JPS62277110A - Emulsion type silicone deforming agent - Google Patents

Abstract

PURPOSE:To obtain a defoaming agent which is stable and is excellent in both foam breakability and defoating sustaining characteristic by using an emulsion consisting of a compsn. contg. an organopolysiloxane and pulverized powder silica as essential components, emulsifier, and water. CONSTITUTION:A silicone oil compd. is pred. into an emulsion by using the emulsifier. Such emulsion is so adjusted that the particles having 6-18mum average volumetric grain size occupy >=40% of the entire part. The silicone oil compd. is obtd. by adding, for example, 1-40pts.wt. pulverized powder silica having >=50m<2>/g specific surface area to 100pts.wt. diorganopolysiloxane. The emulsifier is added thereto at 1-60wt%. The emulsifier is preferably of a nionic system and the emulsifier prepd. by mixing a hydrophilic emulsifier having 8-20 HLB and lipophilic emulsifier having 2-7 HLB so as to have the HLB ranging 3-19 is more preferable.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an emulsion-type silicone antifoaming agent, particularly an emulsion-type silicone antifoaming agent that has excellent foam-breaking properties and defoaming persistence. This is related to drugs.

(Prior Art) It is known that an emulsion-type silicone antifoaming agent can be obtained by emulsifying a silicone oil compound in which finely powdered inorganic fillers such as silica, titanium dioxide, and aluminum oxide are dispersed in silicone oil.
The foam-breaking properties of this product.

Defoaming durability and resistance to acids and alkalis are primarily determined by the properties of the silicone oil compound, and emulsification is considered merely as a means to hydrophilize and disperse the silicone oil compound.

Therefore, improvements in emulsion-type silicone antifoaming agents have focused on the modification of silicone oil compounds. emulsion with enhanced antifoaming effect (see Japanese Patent Publication No. 51-35556);
A composition obtained by adding an organohydrodiene polysiloxane, silica, and a catalyst to an organopolysiloxane is emulsified to improve defoaming durability under alkali-resistant conditions (see JP-A-57-48307), and an emulsifier. It has been proposed that storage stability is improved by adding a silazane-treated silica filler to a suspension of silicone oil (see JP-A-52-2887). All of these are aimed at either foam-breaking properties, defoaming persistence, or storage stability, and are not intended to improve these properties at the same time.

Conventionally, emulsion-type silicone antifoaming agents have been modified to improve the stability of the emulsion by adjusting the amount of emulsifier; Although it is stabilized, it has the disadvantage that initial defoaming and foam-breaking properties deteriorate.

If phase inversion is carried out with the amount of emulsifier as small as possible, the emulsion particles will become coarser and the initial defoaming and foam-breaking properties will be improved, but the problem arises that the defoaming effect will not last because the emulsion particles will aggregate.

In addition, the emulsion formed by controlling the amount of emulsifier to the optimum level also has a constant particle size due to differences in temperature and water temperature between summer and winter, as well as inappropriate phase inversion water amount and phase inversion temperature. Without.

Therefore, there is a disadvantage that its properties cannot be specified.

(Structure of the Invention) The present invention relates to an emulsion-type silicone antifoaming agent that solves these disadvantages, and is an emulsion-type silicone antifoaming agent consisting of a composition containing organopolysiloxane and finely powdered silica as main components, an emulsifier, and water. In 18., this emulsion has a volume average particle diameter of 6 μs or more; It is characterized in that the volume distribution ratio of the following particles is 40% or more.

That is, as a result of various studies on emulsion-type silicone antifoaming agents that are stable and have excellent foam-breaking properties and long-lasting defoaming properties, the present inventor found that an emulsion obtained by using a silicone oil compound with an emulsifier was obtained. If particles with a volume average particle size of 6 to 18-18-20% are made up of 40% or more of the total, a silicone antifoaming agent with an extremely excellent balance between foam-breaking properties and defoaming durability can be obtained. The present invention was completed based on the discovery that the foam approaches the foam membrane, adsorbs it, penetrates the foam, breaks the foam, and maintains its effectiveness for a long time.

The organopolysiloxane constituting the emulsion-type silicone antifoaming agent of the present invention is represented by the general formula %, where R1 is an alkyl group such as a methyl group, ethyl group, propyl group, butyl group, a vinyl group, an allyl group, etc. Aryl groups such as alkenyl groups, phenyl groups, tolyl groups,
Similar types such as chloromethyl groups, 3゜3.3-trifluoropropyl groups, cyanopropyl groups, etc. in which part or all of the hydrogen atoms bonded to carbon atoms of these groups are substituted with halogen atoms, cyano groups, etc. or different carbon number 1~
20 unsubstituted or substituted monovalent hydrocarbon groups, a having an average value of 1.9 to 2.1, include dimethylpolysiloxane, diethylpolysiloxane, methylphenylpolysiloxane, Polydimethyl-polydiphenylsiloxane copolymer, polymethyl-3,3,3
Examples include -trifluoropropylsiloxane and polydimethyl-chloropropylmethylsiloxane.

The finely powdered silica added to this diorganopolysiloxane may be either dry silica or wet silica, which has been conventionally known as a silica-based filler, and includes precipitated silica, silica xerogel, fumed silica, and these. Examples include treated silica whose surface is treated with organic silyl groups, specifically Erosil (trade name, manufactured by Nippon Degussa).

Examples include Nibcil (trade name, manufactured by Nippon Silica Co., Ltd.), Cabosil (trade name, manufactured by Cabot Company, USA), and Santocel (trade name, manufactured by Monsanto Chemical Company, USA). In addition, this fine powder silica has a specific surface area of 50 rd /
If it is less than 1 part by weight, its performance will not be fully exhibited, and if it is more than 40 parts by weight, the viscosity of the base oil will increase. Since this impairs workability and makes handling difficult, it is necessary to use 1 to 40 parts by weight, preferably 3 to 20 parts by weight.

Next, nonionic, cationic, and anionic emulsifiers can be used to form this antifoaming agent, but from the standpoint of antifoaming and dispersion effects, nonionic emulsifiers are preferred. Preferably, and more preferably, a hydrophilic surfactant and a lipophilic surfactant are used in combination; however, if the HLB is 3 or less, it will not function as a dispersion stabilizer, and if the HLB is 19 or more, it will not function as an antifoaming agent. Therefore, a mixture of a hydrophilic surfactant with an HLB of 8 to 20 and a lipophilic surfactant with an HLB of 2 to 7 so that the HLB is in the range of 3 to 19 is preferred. Such surfactants include sorbitan fatty acid esters, glycerin fatty acid esters, sucrose fatty acid esters, higher fatty acid esters of polyoxyethylene compounds, higher alcohol esters, alkylphenol condensates, alkyl quaternary ammonium salts, and higher alkyl Examples include sulfonic acid salts, but preferably those having 12 to 18 carbon atoms.
sorbitan esters, glycerin esters of fatty acids,
Often lipophilic surfactants such as propylene glycol esters or polypropylene glycol, such as sorbitan monostearate, sorbitan sesquioleate, monoglycerol monooleate, triglycerol distearate, Examples include propylene glycol monolaurate, stearic acid, and oleic acid. In addition, examples of this surfactant include polyoxyethylene ester of fatty acid having 12 to 18 carbon atoms, polyoxyethylene sorbitan ester, polyoxyethylene fatty acid alcohol ether, polyoxyethylene alkylphenyl ether, polyoxyethylene-polyoxypropylene block Copolymers, polyoxyethylene castor oil esters, etc. may also be hydrophilic surfactants, including polyoxyethylene monostearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan distearate, polyoxyethylene sorbitan distearate, etc. Ethylene glycerin monooleate, polyoxyethylene cetyl ether, sucrose monostearate,
Examples include polyoxyethylene nonylphenyl ether and polyoxyethylene tridecyl ether.

The amount of the emulsifier added must be sufficient to make the silicone oil compound into an emulsion, but this is usually in the range of 1 to 60% by weight, and this preferred range is The content is 2 to 30% by weight.

Further, a thickener may be added to the antifoaming agent of the present invention if necessary, and examples thereof include cellulose ethers such as carboxymethyl cellulose and carboxyethyl cellulose, and partially saponified polyvinyl alcohol.

Examples include crystalline cellulose and sodium alginate, which are similar to the diorganopolysiloxane 1 mentioned above.
It is usually 5% by weight or less based on 00 parts by weight.

It should be noted that it is optional to add a small amount of a disinfectant to this antifoaming agent for the purpose of preservatives, and sodium hypochlorite, sorbic acid, etc. are said to be effective as disinfectants; 0.05-0.5 for polysiloxane
% range.

The emulsion-type silicone antifoaming agent of the present invention can be obtained by mixing predetermined amounts of each of the above-mentioned components and stirring uniformly, but this emulsion has emulsion particles with a volume average particle diameter of 6 to 18 μm. , and its volume distribution ratio is required to be 40% or more. Such an emulsion can be prepared by, for example, i) uniformly mixing and dispersing an organopolysiloxane composition and an emulsifier;
ii) Dissolve the thickener in water, ni) Add the water necessary for phase inversion and a predetermined amount of the thickened water obtained in step 5) to the mixture obtained in step i), and mix it with a homomixer. , a homogenizer, a colloid mill, etc. to make a homogeneous emulsion, and then K) the above emulsion is mixed with water or ii.
) can be obtained by mixing with the thickened water obtained in ). However, when mixing the organopolysiloxane composition and the emulsifier in step i), if the ratio of emulsifier/organopolysiloxane composition is 0.1 or less, the volume average particle diameter of the emulsion particles in the resulting emulsion becomes coarse. If the antifoaming agent deviates from the objective range of the present invention, the antifoaming durability of this antifoaming agent will deteriorate, and the stability of the emulsion itself will also become very poor, causing the emulsion particles to settle over time and the silicone oil compound to deteriorate. If this ratio is set to 2.0 or more, the volume average particle diameter of the emulsion particles in the generated emulsion becomes finer, which deviates from the scope of the present invention of 6 μm or more, and this antifoaming agent This ratio is preferably in the range of 0.1 to 2.0, since the initial defoaming properties will be poor and the foam-breaking effect on thick and large bubbles will be small.

In addition, in the emulsification in this step, the mixture of the organopolysiloxane composition and the emulsifier may be heated as necessary, and the water added to this dispersion may be
Assuming 0°C, the temperature during emulsification is preferably controlled at 30 to 70°C, and if the temperature during phase inversion is controlled in this way, an emulsion with the above-mentioned particle size distribution can be obtained with good reproducibility. However, it is also an effective method to adjust the particle size distribution of a known particle so that it falls within the scope of the present invention.

Note that the amount of water required for phase inversion in the above in) step is usually the amount necessary for the emulsion to change from wlo to o/w, but the particle size distribution can also be controlled by this amount of phase inversion water. The particle size distribution can also be controlled by the dispersion method during phase inversion, that is, the type of mixer device and stirring conditions.

The emulsion-type silicone antifoaming agent of the present invention produced by the above method has particularly excellent foam-breaking properties and defoaming durability.
It has a good foam-breaking effect on defoaming with a large surface film thickness, and the emulsion itself is stable, so it is particularly useful for defoaming in aqueous systems in food, fermentation, pulp, and paper manufacturing processes, and wastewater treatment processes.

Next, examples of the present invention will be given. In one example, parts are parts by weight, and viscosity is a measured value at 25°C. Defoaming tests using anionic and nonionic foaming liquids in one example are This shows the test results obtained using the following method.

[Defoaming test using anionic foaming liquid] Internal volume 1,00
Weigh out 100g of an ion-exchanged aqueous solution of 0.2% sodium oleate into a measuring cylinder, add a predetermined amount of antifoaming agent, and then pass it through a glass pole filter.
The change over time in the amount of foaming was investigated when air was continuously introduced at a rate of Ω/min.

[Defoaming test using nonionic foaming liquid] Internal volume 1.0o
OIIJ1 graduated cylinder 20, 3% polyoxyethylene nonylphenyl ether (HLB=11.O)
100 g of water was weighed out, a predetermined amount of antifoaming agent was added thereto, and the change over time in the amount of foaming was examined in the same manner as above.

Example 1 94 parts of dimethylpolysiloxane with a viscosity of 1,000cS, in which both ends of the molecular chain are blocked with trimethylsilyl groups, and 6 parts of silica filler Aerosil-300 [part name manufactured by Nippon Aerosil Co., Ltd.] were mixed into 212 parts. Mix in a container to form silicone oil compound A, which is then added with the lipophilic emulsifier sorbitan monostearate Rheodol 5S-
10 (Part name manufactured by Kao Soap Co., Ltd.) 40 parts and 40 parts of a hydrophilic emulsifier polyoxyethylene sorbitan monooleate Rheodol To-120 (trade name manufactured by Kao Soap Co., Ltd.) were charged, and these were maintained at a temperature of 70 to 80°C. While stirring for 15 minutes, the mixture was dispersed.

Next, after adjusting the temperature of this premix to 60°C,
To this, 200 parts of water at 20°C was added, the resulting mixture was dispersed for 5 minutes using a homomixer, 618 parts of water at 20°C was added, and after stirring for another 15 minutes, the final product was filtered through a furnace cloth. By the way.

A stable emulsion (hereinafter abbreviated as emulsion A) was obtained, and when the volume particle size distribution of the emulsion particles was examined using a Coulter counter, the results shown in Table 1 were obtained. .

Table 1 Example 2, Comparative Example 1 Both ends of the molecular chain are blocked with monohydroxydimethylsilyl groups and the viscosity is 10. ○94 parts of 0OcS dimethylpolysiloxane and 6 parts of silica fine powder Nibsil VN-3 [part name manufactured by Nippon Silica Co., Ltd.] were mixed in a 2Q container to make silicone oil compound B, and then added to this. Polypropylene glycol Uniol D-1,000
(Part name manufactured by NOF Corporation), lipophilic emulsifier Rheodol 5S-10 (mentioned above) and hydrophilic emulsifier Rheodol TO
-120 [listed above] in the amount shown in Table 2, and stirred at 70 to 80°C for 15 minutes to prepare a premixed liquid.
The temperature was adjusted to 60°C.

In addition, in a separate container, 800 parts of water and 10 parts of carboxymethylcellulose/cellogen WS-C [part name manufactured by Daiichi Kogyo Seiyaku Co., Ltd.] as a thickener were added to make thickened water. After adjusting the temperature to
This was finely pulverized with a homogenizer and then filtered to prepare emulsions B to H. When the volumetric particle system distribution of particles in these emulsions was examined, the results shown in Table 2 were obtained.

Example 3, Comparative Example 2 10 parts of water was placed in a cleaned container and heated to about 60 to 70°C, and 11 parts of the lipophilic emulsifier Rheodol 5S-10 [previously mentioned above] and 11 parts of the hydrophilic emulsifier Rheodol To-120 ( 1 part of [Pre-Rot] was added with stirring, and the mixture was further stirred for 15 minutes while the temperature was maintained at 60'C.

Next, 10 parts of the silicone oil compound A prepared in Example 1 was added to this while maintaining the temperature at 60°C, and after stirring for 15 minutes, the premix was pulverized to 4 to 6 mil with a colloid mill. Had made.

Also, separately add 48.2 parts of water and thickener/cellogen WS.
-C (30.8 parts above) was added and dissolved.

The above premix adjusted to 55-60'C was added thereto, mixed and stirred for about 20 minutes, 28.8 parts of dilution water was added, and the mixture was transferred to a Manton-Gallalin type homogenizer at 300 kg/aJ. The emulsion was made by passing it once under the pressure of
In this case, four types of emulsions I-L were prepared by changing the composition of the premix and the added amounts of thickening water and diluting water as shown in Table 3, and their volumetric particle system distributions were examined. The results shown in the table were obtained.

Table 3 Example 4 Emulsions M, N, ○, and P were prepared by mixing the emulsions B-L produced in Example 2.3 in the proportions shown in Table 4, and the emulsion particles of these emulsions were The volume particle size distribution of Example 3 is as shown in Table 4. The defoaming test results of emulsions E-L obtained in Comparative Example 2 and emulsions M-P obtained individually using an anionic foaming liquid or a nonionic foaming liquid are shown in Tables 5 and 6.
It was as shown in the table.

Table 4 Example 5 27 parts of dimethylpolysiloxane with a viscosity of 600 cS, in which both ends of the molecular chain are blocked with trimethylsilyl groups, and 3 parts of silica filler R-972 (trade name, manufactured by Nippon Aerosil Co., Ltd.) were mixed. To the obtained silicone oil compound, 3 parts of lipophilic emulsifier Rheodol 5S-10C (mentioned above), 3 parts of hydrophilic emulsifier Rheodol To-120 (32 parts shown above), and 5 parts of glycerin fatty acid ester Excel 200 [mentioned above] were added. A premix was prepared by heating and stirring at 60°C for 3 hours,
Next, this material was gradually added to 60 parts of water to disperse it, and after the whole amount was added, it was stirred with a homo mixer to form an emulsion.The volume particle size of the emulsion particles of this emulsion and its antifoaming properties were investigated. The results shown in Table 7 were obtained depending on the stirring time.

Procedural amendment April 14, 1988 Commissioner of the Japan Patent Office Kuro 1) Mr. Akio ＼ し、・－ 1゜Indication of the case - 1932
1 Year Patent Application No. 101382 2, Name of the invention Emulsion-type silicone defoaming agent 3, Relationship with the amended case Patent applicant name (206) Shin-Etsu Chemical Co., Ltd. 4, Agent ■Detailed description of the invention 7. Contents of the amendment 1) The "Claims" in lines 4 to 10 on page 1 of the specification will be amended as shown in the attached sheet.

2) On page 4, line 17 of the specification, "particles that are 6~]-8β1" are corrected to "particles that are 6~187111! and are within the particle size range in parentheses."

3) [Diorganopolysiloxane] on page 6, lines 4 and 16 of the specification letter has been corrected to “organopolysiloxane 1,”
"Erosil (product name manufactured by Nippon Degussa)" in line 10 of the same page
is corrected to "Aerosil (trade name manufactured by Nippon Anirosil Co., Ltd.)".

4) "r HL B is 8 to 20" on page 7, line 10 of the specification can be replaced with an emulsifier with an rHLB of 3 to 19 or an emulsifier with an HL B of 8 to 8
20”.

5) On page 9, lines 7 to 8 of the specification, "Usually in the range of 1 to 60 weight...30% by weight" has been changed to "Usually based on the total amount of the organopolysiloxane composition and emulsifier." 1-6
0% by weight, and this preferred range is 10-60% by weight.
% by weight. ” he corrected.

6) "Diorganopolysiloxane -00 parts by weight" in line 5 of page 9, line 14 of the specification is corrected to "total amount of organopolysiloxane composition and emulsifier."

7) "With respect to dimethylpolysiloxane" in the last line of page 9 to page 10, line 1 of the specification is corrected to "with respect to the total amount of organopolysiloxane composition and emulsifier", and
Correct "and its volume distribution ratio j" in line 6 of the page to "and its volume distribution ratio of particles within that particle size range".

8) "Moisture content" on page 11, line 17 of the specification is corrected to "temperature of water," and "temperature" on line 18 of the same page is corrected to "temperature (phase inversion temperature)."

9) "Large defoaming" on page 12, line 12 of the specification is corrected to "large foam."

10) Page 14, line 2 of the specification, page 15, line 15, page 17, line 5 of Table 2, page 18, lines 3-4, page 20, line 4 of Table 3, and page 25, line 7 row rSS-10J rsp-
Amended as 8IOJ, page 14, line 5, page 15, line 15 of the specification.
row, page 17, line 6 of table 2, page 18, line 5, line 20
page, row 5 of table 3 and rTo-120 on page 25, row 8
J to rTW-0120J, I-Taneneo A- 11) Change [18 μm or less] to 1 on page 15, line 5 of the specification.
81JM or higher.''

12) Page 25, line 9 of the specification [Excel 200 [mentioned above]]
" is corrected to "Excel 200 (product name manufactured by Kao Soap@)".

Above (Attachment) Claim 1: An emulsion comprising a composition containing organopolysiloxane and finely powdered silica as main components, an emulsifier, and water, wherein the emulsion has a volume average particle diameter of 6 μm or more and 18 μm or less, An emulsion type silicone antifoaming agent characterized in that particles within this particle size range account for 40% or more in volume distribution.

Procedural amendment band June 17, 1988 Commissioner of the Patent Office Black 1) Yu Akira R Shiayu 1, Indication of the case 1986 Patent Application No. 101382 3, Person making the amendment Relationship with the case Patent applicant name (206 ) Shin-Etsu Chemical Co., Ltd. 4, Agent 5, Date of amendment order dated April 14, 1985, "Procedural Amendment Band" 7, Contents of the amendment 1) Paragraph 7 of the "Procedural Amendment Band" dated April 14, 1988 amend the description as follows.

"7) "With respect to dimethylpolysiloxane" in the last line of page 9 to page 10, line 1 of the specification is corrected to "with respect to the total amount of organopolysiloxane composition and emulsifier," and
Correct "and the volume distribution ratio of the particles" on page 0, line 6 to "and the volume distribution ratio of the particles within the particle size range." J or above

Claims (1)

[Claims] 1. In an emulsion consisting of a composition mainly composed of organopolysiloxane and finely powdered silica, an emulsifier, and water, this emulsion has a volume distribution ratio of 40% or more of particles with a volume average particle diameter of 6 μm or more and 18 μm or less An emulsion type silicone antifoaming agent characterized by: