ADHESION PROMOTERS

INTRODUCTION

[0001 ] The present invention relates to compounds that function as adhesion promoters. The present invention also relates to processes for their preparation, to compositions and primer solutions comprising them, and to their use in the promotion of adhesion to a surface.

BACKGROUND OF THE INVENTION

[0002] Adhesion promoters are used to improve the bonding strength between adhesives, sealants, coatings and inks to substrate surfaces where it is sometimes difficult to form a bond. This difficulty in forming a bond of sufficient strength between an adhesive, sealant, coating and/or ink composition and the surface of a substrate is often attributed to either the low surface energy of the substrate surface relative to that of the adhesive, sealant, coating and/or ink composition, or to the presence of a weak boundary layer or a degraded and/or polluted surface.

[0003] The physical and chemical nature of the substrate surface can of course vary greatly. In some instances, the substrate surface may be permeable, which may permit moisture and environmental chemicals to permeate to the interface between the adhesive, sealant, coating or ink composition and the substrate, thereby degrading the performance of the adhesive, sealant, coating or ink composition. Additionally, the porosity of the substrate surface can have an influence on the adhesion between, for example, an adhesive or sealant and the surface of the substrate, because porous surfaces often allow deep penetration of the adhesion promoter, potentially depleting the adhesion promoter at the target surface where bonding is required and thereby causing poor bonding. Furthermore, the surface may be contaminated and/or oxidised, which may also impair the adhesion.

[0004] Adhesion promoters may be used as additives in adhesive or sealant formulations or, alternatively, as surface primers. Primers and adhesion promoters work in a similar way to improve adhesion between two species. Both primers and adhesion promoters typically work by forming a new, usually organic, bifunctional layer, on the surface of the substrate. This new layer can then form bonds to, or interactions with, both the surface of the substrate and the adhesive/sealant matrix, thereby adhering the adhesive/sealant to the surface of the substrate. The main difference between primers and adhesion promoters is that primers are applied to the substrate prior to the application of the adhesive or sealant, whereas adhesion promoters are added in situ with the adhesive or sealant. Typically, adhesion promoters are included in the adhesive or sealant compositions and, once applied to a substrate surface, the adhesion promoter migrates to the substrate surface where it can form chemical bonds between the surface of the substrate and interact with polymer components within the adhesive or sealant. Some of the most commonly used adhesion promoters used in moisture curable hybrid formulations are organosilanes, such as aminosilanes.

[0005] There are an increasing number of moisture-curable sealant and adhesive products being made available to the professional and domestic markets. These products have many performance advantages over alternative sealants. One class of such moisture-curable products are often referred to as hybrid sealants or modified silicone (MS) sealants. These products are typically moisture-curable systems containing silane-modified polyethers. Commercial examples include MS polymers from Kaneka, or a silyl-modified polyurethane, such as Momentive's SPUR® 1015LM. Typically, such formulations contain a silane terminated polyether in conjunction with an amino silane adhesion promoter.

[0006] One issue with hybrid adhesives and sealants is that they sometimes offer inferior adhesion to a number of key substrates such as some plastics, stainless steel and concrete.

[0007] Thus, there remains a need for new adhesion promoters that address the aforementioned problems.

[0008] The present invention was devised with the foregoing in mind.

SUMMARY OF THE INVENTION

[0009] According to a first aspect of the present invention there is provided a compound of formula (I), shown below:

wherein:

Ri , R ₂ and R ₃ are independently selected from hydrogen, (1 -4C)alkyl, hydroxy or (1 -4C)alkoxy;

R ₄ and R ₅ are independently selected from hydrogen or (1 -4C)alkyl; x is an integer selected from 0 to 6;

n is an integer selected from 1 or 2; L is a linker;

Q is a polyether comprising between 3 and 50 repeat units; and when n is 1 , W is selected from:

(i) NRia, O or S(0) _y (wherein y is 0, 1 or 2), wherein Ri _a is selected from hydrogen or (1 -4C)alkyl; or

(ii) a group of the formula:

Wi-(CRwl Rw2)c-[W ₂ -(CRw3Rw4)d]e-W ₃

wherein:

Wi, W ₂ and W ₃ are independently selected from NRi _b , O or S(0) _y i (wherein yi is 0, 1 or 2), and wherein Ri _b is selected from hydrogen or (1 -4C)alkyl;

Rwi , Rw2, Rw3 and R _W 4 are independently selected from hydrogen or (1 -4C)alkyl;

c and d are independently integers from 1 to 4;

e is an integer from 0 to 2; and

when n is 2, W is selected from N or a group of the formula:

W ₄ -(CR _w5 R _w6 ) _f -[W5-(CRw7Rw8)g] _h -W ₆ wherein:

W ₄ and W ₅ are independently selected from NRi _c , O or S(0)y2 (wherein y ₂ is 0, 1 or 2), and wherein Ri _c is selected from hydrogen or (1 -4C)alkyl;

W ₆ is N;

Rw5, Rw6, Rw7 and R _w s are independently selected from hydrogen or (1 -4C)alkyl;

f and g are independently integers from 1 to 4; and h is an integer from 0 to 2;

with the proviso that at least one of Ri, R ₂ or R ₃ is a (1 -4C)alkoxy or hydroxyl group.

[0010] According to a second aspect of the present invention, there is provided a composition comprising a compound as defined herein and optionally a moisture scavenger.

[0011 ] According to a third aspect of the present invention, there is provided a sealant, adhesive, coating or ink composition comprising a compound as defined herein.

[0012] According to a fourth aspect of the present invention, there is provided a primer solution comprising a compound as defined herein and a solvent. [0013] According to a fifth aspect of the present invention, there is provided a use of a compound, a composition or a primer solution as defined herein for promoting adhesion to a surface.

[0014] According to a sixth aspect of the present invention, there is provided a process for the preparation of a compound as defined herein, said process comprising the steps of reacting a compound of formula (III) with a compound with formula (IV):

(IV)

wherein:

W is as defined herein; and

FGi is a functional group that when reacted with W-H links Q to W via linker group L, as defined herein; and

Ri , R ₂ , R3, R4, R5, x and Q are as defined herein.

[0015] According to a seventh aspect of the present invention, there is provided a compound obtained, obtainable or directly obtained by any process defined herein.

[0016] Features, including optional, suitable, and preferred features in relation to one aspect of the invention may also be features, including optional, suitable and preferred features in relation to any other aspect of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

[0017] Unless otherwise stated, the following terms used in the specification and claims have the following meanings set out below.

[0018] In this specification the term "alkyl" includes both straight and branched chain alkyl groups. References to individual alkyl groups such as "propyl" are specific for the straight chain version only and references to individual branched chain alkyl groups such as "isopropyl" are specific for the branched chain version only. For example, "(1 -6C)alkyl" includes (1 -4C)alkyl, (1 -3C)alkyl, propyl, isopropyl and f-butyl. A similar convention applies to other radicals, for example "phenyl(1 -6C)alkyl" includes phenyl(1 -4C)alkyl, benzyl, 1 -phenylethyl and 2-phenylethyl. [0019] The term "(m-nC)" or "(m-nC) group" used alone or as a prefix, refers to any group having m to n carbon atoms.

[0020] The term "alkylene" refers to an alky group that is positioned between and serves to connect two other chemical groups. Thus, "(1 -6C)alkylene" means a linear saturated divalent hydrocarbon radical of one to six carbon atoms or a branched saturated divalent hydrocarbon radical of three to six carbon atoms, for example, methylene, ethylene, propylene, 2- methylpropylene, pentylene, and the like.

[0021 ] The term "moisture curable" used herein will be understood as referring to the process of curing or crosslinking (i.e. the toughening or hardening) of a chemical species, typically a polymer, through contact with water or moisture.

[0022] References to "polymeric components" of the adhesive and/or sealant compositions, as defined herein, will be understood as referring to any polymeric components present in such compositions (e.g. high molecular weight polyethers).

[0023] The phrase "compound of the invention" means those compounds which are disclosed herein, both generically and specifically.

