WO2016026884A1

WO2016026884A1 - An adhesive composition forming structurally integral bonds with the bonding surfaces of the substrates

Info

Publication number: WO2016026884A1
Application number: PCT/EP2015/069012
Authority: WO
Inventors: Wenjie Cao; Nasser ALHARBI; Abdulrahman ALFAWZAN; Khalid AL-ASSAF
Original assignee: Sabic Global Technologies B.V.
Priority date: 2014-08-21
Filing date: 2015-08-19
Publication date: 2016-02-25

Abstract

Methods and compositions to bond at least two substrates by forming structurally integral bonds between an adhesive composition and the substrates are provided herein. The substrates comprise functional polymer A, and the adhesive composition comprises functional polymer A and a suitable dispersing solvent. The dispersing solvent solubilizes the adhesive matrix and at least partially solubilizes the bonding surfaces of the substrates, thereby increasing the mobility of the polymer chains. The polymer chains entangle with each other, and upon removal of the solvent, form structurally integral bonds that are embedded within the substrate and the adhesive matrix.

Description

AN ADHESIVE COMPOSITION FORMING STRUCTURALLY INTEGRAL BONDS WITH THE BONDING SURFACES OF THE SUBSTRATES

TECHNICAL FIELD

The disclosure herein relates to an adhesive composition comprising a functional polymer that structurally integrates with the bonding surfaces of the substrates that comprise the same functional polymer.

BACKGROUND

Adhesive compositions have a wide-spread commercial applications. These have been in use in adhesive tapes, bonding structural materials, hard surfaces, polymer resins and the like. Generally, a mixture of one or more polymeric materials have been used, and various methods of making these compositions are widely available.

Majority of the adhesive composition known to date are curable. Accordingly, one or more polymer (or monomers, or oligomers) components are mixed together with an appropriate curing agent and subjected to the curing

conditions. Normally, these conditions include subjecting the polymer composition to thermal treatments, pressure, free-radical initiation,

photochemical treatments and the like.

Although it is widely used, the curing step adds one additional step to the process of preparing the adhesive composition. Additionally, since the curing step is performed once the adhesive composition is placed on the bonding surfaces of the substrates, the substrates are also subjected to the curing conditions. These substrates may not withstand the curing conditions, and this may result in degradation.

Accordingly, non-curable adhesive compositions can be used as an attractive alternative. Although many are available, the bond strength and the durability are less than the curable compositions. In this regard, the "solvent welding" technique offers some advantages-in particular, because removal of the solvent can be done, in most cases, under milder conditions.

In solvent welding, an appropriate solvent is applied to a polymer composition. The polymer composition swells and becomes temporarily and partially dissolved. Under these conditions, the individual polymer chains become relatively mobile, and when placed in contact with a second polymer

composition that has been similarly been treated with and swollen, the polymer chains of the two compositions can become physically entangled. Once sufficiently intermingled, the resulting bond or weld can be cured by the removal of the solvent by diffusion or evaporation. This process can be expedited by application of heat. Once the solvent is removed, the polymer compositions become hardened and the individual polymer chains lose their mobility. After this step, the two polymer compositions become physically coupled or welded. However, solvent welding is not applicable to all polymeric substrates.

Generally, it is limited to joining compatible polymers. Residual solvent may lead to bleaching of the polymeric substrates, and can reduce the strength as well as the cosmetic appearance. Additionally, the thin layer of solvent cannot be used to fill the gaps. Further, the normally used solvents are organic, volatile and most often, inflammable and toxic.

SUMMARY

The methods and compositions disclosed herein are related to an adhesive composition for bonding at least two structural units. Both the adhesive composition and the structural units comprise a functional polymer A. A dispersing solvent is used to form a homogenous solution of the adhesive composition, and this solvent at least partially dissolves the surfaces of the structural units. The individual polymer chains of the adhesive composition and the structural units become entangled, and form structurally integral bonds with each other. Upon removal of the solvent, the adhesive composition and the structural units become fused through the structurally integral bonds.

In some aspects, the functional polymer A is PMMA. The adhesive composition can comprise other polymers in addition to functional the polymer A. For example, the adhesive composition can comprise functional polymer B. In these instances, the functional polymer B is polycarbonate.

The dispersing solvent is chosen such that it solubilizes the adhesive matrix to form a homogenous solution and at least partially solubilizes the bonding surfaces of the substrates. In some aspects, the dispersing solvent is dichloromethane.

The above described and other features are exemplified by the following Detailed Description.

DETAILED DESCRIPTION

1 . GENERAL

The methods and compositions disclosed herein are for an adhesive

composition that forms structurally integral bonds with the substrates been bonded together. The structurally integral bonds seamlessly fuses the substrates and the adhesive composition together.

