JP7123315B2 - Composite particles - Google Patents

Description

The present invention relates to composite particles. More particularly, it relates to composite particles that are effectively used for recovering water from fluorine-containing surface treatment agents and oil-water mixtures.

In order to impart oil repellency to the surface of a substrate, there is known a method of using a fluorine compound, particularly a polymer of a perfluoroalkyl group-containing compound, as a surface treatment agent. Since it also exhibits water repellency and is not hydrophilized, a state in which only stains remain on the surface of the substrate may occur, which poses a problem.

For this reason, an oil-repellent hydrophilic agent that has both oil repellency and hydrophilicity is required as a surface treatment agent that enables automatic cleaning by washing with water, and an excellent oil-repellent hydrophilic agent exhibits stain resistance. It can be expected not only as a surface treatment agent, but also for quick water drying and oil-water separation by improving wettability.

Conventionally, in order to treat contaminated water containing oil discharged from oil and gas fields, chemical plants, gas stations, and restaurants, oil and water are separated by specific gravity separation, microbial treatment, chemical treatment, etc. However, since this involves problems such as processing time and cost, effective recovery of water from oil-water mixtures is required in fields ranging from industrial use to general households.

JP 2008-38015 A U.S. Pat. No. 3,574,770

An object of the present invention is to provide composite particles that can be effectively used for recovering water from a fluorine-containing surface treatment agent or an oil-water mixture.

Such an object of the present invention is the general formula
HO _{( CH2} ) _aCmF2m ( OCnF2n ) _bO ( _CF2 ) _cO ( _CnF2nO ) _dCmF2m ( _CH2 ) _aOH [ _I ] _ _ _{_} _ _{_ _} _ _{_} _ _{_}
(where a is an integer from 1 to 6, c is an integer from 1 to 6, b+d is an integer from 0 to 50, m is 1 or 2, and n is 1, 2 or 3). ) , magnetic particles and a compound having at least one phosphonic acid site, 1-hydroxyethane-1,1-diphosphonic acid or 2-phosphonobutane-1,2,4-tricarboxylic acid is achieved by composite particles consisting of

By dispersing the composite particles according to the present invention in an organic solvent and treating the surface of a substrate such as glass or metal, a thin film having oil repellency and hydrophilicity can be formed. That is, it is effectively used as a fluorine-containing surface treatment agent.

In addition to oil repellency derived from fluoroether alcohol, hydrophilicity can be obtained by using a compound having a phosphonic acid moiety, and by using magnetic particles such as magnetite fine particles, the composite particles can be made magnetic. can be done.

In this way, the composite particles have oil-repellent hydrophilicity and magnetism, and in a state in which the composite particles are dissolved in a mixture of water and oil, a magnet attracts the composite particles and water, thereby separating the water and the oil. , allowing the water to be recovered from the mixture with the oil.

Specifically, the effect of effectively recovering water from oil-containing polluted water discharged from oil and gas fields, chemical plants, gas stations, and restaurants is brought about.

The composite particles of the present invention consist of a fluoroether alcohol, magnetic particles and a compound containing phosphonic acid moieties.

As a fluoroether alcohol, the general formula
HO _{( CH2} ) _aCmF2m ( OCnF2n ) _bO ( _CF2 ) _cO ( _CnF2nO ) _dCmF2m ( _CH2 ) _aOH [ _I ] _ _ _{_} _ _{_ _} _ _{_} _ _{_}
a: 1 to 6
b+d: 0-50
c: 1-6
m: 1 to 2
n: 1 to 3
The compound represented by is mentioned.

As the fluoroether alcohol represented by the general formula [I] , for example, the general formula
HO( _CH2 ) _aCF ( _CF3 )[OCF2CF _{( CF3} )] _bO (CF2) _cO [CF( _CF3 ) _CF2O ] _dCF ( _CF3 ) _{( CH2} ) _aOH [II]
a: 1 to 6, preferably 1 to 3, particularly preferably 1
b+d: 0-50, preferably 1-20
Regarding the value of b+d, it may be a mixture with a distribution
c: 1-6, preferably 2-4
A compound or the like represented by is used.

Among the fluoroether alcohols represented by the general formula [II] , compounds in which a=1 are described in Patent Documents 1 and 2, and are synthesized through the following series of steps.
_FOCRfCOF → H3 _COOCRfCOOCH3 → _{HOCH2 RfCH2OH}
Rf: -CF( _CF3 )[OCF2CF _{( CF3} )] _bO (CF2)cO[CF _{( CF3} ) _{CF2O ] dCF} ( _CF3 )-

As the fluoroether alcohol having a polyfluoroalkylene ether group represented by the general formula [I], for example, the general formula
HOCH2CF2 ₍ OCF2CF2 ) _q ( OCF2 ) _{OCF2CH2OH [} III ] _{_} _ _{_ _ _} _
q : 0-50, preferably 10-40
A compound or the like represented by is used.

As the magnetic particles, for example, fine particles of magnetite, ferrite, maghemite, silicon iron, permalloy, amorphous metal, etc., preferably nanoparticles of magnetite, etc. are used.

2-ホスホノブタン-1,2,4-トリカルボン酸〔PBTC〕

が挙げられる。 Compounds having at least one phosphonic acid site include:
1-hydroxyethane-1,1-diphosphonic acid [HEDP]

2-phosphonobutane-1,2,4-tricarboxylic acid [PBTC]

is mentioned.

These phosphonic acid site-containing compounds are arbitrarily set within the range of 1 to 99% by weight as long as they exhibit the desired oil repellency and hydrophilicity when the total amount of the fluoroether alcohol and the phosphonic acid site-containing compound is taken as 100. However, it is preferable to use 45 to 80% by weight of fluoroether alcohol and 55 to 20% by weight of phosphonic acid moiety-containing compound . Unless the phosphonic acid moiety-containing compound is used, hydrophilicity is hardly exhibited as shown in the results of Comparative Example 2 described later.

Magnetic particles are used in a proportion of 10 to 90% by weight based on the total amount of fluoroether alcohol and phosphonic acid site-containing compound.

The composite particles are prepared by ultrasonically stirring the fluoroether alcohol and the magnetic particles in tetrahydrofuran at about 40°C or lower for about 3-5 hours, then adding the phosphonic acid moiety-containing compound, and ultrasonically stirring under the same conditions. done.

After removing the solvent, the crude product was dispersed in tetrahydrofuran overnight, then the product was precipitated by a magnet, and the separated product was washed several times with tetrahydrofuran, and after solvent removal, vacuum was applied at about 50-70°C. The product is obtained by drying.

The application of the oil-repellent hydrophilic composite particles to inorganic substrates such as metals and glasses, and organic substrates such as synthetic resins and rubbers can be achieved by any coating means such as dip coating, spray coating, etc. It is carried out by means of brush coating, roller coating, spin coating and the like.

A dispersion of composite particles in tetrahydrofuran is applied to the surface of a substrate, and in order to develop oil-repellent hydrophilicity, it is dried at room temperature and then dried at about 100-200°C, preferably about 120-150°C. ℃ and the firing time is about 1 to 24 hours.

The composite particles of the present invention are effective as an oil-repellent hydrophilic agent having both oil-repellency and hydrophilicity. Surface treatment agents with excellent oil repellency and hydrophilicity not only enable automatic cleaning by washing with water, but are also effectively used for quick-drying water applications and oil-water separation applications due to improved antifouling performance and wettability. can also

In addition, the composite particles have oil-repellent hydrophilicity and magnetism, so that when the composite particles are dispersed in a mixture of water and oil, the composite particles and water are attracted by a magnet to separate water and oil. and allows water to be recovered from the mixture with the oil.

The invention will now be described with reference to examples.

Example 1
Fluoroether alcohol [OXF9PO-OH (b+d=7)] was added to a 13.5 ml reaction vessel.
HO( _CH2 )CF( _CF3 )[OCF2CF( _CF3 )] _bO (CF2) _2O [CF _{( CF3} ) _CF2O ] _dCF ( _CF3 ) _{( CH2} )OH
100 mg, 100 mg of magnetite nanoparticles (Toda Kogyo product, average particle size 10 nm), and 5 ml of tetrahydrofuran were charged, and ultrasonically stirred at 30° C. or lower for 3 hours. Thereafter, 30 mg of pure 1-hydroxyethane-1,1-diphosphonic acid [HEDP] (60% by weight aqueous solution) was added, and ultrasonically stirred for 3 hours.

After ultrasonic stirring, the solvent was removed under reduced pressure conditions at 85° C., and the crude product was dispersed in fresh tetrahydrofuran overnight. The product was then precipitated with a magnet and the separated product was washed several times with tetrahydrofuran. After removing the solvent, the desired composite particles were obtained by drying at 50°C under reduced pressure.

Example 2
In Example 1, the HEDP amount was changed to 90 mg.

Example 3
In Example 1, the HEDP amount was changed to 120 mg.

Example 4
In Example 1, 25 mg of 2-phosphonobutane-1,2,4-tricarboxylic acid [PBTC] (50% by weight aqueous solution) was used instead of HEDP.

Example 5
In Example 1, 50 mg of 2-phosphonobutane-1,2,4-tricarboxylic acid [PBTC] (50% by weight aqueous solution) was used instead of HEDP.

Example 6
In Example 1, 75 mg of 2-phosphonobutane-1,2,4-tricarboxylic acid [PBTC] (50% by weight aqueous solution) was used instead of HEDP.

Example 7
In Example 1, 100 mg of 2-phosphonobutane-1,2,4-tricarboxylic acid [PBTC] (50% by weight aqueous solution) was used instead of HEDP.

Comparative example 1
The contact angle of the coverslip itself was measured.

Comparative example 2
In Example 1, HEDP was not used.

Comparative example 3
In Example 3, no OXF9PO-OH was used.

Comparative example 4
In Example 7, no OXF9PO-OH was used.

For the tetrahydrofuran dispersions of the composite particles obtained in each of the above examples and comparative examples, the contact angle (unit: °) of droplets was measured as follows.

The entire amount of the composite particles obtained by drying was added to 5 ml of tetrahydrofuran, and ultrasonic waves were applied for dispersion for 5 hours to obtain a tetrahydrofuran dispersion of composite particles. 0.30 ml of this composite particle dispersion was taken with a micropipette, dropped onto a cover glass (borosilicate glass manufactured by Matsunami Glass Industry Co., Ltd.; 18 x 18 mm), evaporated at room temperature to evaporate the solvent, and left under vacuum for one day. dried. A 4 μl droplet of n-dodecane or water was gently brought into contact with the modified substrate obtained, and the contact angle of the attached droplet was measured by the θ/2 method using a contact angle meter (Drop Master 300 manufactured by Kyowa Interface Science Co., Ltd.). was used to make measurements over time.

The results obtained are shown in Table 1 below.
Table 1
n-dodecane water
Example 0 minutes 5 minutes 0 minutes 5 minutes 10 minutes 15 minutes 20 minutes 25 minutes 30 minutes
Example 1 59 56 70 0 0 0 0 0 0
〃 2 29 29 12 0 0 0 0 0 0
〃 3 74 66 11 0 0 0 0 0 0
〃 4 22 17 10 0 0 0 0 0 0
〃 5 24 20 9 0 0 0 0 0 0
〃 6 33 26 37 0 0 0 0 0 0
〃 7 26 22 11 0 0 0 0 0 0
Comparative Example 1 0 0 54 42 35 24 20 20 20
〃 2 65 54 138 114 110 107 105 98 96
〃 3 0 0 0 0 0 0 0 0 0
〃 4 3 0 25 13 8 0 0 0 0

Example 8
Using the composite particles obtained in Example 3, the collection of water in oil with a magnet was evaluated.
2 ml of n-dodecane and 0.1 ml of blue colored water were added to a 9 ml screw tube to prepare a mixed solution, and 10 mg of composite particles were added to this solution and stirred for 10 seconds. After that, a magnet was brought close to the side of the screw tube, and the screw tube was tilted to decantation n-dodecane into the empty screw tube. The amount of water in the decanted n-dodecane was visually observed, and was evaluated as ◯ when there was no water, Δ when there was a small amount, and x when there was a large amount.

Comparative example 5
In Example 8, instead of the composite particles obtained in Example 3, the same amount of composite particles obtained in Comparative Example 3 was used.

Comparative example 6
In Example 8, instead of the composite particles obtained in Example 3, the same amount of magnetite nanoparticles was used.

Evaluations in the above Examples and Comparative Examples are shown in Table 2 below.
Table 2
Example Composite particle evaluation result
Example 8 Example 3 ○
Comparative Example 5 Comparative Example 3 △
〃 _{6 Fe3O4} ×

Claims (7)

General formula
HO _{( CH2} ) _aCmF2m ( OCnF2n ) _bO ( _CF2 ) _cO ( _CnF2nO ) _dCmF2m ( _CH2 ) _aOH [ _I ] _ _ _{_} _ _{_ _} _ _{_} _ _{_}
(where a is an integer from 1 to 6, c is an integer from 1 to 6, b+d is an integer from 0 to 50, m is 1 or 2, and n is 1, 2 or 3). ) , magnetic particles and a compound having at least one phosphonic acid site, 1-hydroxyethane-1,1-diphosphonic acid or 2-phosphonobutane-1,2,4-tricarboxylic acid Composite particles consisting of: The fluoroether alcohol represented by the general formula [I] is represented by the general formula
HO( _CH2 ) _aCF ( _CF3 )[OCF2CF _{( CF3} )] _bO (CF2) _cO [CF( _CF3 ) _CF2O ] _dCF ( _CF3 ) _{( CH2} ) _aOH
[II]
(where a is an integer of 1 to 6, c is an integer of 1 to 6, and b+d is an integer of 0 to 50). . Composite particles according to claim 1, wherein the magnetic particles are magnetite. When the total amount of the fluoroether alcohol and the phosphonic acid site-containing compound is 100, the fluoroether alcohol is used at a ratio of 45 to 80% by weight and the phosphonic acid site-containing compound is used at a ratio of 55 to 20% by weight. Composite particles as described. 4. The composite particles according to claim 1, wherein the magnetic particles are used in an amount of 10 to 90% by weight based on the total amount of the fluoroether alcohol and the phosphonic acid moiety-containing compound. 2. The composite particles according to claim 1, which are used as a fluorine-containing surface treatment agent. 2. The composite particles according to claim 1, wherein a magnet is used to remove water in an oil-water mixture.