Patent Description:
Silane compounds and modified siloxane compounds having a primary amino group find a wide variety of use wherein the adsorption and reactivity of the amino group are utilized, including filler surface modifying agents, resin modifying agents, textile treating agents, paint additives, and cosmetic raw materials, as well as synthesis reactants for high-functionality products.

Of the silane compounds and modified siloxane compounds having a primary amino group, those compounds in which the linker between a silicon atom and the primary amino group has a carbon chain length of at least <NUM> carbon atoms are generally well known, whereas few reports refer to modified siloxane compounds having a carbon chain of one carbon atom, i.e., a primary aminomethyl group.

Patent Document <NUM> (<CIT>) describes a primary aminomethyl-functionality polysiloxane and a method for preparing the same. It is reported that a both end primary aminomethyl-modified polysiloxane is synthesized by reacting a polysiloxane having a hydroxy group at a molecular chain end with an alkoxysilane having a primary aminomethyl group.

Patent Document <NUM> (<CIT>) describes a siloxane compound having a primary aminomethyl group as an organofunctionality siloxane mixture and a method for preparing the same. Since examples relating to such compounds are described nowhere, it is unknown whether the compound can be prepared by the proposed method.

Patent Document <NUM> (<CIT>) describes examples relating to pendant primary aminomethyl-modified polysiloxane compounds and branched primary aminomethyl-modified polysiloxane compounds in which among siloxane structural units, D units (R<NUM>SiO<NUM>/<NUM>) and T units (RSiO<NUM>/<NUM>) are modified. Herein, the desired compound is obtained by using an alkoxysilane having a primary aminomethyl group as the reactant and reacting it with a polysiloxane compound having a hydroxy group at a molecular chain end.

In Patent Documents <NUM> to <NUM>, for the synthesis of siloxane compounds having a primary aminomethyl group, alkoxysilanes having a primary aminomethyl group are used as the reactant.

Patent Document <NUM> (<CIT>) describes disiloxane compounds having a primary aminomethyl group and their synthesis. Synthesis is carried out herein by reacting a disiloxane having a chloromethyl group with sodium azide to form an azide product, followed by hydrogenation.

Patent Document <NUM> discloses <NUM>-tris(trimethylsiloxy)silylethylamine, <NUM>-tris(trimethylsiloxy)silylpropylamine and <NUM>-tris(trimethylsiloxy)silylbutylamine, which are prepared by the reaction of bis(trimethylsilyl)oxides with trialkoxysilylalkylamines in the presence of an alkaline catalyst.

Non-Patent Document <NUM> (<NPL>) describes disiloxane compounds and cyclic siloxane compounds having a primary aminomethyl group and their synthesis.

With regard to the synthesis of siloxane compounds having a primary aminomethyl group, it is possible to obtain the desired compounds by reacting alkoxysilanes having a primary aminomethyl group with polysiloxane compounds having a hydroxy group at a molecular chain end, as in Patent Documents <NUM> to <NUM>.

On the other hand, when low molecular siloxane compounds having a hydroxy group at a molecular chain end are used, it is readily presumed that condensation reaction between hydroxy end groups is accelerated, and H<NUM>O is by-produced at the same time as hydroxy groups disappear.

Further, alkoxysilanes having a substituent at α-position are characterized by accelerated hydrolysis reaction. Since alkoxysilanes having a primary aminomethyl group instantly undergo hydrolysis reaction with by-produced H<NUM>O, it is difficult to obtain primary aminomethylsiloxane compounds having branched chain, for example, M<NUM>T: (R<NUM>SiO<NUM>/<NUM>)<NUM>(RSiO<NUM>/<NUM>) from trialkoxysilanes having a primary aminomethyl group and low molecular siloxane compounds having a hydroxy group at a molecular chain end. No exemplary compounds have been reported.

An object of the invention, which has been made under the above-mentioned circumstances, is to provide a method for preparing a novel primary aminosiloxane compound and more particularly, a method for preparing a novel primary aminomethylsiloxane compound.

Making extensive investigations to attain the above object, the inventor has found that a novel primary aminosiloxane compound is obtained by subjecting a siloxane compound having an imide skeleton to deprotection reaction known as Gabriel synthesis. The invention is predicated on this finding.

Accordingly, the invention provides a method for preparing a novel primary aminosiloxane compound, as defined in the claims.

