Method for producing polysiloxane compound

Abstract

To provide a method for producing a polysiloxane compound in which a hydrogen polysiloxane is safely and efficiently processed to a reusable state.SOLUTION: There is provided a method for producing a polysiloxane compound, which comprises a contacting step of contacting a hydrogen polysiloxane having Si-H bond with a hypochlorite in the presence of water to generate a polysiloxane having Si-OH bond or its condensate. The hypochlorite preferably is sodium hypochlorite. The blending amount of the hypochlorite preferably is 0.1 mol or more and 2 mol or less based on 1 mol of the Si-H bond possessed by the hydrogen polysiloxane.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing a polysiloxane compound.

Background Art

[0002] Organic polysiloxanes into which various organic groups have been introduced are widely used in fields such as paints, molding materials, medical materials, various coating materials, cosmetics, personal care compositions, home care compositions, release agents, and fiber treatment agents. Hydrogen polysiloxane, which is a polysiloxane having an Si-H bond, is useful as a precursor for such organic polysiloxanes.

[0003] On the other hand, when hydrogen polysiloxane comes into contact with a substance having active hydrogen such as water, dehydrogenation may occur between adjacent hydrogen atoms under certain conditions, generating hydrogen gas. Hydrogen gas is dangerous in terms of ignition and explosion and must be handled with care. In recent years, from the viewpoints of safety in the working environment and reduction of environmental load, the use of hydrogen polysiloxane in the form of an aqueous emulsion has been increasing, and the frequency of the generation of the hydrogen gas tends to increase. Therefore, a technique for treating excess hydrogen polysiloxane to a safe state is required.

[0004] As the treatment technique, a technique of blowing ethylene gas into hydrogen polysiloxane (Patent Document 1) and a technique of generating a cross-linked product of a vinyl group-containing polysiloxane and hydrogen polysiloxane in the presence of a catalyst (Patent Document 2) have been proposed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, among the above-mentioned treatment techniques, in the former technique, the reaction occurs at the gas-liquid interface and the reaction efficiency is not good, and it is not easy to control the pressure and temperature. In the latter technique, a large amount of vinyl group-containing polysiloxane is required, and the reaction may be difficult to proceed due to steric hindrance, leaving room for improvement. Separating hydrogen polysiloxane from water is also not easy from the same perspective.

[0007] Furthermore, from the perspectives of the environment and sustainability, the demand for reusing the products after treatment is increasing.

[0008] An object of the present invention is to provide a method for producing a polysiloxane compound that safely and efficiently treats hydrogen polysiloxane to make it reusable.

Means for Solving the Problems

[0009] The inventors of the present invention intensively studied to solve the above problems and, unexpectedly, found that hydrogen polysiloxane can be made into a safely and efficiently reusable state by treating it with hypochlorite. The present invention has been completed based on such new findings.

[0010] In one embodiment, the present invention a contacting step of contacting a hydrogen polysiloxane having an Si-H bond with a hypochlorite in the presence of water to produce a polysiloxane having an Si-OH bond or a condensate thereof relates to a method for producing a polysiloxane compound.

[0011] According to the method for producing the polysiloxane compound, in the presence of water, by bringing a hydrogen polysiloxane having an Si-H bond into contact with a hypochlorite, a polysiloxane having an Si-OH bond or a condensate thereof (hereinafter, also collectively referred to as "polysiloxane derivative") can be safely and efficiently produced. The polysiloxane derivative is a reusable and highly functional polysiloxane compound. The polysiloxane derivative can be used as it is, or the hydroxy groups of the polysiloxane derivative can be modified with other substituents to enhance its functionality. Through the method for producing the polysiloxane compound, safe and efficient conversion of the hydrogen polysiloxane into the polysiloxane derivative and its reuse can be achieved, which can greatly contribute to environmental protection and sustainable development.

[0012] As used herein, "polysiloxane" means a compound containing a siloxane bond (-Si-O-Si-).

[0013] In one embodiment, the hypochlorite is preferably sodium hypochlorite in terms of reaction efficiency and ease of reaction control.

