WO2020239596A1

WO2020239596A1 - Prepolymer and composition comprising the same

Info

Publication number: WO2020239596A1
Application number: PCT/EP2020/064167
Authority: WO
Inventors: Jean-François STUMBE; Baptiste CLEMENT; Pascal Pichon; Rémi Perrin; Céline THORR; Pierre Etienne Bindschedler
Original assignee: Soprema; Universite De Haute Alsace
Priority date: 2019-05-24
Filing date: 2020-05-20
Publication date: 2020-12-03

Abstract

The invention relates to a prepolymer comprising α,β-unsaturated carbonyl groups and to a curable composition containing this prepolymer. These compositions are used to make sealants, coatings or adhesives useful in the field pof construction, public works and civil engineering.

Description

PREPOLYMER AND COMPOSITION COMPRISING THE SAME

Technical Field

The invention relates to a prepolymer comprising a,b-unsaturated carbonyl groups and to a curable composition containing said prepolymer. These compositions are used to manufacture sealants, coatings or adhesives useful in the field of construction, public works and civil engineering.

Background of the Invention

In public works or construction works, it is necessary to protect structures, generally made of concrete, against any infiltration of water. To do this, sealants or coatings are applied on the structures.

The use of liquid compositions is preferred over prefabricated membranes as they are easier to apply and lead to flexible and continuous membranes that adhere to the structure.

Sealants or coatings can be obtained from acrylic dispersions in aqueous solution which harden on loss of water. However, these products have the drawback of hardening at the surface after application, forming a very thin coating which makes the evaporation of water difficult, thus giving rise to the formation of blisters. These products cure slowly, especially in cold weather, they are very sensitive to rain before they have totally cured, and they form blisters in summer. What is more, these products show poor resistance to prolonged immersion in water, and are therefore unsuitable for waterproofing horizontal flat surfaces. Finally, their mechanical strength is insufficient for use on traffic-bearing surfaces.

Sealants or coatings obtained with polyurethane resins are also known, for example two-component compositions or one-component compositions containing significant amounts of solvents and/or plasticizers. Polyurethane resins contain residual diisocyanates which are considered as harmful to health and to the environment since they may release free diisocyanate monomers. Further, the use of solvents generates compositions having the following drawbacks:

- an unpleasant odor due to the volatile organic compounds,

- a toxicity that results in specific labeling and specific operating conditions,

- problems with regard to environmental regulations.

Additionally, the use of inert exogenous plasticizers generates compositions having the following drawbacks:

- weakening of the mechanical strength,

- weakening of the adhesion,

- reduced aging over time,

- increased water absorption.

Recently, polyurethane modified (meth)acrylic (PUMA) resins have also been developped so as to combine the advantages of polyurethane resin with those of (meth)acrylic resin. However, the synthesis of PUMAs is multi- step and involves the use of diisocyanates.

There is still a need for prepolymers and liquid two-component curable compositions to provide elastomeric sealants, coatings or adhesives that exhibit one or more of the following properties:

- 0-1 % by weight of free isocyanate monomers - 0-5% by weight of solvent

- fast curing at room temperature (20-25°C)

- complying with the requirements of a liquid waterproofing system in terms of elasticity, hydrophobicity, hydrolysis resistance, mechanical properties (tensile strength and elongation) and durability.

The Applicant has developed a prepolymer comprising a,b-unsaturated carbonyl groups as an alternative to PUMA resins that fulfills the requirements mentionned above.

Summary of the Invention

A first object of the present invention is a prepolymer represented by formula (1 ):

wherein L, X, Ri , R , R_a, Rb, Rd, m and n are as defined herein.

The invention also aims at providing a method for preparing a prepolymer, wherein said method comprises reacting an electrophile of formula (3) with a secondary diamine of formula (4):

wherein X, L, Ri , R , R_a, Rb Rd and n are as defined herein,

the molar ratio between the a,b-unsaturated carbonyl groups of the electrophile and the hydrogens on the amine reactive groups of the secondary diamine being from 1.10 to 1 .99, preferably 1.12 to 1 .67, more preferably 1 .17 to 1 .50.

Another object of the present invention is a composition comprising a prepolymer according to the invention or a mixture thereof; and an initiator.

Yet another object of the present invention is a sealant, coating or adhesive obtained by curing the composition according to the invention, preferably at a temperature of -10 to 50°C, in particular -5 to 45°C, more particularly 0 to 40°C, during a time of 1 to 72 h, in particular 2 to 30 h, more particularly 3 to 24 h. A final object of the present invention is the use of the composition according to the invention for waterproofing exterior or interior traffic-bearing horizontal surfaces, for making flashings, or for renovating roofs.

Definitions

The term "plurivalent radical" means any group having one or more, for example two (divalent), three (trivalent), four (tetravalent), five (pentavalent) or six (hexavalent), single bonds as points of attachment to other groups.

The term“hydrocarbyl radical” means a radical containing 1 to 500 carbon atoms. The hydrocarbyl radical may be linear or branched, cyclic or acyclic, saturated or unsaturated, aliphatic or aromatic. The hydrocarbyl radical may be interrupted by one or more functional groups selected from ether (-0-), thioether (-S-), disulfide (-S-S-), ester (-C(O)-O-), amide (-C(O)-NH-), carbamate (-NH-C(O)-O-), urea (-NH-C(O)-NH-), dimethylsiloxane (-Si(Me)2-0-) and mixtures thereof. One or more of the carbon atoms of the hydrocarbyl radical may be replaced by a nitrogen atom or an isocyanurate group having the following formula:

The hydrocarbyl radical may be unsubstituted or substituted by one or more substituents as defined below.

The term“alkyl” means a hydrocarbyl containing 1 to 20 carbon atoms. The alkyl groups may be linear or branched, acyclic or cyclic. Examples include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, 2-methylbutyl, 2,2-dimethylpropyl, n-hexyl, cyclohexyl, 2-methylpentyl, 2,2-dimethylbutyl, n-heptyl, 2-methylhexyl, and the like. The term "C1 -C20 alkyl" means an alkyl containing 1 to 20 carbon atoms.

When the suffix“ene” or“diyl” is used in conjunction with an alkyl or alkenyl group, this means that the group contains two single bonds as points of attachment to other groups (divalent radical).

The term“aryl” means a polyunsaturated aromatic hydrocarbyl containing one ring (i.e. phenyl), several fused rings (for example naphthyl) or several rings linked via a covalent bond (for example biphenyl), which typically contain 6 to 20, and preferentially 6 to 12, carbon atoms, and wherein at least one ring is aromatic. The aromatic ring may optionally comprise one to two additional fused rings (i.e. cycloalkyl, heterocycloalkyl or heteroaryl). The term“aryl” also encompasses partially hydrogenated derivatives of the carbocyclic system is described above. Examples include phenyl, naphtyl, biphenyl, phenanthrenyl, naphthacenyl, and the like. The term "C6-C12 aryl" means an aryl containing 6 to 12 carbon atoms.

