WO2018160373A1 - Dual cure polyorganosiloxane composition and methods for its preparation and use - Google Patents

Abstract

A curable composition suitable for adhesive and/or coating applications contains a poly(meth)acrylate clustered functional polyorganosiloxane. The curable composition has a dual (radical and condensation) cure system and can cure at room temperature.

Description

DUAL CURE POLYORGANOSILOXANE COMPOSITION AND METHODS FOR ITS

PREPARATION AND USE

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 62/464407 filed on 28 February 2017 under 35 U.S.C. §1 19 (e). U.S. Provisional Patent Application Serial No. 62/464407 is hereby incorporated by reference.

TECHNICAL FIELD

[0002] A curable composition suitable for adhesive and/or coating applications is disclosed. The curable composition has a dual (radical and condensation) cure system.

BACKGROUND

[0003] Adhesive compositions that cure and develop strong adhesion at room temperature have been identified as an unmet need for silicones in various applications, including transportation and/or electronics applications (e.g., automotive electronics adhesives such as for engine and transmission control units). Some currently available adhesives provide good lap shear strength and strong adhesion to plastic substrates such as polypropylene or polybutylene terephthalate. However, adhesives and coatings currently available may suffer from the drawback of requiring heat to cure and develop good lap shear adhesion strength.

SUMMARY OF THE INVENTION

[0004] A multiple part composition comprises:

A) a first part comprising

I) a polyorganosiloxane having an average of at least two silicon bonded hydrolyzable groups per molecule, and

II) an organoboron compound capable of forming a free radical generating species; and

B) a second part comprising

III) a poly(meth)acrylate clustered functional polyorganosiloxane comprising units of formulae: (R2R¹ Si0₁/2)aa(RR¹ Si02/2)bb(R2Si02/2)cc(RSi0₃/2)dd(Si04/2)ee

((Rff)0(3_ff)/2SiD¹ SiRffO(3_ff)/2)gg> where each D¹ independently represents a divalent hydrocarbon group of 2 to 18 carbon atoms; each R independently represents a monovalent hydrocarbon group of 1 to 18 carbon atoms, each R¹ independently represents a methacryl- functional alkyl group or an acryl-functional alkyl group, subscript aa≥ 0, subscript bb≥ 0, a quantity (aa + bb)≥ 4, subscript cc > 0, subscript dd≥ 0, subscript ee≥ 0, subscript ff is 0, 1 or 2, subscript gg≥ 2; IV) an organoborane liberating compound capable of reacting with starting material II) to form the free radical generating species, and

V) a condensation reaction catalyst;

where the multiple part composition further comprises VI) an organosilicon compound having, per molecule, at least one hydrolyzable group and at least one free radical reactive group.

[0005] A method comprises: contacting a substrate with a curable composition prepared by mixing starting materials comprising:

I) the polyorganosiloxane having an average of at least two silicon bonded hydrolyzable groups per molecule,

II) the organoboron compound capable of forming free radical generating species,

III) the poly(meth)acrylate clustered functional polyorganosiloxane, comprising units of formulae:

(R2R¹ Si0₁/2)aa(RR¹ Si02/2)bb(R2Si02/2)cc(RSi0₃/2)dd(Si04/2)ee

((Rff)0(3_ff 2SiD¹ SiRffO(3_ff)/2)gg> where each D¹ independently represents a divalent hydrocarbon group of 2 to 18 carbon atoms; each R independently represents a monovalent hydrocarbon group of 1 to 18 carbon atoms, each R¹ independently represents a methacryl- functional alkyl group or an acryl-functional alkyl group, subscript aa≥ 0, subscript bb≥ 0, a quantity (aa + bb)≥ 4, subscript cc > 0, subscript dd≥ 0, subscript ee≥ 0, subscript ff is 0, 1 , or 2, subscript gg≥2 ;

IV) the organoborane liberating compound capable of reacting with the organoboron compound to form the free radical generating species,

V) the condensation reaction catalyst, and

VI) the organosilicon compound having, per molecule, at least one hydrolyzable group and at least one free radical reactive group.

[0006] The composition and method described above may be used in various applications such as coatings, adhesives and composites.

DETAILED DESCRIPTION

[0007] The polyorganosiloxane having an average of at least two silicon bonded hydrolyzable groups per molecule used in the above method and composition, described above, as starting material I) may have unit formula:

_d(R2Si02/2)e(RSi0₃/2)f(Si04/2)g.

[0008] Each R is independently a monovalent hydrocarbon group of 1 to 18 carbon atoms. Suitable groups for R include, but are not limited to, alkyl and aryl groups, as defined hereinbelow. Suitable alkyl groups are exemplified by methyl, ethyl, propyl, butyl and hexyl. Suitable aryl groups are exemplified by phenyl, tolyl, xylyl, and phenyl-methyl.

[0009] Each D independently represents an oxygen atom or a divalent hydrocarbon group as defined hereinbelow. Each D may have 2 to 18 carbon atoms. Alternatively, each D may be selected from alkylene such as ethylene or propylene, arylene such as phenylene, or alkaralkylene. Alternatively, each D may be an alkylene group such as ethylene or propylene.

[0010] Each X independently represents a hydrolyzable group selected from an acetamido group, an acyloxy group such as acetoxy, an alkoxy group, an amido group, an amino group, an aminoxy group, an oximo group, a ketoximo group, and a methylacetamido group. X is not a hydroxyl group. Alternatively, each X may be an acetoxy group or an alkoxy group.

Alternatively, each X is an alkoxy group, such as methoxy, ethoxy, propoxy or butoxy;

alternatively methoxy.

[0011] In the unit formula for the polyorganosiloxane described above, subscript a is 0 1 , or 2. Alternatively, subscript a may be 0 or 1 . Alternatively, subscript a may be 0. Subscript b≥ 0. Alternatively, subscript b is 0 to 18. Alternatively, subscript b = 0. Subscript c is 0, 1 , 2, or 3. Alternatively, subscript c is 1 , 2, or 3. Alternatively, subscript c is 2 or 3, and alternatively, subscript c is 3. A quantity (a + c) is at least 1 .

[0012] In the unit formula for the polyorganosiloxane described above, subscript d > 0.

Alternatively, subscript d may be 0.01 to 1000, alternatively 1 to 5000, alternatively 2 to 250, and alternatively 3 to 200. Subscript e > 0. Alternatively, subscript e may be 1 to 2,000,000, alternatively 5 to 500,000, alternatively 5 to 100,000, alternatively 5 to 50,000, alternatively from 10 to 50,000, alternatively 10 to 10,000, alternatively 10 to 5,000, and alternatively 20 to 2,000. Subscript f≥ 0. Alternatively, subscript f may be 0 to 2,000,000, alternatively 0 to 1 ,000,000, alternatively 0 to 500,000; alternatively 1 to 500,000; alternatively 0 to 100,000; alternatively 1 to 100,000; alternatively 0 to 50,000; alternatively 1 to 50,000; alternatively 0 to 10,000;

alternatively 1 to 10,000; alternatively 0 to 5,000; and alternatively 1 to 5,000. Subscript g≥ 0. Alternatively, subscript g may be 0 to 2,000,000, alternatively 0 to 1 ,000,000, alternatively 0 to 500,000; alternatively 1 to 500,000; alternatively 0 to 100,000; alternatively 1 to 100,000;

alternatively 0 to 50,000; alternatively 1 to 50,000; alternatively 0 to 10,000; alternatively 1 to 10,000; alternatively 0 to 5,000; and alternatively from 1 to 5,000.

[0013] Alternatively, I) the polyorganosiloxane may have formula:

, where subscript h is an integer having a value sufficient to provide the polyorganosiloxane with a viscosity of at least 10 mPa-s at 25 °C and/or a degree of polymerization of at least 8. Viscosity may be measured by a concentric cylinder or a parallel plate viscometer at a constant shear rate. Degree of polymerization (DP) may be measured by gel permeation chromatography (GPC) using polystyrene standards calibration. Alternatively, subscript h may have a value ranging from 1 to 2,000,000, alternatively 1 to 500,000, alternatively 1 to 100,000, alternatively 1 to 50,000, alternatively 1 to 20,000, alternatively 1 to 10,000, alternatively 1 to 5,000, alternatively 1 to 2,000. Alternatively, where subscript c in the formula above is 1 , the I) the polyorganosiloxane may have formula:

where subscript i is 1 to 2,000,000. Alternatively, subscript i may be 1 to 2,000,000, alternatively 5 to 500,000, alternatively 5 to 100,000, alternatively 5 to 50,000, alternatively 10 to 50,000, alternatively 10 to 10,000, alternatively 10 to 5,000, and alternatively from 20 to 2,000.

[0014] Starting material I) is present in Part A of the multiple part composition described above. All or a portion of starting material I) may be present in Part A. Alternatively, a portion of starting material I) is present in Part A, another portion of starting material I) may be present in Part B, and optionally, another portion of starting material I) may be present in a separate additional part, when the multiple composition has more than two parts. Alternatively, starting material I) may be present in both Part A and Part B of a two part composition. Alternatively, starting material I) may be present in Part A of a two part composition. The total amount of starting material I) depends on various factors including the selections and amounts of all starting materials, however, starting material I) may be present in an amount of 5% to 95% based on combined weights of all starting materials in the multiple part composition. Alternatively, starting material I) may be present in an amount of 5% to 80%, alternatively 5% to 70%, alternatively 5% to 60%, alternatively 5% to 50%, alternatively 5% to 40%, alternatively 5% to 30%, and alternatively 10% to 30%.

[0015] The composition described above further comprises II) the organoboron compound capable of forming free radical generating species. Starting material II) may be selected from the group consisting of: a) an organoborane - organonitrogen compound complex, b) an organoborate containing at least one B-C bond, and c) both a) the organoborane - organonitrogen compound complex and b) the organoborate containing at least one B-C bond. The organoboron compound may be air stable. The organoborane - organonitrogen compound complex may be an organoborane - amine complex, such as those disclosed in U.S. Patent 6,706,831 and U.S. Patent 8,097,689 at col. 10, line 39 - col. 12, line 35.

rane - organonitrogen compound complex may have formula

, where subscript xx is 1 or more, subscript yy is 1 or more, each R^L is independently an alkyl group of 1 to 12 carbon atoms, a cycloalkyl group of 3 to 12 carbon atoms, an alkylaryl group, an organosilane group such as an alkylsilane group or an arylsilane group, an organosiloxane group such as alkyl siloxane or arylsiloxane; and each R^A is a primary amine-functional compound, a secondary amine-functional compound, or an amide- functional compound. Each R^L is covalently bonded to the boron atom, and R^A forms a complex with boron. (The arrow in the formula represents a coordination, not a covalent bond.)