According to the invention, there is provided a method for preparing novel primary aminosiloxane compounds and more particularly, a method for preparing novel primary aminomethylsiloxane compounds. These novel primary aminosiloxane compounds are highly useful in that they find a wide variety of use wherein the adsorption and reactivity of the amino group are utilized, including filler surface modifying agents, resin modifying agents, textile treating agents, paint additives, and cosmetic raw materials, as well as synthesis reactants for high-functionality products, for example, reactants for ligands in hydrosilylation reaction.

The present disclosure provides a primary aminosiloxane compound having the formula (<NUM>), which is not part of the invention.

H<NUM>N-CR<NUM>R<NUM>-Si(OSiR<NUM>R<NUM>R<NUM>)<NUM>     (<NUM>).

In the formula (<NUM>), R<NUM>, R<NUM>, R<NUM>, R<NUM> and R<NUM> are each independently hydrogen or a C<NUM>-C<NUM> monovalent hydrocarbon group in which some or all carbon-bonded hydrogen atoms may be substituted by halogen atoms or hydroxy groups and which may be separated by oxygen or nitrogen.

Suitable halogen atoms include fluorine, chlorine, bromine and iodine.

The C<NUM>-C<NUM> monovalent hydrocarbon groups include straight, branched or cyclic alkyl, alkenyl, alkynyl, aryl and aralkyl groups.

The alkyl groups are preferably of <NUM> to <NUM> carbon atoms, more preferably of <NUM> to <NUM> carbon atoms, and examples thereof include straight or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, and n-eicosanyl; and cyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, norbornyl, and adamantyl.

The alkenyl groups are preferably of <NUM> to <NUM> carbon atoms, and examples thereof include ethenyl (or vinyl), n-<NUM>-propenyl, n-<NUM>-propenyl, <NUM>-methylethenyl, n-<NUM>-butenyl, n-<NUM>-butenyl, n-<NUM>-butenyl, <NUM>-methyl-<NUM>-propenyl, <NUM>-methyl-<NUM>-propenyl, <NUM>-ethylethenyl, <NUM>-methyl-<NUM>-propenyl, <NUM>-methyl-<NUM>-propenyl, n-<NUM>-pentenyl, n-<NUM>-decenyl, and n-<NUM>-eicosenyl.

The alkynyl groups are preferably of <NUM> to <NUM> carbon atoms, and examples thereof include ethynyl, n-<NUM>-propynyl, n-<NUM>-propynyl, n-<NUM>-butynyl, n-<NUM>-butynyl, n-<NUM>-butynyl, <NUM>-methyl-<NUM>-propynyl, n-<NUM>-pentynyl, n-<NUM>-pentynyl, n-<NUM>-pentynyl, n-<NUM>-pentynyl, <NUM>-methyl-n-butynyl, <NUM>-methyl-n-butynyl, <NUM>-methyl-n-butynyl, <NUM>,<NUM>-dimethyl-n-propynyl, n-<NUM>-hexynyl, n-<NUM>-decynyl, n-<NUM>-pentadecynyl, and n-<NUM>-eicosynyl.

The aryl groups are preferably of <NUM> to <NUM> carbon atoms, more preferably of <NUM> to <NUM> carbon atoms, and examples thereof include phenyl, <NUM>-naphthyl, <NUM>-naphthyl, anthryl, phenanthryl, o-biphenylyl, m-biphenylyl, and p-biphenylyl.

The aralkyl groups are preferably of <NUM> to <NUM> carbon atoms, more preferably of <NUM> to <NUM> carbon atoms, and examples thereof include benzyl, phenylethyl, phenylpropyl, naphthylmethyl, naphthylethyl, and naphthylpropyl.

The hydrocarbon group may have a substituent(s) and may have a plurality of identical or different substituents at an arbitrary position or positions.

Exemplary substituents include halogen atoms such as fluorine and chlorine as mentioned above, and hydroxy.

Also, one or more atoms selected from oxygen and nitrogen may intervene in each group R<NUM>, R<NUM>, R<NUM>, R<NUM> and R<NUM> as long as synthesis is possible.

In the formula (<NUM>), R<NUM> and R<NUM> are more preferably hydrogen. When both R<NUM> and R<NUM> are hydrogen, the compound having formula (<NUM>) is a primary aminomethylsiloxane compound.

In the formula (<NUM>), R<NUM>, R<NUM> and R<NUM> are more preferably selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, butyl, n-octyl, n-decyl, n-dodecyl, phenyl, <NUM>-isopropylphenyl, vinyl, hydroxyethyloxypropyl, and trifluoromethylethyl. Methyl is most preferred.

