JP4697447B2 - Method for producing functional group-containing diorganopolysiloxane emulsion - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a functional group-containing diorganopolysiloxane emulsion useful for resin modification, and more specifically, an inexpensive anionic surfactant, preferably an alkyl sulfate ester salt, using an inexpensive terminal hydroxy diorganopolysiloxane as a raw material. The present invention relates to a method for producing a functional group-containing diorganopolysiloxane emulsion having a small median diameter and excellent stability.

  Organopolysiloxane emulsions are useful as mold release agents, various coating agents, water repellents such as organic fibers and inorganic fibers, fiber softeners and smoothing agents, or as components of emulsion paints and antifoaming agents. As such an organopolysiloxane emulsion, it is preferable to use one having a small particle size produced by emulsion polymerization in consideration of various stability and high degree of polymerization.

  The emulsion polymer can be produced by, for example, a method in which a strong acid or strong alkali is used as a polymerization catalyst (Japanese Patent Publication No. 34-2041: Patent Document 1), alkylbenzene sulfonic acid, alkyl naphthalene sulfonic acid, aliphatic sulfonic acid, silylalkyl. A method of emulsifying and polymerizing organopolysiloxane using sulfonic acid, aliphatic substituted diphenyl ether sulfonic acid, alkyl hydrogen sulfate or the like as a polymerization catalyst (Japanese Patent Publication No. 41-13995, Belgian Patent No. 686812, US Pat. No. 3,360,491) Specification: Patent Documents 2 to 4). In addition, a method of polymerizing a polymer by emulsifying and dispersing an organosiloxane tri- or hexamer in an aqueous salt-type surfactant solution, adding an ion-exchange resin to the dispersion, and performing ion-exchange of the salt-type surfactant. Japanese Patent Publication No. 54-19440: Patent Document 5).

  On the other hand, regarding the functional group-containing diorganopolysiloxane emulsion for resin modification, as a method for producing a diorganopolysiloxane graft copolymer, an emulsion of vinyl group-containing diorganopolysiloxane or allyl group-containing diorganopolysiloxane is used. A method of polymerizing a vinyl monomer to prepare a graft polymer and improving impact strength (US Pat. No. 3,898,300: Patent Document 6). In addition, a method for further improving the impact strength by changing the vinyl group to a mercapto group-containing diorganopolysiloxane (US Pat. No. 4,071,577: Patent Document 7). Further, a method of preparing a diorganopolysiloxane using a methacryloxy group or an acryloxy group as a graft crossing agent and graft polymerization with a vinyl monomer to achieve very high graft efficiency (Japanese Patent Publication No. 6-29303, Japanese Patent Publication No. No. 74303: Patent Documents 8, 9) and the like.

  As a method for producing a methacryloxy group or acryloxy group-containing diorganopolysiloxane useful as a graft-crossing agent, a cyclic siloxane (3 to 6-mer) and a methacryloxy group or acryloxy group-containing silane are alkylbenzene sulfonic acids, dodecylbenzene sulfonic acid. In general, emulsion polymerization is carried out using as an emulsifier and polymerization catalyst. Moreover, the method of preparing a mercapto group, (alpha) -alkenyl group, or styryl group containing diorganopolysiloxane can also be adjusted with the same manufacturing method. However, when emulsifying the terminal hydroxydiorganopolysiloxane which is the raw material of the present invention, dodecylbenzenesulfonic acid promotes the formation of low-molecular siloxane {cyclic siloxane (4- to 6-mer)}. Cannot be used as In addition, sodium dodecylbenzenesulfonate, which is an alkylbenzene sulfonate, is used as an emulsifier, and even when high-pressure emulsified, the median diameter cannot be reduced to 0.3 μm or less, and the resulting emulsion lacks stability. there were.

Japanese Patent Publication No.34-2041 Japanese Patent Publication No.41-13995 Belgian Patent No. 686812 U.S. Pat. No. 3,360,491 Japanese Patent Publication No.54-19440 U.S. Pat. No. 3,898,300 U.S. Pat. No. 4,071,577 Japanese Patent Publication No. 6-29303 Japanese Patent Publication No. 6-74303

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for producing a functional group-containing diorganopolysiloxane emulsion that is simple and low-cost, has a small median diameter, and is excellent in stability.

  As a result of intensive studies to solve the above-mentioned object, the inventors of the present invention emulsified a terminal hydroxydiorganopolysiloxane and a functional group-containing organoalkoxysilane using an anionic surfactant and water. High-pressure emulsification is performed under the condition that the emulsion dispersion treatment is performed twice or more at a high pressure of 50 MPa or more so that the diameter becomes 0.30 μm or less, and the emulsion polymerization is carried out in an acid catalyst at a temperature of 20 ° C. or less and a condensation polymerization time within 20 hours. And then neutralizing, it was confirmed that a functional group-containing diorganopolysiloxane emulsion having a small median diameter of 0.30 μm or less and excellent in stability was obtained. It was found that the functional group-containing diorganopolysiloxane emulsion is very useful, and the present invention has been achieved.

In addition, the present inventors previously (A) the following general formula (1)
H- [O-Si (R) ₂ ] _n- OH (1)
(In the formula, R represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and n represents an integer satisfying 10 ≦ n ≦ 200.)
A terminal hydroxydiorganopolysiloxane having a cyclic low molecular siloxane content of 3% by mass or less and having 10 or less silicon atoms,
(B) a functional group-containing organoalkoxysilane,
(C) a surfactant,
(D) Water is emulsified and dispersed to obtain an initial emulsion having an average particle size of 250 nm or more and 350 nm or less. After the emulsion is cooled to a temperature of 20 ° C. or less, emulsion polymerization is performed within 20 hours in the presence of an acidic catalyst, A method for producing a functional group-containing diorganopolysiloxane emulsion having an octamethylcyclotetrasiloxane content in the diorganopolysiloxane of 0.5 to 2.0% by mass, characterized by neutralization (Japanese Patent Application No. 2005-116684).

  In addition, the said average particle diameter is a measured value by the particle size distribution measuring apparatus N4 plus made from Coulter. On the other hand, in the present invention, the median diameter is a value measured using a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.) and is a particle diameter corresponding to 50% of the cumulative distribution. The median diameter is defined as the particle diameter. The former average particle diameter of 0.30 μm (300 nm) is larger than the latter median diameter of 0.30 μm.

  In the above-described method for producing an emulsion in Japanese Patent Application No. 2005-116684, when an initial emulsion is obtained, the emulsification dispersion is performed mainly under a high shear pressure of 50 to 150 MPa, but this emulsification dispersion is usually performed once. However, it has been found that a fine emulsion having a median diameter of 0.30 μm or less can be obtained by repeating emulsification and dispersion at such a high shear pressure twice or more. In this case, in particular, as a high-pressure emulsifier, a high-pressure emulsifier having a double pressure booster pump, for example, a NS2006 type homogenizer manufactured by NIRO-SOAVI, is used, so that the pressure plunger pump is a single type. It has been found that the above fine emulsion can be effectively prepared as compared with the case of using a high-pressure emulsifier, for example, RANNIE-2000 type manufactured by APV GAULIN.

That is, this invention provides the manufacturing method of the functional group containing diorganopolysiloxane emulsion shown below.
[1] (A) The following general formula (1)
H- [O-Si (R) ₂ ] _n- OH (1)
(In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and n is an integer satisfying 10 ≦ n ≦ 200.)
A terminal hydroxydiorganopolysiloxane having a cyclic low molecular siloxane content of 3% by mass or less and having 10 or less silicon atoms,
(B) a methacryloxy group, an acryloxy group, organoalkoxysilane containing a mercapto group, a functional group selected from α- alkenyl and styryl group,
(C) As an anionic surfactant , only sodium lauryl sulfate ,
(D) Water is emulsified and dispersed twice at a high pressure of 50 MPa or more to obtain an initial emulsion having a median diameter of 0.30 μm or less. After cooling the emulsion to a temperature of 20 ° C. or less, in the presence of an acidic catalyst A method for producing a functional group-containing diorganopolysiloxane emulsion having a median diameter of 0.30 μm or less, wherein emulsion polymerization is carried out within 20 hours of condensation polymerization and then neutralized.
[2] The method for producing a functional group-containing diorganopolysiloxane emulsion according to [1], wherein the purity of sodium lauryl sulfate is 99.9% or more.

  According to the present invention, an anionic surfactant, more preferably an alkyl sulfate salt, is used as an emulsifier, and it is reduced in particle size by high-pressure emulsification under specific conditions. A functional group-containing diorganopolysiloxane emulsion useful as can be produced.

  In the method for producing a functional group-containing diorganopolysiloxane emulsion of the present invention, components (A) to (D) described later are emulsified under high pressure under specific conditions to obtain an initial emulsion having a median diameter of 0.30 μm or less. After the emulsion is cooled to a temperature of 20 ° C. or lower, emulsion polymerization is carried out in the presence of an acidic catalyst within 20 hours of condensation polymerization, and then neutralized.

(A) Component The component (A) used in the present invention is represented by the following general formula (1), and the content of the cyclic low molecular siloxane having 10 or less silicon atoms is 3% by mass or less. Siloxane.
H- [O-Si (R) ₂ ] _n- OH (1)
(In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and n is an integer satisfying 10 ≦ n ≦ 200.)