Alkyl groups and cycloalkyl groups suitable for R^L are defined hereinbelow. Suitable alkyl groups include ethyl, propyl and butyl. Suitable compounds for R^A include hydrocarbylene diamines such as 1 ,3-propylene diamine and isophorone diamine; alkoxyalkyl amines such as 3-methoxypropyl amine; amino-functional alkoxysilanes such as 3-aminopropyltriethoxysilane. Alternatively, each subscript xx is 1 and each subscript yy is 1 . Alternatively each subscript xx is 1 .3 and each subscript yy is 1 .

[0017] The organoborane - organonitrogen compound complex may be selected from the group consisting of i) tri-n-butyl borane complex with isophorone diamine; ii) tri-n-butyl borane complex with 1 ,3-propylene diamine; iii) tri-n-butyl borane complex with 3-methoxypropyl amine; iv) triethylborane complex with isophorone diamine; v) triethylborane complex with 1 ,3- propylene diamine; vi) triethylborane complex with 3-methoxypropyl amine; vii) tri-isobutyl borane complex with isophorone diamine; viii) tri-isobutyl borane complex with 1 ,3-propylene diamine; ix) tri-isobutyl borane complex with 3-methoxypropylamine; x) tri-n-butylborane complex with 3-aminopropyltriethoxysilane; xi) tri-n-butylborane complex with 3- aminopropyltrimethoxysilane; xii) triethylborane complex with 3-aminopropyltriethoxysilane; xiii) triethylborane complex with 3-aminopropyltrimethoxysilane, and a combination of two or more of i), ii), iii), iv), v), vi), vii), viii), ix), x), xi), xii), and xiii).

[0018] The organoborate containing at least one B-C bond can be an amido-borate. The

R^L

A ' - L

R— B— R M +

amido - borate may have formula ^R , where R^A and R^L are as described above, RA is bonded to the boron atom via a covalent bond or an ionic bond, and M is a cation. M may be a metal ion or a quaternary ammonium ion. Exemplary amido - borates are exemplified by those disclosed, for example, in U.S. Patent 7,524,907 at col. 6, line 50 to col. 10, line 67; U.S. Patent 7,683,132 at col. 3, line 3 to col. 12, line 54.

[0019] Starting material II) is present in Part A of the multiple part composition. Alternatively, a portion of starting material II) is present in Part A of the multiple part composition, and another portion of starting material II) is present in the separate additional part, when the multiple part composition has more than two parts. Because starting material II) and starting material IV) are kept separate until shortly before use of the composition, starting material II) is not included in Part B of the multiple part composition. The amount of starting material II) may be 0.01 to 35, alternatively 0.1 to 30, alternatively 0.5 to 20, alternatively 1 to 10 part by weight per 100 parts of combined weights of all starting materials in the multiple part composition.

[0020] Starting material III) in the multiple part composition and method described above is the poly(meth)acrylate clustered functional polyorganosiloxane. The poly(meth)acrylate clustered functional polyorganosiloxane has unit formula:

(R2R¹ Si0_{1 /}2)aa(RR¹ Si02/2)bb(^R2Si0₂/2)cc(^RSi03/2)dd(Si04/2)ee

((Rff)0(3-ff)/2SiD¹ SiRffO₍3_ff_)/2)gg.

[0021] In this unit formula, R is as described above and each D¹ independently represents a divalent hydrocarbon group of 2 to 18 carbon atoms, as described above for group D. R and R1 are as described above. Each R¹ independently represents a methacryl-functional alkyl group or an acryl-functional alkyl group. Suitable groups for R¹ include methylmethacrylate, methyl acrylate, butyl methacrylate, 2-ethylhexylacrylate, and 2-ethylhexylmethacrylate.

[0022] In the unit formula above, subscript aa≥ 0, subscript bb≥ 0, a quantity (aa + bb)≥ 4, subscript cc > 0, subscript dd≥ 0, subscript ee≥ 0, subscript ff is 0, 1 , or 2, subscript gg≥ 2. Alternatively, the quantity (aa + bb) may be≥ 6. Alternatively, the quantity (aa + bb) may be≥ 8. By the term "poly(meth)acrylate clustered functional siloxane", it is meant that the siloxane has a linear or branched siloxane backbone structure and in the terminal and/or pendent positions of the siloxane there are methacrylate or acrylate functional groups spatially close to each other. The siloxane has at least 4 total methacrylate plus acrylate functional groups and at least two of them are in close proximity to each other, i.e., they are "clustered".

[0023] Alternatively, III) the poly(meth)acrylate clustered functional polyorganosiloxane may have formula:

, where R, R¹ , and D¹ as described above. Subscript j is 0 to 2,000,000, and each subscript k is independently 1 to 12 (i.e., such that each ring has 4 to 15 silicon atoms). Alternatively, subscript j is 5 to 500,000, alternatively 5 to 100,000, alternatively 5 to 50,000, alternatively 10 to 50,000, alternatively 10 to 10,000, alternatively 10 to 5,000, alternatively 20 to 2,000. Alternatively subscript k is 1 to 8, alternatively 1 to 6, alternatively 1 to 4, alternatively 1 to 2, and alternatively, k = 1 .

Alternatively, III) the poly(meth)acrylate clustered functional polyorganosiloxane may have formula:

, where

R, R¹ , D¹ , and subscripts j and k are as described above. [0024] Poly(meth)acrylate clustered functional polyorganosiloxanes may be prepared by known methods, such as disclosed in U.S. Patent Application Publication 2016/0009865. The poly(meth)acrylate clustered functional polyorganosiloxane used herein may be a hydrosilylation reaction product of starting materials comprising:

a) a polyorganosiloxane having an average of at least two silicon bonded aliphatically unsaturated groups per molecule;

b) an organohydrogensiloxane having an average of 4 to 15 silicon atoms per molecule, where starting material b) has silicon bonded hydrogen atoms;

with the proviso that a molar ratio of aliphatically unsaturated groups in starting material a) to silicon bonded hydrogen atoms in starting material b) is 1 to 3 to 1 to 20; and

c) a reactive species having, per molecule, at least one aliphatically unsaturated group and one or more radical curable groups selected from acrylate functional groups and

methacrylate functional groups.

[0025] Starting material III) is present in Part B of the multiple part composition described above. Because starting material II) and starting material III) are kept separate until shortly before use of the composition, starting material III) is not included in Part A of the multiple part composition. All or a portion of starting material III) may be present in Part B. Alternatively, a portion of starting material III) is present in Part B, and optionally, another portion of starting material III) may be present in the separate additional part, when the multiple part composition has more than two parts. If a portion of III) is present in the separate additional part, the organoboron compound will not be present in the separate additional part. The total amount of starting material III) depends on various factors including the selections and amounts of all starting materials, however, starting material III) may be present in an amount of 5% to 99% based on combined weights of all starting materials in the multiple part composition.

Alternatively it may be present in an amount of 5% to 95%, alternatively from 10% to 95%, alternatively from 10% to 90%, alternatively from 15% to 90%, alternatively from 20% to 90%, alternatively from 30% to 90%, alternatively from 40% to 85%, and alternatively from 50% to 80%.

[0026] Organoborane liberating compounds suitable for use as starting material IV) in the composition and method described herein include the amine reactive compounds disclosed, for example, in U.S. Patent 8,097,689 at col. 12, line 55 - col. 13, line 46. The term "organoborane liberating compound" means a compound that will at least partially react with starting material II) and release another organoboron compound that contains at least one B-C bond that can be readily oxidized and generate free radical. The organoborane liberating compound may be selected from: i) an acid, ii) an aldehyde, iii) an isocyanate, iv) an epoxide, v) an acid chloride, vi) an anhydride, vii) an acyloxysilane, viii) an acyloxysiloxane, ix) a halosilane, x) a

halosiloxane, xi) a carboxylic acid functional silane, xii) a carboxylic acid functional siloxane, xiii) an anhydride functional silane, xiv) an anhydride functional siloxane, xv) an epoxy functional silane, xvi) an epoxy functional siloxane, xvii) a sulphonyl chloride, and a combination of two or more of i), ii), iii), iv), v), vi), vii), viii), ix), x), xi), xii), xiii), xiv), xv), xvi), and xvii). Alternatively, the liberating compound may be selected from, methacrylic acid, isophorone diisocyanate, or a combination thereof.

[0027] Starting material IV) is present in Part B of the multiple part composition. Alternatively, a portion of starting material IV) is present in Part B of the multiple part composition, and another portion of starting material IV) is present in the separate additional part, when the multiple part composition has more than two parts. Because starting material II) and starting material IV) are kept separate until shortly before use of the composition, starting material IV) is not included in Part A of the multiple part composition. The organoborane liberating compound may be present in the composition in an amount of 0.1 to 50, alternatively 0.1 to 40, alternatively 1 to 25 parts by weight, per 100 parts based on combined weights of all starting materials in the multiple part composition. Alternatively, the organoborane liberating compound may be present in an amount sufficient to provide 0.5 or more molar equivalents of liberating compound based on the amount of II) the organoboron compound capable of forming the free radical generating species.

[0028] The multiple part composition described above further comprises a condensation reaction catalyst. The condensation reaction catalyst may be selected from common condensation catalysts that are effective for silanol-silanol condensation reaction, include organometallic compounds, amines, and a wide range of organic and inorganic bases and acids. Organometallic compounds include organic compounds of tin, titanium, zinc, zirconium, hafnium, and others. The condensation reaction catalysts can be an organotin compound and an organotitanium compound. Exemplary organotin compounds may be selected from the group consisting of: a) stannic salts of carboxylic acids such as i) dibutyl tin dilaurate, ii) dimethyl tin dilaurate, iii) di-(n-butyl)tin bis-ketonate, iv) dibutyl tin diacetate, v) dibutyl tin maleate, vi) dibutyl tin diacetylacetonate, vii) dibutyl tin dimethoxide, viii) carbomethoxyphenyl tin tris-uberate, ix) dibutyl tin dioctanoate, x) dibutyl tin diformate, xi) isobutyl tin triceroate, xii) dimethyl tin dibutyrate, xiii) dimethyl tin di-neodeconoate, xiv) dibutyl tin di-neodeconoate, xv) triethyl tin tartrate, xvi) dibutyl tin dibenzoate, xvii) butyltintri-2-ethylhexanoate, xviii) dioctyl tin diacetate, xix) tin octylate, xx) tin oleate, xxi) tin butyrate, xxii) tin naphthenate, xxiii) dimethyl tin dichloride; b) tin (II) salts of organic carboxylic acids such as xxiv) tin (II) diacetate, xxv) tin (II) dioctanoate, xxvi) tin (II) diethylhexanoate, xxvii) tin (II) dilaurate, c) stannous salts of carboxylic acids such as xxviii) stannous octoate, xxix) stannous oleate, xxx) stannous acetate, xxxi) stannous laurate, xxxii) stannous stearate, xxxiii) stannous naphthanate, xxxiv) stannous hexanoate, xxxv) stannous succinate, xxxvi) stannous caprylate, and a combination of two or more of i) to xxxvi). Exemplary organotitanium compounds may be

selected from the group consisting of: i) tetra-n-butyl titanate, ii) tetraisopropyl titanate, iii) tetra- t-butyl titanate, iv) tetrakis(2-ethylhexyl) titanate, v) acetyl aceton ate titanate chelate, vi) ethyl acetoacetate titanate chelate, vii) triethanolamine titanate chelate, and a combination of two or more of i), ii), iii), iv), v), vi) and vii).