The adhesive composition and the substrates been bonded together comprise a functional polymer A. The methods disclosed herein advantageously exploit the chemical and physical similarities of the functional polymer A. A dispersing solvent is used to form a homogenous solution of the adhesive composition, thus enabling the individual polymer chains (for example, of functional polymer A) to become mobile. The solvent in the homogenous solution of the adhesive composition is also sufficient to at least partially solubilize the bonding surfaces of the substrates been bonded together. The mobile polymer chains become entangled with each other and form structurally integral bonds. Upon removal of the solvent, the adhesive composition and the substrates become structurally integrated, and seamlessly fused together.

The Substrates

The present methods and compositions are useful for bonding or fusing at least two substrates together. These substrates could be various structural units that can be found in automotive industry, semiconductor industry, optical lenses, construction materials, aircraft and aircraft building materials, computers and television sets, cameras, cellphones, toys, household gadgets and the like. In any instance where a stable and durable bonding is desirable, the present methods and compositions are useful.

The terms "substrates" and "structural units" are used interchangeably as understood by a person skill in the art. In many instances, a seamless bonding or fusing between the adhesive composition and the substrates is desirable. Such bonding not only improves the cosmetic appearance of the final product, but also improves the strength and the durability of the bonding.

In particular, in an industry like the automotive industry, such a seamless bonding is highly useful, since many parts and pieces must be joined together in these fields. Generally, most of these parts are made up of rigid and

sometimes brittle materials, and must be adaptable to various design concepts. Accordingly, efficient methods to bond or fuse several structural units into one seamlessly integral unit are very important in these industries.

The substrates herein comprise a majority of a functional polymer, "functional polymer" in this context means a polymer comprised of at least 50% w/w of the other polymers in the substrate. In some instances, the functional polymer can be of at least 60%, 70%, 80%, 90% w/w of the substrate. In some other instances, the functional polymer can be of 90-99% w/w of the other polymers in the substrate. Generally, the functional polymer imparts the substrate its particular physical and chemical properties.

The functional polymer, in some instances, can be a thermoplastic or

thermoelastic polymer. The term "thermoplastic" as used herein refers to a material that melts, softens, becomes more flexible, extrudable, deformable, shapable, moldable, flowable, processable, and/or changes rheology when exposed to heat. In some instances, the material generally solidifies, hardens, and/or substantially returns to its original condition, when subsequently cooled. The term "thermoelastic" generally means a material that changes shape, expansion or contraction in response to change in temperature.

For example, the functional polymer can be polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyvinyl chloride (PVC), polystyrene, polycarbonate, polyurethane, polyvinyl ether, polyvinyl acetate and the like. In some instances, it could be a mixture of two or more of the above polymers.

Polymethylmethacrylate (PMMA), also known as acrylic glass, is light weight and shatter-resistant and is an alternative to glass. PMMA is a synthetic polymer of methyl methacrylate (MMA). PMMA products are marketed under various trademarks such as PLEXIGLAS, ACRYLITE, LUCITE and PERSPEX. PMMA is a good alternative to polycarbonate in applications where an extreme strength is not necessary. Often PMMA is a preferred polymer because of the low cost, moderate properties and easy handling and processing.

PMMA is a useful material in a wide range of fields and applications such as rear lights and instrument clusters for vehicles, appliances, lenses for glasses. PMMA in the form of sheets can be used as shatter resistant panels for building windows, skylights, bullet proof security barriers, signs and displays, sanitary ware (bath tubs), LCD screens, furniture and many other applications.

A polycarbonate is generally produced using bisphenols as monomer ingredients and because of its superiority such as transparency, heat resistance and mechanical strength, is widely utilized as a so-called engineering plastic in the fields of electric/electronic parts, automotive parts, optical recording mediums, optics such as lens, and the like.

Generally, the substrates comprise the functional polymer in amounts of at least about 50% or more. The functional polymers can be any of the polymers or mixtures thereof, discussed above. In some instances, the substrates comprise PMMA as the functional polymer. In these cases, the substrate can comprise at least about 50%, 60%, 70%, 80% or 90% of PMMA by w/w of other polymers. In some instances, the substrate can also comprise about 90%-99% PMMA by w/w of other polymers. In other instances, the substrates comprise

polycarbonate as the functional polymer. In these cases, the substrate can comprise at least about 50%, 60%, 70%, 80% or 90% of polycarbonate by w/w of other polymers. In some instances, the substrate can also comprise about 90%-99% polycarbonate by w/w of other polymers.

The substrates can also comprise a mixture of polymers. For example, in these cases, the functional polymer is the major polymer, generally, in at least about 50% by w/w of the other polymers. For example, the substrate can comprise PMMA and polycarbonate. In these cases, the PMMA can be present in about 60%-99% by w/w, and the rest could be polycarbonate. For example, PMMA: polycarbonate can be 70:30, 80:20, 85:15 or 90:10 by w/w.

