Cyclic aminal – functional organosilicon compounds and synthesis thereof

Abstract

A cyclic aminal – functional organosilicon compound and method for preparation thereof are provided. The cyclic aminal – functional organosilicon compound may be used as an additive in a curable siloxane composition.

Description

CYCLIC AMINAL – FUNCTIONAL ORGANOSILICON COMPOUNDS AND SYNTHESIS THEREOF CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefits of U.S. Provisional Patent Application No. 63 / 655,635 and U.S. Provisional Patent Application No.63 / 655,636 both filed June 4, 2024 under 35 U.S.C. §119 (e). U.S. Provisional Patent Application No.63 / 655,635 and U.S. Provisional Patent Application No.63 / 655,636 are hereby incorporated by reference. FIELD

[0002] A cyclic aminal – functional organosilicon compound and method for its preparation are disclosed. The cyclic aminal – functional organosilicon compound may be used as an adhesion promoter. INTRODUCTION

[0003] Degradable thermosets based on imine dynamic bonds were prepared by amine aldehyde condensation. Terephthaldehyde and various diamines were used as monomers, and triethylenetetramine was selected as a cross-linker to prepare the degradable polyaminal. However, no organosilicon compounds have been provided via this method. SUMMARY

[0004] A cyclic aminal – functional organosilicon compound comprises: a silicon bonded cyclic aminal moiety of , where D1is a divalent hydrocarbyl group of 2D3is a divalent linking group comprising at least one carbon atom, R2and R3are each independently selected from the group consisting of H, a monovalent hydrocarbyl group, a monovalent substituted hydrocarbyl group, and an organosilicon moiety.

[0005] A method for synthesizing the cyclic aminal - functional organosilicon compound described above comprises: 1) combining starting materials comprising A) a di- or tri- amine compound, and B) an aldehyde-functional organosilicon compound.

[0006] The cyclic aminal – functional organosilicon compound may be used as an additive in a silicone composition, e.g., as an adhesion promoter.DETAILED DESCRIPTION

[0007] The cyclic aminal – functional organosilicon compound comprises: a cyclic aminal moiety covalently bonded to a silicon atom in the organosilicon compound, D3NR3wherein the cyclic aminal moiety has , wherein D1is a divalent hydrocarbyl group of 2 to 8 carbon group comprising at 23least 1 carbon atom; and R and R are each the group consisting of H, a monovalent hydrocarbyl group, a monovalent substituted hydrocarbyl group, and an organosilicon moiety. The organosilicon moiety for R2and / or R3may be an alkoxysilyl moiety of formula , wherein subscript a is 1, or 2 or 3; D2is adivalent group atoms; and R1is an alkyl group of 1 to 6 carbon atoms. The cyclic aminal – functional organosilicon compound has at least one cyclic aminal moiety per molecule. Alternatively, the cyclic aminal – functional organosilicon compound may have two or more cyclic aminal moieties per molecule.

[0008] In formula (I) shown above, D1is a divalent hydrocarbyl group of 2 to 8 carbon atoms. Alternatively D1may have 2 to 6 carbon atoms, and alternatively 2 to 4 carbon atoms. D1may be linear, branched, cyclic or a combination thereof. Alternatively, D1may be an alkylene group, such ethylene, propylene, butylene, hexylene, or octylene; an arylene group such as phenylene; or an alkylarylene group such as: H2H H21 . Alternatively, each Dpropylene; and alternatively each D1may be ethylene.

[0009] In formula (I) shown above, D3is a divalent linking group comprising at least 1 carbon atom, alternatively 2 to 8 carbon atoms. D3may be a divalent hydrocarbyl group such as an alkylene group; or a 1,2- substituted arylene group. Alternatively, D3may be an alkylene groupsuch as ethylene, propylene, or butylene (exemplified by n-butylene and t-butylene). H H H Alternatively, D3may have , wherein each R’ and each R” are independently selected from hydrocarbyl group, and a substituted monovalentthat R’ and R” may bond together to form a 1,2-substituted arylene moiety; and subscript n is an integer with a value of 0 to 6, alternatively 0 to 4. Alternatively, R’ and R” may each be a hydrogen atom. Alternatively, R’ and R” may bond together to form an aryl group, such as phenyl. Examples of groups of formula (II) for D3include, but are not limited to: -CH2-CH2-; -CH2-CH2-CH2-; -CH2-CH2-CH2-CH2-; -CH2-CH2-CH2-CH2-CH2-CH2- ; and 1,2- HC CH substituted phenylene of .

[0010] Alternatively, D3mayhydrocarbyl group. For purposes of this application, “substituted” means that one or more hydrogen atom(s) covalently bonded to carbon atom(s) in the divalent hydrocarbyl group have been replaced with an atom or group other than hydrogen, such as an amino moiety.

[0011] In formula (I) shown above, each R2and each R3are independently selected from H, monovalent hydrocarbyl group, a substituted monovalent hydrocarbyl group (e.g., substituted with a carbinol moiety or an amino-moiety as described above), or an alkoxysilyl moiety of formula , where subscri2pt a is 1 or 2 or 3, D is a divalent hydrocarbyl group of 2 to 12 carbon atoms, and R1is an alkyl group of 1 to 6 carbon atoms. D2may be as described and exemplified above for D3. Alternatively, D2may be ethylene, propylene, or butylene; alternatively propylene. Subscript a may be 1 or 2 or 3, alternatively 2 or 3, and alternatively 3. R1is an alkyl group exemplified by methyl, ethyl, propyl (including n- propyl and isopropyl), and butyl (including n-butyl, isobutyl, tert-butyl, and sec-butyl).

[0012] Suitable monovalent hydrocarbyl groups for R2and / or R3are exemplified by alkyl, alkenyl, and aryl groups. For example, alkyl groups include methyl, ethyl, propyl (including n-propyl and isopropyl), and butyl (including n-butyl, isobutyl, tert-butyl, and sec-butyl). Suitable alkenyl groups may have terminal aliphatic unsaturation and include vinyl, allyl, and hexenyl. Suitable aryl groups include phenyl, tolyl, xylyl, benzyl, and styryl. Alternatively, the monovalent hydrocarbyl group for R2and / or R3may be an alkyl group, alternatively selected from methyl and ethyl; and alternatively methyl. R2and R3may be the same or different in the cyclic aminal moiety. Alternatively, each R2may be H. Alternatively, each R3may be H or methyl.

[0013] Examples of suitable substituted hydrocarbyl groups for R2and / or R3include, anamino-substituted hydrocarbyl group of subscript jj is 1 to6; alternatively 1 to 4, alternatively 1 to 2, and

[0014] Alternatively, the cyclic aminal may : the divalent hydrocarbyl group of 2 to 8 carbon atoms as group of 1 to 6 carb3on atoms described above; and R is the alkyl group of 1 to 6 carbon atoms or the alkoxysilyl moiety described above.

[0015] Alternatively, the cyclic aminal moiety of formula (I) may have a formula selected ,H H C CH ,or (2) a polyorganosiloxane. For example, (1) the cyclic aminal – functional silane may have formula (1-1): RAxSiR4(4-x), where each RAis an independently selected cyclic aminal moiety as described above; each R4is independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, an acyloxy group of 2 to 18 carbon atoms, and a hydrocarbonoxy-functional group of 1 to 18 carbon atoms; and subscript x is 1 to 4. Alternatively, subscript x may be 1 or 2, alternatively 2, and alternatively 1. Alternatively, each R4may be independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, an acyloxy group of 1 to18 carbon atoms, and a hydrocarbonoxy-functional group of 1 to 18 carbon atoms. Alternatively, each R4may be independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, and an alkoxy-functional group of 1 to 18 carbon atoms. Alternatively, each R4in formula (1-1) may be independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, and a hydrocarbonoxy-functional group of 1 to 18 carbon atoms.

[0017] Suitable alkyl groups for R4may be linear, branched, cyclic, or combinations of two or more thereof. The alkyl groups are exemplified by methyl, ethyl, propyl (including n-propyl and / or isopropyl), butyl (including n-butyl, tert-butyl, sec-butyl, and / or isobutyl); pentyl, hexyl, heptyl, octyl, decyl, dodecyl, undecyl, and octadecyl (and branched isomers having 5 to 18 carbon atoms), and the alkyl groups are further exemplified by cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Alternatively, the alkyl group for R4may be selected from the group consisting of methyl, ethyl, propyl and butyl; alternatively methyl, ethyl, and propyl; alternatively methyl and ethyl. Alternatively, the alkyl group for R4may be methyl.

[0018] Suitable aryl groups for R4may be monocyclic or polycyclic and may have pendant hydrocarbyl groups. For example, the aryl groups for R4include phenyl, tolyl, xylyl, and naphthyl and further include aralkyl groups such as benzyl, 1-phenylethyl and 2-phenylethyl. Alternatively, the aryl group for R4may be monocyclic, such as phenyl, tolyl, or benzyl; alternatively the aryl group for R4may be phenyl.

[0019] Suitable hydrocarbonoxy-functional groups for R4may have the formula -OR5or the formula -OR7-OR5, where each R7is an independently selected divalent hydrocarbyl group of 1 to 18 carbon atoms, and each R5is independently selected from the group consisting of the alkyl groups of 1-18 carbon atoms and the aryl groups of 6-18 carbon atoms, which are as described and exemplified above for R4. Examples of divalent hydrocarbyl groups for R7include alkylene group such as ethylene, propylene, butylene, or hexylene; an arylene group such as phenylene, or an alkylarylene group such as: or. Alternatively, R7may be an alkylene group such noxy-functional group may be an alkoxy-functional group such as methoxy, ethoxy, propoxy, or butoxy; alternatively methoxy or ethoxy, and alternatively methoxy.

[0020] Suitable acyloxy groups for R4may have the as described above. Examples of suitable acyloxy groups

[0021] Alternatively, the cyclic aminal – functional may (2) a cyclic aminal -functional polyorganosiloxane. Said polyorganosiloxane may be cyclic, linear, branched, resinous, or a combination of two or more thereof. Said polyorganosiloxane may comprise unit formula (2-1): (R43SiO1 / 2)a(R42RASiO1 / 2)b(R42SiO2 / 2)c(R4RASiO2 / 2)d(R4SiO3 / 2)e(RASiO3 / 2)f(SiO4 / 2)g(ZO1 / 2)h; where RAand R4are as described above; each Z is independently selected from the group consisting of a hydrogen atom and R5(where R5is as described above), subscripts a, b, c, d, e, f, and g represent average numbers of each unit in formula (2-1) and have values such that subscript a ≥ 0, subscript b ≥ 0, subscript c ≥ 0, subscript d ≥ 0, subscript e ≥ 0, subscript f ≥ 0, and subscript g ≥ 0; a quantity (a + b + c + d + e + f + g) ≥ 2, and a quantity (b + d + f) ≥ 1, and subscript h has a value such that 0 ≤ h / (e + f + g) ≤ 1.5. At the same time, the quantity (a + b + c + d + e + f + g) may be ≤ 10,000. Alternatively, in formula (2-1), each R4may be independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, and a hydrocarbonoxy-functional group of 1 to 18 carbon atoms. Alternatively, each R4may be independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, and an alkoxy-functional group of 1 to 18 carbon atoms. Alternatively, each R4may be independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms and an aryl group of 6 to 18 carbon atoms. Alternatively, each Z may be hydrogen or an alkyl group of 1 to 6 carbon atoms. Alternatively, each Z may be hydrogen.

