WO2019014318A1

WO2019014318A1 - Siloxane compositions

Info

Publication number: WO2019014318A1
Application number: PCT/US2018/041593
Authority: WO
Inventors: Michael S. Ferritto; Nanguo Liu; Kimmai T. Nguyen
Original assignee: Dow Silicones Corporation
Priority date: 2017-07-12
Filing date: 2018-07-11
Publication date: 2019-01-17

Abstract

This disclosure relates to anhydride functional siloxanes containing at least one sulphur atom and their derivatives, and to processes to make the same. Also disclosed are uses of the anhydride functional siloxanes containing at least one sulphur atom and their derivatives.

Description

SILOXANE COMPOSITIONS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and all advantages of U.S. Patent Application No. 62/531 ,716 filed on 12 July 2017, the contents of which is hereby incorporated by reference.

TECHNICAL FIELD

[0002] This disclosure relates to anhydride functional siloxanes containing at least one sulphur atom, to derivatives of such anhydride functional siloxanes, and to processes for producing the same. Also disclosed are uses of the anhydride functional siloxanes containing at least one sulphur atom and uses of the derivatives of such anhydride functional siloxanes.

[0003] Anhydride functional siloxanes can be obtained from hydrosilylation reaction of allylsuccinic anhydride with an organohydrogensiloxane. However, cost may render these materials unattractive.

[0004] The nucleophilic addition of nucleophiles to an a, β-unsaturated carbonyl compound is referred to as Michael addition and is usually catalyzed by a base. Michael addition of organic thiols (R-SH) to a, β-unsaturated carbonyl compounds is known for organic compounds. Triethylamine (TEA) is commonly used as a catalyst for this type of reaction.

[0005] U.S. Pat. No. 5,015,700 to Herzig et al. discloses a process for preparing anhydride- functional organo(poly)siloxanes by reacting maleic anhydride with a butadienyl-functional organo(poly)siloxane without first having to isolate the butadienyl-functional organo(poly)siloxane.

BRIEF SUMMARY OF THE INVENTION

[0006] An anhydride functional siloxane containing at least one sulphur atom is provided. In various embodiments, the anhydride functional siloxane is the reaction product of (A) a mercapto functional siloxane with (B) an a, β-unsaturated carboxylic acid anhydride compound, by way of a Michael addition.

[0007] Derivatives of the anhydride functional siloxane containing at least one sulphur atom are also provided. In addition, processes to prepare the anhydride functional siloxanes containing at least one sulphur atom, and to prepare the derivatives of the anhydride functional siloxanes containing at least one sulphur atom, are provided.

[0008] The anhydride functional siloxanes containing at least one sulphur atom and their derivatives may find uses in various applications, including coating applications, surface treatment of powders and metallic oxides, and personal care applications, among others.

BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is ¹ H NMR (proton nuclear magnetic resonance) spectra of a mercapto functional silicone of the general formula: MD 3D gM; where R^* is -CH2CH2CH2SH, and having a -SH content of 1 .2 mmol/g. The X-axis is chemical shift in parts per million (ppm) and the Y-axis is normalized intensity.

[0010] Figure 2 is FTIR (Fourier-transform infrared) spectra of the anhydride and derivative functional siloxanes. The X-axis is wavenumber in crrf^ . The "A" curve: anhydride functional siloxane. The "B" curve: amide carboxylic acid functional siloxane. The "C" curve: dicarboxylic acid functional siloxane. The "D" curve: ester carboxylic acid functional siloxane. Curves are as illustrated, top ("A") to bottom ("D").

DETAILED DESCRIPTION OF THE INVENTION

[0011] An anhydride functional siloxane containing at least one sulphur atom is provided. The anhydride functional siloxane containing at least one sulphur atom may also be referred to herein as the anhydride functional siloxane. The anhydride functional siloxane has the general formula (I):

za^Rb^Si0(4-a-b)/2 0;

wherein Z is -X-S-A, where X is a linking group containing 1 to 18 carbon atoms, S is a sulphur atom, and A is an anhydride; each R is independently a monovalent hydrocarbon radical; and subscripts "a" and "b" are independently 0 to 3, provided that a+b is on average ≤ 3, and at least one Z is present.

