SILYL TERMINATED POLYURETHANES AND INTERMEDIATES FOR THE PREPARATION THEREOF

Abstract

The present invention relates to silyl terminated polyurethanes and to intermediates for the preparation thereof. In particular to an allyl-monool-containing initiator, allyl-terminated polyurethane prepolymer and to processes for their preparation. According to another of its aspect, the invention relates to a product obtainable by curing the silyl terminated polyurethane of the invention and to uses thereof.

Claims

1. An allyl-monool-containing initiator for the preparation of a Silyl terminated polyurethane, which initiator has the general formula ##STR00017## wherein R.sub.1 is selected from the group consisting of C.sub.1-24 alkyl, hetero C.sub.1-24 alkyl, C.sub.3-24 cycloalkyl, C.sub.6-24 aryl, C.sub.6-24 heteroaryl and a group of formula II ##STR00018## wherein * represents where L.sub.2 is bound to the compound of formula I; and wherein said C.sub.1-24 alkyl, hetero C.sub.1-24 alkyl, C.sub.3-24 cycloalkyl, C.sub.6-24 aryl, or C.sub.6-24 heteroaryl can be unsubstituted or substituted with one or more Z.sub.1; and wherein, L.sub.2 is selected from the group consisting of C.sub.1-6 alkylene, a single bond, C.sub.3-8 cycloalkylene, O, and S; and wherein said C.sub.1-6 alkylene, or C.sub.3-8 cycloalkylene can be unsubstituted or substituted with one or more Z.sub.2; R.sub.3 is selected from the group consisting of C.sub.1-6 alkyl, hetero C.sub.1-6 alkyl, C.sub.3-10 cycloalkyl, and C.sub.6-10 aryl; and wherein said C.sub.1-6 alkyl, hetero C.sub.1-6 alkyl, C.sub.3-10 cycloalkyl, and C.sub.6-10 aryl can be unsubstituted or substituted with one or more Z.sub.3; R.sub.4 is selected from the group consisting of C.sub.1-6 alkyl, hetero C.sub.1-6 alkyl, C.sub.3-10 cycloalkyl, and C.sub.6-10 aryl; and wherein said C.sub.1-6 alkyl, hetero C.sub.1-6 alkyl, C.sub.3-10 cycloalkyl, and C.sub.6-10 aryl can be unsubstituted or substituted with one or more Z.sub.4; or R.sub.3 and R.sub.4 together with the carbon atom to which they are attached form a saturated or unsaturated 3, 4, 5, 6 or 7 membered ring; and R.sub.2 is selected from the group consisting of C.sub.1-24 alkyl, hetero C.sub.1-24 alkyl, C.sub.3-24 cycloalkyl, C.sub.6-24 aryl, C.sub.6-24 heteroaryl and a group of formula III ##STR00019## wherein * represents where L.sub.3 is bound to the compound of formula I; and wherein said C.sub.1-24 alkyl, hetero C.sub.1-24 alkyl, C.sub.3-24 cycloalkyl, C.sub.6-24 aryl, or C.sub.6-24 heteroaryl can be unsubstituted or substituted with one or more Z.sub.5; and wherein, L.sub.3 is selected from the group consisting of C.sub.1-6 alkylene, a single bond, C.sub.3-8 cycloalkylene, O, and S; and wherein said C.sub.1-6 alkylene, or C.sub.3-8 cycloalkylene can be unsubstituted or substituted with one or more Z.sub.6; R.sub.5 is selected from the group consisting of C.sub.1-6 alkyl, hetero C.sub.1-6 alkyl, C.sub.3-10 cycloalkyl, and C.sub.6-10 aryl; and wherein said C.sub.1-6 alkyl, hetero C.sub.1-6 alkyl, C.sub.3-10 cycloalkyl, and C.sub.6-10 aryl can be unsubstituted or substituted with one or more Z.sub.7; R.sub.6 is selected from the group consisting of C.sub.1-6 alkyl, hetero C.sub.1-6 alkyl, C.sub.3-10 cycloalkyl, and C.sub.6-10 aryl; and wherein said C.sub.1-6 alkyl, hetero C.sub.1-6 alkyl, C.sub.3-10 cycloalkyl, and C.sub.6-10 aryl can be unsubstituted or substituted with one or more Z.sub.8; or R.sub.5 and R.sub.6 together with the carbon atom to which they are attached form a saturated or unsaturated 3, 4, 5, 6 or 7 membered ring; and Y is selected from the group consisting of C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, and oxygen or sulfur atom; and wherein, X is selected from the group consisting of C.sub.1-24 hydrocarbon chain, C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, and heteroarylene, wherein said C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, and heteroarylene, can be unsubstituted or substituted with one or more Z.sub.9 with n equal to 1; n is an integer from 1 to 24; and W and the terminal OH group form together a primary or a secondary alcohol each of Z.sub.1 to Z.sub.9 is independently selected from the group consisting of C.sub.1-6alkoxy, halo C.sub.1-6alkoxy, halo, C.sub.1-6 alkyl, halo C.sub.1-6 alkyl, C.sub.3-12 cycloalkyl, C.sub.6-12 aryl, C.sub.6-12 aryl C.sub.1-6 alkyl, C.sub.3-12 heterocyclyl, and C.sub.4-12 heteroaryl.