Compounds of the invention

[0024] As described hereinbefore, the present invention relates to compounds having the structural formula (I) shown below:

wherein:

Ri , R ₂ and R ₃ are independently selected from hydrogen, (1 -4C)alkyl, hydroxy or (1 -4C)alkoxy;

R ₄ and R ₅ are independently selected from hydrogen or (1 -4C)alkyl; x is an integer selected from 0 to 6;

n is an integer selected from 1 or 2;

L is a linker;

Q is a polyether comprising between 3 and 50 repeat units; and when n is 1 , W is selected from: (i) NRia, O or S(0) _y (wherein y is 0, 1 or 2), wherein Ri _a is selected from hydrogen or (1 -4C)alkyl; or

(ii) a group of the formula:

Wi-(CRwl Rw2)c-[W ₂ -(CRw3Rw4)d]e-W ₃

wherein:

Wi, W ₂ and W ₃ are independently selected from NRi _b , O or S(0) _y i (wherein yi is 0, 1 or 2), and wherein Ri _b is selected from hydrogen or (1 -4C)alkyl;

Rwi , Rw2, Rw3 and R _W 4 are independently selected from hydrogen or (1 -4C)alkyl;

c and d are independently selected from integers from 1 to 4;

e is an integer from 0 to 2; and

when n is 2, W is selected from N or a group of the formula:

W ₄ -(CRw5Rw6)f-[W5-(CRw7Rw8)g]h-W ₆ wherein:

W ₄ and W ₅ are independently selected from NRi _c , O or S(0)y2 (wherein y ₂ is 0, 1 or 2), and wherein Ri _c is selected from hydrogen or (1 -4C)alkyl;

W ₆ is N;

Rw5, Rw6, Rw7 and R _w s are independently selected from hydrogen or (1 -4C)alkyl;

f and g are independently integers from 1 to 4; and h is an integer from 0 to 2;

with the proviso that at least one of Ri, R ₂ or R ₃ is a (1 -4C)alkoxy or hydroxyl group.

[0025] The compounds of the present invention function as adhesion promoters, thereby enhancing adhesion between a sealant, adhesive, coating and/or ink composition and the surface of a given substrate. When compared with currently-available adhesion promoters, the compounds of the present invention present a number of performance advantages. Firstly, the adhesion promoters, due to their chemical composition and relatively low molecular weight, are miscible with, and thus may be readily incorporated into, a number of hybrid sealant, adhesive, coating and/or ink compositions using conventional mixing equipment. This not only serves to make the adhesion promoters compatible with a large number of commercially available sealant, adhesive, coating and/or ink compositions, but it also significantly increases the number of bonding interactions between the adhesion promoter and: (i) the sealant, adhesive, coating and/or ink composition; and (ii) the substrate surface. The compounds of the present invention also demonstrate a remarkable promotion of adhesion to surfaces that are typically considered a challenge to adhere to, such as, for example, PVC and stainless steel.

[0026] Furthermore, the compounds of the present invention can also be synthesised extremely easily. For example, the compounds can be synthesised by a facile one-step process, which is solvent-free from readily available reactants and does not require any additional purification steps.

[0027] An additional benefit of the compounds of the present invention is that they are significantly less hazardous to human health when compared to currently available organo silane adhesion promoters such as aminosilanes, epoxy silanes and isocyante-functional silane-based adhesion promoters.

[0028] In an embodiment, the compounds of the present invention have an average molecular weight of between 250 and 3,000 Da. Suitably, the compounds of the present invention have an average molecular weight of between 300 and 2,200 Da.

[0029] It will also be appreciated that the compounds of the present invention, due to their molecular size and presence of a polyether moiety (Q), may also be referred to as polymers or oligomers depending on their molecular weight. A person skilled in the art will understand that a polymer or an oligomer rarely consists of molecules having exactly the same degree of polymerisation, and hence the same molar mass (or molecular weight). More typically, there will be a distribution of molecular sizes and molecular weights for any given polymer. The compounds of the present invention will have a dispersity (D), formerly known as polydispersity index) of less than 2, and more suitably less than 1 .5. The dispersity will be understood by a person skilled in the art as referring to the ratio of the weight average molecular weight to the number average molecular weight of the compound of the present invention.

[0030] The compounds of the present invention are typically liquids. The compounds of the present invention may have any suitable viscosity. Suitably, the compounds of the present invention will have a viscosity that is compatible with either application to a substrate surface (e.g. as a primer) and/or inclusion into a sealant, adhesive, coating and/or ink composition. It will be appreciated that viscosity of the compound of the present invention, or the compositions comprising them, may vary depending upon the surface that they are to be applied to.

[0031] In an embodiment, the compounds or compositions of the present invention have a viscosity of between 10 and 10,000 mPa-S. In another embodiment, the compounds of the present invention have a viscosity of between 10 and 5,000 mPa-S. In another embodiment, the compounds of the present invention have a viscosity of between 10 and 1 ,000 mPa-S. In a further embodiment, the compounds of the present invention have a viscosity of between 50 and 500 mPa-S. In a particular embodiment, the viscosity is between 340 and 370 mPa-S.

[0032] Without wishing to be bound by any particular theory, it is believed that the silane moiety (-SiRiR ₂ R ₃ ) and the heteroatoms of groups W, L and Q of the compounds of the present invention contributes to binding and/or interaction of the compound to a substrate surface. It will be appreciated that at least one of the groups Ri, R ₂ and R ₃ is either a hydroxyl group or an alkoxy group that is susceptible to hydrolysis to form a hydroxyl group upon contact with moisture. These hydroxyl groups may react and crosslink with functional groups present on the substrate surface to covalently bind the adhesion promoter to the substrate surface.

[0033] In an embodiment, Ri, R ₂ and R ₃ are independently selected from hydrogen, (1 - 4C)alkyl, hydroxy or (1 -4C)alkoxy. In an embodiment, Ri, R ₂ and R ₃ are independently selected from (1 -4C)alkyl, hydroxy or (1 -4C)alkoxy. In an embodiment, Ri, R ₂ and R ₃ are independently selected from (1 -4C)alkyl or (1 -4C)alkoxy. In an embodiment, Ri, R ₂ and R ₃ are independently selected from (1 -2C)alkyl or (1 -2C)alkoxy. In an embodiment, Ri, R ₂ and R ₃ are independently selected from methoxy or ethoxy. In an embodiment, Ri, R ₂ and R ₃ are all methoxy.

[0034] In another embodiment of the compounds of the present invention, at least one of Ri, R ₂ or R ₃ is a (1 -4C)alkoxy group (e.g. methoxy). In yet another embodiment, at least two of Ri, R ₂ or R ₃ are (1 -4C)alkoxy groups (e.g. methoxy). In yet another embodiment, all of Ri, R ₂ or R ₃ are (1 -2C)alkoxy groups (e.g. methoxy).

[0035] The siliane (-SiRiR ₂ R ₃ ) group is attached to the compounds of the present invention via the -[C(R ₄ )(R5)]x- group defined hereinabove. In an embodiment, R ₄ and R ₅ are independently selected from hydrogen or (1 -2C)alkyl. In yet another embodiment, R ₄ and R ₅ are both hydrogen.

[0036] In another embodiment, x is an integer selected from 0 to 4. In yet another embodiment, x is an integer selected from 2 to 4. In yet another embodiment, x is 3.

[0037] In an embodiment, n is 1.

[0038] In an embodiment, n is 2.

[0039] In an embodiment, when n is 1 , W is selected from:

(i) NRia, wherein Ri _a is selected from hydrogen or (1 -4C)alkyl; or

(ii) a group of the formula:

Wi-(CRwl Rw ₂ )c-[W ₂ -(CR _w3 Rw4)d]e-W ₃

wherein:

Wi, W ₂ and W ₃ are NRi _b , wherein Ri _b is selected from hydrogen or (1 -4C)alkyl; Rwi , w2, Rw3 and R _W 4 are independently selected from hydrogen or (1 -4C)alkyl;

c and d are independently integers from 1 to 4;

e is an integer from 0 to 1 ; and

when n is 2, W is selected from N or a group of the formula:

W ₄ -(CRw5Rw6)f-[W5-(CRw7Rw8)g]h-W ₆ wherein:

W ₄ and W ₅ are NRi _c , wherein Ri _c is selected from hydrogen or (1 -4C)alkyl;

W ₆ is N;

Rw5, Rw6, Rw7 and R _w s are independently selected from hydrogen or (1 -4C)alkyl;

f and g are independently integers from 1 to 4; and h is an integer from 0 to 1 .