The term“alkylaryl” means a linear or branched alkyl substituent containing a carbon atom attached to an aryl ring. Examples include benzyl, naphthylmethyl, phenethyl, and the like. The term“C6-C12 alkylaryl” means an alkylaryl containing 6 to 12 carbon atoms.

The term“X forms a cycle with Y” means that X and Y, together with the atoms to which they are attached, form an optionally substituted cycle. Examples of cycles are a succinimide, a piperidine, or a piperazine, respectively represented by the following formulae

The following groups: hydrocarbyl radical, alkyl, aryl, alkylaryl and cycle may be unsubstituted or substituted with one or more standard substituents selected from: halogen, alkyl, aryl, hydroxy (-OH), alkoxy (-OR), haloalkyl, cyano (-CN), carboxyl (-COOH), oxo (=0), formyl (-CHO), ester (-COOR), imido (=NR), amido (-CONHR), a tertiary amino group (-NR ), nitro (-NO ), sulfonyl (-SO -R) wherein each R is independently C1 -C20 alkyl, C6-12 aryl or C6-C12 alkylaryl group.

The term“halogen” refers to chlorine, bromine, fluorine and iodine.

The term“haloalkyl” means an alkyl substituted by a halogen atom. Examples include fluoro-, chloro-, bromo-, or iodo-methyl, -ethyl, -propyl, -isopropyl, -butyl, -isobutyl, -tert-butyl, and the like.

The term“alkoxy” means a -OR group, where R represents an alkyl, cycloalkyl, aryl or alkylaryl group. Examples include methoxy, ethoxy, propoxy, butoxy, cyclohexyloxy, phenoxy, benzyloxy, and the like.

The term“hydrocarbyl radical derived from an alkane” means a hydrocarbyl radical obtained by removing one or more terminal hydrogens from an alkane. Said radical may further be functionalized as defined above.

The term“hydrocarbyl radical derived from a polyether” means a hydrocarbyl radical interrupted by one or more ether functional groups (-0-). Said radical may further be functionalized as defined above.

The term“hydrocarbyl radical derived from a polyester” means a hydrocarbyl radical interrupted by one or more ester functional groups (-C(O)O-). Said radical may further be functionalized as defined above.

The term“hydrocarbyl radical derived from a polydimethyl siloxane” means a hydrocarbyl radical interrupted by one or more dimethylsiloxane functional groups (-Si(Me)2-0-). Said radical may further be functionalized as defined above.

The term“hydrocarbyl radical derived from poly(alkyl (meth)acrylate)” means a hydrocarbyl radical substituted by one or more ester functional groups (-COO(C1 -C20 alkyl)). Said radical may further be functionalized as defined above.

The term“hydrocarbyl radical derived from a polybutadiene” means a hydrocarbyl radical comprising one or more butenediyl monomeric units. Said radical may further be functionalized as defined above.

The term“hydrocarbyl radical derived from a polysulfide” means a hydrocarbyl radical interrupted by one or more thioether functional groups (-S-). Said radical may further be functionalized as defined above.

The term“hydrocarbyl radical derived from a polyurethane” means a hydrocarbyl radical interrupted by one or more urethane functional groups (-NH-C(O)-O-). Said radical may further be functionalized as defined above. The term“hydrocarbyl radical derived from an epoxy acrylate” means a hydrocarbyl radical comprising a moiety obtained by reacting an multifunctional epoxy resin and an acrylic acid. Said radical may further be functionalized as defined above.

The term“multifunctional epoxy resin” means a compound or polymer comprising at least two epoxy groups. The term“liquid composition” means that the composition flows under its own weight. In particular, a liquid composition may exhibit a viscosity between 1 ,000 and 40,000 centipoises, said viscosity being measured at 23°C. using a Brookfield viscometer (for viscosities of less than 10,000 centipoises, the measurements are taken with the R5 module at a speed of 30 rpm and for viscosities of greater than 10,000 centipoises, the measurements are taken with the R6 module at a speed of 20 rpm). Such a viscosity allows the application of the composition especially with a roller commonly known as a fabric roller or a brush to form 0.5 to 2 mm thick layers in one or more applications.

The term“two-component composition” means a composition comprising two components that are mixed together before application. The composition is applied in a limited time span (a few hours) after being mixed.

The term“curable composition” means a composition comprising a polymer having functional groups capable of forming covalent bonds with chain extenders, cross-linkers or other polymer molecules to form a cross-linked polymer network.

The term“non-toxic composition” means a composition that contains less than 1 % by weight of free diisocyanate monomers, according to directive 67/548/EEC (30th ATP directive 2008/58/EC), the free diisocyanate monomer content being measured by gas chromatography coupled to a mass spectrometer (according to standard EN ISO 17734-1/2006).

The term“solvent” means any solvent that is conventionally used in curable compositions, said solvent being inert toward the reagents contained in the composition, liquid at room temperature and having a boiling point below 240° C.

Detailed Description of the Invention

Prepolvmer

The prepolymer of the invention is represented by formula (1 ):

wherein

X is O or NRc, preferably X is O ;

each L is independently a plurivalent radical;

R_a is hydrogen;

Rb is hydrogen;

or one Rb forms a cycle with Ri , another Rb forms a cycle with R2 and the remaining Rb are hydrogen, preferably one Rb forms a piperidine with Ri , another Rb forms a piperidine with R2 and the remaining Rb are hydrogen ; Rc is hydrogen;

Rd is hydrogen;

or Rc forms a cycle with Rd, preferably a succinimide;

Ri and R are independently selected from C1 -C20 alkyl, C6-C12 aryl or C6-C12 alkylaryl, preferably methyl, ethyl, phenyl or benzyl, more preferably methyl;

or Ri and R form a cycle, preferably a piperazine, more preferably a non-substituted piperazine;

or Ri forms a cycle with one Rb and R forms a cycle with another Rb, preferably Ri forms a piperidine with one Rb and R forms a piperidine with another Rb ;

n is 2, 3, 4, 5, 6, 7, 8 or 9;

0 < m < 20, preferably 0.5 < m < 10, more preferably 1 < m < 6, even more preferably 1 < m < 4.

The prepolymer of the invention with 1 < m < 4 is particularly interesting since said prepolymer exhibits a very low water uptake.

In particular, groups X and Rd may be selected to form a moiety selected from propanoate, propanamide, and succinimide. As such, the prepolymer of the invention may be represented by one of the following formula (1 a)-

wherein L, Ri , R , R_a, Rb, m and n are as defined above.

In a preferred embodiment, the prepolymer of the invention is represented by formula (1 a).

The prepolymer of the invention may comprise a piperazine moiety, a dipiperidine moiety, an ethylenediamine moiety and/or a homopiperazine moiety. As such, the following moiety (2) present in formula (1 ) of the prepolymer may be represented by one of the following formulae (2a)-(2d):

(2d) .

wherein

is C1 -C20 alkyl, C6-C12 aryl or C6-C12 alkylaryl, preferably methyl, ethyl, phenyl or benzyl, more preferably methyl;

0 is 0, 1 , 2 or 3.