[0022] Alternatively, (2) the cyclic aminal – functional polyorganosiloxane may comprise (2- 2) a linear polydiorganosiloxane having, per molecule, at least one cyclic aminal – functionalgroup; alternatively at least two cyclic aminal – functional groups (e.g., when in formula (2-1) above, subscripts e = f = g = 0). For example, said polydiorganosiloxane may comprise unit formula (2-3): (R43SiO1 / 2)a(RAR42SiO1 / 2)b(R42SiO2 / 2)c(RAR4SiO2 / 2)d, where RAand R4are as described above, subscript a is 0, 1, or 2; subscript b is 0, 1, or 2, subscript c ≥ 0, subscript d ≥ 0, with the provisos that a quantity (b + d) ≥ 1, a quantity (a + b) = 2, and a quantity (a + b + c + d) ≥ 2. Alternatively, in unit formula (2-3) the quantity (a + b + c + d) may be at least 3, alternatively at least 4, and alternatively > 50. At the same time in unit formula (2-3), the quantity (a + b + c + d) may be less than or equal to 10,000; alternatively less than or equal to 4,000; alternatively less than or equal to 2,000; alternatively less than or equal to 1,000; alternatively less than or equal to 500; alternatively less than or equal to 250. Alternatively, subscript c may be 0 to 300. Alternatively, subscript d may be 1 to 10. Alternatively, in unit formula (2-3) each R4may be independently selected from the group consisting of alkyl and aryl; alternatively methyl and phenyl. Alternatively, each R4in unit formula (2-3) may be an alkyl group; alternatively each R4may be methyl.

[0023] Alternatively, the polydiorganosiloxane of unit formula (2-3) may be selected from the group consisting of: unit formula (2-4): (R42RASiO1 / 2)2(R42SiO2 / 2)m(R4RASiO2 / 2)n, unit formula (2-5): (R43SiO1 / 2)2(R42SiO2 / 2)o(R4RASiO2 / 2)p, or a combination of both formulae (2-4) and (2-5).

[0024] In formulae (2-4) and (2-5), each R4and RAare as described above. Subscript m may be 0 or a positive number. Alternatively, subscript m may be at least 2. Alternatively subscript m be 2 to 2,000. Subscript n may be 0 or a positive number. Alternatively, subscript n may be 0 to 2000. Subscript o may be 0 or a positive number. Alternatively, subscript o may be 0 to 2000. Subscript p is at least 2. Alternatively subscript p may be 2 to 2000.

[0025] Alternatively, (2) the cyclic aminal – functional polyorganosiloxane may be a cyclosiloxane, e.g., when in unit formula (2-1), subscripts a = b = c = e = f = g = h = 0. The cyclic aminal – functional cyclosiloxane may have unit formula (2-7): (R4RASiO2 / 2)d, where RAand R4are as described above, and subscript d may be 3 to 12, alternatively 3 to 6, and alternatively 4 to 5.

[0026] Alternatively, the cyclic aminal – functional cyclosiloxane may have unit formula (2- 8): (R42SiO2 / 2)c(R4RASiO2 / 2)d, where R4and RAare as described above, subscript c is > 0 to 6 and subscript d is 3 to 12. Alternatively, in formula (2-8), c may be 3 to 6, and d may be 3 to 6.

[0027] Alternatively, (2) the cyclic aminal – functional polyorganosiloxane may be oligomeric, e.g., when in unit formula (2-1) above the quantity (a + b + c + d + e + f + g) ≤ 50, alternatively ≤ 40, alternatively ≤ 30, alternatively ≤ 25, alternatively ≤ 20, alternatively ≤ 10, alternatively ≤ 5, alternatively ≤ 4, alternatively ≤ 3. The oligomer may be cyclic, linear, branched, or a combination thereof. The cyclic oligomers are as described above as startingmaterial (2-6).

[0028] Examples of cyclic aminal – functional polydiorganosiloxane oligomers may have as described above, each R2is the proviso that atleast

[0029] Alternatively, the cyclic aminal – functional polyorganosiloxane oligomer may be branched. The branched oligomer may have general formula (2-11): RASiR123, where RAis as described above and each R12is selected from R13and -OSi(R14)3; where each R13is a monovalent hydrocarbon group; where each R14is selected from R13, –OSi(R15)3, and – [OSiR132]iiOSiR133; where each R15is selected from R13, –OSi(R16)3, and –[OSiR132]iiOSiR133; where each R16is selected from R13and –[OSiR132]iiOSiR133; and where subscript ii has a value such that 0 ≤ ii ≤ 100. At least two of R12may be -OSi(R14)3. Alternatively, all three of R12may be -OSi(R14)3.

[0030] Alternatively, in formula (2-11) when each R12is –OSi(R14)3, each R14may be – OSi(R15)3moieties such that the branched polyorganosiloxane oligomer has the following structure: are as described above. Alternatively,may be methyl.

[0031] Alternatively, in formula (2-11), when each R12is –OSi(R14)3, one R14may be R13in each –OSi(R14)3such that each R12is –OSiR13(R14)2. Alternatively, two R14in –OSiR13(R14)2may each be –OSi(R15)3 moieties such that the branched polyorganosiloxane oligomer has the following are as described above.

[0032] Alternatively, in formula (2-11), one R12may be R13, and two of R12may be – OSi(R14)3. When two of R12are –OSi(R14)3, and one R14is R13in each –OSi(R14)3then two of R12are –OSiR13(R14)2. Alternatively, each R14in –OSiR13(R14)2 may be –OSi(R15)3 such that the branched polyorganosiloxane oligomer has the following structure: are as described above. Alternatively, Alternatively, the cyclic aminal –16 silicon atoms per molecule, alternatively 4 to 16 silicon atoms per molecule, and alternatively 4 to 10 silicon atoms per molecule.

[0033] Alternatively, (2) the cyclic aminal – functional polyorganosiloxane may be branched, such as the branched oligomer described above and / or a branched cyclic aminal – functional polyorganosiloxane that may have, e.g., more cyclic aminal – functional groups per molecule and / or more polymer units than the branched oligomer described above (e.g., in formula (2-1) when the quantity (a + b + c + d + e + f + g) > 50). The branched cyclic aminal – functional polyorganosiloxane may have (in formula (2-1)) a quantity (e + f + g) sufficient to provide > 0 to 5 mol% of trifunctional and / or quadrifunctional units to the branched cyclic aminal – functional polyorganosiloxane.

[0034] For example, the cyclic aminal – functional branched polyorganosiloxane may comprise a Q branched polyorganosiloxane of unit formula (2-13): (R43SiO1 / 2)q(R42RASiO1 / 2)r(R42SiO2 / 2)s(SiO4 / 2)t, where R4and RAare as described above, and subscripts q, r, s, and t have average values such that 2 ≥ q ≥ 0, 4 ≥ r ≥ 0, 995 ≥ s ≥ 4, t = 1, (q + r) = 4, and (q + r + s + t) has a value sufficient to impart a viscosity > 170 mPa·s measured by rotational viscometry to the branched polyorganosiloxane. Viscosity may be measured at 25 °C using either a Brookfield™ rotational viscometer with spindle LV-4 for viscosities over 15,000 mPa·s (Spindle LV-4 designed for viscosities in the range between 1,000-2,000,000 mPa·s) at an appropriate rpm and using a Brookfield™ viscometer with a cone plate arrangement with cone CP-52 for viscosities up to 15, 000 mPa·s at 25 °C and an appropriate rpm. Alternatively, viscosity may be > 170 mPa·s to 1000 mPa·s, alternatively > 170 to 500 mPa·s, alternatively 180 mPa·s to 450 mPa·s, and alternatively 190 mPa·s to 420 mPa·s.

[0035] Alternatively, the cyclic aminal – functional branched polyorganosiloxane may comprise formula (2-14): [RAR42Si-(O-SiR42)x-O](4-w)-Si-[O-(R42SiO)vSiR43]w, where RAand R4are as described above; and subscripts v, w, and x have values such that 200 ≥ v ≥ 1, 2 ≥ w ≥ 0, and 200 ≥ x ≥ 1. Alternatively, in this formula (2-14), each R4is independently selected from the group consisting of methyl and phenyl, and each RAis the cyclic aminal moiety described above.

[0036] Alternatively, the cyclic aminal – functional branched polyorganosiloxane for starting material (2-11) may comprise a T branched polyorganosiloxane (silsesquioxane) of unit formula (2-15): (R43SiO1 / 2)aa(RAR42SiO1 / 2)bb(R42SiO2 / 2)cc(RAR4SiO2 / 2)ee(R4SiO3 / 2)dd, where R4and RAare as described above, subscript aa ≥ 0, subscript bb > 0, subscript cc is 15 to 995, subscript dd > 0, and subscript ee ≥ 0. Subscript aa may be 0 to 10. Alternatively, subscript aa may have a value such that: 12 ≥ aa ≥ 0; alternatively 10 ≥ aa ≥ 0; alternatively 7 ≥ aa ≥ 0; alternatively 5 ≥ aa ≥ 0; and alternatively 3 ≥ aa ≥ 0. Alternatively, subscript bb ≥ 1. Alternatively, subscript bb ≥ 3. Alternatively, subscript bb may have a value such that: 12 ≥ bb > 0; alternatively 12 ≥ bb ≥ 3; alternatively 10 ≥ bb > 0; alternatively 7 ≥ bb > 1; alternatively 5 ≥ bb ≥ 2; and alternatively 7 ≥ bb ≥ 3. Alternatively, subscript cc may have a value such that: 800 ≥ cc ≥ 15; and alternatively 400 ≥ cc ≥ 15. Alternatively, subscript ee may have a value such that: 800 ≥ ee ≥ 0; 800 ≥ ee ≥ 15; and alternatively 400 ≥ ee ≥ 15. Alternatively, subscript ee may b 0. Alternatively, a quantity (cc + ee) may have a value such that 995 ≥ (cc + ee) ≥ 15. Alternatively, subscript dd ≥ 1. Alternatively, subscript dd may be 1 to 10. Alternatively, subscript dd may have a value such that: 10 ≥ dd > 0; alternatively 5 ≥ dd > 0; and alternatively dd = 1. Alternatively, subscript dd may be 1 to 10, alternatively subscript dd may be 1 or 2. Alternatively, when subscript dd = 1, then subscript bb may be 3 and subscript cc may be 0. The values for subscript bb may be sufficient to provide the silsesquioxane of unit formula (2-15) with a cyclic aminal content of 0.1% to 1%, alternatively 0.2% to 0.6%, based on the weight of the silsesquioxane.