[0014] In one embodiment, the amount of the hypochlorite is preferably 0.1 mol or more and 2 mol or less per 1 mol of the Si-H bond of the hydrogen polysiloxane. By setting the amount of the hypochlorite within the above range, the polysiloxane derivative can be efficiently produced from the hydrogen polysiloxane.

[0015] In one embodiment, it is preferable to coexist an acid in the contacting step. In one embodiment, the acid is more preferably an organic acid. In one embodiment, the acid is even more preferably acetic acid or lactic acid. Since the hypochlorite acts as an oxidizing agent with respect to the hydrogen polysiloxane, by coexisting such an acid, the action of the hypochlorite as an oxidizing agent is enhanced, and the conversion efficiency of the hydrogen polysiloxane into the polysiloxane derivative can be further improved.

[0016] In one embodiment, in the presence of the acid, it is preferable that the pH of the water be 7 or more and 11 or less after 3 hours from the start of the contacting step. By reacting under mild conditions, decomposition of the hypochlorite can be suppressed, and the hydrogen polysiloxane can be more efficiently converted into a polysiloxane derivative.

[0017] In one embodiment, the hydrogen polysiloxane may be present in the form of an emulsion with the water. Even for an aqueous emulsion of hydrogen polysiloxane, which has conventionally been difficult to make safe and reusable, it can be safely converted into a useful polysiloxane derivative simply by contacting it with a hypochlorite if it is a method for producing the polysiloxane compound. As a result, it can also contribute to measures in terms of the environment and sustainability.

Embodiments for Carrying Out the Invention

[0018] A method for producing a polysiloxane compound according to an embodiment of the present invention will be described below. The present invention is not limited to these embodiments. Combinations of suitable aspects are also preferable.

[0019] 《Method for Producing Polysiloxane Compound》 The method for producing a polysiloxane compound according to this embodiment includes a contacting step of contacting a hydrogen polysiloxane having an Si—H bond with a hypochlorite in the presence of water to form a polysiloxane having an Si—OH bond or a condensate thereof.

[0020] The water is not particularly limited, and pure water, ultrapure water, purified water, ion-exchanged water (deionized water), distilled water, etc. can be used.

[0021] Hydrogen polysiloxane is a polysiloxane having Si-H bonds. Hydrogen polysiloxane preferably has a polymer form. "Polymer" refers to a compound having two or more structural units. When two or more identical structural units are consecutive in a polymer, this structural unit is also referred to as a "repeating unit". Hydrogen polysiloxane preferably has a structural unit (α) represented by the following formula (1-1). Hydrogen polysiloxane may have one or more kinds of structural units (α).

[0022]

Chemical formula

[0023] In formula (1-1), a is an integer from 1 to 3. R 1 is a monovalent organic group having 1 to 20 carbon atoms or a halogen atom. b is an integer from 0 to 2. When b is 2, the two Rs 1 are the same as or different from each other. However, a + b is 3 or less.

[0024] In this specification, "organic group" means a group containing at least one carbon atom.

[0025] In the above formula (1-1), examples of the monovalent organic group having 1 to 20 carbon atoms represented by R 1 include, for example a monovalent hydrocarbon group having 1 to 20 carbon atoms, a group containing a divalent heteroatom-containing linking group between carbon-carbon bonds of the above hydrocarbon group or at the end of the above hydrocarbon group (hereinafter also referred to as "group (α)"), a group in which some or all of the hydrogen atoms of the above hydrocarbon group or the above group (α) are substituted with a monovalent heteroatom-containing substituent (hereinafter also referred to as "group (β)"), a group obtained by combining at least two of the above hydrocarbon group, the above group (α) and the above group (β) (hereinafter also referred to as "group (γ)"). and the like can be mentioned.

[0026] Examples of the monovalent hydrocarbon groups having 1 to 20 carbon atoms include monovalent chain hydrocarbon groups having 1 to 20 carbon atoms, monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, and monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms.

[0027] Examples of the monovalent chain hydrocarbon groups having 1 to 20 carbon atoms include monovalent chain aliphatic saturated hydrocarbon groups having 1 to 20 carbon atoms and monovalent chain aliphatic unsaturated hydrocarbon groups having 1 to 20 carbon atoms. Examples of the monovalent chain aliphatic saturated hydrocarbon groups having 1 to 20 carbon atoms include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, and tert-butyl group. Examples of the monovalent chain aliphatic unsaturated hydrocarbon groups having 1 to 20 carbon atoms include alkenyl groups such as ethenyl group, propenyl group, and butenyl group; and alkynyl groups such as ethynyl group, propynyl group, and butynyl group.