Some of the substrates can be covered with protective coatings, paint and the like. In such instances, while the substrates comprise the functional polymer A in major amounts, the top protective layer may contain functional polymer B in major amounts. For example, some substrates are coated with acrylic polymer- based paints or coatings. Accordingly, bonding surfaces of some of the substrates may contain functional polymer B in major amounts.

In some instances, the substrates could be layered structures. In these cases, the layer that is subjected to the bonding with other substrates may contain a majority of functional polymer A, while the other layers can contain different substances or different polymers. The top layer may also contain a protective covering or sheet as discussed above.

In addition to these polymers that make up the structure of the substrate, optionally, other well-known additives can also be present. Non-limiting examples of these optional additives include adhesion promoters; biocides (antibacterials, fungicides, and mildewcides), anti-fogging agents; anti-static agents; bonding, blowing and foaming agents; dispersants; fillers and

extenders; smoke suppresants; expandable char formers; impact modifiers; initiators; lubricants; micas; pigments, colorants and dyes; plasticizers;

processing aids; other polymers; release agents; silanes, titanates and zirconates; slip and anti-blocking agents; stabilizers; stearates; ultraviolet light absorbers; viscosity regulators; waxes; and combinations of them.

The Adhesive Composition

According to the methods and compositions disclosed herein, the above substrates are bonded or fused together using an adhesive composition.

The important feature of these adhesive compositions is that the adhesive matrix of these comprise the same functional polymer as the substrate. The functional polymer has the similar physical and chemical properties, although in some cases may not be identical, between the substrate and the adhesive composition. However, the similarities are close enough such that the mobile polymer chains can entangle and form physical bonds between the substrate and the adhesive composition.

"adhesive matrix" in this context means composition comprising functional polymer A; optionally, functional polymer B; other polymers and additives.

"adhesive composition" means the adhesive matrix solubilized in the dispersing solvent; in other words, adhesive composition comprises the adhesive matrix and the dispersing solvent. The adhesive composition, in its functional form, is present as a homogenous solution. A suitable dispersing solvent solubilizes the adhesive matrix to form a homogenous solution, "dispersing solvent" in this context means an appropriate solvent that can solubilize the adhesive matrix to form a homogenous solution, and that can at least partially solubilize the bonding surfaces of the substrates. The dispersing solvent enables the functional polymer chains to be mobile. As the polymer chains become mobile, they will entangle with each other and embed in the adhesive composition and the substrate. These entangled and embedded polymer chains then form structurally integral bonds between the adhesive composition and the substrate, "structurally integral bond" in this context means physical bonds that extend between the adhesive composition and the substrate and that are structurally integrated between the substrate and the adhesive composition. In some instances, the functional polymer in the adhesive composition becomes integrated in the bonding surfaces of the substrates. In some other instances, the functional polymer in the adhesive composition becomes integrated and embedded within the substrate, i.e., beyond the bonding surfaces of the substrates. In contrast, the adhesive compositions known in the skill of art, bond the substrates together by the adhesive forces. No structurally integral bonds are formed in these instances. The methods and compositions disclosed herein advantageously exploit the similarity in the chemical and physical properties of the functional polymer and form structurally integral bonds between the adhesive composition and the substrate, thereby fusing or bonding substrates together. For example, in some instances, the adhesive composition and the substrates all become one unified structure.

The functional polymer A is the same as the one present in the substrates. Accordingly, the functional polymer A in the adhesive composition can be any one of polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyvinyl chloride (PVC), polystyrene, polycarbonate, polyurethane, polyvinyl ether, polyvinyl acetate and combinations thereof.

In some instances, the functional polymer A can be present in the same amounts as in the materials been bonded together. For example, the functional polymer can be present in the amounts of about 60% to about 99%. In some cases, if the materials comprise the functional polymer in amounts of about 80%, the adhesive composition can also comprise the functional polymer in the amount of 80%.

In some other instances, the materials been bonded together and the adhesive composition have different amounts of functional polymer A. For example, in some instances, the materials may contain more functional polymer than that of the adhesive composition.

Accordingly, in some other instances, the functional polymer A can be present in lesser amounts than that of the substrates. For example, the adhesive composition may comprise the functional polymer in the amounts of less than about 20%, 30%, 40%, 50%, 60% or 70% than that of the substrates. In other words, the adhesive composition can comprise about 80%, 70%, 60%, 50%, 40% or 30% of the functional polymers, while the rest of the composition could be other materials.

