the formulation of the two phase dispersed liquid systems of the present invention.
Premixes An initial step in preparing the thermoset adhesive compositions of the present invention was the preparation of dry powdered thermoset adhesive premix compositions. Premix compositions 1-9 were prepared by dry mixing the various elements listed under each formulation. Once the dry mixing was completed the compositions were melted and then screw extruded and cast into a uniform sheet. Once solidified, the premix compositions were pulverized into a fine powder. The premix compositions were either taken from production runs of 295.6 to 454.8 Kg (650 to 1,000 pounds) each or taken from lab batches which were made 1,000 grams at a time.
a~, a:
-H.3~1 1 WO 94/16027 , PCTIUS93I04679 Ingredient Parts By Weight RUCOTE*HBF (Aliphatic-urethane 80.3213 epoxy reaction product of unblocked isopherone diisocyanate-E-caprolactone monomer commercially available from Ruco Polymer Corporation) 2 Methyl Imidazole 17.6707 RESIFLOW*P-67 (acrylate/silicon ~ 1.2048 dioxide compound commercially available from Estron Chemical, Inc.) Benzoin 0.8032 Ingredient Parts By Weight ARAKOTE~3010 (carboxylated 90.9091 saturated polyester resin commercially available from Ciba-Geigy Corporation) triglycidyl isocyanurate 6.8426 RESIFLOW P-67 (acrylate~silicon 1.4663 dioxide compound commercially available from Estron Chemical, Inc.) Benzoin 0.7820 *Trademark t.
WO 94/16027 ~ PCTIUS93/04679 Ingredient Parts By Weight Araldite GT 7013 (bisphenol 58.6262 A-epichlorohydrin commercially available from Ciba-Geigy Corporation ARAKOTE 3001 (carboxylated saturate 37.9839 polyester resin commercially available from Ciba-Geigy Corporation) RESIFLOW P-67 (acrylate~silicon 1.6910 dioxide compound commercially available from Estron Chemicals, Inc.) Benzoin ~ 0.9813 XB-3126 (curing accelerator 0.7136 commercially available from Ciba-Geigy) Ingredient Parts By Weight Araldite GT 7013 (Bisphenol A- 93.3707 Epichlorohydin commercially available from Ciba-Geigy Corporation) Orthotolylbiguanide 1.8553 Benzoin 0.8735 RESIFLOW P-67 (acrylate~silicon 1.4006 dioxide compound commercially available from Estron Chemicals, Inc.) t...a~' WO 94/16027 ~ PCTlUS93104679 ._ Ingredient Parts By Weight Araldite GT 7013 (Bisphenol A- 97.9132 Epichlorohydrin commercially available from Ciba-Geigy Corporation) 2 methylimidazole 0.5877 RESIFLOW P-67 (acrylate/silicon 1.4691 dioxide compound commercially available from Estron Chemicals, Inc.) Ingredient Parts By Weight Araldite GT 7013 (bisphenol A- 94.1620 epichlorohydrin commercially available from Ciba-Geigy Corporation) 2-methylimidazole 0.1883 dicyandiamide 4.2373 RESIFLOW P-67 (acrylate/silicon ~ 1.4124 dioxide compound commercially available from Estron Chemicals, Inc.) Ingredient Parts By Weight Araldite GT 7013 (bisphenol 85.7633 A-epichlorohydrin commercially available from Ciba-Geigy Corporation) 3,3,4,4-Benzophenone 11.14192 Tetracarboxylic Dianhydride RESIFLOW P-67 (acrylate/silicon 1.2865 dioxide compound commercially available from Estron Chemical, Inc.) Benzoin ' 0.6861 OCTAFLOW*ST70 (stannous 1.1149 octoate/amorphous silica catalyst commercially available from Estron Chemical, Inc.) .- *Trademark ~c _24 Ingredient _ Parts by Weight Aralidite GT 7013 (bisphenol 72.8332 A-epichlorohydrin commercially available from Ciba-Geigy Corporation) DEH 84 (phenolic curing . 25.4916 commercially available from Dow Chemical Company) RESIFLOW P-67 (acrylat:e/silicon - 1.0925 dioxide compound commercially available from Estron Chemicals, Inc.) Benzoin 0.5827 Ingredient Parts by Weight Shell*2002 60.1400 (bisphenol A-epichlorohydrin commercially available from Shell Chemical Company) Dicyandiamide 1.4700 Epon P101 Curing Agent (amine 0.6300 condensate of an epoxy resin commercially available from Shell Oil Company) RESIFLOW P-67 (acrylate/silicon 0.8700 dioxide compound commercially available from Estron Chemical, Inc.) Pigments (titanium dioxide and 30.0030 carbozole violet) Barium Sulfate 5.8870 1 Tetramethyl decynediol 1.0000 Storage Stability The solid phase premix formulations were thEm formulated into aqueous dispersion compositions generally comprising parts powdered premix, 50.5 parts water as a liquidvehicle, parts of a vinyl acrylic latex binder composition (available from Union Oil Company as 76 Res 661), and 1.5 parts of a magnesium *Trademark WO 94!16027 PCT/US93104679 aluminum silicate thixotrope and defoamer comprising a blend of emulsifiable mineral oils, silica derivatives and esters (available from Drew Chemical Company as surfactant Y-250). The resulting compositions were then 5 subjected to stability testing at room temperature (approximately 25" C.) over a period of 100 days.
TABLE I
WORKING EXAMPLE MATERIAL STABILITY AT ROOM
TEMPERATURE
10 Aqueous Consistency 24 Hours 10 Days 100 Days 1 Ok - low Ok - low Ok 15 (Premix 4) visc. visc.
2 Ok - low Ok - low Ok (Premix 2) visc. visc.
20 3 Ok - law Ok - low Ok (Premix 1) visc. visc.
Field of the Invention The invention generally relates to liquid, film-forming, thermosetting adhesive compositions. More specifically, the invention relates to adhesive compositions that can form an adhesive film which cures to a rigid bond.
Background of the Invention Thermoset compositions are well-known within the coating, adhesive, composite, and plastics industry.
Recently, powdered thermosets have become desirable due to their long-term storage stability and ease of handling. However, difficult problems arise when applying powdered compositions in various applications.
For instance, in applications where the powder is applied directly to a substrate, the substrate must be held stationary until the powdered thermoset is cured.
Exposure of the powder-laden substrate to movement, vibration, air flow or other environmental stresses may result in the removal of the powdered.thermoset from the substrate. Moreover, simply applying the powdered thermoset from a solvent such as water or ethanol often does not provide the means necessary to maintain the powder on the intended surface as these solvents may evaporate leaving the powdered thermoset free to fall from the intended surface.
Certain solvents may not allow for the long term storage of the adhesive composition in the liquid state.
Also, once the thermoset composition is applied onto or into a carrier to form a preimpregnated composite or deposited film, the system may require refrigeration to ensure that the composite will remain reactive and capable of curing once applied to the desired application. In fact, even when refrigerated the shelf life of certain composite materials may often be measured in terms of days or weeks instead of months.
Furthermore, certain methods of applying powders such as electrostatic applications are limited by factors such as the particle size of the powdered thermoset composition or the geometry of the area of application. These methods may not allow for the most uniform application of particles into narrow or tight areas due to electrical forces created by the surfaces of application. Overall, present methods of applying powdered thermoset compositions do not accurately control particle concentration over the surface of application, or the size of the particle domaine for each individual particle. As a result, present compositions and processes of application may result in a bond having variable uniformity and strength.
Accordingly, there is a need for a powdered thermoset composition which has extended stability at room temperature and preferably avoids stability and toxicity problems as well as providing for a method of application which results in a bond having a higher degree of uniform strength than those found in the prior art.
Summary of the Invention The present invention comprises a liquid adhesive dispersion which can cure to a thermoset bond, comprising an effective amount of film forming agent; and comprising in solid phase: an effective amount of a powdered thermosetting resin or composition having a particle size of 1 to 5 microns;
and in a liquid phase: a liquid vehicle; wherein said dispersion remains storage stable at ambient temperatures, and after application, said dispersion forms a physically stable intermediate film.
