JP2017160321A - Composite particle, method of producing the same and oil-water separation material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite particle that has excellent hydrophilicity and oil repellency and can be suitably used as an oil-water separation material.SOLUTION: A composite particle comprises a condensate obtained by condensing a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by general formula (1), and a condensate of polyisocyanate and polyethylene glycol (Rand Rare -(CF) p-Y group or -CF(CF)-[OCFCF(CF)]q-OCFgroup; Y is H, F or Cl; p and q are 0-10; m is 2 or 3).SELECTED DRAWING: None

Description

  The present invention relates to composite particles, a method for producing the same, and an oil / water separator using the composite particles.

  Fluorine compounds can be expected to be applied to paints, cosmetics, etc. by taking advantage of features such as water / oil repellency, oxygen permeability and low refractive index. However, since the fluorine-based compound has too high water and oil repellency, it is difficult to maintain dispersion stability with respect to the non-fluorine raw material.

  In addition, fluorine compounds that exhibit high oil repellency in air have the disadvantage that the oil repellency disappears in water and the oil spreads wet.

  Wastewater containing oil is a major cause of environmental pollution and is required to be treated appropriately. Conventionally, methods such as stationary separation such as specific gravity separation, centrifugal separation, and adsorption separation are used for oil-water separation treatment.

  However, stationary separation requires a lot of time, centrifugation requires a large-scale apparatus, and adsorption separation is unsuitable for processing a large amount of oil-water mixture.

  The present inventors have previously proposed various new functional materials using a fluoroalkyl group-containing oligomer and imparting excellent characteristics resulting from the fluoroalkyl group-containing oligomer (for example, Patent Documents 1 to 3) reference).

  In addition, the present inventors previously obtained a nanocomposite obtained by a sol-gel reaction under alkaline or acidic conditions of a fluoroalkyl group-containing oligomer having an alkoxysilyl group in the presence of 4,4′-diphenylmethane diisocyanate. Particles were proposed (see Non-Patent Document 1).

JP 2010-209300 A JP 2010-235943 A JP2013-185071A

Proceedings of the Chemical Society of Japan, Vol.95th, No.3, Page1007 (2015)

For example, when the mixed liquid contains a large percentage of oil or contains an oil having high utility value, a type in which only water passes through the oil / water separator may be advantageous to the user. This type of oil-water separator is required to be excellent in hydrophilicity and oil repellency.
However, there is a problem that it is particularly difficult to impart hydrophilicity to the fluorine-based compound.
In addition, the nanocomposite particles of Non-Patent Document 1 exhibit excellent water repellency, and those having excellent hydrophilicity and oil repellency have not been obtained.

  Accordingly, an object of the present invention is to provide composite particles excellent in hydrophilicity and oil repellency that can be suitably used as an oil / water separator, an industrially advantageous production method thereof, and an oil / water separator using the composite particles. There is to do.

  In the course of developing a new functional material using a fluoroalkyl group-containing oligomer, the present inventors have condensed a condensate obtained by condensing a specific fluoroalkyl group-containing oligomer with polyisocyanate and polyethylene glycol. It has been found that composite particles containing a product have excellent hydrophilicity and oil repellency, and can be suitably used as an oil-water separator, and the present invention has been completed.

That is, the first invention to be provided by the present invention is a condensate obtained by condensing a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by the following general formula (1), a polyisocyanate and a polyethylene glycol. It is a composite particle characterized by containing a condensate.
(Wherein, R ¹ and R _{^2, - (CF 2) p-} Y group, or _{-CF (CF 3) - [OCF} 2 CF (CF 3)] indicates the q-OC ₃ F ₇ group, R ¹ And R ² may be the same group or different groups, Y in R ¹ and R ² represents a hydrogen atom, a fluorine atom or a chlorine atom, and p and q are integers of 0 to 10. R ³ , R ⁴ and R ⁵ may be the same or different groups, and R ³ , R ⁴ and R ⁵ are linear or branched alkyl groups having 1 to ⁵ carbon atoms. M is an integer of 2 to 3.)