The functional polymer in the adhesive composition, in some instances, can be PMMA. In these instances, PMMA can be present in amounts of about 80%, 70%, 60%, 50%, 40% or 30%. In general, PMMA can be present in any amount in the range of about 30% to about 70%. In some particular instances, PMMA can be present in amounts of about 40%.

In addition to the functional polymer A, other polymers can be present. For example, the adhesive composition can comprise the functional polymer B. Generally, the functional polymer B is in amounts less than those of the functional polymer A. Accordingly, the functional polymer B can be present in amounts of about 20%, 30%, 40% or about 50%. Compared to other polymers (Other than functional polymer A), additives or substances, functional polymer B, when present, is present in higher amounts.

The functional polymer B can be selected from any one of

polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyvinyl chloride (PVC), polystyrene, polycarbonate, polyurethane, polyvinyl ether and polyvinyl acetate provided that functional polymer A and B are not the same at any given instance. For example, if the functional polymer A is PMMA, the functional polymer B is polycarbonate. In some instances, the adhesive composition comprises about 1 % to about 60% functional polymer A. In some other instances, the functional polymer A is present in about 1 % to about 40%. Functional polymer B can be present in about 1 % to about 40%. In some instances, the functional polymer B can be present in about 1 % to about 20%.

In some instances, the adhesive composition comprises 1 % to 60% by weight of functional polymer A compared to the total weight of the adhesive

composition. In some other instances, the functional polymer A is present in 1 % to 40% by weight, alternatively 5% to 40% by weight, alternatively 1 0% to 40% by weight, alternatively 20% to 40% by weight, alternatively 25% to 35% by weight, compared to the total weight of the adhesive composition. Functional polymer B can be present in 1 % to 40% by weight, compared to the total weight of the adhesive composition. In some instances, the functional polymer B can be present in 1 % to 20% by weight, alternatively 5% to 20% by weight, alternatively 1 0% to 20% by weight, compared to the total weight of the adhesive composition.

When both functional polymer A and B are present, the functional polymer A can be in amounts of about 1 % to about 60%, and the functional polymer B can be in amounts of about 1 % to about 40%. In some of these instances, the functional polymer A can be present in amounts of about 1 % to about 40%, while the functional polymer B can be present in amounts of about 1 % to about 20%. For example, if the functional polymer A is PMMA, it can be present in amounts of 1 % to about 40% and if the functional polymer B is polycarbonate, it can be present in amounts of about 1 % to about 20%.

Alternatively, when both functional polymer A and B are present, the functional polymer A can be present in amounts of 1 % to 60% by weight, and the functional polymer B can be present in amounts of 1 % to 40% by weight, compared to the total weight of the adhesive composition. In some of these instances, the functional polymer A can be present in amounts of 1 % to 40% by weight, while the functional polymer B can be present in amounts of 1 % to 20% by weight, compared to the total weight of the adhesive composition.

Alternatively, the functional polymer A can be present in amounts of 5% to 40% by weight, while the functional polymer B can be present in amounts of 5% to 20% by weight, compared to the total weight of the adhesive composition.

Alternatively, the functional polymer A can be present in amounts of 10% to 40% by weight, while the functional polymer B can be present in amounts of 10% to 20% by weight, compared to the total weight of the adhesive

composition. For example, if the functional polymer A is PMMA, it can be present in amounts of 1 % to 40% by weight, and if the functional polymer B is polycarbonate, it can be present in amounts of 1 % to 20% by weight, compared to the total weight of the adhesive composition. For example, if the functional polymer A is PMMA, it can be present in amounts of 5% to 40% by weight, and if the functional polymer B is polycarbonate, it can be present in amounts of 5% to 20% by weight, compared to the total weight of the adhesive composition. For example, if the functional polymer A is PMMA, it can be present in amounts of 10% to 40% by weight, and if the functional polymer B is polycarbonate, it can be present in amounts of 10% to 20% by weight, compared to the total weight of the adhesive composition.

In some other instances, the adhesive compositions comprise only the functional polymer A. In other words, these compositions do not comprise functional polymer B. Accordingly, these compositions can comprise the functional polymer B in amounts of about 0% to about 40%.

In addition to the functional polymers A and B, various amounts of other optional additives, polymers, reagents and the like that impart the desired physical and chemical properties can also be present. Non-limiting examples of these optional additives include adhesion promoters; biocides (antibacterials, fungicides, and mildewcides), anti-fogging agents; anti-static agents; bonding, blowing and foaming agents; dispersants; fillers and extenders; smoke suppresants; expandable char formers; impact modifiers; initiators; lubricants; micas; pigments, colorants and dyes; plasticizers; processing aids; other polymers; release agents; silanes, titanates and zirconates; slip and antiblocking agents; stabilizers; stearates; ultraviolet light absorbers; viscosity regulators; waxes; and combinations of them.