2. The allyl-monool-containing initiator according to claim 1, wherein: R.sub.1 and R.sub.2 are both C.sub.1-3 alkyl, Y is selected from the group consisting of C.sub.1-24 alkyl, hetero C.sub.1-24 alkyl, C.sub.3-24 cycloalkyl, C.sub.6-24 aryl, O and S; X is selected from the group consisting of C.sub.1-24 hydrocarbon chain, C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, and heteroarylene, wherein said C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene or heteroarylene, can be unsubstituted or substituted with one or more Z.sub.9, with n equal to 1; and W and the terminal OH group form together an alcohol.

3. The allyl-monool-containing initiator according to claim 1, wherein: R.sub.1 and R.sub.2 are both C.sub.1-3 alkyl, Y is —CH.sub.2; X is selected from the group consisting of C.sub.1-24 hydrocarbon chain, C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, and heteroarylene, wherein said C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, or heteroarylene, can be unsubstituted or substituted with one or more Z.sub.9, with n equal to 1; and W and the terminal OH group form together a primary or a secondary alcohol.

4. The allyl-monool-containing initiator according to claim 1, wherein: R.sub.1 and R.sub.2 are both C.sub.1-3 alkyl, when Y is O or S; X is selected from the group consisting of C.sub.1-24 hydrocarbon chain, C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, and heteroarylene, wherein said C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, or heteroarylene, can be unsubstituted or substituted with one or more Z.sub.9, with n equal to 1; and R.sub.3 and the terminal OH group form together a primary or a secondary alcohol.

5. The allyl-monool-containing initiator according to claim 1, wherein the initiator is aliphatic.

6. An allyl terminated polyurethane prepolymer obtained by a process comprising the following steps: (i) reacting the allyl-monool-containing initiator as defined in claim 1 with at least one alkylene oxide having from 2 to 6 carbon atoms; and (ii) directly reacting the reaction product obtained in step (i) with an isocyanate-containing compound with the formation of an allyl terminated polyurethane prepolymer.

7. The allyl terminated polyurethane prepolymer according to claim 6, wherein step (i) is performed in the presence of a catalyst selected from the list consisting of basic catalysts, and a double metal cyanide catalysts.

8. The allyl terminated polyurethane prepolymer according to claim 7, wherein said catalyst is totally or partly removed before step (ii) and is present in an amount of at most 0.500% by weight based on the total weight of the reaction mixture.

9. The allyl terminated polyurethane prepolymer according to claim 6, wherein said at least one alkylene oxide having from 2 to 6 carbon atoms is selected from propylene oxide, ethylene oxide and mixtures thereof.

10. The allyl terminated polyurethane prepolymer according to claim 6, wherein the allyl terminated prepolymer has a molecular weight comprised between 500 and 15000 Dalton.

11. The allyl terminated polyurethane prepolymer according to claim 6, wherein step (ii) is carried out at a temperature below 100° C.

12. A silyl terminated polyurethane obtained by a process comprising reacting the allyl terminated polyurethane prepolymer according to claim 6 with at least one hydrosilane of formula IV:
H—Si—(OR.sub.7).sub.3-p(R.sub.8).sub.p  (IV) wherein, R.sub.7 is selected from C.sub.1-20 alkyl; and C.sub.6-20 aryl; R.sub.8 is selected from C.sub.1-20 alkyl; C.sub.6-20 aryl, C.sub.1-20alkoxy; p is an integer selected from 0, 1 or 2, with the proviso that when p is o or 1, then all the OR.sub.7 groups are identical and when p is 2, the R.sub.8 groups can be different.

13. The silyl terminated polyurethane according to claim 12, wherein said at least one hydrosilane is selected from the group comprising diethoxymethylsilane, triethoxysilane, trimethoxysilane, diethoxyethylsilane, dimethoxymethylsilane, tri(propan-2-yloxy)silane, tributoxysilane, 7-(2-ethoxyethoxy)-3,6,8,1 1-tetraoxa-7-silatridecane, and mixtures thereof.

14.-15. (canceled)

Description

[0058] In a preferred embodiment, [0059] R.sub.1 and R.sub.2 are both C.sub.1-3 alkyl, preferably —CH.sub.3, [0060] Y is selected from the group consisting of C.sub.1-24 alkyl, preferably —CH.sub.2, hetero C.sub.1-24 alkyl, C.sub.3-24 cycloalkyl, C.sub.6-24 aryl, O and S; [0061] X is selected from the group consisting of C.sub.1-24 hydrocarbon chain, C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, and heteroarylene, wherein said C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene or heteroarylene, can be unsubstituted or substituted with one or more Z.sub.9, with n equal to 1; and [0062] W and the terminal OH group form together an alcohol, preferably a primary or a secondary alcohol.

