JP2017160322A - Composite particle and method of producing the same - 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 formula (1), talc and polyethylene glycol (Rand Rindependently represent -(CF) p-Y group or -CF(CF)-[OCFCF(CF)]q-OCFgroup; Y is H, F or Cl; p and q are an integer of 0-10; R-Rindependently represent C1-5 linear/branched alkyl group; m is an integer of 2-3).SELECTED DRAWING: None

Description

  The present invention relates to composite particles useful as an oil-water separator and a method for producing the same.

  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 have previously obtained a fluoroalkyl group-containing oligomer having an alkoxysilyl group, talc, and further under alkaline conditions in the presence of various organic compounds such as 2-hydroxy-4-methoxybenzophenone, bisphenol AF, bisphenol A and the like. Proposed nano-composite particles in which talc and an organic compound are encapsulated by a sol-gel reaction in the method (see Non-Patent Document 1).

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

Proceedings of the Chemical Society of Japan, Vol.94th, No.3, Page.825 (2014)

However, when the nanocomposite particles of Non-Patent Document 1 are used as oil-water separators, there are concerns about problems such as durability to solvents, and it is difficult to use them as oil-water separators.
In addition, when the oil content is high or the oil content is high, it may be advantageous for the user to use a type in which only water passes through the oil-water separator. 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.

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

  In the course of developing a new functional material using a fluoroalkyl group-containing oligomer, the present inventors have developed a composite particle containing a condensate obtained by condensing a specific fluoroalkyl group-containing oligomer, talc and polyethylene glycol. Has been found to have excellent hydrophilicity and oil repellency, and has completed the present invention.

That is, the first invention to be provided by the present invention includes a condensate obtained by condensing a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by the following general formula (1), talc and polyethylene glycol. Is a composite particle characterized by
(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 second invention to be provided by the present invention is a reaction raw material solution containing a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by the following general formula (1), talc, polyethylene glycol and a reaction solvent. A method for producing composite particles, comprising a reaction step of adding an alkali to perform a hydrolysis reaction of the 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 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.)

ADVANTAGE OF THE INVENTION According to this invention, the composite particle which has the outstanding hydrophilic property and oil repellency useful as an oil-water separator can be provided.
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. The photograph which shows the glass surface after 15 minutes, after dripping one drop of dodecane on the glass plate surface modified with the composite particle of Example 1.

Hereinafter, the present invention will be described based on preferred embodiments thereof.
The composite particle according to the present invention is 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”), It contains talc and polyethylene glycol.

  In the composite particles according to the present invention, talc is 10 to 1000 parts by mass, preferably 30 to 500 parts by mass, and polyethylene glycol is 5 to 1000 parts by mass, preferably 100 parts by mass of the condensate of fluoroalkyl group-containing oligomer. It is preferable from the viewpoint of having excellent hydrophilicity and oil repellency that it contains 10 to 500 parts by mass.

  The composite particles according to the present invention are obtained by performing a reaction step of adding an alkali to a reaction raw material solution containing a fluoroalkyl group-containing oligomer, talc, polyethylene glycol, and a reaction solvent and performing a hydrolysis reaction of the alkoxysilyl group. It is preferable.

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).

Talc (Mg ₃ Si ₄ O ₁₀ (OH) ₂ ) related to the reaction step is a component mainly imparting excellent roughness to the composite particles of the present invention.

  As the talc, it is preferable to use a fine talc from the viewpoint of producing fine composite particles, and the average particle diameter determined by the dynamic light scattering method is preferably 5 to 1000 nm, and more preferably 20 to 500 nm. In the present invention, a commercially available talc can be suitably used.

  The polyethylene glycol according to the reaction step is mainly used for imparting excellent hydrophilicity to the composite particles of the present invention. The polyethylene glycol is a polymer compound, and can improve the solvent resistance of the composite particles.

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.

  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 among these, methanol is particularly preferable.

  In the reaction step of the present invention, when preparing the reaction raw material solution, the order of mixing the fluoroalkyl group-containing oligomer, talc and polyethylene glycol with the reaction solvent is not particularly limited.

  The content of talc in the reaction raw material solution is a value converted to 100 mg of the fluoroalkyl group-containing oligomer represented by the general formula (1), and is 10 to 1000 mg, preferably 30 to 500 mg. When the content of the talc in the reaction raw material solution is in the above range, the hydrophilicity and oil repellency are excellent.