Preferably the thermosetting resin or composition is selected from the group of polymeric material consisting of an epoxy, a polyurethane, a polyester, a bis-maleimide, an acrylic, mixtures thereof and hybrids thereof.
Preferably the film forming agent comprises a theromplastic polymer composed of one or more monomers selected from the group consisting of vinyl acetate, ethylene, - 2a -acrylic acid, methacrylic acid, crotonic acid, itaconic acid, esters of acrylic acid, esters of methacrylic acid, stylene, butadiene, vinyl chloride, vinyllidene chloride, isoprene, chlorprene, polyvinyl alcohol, and malefic anhydride.
Preferably the film-forming agent comprises a polymer selected from the group consisting of cellulose polymers, ether cellulose polymers, derivatized cellulosic and ether cellulosic polymers, starch, starch grafted copolymers, guar gum, karaya gum, and dextrine.
Preferably the dispersion comprises a dispersant selected from the group consisting of silicates, polyphosphate salts, colloidal proteins, surfactants, cellulosic polymers, starch compositions and fatty acid soups.
A further aspect of the present invention is a method of using this liquid adhesive dispersion comprising the steps of applying the liquid adhesive dispersion composition to a substrate and forming a physically stable intermediate film capable of curing to a thermoset bond. Optionally the method may include forming a workpiece by placing a second substrate onto said intermediate film and curing tha thermosetting resin or composition contained within said intermediate film to create an adhesive bond.
The method may additionally comprising the steps of:-placing a plurality of said thermosetting film laden carriers together in series; and heat curing said thermosetting f~.lm laden carrier to produce a composite laminate structure.
An additional aspect of the invention. is an article of manufacture or a workpiece comprising a substrate coated with a physically stable adhesive dispersion which can cure to a thermoset bond, the liquid adhesive disper3ion comprising an effective amount of a film farming agent; in a solid phase: an effective amount of a thermosetting resin or composition having a particle size of 1-5 microns; and in a liquid. phase: a liquid vehicle; wherein said film dispersion remains storage stable at ambient temperatures and after application said dispersion forms a physically stable intermediate phase. The article may optionally include a second substrate or a series of substrates to forth a composite matrix.
Prior to deposition, the dispersion composition of the present invention is storage stable. storage stability in accordance with the present invention means that the level of particle separation or the degree of particle dispersion present after storage of the dispersion for the desired period of~~time remains substantially constant and will. not prevent the formation ~of an effective bond. Moreover, the dispersion composition of the present invention remains substantially unreacted and the solid phase remains partially, if not wholly, undissolved in the solvsnt over the intended storage period.
After deposition on a substrate but prior to curing, the composition of the present invention forms an intermediate film. The intermediate film results from the evaporation of the liquid vehicle from the composition which, in turn, tends to congeal the film-forming polymer composition. The particulate thermoset adhesive becomes cast within the resulting film.
. .r ~i . -3$-Prior to curing, the film formed by .the present composition provides a high degree of physical stability holding the powdered thermoset material on thQ surface where it was deposited. This stabilizing character is effective against mechan~.cal stresses which arise in the environment of use such as vibration, water or air flow, horizontal or inclined movement, and prolonged exposure of the adhesive to ambient atmospheric conditions among other factors.
Upon curing, the resulting film may become an integral element of the crosslinked bond or the film-forming polymer may be fugitive (i.e. may leave or be removed from the bond site).
Brief Description of the Figure Figure 1 is a graphical depiction of lap shear strengths plotted against compositional particle size.
Detailed Description of the Preferred Embodiment The composition of the present invention comprises a dispersion having at least two phases containing a thermosetting composition, a film-forming polymer, and a liquid vehicle. The first phase comprises a solid powdered thermosetting composition and may additionally comprise any of a variety of curing agents, fillers, or added functional elements as needed. The second phase of the present composition is a liquid vehicle, a film-forming agents being provided in the liquid or solid phase. While the film-forming polymer has been preferably included in the liquid phase it should be understood that the film-forming agents may be dissolved in the liquid vehicle or, alternatively, dispersed in the liquid vehicle as either a liquid a solid. The liquid vehicle may be aqueous, organic in nature, or a combination thereof. Optionally, as desired, the liquid phase of the present composition may also comprise dispersing agents, thixotropes, wetting agents, or any other variety or constituents depending on the intended application.
Solid Phase The first phase of the present invention comprises a powdered solid composition. The solid powdered phase, in turn, comprises at least the powdered thermosetting resin and any needed curing agent in each discrete particle.
Optionally, the solid phase may also comprise fillers or the functional material, such as, conductive particles depending on the intended application.
Thermosetting Composition The thermosetting composition functions to promote adhesion to the substrate and to form a cohesively stable bonding mass after curing. The thermoset composition also functions together with the film-forming phase of the present invention as a carrier for any particulate substance included in the composition such as, for example fillers, electrically conductive particle or constituents which may add flexibility, high temperature resistance or any number of other pre-cured physical characteristics to the liquid adhesive once the film is formed.
Thermosetting coating powders, with some exceptions, are based on resins that are cured by addition reactions rather than condensation reactions. Thermosets are synthetic resins which solidify or set upon heating and cannot be remelted.
Generally, thermosetting compositions useful in the present composition are those thermosetting compositions which can be powdered and which remain stable once combined with the chosen film-forming polymer and solvent in the liquid pre-application state.
In sharp contrast, prior art compositions using thermoset powders having particle sizes in excess of 150 microns may fail to effectively deposit onto or into the intended surface especially when applied by methods such as electrostatic deposition.
The thermoset composition useful in the present invention are partially or wholly insoluble in the liquid vehicle comprising a solid phase within the dispersion composition. Thermosetting compositions useful in the present invention are also those which provide chemical and physical storage stability upon film deposition given evaporation of the liquid vehicle under elevated heat and prolonged stability over time in the intermediate film state.
Generally, any well known thermosetting composition can be used in the present invention. Thermosetting compositions useful in the present invention include those selected from the group of polymeric materials consisting of an epoxy, a polyurethane, a polyester, a bis-maleimide, an acrylic, mixtures thereof and hybrides thereof among a large number of other compositions. Also useful in the present invention are bis-maleimides such as the partial reaction product of the bis maleimide of methylene dianaline with methylene dianaline.
Examplary thermosetting compositions useful in the present invention include the reaction product of orthotolybiguanide known as Casmine and commercially available from SES Chemicals Inc. and bisphenol A-epichlorohydein available from Ciba-Geigy Corporation under the commerical name Araldite* GT 7013 triglycidyl isocyanurate thermosetting compositions; bisphenol A-epichlorohydrin cured with phenolic crosslinking agents, the epoxy composition being available from Ciba-Geigy Corporation Araldite GT 7013 and the phenolic curing agent being available from Cow Chemical Company under the brand name DEH 84; aliphatic urethane thermosetting compositions such as an unblocked isophorone diisocyanate-Epcaprolactam available from Ruco Polymer Corporation under the commercial name NI2 which may be used with Rucote HBF
which is a hydroxyl terminated polyester resin also available from Ruco Chemicals; BTDA thermosetting compositions which are generally the reaction product of 3,3,4,4-benzophenone tetracarboxylic dianhydride and a disphenol A-epichlorohydrin;
hybrid thermosetting compositions which are the reaction product of a carboxylated *Trademark ..~~i~2~'~6 WO 94116027 ~ ' PCT/US93/04679 saturated polyester curing agent such as Arakote 3001 available from Ciba-Geigy Corporation and a bisphenol A-epichlorohydrin; standard bisphenol A-epichlorohydrin thermosets such as those which are cured with 2-methyl imidazole; and standard bisphenol A-epichlorohydrin thermosets which are cured with 2-methyl imidazole and dicyandiamide.
Preferably, the thermosetting composition used in the present invention are those selected from the group consisting of polymerized triglycidyl isocyanurate, aliphatic urethane thermosets, BTDA cured bisphenol A-epichlorohydrin thermosets, polyester-bisphenol A-epichlorohydrin thermoset complexes, 2-methylimidazole cured bisphenol A-epichlorohydrin thermosets, and orthotolylbiguanide cured bisphenol A-epichlorohydrin thermosets. These compositions, as can be seen in Table I, provide maximum storage stability in the liquid state when used in the preferred mode with an aqueous carrier.