[0063] Those allyl-monool-containing initiators are preferred because they increase the reactivity and/or selectivity of the subsequent reactions.

[0064] In a more preferred embodiment, [0065] R.sub.1 and R.sub.2 are both C.sub.1-3 alkyl, preferably —CH.sub.3, [0066] Y is —CH.sub.2; [0067] X is selected from the group consisting of C.sub.1-24 hydrocarbon chain, C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, and heteroarylene, wherein said C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, or heteroarylene, can be unsubstituted or substituted with one or more Z.sub.9, with n equal to 1; and [0068] W and the terminal OH group form together a primary or a secondary alcohol, preferably W and said terminal OH group are —CH.sub.2—OH or —CH—OH—CH.sub.3.

[0069] Those allyl-monool-containing initiators are more preferred because they increase even more the reactivity of the allyl group in the subsequent reaction of hydrosilylation.

[0070] In another advantageous embodiment, [0071] R.sub.1 and R.sub.2 are both C.sub.1-3 alkyl, preferably —CH.sub.3, when Y is O or S; [0072] X is selected from the group consisting of C.sub.1-24 hydrocarbon chain, C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, and heteroarylene, wherein said C.sub.1-24 alkylene, hetero C.sub.1-24 alkylene, C.sub.3-24 cycloalkylene, C.sub.6-24 arylene, poly C.sub.1-6 alkyleneoxide, poly C.sub.6-10 aryleneoxide, heterocyclylene, or heteroarylene, can be unsubstituted or substituted with one or more Z.sub.9, with n equal to 1; and [0073] R.sub.3 and the terminal OH group form together a primary or a secondary alcohol.

[0074] Those allyl-monool-containing initiators are the most preferred because they increase the most the reactivity of the allyl group in the subsequent reaction of hydrosilylation.

[0075] Advantageously, the monool-containing initiator is aliphatic. It has indeed been observed that aromatic groups can deactivate the allyl group and it is also suspected that such aromatic groups will increase the rigidity of the final product, which is undesirable for elastomeric products.

[0076] According to another aspect of the invention, the above defined allyl monool-containing initiator is alkoxylated to provide the allyl monool of the general formula V.

##STR00005##

wherein R.sub.9 and R.sub.10 are, independently from each other, H or a linear or branched C.sub.1-4 alkyl.

[0077] The above defined allyl-monool-containing initiator of formula I is thus reacted with at least one alkylene oxide having from 2 to 6 carbon atoms. Suitable alkylene oxide are propylene oxide, ethylene oxide and mixtures thereof.

[0078] The allyl monool of the general formula V generally have a molecular weight of 500 to 25000 Dalton, preferably of 800 to 15000 Dalton, more preferably of 800 to 6000 Dalton and most preferably of 1000 to 4000 Dalton.

[0079] In an advantageous embodiment, the alkoxylation reaction is performed in the presence of a catalyst selected from the list consisting of basic catalysts, such as KOH, CsOH, potassium methoxide, and double metal cyanide catalysts, such as cobalt, chlorocyano-1,2-dimethoxyethane Zinc complexes.

[0080] Preferably the catalyst is removed before the subsequent reaction. Advantageously, said catalyst remains in the solution in an amount of at most 0.500% by weight, preferably at most 0.250% by weight, more preferably at most 0.050% by weight, even more preferably at most 0.001% by weight, based on the total weight of the reaction mixture.

[0081] The presence of the catalyst in the subsequent reaction with the isocyanate compound can indeed cause undesirable side reactions.

[0082] In some preferred embodiments, the allyl monool of the general formula V can have no covalent hydrogen in gamma position of the allyl moiety. Suitable allyl-terminated polyethers are polyalkylene glycol derivatives wherein one of the terminal hydroxyl groups of the polyalkylene glycol has been exchanged by an allyl group. The polyalkylene glycol may be a homopolymer of alkylene oxide, or a copolymer, resulting from the copolymerization of a mixture of two or more different alkylene oxides.

[0083] In some embodiments, the reaction product (allyl monool of the general formula V) according to the present invention can be reacted with the isocyanate-containing compound, along with extender glycol. The extender glycol can be added as part of the chain, but not at all terminal positions of the prepolymer. Non-limiting examples of suitable extender glycols (i.e., chain extenders) include lower aliphatic or short chain glycols having from about 2 to about 10 carbon atoms and include, for instance, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,3-butanediol, 1,5-pentanediol, 1,4-cyclohexanedimethanol, hydroquinone di(hydroxyethyl)ether, neopentylglycol, and the like.