[0040] In another embodiment, when n is 1 , W is selected from:

(i) NRia, wherein Ri _a is selected from hydrogen or methyl; or

(ii) a group of the formula:

Wi-(CH ₂ )c-[W2-(CH ₂ )d]e-W3

wherein:

Wi, W ₂ and W ₃ are NRi _b , wherein Ri _b is selected from hydrogen or (1 -4C)alkyl;

c and d are independently integers from 2 to 4;

e is an integer from 0 to 1 ; and

when n is 2, W is selected from N or a group of the formula:

W4-(CH2) _f -[W5-(CH ₂ )g]h-W ₆ wherein:

W ₄ and W ₅ are NRi _c , wherein Ri _c is selected from hydrogen or (1 -4C)alkyl;

W ₆ is N;

f and g are independently integers from 2 to 4; and h is an integer from 0 to 1 .

[0041 ] In another embodiment, when n is 1 , W is selected from: (i) NRia, wherein Ri _a is selected from hydrogen or methyl; or

(ii) a group of the formula:

Wi-(CH ₂ CH2)-[W2-(CH ₂ CH2)]e-W3

wherein:

Wi, W ₂ and W ₃ are NRi _b , wherein Ri _b is selected from hydrogen or (1 -4C)alkyl;

e is an integer from 0 to 1 ; and

when n is 2, W is selected from N or a group of the formula:

W ₄ -(CH2CH2)-[W5-(CH2CH ₂ )]h-W6 wherein:

W ₄ and W ₅ are NRi _c , wherein Ri _c is selected from hydrogen or (1 -4C)alkyl;

W ₆ is N;

f and g are independently integers from 2 to 4; and h is an integer from 0 to 1.

[0042] In an embodiment, W is N when n is 2, or W is selected from NRi _a , O or S when n is 1.

[0043] In another embodiment, W is N when n is 2, or W is NRi _a when n is 1.

[0044] In another embodiment, W is N and n is 2.

[0045] In another embodiment, W is NRi _a and n is 1.

[0046] In an embodiment, Ri _a is selected from hydrogen or (1 -2C)alkyl.

[0047] In another embodiment, Ri _a is selected from hydrogen or methyl. In another embodiment, Ri _a is hydrogen. In another embodiment, Ri _a is methyl.

[0048] L is a linker group, which may be a bond or any suitable linker capable of connecting Q to W.

[0049] In an embodiment, the backbone moiety of L contains 2-10 atoms. The term backbone moiety will be understood to refer those atoms disposed in the atomic chain linking W to Q, excluding the atoms of any branched groups. Suitably, the backbone moiety of L contains 2-6 atoms. More suitably, the backbone moiety of L contains 2-4 atoms. Most suitably, the backbone moiety of L contains 3 atoms. The backbone atoms may have any of the definitions discussed herein in respect of L.

[0050] In an embodiment, L is a group of formula A, shown below:

-Y-Z- (Formula A) wherein:

Y is:

absent;

a (1 -6C)alkylene optionally substituted by one or more

substituents selected from (1 -2C)alkyl or oxo;

or a group of the formula:

-(CR _b Rc)p-[A-(CR _d Re)q]s- wherein:

p is an integer selected from 1 to 4;

A is selected from NR _f , O or S(0) _y (wherein y is 0, 1 or 2), wherein Rf is selected from hydrogen or (1 -4C)alkyl;

q is an integer selected from 1 to 4;

s is an integer selected from 0, 1 or 2;

Rb, Rc, Rd and R _e are independently selected from hydrogen or (1 -4C)alkyl; and

Z is selected from C(O), C(0)0, C(0)NR _g or S(0) _y (wherein y is 0, 1 or 2), wherein R _g is selected from hydrogen or (1 -4C)alkyl.

[0051 ] Particular linkers of the invention include, for example, linkers of the formula A, wherein, unless otherwise stated, L, Y and Z each have any of the meanings defined hereinbefore or in any of paragraphs (1 ) to (9) hereinafter:

1 ) L is a group of the formula:

-Y-Z- (Formula A)

wherein:

Y is:

absent;

a (1 -6C)alkylene optionally substituted by one or more

substituents selected from (1 -2C)alkyl or oxo;

or a group of the formula:

-(CR _b Rc)p-[A-(CR _d Re)q]s- wherein:

p is an integer selected from 1 to 4;

q is an integer selected from 1 to 4;

s is an integer selected from 0, 1 or 2;

Rb, Rc, Rd and R _e are independently selected from hydrogen or (1 -4C)alkyl; A is NR _f or O, wherein R _f is selected from hydrogen or (1 - 4C)alkyl; and

Z is selected from C(O), C(0)0 or C(0)NR _g , wherein R _g is selected from hydrogen or (1 -4C)alkyl;

L is a group of the formula:

-Y-Z- (Formula A)

wherein:

Y is:

absent;

a (1 -6C)alkylene optionally substituted by one or more substituents selected from (1 -2C)alkyl or oxo;

or a group of the formula:

-(CR _b Rc)p-[A-(R _d Re)q]s- wherein:

p is an integer selected from 1 to 4;

q is an integer selected from 1 to 4;

s is an integer selected from 1 or 2;

Rb, Rc, Rd and R _e are independently selected from hydrogen or methyl;

A is NR _f , wherein R _f is selected from hydrogen or (1 - 2C)alkyl; and

Z is selected from C(O), C(0)0 or C(0)NR _g , wherein R _g is selected from hydrogen or (1 -4C)alkyl;

L is a group of the formula:

-Y-Z- (Formula A)

wherein:

Y is:

absent;

a (1 -6C)alkylene, optionally substituted by one or more substituents selected from (1 -2C)alkyl;

or a group of the formula:

-(CH ₂ CH2)-[A-(CH ₂ CH2)]s- wherein: s is an integer selected from 1 or 2;

A is NRf, wherein Rf is selected from hydrogen or methyl; and

Z is selected from C(O), C(0)0 or C(0)NR _g , wherein R _g is selected from hydrogen or (1 -2C)alkyl;

) L is a group of the formula:

-Y-Z- (Formula A)

wherein:

Y is (1 -4C)alkylene or a group of the formula:

-(CH ₂ CH ₂ )-[A-(CH ₂ CH ₂ )] _S - wherein:

s is an integer selected from 1 or 2;

A is NRf, wherein Rf is selected from hydrogen or methyl; and

Z is selected from C(O), C(0)0 or C(0)NR _g , wherein R _g is selected from hydrogen or (1 -4C)alkyl;

) L is a group of the formula:

-Y-Z- (Formula A)

wherein:

Y is (1 -4C)alkylene or a group of the formula:

-(CH ₂ CH ₂ )-[A-(CH ₂ CH ₂ )] _S - wherein:

s is an integer selected from 1 or 2;

A is NRf, wherein Rf is selected from hydrogen or methyl; and

Z is selected from C(O), C(0)0 or C(0)NR _g , wherein R _g is selected from hydrogen or methyl;

) L is a group of the formula:

-Y-Z- (Formula A)

wherein:

Y is (1 -3C)alkylene or a group of the formula: -(CH ₂ CH2)-[NH-(CH ₂ CH2)]s- wherein:

s is an integer selected from 1 or 2;

Z is selected from C(O) , C(0)0 or C(0)NR _g , wherein R _g is selected from hydrogen or (1 -4C)alkyl;

7) L is selected from -(CH ₂ CH2)-[NH-(CH ₂ CH2)]s-C(0)- or a group of the formula:

wherein:

s is an integer selected from 1 or 2;

R6 is selected from hydrogen or methyl; and

^ denotes the point of attachment;

L is selected from -(CH ₂ CH ₂ )-[NH-(CH ₂ CH ₂ )] _s -C(0)- or a group of the formula:

wherein:

s is an integer selected from 1 or 2; and

*> denotes the point of attachment;

9) L is a group of the formula:

wherein *> denotes the point of attachment.

[0052] In an embodiment of the compounds of formula (I), L is as defined in any one of paragraphs (1 ) to (9) above. In another embodiment of the compounds of formula (I), L is as defined in any one of paragraphs (4) to (9) above. In an embodiment of the compounds of formula (I), L is as defined in paragraph (9) above. [0053] Q is a polyether of between 2 and 50 repeat units. The term "polyether" will be understood as referring to groups comprising two or more ether functional groups. Thus the term "polyether" will be understood to comprise diethers, triether, tetraethers, oligoether, polyethers and the like. The term "repeat unit" will also be understood to mean a monomer of the polyether chain that is successively linked to one or more other repeat units so as to form the polyether. Thus, the repeat unit will be understood as referring to individual ether monomers.