Generally, the concentration of the powdered thermoset may be varied from 5 wt-~ to 95 wt-~ of the adhesive dispersion, preferably 20 wt-~ to 80 wt-~ of the adhesive dispersion and most preferably 40 wt-~ to 60 wt-~ of the adhesive dispersion. The concentration of powdered thermoset in the resulting film will range from about 30 wt-~ to 95 wt-$, preferably 60 wt-~ to 95 wt-$ and most preferably 80 wt-~ to 95 wt-$ depending on the specific application. The concentration of thermoset may range as a percentage of either the liquid composition or the resulting film outside the range as provided above depending on the application.
Increasing the concentration of the powdered thermoset will tend to increase the viscosity of the aqueous liquid composition depending on the relative particle size of the powdered thermoset used. A higher viscosity may be desirable to develop a compositional consistency of a caulk or putty which may be used as an _8_ adhesive sealing agent for any variety of applications.
Moreover, the use of an increased concentration of powdered thermoset may be desirable to promote an increased spreading or wetting of the surface of application once the thermoset adhesive is heated.
In contrast, reducing the relative concentration of the powdered thermoset within the composition of the present invention may reduce the degree of relative bonding strength in the resulting composition. Moreover, reducing the relative concentration of the powdered thermoset may potentially allow for a thinner more uniform film as deposited across the surface of application.
The present invention allows for varying the concentration of the thermoset composition within the dispersion and as a result varying the domain size of each powdered thermoset particle. The present invention also allows for the deposition of very fine particle thermoset powders of 1 to 5 microns. The ability to vary particle concentration and, in turn, particle domain size combined with the use of very fine particle size thermosets allows the resulting adhesive composition to have a higher relative adhesion than higher particle size thermosets which are applied in a less uniform manner.
The powdered thermoset may be combined with a curing agent commonly used to promote cross-linking within the powdered thermoset. Curing agents commonly known to the art include melamine such as dialkylmelamine; amides such as dicyandiamide, adipamide, and isophthalyl diamide; ureas such as ethylene thiourea or guyanylurea; azides such as thiosemicarbazide, or adipyl dihydrazide, and isophthalyl dihydrazide; azoles such as guanazole, or 3 amino-1,2,4 triazole; and anilines such as diethylaniline.
-g-The curing agents generally useful in the composition of the present invention are subject to the same stability limitations as the powdered thermoset resin. Specifically, the curing agent may be partially or wholly insoluble in the liquid vehicle. However, the curing agent must have an effective degree of chemical stability so that the required amount of cross-linking takes place at the intended point of curing. Accordingly, the curing agent may be solubilized in the liquid vehicle or remain in powder form with the powdered thermoset. Crosslinking mechanisms may be additionally retarded by intentionally including a crosslinking agent which will be solubilized within the liquid vehicle while retaining the powdered themoset in the powdered form as a separate solid phase.
When present, the curing mechanism may be a single curing agent or any combination of curing agents having a concentration between about 0.1 wt-o and 50 wt-% of the initial solid phase, preferably between about 1 wt-% and 30 wt-°s of the initial solid phase, and most preferably about 5 wt-% and 25 wt-% of the initial solid phase.
The solid phase may also contain other constituents including dispersing agents, fillers or any other element which is insoluble in the liquid phase, remains effectively dispersed in the composition and provides the intended functional characteristic to the composition.
Preferably, the solid phase of the invention will comprise a powdered composition of minimal particle size which comprises both thermoset and curing agent within each individual powdered particle. Individual particles may be formed by melt mixing and extruding thermoset and curing agents below curing temperatures.
The resulting extrudate, in the form of, for example, a rope, a sheet, etc., may then be particlized. Particle sizes range from about 5 microns to 1 micron.
As will be reflected in the working examples, and as can be seen in Figure 1, smaller particle size compositions are ._ believed to provide more uniform domains and as such result in higher lap shear strengths.
Liquid Phase The liquid phase of the present invention generally comprises the film-forming polymer, a solvent and optionally solubilized dispersing agents, thixotropes, or hardeners among other potential constituents, which.-may be wholly or partially dissolved in the liquid phase Of the~present invEmtion.
Film-Forminq Agent The function of the.film-forming agent is to carry the thermoset and deposit it on the surface. After liquid vehicle removal the film holds the powdered thermosettinq_ composition on the surface of application. Specifically, the film-forming polymer may form a liquid solution or an insolub7.e dispersion in the liquid vehicle (i.e. the film former may be a part of the dispersed solid phase or in solution as part of the liquid phase) .
Preferably, the film-forming polymer should not impair the reactivity of the powdered thermosetting composition. Once the film-forming polymer is either dispersed or dissolved, the liquid is applied through any variety of means. The liquid vehicle may be evaporated from the surface of application and the powdered thermosetting composition is retained or encapsulated on the surface by the film-forming polymer. The film-forming polymer may also be used to provide added functional character to the pre-cured or post-cured composition such as, for instance, pre- cured tack, solubil.it:y, adhesion, or wettability as well as post-cured hardness, or water-resistance.
Generally, compounds useful in the present invention are organic or inorganic film-forming agent which impart the intended character to the resulting film.
Generally, thermoplastic resins are preferred film-forming agents as they soften or melt at a given temperature, and when cooled, recover the physical and chemical properties of the original resin.
Generally, the physical and chemical properties of the original resin as well as any resulting films formed from the thermoplastic include a variable degree of plasticized flexibility, easy solubilization and emulsification in various liquid aqueous and organic vehicles, variable surface stability and stability against mechanical forces such as vibration, and horizontal or inclined movement, various degrees of stability when subjected to environmental forces such as heat, wind, or any other number of environmental forces which might impinge upon the composition within the area of use or application, various degrees of pre-application thickness or viscosity depending upon the choice of liquid vehicle.
At a minimum, any thermoplastic film-forming agent may be used which encapsulates the powdered thermosetting composition and does not adversely detract from the functioning of the thermoset once it is applied to the intended surface. Compounds and polymers which may function as film formers include plasticizers, wetting agents, tackifiers, elastomers, thixotropes, as well as coalescing agents used alone or with inert fillers .
Exemplary polymeric film-forming dispersions or solutions can be made from polymerizing one or more of the following monomers in a solvent medium, such as, vinyl acetate, ethylene, acrylic acid, methacrylic acid, crotonic acid, or itaconic acid; esters of acrylic and methacrylic acid including methyl esters, ethyl esters, butyl and 2-ethylhexyl esters; as well as styrene, butadiene, vinyl chloride, vinylidene chloride, isoprene, and chloroprene.
Synthetic polymers resulting from polymerization of many of the preceding monomers which are useful as film-forming elements of the present composition include generally, polyvinyl alcohol (with varying degrees of hydrolysis), ethylene/acrylic acid copolymers, ethylene/maleic anhydride copolymers, and styrene/maleic anhydride copolymers among others.
Naturally derivativized and naturally occurring polymers such as casein compositions, natural gum compositions including karaya gum and guar gum, cellulosic and ether cellulosic compositions, starch, protein compositions, and starch-grafted copolymers are also useful as a film-forming polymer of the present invention. Inorganic compounds such as sodium silicate may also be useful as the film-forming agent in the present invention. Those skilled in the art will realize that the preceding compounds and polymers are only exemplary of compounds and polymers which may be used as film-forming agents in the composition of the present invention and this list should not be viewed as limiting.
The concentration of the film-forming polymer used in the composition of the present invention will generally range from about 1 to 99 wt-~, preferably range from about 2 to 50 wt-$, and most preferably range from about 4 to 7 wt-~ depending on the characteristics to be imparted to the resulting film and the physical and chemical characteristic of the powdered thermoset adhesive. As a percentage of the resulting film, the film- forming polymer may again generally range from about 1 to 99 wt-~, preferably range from about 4 to 75 wt-~, and most preferably range from about 8 to 14 wt-~
again depending upon the character and quantity of powdered thermoset adhesive to be encapsulated within ~I ~~'~~'6 the film and the desired character which the film is intended to have in either the pre-cured or post-cured state.