Examples of the primary aminosiloxane compound having the formula (<NUM>) are shown below. <CHM>
<CHM>
<CHM>.

The method for preparing the primary aminosiloxane compound having the formula (<NUM>) involves the step of reacting a siloxane compound having the following formula (<NUM>) as a precursor with a deprotecting agent.

R<NUM>-C(=O)-NR<NUM>-CR<NUM>R<NUM>-Si(OSiR<NUM>R<NUM>R<NUM>)<NUM>     (<NUM>).

In the formula (<NUM>), R<NUM>, R<NUM>, R<NUM>, R<NUM> and R<NUM> are as defined above.

Of the groups R<NUM>, R<NUM>, R<NUM>, R<NUM> and R<NUM>, more preferably R<NUM> and R<NUM> are hydrogen, and R<NUM>, R<NUM> and R<NUM> are selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, butyl, n-octyl, n-decyl, n-dodecyl, phenyl, <NUM>-isopropylphenyl, vinyl, hydroxyethyloxypropyl, and trifluoromethylethyl.

R<NUM> is hydrogen or -C(=O)-R<NUM>, and R<NUM> and R<NUM> each are a C<NUM>-C<NUM> monovalent hydrocarbon group, with the proviso that when R<NUM> is -C(=O)-R<NUM>, R<NUM> may bond with R<NUM> to form a divalent hydrocarbon group to construct a cyclic structure.

In the formula (<NUM>), examples of the C<NUM>-C<NUM> monovalent hydrocarbon groups R<NUM> and R<NUM> are as exemplified above for R<NUM> to R<NUM>.

In the formula (<NUM>), R<NUM> is preferably -C(=O)-R<NUM>. Preference is given to a compound having the formula (<NUM>) wherein R<NUM> is -C(=O)-R<NUM>, and R<NUM> bonds with R<NUM> to form a divalent hydrocarbon group to construct a cyclic structure, that is, a cyclic imidosiloxane compound having the following formula (<NUM>):.

R<NUM>N-CR<NUM>R<NUM>-Si(OSiR<NUM>R<NUM>R<NUM>)<NUM>     (<NUM>).

wherein R<NUM>, R<NUM>, R<NUM>, R<NUM> and R<NUM> are as defined above, R<NUM> is a divalent group: -C(=O)-X-C(=O)-, and X is a C<NUM>-C<NUM> divalent hydrocarbon group.

In the formula (<NUM>), X is selected from C<NUM>-C<NUM> divalent hydrocarbon groups, for example, unsubstituted or substituted alkylene, alkenylene, arylene, and aralkylene groups.

The alkylene groups may be straight, branched or cyclic and are preferably of <NUM> to <NUM> carbon atoms, more preferably of <NUM> to <NUM> carbon atoms. Examples thereof include straight or branched alkylene groups such as methylene, ethylene, propylene, trimethylene, n-butylene, isobutylene, s-butylene, n-octylene, <NUM>-ethylhexylene, n-decylene, n-undecylene, n-dodecylene, n-tridecylene, n-tetradecylene, n-pentadecylene, n-hexadecylene, n-heptadecylene, n-octadecylene, n-nonadecylene, and n-eicosanylene; and cyclic alkylene groups such as <NUM>,<NUM>-cyclohexylene.

The alkenylene groups may be straight, branched or cyclic and are preferably of <NUM> to <NUM> carbon atoms, more preferably of <NUM> to <NUM> carbon atoms. Examples thereof include straight or branched alkenylene groups such as ethenylene, propenylene, and butenylene.

The arylene groups are preferably of <NUM> to <NUM> carbon atoms, more preferably of <NUM> to <NUM> carbon atoms. Examples thereof include o-phenylene, m-phenylene, p-phenylene, <NUM>,<NUM>-naphthylene, <NUM>,<NUM>-naphthylene, <NUM>,<NUM>-naphthylene, and <NUM>,<NUM>'-biphenylene.

The aralkylene groups are preferably of <NUM> to <NUM> carbon atoms, more preferably of <NUM> to <NUM> carbon atoms. Examples thereof include -(CH<NUM>)k-Ar- wherein Ar is a C<NUM>-C<NUM> arylene group and k is an integer of <NUM> to <NUM>, -Ar-(CH<NUM>)k- wherein Ar and k are as defined above, and -(CH<NUM>)k-Ar-(CH<NUM>)k- wherein Ar is as defined above and k is each independently as defined above.

Of these groups, ethylene, ethenylene, and o-phenylene are preferred.