[0054] Without wishing to be bound by any particular theory, it is believed that the polyether component, Q, of the compounds of the present invention, contributes towards the bonding (or interaction) of the compounds of the present invention with the sealant, adhesive, coating and/or ink composition. The polarity of the polyether is believed to aid miscibility of this moiety of the compounds of the present invention with polymeric components having similar polarities (e.g. poly(ethylene glycol) and poly(propylene glycol)) present in the sealant, adhesive, coating and/or ink composition, thereby aiding bonding of the compound of the invention to the sealant, adhesive, coating and/or ink composition, and/or reducing the risk of phase separation.

[0055] It will be understood by a person skilled in the art that the hydrophobicity and so compatibility of the polyether may be varied through the specific selection of the ether repeat units that are used to form the polymer. For example, a poly(ethylene oxide) polyether may be used to obtain a compound of the present invention which is more hydrophilic in nature. Conversely, a poly(propylene oxide) based polyether may be used to obtain a compound of the present invention, which is more hydrophobic in nature. It will be understood by those skilled in the art that poly(ethylene oxide) (PEO) is also commonly referred to as poly(ethylene glycol) (PEG) and polypropylene oxide) is known as polypropylene glycol) (PPG).

[0056] In a particular embodiment, Q is a polyether selected from poly(ethylene oxide), polypropylene oxide), poly(butylene oxide), poly(tetramethylene oxide) or a co-polymer thereof. Suitably, Q is a polyether selected from poly(ethylene oxide), polypropylene oxide), polyputylene oxide) or a co-polymer thereof. More suitably, Q is a polyether selected from poly(ethylene oxide), polypropylene oxide) or a co-polymer thereof. Yet more suitably, Q is a polyether selected from poly(ethylene oxide), polypropylene oxide) or a block co-polymer thereof. Most suitably, Q is a polyether selected from poly(ethylene oxide) or polypropylene oxide).

[0057] It will be appreciated that the term "co-polymer thereof" refers to both random and block co-polymers. For example, the term "poly(ethylene oxide), polypropylene oxide) and copolymers thereof" will be understood to include poly(ethylene oxide), polypropylene oxide, random co-polymers comprising ethylene oxide and propylene oxide repeat units, and block copolymers comprising ethylene oxide and propylene oxide repeat units.

[0058] The person skilled in the art will also understand that the polyether, Q, has two termini, one of which is bound to L and the other of which is the terminus of the compound of the invention. Suitably, the terminus of the polyether connected to L comprises either a hydroxyl (OH) or amino (NH ₂ ) group, most suitably a hydroxyl group. Accordingly, it will be understood by the person skilled in the art that once connected to L the oxygen or nitrogen atom of the hydroxyl or amino group respectively will form part of the linker L.

[0059] The other terminus of the polyether (i.e. the terminus not connected to L) may comprise any suitable terminal group. Any suitable terminal group may be present, but typically it will be a hydroxy or (1 -4C)alkoxy (e.g. methoxy) group or an ester or urethane. Suitably, the terminal group is selected from hydroxy and (1 -4C)alkoxy (e.g. methoxy). Most suitably, the terminal group is hydroxy.

[0060] It will be understood that the term "polyether" refers to a group consisting of the repeating monomeric units discussed herein (of which there may be one or more type), wherein the end-most repeating monomeric unit (i.e. the repeating monomeric unit most distant from L) is terminated in a terminal group discussed herein. Suitably, the terminal group is selected from hydroxy and (1 -4C)alkoxy (e.g. methoxy). Most suitably, the terminal group is hydroxy.

[0061 ] Polyethers that comprise an amino group at the terminal end of the polyether to be connected to the linker, L, are commonly referred to as polyetheramines, and are commercially available from Huntsman under the trade name Jeffamine™. Typically, polyetheramines are supplied as block co-polymers of ethylene and propylene oxide and thus will be understood as being encompassed by the term "poly(ethylene oxide), poly(propylene oxide) and co-polymers thereof".

[0062] The general structure of polyetheramines supplied by Huntsman is as shown below:

wherein:

R _p is selected from H or methyl; and

a and b are integers.

[0063] In an embodiment of the present invention, Q is a polyether comprising between 3 and 50 repeat units. In another embodiment of the present invention, Q is a polyether comprising between 3 and 40 repeat units. In another embodiment of the present invention, Q is a polyether comprising between 3 and 20 repeat units. In another embodiment of the present invention, Q is a polyether comprising between 4 and 10 repeat units.

[0064] In another embodiment, Q is of the formula shown below:

wherein:

X is a NH or O;

R _p is selected from H or methyl;

R ₈ is selected from hydrogen or (1 -4C)alkyl;

a and b are integers; and

^ denotes the point of attachment to L.

[0065] Suitably, the sum of integers a and b is an integer 3 to 50. More suitably, the sum of integers a and b is an integer 3 to 40. More suitably, the sum of integers a and b is an integer 3 to 20. Most suitably, the sum of integers a and b is an integer 4 to 10.

[0066] In yet another embodiment, Q is a polyether of the formula shown below:

R7 is selected from hydrogen or methyl;

R ₈ is selected from hydrogen or (1 -4C)alkyl;

n integer between 4 and 10; and denotes the point of attachment to L.

Particular compounds of the present invention [0067] The following numbered paragraphs represent particular compounds of the present invention:

1 .1 A compound of the structural formula (la), shown below:

(la)

Ri, R2 and R ₃ are independently selected from (1 -4C)alkyl, hydroxy or 4C)alkoxy;

R ₄ and R ₅ are independently selected from hydrogen or (1 -4C)alkyl; x is an integer selected from 0 to 4;

n is an integer selected from 1 or 2;

when n is 1 , W is selected from:

(i) NRia wherein Ri _a is selected from hydrogen or (1 -4C)alkyl; or

(ii) a group of the formula:

Wi-(CRwl Rw2)c-[W ₂ -(CRw3Rw4)d]e-W ₃

wherein:

Wi, W ₂ and W ₃ are NRi _b , wherein Ri _b is selected from hydrogen or (1 -4C)alkyl;

Rwi , Rw2, Rw3 and R _W 4 are independently selected from hydrogen or (1 -4C)alkyl;

c and d are independently integers from 1 to 4;

e is an integer from 0 to 1 ; and

when n is 2, W is selected from N or a group of the formula:

W ₄ -(CRw5Rw6)f-[W5-(CRw7Rw8)g]h-W ₆ wherein:

W ₄ and W ₅ are NRi _c , wherein Ri _c is selected from hydrogen or (1 -4C)alkyl;

W ₆ is N; Rw5, w6, Rw7 and R _w s are independently selected from hydrogen or (1 -4C)alkyl;

f and g are independently integers from 1 to 4; and h is an integer from 0 to 1 .;

Y is absent, a (1 -6C)alkylene optionally substituted by one or more substituents selected from (1 -2C)alkyl, or a group of the formula:

-(CR _b Rc)p-[A-(R _d Re)q]s- wherein:

p is an integer selected from 1 to 3;

q is an integer selected from 1 to 3;

s is an integer selected from 0, 1 or 2;

Rb, Rc, Rd and R _e are independently selected from hydrogen or methyl;

A is NRf, wherein Rf is selected from hydrogen or (1 -2C)alkyl; and Z is selected from C(O), C(0)0 or C(0)NR _g , wherein R _g is selected from hydrogen or (1 -4C)alkyl; and

Q is a polyether comprising between 3 and 50 repeat units; with the proviso that at least one of Ri , R ₂ or R ₃ is a hydroxyl or (1 -4C)alkoxy; A compound of the structural formula (lb), shown below:

0(1 -4C)alkyl

(lb)

R ₂ and R ₃ are independently selected from (1 -4C)alkyl, hydroxy or (1 - 4C)alkoxy;

R ₄ and R ₅ are independently selected from hydrogen or methyl;

x is an integer selected from 0 to 4;

n is an integer selected from 1 or 2;

W is N when n is 2, or W is NRi _a when n is 1 ; wherein Ri _a is selected from hydrogen or (1 -4C)alkyl; Y is absent, a (1 -6C)alkylene optionally substituted by one or more substituents selected from (1 -2C)alkyl, or a group of the formula:

-(CH ₂ CH2)-[A-(CH ₂ CH2)]s- wherein:

s is an integer selected from 1 or 2;

A is NRf, wherein Rf is selected from hydrogen or (1 -2C)alkyl; and Z is selected from C(O), C(0)0 or C(0)NR _g , wherein R _g is selected from hydrogen or (1 -4C)alkyl; and

Q is a polyether comprising between 3 and 50 repeat units; A compound of the structural formula (lc), shown below:

(lc)

wherein:

R ₂ and R ₃ are independently selected from (1 -4C)alkyl, hydroxy or (1 - 4C)alkoxy;

x is an integer selected from 2 to 4;

n is an integer selected from 1 or 2;

W is N when n is 2, or W is NRi _a when n is 1 ; wherein Ri _a is selected from hydrogen or methyl;

Y is (1 -6C)alkylene or a group of the formula:

-(CH ₂ CH2)-[A-(CH ₂ CH2)]s- wherein:

s is an integer selected from 1 or 2;

A is NRf, wherein Rf is selected from hydrogen or (1 -2C)alkyl; and Z is selected from C(O), C(0)0 or C(0)NR _g , wherein R _g is selected from hydrogen or (1 -4C)alkyl; and

Q is a polyether comprising between 3 and 50 repeat units; A compound of the structural formula (Id), shown below:

(Id)

wherein:

R ₂ and R ₃ are independently selected from (1 -4C)alkyl, hydroxy or (1 - 4C)alkoxy;

n is an integer selected from 1 or 2;

W is N when n is 2, or W is NRi _a when n is 1 ; wherein Ri _a is selected from hydrogen or methyl;

Y is (1 -3C)alkylene or a group of the formula:

-(CH ₂ CH2)-[A-(CH ₂ CH2)]s- wherein:

s is an integer selected from 1 or 2;

A is NRf, wherein Rf is selected from hydrogen or (1 -2C)alkyl; and Z is absent or selected from C(O) or C(0)NR _g , wherein R _g is selected from hydrogen or methyl; and

Q is a polyether comprising between 3 and 50 repeat units; A compound of the structural formula (le), shown below:

(le)

wherein:

R ₂ and R ₃ are independently selected from (1 -4C)alkyl, hydroxy or (1 - 4C)alkoxy;

R ₄ and R ₅ are independently selected from hydrogen or (1 -4C)alkyl; x is an integer selected from 0 to 4;

n is an integer selected from 1 or 2;

W is N when n is 2, or W is NH when n is 1 ;

R ₆ is selected from hydrogen or methyl; and Q is a polyether comprising between 3 and 50 repeat units, selected from poly(ethylene oxide), polypropylene oxide), poly(butylene oxide), poly(tetramethylene oxide) or a co-polymer thereof;

1 .6 A compound of the structural formula (If), shown below:

(if)

wherein:

R ₂ and R ₃ are independently selected from (1 -4C)alkyl, hydroxy or (1 - 4C)alkoxy;

x is an integer selected from 2 to 4;

n is an integer selected from 1 or 2;

W is N when n is 2, or W is NH when n is 1 ;

R ₆ is selected from hydrogen or methyl; and

Q is a polyether comprising between 4 and 10 repeat units, selected from poly(ethylene oxide), polypropylene oxide) or a co-polymer thereof;

1 .7 A compound of the structural formula (II), shown below:

0-(1 -4C)alkyl R ₇

wherein:

R ₂ and R ₃ are independently selected from (1 -4C)alkyl, hydroxy or (1 -4C)alkoxy; R7 is selected from hydrogen or methyl;

W is N when n is 2, or W is NH when n is 1 ;

n is an integer selected from 1 or 2; and

y is an integer selected from 4 to 10;

[0068] Particular compounds of the invention include any one of the following:

wherein y is selected from 2 to 50, 3 to 50, 3 to 40, 3 to 20, or 4 to 10.

[0069] It is also to be understood that certain compounds of the formula (I) may exist in solvated as well as unsolvated forms such as, for example, hydrated forms. It is to be understood that the invention encompasses all such solvated forms that function as adhesion promoters.

[0070] Compounds of the present invention may also exist in any suitable salt form. Suitable salt forms of the present invention include, but are not limited to, acid addition salts or base salts.

Preparations of the compounds of the present invention

[0071 ] The compounds of the present invention can be prepared by any suitable technique known in the art. Particular processes for the preparation of these compounds are described further in the accompanying examples. [0072] In the description of the synthetic methods described herein and in any referenced synthetic methods that are used to prepare the starting materials, it is to be understood that all proposed reaction conditions, including choice of solvent, reaction atmosphere, reaction temperature, duration of the experiment and workup procedures, can be selected by a person skilled in the art.

[0073] It is understood by one skilled in the art of organic synthesis that the functionality present on various portions of the molecule must be compatible with the reagents and reaction conditions utilised.

[0074] The methodology employed to synthesise a compound of formula (I) will vary depending on the nature of Ri , R ₂ , R3, L, W, Q and any substituent groups associated therewith. Suitable processes for their preparation are described further in the accompanying Examples.

[0075] Once a compound of formula (I) has been synthesised by any one of the processes defined herein, the processes may then further comprise one or more of the following additional steps of:

(i) converting the compound formula (I) into another compound of formula (I); and/or

(ii) forming a salt, hydrate or solvate thereof.

[0076] The resultant compounds of formula (I) may be isolated and purified using techniques well known in the art.

[0077] In an aspect of the present invention, the compounds of formula (I) may be synthesised by a process comprising reacting a compound of formula (III) with a compound with formula (IV):

(III) (IV)

wherein:

W is as defined herein; and

FGi is a functional group that when reacted with W-H links Q to W via linker group L, as defined herein; and

Ri , R ₂ , R3, R4, R5, x and Q are as defined herein. [0078] In another aspect of the present invention, the compounds of formula (I) may be synthesised by a process comprising reacting an aminosilane with a polyether acrylate or polyether methacrylate.

[0079] Thus, the silane-terminated polyethers can be prepared by reacting an acrylate- or methacrylate-functional polyether with an amine-functional silane. The (meth)acrylate functionality of the functional polyether readily reacts with the primary amine functionality of the aminosilane via a Michael addition process. When the reaction is between a primary amine and an acrylate, this process takes place at ambient temperatures, does not form any byproducts and does not require any additional catalyst.

[0080] The polyether (meth)acrylate may be selected from poly(propylene oxide) acrylate, polypropylene oxide) methacrylate, poly(ethylene oxide) acrylate, poly(ethylene oxide) methacrylate, poly(tetrahydrofuran) acrylate and poly(tetrahydrofan) methacrylate. Block or random copolymers of these units can also be used. Due to the increased reactivity, it is preferred that acrylate-functional polyethers are utilised. It is also preferable if the mono- functional polyether is used in the reaction.

[0081 ] Suitable polyether methacrylate are polyether methacrylates of the formula:

wherein a+b is between 3 and 50, most preferably between 4 and 20.

[0082] This polymer (above) is commercially available from Clariant under the trade names Polyglykol MA 350 and Polyglykol MA 750.

[0083] A particular polyether acrylate is polypropylene oxide) acrylate

wherein y is between 3 and 50, most preferably between 4 and 10.

[0084] This polymer (above), where y=6, is commercially available from GEO Specialty Chemicals Inc under the trade name Bisomer PPA6.

[0085] Another polyether acrylate is poly(ethylene oxide) acrylate:

wherein y is between 3 and 50, most preferably between 4 and 10.

[0086] This polymer (where y=6) is commercially available from GEO Specialty Chemicals Inc under the trade name Bisomer PEA6.

[0087] In an embodiment, the aminosilane is selected from to 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3- aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(2-aminoethyl)- 3-aminopropylmethyldimethoxysilane N-(3-Trimethoxysilylpropyl)diethylenetriamine or N-(3- Triethoxysilylpropyl)diethylenetriamine and N-(3-methyldimethoxysilylpropyl)diethylenetriamine.

[0088] In another embodiment, the process for the preparation of a compound of formula (I) is solvent free.

[0089] In another embodiment, the process for the preparation of a compound of formula (I) is catalyst free.

[0090] In yet another embodiment, the process for the preparation of a compound of formula (I) is conducted at a temperature of between 0 and l OCO. Suitably, the process for the preparation of a compound of formula (I) is conducted at a temperature of between 0 and 75 °C. More suitably, the process for the preparation of a compound of formula (I) is conducted at a temperature of between 10 and 60 °C.