Generally, the film-forming ability of the polymer depends on the film's ability to support the powdered thermoset. However, diminishing or increasing the concentration of film-forming agent within the composition of the present invention may limit or increase, respectively, the thermoplastic character of the film former and the ability of the film-former to retain the powdered thermoset on the surface of application. Moreover, pre-cure and post-cure film characteristics may be increased or diminished by the use of, for instance, thixotropes which can be used to affect changes in the viscosity and flowability of the composition of the present invention.
Liauid Vehicle The liquid phase of the present composition also principally contains a liquid vehicle. The liquid vehicle facilitates transport and deposition of the adhesive used in the composition of the present invention. Use of the liquid vehicle may also allow reduction of the concentration of the film-forming component.
Generally, the liquid vehicle may be aqueous, organic or a mixture thereof. While the liquid vehicle preferably does not interact with the thermoset, the liquid vehicle may generally be used to modify the effect of the thermoset by enhancing or reducing adhesion.
Organic liquid vehicles useful in the present invention are limited to those which maintain the dispersed character of the thermoset within the liquid phase of the present invention without reacting and destabilizing either the thermoset or any curing agent which may be present in the system. Organic liquid vehicles which function accordingly may partially or wholly displace any aqueous solvent used in the composition.
Organic liquid vehicles useful in the present invention include but~are not limited to low molecular weight (600-650 m.w.) fatty acid polymers including dimer and trimer acid compositions resulting from the polymerization of long chain (CV24-C40) aliphatic dibasic acids with long chain (C50-C60) aliphatic tribasic acids polymers such as those fatty acid polymers available from Emery under_,the Empol brand name; liquid curing agents including dicyanamide; liquid epoxy compositions including liquid bisphenol A-epichlorohydrin low molecular weight epoxies such as the Epon* brand epoxies available from Shell Chemical Company; mineral solvents; naptha; and liquid polyamides such as N-ethyl 0. P-toluene sulfanamide available from Monsanto Corporation as Saniticizer 8.
Alternatively, the liquid vehicle may be aqueous or an aqueous-organic solvent mixture. Such a liquid vehicle is useful in minimizing environmental and safety hazards often prevalent with the use of volatile organic. Also, a mixture of aqueous and organic liquid vehicles may be useful in maintaining, for example, a curing agent and resin in separate phases and thus increasing the chemical stability and storage life of the present composition prior to application. Such a system will comprise a liquid vehicle or combination of liquid vehicles which may completely solubilize the curing agent yet retain the thermoset resin in solid undissolved form.
Preferably, if minimal toxicity and flammability is desired the liquid vehicle is water. Generally, an aqueous or aqueous-organic may avoid or reduce toxicity and volatility problems which may be prevalent with certain organics, and is generally compatible with many known powdered thermoset adhesive compositions resulting in an unreacted composition having an extended *Trademxrk shelf life. Water provides a nonreactive environment together with the film-forming polymer which can be used to store the powdered adhesive for extended periods of time. Moreover, water may be readily vaporised to form the thermoset encapsulating stable intermediate film.
Generally, regardless of the aqueous or organic character of the liquid vehicle, concentrations of the liquid vehicle will range from about 1 to 99 wt-%_ of the :liquid dispersion composition of the present invention, preferably From about 25 to 75 wt-% and most preferably from about 45 to ~i5 ~wt-%.
Varying the concentration of the liquid vehicle promotes differing characteristics within the composition. For instance, reducing the concentration of liquid vehicle within the composition of the present invention may increase the viscosity of the composition and may provide for a material which has a physical character somewhat like a paste or a putty. Such a character is more applicable to environments which do not require a uniform coating.
In contrast, increasing the concentration of liquid vehicle within the composition of the present invention may result in a much less viscous composition. Such ~i formulation allows for the application of a thinner adhesive coat.
However, higher liquid vehicle concentrations may result in a settling of the thermoset powder making the composition inoperable as an adhesive dispersion. As a result, some thixotropic character is preferred within the composition in order to provide the proper level of dispersion necessary to provide an effective adhesive composition.
Dispersing' Agents Optionally, the composition of the present invention may also contain a dispersing agent dispersed as a element of the solid phase or dissolved or dispersed as an element of the liquid phase. The dispersing agent functions to efficiently disperse the powdered thermoset S
WO 94/16027 ~ PCT/US93104679 composition of the present invention when the film-forming agent alone is not adequate to keep the powdered thermoset dispersed within the solvent. The dispersing agent may also assist in forming the stable intermediate film used to hold the powdered thermoset on the surface of application prior to curing. Dispersing agents may also be used to lower surface tension and modify rheology within the system providing a thermoset composition which has a higher degree of wettability once applied to the intended surface.
Dispersing agents which can be used in the composition of the present invention generally include any physical or electrical dispersant which is not deleterious to the stability or curing ability of the thermoset. The dispersing agents preferably does not affect the chemical stability of the powdered thermoset adhesive by reducing shelf life either in the liquid state or in the solid film state prior to cure but after the composition is applied. To this end, the dispersants used in the composition of- the present invention may either be retained in the film once formed or vaporized upon evaporation of the liquid vehicle from the composition or upon curing of the powdered thermoset.
Solid and liquid dispersing agents which are exemplary of those useful in the present invention include those film-forming agents having a dispersing character disclosed as useful in the liquid phase of the present composition. Also useful as dispersants in the present invention are compounds such as complex phosphates such as sodium hexametaphosphate, sodium tetraphosphate, sodium tripolyphosphate, and tetrasodium pyrophosphate; colloidal compositions such as casein, soybean protein; cellulosic compositions such as carboxymethyl cellulose, carboxymethyl starch, and hydroxyethyl starch; silicates, such as sodium orthosilicate, sodium sesquasilicate, sodium 2 ~ 5 2 7 '~ 6 PCT/US93104679 methylsilicate, and sodium disilicate; various surface active agents including nonionic surfactants such as the condensation products of alkanols or ethylene oxide and the condensation products of fatty acids and ethylene oxide, anionic surfactants such as the alkali metal salts of alkyl or alkyl aryl sulfonic acid, and cationic surfactants such as alkyl and alkyl aryl quaternary ammonium salts; as well as miscellaneous other compositions such as polyacrylate polymers composed of monomers such as methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate or ethyl hexyl acrylate.
In the liquid state, prior to application of the composition of the present invention, the concentration of dispersant within the present invention may generally vary from 0 wt-$ to 5 wt-~, preferably from 0.5 to 4 wt-~ and most preferably from 1 to 3 wt-~.
Generally, increasing the concentration of dispersant within the composition of the present invention tends to decrease the adhesive effect of the powdered thermoset. Accordingly, a dispersant may be used to regulate or reduce the bonding ability of the powdered thermoset adhesive. In sharp contrast, reducing the concentration of the dispersant may also result in a settling out of the thermoset powder in instances where the film-forming composition does not provide an adequate dispersing effect.
Concentration Ranges in Liquid Composition CONSTITUENT USEFUL WORKING PREFERRED
Thermoset 5-95 wt-% 20-80 wt-% 40-60 wt-Curing Agent 0.1-50 wt-% 1-30 wt-% 5-25 wt-%
(when present) Film-Forming 1-99 wt-% 2-50 wt-% 4-7 wt-%
Polymer Liquid Vehicle 1-99 wt-% 25-75 wt-% 45-55 wt-%
Dispersing Agent 0-5 wt-% 0.5-4 wt-% 1-3 wt-%
Particle Size 1-5E.sm 1-5,um 1-SE.sm Applications The liquid thermoset dispersion of the present invention may be incorporated into any number of products useful in a variety of applications.
The liquid thermoset dispersion of the present invention can easily be applied onto almost any surface. The liquid dispersion of the present invention may be cast into or onto an unidirectional, woven, or nonwoven carrier for a later application to a substrate or in the formation of a composite laminate. At the point of application the solvent may be flashed off or dried from the composition. If the surface is a unidirectional, woven or nonwoven carrier a film adhesion impregnate is formed. Generally, tack, drape or the ability to conform a material to a specific surface, and adhesion can be varied as desired by varying the concentration of film-forming agent, and liquid vehicle.
