JP7848355B2 - Method for producing organopolysiloxane emulsion composition - Google Patents

Description

The present invention relates to a method for producing a branched, high-viscosity organopolysiloxane emulsion composition used in products such as cosmetics, personal care compositions, home care compositions, mold release agents, lubricants, coating agents, fiber treatment agents, and resin modifiers.

There is a demand for high-viscosity organopolysiloxane emulsions with small particle size and good temporal stability for use in products such as cosmetics, personal care compositions, home care compositions, mold release agents, lubricants, coating agents, fiber treatment agents, and resin modifiers. However, when high-viscosity organopolysiloxane with a branched structure is directly emulsified, the particle size of the emulsion is limited to a few microns, and it is difficult to obtain smaller particles, and the resulting emulsion has poor temporal stability. Therefore, various methods for producing high-viscosity organopolysiloxane emulsions with a branched structure by emulsion polymerization have been investigated in order to obtain emulsion particles with small particle size and good temporal stability.

For example, a method is known in which emulsion polymerization is carried out by emulsifying a cyclic siloxane oligomer and a trialkoxysilane using a strong acid or strong alkali. Using these methods, emulsions with a particle size of 300 nm or less can be obtained.

In recent years, there has been a growing demand for products with reduced octamethylcyclotetrasiloxane (D4) content. However, it is known that the organopolysiloxane contained in the resulting emulsion using the above method contains more than 40,000 ppm of octamethylcyclotetrasiloxane, and methods to reduce this content are being investigated.

For example, a method is known in which an organopolysiloxane with a viscosity of 3,000 to 100,000 ^mm² /s at 25°C and an octamethylcyclotetrasiloxane content of 1,000 ppm or less, in which the molecular chain ends are sealed with silanol groups, is emulsified, and then emulsion polymerization is carried out at a temperature of less than 40°C in the presence of an acid catalyst (Patent Document 1). It is said that using these methods, an emulsion can be obtained in which the amount of octamethylcyclotetrasiloxane contained in the organopolysiloxane is 3,000 ppm or less. Furthermore, it is stated that by adding trialkoxysiloxane to this emulsion, it is possible to introduce branched units into the resulting organopolysiloxane chain. However, even when a high-viscosity organopolysiloxane is reacted with trialkoxysilane, the resulting organopolysiloxane chain does not become thicker due to differences in reactivity between the organopolysiloxane, whose molecular chain ends are sealed with silanol groups, and the trialkoxysilane. This prevents the branched units from being uniformly incorporated into the siloxane chain.
In addition, Patent Documents 2 and 3 describe a method for emulsion polymerization of an organopolysiloxane in which the molecular chain ends are sealed with silanol groups and the octamethylcyclotetrasiloxane content is 1,000 ppm or less, in the presence of an acid catalyst at a temperature of less than 40°C.

On the other hand, regarding emulsion polymerization methods using base catalysts, Patent Documents 4 and 5 describe polymerization methods using ammonium salts as surfactants. However, these patent documents make no mention whatsoever of the octamethylcyclotetrasiloxane content.

These prior art applications utilize either anionic surfactants or acid catalysts, or cationic surfactants or inorganic base catalysts. When organopolysiloxane emulsions are used in products such as cosmetics, personal care compositions, home care compositions, mold release agents, lubricants, coatings, fiber treatment agents, and resin modifiers, the use of ionic surfactants often presents challenges. Specifically, organopolysiloxane emulsions containing anionic surfactants may experience reduced stability when mixed with other agents containing cationic surfactants, and organopolysiloxane emulsions containing cationic surfactants may experience reduced stability when mixed with other agents containing anionic surfactants. In other words, organopolysiloxane emulsions containing ionic surfactants such as anionic and cationic surfactants may have limitations on the ionic properties of the agents they can be blended with.

Therefore, even without ionic surfactants, it is necessary to establish a method for producing a high-viscosity organopolysiloxane emulsion composition that suppresses the by-product formation of octamethylcyclotetrasiloxane contained in organopolysiloxane, and has a branched structure with small particle size and good temporal stability.

Patent No. 5382273 Japanese Patent Publication No. 2016-166324 Japanese Patent Publication No. 2017-48342 Patent No. 4683203 Japanese Patent Publication No. 2021-95455

Therefore, the object of the present invention is to provide a method for producing a high-viscosity organopolysiloxane emulsion composition that has a small particle size and good temporal stability, while suppressing the by-product formation of octamethylcyclotetrasiloxane contained in organopolysiloxane, even when ionic surfactants are not included.

In order to solve the above problems, the present invention provides:
(I) (A) Organopolysiloxane represented by the following general formula (1) and having an octamethylcyclotetrasiloxane content of 3,000 ppm or less: 100 parts by mass,
(In the formula, ^R1 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and ^R2 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. n is the number at which the viscosity of the organopolysiloxane at 25°C is between 15 mPa·s and 100,000 mPa·s.)
(B) Organoalkoxysilanes represented by the following general formula (2), partially hydrolyzed condensates thereof, or mixtures thereof: 0.2 to 20 parts by mass,
(In the formula, ^R3 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and ^R4 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. m is 3 to 4.)
(C) Nonionic surfactant: 2 to 30 parts by mass and
(D-1) A mixture containing 1 to 10,000 parts by mass of water is emulsified to prepare a first emulsion composition.
(II) The first emulsion composition,
(D-2) Water: After adding 0 to 10,000 parts by mass,
The present invention provides a method for producing an organopolysiloxane emulsion composition, characterized by emulsion polymerization at a temperature below 40°C in the presence of 0.1 to 20 parts by mass of (E) an organic base catalyst, wherein the viscosity of the resulting organopolysiloxane at 25°C is 300,000 mPa·s or more, the amount of octamethylcyclotetrasiloxane contained in the organopolysiloxane is 3,000 ppm or less, and the average particle size of the emulsion particles of the target emulsion composition is 1 μm or less.

The present invention provides a method for producing organopolysiloxane emulsion compositions that, even without the use of ionic surfactants, suppresses the by-product formation of octamethylcyclotetrasiloxane (D4) contained in organopolysiloxane, and efficiently produces a high-viscosity organopolysiloxane emulsion composition containing small-particle emulsion particles and exhibiting good long-term stability.

In this case, it is preferable to use an organopolysiloxane as component (A) in which n in the general formula (1) is the number such that the viscosity of the organopolysiloxane at 25°C is 15 mPa·s or more and 1,800 mPa·s or less.