[0091 ] In a further embodiment of the process for the preparation of a compound of formula (I), the reaction between the compounds of formula (III) and (IV) is a Michael addition reaction.

[0092] In yet another embodiment of the process for the preparation of a compound of formula (I), FGi is an acrylate or a methacrylate.

[0093] In another aspect of the present invention, there is provided a compound obtained, obtainable or directly obtained by a process defined herein.

Compositions of the invention

Compound and moisture scavenger compositions

[0094] In one aspect of the present invention, the compound is mixed with a moisture scavenger and could be stored and/or supplied to consumers in this form. Thus, in another aspect, the present invention provides a composition comprising, or consisting essentially of, or consisting of, a compound, as defined herein, and a moisture scavenger.

[0095] In an embodiment, the moisture scavenger is an alkoxysilane or oxazolidine-based moisture scavengers (e.g. Incozol 2 supplied by Incorez). Suitably, the moisture scavenger is selected from vinyltrimethoxysilane, vinyltriethoxysilane or Incozol 2. Most suitably, the moisture scavenger is vinyltrimethoxysilane or vinyltriethoxysilane.

[0096] The compound and moisture scavenger composition of the present invention may also comprise any suitable amount of moisture scavenger. Suitably, the compositions of the present invention comprises between 0.1 and 10% w/w of moisture scavenger. More suitably, the compositions of the present invention comprises between 0.1 and 5% w/w of moisture scavenger. Yet more suitably, the compositions of the present invention comprises between 0.1 and 3% w/w of moisture scavenger. Most suitably, the compositions of the present invention comprises between 0.1 and 1 % w/w of moisture scavenger.

[0097] In another embodiment, the compound and moisture scavenger composition comprises between 0.1 and 99% w/w of a compound, as defined herein. Suitably, the compound and moisture scavenger composition comprises between 0.1 and 95% w/w of a compound, as defined herein. More suitably, the compound and moisture scavenger composition comprises between 0.1 and 90% w/w of a compound, as defined herein. Yet more suitably, the compound and moisture scavenger composition comprises between 0.1 and 75% w/w of a compound, as defined herein. Most suitably, the compound and moisture scavenger composition comprises between 0.1 and 50% w/w of a compound, as defined herein.

Sealant, Adhesive, Coating and/or Ink Compositions

[0098] In a further aspect of the present invention, there is provided a sealant, adhesive, coating or ink composition comprising a compound, as defined herein, and a moisture scavenger. Suitably, there is provided a sealant or adhesive composition comprising a compound, as defined herein, and a moisture scavenger. More suitably, there is provided a sealant composition comprising a compound, as defined herein, and a moisture scavenger. Most suitably, there is provided a moisture-curable sealant composition comprising a compound, as defined herein, and a moisture scavenger.

[0099] In an embodiment, the moisture scavenger is an alkoxysilane or oxazolidine-based moisture scavengers (e.g. Incozol 2 supplied by Incorez). Suitably, the moisture scavenger is selected from vinyltrimethoxysilane, vinyltriethoxysilane or Incozol 2. Most suitably, the moisture scavenger is vinyltrimethoxysilane or vinyltriethoxysilane. [00100] The compositions of the present invention may comprise any suitable amount of compound of formula (I). Suitably, the compositions of the present invention comprises between 0.1 and 75% w/w of a compound of formula (I). More suitably, the compositions of the present invention comprises between 0.1 and 50% w/w of a compound of formula (I). Yet more suitably, the compositions of the present invention comprises between 0.1 and 20% w/w of a compound of formula (I). Most suitably, the compositions of the present invention comprises between 0.1 and 10% w/w of a compound of formula (I).

[00101] The sealant, adhesive, coating and/or ink composition compositions of the present invention may also comprise any suitable amount of moisture scavenger. Suitably, the compositions of the present invention comprises between 0.1 and 10% w/w of moisture scavenger. More suitably, the compositions of the present invention comprises between 0.1 and 5% w/w of moisture scavenger. Yet more suitably, the compositions of the present invention comprises between 0.1 and 3% w/w of moisture scavenger. Most suitably, the compositions of the present invention comprises between 0.1 and 1 % w/w of moisture scavenger.

[00102] In another embodiment, the compositions of the present invention comprises a solvent. Suitably, the composition comprises an organic solvent.

[00103] It will be appreciated that the compositions of the present invention may comprise additional formulation components. Additional formulation components may be included to improve various properties of the formulation, such as, for example, viscosity, open time, modulus, mechanical resistance, UV resistance, formulation stability and ease of application. A person skilled in the art will be able to select suitable formulation components to include based on conventional knowledge in the formulation field.

[00104] A non-limiting list of possible additional formulation components that may be added to the compositions of the present invention include: pH modifiers, surfactants and solubility enhancers such as dispersants and emulsifiers, viscosity modifiers, wetting agents, preservatives, lubricants, fillers, film formers and resins, extenders, sizing agents, antifouling agents, barriers to moisture and gas, catalysts, curing and drying agents, antifoam and defoaming agents, plasticisers, UV-stabilisers, and colorants including pigments and dyes

[00105] In an embodiment, the compositions may also comprise one or more additional adhesion promoters.

[00106] It will be appreciated that the sealant and/or adhesive composition defined hereinabove may comprise any suitable sealant and/or adhesive formulation commercially available or known in the art, or may comprise a model sealant and/or adhesive composition comprising the ingredients listed in the table below: Component % w/w

MS prepolymer 10- 50

Plasticiser 10-30

Moisture Scavenger 0.1 -1

Calcium Carbonate 30-60

UV Stabilizers 0.1 -1

Thixotropic Agent (e.g. S1O2) 0.1 -1

Colourant (e.g. T1O2) 0.1 -5

Adhesion Promoter 0.1 -10

Catalyst (e.g. dibutyltin dilaurate) 0.01 -1

[00107] The choice of ingredients for, and method of manufacture of, such sealant, adhesive, coating and or ink compositions is well known to those skilled in the art. For instance the reader is referred to Handbook of Adhesives and Sealants, Edward M. Petrie, 2 ^nd Ed, 2007, McGraw-Hill; and A. Goldschmidt, H-J Streitberger, BASF Handbook on Basics of Coating Technology, 2 ^nd Ed, 2007, Vincentz Network, Hannover; the contents of which are incorporated by way of example. As will be appreciated by the person skilled in the art, the properties (e.g. solubility, viscosity, chemical functionality) of the compound of the invention should be considered when assessing how to add the compound to a composition.

Primer solutions

[00108] According to another aspect of the present invention, there is provided a primer solution comprising a compound, as defined herein, and a solvent.

[00109] It will be appreciated that the primer solution may comprise any suitable amount of compound, which may vary according to the intended use and storage of the primer solution. In an embodiment, the primer solution comprises between 0.5 and 90% w/w of a compound of formula (I). Suitably, the primer solution comprises between 0.5 and 75% w/w of a compound of formula (I). More suitably, the primer solution comprises between 0.5 and 50% w/w of a compound of formula (I). Most suitably, the primer solution comprises between 0.5 and 25% w/w of a compound of formula (I).

[00110] In another embodiment, the primer solution comprises a moisture scavenger. Suitably, the moisture scavenger is an alkoxysilane or oxazolidine-based moisture scavengers (e.g. Incozol 2 supplied by Incorez). More suitably, the moisture scavenger is selected from vinyltrimethoxysilane, vinyltriethoxysilane or Incozol 2. Most suitably, the moisture scavenger is vinyltrimethoxysilane or vinyltriethoxysilane. [00111] In a further embodiment, the primer solution comprises between 0.1 and 10% w/w of moisture scavenger. Suitably, the compositions of the present invention comprises between 0.1 and 5% w/w of moisture scavenger. More suitably, the compositions of the present invention comprises between 0.1 and 3% w/w of moisture scavenger. Most suitably, the compositions of the present invention comprises between 0.1 and 1 % w/w of moisture scavenger.

[00112] In yet another embodiment of the primer solution, the solvent is an organic solvent. Suitably, the solvent is a non-reactive organic solvent. More suitably, the solvent is a non- reactive organic solvent the selected from n-butyl acetate, methylethyl ketone, acetone, toluene, xylene, ethyl benzene, naptha, mineral spirits, oxides such as propylene oxide, tetrahydrofuran and turpentine.

