US20080098668A1

US20080098668A1 - Systems for Attaching Wood Products

Info

Publication number: US20080098668A1
Application number: US11/554,766
Authority: US
Inventors: Jack G. Winterowd; Jerry D. Izan; Naomi High; Douglas R. Loates; Amar N. Neogi; Parry M. Ipsen; Glen Robak
Original assignee: Weyerhaeuser Co
Current assignee: Weyerhaeuser NR Co
Priority date: 2006-10-31
Filing date: 2006-10-31
Publication date: 2008-05-01

Abstract

The present invention is a system of building materials with surface regions destined for joint formation that are treated with an adhesive partially comprised of a mixture of epoxy resin (96.0-99.9 parts) and hardener (4.0-0.1 parts), such that the epoxy resin/hardener mixture constitutes 50-100% of the adhesive. In an alternative embodiment, the adhesive may have epoxy resin (96.0-99.9 parts) such that the epoxy resin constitutes 45-95% of the adhesive. The remainder of the adhesive may be one or more of the following: hardeners, plasticizing agents, diluents, thickeners, fillers, colorants, opacifying agents, preservatives, and surfactants.

Description

FIELD OF THE INVENTION

This invention relates generally to wood products which may be attached via an adhesive which is applied at a manufacturing stage such as, for example, a factory, prior to a construction phase, i.e., when the wood products are assembled together to form structural components.

