New moisture curable silane-modified polyacrylates with improved mechanical performance

Abstract

The invention relates to moisture curable polyacrylate polymer. The moisture curable polyacrylate polymer provides good strength, elongation and weather exposure resistance and is particularly suitable for exterior use.

Description

New Moisture Curable Silane-Modified Polyacrylates with Improved Mechanical PerformanceFIELD OF THE INVENTION

[0001] The invention relates to moisture curable polyacrylate polymer. The moisture curable polyacrylate polymer provides good strength, elongation and weather exposure resistance and is particularly suitable for exterior use.BACKGROUND OF THE INVENTION

[0002] Curable adhesives and sealants are extensively used to seal building exteriors and building fenestrations from air, moisture and water infiltration. The sealants are applied on a surface and once cured the cured reaction products seal the surface from air, moisture and water infiltration.

[0003] Exterior sealants have been based on silicone, polyurethane and other curable polymer chemistries. However, curable polymers with desirable combinations of strength, elongation and weather resistance would be beneficial.

[0004] Curable polyacrylate polymers and compositions are used as adhesives, sealants, coatings, paintings, encapsulants, and the like, in a broad range of applications including packaging, automotive, highway, electronic device, appliance assembly and consumer uses. Polyacrylate polymers are an important class of polymers that are soft, tough and rubbery. Their glass transition temperature is well below room temperature. They are known for their high transparency, good impact toughness and elasticity, and have fairly good heat resistance up to 450 K under dry heat. They also have good weatherability, UV resistance and ozone resistance since they do not have double bonds in the backbone. Typically, curable polyacrylate based compositions and compositions used in these applications have been tailored to provide strength, toughness, cure speed, modulus, elongation; and resistance to high temperatures, petroleum oils and humidity.

[0005] U.S. Pat. Nos. 7129294, 6274688, 6420492, 6441101 , 6667369, 4334036, 7439308, 7276574 and 5986014 disclose oil resistant (meth)acrylic polymers havingalkenyl or curable silyl groups at the chain ends in high functionality ratios. These (meth)acrylic polymers are prepared by a process which comprises (i) preparing a (meth)acrylic polymer having halogen atoms at the chain ends, using an organohalogenated compound or a halosulfonyl compound as an initiator and a metal complex catalyst wherein the central metal atom is selected from the group consisting of the elements of Groups 8, 9, 10 and 11 of the periodic table; and (ii) transforming the halogen atom into an alkenyl group- or a curable silyl group-containing substituent. The obtained (meth)acrylic polymers form homogeneous curing materials. Methods for producing these (meth)acrylic polymer having crosslinkable silyl groups at the termini, comprising a step of adding a hydrosilane compound having a crosslinkable silyl group to an alkenyl-term inated (meth)acrylic polymer (A), which is prepared by atom transfer radical polymerization, in the presence of a platinum hydrosilylation catalyst. The amount of the platinum hydrosilylation catalyst is 0.1 to 10 mg on a platinum metal basis per kilogram of the alkenyl-term inated (meth)acrylic polymer (A). These moisture curable alkoxysilane terminated polyacrylate polymers are commercially available from Kaneka Corporation, Japan, which are currently prepared in a two-step process. In the disclosed processes, bromine substitution with an unsaturated carboxylic acid is followed by hydrosilation with an alkoxysilane. This two-step process can be expensive and time consuming for the manufacturer.

[0006] Therefore, it would be desirable to provide a curable polyacrylate polymer that can be applied to surfaces easily and when cured provides a desirable combination of strength, elongation and weather resistance. It is also desirable to identify simple and alternative synthetic schemes to make moisture curable polyacrylate polymers.BRIEF SUMMARY OF THE INVENTION

[0007] The invention provides a moisture curable polyacrylate polymer formed by random polymerization and compositions thereof. That can be applied to surfaces easily; when cured provides a desirable combination of strength, elongation and weather resistance; and are particularly suitable as construction sealants for exterior use.

[0008] One aspect of the invention is directed to a polyacrylate polymer with pendant alkoxy or other moisture reactive silyl-functional groups bound to the polymer chain.

[0009] The polyacrylate polymer is prepared, according to one aspect of the invention, with: i) 30 to 90% by weight of a first acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR4, where R3is H or CH3 and R4is a C4-24 linear, branched or cyclic alkyl chain, or combination thereof, ii) 1 to 50% by weight of a second acrylic or methacrylic acid derivative having a structure of CH2=CR3COOZXR5, where R3is H or CH3; X is O, S, NR5or a covalent bond; Z is an optionally present C1-6 alkylene chain; and each R5is independently H, C1-2 alkyl chain or a combination thereof, and iii) 0.1 to 40% by weight of a third acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR6, where R3is H or CH3 and R6is a C7-20 fused or bridged ring system that can be substituted with one or more alkyl groups, and iv) 1 .0 to 5% by weight of a silane functional acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR7SiR83-n Yn, where R3is H or CH3; R7is a C1-24 linear, branched or cyclic alkylene or arylene chain; R8is a C1-24 linear, branched or cyclic alkyl chain; Y is C1-3 alkoxy, aryloxy, acetoxy, oximino, enoxy, amino, ester, amide, lactate ester, lactate amide, H, OH, halogen, or combination thereof; and n = 1 , 2, or 3.