[00113] It will be appreciated that the primer solutions of the present invention may comprise additional adjuncts. Additional adjuncts may be included to improve various properties of the formulation, such as, for example, formulation stability and administrability. A person skilled in the art will be able to select suitable adjuncts to include based on conventional knowledge in the formulation field.

[00114] A non-limiting list of possible additional adjuncts that may be added to the primer solutions of the present invention include: pH modifiers, surfactants, viscosity modifiers, preservatives, lubricants and solubility enhancers.

[00115] In an embodiment, the primer solutions may also comprise one or more additional adhesion promoters.

Applications

[00116] As described hereinabove, the present invention provides compounds, compositions and primer solutions that function as adhesion promoters.

[00117] The present invention therefore provides a method for promoting adhesion to a surface, said method comprising contacting a surface with a compound, a composition or a primer solution, as defined herein.

[00118] The present invention further provides a method for promoting adhesion of a sealant, adhesive, coating or ink to a surface, said method comprising contacting a surface with a compound, a composition or a primer solution, as defined herein. Suitably, the present invention provides a method for promoting adhesion of a sealant or adhesive to a surface, said method comprising contacting a surface with a compound, a composition or a primer solution, as defined herein. [00119] In an embodiment, the present invention provides a method for promoting adhesion of a sealant, adhesive, coating or ink to a surface, wherein the surface is selected from glass, plastic [e.g. poly(ethylene terephthalate) (PET), high and low density polyethylene, PVC, polypropylene or polystyrene], rubber (e.g. natural rubber, styrene-butadiene-styrene (SBS) rubber, polyisoprene, polybutadiene, polycarbonates, melamine-formaldehyde resins, polyurea or polyurethane resins), concrete, leather, paper, card, plaster, plasterboard, wood, chipboard, fabric (e.g. cotton, canvas, nylon, polyesters or high performance fabrics such as Kevlar®) or a metal (e.g. as steel, stainless steel, copper, aluminium or copper alloys such as brass or bronze). Suitably, the surface is selected from plastic, rubber, concrete or a metal. More suitably, the surface is selected from stainless steel, concrete, plastic or rubber. Most suitably, the surface is selected from stainless steel, concrete, polyvinyl chloride) (PVC) or ethylene propylene diene monomer (EPDM) rubber.

[00120] The present invention also provides a compound, a composition or a primer solution, as defined herein, for use in promoting adhesion to a surface.

[00121] The present invention further provides a compound, a composition or a primer solution, as defined herein, for use in promoting adhesion of a sealant, adhesive, coating or ink to a surface.

[00122] In an embodiment, the present invention provides a compound, a composition or a primer solution, as defined herein, for use in promoting adhesion of a sealant, adhesive, coating or ink to a surface, wherein the surface is selected from glass, plastic, rubber, concrete, leather, paper, card, wood or a metal. Suitably, the surface is selected from plastic, rubber, concrete or a metal. More suitably, the surface is selected from stainless steel, concrete, plastic or rubber. Most suitably, the surface is selected from stainless steel, concrete, polyvinyl chloride) (PVC) or ethylene propylene diene monomer (EPDM) rubber.

EXAMPLES

Material, Abbreviations and Suppliers

[00123] The materials used throughout the Examples section are as follows:

3-Aminopropytrimethoxysilane - Sigma Aldrich

Bisomer PPA6 - poly(propylene oxide) acrylate ^* - GEO Specialty Chemicals

Bisomer PEA6 - poly(ethylene oxide) acrylate - GEO Specialty Chemicals

Dynasylan AMMO - 3-aminopropytrimethoxysilane - Evonik

Dynasylan VTMO - vinyltrimethoxysilane - Evonik

Onichem A31 1 - 3-aminopropymethyldimethoxysilane - Onichem Polypropylene oxide) acrylate, Mn -475 Da Sigma Aldrich Silquest A-171 - vinyltrimethoxysilane Momentive

Silquest A-1 100 - 3-aminopropytriethoxysilane Momentive

(3-trimethoxysilylpropyl)diethylenetriamine United Chemical

Technologies

^* N.B. Bisomer PPA6 polypropylene oxide) acrylate is also known as polypropyleneglycol (6) acrylate. Bisomer PEA6 poly(ethylene oxide) acrylate is also known as polyethyleneglycol (6) acrylate.

[00124] The compounds of the present invention were prepared using the following general procedure:

EXAMPLE 1

[00125] Polypropylene oxide) acrylate, Mn 475 (427.5g, 0.9 moles) was charged to a 1 litre flange flask fitted with an overhead stirrer, after addition the internal temperature of the flask was 18.7 °C. 3-Aminopropyltrimethoxysilane (161 .29 g, 0.9 moles) was added drop-wise through an equalising pressure dropping funnel. A slight exotherm was noted and the temperature steadily rose during the addition. The total addition time was 35 mins during which time the temperature increased to 32.2 °C. The internal temperature was increased to 50 °C and heating and stirring was continued for a further hour. Vinyltrimethoxysilane (1 1 .77 g, 85 mmoles) was added slowly. The polymer was allowed to cool to ambient temperature before being discharged from the flask. The product was a clear, low viscosity liquid.

Table 1 - Synthetic details of the compounds of the present invention

Example Polyether Aminosilane - Vinyltrimethoxy Reaction

No acrylate - (Weight added silane temperature

(Weight added and No. Moles) grade/supplier- (°C) and time and No. Moles) (Weight added)

1 PPG acrylate, 3- Sigma Aldrich

Mn 475 aminopropytrimeth

(Sigma Aldrich oxysilane (1 1 .77 g) 50 °C, 60

g ade) (Sigma Aldrich) mins

(427.5 g, 0.9 (161 .29 g, 0.9

moles) moles)

2 Bisomer PPA6 Dynasylan AMMO Dynasylan VTMO

3- (Evonik)

(1236.18 g, 2.94 aminopropytrimeth 50 °C, 75 Example Polyether Aminosilane - Vinyltrimethoxy Reaction No acrylate - (Weight added silane temperature

(Weight added and No. Moles) grade/supplier- (°C) and time and No. Moles) (Weight added)

moles) oxysilane (36.00 g) mins

Evonik

(527.82 g, 2.944

moles)

3 Bisomer PPA6 (3- Sigma Aldrich

trimet oxysilylprop

(240.0 g, 0.571 yi) (8.00g) 25 °C, 17 moles) diet ylenetriamine hours

(United Chemical

Technologies)

(151 .67 g, 0.571

moles)

4 Bisomer PPA6 Silquest A-1 1 00 Silquest A-171

3- (Momentive)

(21 0 g, 0.5 aminopropytrietho 25 °C, 2 moles) xysilane (6.41 g) hours

(Momentive)

(1 10.69 g, 0.5

moles)

5 Bisomer PPA6 Onichem A31 1 Silquest A-171

3- (Momentive)

(21 0.0 g, 0.5 aminopropymethyl 25 °C, 2 moles) dimethoxysilane (5.83 g, ) hours

(Onichem)

(81 .65 g, 0.5

moles)

6 Bisomer PEA6 Dynasylan AMMO Silquest A-171

3- (Momentive)

(1 68.0 g, 0.500 aminopropytrimeth 50 °C, 60 mol) oxysilane (5.1 5 g) minutes Example Polyether Aminosilane - Vinyltrimethoxy Reaction No acrylate - (Weight added silane temperature

(Weight added and No. Moles) grade/supplier- (°C) and time and No. Moles) (Weight added)

Evonik

(89.65 g, 0.500

mol)

7 BEA F1822 Dynasylan AMMO Silquest A-171

3- (Momentive)

86.38 g, 0.245 aminopropytrimet 50 °C, 4 mol) oxysilane (3 g) hours

Evonik

(43.98 g, 0.245

mol)

8 Jeffamine M- Silquest A-link 35 Silquest A-171

600 3- (Momentive)

Isoxyanatopropyltri 25 °C, 5

(120 g, 0.2 mol) methoxysilane (3.22 g) minutes

(41 g, 0.2 mol)

9 Jeffamine Silquest A-link 35 Silquest A-171

M-2070 3- (Momentive)

Isoxyanatopropyltri 25 °C, 10

(120 g, 0.06 mol) methoxysilane (2.646 g) minutes

(12.3 g, 0.06 mol)

10 Jeffamine Silquest A-link 35 Silquest A-171

M-1000 3- (Momentive)

Isoxyanatopropyltri 30 °C, 10

(120 g, 0.12 mol) methoxysilane (2.89 g) minutes

(24.6g, 0.12mol)

1 1 PPG diacrylate 3- Silquest A-171

aminopropytrimeth (Momentive)

(98 g, 0.1225 oxysilane 25 °C, 2 mol) (2.89 g) hours Example Polyether Aminosilane - Vinyltrimethoxy Reaction No acrylate - (Weight added silane temperature

(Weight added and No. Moles) grade/supplier- (°C) and time and No. Moles) (Weight added)

(43.98 g, 0.245

mol)

12 Jeffamine (3- Silquest A-171

M-2070 acryoxpropyl)trime (Momentive)

thoxysilane 25 °C, 10

(150 g, 0.075 (3.35 g) minutes

mol) (17.57 g, 0.075

mol)

13 Jeffamine (3- Silquest A-171

M-1000 acryoxpropyl)trime (Momentive)

thoxysilane 25 °C, 10

(125 g, 0.125 (3.09g) minutes

mol) (29.29 g, 0.125

mol)

14 Jeffamine (3- Silquest A-171

M-600 acryoxpropyl)trime (Momentive)

thoxysilane 25 °C, 70

(125 g, 0.2mol) (3.34 g) minutes

(46.86 g, 0.2 mol)

Screening procedures

Mixing process

[00126] The blending of a selection of compounds of the present invention with the sealant matrix (Tremco illbruck SP525) was performed in a Plastigraph Brabender mixer (Nr 174510, model 824300, head 60/30cc with roller blades). The mixtures of the sealant with the compounds of the present invention were stirred in the Plastigraph Brabender mixer for 5-10 minutes at room temperature and under an inert gas to ensure full dispersion of the ingredients.

[00127] The prepared sealant blends were then transferred to plastic 60 mL syringes which, if not used straight away, were sealed with a plastic cup to ensure that the sealant was not exposed to the atmospheric humidity. The samples were then applied on to the substrates for the peel adhesion test. [00128] Both commercial and model sealant formulations were used for these experiments. The commercial formulation used was Tremco illbruck SP525 -a low modulus frame and facade MS sealant formulation.

[00129] Model formulations were typically prepared by making a premix in two steps. In the first step, the prepolymer and the plasticizer ware mixed together. In the second step the premix was mixed with a moisture scavenger, the silica and the catalyst. The premix was then put into a Plastigraph Brabender mixer (Nr 174510, model 824300, head 60/30cc with roller blades) where calcium carbonate and titanium oxide were added. The sealant was then mixed for 10-15 minutes at room temperature at 40 rpm then the adhesion promoter was added under nitrogen and mixed for further 5 minutes under inert conditions.

Substrates & Application Process

Dry concrete blocks: with dimensions 100mm x 100mm x 50mm.

[00130] The surface was brushed with a metal brush to expose the grains. The sealant composition was then applied on top of the surface to create a strip that was at least 3 mm thick, 10 mm wide and 150 mm long. The samples were then cured for 7 days at 25 °C and 60 % relative humidity and a hand peel adhesion test (see below) is performed. Following this, the samples were cured for further 7 days - to make a 2 week curing cycle and the hand peel adhesion test was repeated.

Wet concrete blocks: with dimensions 100mm x 100mm x 50mm

[00131] The blocks were cleaned and immersed in water for 48 hours prior to use, the blocks were then removed from the water and padded dry with tissue paper. The sealant was then applied and assessed as for the dry concrete blocks.

Stainless steel

[00132] The brushed f350 stainless steel substrates were pre-cut into dimensions of 200 mm x 15 mm x 1 mm. The surface was wiped clean with methylated spirits and tissue, and then the sealant composition was then applied and assessed as for the dry concrete blocks. PVC

[00133] With dimensions of 200 mm x 20 mm with thickness of the PVC sheet already being set 2 mm. The surface was wiped clean with methylated spirits and tissue, and then the sealant composition was then applied and assessed as for the dry concrete blocks.

EPDM

[00134] The Arbo EPDM membrane is cut into 200 x 20mm with the thickness of the EPDM already being set at 0.75mm, for ease of application the strips are attached to a hard surface. The surface was wiped clean with methylated spirits and tissue, and then the sealant composition was then applied and assessed as for the dry concrete blocks.

Manual Peel Adhesion test

[00135] The hand peel adhesion test was performed for all samples of sealant composition after addition of the compounds of the present invention to commercial hybrid sealant (Tremco illbruck SP525) and to a frame (model) formulation of a hybrid sealant. The products were applied onto the substrate surfaces and cured for 2 weeks at 25 °C and 60% relative humidity.

[00136] The peel adhesion test is the most effective test to verify sealant adhesion to a substrate surface. The procedure for the peel adhesion test was undertaken in the following steps:

1 . The substrate was wiped cleaned with methylated spirits and tissue.

2. A piece of marine bond breaker tape, obtained from Aquaseal, was placed across the surface of the substrate.

3. A strip of the sealant containing the adhesion promoter was applied onto the substrate using the syringe as described previously

4. A 2 mm x 3 mm stainless steel wire mesh, with dimensions of the 150 mm x 10 mm was imbedded halfway within the body of the sealant.

5. After sealant cured, the 2cm of the sealant which overlaid the bond breaker tape was grasped and pulled at a 180 ° angle. Only 1 -2cm of sealant was pulled, leaving the remainder in place for additional testing.

6. When the sealant ripped within itself and remained fully bonded to the substrate, this gives 'cohesion failure'. 100% cohesive failure is desirable since this indicates that the strength of adhesion is greater than the strength of cohesion.

7. When the sealant released from the substrate, the sample indicates 100% adhesive failure (or 0% cohesive failure) - this behaviour is not desirable

The samples were scored as follows: - Ί ' 100% Adhesion failure: the sealant failed to adhere to the substrate

- '2' 25% Adhesion failure: some sealant left on the surface of the substrate, but most released

- '3' 25% Cohesion failure: some of the sealant released from the substrate but most remained on the surface

- '4' Cohesion failure: the sealant didn't release from the substrate

[00137] Since the sealant adhesion develops over time, the test is done after 7 days of curing time and then repeated again after further 7 days which makes the 2 weeks curing cycle.

Tensiometer Testing

[00138] The samples which successfully passed the hand peel adhesion test are then tested on the Testometric micro 350 tensiometer. The tensile modulus, tensile strength and elongation at break for each sample are noted.

[00139] The sample preparation and test methodology undertaken were as follows:

1 . A poly(tetrafluoroethylene)PTFE cast containing internal dimension of 75 mm x 50 mm x 2.4 mm was place upon the top of a PE300/PE-HWST (high density poly(ethylene) HDPE 2 mm sheet.

2. The sealant composition was then placed inside the internal cavity of the PTFE cast and scraped to be level with the upper rim of the cast and left to cure in a humidity cabinet at 25 °C for 60% RH and tested after 7 and 14 days.

3. Once cured, five 75 mm x 10 mm x 2.4 mm strips were cut in preparation for testing using the tensiometer.

4. The testometric micro 350 settings were as follows:

a. Jaw separation/Test gap: 26.87 mm

b. Speed: 200 mm/min

c. Load Cell 5 kg

Table 2. PPG acrylate with different aminosilanes cured at 25 V and 60% relative humidity

n/d - not determined Table 2a. PPG acrylate with different aminosilanes cured at 25 V and 60% relative humidity

Table 3. 3-aminopropytrimethoxysilane with different acrylate cured at 25 V and 60% relative humidity

n/d - not determined Table 3a. 3-aminopropytrimethoxysilane with different acrylate cured at 25 V and 60% relative humidity

n/d - not determined Table 4. Screening data for different adhesion promoters cured at 25 V and 60% relative humidity

n/d - not determined Table 4a. Screening data for different adhesion promoters cured at 25 V and 60% relative humidity

n/d - not determined Table 5. PPG acrylate with different aminosilanes cured at ambient conditions

n/d - not determined

Table 6. Adhesion to EPDM rubber; PPG acrylate with different aminosilanes cured at 25 V and 60% relative humidity

[00140] While specific embodiments of the invention have been described herein for the purpose of reference and illustration, various modifications will be apparent to a person skilled in the art without departing from the scope of the invention as defined by the appended claims.