[0029] Starting material V) is present in Part B of the multiple part composition described above. All or a portion of starting material V) may be present in Part B. Alternatively, a portion of starting material V) is present in Part B, another portion of starting material V) may be present in Part A, and optionally, another portion of starting material V) may be present in the separate additional part, when the multiple part composition has more than two parts. Alternatively, starting material V) may be present in both Part A and Part B of a two part composition.

Alternatively, starting material V) may be present in Part B of a two part composition. The amount of condensation reaction catalyst in the composition depends on various factors including the selection of the other starting materials, whether any additional starting materials are added, and the end use of the composition. However, the condensation reaction catalyst may be present in an amount ranging from 0.01 % to 10% based on combined weights of all starting materials in the multiple part composition. Alternatively, starting material V) is present in an amount of 0.01 % to 5%, alternatively 0.1 % to 5%, alternatively 0.1 % to 3%, and alternatively 0.1 % to 2%.

[0030] The multiple part composition described above further comprises VI) the organosilicon compound having, per molecule, at least one hydrolyzable group and at least one free radical reactive group. Starting material VI) may be added to Part A) of the multiple part composition, to Part B), to a separate additional part, or combinations of two or more of Part A), Part B) and the separate part.

[0031] The organosilicon compound for starting materials VI) may comprise a silane of formula R¹ _mR_nSiX(4__m__n), where R, R¹ , and X are as described above, subscript m is 1 to 2, subscript n is 0 to 2, and a quantity (m + n) is 2 to 3. Alternatively, the organosilicon compound for starting material VI) may comprise a polyorganosiloxane of unit formula: (X_cR₃__cSi0_{1 /2})o( ¹ R2Si0_{1 /2})p(R2Si02/2)q( XSi02/2)r(R¹ RSi0₂/₂)_s(R¹ Si0₃/2)w(RSi03/2)_t

(Si04/2)_u, where R, R¹ , and X are as described above, subscript o≥ 0, subscript p≥ 0, subscript q > 0, subscript r≥ 0, subscript s≥ 0, subscript w > 0, subscript t≥ 0, and subscript u≥ 0, with the provisos that a quantity (o + r)≥ 1 , a quantity (p + s + w)≥ 1 , and a quantity (o + p + q + r + s + w + t + u) > 2. Alternatively, subscript o is 0 to 100, alternatively 0 to 50, alternatively 0 to 20, alternatively 0 to 10, alternatively, 1 to 50, alternatively, 1 to 20, and alternatively 1 to 10. Alternatively, subscript p may be 0 to 100, alternatively 0 to 50, alternatively 0 to 20, alternatively 0 to 10, alternatively 1 to 50, alternatively 1 to 20, and alternatively 1 to 10.

Alternatively, subscript q is 0 to 1 ,000, alternatively 0 to 500, alternatively 0 to 200, alternatively 0 to 100, alternatively 1 to 500, alternatively 1 to 200, and alternatively 1 to 100. Alternatively, subscript r is 0 to 100, alternatively 0 to 50, alternatively 0 to 20; alternatively 0 to 10, alternatively 1 to 50, alternatively 1 to 20, and alternatively 1 to 10. Alternatively, subscript s is 0 to 100, alternatively 0 to 50, alternatively 0 to 20, alternatively 0 to 10, alternatively 1 to 50, alternatively 1 to 20, and alternatively 1 to 10. Alternatively, subscript w is 0 to 100, alternatively 0 to 50, alternatively 0 to 20, alternatively 0 to 10, alternatively 1 to 50, alternatively 1 to 20, and alternatively 1 to 10. Alternatively, subscript t is 0 to 1 ,000, alternatively 0 to 500, alternatively 0 to 200; alternatively 0 to 100, alternatively 1 to 500, alternatively 1 to 200, and alternatively 1 to 100. Alternatively, subscript u is 0 to 1 ,000, alternatively 0 to 500, alternatively 0 to 200, alternatively 0 to 100, alternatively 1 to 500, alternatively 1 to 200, and alternatively 1 to 100.

[0032] Examples of starting material VI) include silanes, such as

methacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane,

acryloxypropyltriethoxysilane, methacryloxypropyltriethoxysilane,

methacryloxypropylmethyldimethoxysilane, acryloxypropylmethyldimethoxysilane,

acryloxypropyldimethylmethoxysilane, and methacryloxypropyldimethylmethoxysilane.

[0033] Starting material VI) may be present in the multiple part composition in Part A, Part B, and optionally the separate additional part. Alternatively, all or a portion of starting material VI) may be present in Part A. Alternatively, a portion of starting material VI) is present in Part A, another portion of starting material VI) may be present in Part B, and optionally, another portion of starting material VI) may be present in the separate additional part, when the multiple part composition has more than two parts. Alternatively, starting material VI) may be present in both Part A and Part B of a two part composition. Alternatively, starting material VI) may be present in Part B of a two part composition. Alternatively, starting material VI) may be present in Part A of a two part composition. The amount of condensation reaction catalyst in the composition depends on various factors including the selection of the other starting materials, whether any additional starting materials are added, and the end use of the composition. However, the condensation reaction catalyst may be present in an amount ranging from 0.01 % to 25% based on combined weights of all starting materials in the multiple part composition. Alternatively it is present in an amount of 0.1 % to 25%, alternatively 0.1 % to 15%, alternatively 0.5% to 15%, alternatively 0.5% to 10%, alternatively 0.1 % to 5%.

[0034] The multiple part composition described above may further comprise an additional starting material selected from the group consisting of: VII) an adhesion promoter, VIII) a corrosion inhibitor, IX) a rheology modifier, X) a free radical initiator, XI) a drying agent, XII) a crosslinker, XIII) a filler, XIV) a spacer, XV) an acid scavenger, XVI) a silanol functional polydiorganosiloxane, XVII) a fluorescent optical brightener, XVIII) a chain transfer agent, XIX) a (meth)acrylate monomer, and two or more of VII), VI II), IX), X), XI), XII), XIII), XIV), XV), XVI), XVII), XVIII), and XIX). The additional starting material may be added to Part A), Part B), the separate additional part, described above, or a combination of two or more of Part A), Part B) and the separate additional part. Alternatively, one or more starting materials selected from the group consisting of VII), VIII), XI), XII), XIII) and, XIV) may be added to Part A of a two part composition. Alternatively, one or more of starting materials VII), VIII), X), XVII), and XIV) may be added to part B of a two part composition.

[0035] The composition described above may optionally further comprise VII) an adhesion promoter. Suitable adhesion promoters may comprise a transition metal chelate, a

hydrocarbonoxysilane such as an alkoxysilane, a combination of an alkoxysilane and a hydroxy- functional polyorganosiloxane, an aminofunctional silane, or a combination thereof. Adhesion promoters are known in the art and may comprise silanes having the formula

^R4jj^R^kkSi(OR⁶)4-(jj ₊ kk) where each R⁴ is independently a monovalent organic group having at least 3 carbon atoms; R5 contains at least one SiC bonded substituent having an adhesion- promoting group, such as amino, epoxy, mercapto or acrylate groups; each R⁶ is independently a saturated hydrocarbon group such as an alkyl group of 1 to 4 carbon atoms; subscript jj has a value ranging from 0 to 2; subscript kk is either 1 or 2; and a quantity (jj + kk) is not greater than 3. Alternatively, the adhesion promoter may comprise a partial condensate of the above silane. Alternatively, the adhesion promoter may comprise a combination of an alkoxysilane and a hydroxy-functional polyorganosiloxane.

[0036] Alternatively, the adhesion promoter may comprise an unsaturated or epoxy-functional compound. The adhesion promoter may comprise an unsaturated or epoxy-functional alkoxysilane. For example, the functional alkoxysilane can have the formula R⁷ _mmSi(OR8) 4_ _mm), where subscript mm is 1 , 2, or 3, alternatively subscript mm is 1 . Each R⁷ is

independently a monovalent organic group with the proviso that at least one R⁷ is an unsaturated organic group or an epoxy-functional organic group. Epoxy-functional organic groups for R⁷ are exemplified by 3-glycidoxypropyl and (epoxycyclohexyl)ethyl. Unsaturated organic groups for R⁷ are exemplified by 3-methacryloyloxypropyl, 3-acryloyloxypropyl, and unsaturated monovalent hydrocarbon groups such as vinyl, allyl, hexenyl, undecylenyl. Each

R8 is independently a saturated hydrocarbon group of 1 to 4 carbon atoms, alternatively 1 to 2 carbon atoms. R^ is exemplified by methyl, ethyl, propyl, and butyl.

[0037] Examples of suitable epoxy-functional alkoxysilanes include 3- glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane,

(epoxycyclohexyl)ethyldimethoxysilane, (epoxycyclohexyl)ethyldiethoxysilane,

(epoxycyclohexyl)ethyltrimethoxysilane, (epoxycyclohexyl)ethyltriethoxysilane, and

combinations thereof. Examples of suitable unsaturated alkoxysilanes include

vinyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, hexenyltrimethoxysilane, undecylenyltrimethoxysilane, 3-methacryloyloxypropyl trimethoxysilane, 3- methacryloyloxypropyl triethoxysilane, 3-acryloyloxypropyl trimethoxysilane, 3-acryloyloxypropyl triethoxysilane, and combinations thereof.

[0038] Alternatively, the adhesion promoter may comprise an epoxy-functional siloxane such as a reaction product of a hydroxy-terminated polyorganosiloxane with an epoxy-functional alkoxysilane, as described above, or a physical blend of the hydroxy-terminated

polyorganosiloxane with the epoxy-functional alkoxysilane. The adhesion promoter may comprise a combination of an epoxy-functional alkoxysilane and an epoxy-functional siloxane. For example, the adhesion promoter is exemplified by a mixture of 3- glycidoxypropyltrimethoxysilane and a reaction product of hydroxy-terminated

methylvinylsiloxane with 3-glycidoxypropyltrimethoxysilane, or a mixture of 3- glycidoxypropyltrimethoxysilane and a hydroxy-terminated methylvinylsiloxane, or a mixture of 3-glycidoxypropyltrimethoxysilane and a hydroxy-terminated methylvinyl/dimethylsiloxane copolymer.