Using such organopolysiloxanes allows for efficient emulsion polymerization to obtain the desired organopolysiloxane, while also reducing the amount of D4 produced as a by-product during polymerization. Furthermore, it reduces the amount of emulsifier needed to achieve the desired emulsion particle size.

Furthermore, it is preferable to use the above-mentioned component (B) in an amount of 0.4 to 10 parts by mass.

This method makes the viscosity of the target organopolysiloxane more suitable, resulting in superior strength and durability of the resulting coating.

Furthermore, it is preferable to use one or more selected from tetramethylguanidine, diazabicycloundecene, diazabicyclononene, triazabicyclodecene, methyltriazabicyclodecene, and diazabicyclooctane as the (E) organic base catalyst.

By using such component (E), the desired organopolysiloxane emulsion composition can be produced more efficiently.

Furthermore, it is preferable to use 0.5 to 7 parts by mass of the (E) organic base catalyst per 100 parts by mass of component (A).

By using such an amount of component (E), the desired organopolysiloxane emulsion composition can be produced more efficiently.

In this invention, an organopolysiloxane emulsion composition can be produced without using anionic surfactants, and an organopolysiloxane emulsion composition can also be produced without using cationic surfactants.

This manufacturing method allows for the production of organopolysiloxane emulsion compositions that do not contain ionic surfactants, and their stability is not reduced even when mixed with ionic drugs, thus there are no restrictions on the ionic properties of the drugs that can be incorporated.

In the present invention, it is preferable to carry out the emulsion polymerization described in (II) above at a temperature of less than 25°C, and it is also preferable to limit the polymerization time to 48 hours or less.

By performing emulsion polymerization at such temperatures and/or polymerization times, the amount of D4 produced as a by-product can be reduced.

Furthermore, in the present invention, it is preferable that the average particle size of the emulsion particles in the aforementioned emulsion composition be 500 nm or less.

According to the present invention, emulsion particles of such small particle size can be efficiently obtained.

Furthermore, it is preferable that the content of octamethylcyclotetrasiloxane (D4) in the organopolysiloxane in the emulsion composition for the above purpose be 2,000 ppm or less.

According to the present invention, such emulsion compositions with a low D4 content can be efficiently obtained.

According to the present invention, even without using ionic surfactants, it is possible to suppress the by-product formation of octamethylcyclotetrasiloxane contained in organopolysiloxane and obtain a high-viscosity organopolysiloxane emulsion composition with small particle size and good temporal stability.

As a result of diligent research to achieve the above objective, the present inventors have found that by using a linear organopolysiloxane and an organoalkoxysilane with an octamethylcyclotetrasiloxane content of 3,000 ppm or less as emulsion polymerization monomers, and by using an organic base as a polymerization catalyst, it is possible to obtain an emulsion composition in which the amount of octamethylcyclotetrasiloxane contained in the organopolysiloxane is 3,000 ppm or less, the average particle size of the emulsion particles is very small, at an average particle size of 1 μm or less, and the emulsion has good stability over time, thus completing the present invention.

That is, the present invention relates to (I) (A) an organopolysiloxane represented by the following general formula (1) and having an octamethylcyclotetrasiloxane content of 3,000 ppm or less: 100 parts by mass,
(In the formula, ^R1 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and ^R2 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. n is the number at which the viscosity of the organopolysiloxane at 25°C is between 15 mPa·s and 100,000 mPa·s.)
(B) Organoalkoxysilanes represented by the following general formula (2), partially hydrolyzed condensates thereof, or mixtures thereof: 0.2 to 20 parts by mass,
(In the formula, ^R3 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and ^R4 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. m is 3 to 4.)
(C) Nonionic surfactant: 2 to 30 parts by mass and
(D-1) A mixture containing 1 to 10,000 parts by mass of water is emulsified to prepare a first emulsion composition.
(II) The first emulsion composition,
(D-2) Water: After adding 0 to 10,000 parts by mass,
This is a method for producing an organopolysiloxane emulsion composition, characterized by emulsion polymerization at a temperature below 40°C in the presence of 0.1 to 20 parts by mass of (E) an organic base catalyst, wherein the viscosity of the resulting organopolysiloxane at 25°C is 300,000 mPa·s or more, the amount of octamethylcyclotetrasiloxane contained in the organopolysiloxane is 3,000 ppm or less, and the average particle size of the emulsion particles of the target emulsion composition is 1 μm or less.

The present invention will be described in detail below, but the present invention is not limited to these descriptions.

The present invention provides a method for producing an organopolysiloxane emulsion composition, comprising the steps of (I) preparing a first emulsion composition and (II) emulsion polymerization of the first emulsion composition to obtain a target emulsion composition.
In step (I) above, a mixture containing (A) a specific organopolysiloxane, (B) a specific organoalkoxysilane, (C) a nonionic surfactant, and (D-1) water is emulsified to prepare a first emulsion composition.
In step (II), the first emulsion composition prepared in step (I) is optionally mixed with (D-2) water, and then emulsion polymerization is carried out at a temperature of less than 40°C in the presence of (E) an organic base catalyst to obtain the desired emulsion composition.
The following describes each step.

The raw materials used in the manufacturing method of the present invention will be described below.
In this invention, viscosity is the value measured at 25°C using a BM-type or BH-type rotational viscometer.
<(A) Organopolysiloxane>
The organopolysiloxane of the present invention (A) is an organopolysiloxane represented by the following general formula (1), wherein the content of octamethylcyclotetrasiloxane (D4) is 3,000 ppm or less.
(In the formula, ^R1 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and ^R2 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. n is the number at which the viscosity of the organopolysiloxane at 25°C is between 15 mPa·s and 100,000 mPa·s.)

^R1 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. Examples of unsubstituted monovalent hydrocarbon groups having 1 to 20 carbon atoms include alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, and aralkyl groups having 7 to 20 carbon atoms. Specifically, examples include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, and octadecyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; alkenyl groups such as vinyl, allyl, and hexenyl groups; and aryl groups such as phenyl, tolyl, and naphthyl groups. Examples of substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms include those in which some of the hydrogen atoms in the monovalent hydrocarbon groups having 1 to 20 carbon atoms exemplified above are replaced with halogen atoms such as F and Cl, amino groups, acryloxy groups, methacryloxy groups, epoxy groups, mercapto groups, carboxyl groups, hydroxyl groups, etc. Preferably, the monovalent hydrocarbon group has 1 to 6 carbon atoms, such as a methyl group, ethyl group, propyl group, butyl group, or phenyl group. It is even more preferable that 80% or more of the total ^R1 are methyl groups.