[0012] In various embodiments, X is a divalent group of the general formula -(CH₂)_n- wherein subscript "n" is 1 to 18, optionally 1 to 15, optionally 1 to 12, optionally 1 to 9, optionally 1 to 6, optionally 1 to 3, optionally 1 , 2, or 3. In specific embodiments, X is - (CH₂)₃-.

[0013] In various embodiments, each R is independently a monovalent hydrocarbon radical containing up to 18 carbon atoms, optionally from 1 to 12 carbon atoms, optionally from 1 to 6 carbon atoms. Examples of suitable hydrocarbon radicals for R include: alkyi radicals, such as methyl, ethyl, propyl, pentyl, octyl, undecyl and octadecyl; alkenyl radicals, such as vinyl, allyl and 5-hexenyl; cycloaliphatic radicals, such as cyclohexyl and cyclohexenylethyl; and aryl radicals, such as phenyl, tolyl, xylyl, benzyl, and 2-phenylethyl. Non-reactive substituents that can be present on R include, but are not limited to, halogen and cyano. Substituted hydrocarbon radicals that can be represented by R include, but are not limited to, chloromethyl and 3,3,3-trifluoropropyl. In certain embodiments, each R is independently an alkyi or aryl radical. In further embodiments, each R is independently an alkyi radical, e.g. a methyl.

[0014] In various embodiments, subscript "a" is 1 to 3, optionally is 1 to 2 or 2 to 3. In various embodiments, subscript "b" is 1 to 3, optionally is 1 to 2 or 2 to 3. In certain embodiments, subscripts "a" and "b" have, on average, a value of from 1 to 3, optionally a value of from 1 .8 to 2.2.

[0015] A process (P1 ) to produce the anhydride functional siloxanes containing at least one sulphur atom is also provided. The process (P1 ) comprises the steps of:

providing (A) a mercapto functional siloxane, (B) an a, β-unsaturated carboxylic acid anhydride compound (B), and (C) a catalyst; and

reacting the mercapto functional siloxane (A) with the a, β-unsaturated carboxylic acid anhydride compound (B) in the presence of the catalyst (C);

optionally, in the presence of (D) a solvent.

[0016] In various embodiments, the mercapto functional siloxane (A) may be a linear polymer and/or a branched polymer, having the general formula (II):

R⁴ _cR⁵ _dSiO₍₄._a._b)/2 (II); wherein R⁴ and R^ may be the same or different and denotes, hydrogen, a hydrocarbon group having from 1 to 18 carbon atoms, a substituted hydrocarbon group having from 1 to 18 carbon atoms or a hydrocarbonoxy group having up to 18 carbon atoms; wherein subscripts "c" and "d" have, on average, a value of from 1 to 3, optionally a value of from 1 .8 to 2.2; and wherein at least one R^ contains a sulphur atom, optionally at least one R^ is a mercapto group.

[0017] For the purpose of this disclosure, "substituted" means one or more hydrogen atoms in a hydrocarbon group has been replaced with another substituent. Examples of such substituents include, but are not limited to, halogen atoms such as chlorine, fluorine, bromine, and iodine; halogen atom containing groups such as chloromethyl, perfluorobutyl, trifluoroethyl, and nonafluorohexyl; oxygen atoms; oxygen atom containing groups such as (meth)acrylic and carboxyl; nitrogen atoms; nitrogen atom containing groups such as amino- functional groups, amido-functional groups, and cyano-functional groups; sulphur atoms; and sulphur atom containing groups such as mercapto groups.