  In the above formula, examples of the substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms of R include, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl , Alkyl groups such as hexadecyl, octadecyl, eicosyl, cycloalkyl groups such as cyclopentyl and cyclohexyl, aryl groups such as phenyl and tolyl, alkenyl groups such as vinyl and allyl, and part of their hydrogen atoms replaced with chlorine or fluorine Examples include halogenoalkyl groups. Among these, it is industrially preferable that 90 mol% or more is a methyl group.

  When the diorganopolysiloxane contains more than 3% by mass of cyclic low molecular siloxane having 10 or less silicon atoms, the content of volatile low molecular siloxane in the siloxane polymer after condensation polymerization (the number of silicon atoms is 10 or less). Cyclic low-molecular siloxane) exceeds 5% by mass, which causes a problem of working environment due to volatile low-molecular siloxane during or after use of the emulsion. Therefore, it is necessary to use a material in which the amount of low molecular siloxane is reduced to 3% by mass or less, preferably 2% by mass or less. A terminal hydroxydiorganopolysiloxane having a cyclic low molecular siloxane content of 10 or less silicon atoms and having a content of 2 to 3% by mass is industrially the lowest cost and is most advantageous when used as a raw material.

  Furthermore, if n is smaller than 10, it is difficult to adjust the content of cyclic low molecular siloxane having 10 or less silicon atoms to 3% by mass or less, and if it is larger than 200, the storage stability when made into an emulsion is deteriorated. n needs to be 10 ≦ n ≦ 200.

(B) As a functional group containing organoalkoxysilane of a component (B), what is represented, for example by following formula (2) can be used.
R ¹ R ² _m Si (OR ³ ) _3-m (2)
(In the formula, R ¹ is an organic group containing a methacryloxy group, acryloxy group, mercapto group, α-alkenyl group or styryl group, R ² is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R ³ is 1 carbon atom. -6 monovalent hydrocarbon group, m is an integer of 0-2.)

Here, as R ¹ , an organic group containing a methacryloxy group, an acryloxy group, a mercapto group, an α-alkenyl group, or a styryl group is used. Examples of the substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms of R ² include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, Alkyl groups such as hexadecyl, octadecyl, eicosyl, cycloalkyl groups such as cyclopentyl and cyclohexyl, aryl groups such as phenyl and tolyl, alkenyl groups such as vinyl and allyl, and halogeno in which some of their hydrogen atoms are substituted with chlorine or fluorine Examples include an alkyl group. Furthermore, specific examples of the monovalent hydrocarbon group having 1 to 6 carbon atoms for R ³ include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl. m is an integer of 0-2.

  As the functional group-containing organoalkoxysilane represented by the above formula (2), methacryloxy group-containing organoalkoxysilane, acryloxy group-containing organoalkoxysilane, mercapto group-containing organoalkoxysilane, vinyl group-containing organoalkoxysilane, styryl group-containing organo An alkoxysilane can be illustrated.

  Specific examples of the methacryloxy group and acryloxy group functional organoalkoxysilane include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxy. Examples include silane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldiethoxysilane, and 3-acryloxypropyltriethoxysilane. Specific examples of the mercapto group-functional organoalkoxysilane include 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane. Specific examples of the α-alkenyl group-functional organoalkoxysilane include vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane. Furthermore, specific examples of the styryl group-functional organoalkoxysilane include p-styrylmethyldimethoxysilane and p-styryltrimethoxysilane.

  In the present invention, the partial hydrolysis-condensation product of the functional group-containing organoalkoxysilane and the organosiloxane oligomer having a functional group-containing siloxane unit are added within a range that does not impair the object of the present invention, and polymerization is performed. Also good.

  The total proportion of the (A) component diorganopolysiloxane and the (B) component functional group-containing organoalkoxysilane is preferably 10 to 70% by mass as the solid content in the emulsion, which is 10% by mass. When it is less than%, it is not economical, and when it is more than 70% by mass, the stability of the emulsion may be lowered. More preferably, it is 30-55 mass%.

  Moreover, the compounding quantity of the functional group containing organoalkoxysilane of (B) component becomes like this. Preferably it is 0.1-20 mass parts per 100 mass parts of organopolysiloxane of (A) component, More preferably, it is 1-10 mass parts. is there. If the component (B) is less than 0.1 part by mass, the contribution of the organic functional group in the emulsion may be low, and if it exceeds 20 parts by mass, the amount of polymerizable functional groups increases, and reaction control is performed when modifying the resin. It may be difficult to remove.