Multiple layers or different or similar materials can be applied to achieve desired characteristics. The unique advantage of this type of film adhesive or impregnated composition is the room temperature stability of the composition which does not require refrigeration of the material, specifically, once deposited on or in the carrier the powdered thermoset remains reactive and storage stable for extended periods of time.
Additionally, the liquid thermoset dispersion may be used as a film adhesive. In this case, the liquid dispersion may be cast onto a release liner where the intermediate film is formed. At a later time the film adhesive is applied to the intended substrate and the release liner removed. Furthermore, the liquid dispersion may be cast into or onto a unidirectional, woven, or nonwoven carrier and then combined with a release liner. In application the composite complete with the release liner is applied onto a substrate and the release liner is~then removed from the composite system.
The adhesive composition of the present invention can be loaded into or onto a woven or nonwoven carrier which could be used by itself or in a multiple layer composite system for the fabrication of a rigid composite laminate. Carrier systems commonly used in the formation of a composite include but are not limited to nonwoven carriers such as glass or polyester mats. Unidirectional or woven carriers include but are not limited to carbon, ceramic, thermoplastic, aramide, natural clothing fibers such as wool or cotton, synthetic clothing fibers, glass fibers and hybrids thereof .
The systems may be used in any number of applications by providing an adhesive with or without a carrier as well as including any number of additives in the adhesive composition. For instance, these systems could be used to replace sewing by heat sealing fabrics, the unused thermoset being washed out after the fusing processes are completed. This composition may be used to precoat metal against corrosion by forming the intermediate thermoset film on a substrate and then structurally bonding additional substrates to the ' surface of application by heat activating and curing the thermoset.
The easy application of the composition of the present invention allows the adhesive to be used as a primer for application to surfaces having a lower affinity for accepting a continuous adhesive layer. Intumescents or flame retardants may be used in the adhesive composition of the present invention which once applied may additionally function to protect the substrates carrying the adhesive layer.
Additionally, hydrophobic particulate elements may .be included within the composition of the present invention to define a resulting bond which is highly water resistant. These applications are only representative of the number of uses for the composition of the present invention.
Working Examples The Working Examples of the present invention were formulated first as solid phase premixes comprising dry thermoset compositions additionally containing curing agents, preservatives, defoamers, and fillers among other agents. The premixes were then used in the formulation of the two phase dispersed liquid systems of the present invention.
Premixes An initial step in preparing the thermoset adhesive compositions of the present invention was the preparation of dry powdered thermoset adhesive premix compositions. Premix compositions 1-9 were prepared by dry mixing the various elements listed under each formulation. Once the dry mixing was completed the compositions were melted and then screw extruded and cast into a uniform sheet. Once solidified, the premix compositions were pulverized into a fine powder. The premix compositions were either taken from production runs of 295.6 to 454.8 Kg (650 to 1,000 pounds) each or taken from lab batches which were made 1,000 grams at a time.
a~, a:
-H.3~1 1 WO 94/16027 , PCTIUS93I04679 Ingredient Parts By Weight RUCOTE*HBF (Aliphatic-urethane 80.3213 epoxy reaction product of unblocked isopherone diisocyanate-E-caprolactone monomer commercially available from Ruco Polymer Corporation) 2 Methyl Imidazole 17.6707 RESIFLOW*P-67 (acrylate/silicon ~ 1.2048 dioxide compound commercially available from Estron Chemical, Inc.) Benzoin 0.8032 Ingredient Parts By Weight ARAKOTE~3010 (carboxylated 90.9091 saturated polyester resin commercially available from Ciba-Geigy Corporation) triglycidyl isocyanurate 6.8426 RESIFLOW P-67 (acrylate~silicon 1.4663 dioxide compound commercially available from Estron Chemical, Inc.) Benzoin 0.7820 *Trademark t.
WO 94/16027 ~ PCTIUS93/04679 Ingredient Parts By Weight Araldite GT 7013 (bisphenol 58.6262 A-epichlorohydrin commercially available from Ciba-Geigy Corporation ARAKOTE 3001 (carboxylated saturate 37.9839 polyester resin commercially available from Ciba-Geigy Corporation) RESIFLOW P-67 (acrylate~silicon 1.6910 dioxide compound commercially available from Estron Chemicals, Inc.) Benzoin ~ 0.9813 XB-3126 (curing accelerator 0.7136 commercially available from Ciba-Geigy) Ingredient Parts By Weight Araldite GT 7013 (Bisphenol A- 93.3707 Epichlorohydin commercially available from Ciba-Geigy Corporation) Orthotolylbiguanide 1.8553 Benzoin 0.8735 RESIFLOW P-67 (acrylate~silicon 1.4006 dioxide compound commercially available from Estron Chemicals, Inc.) t...a~' WO 94/16027 ~ PCTlUS93104679 ._ Ingredient Parts By Weight Araldite GT 7013 (Bisphenol A- 97.9132 Epichlorohydrin commercially available from Ciba-Geigy Corporation) 2 methylimidazole 0.5877 RESIFLOW P-67 (acrylate/silicon 1.4691 dioxide compound commercially available from Estron Chemicals, Inc.) Ingredient Parts By Weight Araldite GT 7013 (bisphenol A- 94.1620 epichlorohydrin commercially available from Ciba-Geigy Corporation) 2-methylimidazole 0.1883 dicyandiamide 4.2373 RESIFLOW P-67 (acrylate/silicon ~ 1.4124 dioxide compound commercially available from Estron Chemicals, Inc.) Ingredient Parts By Weight Araldite GT 7013 (bisphenol 85.7633 A-epichlorohydrin commercially available from Ciba-Geigy Corporation) 3,3,4,4-Benzophenone 11.14192 Tetracarboxylic Dianhydride RESIFLOW P-67 (acrylate/silicon 1.2865 dioxide compound commercially available from Estron Chemical, Inc.) Benzoin ' 0.6861 OCTAFLOW*ST70 (stannous 1.1149 octoate/amorphous silica catalyst commercially available from Estron Chemical, Inc.) .- *Trademark ~c _24 Ingredient _ Parts by Weight Aralidite GT 7013 (bisphenol 72.8332 A-epichlorohydrin commercially available from Ciba-Geigy Corporation) DEH 84 (phenolic curing . 25.4916 commercially available from Dow Chemical Company) RESIFLOW P-67 (acrylat:e/silicon - 1.0925 dioxide compound commercially available from Estron Chemicals, Inc.) Benzoin 0.5827 Ingredient Parts by Weight Shell*2002 60.1400 (bisphenol A-epichlorohydrin commercially available from Shell Chemical Company) Dicyandiamide 1.4700 Epon P101 Curing Agent (amine 0.6300 condensate of an epoxy resin commercially available from Shell Oil Company) RESIFLOW P-67 (acrylate/silicon 0.8700 dioxide compound commercially available from Estron Chemical, Inc.) Pigments (titanium dioxide and 30.0030 carbozole violet) Barium Sulfate 5.8870 1 Tetramethyl decynediol 1.0000 Storage Stability The solid phase premix formulations were thEm formulated into aqueous dispersion compositions generally comprising parts powdered premix, 50.5 parts water as a liquidvehicle, parts of a vinyl acrylic latex binder composition (available from Union Oil Company as 76 Res 661), and 1.5 parts of a magnesium *Trademark WO 94!16027 PCT/US93104679 aluminum silicate thixotrope and defoamer comprising a blend of emulsifiable mineral oils, silica derivatives and esters (available from Drew Chemical Company as surfactant Y-250). The resulting compositions were then 5 subjected to stability testing at room temperature (approximately 25" C.) over a period of 100 days.
TABLE I
WORKING EXAMPLE MATERIAL STABILITY AT ROOM
TEMPERATURE
10 Aqueous Consistency 24 Hours 10 Days 100 Days 1 Ok - low Ok - low Ok 15 (Premix 4) visc. visc.
2 Ok - low Ok - low Ok (Premix 2) visc. visc.
20 3 Ok - law Ok - low Ok (Premix 1) visc. visc.