BACKGROUND OF THE INVENTION

It is common practice in North America for buildings and/or residential structures to be comprised of discrete structural building materials, which include framing members and sheet goods. The building materials are typically connected in these structures by use of common mechanical fasteners, such as nails, screws, and staples. Other mechanical fasteners that are used include plates, anchors, hangers, bolts, split rings and clips. Adhesives are also commonly used in combination with mechanical fasteners to help connect certain types of building materials. For example, liquid construction adhesives are commonly utilized in joist-to-subfloor panel connections in order to improve the strength and durability of these joints. In some cases, liquid construction adhesives are also used in tongue-and-groove joints between adjacent subfloor panels. Additionally, certain liquid construction adhesives are sometimes applied to the interior face of wall studs just prior to installation of interior sheetrock. The use of adhesives at the stud-to-sheetrock interface allows the builder to reduce the number of mechanical fasteners, which yields an interior wall with fewer surface defects. In all of these cases, the construction adhesive is applied to the building material during the construction process.
In spite of the advantages associated with construction adhesives, their usage is somewhat limited, due in part to the difficulty and time required to apply them to building materials during the construction process. Although it is vital for connections between building materials to be strong and highly durable, it is also very important to have connections that are easy and fast to assemble. In most cases, construction adhesives are applied to building materials at a job site with a manual dispensing device that is commonly referred to as a caulking gun. This device is relatively slow and labor intensive. In cold or freezing weather, there is a tendency for the viscosity of liquid construction adhesives to increase, which makes them even more difficult to apply. Thus, some builders choose not to use construction adhesives because of the time and difficulty associated with their use.
Conventional construction adhesives are generally designed to be applied to building materials as a specific bead size and pattern, and for the joint to be closed within a certain period of “open-assembly-time”. The “open-assembly-time” is the time between adhesive application to one adherent and the closing of the joint by mating with the corresponding adherent. Recommended open-assembly-time values for conventional subfloor construction adhesives are often only 15 minutes and can be as brief as 10 minutes. Long “open-assembly-times” can result in partial or complete solidification of the applied adhesive prior to contact with the corresponding substrate in the joint. When this occurs, the contribution of the adhesive to the strength of the joint will be diminished, and in many cases it will obstruct the fit of the joint. Another failure mode associated with conventional construction adhesives relates to their use on building materials that are wet from exposure to rain or snow. We have found that most commercially available construction adhesives yield weaker joints when they are applied to wet building materials. Yet another failure mode relates to incomplete or non-uniform adhesive application rates. In this situation, at least some portion of the joint surface receives an insufficient amount of adhesive. Accordingly, a need was created for building materials with joint formation zones, including floor joists, which are treated more uniformly and completely with “special” adhesives in a manufacturing environment, stored for some period of time, and then delivered to a secondary site, such as a construction site, for assembly. The adhesives for this application must be “special” in the sense that they can be applied to a building material in a manufacturing environment, and yet retain the ability to form bonds to another building material after prolonged storage periods. Thus, this special adhesive must tolerate very long open-assembly-times.
Pressure sensitive adhesives (“PSAs”) are known to tolerate very long open-assembly-times. In fact, non-structural building materials, which have been treated with PSAs in a factory-setting and subsequently sent to secondary sites for assembly, are known to exist. Examples include decorative sheets of veneer that have been treated on one side with pressure sensitive adhesive and a protective backing layer and then sold in a “ready-to-use” state (see FormWood™ PSA Veneer by FormWood Industries, Incorporated in Jeffersonville, Ind.); peel-and-stick vinyl flooring tile (see peel and stick vinyl flooring products by Armstrong World Industries in Lancaster, Pa.); self-adhered roof underlayments (see DuraGuard™ by the Georgia-Pacific Corporation in Atlanta, Ga.); a preglued lock profile, known as “Knock 'n Lock Seal”, for decorative wood flooring products from Universal Flooring in Danville, Va.; and decorative peel & stick trim (see adhesive-backed trim by Barbour Plastics Incorporated in Brockton, Mass.). It is important to note that all of these products are used in non-structural applications and the long-term stresses applied to the adhesive bonds are relatively small.
Pressure sensitive adhesives (“PSAs”) are amorphous, viscoelastic materials that are generally comprised of a mixture of elastomer (such as butyl rubber, styrene-butadiene resin, polyisoprene, poly(ethylene vinylacetate), or acrylate resins) and tackifier (such as aliphatic petroleum hydrocarbons, terpenes, and diolefins) [1) Benedek, Istvan Pressure-Sensitive Adhesives and Applications, 2^ndEdition, Marcel Dekker, Inc., New York, N.Y. (2004). 2) Goulding, T. M. “Pressure-Sensitive Adhesives” in Handbook of Adhesive Technology 2^ndEdition, edited by Pizzi, A & Mittal, K. L., Marcel Dekker, Inc., New York, N.Y. (2003) p 839-854.1 The tackifier imparts a viscous attribute and permanent “stickiness” to the PSA. Thus, PSAs applied to building products can generally remain sticky and receptive to bond formation for very long periods of time. Other viscous components that can be incorporated into PSAs include solvents and plasticizers. PSAs commonly exist as hot-melt adhesives, such as Robond™ by Rohm and Haas in Philadelphia, Pa., and tapes, such as VHB™ Tape by the 3M Industrial Adhesives and Tapes Division in St. Paul, Minn. PSAs can be designed to rapidly bond to substrates at ambient temperatures, and the resulting adhesive bonds can provide high strength values when subjected to loads for very short periods of time. Unfortunately, these PSAs also exhibit non-reversible deformation when subjected to high stress loads (greater than about 1 psi) for prolonged periods of time. For instance, 3M recommends the use of four square inches of VHB tape per one pound of stress in situations in which the load will be sustained. This last attribute makes PSAs unsuitable for applications involving large, sustained loads, such as those experienced by adhesives at the joist-to-subfloor panel connection.
Thus, building materials that are treated with an adhesive in a factory-setting, and subsequently employed in a structural application after a prolonged storage period, are needed.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is a system of building materials with surface regions destined for joint formation that are treated with an adhesive partially comprised of a mixture of epoxy resin (96.0-99.9 parts) and hardener (4.0-0.1 parts), such that the epoxy resin/hardener mixture constitutes 50-100% of the adhesive. The adhesive has an open assembly time of at least 24 hours. In some cases, the adhesive may have an open assembly time greater than or approximately equal to 7 days (168 hours).