In a preferred embodiment, the moiety of formula (2) is represented by formula (2a).

Group L can be any group. The L groups may be the same or different. In particular, each L may independently be a plurivalent hydrocarbyl radical containing 1 to 500 carbon atoms. Said plurivalent hydrocarbyl radical may be linear or branched, cyclic or acyclic, saturated or unsaturated, aliphatic or aromatic. Said plurivalent hydrocarbyl radical may be interrupted by one or more functional groups selected from ether, thioether, disulfide, ester, amide, carbamate, urea, dimethylsiloxane and mixtures thereof. One or more of the carbon atoms of said plurivalent hydrocarbyl radical may be replaced by a nitrogen atom or an isocyanurate group. Said plurivalent hydrocarbyl radical may be substituted by one or more substituents selected from halogen, alkyl, aryl, hydroxy, alkoxy, haloalkyl, cyano, carboxyl, oxo, formyl, ester, imido, amido, a tertiary amino group, nitro, sulfonyl and mixtures thereof.

Preferably each L has a molecular weight above 500 g.mol ¹. In this preferred embodiment, m is preferably as follows: 1 < m < 4.

In particular, each L may independently be a plurivalent hydrocarbyl radical derived from

an alkane;

a polyether, preferably a polypropylene glycol, a copolymer of ethylene glycol and propylene glycol, a polytetramethylene glycol, an ethoxylated bisphenol;

a polyester, preferably a polyester based on a fatty acid dimer;

a polyurethane; an isocyanurate;

an epoxy acrylate, preferably a bio-based acrylated epoxidized resin;

a polydimethyl siloxane;

a poly (alkyl (meth)acrylate) ;

a polybutadiene;

a polysulfide;

and combinations thereof.

Preferably, each L is independently a plurivalent hydrocarbyl radical derived from a polyether, an alkane, a polyurethane, a polybutadiene and combinations thereof. More preferably, each L is independently a plurivalent hydrocarbyl radical comprising 3-200 carbon atoms derived from a polyether, an alkane, a polyurethane, a polybutadiene and combinations thereof. Even more preferably, each L is independently a plurivalent hydrocarbyl radical comprising 30-150 carbon atoms derived from a polyether, a plurivalent hydrocarbyl radical comprising 3- 20 carbon atoms derived from an alkane, a plurivalent hydrocarbyl radical comprising 30-150 carbon atoms derived from a polyurethane or a plurivalent hydrocarbyl radical comprising 50-200 carbon atoms derived from a polybutadiene.

In one embodiment, each L may preferably be independently represented by one of the following formulae (La)- (LI3), preferably with each L having a molecular weight above 500 g.mol ¹ :

preferably C1 -C20 alkyl, more preferably methyl;

each FU, Rs and R7 is independently H or methyl; preferably R7 is methyl

each A is independently a linear or branched, cyclic or acyclic, saturated or unsaturated alkylene comprising 2 to 20 carbon atoms;

each B is independently a linear or branched, cyclic or acyclic, saturated or unsaturated alkylene comprising 2 to 20 carbon atoms;

C is a linear or branched, cyclic or acyclic, saturated or unsaturated alkylene comprising 4 to 100 carbon atoms optionally interrupted by one or more ether and/or ester functional groups;

each D is independently a linear or branched, cyclic or acyclic, saturated or unsaturated alkylene comprising 2 to 20 carbon atoms;

each E is independently a linear or branched, cyclic or acyclic, saturated or unsaturated alkylene comprising 4 to 100 carbon atoms optionally interrupted by one or more ether and/or carbamate functional groups;

each F is independently a linear or branched, cyclic or acyclic, saturated or unsaturated alkylene comprising 4 to 100 carbon atoms optionally interrupted by one or more ether and/or carbamate functional groups;

each G is independently a linear or branched alkylene comprising 0 to 100 carbon atoms optionally interrupted by one or more ether and/or ester functional groups;

each G’ is independently a linear or branched alkylene comprising 0 to 100 carbon atoms optionally interrupted by one or more ether and/or ester functional groups;

each G^* is independently a linear or branched alkylene comprising 0 to 100 carbon atoms;

J, J’ and J^* are independently H or a linear or branched alkyl comprising 1 to 20 carbon atoms, optionally substituted by hydroxy or alkoxy;

each M is independently a linear or branched, cyclic or acyclic alkylene comprising 1 to 20 carbon atoms optionally interrupted by one or more ether and/or carbamate functional groups;

each Q is independently a linear or branched alkylene comprising 0 to 100 carbon atoms optionally interrupted by one or more ether functional groups;

each Q^* is independently a linear or branched alkylene comprising 0 to 100 carbon atoms optionally interrupted by one or more ether and/or ester functional groups;

R’ is a linear or branched alkylene comprising 1 to 20 carbon atoms optionally interrupted by one or more ether functional groups;

T is a linear or branched, cyclic or acyclic, saturated or unsaturated alkylene comprising 4 to 100 carbon atoms optionally interrupted by one or more ether and/or carbamate functional groups;

each U is independently a linear or branched alkylene comprising 0 to 100 carbon atoms optionally interrupted by one or more ether and/or ester functional groups;

each Z is independently represented by the following formula:

wherein X, Ri , R2, R_a, Rb ,Rd and n are as defined above ; b is 1 to 10;

s, t and u are independently 0 to 10;

r, r’, v, v’, w, x, y, y^*, z and z^* are independently 0 to 50; preferably (x+y+w) is between 20 to 70 and preferably z is 5 to 50;

z’ is 5 to 150;

each a^* is independently 0 or 1 with the proviso that formula (LI3) comprises two a^* units;

each b^* is independently 0, 1 , 2 or 3 with the proviso that that formula (LI3) does not comprise more than four b^* units.

Preferably, each L is independently represented by one of formulae (La) and (Lc), more preferably (Lc).

In a preferred embodiment, each L may independently be represented by one of the following formulae (Lc)-(Ld) and (Lo)-(Ly), preferably with each L having a molecular weight above 500 g.mol ¹ :

(Ly) ;

wherein

Z, Q^*, R5, Ri, Rj, r’, v’, w, x and y are as defined above; preferably (x+y+w) is between 20 to 70 each Re is independently H or methyl; preferably methyl;

k is 2 to 1 00; preferably is 1 0 to 50; more preferably is 25 to 40, for example is 33;

r and r^* are independently 1 to 70; preferably r is 14 to 70 and preferably r^* is 14 to 70;

s^* is 1 to 20;

z” is 5 to 50, preferably 8 to 30, more preferably 1 0 to 20 or more preferably 25 to 30, for example is 27.

Preferably, each L is independently represented by one of formulae (Lc), (Lm) (Lp) and (Lo), more preferably (Lp) and (Lo).

The L group may also be a compound resulting from reduction of fatty acid dimers or a hydrogenated polybutadienes, preferably with each L having a molecular weight above 500 g.moL¹ : Examples of fatty acid dimers include but are not limited to compounds of general formula (Lz) resulting from reduction of fatty acid dimers such as Pripol® compounds sold by Croda Company:

(Lz).