4 Ok - low Ok - low Ok (Premix 3) visc. visc.
5 Very Ok - low Ok (Premix 5) thix. visc.
As can be seen, the compositions reported in Table I
had a stability of at least to 100 days. While other premix formulations did not provide this degree of storage stability, these dispersions did provide compositions useful for applications which allowed for, or required, more immediate deposition on the intended surface.
Another set of Working Examples, Numbers 6-22 were then prepared using the premix formulations previously prepared. Generally, the Working Examples were prepared in three steps. First, a liquid vehicle, was introduced into a mixing vessel with an appropriate amount of surfactant. Once the surfactant was~dispersed in the liquid vehicle a dispersant and the intended premix formulation was added to the mixture. Once the premix was fully dispersed, an additional amount of thixotrope and liquid vehicle was added to the mix and stirred until homogeneous.
Ingredient Parts By Weight HZO 49.50 Defoamer (Blend of .50 emulsifiable mineral oils, 10silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 4 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) 20Magnesium Aluminum 1.00 Silicate (5~ w/v) Ingredient Parts By Weight g2p 4 9 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 2 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~ w/v) ~15~~76 Ingredient Parts By Weight H20 4 9 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 8 4.3.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~ w/v) Ingredient Parts By Weight H20 4 9 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 1 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~k w/v) WO 94/16027 ~ PCT/US93104679 Ingredient Parts By Weight H20 4 9 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 3 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~ w/v) Ingredient Parts By Weight H20 4 9 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 5 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5$ w/v) 21 ~ ~'~'~ 6 Ingredient Parts By Weight H20 4 9 . 5 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 6 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~ w/v) Incrredient Parts By Weight H20 5 0 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 6 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~ w/v) Ingredient Parts By Weight 5 Hz0 51.00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters 10 available from Drew Chemical Company as blend Y-250) Pxe-Mix 4 43.00 15 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 20 Silicate (5~k w/v) Ingredient Parts By Weight HZO 51. 00 30 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 2 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5$ w/v) 21 ~ 2'~'~ ~
WO 94!16027 PCT/US93I04679 Inctredient Parts By Weight H20 51.00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 8 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) WORKING ERAMPI~E 17 Ingredient Parts By Weight Hz0 51. 00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 1 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) WO 94/16027 ~ PCT/US93104679 Ingredient Parts By Weight H20 51. 00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 7 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) Ingredient Parts By Weight H20 51. 00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 3 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) WO 94116027 ~ PCTIUS93104679 Ingredient Parts By Weight HZO 51. 0 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 5 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) .
Ingredient Parts By Weight H20 51. 00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 9 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) Ingredient Parts by Weight Hz0 51 . 00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 2 ~ 43.00 Gion Brand 5.00 acrylonitrile latex butadiene styrene terpolymer (commercially available from B. F. Goodrich) Magnesium Aluminium 0.50 Silicate (5o w/v) Cured Strength In working Examples 23-26 a slightly different mixing process was used. First a surfactant was dispersed in a liquid vehicle after which the powdered adhesive premix and a dispensing agent were mixed slowly into the composition. The strength of these compositions was then tested and is shown in Table II.
Ingredient Parts by Weight 4 5 . 0 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) ' Pre-mix 4 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.
s' ~.
Ingredient Parts By Weight 5 H20 4 5 . 0 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters 10 available from Drew Chemical Company as blend Y-250) Pre-Mix 2 43.00 15 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Ingredient Parts By Weight H20 45.00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical 30 Company as blend Y-250) Pre-Mix 8 43.00 76 RES 661 (vinyl 5.00 35 acrylic latex copolymer available from Union Oil Corp.) Ingredient Parts By Weight H20 45.00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 2 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Cured Bond Strength The lap sheer strength and T-Peel strength Working Examples 23 through 26 was then compared with the following results provided in Table II.
TABLE II
Lap Sheer Working Example Strength T-Peel Strength kg-force/cm' N/m (lb/in') (lb~/inch width init./open 2 days) 23 169.7~ 19.3 75.9/116.7 (2413.7 ~ 275) (5.2/8.0) 24 (cohesive) 272.7 ~ 24.8 157.6/106.5 (3878.4 ~ 352.8) (10.8/7.3) 25 (adhesive) 267.9 ~ 6.9 131.3/102.1 (3810.7 ~ 96.5) (9.0/7.0) 26 (cohesive) 303.9 ~ 29.5 160.5/68.6 (4322.2 ~ 419.4) (11.0/4.7) As can be seen from Table II Working Examples 23-26 showed substantial lap sheer strength and T-Peel strength both initially and after two days. Working Examples 24 and 26 provided a cohesive bond where upon failure, the bond was split evenly down the middle leaving adhesive material on both substrates. Working Example 25 provided an adhesive bond leaving areas on both substrates where the adhesive material was completely stripped from the surface of application.
r Lapsheer Strength as a Function of Particle Size A tenth premix was formulated as shown below:
Material Premix 10 WT-Araldite GT 7013 (bisphenol A- 75.4717 epichlorohydrin available from Ciga-Geigy Corporation) P-101 Curing Agent (Amine 2.6415 Condensate of an epoxy resin -.
available from Shell Oil Company) RESIFLOW P-67 . 1.1321 (acrylate/silicon dioxide compound available from Estron Chemicals, Inc.) x Uraflow B (benzoin flow agent, 0.7517 GCA Chemical Co.) BARTEX X65 , 1 8 . 8679 Chromalloy Industrial Minerals) Pigments (Black beads) 1.1321 An eleventh premix was formulated as shown below:
Pre-Mix 11 Material Wt-Araldite GT 7013 (bisphanol A- 94.1620 epichlorohydrin available from Ciba-Geigy Corporation) 2-methylimidazole 0.1883 dicyandiamide 4.2373 RESIFLOW P-67 1.4124 (acrylate/silicon dioxide compound available from Estron Chemicals, Inc.) The premixes were then used in the thermosetting compositions shown in Table 3. In each instance, the particle size of the_powder coating used in the composite is shown in Table III.
*T~'ademark Table III
Formulations regarding micron size:
3 Micron 4.9 Micron 62 Micron 103 Micron 8% 8% 8% 8%
Carboxylated Carboxylated Carboxylated Carboxylated Acrylic Acrylic Acrylic - Acrylic Copolymer Copolymer Copolymer Copolymer 44% Premix 44% Premix 11 44% Premix 11 44% Premix 11 .4% TAMOLk850.4% TAMOL~~850 .4% TAMOL*850 ~ .4% TAMOL 850 ~
(Sodium Salt (Sodium Salt (Sodium Salt (Sodium Salt of Polymeric of Polymeric of Polymeric of Polymeric Carboxylic Carboxylic Carboxylic Carboxylic Acid Acid Acid Acid Dispersing Dispersing Dispersing Dispersing Agent; Rohm Agent; Rohm Agent; Rohm Agent; Rohm & Haas & Haas & Haas & Haas 47 . 48&H20 47 . 6 % Hz0 47 . 48 % H,0 47 . 48 % H20 .03% XANTHAN .03% XANTHAM .03% XANTHAM
GUM GUM GUM
.09% Guar Gum .09% Guar Gum .09% Guar Gum Aluminium lapshears were. wiped with methyl ethyl ketone, acid etched for ten minutes and washed in deionized water before being air dried. Lapshears were assembled with 7781 volan (registered trade mark) fiberglass cloth which was impregnated with products above. Coat weights were 28% by weight of epoxy powder. The impregnated cloth was sandwiched between the lapshears and cured for one hour at 177°C at 6.9 x 1 0'' Pa ( 350°F at 1 , 000 psi ) . Lapshears were evaluated using ASTM D1002-72.
As can be seen in Figure One, 3 micron and 4,9 micron particle size compositions were compared to 62 and 103 micron formulations to determine lapshear strength. The difference in strength with smaller particle size compositions was notable.
The above discussion, Examples and data illustrate our current understanding of the invention. However, since many variations of the invention can be made without *Trademark departing from the scope of the invention, the invention resides wholly in the claims hereinafter appended.
'r~ ~'
As can be seen, the compositions reported in Table I
had a stability of at least to 100 days. While other premix formulations did not provide this degree of storage stability, these dispersions did provide compositions useful for applications which allowed for, or required, more immediate deposition on the intended surface.