In the hydrocarbon group X, any carbon-bonded hydrogen may be substituted, and exemplary substituents include halogen atoms such as fluorine, chlorine, bromine and iodine, and alkoxy groups such as methoxy, ethoxy and propoxy. Preferably X is unsubstituted.

Examples of the siloxane compound having the formula (<NUM>), preferably the formula (<NUM>) are shown below. <CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

While the primary aminosiloxane compound having the formula (<NUM>) is obtained by deprotecting the siloxane compound having the formula (<NUM>), preferably the formula (<NUM>) as precursor, the method for preparing the siloxane compound having the formula (<NUM>), preferably the formula (<NUM>) as precursor is, for example, by reacting a siloxane compound having a chloromethyl group with an alkali metal salt of an amide compound or imide compound.

The siloxane compound having a chloromethyl group can be prepared by reacting a chloromethyltrialkoxysilane, chloromethyldialkoxymethylsilane or chloromethylalkoxydimethylsilane with a disiloxane compound such as <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexamethyldisiloxane or <NUM>,<NUM>,<NUM>,<NUM>-tetramethyldisiloxane in the presence of an acid catalyst.

When the siloxane compound having a chloromethyl group has a Si-H group, a substituent may be introduced by hydrosilylation reaction with the aid of a platinum catalyst (e.g., Karstedt catalyst or Speier catalyst) or Rh catalyst.

The alkali metal salt of an amide compound or imide compound is obtained by reacting an amide compound such as acetamide or an imide compound such as succinimide, maleimide or phthalimide with an alkali metal alkoxide such as sodium methoxide, sodium t-butoxide or potassium t-butoxide. Besides, potassium phthalimide is commercially available.

In preparing the siloxane compound having the formula (<NUM>), the alkali metal salt of an amide compound or imide compound is used in an amount of <NUM> to <NUM> moles, preferably <NUM> to <NUM> moles per mole of chloromethyl group on the siloxane compound having a chloromethyl group. In order to accelerate the reaction, for example, a catalytic amount of alkali metal iodide such as sodium iodide may be added.

In preparing the siloxane compound having the formula (<NUM>), an organic solvent may be used. For example, ether compounds such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and tetrahydrofuran, and amide compounds such as N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone are used.

The reaction conditions under which the siloxane compound having the formula (<NUM>) is prepared are not particularly limited and typically include a reaction temperature of room temperature (<NUM>±<NUM>) to <NUM>, preferably <NUM> to <NUM> and a reaction time of <NUM> to <NUM> hours.

At the end of reaction, the reaction product is subjected to filtration or separatory washing with distilled water or neutral aqueous solution of a salt such as NaCl or Na<NUM>SO<NUM>, and the organic layer is dried over Na<NUM>SO<NUM>. These treatments are followed by vacuum drying, yielding the siloxane compound having the formula (<NUM>). It is noted that the reaction product may be diluted with a solvent such as hexane prior to the filtration or separatory washing.

Further, a deprotecting agent is added to the siloxane compound having the formula (<NUM>), preferably the formula (<NUM>) as precursor to induce deprotection to produce the primary aminosiloxane compound having the formula (<NUM>).

The deprotecting agent used for deprotection of the siloxane compound having the formula (<NUM>) may be one capable of converting the amide skeleton (e.g., R<NUM>-C(=O)-N) or imide skeleton (e.g., R<NUM>-C(=O)-N-C(=O)-R<NUM>) to an amino group. It is selected from, for example, the compounds described in <NPL>, preferably hydrazine monohydrates and primary amine compounds, more preferably primary amine compounds.

The primary amine compounds are not particularly limited as long as the reaction takes place. Compounds having an amino group and containing a C<NUM>-C<NUM> straight, branched or cyclic hydrocarbon group are preferred, with primary alkylamine compounds being more preferred.

The primary alkylamine compounds are not particularly limited as long as the reaction takes place. Examples include alkylamines such as methylamine, n-butylamine, hexylamine, and octylamine, as well as ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenehexamine.

The amount of the deprotecting agent used may be about <NUM> to about <NUM> moles, preferably <NUM> to <NUM> moles, more preferably <NUM> to <NUM> moles per mole of the compound having formula (<NUM>).

In preparing the primary aminosiloxane compound having the formula (<NUM>), an organic solvent may be added. Any organic solvent may be used as long as it does not interfere with the reaction. Use may be made of aliphatic hydrocarbons such as pentane, hexane, heptane, octane, and cyclohexane; ethers such as diethyl ether, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether, tetrahydrofuran, and <NUM>,<NUM>-dioxane; and aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene.