Examples of hydrogenated polybutadienes include, but are not limited to, compounds of general formula (Lz’):

wherein

each Q^** is independently a linear or branched alkylene comprising 0 to 100 carbon atoms optionally interrupted by one or more ether and/or ester functional groups,

(W + X + Y) is between 20 and 70.

In all embodiments, the prepolymer of the invention may exhibit a number average molecular weight (Mn) of 800 to 10,000, preferably 1 ,000 to 6,000, more preferably 2,000 to 5,000. The number average molecular weight may be determined by steric exclusion chromatography (SEC) or nuclear magnetic resonance (NMR). Such number average molecular weight notably of 1 ,000 to 5,000, preferably above 1 ,500, even more preferably above 2,000, for example of 2,000 to 5,000 or of 2,500 to 5,000 enable to get a sealant, coating or adhesive with good mechanical properties, in particular exhibit good elongation at break.

The prepolymer of the invention may be obtained according to the method described below.

Method for preparing the prepolymer of the invention

The prepolymer of the invention may be obtained by a Michael addition. Michael addition is a chemical reaction in which an enolate anion (nucleophile) reacts with an activated a,b-unsaturated carbonyl compound

(electrophile) according to a 1 ,4-addition. A wide range of functional groups possess sufficient nucleophilicity to react in a Michael addition, such as amines (aza-addition) and thiols (thio-addition). Michael addition is one of the most versatile reactions in organic synthesis with its click chemistry nature, no byproducts, and the mild The first step of a Michael reaction is transforming a ketone to an enolate, or nucleophile, through deprotonation due to the addition of a base. This negative charge initiates 1 ,4-addition on an a,b-unsaturated carbonyl compound which is then protonated and forms the final product. The reaction is thermodynamically controlled as the donors are active methylenes and the acceptors are activated olefins.

In accordance with an aspect, a Michael addition reaction can be employed to manufacture prepolymers comprising a,b-unsaturated carbonyl groups useful for obtaining two-component curable sealants, coatings or adhesives. The method involves reacting an excess of a multifunctional a,b-unsaturated carbonyl compound with a secondary diamine. The secondary diamine is a Michael donor and the multifunctional a,b-unsaturated carbonyl compound is a Michael acceptor.

wherein X, L, Ri , R2, R_a, Rb Rd and n are as defined above for the prepolymer;

the molar ratio between the a,b-unsaturated carbonyl groups of the electrophile and the hydrogens on the amine reactive groups of the secondary diamine being from 1 .1 0 to 1 .99, preferably 1 .12 to 1 .67, more preferably 1 .17 to 1 .50. The molar ratio between the a,b-unsaturated carbonyl groups and the hydrogens on the amine reactive groups used in the method of preparing the prepolymer determines the number of repeating units, and hence the value of m, of the prepolymer. In particular, the following equation gives the relation between the molar ratio (r) and the value of m in formula (1 ) of the prepolymer:

m + 2

r =

m + 1 In the method of the invention, the secondary diamine may react with a mixture of electrophiles, for example a mixture of electrophiles of formula (3).

In one embodiment, the electrophile may be represented by one of the following formulae (3a)-(3c):

wherein L is as defined above for the prepolymer.

In a preferred embodiment, the electrophile may be represented by formula (3a).

Preferably, in formulae (3a)-(3c), L may be represented by one of formulae (La)-(LI3) as defined above for the prepolymer; more preferably L may be represented by one of formulae (La) and (Lc); even more preferably L may be represented by one of formulae (Lc)-(Ld) and (Lm)-(Ly); more preferably still L may be represented by one of formulae (Lc), (Lm) and (Lo).

Examples of electrophiles of formula (3) include a polypropylene glycol) diacrylate, a polyethylene glycol) diacrylate, butanediol diacrylate, 1 ,6-hexanediol diacrylate, an ethoxylated 1 ,6-hexanediol diacrylate, 1 ,10- decanediol diacrylate, 3-methyl-1 ,5-pentanediol diacrylate, neopentylglycol diacrylate, a propoxylated neopentylglycol diacrylate, dimethylol tricyclodecane diacrylate, an ethoxylated bisphenol A diacrylate, trimethylol propane triacrylate, an ethoxylated trimethylol propane triacrylate, a propoxylated trimethylol propane triacrylate, tris[2-(acryloyloxy)ethyl] isocyanurate, pentaerythritol triacrylate, glycerol triacrylate, a propoxylated glycerol triacrylate, pentaerythritol tetracrylate, an ethoxylated pentaerythritol tetracrylate, an epoxydized soybean oil (AESO) and a polycaprolactone triacrylate.

Another example of an electrophile of formula (3a) is an esterdiol diacrylate (available under reference SR 606A by Sartomer) having the following formula:

Another example of an electrophile of formula (3a) is an aliphatic urethane acrylate oligomer (available under reference CN 9002 by Sartomer) having the following formula:

or an aromatic urethane oligomer (available under reference CN 9761 by Sartomer) having the following formula:

Another example of an electrophile of formula (3a) is a polybutadiene diacrylate (available under reference SR 307 by Sartomer) having the following formula:

In a particularly preferred embodiment, the electrophile is selected from 1 ,6-hexanediol diacrylate, tripropylene glycol diacrylate, a polypropylene glycol) diacrylate, a polyethylene glycol) diacrylate, an ethoxylated bisphenol A diacrylate and mixtures thereof.

The secondary diamine of formula (4) may be represented by one of the following formulae (4a)-(4d):

wherein R3 and 0 are as defined above for the prepolymer.

Preferably the secondary diamine is represented by formula (4a).

In the method of the invention, the reaction between the electrophile and the secondary diamine may be carried out in the presence or in the absence of a solvent. Preferably, the reaction between the electrophile and the secondary diamine is carried out in the absence of a solvent.

In the method of the invention, the reaction between the electrophile and secondary diamine may be carried out in the presence or in the absence of a catalyst. In particular, said catalyst may be a base, more particularly 1 ,4- diazabicyclo[2.2.2]octane (DABCO) or 1 ,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Preferably, the reaction between the electrophile and the secondary diamine is carried out in the absence of a catalyst. In the method of the invention, the reaction between the electrophile and the secondary diamine may be carried out at a temperature of 10 to 80°C, in particular 15 to 60°C, more particularly 20 to 40°C, during a time of 10 min to 8 h, in particular 30 min to 4 h, more particularly 1 to 2 h.

The completion of the reaction may be monitored by Fourier-transform infrared (FT IR) spectroscopy. FT IR spectroscopy works by sending infrared radiation through a chemical sample, where some radiation is absorbed into the sample and some passes through. The radiation that is absorbed is converted to vibrational energy, which produces a unique signal that identifies the compound. During the Michael addition, the carbon-carbon double bond of the electrophile is transformed into a carbon-carbon single bond. Once the FT IR signal of the carbon-carbon double bond disappears, the reaction may be considered as finished. The reaction may alternatively be monitored by Proton Nuclear Magnetic Resonance (¹ H-NMR). Once the a,b-unsaturated carbonyl group has reacted, the signals of the ethylenic protons (between 5.8 and 6.5 ppm) are no longer visible and a new signals relative to single bonds CH2-CH2 are present.