[0018] Particular examples of groups R⁴ include methyl, ethyl, propyl, butyl, vinyl, cyclohexyl, phenyl, tolyl group, and a propyl group substituted with chlorine or fluorine, such as a 3,3,3-trifluoropropyl, a chlorophenyl, a beta-(perfluorobutyl)ethyl or a chlorocyclohexyl group. In various embodiments, at least some, optionally substantially all, of the groups R⁴ are methyl. Some R⁴ groups may be hydrogen. The siloxane containing oligomers may be linear or branched polydialkylsiloxanes. [0019] In various embodiments, at least one is a mercapto group. Examples of mercapto groups include a 3-mercaptopropyl functional group, a mercaptomethyl group, a 2- mercaptoethyl group, a 1 1 -mercaptoundecyl group, or combinations thereof.

[0020] In various embodiments, the mercapto functional siloxane (A) has a molecular weight of from about 1000 to about 100000 dalton (Da). In certain embodiments, the mercapto functional siloxane (A) has viscosity of from about 10 to about 50000 mPa-s at 25°C. In various embodiments, the mercapto functional siloxane (A) has a -SH content of from about 0.1 to about 5 mmol/g, optionally of from about 0.2 to about 2.5 mmol/g.

[0021] In general, the a, β-unsaturated carboxylic acid anhydride compound (B) will react in a Michael addition reaction. Examples of the a, β-unsaturated carboxylic acid anhydride compound include maleic anhydride, itaconic anhydride, or combinations thereof. The Michael reaction addition will proceed by addition of the anhydride to the mercapto functional group via the a, β-unsaturation of compound (B). The amount of the a, β-unsaturated carboxylic acid anhydride compound (B) is generally based on the sulphur content of the mercapto functional siloxane (A) such as to provide for a ratio (B)/(A) of from about 0.9 to about 1 .

[0022] In various embodiments, the Michael addition reaction may proceed in the presence of an acid catalyst or a base (or basic) catalyst. Examples of acid catalysts include perchloric acid, sulfuric acid, phosphoric acid, hexafluorophosphoric acid, trichloroacetic acid, fumaric acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, or combinations thereof. Examples of base catalysts include trialkylamines, such as triethylamine (TEA), pyridine, diazobicyclo-undecene (DBU), or combinations thereof. In certain embodiments, the catalyst is present in an amount of from about 100 to about 1000 parts per million (ppm).

[0023] In various embodiments, the solvent (D) is an anhydrous, chemically inert, solvent to compatibilize the mercapto functional siloxane (A) and the a, β-unsaturated carboxylic acid anhydride compound (B). In certain embodiments, the solvent (D) may be selected from organic solvents.

[0024] Examples of organic solvents include aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, esters, ethers, glycols, glycol ethers, alkyl halides, aromatic halides, or combinations thereof. Particular examples of organic solvents include 1 ,4-dioxane, acetone, toluene, xylene, chloroform, tetrahydrofuran, or combinations thereof.

[0025] In various embodiments, the process (P1 ), e.g. reaction step, is performed at a temperature of from about 20°C to about 180°C, optionally of from about 40°C to about 120°C. In certain embodiments, the duration of the process (P1 ), e.g. reaction step, is of from about 1 to about 9 hour(s), optionally of from about 1 to about 6 hour(s). The order of addition of components for the process (P1 ) is not critical. In certain embodiments, all components are combined with mixing, and the mixture is set to a temperature of from about 20°C to about 180°C.

[0026] After reaction, the solvent (D) may be removed by any conventional means to remove solvents, or be retained in the system to aid in handling of the produced anhydride functional siloxanes containing at least one sulphur atom. Examples of methods to remove solvents include distillation, open-dish evaporation, reduced-pressure evaporation, rotary evaporation, and lyophilisation. Rotary evaporation may allow flexibility of process.