^R2 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. Examples of unsubstituted monovalent hydrocarbon groups having 1 to 20 carbon atoms include alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, and aralkyl groups having 7 to 20 carbon atoms. Specifically, examples include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, and octadecyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; alkenyl groups such as vinyl, allyl, and hexenyl groups; and aryl groups such as phenyl, tolyl, and naphthyl groups. Examples of substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms include those obtained by substituting some of the hydrogen atoms in the monovalent hydrocarbon groups having 1 to 20 carbon atoms exemplified above with halogen atoms such as F and Cl, amino groups, acryloxy groups, methacryloxy groups, epoxy groups, mercapto groups, carboxyl groups, hydroxyl groups, etc. Preferably, it is a monovalent hydrocarbon group having 1 to 6 carbon atoms, such as a methyl group, ethyl group, propyl group, butyl group, or phenyl group. ^R2 is preferably a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

In general formula (1), n is a number such that the viscosity of the organopolysiloxane at 25°C is between 15 mPa·s and 100,000 mPa·s, and can be a number such that the viscosity is between 15 mPa·s and 1,800 mPa·s. A number such that n is particularly preferably between 100 mPa·s and 3,000 mPa·s, and most preferably between 500 and 1,800 mPa·s. A number such that n is even more preferably between 500 and 800 mPa·s. If the viscosity is less than 15 mPa·s, it becomes necessary to increase the emulsion polymerization time to achieve the desired viscosity of the organopolysiloxane contained in the target emulsion, or the amount of octamethylcyclotetrasiloxane produced as a by-product during emulsion polymerization increases. On the other hand, a viscosity exceeding 100,000 mPa·s is undesirable because it requires a large amount of emulsifier to reduce the particle size of the resulting emulsion.

The content of octamethylcyclotetrasiloxane in the organopolysiloxane of component (A) is 3,000 ppm (by mass, the same applies hereinafter) or less, particularly preferably 1,000 ppm or less, and more preferably 500 ppm or less. The lower limit is not particularly limited and may be 0 ppm.
In order to keep the amount of D4 in the organopolysiloxane in the target emulsion composition below 3,000 ppm, the D4 content in the organopolysiloxane of component (A) must be below 3,000 ppm by mass.

<(B) Organoalkoxysilanes>
The organoalkoxysilane of the present invention (B) is an organoalkoxysilane represented by the following general formula (2), a partially hydrolyzed condensate thereof, or a mixture thereof.
(In the formula, ^R3 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and ^R4 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. m is 3 to 4.)

^R3 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. Examples of unsubstituted monovalent hydrocarbon groups having 1 to 10 carbon atoms include alkyl groups having 1 to 10 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aralkyl groups having 7 to 10 carbon atoms. Specifically, examples include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; alkenyl groups such as vinyl, allyl, and hexenyl groups; and aryl groups such as phenyl, tolyl, and naphthyl groups. Examples of substituted monovalent hydrocarbon groups having 1 to 10 carbon atoms include those obtained by substituting some of the hydrogen atoms in the monovalent hydrocarbon groups having 1 to 10 carbon atoms exemplified above with halogen atoms such as F and Cl, amino groups, acryloxy groups, methacryloxy groups, epoxy groups, mercapto groups, carboxyl groups, hydroxyl groups, etc. Preferably, the hydrogen atom or the monovalent hydrocarbon group having 1 to 6 carbon atoms, such as the methyl group, ethyl group, propyl group, butyl group, or phenyl group. The hydrogen atom, methyl group, ethyl group, and propyl group are particularly preferred.

^R4 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. Examples of unsubstituted monovalent hydrocarbon groups having 1 to 10 carbon atoms include alkyl groups having 1 to 10 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aralkyl groups having 7 to 10 carbon atoms. Specifically, examples include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; alkenyl groups such as vinyl, allyl, and hexenyl groups; and aryl groups such as phenyl, tolyl, and naphthyl groups. Examples of substituted monovalent hydrocarbon groups having 1 to 10 carbon atoms include those in which some of the hydrogen atoms in the monovalent hydrocarbon groups having 1 to 10 carbon atoms exemplified above are replaced with halogen atoms such as F and Cl, amino groups, acryloxy groups, methacryloxy groups, epoxy groups, mercapto groups, carboxyl groups, hydroxyl groups, etc. Preferably, the monovalent hydrocarbon group has 1 to 6 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a butyl group, or a phenyl group. Examples of substituted groups include 3-aminopropyl group, N-(2-aminoethyl)-3-aminopropyl group, 3-glycidoxypropyl group, trifluoromethyl group, and 3,3,3-trifluoropropyl group. Methyl group, ethyl group, propyl group, and phenyl group are particularly preferred.

m is 3 to 4. m being 3 is particularly preferable.

(B) Specific examples of component (B) are listed below, but are not limited to these.
Methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, isooctyltrimethoxysilane, isooctyltriethoxysilane, 2-ethylhexyltrimethoxysilane, 2-ethylhexyltriethoxysilane, decyltrimethoxysilane, decyltriethoxy Examples include silane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, trifluoromethyltrimethoxysilane, and 3,3,3-trifluoropropyltrimethoxysilane.

Component (B) is more preferably methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane, with methyltrimethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane being particularly preferred.
The organoalkoxysilanes mentioned above may be a single type or a mixture of two or more types.

As component (B) of the present invention, oligomers or polymers (hereinafter referred to as "partial hydrolysis condensates") obtained by hydrolyzing a portion of the alkoxy groups of the above organoalkoxysilane and undergoing intermolecular condensation reactions may be used. Alternatively, the above organoalkoxysilane and the partial hydrolysis condensate of the organoalkoxysilane may be used in mixture form. Partial hydrolysis condensates of organoalkoxysilane can be synthesized by hydrolyzing and condensing the organoalkoxysilane in the presence of an acid catalyst or an alkali catalyst.

The amount of component (B) is 0.2 to 20 parts by mass per 100 parts by mass of component (A). Preferably, it is 0.4 to 10 parts by mass, more preferably 0.5 to 7.5 parts by mass, and particularly preferably 1 to 5 parts by mass.

<(C) Nonionic surfactant>
Component (C) is a nonionic surfactant. It can be used alone or in combination of two or more types.