(C) Component (C) Surfactant is used to uniformly disperse component (A) and component (B) in water, and a surfactant used as an equilibration catalyst or a condensation polymerization catalyst is used. There is no particular limitation except that it is not possible, but an anionic surfactant is most suitable because an acidic catalyst is used as the condensation polymerization catalyst.

  Examples of the anionic surfactant include alkyl sulfate ester salts, sulfonate salts, carboxylate salts, and phosphate ester salts. Examples of the alkyl sulfate ester salt include higher alcohol sulfate ester salt, higher alkyl ether sulfate ester salt, sulfated oil, sulfated fatty acid ester, sulfated olefin and the like. Examples of the sulfonate include alkyl benzene sulfonate, alkyl naphthalene sulfonate, paraffin sulfonate, and N-acyl taurate. Specific examples of the alkyl sulfate salt include sodium octyl sulfate, sodium 2-ethylhexyl sulfate, sodium decyl sulfate, sodium lauryl sulfate, potassium lauryl sulfate, ammonium lauryl sulfate, triethanolamine lauryl sulfate, sodium myristyl sulfate, sodium cetyl sulfate, Examples thereof include sodium polyoxyethylene lauryl ether sulfate, and examples of the sulfonate include sodium octylbenzenesulfonate, sodium decylbenzenesulfonate, sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, and sodium dialkylsulfosuccinate. . These may be used singly or in combination of two or more. Particularly preferred are alkyl sulfates, and more specifically sodium lauryl sulfate is most preferred.

  The amount of component (C) is preferably 0.1 to 10% by mass of the emulsion of the present invention {total amount of components (A) to (D)}, which is less than 0.1% by mass. In some cases, the stability of the emulsion may be insufficient, and if it exceeds 10% by mass, the heat resistance of the resulting emulsion may be reduced, and the cost may be disadvantageous. More preferably, it is the range of 0.5-5 mass%.

  The functional group-containing diorganopolysiloxane emulsion of the present invention is obtained by emulsifying and dispersing diorganosiloxane and functional group-containing organoalkoxysilane as described above in the presence of an anionic surfactant sodium lauryl sulfate in an aqueous medium. It can be produced by performing condensation polymerization at 20 ° C. or lower and further neutralizing to pH 4-9.

  In the present invention, after (A) component, (B) component and (C) component described above are first uniformly emulsified and dispersed in ion-exchanged water as component (D) with an emulsifier such as a homomixer or homogenizer, Further, high-pressure emulsification is performed with a high-pressure emulsifier to prepare an initial emulsion having a median diameter of 0.30 μm or less.

  Here, the mixing ratio of the water of the component (D) is preferably 30 to 90% by mass, particularly 45 to 70% by mass of the total amount of the components (A) to (D). If the blending amount is too small, the emulsion becomes highly viscous, which may make it difficult to convey and fill. If it is too large, it may be disadvantageous in terms of cost.

The emulsion after this initial emulsification and dispersion needs to have a median diameter of 0.30 μm or less, and particularly preferably 0.15 to 0.25 μm. If the median diameter is not less than 0.30 μm, the storage stability of the emulsion is lowered.
In the present invention, the median diameter can be measured with a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.).

In order to obtain such a specific median diameter, the above components (A) to (D) are emulsified and dispersed using a high-pressure emulsifier under a high shear pressure of 50 to 120 MPa, particularly 70 to 100 MPa. In addition, the median diameter of the emulsion can be reduced to 0.30 μm or less by performing emulsification at a high shear pressure for 2 to 5 times, preferably 2 to 3 times.
Here, examples of the high-pressure emulsifier to be used include an ultra-high pressure Gaurin homogenizer, a microfluidizer, a nanomizer, an optimizer, and the like. It is preferable to use a high-pressure emulsifier excellent in reducing the particle size of the resulting emulsion.

  Under the high-pressure emulsification conditions described above, the median diameter of the initial emulsion can be 0.30 μm or less. Among the anionic surfactants of the component (C) used in the present invention, an alkyl sulfate ester salt is preferable because the median diameter can be reduced. Of the alkyl sulfate salts, sodium lauryl sulfate having an alkyl group with 12 carbon atoms can minimize the median diameter. Sodium lauryl sulfate can be made smaller in particle size than when sodium octyl sulfate or sodium decyl sulfate having 8 or 10 carbon atoms is used. Similarly, sodium myristyl sulfate having 14 or 16 carbon atoms. The particle size can be made smaller than when sodium cetyl sulfate is used.

  In addition, anionic surfactants containing sodium lauryl sulfate as a main component and a small amount of sodium myristyl sulfate and sodium cetyl sulfate are also commercially available. Similarly, sodium lauryl sulfate having 100% lauryl group is used. Therefore, it is most preferable to use sodium lauryl sulfate having a lauryl group of 100% and a purity of 99.9% or more.