[0037] Alternatively, (2) the cyclic aminal – functional polyorganosiloxane may comprise an cyclic aminal – functional polyorganosilicate resin, which comprises monofunctional units (“M” units) of formula RM3SiO1 / 2and tetrafunctional silicate units (“Q” units) of formula SiO4 / 2, where each RMis an independently selected monovalent hydrocarbon group; each RMmay be independently selected from the group consisting of R4and RAas described above. Alternatively, each RMmay be selected from the group consisting of alkyl, alkenyl and aryl. Alternatively, each RMmay be selected from methyl, vinyl and phenyl. Alternatively, each RMmay be selected from the group consisting of alkyl and aryl. Alternatively, each RMmay be selected from methyl and phenyl. Alternatively, at least one-third, alternatively at least two thirds of the RMgroups are methyl groups. Alternatively, the M units may be exemplified by (Me3SiO1 / 2) and (Me2PhSiO1 / 2), and (Me2RASiO1 / 2). The polyorganosilicate resin is soluble in solvents such as those described herein as starting material (D), exemplified by liquidhydrocarbons, such as benzene, ethylbenzene, toluene, xylene, and heptane, or in liquid non- functional organosilicon compounds such as low viscosity linear and cyclic polydiorganosiloxanes.

[0038] When prepared, the polyorganosilicate resin comprises the M and Q units described above, and the polyorganosiloxane further comprises units with silicon bonded hydroxyl groups, and / or hydrolyzable groups, described by moiety (ZO1 / 2), above, and may comprise neopentamer of formula Si(OSiRM3)4, where RMis as described above, e.g., the neopentamer may be tetrakis(trimethylsiloxy)silane.29Si NMR and13C NMR spectroscopies may be used to measure hydroxyl and alkoxy content and molar ratio of M and Q units, where said ratio is expressed as {M(resin)} / {Q(resin)}, excluding M and Q units from the neopentamer. M / Q ratio represents the molar ratio of the total number of triorganosiloxy groups (M units) of the resinous portion of the polyorganosilicate resin to the total number of silicate groups (Q units) in the resinous portion. M / Q ratio may be 0.5 / 1 to 1.5 / 1, alternatively 0.6 / 1 to 0.9 / 1.

[0039] The Mn of the polyorganosilicate resin depends on various factors including the types of groups represented by RMthat are present. The Mn of the polyorganosilicate resin refers to the number average molecular weight measured using GPC, when the peak representing the neopentamer is excluded from the measurement. The Mn of the polyorganosilicate resin may be 1,500 Da to 30,000 Da; alternatively 1,500 Da to 15,000 Da; alternatively >3,000 Da to 8,000 Da. Alternatively, Mn of the polyorganosilicate resin may be 3,500 Da to 8,000 Da.

[0040] The polyorganosilicate resin described above typically contains silicon bonded hydroxyl groups, e.g., of formula, HOSiO3 / 2. The polyorganosilicate resin may comprise up to 3.5% of silicon bonded hydroxyl groups, as measured by FTIR spectroscopy and / or NMR spectroscopy, as described above. For certain applications, it may be desirable for the amount of silicon bonded hydroxyl groups to be below 0.7%, alternatively below 0.3%, alternatively less than 1%, and alternatively 0.3% to 0.8%. Silicon bonded hydroxyl groups formed during preparation of the polyorganosilicate resin can be converted to trihydrocarbon siloxane groups or to a different hydrolyzable group by reacting the silicone resin with a silane, disiloxane, or disilazane containing the appropriate terminal group. Silanes containing hydrolyzable groups may be added in molar excess of the quantity required to react with the silicon bonded hydroxyl groups on the polyorganosilicate resin.

[0041] Alternatively, the polyorganosilicate resin may further comprise 2% or less, alternatively 0.7% or less, and alternatively 0.3% or less, and alternatively 0.3% to 0.8% of units containing hydroxyl groups, e.g., those represented by formula XSiO3 / 2 where RMis as described above, and X represents a hydrolyzable substituent, e.g., OH. The concentration of silanol groups (where X = OH) present in the polyorganosilicate resin may be determined using FTIRspectroscopy and / or NMR as described above.

[0042] Alternatively, the polyorganosilicate resin may comprise unit formula (2-17): (R43SiO1 / 2)mm(R42RASiO1 / 2)nn(SiO4 / 2)oo(ZO1 / 2)h, where Z, R4, and RA, and subscript h are as described above and subscripts mm, nn and oo have average values such that mm ≥ 0, nn > 0, oo > 0, and 0.5 < (mm + nn) / oo < 4. Alternatively, 0.6 < (mm + nn) / oo < 4; alternatively 0.7 < (mm + nn) / oo < 4, and alternatively 0.8 < (mm + nn) / oo < 4.

[0043] Alternatively, (2) the cyclic aminal – functional polyorganosiloxane may comprise (2- 18) a cyclic aminal – functional silsesquioxane resin, i.e., a resin containing trifunctional (T) units, wherein the cyclic aminal – functional silsesquioxane resin comprises unit formula: (R43SiO1 / 2)a(R42RASiO1 / 2)b(R42SiO2 / 2)c(R4RASiO2 / 2)d(R4SiO3 / 2)e(RASiO3 / 2)f(ZO1 / 2)h; where R4and RAare as described above, subscript f > 1, 2 < (e + f) < 10,000; 0 < (a + b) / (e + f) < 3; 0 < (c + d) / (e + f) < 3; and 0 < h / (e + f) < 1.5. Alternatively, the cyclic aminal – functional silsesquioxane resin may comprise unit formula (2-19): (R4SiO3 / 2)e(RASiO3 / 2)f(ZO1 / 2)h, where R4, RA, Z, and subscripts h, e and f are as described above. Alternatively, the cyclic aminal – functional silsesquioxane resin may further comprise difunctional (D) units of formulae (R42SiO2 / 2)c(R4RASiO2 / 2)d in addition to the T units described above, i.e., a DT resin, where subscripts c and d are as described above. Alternatively, the cyclic aminal – functional silsesquioxane resin may further comprise monofunctional (M) units of formulae (R43SiO1 / 2)a(R42RASiO1 / 2)b, i.e., an MDT resin, where subscripts a and b are as described above for unit formula (2-1). Method for Making the Cyclic – Aminal Functional Organosilicon Compound

[0044] The cyclic aminal – functional organosilicon compound described above may be prepared by a method comprising: 1) combining starting materials comprising A) a di- or tri- amine compound comprising two or three amino groups per molecule, wherein the amino groups are selected from NH, NH2, or both, and B) an aldehyde-functional organosilicon compound; thereby preparing a reaction product comprising the cyclic aminal – functional organosilicon compound and a side product comprising water. The method introduced above may optionally further comprise one or more additional steps. For example, the method may further comprise 2) scavenging water during and / or after step 1) and / or 3) recovering the cyclic aminal functional organosilicon compound. Step 1) may be performed by any convenient means, such as mixing under ambient conditions, e.g., at r.t. Alternatively, the starting materials may be combined by mixing and heating at a temperature of > r.t. to 150 °C, alternatively 50 to 100 °C. Scavenging water may be performed by any convenient means, such as stripping, with heating and optionally with reduced pressure.Alternatively, scavenging may be performed by mixing D) a drying agent with the starting materials in step 1) and / or with the reaction product formed in step 1). Recovering in step 3) may be performed by any convenient means, such as stripping and / or distillation, optionally with reduced pressure. Recovering may further comprise filtration, e.g., to remove D) the drying agent, particularly when a physical drying agent is used in step 2). One or more additional starting materials may be used in the method. For example, C) a solvent may be used to facilitate contacting and mixing, e.g., by dissolving A) the di- or tri- amine compound, B) the aldehyde-functional organosilicon compound, or both. The starting materials used in the method are described in detail, below. A) Di- or Tri- amine Compound

[0045] Starting material A), the di- or tri- amine compound, has two or three amino groups per molecule, wherein the amino groups are selected from NH, NH2, or both. Alternatively, starting material A) may be a diamine compound, having 2 amino groups per molecule. The di- or tri- amine compound may be A1) an organic di- or tri- amine, A2) a diaminofunctional organosilicon compound, or a combination thereof. A1) Organic Di- or Tri- amine Compound

[0046] Starting material A) may comprise A1) an organic di- or tri- amine compound. The organic di- or tri- amine may have , wherein R2, R3, and D3are as defined above. The organic di-an organic diamine or an organic triamine, or a combination thereof; alternatively an organic diamine. Examples of organic diamines, which are commercially available, include N1-methylethane-1,2-diamine (CAS No.109-81-9), N1,N2-dimethylethane-1,2-diamine, Ethane-1,2-diamine (CAS No.107-15- 3), Benzene-1,2-diamine (CAS No.95-54-5), propane-1,3-diamine (CAS No.109-76-2), butane- 1,4-diamine (CAS No.110-60-1), hexane-1,6-diamine (CAS No.124-09-4), and a combination of two or more thereof. Alternatively, starting material A1) may comprise an organic triamine, such as N1-(2-aminoethyl)ethane-1,2-diamine (CAS No.111-40-0). The organic triamine may be used to prepare a cyclic aminal moiety with a substituted hydrocarbyl group (e.g., an amino- substituted hydrocarbyl group). This is as shown in Example 11, below, in which N1-(2- aminoethyl)ethane-1,2-diamine (a triamine) was used, and the resulting cyclic aminal group had an aminoethyl moiety. The organic di- or tri- amine compounds described above are commercially available, for example, from TCI, Oakwood Chemical, or Sigma Aldrich, Inc. of St. Louis, Missouri, USA.A2) Diamino-functional Organosilicon Compound

[0047] Alternatively, starting material A) may comprise A2) a diaminofunctional organosilicon compound, wherein in the above formula (IV), R2and / or R3is an organosiliconmoiety, such as the alkoxysilyl moiety of formula , whereinD2, R1, and subscript a are as described above.compound may comprise a diamino-functional alkoxysilane. The diamino-functional alkoxysilane may have formula: R6Si(OR1)a, wherein R6is a diamino-functional group, and R1and subscript a are as described above. R6may be for example, aminoethylaminopropyl or aminoethylaminoisobutyl. Alternatively, the diamino-functional alkoxysilane may be selected from the group consisting of N1-(3-(trimethoxysilyl)propyl)ethane-1,2-diamine (CAS No.1760- 24-3) and N1-(3-(triethoxysilyl)propyl)ethane-1,2-diamine (CAS No.5089-72-5), both of which are commercially available from Alfa Chemistry of Holbrook, New York, USA. Alternatively, the diamino-functional organosilicon compound may comprise a diamino-functional polyorganosiloxane, e.g., a polydiorganosiloxane having one or more silicon bonded groups R6, as described above. The diamino-functional polydiorganosiloxane may have a terminal aminoethyl,aminoisobutyl group, a pendant aminoethyl,aminoisobutyl group, or both terminal and pendant aminoethyl,aminoisobutyl groups. Diamino-functional polyorganosiloxanes are known in the art and may be made by known methods such as those described in US Patent 7238768 to Hupfield, et al., US Patent 11028229 to Suthiwangcharoen, et al., and US Patent 11028233 to Suthiwangcharoen, et al. Furthermore, diamino-functional polydiorganosiloxanes are commercially available and include DOWSIL™ 2-8566 Amino Fluid, which is commercially available from TDCC. B) Aldehyde Functional Organosilicon Compound

[0048] Starting material B) used in the method for making the cyclic aminal – functional organosilicon compound is an aldehyde-functional organosilicon compound. Aldehyde- functional organosilicon compounds suitable for use in the method for making the cyclic aminal – functional organosilicon compound are known and may be made by known methods, such as those described in US Patent 4424392 to Petty; US Patent 5021601 to Frances et al.; US Patent 5739246 to Graiver et al.; US Patent 7696294 to Asirvatham; and US Patent 7999053 to Sutton et al.; European Patent Application Publication EP 0392948 A1 to Frances, and PCT Patent Application Publication WO2006027074 to Kühnle et al. Alternatively, the aldehyde-functional organosilicon compound may be prepared via hydroformylation reaction, as described in USPatent Publication 20230242711 or PCT Patent Publication WO2023200934 corresponding to US Provisional Patent Application Serial No.63 / 330571, all of which are hereby incorporated by reference.