[0027] In various embodiments, the anhydride functional siloxanes containing at least one sulphur atom produced by the process (P1 ) have a molecular weight of from about 1000 to about 100000 Da, optionally of from about 1000 to about 50000 Da, optionally of from about 1000 to about 10000 Da.

[0028] The progress of the reaction in the process (P1 ) may be assessed by way of ¹ H NMR (proton-NMR). In general, the chemical shift (in chloroform) of the two protons in maleic anhydride is at about 7.0 ppm and the chemical shift of the -SH proton in the mercapto functional silicone is about 1 .25 ppm to about 1 .35 ppm (see Figure 1 - on Agilent 400MR (400MHz)). As the reaction of the process (P1 ) proceeds, the peaks at -7.0 ppm and ~1 .25- 1 .35 ppm typically decrease and eventually disappear upon completion of the reaction (100%).

[0029] A side reaction may occur between triethylamine and maleic anhydride, providing for coloration of the anhydride functional siloxane. It is thought that this side reaction does not negatively impact the reaction of the process (P1 ).

[0030] In various embodiments, the process (P1 ) is performed under anhydrous conditions, to avoid unwanted reaction of the a, β-unsaturated carboxylic acid anhydride compound (B) with water. In certain embodiments, the process (P1 ) is carried out under a nitrogen controlled atmosphere (e.g. a N₂ blanket).

[0031] In various embodiments, the anhydride functional siloxane containing at least one sulphur atom may further be reacted with water, alcohols, or amines to form dicarboxylic acid, ester carboxylic acid, or amide carboxylic acid/imide groups, respectively. In certain embodiments, the anhydride functional siloxane is reacted with water. In other embodiments, the anhydride functional siloxane is reacted with at least one alcohol. In yet other embodiments, the anhydride functional siloxane is reacted with at least one amine. Using a combination of such reactants is also contemplated, e.g. water and alcohol(s), water and amine(s), alcohol(s) and/or amine(s), etc.

[0032] Therefore, derivatives of the anhydride functional siloxane containing at least one sulphur atom, in the form of either one of a dicarboxylic acid functional siloxane, an ester carboxylic acid functional siloxane, or an amide carboxylic acid/imide functional siloxane, are also provided.

[0033] In various embodiments, the derivatives of the anhydride functional siloxane containing at least one sulphur atom have the general formula (III):

z a^Rb^Si0(4-a-b)/2 ("I"):

wherein Z' is -X-S-A', where X is a linking group containing 1 to 18 carbon atoms, S is a sulphur atom, and A' is an anhydride derivative. The anhydride derivative (Α') is generally selected from an ester carboxylic acid, a dicarboxylic acid, or an amide carboxylic acid. Each R is independently a monovalent hydrocarbon radical, as described above. Subscripts "a" and "b" are also as described above, provided that a+b is on average≤ 3, and at least one Z' is present.

[0034] A process (P2) to produce the derivatives of the anhydride functional siloxanes containing at least one sulphur atom is also provided. The process (P2) comprises the steps of:

providing the anhydride functional siloxane containing at least one sulphur atom (as described above); and

reacting the anhydride functional siloxane containing at least one sulphur atom with either one or more of water, an amine, or an alcohol;

optionally, in the presence of a solvent.

[0035] Examples of the amine include any primary or secondary amines. Examples of primary amines include R^NH₂, where is an alkyl or aryl group having 1 to 18 carbon atoms. Examples of secondary amines include R^ R²NH, where R^ and R² are independently an alkyl or aryl group having 1 to 18 carbon atoms. Suitable alkyl and aryl groups are generally as described above for the R group.

[0036] Examples of the alcohol include R^OH, where R^ is an alkyl or aryl group having 1 to 18 carbon atoms. Suitable alkyl and aryl groups are generally as described above for the R group. Specific examples of suitable alcohols include ethanol, butanol, and isopropyl alcohol.

[0037] The solvent for the process (P2) may be the same or different from the solvent (D) described above for the process (P1 ). In certain embodiments, the solvents are the same. In other embodiments, the solvents are different.