[0028] Examples of the monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include monocyclic alicyclic saturated hydrocarbon groups such as cyclopentyl group and cyclohexyl group; polycyclic alicyclic saturated hydrocarbon groups such as norbornyl group, adamantyl group, tricyclodecyl group, and tetracyclododecyl group; monocyclic alicyclic unsaturated hydrocarbon groups such as cyclopentenyl group and cyclohexenyl group; and polycyclic alicyclic unsaturated hydrocarbon groups such as norbornenyl group, tricyclodecenyl group, and tetracyclododecenyl group.

[0029] Examples of the monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, and anthryl group; and aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, and anthrylmethyl group.

[0030] Examples of the heteroatoms constituting the divalent heteroatom-containing linking group and the monovalent heteroatom-containing substituent include, for example, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, a halogen atom, etc. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom (in this specification, unless otherwise specified, these atoms are included as the "halogen atom").

[0031] Examples of the divalent heteroatom-containing linking group include, for example, -O-, -C(=O)-, -S-, -C(=S)-, -NR’-, -SO2-, and groups formed by combining two or more of these. R’ is a hydrogen atom or a monovalent hydrocarbon group.

[0032] Examples of the monovalent heteroatom-containing substituent include, for example, a halogen atom, a hydroxy group, a carboxy group, a cyano group, an amino group, a sulfanyl group, etc.

[0033] R 1 The number of carbon atoms of the monovalent organic group represented by is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4.

[0034] R 1 As the halogen atom represented by, a chlorine atom is preferred.

[0035] R 1 is preferably a monovalent chain hydrocarbon group, a monovalent aromatic hydrocarbon group, or a monovalent group in which some or all of the hydrogen atoms of a monovalent hydrocarbon group are substituted with a monovalent heteroatom-containing group, more preferably an alkyl group or an aryl group, even more preferably a methyl group, an ethyl group, or a phenyl group, and particularly preferably a methyl group.

[0036] In the above formula (1-1), a is preferably 1 or 2, and more preferably 1. In the above formula (1-1), b is preferably 0 or 1, and more preferably 1.

[0037] (Structural unit (β)) The hydrogen polysiloxane may have a structural unit (β) represented by the following formula (2-1). The hydrogen polysiloxane may have one or more kinds of the structural unit (β).

[0038] [Chemical formula] (In the above formula (2-1), R 12 is a monovalent organic group having 1 to 20 carbon atoms or a halogen atom. e is an integer of 0 to 3. When e is 2 or more, a plurality of R 12 are the same or different.)

[0039] As the monovalent organic group having 1 to 20 carbon atoms represented by R 12 , the monovalent organic group having 1 to 20 carbon atoms represented by R 1 in the above formula (1-1) can be preferably adopted.

[0040] As R 12 , it is preferably a substituted or unsubstituted monovalent alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.

[0041] Specific examples of the monovalent alkoxy group having 1 to 20 carbon atoms include alkoxy groups such as a methoxy group, an ethoxy group, an n-propoxy group, and an isopropoxy group.

[0042] Examples of the aryl group having 6 to 20 carbon atoms include a phenyl group, a naphthyl group, and an anthracenyl group.

[0043] Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, and a t-butyl group.

[0044] When the above alkoxy group, aryl group, and alkyl group have substituents, the monovalent heteroatom-containing substituents described above can be preferably adopted as the substituents. Further, as the substituents of the aryl group, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkoxycarbonyloxy group, an acyl group, an acyloxy group, or a group in which a hydrogen atom of these groups is substituted with a halogen atom, etc. may be mentioned.

[0045] e is preferably an integer of 0 to 2, more preferably 1 or 2, and even more preferably 2.