[0010] Aspect 2 comprises the moisture curable polyacrylate polymer according to any of the foregoing aspects, wherein i.) the first acrylic or methacrylic acid derivative is selected from n-butyl acrylate, n-butyl methacrylate, n-pentyl acrylate, n-hexyl acrylate, n- heptyl acrylate, and n-octyl acrylate, n-nonyl acrylate, lauryl methacrylate, cyclohexyl acrylate, and branched (meth)acrylic isomers, such as i-butyl acrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, stearyl methacrylate, isooctyl acrylate, or combination thereof.

[0011] Aspect 3 comprises the moisture curable polyacrylate polymer according to any of the foregoing aspects, the moisture curable polyacrylate composition according to any of the foregoing aspects, wherein the ii. second acrylic or methacrylic acidderivative is selected from methyl acrylate, ethyl acrylate, methoxyethyl acrylate, ethyl methacrylate, methyl methacrylate, or combination thereof.

[0012] Aspect 4 comprises the moisture curable polyacrylate polymer according to any of the foregoing aspects, wherein the iii. third acrylic or methacrylic acid derivative is selected from isobornyl (meth)acrylate, ethylene glycol dicyclopentenylether (meth)acrylate, or combination thereof.

[0013] Aspect 5 comprises the moisture curable polyacrylate polymer according to any of the foregoing aspects, wherein the iv. silane functional acrylic or methacrylic acid derivative is selected from trimethoxysilylpropyl (meth)acrylate, triethoxysilylpropyl (meth)acrylate, trimethoxysilylethyl (meth)acrylate, methyldimethoxysilylpropyl (meth)acrylate, methacryloxypropyltrimethoxysilane, 3- (methacryloyloxy)propyltrimethoxysilane, (meth)acryloxypropylSi(OCHCH3CON(CH3)2)3, (meth)acryloxypropylSi(OCHCH3COOCH2CH3), or combination thereof.

[0014] Aspect 6 comprises the moisture curable polyacrylate polymer according to any of the foregoing aspects, wherein the i. first acrylic or methacrylic acid derivative is selected from butyl acrylate and / or 2-ethylhexyl acrylate; and / or the ii. second acrylic or methacrylic acid derivative methyl acrylate, ethyl acrylate, and / or methoxyethyl acrylate; and / or the iii. third acrylic or methacrylic acid derivative is isobornyl acrylate; and / or the iv. silane functional acrylic or methacrylic acid derivative is methacryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane or combination thereof.

[0015] Aspect 7 comprises the moisture curable polyacrylate polymer according to any of the foregoing aspects, having have a weight average molecular weight (Mw) of from 4,700 to 25,000 g / mol, more preferably between 10,000 and 20,000 g / mol; and / or having have a number average molecular weight (Mw) of from 4,500 to 8,000 g / mol.

[0016] Yet another aspect of the invention is directed to a method of forming the moisture curable polyacrylate polymer comprising:1 ) polymerizing with a reaction temperature of about 50 to about 120°C for about 4 to 24 hours of: a. 40 to 90% by weight of a mixture of: i. 30 to 90% by weight of a first acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR4, where R3is H or CH3 and R4is a C4-24 linear, branched or cyclic alkyl chain, or combination thereof, ii. 1 to 50% by weight of a second acrylic or methacrylic acid derivative having a structure of CH2=CR3COOZXR5, where R3is H or CH3; X is O, S, NR5or a covalent bond; Z is an optionally present C1-6 alkylene chain; and each R5is independently H, C1-2 alkyl chain or a combination thereof, and iii. 0.1 to 40% by weight of a third acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR6, where R3is H or CH3 and R6is a C7-20 fused or bridged ring system that can be substituted with one or more alkyl groups, and iv. 1 .00 to 5% by weight of a silane functional acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR7SiR83-n Yn, where R3is H or CH3; R7is a C1-24 linear, branched or cyclic alkylene or arylene chain; R8is a C1-24 linear, branched or cyclic alkyl chain; Y is C1-3 alkoxy, aryloxy, acetoxy, oximino, enoxy, amino, ester, amide, lactate ester, lactate amide, H, OH, halogen, OCHCH3CON(CH3)2, OCHCH3COOCH2CH3, or combination thereof; n = 1 , 2, or 3, b. 10-60% by weight of an alcohol of the formula HOR9, where R9is C1-4 linear or branched alkyl chain, c. 0-60% by weight of an ester of the formula R9COOR9, where each R9is independently a C1-4 linear or branched alkyl chain, d. 0.01 to 5% of an azo or peroxide radical initiator, and2) removing the solvents and any volatile at the temperature from about 50 to about 120°C under a vacuum from about 0.2 to 200 mbar.

[0017] Another aspect of the invention is directed to the method of forming the moisture curable polyacrylate polymer according to any of the foregoing aspects, wherein the reaction mixture comprises c. the ester of the formula R9COOR9.

[0018] A further aspect of the invention is directed to the method of forming the moisture curable polyacrylate polymer according to any of the foregoing aspects, wherein d. the radical initiator is an azo radical initiator.

[0019] Another aspect of the invention is directed to the method of forming the moisture curable polyacrylate polymer according to any of the foregoing aspects, wherein d. the radical initiator is a peroxide radical initiator.DETAILED DESCRIPTION OF THE INVENTION

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Preferred methods and materials are described below, although methods and materials similar or equivalent to those described herein can be used in practice or testing of the present disclosure. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.

[0021] As used in the specification and in the claims, the term "comprising" may include the embodiments "consisting of and "consisting essentially of." The terms "comprise(s)," "include(s)," "having," "has," "can," "contain(s)," and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that require the presence of the named ingredients / steps and permit the presence of other ingredients / steps. However, such description should be construed as also describing compositions or processes as "consisting of and "consisting essentially of the enumerated ingredients / steps, which allows the presence of only the named ingredients / steps, along with any impurities that might result therefrom, and excludes other ingredients / steps.