[0039] Alternatively, the adhesion promoter may comprise an aminofunctional silane, such as an aminofunctional alkoxysilane exemplified by H2N(CH2)2Si(OCH3)3,

H₂N(CH2)2Si(OCH₂CH3)3, H₂N(CH₂)3Si(OCH3)3, H₂N(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)3Si(OCH3)3, CH₃NH(CH2)3Si(OCH₂CH3)3, CH₃NH(CH₂)5Si(OCH3)3,

CH₃NH(CH2)5Si(OCH₂CH3)3, H₂N(CH2)2 H(CH2)3Si(OCH₃)3,

H₂N(CH2)2 H(CH2)3Si(OCH2CH₃)3, CH₃NH(CH2)2 H(CH2)3Si(OCH₃)3,

CH₃NH(CH2)2 H(CH2)3Si(OCH₂CH3)3, C₄HgNH(CH2)2 H(CH2)3Si(OCH₃)3,

C₄HgNH(CH2)2 H(CH2)3Si(OCH2CH₃)3, H₂N(CH2)2SiCH3(OCH₃)2,

H₂N(CH2)2SiCH3(OCH2CH₃)2, H₂N(CH2)3SiCH3(OCH₃)2, H₂N(CH2)3SiCH3(OCH2CH₃)2, CH₃NH(CH₂)3SiCH3(OCH3)2, CH₃NH(CH2)3SiCH3(OCH₂CH3)2,

CH₃NH(CH2)5SiCH3(OCH₃)2, CH₃NH(CH2)5SiCH3(OCH2CH₃)2,

H₂N(CH2)2 H(CH2)3SiCH3(OCH₃)2, H₂N(CH2)2 H(CH2)3SiCH3(OCH2CH₃)2,

CH₃NH(CH2)2 H(CH2)3SiCH3(OCH₃)2, CH₃NH(CH2)2 H(CH2)3SiCH3(OCH2CH₃)2, C₄HgNH(CH2)2 H(CH2)3SiCH3(OCH₃)2, C₄HgNH(CH2)2 H(CH2)3SiCH3(OCH2CH3)₂, and a combination thereof.

[0040] Alternatively, the adhesion promoter may comprise a transition metal chelate. Suitable transition metal chelates include titanates, zirconates such as zirconium acetyl aceton ate, aluminum chelates such as aluminum acetyl aceton ate, and combinations thereof.

[0041] Alternatively, the adhesion promoter may comprise a triazine based compound that bears functionality to react with starting material I), starting material III) and/or starting material VI). The triazine ring can be mono-, di-, or tri-substituted and at least one of the substitute group is the functionality to react. The functionality can be a free radical reactive one or a

condensation reactive one. Examples of triazine compound with free radical reactive functional groups include triallylisocyanurate, diallylpropylisocyanurate, tri- (methacryloxypropyl)isocyanurate, triallyloxytriazine, trimethacryloxytriazine,

triacryloylhexahydrotriazine, and tris[2-(acryloyloxy)ethyl] isocyanurate. Examples of triazine compound with condensation reactive group include 2,4,6-tris(methyldimethoxysilyl)triazine, and tris[3-(trimethoxysilyl)propyl] isocyanurate.

[0042] The exact amount of adhesion promoter depends on various factors including the type of surface modifier selected and the end use of the composition and its reaction product.

However, the adhesion promoter, when present, may be added to the composition in an amount of 0.01 to 50 weight parts based on combined weight of all starting materials in the composition, alternatively 0.01 to 10 weight parts, and alternatively 0.01 to 5 weight parts. Examples of suitable adhesion promoters are described in U.S. Patent 9,156,948. [0043] The composition may optionally further comprise VIII), a corrosion inhibitor. Examples of suitable corrosion inhibitors include benzotriazole, mercaptobenzothiazole,

mercaptabenzotriazole and commercially available corrosion inhibitors such as 2,5-dimercapto- 1 ,3,4-thiadiazole derivative (CUVAN® 826) and alkylthiadiazole (CUVAN® 484) from R. T. Vanderbilt of Norwalk, Connecticut, U.S.A. Examples of suitable corrosion inhibitors are exemplified by those described in U.S. Patent 9,156,948. When present, the amount of starting material VIII) may be 0.05% to 0.5% based on combined weights of all starting materials in the composition.

[0044] The composition may optionally further comprise up to 5%, alternatively 1 % to 2% based on combined weights of all starting materials in the composition, of starting material IX) a rheology modifier. Rheology modifiers are known in the art and are commercially available. Examples of suitable rheology modifiers include polyamides, hydrogenated castor oil derivatives, metal soaps, microcrystalline waxes, and combinations thereof. Examples of suitable rheology modifiers are exemplified by those described in U.S. Patent 9,156,948. The amount of rheology modifier depends on various factors including the specific rheology modifier selected and the selections of the other starting materials used in the composition. However, the amount of rheology modifier may be 0 parts to 20 parts, alternatively 1 part to 15 parts, and alternatively 1 part to 5 parts based on combined weights of all starting materials in the composition.

[0045] The composition may optionally further comprise starting material X) a free radical initiator. The free radical initiator may comprise an azo compound or an organic peroxide compound. Suitable azo compounds include azobenzene, azobenzene-p-sulfonic acid, azobisdimethylvaleronitrile, azobisisobutyronitrile, and a combination thereof. Suitable organic peroxide compounds include dialkyl peroxides, diaryl peroxides, diacyl peroxides, alkyl hydroperoxides, and aryl hydroperoxides. Specific organic peroxide compounds are

exemplified by benzoyl peroxide; dibenzoyl peroxide; 4-monochlorobenzoyl peroxide; dicumyl peroxide; tert-butylperoxybenzoate; tert-butyl cumyl peroxide; tert-butyloxide 2,5-dimethyl-2,5- di-tert-butylperoxyhexane; 2,4-dichlorobenzoyl peroxide; di-tertbutylperoxy-diisopropyl benzene; 1 ,1 -bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane; 2,5-di-tert-butylperoxyhexane-3,2,5- dimethyl-2,5-bis(tert-butylperoxy) hexane; cumyl-tert-butyl peroxide; or combinations of two or more thereof. The amount of free radical initiator added to the composition depends on various factors including the type and amount of catalyst selected and the selection of other starting materials in the composition, however, the free radical initiator may be present in an amount of 0.1 % to 5%, alternatively 0.2% to 3%, alternatively 0.5% to 2%, based on the combined weights of all starting materials in the composition.

[0046] The composition described above may optionally further comprise starting material XI) a drying agent. The drying agent binds water from various sources. For example, the drying agent may bind by-products of the condensation reaction, such as water and alcohols.

Examples of suitable drying agents are disclosed, for example, in U.S. Patent 9,156,948.

Examples of suitable adsorbents for the drying agent may be inorganic particulates, e.g., zeolites such as chabasite, mordenite, and analcite; molecular sieves such as alkali metal alumino silicates, silica gel, silica-magnesia gel, activated carbon, activated alumina, calcium oxide, and combinations thereof. The adsorbent may have a particle size of 10 micrometers or less. The adsorbent may have average pore size sufficient to adsorb water and alcohols, for example 10 A (Angstroms) or less.

[0047] Alternatively, the drying agent may bind the water and/or other by-products by chemical means. An amount of a silane crosslinker added to the composition (in addition to any silane crosslinker used as starting material XII)) may function as a chemical drying agent.

Without wishing to be bound by theory, it is thought that the chemical drying agent may be added to the dry part of a multiple part composition to keep the composition free from water after the parts of the composition are mixed together. For example, alkoxysilanes suitable as drying agents include vinyltrimethoxysilane, vinyltriethoxysilane, isobutyltrimethoxysilane, and combinations thereof. The amount of drying agent depends on the specific drying agent selected. However, when starting material XI) is a chemical drying agent, the amount may range from 0 parts to 15 parts, alternatively 0 parts to 10 parts, alternatively 0 parts to 5 parts, alternatively 0.1 parts to 0.5 parts, based on combined weights of all starting materials in the composition.

[0048] The composition described above may optionally further comprise starting material XII) a crosslinker. The crosslinker may comprise a silane crosslinker having hydrolyzable groups or partial or full hydrolysis products thereof. The crosslinker has an average, per molecule, of greater than two substituents reactive with the hydrolyzable groups on I) the

polyorganosiloxane. Examples of suitable silane crosslinkers for starting material XII) may have the general formula R²jjSi(R3)(4_jj), where each R² is independently a monovalent hydrocarbon group such as an alkyl group; each R^ is a hydrolyzable substituent, which may be the same as

X described above. Alternatively, each R3 may be, for example, a hydrogen atom, a halogen atom, an acetamido group, an acyloxy group such as acetoxy, an alkoxy group, an amido group, an amino group, an aminoxy group, a hydroxyl group, an oximo group, a ketoximo group, or a methylacetamido group; and each instance of subscript ii may be 0, 1 , 2, or 3. For the silane crosslinker, subscript ii has an average value greater than 2. Alternatively, subscript ii may have a value ranging from 3 to 4. Alternatively, each R3 may be independently selected from hydroxyl, alkoxy, acetoxy, amide, or oxime. Alternatively, the silane crosslinker may be selected from an acyloxysilane, an alkoxysilane, a ketoximosilane, and an oximosilane.

[0049] The silane crosslinker may comprise an alkoxysilane exemplified by a dialkoxysilane, such as a dialkyldialkoxysilane; a trialkoxysilane, such as an alkyltrialkoxysilane; a

tetraalkoxysilane; or partial or full hydrolysis products thereof, or another combination thereof. Examples of suitable trialkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, and a combination thereof, and alternatively methyltrimethoxysilane. Examples of suitable tetraalkoxysilanes include tetraethoxysilane. Alternatively, the silane crosslinker may comprise an acyloxysilane, such as an acetoxysilane. Acetoxysilanes include a tetraacetoxysilane, an organotriacetoxysilane, a diorganodiacetoxysilane, or a combination thereof. Exemplary acetoxysilanes include, but are not limited to, tetraacetoxysilane, methyltriacetoxysilane, ethyltriacetoxysilane, vinyltriacetoxysilane, propyltriacetoxysilane, butyltriacetoxysilane, phenyltriacetoxysilane, octyltriacetoxysilane, dimethyldiacetoxysilane,

phenylmethyldiacetoxysilane, vinylmethyldiacetoxysilane, diphenyl diacetoxysilane,

tetraacetoxysilane, and combinations thereof. Alternatively, ingredient (C) may comprise organotriacetoxysilanes, for example mixtures comprising methyltriacetoxysilane and

ethyltriacetoxysilane. Examples of silanes suitable for starting material XII) containing both alkoxy and acetoxy groups that may be used in the composition include

methyldiacetoxymethoxysilane, methylacetoxydimethoxysilane, vinyldiacetoxymethoxysilane, vinylacetoxydimethoxysilane, methyldiacetoxyethoxysilane, metylacetoxydiethoxysilane, and combinations thereof.