[0038] In various embodiments, the process (P2), e.g. reaction step, is performed at a temperature of from about 20°C to about 180°C, optionally of from about 40°C to about 120°C. In certain embodiments, the duration of the process (P2), e.g. reaction step, is of from about 1 to about 9 hour(s), optionally of from about 1 to about 6 hour(s). The order of addition of components for the process (P2) is not critical. In certain embodiments, all components are combined with mixing, and the mixture is set to a temperature of from about 20°C to about 180°C.

[0039] The progress of the reaction in the process (P2) may be assessed by way of Attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FTIR). An example of ATR-FTIR spectra of the anhydride and derivative functional siloxanes is shown in Figure 2 - on Nicolet 6700 from Thermo Electron Corporation. The anhydride functional siloxane has two characteristic vibrational peaks at 1865 cm^{" 1} and 1790 cm^"1 . The dicarboxylic acid functional siloxane has a characteristic vibrational peak at 1714 cm^{" 1} . The amide carboxylic acid functional siloxane exhibits characteristic vibrational peaks for an amide (-CONH-; 1645 cm^"1 and 1551 cm^"1 ) as well as a vibrational peak for a carboxylic acid (-COOH; 1712 cm^"1 ). The ester carboxylic acid functional siloxane exhibits characteristic vibrational peaks for an ester (-COO-; 1740 cm^{" 1} ) and a carboxylic acid (-

COOH; 1714 cm^"1 ). As shown in Figure 2, the conversion of the anhydride group to other organofunctional groups is near 100%.

[0040] In various embodiments, the derivatives of the anhydride functional siloxanes containing at least one sulphur atom produced by the process (P2) have a molecular weight of from about 1000 to about 100000 Da, optionally of from about 1000 to about 50000 Da, optionally of from about 1000 to about 10000 Da.

[0041] In various embodiments, the anhydride functional siloxane, and the derivatives of the anhydride functional siloxane, are of the general formula (IV):

(IV);

wherein each R is as described above, R^b is Z as described above (for the anhydride functional siloxane) or R⁶ is 71 as described above (for the derivatives), subscript "x" is≥0; and subscript "y" is≥1 .

[0042] In certain embodiments, subscript "x" is from about 1 to about 500, optionally about 25 to about 250, optionally about 50 to about 150, optionally about 50 to about 125. In certain embodiments, subscript "y" is from about 1 to about 50, optionally about 2 to about 25, optionally about 3 to about 10, optionally about 5 to about 10. In specific embodiments, x+y is from about 5 to about 500, optionally about 10 to about 250, optionally about 25 to about 150, optionally about 50 to about 125. [0043] The anhydride functional siloxanes containing at least one sulphur atom and their derivatives containing at least one sulphur atom described herein may be useful in a variety of applications. Such applications include, but are not limited to, use in personal care compositions, as surface treatments of powders or metal oxides particles, as textile treatments, as leather treatments, use in coating applications, and the like.

EXAMPLES

[0044] The following examples, illustrating certain embodiments of the invention, are intended to illustrate and not to limit the invention. All percentages are in wt. % unless otherwise stated. Siloxy units "M" are of the general formula [R3S1O-1/2] ^ancl siloxy units "D" are of the general formula [R₂Si0₂/2]- In such siloxy units, each R is independently as described above (e.g. are alkyl groups, such as -CH3), unless stated otherwise (e.g. where an R is an alternate group, e.g. R^* described below).

Example 1 : Synthesis of anhydride functional siloxane 1

[0045] 200.2g of mercapto functional siloxane (MD₅₃D^R* ₆M; where R^* is -

CH2CH2CH2SH, and having a -SH content of 1 .2 mmol/g), 23.6g of maleic anhydride (1 .0 equivalent to -SH), and 103g of anhydrous 1 ,4-dioxane were mixed in a pre-dried 4-neck round bottom flask in a glove box. Then, the flask was taken out from the glove box and equipped with a water-cooled condenser, mechanical stirrer, N₂ blanket, and thermal couple.