[0046] The above hydrogen polysiloxane can be produced by a known method. Specific structures of the hydrogen polysiloxane include methylhydrogen polysiloxane, dimethylsiloxane·methylhydrogen siloxane copolymer, methylphenylsiloxane·methylhydrogen siloxane copolymer, etc. The hydrogen polysiloxane may be cyclic or chain-like. The chain-like may be either linear or branched. In the contacting step, the hydrogen polysiloxane may be used alone or a plurality of types may be mixed and used. The hydrogen atoms in the hydrogen polysiloxane may be bonded only to the silicon atoms at the (both) ends of the molecular chain of the hydrogen polysiloxane (hereinafter, also referred to as "terminal hydrogen polysiloxane"), may not be bonded to the silicon atoms at the (both) ends of the molecular chain, and may be bonded only to the silicon atoms as side chains of the molecular chain (hereinafter, also referred to as "side chain hydrogen polysiloxane"), or may be bonded to the silicon atoms at the (both) ends of the molecular chain and the silicon atoms as side chains of the molecular chain (hereinafter, also referred to as "both-type hydrogen polysiloxane").

[0047] Although the content of hydrogen atoms in the hydrogen polysiloxane (the ratio of the total atomic weight of hydrogen atoms in the molecular weight of the hydrogen polysiloxane) is not particularly limited, the lower limit of the content may be 0.005%, may be 0.01%, or may be 0.02%. The upper limit of the content may be 3%, may be 2%, or may be 1.8%.

[0048] The hydrogen polysiloxane according to this embodiment exists in the form of an emulsion with the water. As the form of the emulsion, it may be an oil-in-water (o / w) emulsion or a water-in-oil (w / o) emulsion. From the viewpoint of the contact efficiency with the hypochlorite, it is preferable that the hydrogen polysiloxane exists as an oil-in-water emulsion.

[0049] The method for forming the emulsion is not particularly limited, and known methods such as a liquid crystal emulsification method, a mechanical emulsification method, a phase inversion emulsification method, a phase inversion temperature emulsification method, and a D-phase emulsification method can be adopted.

[0050] The concentration of the hydrogen polysiloxane in water is not particularly limited and can be appropriately set in consideration of the contact efficiency and reaction efficiency with the hypochlorite, workability, etc. For example, when the hydrogen polysiloxane is in an emulsion state, the lower limit of the concentration may be 5% by mass, 10% by mass, 20% by mass, or 30% by mass. The upper limit of the concentration may be 70% by mass, 60% by mass, or 50% by mass.

[0051] When forming the emulsion of the hydrogen polysiloxane, optional components such as a surfactant, a stabilizer, and a preservative may be added, for example.

[0052] The hypochlorite is a salt of hypochlorous acid and functions as an oxidizing agent for the hydrogen polysiloxane. As the salt, an alkali metal salt such as sodium or potassium, or an alkaline earth metal salt such as magnesium, calcium, or barium is preferable. The hypochlorite is preferably an alkali metal salt of hypochlorous acid, and more preferably sodium hypochlorite.

[0053] By bringing the hydrogen polysiloxane having an Si-H bond into contact with the hypochlorite, a polysiloxane having an Si-OH bond or a condensate thereof can be produced safely and efficiently. Although this reaction mechanism is not clear, for example, when using sodium hypochlorite, it is presumed to proceed according to the following reaction scheme.

[0054]

Chem.

[0055] In the above scheme, each R is independently a monovalent organic group or a halogen atom.

[0056] The -O of sodium hypochlorite - Na + attacks the silicon atom of the Si-H bond, and as a transition state, Si-O - Na + bonds are formed. Along with this, the hydrogen atom of the Si-H bond desorbs to generate hydrogen chloride. Finally, the sodium of the Si-O - Na + bond is exchanged with the hydrogen atom to generate a polysiloxane having an Si-OH bond. In this scheme, hydrogen gas is not generated at any stage of the reaction, and the final by-product is sodium chloride, which is highly safe.

[0057] The generated polysiloxane having an Si-OH bond may condense between the Si-OH bonds to form a crosslinked product. According to the method for producing the polysiloxane compound, the polysiloxane having an Si-OH bond and its condensate can be safely and efficiently produced as a polysiloxane derivative.

[0058] In addition, the polysiloxane having an Si-O - Na + bond purified in the transition state may be included as the final product while maintaining its original form.