In addition, the second invention to be provided by the present invention includes a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by the following general formula (1), and the following components (A) and / or (B): A reaction step of adding an alkali or an acid to a reaction raw material solution containing a hydrolysis reaction of the alkoxysilyl group, and then a heat treatment step of heat-treating the resulting reaction solution. Is the method.
(A) Polyisocyanate and polyethylene glycol (B) Condensate of polyisocyanate and polyethylene glycol
(Wherein, R ¹ and R _{^2, - (CF 2) p-} Y group, or _{-CF (CF 3) - [OCF} 2 CF (CF 3)] indicates the q-OC ₃ F ₇ group, R ¹ And R ² may be the same group or different groups, Y in R ¹ and R ² represents a hydrogen atom, a fluorine atom or a chlorine atom, and p and q are integers of 0 to 10. R ³ , R ⁴ and R ⁵ may be the same or different groups, and R ³ , R ⁴ and R ⁵ are linear or branched alkyl groups having 1 to ⁵ carbon atoms. M is an integer of 2 to 3.)

  A third invention to be provided by the present invention is an oil / water separator characterized by using the composite particles of the first invention.

According to the present invention, composite particles having excellent hydrophilicity and oil repellency can be provided. The composite particles can be suitably used as an oil-water separator that separates water and oil.
Further, according to the present invention, the composite particles can be provided by an industrially advantageous method.

Schematic which shows one of embodiment which performs oil-water separation using the oil-water separation material of this invention. Schematic which shows one of embodiment which performs oil-water separation using the oil-water separation material of this invention. 6 is an SEM photograph of the surface of a modified glass plate modified with composite particles obtained in Example 7. FIG. 5 is an SEM photograph of the surface of a modified filter paper modified with the composite particles obtained in Example 7. FIG. A photograph of a mixed solution of dodecane and water. Top: Unmodified filter paper is used. Bottom: Modified filter paper modified with the composite particles obtained in Example 7 is used.

Hereinafter, the present invention will be described based on preferred embodiments thereof.
The composite particle according to the present invention includes a condensate obtained by condensing a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by the general formula (1) (hereinafter also referred to as “fluoroalkyl group-containing oligomer”). And a condensate of polyisocyanate and polyethylene glycol.

  The composite particles according to the present invention are 0.01 to 5000 parts by mass, preferably 0.1 to 1000 parts by mass, of the condensate of polyisocyanate and polyethylene glycol with respect to 100 parts by mass of the condensate of fluoroalkyl group-containing oligomer. From the viewpoint that the inclusions have excellent hydrophilicity and oil repellency.

In the composite particle according to the present invention, an alkali or acid is added to a reaction raw material solution containing a fluoroalkyl group-containing oligomer and the following components (A) and / or (B) to hydrolyze the alkoxysilyl group: It is preferable that it is a thing obtained by performing the heat treatment process which heat-processes the reaction process which performs this, and the reaction liquid obtained then.
(A) Polyisocyanate and polyethylene glycol (B) Condensate of polyisocyanate and polyethylene glycol

The fluoroalkyl group-containing oligomer according to the reaction step is represented by the following general formula (1) and has a hydrolyzable alkoxysilyl group.
(Wherein, R ¹ and R _{^2, - (CF 2) p-} Y group, or _{-CF (CF 3) - [OCF} 2 CF (CF 3)] indicates the q-OC ₃ F ₇ group, R ¹ And R ² may be the same group or different groups, Y in R ¹ and R ² represents a hydrogen atom, a fluorine atom or a chlorine atom, and p and q are integers of 0 to 10. R ³ , R ⁴ and R ⁵ may be the same group or different groups, and R ³ , R ⁴ and R ⁵ are linear or branched alkyl groups having 1 to ⁵ carbon atoms. M is an integer of 2 to 3.)

  The fluoroalkyl group-containing oligomer represented by the general formula (1) is mainly used for imparting excellent oil repellency to the composite particles of the present invention.

Examples of the linear or branched alkyl group having 1 to 5 carbon atoms represented by R ³ , R ⁴ and R ⁵ in the general formula (1) include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. Etc.
Formula (1) of R ¹ and _{^{R 2 - (CF 2) p}} -Y group, or _{-CF (CF 3) - [OCF} 2 CF (CF 3)] p and q-OC ₃ F ₇ group q is 0-10, preferably 0-3. In particular, R ¹ and R ² are preferably —CF (CF ₃ ) OC ₃ F ₇ .