[0049] Starting material (B) the aldehyde-functional organosilicon compound has, per molecule, at least one aldehyde-functional group covalently bonded to silicon. Alternatively, the aldehyde-functional organosilicon compound may have, per molecule, more than one aldehyde- functional group covalently bonded to silicon. The aldehyde-functional group covalently bonded to silicon may have a divalent hydrocarbon group free of aliphatic unsaturation may be linear or branched.Examples of divalent hydrocarbyl groups groups of empirical formula -CrH2r-, where subscript r is 2 to 8. The alkane-diyl group may be a linear alkane-diyl, e.g., - CH2-CH2-, -CH2-CH2-CH2-, -CH2-CH2-CH2-CH2-, or -CH2-CH2-CH2-CH2-CH2-CH2-, or abranched alkane- or. Alternatively, each G may be an alkane-diyl group of 2 to 6 carbon atoms;3, or 6 carbon atoms. The aldehyde-functional organosilicon compound may be one aldehyde-functional organosilicon compound. Alternatively, two or more aldehyde- functional organosilicon compounds that differ from one another may be used in the process described herein. For example, the aldehyde-functional organosilicon compound may comprise one or both of an aldehyde-functional silane and an aldehyde-functional polyorganosiloxane.

[0050] The aldehyde-functional organosilicon compound may comprise an aldehyde- functional silane of formula (B1): RAldxSiR4(4-x), where each RAldis an independently selected group of the described above; and R4and subscript x are as described above,selected from the group consisting of an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, an acyloxy group of2 to 18 carbon atoms, and an hydrocarbonoxy-functional group of 1 to 18 carbon atoms; and subscript x is 1 to 4.

[0051] Suitable aldehyde-functional silanes are exemplified by aldehyde-functional trialkylsilanes such as (propyl-aldehyde)-trimethylsilane, (propyl-aldehyde)-triethylsilane, and (butyl-aldehyde)trimethylsilane; aldehyde-functional trialkoxysilanes such as (butyl- aldehyde)trimethoxysilane, (propyl-aldehyde)-trimethoxysilane, (propyl-aldehyde)- triethoxysilane, (propyl-aldehyde)-triisopropoxysilane, and (propyl-aldehyde)- tris(methoxyethoxy)silane; aldehyde-functional dialkoxysilanes such as (propyl-aldehyde)- phenyldiethoxysilane, (propyl-aldehyde)-methyldimethoxysilane, and (propyl-aldehyde)- methyldiethoxysilane; aldehyde-functional monoalkoxysilanes such as tri(propyl-aldehyde)- methoxysilane; aldehyde-functional triacyloxysilanes such as (propyl-aldehyde)- triacetoxysilane, and aldehyde-functional diacyloxysilanes such as (propyl-aldehyde)- methyldiacetoxysilane.

[0052] Alternatively, the aldehyde-functional organosilicon compound may comprise (B2) an aldehyde-functional polyorganosiloxane. Said aldehyde-functional polyorganosiloxane may be cyclic, linear, branched, resinous, or a combination of two or more thereof. Said aldehyde- functional polyorganosiloxane may comprise unit formula (B2-1): (R43SiO1 / 2)a(R42RAldSiO1 / 2)b(R42SiO2 / 2)c(R4RAldSiO2 / 2)d(R4SiO3 / 2)e(RAldSiO3 / 2)f(SiO4 / 2)g(ZO1 / 2)h; where each RAldis an independently selected aldehyde group of the , as described above, and R4, Z, and subscripts a, b, c, d, e, f, g, and h areAlternatively, each R4may be independently selected from the group consisting of H, an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, and an hydrocarbonoxy group of 1 to 18 carbon atoms. Each Z is independently selected from the group consisting of a hydrogen atom and R5, where each R5is independently selected from the group consisting of alkyl groups of 1 to 18 carbon atoms and aryl groups of 6 to 18 carbon atoms. Subscripts a, b, c, d, e, f, and g represent average numbers, per molecule, of each unit in the unit formula. Subscripts a, b, c, d, e, f, and g and have values such that subscript a ≥ 0, subscript b ≥ 0, subscript c ≥ 0, subscript d ≥ 0, subscript e ≥ 0, subscript f ≥ 0, subscript g ≥ 0; and subscript h has a value such that 0 ≤ h / (e + f + g) ≤ 1.5, 10,000 ≥ (a + b + c + d + e + f + g) ≥ 2, and a quantity (b + d + f) ≥ 1. At the same time, the quantity (a + b + c + d + e + f + g) may be ≤ 10,000. Alternatively, in the unit formula (B2-1) for the aldehyde-functional polyorganosiloxane, each R4may be independently selected from the group consisting of a hydrogen atom, an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms,and a hydrocarbonoxy-functional group of 1 to 18 carbon atoms. Alternatively, each R4may be independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, and an alkoxy-functional group of 1 to 18 carbon atoms. Alternatively, each R4may be independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms and an aryl group of 6 to 18 carbon atoms. Alternatively, each Z may be hydrogen or an alkyl group of 1 to 6 carbon atoms. Alternatively, each Z may be hydrogen.

[0053] Alternatively, (B2) the aldehyde-functional polyorganosiloxane may comprise (B-2) a linear polydiorganosiloxane having, per molecule, at least one aldehyde-functional group; alternatively at least two aldehyde-functional groups (e.g., when in the formula (B2-1) for the aldehyde-functional polyorganosiloxane above, subscripts e = f = g = 0). For example, said polydiorganosiloxane may comprise unit formula (B2-3): (R43SiO1 / 2)a(RAldR42SiO1 / 2)b(R42SiO2 / 2)c(RAldR4SiO2 / 2)d, where RAldand R4are as described above, subscript a is 0, 1, or 2; subscript b is 0, 1, or 2, subscript c ≥ 0, subscript d ≥ 0, with the provisos that a quantity (b + d) ≥ 1, a quantity (a + b) = 2, and a quantity (a + b + c + d) ≥ 2. Alternatively, in the unit formula (B2-3) for the linear aldehyde-functional polyorganosiloxane, above, the quantity (a + b + c + d) may be at least 3, alternatively at least 4, and alternatively > 50. At the same time said formula, the quantity (a + b + c + d) may be less than or equal to 10,000; alternatively less than or equal to 4,000; alternatively less than or equal to 2,000; alternatively less than or equal to 1,000; alternatively less than or equal to 500; alternatively less than or equal to 250. Alternatively, in the unit formula for the linear aldehyde-functional polyorganosiloxane, each R4may be independently selected from the group consisting of alkyl and aryl; alternatively methyl and phenyl. Alternatively, each R4in said formula may be an alkyl group; alternatively each R4may be methyl. Alternatively, in the formulas above for the aldehyde-functional organosilicon compound, each RAldmay be propyl aldehyde, butyl aldehyde or heptyl aldehyde. Alternatively, each RAldmay be propyl aldehyde.

[0054] Alternatively, the linear aldehyde-functional polydiorganosiloxane of unit formula (B2- 3) may be selected from the group consisting of: unit formula (B2-4): (R42RAldSiO1 / 2)2(R42SiO2 / 2)m(R4RAldSiO2 / 2)n, unit formula (B2-5): (R43SiO1 / 2)2(R42SiO2 / 2)o(R4RAldSiO2 / 2)p, or a combination of both formulae (B2-4) and (B2-5).

[0055] In formulae (B2-4) and (B 2-5), each R4and RAldare as described above. Subscript m may be 0 or a positive number. Alternatively, subscript m may be at least 2. Alternatively subscript m be 2 to 2,000. Subscript n may be 0 or a positive number. Alternatively, subscript n may be 0 to 2000. Subscript o may be 0 or a positive number. Alternatively, subscript o may be 0 to 2000. Subscript p is at least 2. Alternatively subscript p may be 2 to 2000.

[0056] Starting material (B2) may comprise an aldehyde-functional polydiorganosiloxane such as i) bis-dimethyl(propyl-aldehyde)siloxy-terminated polydimethylsiloxane, ii) bis- dimethyl(propyl-aldehyde)siloxy-terminated poly(dimethylsiloxane / methyl(propyl- aldehyde)siloxane), iii) bis-dimethyl(propyl-aldehyde)siloxy-terminated polymethyl(propyl- aldehyde)siloxane, iv) bis-trimethylsiloxy-terminated poly(dimethylsiloxane / methyl(propyl- aldehyde)siloxane), v) bis-trimethylsiloxy-terminated polymethyl(propyl-aldehyde)siloxane, vi) bis-dimethyl(propyl-aldehyde)siloxy-terminated poly(dimethylsiloxane / methylphenylsiloxane / methyl(propyl-aldehyde)siloxane), vii) bis- dimethyl(propyl-aldehyde)siloxy-terminated poly(dimethylsiloxane / methylphenylsiloxane), viii) bis-dimethyl(propyl-aldehyde)siloxy-terminated poly(dimethylsiloxane / diphenylsiloxane), ix) bis-phenyl,methyl,(propyl-aldehyde)-siloxy-terminated polydimethylsiloxane, x) bis- dimethyl(heptyl-aldehyde)siloxy-terminated polydimethylsiloxane, xi) bis-dimethyl(heptyl- aldehyde)siloxy-terminated poly(dimethylsiloxane / methyl(heptyl-aldehyde)siloxane), xii) bis- dimethyl(heptyl-aldehyde)siloxy-terminated polymethyl(heptyl-aldehyde)siloxane, xiii) bis- trimethylsiloxy-terminated poly(dimethylsiloxane / methyl(heptyl-aldehyde)siloxane), xiv) bis- trimethylsiloxy-terminated polymethyl(heptyl-aldehyde)siloxane, xv) bis-dimethyl(heptyl- aldehyde)-siloxy terminated poly(dimethylsiloxane / methylphenylsiloxane / methyl(heptyl- aldehyde)siloxane), xvi) bis-dimethyl(propyl-aldehyde)siloxy-terminated poly(dimethylsiloxane / methyl(heptyl-aldehyde)siloxane), xvii) bis-dimethyl(heptyl-aldehyde)- siloxy-terminated poly(dimethylsiloxane / methylphenylsiloxane), xviii) dimethyl(heptyl- aldehyde)-siloxy-terminated poly(dimethylsiloxane / diphenylsiloxane), and xix) a combination of two or more of i) to xviii).

[0057] Alternatively, (B2) the aldehyde-functional polyorganosiloxane may be cyclic, e.g., when in unit formula (B2-1), subscripts a = b = c = e = f = g = h = 0. The (B2-6) cyclic aldehyde-functional polydiorganosiloxane may have unit formula (B2-7): (R4RAldSiO2 / 2)d, where RAldand R4are as described above, and subscript d may be 3 to 12, alternatively 3 to 6, and alternatively 4 to 5. Examples of cyclic aldehyde-functional polydiorganosiloxanes include 2,4,6-trimethyl-2,4,6-tri(propyl-aldehyde)-cyclotrisiloxane, 2,4,6,8-tetramethyl-2,4,6,8- tetra(propyl-aldehyde)-cyclotetrasiloxane , 2,4,6,8,10-pentamethyl-2,4,6,8,10-penta(propyl- aldehyde)-cyclopentasiloxane, and 2,4,6,8,10,12-hexamethyl-2,4,6,8,10,12-hexa(propyl- aldehyde)-cyclohexasiloxane.

[0058] Alternatively, (B2-6) the cyclic aldehyde-functional polydiorganosiloxane may have unit formula (B2-8): (R42SiO2 / 2)c(R4RAldSiO2 / 2)d, where R4and RAldare as described above, subscript c is > 0 to 6 and subscript d is 3 to 12. Alternatively, in formula (B2-8), a quantity (c + d) may be 3 to 12. Alternatively, in formula (B2-8), c may be 3 to 6, and d may be 3 to 6.

[0059] Alternatively, (B2) the aldehyde-functional polyorganosiloxane may be (B2-9) oligomeric, e.g., when in unit formula (B2-1) above the quantity (a + b + c + d + e + f + g) ≤ 50, alternatively ≤ 40, alternatively ≤ 30, alternatively ≤ 25, alternatively ≤ 20, alternatively ≤ 10, alternatively ≤ 5, alternatively ≤ 4, alternatively ≤ 3. The oligomer may be cyclic, linear, branched, or a combination thereof. The cyclic oligomers are as described above as starting material (B2-6).

[0060] Examples of linear aldehyde-functional polyorganosiloxane oligomers may have as described above, each R2is the proviso that atleast one per z of linear aldehyde- functional polyorganosiloxane oligomers include 1,3-di(propyl-aldehyde)-1,1,3,3- tetramethyldisiloxane; 1,1,1,3,3-pentamethyl-3-(propyl-aldehyde)-disiloxane; and 1,1,1,3,5,5,5- heptamethyl-3-(propyl-aldehyde)-trisiloxane.

[0061] Alternatively, the aldehyde-functional polyorganosiloxane oligomer may be branched. The branched oligomer may have general formula (B2-11): RAldSiR123, where RAldis as described above and each R12is selected from R13and -Osi(R14)3; where each R13is a monovalent hydrocarbon group; where each R14is selected from R13, –Osi(R15)3, and – [OSiR132]iiOSiR133; where each R15is selected from R13, –OSi(R16)3, and –[OSiR132]iiOSiR133; where each R16is selected from R13and –[OSiR132]iiOSiR133; and where subscript ii has a value such that 0 ≤ ii ≤ 100. At least two of R12may be -OSi(R14)3. Alternatively, all three of R12may be -OSi(R14)3.

[0062] Alternatively, in formula (B2-11) when each R12is –OSi(R14)3, each R14may be – OSi(R15)3 moieties such that the branched polyorganosiloxane oligomer has the following structure: are as described above. Alternatively,may be methyl.

[0063] Alternatively, in formula (B2-11), when each R12is –OSi(R14)3, one R14may be R13in each –OSi(R14)3such that each R12is –OSiR13(R14)2. Alternatively, two R14in –OSiR13(R14)2may each be –OSi(R15)3 moieties such that the branched aldehyde-functional polyorganosiloxane oligomer has the following where RAld, R13, and R15are as described above. and each 1R3may be methyl.

[0064] Alternatively, in formula (B2-11), one R12may be R13, and two of R12may be – OSi(R14)3. When two of R12are –OSi(R14)3, and one R14is R13in each –OSi(R14)3then two of R12are –OSiR13(R14)2. Alternatively, each R14in –OSiR13(R14)2 may be –OSi(R15)3 such that the branched polyorganosiloxane oligomer has the following structure: OSiR153R13are as described above. Alternatively,the aldehyde-functional branched polyorganosiloxane may have 3 to 16 silicon atoms per molecule, alternatively 4 to 16 silicon atoms per molecule, and alternatively 4 to 10 silicon atoms per molecule. Examples of aldehyde-functional branched polyorganosiloxane oligomers include propyl-aldehyde- tris(trimethyl)siloxy)silane, which has ; methyl-(propyl-aldehyde)-di((1,1,1,3,5,5,5-;oxy)-silane, which has formuland 3-yl)oxy)-silane, which has formula .be branched, such as the branched oligomer described above and / or a branched aldehyde-functional polyorganosiloxane that may have, e.g., more aldehyde groups per molecule and / or more polymer units than the branched oligomer described above (e.g., in formula (B2-1) when the quantity (a + b + c + d + e + f + g) > 50). The branched aldehyde-functional polyorganosiloxane may have (in formula (B2-1)) a quantity (e + f + g) sufficient to provide > 0 to 5 mol% of trifunctional and / or quadrifunctional units to the branched aldehyde-functional polyorganosiloxane.

[0066] For example, the branched aldehyde-functional polyorganosiloxane may comprise a Q branched polyorganosiloxane of unit formula (B2-13): (R43SiO1 / 2)q(R42RAldSiO1 / 2)r(R42SiO2 / 2)s(SiO4 / 2)t, where R4and RAldare as described above, and subscripts q, r, s, and t have average values such that 2 ≥ q ≥ 0, 4 ≥ r ≥ 0, 995 ≥ s ≥ 4, t = 1, (q + r) = 4, and (q + r + s + t) has a value sufficient to impart a viscosity > 170 mPa·s measured by rotational viscometry (as described above) to the branched polyorganosiloxane. Alternatively, viscosity may be > 170 mPa·s to 1000 mPa·s, alternatively > 170 to 500 mPa·s, alternatively 180 mPa·s to 450 mPa·s, and alternatively 190 mPa·s to 420 mPa·s.

[0067] Alternatively, the branched aldehyde-functional polyorganosiloxane may comprise formula (B2-14): [RAldR42Si-(O-SiR42)x-O](4-w)-Si-[O-(R42SiO)vSiR43]w, where RAldand R4are as described above; and subscripts v, w, and x have values such that 200 ≥ v ≥ 1, 2 ≥ w ≥ 0, and 200 ≥ x ≥ 1. Alternatively, in this formula (B2-14), each R4is independently selected from the group consisting of methyl and phenyl, and each RAldhas the formula above, wherein G has 2, 3, or 6 carbon atoms.

[0068] Alternatively, the branched aldehyde-functional polyorganosiloxane for startingmaterial (B2-11) may comprise a T branched polyorganosiloxane (silsesquioxane) of unit formula (B2-15): (R43SiO1 / 2)aa(RAldR42SiO1 / 2)bb(R42SiO2 / 2)cc(RAldR4SiO2 / 2)ee(R4SiO3 / 2)dd, where R4and RAldare as described above, subscript aa ≥ 0, subscript bb > 0, subscript cc is 15 to 995, subscript dd > 0, and subscript ee ≥ 0. Subscript aa may be 0 to 10. Alternatively, subscript aa may have a value such that: 12 ≥ aa ≥ 0; alternatively 10 ≥ aa ≥ 0; alternatively 7 ≥ aa ≥ 0; alternatively 5 ≥ aa ≥ 0; and alternatively 3 ≥ aa ≥ 0. Alternatively, subscript bb ≥ 1. Alternatively, subscript bb ≥ 3. Alternatively, subscript bb may have a value such that: 12 ≥ bb > 0; alternatively 12 ≥ bb ≥ 3; alternatively 10 ≥ bb > 0; alternatively 7 ≥ bb > 1; alternatively 5 ≥ bb ≥ 2; and alternatively 7 ≥ bb ≥ 3. Alternatively, subscript cc may have a value such that: 800 ≥ cc ≥ 15; and alternatively 400 ≥ cc ≥ 15. Alternatively, subscript ee may have a value such that: 800 ≥ ee ≥ 0; 800 ≥ ee ≥ 15; and alternatively 400 ≥ ee ≥ 15. Alternatively, subscript ee may b 0. Alternatively, a quantity (cc + ee) may have a value such that 995 ≥ (cc + ee) ≥ 15. Alternatively, subscript dd ≥ 1. Alternatively, subscript dd may be 1 to 10. Alternatively, subscript dd may have a value such that: 10 ≥ dd > 0; alternatively 5 ≥ dd > 0; and alternatively dd = 1. Alternatively, subscript dd may be 1 to 10, alternatively subscript dd may be 1 or 2. Alternatively, when subscript dd = 1, then subscript bb may be 3 and subscript cc may be 0. The values for subscript bb may be sufficient to provide the silsesquioxane of unit formula (B2-15) with an aldehyde content of 0.1% to 1%, alternatively 0.2% to 0.6%, based on the weight of the silsesquioxane.

[0069] Alternatively, (B2) the aldehyde-functional polyorganosiloxane may comprise an aldehyde-functional polyorganosiloxane resin, such as an aldehyde-functional polyorganosilicate resin and / or an aldehyde-functional silsesquioxane resin. Such resins may be prepared, for example, by hydroformylating an alkenyl-functional polyorganosiloxane resin. The aldehyde- functional polyorganosilicate resin comprises monofunctional units (“M’” units) of formula RM’3SiO1 / 2 and tetrafunctional silicate units (“Q” units) of formula SiO4 / 2, where each RM’may be independently selected from the group consisting of R4and RAldas described above. Alternatively, each RM’may be selected from the group consisting of an alkyl group, an aldehyde-functional group of the formula shown above, and an aryl group. Alternatively, each RM’may be selected from methyl, (propyl-aldehyde) and phenyl. Alternatively, at least one- third, alternatively at least two thirds of the RM’groups are methyl groups. Alternatively, the M’ units may be exemplified by (Me3SiO1 / 2), (Me2PhSiO1 / 2), and (Me2RAldSiO1 / 2). The polyorganosilicate resin is soluble in solvents such as liquid hydrocarbons, such as benzene, ethylbenzene, toluene, xylene, and heptane, or in liquid non-functional organosilicon compounds such as low viscosity linear and cyclic polydiorganosiloxane.

[0070] When prepared, the polyorganosilicate resin comprises the M’ and Q units describedabove, and the polyorganosiloxane further comprises units with silicon bonded hydroxyl groups, and / or hydrolyzable groups, described by moiety (ZO1 / 2), above, and may comprise neopentamer of formula Si(OSiRM’3)4, where RM’is as described above, e.g., the neopentamer may be tetrakis(trimethylsiloxy)silane.29Si NMR and13C NMR spectroscopies may be used to measure hydroxyl and alkoxy content and molar ratio of M’ and Q units, where said ratio is expressed as {M’(resin)} / {Q(resin)}, excluding M’ and Q units from the neopentamer. M’ / Q ratio represents the molar ratio of the total number of triorganosiloxy groups (M’ units) of the resinous portion of the polyorganosilicate resin to the total number of silicate groups (Q units) in the resinous portion. M’ / Q ratio may be 0.5 / 1 to 1.5 / 1, alternatively 0.6 / 1 to 0.9 / 1.