The functional polymers A, functional polymer B when present, along with the optional additives (adhesive matrix) form a homogenous solution upon mixing with a suitable dispersing solvent. The Dispersing Solvent

The above mixture of one or more of functional polymer A, B and the optional additives (adhesive matrix) are then dissolved in a suitable dispersing solvent. The dispersing solvent is chosen such that it forms a homogenous solution of the adhesive matrix. The solution is of a sufficient viscosity such that it can be used as an adhesive composition. For example, the adhesive composition has the viscosity levels generally known in the skill of art for adhesive compositions. The dispersing solvent can be used such that in addition to a homogenous solution, the contents of the adhesive composition can also be present as a gel. In some instances, the adhesive matrix, together with the solvent can be present in any other physical form well-known in the skill of art.

Additionally, the dispersing solvent is chosen such that it could solubilize, at least partially, the bonding surfaces of the materials been bonded. This facilitates the mobility of the polymer chains. The mobile polymer chains in the bonding surfaces then entangle with the mobile polymer chains in the adhesive composition. The polymer chains form physical bonds with each other. As the solvent is removed, the mobility of the polymer chains will decrease, and the physical bonds will stabilize. These polymer bonds will integrate structurally between the adhesive composition and the bonding surfaces forming

structurally integral bonds.

In contrast to the adhesive compositions known in the skill of art, where the surfaces are attached together by adhesive forces, these structural bonds integrate into and reside within both the adhesive composition and the bonding surfaces. Accordingly, these bonds provide greater stability and durability. In some instances, the structural bonds are seamless, the materials been bonded together and the adhesive composition become one structural unit.

The dispersing solvent is mixed with the components of the adhesive

composition according to the methods well-known in the art. The solvent is used in appropriate amounts to obtain the desirable physical characteristics such as viscosity depending on the application. The solvent can be used in amount of about 20% to about 80%, about 20% to about 70%, about 20% to about 60%, about 20% to about 50%, about 20% to about 40% or 20% to about 30% by w/w of the other components. Accordingly, in some instances, the adhesive composition comprises about 1 % to about 40% functional polymer A, about 1 % to about 20% functional polymer B and about 20% to about 60% dispersing solvent. In some of these instances, the functional polymer A is PMMA and the functional polymer B is

polycarbonate.

Accordingly, in some instances, the adhesive composition comprises 1 % to 40% functional polymer A, 1 % to 20% functional polymer B and 20% to 60% dispersing solvent. In some of these instances, the functional polymer A is PMMA and the functional polymer B is polycarbonate.

Generally, the dispersing solvent is a solvent with a boiling point between 40 and 220 °C. In some instances the boiling point is between 40 and 150 °C, and in some other instances, the boiling point is between 40 and 100 °C. In some cases, the boiling can be below 150 °C, 100 °C or 50 °C. In some instances, the boiling point of the solvent is below 40 °C. Some suitable solvents include the solvents that can be removed by ambient temperature evaporation or by milder heat treatments.

Some examples of suitable dispersing solvents are dichloromethane, chloroform, carbon tetrachloride, acetone, butanone, methanol, ethanol, butanol, propanol, iso-propanol, iso-butanol, THF, acetonitrile, toluene, xylene, monochlorobenzene (MCB), dichlorobenzene (DCB), trichlorobenzene (TCB), dimethylformamide (DMF), dimethylacetate (DMAC), ethylacetate and combinations thereof. In some instances, the dispersing solvent is

dichloromethane. In these cases, dichloromethane can be present in about 20% to about 60%. Accordingly, one embodiment of the adhesive composition comprises about 1 % to about 40% functional polymer A, about 1 % to about 20% of the functional polymer B and dispersing solvent in about 20% to about 60%. In some of these instances, the functional polymer A is PMMA, functional polymer B is polycarbonate and the dispersing solvent is dichloromethane. The adhesive composition can be applied to the substrates been bonded by any of the known methods. For example, the adhesive composition can be applied to the bonding surfaces using a syringe, drop bottle, squeezable tube or bottle and the like. Additionally, the adhesive matrix and the solvent can be supplied in the same container or different container. When the adhesive matrix (without the dispersing solvent) and the dispersing solvent are supplied separately, the customer can mix the adhesive matrix and the solvent together according to the instructions provided.

The disclosure herein also provides a method of bonding two structural units or substrates together, "structural units" in this context means any solid, or semisolid, rigid, semi-rigid or flexible materials. In some instances, these by themselves or with other units together form structural designs or architecture. Assembly of automobile parts, machine components, consumer electronic components are good examples.