Examples of nonionic surfactants include polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, and polyoxyethylene alkylphenyl ether; polyethylene glycol fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyglycerin fatty acid ester, propylene glycol fatty acid ester, fatty acid esters such as polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, and polyoxyethylene hydrogenated castor oil fatty acid ester; polyoxyethylene alkylamine, polyoxyethylene fatty acid amide, polyoxyethylene-modified organopolysiloxane, and polyoxyethylene polyoxypropylene-modified organopolysiloxane. Commercial products such as Newcol 1310 (manufactured by Nippon Emulsifier Co., Ltd.) may also be used.
Among these, polyoxyethylene alkyl ethers and polyoxyethylene polyoxypropylene alkyl ethers are preferred. The alkyl group can be either linear or branched.

From the viewpoint of emulsion stability, the HLB value of the nonionic surfactant (or the total HLB value of the mixture if multiple surfactants are used) is preferably in the range of 9.0 to 18.0, more preferably 10.0 to 17.0, and even more preferably 11.0 to 16.0. The HLB values are calculated using the Griffin method. The HLB value is calculated using the following formula.
N=N1×W1+N2×W2
N: HLB value when using two surfactants with different HLB values N1, N2: HLB value of each surfactant W1, W2: Mass fraction of each surfactant (W1 + W2 = 1)

In addition to the nonionic surfactant of component (C), the composition of the present invention may also use ionic surfactants such as cationic surfactants and anionic surfactants.

Examples of anionic surfactants include alkyl sulfate esters such as sodium lauryl sulfate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkylphenyl ether sulfate, alkylbenzene sulfonate, polyoxyethylene alkylphenyl ether sulfonate, alkyl diphenyl ether disulfonate, alkanesulfonate, N-acyl taurate, dialkyl sulfosuccinate, monoalkyl sulfosuccinate, polyoxyethylene alkyl ether sulfosuccinate, fatty acid salts, polyoxyethylene alkyl ether carboxylate, N-acyl amino acid salt, monoalkyl phosphate salt, dialkyl phosphate salt, and polyoxyethylene alkyl ether phosphate salt.

Examples of cationic surfactants include quaternary ammonium salts such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, polyoxyethylenealkyldimethylammonium salts, dipolyoxyethylenealkylmethylammonium salts, tripolyoxyethylenealkylammonium salts, and alkylbenzyldimethylammonium salts, as well as alkylpyridinium salts, monoalkylamine salts, and monoalkylamidoamine salts.

As the ionic surfactant mentioned above, amphoteric surfactants such as alkyl betaine and alkylimidazoline can also be used.

The organopolysiloxane emulsion composition of the present invention may optionally contain an ionic surfactant. However, as mentioned above, using cationic or anionic surfactants may reduce stability when mixed with ionic agents such as shampoos. Therefore, it is preferable not to use cationic or anionic surfactants in the method for producing the composition of the present invention.

The amount of component (C) used is 2 to 30 parts by mass per 100 parts by mass of component (A), preferably 4 to 20 parts by mass, and more preferably 5 to 15 parts by mass.

<(D) Water>
The water component (D) is used in process (I) (D-1) and, if necessary, in process (II) (D-2).
In step (I), the amount of water used for component (D-1) is 1 to 10,000 parts by mass per 100 parts by mass of (A), and can vary depending on the type of emulsifier used to reduce the particle size of the emulsion.

For example, when using a high-pressure homogenizer that reduces the particle size of emulsion particles using high pressure (such as an emulsifier that pressurizes the processing liquid to high pressure or ultra-high pressure and obtains shear force by passing it through a slit, or an emulsifier that atomizes pressurized processing liquids by causing them to collide obliquely at ultra-high speed), the amount of component (D-1) used is preferably 2 to 8,000 parts by mass, more preferably 4 to 6,000 parts by mass, and even more preferably 6 to 4,000 parts by mass, per 100 parts by mass of component (A).

Furthermore, when using emulsifiers such as homodispers (emulsifiers that obtain shear force by rapidly rotating a circular disc with saw-toothed teeth on its outer circumference), homomixers (emulsifiers that generate shear force by rapidly rotating a rotor installed inside with a stator installed on the outer circumference), and colloid mills (emulsifiers that generate shear force by feeding each component into the gap between a rapidly rotating disc and a fixed disc to generate shear force), the amount of component (D-1) used is preferably 1 to 30 parts by mass, more preferably 2 to 25 parts by mass, and even more preferably 5 to 20 parts by mass, per 100 parts by mass of component (A). Here, if it is 30 parts by mass or less, it becomes easy to obtain an emulsion composition with an average particle size of 1 μm or less, and if it is 1 part by mass or more, it is easy to obtain an O/W type emulsion.

In step (II), water of component (D-2) may or may not be added, and it is preferable that it be 10,000 parts by mass or less (0 to 10,000 parts by mass) per 100 parts by mass of component (A). If component (D-2) is added, it is preferable that it be 0.1 to 1,000 parts by mass. In addition, it is preferable to add water of component (D-2) when using emulsifiers such as homodispersers, homomixers and colloid mills.
The total amount of component (D) (the sum of (D-1) and (D-2)) can be 30 to 10,000 parts by mass per 100 parts by mass of component (A).

<(E) Organic base catalyst>
Component (E) is an organic base catalyst. The organic base catalyst (hereinafter also referred to as "organic base") can be any organic electron pair donor (a so-called Lewis base), and is not particularly limited. The structure of the organic base is also not particularly limited; it can be saturated or unsaturated, linear, branched, or any cyclic structure of three or more members. The cyclic structure may consist of one ring or two or more rings. The organic base may contain one or more heteroatoms such as nitrogen, oxygen, sulfur, or phosphorus in its molecule, and if it contains two or more heteroatoms, they may be the same or different.
Examples of organic bases include amines, quaternary ammonium hydroxides such as tetramethylammonium hydroxide, phosphorus-based phosphazene bases such as guanidinophosphazene, and amino acids.
The amine may be a primary, secondary, or tertiary amine, and may be an aliphatic amine, aromatic amine, heterocyclic amine, alkanolamine, or etheramine. Among these, linear, branched, or cyclic tertiary amines are preferred. The tertiary amine may include those having one or more tertiary nitrogen atoms in its molecule. The number of carbon atoms in the amine is not particularly limited, but can be, for example, C1 to C30, preferably C4 to C25.
(E) Component can be used alone or in appropriate combination of two or more types.