[0050] Alternatively, the crosslinker may comprise an aminofunctional such as

H₂N(CH₂)2Si(OCH3)3, H₂N(CH2)2Si(OCH₂CH3)3, H₂N(CH2)3Si(OCH₃)3,

H₂N(CH2)3Si(OCH₂CH3)3, CH₃NH(CH₂)3Si(OCH₃)3, CH₃NH(CH₂)3Si(OCH₂CH₃)3,

CH₃NH(CH₂)5Si(OCH₃)3, CH₃NH(CH₂)5Si(OCH₂CH₃)3, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₃)₃,

H₂N(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₂NH(CH₂)3Si(OCH₃)3,

CH₃NH(CH₂)₂NH(CH₂)3Si(OCH₂CH₃)3, C₄HgNH(CH₂)₂NH(CH₂)3Si(OCH₃)3,

C₄HgNH(CH₂)₂NH(CH₂)3Si(OCH₂CH₃)3, H₂N(CH₂)₂SiCH₃(OCH₃)₂, H₂N(CH2)2SiCH3(OCH₂CH3)2, H₂N(CH₂)3SiCH3(OCH3)2, H₂N(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)3SiCH3(OCH₃)₂, CH₃NH(CH₂)3SiCH3(OCH₂CH₃)₂,

CH₃NH(CH₂)5SiCH3(OCH₃)₂, CH₃NH(CH₂)5SiCH3(OCH₂CH₃)₂,

H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂,

CH₃NH(CH₂)₂NH(CH₂)3SiCH3(OCH₃)₂, CH₃NH(CH₂)₂NH(CH₂)3SiCH3(OCH₂CH₃)₂, C₄HgNH(CH₂)₂NH(CH₂)3SiCH3(OCH₃)₂, C₄HgNH(CH₂)₂NH(CH₂)3SiCH3(OCH₂CH₃)₂, or a combination thereof, and a combination thereof. Examples of suitable silane crosslinkers are disclosed in U.S. Patent 9,156,948.

[0051] Alternatively, the crosslinker may comprise a multifunctional (meth)acrylate crosslinker, such as a di(meth)acrylate exemplified Such crosslinkers are exemplified by ethylene glycol dimethacrylate, ethylene glycol diacrylate, triethylene glycol dimethacrylate, diethylene glycol bismethacryloxy carbonate, polyethylene glycol diacrylate, tetraethylene glycol dimethacrylate, diglycerol diacrylate, diethylene glycol dimethacrylate, pentaerythritol triacrylate,

trimethylolpropane triglycidyl ether, trimethylolpropane tris(2-methyl-1 -aziridine)propionate, trimethylol propane trimethacrylate, acrylate tipped urethane containing prepolymers, polyether diacrylates, and dimethacrylates, and combinations of two or more thereof. Suitable

multifunctional (meth)acrylate crosslinkers are disclosed, for example, in U.S. Patent 8,304,543 at col. 1 1 lines 46-65.

[0052] When present, the crosslinker may be added in an amount ranging from 0.1 % to 10% based on the combined weights of all starting materials in the composition.

[0053] The composition described above may optionally further comprise XIII) a filler. The filler may comprise a reinforcing filler, an extending filler, a conductive filler, or a combination thereof. For example, the composition may optionally further comprise ingredient (f 1 ), a reinforcing filler, which when present may be added in an amount of 0.1 % to 95%, alternatively 1 % to 60%, based on combined weights of all starting materials in the composition. The exact amount of ingredient (f1 ) depends on various factors including the form of the reaction product of the composition and whether any other fillers are added. Examples of suitable reinforcing fillers include reinforcing silica fillers such as fume silica, silica aerogel, silica xerogel, and precipitated silica. Fumed silicas are known in the art and commercially available; e.g., fumed silica sold under the name CAB-O-SIL by Cabot Corporation of Massachusetts, U.S.A.

[0054] The composition may optionally further comprise ingredient (f2) an extending filler in an amount ranging from 0.1 % to 95%, alternatively 1 % to 60%, and alternatively 1 % to 20%, based on combined weights of all starting materials in the composition. Examples of extending fillers include crushed quartz, aluminum oxide, magnesium oxide, calcium carbonate such as precipitated calcium carbonate, zinc oxide, talc, diatomaceous earth, iron oxide, clays, mica, chalk, titanium dioxide, zirconia, sand, carbon black, graphite, or a combination thereof.

Extending fillers are known in the art and commercially available; such as a ground silica sold under the name MIN-U-SIL by U.S. Silica of Berkeley Springs, WV. Suitable precipitated calcium carbonates included Winnofil® SPM from Solvay and Ultrapflex® and Ultrapflex® 100 from SMI. Examples of suitable fillers are disclosed in U.S. Patent 9, 1 56,948.

[0055] The composition described above may optionally further comprise XIV) a spacer.

Spacers can comprise organic particles, inorganic particles, or a combination thereof. Spacers can be thermally conductive, electrically conductive, or both. Spacers can have a desired particle size, for example, particle size may range from 25 micrometers (μηι) to 125 μηι.

Spacers can comprise monodisperse beads, such as glass or polymer (e.g., polystyrene) beads. Spacers can comprise thermally conductive fillers such as alumina, aluminum nitride, atomized metal powders, boron nitride, copper, and silver. The amount of spacer depends on various factors including the particle size distribution, pressure to be applied during use of the composition prepared by mixing the parts, or the cured product prepared therefrom,

temperature during use, and desired thickness of the mixed composition or the cured product prepared therefrom. However, the composition may contain an amount of spacer of 0.05% to 2%, alternatively 0.1 % to 1 % based on combined weights of all starting materials in the composition.

[0056] The composition described above may optionally further comprise XV) an acid scavenger. Suitable acid scavengers include various inorganic and organic compounds that are basic in nature, such as magnesium oxide, calcium oxide, and combinations thereof. The composition may comprise 0% to 1 0% of acid scavenger based on the combined weights of all starting materials in the composition.

[0057] The composition described above may optionally further comprise XVI) a silanol functional polydiorganosiloxane. Starting material XVI) may comprise a polydiorganosiloxane of the formula HOR2SiO(R2SiO)pp((HO)RSiO)_qqSiR20H, the formula

R3SiO(R2SiO)_rr((HO)RSiO)_ssSiR3, or a combination thereof, where R is as described above.

Subscript pp may be 0 or a positive number. Alternatively, subscript pp has an average value of at least 2. Alternatively subscript pp may have a value ranging from 2 to 2000. Subscript qq may be 0 or a positive number. Alternatively, subscript qq may have an average value ranging from 0 to 2000. Subscript rr may be 0 or a positive number. Alternatively, subscript rr may have an average value ranging from 0 to 2000. Subscript ss has an average value of at least 2. Alternatively subscript ss may have an average value ranging from 2 to 2000.

[0058] Starting material (XVI) may comprise a polydiorganosiloxane such as

i) hydroxy-terminated polydimethylsiloxane,

ii) hydroxy-terminated poly(dimethylsiloxane/methylphenylsiloxane),

iii) trimethylsiloxy-terminated poly(dimethylsiloxane/methylhydroxysiloxane), and

iv) a combination of two or more of i), ii) and iii).

[0059] Hydroxyl-endblocked polydiorganosiloxanes suitable for use as starting material XVI) may be prepared by methods known in the art, such as hydrolysis and condensation of the corresponding organohalosilanes or equilibration of cyclic polydiorganosiloxanes. When added to the composition, starting material (XVI) may be present in an amount of 0.1 % to 20%, alternatively 0.1 % to 10%, and alternatively 0.1 % to 5% based on combined weights of all starting materials in the composition.

[0060] The composition described above may optionally further comprise XVII) an optical brightener. Suitable optical brighteners are known in the art and are commercially available, such as 2,5-thiophenediylbis(5-tert-butyl-1 ,3-benzoxazole), commercially available as TINOPAL OB. When added to the composition, the optical brightener may be present in an amount of 0.1 % to 2% based on combined weights of all starting materials in the composition.

[0061] The composition described above may optionally further comprise a XVIII) chain transfer agent. When added to the composition, the chain transfer agent may be present in an amount of 0.01 % to 5%, alternatively 0.01 % to 2%, and alternatively 0.1 to 2%, based on combined weights of all starting materials in the composition.

[0062] The composition described above may optionally further comprise XIX) a

(meth)acrylate monomer. The (meth)acrylate monomer is exemplified by methylacrylate, butylacrylate, 2-ethylhexylacrylate, isobornylacrylate, terahydrofurfuryl acrylate,

cyclohexylmethylacrylate methylmethacrylate, butylmethacrylate, 2-ethylhexylmethacrylate, isobornylmethacrylate, terahydrofurfuryl methacrylate, and cyclohexylmethylmethacrylate. When added to the composition, the (meth)acrylate monomer may be present in an amount of 0.1 % to 35%, alternatively 0.1 % to 25%, alternatively 0.1 to 15%, and alternatively 0.1 % to 10%, based on combined weights of all starting materials in the composition.

[0063] When selecting starting materials for the composition described above, there may be overlap between types of ingredients because certain ingredients described herein may have more than one function. For example, certain alkoxysilanes may be useful as crosslinkers and/or adhesion promoters and/or drying agents. Certain particulates may be useful as fillers and spacers. When adding additional starting materials to the composition, the additional starting materials are distinct from one another.

[0064] The composition is typically prepared as a multiple part {e.g., 2 part) composition. The composition is such that II) the organoboron compound capable of forming a free radical generating species; and IV) the organoborane liberating compound capable of reacting with the organoboron compound to form the free radical generating species are stored in separate parts. The parts can be combined, e.g., by mixing, shortly before use. For example, a two part curable composition may be prepared by mixing starting materials comprising I), II), and III), described above to form Part A), the first part. All or a portion of starting material VI) may be added to the first part. The second part, Part B), may be prepared by mixing starting materials comprising IV) and V), described above. All or a portion of starting material VI) may be added to the second part. The starting materials may be combined at ambient or elevated temperature and under ambient or anhydrous conditions, depending on various factors including ambient temperature and relative humidity. Part A), Part B, and, if any, the separate additional part may be combined by any convenient means, such as mixing, shortly before use. Part A and Part B may be combined in relative amounts of Part B) : Part A) of 1 :1 to 10:1 , alternatively 1 :1 to 4:1 , alternatively 1 :1 to 2:1 . Please confirm the ranges for the ratios.