The reaction conditions under which the primary aminosiloxane compound having the formula (<NUM>) is prepared are not particularly limited and typically include a reaction temperature of <NUM> to <NUM>, preferably <NUM> to <NUM> and a reaction time of <NUM> to <NUM> hours.

The primary aminosiloxane compounds thus obtained, especially primary aminomethylsiloxane compounds are highly useful in that they find a wide variety of use where the adsorption and reactivity of the amino group are utilized, including filler surface modifying agents, resin modifying agents, textile treating agents, paint additives, and cosmetic raw materials, as well as synthesis reactants for high-functionality products, for example, reactants for ligands in hydrosilylation reaction.

Synthesis Examples and Examples are given below for illustrating the invention. In Synthesis Examples and Examples, reactions and storage of products are conducted in nitrogen atmosphere unless otherwise stated.

For <NUM>H-NMR analysis, Advance III <NUM> (Bruker Analytik) was used. GC yield was measured by system 7890B (column HP-<NUM>, Agilent Technologies) at a rate of <NUM>/min from <NUM>.

A <NUM>-mL separable flask was charged with <NUM> (<NUM> mol) of chloromethyltrimethoxysilane, <NUM> of methanol, <NUM> (<NUM> mol) of <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexamethyldisiloxane, and <NUM> of sulfuric acid, and ice cooled. With the flask kept below <NUM>, <NUM> of distilled water was added dropwise over <NUM> minutes. At the end of addition, stirring was continued at room temperature for <NUM> hours. The organic layer was recovered by separatory operation and washed with sodium chloride aqueous solution until the water layer became neutral. Thereafter, the organic layer was purified by distillation, yielding <NUM> of colorless clear solution (yield <NUM>%, GC purity > <NUM>%). The resulting compound is shown below.

A <NUM>-mL separable flask was charged with <NUM> (<NUM> mol) of potassium phthalimide (Tokyo Chemical Industry Co. ), <NUM> (<NUM> mol) of sodium iodide (Fujifilm Wako Pure Chemical Corp. ), and <NUM> (<NUM> mol) of <NUM>-(chloromethyl)-<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexamethyl-<NUM>-[(trimethylsilyl)oxy]trisiloxane obtained in Synthesis Example <NUM>. The flask was equipped with a stirring impeller and condenser, and <NUM> of dry N,N-dimethylformamide (Fujifilm Wako Pure Chemical Corp. ) was added thereto, after which reaction was carried out in an oil bath at <NUM> for <NUM> hours. Thereafter, <NUM> of hexane was added to the reaction solution. The subsequent filtration and vacuum drying yielded <NUM> of a pale yellow solution (yield <NUM>%, GC purity <NUM>%). <FIG> shows the data of <NUM>H-NMR analysis of the resulting compound. The compound is shown below. <NUM>H-NMR (CDCl<NUM>, <NUM>) δ: <NUM>-<NUM> (m, <NUM>), <NUM>-<NUM> (m, <NUM>), <NUM> (s, <NUM>), <NUM> (s, <NUM>), <NUM> (s, <NUM>)
<CHM>.

Claim 1:
A method for preparing a primary aminosiloxane compound having the formula (<NUM>), comprising the step of reacting a siloxane compound with a deprotecting agent to produce the primary aminosiloxane compound having the formula (<NUM>), said siloxane compound having the formula (<NUM>):

        H<NUM>N-CR<NUM>R<NUM>-Si(OSiR<NUM>R<NUM>R<NUM>)<NUM>     (<NUM>)

        R<NUM>-C(=O)-NR<NUM>-CR<NUM>R<NUM>-Si(O SiR<NUM>R<NUM>R<NUM>)<NUM>     (<NUM>)

wherein R<NUM>, R<NUM>, R<NUM>, R<NUM> and R<NUM> are each independently hydrogen or a C<NUM>-C<NUM> monovalent hydrocarbon group in which some or all carbon-bonded hydrogen atoms may be substituted by halogen atoms or hydroxy groups and which may be separated by oxygen or nitrogen, R<NUM> is hydrogen or -C(=O)-R<NUM>, R<NUM> and R<NUM> each are a C<NUM>-C<NUM> monovalent hydrocarbon group, with the proviso that when R<NUM> is -C(=O)-R<NUM>, R<NUM> may bond with R<NUM> to form a divalent hydrocarbon group to construct a cyclic structure.