[0071] The Mn of the polyorganosilicate resin depends on various factors including the types of hydrocarbon groups represented by RM’that are present. The Mn of the polyorganosilicate resin refers to the number average molecular weight measured using GPC, when the peak representing the neopentamer is excluded from the measurement. The Mn of the polyorganosilicate resin may be 1,500 Da to 30,000 Da, alternatively 1,500 Da to 15,000 Da; alternatively >3,000 Da to 8,000 Da. Alternatively, Mn of the polyorganosilicate resin may be 3,500 Da to 8,000 Da.

[0072] Alternatively, the polyorganosilicate resin may comprise unit formula (B2-17): (R43SiO1 / 2)mm(R42RAldSiO1 / 2)nn(SiO4 / 2)oo(ZO1 / 2)h, where Z, R4, and RAld, and subscript h are as described above and subscripts mm, nn and oo have average values such that mm ≥ 0, nn > 0, oo > 0, and 0.5 < (mm + nn) / oo < 4. Alternatively, 0.6 < (mm + nn) / oo < 4; alternatively 0.7 < (mm + nn) / oo < 4, and alternatively 0.8 < (mm + nn) / oo < 4.

[0073] Alternatively, (B2) the aldehyde-functional polyorganosiloxane may comprise (B2-18) an aldehyde-functional silsesquioxane resin, i.e., a resin containing trifunctional (T’) units of unit formula: (R43SiO1 / 2)a(R42RAldSiO1 / 2)b(R42SiO2 / 2)c(R4RAldSiO2 / 2)d(R4SiO3 / 2)e(RAldSiO3 / 2)f(ZO1 / 2)h; where R4and RAldare as described above, subscript f > 1, 2 < (e + f) < 10,000; 0 < (a + b) / (e + f) < 3; 0 < (c + d) / (e + f) < 3; and 0 < h / (e + f) < 1.5. Alternatively, the aldehyde-functional silsesquioxane resin may comprise unit formula (B2-19): (R4SiO3 / 2)e(RAldSiO3 / 2)f(ZO1 / 2)h, where R4, RAld, Z, and subscripts h, e and f are as described above. Alternatively, the alkenyl-functional silsesquioxane resin may further comprise difunctional (D’) units of formulae (R42SiO2 / 2)c(R4RAldSiO2 / 2)d in addition to the trifunctional units described above, i.e., a D’T’ resin, where subscripts c and d are as described above. Alternatively, the aldehyde-functional silsesquioxane resin may further comprise monofunctional (M’) units of formulae (R43SiO1 / 2)a(R42RAldSiO1 / 2)b, i.e., an M’D’T’ resin, where subscripts a and b are as described above for unit formula (B2-1).

[0074] Starting material B) may be any one of the aldehyde-functional organosilicon compounds described above. Alternatively, starting material B) may comprise a mixture of two or more of the aldehyde-functional organosilicon compounds.

[0075] The amounts of starting materials A) and B) depend on various factors including the desired degree of substitution, however, the amounts may be sufficient to provide a 1:1 to > 1:1 molar ratio of aminofunctional groups : aldehyde functional groups (NH:CHO ratio). C) Solvent

[0076] Starting material C), a solvent, may be used in the method described above, to facilitate mixing starting materials A) and B). Solvents that can be used herein are those that help fluidize starting materials A) and B), but essentially do not react with starting materials A) and B). The solvent may be selected based on solubility the starting materials and volatility of the solvent. The solubility refers to the solvent being sufficient to dissolve and / or disperse a starting material. Volatility refers to vapor pressure of the solvent. If the solvent is too volatile (having too high vapor pressure) the solvent may vaporize prematurely, before completion of the reaction. However, if the solvent is not volatile enough (too low vapor pressure) the solvent may remain as a plasticizer in the reaction product comprising the cyclic aminal – functional organosilicon compound.

[0077] Suitable solvents include polyorganosiloxanes with suitable vapor pressures, such as hexamethyldisiloxane, octamethyltrisiloxane, hexamethylcyclotrisiloxane and other low molecular weight polyorganosiloxanes, such as 0.5 to 1.5 cSt DOWSIL™ 200 Fluids and DOWSIL™ OS FLUIDS, which are commercially available from TDCC.

[0078] Alternatively, the solvent may comprise an organic solvent. The organic solvent can be an aromatic hydrocarbon such as benzene, toluene, ethylbenzene or xylene; an aliphatic hydrocarbon such as heptane, hexane, or octane; a halogenated hydrocarbon such as dichloromethane, 1,1,1-trichloroethane or methylene chloride; chloroform; or a combination thereof.

[0079] The amount of solvent will depend on various factors including the type of solvent selected and the amount and type of other starting materials selected for use in the method. However, the amount of solvent may range from 1 % to 99%, alternatively 2 % to 90 %, based on the weight of starting materials A) and B) combined. Solvent can be added during step 1), to aid mixing and delivery. All or a portion of the solvent may optionally be removed after step 1). D) Drying Agent

[0080] Starting material D) is a drying agent that may be used in the method described above when step 2) is present, for scavenging water formed by the reaction in step 1). The drying agent binds water from various sources. For example, the drying agent may bind waterproduced as a side product of the reaction in step 1). Starting material D) may be a physical drying agent, a chemical drying agent, or a combination thereof.

[0081] The physical drying agent is exemplified by an adsorbent, which may be made up of inorganic particulates. The adsorbent may have a particle size of 10 micrometers or less, alternatively 5 micrometers or less. The adsorbent may have average pore size sufficient to adsorb water and alcohols, for example 10 Å (Angstroms) or less, alternatively 5 Å or less, and alternatively 3 Å or less. Examples of adsorbents include 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.

[0082] Examples of commercially available physical drying agents include dry molecular sieves, such as 3 Å (Angstrom) molecular sieves, which are commercially available from Grace Davidson under the trademark SYLOSIV™ and from Zeochem of Louisville, Kentucky, U.S.A. under the trade name PURMOL, and 4 Å molecular sieves such as Doucil zeolite 4A available from Ineos Silicas of Warrington, England. Other useful molecular sieves include MOLSIV ADSORBENT TYPE 13X, 3A, 4A, and 5A, all of which are commercially available from UOP of Illinois, U.S.A.; SILIPORITE NK 30AP and 65xP from Atofina of Philadelphia, Pennsylvania, U.S.A.; and molecular sieves available from W.R. Grace of Maryland, U.S.A.

[0083] Alternatively, the drying agent may bind the water by chemical means (a chemical drying agent). An amount of a silane crosslinker added (in addition to starting material A) or B), when an alkoxysilane is used for one of these starting materials) may function as a chemical drying agent. For example, alkoxysilanes suitable as drying agents include vinyltrimethoxysilane, vinyltriethoxysilane, cyanoethyltrimethoxysilane, cyanoethyltriethoxysilane, and combinations thereof.

[0084] The amount of starting material D) depends on the specific drying agent selected. However, when starting material D) is a chemical drying agent, the amount may range from 0 parts to 5 parts, alternatively 0.1 parts to 0.5 parts, per 100 parts of starting materials A) and B) combined. Method of Use

[0085] The method described above may be used to make a variety of cyclic aminal – functional organosilicon compounds, which may be silanes or siloxanes that may be linear, cyclic, branched, resinous, or combinations thereof. The cyclic aminal – functional organosilicon compounds may find use in a myriad of end use applications, such as additives for use in polyorganosiloxane compositions. The cyclic aminal – functional organosilicon compound may be useful as an adhesion promoting additive or as a component of a cure system.EXAMPLES

[0086] The following examples are provided to illustrate the invention to those skilled in the art and are not to be interpreted as to limit the scope of the invention set forth in the claims. The starting materials used in these examples are summarized below in Table 1. Table 1 – Starting Materials Starting Product Name Chemical Description, Source Material Chemical formula, or e 4 e 4 e 4 e 4 o QStarting Product Name Chemical Description, Source Material Chemical formula, or T Str tr .Starting Product Name Chemical Description, Source Material Chemical formula, or T Str t r .

[0087] In Table 1, above, Reagent A-1) isobutyl amine has structure: . Reagent A- 12) N -methylethane- 1,2-diamine has structure .triethoxysilane has . Reagent A-4) 3-Aminopropyltrimethoxysilane has . Reagent A-5) N1-(3-(trimethoxysilyl)propyl)ethane-1,2-diamine has . Reagent A-6) N1,N2-dimethylethane-1,2-diamine has . Reagent A-7) Ethane-1,2-diamine hasstructure . Reagent A-8) Benzene-1,2-diamine has structure .Reagent A-9) N1-(2-aminoethyl)ethane-1,2-diamine has structure . Reagent A-10) N1-(3-(triethoxysilyl)propyl)ethane-1,2-. Reagent A-13) propane-1,3-diamine has structure. Reagent A-14) butane-1,4-diamine has .Reagent A-15) hexane-1,6-diamine has . Antioxidant 1: Octadecyl 3-(3,5-di-tert-butyl-has structure. Antioxidant 2: 1,3,5- as structure . Antioxidant 3: 2,6-Di-tert-butyl-4-methylphenol has structure 4: 2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)chroman-6-olhas .

[0088] InMDPr-aldM (0.085 g, 0.31 mmol, 1 eq.), C6D6(0.6 mL), and then N1-methylethane-1,2-g, 0.32 mmol, 1.04 eq.). After the addition of the N1-methylethane-1,2-diamine, a white mixture formed. The sample was analyzed by1H and13C NMR spectroscopy as well as high-resolution mass spectrometry and gas chromatography-mass spectrometry (GC-MS). Together, the analytical results indicated formation of a new species, 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)-1-methylimidazolidine, with formula: .mL vial was added MDPr-aldM (0.961 g, 3.45 mmol, 1 eq.) and N1-methylethane-1,2-diamine (0.256 g, 3.45 mmol, 1.0 eq.). After the addition of the N1-methylethane-1,2-diamine, a white mixture formed. Half of the reaction mixture was transferred to an 8 mL vial and heated at 100 ºC (via a pre-heated aluminum block) for 1 h. At this time, a 100 uL aliquot was removed, combined with CDCl3 (0.7 mL) and analyzed by1H and13C NMR spectroscopy. After analysis, it was determined that the new species shown above in Example 1 remained intact. The sample was clear and colorless. The remainder of the sample that was not heated was stirred at r.t. for 3 d. After this time, no color change was observed. After 10 d, the sample was still colorless. This Example 2 indicates that the new species of the formula shown above in Table 1 is stable even after heating and aging, under the conditions tested.

[0090] In this Example 3 (comparative), to a 30 mL vial was added MDPr-aldM (0.969 g, 3.48 mmol, 1 eq.) and isobutylamine (0.257 g, 3.51 mmol, 1.01 eq.). After the addition of the isobutylamine, a white mixture formed, containing an organosilicon compound having a pendant imine group. Half of the reaction mixture was transferred to an 8 mL vial and heated at 100 ºC (via a pre-heated aluminum block) for 1 h. At this time, a 100 uL aliquot was removed, combined with CDCl3 (0.7 mL) and analyzed by1H and13C NMR spectroscopy. After heating, the sample was dark orange. The remainder of the sample that was not heated was stirred at r.t. for 3 d. After this time, the sample became yellow in color. After 10 d, the sample was a deeper yellow. Examples 2 and 3 demonstrate that the cyclic aminal – functional organosilicon compound of the present invention may be more stable than an imine – functional organosilicon compound with comparable siloxane architecture because the cyclic aminal – functional organosilicon compound of Example 2 did not exhibit yellowing after heating and aging, but the imine-functional material of comparative example 3 became yellow in color after heating and aging under the same conditions.