[0084] In some embodiments, the reaction product (allyl monool of the general formula V) of the present invention has an average reactive functionality of at least about 1 for each of the alcohol and allyl ends thereof. As used herein, the term “average reactive functionality” refers to the average number of reactive groups (functionality) per molecule, averaged over a statistically relevant number of molecules present in the reaction product (allyl-terminated polymer).

[0085] In a further step, the product obtained from the above described alkoxylation reaction is further reacted with an isocyanate-containing compound with the formation of an allyl terminated polyurethane prepolymer. Preferably, this step is carried out at a temperature below 100° C., preferably below 90° C., more preferably below 85° C.

[0086] Suitable isocyanate-containing compound according to the present invention may be aromatic, cycloaliphatic, heterocyclic, araliphatic or aliphatic organic isocyanates. Suitable isocyanates include also polyisocyanates. Suitable polyisocyanates for use in preparing the allyl-terminated prepolymers of the invention comprise polyisocyanates of the type R.sub.a—(NCO).sub.r with r being at least 2 and R.sub.a being an aromatic or aliphatic group, such as diphenylmethane, toluene, dicyclohexylmethane, hexamethylene, or a similar polyisocyanate and mixtures thereof.

[0087] Non-limiting examples of suitable polyisocyanates that can be used in the present invention can be any organic polyisocyanate compound or mixture of organic polyisocyanate compounds, preferably wherein said compounds comprise at least two isocyanate groups.

[0088] Non-limiting examples of organic polyisocyanates include diisocyanates, particularly aromatic diisocyanates, and isocyanates of higher functionality. Non-limiting examples of organic polyisocyanates which may be used in the present invention include aliphatic isocyanates such as hexamethylene diisocyanate; and aromatic isocyanates such as diphenylmethane diisocyanate (MDI) in the form of its 2,4′-, 2,2′- and 4,4′-isomers and mixtures thereof (also referred to as pure MDI), the mixtures of diphenylmethane diisocyanates (MDI) and oligomers thereof (known in the art as “crude” or polymeric MDI), m- and p-phenylene diisocyanate, tolylene-2,4- and tolylene-2,6-diisocyanate (also known as toluene diisocyanate, and referred to asTDI, such as 2,4 TDI and 2,6 TDI) in any suitable isomer mixture, chlorophenylene-2,4-diisocyanate, naphthylene-1,5-diisocyanate, diphenylene-4,4′-diisocyanate, 4,4′-diisocyanate-3,3′-dimethyl-diphenyl, 3-methyl-diphenylmethane-4,4′-diisocyanate and diphenyl ether diisocyanate; and cycloaliphatic diisocyanates such as cyclohexane-2,4- and -2,3-diisocyanate, 1-methylcyclohexyl-2,4- and -2,6-diisocyanate and mixtures thereof and bis-(isocyanatocyclohexyl)methane (e.g. 4,4′-diisocyanatodicyclohexylmethane (H12MDI)), triisocyanates such as 2,4,6-triisocyanatotoluene and 2,4,4-triisocyanatodiphenylether, isophorone diisocyanate (IPDI), butylene diisocyanate, trimethylhexamethylene diisocyanate, isocyanatomethyl-1,8-octane diisocyanate, tetramethylxylene diisocyanate (TMXDI), 1,4-cyclohexanediisocyanate (CDI), and tolidine diisocyanate (TODI); any suitable mixture of these polyisocyanates, and any suitable mixture of one or more of these polyisocyanates with MDI in the form of its 2,4′-, 2,2′- and 4,4′-isomers and mixtures thereof (also referred to as pure MDI), the mixtures of diphenylmethane diisocyanates (MDI) and oligomers thereof (known in the art as “crude” or polymeric MDI), and reaction products of polyisocyanates (e.g. polyisocyanates as set out above, and preferably MDI-based polyisocyanates). Preferably diphenylmethane diisocyanate (MDI) or toluene diisocyanates (TDI)-type isocyanates are used.

[0089] In some embodiments, the at least one isocyanate may include a carbodiimide and/or uretonimine modified variant of a diisocyanate or higher functionality polyisocyanate as well as isocyanate ended prepolymers made by reaction of an excess of a diisocyanate or higher functionality polyisocyanate with a hydroxyl ended polyester or hydroxyl ended polyether and products obtained by reacting an excess of diisocyanate or higher functionality polyisocyanate with a monomeric polyol or mixture of monomeric polyols such as ethylene glycol, trimethylol propane or butane-diol.

[0090] In some embodiments, said at least one isocyanate comprises a polymeric methylene diphenyl diisocyanate.

[0091] The polymeric methylene diphenyl diisocyanate can comprise any mixture of pure MDI (2,4′-, 2,2′- and 4,4′-methylene diphenyl diisocyanate) and higher homologues of formula (A):

##STR00006##

wherein q is an integer which can be from 1 to 10 or higher, preferably does not exclude branched version thereof.