[0059] The lower limit of the amount of hypochlorite may be 0.1 mol, 0.5 mol, or 0.8 mol per 1 mol of Si-H bonds in the hydrogen polysiloxane. The upper limit of the amount may be 2 mol, 1.5 mol, or 1.2 mol per 1 mol of Si-H bonds in the hydrogen polysiloxane. The amount of hypochlorite can be appropriately set according to the purpose while considering the conversion degree of Si-H bonds in the hydrogen polysiloxane to Si-OH bonds, reaction efficiency, etc.

[0060] The mode of contact between the hydrogen polysiloxane and the hypochlorite in the presence of water is not particularly limited. Examples include a method of preparing a mixture of water and the hydrogen polysiloxane (preferably an emulsion) and adding the hypochlorite thereto, a method of adding the hydrogen polysiloxane to an aqueous solution of the hypochlorite, and a method of preparing a mixture of water and the hydrogen polysiloxane (preferably an emulsion) and mixing this mixture with an aqueous solution of the hypochlorite prepared separately. From the viewpoint of the contact efficiency between the hydrogen polysiloxane and the hypochlorite, a method of mixing a mixture of water and the hydrogen polysiloxane with an aqueous solution of the hypochlorite is preferred.

[0061] When preparing an aqueous solution of the hypochlorite, the concentration of the hypochlorite in the aqueous solution is not particularly limited and can be appropriately set in consideration of the reaction efficiency and workability. The lower limit of the concentration of the hypochlorite is preferably 0.1% by mass, preferably 1% by mass, and preferably 3% by mass. The upper limit of the concentration of the hypochlorite is preferably 12% by mass, preferably 10% by mass, and preferably 8% by mass. The amount of the aqueous solution of the hypochlorite can be appropriately set so as to obtain the amount of the hypochlorite compounded with respect to the hydrogen polysiloxane. Note that, depending on the solubility of the hypochlorite, a mixture with water may be prepared in the form of a suspension instead of an aqueous solution.

[0062] In the contacting step, it is preferable to coexist an acid. The acid may be either an organic acid or an inorganic acid. Examples of the organic acid include carboxylic acids and sulfonic acids. Examples of the carboxylic acid include monocarboxylic acids such as formic acid, acetic acid, and propionic acid; dicarboxylic acids such as oxalic acid, malonic acid, and succinic acid; and hydroxy acids such as lactic acid, malic acid, tartaric acid, and citric acid. Examples of the sulfonic acid include methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. Examples of the inorganic acid include hydrochloric acid, nitric acid, and sulfuric acid. Among them, as the acid, an organic acid is preferable, and acetic acid or lactic acid is more preferable.

[0063] The lower limit of the blending amount of the acid is preferably 0.01 mol, more preferably 0.05 mol, and even more preferably 0.1 mol with respect to 1 mol of the hypochlorite. The upper limit of the blending amount is preferably 0.5 mol, more preferably 0.3 mol with respect to 1 mol of the hypochlorite. By setting the blending amount of the acid within the above range, the activity of the hypochlorite can be improved, and the decomposition of the hypochlorite to generate chlorine gas can be suppressed.

[0064] When an acid coexists in the contacting step, it may coexist from the initial stage of the contact between the hydrogen polysiloxane and the hypochlorite, or an acid may be added and made to coexist after a predetermined time has elapsed from the contact between the hydrogen polysiloxane and the hypochlorite. Further, the addition of the acid may be carried out at once, continuously over time, or stepwise with intervals. Due to the coexistence of the acid, in the above reaction scheme, the attack on the silicon atom of the Si-H bond at the -O - Na + portion of sodium hypochlorite is promoted, while the decomposition of sodium hypochlorite may be induced. The timing of the addition of the acid may be appropriately set in consideration of these points. As a result, the conversion to the Si-OH bond can proceed more efficiently. When the acid coexists, it is preferable to add it in the form of an aqueous solution of the acid. The concentration of the acid in the aqueous solution can be appropriately set within the range of 1% by mass or more and 15% by mass or less.