According to these methods, bonding or fusing two substrate surfaces together involves forming a structurally integral bond between the adhesive composition and the bonding surfaces of the substrates. The two substrates comprise a functional polymer A. These methods comprise providing an adhesive matrix comprising the functional polymer A, the functional polymer is capable of forming structurally integral physical bonds with the functional polymer chains in the bonding surfaces of the substrates when the freedom of mobility increases, i.e., upon addition of the dispersing solvent. In this instance, the "adhesive matrix" means a composition comprising the functional polymer A; optionally the functional polymer B; and other polymers and additives etc., without the dispersing solvent. The methods further comprise providing a dispersing solvent that can solubilize the adhesive matrix to form a homogenous solution. Additionally, the dispersing solvent at least partially solubilizes the bonding surfaces of the substrates. The homogenous solution of adhesive composition is then applied on the bonding surfaces of the substrates, which will at least partially solubilize the bonding surfaces, thereby increasing the mobility of the polymer chains, "partially soluble" means that the solvent does not completely solubilize the bonding surfaces; the dispersing solvent is not present in sufficient amounts to do so-instead, the dispersing solvent makes the bonding surfaces soluble enough such that the polymer chains have the sufficient mobility to entangle and form physical bonds with the polymer chains in the adhesive composition. The solvent is then removed by any of the known techniques such as air drying, blow drying, evaporation, mild heat treatment and the like. Generally, milder conditions are used to remove the solvent. Articles and structures can be bonded and assembled into unitary structures using the methods and compositions disclosed herein. Such a bonded article comprises at least two structural units comprising a functional polymer A and an adhesive composition comprising a functional polymer A. The structural units are bonded or fused together by structurally integral bonds formed by the polymer chains of the functional polymer A. In some of these cases, the functional polymer is PMMA. In some instances, when the adhesive

composition comprises the functional polymer B in addition to the functional polymer A, functional polymer B is polycarbonate.

The adhesive compositions can be provided in a kit. In some instances, the kit comprises adhesive composition comprising functional polymer A and a dispersing solvent. In some instances, the adhesive matrix (i.e., solid components of the adhesive composition) can be in one container and the dispersing solvent is in another, separate container. In other instances, the adhesive matrix and the dispersing solvent are in one container. When the adhesive matrix and the dispersing solvent are in different containers, a set of instructions is provided so that a purchaser can proportionately mix the two items as needed for the particular application.

The disclosed methods and compositions provide several advantages over the existing methods known in the art. The advantages are ease of use, strength and durability, cleanliness and not subjected to solvent run off, easy to make, less toxic solvents, can be used on-demand without pre-mixing the precursors etc. Additionally, since less toxic, inflammable solvents and smaller amounts are used, the safety profile is better than the available methods. In fact, using the methods and compositions disclosed herein, the solvent levels can be reduced by at least about 30%, 40%, 50%, 60%, 70% or 80%, compared to other known methods such as solvent welding.

In addition, in techniques such as solvent welding, the solvent cannot be used to fill the gaps, cracks or spaces. The methods and compositions provided herein are attractive alternatives, where these gaps, cracks or spaces can be filled without the need for additional filler materials or cements.

In general, the invention may alternately comprise, consist of, or consist essentially of, any appropriate components herein disclosed. The invention may additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any components, materials, ingredients, adjuvants or species used in the prior art compositions or that are otherwise not necessary to the

achievement of the function and/or objectives of the present invention.

EXPERIMENTAL

Exemplary Formulation I (For bonding coated PMMA substrates)

• 35% weight of functional polymer A, polymethylmethacrylate, which

forms the base of the structural formulation.

· 15% of functional polymer B, polycarbonate, which compensates or is complimentary to the functions of polymer A, and helps to form the base of the structural formulation.

• Dispersing solvent, methylenechloride, which dissolves or disperses all the components into one homogeneous solution or glue, 47%.

· Stabilizing agent, Irganox 1076 and Irgafos 1 68, which makes the

bonding lasts as long as or longer than the parts, 0.1 % each.

• 2.8% high-impact modifier, rubber, which may make the bonding material more impact-resistant. Exemplary Formulation II (for bonding PMMA substrates)

• 50% weight of functional polymer A, polymethylmethacrylate, which

forms the base of the structural formulation.

· Stabilizing agent, Irganox 1076 and Irgafos 1 68, which makes the

bonding lasts as long as or longer than the parts, 0.1 % each.

• 2.8% high-impact modifier, rubber, which may make the bonding material more impact-resistant. Experimental Procedure

For each formulation, weighted amounts of the solids, polymers and additives are placed in a container, usually a glass bottle. The weighted dispersing solvent is then added to the bottle, and the bottle is covered with a lid. The screw is not tightened and kept lose. The bottle was then sonicated in a water batch sonicator, and the mixture was sonicated for about 10 to 15 minutes, or a little longer as long as the temperature is below the boiling point of the particular solvent used, until a homogenous solution is obtained. Alternatively, the tightly capped bottle is shaken in an automatic shaker for about 1 to 2 hours, or overnight, until a homogenous solution is obtained.