Composition comprising a prepolymer

The composition according to the invention comprises the prepolymer of the invention and an initiator. The composition may further optionally comprise a mono(meth)acrylate, a multifunctional (meth)acrylate, a poly(meth)acrylic resin and/or an additive.

The prepolymer introduced in the composition of the invention is as defined above. The composition may comprise a mixture of prepolymers according to the invention.

The amount of the prepolymer according to the invention in the composition may be from 10 to 70%, in particular 20 to 60%, more particularly 30 to 50%, by weight based on the weight of the composition.

The initiator that is introduced in the composition may be selected from an organic peroxide, an organic azo compound, and mixtures thereof.

Preferably, the initiator is selected from benzoyl peroxide, methyl ethyl peroxide, methyl ethyl ketone peroxide, di-t-butyl peroxide, lauroyl peroxide, acetyl peroxide, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, t-butyl peroxy-2-ethylhexanoate, t-hexyl peroxy-2-ethylhexanoate, 2,2'-azobisisobutyronitrile, dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 4,4'-azobis(4-cyanopentanoic acid), and mixtures thereof.

More preferably the initiator is benzoyl peroxide.

The amount of initiator in the composition may be adjusted according to the temperature at which the composition is cured. In particular, the amount of initiator in the composition may be from 0.01 to 5%, more particularly 0.05 to 4.5%, even more particularly 0.1 to 4%, by weight based on the weight of the composition.

The composition may comprise an accelerator. The accelerator advantageously promotes the decomposition of the initiator at room temperature.

The accelerator that is introduced in the composition may be A/,A/-diisopropanol-p-toluidine, A/,A/-dimethyl-p- toluidine or A/,A/-bis(2-hydroxyethyl)-p-toluidine. The amount of accelerator in the composition may be from 0.01 to 3%, in particular 0.05 to 2.5%, more particularly 0.1 to 2%, by weight based on the weight of the composition.

The composition may comprise a mono(meth)acrylate. The mono(meth)acrylate that is optionally introduced in the composition of the invention is a monomer comprising a single acrylate or methacrylate group. The composition may comprise a mixture of mono(meth)acrylates.

Preferably, the mono(meth)acrylate is selected from methyl (meth)acrylate, n-butyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, phenyl (meth)acrylate, glycidyl (meth)acrylate and benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 3-phenoxy-2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate and mixtures thereof.

More preferably the mono(meth)acrylate is selected from methyl methacrylate, 2-ethylhexyl acrylate and mixtures thereof.

The amount of mono(meth)acrylate in the composition may be from 1 to 70%, in particular 20 to 60%, more particularly 30 to 50%, by weight based on the weight of the composition.

The composition may comprise a poly(meth)acrylic resin. The poly(meth)acrylic resin that is optionally introduced in the composition of the invention is a polymer comprising monomeric units derived from acrylic acid, a mono acrylate, methacrylic acid, a mono-methacrylate, cyanoacrylic acid, a mono-cyanoacrylate, acrylonitrile and mixtures thereof. Said polymer may be an acrylic co-polymer which further comprises monomeric units derived from compounds other than those cited above, such as, for example, acrylamide, a N-substituted acrylamide, a styrene, or vinylacetate. The poly(meth)acrylic resin is distinct from the prepolymer of the invention. The composition may comprise a mixture of poly(meth)acrylic resins.

Preferably, the poly(meth)acrylic resin is selected from a methyl methacrylate/n-butyl methacrylate copolymer (such as Elvacite® 2016 and Elvacite® 2013 from Lucite), a methacrylic resin (such as Degalan® LP 66/02 and Degalan® LL 64/12 from Evonik) and mixtures thereof.

More preferably the poly(meth)acrylic resin is a methyl methacrylate/n-butyl methacrylate copolymer.

The amount of poly(meth)acrylic resin in the composition may be from 1 to 40%, in particular 5 to 20%, more particularly 7 to 15%, by weight based on the weight of the composition.

The composition may comprise a multifunctional (meth)acrylate. The multifunctional (meth)acrylate that is optionally introduced in the composition of the invention is a monomer comprising two or more acrylate or methacrylate groups. The multifunctional (meth)acrylate is distinct from the prepolymer of the invention. The composition may comprise a mixture of multifunctional (meth)acrylates.

Preferably, the multifunctional (meth)acrylate is selected from a di(meth)acrylate such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1 ,3-butylene glycol di(meth)acrylate, 1 ,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2-hydroxy-1 ,3-di(meth)acryloxypropane, 2,2-bis[4- ((meth)acryloxyethoxy)phenyl]propane, 2,2-bis[4-((meth)acryloxydiethoxy)phenyl]propane, 2,2-bis[4-((meth)- acryloxypolyethoxy)phenyl]propane, a polyurethane modified acrylate (PUMA), and mixtures thereof.

The amount of multifunctional (meth)acrylate in the composition may be from 0 to 40%, in particular s to 20%, more particularly 7 to 15%, by weight based on the weight of the composition.

The composition may comprise an additive. The additive that is optionally introduced in the composition of the invention is a conventional additive used in the manufacture of sealants, coatings and adhesives. The composition may comprise a mixture of additives. The additive introduced in the composition of the invention is selected from a plasticizer, a filler, an adhesion promoter, a pigment or dye, a UV-absorber, an antioxidant, a UV- stabilizer, a moisture scavenger, a fungicide, a biocide, a root-penetration preventer, a fire-retardant, a rheology modifier, an oxygen barrier and mixtures thereof.

Examples of suitable plasticizers are aromatic oils, such as diisopropyl naphthalene (Ruetasolv® Dl) or NYTEX® 820; esters of polycarboxylic acids with linear or branched aliphatic alcohols, such as phthalates and adipates, for example dioctyl phthalate (DOP), diisodecyl phthalate (DIDP), diisononyl phthalate (DINP), butylbenzyl phthalate and di(2-ethylhexyl)adipate (DEHA); esters of polyols with linear or branched carboxylic acids, such as trimethyl pentanediol diisobutyrate (TXIB) ; alkylsulfonic acid phenylesters, such as Mesamoll®; and mixtures thereof.

Examples of suitable fillers are mineral or organic fillers, such as calcium carbonate, silica, talc, dolomite, kaolin, carbon black, titanium dioxide, and mixtures thereof. Preferably, said filler is calcium carbonate. Fillers derived from recycling can also be used (lignin, recycled fibers, ground polymer materials, coke, ground cement materials).

Examples of suitable biocides and fungicides are 2-octyl-2H-isothiazol-3-one (OIT) in diisododecylphthalate (Fungitrol® PA10), N-(Trichloromethylthio) phthalimide (Fungitrol® 1 1 ), 3-iodo-2-propynyl butylcarbamate (IPBC) (Fungitrol® C450 or Preventol® MP100).