[0065] The reaction time and reaction temperature in the contacting step can be appropriately set so that the conversion degree of the target hydrogen polysiloxane to the polysiloxane derivative can be obtained. The lower limit of the reaction time is preferably 20 minutes, more preferably 40 minutes, and even more preferably 60 minutes. The upper limit of the reaction time is preferably 600 minutes, more preferably 300 minutes, and even more preferably 150 minutes. In the method for producing the polysiloxane compound, since the conversion by the hypochlorite is achieved, the reaction can proceed at room temperature (20 °C) without heating. The lower limit of the reaction temperature may be 10 °C, may be 15 °C, or may be 20 °C. The upper limit of the reaction temperature may be 60 °C, may be 50 °C, or may be 40 °C.

[0066] When an acid is added after a predetermined time has elapsed from the contact between the hydrogen polysiloxane and the hypochlorite, as the timing of the acid addition, it is preferably 1 minute later, more preferably 5 minutes later, and even more preferably 8 minutes later as the lower limit of the elapsed time from the contact. The upper limit of the elapsed time is preferably 30 minutes later, more preferably 20 minutes later, and even more preferably 15 minutes later.

[0067] When the acid is added, in the case of an aqueous solution of the acid, it may be added all at once or may be added over a certain period of time. From the viewpoint of allowing the reaction to proceed gently and suppressing undesirable side reactions, it is preferable to add the aqueous solution of the acid over a certain period of time. The addition over a certain period of time may be carried out continuously or discontinuously (for example, by dropping). The lower limit of the addition time from the start to the end of the addition is preferably 1 minute, more preferably 5 minutes, and even more preferably 8 minutes. The upper limit of the addition time is preferably 30 minutes, more preferably 20 minutes, and even more preferably 15 minutes.

[0068] In the presence of the acid, the pH of the water 3 hours after the start of the contacting step is preferably 7 or more and 11 or less from the viewpoints of suppressing the decomposition of the hypochlorite and reaction efficiency. The lower limit of the pH of the water is preferably 8, more preferably 9. The upper limit of the pH of the water is preferably 10.5, more preferably 10.2.

[0069] When the acid is not allowed to coexist, it is preferable to make the reaction time in the contacting step longer and the reaction temperature higher. When the acid does not coexist, the lower limit of the reaction time is preferably 40 minutes, more preferably 80 minutes, and even more preferably 120 minutes. The upper limit of the reaction time is preferably 900 minutes, more preferably 600 minutes, and even more preferably 300 minutes. When the acid does not coexist, the lower limit of the reaction temperature is preferably 20°C, more preferably 30°C, and even more preferably 40°C. The upper limit of the reaction temperature is preferably 80°C, more preferably 70°C, and even more preferably 60°C.

[0070] After the contacting step, separation, washing, drying, etc. of the polysiloxane derivative may be carried out as necessary. Thereby, a polysiloxane derivative as a target polysiloxane compound can be produced.

Examples

[0071] Hereinafter, the present invention will be described in detail using examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[0072] <Preparation of oil-in-water emulsion of hydrogen polysiloxane> [Preparation Example 1] In a 200 mL beaker, 40 parts by mass of a side-chain hydrogen siloxane (dimethylsiloxane·methylhydrogen siloxane copolymer) having a viscosity of 50 mPa·s and a hydrogen content (H%) of 0.73%, 1.0 part by mass of polyoxyethylene tridecyl ether having an ethylene oxide addition number of 10 moles as a surfactant, and purified water were added to make a total of 100 parts by mass and mixed. This mixture was stirred at 3000 rpm for 20 minutes at room temperature using a homogenizer (manufactured by IKA, "Ultra Turrax T50 Basic Shaft Generator G45G") to obtain oil-in-water emulsion 1. The particle diameter of the emulsion measured by a laser diffraction particle size analyzer (manufactured by Malvern, "MASTERSIZER 3000") was 0.5 μm. Hereinafter, the particle diameter of the emulsion was measured by the same apparatus.

[0073] [Preparation Example 2] An oil-in-water emulsion 2 was obtained in the same manner as in Preparation Example 1, except that the blending amount of polyoxyethylene tridecyl ether as a surfactant was 3.0 parts by mass. The particle diameter of the emulsion was 0.2 μm.