In general, building materials suitable for this invention are those which will be incorporated into either floor, wall or roof segments of buildings, houses or dwellings and are incorporated into said structures through joints that are secured with either mechanical fasteners and/or adhesives. Specific examples of building materials suitable for this invention include framing members such as solid-sawn wooden lumber, Parallam, TimberStrand, Microllam, laminated veneer lumber, wood-based composite I-joists, glulam, finger-jointed lumber, oriented strand board, oriented strand lumber, medium density fiberboard, and even metallic framing members, which are commonly referred to as “steel-studs”. Framing members are commonly used in support of floor, wall and roof structures as joists, rim boards, studs, trusses, headers, rafters, beams, columns, sill plates, posts, girders, blocking, cripples, trimmers, rough sill, top plate, and inset bracing. Other building materials suitable for this invention are structural panels, which generally include OSB and plywood. Sheetrock, such as that manufactured by the Georgia-Pacific Corporation in Atlanta Ga., can also be used as a substrate for this invention. Panels are commonly used as sheathing and are attached to the framing members in floor, wall and roof structures. Other building materials appropriate for this invention include siding products (wooden, plastic, and cement-based), roofing (wooden, tile and metallic), decorative fascia and trim (wooden, plastic, cement, metallic), as well as stair treads and stringers.
Joints in buildings, residential structures or dwellings that would be improved or modified by this invention include, but are not limited to, sill plate-to-foundation, rim board-to-sill plate, rim board-to-foundation, rim board-to-joist, girder-to-joist, joist-to-rim board, joist-to-blocking, joist-to-subfloor, sole plate-to-subfloor, corner post-to-stud, sheathing-to-stud, sheetrock-to-stud, siding-to-stud, siding-to-sheathing, trimmer-to-stud, header-to-stud, rafter stud-to-top plate, rafter-to-ridge board, rafter-to-sheathing, rafter-to-decking, and collar beam-to-rafter.
Adhesives appropriate for this invention are homogenous mixtures partially comprised of a mixture of epoxy resin (96.0-99.9 parts) and hardener (4.0-0.1 parts), such that the epoxy resin/hardener mixture constitutes 50-100% of the adhesive. In an alternative embodiment, the adhesive may have epoxy resin (96.0-99.9 parts) such that the epoxy resin constitutes 45-95% of the adhesive. The remainder of the adhesive may be one or more of the following: hardeners, plasticizing agents, diluents, thickeners, fillers, colorants, opacifying agents, preservatives, and surfactants.
Epoxy resins suitable for this invention can include liquid or solid adducts of bisphenol ‘A’ and epichlorohydrin; or liquid or solid adducts of phenol novolac resins and epichlorohydrin; or liquid or solid adducts of cresol novolac resins and epichlorohydrin. The epoxy resin can also be a mixture of two or more epoxy resins, including liquid epoxy resins and solid epoxy resins. These liquid epoxy resins generally have an epoxide equivalent weight of about 180-210 g/equivalent. The solid epoxy resins generally have an epoxide equivalent weight of about 200-600 g/equivalent, although there are some solid epoxy resins that are suitable for this invention and have epoxide equivalent values that are substantially less than 200 g/eq. Manufacturers of liquid and solid epoxy resins include Hexion Specialty Chemicals [Houston, Tex.] and the Dow Chemical Company [Midland, Mich.].
Hardeners suitable for this invention include aliphatic polyamines such as diethylene triamine, tetraethylene pentamine, diethylamine, propylamine and n-aminoethyl piperazine. Aromatic polyamines suitable as hardeners for this invention include m-phenylenediamine and tris(dimethylaminomethyl)phenol. Amidopolyamines, which are formed by reacting polyamines with fatty acids are also suitable as hardeners for this invention. Lastly, certain polyamide hardeners suitable for this invention include dicyandiamide. Proprietary hardeners such as D.E.H. 52 from the Dow Chemical Company or Epikure 3140 from Hexion Specialty Chemicals are also suitable for this invention.
Although not required, additional components can be incorporated into the adhesive formulation up to a level of about 50%. These additional components can include plasticizing agents, diluents, thickeners, fillers, colorants, opacifying agents, preservatives, surfactants or any other compound that improves the performance, processing characteristics, costs, appearance, or some other property of the adhesive. Preferred plasticizing agents include dioctylphthalate, dibutylphthalate, benzylbutylphthalate, diethylphthalate, butyl diphenylmethane and butyl diphenylethane.
Preferred adhesive formulations are comprised of solid epoxy resin (40-85 parts), liquid epoxy resin (5-45 parts), plasticizing agent (5-20 parts) and hardener (0.5-4 parts). Highly preferred adhesive formulations are comprised of solid epoxy resin (43-48 parts), liquid epoxy resin (40-45 parts), plasticizing agent (8-12 parts) and hardener (1.6-2.7 parts).
Adhesive can be prepared by loading all of the required solid epoxy, liquid epoxy and plasticizing agent into a glass vessel and heating to a temperature of about 70-100° C. in order to melt the solid epoxy resin. The mixture can then be mixed while maintaining the temperature at 70-100° C. to form a single phase liquid. All of the hardener can then be added with continued stirring until a homogenous mixture is obtained. Many other blending and mixing strategies are known to individuals who are skilled-in-the-art and these methods are within the scope of this invention. Immediately after preparation, such adhesive formulations have a melt point of about 35-50° C. Adhesive formulation batch size should be minimized and/or cooling coils should be used in order to avoid excessive formulation temperatures due to exothermic reactions between the epoxy resins and the hardener.
Freshly prepared adhesive can be cooled and stored as a glassy solid for several days prior to application to a building material, but it may be preferable to apply the freshly prepared molten adhesive formulation to the building material immediately after preparation. The adhesive temperature at the time of application should be in the range of about 60-100° C., and the exact temperature should be selected as a function of the specific adhesive composition and the method of application. Suitable methods of molten adhesive application to building materials include extrusion, spray, roll-coating, brushing and others known by those skilled in the art. It is also within the scope of this invention to apply the molten adhesive to a carrier, which is subsequently applied to the building material as a roll good or tape. Generally, the adhesive will be applied to the building material over a surface region that is destined for joint formation at some point in the construction process. In some cases it will be helpful to cover the applied adhesive with a release film. Suitable release films include polyethylene or polypropylene films that have been coated on at least one side with silicone release agents. Said release film would help to protect the applied adhesive during shipping and storage, and would be removed sometime prior to joint formation at the construction site. During construction the adhesive treated building material would be placed in contact with an adherent along the joint formation zone and the two components would be mechanically fastened with screws, nails or staples in the typical fashion. In this situation builders may eliminate the step of applying the adhesive during the construction process.
In a more specific example, adhesive would be applied to the top side of an I-joist in a factory and then covered with a release film. The treated joist would then be transported to a field construction site. Builders would install the treated joist into the frame of the structure, remove the release film, and then install subfloor panels directly onto the treated joist, such that the subfloor panels directly contact the previously applied adhesive on the joist. Subfloor panels would then be mechanically fastened to the joist in the typical manner. The adhesive initially exists as a soft, conformable solid, which promotes intimate contact between both substrates during the installation process. Over a period of about two weeks to two months the adhesive becomes hard and able to withstand shear loads in excess of about 200 psi.
The invention is further illustrated by the following examples:

EXAMPLE 1

A 600 mL glass beaker was charged with a solid epoxy resin (100 g), known as D.E.R. 661 [epoxide equivalent weight=500-560 g/eq.], a liquid epoxy resin (96.0 g), known as D.E.R. 317 [epoxide equivalent weight=192-203 g/eq.], and an aliphatic polyamine hardener (4.0 g), known as D.E.H. 52 [amine hydrogen equivalent weight=42-47 g/eq.]. All materials were manufactured by the Dow Chemical Company [Midland, Mich.]. The mixture was heated to a temperature of about 110° C. and stirred until a single-phase solution was obtained. This mixture was cooled to a temperature of 22° C. It solidified at about 45-50° C.
The frozen resin was aged at a temperature of 22° C. for a period of about 25 hours and was then heated to a temperature of about 100-110° C. The molten adhesive was then brushed onto one surface (1.75″×10.0″) of five different sections of Microllam™ (1.75″×0.75″×10.0″), manufactured by Weyerhaeuser Company, at an application level of about 3-5 g per section. The temperature of the Microllam™ sections was about 22° C. at the time of the application. These sections were previously isolated from the flange of I-joists. The applied adhesive solidified almost instantly after application to the Microllam™.
The treated Microllam sections were then aged at a temperature of 20° C. and a relative humidity value of 50% for a period of seven days.
Sections of OSB flooring (0.72″×1.75″×10.0″), known as Edge Gold and manufactured by the Weyerhaeuser Company [Federal Way, Wash.], were placed on top of each treated Microllam™ section so that the previously applied adhesive was in direct contact with the smooth side of the OSB (1.75″×10.0″). Each stack was fastened together with screws at locations that were 1.0″ from each end.
The resulting laminate was allowed to age at a temperature of 20° C. and a relative humidity of 50% for a period of five days. Four notched shear-block specimens (shear plane area=1.0″×1.5″) were then cut from each laminate and tested for compression shear strength at a displacement rate of 0.2 inch/minute on the seventh day subsequent to lamination.
The average shear strength of the test specimens was 311 psi (standard deviation =193).