An example of a suitable root-penetration preventer is 2-(4-chloro-2-methylphenoxy)-propionic acid octyl ester (Preventol® B5).

Examples of suitable UV-absorbers and antioxidants are Irganox® 565 (2,4-Bis(octylthio)-6-(4-hydroxy-3,5-di- tert-butylanilino)-1 ,3,5-triazine), IONOL® CP (2,6-Di-tert-butyl-4-methylphenol), Tinuvin® 1 130 (2-(2- hydroxyphenyl)-benzotriazole), Tinuvin® 400 (2-hydroxyphenyl-s-triazine).

Examples of suitable UV-stabilizers are Tinuvin® 292 ((Bis(1 ,2,2,6,6-pentamethyl-4-piperidyl) sebacate), Tinuvin® 123 (Bis(1 -octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate).

Examples of suitable moisture scavenger and adhesion promoters are silanes, such as vinyltrimethoxysilane (Geniosil® XL 10) and N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane (Geniosil® GF91 ).

Examples of suitable rheology modifiers are a hydrophobically modified alkali swellable emulsion (HASE) such as Acrysol® TT 935 and Acrysol® DR-1 10 ER; a cellulose or cellulose derivative such as CMC, HMC, HPMC; a polysaccharide such as carrageenan, pullulan, konjac, and alginate; a clay such as attapulgite, bentonite and montmorillonite; a gum such as guar gum, xanthan gum, cellulose gum, locust bean gum, and acacia gum. Examples of suitable fire retardants are borates, such as colemanite, halogenated compounds

(tris(chloropropyl)phosphate = TCPP or tetrabromobisphenol-A = TBBA or Hexabromocyclododecane = HBCD), triaryl phosphate, melamine (non-halogenated flame retardant), alumina trihydrate, DOPO (9,10-dihydro-9-oxa- 10-phosphaphenanthrene-10-oxide = Polyphlox® 3710).

An example of a suitable oxygen barrier is a wax, such as paraffin wax (Sasolwax® 5603).

The amount of the additive in the composition may be from 0 to 50%, in particular 5 to 45%, more particularly 10 to 40%, by weight based on the weight of the composition.

In one embodiment, the composition of the invention comprises the following constituents, the % being % by weight based on the weight of the composition:

20-70% of the prepolymer of the invention;

20-70% of a mono(meth)acrylate, in particular methyl (meth)acrylate;

0-30% of a poly(meth)acrylic resin, in particular a methyl methacrylate/n-butyl methacrylate copolymer;

0-30% of a multifunctional (meth)acrylate;

0-20 % of a filler, in particular calcium carbonate;

0-30 % of a plasticizer, in particular diisodecyl phthalate (DIDP);

0-2 % of a moisture scavenger, in particular vinyltrimethoxysilane;

0-5% of an adhesion promoter, in particular N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane;

0-10% of a pigment or dye;

0.01 -5% of an initiator, in particular benzoyl peroxide;

0.01 to 3% of an accelerator, such as A/,A/-diisopropanol-p-toluidine;

0 to 2% of an antioxidant, such as 2,6-di-tert-butyl-4-methylphenol;

0 to 2% of an oxygen barrier, such as a wax.

The composition of the invention may advantageously be a liquid two-component curable composition. Further, the composition of the invention may be a non-toxic composition. Additionally, the composition of the invention may have a low solvent content, i.e. less than 5%, in particular less than 2%, more particularly less than 1 %, by weight of solvent based on the weight of the composition, or the composition may be substantially free of any solvent.

The composition of the invention is obtained by mixing the prepolymer, the initiator and the other optional ingredients shortly before use.

The composition of the invention may be used to obtain a sealant, coating or adhesive.

Sealant, coating or adhesive

The sealant, coating or adhesive of the invention is obtained by curing the composition according to the present invention.

The curing may be carried out rapidly under ambient conditions, in the presence of atmospheric moisture. In one embodiment, the curing may be carried out at a temperature of -10 to 50°C, in particular -5 to 45°C, more particularly 0 to 40°C, during a time of 1 to 72 h, in particular 2 to 30 h, more particularly 3 to 24 h.

The sealant, coating or adhesive according to the invention may exhibit a glass transition temperature of -120 to 80°C, preferably -100 to 60°C, more preferably -80 to 50°C. The sealant, coating or adhesive according to the invention may exhibit excellent mechanical properties. As such, the sealant, coating or adhesive may exhibit a tensile strength at 20°C of 0.1 to 100 MPa, preferably 1 to 50 MPa, more preferably 5 to 20 MPa. Further, the sealant, coating or adhesive may exhibit an elongation at break at 20°C of 10 to 1 ,000%, preferably 50 to 800%, more preferably 100 to 600%.

Use of the composition

The invention also relates to the use of the composition according to the invention for producing a sealant, coating or adhesive, especially a leaktight sealant or coating, which has good mechanical strength, is resistant to UV, to oxidation aging, to water and to chemical attack, and which does not have any surface defects or adhesion defects (bubbles, swelling or exudation). The sealants or coatings may be circulable and are particularly suitable for use in an unprotected exterior medium as leaktight sealants or coatings. The sealants, coatings or adhesives obtained have an entirely satisfactory water uptake, i.e. less than 8% after 28 days of immersion in water at 20°C. The sealants, coatings or adhesives obtained by the use of the composition according to the invention can cover horizontal, oblique, vertical or rough surfaces and/or surfaces comprising singular points.

The composition of the invention may be used for waterproofing exterior or interior traffic-bearing horizontal surfaces, for making flashings, or for renovating roofs.

In one embodiment, the composition of the invention may be used for waterproofing exterior circulable horizontal surfaces, such as, for example, balconies, stadiums, terraces, car parks, building courtyards, etc.

In another embodiment, the composition of the invention may be used for making upstand flashings, i.e. for making a waterproof coating between a bituminous surface and a vertical wall or a singular point, or alternatively for renovating roofs.

In another embodiment, the composition of the invention may be used to bind two elements together.

The invention will be described in greater detail with the aid of the examples that follow, which are given for purely illustrative purposes.

Examples

Measuring methods:

In the examples, the following methods were used to determine the glass transition temperature (Tg), the ultimate tensile strength, the Young’s modulus and the elongation at break.

Glass transition temperature

The glass transition temperature is determined on a dry material at least 7 days after its preparation by differential scan calorimetry (DSC). The DSC analyses were performed on a 10 mg sample using a Q200 apparatus from TA Instruments. The following cycles were applied:

Cycle 1 : temperature increase from room temperature to 170°C at 10°C/min and remaining at 170°C for 5 min; Cycle 2: temperature decrease to -80°C at 20°C/min and remaining at -80°C for 5 min; Cycle 3: temperature increase to 170°C at 10°C/min.

The Tg was measured during the third cycle.

Mechanical analysis:

The mechanical analyses were determined on a dry material 7 days after its preparation according to standard NF EN ISO 527, February 2012 on an extensometer from Instron. The following parameters were used:

tensile speed: 100 mm/min

temperature: 23°C

test specimen: dumbbell-shaped type 5.