[0092] Preferably, the at least one isocyanate is diphenylmethane diisocyanate.

[0093] The at least one isocyanate-containing compound for use in the preparation of the allyl-terminated prepolymer of the present invention can have an NCO values ranging from 0.5 wt % to 50 wt % by weight. Preferably from 0.5 wt % to 45 wt %; preferably from 1.0 wt % to 40 wt %; preferably from 1.5 wt % to 35 wt % by weight.

[0094] The NCO value (also referred to as percent NCO or NCO content) of the isocyanate-containing compound can be measured by titration with dibutylamine according to standard ASTM D5155 method. The NCO value is expressed in weight %.

[0095] In some embodiments, the molar ratio of the NCO of said at least one isocyanate-containing compound, to the OH of said reaction product (allyl-terminated polymer) is ranging from 0.90 to 1.20, preferably from 0.95 to 1.10.

[0096] The OH value (also referred to as OH number or OH content) can be measured according to the ASTM D 1957 standard. The OH value is expressed in mg KOH/g.

[0097] According to another of its aspects, the invention relates to an allyl terminated polyurethane prepolymer obtainable by the above described process and variants.

[0098] Advantageously, the allyl terminated polyurethane prepolymer has a molecular weight comprised between 500 and 15000 Dalton.

[0099] In an additional step, the allyl terminated polyurethane prepolymer obtained from the above described process and variants is further reacted with at least one hydrosilane of formula IV to provide a silyl terminated polyurethane:

H—Si—(OR.sub.7).sub.3-p(R.sub.8).sub.p  (IV)

wherein,
R.sub.7 is selected from C.sub.1-20 alkyl or C.sub.6-20 aryl;
R.sub.8 is selected from C.sub.1-20 alkyl, C.sub.6-20 aryl, or C.sub.1-20alkoxy;
p is an integer selected from 0, 1 or 2. When p is o or 1, there are three or two OR.sub.7 groups that must be identical. When p is 2, there are two R.sub.9 groups that do not need to be identical.

[0100] Unlike with the prior art where this reaction is generally accompanied by undesirable isomerization or/and β-elimination, the allyl terminated polyurethane prepolymer according to this invention can be hydrosilylated without causing a side reaction, which in turn promotes the cure efficiency in the final product.

[0101] Non-limiting examples of hydrosilanes suitable for the present invention include diethoxymethyl silane, triethoxysilane, trimethoxysilane, diethoxyethylsilane, dimethoxymethylsilane, tri(propan-2-yloxy)silane, tributoxy silane, 7-(2-ethoxyethoxy)-3,6,8,11-tetraoxa-7-silatridecane, and mixtures thereof. Preferred hydrosilanes are triethoxysilane, trimethoxysilane, 7-(2-ethoxyethoxy)-3,6,8,11-tetraoxa-7-silatridecane, diethoxyethylsilane, dimethoxymethylsilane, and mixtures thereof.

[0102] This step of hydrosilylation can be performed without catalyst or in the presence of at least one catalyst.

[0103] Non-limiting examples of suitable catalyst platinum-based catalysts, such as Speier's, Adam's, Ossko's and Karstedt's catalysts; rhodium-based catalysts, such as [Rh(cod).sub.2]BF.sub.4 and [RhCl(nbd)].sub.2, and Wilkinson's catalyst (RhCl(PPh.sub.3).sub.3); ruthenium-based catalysts, such as [Ru(benzene)Cl.sub.2], [Ru(p-cymene)Cl.sub.2], Grubb's 1.sup.st generation catalyst and [Cp*Ru(MeCN).sub.3]PF.sub.6. Adam's catalyst corresponds to platinum oxide (PtO.sub.2), while Ossko's catalyst corresponds to Platinum Carbonyl Cyclovinylmethylsiloxane Complex.

##STR00007##

[0104] Preferably, the catalyst can be present in an amount of at most 0.0001% by weight, for example at most 0.0009% by weight, for example at most 0.0008% by weight, for example at most 0.0007% by weight, for example at most 0.0006% by weight, for example at most 0.0005% by weight, with % by weight being based on the total weight of the reaction mixture.

[0105] According to another of its aspects, the invention relates thus to the silyl terminated polyurethane obtainable by such a process.

[0106] Preferably, the silyl-terminated polyurethane comprises at least 0.1% by weight of alkoxyalkylsilane, for example at least 1.0% by weight of alkoxyalkylsilane, for example at least 5.0% by weight of alkoxyalkylsilane, preferably at least 10.0% by weight of hydrosilane, for example at least 15.0% by weight of alkoxyalkylsilane, for example at least 20.0% by weight of alkoxyalkylsilane, for example at least 25.0% by weight of alkoxyalkylsilane, based on the total weight of the polyurethane.