Heat was turned on. 0.2g of triethylamine was added to the flask at T = 44°C. The solution turned to yellow color quickly. The solution was stirred at 60°C for 4 hours. 0.2 ml of sulfuric acid was added to neutralize the triethylamine catalyst and the pot temperature was cooled down to <35°C. Volatiles were removed via rotary evaporation at 80°C and <3 mmHg for 60 minutes. The product (218.5g) was a viscous fluid with dark brown color.

Example 2: Synthesis of anhydride functional siloxane 2

[0046] 201 .6g of mercapto functional siloxane (MD-| D^R* _{7 7}M; where R^* is -

CH2CH2CH2SH, and having a -SH content of 0.82 mmol/g), 16.3g of maleic anhydride (1 .0 equivalent to -SH), and 105.5g of anhydrous 1 ,4-dioxane were mixed in a pre-dried 4-neck round bottom flask in a glove box. Then, the flask was taken out from the glove box and equipped with a water-cooled condenser, mechanical stirrer, N₂ blanket, and thermal couple.

Heat was turned on. 31 μΙ of triethylamine was added to the flask at T = 40°C. The solution turned to yellow color quickly. The solution was stirred at 60°C for 4 hours. 46 μΙ of sulfuric acid was added to neutralize the triethylamine catalyst and the pot temperature was cooled down to <30°C. Volatiles were removed via rotary evaporation at 80°C and <3 mmHg for 30 minutes. The product (210.3g) was a viscous fluid with dark brown color. Example 3 Synthesis of dicarboxylic acid functional siloxane

[0047] The dicarboxylic acid functional siloxane of Example 3 was obtained by reacting the anhydride functional siloxane of Example 1 with water. 155g of anhydride functional siloxane of Example 1 was dissolved into 137g of acetone and 52g of toluene. 20g of deionized water was added to the solution and the solution was heated to reflux at 62-63°C for 6 hours. Volatiles were removed via rotary evaporation at 80°C and <0.3 mmHg for 30 minutes. Yield was 146.1 g. The product was a very viscous fluid with yellow color at 80°C. At room temperature (~23-25°C), it was not flowable due to the extensive hydrogen bonding between -COOH groups.

Example 4: Synthesis of ester carboxylic acid functional siloxane

[0048] The ester carboxylic acid functional siloxane of Example 4 was formed by reacting the anhydride functional siloxane of Example 2 with n-butanol. 29.8g of anhydride functional siloxane of Example 2 was dissolved into 18.8g of tetrahydrofuran and 47g of toluene. 5.5g of n-butanol was added into the solution and the solution was heated to reflux at 107-108°C for 4.5 hours. Volatiles were removed via rotary evaporation at 90°C and <0.3 mmHg for 30 minutes. The product had less color and lower viscosity than the anhydride functional siloxane.

Example 5: Synthesis of amide carboxylic acid functional siloxane

[0049] The amide carboxylic acid functional siloxane of Example 5 was created by reacting the anhydride functional siloxane of Example 2 with hexyl amine. 19.2g of anhydride functional siloxane of Example 2 was dissolved into 12.1 g of tetrahydrofuran and 18.2g of toluene. 1 .46g of hexyl amine (1 .0 equivalent to the amount of the anhydride) was added into the solution and the solution was rotated in an oil bath at 90°C for 2 hours. Volatiles were removed via rotary evaporation at 90°C and <0.3 mmHg for 30 minutes. The product had less color and lower viscosity than the anhydride functional siloxane.