[0074] [Preparation Example 3] An oil-in-water emulsion 3 was obtained in the same manner as in Preparation Example 1, except that a side-chain type hydrogen siloxane (dimethylsiloxane·methylhydrogen siloxane copolymer) having a viscosity of 50 mPa·s and a hydrogen content (H%) of 1.60% was used as the hydrogen siloxane. The particle diameter of the emulsion was 15 μm.

[0075] [Preparation Example 4] An oil-in-water emulsion 4 was obtained in the same manner as in Preparation Example 1, except that a side-chain type hydrogen siloxane (dimethylsiloxane·methylhydrogen siloxane copolymer) having a viscosity of 500 mPa·s and a hydrogen content (H%) of 0.45% was used as the hydrogen siloxane. The particle diameter of the emulsion was 5 μm.

[0076] [Preparation Example 5] An oil-in-water emulsion 5 was obtained in the same manner as in Preparation Example 1, except that a terminal type hydrogen siloxane (a compound in which both ends of dimethylpolysiloxane are hydrogen atoms) having a viscosity of 70 mPa·s and a hydrogen content (H%) of 0.04% was used as the hydrogen siloxane. The particle diameter of the emulsion was 5 μm.

[0077] [Preparation Example 6] An oil-in-water emulsion 6 was obtained in the same manner as in Preparation Example 1, except that a both-type hydrogen siloxane (a compound in which both ends of dimethylsiloxane·methylhydrogen siloxane copolymer are hydrogen atoms) having a viscosity of 1000 mPa·s and a hydrogen content (H%) of 0.012% was used as the hydrogen siloxane. The particle diameter of the emulsion was 10 μm.

[0078] <Treatment of Hydrogen Polysiloxane with Hypochlorite> [Example 1] A dropping funnel and a two-way cock were attached to one mouth of a 200 mL two-necked flask, and a gas burette filled with silicone oil was connected to the other mouth with a rubber tube. 5 parts by mass of an oil-in-water emulsion 1 was put into the flask. Separately, 20 parts by mass of a 5.50 mass% aqueous sodium hypochlorite solution was put into a dropping funnel with the two-way cock closed. While stirring with a magnetic stirrer, the entire amount of the aqueous sodium hypochlorite solution in the dropping funnel was added dropwise. Then, it was stirred for 10 minutes. After confirming that there was no gas generation or that the gas generation had stopped, the upper part of the dropping funnel was unplugged, 1.9 mL of a 5 mass% aqueous acetic acid solution was put into the dropping funnel, and it was sealed again. While stirring with a magnetic stirrer, the entire amount of the aqueous acid solution was added dropwise from the dropping funnel over 10 minutes (first acid addition). Then, it was stirred for 60 minutes. After confirming that there was no gas generation or that the gas generation had stopped, the stirring was stopped and the treatment reaction of hydrogen polysiloxane was terminated. The pH of the liquid after stirring for 3 hours after completion of the acid addition is also shown in Table 2 below. The pH is shown in the same manner in the following Examples and Comparative Examples.

[0079] [Examples 2 to 4, 6 to 11] Hydrogen polysiloxane was treated in the same manner as in Example 1, except that a hydrogen siloxane emulsion of the type and amount shown in Table 1 below, an aqueous sodium hypochlorite solution of the amount shown in Table 2 below, and an aqueous acid solution of the type and amount shown in Table 2 below were used.

[0080] [Example 5] Hydrogen polysiloxane was treated in the same manner as in Example 4, except that after stirring for 60 minutes after the first acid addition, an aqueous acid solution of the type and amount shown in Table 2 below was added from the dropping funnel over 10 minutes (second acid addition), and then it was stirred for 10 minutes.

[0081] [Comparative Example 1] Hydrogen polysiloxane was treated in the same manner as in Example 1, except that neither the aqueous sodium hypochlorite solution nor the aqueous acid solution was added, and it was stirred for the total of the dropping time and the stirring time when both the aqueous sodium hypochlorite solution and the aqueous acid solution were added.

[0082] [Comparative Example 2] The hydrogen polysiloxane was treated in the same manner as in Example 1, except that an aqueous sodium hypochlorite solution was not added and the mixture was stirred for the same stirring time as when the aqueous sodium hypochlorite solution was added.