Materials:

In the examples, the following materials were used:

Piperazine was obtained from BASF;

PPG1 (polypropylene glycol) diacrylate) having a number average molecular weight of 840 g.mol ¹ was obtained from Sigma-Aldrich;

PPG2 (polypropylene glycol) diacrylate) having a number average molecular weight of 508 g.mol ¹ was obtained from Miwon under reference Miramer® M2040;

1 ,6-hexanediol diacrylate was obtained from Sartomer under reference SR 238;

Ethoxylated bisphenol A diacrylate having a number average molecular weight of 512 g.mol ¹ was obtained from Sigma-Aldrich;

Tripropylene glycol) diacrylate having a number average molecular weight of 300.4 g.mol ¹ was obtained from Sartomer under reference SR 306;

Polypthylene glycol) diacrylate having a number average molecular weight of 575 g.mol ¹ was obtained from Sigma-Aldrich;

MMA (methyl methacrylate - mono(meth)acrylate) was obtained from Evonik under reference Visiomer® MMA; co-MMA/BA (methyl methacrylate/n-butyl methacrylate copolymer - poly(meth)acrylic resin) was obtained from Lucite International under reference Elvacite® 2016;

DPpT (A/,A/-diisopropanol-p-toluidine - accelerator) was obtained from BASF;

Benzoyl peroxide (initiator) was obtained from Soprema under reference Alsan® 070;

Paraffin wax (oxygen barrier) was obtained from Sasol under reference Sasolwax® 5603;

BHT (2,6-di-tert-butyl-4-methylphenol - antioxidant) was obtained from Oxiris under reference lonol® CP. Example 1: Preparation of an acrylic prepolymer of formula (!)

Piperazine (20 g, 0.232 mol) and PPG1 (234 g, 0.279 mol) were mixed in a reactor under nitrogen atmosphere, without any catalyst or solvent. The mixture was stirred at 70°C for 1 hour. The reaction was considered complete when the NMR peaks corresponding to the piperazine disappeared (2.86 ppm). The resulting product was a colorless viscous liquid. NMR analysis confirmed that the structure of resulting product corresponded to formula (I). The number average molecular weight was determined by NMR.

NMR-¹ H : (d ppm, CDCb) 0.90-1.30 (302H), 2.25-2.75 (1 15H), 3.20-3.75 (287H), 4.90-5.15 (15H), 5.80 (2H), 6.08-6.18 (2H), 6.40 (2H).

The number average molecular weight was determined to be about 6,000 g.mol ¹.

Example 2: Preparation of an acrylic prepolvmer of formula ill)

The prepolymer of formula (II) was obtained according to example 1 by reacting piperazine (20.0 g, 0.232 mol) with PPG1 (156 g, 0.186 mol) and 1 ,6-hexanediol diacrylate (21.0 g, 0.093 mol) at 70°C for 2 hours. The resulting product was a pale yellow viscous liquid. NMR analysis confirmed that the structure of resulting product corresponded to formula (II).

NMR-¹ H : (d ppm, CDCb) 0.90-1.30 (185H), 1.30-1 .45 (1 1 H), 1.55-1.70 (1 1 H), 2.25-2.60 (74H), 2.60-2.80 (29H), 3.20-3.75 (177H), 4.00-4.20 (10H), 4.90-5.15 (10H), 5.80 (2H), 6.08-6.18 (2H), 6.40 (2H).

The number average molecular weight was determined to be about 5,400 g.mol ¹.

Example 3: Preparation of an acrylic prepolvmer of formula (III)

The prepolymer of formula (III) was obtained according to example 1 by reacting piperazine (20.0 g, 0.232 mol) with PPG1 (1 17 g, 0.139 mol) and ethoxylated bisphenol A diacrylate (77.8 g, 0.152 mol) at 70°C for 1 hour. The resulting product was a pale yellow viscous liquid. NMR analysis confirmed that the structure of resulting product corresponded to formula (III).

NMR-¹ H : (d ppm, CDCb) 1.00-1.35 (1 11 H), 1.62 (18H), 2.20-2.60 (58H), 2.60-2.80 (23H), 3.20-3.90 (134H), 4.05-4.15 (12H), 4.20-4.35 (9H), 4.41 (3H), 4.97-5.17 (6H), 5.80 (2H), 6.08-6.18 (2H), 6.40 (2H), 6.80 (12H), 7.12 (12H).

The number average molecular weight was determined to be about 4,600 g.moh¹.

Example 4: Preparation of an acrylic prepolvmer of formula (I V)

The prepolymer of formula (IV) was obtained according to example 1 by reacting piperazine (30.9 g, 0.359 mol) with tri(propylene glycol) diacrylate (125.7 g, 0.418 mol) at 70°C for 2 hours. The resulting product was a yellow viscous liquid. NMR analysis confirmed that the structure of resulting product corresponded to formula (IV). NMR-¹ H : (d ppm, CDCb) 1.00-1.35 (156H), 2.20-2.75 (230H), 3.20-3.85 (1 1 OH), 3.90-4.20 (26H), 4.33 (2H), 4.95-5.20 (19H), 5.80 (2H), 6.08-6.18 (2H), 6.40 (2H).

The number average molecular weight was determined to be about 5,900 g.mol ¹. Example 5: Preparation of an acrylic prepolymer of formula (V)

The prepolymer of formula (V) was obtained according to example 1 by reacting piperazine (14.7 g, 0.171 mol) with polyethylene glycol) diacrylate (1 12.0 g, 0.195 mol) at 70°C for 1 hour. The resulting product was a colorless viscous liquid. NMR analysis confirmed that the structure of resulting product corresponded to formula (V).

NMR-¹ H : (d ppm, CDCb) 2.20-2.57 (53H), 2.60-2.75 (21 H), 3.50-3.90 (191 H), 4.15-4.40 (24H), 5.80 (2H), 6.08- 6.18 (2H), 6.40 (2H).

The number average molecular weight was determined to be about 4,000 g.mol ¹.

Example 6: Preparation of an acrylic prepolvmer of formula (VI )

The prepolymer of formula (VI) was obtained according to example 1 by reacting piperazine (14.6 g, 0.169 mol) with PPG2 (1 12.0 g, 0.190 mol) at 70°C for 1 hour. The resulting product was a pale yellow viscous liquid. NMR analysis confirmed that the structure of resulting product corresponded to formula (VI).

NMR-¹ H : (d ppm, CDCb) 1.00-1.35 (215H), 2.20-2.75 (148H), 3.20-3.80 (193H), 4.90-5.15 (20H), 5.80 (2H), 6.08-6.18 (2H), 6.40 (2H).

The number average molecular weight was determined to be about 6,000 g.mol ¹.