[0022] Numerical values in the specification and claims of this application, particularly as they relate to polymers or polymer compositions, reflect average values for a composition that may contain individual polymers of different characteristics. Furthermore, unless indicated to the contrary, the numerical values should be understood to include numerical values which are the same when reduced to the same number of significant figures and numerical values which differ from the stated value by less than the experimental error of conventional measurement technique of the type described in the present application to determine the value.

[0023] All ranges disclosed herein are inclusive of the recited endpoint and independently combinable (for example, the range of "from 2 to 10" is inclusive of the endpoints, 2 and 10, and all the intermediate values). The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value; they are sufficiently imprecise to include values approximating these ranges and / or values. As used herein, approximating language may be applied to modify any quantitative representation that may vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as "about," may not be limited to the precise value specified, in some cases. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. The modifier "about" should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression "from about 2 to about 4" also discloses the range "from 2 to 4." The term "about" may refer to plus or minus 10% of the indicated number. For example, "about 10%" may indicate a range of 9% to 11 ", and "about 1" may mean from 0.9-1.1. Other meanings of "about" may be apparent from the context, such as rounding off, so, for example "about 1 " may also mean from 0.5 to 1 .4.

[0024] As used herein, a polymer or an oligomer is a macromolecule that consists of monomer units is equal or greater than about one monomer unit. Polymer and oligomer, or polymeric and oligomeric, are used interchangeably here in the invention.

[0025] As used herein, the term "alkyl" refers to a monovalent linear, cyclic or branched moiety containing C1 to C24 carbon and only single bonds between carbonatoms in the moiety and including, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, heptyl, 2,4,4-trimethylpentyl, 2-ethylhexyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-hexadecyl, and n-octadecyl.

[0026] As used herein, the term "aryl" refers to a monovalent unsaturated aromatic carbocyclic group of from 6 to 24 carbon atoms having a single ring (e.g., phenyl) or multiple condensed (fused) rings, wherein at least one ring is aromatic (e.g., naphthyl, dihydrophenanthrenyl, fluorenyl, or anthryl). Preferred examples include phenyl, methyl phenyl, ethyl phenyl, methyl naphthyl, ethyl naphthyl, and the like.

[0027] As used herein, the term "alkoxy" refers to the group -O-R, wherein R is alkyl as defined above.

[0028] As used herein, the above groups may be further substituted or unsubstituted. When substituted, hydrogen atoms on the groups are replaced by substituent group(s) that is one or more groups independently selected from alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heteroalicyclyl, aralkyl, heteroaralkyl, (heteroalicyclyl)alkyl, hydroxy, protected hydroxyl, alkoxy, aryloxy, acyl, ester, mercapto, alkylthio, arylthio, cyano, halogen, carbonyl, thiocarbonyl, O-carbamyl, N-carbamyl, O- thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, S-sulfonamido, N-sulfonamido, C- carboxy, protected C-carboxy, O-carboxy, isocyanato, thiocyanato, isothiocyanato, nitro, silyl, sulfenyl, sulfinyl, sulfonyl, haloalkyl, haloalkoxy, trihalomethanesulfonyl, trihalomethanesulfonamido, and amino, including mono- and di-substituted amino groups, and the protected derivatives thereof. In case that an aryl is substituted, substituents on an aryl group may form a non-aromatic ring fused to the aryl group, including a cycloalkyl, cycloalkenyl, cycloalkynyl, and heterocyclyl.

[0029] The term, “polyacrylates” herein refers to acrylic polymers, acrylates, or acrylics, acrylic resins. They are used interchangeably here in the invention. A (meth)acrylate includes both acrylate and methacrylate.

[0030] The term, “moisture cure” herein refers to hardening or vulcanization of the curable portion of the material or polymer by condensation crosslinking reaction of terminal functional group of polymer chains, brought about by water or moisture in the air and / or on a substrate, in the presence of a moisture curing catalyst.

[0031] The invention provides the art with polyacrylate polymer comprising pedant alkoxy or other moisture reactive silyl-functional groups bound to the polymer chain. This polyacrylate polymer, when combined with other components, such as moisture and acid scavengers, moisture cure catalyst, fillers and adhesion promoters, provides a moisture curable composition. The choice and relative amount of the specific moisture reactive silyl functional acrylic and vinyl monomers making up the said polyacrylate polymers used in the moisture curable compositions of this invention depend upon the desired final properties and contemplated end uses of the sealants. The adjustable concentration of the pedant moisture curable functional groups on the polymer backbone will make the cure speed of the sealants faster if necessary. The acrylic and vinyl monomers and their relative amounts in the polyacrylate polymer compositions to achieve the desired properties is within the expertise of those skilled in the art. The invention provides the art with a novel class of polyacrylate compositions with storage stable pedant group moisture curable silyl groups and that can undergo moisture cure.