EXAMPLE 2

A 600 mL glass beaker was charged with a solid epoxy resin (100 g), known as D.E.R. 661 [epoxide equivalent weight=500-560 g/eq.], a liquid epoxy resin (97.0 g), known as D.E.R. 317 [epoxide equivalent weight=192-203 g/eq.], and an aliphatic polyamine hardener (3.0 g), known as D.E.H. 52 [amine hydrogen equivalent weight=42-47 g/eq.]. All materials were manufactured by the Dow Chemical Company [Midland, Mich.]. The mixture was heated to a temperature of about 110° C. and stirred until a single-phase solution was obtained. This mixture was cooled to a temperature of 22° C. It solidified at about 45-50° C.
The frozen resin was aged at a temperature of 22° C. for a period of about 23 hours and was then heated to a temperature of about 100-110° C. The molten adhesive was then brushed onto one surface (1.75″×10.0″) of five different sections of Microllam™ (1.75″×0.75″×10.0″) at an application level of about 3-4 g per section. The temperature of the Microllam™ sections was about 22° C. at the time of the application. These sections were previously isolated from the flange of I-joists. The applied adhesive solidified almost instantly after application to the Microllam™.
The treated Microllam sections were then aged at a temperature of 20° C. and a relative humidity value of 50% for a period of seven days.
Sections of OSB flooring (0.72″×1.75″×10.0″), known as Edge Gold and manufactured by the Weyerhaeuser Company [Federal Way, Wash.], were placed on top of each treated Microllam™ section so that the previously applied adhesive was in direct contact with the smooth side of the OSB (1.75″×10.0″). Each stack was fastened together with screws at Locations that were 1.0″ from each end.
The resulting laminate was allowed to age at a temperature of 20° C. and a relative humidity of 50% for a period of five days. Four notched shear-block specimens (shear plane area=1.0″×1.5″) were then cut from each laminate and tested for compression shear strength at a displacement rate of 0.2 inch/minute on the seventh day subsequent to lamination.
The average shear strength of the test specimens was 201 psi (standard deviation =100).

EXAMPLE 3

A 600 mL glass beaker was charged with a solid epoxy resin (100 g), known as D.E.R. 661 [epoxide equivalent weight=500-560 g/eq.], a liquid epoxy resin (98.0 g), known as D.E.R. 317 [epoxide equivalent weight=192-203 g/eq.], and an aliphatic polyamine hardener (2.0 g), known as D.E.H. 52 [amine hydrogen equivalent weight=42-47 g/eq.]. All materials were manufactured by the Dow Chemical Company [Midland, Mich.]. The mixture was heated to a temperature of about 110° C. and stirred until a single-phase solution was obtained. This mixture was cooled to a temperature of 22° C. It solidified at about 45-50° C.
The frozen resin was aged at a temperature of 22° C. for a period of about 25 hours and was then heated to a temperature of about 100-110° C. The molten adhesive was then brushed onto one surface (1.75″×10.0″) of five different sections of Microllam™ (1.75″××0.75″×10.0″) at an application level of about 3-4 g per section. The temperature of the Microllam™ sections was about 22° C. at the time of the application. These sections were previously isolated from the flange of I-joists. The applied adhesive solidified almost instantly after application to the Microllam™.
The treated Microllam sections were then aged at a temperature of 20° C. and a relative humidity value of 50% for a period of seven days.
Sections of OSB flooring (0.72″×1.75″×10.0″), known as Edge Gold and manufactured by the Weyerhaeuser Company [Federal Way, Wash.], were placed on top of each treated Microllam™ section so that the previously applied adhesive was in direct contact with the smooth side of the OSB (1.75″×10.0″). Each stack was fastened together with screws at locations that were 1.0″ from each end.
The resulting laminate was allowed to age at a temperature of 20° C. and a relative humidity of 50% for a period of five days. Four notched shear-block specimens (shear plane area=1.0″×1.5″) were then cut from each laminate and tested for compression shear strength at a displacement rate of 0.2 inch/minute on the seventh day subsequent to lamination.
The average shear strength of the test specimens was 92 psi (standard deviation=24).