[0091] In this Example 4, to an NMR tube was added MDPr-aldM (0.086 g, 0.31 mmol, 1 eq.), C6D6(0.6 mL), and then N1-(3-(trimethoxysilyl)1,2-diamine (0.0704 g, 0.32 mmol, 1.03 eq.). After the addition of the diamine, a turbid mixture formed. The sample was analyzed by1H and13C NMR spectroscopy. The NMR results indicated formation of a new species, 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)-1-(3- (trimethoxysilyl)propyl)imidazolidine, with formula:.

[0092] In this Example 5 (comparative), to a 30 mL vial was added a magnetic stir bar, MPr-ald 2D180 (1.9854 g, 0.15 mmol, 0.30 mmol CHO 1 eq.) and then 3-aminopropyltriethoxysilane (0.0712 g, 0.32 mmol, 1.07 eq.). After the addition of the 3-aminopropyltriethoxysilane, the mixture became turbid. At this time, the sample was transferred to a pre-heated aluminum block at 100 ºC. The sample was heated (loosely capped) at 100 ºC. After 40 min, the sample became more viscous (difficult to be stirred by the stir bar). After 80 min, the sample was fully cured and had turned bright yellow.

[0093] In this Example 6 (comparative), to a 30 mL vial was added a magnetic stir bar, MPr-ald 2D180 (1.9945 g, 0.15 mmol, 0.30 mmol CHO 1 eq.) and then 3-aminopropyltrimethoxysilane (0.0551 g, 0.31 mmol, 1.02 eq.). After the addition of the 3-aminopropyltrimethoxysilane, the mixture became turbid. At this time, the sample was transferred to a pre-heated aluminum block at 100 ºC. The sample was heated (loosely capped) at 100 ºC. After 4 min, the sample became more viscous (difficult to be stirred by the stir bar). After 20 min, the sample was fully cured and had turned bright yellow.

[0094] In this Example 7, to a 30 mL vial was added a magnetic stir bar, MPr-ald2D180(1.981 g, 0.15 mmol, 0.30 mmol CHO 1 eq.) and then N1-(3-(trimethoxysilyl)propyl)ethane-1,2-diamine (0.0705 g, 0.32 mmol, 1.07 eq.). After the addition of the N1-(3-(trimethoxysilyl)propyl)ethane- 1,2-diamine, the mixture became turbid. The reaction product was analyzed, and the results showed that a cyclic aminal – functional siloxane, shown below, had formed.ple was heated (loosely capped) at 100 ºC. After 4 min, the sample became more viscous (difficult to be stirred by the stir bar). After 20 min, the sample was fully cured and had not turned bright yellow as the materials in Examples 5 and 6 had.

[0096] In this Example 8, to a 30 mL vial was added a magnetic stir bar, MDPr-aldM (0.506 g, 1.81 mmol, 1 eq.) and then N1,N2-dimethylethane-1,2-diamine (0.160 g, 1.81 mmol, 1.00 eq.). After the addition of the N1,N2-dimethylethane-1,2-diamine, the mixture became turbid. The sample was analyzed by1H and13C NMR spectroscopy as well as high-resolution mass spectrometry and gas chromatography-mass spectrometry (GC-MS). Together, the analytical results indicated formation of a new species, 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3- yl)ethyl)-1,3-dimethylimidazolidine shown below.

[0097] In this Example 9, to a 30 mL vial was added a magnetic stir bar, MDPr-aldM (0.540 g, 1.94 mmol.1 eq.) and then ethane-1,2-diamine (0.124 g, 0.138 mL, 2.06eq.). After the addition of the ethane-1,2-diamine, the clear and colorless sample became turbid and more viscous with a slight yellow color. The sample was analyzed by1H and13C NMR spectroscopy as well as high-resolution mass spectrometry. Together, the analytical results indicatedformation of a new species, 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)imidazolidine shown below,

[0098] In this a vial was added a magnetic stir bar, benzene-1,2- diamine (0.06 g, 0.55 mmol, 1.04 eq.) and CDCl3 (1 mL). Upon stirring, a pale yellow solution formed. To this solution was added MDPr-aldM (0.148 g, 0.53 mmol, 1 eq.). Upon the addition of MDPr-aldM, the mixture became turbid and remained pale yellow. The sample was analyzed by1H and13C NMR spectroscopy as well as high-resolution mass spectrometry. Together, the analytical results indicated formation of a new species, 2-(2-(1,1,1,3,5,5,5- heptamethyltrisiloxan-3-yl)ethyl)-2,3-dihydro-1H-benzo[d]imidazole shown below, as well as unreacted MDPr-aldM, and N,N'-(1,2-phenylene)bis(3-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3- yl)propan-1-imine).

[0099] In this Example 11, to a 30 mL vial was added a magnetic stir bar, MDPr-aldM (0.0847 g, 0.304 mmol, 1 eq.), C6D6(0.6 mL) and then N1-(2-aminoethyl)ethane-(0.038 g, 0.368 mmol, 1.21 eq.). After the addition of the amine, a turbid mixture formed. The sample was analyzed by1H and13C NMR spectroscopy. Together, the analytical results indicated formation of a new species, 2-(2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)imidazolidin-1- yl)ethan-1-amine shown below,

[0100] In this Example 12, to a 30 mL vial was added a magnetic stir bar, MPr-ald2D180 (1.9872 g, 0.15 mmol, 0.30 mmol CHO 1 eq.) and then N1-(2-aminoethyl)ethane-1,2-diamine (0.034 g, 0.33 mmol, 2.2 eq.). After the addition of the amine, a highly viscous, turbid mixture formed. The sample was analyzed by1H and13C NMR spectroscopy, which showed that a cyclic aminal – functional siloxane, shown below, had formed. ald2D180(8.03 g, 0.61 mmol, 1.21 mmol CHO 1 eq.) and then N1-(3-(triethoxysilyl)propyl)ethane-1,2-diamine (0.34 g, 1.29 mmol, 1.06 eq.). After the addition of the N1-(3-(triethoxysilyl)propyl)ethane-1,2- diamine, the mixture became turbid. The reaction product was analyzed, and the results showed that a cyclic aminal – functional siloxane, shown below, had formed.DOWSIL™ 2-8566 Amino Fluid (2.02 g, 0.096 mmol, 0.59 mmol NH21.08 eq.) and then MDPr-aldM (0.154 g, 0.55 mmol, 1.0 eq.). After the addition of the aldehyde siloxane to the amine siloxane, the mixture became turbid. The reaction product was analyzed after 10 min by1H and 13C NMR. The results indicated formation of a cyclic aminal – functional siloxane copolymer, shown below. , wherein the difunctional units in the copolymer may bea block copolymer, as shown).

[0103] In this Example 15, to a 30 mL vial was added MD268D”6.2M DOWSIL™ 2-8566 Amino Fluid (2.00 g, 0.095 mmol, 0.59 mmol NH21.05 eq.) and then 3- (trimethoxysilyl)propanal (0.099 g, 0.56 mmol, 1.0 eq.). After the addition of the aldehyde silane to the amine fluid, the mixture manually stirred using a plastic pipette. After 8 seconds, an elastomeric material with silicon bonded cyclic aminal functional groups had formed.

[0104] In this Example 16, to a 30 mL vial was added MD268D”6.2M DOWSIL™ 2-8566 Amino Fluid (2.00 g, 0.095 mmol, 0.59 mmol NH21.09 eq.) and then 3-(triethoxysilyl)propanal (0.119 g, 0.54 mmol, 1.0 eq.). After the addition of the aldehyde silane to the amine fluid, the mixture manually stirred using a plastic pipette. After 13 seconds, an elastomeric material with silicon bonded cyclic aminal functional groups had formed.

[0105] In this Example 17, to a 40 mL vial was propane-1,3-diamine (0.0859 g, 1.16 mmol, 2.32 mmol NH2) followed by MDPr-aldM (0.6772 g, 2.43 mmol, 2.43 mmol CHO). Upon the addition of MDPr-aldM, the mixture became turbid. The sample was analyzed by1H and13C NMRwell as high-resolution mass spectrometry. Together,analytical results indicated formation of the cyclic aminal, 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3- yl)ethyl)hexahydropyrimidine, shown below, as well as unreacted MDPr-aldM and imine- functional siloxanes such as N,N’-(propane-1,3-diyl)bis(3-(1,1,1,3,5,5,5-heptamethyltrisiloxan- 3-yl)propan-1-imine).

[0106] In this Example 18, to a 40 mL vial was added butane-1,4-diamine (0.077 g, 0.87 mmol, 1.74 mmol NH2) followed by MDPr-aldM (0.4943 g, 1.77 mmol, 1.77 mmol CHO). Upon the addition of MDPr-aldM, the mixture became turbid. The sample was analyzed by1H and13C NMR spectroscopy as well as high-resolution mass spectrometry. Together, the analytical results indicated formation of the cyclic aminal, 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)- 1,3-diazepane, shown below, as well as unreacted MDPr-aldM and imine-functional siloxanes such as N,N'-(butane-1,4-diyl)bis(3-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)propan-1-imine).

[0107] In this Example 19, to a 30 mL vial was added a magnetic stir bar, hexane-1,6-diamine (0.132 g, 1.14 mmol, 2.27 mmol NH2) and C6D6 (0.3 mL). To this solution was added MDPr-aldM (0.298 g, 1.07 mmol, 1.07 mmol CHO). Upon the addition of MDPr-aldM, the mixture became turbid. The sample was analyzed by1H and13C NMR well as high-resolutionmass spectrometry. The analytical results indicated a new species, 2-(2- (1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)-1,3-diazonane as a minor product, shown below, along with N,N'-(hexane-1,6-diyl)bis(3-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)propan-1- imine) as the major product.

[0108] In this Example 20, Reagents B-5 and A-11 or A-12 were pre-dissolved in toluene at 70% solids content prior to mixing. Reagent B-5 was added to Reagent A-11 / A-12 while vigorously mixing with a magnetic stir bar. Mixtures almost instantaneously formed a gel. The solvent swollen products were transferred into an open Al dish and placed in a forced air oven set at 120 °C for 30 min followed by 150 °C for 30 min. The results table 2, below shows observations taken after this processing step. Results table 2: Example Amine Aldehyde Amine, g Aldehyde, g Wt% MQResults table 2 Observations: Example Observation

[0109] Example 20 demonstrated that a cyclic aminal – functional polyorganosiloxane resin was produced using the method described herein.

[0110] In the examples above, NMR spectra were recorded on a 400 MHz (1H: 399.8 MHz;13C: 100.5 MHz) or 500 MHz (1H: 500.1 MHz;13C: 125.8 MHz) Bruker Spectrometer at 25 °C.1H NMR spectra were referenced to residual protons in C6D6 (δ = 7.16) or CDCl3 (δ = 7.26).13C spectra were referenced to C6D6(δ = 128.1) or CDCl3(δ = 77.2).