[0032] In one embodiment of the invention, the polyacrylate polymer with pedant moisture curable functional groups is prepared by polymerizing: i. 30 to 90% by weight of a first acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR4, where R3is H or CHs and R4is a C4-24 linear, branched or cyclic alkyl chain, or combination thereof, ii. 1 to 50% by weight of a second acrylic or methacrylic acid derivative having a structure of CH2=CR3COOZXR5, where R3is H or CH3; X is O, S, NR5or a covalent bond; Z is an optionally present C1-6 alkylene chain; and each R5is independently H, C1-2 alkyl chain or a combination thereof, and iii. 0.1 to 40% by weight of a third acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR6, where R3is H or CH3 and R6is a C7-20 fused or bridged ring system that can be substituted with one or more alkyl groups, and iv. 1 .0 to 5% by weight of a silane functional acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR7SiR83-n Yn, where R3is H or CH3; R7is a C1-24 linear, branched or cyclic alkylene or arylene chain; R8is a C1-24 linear, branched or cyclic alkyl chain; Y is C1-3 alkoxy, aryloxy, acetoxy, oximino,enoxy, amino, ester, amide, lactate ester, lactate amide, H, OH, halogen, OCHCH3CON(CH3)2, OCHCH3COOCH2CH3 or combination thereof; n = 1 , 2, or 3.

[0033] In one embodiment of the invention, the polyacrylate polymer with pendant moisture curable functional groups is prepared by polymerizing: i. 50 to 80% by weight of a first acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR4, where R3is H or CH3 and R4is a C4-24 linear, branched or cyclic alkyl chain, or combination thereof, ii. 3 to 30% by weight of a second acrylic or methacrylic acid derivative having a structure of CH2=CR3COOZXR5, where R3is H or CH3; X is O, S, NR5or a covalent bond; Z is an optionally present C1-6 alkylene chain; and each R5is H, C1-2 alkyl chain or a combination thereof, and iii. 5.0 to 12% by weight of a third acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR6, where R3is H or CH3 and R6is a C7-20 fused and / or bridged ring system that can be substituted with one or more alkyl groups, and iv. 1 .5 to 3% by weight of a silane functional acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR7SiR83-n Yn, where R3is H or CH3; R7is a C1-24 linear, branched or cyclic alkylene or arylene chain; R8is a C1-24 linear, branched or cyclic alkyl chain; Y is C1-3 alkoxy, aryloxy, acetoxy, oximino, enoxy, amino, ester, amide, lactate ester, lactate amide, H, OH, halogen, OCHCH3CON(CH3)2, OCHCH3COOCH2CH3, or combination thereof; n = 1 , 2, or 3.

[0034] Yet another aspect of the invention is directed to a method of forming the moisture curable polyacrylate polymer comprising:1 ) polymerizing with a reaction temperature of about 50 to about 120°C for about 4 to 24 hours of: a. 40 to 90% by weight of a mixture of: i. 30 to 90% by weight of a first acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR4, where R3is H or CH3 and R4is a C4-24 linear, branched or cyclic alkyl chain, or combination thereof,ii. 1 to 50% by weight of a second acrylic or methacrylic acid derivative having a structure of CH2=CR3COOZXR5, where R3is H or CH3; X is 0, S, NR5or a covalent bond; Z is an optionally present C1-6 alkylene chain; and each R5is independently H, C1-2 alkyl chain or a combination thereof, and iii. 0.1 to 40% by weight of a third acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR6, where R3is H or CH3 and R6is a C7-20 fused and / or bridged ring system that can be substituted with one or more alkyl groups, and iv. 1 .00 to 5% by weight of a silane functional acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR7SiR83-n Yn, where R3is H or CH3; R7is a C1-24 linear, branched or cyclic alkylene or arylene chain; R8is a C1-24 linear, branched or cyclic alkyl chain; Y is C1-3 alkoxy, aryloxy, acetoxy, oximino, enoxy, amino, ester, amide, lactate ester, lactate amide, H, OH, halogen, OCHCH3CON(CH3)2, OCHCH3COOCH2CH3, or combination thereof; n = 1 , 2, or 3, b. 10-60% by weight of an alcohol of the formula HOR9, where R9is C1-4 linear or branched alkyl chain, c. 0-60% by weight of an ester of the formula R9COOR9, where each R9is independently a C1-4 linear or branched alkyl chain, d. 0.01 to 5% of an azo or peroxide radical initiator, and2) removing the solvents and any volatile at the temperature from about 50 to about 120°C under a vacuum from about 0.2 to 200 mbar.

[0035] The free radical process can use 2,2 azobis- (2 - methyl propionitrile (AIBN) as an initiator and isopropyl alcohol as a chain transfer agent.

[0036] The monomers of components (i), (ii) (iii) and (iv) of above are converted by polymerization into the moisture curable polyacrylates.

[0037] Examples of the first acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR4include n-butyl acrylate, n-butyl methacrylate, n-pentyl acrylate, n- hexyl acrylate, n-heptyl acrylate, and n-octyl acrylate, n-nonyl acrylate, lauryl methacrylate, cyclohexyl acrylate, and branched (meth)acrylic isomers, such as i-butylacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, stearyl methacrylate, isooctyl acrylate, or combination thereof.

[0038] Examples of the second acrylic or methacrylic acid derivative having a structure CH2=CR3COOZXR5, include methyl acrylate, ethyl acrylate, methoxyethyl acrylate, ethyl methacrylate, methyl methacrylate, or combination thereof.

[0039] Examples of the third acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR6include isobornyl (meth)acrylate and ethylene glycol dicyclopentenylether (meth)acrylate,

[0040] Examples of the silane functional acrylic or methacrylic acid derivative having a formula CH2=CR3COOR7SiR83-n Yninclude trimethoxysilylpropyl (meth)acrylate, triethoxysilylpropyl (meth)acrylate, trimethoxysilylethyl (meth)acrylate, methyldimethoxysilylpropyl (meth)acrylate, methacryloxypropyltrimethoxysilane, 3- (methacryloyloxy)propyltrimethoxysilane, (meth)acryloxypropyl Si(OCHCH3CON(CH3)2)3, (meth)acryloxypropylSi(OCHCH3COOCH2CH3), or combination thereof.