Example 7: Preparation of sealant composition

Compositions 1 and 2 were prepared using the ingredients and the respective amounts in grams listed in the following table:

The mono(meth)acrylate, the oxygen barrier, the antioxidant and the accelerator were mixed in a disperser and stirred at 90°C for 30 minutes. The poly(meth)acrylic resin was then added and the mixture was stirred for 20 minutes at room temperature (20-25°C). The acrylic prepolymer of the invention was then added and the mixture was stirred for 20 minutes at room temperature. The initiator was then added and the mixture was stirred for 30 minutes at room temperature. The composition was casted on a plate in order to obtain a uniform film having a thickness of about 1 mm and was left to dry during 7 days.

The thermal and mechanical properties of the resulting sealants are listed in the table below:

Claims

wherein L, Ri , Fte, R_a, Rb, m and n are as defined in claim 1 ;

preferably the prepolymer is represented by formula (1 a).

3. Prepolymer according to claim 1 or 2, wherein the following moiety (2) present in formula (1 ) of the prepolymer:

is represented by one of the following formulae (2a)-(2d):

(2d) .

wherein

R is C1 -C20 alkyl, C6-C12 aryl or C6-C12 alkylaryl, preferably methyl, ethyl, phenyl or benzyl, more preferably methyl;

is 0, 1 , 2 or 3 ;

preferably moiety (2) is represented by formula (2a).

4. Prepolymer according to any one of claims 1 to 3, wherein each L is independently selected from a linear or branched, cyclic or acyclic, saturated or unsaturated, aliphatic or aromatic, plurivalent hydrocarbyl radical containing 1 to 500 carbon atoms, said radical being optionally interrupted by one or more functional groups selected from ether (-0-), thioether (-S-), disulfide (-S-S-), ester (-C(O)-O-), amide (-C(O)-NH-), carbamate (-NH- C(O)-O-), urea (-NH-C(O)-NH-), dimethylsiloxane (-Si(Me)2-0-) and mixtures thereof, said radical optionally having one or more carbon atoms replaced by a nitrogen atom or an isocyanurate group having the following formula:

said radical being optionally substituted by one or more substituents selected from halogen, alkyl, aryl, hydroxy (-OH), alkoxy (OR), haloalkyl, cyano (-CN), carboxyl (-COOH), oxo (=0), formyl (-CHO), ester (-COOR), imido (=NR), amido (-CONHR), a tertiary amino group (-NR ), nitro (-NO ), sulfonyl (-SO -R) and mixtures thereof, wherein each R is independently C1 -C20 alkyl, C6-12 aryl or C6-C12 alkylaryl group.

5. Prepolymer according to any one of claims 1 to 4, wherein each L is independently represented by one of the following formulae (La)-(LI3), preferably each L having a molecular weight above 500 g.mol ¹ :

wherein

R_g and Rh are independently H or C1 -C20 alkyl, preferably H, methyl or ethyl, more preferably H or methyl;

Ri and are independently H, halogen, C1 -C20 alkyl, C1 -C20 haloalkyl, C6-C12 aryl or C6-C12 alkylaryl; preferably C1 -C20 alkyl, more preferably methyl;

each R4, RS and R7 is independently H or methyl;

each D is independently a linear or branched, cyclic or acyclic, saturated or unsaturated alkylene comprising 2 to 20 carbon atoms; each E is independently a linear or branched, cyclic or acyclic, saturated or unsaturated alkylene comprising 4 to 100 carbon atoms optionally interrupted by one or more ether and/or carbamate functional groups;

each Z is independently represented by the following formula:

wherein X, Ri , R , R_a, Rb ,Rd and n are as defined in any one of claims 1 to 3;

b is 1 to 10;

s, t and u are independently 0 to 10;

r, r’, v, v’, w, x, y, y^*, z and z^* are independently 0 to 50;

z’ is 5 to 150;

6. Prepolymer according to any one of claims 1 to 4, wherein each L is independently represented by one of the following formulae (Lc)-(Ld) and (Lo)-(Ly), preferably each L having a molecular weight above 500 g / mol ¹ :

(Ly) ;

wherein

Z, Q^*, R5, Ri, Rj, r’, v’, w, x and y are as defined above;

each Re is independently H or methyl, preferably methyl ;

k is 2 to 100, preferably is 10 to 50; more preferably is 25 to 40, for example is 33;

r and r^* are independently 1 to 70, preferably r is 14 to 70 and preferably r^* is 14 to 70;

s^* is 1 to 20;

z” is 5 to 50, preferably 8 to 30, more preferably 10 to 20 or 25 to 30, for example is 27.

7. A method for preparing a prepolymer, wherein said method comprises reacting an electrophile of formula (3) with a secondary diamine of formula (4) :

wherein X, L, Ri , R2, R_a, Rb Rd and n are as defined in any one of claims 1 to 6,

8. The method of claim 7, wherein the electrophile is represented by one of the following formula (3a)-(3c):

wherein L is as defined in any one of claims 4 to 6;

preferably the electrophile is represented by formula (3a).

9. The method of claim 7 or 8, wherein the secondary diamine is represented by one of the following formula (4a)-(4d):

wherein F¾ and o are as defined in claim 3,

preferably the secondary diamine is represented by formula (4a).

10. A composition comprising:

- a prepolymer as defined in any one of claims 1 to 6 or as obtained according to the method of any one of claims 7 to 9 or a mixture thereof; and

- an initiator.

1 1. The composition of claim 10, wherein the initiator is selected from an organic peroxide, an organic azo compound, and mixtures thereof; preferably the initiator is selected from benzoyl peroxide, methyl ethyl peroxide, methyl ethyl ketone peroxide, di-t-butyl peroxide, lauroyl peroxide, acetyl peroxide, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, t-butyl peroxy-2-ethylhexanoate, t-hexyl peroxy-2- ethylhexanoate, 2,2'-azobisisobutyronitrile, dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis(2- methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 4,4'-azobis(4-cyanopentanoic acid), and mixtures thereof; more preferably the initiator is benzoyl peroxide.

12. The composition of claim 10 or 1 1 , further comprising a mono(meth)acrylate, preferably selected from methyl (meth)acrylate, n-butyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, 3-chloro-2- hydroxypropyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, phenyl (meth)acrylate, glycidyl (meth)acrylate and benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3- hydroxypropyl (meth)acrylate, 3-phenoxy-2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate and mixtures thereof; more preferably selected from methyl methacrylate, 2-ethylhexyl acrylate and mixtures thereof.

13. The composition of any one of claims 10 to 12, further comprising a poly(meth)acrylic resin, preferably selected from a methyl methacrylate/n-butyl methacrylate copolymer, a methacrylic resin, and mixtures thereof, more preferably a methyl methacrylate/n-butyl methacrylate copolymer.

14. Sealant, coating or adhesive obtained by curing the composition as defined in any one of claimsI O to 13, preferably at a temperature of -10 to 50°C, in particular -5 to 45°C, more particularly 0 to 40°C, during a time of 1 to 72 h, in particular 2 to 30 h, more particularly 3 to 24 h.

15. Use of the composition as defined in any one of claims 10 to 13, for waterproofing exterior or interior traffic- bearing horizontal surfaces, for making flashings, or for renovating roofs.