Testing the Bond Strength

A bonded article, an automotive rear light panel, was raised up to about 2 meters and dropped on a hard surface such as a concrete floor. The

automotive rear light panel broken up into pieces while the adhesive bond remained intact. This demonstrates the strength and durability of the adhesive bond between the two substrates (two rear light panels).

The adhesive composition and methods, articles and process of making the adhesive composition are further illustrated by the following embodiments, which are non-limiting.

Aspect 1 . An adhesive composition for bonding surfaces of at least two structural units comprising a functional polymer A, comprising:

An adhesive matrix comprising the functional polymer A, and

a dispersing solvent, which solubilizes the adhesive matrix to form a

homogeneous solution and at least partially solubilizes the bonding surfaces of the structural units, and wherein the functional polymer A in the adhesive matrix and the functional polymer A in the structural units form structurally integral bonds with each other.

Aspect 2. The adhesive composition of aspect 1 , wherein the adhesive matrix further comprising a functional polymer B.

Aspect 3. The adhesive composition of aspect 2, wherein at least one of the functional polymer A and B is a thermoplastic or thermoelastic polymer.

Aspect 4. The adhesive composition of aspect 1 , wherein the functional polymer A is selected from at least one of polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyvinyl carbonate (PVC), polystyrene,

polycarbonate, polyurethane, polyethylene glycol, polyvinyl acetate,

polyacrylamide, polyvinyl alcohol and combinations thereof. Aspect 5. The adhesive composition of aspect 1 , wherein the functional polymer A is PMMA.

Aspect 6. The adhesive composition of aspect 2, wherein the functional polymer B is selected from at least one of polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyvinyl carbonate (PVC), polystyrene,

polycarbonate, polyurethane, polyethylene glycol, polyvinyl acetate,

polyacrylamide, polyvinyl alcohol and combinations thereof.

Aspect 7. The adhesive composition of aspect 2, wherein the functional polymer B is polycarbonate.

Aspect 8. The adhesive composition of aspect 2, wherein the functional polymer A is PMMA AND the functional polymer B is polycarbonate.

Aspect 9. The adhesive composition of aspect 1 , comprising a functional polymer A and functional polymer B, wherein the polymer A and B are selected from at least one of polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyvinyl carbonate (PVC), polystyrene, polycarbonate, polyurethane, polyvinyl alcohol with the proviso that polymers A and B are not the same at one instance.

Aspect 10. The adhesive composition of aspect 1 further comprising one or more of stabilizing agents, high-impact modifiers, rheological modifiers, antioxidant agents, dispersing agents, colorants or pigments, antifungal or antibacterial agents, fillers and extenders; smoke suppresants; expandable char formers; initiators; lubricants; micas; dyes; plasticizers; processing aids; other polymers; release agents, silanes, titanates and zirconates; slip and antiblocking agents; stearates; ultraviolet light absorbers; viscosity regulators;

waxes and combinations thereof.

Aspect 1 1 . The adhesive composition of aspect 1 , comprising about 1 % to about 40% functional polymer A.

Aspect 12. The adhesive composition of aspect 1 , comprising about 0% to about 20% functional polymer B.

Aspect 13. The adhesive composition of aspect 2, wherein the functional polymer A is PMMA and the functional polymer B is polycarbonate.

Aspect 14. The adhesive composition of aspect 1 , comprising:

about 1 % to about 40% of functional polymer A; about 1 % to about 20% of functional polymer B; and

about 20% to 60% of dispersing solvent.

Aspect 1 5. The adhesive composition of aspect 14, wherein the functional polymer A is PMMA, functional polymer B is polycarbonate.

Aspect 1 6. The adhesive composition of aspect 1 , wherein the dispersing solvent is selected from dichloromethane, chloroform, acetone, methanol, ethanol, propanol, butanol, iso-propanol, iso-butanol, THF, dimethylformamide, dimethylacetate and combinations thereof.

Aspect 1 7. The adhesive composition of Aspect 1 , wherein the dispersing solvent is dichloromethane.

Aspect 1 8. The process of making the adhesive composition of aspect 1 , comprising the steps of:

providing an adhesive matrix comprising functional polymer A; and

solubilizing the adhesive matrix comprising the functional polymer A in a dispersing solvent to make a homogeneous solution.

Aspect 1 9. A method of forming a structurally integral bond between bonding surfaces of at least two structural units comprising functional polymer A, comprising the step of providing an adhesive matrix comprising functional polymer A.