[0041] The polyacrylate polymers may be prepared by solution, emulsion, or bulk polymerization procedures using well-known polymerization techniques, such as free radical, anionic, and cationic techniques. The polymers can then be formed into a neat polymer after the removal of the solvent, coagulation of the latex or melt-processing.

[0042] The polymerization is prepared in the presence of one or more organic solvents. Suitable organic solvents or mixtures of solvents are alkanes, such as hexane, heptane, octane, and isooctane; aromatic hydrocarbons, such as benzene, toluene, and xylene; esters, such as ethyl, propyl, butyl and heptyl acetate; halogenated hydrocarbons, such as chlorobenzene; alcohols, such as methanol, ethanol, isopropanol, ethylene glycol, and ethylene glycol; ethers, such as THF, diethyl ether and dibutyl ether; or mixtures thereof.

[0043] In one advantageous embodiment of the process, the polymerization reactions proceed in isopropanol using AIBN as a radical initiator. In other variant, the polymerization reactions are conducted with a mixture of isopropanol and ethyl acetate.The acrylic polymers prepared will generally have a weight average molecular weight (Mw) of from 4,700 to 25,000 g / mol, preferably 10,000 to 20,000 g / mol and a number average molecular weight (Mn) of 4,500 to 8,000 g / mol. The Mw is determined by gel permeation chromatography (GPC) or matrix-assisted laser desorption / ionization mass spectrometry (MALDI-MS).

[0044] The disclosed moisture curable polyacrylate polymers are useful as one component of a moisture curable adhesive composition or moisture curable sealant composition. Other optionally useful components of the moisture curable adhesive composition or moisture curable sealant include, for example, one or more of moisture and acid scavengers, moisture cure catalyst, filler, solvent, and adhesion promoters. Preferably the moisture curable adhesive composition or moisture curable sealant is free or substantially free of added solvents.

[0045] To increase the shelf-life stability of the moisture curable polyacrylate polymers, antioxidants and moisture scavengers may be added to the polymer. Examples of the moisture scavenger include vinyltrimethoxysilane, vinylmethyldimethoxysilane, hexamethyldisilazane, methyltriethoxysilane, 3- vinylpropyltriethoxysilane, oxime silanes such as methyl-O,O',O"-butan-2- onetrioximosilane or O,O',O",O"'-butan-2-one-tetraoximosilane or benzamidosilanes such as bis(N-methylbenzamido)methylethoxysilane or carbamatosilanes such as carbamatomethyltrimethoxysilane; or combination thereof. The use of methyl, ethyl or vinyl trimethoxysilane, tetramethyl- or tetraethyl-ethoxysilane is also possible.Vinyltrimethoxysilane and tetraethoxysilane are particularly preferred in terms of cost and efficiency. The compositions generally contain up to about 6% by weight.

[0046] In one preferred embodiment, the moisture curable polyacrylate polymer is prepared from the following mixture. This embodiment provides good, cured strength and elongation properties while having superior UV weathering properties. The weight percent in each case is based on the total mixture of i+ii+iii+iv, as shown in Table 1.

[0047] In one preferred embodiment the moisture curable polyacrylate polymer when cured has the following properties, shown in Table 2.

[0048] Conventional silane polyacrylate polymers have little miscibility with silane modified polyurethane polymers, especially silane modified polyurethane polymers based on polyether polyols. The disclosed silane-modified polyacrylate polymers made by a free radical polymerisation process have increased miscibility with silane-modified polyurethane polymers.

[0049] The disclosed silane-modified polyacrylate polymers made by a free radical polymerisation process achieve good (synergetic) mechanical performance. The disclosed silane-modified polyacrylate polymers made by a free radical polymerisation process after curing have higher elongation than conventional silane polyacrylate polymers. The disclosed silane-modified polyacrylate polymers made by a free radical polymerisation process after curing have good modulus, moderate to low tack, and UV resistance.EXAMPLES

[0050] The following examples are provided for illustrative purposes only, without wishing to subject them to any unnecessary restriction.- Butyl acrylate (BA), ethyl acrylate (EA), 2,2’-azobis-(2-methyl propionitrile (AIBN), isopropanol (IPA), ethyl acetate (EAc), and dibutyltin dilaurate (DBTL) are available from Sigma-Aldrich.- t-Amyl peroxypivalate (t-APP, 75%, 0.5 g) is available from Akzo Nobel.- Methacryloxypropyl trimethoxysilane (MATMS), and vinyltrimethoxysilane are available from Evonik. 3-methacryloxypropyltrimethoxysilane (MEMO) is available from Evonik as Dynasylan MEMO.- All fillers and additives are commercially available from various suppliers.

[0051] Skin-over Time Measurement was measured according to ASTM 725: The skin-over time was determined under standard climatic conditions (25 + / - 2°C, relative humidity 50 + / - 5%). The samples were applied to a sheet of paper and drawn out to a skin with a putty knife (thickness of about 2 mm, width of about 7 cm). A stopwatch was started immediately. The surface was touched lightly with the fingertip until the composition no longer adheres to the fingertip. The skin-over time was recorded.