Another set of Working Examples, Numbers 6-22 were then prepared using the premix formulations previously prepared. Generally, the Working Examples were prepared in three steps. First, a liquid vehicle, was introduced into a mixing vessel with an appropriate amount of surfactant. Once the surfactant was~dispersed in the liquid vehicle a dispersant and the intended premix formulation was added to the mixture. Once the premix was fully dispersed, an additional amount of thixotrope and liquid vehicle was added to the mix and stirred until homogeneous.
Ingredient Parts By Weight HZO 49.50 Defoamer (Blend of .50 emulsifiable mineral oils, 10silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 4 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) 20Magnesium Aluminum 1.00 Silicate (5~ w/v) Ingredient Parts By Weight g2p 4 9 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 2 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~ w/v) ~15~~76 Ingredient Parts By Weight H20 4 9 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 8 4.3.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~ w/v) Ingredient Parts By Weight H20 4 9 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 1 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~k w/v) WO 94/16027 ~ PCT/US93104679 Ingredient Parts By Weight H20 4 9 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 3 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~ w/v) Ingredient Parts By Weight H20 4 9 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 5 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5$ w/v) 21 ~ ~'~'~ 6 Ingredient Parts By Weight H20 4 9 . 5 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 6 43.00 76 RES 661 (vinyl 6.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~ w/v) Incrredient Parts By Weight H20 5 0 . 5 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 6 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 1.00 Silicate (5~ w/v) Ingredient Parts By Weight 5 Hz0 51.00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters 10 available from Drew Chemical Company as blend Y-250) Pxe-Mix 4 43.00 15 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 20 Silicate (5~k w/v) Ingredient Parts By Weight HZO 51. 00 30 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 2 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5$ w/v) 21 ~ 2'~'~ ~
WO 94!16027 PCT/US93I04679 Inctredient Parts By Weight H20 51.00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 8 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) WORKING ERAMPI~E 17 Ingredient Parts By Weight Hz0 51. 00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 1 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) WO 94/16027 ~ PCT/US93104679 Ingredient Parts By Weight H20 51. 00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 7 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) Ingredient Parts By Weight H20 51. 00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 3 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) WO 94116027 ~ PCTIUS93104679 Ingredient Parts By Weight HZO 51. 0 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 5 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) .
Ingredient Parts By Weight H20 51. 00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 9 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Magnesium Aluminum 0.50 Silicate (5~ w/v) Ingredient Parts by Weight Hz0 51 . 00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 2 ~ 43.00 Gion Brand 5.00 acrylonitrile latex butadiene styrene terpolymer (commercially available from B. F. Goodrich) Magnesium Aluminium 0.50 Silicate (5o w/v) Cured Strength In working Examples 23-26 a slightly different mixing process was used. First a surfactant was dispersed in a liquid vehicle after which the powdered adhesive premix and a dispensing agent were mixed slowly into the composition. The strength of these compositions was then tested and is shown in Table II.
Ingredient Parts by Weight 4 5 . 0 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) ' Pre-mix 4 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.
s' ~.
Ingredient Parts By Weight 5 H20 4 5 . 0 0 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters 10 available from Drew Chemical Company as blend Y-250) Pre-Mix 2 43.00 15 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Ingredient Parts By Weight H20 45.00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical 30 Company as blend Y-250) Pre-Mix 8 43.00 76 RES 661 (vinyl 5.00 35 acrylic latex copolymer available from Union Oil Corp.) Ingredient Parts By Weight H20 45.00 Defoamer (Blend of .50 emulsifiable mineral oils, silica derivatives and esters available from Drew Chemical Company as blend Y-250) Pre-Mix 2 43.00 76 RES 661 (vinyl 5.00 acrylic latex copolymer available from Union Oil Corp.) Cured Bond Strength The lap sheer strength and T-Peel strength Working Examples 23 through 26 was then compared with the following results provided in Table II.
TABLE II
Lap Sheer Working Example Strength T-Peel Strength kg-force/cm' N/m (lb/in') (lb~/inch width init./open 2 days) 23 169.7~ 19.3 75.9/116.7 (2413.7 ~ 275) (5.2/8.0) 24 (cohesive) 272.7 ~ 24.8 157.6/106.5 (3878.4 ~ 352.8) (10.8/7.3) 25 (adhesive) 267.9 ~ 6.9 131.3/102.1 (3810.7 ~ 96.5) (9.0/7.0) 26 (cohesive) 303.9 ~ 29.5 160.5/68.6 (4322.2 ~ 419.4) (11.0/4.7) As can be seen from Table II Working Examples 23-26 showed substantial lap sheer strength and T-Peel strength both initially and after two days. Working Examples 24 and 26 provided a cohesive bond where upon failure, the bond was split evenly down the middle leaving adhesive material on both substrates. Working Example 25 provided an adhesive bond leaving areas on both substrates where the adhesive material was completely stripped from the surface of application.
r Lapsheer Strength as a Function of Particle Size A tenth premix was formulated as shown below:
Material Premix 10 WT-Araldite GT 7013 (bisphenol A- 75.4717 epichlorohydrin available from Ciga-Geigy Corporation) P-101 Curing Agent (Amine 2.6415 Condensate of an epoxy resin -.
available from Shell Oil Company) RESIFLOW P-67 . 1.1321 (acrylate/silicon dioxide compound available from Estron Chemicals, Inc.) x Uraflow B (benzoin flow agent, 0.7517 GCA Chemical Co.) BARTEX X65 , 1 8 . 8679 Chromalloy Industrial Minerals) Pigments (Black beads) 1.1321 An eleventh premix was formulated as shown below:
Pre-Mix 11 Material Wt-Araldite GT 7013 (bisphanol A- 94.1620 epichlorohydrin available from Ciba-Geigy Corporation) 2-methylimidazole 0.1883 dicyandiamide 4.2373 RESIFLOW P-67 1.4124 (acrylate/silicon dioxide compound available from Estron Chemicals, Inc.) The premixes were then used in the thermosetting compositions shown in Table 3. In each instance, the particle size of the_powder coating used in the composite is shown in Table III.
*T~'ademark Table III
Formulations regarding micron size:
3 Micron 4.9 Micron 62 Micron 103 Micron 8% 8% 8% 8%
Carboxylated Carboxylated Carboxylated Carboxylated Acrylic Acrylic Acrylic - Acrylic Copolymer Copolymer Copolymer Copolymer 44% Premix 44% Premix 11 44% Premix 11 44% Premix 11 .4% TAMOLk850.4% TAMOL~~850 .4% TAMOL*850 ~ .4% TAMOL 850 ~
(Sodium Salt (Sodium Salt (Sodium Salt (Sodium Salt of Polymeric of Polymeric of Polymeric of Polymeric Carboxylic Carboxylic Carboxylic Carboxylic Acid Acid Acid Acid Dispersing Dispersing Dispersing Dispersing Agent; Rohm Agent; Rohm Agent; Rohm Agent; Rohm & Haas & Haas & Haas & Haas 47 . 48&H20 47 . 6 % Hz0 47 . 48 % H,0 47 . 48 % H20 .03% XANTHAN .03% XANTHAM .03% XANTHAM
GUM GUM GUM
.09% Guar Gum .09% Guar Gum .09% Guar Gum Aluminium lapshears were. wiped with methyl ethyl ketone, acid etched for ten minutes and washed in deionized water before being air dried. Lapshears were assembled with 7781 volan (registered trade mark) fiberglass cloth which was impregnated with products above. Coat weights were 28% by weight of epoxy powder. The impregnated cloth was sandwiched between the lapshears and cured for one hour at 177°C at 6.9 x 1 0'' Pa ( 350°F at 1 , 000 psi ) . Lapshears were evaluated using ASTM D1002-72.
As can be seen in Figure One, 3 micron and 4,9 micron particle size compositions were compared to 62 and 103 micron formulations to determine lapshear strength. The difference in strength with smaller particle size compositions was notable.
The above discussion, Examples and data illustrate our current understanding of the invention. However, since many variations of the invention can be made without *Trademark departing from the scope of the invention, the invention resides wholly in the claims hereinafter appended.