Aspect 20. The method of aspect 1 9, further comprising:

providing a dispersing solvent that solubilizes the adhesive matrix comprising functional polymer A to form a homogenous solution and at least partially solubilizes the surfaces of the two structural units;

applying the homogeneous solution of the adhesive composition on the surfaces; and

drying the solvent to establish a structurally integral bond between the surfaces and the adhesive composition.

Aspect 21 . A bonded article comprising:

at least two structural units having bonding surfaces, the two structural units comprising a functional polymer A, and

an adhesive matrix comprising functional polymer A, wherein the bonding surfaces and the adhesive matrix form a structurally integral bond. Aspect 22. The bonded article of aspect 21 , wherein the functional polymer A is selected from at least one of polymethylmethacrylate (PMMA),

polymethylacrylate (PMA), polyvinyl carbonate (PVC), polystyrene,

polycarbonate, polyurethane, polyvinyl alcohol and combinations thereof.

Aspect 23. A kit comprising:

an adhesive matrix for bonding surfaces of at least two structural units comprising functional polymer A, wherein the adhesive matrix comprises functional polymer A in one container; and

a dispersing solvent that solubilizes the adhesive matrix to form a homogenous solution and at least partially solubilizes the bonding surfaces; and wherein, the dispersing solvent is in the same container or in a different container. While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art.

Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations,

improvements, and substantial equivalents.

Claims

1 . An adhesive composition for bonding surfaces of at least two structural units comprising a functional polymer A, comprising:

an adhesive matrix comprising the functional polymer A, and

a dispersing solvent, which solubilizes the adhesive matrix to form a homogeneous solution and at least partially solubilizes the bonding surfaces of the structural units, and wherein the functional polymer A in the adhesive matrix and the functional polymer A in the structural units form structurally integral bonds with each other.

2. The adhesive composition of claim 1 , wherein the adhesive matrix further comprising a functional polymer B.

3. The adhesive composition of any one of claims 1 -2 , wherein the

functional polymer A is selected from at least one of

polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyvinyl carbonate (PVC), polystyrene, polycarbonate, polyurethane,

polyethylene glycol, polyvinyl acetate, polyacrylamide, polyvinyl alcohol and combinations thereof.

4. The adhesive composition of any one of claims 2-3, wherein the

functional polymer B is selected from at least one of

polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyvinyl chloride (PVC), polystyrene, polycarbonate, polyurethane, polyethylene glycol, polyvinyl acetate, polyacrylamide, polyvinyl alcohol and

combinations thereof.

5. The adhesive composition of claim 2-4, wherein the functional polymer A is PMMA and the functional polymer B is polycarbonate.

6. The adhesive composition of any one of claims 2-5, comprising 1 % to 40% functional polymer A and 1 % to 20% functional polymer B.

7. The adhesive composition of any one of claims 2-6, comprising 1 % to 40% of functional polymer A, 1 % to 20% of functional polymer B, and 20% to 60% of dispersing solvent.

8. The adhesive composition of any one of claims 2-7, wherein the

functional polymer A is PMMA, and functional polymer B is

polycarbonate.

9. The adhesive composition of any one of claims 1 -8, wherein the

dispersing solvent is selected from dichloromethane, chloroform, acetone, methanol, ethanol, propanol, butanol, iso-propanol, iso-butanol, tetrahydrofuran, dimethylformamide, dimethylacetate and combinations thereof.

10. The process of making the adhesive composition of any one of claims 1 - 9, comprising the steps of:

providing an adhesive matrix comprising functional polymer A; and solubilizing the adhesive matrix comprising the functional polymer A in a dispersing solvent to make a homogeneous solution.

1 1 .A method of forming a structurally integral bond between bonding

surfaces of at least two structural units comprising functional polymer A, comprising the step of providing an adhesive matrix comprising functional polymer A, the method further comprising:

removing the solvent to establish a structurally integral bond between the surfaces and the adhesive composition.

12. A method according to claim 1 1 wherein the functional polymer A is selected from at least one of polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyvinyl carbonate (PVC), polystyrene, polycarbonate, polyurethane, polyethylene glycol, polyvinyl acetate, polyacrylamide, polyvinyl alcohol and combinations thereof.

13. A bonded article comprising:

an adhesive matrix comprising functional polymer A, wherein the bonding surfaces and the adhesive matrix form a structurally integral bond wherein the functional polymer A is selected from at least one of polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyvinyl chloride (PVC), Polycarbonate (PC), polystyrene (PS), polyurethane, polyvinyl alcohol, polyvinyl acetate (PVA) and combinations thereof.

14. A kit comprising:

a dispersing solvent that solubilizes the adhesive matrix to form a homogenous solution and at least partially solubilizes the bonding surfaces; and wherein,

the dispersing solvent is in the same container or in a different container.