[0107] This silyl terminated polyurethane has a much lower viscosity at room temperature than conventional silylated polyurethane and are thereby much easier to use in certain application such as for the preparation of a coating, adhesive or foam. In some preferred embodiments, the viscosity at room temperature of the (non-plasticized) prepolymer ranges from at least 1.0 to at most 50 Pa.Math.s, for example from at least 1.5 to at most 50 Pa.Math.s, for example from at least 1 to at most 25 Pa.Math.s, for example from at least 1 to at most 20 Pa.Math.s, for example from at least 1.5 to at most 25 Pa.Math.s, for example from at least 1.5 to at most 20 Pa.Math.s, measured with a Brookfield Rheometer with a cone and plate geometry using a shear rate of 1 rotation per second and a 100-micron truncation gap.

[0108] In another of its aspects, the invention relates to the use of such silyl terminated polyurethane for the preparation of a adhesives, coatings, elastomers, foams, sealants, gaskets and grouts and the like. In some embodiments, the product may be an adhesive. In some embodiments, the product may be an elastomer. In some other embodiments, the product may be a foam such as a one component foam. In yet other embodiments, the product may be a coating. In yet other embodiments, the product may be a sealant.

[0109] To this end, the above defined silyl terminated polyurethane is cured (for example with the moisture of the ambient atmosphere or with added water or another curing agent) at a temperature below 70° C., preferably below 60° C., more preferably below 40° C., even more preferably between 0 and 25° C. The invention also relates to the product of this curing.

[0110] The silyl-terminated polyurethane may comprise one or more additives. In some embodiments, the additive is present in an amount of at least 0.01% by weight, for example at least 0.03% by weight, for example at least 0.1% by weight, preferably at least 0.3% by weight, for example at least 0.5%, for example at least 1.0% by weight, based on the total weight of the silyl-terminated polyurethane. The additives collectively can be up to 300% by weight based on the total weight of the silyl-terminated polyurethane.

[0111] Non-limiting examples of suitable additives include surfactants, fire retardants, chain extenders, cross-linkers, antioxidants, fillers, and mixture thereof.

[0112] Examples of surfactants are nonylphenols, fatty acid ethylene oxide condensates and alkylene oxide block co-polymers. The surfactants are used in an amount of 0.1-5% by weight (typically on all isocyanate reactive ingredients). Examples of commercially available surfactants are Tegostab® B 8017 and Ortegol® 501.

[0113] Fire retardants include, for example, a phosphorus-based flame retardant, a halogen-based flame retardant, an inorganic flame retardant and expandable graphite. Specific examples of fire retardants include, for example, 2-chloro-1-methylethyl phosphate, tetrabromobisphenol A, tris-chloroethyl phosphates, ammonium phosphate and polyphosphate.

[0114] Non-limiting examples of antioxidants are sterically hindered phenols, diphenylamines and benzofuranone derivatives. Examples of commercially available anti-oxidants: Vanox® 945 available from Vanderbilt Chemicals and Irganox® 1135 available from BASF.

[0115] Non-limiting examples of fillers are mineral fillers like BaSO.sub.4 and CaCO.sub.3, carbon black, mineral fibers like glass fibers and rock wool fibers, micro-spheres, fumed silica, titanium dioxide, wood chips, wood dust, wood flakes, wooden plates; paper and cardboard (both shredded or layered); sand, vermiculite, clay, cement and other silicates; ground rubber, ground thermoplastics, ground thermoset materials; metal particles and plates; cork in particulate form or in layers; natural fibers, like flax, hemp and sisal fibers; synthetic fibers, like polyamide, polyolefin, polyaramide, polyester and carbon fibers; nanoparticles like clays, inorganic oxides and carbons; glass beads, ground glass, hollow glass beads; expanded or expandable beads; untreated or treated waste like milled, chopped, crushed or ground waste and in particular fly ash; woven and non-woven textiles; and combinations of two or more of these materials. In certain embodiments, such fillers can be coated with functionalized hydrocarbon.

[0116] Other suitable additives include plasticizer, smoke-suppressants, catalysts, coloring agents and/or pigments (inorganic and organic, such as carbon black, iron oxide, etc.), antimicrobial agents, mould release agents, hindered amine light stabilizers (HALS), UV absorbers, water scavenger, emulsifiers, thixotropic agents (such as polyamide waxes, aerosols, etc.), adhesion promotors, rheology modifiers, reactive diluents, anti-foaming agents, blowing agents, co-polymers, possibly multiple versions of each type of additive and combinations thereof.