[0052] The elongation at break, and tensile stress values (E modulus) were determined in accordance with ASTM 708 using a standard tensile test apparatus. Sample dumbbell specimens with the following dimensions were used as the test pieces: thickness: 2 + / - 0.2 mm; gauge width: 10 + / - 0.5 mm; gauge length: about 45 mm; total length: 9 cm. The test took place after seven days of curing. A two mm-thick film was drawn out of the material. The film was stored for seven days under standard climatic conditions, and the dumbbells were then punched out. Three dumbbells were made for each test. The test was carried out under standard climatic conditions. The specimens were acclimatized to the test temperature (i.e. , stored) for at least 20 minutes before the measurement. Before the measurement, the thickness of the test specimens was measured at three places at room temperature using a vernier caliper; i.e., for the dumbbells, at the ends, and the middle within the initial gauge length. The average values were entered in the measuring program. The test specimens wereclamped in the tensile testing machine so that the longitudinal axis coincided with the mechanical axis of the tensile testing machine and the largest possible surface of the grips was grasped, without the narrow section being clamped. At a test speed of 50 mm / min, the dumbbell tensioned to a preload of <0.1 MPa.

[0053] Weathering was tested using a Q-Labs QUV accelerated weathering vertical test chamber. The QUV cycle is about 6 hours exposure to 340 nm radiation at 0.89 W / M2 / nm irradiance with 60 degree C black panel temperature followed by five minutes of water spray. Samples are positionally rotated daily in the chamber. To accelerate test results a sample thickness of 1 mil (0.001 inches) was used in place of the standard 0.125 inch sample thickness. A 6 inch by 12 inch (15.2 cm by 30.5 cm) mylar sheet was placed on a hard surface. A 3 / 16 inch (4.8 mm) diameter bead of sample about 3 inches (6.6 mm) long on a Mylar sheet. The sample bead should be parallel to and about 1 inch (2.5 cm) away from the edge of the mylar sheet. The sample bead was drawn down to a thickness of 1 mil (0.001 inches, 0.025 mm) along the 12 inch length of the mylar film. The drawn down sample was allowed to fully cure on the mylar sheet for a minimum of 7 days at standard room conditions, about 20 ± 3 °C and 40 to 60% relative humidity. The mylar sheet and cured sample was then cut to fit the QUV holder, thickness was measured and the sample placed in the QUV sample holder so that half of the sample is exposed and half of the sample is masked from exposure by the holder. The assembled sample was placed in the QUV test chamber and testing started. Samples are checked every 48 hours to document fading. The test is considered finished when the specification time is met or when the first white spot appears in the exposed sample.EXAMPLE 1

[0054] A 1 L 5-neck-round-bottom reaction flask was equipped with a temperature control device, a condenser, a mechanical stirrer, two addition funnels and nitrogen inlet / outlet. The set - up was purged with nitrogen gas for 15 min. To one of the addition funnels was charged a monomer mixture of methyl acrylate ( 60 g ), 2-ethylhexyl- acrylate (210 g ), isobornylacrylate (24 g ) methacryloxypropyltrimethoxysilane (MATMS, 6 g ). To another funnel was charged the initiator solution of 2,2 azobis- (2 -methyl propionitrile) (AIBN , 0.367 g ) and isopropanol (IPA 51.64 g ) / ethyl-acetate (EA, 3.67 g) . To the reaction flask was charged initiator 2,2 ' - azobis- (2 - methyl propionitrile) (AIBN , 0.15 g ) and IPA (120 g ) and ethyl acetate (1.5 g), and 40 g of the monomer acrylate mix (see above).

[0055] The reaction flask was heated to a reflux and held for 15 min. Then, the monomer mixture in the funnel was added continuously over 1 h 45 min hours at a constant rate. Simultaneously, the initiator solution in the funnel was added continuously over 2 hours 45 minute a constant rate. Upon complete addition, the mixture was stirred for extra 3 hours at reflux. The reaction solvent and any volatiles were stripped off under vacuum at 95 °C and 2 mbar. The resulting polyacrylate polymer was cooled to room temperature under nitrogen. The final obtained polyacrylate polymer has a weight average molecular weight (Mw) of 14765 Da and polydispersity (PDI) of 2.2 determined by GPC. This polyacrylate polymer had a cured tensile strength of 110 psi, a cured elongation of 460%, a skin over time (SOT) of 30 minutes with the skinned material being very lightly tacky and a QUV weathering result of 1270 hours.EXAMPLE 2

[0056] A 1 L 5-neck-round - bottom reaction flask was equipped with a temperature control device, a condenser, a mechanical stirrer, two addition funnels and nitrogen inlet / outlet. The set - up was purged with nitrogen gas for 15 min. To one of the addition funnels was charged a monomer mixture of butyl acrylate (267 g ), methyl acrylate (3 g ), isobornylacrylate (24 .0 g ) and Dynasylan (MEMO, 6 g ). To another funnel was charged the initiator solution of 2,2 azobis- (2 - methyl propionitrile) (AIBN , 0.4 g ) and isopropanol (IPA , 55 g ) / ethyl-acetate (EA, 5 g) . To the reaction flask was charged initiator 2,21- azobis- (2 - methyl propionitrile) (AIBN , 0.1 g ); IPA (97.5 g ); ethyl- acetate (EA 2.5 g); and 50 g of the acrylic monomer mix described above.