  The fluoroalkyl group-containing oligomer represented by the general formula (1) is produced, for example, by reacting a trialkoxyvinylsilane such as trimethoxyvinylsilane with a fluoroalkanoyl peroxide (for example, JP-A-2002-338691, JP, 2010-77383, A).

  The polyethylene glycol according to the reaction step mainly imparts excellent hydrophilicity to the composite particles of the present invention, and polycondensation with polyisocyanate improves the solvent resistance of the composite particles of the present invention. Excellent oil / water separation ability can be imparted.

In the present invention, polyethylene glycol that can be used is not particularly limited, but those having an average molecular weight of several hundred to several thousand are preferable.
In the present invention, a commercially available product can be suitably used as the polyethylene glycol.

The polyisocyanate according to the reaction step is a compound having two or more isocyanate groups (—NCO) in one molecule.
Examples of the polyisocyanate include aromatic polyisocyanate, aliphatic polyisocyanate, and alicyclic polyisocyanate.

  Specific examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, 4,4′-. Diphenylmethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4′-diisocyanatobiphenyl, 3,3′-dimethyl-4,4′-diisocyanatobiphenyl, 3,3′-dimethyl-4,4 Examples include '-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4', 4 ''-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl isocyanate.

  Specific examples of the aliphatic polyisocyanate include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate. (THDI), lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanate And natohexanoate.

  Specific examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis (2 -Isocyanatoethyl) -4-dichlorohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate and the like.

  In the present invention, the polyisocyanate is preferably a diisocyanate having two isocyanate groups in one molecule from the viewpoint of obtaining those having improved hydrophilicity and oil repellency, particularly 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (TDI), hexane 1,6-diisocyanate, and hexamethylene diisocyanate (HDI) are preferred.

  As the reaction solvent for the reaction step, a solvent capable of dissolving the fluoroalkyl group-containing oligomer is used. Examples of the reaction solvent in the reaction step include lower alcohols such as methanol, ethanol, and isopropyl alcohol, and these may be a mixed solvent of two or more. Of these, methanol is particularly preferred.

  The content of polyethylene glycol in the reaction raw material solution is a value converted to 200 mg of the fluoroalkyl group-containing oligomer represented by the general formula (1), and is 5 to 400 mg, preferably 10 to 200 mg. When the content of the polyethylene glycol in the reaction raw material solution is in the above range, the hydrophilicity and oil repellency are excellent.

  The content of polyisocyanate in the reaction raw material solution is a value converted to 200 mg of the fluoroalkyl group-containing oligomer represented by the general formula (1), and is 5 to 400 mg, preferably 10 to 200 mg, and polyethylene glycol 200 mg. A value converted to 10 to 400 mg, preferably 20 to 300 mg, is preferable from the viewpoint of excellent hydrophilicity and oil repellency, and further excellent durability and oil-water separation ability.

In the present invention, the polyethylene glycol and polyisocyanate may be added to the reaction raw material solution as a condensate obtained by polycondensation reaction in advance.
The condensate of polyisocyanate and polyethylene glycol can be obtained by heat-treating a solvent containing 10 to 100 mg, preferably 20 to 80 mg, of polyisocyanate at a value converted to 40 mg of polyethylene glycol.
As the solvent that can be used, ethers such as tetrahydrofuran, diethyl ether, dioxane and the like can be preferably used.
The heat treatment conditions are a heating temperature of 10 to 90 ° C., preferably 25 to 80 ° C., and a heat treatment time of 0.5 hours or more, preferably 1 to 10 hours.
This heat treatment may be performed while removing the solvent in an apparatus that removes the solvent simultaneously with the heat treatment.

  In the present invention, both the components (A) and (B) of (A) polyisocyanate and polyethylene glycol and (B) polyisocyanate and polyethylene glycol condensate may be added to the reaction raw material solution. Needless to say.

  In the reaction step, the acid or alkali added to the reaction raw material solution is not particularly limited as long as it can hydrolyze alkoxysilane. For example, the alkali includes ammonium hydroxide, sodium hydroxide or water. Examples include potassium oxide, and examples of the acid include sulfuric acid, hydrochloric acid, nitric acid, and acetic acid. From the viewpoint of high reactivity, ammonium hydroxide or hydrochloric acid is preferable, and ammonium hydroxide is particularly preferable.

  The mixing amount of the acid or alkali added to the reaction raw material solution is not particularly limited and is appropriately selected. Moreover, the reaction temperature at the time of hydrolyzing alkoxysilane by mixing an acid or an alkali with a reaction raw material solution is -5-50 degreeC, Preferably it is 0-30 degreeC. If the reaction temperature is less than −5 ° C., the hydrolysis rate of the alkoxysilyl group becomes too slow, so that the reaction efficiency is poor, and if it exceeds 50 ° C., the dispersion stability of the composite particles tends to be low. The reaction time when the reaction raw material solution is mixed with an acid or alkali to hydrolyze the alkoxysilyl group is not particularly limited and is appropriately selected, but is preferably 1 to 72 hours, particularly preferably. 1 to 24 hours.

  And the reaction liquid (1) containing the composite particle | grains which have a siloxane bond as a main skeleton is obtained by performing a reaction process.

Subsequently, the heat processing process which heat-processes with respect to the reaction liquid (1) obtained at the reaction process is performed.
In this production method, by performing this heat treatment, the polycondensation reaction of polyisocyanate and polyethylene glycol can be started or the polycondensation reaction of polyisocyanate and polyethylene glycol can be completed.

The heat treatment temperature related to the heat treatment step is 30 to 90 ° C., preferably 35 to 80 ° C., and the heat treatment time is 0.1 hour or more, preferably 1 to 10 hours.
And the reaction liquid (2) containing the composite particle which concerns on this invention is obtained by performing a heat processing process.

After completion of the reaction, the solvent is removed under reduced pressure by a conventional method, and purification such as washing is performed as necessary to obtain the desired composite particles.
In the present manufacturing method, the heat treatment step may be performed while removing the solvent in an apparatus that removes the solvent simultaneously with the heat treatment.

  In the present invention, the reaction liquid (2) containing the composite particles obtained after the heat treatment step is used as it is as a reforming liquid for modifying various substrates for use as an oil-water separator as described later. I can do it.

  Moreover, as another preferable physical property of the composite particles of the present invention, the average particle size determined by a dynamic light scattering method is preferably 0.01 to 10 μm, and preferably 0.02 to 1 μm. When the average particle diameter is within the above range, it is preferable in terms of good dispersibility in various dispersion solvents, resin materials, various base materials and the like.

  The oil-water separator according to the present invention is characterized by using the composite particles.

  Water and oil can be separated by bringing the oil / water separator according to the present invention into contact with a mixed liquid containing water and oil.

The composite particles of the invention can be used, for example, as an oil / water separator by the following two methods.
(1) A method of modifying a base material insoluble in water with the composite particles of the present invention.
(2) A method in which the composite particle itself of the present invention is used as it is as a filter medium.

  As the base material according to (1), an inorganic substance or an organic substance that is insoluble in water can be used. Examples of the inorganic substance include glass fiber, silica, silica gel, alumina, slag wool, molecular sieve, zeolite, activated carbon, diatomaceous earth, sand, asbestos and the like. The organic substance may be a natural polymer or a synthetic polymer. Examples of the natural polymer include cellulose, wool, cotton, silk and the like. Examples of synthetic polymers include condensation-type or addition-type polymer polymers such as polyurethane, polyethylene terephthalate, nylon, and polycarbonate, and ethylenically unsaturated polymer polymers such as polyethylene, polypropylene, vinyl chloride, and vinyl acetate. It is done.

  In addition, the shape of the substrate is not particularly limited, and examples thereof include a strip shape, a sponge shape, a ribbon shape, a fibril shape, a web shape, a mat shape, a cotton cloth shape, and a non-woven cloth shape.

  In the present invention, a commercially available filter paper or the like may be used as a base material for modifying. In this case, the pore diameter of the filter paper is preferably 5 μm or less, and preferably 0.1 to 3 μm from the viewpoint of efficient oil / water separation.

  In the above (1), the method for modifying the base material with the composite particles of the present invention is not particularly limited as long as the composite particles of the present invention can be fixed or supported on the surface or inside of the base material. A known method can be used. As an example, there is a method in which a base material is brought into contact with a dispersion liquid in which the composite particles of the present invention are dispersed at a concentration of 1 to 50 wt% and then dried. Further, the contact between the dispersion and the substrate can be performed by a method of immersing the substrate in the dispersion, a method of spraying the substrate by spraying, a method of applying the dispersion to the substrate, or the like.

  In addition, as the dispersion liquid in which the composite particles are dispersed, the reaction liquid (2) containing the composite particles after the completion of the reaction may be used as it is.

  FIG. 1 is a schematic view showing an embodiment in the case where a mixed solution of water and oil is separated using a filter paper modified with the composite particles of the present invention.

In the embodiment shown in FIG. 1, a simple separation system (A) comprising a column (1b) and a modified filter paper (1a) is provided, and the modified filter paper (1a) is modified with the composite particles of the present invention. It is.
By biting the modified filter paper (1a) in the middle of the column (1b), the mixed liquid (1) of water and oil charged into the column (1b) comes into contact with the modified filter paper (1a). Since water (1 ′) passes through the modified filter paper (1a) and oil cannot pass through the modified filter paper (1a), water and oil can be separated. If necessary, the separation operation can be performed under pressure or under reduced pressure in order to increase the separation efficiency. In this case, the water (1 ′) may first pass through the modified filter paper (1a) selectively, and then the oil may pass through the modified filter paper with a delay due to strong external force. After elution, water and oil can be separated through the oil / water separator by means such as finishing the oil / water separation operation.

FIG. 2 is a schematic view showing one embodiment in the case where a mixed liquid of water and oil is separated using the composite particles of the present invention as a filter medium.
In the embodiment shown in FIG. 2, a simple separation system (B) comprising a filter medium layer (2a) including a column (2b) and a filter medium (2c) is provided.
The column (2b) is filled with the composite particles of the present invention as a filter medium (2c) to form a filter medium layer (2a). By putting the mixed liquid (1) of water and oil into the column (2b), the filter medium (2c) and the mixed liquid can be brought into contact with each other. Since water (1 ′) passes through the filter medium layer (2a) and oil cannot pass through the filter medium layer (2a), water and oil can be separated. If necessary, the separation operation can be performed under pressure or under reduced pressure in order to increase the separation efficiency. Moreover, in order to suppress clogging etc., the layer which filled the filter aid in the upper part and / or lower part of the filter material layer (2a) can be provided if needed.

  The filter aid that can be used is not particularly limited and widely known ones can be used. For example, diatomaceous earth, sand particles, pearlite, anthracite, cellulose, wool, cotton, silk, carbonaceous filter aid, acid clay, bentonite, celite, talc, mica, kaolinite, etc. Two or more types can be used.

  The mixed liquid of water and oil to be treated with the oil / water separator according to the present invention may be in a solution state or an emulsion.

  The oil / water separator according to the present invention can be used for, for example, wastewater treatment containing oil, means for separating or purifying water and oil at production sites in various industrial fields, and the like.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.
<Fluoroalkyl group-containing oligomer sample>
As the fluoroalkyl group-containing oligomer (hereinafter referred to as “VM”), those shown in Table 1 below were used.
In Table 1, the molecular weight is a number average molecular weight determined by gel permeation chromatography (GPC, polystyrene conversion).

<Polyisocyanate>
As the polyisocyanate, the following commercially available products were used.

<Polyethylene glycol>
The following commercially available polyethylene glycol was used.

{Examples 1-5}
VM (200 mg) was dissolved in 3 ml of methanol, polyisocyanate and polyethylene glycol were added in the amounts shown in Table 3, then 25 wt% aqueous ammonia solution was added, and the mixture was stirred for 5 hours at room temperature (25 ° C.) with a magnetic stirrer. It was.
After completion of the reaction, the reaction solution was subjected to heat treatment and removal of the solvent at 85 ° C. using an evaporator, and then the obtained crude product was dispersed in methanol overnight. Subsequently, the target product was separated as a solid content by centrifugation, dried in an oven at 70 ° C. for 1 day, and then dried in a vacuum oven at 50 ° C. for 1 day to obtain the target product (composite particle sample).

{Comparative Examples 1-5}
Except not adding polyethylene glycol, it reacted like Example 1-5 and obtained the target object (composite particle sample).

{Example 6}
VM (200 mg) was dissolved in 3 ml of methanol, polyisocyanate and polyethylene glycol were added in the amounts shown in Table 3, then 1N hydrochloric acid (1 ml) was added, and the mixture was stirred with a magnetic stirrer at room temperature (25 ° C.) for 5 hours. It was.
After completion of the reaction, the reaction solution was subjected to heat treatment and removal of the solvent at 85 ° C. using an evaporator, and then the obtained crude product was dispersed in methanol overnight. Subsequently, the target product was separated as a solid content by centrifugation, dried in an oven at 70 ° C. for 1 day, and then dried in a vacuum oven at 50 ° C. for 1 day to obtain the target product (composite particle sample).

Note) MDI: 4,4'-diphenylmethane diisocyanate, TDI; 2,4-tolylene diisocyanate, HDI; hexane 1,6-diisocyanate, THDI; 2,2,4-trimethylhexamethylene diisocyanate

{Examples 7 to 11}
Polyisocyanate and polyethylene glycol were added to THF in the proportions shown in Table 4 (solution A), this was stirred at room temperature (25 ° C.) for 24 hours, and then the reaction solution was heated at 80 ° C. using an evaporator and solvent. The viscous product (1) was obtained.

Note) MDI: 4,4'-diphenylmethane diisocyanate, TDI; 2,4-tolylene diisocyanate, HDI; hexane 1,6-diisocyanate, THDI; 2,2,4-trimethylhexamethylene diisocyanate

Next, the obtained product (1) was dispersed in 3 ml of methanol at the blending amount shown in Table 5, and then VM (200 mg) was added. Next, a 25 wt% aqueous ammonia solution (2 ml) was added, and the mixture was stirred at room temperature (25 ° C.) for 5 hours with a magnetic stirrer.
After completion of the reaction, the reaction solution was subjected to heat treatment and removal of the solvent at 85 ° C. using an evaporator, and then the obtained crude product was dispersed in methanol overnight. Subsequently, the target product was separated as a solid content by centrifugation, dried in an oven at 70 ° C. for 1 day, and then dried in a vacuum oven at 50 ° C. for 1 day to obtain the target product (composite particle sample).

<Evaluation of physical properties>
The average particle diameter and the contact angle between dodecane and water were measured for the composite particles prepared above.
In addition, the average particle diameter and the contact angle of dodecane and water were measured as follows.

(Evaluation of average particle size)
The obtained composite particles were redispersed in methanol and measured using a particle size meter (SALD-200 V manufactured by Shimadzu).

(Evaluation of contact angle between dodecane and water)
<Evaluation 1>;
The glass plate is immersed in a 5 wt% methanol solution in which the composite particles obtained in each Example and Comparative Example are dispersed for 1 minute at room temperature (25 ° C.), pulled up, then naturally dried and further vacuumed overnight. Drying was performed to prepare a modified glass plate sample. The contact angle of dodecane and water on the surface of the modified glass plate sample was evaluated using Drop Master 300 made by Kyowa Interface Science. The results are shown in Table 6.
The contact angle was evaluated as a value 30 minutes after dropping water and dodecane.
Moreover, the thing which processed only the non-processed thing with the blank 1 and VM was evaluated as the blank 2, and the evaluation result was written together in Table 6. Moreover, the SEM photograph of the surface of the modified glass sample modified with the composite particles of Example 7 is shown in FIG.

Evaluation 2;
Filter paper (Advantec: 131, pore size 3 μm) cut into 3 cm squares in a 5 wt% methanol solution in which the composite particles obtained in Example 2, Example 7, Example 9 and Comparative Example 2 were dispersed was allowed to stand at room temperature for 1 minute. After soaking at (25 ° C.), the filter paper was pulled up, and then naturally dried and further vacuum dried overnight to prepare a modified filter paper sample.
About the obtained modified filter paper sample, the contact angles of water and dodecane were measured in the same manner as in Evaluation 1. The results are shown in Table 7. What was processed only by VM was evaluated as the blank 1, and the evaluation result was written together in Table 7. Moreover, the SEM photograph of the surface of the modified filter paper sample modified with the composite particles of Example 7 is shown in FIG.

Evaluation 3:
The polyester fiber was immersed in a 5 wt% methanol solution in which the composite particles obtained in Example 9 were dispersed in 3 cm square for 1 minute at room temperature (25 ° C.), the polyester fiber was pulled up, dried naturally, and further vacuumed overnight. Drying was performed to prepare a modified polyester fiber sample.
About the obtained modified polyester fiber sample, the contact angles of water and dodecane were measured in the same manner as in Evaluation 1. The results are shown in Table 8. What was processed only by VM was evaluated as the blank 1, and the evaluation result was written together in Table 8.

(Evaluation as oil / water separator)
After immersing filter paper (Advantec: 131, pore size 3 μm) cut into 3 cm square in a 5 wt% methanol solution in which the composite particles obtained in Example 7 are dispersed for 1 minute at room temperature (25 ° C.), the filter paper is pulled up The sample was subjected to natural drying and then vacuum drying overnight to prepare a modified filter paper sample.
The water-oil separation by this modified filter paper was examined using 2 ml of a mixed solution of dodecane and water (1: 1 vol.). The water in the mixture was colored red with Rhodamine B.
In addition, the same evaluation was performed for the case of using filter paper that was not subjected to the modification treatment.

As shown in FIG. 5, a modified filter paper sample was sandwiched between funnels, and a water-oil separation test was performed by filtering the mixed solution under reduced pressure. The results are shown in Table 9. The symbols in Table 9 indicate the following.
○: No oil is visually observed in the filtrate 10 seconds after the start of filtration.
Δ: Some oil was visually observed in the filtrate 10 seconds after the start of filtration.
X: A large amount of oil was visually observed in the filtrate 10 seconds after the start of filtration.

Further, as shown in FIG. 5, it can be seen that only water first passes through the modified filter paper by filtering the mixed solution under reduced pressure using the modified filter paper sample.
On the other hand, when the mixed solution was filtered under reduced pressure using filter paper that was not subjected to modification treatment, both water and dodecane passed through the filter paper from the beginning.

Claims (8)

A composite particle comprising a condensate obtained by condensing a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by the following general formula (1) and a condensate of polyisocyanate and polyethylene glycol.
(Wherein, R ¹ and R _{^2, - (CF 2) p-} Y group, or _{-CF (CF 3) - [OCF} 2 CF (CF 3)] indicates the q-OC ₃ F ₇ group, R ¹ And R ² may be the same group or different groups, Y in R ¹ and R ² represents a hydrogen atom, a fluorine atom or a chlorine atom, and p and q are integers of 0 to 10. R ³ , R ⁴ and R ⁵ may be the same or different groups, and R ³ , R ⁴ and R ⁵ are linear or branched alkyl groups having 1 to ⁵ carbon atoms. M is an integer of 2 to 3.)   The composite particle according to claim 1, wherein the polyisocyanate is a diisocyanate. The composite particle according to claim ^1, wherein R ¹ and R ² in the general formula (1) are —CF (CF ₃ ) OC ₃ F ₇ .   The composite particle according to any one of claims 1 to 3, wherein an average particle diameter is 0.01 to 10 µm. An alkali or acid is added to a reaction raw material solution containing a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by the following general formula (1) and the following components (A) and / or (B), A method for producing composite particles, comprising: a reaction step of hydrolyzing an alkoxysilyl group; and a heat treatment step of heat-treating the resulting reaction liquid.
(A) Polyisocyanate and polyethylene glycol (B) Condensate of polyisocyanate and polyethylene glycol
(Wherein, R ¹ and R _{^2, - (CF 2) p-} Y group, or _{-CF (CF 3) - [OCF} 2 CF (CF 3)] indicates the q-OC ₃ F ₇ group, R ¹ And R ² may be the same group or different groups, Y in R ¹ and R ² represents a hydrogen atom, a fluorine atom or a chlorine atom, and p and q are integers of 0 to 10. R ³ , R ⁴ and R ⁵ may be the same or different groups, and R ³ , R ⁴ and R ⁵ are linear or branched alkyl groups having 1 to ⁵ carbon atoms. M is an integer of 2 to 3.)   6. Composite according to claim 5, characterized in that the polyisocyanate is selected from 4,4'-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (TDI) and hexane 1,6-diisocyanate (HDI). Particle production method.   An oil-water separator using the composite particles according to any one of claims 1 to 4.   An oil-water separation method, wherein the oil-water separator according to claim 7 is brought into contact with a mixed liquid containing water and oil.