  The content of polyethylene glycol in the reaction raw material solution is a value converted to 100 mg of the fluoroalkyl group-containing oligomer represented by the general formula (1), and is 5-1000 mg, preferably 10-500 mg. When the content of the polyethylene glycol in the reaction raw material solution is in the above range, the hydrophilicity is improved while maintaining excellent oil repellency, and the durability and adhesion to the substrate are also excellent. become.

  In the reaction step, the alkali added to the reaction raw material solution is not particularly limited as long as it can hydrolyze the alkoxysilyl group in the fluoroalkyl group-containing oligomer. For example, the alkali includes ammonium hydroxide. Sodium hydroxide or potassium hydroxide, and ammonium hydroxide is preferred because of its high reactivity.

  The mixing amount of the 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 the alkoxysilyl group in a fluoroalkyl group containing oligomer by mixing 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 alkali to hydrolyze the alkoxysilyl group is not particularly limited and is appropriately selected, but is preferably 1 to 72 hours, and particularly preferably 1 to 72 hours. 24 hours.

  And by performing a reaction process, the composite particle which has a siloxane bond as a main skeleton produces | generates, and the reaction liquid containing the composite particle which concerns on this invention is obtained.

  After completion of the reaction, the solvent is removed under reduced pressure by a conventional method, and if necessary, purification such as washing is performed to obtain composite particles.

  In the present invention, the reaction liquid containing the composite particles can be used as it is as a modifying liquid for modifying various base materials for use as an oil-water separator as described later.

  Moreover, as another preferable physical property of the composite particles of the present invention, the average particle size determined by the dynamic light scattering method is preferably 0.01 to 10 μm, and preferably 0.03 to 1.0 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 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 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).

{Examples 1-2}
VM (100 mg) was dissolved in 5 ml of methanol solution, 100 mg of talc (Asada Flour Mills average particle size; 131 nm) and polyethylene glycol (average molecular weight; 600) in the amount shown in Table 2 were added, and then 25 wt% aqueous ammonia solution ( 2 ml) and a magnetic stirrer was stirred at room temperature (25 ° C.) for 1 hour to obtain a reaction liquid sample.
After completion of the reaction, the solvent was removed from the reaction solution sample under reduced pressure, and the resulting crude product was dispersed in methanol overnight. Subsequently, the target product was separated as a solid content by centrifugation, the obtained solid content was washed several times with methanol, and after removing the solvent, vacuum-dried at 50 ° C. to obtain the target product (composite particle sample). .
The obtained composite particles were redispersed in methanol, and the average particle size was measured using a light scattering photometer (DLS-6000HL manufactured by Otsuka Electronics). The results are also shown in Table 2.

{Comparative Examples 1-2}
The reaction was carried out under the same reaction conditions as in Example 1 except that the reaction was carried out without adding talc or polyethylene glycol to obtain a reaction liquid sample and a composite particle sample. Further, the average particle diameter was measured in the same manner as in Examples 1 and 2. The results are also shown in Table 2.

Note) PEG: Polyethylene glycol

(Evaluation of contact angle between dodecane and water)
A glass plate is immersed in the reaction solution sample obtained in each of the examples and comparative examples for 1 minute at room temperature (25 ° C.), the glass plate is pulled up, and then naturally dried and further vacuum-dried overnight for modified glass. Plate samples were prepared. 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 3.
In addition, blank 1 was treated with blank 1, VM 2 was treated with blank 2, blank 3 was treated with talc alone, and the evaluation results are also shown in Table 3.
The contact angle was evaluated as a value 30 minutes after dropping water and dodecane.
FIG. 3 shows a photograph showing the surface state of the glass surface after 15 minutes when one drop of dodecane was dropped on the surface of the glass plate modified with the composite particles of Example 1.

From Table 3, it can be seen that the surfaces of the glass plates modified with the composite particles obtained in the examples of the present invention are both superhydrophilic and superoleophobic.
In addition, even if the surface of the glass plate modified with the composite particles obtained in this example was strongly rubbed with a finger, the modified surface did not peel off, so the modified layer obtained in the present invention also has good adhesion. It was confirmed that it was excellent.

Claims (5)

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), talc 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.) ^2. The composite particle according to claim ^1, wherein R ¹ and R ² in the formula (1) are —CF (CF ₃ ) OC ₃ F ₇ .   3. The composite particle according to claim 1, wherein the average particle size is 0.01 to 10 μm.   The composite particle according to any one of claims 1 to 3, wherein the composite particle is used as an oil-water separator. An alkali 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), talc, polyethylene glycol and a reaction solvent, and the alkoxysilyl group is hydrolyzed. A method for producing composite particles, comprising a reaction step.
(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.)