[0057] The reaction flask was heated to a reflux (about 85°C) and hold at reflux for 10-15 minutes. Then the monomer mixture in the funnel was added continuously over 2 hours at a constant rate. Simultaneously, the initiator solution in the funnel was added continuously over 3 hours at a constant rate. Upon complete addition, the mixture was stirred for an extra 3 hours at reflux. The reaction solvent and any volatiles werestripped off under vacuum at the reflux temperature. The resulting polyacrylate polymer was cooled to room temperature under nitrogen. The final obtained polyacrylate polymer has a weight average molecular weight (Mw) of 19,519 and polydispersity (PDI) of 3.3 determined by GPC. This polyacrylate polymer had a cured tensile strength of 140 psi, a cured elongation of 400%, a skin over time (SOT) of about 30 minutes with the skinned material being very lightly tacky and a QUV weathering result of 940 hours.EXAMPLE 3

[0058] A 1 L 5-neck- round - bottom reaction flask was equipped with a temperature control device, a condenser, a mechanical stirrer, two addition funnels and nitrogen inlet / outlet. The set - up was purged with nitrogen gas for 15 min. To one of the addition funnels was charged a monomer mixture of methyl acrylate (60 g ), 2-ethylhexyl- acrylate (210 g ), isobornylacrylate (24.0 g ), and Dynasylan (MEMO, 6 g ). To another funnel was charged the initiator solution of 2,2 azobis- (2 - methyl propionitrile) (AIBN , 0.4 g ) and isopropanol (IPA , 56g ) / ethyl-acetate (EA, 4g) . To the reaction flask was charged initiator 2,2 ' - azobis- (2 - methyl propionitrile) (AIBN , 0.116 g ); IPA (116.5 ).

[0059] The reaction flask was heated to a reflux (about 85°C). Once the AIBN is dissolved then the monomer mixture in the funnel was added continuously over 2 hours at a constant rate. Simultaneously, the initiator solution in the funnel was added continuously over 3 hours at a constant rate. Upon complete addition, the mixture was stirred for an extra 1 hour at reflux. Monomer scavenger solution of t-APP (t-amyl peroxypivalate, 0.5 g dissolved in 20 g of isopropanol) were charged into the initiator funnel and then added into the reaction mixture over 1 hour and hold for 1 hour at reflux. The reaction solvent and any volatiles were stripped off under vacuum at the reflux temperature. The resulting polyacrylate polymer was cooled to room temperature under nitrogen. The final obtained polyacrylate polymer has a weight average molecular weight (Mw) of 18,520 Da and polydispersity (PDI) of 2.1 determined by GPC. This polyacrylate polymer had a cured tensile strength of 160 psi, a cured elongation of 600%, QUV of 830 hours, a skin over time (SOT) of about 60 minutes with the skinned material being very much tacky.

Claims

CLAIMSWe claim:1 . A moisture curable polyacrylate polymer prepared by polymerizing: i. 30 to 90% by weight of a first acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR4, where R3is H or CH3 and R4is a C4-24 linear, branched or cyclic alkyl chain, or combination thereof, ii. 1 to 50% by weight of a second acrylic or methacrylic acid derivative having a structure of CH2=CR3COOZXR5, where R3is H or CH3; X is 0, S, NR5or a covalent bond; Z is an optionally present C1-6 alkylene chain; and each R5is independently H, C1-2 alkyl chain or a combination thereof, and iii. 0.1 to 40% by weight of a third acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR6, where R3is H or CH3 and R6is a C7-20 fused or bridged ring system that can be substituted with one or more alkyl groups, and iv. 1 .0 to 5% by weight of a silane functional acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR7SiR83-n Yn, where R3is H or CH3; R7is a C1-24 linear, branched or cyclic alkylene or arylene chain; R8is a C1-24 linear, branched or cyclic alkyl chain; Y is C1-3 alkoxy, aryloxy, acetoxy, oximino, enoxy, amino, ester, amide, lactate ester, lactate amide, H, OH, halogen, OCHCH3CON(CH3)2, OCHCH3COOCH2CH3, or combination thereof; n = 1 , 2, or 3.

2. The moisture curable polyacrylate polymer of claim 1 , wherein the i. first acrylic or methacrylic acid derivative is selected from n-butyl acrylate, n-butyl methacrylate, n- pentyl acrylate, n-hexyl acrylate, n-heptyl acrylate, and n-octyl acrylate, n-nonyl acrylate, lauryl methacrylate, cyclohexyl acrylate, and branched (meth)acrylic isomers, such as i- butyl acrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, stearyl methacrylate, isooctyl acrylate, or combination thereof.

3. The moisture curable polyacrylate composition of claim 1 , wherein the ii. second acrylic or methacrylic acid derivative is selected from methyl acrylate, ethyl acrylate, methoxyethyl acrylate, ethyl methacrylate, methyl methacrylate, or combination thereof.

4. The moisture curable polyacrylate composition of claim 1 , wherein the iii. third acrylic or methacrylic acid derivative is selected from isobornyl (meth)acrylate, ethylene glycol dicyclopentenylether (meth)acrylate, or combination thereof.

5. The moisture curable polyacrylate composition of claim 1 , wherein the iv. silane functional acrylic or methacrylic acid derivative is selected from trimethoxysilylpropyl (meth)acrylate, triethoxysilylpropyl (meth)acrylate, trimethoxysilylethyl (meth)acrylate, methyldimethoxysilylpropyl (meth)acrylate, methacryloxypropyltrimethoxysilane, 3- (methacryloyloxy)propyltrimethoxysilane, (meth)acryloxypropylSi(OCHCH3CON(CH3)2)3, (meth)acryloxypropylSi(OCHCH3COOCH2CH3), or combination thereof.