[0065] The equipment used for mixing the ingredients is not specifically restricted. Examples of suitable mixing equipment may be selected depending on the type and amount of each ingredient selected. For example, agitated batch kettles may be used for relatively low viscosity compositions, such as compositions that would react to form gums or gels. Alternatively, continuous compounding equipment, e.g., extruders such as twin screw extruders, may be used for more viscous compositions and compositions containing relatively high amounts of particulates. Exemplary methods that can be used to prepare the compositions described herein include those disclosed in, for example, U.S. Patent Publications US 2009/0291238 and US 2008/0300358.

[0066] These compositions made as described above may be stable when the parts are stored in containers that protect the parts from exposure to moisture, but these compositions may react via condensation reaction when exposed to atmospheric moisture.

[0067] The composition described above may be contacted with a substrate using

conventional equipment, such as a dispenser exemplified by those in U.S. Patents 4,538,920 and 5,082,147. The dispenser may comprise a pair of tubular receptacles adjacent one another. One receptacle may contain Part A and the other may contain Part B, as described above. Each receptacle may be fitted with a plunger, and the plungers may be concurrently advanced to evacuate the contents of the receptacles into a common mixing chamber, optionally containing a static mixer to facilitate mixing Parts A and B. The resulting mixture may be extruded from the mixing chamber onto the substrate.

[0068] The multiple part composition described above may be used for various applications, such as coatings, adhesives, and composites. For example, a method comprises: contacting a substrate with a curable composition prepared by mixing starting materials comprising:

I) a polyorganosiloxane having an average of at least two silicon bonded hydrolyzable groups per molecule,

II) an organoboron compound capable of forming free radical generating species,

III) a poly(meth)acrylate clustered functional polyorganosiloxane, comprising units of formulae:

(R2R¹ Si0₁/2)aa(RR¹ Si02/2)bb(R2Si02/2)cc(RSi0₃/2)dd(Si04/2)ee((Rff)0(3- ff)/2SiD¹ SiRffO(3_ff)/2)gg_> where each D¹ independently represents a divalent hydrocarbon group of 2 to 18 carbon atoms; each R independently represents a monovalent hydrocarbon group of 1 to 18 carbon atoms, each R¹ independently represents a methacryl-functional alkyl group or an acryl-functional alkyl group, subscript aa≥ 0, subscript bb≥ 0, a quantity (aa + bb)≥ 4, subscript cc > 0, subscript dd≥ 0, subscript ee≥ 0, subscript ff is 0, 1 , or 2, subscript gg≥ 2;

IV) an organoborane liberating compound capable of reacting with the organoboron compound to form the free radical generating species,

V) a condensation reaction catalyst, and

VI) an organosilicon compound having, per molecule, at least one hydrolyzable group and at least one free radical reactive group. Starting material II) the organoboron compound capable of forming free radical generating species, and starting material IV) the organoborane liberating compound are kept separate until initiation is desired, e.g., by mixing Part A) and Part B) (and, if any, a separate additional part) as described above. The curable composition may cure to form a coating on the substrate. Alternatively, the method may further comprise: 3) contacting the curable composition with at least one other substrate, thereby adhering the substrates together. The curable composition may be cured to form an adhesive for adhering two or more substrates together. The curable composition does not require external heating to cure. The curable composition may cure at room temperature of 25°C. However, the method may optionally further comprise a post curing step 4) after step 2) or step 3) described above, wherein the composition is heated at a temperature of 150°C or less, alternatively 125°C or less.

[0069] Low surface energy plastics such as polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA), polystyrene (PS), and copolymers thereof may be used as a substrate in the method described above. Other plastics suitable for the substrate include acrylonitrile- butadiene-styrene copolymer (ABS), polyvinyl chloride (PVC), polycarbonate (PC), epoxies, polyimides (PI), poly(phenyleneoxide), polyphthalamides, polymethylmethacrylate (PMMA), and combinations thereof may also be used.

EXAMPLES

[0070] These examples are intended to illustrate some embodiments of the invention and should not be interpreted as limiting the scope of the invention set forth in the claims. The following starting materials were used in the examples.

Table 1 - Starting Materials

Abbreviation Chemical Name or Source Function

CF siloxane Tris(methacryloxypropyl) terminated Polyacrylate clustered

polydimethylsiloxane (PDMS) with degree of functional polymerization (DP) of 770, which is a polyorganosiloxane III) hydrosilylation reaction product of

tetramethylcyclotetrasiloxane (D4H) with

vinyl-terminated PDMS, subsequently

hydrosilylated with allyloxymethacrylate to the

hydrogens on the D4H

Hydrolyzable Trimethoxysilylethyl terminated PDMS treated Polyorganosiloxane having Siloxane 1 silica and polydimethylsiloxane mixture hydrolyzable groups I)

Hydrolyzable Trimethoxysilylethyl terminated PDMS Polyorganosiloxane having Siloxane 2 hydrolyzable groups I)

Tinopal OB 2,5-thiophenediylbis(5-tert-butyl-1 ,3- Fluorescent brightener XVII) benzoxazole)

BPO paste Dibenzoyl Peroxide (BPO) delivered 50% in Free radical initiator X) polydimethylsiloxane

IPDA Isophorone Diamine Complexing

agent/complexing amine for the organoborane

IPDI Isophorone Diisocyanate Liberating compound for organoborane-amine complex IV)

PDA 1 ,3 Propylene diamine Complexing

agent/complexing amine for the organoborane

TnBB Tri-n-butyl borane Organoborane

TnBB-IPDA TnBB-IPDA complex, solventless, containing Organoborane amine

3.6% boron. complex II)

MOPA 3-methoxypropyl amine Complexing

agent/complexing amine for the organoborane

TnBB-MOPA TnBB-MOPA complex, solventless, containing Organoborane - amine

3.6 wt.% boron complex II)

TEB Triethylborane Organoborane

(organoborane initiator)

TEB-PDA TEB-PDA complex, solventless, containing Organoborane - amine

5.4 wt.% boron complex II)

Z-601 1 3-aminopropyl triethoxysilane Complexing agent for the alkylborane and also acts as condensation reactive species/ crosslinkable complexing agent

TEB-Z-601 1 TEB-Z-601 1 complex, solventless, containing Organoborane amine

3.0 wt.% boron complex II) Abbreviation Chemical Name or Source Function

Meth acrylic Meth acrylic acid Liberating agent IV) acid

PBT 30% glass fiber filled PBT injection molded Substrate for testing

into 25.4 x 200 x 3 mm strips adhesion strength.

Cabosil TS- A dimethylsilicone treated fumed silica from Filler

720 Cabot Corporation.

Reference Example 1 - Sample Preparation and Test Methods

[0071] Starting materials were weighed into a mixer cup of appropriate size, hand stirred to pre-mix them together, then mixed on a FlackTek SpeedMixer (model DAC 150.1 FVZ.K) for 1 minute at 2000 revolutions per minute (rpm).

[0072] With two part compositions, the two separate parts were hand transferred into the two barrels of either a 10:1 ratio or 4:1 ratio two part adhesive cartridge of appropriate size, 60 g capacity, with a Bayonet connection. Once the materials are loaded into the cartridge and barrels are capped, it is vibrated briefly on a table to help eliminate trapped air pockets. A 74 mm long mixing nozzle was then fitted onto the cartridge.

[0073] PBT strips were cleaned with isopropanol (IPA) and dried in air. On one side of the strip, a distance half an inch away from the end was marked. The adhesive composition was applied to the other side. With a dispensing gun, an appropriate amount of adhesive

composition was dispensed on the unmarked side of the PBT strip directly opposite the marked area on the back side. Another PBT strip was placed on the adhesive composition to overlap the marked area, and the resulting assembly was clamped with spring clamp applying 50 pounds (lb) of force. The squeezed out excess adhesive was cleaned off, and the assembled samples were left in a ventilated hood to cure for desired length of time at room temperature, and then tested promptly.

[0074] For some samples, after a desired length of curing time, they were placed in a ventilated oven set at 125°C, and heated in air for 20 minutes to see the effect of further cure, or at 150°C, and heated in air for 72 hours to check the effect of accelerated aging.

[0075] The above prepared lap shear test specimens were loaded onto the clamps of a MTS Alliance RT/5 testing frame using a 2000 Newton (N) load cell. The testing speed was 25.4 mm/min. The peak load was recorded and divided by the overlapping area of the lap shear specimens to calculate the adhesion strength. The tested specimens were examined visually to determine the mode of failure, cohesive or adhesive. Compositions tested and results are in the tables below. Comparison Example 1 . (1 -part, different curing mechanism)

[0076] The starting materials in Table 2 were mixed in the order listed to become a one part composition. This composition was applied onto PBT strips as described above in Reference Example 1 , and lap shear specimens were prepared. The specimens were cured in an air circulating oven at 100 °C for 30 minutes.

Table 2. Formulation for Comparison Example 1 .

[0077] Samples according to the invention were prepared and tested according to Reference Example 1 . The starting materials and test results are below in Tables 3-1 1 .

Ό078] Table 3. Formulation for Example 1 .

Starting Material Wt., g Starting Material Wt., g

Part A Part B

A1 1 10 0.023 A186 0.125

MBT 0.032 TBT 0.129

IBTMS 0.023 IBTMS 0.392

Z-6030 0.418 TAIC 0.104

Hydrolyzable Siloxane 1 4.102 CF Siloxane 9.520

CF Siloxane 5.694 Hydrolyzable Siloxane 2 0.021

TnBB-IPDA Complex 0.791 Tinopal OB 0.004

Glass Beads 249 micrometers (urn) 0.412 IPDI 1 .108

Glass Beads 249 urn 0.103

Total Part A 1 1 .495 Total Part B 1 1 .508 Table 4. Formulation for Example 2.

Starting Material Wt., g Starting Material Wt., g

Part A Part B

Cabosil TS-720 0.307 DBTDA 0.086

A1 1 10 0.035 TAIC 0.156

A186 0.1876 Hydrolyzable Siloxane 1 5.875

MBT 0.0477 CF Siloxane 22.810

IBTMS 0.6233 Hydrolyzable Siloxane 2 0.032

Z-6030 0.6265 Tinopal OB 0.006

Hydrolyzable Siloxane 1 0.275 IPDI 1 .662

TnBB-IPDA 1 .1858 Glass Beads 249um 0.515

Total Part A 3.1 18 Total Part B 31 .142

0080] Table 5. Formulation for Example 3.

Starting Material Wt., g Starting Material Wt., g

Part A Part B

Cabosil TS-720 0.280 DBTDA 0.086

A1 1 10 0.035 TAIC 0.156

A186 0.188 Hydrolyzable Siloxane 1 1 .915

MBT 0.048 CF Siloxane 23.180

IBTMS 0.623 Hydrolyzable Siloxane 2 0.032

Z-6030 0.627 Tinopal OB 0.006

Hydrolyzable Siloxane 1 4.235 Met acrylic Acid 0.643

TnBB-MOPA 0.593 Glass Beads 249 urn 0.515

Total Part A 6.640 Total Part B 26.534

Ό081] Table 6. Formulation for Example 4.

Starting Material Wt., g Starting Material Wt., g

Part A Part B

Cabosil TS-720 0.488 DBTDA 0.128

A1 1 10 0.053 TAIC 0.234

A186 0.281 Hydrolyzable Siloxane 1 3.855

MBT 0.072 CF Siloxane 34.770

IBTMS 0.935 Hydrolyzable Siloxane 2 0.048

Z-6030 0.940 Tinopal OB 0.010

Hydrolyzable Siloxane 1 5.370 IPDI 0.974

TEB-Z-601 1 2.105 Glass Beads 249 urn 0.773 Total Part A 10.243 Total Part B 40.792

Table 7. Formulation for Example 5.

Starting Material Wt., g Starting Material Wt., g

Part A Part B

Cabosil TS-720 0.000 Premix 2 0.505

Premix 3 0.053 Premix 4 0.587

Premix 1 0.176 Hydrolyzable Siloxane 1 0.383

MBT 0.000 CF Siloxane 17.385

IBTMS 0.000 Hydrolyzable Siloxane 2 0.024

Z-6030 0.000 Tinopal OB 0.005

Hydrolyzable Siloxane 1 4.230 IPDI 0.768

TEB-PDA 0.558 Glass Beads 249 urn 0.387

Total Part A 5.017 Total Part B 20.043

0083] Table 8. Formulation for Example 6.

Starting Material Wt., g Starting Material Wt., g

Part A Part B

Cabosil TS-720 0.000 Premix 2 0.505

Premix 3 0.053 Premix 4 0.587

Premix 1 0.176 Hydrolyzable Siloxane 1 0.188

MBT 0.000 CF Siloxane 17.385

IBTMS 0.000 Hydrolyzable Siloxane 2 0.024

Z-6030 0.000 Tinopal OB 0.005

Hydrolyzable Siloxane 1 4.425 IPDI 0.248

TEB-PDA 0.180 Glass Beads 249 urn 0.387

Total Part A 4.834 Total Part B 19.328

Ό084] Table 9. Formulation for Example 7.

Starting Material Wt., g Starting Material Wt., g

Part A Part B

Cabosil TS-720 0.000 Premix 2 0.505

Premix 3 0.053 Premix 4 0.587

Premix 1 0.176 Hydrolyzable Siloxane 1 0.1 16

MBT 0.000 CF Siloxane 17.385

IBTMS 0.000 Hydrolyzable Siloxane 2 0.024

Z-6030 0.000 Tinopal OB 0.005

Hydrolyzable Siloxane 1 4.500 IPDI 0.248

TEB-PDA 0.180 Glass Beads 249 urn 0.387 BPO 0.362

Total Part A 4.909 Total Part B 19.619

Industrial Applicability

[0086] Plastics such as those described above, particularly low surface energy plastics, are used in various applications such vehicle (e.g., automobile) parts. It can be difficult to find compositions that form cured products such as coatings and/or adhesives, that bond to these plastics. The examples herein show that the composition and method described herein can be used to form adhesives with good adhesion to plastics, as shown by lap shear strength test results.

[0087] Table 1 1 - Lap Shear Strength measured at different cure conditions for the samples prepared above

Cure Comparative Example 1 Example Example Example Example Example Example Example Schedule Example 1 2 3 4 5 6 7 8

100°C/30 334.8 +/- 25.4 Not Not Not Not Not Not Not Not min std applicable applicable applicable applicable applicable applicable applicable applicable TRC Cure

5 min/RT + Not applicable Not Not Not 31 .8 Not Not Not Not 125 C 20 applicable applicable applicable applicable applicable applicable applicable min post

cure

1 hour/ RT Not applicable 26.3 +/- 1 .1 63.5 +/- 18.6 +/- 31 .3 +/- 70.2 63.9 +/- 39.4 +/- 19.8 +/- 23.9 2.7 7.8 9.0 10.3 6.9

24 hour/ RT Not applicable 123.5 +/- Not Not 134.3 +/- Not 175.8 +/- 209.8 +/- 120.0 +/- 17.7 applicable applicable 1 1 .8 applicable 2.4 7.5 3.6

+125°C, Not applicable Not Not Not Not Not Not 310.2 290.0 20 min post applicable applicable applicable applicable applicable applicable

cure

+150C, Not applicable Not Not Not Not Not Not 357.7 +/- 359.7 +/- 72 hour applicable applicable applicable applicable applicable applicable 73.3 36.0 aging

% change Not applicable Not Not Not Not Not Not 79.08 199.75 after aging applicable applicable applicable applicable applicable applicable

2 weeks/ 395.4 +/- 95.2 227.1 +/- 343.5 +/1 120.4 227.7 +/- 367.1 +/- Not 400.8 +/- 237.7 +/- RT 15.1 60.8 29.1 18.2 applicable 48.2 36.5

[0088] All amounts, ratios, and percentages are^' by weight unless otherwise indicated. The articles 'a', 'an', and 'the' each refer to one or more, unless otherwise indicated. The disclosure of ranges includes the range itself and also anything subsumed therein, as well as endpoints. For example, disclosure of a range of 2.0 to 4.0 includes not only the range of 2.0 to 4.0, but also 2.1 , 2.3, 3.4, 3.5, and 4.0 individually, as well as any other number subsumed in the range. Furthermore, disclosure of a range of, for example, 2.0 to 4.0 includes the subsets of, for example, 2.1 to 3.5, 2.3 to 3.4, 2.6 to 3.7, and 3.8 to 4.0, as well as any other subset subsumed in the range. Similarly, the disclosure of Markush groups includes the entire group and also any individual members and subgroups subsumed therein. For example, disclosure of the Markush group a hydrogen atom, an alkyl group, an alkenyl group, or an aryl group, includes the member alkyl individually; the subgroup alkyl and aryl; and any other individual member and subgroup subsumed therein.

[0089] "Alkyl" means a saturated monovalent hydrocarbon group. Alkyl is exemplified by, but not limited to, methyl, ethyl, propyl {e.g., iso-propyl and/or n-propyl), butyl {e.g., isobutyl, n-butyl, tert-butyl, and/or sec-butyl), pentyl {e.g., isopentyl, neopentyl, and/or tert-pentyl); hexyl, heptyl, octyl, nonyl, and decyl, as well as branched saturated monovalent hydrocarbon groups of 6 or more carbon atoms.

[0090] "Alkenyl" means a monovalent hydrocarbon group containing a double bond. Alkenyl groups are exemplified by, but not limited to, ethenyl, propenyl {e.g., iso-propenyl and/or n- propenyl), butenyl {e.g., isobutenyl, n-butenyl, tert-butenyl, and/or sec-butenyl), pentenyl {e.g., isopentenyl, n-pentenyl, and/or tert-pentenyl), hexenyl, heptenyl, octenyl, nonenyl, and decenyl, as well as such branched groups of 6 or more carbon atoms.

[0091] "Alkynyl" means a monovalent hydrocarbon group containing a triple bond. Alkynyl groups are exemplified by, but not limited to, ethynyl, propynyl {e.g., iso-propynyl and/or n- propynyl), butynyl {e.g., isobutynyl, n-butynyl, tert-butynyl, and/or sec-butynyl), pentynyl {e.g., isopentynyl, n-pentynyl, and/or tert-pentynyl), hexynyl, heptynyl, octynyl, nonynyl, and decynyl, as well as such branched groups of 6 or more carbon atoms.

[0092] "Aryl" means a cyclic, fully unsaturated, hydrocarbon group. Aryl is exemplified by, but not limited to, cyclopentadienyl, phenyl, anthracenyl, and naphthyl. Monocyclic aryl groups may have 5 to 9 carbon atoms, alternatively 6 to 7 carbon atoms, and alternatively 5 to 6 carbon atoms. Polycyclic aryl groups may have 10 to 18 carbon atoms, alternatively 10 to 14 carbon atoms, and alternatively 12 to 14 carbon atoms. [0093] "Aralkyl" means an alkyi group having a pendant and/or terminal aryl group or an aryl group having a pendant alkyi group. Exemplary aralkyl groups include tolyl, xylyl, benzyl, phenylethyl, phenyl propyl, and phenyl butyl.

[0094] "Carbocycle" and "carbocyclic" each mean a hydrocarbon ring. Carbocycles may be monocyclic or alternatively may be fused, bridged, or spiro polycyclic rings. Monocyclic carbocycles may have 3 to 9 carbon atoms, alternatively 4 to 7 carbon atoms, and alternatively 5 to 6 carbon atoms. Polycyclic carbocycles may have 7 to 18 carbon atoms, alternatively 7 to 14 carbon atoms, and alternatively 9 to 10 carbon atoms. Carbocycles may be saturated or partially unsaturated.

[0095] "Cycloalkyi" means saturated carbocycle. Monocyclic cycloalkyi groups are exemplified by cyclobutyl, cyclopentyl, and cyclohexyl.

[0096] Collectively, the term "monovalent hydrocarbon group" includes alkyi, alkenyl, aryl, aralkyl, and carbocyclic groups, as defined above.

[0097] "Divalent hydrocarbon group" includes alkylene groups such as ethylene, propylene (including isopropylene and n-propylene), and butylene (including n-butylene, t-butylene and isobutylene); and pentylene, hexylene, heptylene, octylene, and branched and linear isomers thereof; arylene groups such as phenylene; and alkaralkylene groups such as:

Alternatively, each divalent hydrocarbon group may be ethylene, propylene, butylene or hexylene. Alternatively, each divalent hydrocarbon group may be ethylene or propylene.

[0098] "Halogenated hydrocarbon" means a hydrocarbon group as defined above, but where one or more hydrogen atoms bonded to a carbon atom have been formally replaced with a halogen atom. For example, monovalent halogenated hydrocarbon groups can be any one of alkyi, alkenyl, aryl, aralkyl, and carbocyclic groups in which one or more hydrogen atoms bonded to a carbon atom have been replaced with a halogen atom. Monovalent halogenated hydrocarbon groups include haloalkyi groups, halogenated carbocyclic groups, and haloalkenyl groups. Halogenated alkyi groups include fluorinated alkyi groups such as trifluoromethyl (CF3), fluoromethyl, trifluoroethyl, 2-fluoropropyl, 3,3,3-trifluoropropyl, 4,4,4-trifluorobutyl, 4,4,4,3,3- pentafluorobutyl, 5,5,5,4,4, 3, 3-heptafluoropentyl, 6,6, 6,5,5,4,4,3, 3-nonafluorohexyl, and

8,8,8,7,7-pentafluorooctyl; and chlorinated alkyi groups such as chloromethyl and 3- chloropropyl. Halogenated carbocyclic groups include fluorinated cycloalkyi groups such as 2,2- difluorocyclopropyl, 2,3-difluorocyclobutyl, 3,4-difluorocyclohexyl, and 3,4-difluoro-5- methylcycloheptyl; and chlorinated cycloalkyi groups such as 2,2-dichlorocyclopropyl, 2,3- dichlorocyclopentyl. Halogenated alkenyl groups include chloro allyl.

Claims

Claims:

1 . A multiple part composition comprising:

A) a first part comprising

I) a polyorganosiloxane having an average of at least two silicon bonded hydrolyzable groups per molecule, and

II) an organoboron compound capable of forming free radical generating species;

B) a second part comprising

III) a poly(meth)acrylate clustered functional polyorganosiloxane comprising units of formulae: (R₂R¹ Si0_{1 /2})_aa(RR¹ Si02/2)bb(R2Si02/2)cc(RSi0₃/2)dd(Si04/2)ee((Rff)0(3- ff)/2SiD¹ SiRffO(3_ff)/2)gg_> where each D¹ independently represents a divalent hydrocarbon group of 2 to 18 carbon atoms; each R independently represents a monovalent hydrocarbon group of 1 to 18 carbon atoms, each R¹ independently represents a methacryl-functional alkyl group or an acryl-functional alkyl group, subscript aa≥ 0, subscript bb≥ 0, a quantity (aa + bb)≥ 4, subscript cc > 0, subscript dd≥ 0, subscript ee≥ 0, subscript ff is 0, 1 , or 2, subscript gg≥ 2;

IV) an organoborane liberating compound capable of reacting with the organoboron compound to form the free radical generating species, and

V) a condensation reaction catalyst;

where the multiple part composition further comprises VI) an organosilicon compound having, per molecule, at least one hydrolyzable group and at least one free radical reactive group.

2. The composition of claim 1 , where the multiple part composition further comprises one or more additional starting materials selected from the group consisting of: VII) an adhesion promoter, VIII) a corrosion inhibitor, IX) a rheology modifier, X) a free radical initiator, XI) a drying agent, XII) a crosslinker, XIII) a filler, XIV) a spacer, XV) an acid scavenger, XVI) a silanol functional polydiorganosiloxane, XVII) a fluorescent optical brightener, XVIII) a chain transfer agent, XIX) a (meth)acrylate monomer, and two or more of or two or more of VII), VIII), IX), X), XI), XII), XIII), XIV), XV), XVI), XVII), XVIII), and XIX).

3. The composition of claim 1 or claim 2, where I) the polyorganosiloxane has unit formula:

_Cj(R2Si02/2)e(^RSi03/2)f(Si04/2)g, where each R is independently a monovalent hydrocarbon group of 1 to 18 carbon atoms, each D independently represents an oxygen atom or a divalent hydrocarbon group of 2 to 18 carbon atoms; each X independently represents a hydrolyzable group selected from an acetamido group, an acyloxy group such as acetoxy, an alkoxy group, an amido group, an amino group, an aminoxy group, an oximo group, a ketoximo group, and a methylacetamido group; subscript c represents 0, 1 , 2, or 3; subscript a represents 0, 1 , or 2; and subscript b has a value of 0 or greater, with the proviso that a quantity (a + c) is at least 1 ; subscript d > 0; subscript e > 0, subscript f≥ 0, and subscript g≥ 0.

4. The composition of claim 1 or claim 2, where II) the organoboron compound capable of forming free radical generating species is selected from the group consisting of: a) an organoborane - organonitrogen compound complex,

b) an organoborate containing at least one boron-carbon bond , and c) both a) the organoborane - organonitrogen compound complex and

organoborate containing at least one boron-carbon bond;

5. The composition of claim 1 or claim 2, where III) the poly(meth)acrylate clustered functional polyorganosiloxane is a hydrosilylation reaction product of starting materials comprising

a) a polyorganosiloxane having an average of at least two silicon bonded aliphatically unsaturated groups per molecule;

b) an organohydrogensiloxane having an average of 4 to 15 silicon atoms per molecule, where component b) has silicon bonded hydrogen atoms;

with the proviso that a molar ratio of aliphatically unsaturated groups in starting material a) to silicon bonded hydrogen atoms in starting material b) is 1 to 3 to 1 to 20; and

c) a reactive species having, per molecule, at least one aliphatically unsaturated group and one or more radical curable groups selected from acrylate functional groups and methacrylate functional groups.

6. The composition of claim 1 or claim 2, where III) the clustered functional polyorganosiloxane has formula:

, where each

independently represents a divalent hydrocarbon group of 2 to 18 carbon atoms; each R is independently a monovalent hydrocarbon group of 1 to 18 carbon atoms, each R¹ is a methacryl-functional alkyl group or an acryl-functional alkyl group, subscript j is 0 to 2,000,000, and each subscript k is independently 1 to 12.

7. The composition of claim 1 or claim 2, where IV) the organoborane liberating compound is selected from: i) an acid, ii) an aldehyde, iii) an isocyanate, iv) an epoxide, v) an acid chloride, vi) an anhydride, vii) an acyloxysilane, viii) an acyloxysiloxane, ix) a halosilane, x) a

halosiloxane, xi) a carboxylic acid functional silane, xii) a carboxylic acid functional siloxane, xiii) an anhydride functional silane, xiv) an anhydride functional siloxane, xv) an epoxy functional silane, xvi) an epoxy functional siloxane, xvii) a sulphonyl chloride, and a combination of two or more of i), ii), iii), iv), v), vi), vii), viii), ix), x), xi), xii), xiii), xiv), xv), xvi), and xvii).

8. The composition of claim 1 or claim 2, where V) the condensation reaction catalyst is selected from an organotin compound, an organotitanium compound, an organozinc, and an organozirconium compound.

9. The composition of claim 1 or claim 2, where VI) the organosilicon compound having, per molecule, at least one hydrolyzable group and at least one free radical reactive group is a silane of formula R¹ m^RnSiX(4-m-n)' where each R is independently a monovalent hydrocarbon group of 1 to 18 carbon atoms, each R¹ is a methacryl-functional alkyl group or an acryl-functional alkyl group, each X independently represents a hydrolyzable group selected from an acetamido group, an acyloxy group such as acetoxy, an alkoxy group, an amido group, an amino group, an aminoxy group, an oximo group, a ketoximo group, and a methylacetamido group, subscript m is 1 to 2, subscript n is 0 to 2, and a quantity (m + n) is 2 to 3.

10. The composition of claim 1 or claim 2, where VI) the organosilicon compound having, per molecule, at least one hydrolyzable group and at least one free radical reactive group is a polyorganosiloxane of unit formula:

(X_CR3- _cSiO_{1 /}2)0( ¹ 2SiO_{1 /}2)p(R2SiO2/2)q( XSiO2/2)r(R¹ RSiO2/2)s(R¹ SiO3_/2)_w(RSiO_3/2)t(SiO4_/2 )_u, where each R is independently a monovalent hydrocarbon group of 1 to 18 carbon atoms, each R¹ is a methacryl-functional alkyl group or an acryl-functional alkyl group, each X independently represents a hydrolyzable group selected from an acetamido group, an acyloxy group such as acetoxy, an alkoxy group, an amido group, an amino group, an aminoxy group, an oximo group, a ketoximo group, and a methylacetamido group, subscript o≥ 0, subscript p≥ 0, subscript q > 0, subscript r≥ 0, subscript s≥ 0, subscript w > 0, subscript t≥ 0, and subscript u≥ 0, with the provisos that a quantity (o + r)≥ 1 , a quantity (p + s + w)≥ 1 , and a quantity (o + p + q + r + s + w + t + u) > 2.

1 1 . A method comprising: contacting a substrate with a curable composition prepared by mixing starting materials comprising:

I) a polyorganosiloxane having an average of at least two silicon bonded hydrolyzable groups per molecule,

II) an organoboron compound capable of forming free radical generating species,

III) a poly(meth)acrylate clustered functional polyorganosiloxane, comprising units of formulae:

(R2R¹ Si0_{1 /}2)aa(RR¹ Si02/2)bb(R2Si0₂/2)cc(RSi03/2)dd(Si04/2)ee((Rff)0(3- ff 2SiD¹ SiRffO(3_ff)/2)gg_> where each D¹ independently represents a divalent hydrocarbon group of 2 to 18 carbon atoms; each R independently represents a monovalent hydrocarbon group of 1 to 18 carbon atoms, each R¹ independently represents a methacryl-functional alkyl group or an acryl-functional alkyl group, subscript aa≥ 0, subscript bb≥ 0, a quantity (aa + bb)≥ 4, subscript cc > 0, subscript dd≥ 0, subscript ee≥ 0, subscript ff isO, 1 , or 2, subscript gg≥ 2;

IV) an organoborane liberating compound capable of reacting with the organoboron compound to form the free radical generating species, V) a condensation reaction catalyst, and

VI) an organosilicon compound having, per molecule, at least one hydrolyzable group and at least one free radical reactive group.

12. The method of claim 1 1 , where II) organoboron compound capable of forming free radical generating species, and IV) the organoborane liberating compound are kept separate until initiation is desired.

13. The method of claim 1 1 or claim 12, where the curable composition cures to form a coating on the substrate.

14. The method of claim 1 1 or claim 12, further comprising 3) contacting the curable

composition with at least one other substrate, thereby adhering the substrates together.

15. The method of claim 1 1 or claim 12, where the starting materials further comprise one or more additional starting materials selected from the group consisting of: VII) an adhesion promoter, VIII) a corrosion inhibitor, IX) a rheology modifier, X) a free radical initiator, XI) a drying agent, XII) a crosslinker, XIII) a filler, XIV) a spacer, XV) an acid scavenger, XVI) a silanol functional polydiorganosiloxane, XVII) a fluorescent optical brightener, XVIII) a chain transfer agent, XIX) a (meth)acrylate monomer, and two or more of or two or more of VII), VIII), IX), X), XI), XII), XIII), XIV), XV), XVI), XVII), XVIII), and XIX).