EXAMPLE 4

An adhesive formulation suitable for use in this invention was prepared in the following manner. A 600 mL glass beaker was charged with a liquid epoxy resin (96 g), known as D.E.R. 317 [epoxide equivalent weight=192-203 g/eq.] and an aliphatic polyamine hardener (4.0 g), known as D.E.H. 52 [amine hydrogen equivalent weight=42-47 g/eq.]. The mixture was heated to a temperature of about 40° C. and mixed with a metal spatula for about 5 minutes in order to obtain a single-phase solution. A solid epoxy resin (100 g), known as D.E.R. 661 [epoxide equivalent weight=500-560 g/eq.] was added to the solution and the mixture was heated to a temperature of about 110° C. and stirred until all of the solid epoxy resin had melted and the mixture was a single-phase solution. Both epoxy resins and the hardener were manufactured by the Dow Chemical Company [Midland, Mich.]. A mixture (20 g) of butyl diphenylmethane and butyl diphenylethane, known as Vycel U-2000 (supplied by the Crowly Chemical Company in New York, N.Y.), and was added to the mixture with further stirring. The resulting mixture was a single-phase solution. It was cooled to 20° C. and solidified at a temperature of about 45-50° C. This adhesive was suitable for use in this invention.

EXAMPLE 5

An adhesive formulation suitable for use in this invention was prepared in the following manner. A 600 mL glass beaker was charged with a mixture (15 g) of butyl diphenylmethane and butyl diphenylethane, known as Vycel U-2000 (supplied by the Crowly Chemical Company in New York, N.Y.), a liquid epoxy resin (95 g), known as D.E.R. 317 [epoxide equivalent weight=192-203 g/eq.] and an aliphatic polyamine hardener (5.0 g), known as D.E.H. 52 [amine hydrogen equivalent weight=42-47 g/eq.]. The mixture was heated to a temperature of about 40° C. and mixed with a metal spatula for about 5 minutes in order to obtain a single-phase solution. A solid epoxy resin (100 g), known as D.E.R. 661 [epoxide equivalent weight=500-560 g/eq.] was added to the solution and the mixture was heated to a temperature of about 110° C. and stirred until all of the solid epoxy resin had melted and the mixture was a single-phase solution. Both epoxy resins and the hardener were manufactured by the Dow Chemical Company [Midland, Mich.]. The resulting mixture was a single-phase solution. It was cooled to 20° C. and solidified at a temperature of about 45-50° C. This adhesive was suitable for use in this invention.

EXAMPLE 6

An adhesive formulation suitable for use in this invention was prepared in the following manner. A 600 mL glass beaker was charged with a mixture (8 g) of butyl diphenylmethane and butyl diphenylethane, known as Vycel U-2000 (supplied by the Crowly Chemical Company in New York, N.Y.), a liquid epoxy resin (95 g), known as D.E.R. 317 [epoxide equivalent weight=192-203 g/eq.] and an aliphatic polyamine hardener (5.0 g), known as D.E.H. 52 [amine hydrogen equivalent weight=42-47 g/eq.]. The mixture was heated to a temperature of about 40° C. and mixed with a metal spatula for about 5 minutes in order to obtain a single-phase solution. A solid epoxy resin (100 g), known as D.E.R. 661 [epoxide equivalent weight=500-560 g/eq.] was added to the solution and the mixture was heated to a temperature of about 110° C. and stirred until all of the solid epoxy resin had melted and the mixture was a single-phase solution. Both epoxy resins and the hardener were manufactured by the Dow Chemical Company [Midland, Mich.]. The resulting mixture was a single-phase solution. It was cooled to 20° C. and solidified at a temperature of about 45-50° C.