[0111] Gas-Chromatography / Mass Spectrometry (GC-MS) data were recorded using an Agilent Technologies 7890A GC system fitted with a 7693 autosampler and connected to a flame ionization detector and 5975C mass spectrometer. Column: Agilent DB-5MS (phenyl- arylene, 30 m × 250 µm × 0.25 µm). The samples were prepared by diluting an aliquot of the reaction mixture (20 µL) in pentane (1 mL). Injection volume 1 µL. Inlet temperature: 250°C. Oven program: 50°C for 1 min; 10 °C / min to 275 °C; 275 °C for 5 min. Total run time: 28.5 min. Mass spectrometer operated in chemical ionization mode / positive ion mode with methane as the reagent gas. Mass range: 50–1000. Solvent delay: 3.5 min.

[0112] High Resolution Mass Spectrometry (HRMS) data were recorded using an Agilent Technologies 6230 TOF LC / MS coupled with a 1290 Infinity UPLC using a Zorbax Eclipse Plus C18 Rapid Resolution HD 2.1 x 50 mm 1.8 micron column. A solution of 95% acetonitrile in 5% HPLC grade water with 0.1% formic acid was used for injection and by-passed the column. The samples were prepared by diluting an aliquot of the reaction mixture (20 µL) in pentane (1 mL) or toluene (1 mL). INDUSTRIAL APPLICABILITY

[0113] The method described herein is capable of producing a wide variety of cyclic – aminal functional organosilicon compounds, including a cyclic – aminal functional silane with one silicon atom per molecule and a cyclic – aminal functional siloxane with 2 to 10,000 silicon atoms per molecule, and a structure that may be linear, cyclic, branched, resinous or combinations thereof. The cyclic aminal – functional organosilicon compounds demonstrate improved stability over imine functional organosilicon compounds, as shown by the lack of yellowing after heat aging. Definitions and Usage of Terms

[0114] All amounts, ratios, and percentages herein are by weight, unless otherwise indicated. The amounts of all starting materials in a composition total 100% by weight. The SUMMARY and ABSTRACT are hereby incorporated by reference. The articles ‘a’, ‘an’, and ‘the’ each refer to one or more, unless otherwise indicated by the context of specification. The singular includes the plural unless otherwise indicated. The transitional phrases “comprising”, “consisting essentially of”, and “consisting of” are used as described in the Manual of PatentExamining Procedure Ninth Edition, Revision 08.2017, Last Revised January 2018 at section §2111.03 I., II., and III. The abbreviations used herein have the definitions in Table 3. Table 3 - Abbreviations Abbreviation Definitions °C degrees Celsius - 2 a

Claims

CLAIMS 1. A cyclic aminal – functional organosilicon compound comprising: a cyclic aminal moiety covalently bonded to a silicon atom in the organosilicon D3NR3compound, wherein the cyclic aminal moiety has , wherein D1is a divalent hydrocarbyl group of 2 to 8D3is a divalent linking group comprising at least one carbon atom; and R2and R3are each independently selected from the group consisting of H, a monovalent hydrocarbyl group, a monovalent substituted hydrocarbyl group, and an organosilicon moiety.

2. The cyclic aminal – functional organosilicon compound of claim 1, wherein D3has formula H , wherein each R’ and each R” are independently selected from the grouphydrocarbyl group, and a substituted monovalent hydrocarbyl group, with the proviso that alternatively R’ and R” may bond together to form a cyclic moiety; and subscript n is an integer with a value of 0 to 6.

3. The cyclic aminal – functional organosilicon compound of claim 1 or claim 2, wherein R2is selected from the group consisting of H and an alkyl group of 1 to 6 carbon atoms, and R3is selected from the group consisting of H and an alkyl group of 1 to 6 carbon atoms.

4. The cyclic aminal – functional organosilicon compound of claim 1 or claim 2, wherein one or both of R2and R3is the organosilicon moiety, and the organosilicon moiety is an alkoxysilylmoiety of formula, wheresubscript a is 1 to 3,D2is a divalent hydrocarbyl group of 2 to 12 carbon atoms, and R1is an alkyl group of 1 to 6 carbon atoms.

5. The cyclic aminal - functional organosilicon compound of any one of claims 1 to 4, wherein the cyclic aminal - functional organosilicon compound is a silane of formula: RAxSiR4(4-x), wherein each RAis the cyclic aminal moiety; each R4is independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, an acyloxy group of 2 to 18 carbon atoms, and a hydrocarbonoxy-functional group of 1 to 18 carbon atoms; and subscript x is 1 to 4.

6. The cyclic aminal - functional organosilicon compound of any one of claims 1 to 4, wherein the cyclic aminal - functional organosilicon compound is a polyorganosiloxane of unit formula: (R43SiO1 / 2)a(R42RASiO1 / 2)b(R42SiO2 / 2)c(R4RASiO2 / 2)d(R4SiO3 / 2)e(RASiO3 / 2)f(SiO4 / 2)g(ZO1 / 2)h; where each RAis the cyclic aminal moiety; each R4is independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, an acyloxy group of 2 to 18 carbon atoms, and a hydrocarbonoxy-functional group of 1 to 18 carbon atoms; each Z is independently selected from the group consisting of a hydrogen atom and R5, where each R5is independently selected from the group consisting of alkyl groups of 1 to 18 carbon atoms and aryl groups of 6 to 18 carbon atoms; subscripts a, b, c, d, e, f, and g represent numbers of each unit in the unit formula and have values such that subscript a ≥ 0, subscript b ≥ 0, subscript c ≥ 0, subscript d ≥ 0, subscript e ≥ 0, subscript f ≥ 0, subscript g ≥ 0, and subscript h has a value such that 0 ≤ h / (e + f + g) ≤ 1.5, with the provisos that a quantity (b + d + f) ≥ 1, and 10,000 ≥ (a + b + c + d + e + f + g) ≥ 2.

7. The cyclic aminal - functional organosilicon compound of claim 6, wherein said compoundcomprises unit formula: (R43SiO1 / 2)a(R42RASiO1 / 2)b(R42SiO2 / 2)c(R4RASiO2 / 2)d, where each R4is alkyl or aryl; H2C H2C R3each RA, the cyclic aminal moiety, has , wherein subscript n is an integer with a valueD1is a divalent hydrocarbyl group of 2 to 8 carbon atoms; R2and R3are each independently selected from the group consisting of H, an alkyl group of 1 to 6 carbon atoms, and an alkoxysilyl moiety of formula , whereina hydrocarbyl group of 2 to 8 carbon atoms, and R1is an alkyl group of 1 to 4 carbon atoms; subscript a is 0, 1, or 2; subscript b is 0, 1, or 2; a quantity (a + b) has an average value of 2; subscript c is 0 or greater, subscript d is 0 or greater; and a quantity (b + d) is 1 or greater.

8. The cyclic aminal - functional organosilicon compound of claim 1, wherein said compound is selected from the group consisting of: 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)imidazolidine; 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)-1-methylimidazolidine; 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)-1,3-dimethylimidazolidine; 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)-1-(3-(trimethoxysilyl)propyl)imidazolidine; 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)-2,3-dihydro-1H-benzo[d]imidazole; 2-(2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)imidazolidin-1yl)ethan-1-amine; 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)hexahydropyrimidine;2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)-1,3-diazepane; and 2-(2-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)ethyl)-1,3-diazonane.

9. The cyclic aminal – functional organosilicon compound of claim 7, where said compound is a 2,2'-((polydimethylsiloxy-diyl)bis(ethane-2,1-diyl))bis(1-(3- (trimethoxysilyl)propyl)imidazolidine) of formula:

10. A method for synthesizing the cyclic aminal - functional organosilicon compound of any one of claims 1 to 9, where the method comprises: 1) combining starting materials comprising A) a di- or tri- amine compound comprising two or three amino groups per molecule, wherein the amino groups are selected from NH, NH2, or both, and B) an aldehyde-functional organosilicon compound; optionally C) a solvent, thereby preparing a reaction product comprising the cyclic aminal - functional organosilicon compound and a side product comprising water; and optionally 2) scavenging the water; andoptionally 3) recovering the cyclic aminal - functional organosilicon compound from the reaction product.

11. The method of claim 10, where A) the di- or tri- amine compound is selected from the group consisting of A1) an organic di- or tri- amine and A2) a diamino-functional organosilicon compound.

12. The method of claim 11, where starting material A1) is an organic diamine selected from the group consisting of N1-methylethane-1,2-diamine;N1,N2-dimethylethane-1,2-diamine; Ethane- 1,2-diamine; Benzene-1,2-diamine; propane-1,3-diamine; butane-1,4-diamine; hexane-1,6- diamine; N1-(2-aminoethyl)ethane-1,2-diamine; N1,N1’-(ethane-1,2-diyl)bis(ethane-1,2-diamine); and a combination thereof.

13. The method of claim 11, where starting material A2), the diaminofunctional organosilicon compound, is A2-a) a diamino-functional alkoxysilane.

14. The method of claim 13, where A2-a) the diamino-functional alkoxysilane is selected from the group consisting of N1-(3-(trimethoxysilyl)propyl)ethane-1,2-diamine and N1-(3- (triethoxysilyl)propyl)ethane-1,2-diamine.

15. The method of any one of claims 10 to 14, where the aldehyde functional organosilicon compound is a silane of formula (B1): RAldxSiR4(4-x), where each RAld is an independently selected aldehyde group of ,where G is a divalent hydrocarbon group free of aliphaticatoms; each R4is independently selected from the group consisting of an alkyl group of 1 to 18 carbon atoms, an aryl group of 6 to 18 carbon atoms, an acyloxy group of 2 to 18 carbon atoms, and an hydrocarbonoxy-functional group of 1 to 18 carbon atoms; and subscript x is 1 to 4.

16. The method of any one of claims 10 to 14, where the aldehyde-functional organosilicon compound is an aldehyde-functional polyorganosiloxane of unit formula: (R43SiO1 / 2)a(R42RAldSiO1 / 2)b(R42SiO2 / 2)c(R4RAldSiO2 / 2)d(R4SiO3 / 2)e(RAldSiO3 / 2)f(SiO4 / 2)g(ZO1 / 2)h;where each RAld is an independently aldehyde group of adivalent hydrocarbon group free of aliphatic unsaturation that each R4is independently selected from the group18 carbon atoms, an aryl group of 6 to 18 carbon atoms, and an hydrocarbonoxy group of 1 to 18 carbon atoms; each Z is independently selected from the group consisting of a hydrogen atom and R5, where each R5is independently selected from the group consisting of alkyl groups of 1 to 18 carbon atoms and aryl groups of 6 to 18 carbon atoms; subscripts a, b, c, d, e, f, and g represent numbers of each unit in the unit formula and have values such that subscript a ≥ 0, subscript b ≥ 0, subscript c ≥ 0, subscript d ≥ 0, subscript e ≥ 0, subscript f ≥ 0, subscript g ≥ 0, with the provisos that a quantity (b + d + f) ≥ 1, and 10,000 ≥ (a + b + c + d + e + f + g) ≥ 2; and subscript h has a value such that 0 ≤ h / (e + f + g) ≤ 1.5.

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