  In addition, when using the cyclic siloxane (3-6 mer) instead of the terminal hydroxy diorganopolysiloxane of the present invention as the siloxane raw material and performing similar emulsion polymerization, any of the anionic surfactants described above is used. Even if it is used, it is possible to obtain an emulsion having a median diameter of 0.30 μm or less. This can be confirmed by any anionic surfactant that cyclic siloxane has a ring-opening reaction and a phenomenon that the particle size is reduced during condensation polymerization. On the other hand, in the case of the terminal hydroxydiorganopolysiloxane raw material of the present invention, there is no phenomenon that the particle size is reduced during the condensation polymerization, and the particle size after high pressure emulsification becomes the particle size after polymerization. The selection of the active agent is important.

  In the case of a methacryloxy group / acryloxy group-containing diorganopolysiloxane emulsion having a median diameter larger than 0.30 μm, the grafting efficiency of the graft polymerization with the vinyl monomer is lowered, and the physical properties as a resin modifier are adversely affected. Therefore, it is not preferable.

  A functional group-containing diorganopolysiloxane emulsion can be produced by obtaining an initial emulsion having a specific median diameter, followed by condensation polymerization at a temperature of 20 ° C. or less and further neutralizing to pH 4-9.

  The liquid temperature of the initial emulsion is 20 ° C. or less, preferably 0 to 20 ° C., and an acidic substance such as hydrochloric acid, sulfuric acid, methanesulfonic acid or dodecylbenzenesulfonic acid is added as a silanol group condensation polymerization catalyst for 20 hours. Within 5 minutes, preferably 5 to 20 hours.

  In this case, in order to suppress the formation of low-molecular cyclic siloxanes such as octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane, the liquid temperature needs to be 20 ° C. or less, and preferably 0 to 10 ° C. If it is lower than 0 ° C., the emulsion may be broken by freezing.

  In addition, when the condensation polymerization reaction is shorter than 5 hours, the condensation polymerization reaction is insufficient and the molecular weight may not be increased. When the condensation polymerization reaction is longer than 20 hours, the molecular weight is increased, but octamethylcyclotetrasiloxane or decamethylcyclopenta Since siloxane production | generation increases, 5 to 20 hours are preferable, More preferably, it is 10 to 15 hours.

The compounding amount of the acidic substance that is the condensation polymerization catalyst is preferably about 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, about the amount of component (C). From the balance between the molecular weight and the suppression of the formation of low molecular siloxanes such as octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane, it is more preferably in the range of 0.5 to 2% by mass.
After completion of the polymerization, neutralization is performed with an alkaline substance such as sodium carbonate, sodium hydroxide, triethanolamine, or ammonia.

  In addition, in order to improve the stability of the functional group-containing diorganopolysiloxane emulsion of the present invention obtained by emulsion polymerization, other nonionic surfactants, amphoteric surfactants and the like are within the range not impairing the object of the present invention. You may add after neutralization.

  By this condensation polymerization reaction, a functional group-containing diorganopolysiloxane having a polymerization degree of 1,000 to 3,000, particularly 1,500 to 2,500 is obtained. This organopolysiloxane is obtained as an emulsion emulsified and dispersed in water. In this case, the solid content (the above-mentioned target organopolysiloxane) concentration in the emulsion is preferably 10 to 70% by mass.

The functional group-containing diorganopolysiloxane emulsion of the present invention is characterized by extremely excellent stability because it has a median diameter of 0.30 μm or less, particularly 0.20 to 0.25 μm. is there.
The functional group-containing diorganopolysiloxane emulsion of the present invention contains a methacryloxy group, an acryloxy group, a mercapto group, an α-alkenyl group or a styryl group as a functional group, and is prepared under the above-mentioned emulsion and polycondensation conditions. The amount of octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane produced in the functional group-containing diorganopolysiloxane emulsion produced is smaller than that of the component (B) containing no functional group-containing organoalkoxysilane. It is also characterized by being suppressed.

  Specific embodiments of the present invention will be described below in more detail with reference to examples, but the present invention is not limited to the following examples. In the following examples, the viscosity is a value measured at 25 ° C. measured with a BH viscometer (manufactured by Tokyo Keiki Co., Ltd.), and the median diameter is a laser diffraction / scattering particle size distribution measuring apparatus LA-920 (Horiba, Ltd.). The average particle size is a value measured by a Coulter N4 Plus submicron particle size distribution measuring device (manufactured by Coulter Co., Ltd.).