EXAMPLE 7

An adhesive formulation suitable for use in this invention was prepared in the following manner. A 600 mL glass beaker was charged with dioctylphthalate (15 g), a liquid epoxy resin (95 g), known as D.E.R. 317 [epoxide equivalent weight=192-203 g/eq.] and an aliphatic polyamine hardener (5.0 g), known as D.E.H. 52 [amine hydrogen equivalent weight=42-47 g/eq.]. The mixture was heated to a temperature of about 40° C. and mixed with a metal spatula for about 5 minutes in order to obtain a single-phase solution. A solid epoxy resin (100 g), known as D.E.R. 661 [epoxide equivalent weight=500-560 g/eq.] was added to the solution and the mixture was heated to a temperature of about 110° C. and stirred until all of the solid epoxy resin had melted and the mixture was a single-phase solution. Both epoxy resins and the hardener were manufactured by the Dow Chemical Company [Midland, Mich.]. The resulting mixture was a single-phase solution. It was cooled to 20° C. and solidified at a temperature of about 45-50° C.

EXAMPLE 8

An adhesive formulation suitable for use in this invention was prepared in the following manner. A 600 mL glass beaker was charged with benzylbutylphthalate (15 g), a liquid epoxy resin (95 g), known as D.E.R. 317 [epoxide equivalent weight=192-203 g/eq.] and an aliphatic polyamine hardener (5.0 g), known as D.E.H. 52 [amine hydrogen equivalent weight=42-47 g/eq.]. The mixture was heated to a temperature of about 40° C. and mixed with a metal spatula for about 5 minutes in order to obtain a single-phase solution. A solid epoxy resin (100 g), known as D.E.R. 661 [epoxide equivalent weight=500-560 g/eq.] was added to the solution and the mixture was heated to a temperature of about 110° C. and stirred until all of the solid epoxy resin had melted and the mixture was a single-phase solution. Both epoxy resins and the hardener were manufactured by the Dow Chemical Company [Midland, Mich.]. The resulting mixture was a single-phase solution. It was cooled to 20° C. and solidified at a temperature of about 45-50° C.

EXAMPLE 9

An adhesive formulation suitable for use in this invention was prepared in the following manner. A 600 mL glass beaker was charged with a mixture (15 g) of butyl diphenylmethane and butyl diphenylethane, known as Vycel U-2000 (supplied by the Crowly Chemical Company in New York, N.Y.), a liquid epoxy resin (94 g), known as D.E.R. 317 [epoxide equivalent weight=192-203 g/eq.] and an aliphatic polyamine hardener (6.0 g), known as D.E.H. 52 [amine hydrogen equivalent weight=42-47 g/eq.]. The mixture was heated to a temperature of about 40° C. and mixed with a metal spatula for about 5 minutes in order to obtain a single-phase solution. A solid epoxy resin (100 g), known as D.E.R. 661 [epoxide equivalent weight=500-560 g/eq.] was added to the solution and the mixture was heated to a temperature of about 110° C. and stirred until all of the solid epoxy resin had melted and the mixture was a single-phase solution. Both epoxy resins and the hardener were manufactured by the Dow Chemical Company [Midland, Mich.]. The resulting mixture was a single-phase solution. It was cooled to 20° C. and solidified at a temperature of about 45-50° C.

EXAMPLE 10

An adhesive formulation suitable for use in this invention was prepared in the following manner. A 600 mL glass beaker was charged with a solid epoxy resin (100 g), known as D.E.R. 661 [epoxide equivalent weight=500-560 g/eq.], a liquid epoxy resin (99.0 g), known as D.E.R. 317 [epoxide equivalent weight=192-203 g/eq.], and an aliphatic polyamine hardener (1.0 g), known as D.E.H. 52 [amine hydrogen equivalent weight=42-47 g/eq.]. All materials were manufactured by the Dow Chemical Company [Midland, Mich.]. The mixture was heated to a temperature of about 110° C. and stirred until a single-phase solution was obtained. This mixture was cooled to a temperature of 22° C. It solidified at about 45-50° C.
While the embodiments of the invention have been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the embodiments. Instead, the invention should be determined entirely by reference to the claims that follow.

Claims

1. A system for attaching a plurality of wood products:

a first wood product;

a second wood product; and

an adhesive applied to at least one of the first wood product and the second wood product wherein the adhesive comprises a mixture of epoxy resin (96.0-99.9 parts), such that the epoxy resin constitutes 45-95% of the adhesive and wherein the adhesive has an open assembly time of at least 24 hours.