[0050] The terms "comprising" or "comprise" are used herein in their broadest sense to mean and encompass the notions of "including," "include," "consist(ing) essentially of," and "consist(ing) of." The use of "for example," "e.g.," "such as," and "including" to list illustrative examples does not limit to only the listed examples. Thus, "for example" or "such as" means "for example, but not limited to" or "such as, but not limited to" and encompasses other similar or equivalent examples. The term "about" as used herein serves to reasonably encompass or describe minor variations in numerical values measured by instrumental analysis or as a result of sample handling. Such minor variations may be in the order of ±0-25, ±0-10, ±0-5, or ±0-2.5, % of the numerical values. Further, The term "about" applies to both numerical values when associated with a range of values. Moreover, the term "about" may apply to numerical values even when not explicitly stated.

[0051] Generally, as used herein a hyphen "-" or dash "-" in a range of values is "to" or "through"; a ">" is "above" or "greater-than"; a "≥" is "at least" or "greater-than or equal to"; a "<" is "below" or "less-than"; and a "≤" is "at most" or "less-than or equal to." On an individual basis, each of the aforementioned applications for patent, patents, and/or patent application publications, is expressly incorporated herein by reference in its entirety in one or more non- limiting embodiments.

[0052] It is to be understood that the appended claims are not limited to express and particular compounds, compositions, or methods described in the detailed description, which may vary between particular embodiments which fall within the scope of the appended claims. With respect to any Markush groups relied upon herein for describing particular features or aspects of various embodiments, it is to be appreciated that different, special, and/or unexpected results may be obtained from each member of the respective Markush group independent from all other Markush members. Each member of a Markush group may be relied upon individually and or in combination and provides adequate support for specific embodiments within the scope of the appended claims.

[0053] It is also to be understood that any ranges and subranges relied upon in describing various embodiments of the present invention independently and collectively fall within the scope of the appended claims, and are understood to describe and contemplate all ranges including whole and/or fractional values therein, even if such values are not expressly written herein. One of skill in the art readily recognizes that the enumerated ranges and subranges sufficiently describe and enable various embodiments of the present invention, and such ranges and subranges may be further delineated into relevant halves, thirds, quarters, fifths, and so on. As just one example, a range "of from 0.1 to 0.9" may be further delineated into a lower third, i.e., from 0.1 to 0.3, a middle third, i.e., from 0.4 to 0.6, and an upper third, i.e., from 0.7 to 0.9, which individually and collectively are within the scope of the appended claims, and may be relied upon individually and/or collectively and provide adequate support for specific embodiments within the scope of the appended claims. In addition, with respect to the language which defines or modifies a range, such as "at least," "greater than," "less than," "no more than," and the like, it is to be understood that such language includes subranges and/or an upper or lower limit. As another example, a range of "at least 10" inherently includes a subrange of from at least 10 to 35, a subrange of from at least 10 to 25, a subrange of from 25 to 35, and so on, and each subrange may be relied upon individually and/or collectively and provides adequate support for specific embodiments within the scope of the appended claims. Finally, an individual number within a disclosed range may be relied upon and provides adequate support for specific embodiments within the scope of the appended claims. For example, a range "of from 1 to 9" includes various individual integers, such as 3, as well as individual numbers including a decimal point (or fraction), such as 4.1 , which may be relied upon and provide adequate support for specific embodiments within the scope of the appended claims.

[0054] The present invention has been described herein in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. The present invention may be practiced otherwise than as specifically described within the scope of the appended claims. The subject matter of all combinations of independent and dependent claims, both single and multiple dependent, is herein expressly contemplated.

Claims

What is claimed is:

1 . An anhydride functional siloxane containing at least one sulphur atom, the anhydride functional siloxane having the general formula (I):

za^Rb^Si0(4-a-b)/2 0;

2. A process to produce the anhydride functional siloxane containing at least one sulphur atom of claim 1 , said process comprising the steps of:

providing (A) a mercapto functional siloxane, (B) an a, β-unsaturated carboxylic acid anhydride compound, and (C) a catalyst; and

reacting the mercapto functional siloxane (A) with the a, β-unsaturated carboxylic acid anhydride compound (B) in the presence of the catalyst (C), and optionally in the presence of (D) a solvent, to produce the anhydride functional siloxane containing at least one sulphur atom.

3. The process of claim 2, wherein the mercapto functional group(s) of the mercapto functional siloxane (A) is(are) selected from the group consisting of a 3-mercaptopropyl group, a mercaptomethyl group, a 2-mercaptoethyl group, a 1 1 -mercaptoundecyl group, or combinations thereof.

4. The process of claim 2 or 3, wherein the a, β-unsaturated carboxylic acid anhydride compound (B) is selected from the group consisting of maleic anhydride, itaconic anhydride, or a combination thereof.

5. The process of any one of claims 2 to 4, wherein the catalyst (C) is selected from the group consisting of trialkyi amines, pyridine, diazobicyclo-undecene (DBU), or combinations thereof.

6. The process of any one of claims 2 to 5, wherein the solvent (D) is present during reaction and is selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, esters, ethers, glycols, glycol ethers, alkyl halides, aromatic halides, or combinations thereof.

7. The process of any one of claims 2 to 6, wherein the solvent (D) is present during reaction and is selected from the group consisting of 1 ,4-dioxane, acetone, toluene, xylene, chloroform, tetrahydrofuran, or combinations thereof.

8. The process of any one of claims 2 to 7, wherein reaction is performed at a temperature of from about 20°C to about 180°C.

9. A derivative of an anhydride functional siloxane containing at least one sulphur atom, the derivative having the general formula (III):

z a^Rb^Si0(4-a-b)/2 ("I"):

wherein Z' is -X-S-A', where X is a linking group containing 1 to 18 carbon atoms, S is a sulphur atom, and A' is an anhydride derivative, with the anhydride derivative selected from the group consisting of an ester carboxylic acid, a dicarboxylic acid, or an amide carboxylic acid; each R is independently a monovalent hydrocarbon radical; and subscripts "a" and "b" are independently 0 to 3, provided that a+b is on average≤ 3, and at least one Z' is present.

10. The derivative of claim 9, selected from the group consisting of a dicarboxylic acid functional siloxane, an ester carboxylic acid functional siloxane, or an amide carboxylic acid/imide functional siloxane.

1 1 . A process to produce the derivative of claim 9 or 10, said process comprising the steps of:

providing an anhydride functional siloxane containing at least one sulphur atom; and reacting the anhydride functional siloxane containing at least one sulphur atom with one or more of water, an amine, or an alcohol, optionally in the presence of a solvent, to produce the derivative;

wherein the anhydride functional siloxane containing at least one sulphur atom is according to claim 1 or is produced according to the method of any one of claims 2 to 8.

12. The process of claim 1 1 , wherein the amine is used for reaction and is selected from a primary amine, R^NH₂, or a secondary amine, R^ R²NH, where R^, R^ and R² are independently an alkyl or aryl group having 1 to 18 carbon atoms.

13. The process of claim 1 1 or 12, wherein the alcohol is used for reaction and is of the general formula R^OH where R^ is an alkyl or aryl group having 1 to 18 carbon atoms. according to claim 1 or produced according to the method of any one of claims 2 to 8 to provide a dicarboxylic acid functional siloxane, an ester carboxylic acid functional siloxane, or an amide carboxylic acid/imide functional siloxane.

15. Use of the anhydride functional siloxane containing at least one sulphur atom according to claim 1 or produced according to the method of any one of claims 2 to 8, or use of the dicarboxylic acid functional siloxane containing at least one sulphur atom, the ester carboxylic acid functional siloxane containing at least one sulphur atom, or the amide carboxylic acid/imide functional siloxane containing at least one sulphur atom according to claim 9 or 10 or produced according to the method of any one of claims 1 1 to 13, in personal care compositions, as surface treatments of powders or metal oxides particles, as textile treatments, as leather treatments, or in coating applications.

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