[Example 1]
Cyclic low-molecular siloxane content with 10 or less Si atoms is 2.4% by mass (octamethylcyclotetrasiloxane (hereinafter D4) content: 0.69% by mass, other low-molecular siloxane contents are shown in Table 1) And the formula (3)
_{H- [O-Si (CH 3} ) 2] 40 -OH (3)
A mixture of 487 g of terminal hydroxy diorganopolysiloxane (viscosity: 65 mPa · s) and 13 g of 3-methacryloxypropylmethyldimethoxysilane was charged into a 2 liter polyethylene beaker and 50 g of 10% by weight aqueous sodium lauryl sulfate solution (Nikkor SLS). Manufactured by Nikko Chemical Co., Ltd., lauryl group: 100%, purity: 99.9% or more) and ion-exchanged water (50 g) were added, and the resulting mixture was gradually added dropwise with stirring at 2,000 rpm with a homomixer. After thickening, the stirring speed was increased to 5,000 rpm and stirring was continued for 15 minutes, and then 340 g of deionized water was added for dilution. Subsequently, this was emulsified and dispersed twice at 100 MPa with an “NS2006 type homogenizer” (manufactured by NIRO-SOAVI, double-pressurized plunger pump). The median diameter at this time was measured and found to be 0.25 μm. Moreover, it was 0.31 micrometer when the average particle diameter was measured. After the obtained emulsion was cooled in a low temperature incubator at 5 ° C. for 12 hours, the internal temperature became 7 ° C. 50 g of 10% by mass dodecylbenzenesulfonic acid, which is a condensation polymerization catalyst, was added and stirred, and then a condensation polymerization reaction was carried out for 10 hours. Subsequently, 10 g of 10% by mass sodium carbonate was added to adjust the pH to 7. As a result, milky white “Emulsion A” having a median diameter of 0.26 μm was obtained. This emulsion had a non-volatile content of 49.0% by mass after 3 hours at 105 ° C., and low molecular weight siloxane was measured by gas chromatography. As a result, the D4 content was 0.9% by mass. Even when this emulsion was allowed to stand at room temperature for 1 month, no layer separation was observed, and the emulsion showed excellent stability. 200 g of isopropyl alcohol was added to 200 g of this emulsion, and the oil component was extracted to obtain a highly viscous diorganopolysiloxane. After drying (105 ° C. × 3 hours), the PS conversion Mw measured by GPC was 170,000. The viscosity of this oil was 410,000 mPa · s. The physical properties are shown in Table 2.

Low molecular siloxane content of terminal hydroxy diorganopolysiloxane represented by formula (3)

Low molecular weight siloxane determination method 0.1 g of the prepared emulsion was extracted with 10 ml of internal standard acetone (shaking for 1 hour) and allowed to stand overnight, and then the acetone layer was determined by gas chromatography analysis.

[Example 2]
In Example 1, a mixture of 487 g of the terminal dihydroxyorganopolysiloxane represented by the formula (3) and 13 g of 3-acryloxypropylmethyldimethoxysilane used was charged into a 2 liter polyethylene beaker and 50 g of a 10% by mass aqueous sodium lauryl sulfate solution. And 50 g of ion-exchanged water was gradually added dropwise with stirring at 2,000 rpm with a homomixer to cause phase inversion. After thickening, the stirring speed was increased to 5,000 rpm and stirring was continued for 15 minutes, and then 340 g of deionized water was added for dilution. Next, this was emulsified and dispersed twice at 100 MPa with an “NS2006 type homogenizer” (manufactured by NIRO-SOAVI, double plunger pump). The median diameter at this time was measured and found to be 0.27 μm. After the obtained emulsion was cooled in a low-temperature incubator at 5 ° C. for 12 hours, the internal temperature became 7.5 ° C. 50 g of 10% by mass dodecylbenzenesulfonic acid, which is a condensation polymerization catalyst, was added and stirred, and then a condensation polymerization reaction was carried out for 10 hours. Subsequently, 10 g of 10% by mass sodium carbonate was added to adjust the pH to 7, whereby milky white “Emulsion B” having a median diameter of 0.27 μm was obtained. This emulsion had a non-volatile content of 48.8% by mass after 3 hours at 105 ° C., and the low molecular weight siloxane was measured by gas chromatography. As a result, the D4 content was 1.0% by mass. Even when this emulsion was allowed to stand at room temperature for 1 month, no layer separation was observed, and the emulsion showed excellent stability. 200 g of isopropyl alcohol was added to 200 g of this emulsion, and the oil component was extracted to obtain a highly viscous diorganopolysiloxane. The result of measuring PS converted Mw by GPC after drying was 160,000. The viscosity of this oil was 390,000 mPa · s. The physical properties are shown in Table 2.

[Example 3]
“Emulsion C” was prepared in the same manner as in Example 1 except that 3-methacryloxypropylmethyldimethoxysilane was changed to 3-mercaptopropylmethyldimethoxysilane in Example 1.
The median diameter before condensation polymerization is 0.26 μm, and the prepared emulsion has a median diameter of 0.27 μm and a non-volatile content after 3 hours at 105 ° C. of 48.7% by mass. As a result, the D4 content was 1.1% by mass. Even when this emulsion was allowed to stand at room temperature for 1 month, no layer separation was observed, and the emulsion showed excellent stability. 200 g of isopropyl alcohol was added to 200 g of this emulsion, and the oil component was extracted to obtain a highly viscous organopolysiloxane. The result of measuring PS converted Mw by GPC after drying was 170,000. The oil had a viscosity of 407,000 mPa · s. The physical properties are shown in Table 2.

[Example 4]
“Emulsion D” was prepared in the same manner as in Example 1 except that 3-methacryloxypropylmethyldimethoxysilane was changed to vinylmethyldimethoxysilane in Example 1.
The median diameter before condensation polymerization is 0.28 μm, and the prepared emulsion has a median diameter of 0.28 μm and a non-volatile content after 4 hours at 105 ° C. of 48.9% by mass. As a result of chromatography, the D4 content was 1.0% by mass. The physical properties are shown in Table 2.

[Example 5]
“Emulsion E” was prepared in the same manner as in Example 1 except that 3-methacryloxypropylmethyldimethoxysilane was changed to p-styrylmethyldimethoxysilane in Example 1.
The median diameter before condensation polymerization is 0.27 μm, and the prepared emulsion has a median diameter of 0.28 μm and a non-volatile content of 49.0% by mass after 3 hours at 105 ° C. As a result of chromatography, the D4 content was 1.0% by mass. The physical properties are shown in Table 2.

[Comparative Example 1]
In Example 1, “Emulsion F” was prepared in the same manner as in Example 1 except that the 10% by mass sodium lauryl sulfate aqueous solution was changed to 10% by mass sodium octyl sulfate (Pionin A-20; manufactured by Takemoto Yushi). The median diameter before condensation polymerization was 0.37 μm, and the prepared emulsion had a median diameter of 0.39 μm and a non-volatile content after 3 hours at 105 ° C. of 48.5% by mass. As a result of measuring low molecular weight siloxane by gas chromatography, the D4 content was 1.3% by mass. The physical properties are shown in Table 2.

[Comparative Example 2]
In Example 1, “Emulsion G” was prepared in the same manner as in Example 1 except that the 10% by mass sodium lauryl sulfate aqueous solution was changed to 10% by mass sodium 2-ethylhexyl sulfate (Sintrekki EH-R; manufactured by NOF Corporation). did. The median diameter before condensation polymerization was 0.34 μm, and the prepared emulsion had a median diameter of 0.36 μm and a non-volatile content after 3 hours at 105 ° C. of 48.3 mass%. As a result of measuring the low molecular siloxane by gas chromatography, the D4 content was 1.5% by mass. The physical properties are shown in Table 2.

[Comparative Example 3]
“Emulsion H” was prepared in the same manner as in Example 1 except that the 10 mass% sodium lauryl sulfate aqueous solution was changed to 10 mass% sodium myristyl sulfate (Nikkor SMS-F; manufactured by Nikko Chemical). The median diameter before condensation polymerization was 0.41 μm, and the prepared emulsion had a median diameter of 0.42 μm and a non-volatile content after 3 hours at 105 ° C. of 48.6% by mass. As a result of measuring the low molecular siloxane by gas chromatography, the D4 content was 1.4% by mass. The physical properties are shown in Table 2.

[Comparative Example 4]
In Example 1, a 10% by mass sodium lauryl sulfate aqueous solution was mixed with 10% by mass sodium lauryl sulfate (Emar 2F-G; manufactured by Kao; lauryl group / myristyl group / cetyl group = 60% / 26% / 14%, purity: 98.%. “Emulsion I” was prepared in the same manner as in Example 1 except that the content was changed to 3%. The median diameter before condensation polymerization was 0.33 μm, and the prepared emulsion had a median diameter of 0.32 μm and a non-volatile content after 3 hours at 105 ° C. of 48.7% by mass. As a result of measuring the low molecular weight siloxane by gas chromatography, the D4 content was 1.2% by mass. The physical properties are shown in Table 2.

[Comparative Example 5]
In Example 1, “Emulsion J” was prepared in the same manner as in Example 1 except that the 10% by mass sodium lauryl sulfate aqueous solution was changed to 10% by mass sodium dodecylbenzenesulfonate (Neopelex G-15; manufactured by Kao). did. The median diameter before condensation polymerization was 0.34 μm, and the prepared emulsion had a median diameter of 0.35 μm and a non-volatile content after 3 hours at 105 ° C. of 48.2% by mass. As a result of measuring the low molecular siloxane by gas chromatography, the D4 content was 1.6% by mass. The physical properties are shown in Table 2.

[Comparative Example 6]
In Example 1, “Emulsion K” was prepared in the same manner as in Example 1 except that the 10% by mass sodium lauryl sulfate aqueous solution was changed to 10% by mass N-lauroylmethyl taurine sodium (Nikkor LMT; manufactured by Nikko Chemical). . The median diameter before condensation polymerization was 0.40 μm, and the prepared emulsion had a median diameter of 0.41 μm and a non-volatile content after 3 hours at 105 ° C. of 48.0% by mass. As a result of measuring the low molecular siloxane by gas chromatography, the D4 content was 1.6% by mass. The physical properties are shown in Table 2.

Low molecular weight siloxane determination method 0.1 g of the prepared emulsion was extracted with 10 ml of internal standard acetone (shaking for 1 hour) and allowed to stand overnight, and then the acetone layer was determined by gas chromatography analysis.

Storage stability 100 g of each emulsion was placed in a glass bottle and stored in a thermostatic bath at 50 ° C. for 30 days. Then, the appearance and the nonvolatile content of the upper and lower layers were measured, and the stability was evaluated according to the following criteria.
(Evaluation criteria)
○: No light / dark separation is observed.
Δ: Slight density separation was confirmed in the upper and lower layers.
X: Two-layer separation.

Dilution stability Each emulsion was diluted to 2% by mass with ion-exchanged water, and the surface state after 24 hours was visually observed.

Mechanical stability Each emulsion was diluted to 2% by mass with ion-exchanged water, and the surface state after stirring at 5000 rpm for 10 minutes was visually observed.

[Comparative Example 7]
In Example 1, emulsification dispersion performed twice at 100 MPa with “NS2006 type homogenizer” (manufactured by NIRO-SOAVI, double pressure pump / pump) was used as “table homogenizer RANNIIE-2000” (manufactured by APV GAULIN). “Emulsion L” was prepared in the same manner as in Example 1 except that the emulsion was changed to one emulsification dispersion at 70 MPa with a single pressurizing plunger pump. The median diameter before condensation polymerization was 0.52 μm, and the average particle diameter was 0.29 μm.

[Comparative Example 8]
In Example 1, emulsification dispersion performed twice at 100 MPa with “NS2006 type homogenizer” (manufactured by NIRO-SOAVI, double pressure pump / pump) was used as “table homogenizer RANNIIE-2000” (manufactured by APV GAULIN). “Emulsion M” was prepared in the same manner as in Example 1 except that it was changed to one emulsification dispersion at 100 MPa with a single pressurizing plunger pump. The median diameter before condensation polymerization was 0.46 μm, and the average particle diameter was 0.30 μm.

[Comparative Example 9]
In Example 1, emulsification dispersion performed twice at 100 MPa with “NS2006 type homogenizer” (manufactured by NIRO-SOAVI, double pressure pump / pump) was used as “table homogenizer RANNIIE-2000” (manufactured by APV GAULIN). “Emulsion N” was prepared in the same manner as in Example 1 except that the emulsion was changed to one emulsification dispersion at 150 MPa with a single pressurizing plunger pump. The median diameter before condensation polymerization was 0.45 μm, and the average particle diameter was 0.29 μm.

The median diameters and average particle diameters of Example 1 and Comparative Examples 7 to 9 before condensation polymerization are shown in Table 3 below.

Claims (2)

(A) The following general formula (1)
H- [O-Si (R) ₂ ] _n- OH (1)
(In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and n is an integer satisfying 10 ≦ n ≦ 200.)
A terminal hydroxydiorganopolysiloxane having a cyclic low molecular siloxane content of 3% by mass or less and having 10 or less silicon atoms,
(B) a methacryloxy group, an acryloxy group, organoalkoxysilane containing a mercapto group, a functional group selected from α- alkenyl and styryl group,
(C) As an anionic surfactant , only sodium lauryl sulfate ,
(D) Water is emulsified and dispersed twice at a high pressure of 50 MPa or more to obtain an initial emulsion having a median diameter of 0.30 μm or less. After cooling the emulsion to a temperature of 20 ° C. or less, in the presence of an acidic catalyst A method for producing a functional group-containing diorganopolysiloxane emulsion having a median diameter of 0.30 μm or less, wherein emulsion polymerization is carried out within 20 hours of condensation polymerization and then neutralized.   The method for producing a functional group-containing diorganopolysiloxane emulsion according to claim 1, wherein the purity of sodium lauryl sulfate is 99.9% or more.