'r~ ~'
Claims (10)
1. A liquid adhesive dispersion which can cure to a thermoset bond, comprising an effective amount of film-forming agent; and in a solid phase: an effective amount of a powdered thermosetting resin or composition having a particle size of 1 to 5 microns; and in a liquid phase: a liquid vehicle;
wherein said dispersion remains storage stable at ambient temperatures and, after application, said dispersion can form a physically stable intermediate film.
wherein said dispersion remains storage stable at ambient temperatures and, after application, said dispersion can form a physically stable intermediate film.
2. The composition of claim 1 wherein said thermosetting resin or composition is selected from the group of polymeric materials consisting of an epoxy, a polyurethane, a polyester, a bis-maleimide, an acrylic, mixtures thereof and hybrids thereof.
3. The composition of claim 1 or claim 2 wherein said film forming agent comprises a thermoplastic polymer composed of one or more monomers selected from the group consisting of vinyl acetate, ethylene, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, esters of acrylic acid, esters of methacrylic acid, styrene, butadiene, vinyl chloride, vinylidene chloride, isoprene, chlorprene, polyvinyl alcohol, and malefic anhydride.
4. The composition of any of claims 1 to 2 wherein said film-forming agent comprises a polymer selected from the group consisting of cellulose polymers, ether cellulose polymers, derivatized cellulosic and ether cellulosic polymers, starch, starch grafted copolymers, guar gum, karaya gum, and dextrine.
5. The composition of any of claims 1 to 4 additionally comprising a dispersant selected from the group consisting of silicates, polyphosphate salts, colloidal proteins, surfactants, cellulosic polymers, starch compositions, and fatty acid soaps.
6. An article of manufacture comprising a substrate coated with a physically stable adhesive dispersion which can cure to a thermoset bond, the liquid adhesive dispersion comprising an effective amount of a film forming agent; in a solid phase:
an effective amount of a thermosetting resin or composition having a particle size of 1 to 5 microns;
and in a liquid phase: a liquid vehicle; wherein said adhesive dispersion remains storage stable at ambient temperatures and after application said dispersion forms a physically stable intermediate film.
an effective amount of a thermosetting resin or composition having a particle size of 1 to 5 microns;
and in a liquid phase: a liquid vehicle; wherein said adhesive dispersion remains storage stable at ambient temperatures and after application said dispersion forms a physically stable intermediate film.
7. A method of using a liquid adhesive dispersion composition which can cure to a thermoset bond, said adhesive composition comprising an effective amount of film-forming agent; and comprising in a solid phase: an effective amount of a powdered thermosetting resin or composition having a particle size of 1 to 5 microns and in a liquid phase: a liquid vehicle;
wherein said dispersion remains storage stable at ambient temperatures and after application said dispersion forms a physically stable intermediate film, said method comprising the step of applying said liquid adhesive dispersion composition to a substrate and forming a physically stable intermediate film capable of curing to a thermoset bond.
wherein said dispersion remains storage stable at ambient temperatures and after application said dispersion forms a physically stable intermediate film, said method comprising the step of applying said liquid adhesive dispersion composition to a substrate and forming a physically stable intermediate film capable of curing to a thermoset bond.
8. The method of claim 7 additionally comprising the steps of:
(a) placing a second substrate onto said intermediate film; and (b) curing said thermosetting resin or composition contained within said intermediate film to create an adhesive bond.
(a) placing a second substrate onto said intermediate film; and (b) curing said thermosetting resin or composition contained within said intermediate film to create an adhesive bond.
9. The method of claim 7 additionally comprising the steps of (a) placing a plurality of said thermosetting film laden substrates together in series; and (b) heat curing said thermosetting film laden substrates to produce a composite laminate structure.
10. The product resulting from the method of any one of claims 7 to 9.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US99851592A | 1992-12-30 | 1992-12-30 | |
| US998,515 | 1992-12-30 | ||
| PCT/US1993/004679 WO1994016027A1 (en) | 1992-12-30 | 1993-05-18 | Liquid adhesive thermoset composition |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2152776A1 CA2152776A1 (en) | 1994-07-21 |
| CA2152776C true CA2152776C (en) | 1999-11-16 |
Family
ID=25545319
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002152776A Expired - Fee Related CA2152776C (en) | 1992-12-30 | 1993-05-18 | Liquid adhesive thermoset composition |
Country Status (5)
| Country | Link |
|---|---|
| AU (1) | AU676170B2 (en) |
| CA (1) | CA2152776C (en) |
| GB (1) | GB2289683B (en) |
| NZ (1) | NZ253458A (en) |
| WO (1) | WO1994016027A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6300414B1 (en) | 1998-08-28 | 2001-10-09 | Basf Corporation | Additive for coating compositions for adhesion to TPO substrates |
| US6423778B1 (en) | 1999-06-30 | 2002-07-23 | Basf Corporation | Process for coating olefinic substrates |
| EP1332190A2 (en) * | 2000-11-07 | 2003-08-06 | Basf Corporation | Coating compositions for adhesion to olefinic substrates |
| US9795141B2 (en) * | 2013-01-14 | 2017-10-24 | Dmr International, Inc. | Antimicrobial polymer systems using multifunctional organometallic additives for polyurethane hosts |
| CN114672273A (en) * | 2022-04-21 | 2022-06-28 | 宜兴市祥业化工有限公司 | Thermosetting resin composition for water-based adhesive and preparation method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1991002038A1 (en) * | 1989-08-01 | 1991-02-21 | H.B. Fuller Company | Liquid thermosetting composition |
-
1993
- 1993-05-18 AU AU43793/93A patent/AU676170B2/en not_active Ceased
- 1993-05-18 GB GB9512788A patent/GB2289683B/en not_active Expired - Fee Related
- 1993-05-18 WO PCT/US1993/004679 patent/WO1994016027A1/en active Application Filing
- 1993-05-18 NZ NZ253458A patent/NZ253458A/en unknown
- 1993-05-18 CA CA002152776A patent/CA2152776C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2152776A1 (en) | 1994-07-21 |
| NZ253458A (en) | 1996-09-25 |
| AU4379393A (en) | 1994-08-15 |
| WO1994016027A1 (en) | 1994-07-21 |
| AU676170B2 (en) | 1997-03-06 |
| GB9512788D0 (en) | 1995-10-11 |
| GB2289683B (en) | 1997-08-06 |
| GB2289683A (en) | 1995-11-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1252217B1 (en) | Ambient-temperature-stable, one-part curable epoxy adhesive | |
| US4070225A (en) | Method of using structural adhesive | |
| DE4408865C2 (en) | Use of a one-component, adhesive coating material for equipping the surfaces of fastening elements with a reactive adhesive layer | |
| US3449273A (en) | Hot melt adhesive | |
| JPH08104854A (en) | Dimensionally thermally recoverable article | |
| CA2152776C (en) | Liquid adhesive thermoset composition | |
| JPS6038485A (en) | Mixture comprising polyol and/or polyamine and polyisocyanate for polyurethane adhesive | |
| US4980229A (en) | Article surface coated with curable particulate or filamentary material | |
| US4117038A (en) | Storable, rapidly hardening epoxy resin adhesive | |
| KR960004521B1 (en) | Coated article | |
| WO1991002038A1 (en) | Liquid thermosetting composition | |
| JP3543613B2 (en) | One-part heat-curable aqueous epoxy resin composition | |
| KR100491844B1 (en) | Adhesive powder | |
| US6110993A (en) | Thermosetting epoxy resin composition | |
| JPS61188478A (en) | Adhesive composition | |
| JPH10168400A (en) | Sheetlike tacky body and its production | |
| JPH03281625A (en) | Liquid epoxy resin composition | |
| JP3477854B2 (en) | Method for bonding pre-coated adhesive composition | |
| US4500703A (en) | Reactive adhesive dispersion and method of use | |
| JPH02102281A (en) | Production of filmy adhesive | |
| JPS61197664A (en) | Adhesive composition | |
| JPS594619A (en) | Manufacture of epoxy-polyamide resin composition | |
| JP2000007951A (en) | Epoxy resin powder coating material | |
| JPH04335081A (en) | Epoxy resin adhesive composition |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |