JP6644589B2 - Composite particles, method for producing the same, and oil / water separation material - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a composite particle, a method for producing the same, and an oil-water separator using the composite particle.

  Fluorine compounds can be expected to be applied to paints, cosmetics, and the like by utilizing features such as water / oil repellency, oxygen permeability, and low refractive index. However, since fluorine-based compounds have too high water and oil repellency, it is difficult to maintain dispersion stability with respect to non-fluorine materials.

  On the other hand, a fluorine compound which exhibits high oil repellency in air has a disadvantage that oil repellency disappears in water and oil spreads wet.

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

  However, static separation requires a great deal of time, centrifugation requires a large-scale apparatus, and adsorption separation is not suitable for treating a large amount of an oil-water mixture.

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

JP 2010-209300 A JP 2010-235943 A JP 2013-185071 A

  The present inventors further promoted the development of a new functional material using a fluoroalkyl group-containing oligomer, and condensed a specific fluoroalkyl group-containing oligomer having an alkoxysilyl group with a water-soluble cellulose ether. The composite particles containing are excellent in adhesion to various base materials. Further, they have found that the composite particles have excellent water repellency and lipophilicity and can be suitably used as an oil-water separator, and have completed the present invention.

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

That is, the first invention to be provided by the present invention includes a water-soluble cellulose ether and a condensate obtained by condensing a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by the following general formula (1). It is a characteristic composite particle.
(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 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 a linear or branched alkyl group having 1 to ⁵ carbon atoms. And m is an integer of 2 to 3.)

Further, a second invention which is to be provided by the present invention is a method for preparing a reaction solution containing a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by the following general formula (1) and a water-soluble cellulose ether. A method for producing a composite particle, comprising a reaction step of performing a hydrolysis reaction of a silyl 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 or different groups, and 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. And m is an integer of 2 to 3.)

  A third invention to be provided by the present invention is an oil-water separation material using the composite particles of the first invention.

According to the present invention, composite particles having excellent water repellency and lipophilicity can be provided. Further, it can be suitably used as an oil / water separator for separating water and oil.
Further, according to the present invention, the composite particles can be provided by an industrially advantageous method.

The schematic diagram showing one of the embodiments which performs oil-water separation using the oil-water separation material of the present invention. The schematic diagram showing one of the embodiments which performs oil-water separation using the oil-water separation material of the present invention. FT-IR spectrum of the composite particle sample obtained in Examples 1 to 3. 5 is a photograph of a modified filter paper modified with the composite particle sample obtained in Example 2 and a filter paper before modification. 5 is an SEM photograph of a modified filter paper modified with the composite particle sample obtained in Example 2 and a filter paper before modification. FIG. 4 is a photograph of the treated water separated by a modified filter paper modified with the composite particles of Example 2. FIG.

Hereinafter, the present invention will be described based on preferred embodiments.
The composite particles according to the present invention include 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 is characterized by containing a water-soluble cellulose ether.

  In the composite particles according to the present invention, the water-soluble cellulose ether may contain 0.01 to 5000 parts by mass, preferably 0.1 to 1000 parts by mass, based on 100 parts by mass of the condensate of the fluoroalkyl group-containing oligomer. It is preferable from the viewpoint that lipophilicity and water repellency are excellent.

  The composite particles according to the present invention are preferably obtained by performing a reaction step of performing a hydrolysis reaction of the fluoroalkyl group-containing oligomer in a reaction raw material solution containing a fluoroalkyl group-containing oligomer and a water-soluble cellulose ether. .

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 or different groups, and 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. And m is an integer of 2 to 3.)

  The fluoroalkyl group-containing oligomer represented by the general formula (1) is used mainly for imparting excellent water 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. And the like.
In the general formula (1), p and R of — (CF ₂ ) p—Y group of R ¹ and R ² or —CF (CF ₃ ) — [OCF ₂ CF (CF ₃ )] 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, Japanese Patent Application Laid-Open No. 2010-77383).

As the water-soluble cellulose ether used in the reaction step, a water-soluble cellulose ether having a hydroxyl group of cellulose substituted with ether and having water solubility is used. Examples of the water-soluble cellulose ether include alkyl cellulose, hydroxyalkyl alkyl cellulose, and hydroxyalkyl cellulose.
Specific compounds include, for example, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose and the like.
In the present invention, the water-soluble cellulose ether can be used without any particular limitation in physical properties as long as it is industrially available. In the present invention, the water-soluble cellulose ether is mainly used for imparting excellent lipophilicity to the composite particles according to the present invention while maintaining excellent water repellency caused by the fluoroalkyl group-containing oligomer.
In addition, in the present invention, by containing a water-soluble cellulose ether, it is possible to uniformly disperse the composite particles in various base materials, and is excellent for a cellulose material used as a filter of a filter material. It has adhesiveness.

  In the present invention, in the reaction step, it is preferable to carry out the reaction using a reaction solvent in order to carry out the reaction efficiently.

  As the reaction solvent that can be used, those capable of dissolving the fluoroalkyl group-containing oligomer and the water-soluble cellulose ether are used, and examples thereof include water, lower alcohols such as methanol, ethanol, and isopropyl alcohol. It may be used as a mixed solvent of more than one kind. Among them, a mixed solvent of water and methanol is particularly preferred.

  In the reaction step of the present invention, the order of adding the fluoroalkyl group-containing oligomer and the water-soluble cellulose ether when preparing the reaction raw material solution is not particularly limited.

  The content of the water-soluble cellulose ether in the reaction raw material solution is 0.01 to 5000 mg, preferably 0.1 to 1000 mg in terms of a value converted to 100 mg of the fluoroalkyl group-containing oligomer represented by the general formula (1). is there. When the content of the water-soluble cellulose ether in the reaction raw material solution is within the above range, the obtained composite particles have excellent lipophilicity and water repellency.

  In the reaction step, the hydrolysis reaction of the fluoroalkyl group-containing oligomer may be performed using an acid catalyst or an alkali catalyst, or may be performed without a catalyst.

The acid catalyst to be 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, and examples thereof include sulfuric acid, hydrochloric acid, nitric acid, and acetic acid. .
The alkali catalyst is not particularly limited as long as it can hydrolyze the alkoxysilyl group in the fluoroalkyl group-containing oligomer, and examples thereof include ammonium hydroxide, sodium hydroxide, and potassium hydroxide.

  In the present production method, it is preferable that the hydrolysis reaction of the fluoroalkyl group-containing oligomer be performed without a catalyst from the viewpoint of obtaining a product having particularly excellent water repellency and lipophilicity. When an acid catalyst or an alkali catalyst is added to the reaction raw material solution, the addition amount is not particularly limited, and is appropriately selected.

  The reaction temperature at the time of performing the hydrolysis is -5 to 50C, preferably 0 to 30C. If the reaction temperature is lower than -5 ° C, the hydrolysis rate becomes too slow, so that the reaction efficiency is poor. If the reaction temperature is higher than 50 ° C, the dispersion stability of the composite particles tends to be low. The reaction time for performing the hydrolysis is not particularly limited and may be appropriately selected, but is preferably 1 to 72 hours, particularly preferably 1 to 50 hours.

  Then, by performing the reaction step, composite particles having a siloxane bond as a main skeleton are generated, and a reaction liquid containing the composite particles according to the present 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 reforming liquid for modifying various base materials for use as an oil-water separator as described below.

  As other preferable physical properties of the composite particles of the present invention, the average particle diameter determined by a dynamic light scattering method is preferably from 5 to 1,000 nm, and more preferably from 10 to 800 nm. It is preferable that the average particle diameter is within the above range, since the dispersibility in various dispersion solvents, resin materials, various base materials, and the like is good.

Further, the composite particles according to the present invention, the water-soluble cellulose ether contained in the composite particles further agglomerated more strongly, the surface of the modified film formed using the composite particles of the present invention, a more rough state. Heat treatment can be performed at 50 ° C. or higher, preferably 60 to 90 ° C. for the purpose of performing the heat treatment.
This heat treatment may be performed after forming a modified film on the surface of the base material using the composite particles of the present invention.

The oil-water separation material 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 solution containing water and oil.

The composite particles of the present invention can be used as an oil-water separator by the following two methods, for example.
(1) A method of modifying a water-insoluble substrate with the composite particles of the present invention.
(2) A method of using the composite particles of the present invention per se as a filtering material.

  As the substrate according to the above (1), an inorganic or 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, and asbestos. 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 the synthetic polymer include condensation or addition polymer polymers such as polyurethane, polyethylene terephthalate, nylon and polycarbonate, and ethylenically unsaturated polymer polymers such as polyethylene, polypropylene, vinyl chloride and vinyl acetate. Can be

  The shape of the substrate is not particularly limited, and examples thereof include a strip, a sponge, a ribbon, a fibril, a web, a mat, a cotton cloth, and a nonwoven cloth.

  Further, 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 size of the filter paper is preferably 5 μm or less, and more preferably 0.1 to 3 μm, from the viewpoint of efficient oil-water separation.

  In the above (1), the method for modifying the substrate with the composite particles of the present invention is not particularly limited as long as the method can fix or support the composite particles of the present invention on the surface or inside of the substrate. 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 0.1 to 50% by weight, followed by drying. The contact between the dispersion and the substrate can be carried out by a method of dipping the substrate into the dispersion, a method of spraying the substrate with a spray, or a method of applying the dispersion to the substrate.

  As the dispersion liquid in which the composite particles are dispersed, the reaction liquid containing the composite particles after the above-described reaction may be used as it is.

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

  The embodiment shown in FIG. 1 comprises a simple separation system (A) consisting of a column (1b) and a modified filter paper (1a), the modified filter paper (1a) being modified with the composite particles of the invention. It is.

  By biting the modified filter paper (1a) in the middle of the column (1b), the water-oil mixture (1) charged into the column (1b) comes into contact with the modified filter paper (1a). The oil (1 ′) passes through the modified filter paper (1a), and water cannot pass through the modified filter paper (1a), so that water and oil can be separated. The separation operation can be performed under pressure or under reduced pressure, if necessary, to increase the separation efficiency. In this case, first, the oil (1 ′) selectively passes through the modified filter paper (1a), and then water may pass through the modified filter paper later due to strong external force, but water is eluted. Before, the oil and water can be separated through the oil-water separator by means such as finishing the oil-water separation operation.

  FIG. 2 is a schematic diagram 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 filtering material.

In the embodiment shown in FIG. 2, a simple separation system (B) comprising a column (2b) and a filter medium layer (2a) including 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 solution (1) of water and oil into the column (2b), the mixed solution can be brought into contact with the filter medium (2c). The oil (1 ′) passes through the filter medium layer (2a) and water cannot pass through the filter medium layer (2a), so that water and oil can be separated. The separation operation can be performed under pressure or under reduced pressure, if necessary, to increase the separation efficiency. Further, in order to suppress clogging or the like, a layer filled with a filter aid may be provided on the upper and / or lower part of the filter medium layer (2a) if necessary.

  There is no particular limitation on the filter aid that can be used, and known ones can be widely used. For example, diatomaceous earth, sand particles, perlite, 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 by the oil-water separation material according to the present invention may be in a solution state or an emulsion.

  The oil-water separation material according to the present invention can be used for, for example, treatment of wastewater containing oil, separation or purification of water and oil at production sites in various industrial fields, and the like.

Hereinafter, the present invention will be described with reference to examples, but the present 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, converted to polystyrene).

<< Examples 1-11 >>
VM, hydroxypropyl methylcellulose (manufactured by Shin-Etsu Chemical Co., Ltd., 90SH-100), methanol and water were charged into a container in the amounts shown in Table 2 to prepare a reaction raw material solution. Next, the mixture was stirred at room temperature (25 ° C.) for 5 hours with a magnetic stirrer to obtain a reaction liquid sample.
After completion of the reaction, the solvent was removed from the reaction solution sample under reduced pressure, then re-dispersed in methanol, and centrifuged to obtain a target substance (composite particle sample) as a white powder.
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 Co., Ltd.). The results are shown in Table 2.
FIG. 3 shows FT-IR spectra of the composite particles and hydroxypropylmethylcellulose obtained from Examples 1 to 3.

Note) HPMC; hydroxypropyl methylcellulose, "-"; not measured

<Evaluation of contact angle between dodecane and water>
Evaluation 1; A glass plate was immersed in the reaction solution sample obtained in Example 2 for 1 minute at room temperature (25 ° C.), and the glass plate was pulled up, followed by natural drying and further vacuum drying at 20 ° C. overnight. . Next, heat treatment was performed at a temperature of 20 to 70 ° C. for 1 hour to prepare various modified glass plate samples. The contact angle of dodecane and water on the surface of this modified glass plate sample was evaluated using Drop Master.300 manufactured by Kyowa Interface Science. Table 3 shows the results.

Note) "-" indicates that there was no change in the contact angle.

  From the results in Table 3, it can be seen that the properties of the modified glass plate sample are stabilized by performing the heat treatment, and the performance of water repellency and lipophilicity is also improved.

Evaluation 2: Filter paper (Advantec: 131, pore size: 3 μm; cellulose material) cut into a square of 3 cm was immersed in the reaction solution sample obtained in the example for 1 minute at room temperature, the filter paper was pulled up, air dried, and further dried. Vacuum drying was performed at 20 ° C. overnight to prepare various modified filter paper samples.
After treating the modified filter paper sample at 70 ° C. for 1 hour, the contact angle of dodecane and water on the surface of the modified filter paper sample is maintained at 25 ° C. or 70 ° C., using Drop Master.300 manufactured by Kyowa Interface Science. And evaluated. Table 4 shows the results.
Untreated samples were evaluated as blank 1, and those treated with only VM were evaluated as blank 2, and the evaluation results are shown in Table 4.

Note) "-" indicates that there was no change in the contact angle.

  Table 4 shows that the composite particles of the present invention impart excellent water repellency and lipophilicity to the cellulose substrate, and are obtained as super water repellent and super lipophilic.

<Evaluation as oil-water separation material>
A filter paper (Advantec: 131, pore size: 3 μm) cut into a 3 cm square was immersed in the reaction solution sample obtained in Example 2 for 1 minute at room temperature, the filter paper was pulled up, air dried, and vacuum dried overnight. C. to prepare a modified filter paper sample.
FIG. 4 shows photographs of the surface of the filter paper sample before and after the modification, and FIG. 5 shows SEM photographs. 4 and 5 that the surface state of the base material does not change even after the modification, and is uniformly dispersed and adhered. Further, even if the surface of the filter paper sample modified with the composite particles obtained in the present example was strongly rubbed with a finger, the modified surface did not peel off, so that the modified layer obtained in the present invention also has an adhesive property. We confirmed that it was excellent.
The water-oil separation by the modified filter paper was examined using 2 ml of a mixed liquid (1: 1 vol.) Of 1,2-dichloroethane (1.256 g / ml) and water (1.0 g / ml). The water in the mixture was colored blue by copper sulfate pentahydrate.
In addition, the same evaluation was performed for a case where a filter paper that was not subjected to the modification treatment (Comparative Example 1) was used.

(Evaluation results)
As shown in FIG. 6, a modified filter paper sample was sandwiched between funnels, and a water-oil separation test was conducted by filtering the mixture under reduced pressure. Table 5 shows the results. The symbols in Table 5 indicate the following.
；: Water was not visually observed in the filtrate 10 seconds after the start of filtration.
Δ: A slight amount of water was visually observed in the filtrate 10 seconds after the start of filtration.
×: A large amount of water is visually observed in the filtrate 10 seconds after the start of filtration.

From the results shown in Table 5 and FIG. 6, in the case of the comparative example, immediately after the separation operation, the mixed liquid containing water and oil passed through the filter paper as it was, and water and oil could not be separated at all. On the other hand, it can be seen that by using the modified filter paper of the example, water and oil can be separated from the mixed liquid containing water and oil via the modified filter paper.

Claims (7)

Composite particles comprising a co-condensate of a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by the following general formula (1) and a water-soluble cellulose ether.

(Wherein, R ¹ and R ² represent a —CF (CF ₃ ) — [OCF ₂ CF (CF ₃ )] q-OC ₃ F ₇ group, and R ¹ and R ² are the same group. ^May be different groups, and q is an integer 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 represents a linear or branched alkyl group having 1 to ⁵ carbon atoms, and m is an integer of 2 to 3.) ^2. 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. 3} .   The composite particle according to claim 1, wherein the water-soluble cellulose ether is selected from methyl cellulose, hydroxypropyl methyl cellulose, and hydroxyethyl methyl cellulose.   The composite particles according to any one of claims 1 to 3, wherein the composite particles have an average particle diameter of 5 to 1000 nm. It is characterized by having a reaction step of performing a hydrolysis reaction of the alkoxysilyl group in a reaction raw material solution containing a fluoroalkyl group-containing oligomer having an alkoxysilyl group represented by the following general formula (1) and a water-soluble cellulose ether. A method for producing composite particles.

(Wherein, R ¹ and R ² represent a —CF (CF ₃ ) — [OCF ₂ CF (CF ₃ )] q-OC ₃ F ₇ group, and R ¹ and R ² are the same group. ^May be different groups, and q is an integer 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 represents a linear or branched alkyl group having 1 to ⁵ carbon atoms, and m is an integer of 2 to 3.)   An oil-water separator comprising the composite particles according to any one of claims 1 to 4.   An oil-water separation method, comprising bringing a mixed liquid containing water and oil into contact with the oil-water separation material according to claim 6.