(E) Specific examples of component include, but are not limited to, the following.
Trialkylamines such as triethylamine, diisopropylethylamine (DIPEA), tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, and tri-n-octylamine; N-alkylcyclic amines such as N-methylpyrrolidine and N-methylpiperidine; N-alkylcyclic etheramines such as N-methylmorpholine; N-alkyldiamines such as N,N,N',N'-tetramethylethylenediamine (TMEDA); N-alkylimidazoles such as N-methylimidazole (NMI); 1,8-diazabicyclo-[5.4.0]-7-undecene (DBU), 1,5-diazabicyclo[4.3.0]nonene-5 (DBN), 1,4-diazabicyclo-[2.2.2. Examples include diazabicyclo compounds such as octane (DABCO), alkylpyridines such as pyridine, 2,6-lutidine, and 1,3,5-collidine, aminopyridines such as N,N-dimethylaminopyridine (DMAP), pyrazines, quinolines, triazabicyclo compounds such as 1,5,7-triazabicyclo[4.4.0]deca-5-ene (TBD) and 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-5-ene (MTBD), and guanidine compounds such as 1,1,3,3-tetramethylguanidine (TMG).

Component (E) is preferably a nonionic organic base catalyst, and one or more selected from tetramethylguanidine, diazabicycloundecene, diazabicyclononene, triazabicyclodecene, methyltriazabicyclodecene, and diazabicyclooctane can be used, with DBN, DBU, TBD, MTBD, DABCO, and 1,1,3,3-tetramethylguanidine being more preferred, and DBN and DBU being particularly preferred.

In particular, nonionic organic bases such as tetramethylguanidine, diazabicycloundecene, diazabicyclononene, triazabicyclodecene, methyltriazabicyclodecene, and diazabicyclooctane are strongly basic. Therefore, they promote the condensation reaction between the hydrolyzable organopolysiloxane of component (A) and the organoalkoxysilane of component (B) (as a source of T and/or D units), and even after neutralization following emulsion polymerization, their high proton-scavenging ability allows for a lower ionic character of the emulsion composition. Due to this effect, the emulsion composition of the present invention is expected to maintain the emulsion stably for a long period of time, even when used in products containing ionic agents.

The amount of component (E) used is 0.1 to 20 parts by mass per 100 parts by mass of component (A). Preferably, it is 0.3 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, even more preferably 0.5 to 7 parts by mass, and particularly preferably 0.7 to 5 parts by mass.

The manufacturing method of the present invention will be described below.
<Step (I)>
An emulsion composition is prepared by emulsifying a mixture containing the above components (A), (B), (C), and (D). Emulsification can be performed using emulsifiers such as homodispersers, homomixers, colloid mills, line mixers, universal mixers, ultramixers, planetary mixers, combimixes, and high-pressure homogenizers. Preferably, an emulsifier such as a homodisperser, homomixer, or colloid mill is used to reduce the particle size of the emulsion using shear force, and more preferably a homodisperser.

In this process, the emulsification temperature is preferably 1 to 80°C, and more preferably at a temperature below 25°C.

In step (I), the mixture is mixed under high shear force until the average particle size of the emulsion particles in the emulsion composition is preferably 1 μm or less, more preferably 800 nm or less, and even more preferably 500 nm or less. The smaller the particle size of the emulsion particles obtained in step (I), the higher the polymerization rate in step (II), leading to a reduction in polymerization time. As a result of the particle size of the emulsion particles in the emulsion composition obtained in step (I) being 500 nm or less, the particle size of the final emulsion particles obtained in the next step will also be 500 nm or less. In this invention, the particle size of the emulsion particles is the median diameter (volume-based) value measured by a laser diffraction/scattering particle size distribution analyzer LA-960 (manufactured by Horiba, Ltd.).

<Step (II)>
After dispersing the obtained emulsion composition with (D-2) water as needed, component (E) is added at a temperature of less than 40°C and emulsion polymerization is carried out until the viscosity of the organopolysiloxane in the emulsion composition at 25°C is 300,000 mPa·s or more, and the average particle size of the emulsion particles of the target emulsion composition is 1 μm or less.

When emulsion polymerization is performed on an emulsion composition, it is recommended that the polymerization process be carried out at a temperature below 40°C for no more than 48 hours. Polymerization at temperatures above 40°C may result in excessive production of octamethylcyclotetrasiloxane. Therefore, temperatures below 25°C are preferred, and below 20°C is more preferred. The lower limit temperature is not particularly limited, but from the viewpoint of productivity, it can be 4°C or higher. Furthermore, if the polymerization time is within 48 hours, the amount of octamethylcyclotetrasiloxane by-product will be reduced, so 1 to 40 hours is preferred, and 5 to 30 hours is more preferred.
The emulsification method can be one of those listed in step (I), preferably an emulsifier that reduces the particle size of emulsion particles using shear force, and more preferably dilution and dispersion using a homomixer.

<Other processing>
Once polymerization is complete, the resulting emulsion composition can usually be neutralized with an acidic substance. Examples of acidic substances include hydrochloric acid, formic acid, acetic acid, propionic acid, and citric acid. Alternatively, neutralization can be performed using an ion exchange resin instead of an acidic substance.
At this time, water can be added to adjust the silicone concentration, and preservatives can be added to improve the shelf life of the emulsion composition.

The viscosity of the organopolysiloxane obtained by the manufacturing method of the present invention is the measured value obtained using a BM-type or BH-type rotational viscometer at 25°C. For viscosity that could be measured in liquid form, the viscosity was measured directly; for viscosity that was too high to measure, the viscosity dissolved in 5% or 10% toluene was measured. For viscosity that was too high to measure even after toluene dilution, for viscosity that wrapped around the rotor of the BM-type or BH-type rotational viscometer and could not be measured, or for viscosity that did not dissolve in toluene and could not be measured, the viscosity was all 300,000 mPa·s or higher.

In this invention, the average particle size of the emulsion particles in the target emulsion composition is 1 μm or less, preferably 800 nm or less, and particularly preferably 500 nm or less. The lower limit is not particularly limited, but is approximately 30 nm or more. According to this invention, the average particle size of the emulsion particles in the emulsion composition becomes 1 μm or less, resulting in extremely fine particles. The average particle size of the emulsion particles is the median diameter value obtained by laser diffraction/scattering method.

The content of octamethylcyclotetrasiloxane in organopolysiloxane is 3,000 ppm or less, preferably 2,000 ppm or less, and more preferably 1,000 ppm or less. The lower limit is not particularly limited, but it is 0 ppm or more.

As described above, according to the present invention, even without containing ionic surfactants, it is possible to suppress the by-product formation of octamethylcyclotetrasiloxane contained in organopolysiloxane and efficiently produce a high viscosity (high degree of polymerization) organopolysiloxane emulsion composition having a small particle size and a branched structure with good temporal stability.
Specifically, by using a linear organopolysiloxane with an octamethylcyclotetrasiloxane content of 3,000 ppm or less as the emulsion polymerization monomer, an organoalkoxysilane as a T unit and/or Q unit source, and a nonionic surfactant, and using an organic base as the polymerization catalyst, and emulsifying and polymerizing these mixtures, it is possible to obtain an organopolysiloxane emulsion composition with an average particle size of 1 μm or less, while keeping the amount of octamethylcyclotetrasiloxane contained in the organopolysiloxane in the emulsion composition at 3,000 ppm or less.
In this invention, organopolysiloxane emulsion compositions can be produced while suppressing the generation of low molecular weight cyclic siloxanes, and there is less possibility of the siloxanes volatilizing and contaminating the equipment during heat treatment, thus making it highly useful in industry.

In the present invention, the organopolysiloxane produced by emulsion polymerization has a high viscosity of 300,000 mPa·s or more at 25°C, and branched units are uniformly introduced into the resulting organopolysiloxane chain.
In particular, the present invention has the excellent characteristic that, since emulsion polymerization can be performed without ionic surfactants in the preparation of the emulsion, the stability does not decrease when mixed with other agents containing ionic surfactants, and there is no limitation on the ionicity of the agents that can be blended. Furthermore, by using a nonionic organic base catalyst, the total amount of ionic components in the resulting composition can be reduced, thus broadening the range of applications for the emulsion composition of the present invention.

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. "Parts" refers to parts by mass. Viscosity is measured at 25°C using a BM-type or BH-type rotational viscometer.

[Example 1]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) 2.4 parts of phenyltriethoxysilane, (C-1) 13.5 parts of Newcol 1310 (trade name, manufactured by Nippon Emulsifier Co., Ltd., polyoxyethylene tridecyl ether, HLB value = 13.7), and (D-1) 11.3 parts of water were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the diameter of the emulsion. To the obtained first emulsion, (D-2) 109.3 parts of water were added and diluted and dispersed by homomixer. Next, after cooling to 15°C, 2.5 parts of (E-1)1,5-diazabicyclo[4.3.0]nonene-5(DBN) were added, and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 1.8 parts of acetic acid were added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 1.

[Example 2]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) phenyltriethoxysilane, (C-1) Newcol 1310, and (D-1) water, were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) water, 110.9 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, 1.3 parts of (E-1)1,5-diazabicyclo[4.3.0]nonene-5(DBN) were added, and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 0.9 parts of acetic acid were added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 1.

[Example 3]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) phenyltriethoxysilane, (C-1) Newcol 1310, and (D-1) water, were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) water, 110.9 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, 1.6 parts of (E-2)1,8-diazabicyclo-[5.4.0]-7-undecene (DBU) were added, and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 1.0 part of acetic acid was added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 1.

[Example 4]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content 50 ppm or less), (B-1) phenyltriethoxysilane: 2.4 parts, (C-1) Newcol 1310: 12.4 parts, and (D-1) water: 10.8 parts were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) water: 110.9 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, (E-3) 1,1,3,3-tetramethylguanidine (TMG): 1.2 parts was added and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 1.0 part of acetic acid was added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 1.

[Example 5]
(A-2) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 1450 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) phenyltriethoxysilane, (C-1) Newcol 1310, and (D-1) water, 10.8 parts were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) water, 110.9 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, 1.6 parts of (E-2)1,8-diazabicyclo-[5.4.0]-7-undecene (DBU) were added, and emulsion polymerization was carried out at 15°C for 18 hours. Subsequently, 1.0 part of acetic acid was added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 2.

[Example 6]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-2) methyltrimethoxysilane, (C-1) Newcol 1310, and (D-1) water, were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) water, 110.9 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, 1.6 parts of (E-2)1,8-diazabicyclo-[5.4.0]-7-undecene (DBU) were added, and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 1.0 part of acetic acid was added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 2.

[Example 7]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) phenyltriethoxysilane, (C-1) Newcol 1310, and (D-1) water, were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) water, 111.8 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, 1.6 parts of (E-2)1,8-diazabicyclo-[5.4.0]-7-undecene (DBU) were added, and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 1.0 part of acetic acid was added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 2.

[Example 8]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) 3.3 parts of phenyltriethoxysilane, (B-3) 0.7 parts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, (C-1) 9.4 parts of Newcol 1310, and (D-1) 9.7 parts of water were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) 165.5 parts of water were added and diluted and dispersed by homomixer. Next, after cooling to 15°C, 4.7 parts of (E-2)1,8-diazabicyclo-[5.4.0]-7-undecene (DBU) were added, and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 3.7 parts of acetic acid were added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 2.

[Comparative Example 1]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) phenyltriethoxysilane, (C-1) Newcol 1310, and (D-1) water, 10.8 parts were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) water, 110.9 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, lactic acid, 5.6 parts was added and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 35.4 parts of a 10% aqueous solution of sodium carbonate were added to the obtained emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 3.

[Comparative Example 2]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) phenyltriethoxysilane, (C-1) Newcol 1310, and (D-1) water, 11.3 parts were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the diameter of the emulsion. To the obtained first emulsion, (D-2) water, 109.3 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, 3.6 parts of 30% aqueous ammonia were added and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 1.3 parts of acetic acid were added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 3.

[Comparative Example 3]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) phenyltriethoxysilane, (C-1) Newcol 1310, and (D-1) water, 11.3 parts were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the diameter of the emulsion. To the obtained first emulsion, (D-2) water, 101.04 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, 5.8 parts of 30% potassium hydroxide aqueous solution were added and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 0.6 parts of acetic acid were added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 3.

[Comparative Example 4]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) phenyltriethoxysilane: 0.05 parts, (C-1) Newcol 1310: 12.4 parts, and (D-1) water: 10.8 parts were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) water: 110.9 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, 1.6 parts of (E-2)1,8-diazabicyclo-[5.4.0]-7-undecene (DBU) were added, and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 1.0 part of acetic acid was added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 3.

[Comparative Example 5]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) phenyltriethoxysilane, (C-1) Newcol 1310, and (D-1) water, were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) water, 110.9 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, 25.0 parts of (E-2)1,8-diazabicyclo-[5.4.0]-7-undecene (DBU) were added, and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 15.6 parts of acetic acid were added to the resulting emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 4.

[Comparative Example 6]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) phenyltriethoxysilane, (C-1) Newcol 1310, and (D-1) water, were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) water, 110.9 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, concentrated sulfuric acid, 1.2 parts was added and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 20.9 parts of a 10% aqueous solution of sodium carbonate were added to the obtained emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 4.

[Comparative Example 7]
(A-1) 100 parts of organopolysiloxane having silanol groups at the end of the molecular chain with a viscosity of 680 mPa·s (general formula (1), ^R1 = methyl group, ^R2 = hydrogen atom, octamethylcyclotetrasiloxane content of 50 ppm or less), (B-1) phenyltriethoxysilane, (C-1) Newcol 1310, and (D-1) water were emulsified by homodisperser. After emulsification, shearing was applied by homodisperser to reduce the particle size of the emulsion. To the obtained first emulsion, (D-2) water: 110.9 parts was added and diluted and dispersed by homomixer. Next, after cooling to 15°C, dodecylbenzenesulfonic acid: 3.5 parts was added and emulsion polymerization was carried out at 15°C for 24 hours. Subsequently, 12.8 parts of a 10% aqueous solution of sodium carbonate were added to the obtained emulsion, and the emulsion composition was obtained by dilution and dispersion using a homomixer. The results are shown in Table 4.

The following properties of the emulsion compositions obtained in the above example were measured or evaluated by the methods shown below. The results are shown in Table 1-4.

[Average particle size of emulsion]
This is the median diameter value measured using the LA-960 laser diffraction/scattering particle size distribution analyzer (manufactured by Horiba, Ltd.).

[Viscosity of organopolysiloxanes]
The viscosity was measured at 25°C using a BM or BH type rotational viscometer. The measured viscosity was obtained by adding 30 g of isopropyl alcohol to 30 g of the prepared emulsion composition while stirring, separating the precipitated organopolysiloxane, drying it at 105°C for 3 hours, and measuring it with a BM or BH type rotational viscometer. For samples where the viscosity could be measured in liquid form, the viscosity was measured directly. For samples where the viscosity was too high to measure in liquid form, the viscosity in 5% toluene was measured. Samples that were still too high to measure after dilution with 5% toluene, those that wrapped around the rotor of the BM or BH type rotational viscometer and could not be measured, or those that did not dissolve in toluene and could not be measured were deemed unmeasurable. In the case of unmeasurable samples, the viscosity was always 300,000 mPa·s or higher. In Tables 1 and 2, "(5% toluene)" indicates that the organopolysiloxane itself could not be measured and was measured as a 5% toluene solution. In this case, the viscosity of the organopolysiloxane was 300,000 mPa·s or higher, which is a favorable result. The entries marked "Unmeasurable" indicate that measurement was not possible due to the difficulty in preparing the 5% toluene solution. In this case, the viscosity of the organopolysiloxane is 300,000 mPa·s or higher, which is a particularly favorable result.

[Octamethylcyclotetrasiloxane (D4) content in organopolysiloxanes]
0.1 g of the emulsion composition was extracted with 10 mL of acetone containing 20 ppm (by mass) of tetradecane as an internal standard (shaking for 3 hours). After standing overnight, the acetone layer was collected and octamethylcyclotetrasiloxane was quantified by gas chromatography analysis.

[Emulsion Stability]
100 g of the emulsion composition was placed in a 100 mL glass bottle and left at 50°C for 3 months, after which its appearance was observed. If the emulsion formed a uniform single phase and no separation was observed, it was evaluated as having good stability and was indicated with a "○". If separation into two phases was observed, it was evaluated as having poor stability and was indicated with a "×".

According to the manufacturing method of the present invention (Examples 1 to 8), even without the presence of ionic surfactants, it is possible to obtain a high-viscosity organopolysiloxane emulsion with an extremely low cyclic siloxane content, and an organopolysiloxane emulsion composition with a small average particle size and good temporal stability can be obtained.
On the other hand, without using an organic base catalyst (Comparative Examples 1-3, 6, and 7), it is not possible to simultaneously satisfy the viscosity, D4 content, and emulsion stability of the organopolysiloxane. In particular, even when a base catalyst is used, if an inorganic weak base is used as the catalyst (Comparative Example 2), the viscosity of the resulting organopolysiloxane is low and the emulsion stability is poor, and if an inorganic strong base is used as the catalyst (Comparative Example 3), the D4 content (by-product amount of D4) increases further.
Furthermore, even when using an organic base catalyst, if the amount of component (B) used is small (Comparative Example 4), the viscosity of the resulting organopolysiloxane is low, and if the amount of organic base catalyst used is too large (Comparative Example 5), although a high-viscosity organopolysiloxane is obtained, it is inferior in terms of D4 content and emulsion stability.

When inorganic strong bases or inorganic strong acids are used as catalysts, the viscosity, D4 content, and emulsion stability of the organopolysiloxane all deteriorate (Comparative Examples 3 and 6). This is thought to be because these catalysts promote the decomposition of the organopolysiloxane. On the other hand, in the present invention, even when strong basic compounds such as DBU, DBN, and TMG are used as organic base catalysts, the decomposition of the organopolysiloxane is suppressed, and the above-mentioned excellent effects are exhibited. This effect is achieved for the first time by the distinctive configuration of the present invention, which could not be predicted from the prior art.

[Industrial applicability]
The manufacturing method of the present invention makes it possible to obtain a high-viscosity organopolysiloxane emulsion with an extremely low cyclic siloxane content. Because there is less possibility of cyclic siloxane volatilizing and contaminating the equipment during heat treatment, it is industrially useful. Furthermore, due to its excellent stability and feel, it is particularly useful as a cosmetic and household product, and can be used, for example, in hair care products such as shampoos and conditioners. It can also be used as a protective material for furniture and miscellaneous goods, a coating agent for rubber, plastics, concrete, mortar, wood, and paper, a mold release agent for molds used when processing rubber and plastic products, and a fiber treatment agent to impart water repellency and flexibility to fibers.

This specification includes the following embodiments:
[1]: (I) (A) Organopolysiloxane represented by the following general formula (1) and having an octamethylcyclotetrasiloxane content of 3,000 ppm or less: 100 parts by mass,
(In the formula, ^R1 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and ^R2 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. n is the number at which the viscosity of the organopolysiloxane at 25°C is between 15 mPa·s and 100,000 mPa·s.)
(B) Organoalkoxysilanes represented by the following general formula (2), partially hydrolyzed condensates thereof, or mixtures thereof: 0.2 to 20 parts by mass,
(In the formula, ^R3 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and ^R4 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. m is 3 to 4.)
(C) Nonionic surfactant: 2 to 30 parts by mass and
(D-1) A mixture containing 1 to 10,000 parts by mass of water is emulsified to prepare a first emulsion composition.
(II) The first emulsion composition,
(D-2) Water: After adding 0 to 10,000 parts by mass,
A method for producing an organopolysiloxane emulsion composition, characterized by emulsion polymerization at a temperature below 40°C in the presence of 0.1 to 20 parts by mass of (E) an organic base catalyst, wherein the viscosity of the resulting organopolysiloxane at 25°C is 300,000 mPa·s or more, the amount of octamethylcyclotetrasiloxane contained in the organopolysiloxane is 3,000 ppm or less, and the average particle size of the emulsion particles of the target emulsion composition is 1 μm or less.
[2]: A method for producing the organopolysiloxane emulsion composition according to [1], characterized in that the component (A) is an organopolysiloxane in which n in the general formula (1) is a number such that the viscosity of the organopolysiloxane at 25°C is 15 mPa·s or more and 1,800 mPa·s or less.
[3]: A method for producing the organopolysiloxane emulsion composition according to [1] or [2], characterized in that the content of component (B) is 0.4 to 10 parts by mass.
[4]: A method for producing any one of the organopolysiloxane emulsion compositions according to [1] to [3], characterized in that one or more selected from tetramethylguanidine, diazabicycloundecene, diazabicyclononene, triazabicyclodecene, methyltriazabicyclodecene, and diazabicyclooctane are used as the (E) organic base catalyst.
[5] A method for producing any one of the organopolysiloxane emulsion compositions according to [1] to [4], characterized in that the (E) organic base catalyst is used in an amount of 0.5 to 7 parts by mass per 100 parts by mass of component (A).
[6] A method for producing any one of the organopolysiloxane emulsion compositions according to [1] to [5], characterized by not using an anionic surfactant.
[7]:
A method for producing any one of the organopolysiloxane emulsion compositions [1] to [6], characterized by not using a cationic surfactant.
[8]: A method for producing any one of the organopolysiloxane emulsion compositions from [1] to [7], characterized in that the emulsion polymerization described in (II) is carried out at a temperature of less than 25°C.
[9] A method for producing any one of the organopolysiloxane emulsion compositions according to [1] to [8], characterized in that the polymerization time in the emulsion polymerization of (II) is 48 hours or less.
[10] A method for producing an organopolysiloxane emulsion composition according to any one of [1] to [9], characterized in that the average particle size of the emulsion particles of the target emulsion composition is 500 nm or less.
[11]: A method for producing any one of the organopolysiloxane emulsion compositions from [1] to [10], characterized in that the content of octamethylcyclotetrasiloxane contained in the organopolysiloxane in the emulsion composition for the objective is 2,000 ppm or less.

Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that has substantially the same technical idea as described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention.

Claims (10)

(I) (A) Organopolysiloxane represented by the following general formula (1) and having an octamethylcyclotetrasiloxane content of 3,000 ppm or less: 100 parts by mass,
(In the formula, ^R1 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and ^R2 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. n is the number at which the viscosity of the organopolysiloxane at 25°C is between 15 mPa·s and 100,000 mPa·s.)
(B) Organoalkoxysilanes represented by the following general formula (2), partially hydrolyzed condensates thereof, or mixtures thereof: 0.2 to 20 parts by mass,
(In the formula, ^R3 is independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and ^R4 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. m is 3 to 4.)
(C) Nonionic surfactant: 2 to 30 parts by mass and
(D-1) A mixture containing 1 to 10,000 parts by mass of water is emulsified to prepare a first emulsion composition.
(II) The first emulsion composition,
(D-2) Water: After adding 0 to 10,000 parts by mass,
A method for producing an organopolysiloxane emulsion composition, characterized by emulsion polymerization at a temperature below 40°C in the presence of 0.1 to 20 parts by mass of an organic base catalyst, one or more selected from (E)tetramethylguanidine, diazabicycloundecene, diazabicyclononene, triazabicyclodecene, methyltriazabicyclodecene, and diazabicyclooctane, wherein the viscosity of the resulting organopolysiloxane at 25°C is 300,000 mPa·s or more, the amount of octamethylcyclotetrasiloxane contained in the organopolysiloxane is 3,000 ppm or less, and the average particle size of the emulsion particles of the target emulsion composition is 1 μm or less. The method for producing an organopolysiloxane emulsion composition according to claim 1, characterized in that, as component (A), an organopolysiloxane is used in which n in the general formula (1) is a number such that the viscosity of the organopolysiloxane at 25°C is 15 mPa·s or more and 1,800 mPa·s or less. A method for producing an organopolysiloxane emulsion composition according to claim 1, characterized in that the content of component (B) is 0.4 to 10 parts by mass. The method for producing an organopolysiloxane emulsion composition according to claim 1, characterized in that 0.5 to 7 parts by mass of the (E) organic base catalyst is used per 100 parts by mass of component (A). A method for producing an organopolysiloxane emulsion composition according to claim 1, characterized by not using anionic surfactants. A method for producing an organopolysiloxane emulsion composition according to claim 1, characterized by not using a cationic surfactant. A method for producing an organopolysiloxane emulsion composition according to claim 1, characterized in that the emulsion polymerization described in (II) above is carried out at a temperature of less than 25°C. A method for producing an organopolysiloxane emulsion composition according to claim 1, characterized in that the polymerization time in the emulsion polymerization described in (II) above is 48 hours or less. A method for producing an organopolysiloxane emulsion composition according to claim 1, characterized in that the average particle size of the emulsion particles in the aforementioned target emulsion composition is 500 nm or less. A method for producing an organopolysiloxane emulsion composition according to any one of claims 1 to 9 , characterized in that the content of octamethylcyclotetrasiloxane contained in the organopolysiloxane in the aforementioned target emulsion composition is 2,000 ppm or less.