[0117] The additive may be a plasticizer. Preferably, the amount of plasticizer in the silyl-terminated polyurethane is limited. Suitable plasticizers, for purposes of the present invention, comprise conventional plasticizers known in the art, such as esters of dibasic or polybasic carboxylic acids with monohydric alcohols. Other examples of suitable plasticizers may be selected from the group comprising phthalates, such as dioctyl phthalate, diisooctyl phthalate, diisononyl phthalate, dimethyl phthalate, dibutyl phthalate; the phthalates with more than eight carbon atoms are preferred; phosphates, such as tributyl phosphate, triethyl phosphate (TEP), triphenyl phosphate and cresyl diphenyl phosphate; chlorinated biphenyls; aromatic oils; adipates, such as diisononyl adipate and di-(2-ethylhexyl) adipate; and combinations thereof. Other examples of suitable plasticizers comprise phosphoric acid esters of the branched and unbranched aliphatic, cycloaliphatic and aromatic alcohols. If appropriate, phosphates of halogenated alcohols can also be employed. So called polymeric plasticizers can also be employed. Examples of such plasticizers may be selected from the group comprising polyesters of adipic acid, sebacic acid or phthalic acid. Phenol alkysulfonates, e.g. phenyl paraffinsulfonates, can also be employed. Plasticizers may also be selected from alkylene carbonates, such as propylene carbonate and ethylene carbonate.

[0118] The invention is illustrated but not limited by the following examples.

Comparative Example 1 (Preparation of the Allyl Monool of Formula V, Wherein R.SUB.1 .and R.SUB.2 .Represent H, Y Represents an Oxygen Atom, X and W Represent CH.SUB.2., R.SUB.9 .is CH.SUB.3 .and n is 1)

[0119] 0.49 g of DMC catalyst (double metal cyanide-Cobalt, chloro cyano 1,2-dimethoxyethane zinc complexes, sold by Hongkong Huarun International Co. Ltd., RN: 116912-63-1) was added to 312 g of 2-allyloxyethanol (allyl-monool-containing initiator of formula I, wherein R.sub.1 and R.sub.2 represent H, Y represents an oxygen atom, X and W represent CH.sub.2 and n is 1) in a pressure vessel and the temperature was raised to 110° C. A small amount of propylene oxide was added to the reaction vessel. As a result, the pressure in the vessel (1 bar) increased due to the charging of the latter product. After an observed pressure drop (alkoxylation reaction taking place), the remaining required theoretical mass of propylene oxide was added (4460 g in total) in order to target a molecular weight around 2000 g/mol. The mixture was blanketed with nitrogen and the reaction mixture was pressurized with one bar of propylene oxide. Alter the complete addition of propylene oxide, no subsequent pressure drop was observed. Finally, 500 ppm of antioxidant (Irganox® 1076) were added to the product and the material was discharged in a 5 L metal can.

[0120] The obtained product has an acid value of 37.4 mg KOH/g, an unsaturation value of 0.667 meq/g and a molecular weight of 1500 Dalton.

Comparative Example 2 (Preparation of an Allyl Terminated Polyurethane Prepolymer)

[0121] The product obtained at example 1 was placed in the reaction vessel, pro-flushed with nitrogen and heated to 80° C. The required stoichiometric amount of 1,1′-methylenebis(4-isocyanatobenzene) (4,4′-MDI sold as SUPRASEC® 1306 by HUNTSMAN) was added via heated addition funnel in order to maintain the material as a liquid. The addition rate was 1.5 mL/min. The reaction mixture was mechanically stirred at 350 rpm and left to react under nitrogen. The isocyanate value was monitored over time and when the value was constant (3 titrations performed every 15 min) the vessel was cooled to room temperature. The product was then discharged in a tin can and characterized.

Comparative Examples 3.1 to 3.4 (Preparation of a Silyl Terminated Polyurethane)

[0122] 50 g of the product obtained at comparative example 2 are introduced (without any solvent) in a reaction vessel together with 1.05 equivalents of diethoxymethyl silane (hydrosilane of formula IV wherein R.sub.7 represents an ethoxy, R8 a methoxy and p is 2). The temperature was set to 90° C. DMC catalyst (double metal cyanide-Cobalt, chloro cyano 1,2-dimethoxyethane zinc complexes, sold by Hongkong Huarun International Co. Ltd., RN: 116912-63-1) in several quantities was added to the reaction vessel as well as the hydrosilylation catalyst (Karstedt's catalyst is an organoplatinum compound derived from divinyl-containing disiloxane) in several quantities.

[0123] The viscosity was measured via Rheometrics (a Brookield Rheometer (325-1 spindle at 350 Pa) with a cone and plate geometry (CONE SST 20 mm×0.5), using a shear rate of 1 rotation per second, and a 100 micron truncation gap. The viscosity was measured at ambient temperature. TABLE I provides the details of these examples.

TABLE-US-00001 TABLE 1 Comparative DMC Catalyst Karstedt's catalyst Yield Viscosity Example (ppm) (ppm) (mol %) (Pa.s) 3.1  0  10 ppm 95.0 4.8 3.2 100   5 ppm 92.5 4.9 3.3 100 2.5 ppm 91.5 5.1 3.4 100  20 ppm 90.5 5.3

[0124] As can be seen in TABLE I, all the silyl terminated polyurethane have a viscosity of about 5 Pa.Math.s. This value of the viscosity is to be compared with conventional silylated polyurethane having generally a viscosity of 50 Pa.Math.s or above.

Comparative Example 4 (Use of the Silyl Terminated Polyurethane)

[0125] Lap joints were prepared from beech wood, PVC and Aluminum substrates (Rochell, 4×25×100 mm) loaded with the silyl terminated polyurethane of example 3.4 with a 0.45 g glue load (6.25 cm.sup.2 overlap area, 0.1 mm thickness). Prior to lap join, PVC and Aluminum was washed with acetone followed by drying or evaporation; and wood was pro-heated and cured in a Weiss cabinet at 23° C. and 50% RH for two days. The lap joints were placed between 2 metal plates and pressed with a constant weight load (2.6 kg). Lap shear strength was determined with an Instron universal testing instrument using a 50 mm/min deformation rate. For that test, spacers were used, identical to the lap joints substrate thickness to ensure parallel application of strain before tangential force is applied.

[0126] The tensile shear and elongation at break were measured for all the coatings. The results are provided in TABLE II.

TABLE-US-00002 TABLE 11 Comparative Tensile shear Elongation at break Example Substrate (MPa) % 4.1 Beech wood 0.27 ± 1.3 15 ± 5 4.2 Aluminum 0.34 ± 0.7 15 ± 5 4.3 PVC 0.44 ± 0.6 15 ± 5

Example 1 According to the Invention

[0127] 0.197 g of DMC catalyst (double metal cyanide-Cobalt, chloro cyano 1,2-dimethoxyethane zinc complexes, sold by Hongkong Huarun International Co. Ltd., RN: 116912-63-1) were added to 75 g of 3,3-dimethyl-4-penten-1-ol (allyl monool-containing initiator of formula 1, wherein R.sub.1 and R.sub.2 represent CH.sub.3, Y and W represent CH.sub.2 and n is 0) in a pressure vessel and the temperature was raised to 120° C. keeping the system under vacuum until 60° C. Propylene oxide is then added to the reaction vessel. As a result, the pressure of the vessel (1 bar) increased due to the charging of the latter product. After an observed pressure drop (alkoxylation reaction taking place), the remaining required theoretical mass of propylene oxide (719 g in total) was added in order to get a molecular weight around 1500 g/mol. The mixture was blanketed with nitrogen and the reaction mixture was pressurized with 1 bar of propylene oxide. After the complete addition of propylene oxide, no subsequent pressure drop was observed.

[0128] The obtained product has a hydroxyl value of 37.4 mg KOH/g, an unsaturation content of approximately 0.667 meq/g and a molecular weight of 1500 Dalton.

Example 2 According to the Invention

[0129] The product obtained in example 1 according to the invention was placed in a reaction vessel pre-flushed with nitrogen and heated to 80° C. A stoichiometric amount of 1,1′-methylenebis(4-isocyanatobenzene) (4,4′-MDI, SUPRASEC® 1306 by HUNTSMAN) was added via heated addition funnel to maintain the product liquid. The addition rate was 1.5 ml/min. The reaction mixture was allowed to react without any additional catalyst under mechanical stirring (350 rpm) in nitrogen atmosphere. The isocyanate value was monitored to follow the reaction until constant value (3 titrations performed every 15 minutes), then the vessel was discharged. The product was stored in a metal container under nitrogen and allowed to cool down at room temperature. All the hydroxyl groups were fully reacted with the isocyanate to form an allyl terminated polyurethane prepolymer.

Example 3 According to the Invention

[0130] 50 g of the product of example 2 according to the invention were dissolved in 100 ml of toluene and introduced in a reaction vessel. 40 ppm of Karsted's catalyst are added together with 1.95 equivalents of trimethoxysilane. The temperature was increased to 90° C. and the mixture was allowed to react for 3 hours under magnetic stirring. The reaction was followed by 1H NMR until no further changes were observed in the spectrum. Once the reaction was completed, the solvent was stripped and the product isolated as a low-viscosity liquid resin.

[0131] As shown in table Ill, when R.sub.1═R.sub.2═CH.sub.3 the known isomerization and elimination side products are not formed because of the presence of substituents on the γ-carbon. Therefore, an accurate choice of propoxylation initiator will lead to higher selectivity towards the desired reaction product.

TABLE-US-00003 TABLE III Comparison of reaction products obtained starting from different initiators. Target product (trimethoxysilane) Side products Initiator Hydrosilylated material Isomerized unsaturated end groups [00008] [00009] [00010] [00011] [00012] Comparison of reaction products obtained starting from different initiators. Side products Initiator β-elimination silylated end groups [00013] [00014] [00015] [00016]