[0083] <Confirmation of the formation of polysiloxane derivative by IR>[[]] The formation of the polysiloxane derivative was confirmed by IR measurement according to the following procedure. The results are shown in Table 1.

[0084] In Example 1, polysiloxane was obtained at each stage before the addition of the aqueous sodium hypochlorite solution, before the first addition of the aqueous acid solution, and after the first addition of the aqueous acid solution. When water was present, the water was evaporated by heating. For this dried product, a Fourier transform infrared spectrophotometer (NICOLET iS 10, manufactured by ThermoFisher SCIENTIFIC) was used to measure the absorption intensity of the Si-O-Si group (around 1100 cm -1 -1), the CH3 group (around 3000 cm -1 -1), and the Si-OH group (around 3300 cm -1 -1). When the absorption intensity of the CH3 group was set to 10, the absorption intensity ratio of the Si-OH group was 2.8 before the addition of the aqueous sodium hypochlorite solution, 3.4 before the first addition of the aqueous acid solution, and 4.6 after the first addition of the aqueous acid solution. Therefore, as the reaction proceeded, the intensity of the Si-OH peak increased, and the formation of the polysiloxane derivative was confirmed.

[0085] Also, when the absorption intensity of the CH3 group was set to 10, the absorption intensity of the Si-O-Si group was 38.1 before the addition of the aqueous sodium hypochlorite solution, 37.8 before the first addition of the aqueous acid solution, and 53.4 after the first addition of the aqueous acid solution. Therefore, as the reaction proceeded, the intensity of the Si-O-Si increased, and the formation of the polysiloxane was confirmed.

[0086]

Table 1

[0087] <Gas generation test> After completing the procedure of the above example, 20 mL of a 10% potassium hydroxide aqueous solution was added to the dropping funnel with the two-way cock closed. After confirming that the reading of the gas burette was zero (initial value), with the entire system sealed, the entire amount of the potassium hydroxide aqueous solution was added dropwise under stirring with a magnetic stirrer. After completion of the addition dropwise, stirring was carried out for 4 hours, and the value (end point) of the gas burette was read. The reading of the gas burette at the end point was taken as the gas generation amount (mL).

[0088]

Table 2

[0089] In the examples, the amount of hydrogen gas generated was reduced in comparison with the comparative examples. From this result and the above IR measurement results, it can be seen that the Si-H bond of the hydrogen polysiloxane was converted to an Si-OH bond by contact with the hypochlorite. In addition, in Examples 1 to 10 to which the acid aqueous solution was added, the amount of hydrogen gas generated was significantly reduced compared to Example 11 to which the acid aqueous solution was not added. It is presumed that the hypochlorite was activated by the added acid, and efficient conversion of the Si-H bond to the Si-OH bond proceeded. Therefore, it can be said that it is preferable that an acid coexists when the hydrogen polysiloxane and the hypochlorite are in contact with each other.

Claims

1. A contacting step of bringing a hydrogen polysiloxane having an Si—H bond into contact with a hypochlorite in the presence of water to produce a polysiloxane having an Si—OH bond or a condensate thereof A method for producing a polysiloxane compound, comprising:

2. The method for producing a polysiloxane compound according to claim 1, wherein the hypochlorite is sodium hypochlorite.

3. The method for producing a polysiloxane compound according to claim 1, wherein the amount of the hypochlorite is 0.1 mol or more and 2 mol or less per 1 mol of the Si—H bond of the hydrogen polysiloxane.

4. The method for producing a polysiloxane compound according to any one of claims 1 to 3, wherein an acid coexists in the contacting step.

5. The method for producing a polysiloxane compound according to claim 4, wherein the acid is an organic acid.

6. The method for producing a polysiloxane compound according to claim 4, wherein the acid is acetic acid or lactic acid.

7. The method for producing a polysiloxane compound according to claim 4, wherein the pH of the water is 7 or more and 11 or less after 3 hours from the start of the contacting step in the presence of the acid.

8. The method for producing a polysiloxane compound according to any one of claims 1 to 3, wherein the hydrogen polysiloxane is present in the form of an emulsion with the water.

Images