6. The moisture curable polyacrylate polymer of claim 1 , wherein the i. first acrylic or methacrylic acid derivative is selected from butyl acrylate and / or 2-ethylhexyl acrylate; and / or the ii. second acrylic or methacrylic acid derivative methyl acrylate, ethyl acrylate, and / or methoxyethyl acrylate; and / or the iii. third acrylic or methacrylic acid derivative is isobornyl acrylate; and / or the iv. silane functional acrylic or methacrylic acid derivative is methacryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane or combination thereof.

7. The moisture curable polyacrylate polymer of claim 1 having have a weight average molecular weight (Mw) of from 4,700 to 25,000 g / mol, optionally between10,000 and 20,000 g / mol; and / or having have a number average molecular weight (Mw) of from 4,500 to 8,000 g / mol.A method of preparing a moisture curable polyacrylate polymer comprising: i) providing 40 to 90 wt.% of a mixture of:30 to 90% by weight of a first acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR4, where R3is H or CH3 and R4is a C4-24 linear, branched or cyclic alkyl chain, or combination thereof,5 to 50% by weight of a second acrylic or methacrylic acid derivative having a structure of CH2=CR3COOZXR5, where R3is H or CH3; X is O, S, NR5or a covalent bond; Z is an optionally present C1-6 alkylene chain; and each R5is independently H, C1-2 alkyl chain or a combination thereof, and0.1 to 40% by weight of a third acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR6, where R3is H or CH3 and R6is a C7-20 fused or bridged ring system that can be substituted with one or more alkyl groups, and1 .00 to 5% by weight of a silane functional acrylic or methacrylic acid derivative having a structure of CH2=CR3COOR7SiR83-n Yn, where R3is H or CH3; R7is a C1-24 linear, branched or cyclic alkylene or arylene chain; R8is a C1-24 linear, branched or cyclic alkyl chain; Y is C1-3 alkoxy, aryloxy, acetoxy, oximino, enoxy, amino, ester, amide, lactate ester, lactate amide, H, OH, halogen, OCHCH3CON(CH3)2, OCHCH3COOCH2CH3, or combination thereof; and n = 1 , 2, or 3; ii) providing 10-60% by weight of an alcohol of the formula HOR9, where R9is C1-4 linear or branched alkyl chain; iii) optionally providing 0-60% by weight of an ester of the formula R9COOR9, where each R9is independently a C1-4 linear or branched alkyl chain; iv) providing 0.01 to 5% of a radical initiator; v) mixing the mixture, alcohol, optional ester and radical initiator to form a reaction mixture; vi) polymerizing the reaction mixture at a reaction temperature of about 50 to about 120°C for about 4 to 24 hours to obtain a reaction product; and vii) removing the solvent from the reaction product to obtain the moisture curable polyacrylate polymer.

9. The method of claim 8 wherein the radical initiator is an azo or peroxide radical initiator.

10. The method of claim 8 wherein the reaction mixture includes the ester of the formula R9COOR9.11 . The method of claim 8 wherein Z is present in the second acrylic or methacrylic acid derivative.

12. The moisture curable polyacrylate polymer of claim 1 , wherein the i. first acrylic or methacrylic acid derivative is selected from n-butyl acrylate, n-butyl methacrylate, n- pentyl acrylate, n-hexyl acrylate, n-heptyl acrylate, and n-octyl acrylate, n-nonyl acrylate, lauryl methacrylate, cyclohexyl acrylate, and branched (meth)acrylic isomers, such as i- butyl acrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, stearyl methacrylate, isooctyl acrylate, or combination thereof.

13. The moisture curable polyacrylate composition of claim 12, wherein the ii. second acrylic or methacrylic acid derivative is selected from methyl acrylate, ethyl acrylate, methoxyethyl acrylate, ethyl methacrylate, methyl methacrylate, or combination thereof.

14. The moisture curable polyacrylate composition of claim 13, wherein the iii. third acrylic or methacrylic acid derivative is selected from isobornyl (meth)acrylate, ethylene glycol dicyclopentenylether (meth)acrylate, or combination thereof.

15. The moisture curable polyacrylate composition of claim 14, wherein the iv. silane functional acrylic or methacrylic acid derivative is selected from trimethoxysilylpropyl (meth)acrylate, triethoxysilylpropyl (meth)acrylate, trimethoxysilylethyl (meth)acrylate, methyldimethoxysilylpropyl (meth)acrylate, methacryloxypropyltrimethoxysilane, 3- (methacryloyloxy)propyltrimethoxysilane, (meth)acryloxypropylSi(OCHCH3CON(CH3)2)3, (meth)acryloxypropylSi(OCHCH3COOCH2CH3), or combination thereof.

16. The moisture curable polyacrylate polymer of claim 15, wherein the i. first acrylic or methacrylic acid derivative is selected from butyl acrylate and / or 2-ethylhexyl acrylate; and / or the ii. second acrylic or methacrylic acid derivative methyl acrylate, ethyl acrylate, and / or methoxyethyl acrylate; and / or the iii. third acrylic or methacrylic acid derivative is isobornyl acrylate; and / or the iv. silane functional acrylic or methacrylic acid derivative is methacryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane or combination thereof.

17. The moisture curable polyacrylate polymer of claim 16, having have a weight average molecular weight (Mw) of from 4,700 to 25,000 g / mol, optionally between10,000 and 20,000 g / mol; and / or having have a number average molecular weight (Mw) of from 4,500 to 8,000 g / mol.

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