2. The system of claim 1 wherein the first wood product and the second wood product are combined to form at least one of the following types of joints: sill plate-to-foundation, rim board-to-sill plate, rim board-to-foundation, rim board-to-joist, girder-to-joist, joist-to-rim board, joist-to-blocking, joist-to-subfloor, sole plate-to-subfloor, corner post-to-stud, sheathing-to-stud, sheetrock-to-stud, siding-to-stud, siding-to-sheathing, trimmer-to-stud, header-to-stud, rafter stud-to-top plate, rafter-to-ridge board, rafter-to-sheathing, rafter-to-decking, and collar beam-to-rafter.

3. The system of claim 1 wherein the first wood product is constructed from one or more of the following: solid-sawn wooden lumber, Parallam, TimberStrand, Microllam, laminated veneer lumber, wood-based composite, glulam, finger-jointed lumber, oriented strand board, oriented strand lumber, particleboard, medium density fiberboard, and metal.

4. The system of claim 1 wherein the epoxy resin includes one or more of the following: liquid or solid adducts of bisphenol ‘A’ and epichlorohydrin, liquid or solid adducts of phenol novolac resins and epichlorohydrin, and liquid or solid adducts of cresol novolac resins and epichlorohydrin.

5. The system of claim 1 wherein the epoxy resin has an epoxide equivalent weight of about 180-210 g/equivalent.

6. The system of claim 1 wherein the epoxy resin has an epoxide equivalent weight of about 200-600 g/equivalent.

7. The system of claim 1 wherein the adhesive further comprises one or more of the following: hardeners, plasticizing agents, diluents, thickeners, fillers, colorants, opacifying agents, preservatives, and surfactants.

8. The system of claim 1 wherein the adhesive has an open assembly time greater than or approximately equal to 168 hours.

9. A system for attaching a plurality of wood products:

a first wood product;

a second wood product; and

an adhesive applied to at least one of the first wood product and the second wood product wherein the adhesive comprises a mixture of epoxy resin (96.0-99.9 parts) and hardener (4.0-0.1 parts), such that the epoxy resin/hardener mixture constitutes 50-100% of the adhesive and wherein the adhesive has an open assembly time of at least 24 hours.

10. The system of claim 9 wherein the first wood product and the second wood product are combined to form at least one of the following types of joints: sill plate-to-foundation, rim board-to-sill plate, rim board-to-foundation, rim board-to-joist, girder-to-joist, joist-to-rim board, joist-to-blocking, joist-to-subfloor, sole plate-to-subfloor, corner post-to-stud, sheathing-to-stud, sheetrock-to-stud, siding-to-stud, siding-to-sheathing, trimmer-to-stud, header-to-stud, rafter stud-to-top plate, rafter-to-ridge board, rafter-to-sheathing, rafter-to-decking, and collar beam-to-rafter.

11. The system of claim 9 wherein the first wood product is constructed from one or more of the following: solid-sawn wooden lumber, Parallam, TimberStrand, Microllam, Laminated veneer Lumber, wood-based composite, glulam, finger-jointed lumber, oriented strand board, oriented strand lumber, particleboard, medium density fiberboard, and metal.

12. The system of claim 9 wherein the epoxy resin includes one or more of the following: liquid or solid adducts of bisphenol ‘A’ and epichlorohydrin, liquid or solid adducts of phenol novolac resins and epichlorohydrin, and liquid or solid adducts of cresol novolac resins and epichlorohydrin.

13. The system of claim 9 wherein the epoxy resin has an epoxide equivalent weight of about 180-210 g/equivalent.

14. The system of claim 9 wherein the epoxy resin has an epoxide equivalent weight of about 200-600 g/equivalent.

15. The system of claim 9 wherein the hardener is an aliphatic polyamine selected from the group consisting of: diethylene triamine, tetraethylene pentamine, diethylamine, propylamine and n-aminoethyl piperazine. Amidopolyamines, which are formed by reacting polyamines with fatty acids are also suitable as hardeners for this invention. Lastly, certain polyamide hardeners suitable for this invention include dicyandiamide.

16. The system of claim 9 wherein the hardener is an aromatic polyamine selected from the group consisting of: m-phenylenediamine and tris(dimethylaminomethyl)phenol.

17. The system of claim 9 wherein the adhesive further comprises one or more of the following: plasticizing agents, diluents, thickeners, fillers, colorants, opacifying agents, preservatives, and surfactants.

18. The system of claim 9 wherein the adhesive has an open assembly time greater than or approximately equal to 168 hours.