JP7184255B2 - FLUORINE-CONTAINING SILICA COMPOSITE PARTICLES, METHOD FOR PRODUCING THEREOF, AND HYDROPHILIC AND HYDROPHILIC AGENT CONTAINING SAME AS ACTIVE INGREDIENT - Google Patents

Description

TECHNICAL FIELD The present invention relates to fluorine-containing silica composite particles, a method for producing the same, and a water-repellent and lipophilic agent containing the same as an active ingredient. More particularly, it relates to fluorine-containing silica composite particles using fluorine-containing alcohol, a method for producing the same, and a water-repellent and oil-repellent agent containing the same as an active ingredient.

US Pat. No. 5,300,000 describes liquid, fluorine-containing and single-component compositions having a fluorine content of 5-75% by weight relative to the solid resin for the permanent oil- and water-resistant surface treatment of porous and non-porous substrates. Compositions are described which, in combination with a suitable stabilizing component and a hydrophilic silane component, have excellent storage stability, hydrophobicity, oleophobicity and dust resistance.

However, not only are perfluorooctanoic acid and its precursor fluorine-containing alcohol having a _C8 or higher perfluoroalkyl group, which are currently required to be reduced from an environmental point of view, but also mineral and non-mineral In the preparation of the substrate surface treatment agent, a highly toxic isocyanate compound is used to introduce a silyl group into the fluorine compound.

The present applicants have previously proposed fluorine-containing silica composite particles using a fluorine-containing alcohol that does not generate perfluorooctanoic acid or the like even when released into the environment and has units that are easily decomposed into short-chain compounds. General formula
HO- _ARF' -A-OH [Ib]
(Here, R _F 'is a perfluoroalkylene group having less than 8 carbon atoms and is a linear or branched perfluoroalkylene group containing O, S or N atoms, and A is an alkylene group. ) and a fluorine-containing silica composite particle composed of a condensate of silica particles with a fluorine-containing alcohol and an alkoxysilane (Patent Document 2).

Japanese Patent Publication No. 2011-511113 JP 2014-196480 A JP 2008-38015 A U.S. Pat. No. 3,574,770

A first object of the present invention is the general formula
HO(CH2 ₎ aCF ₍ CF3 ₎ [OCF2CF ₍ CF3 ₎ ] _{bO (} CF2 ₎ cO _[ CF(CF3 ₎ CF2O ] dCF ₍ CF3 ₎ ( _CH2 ) _aOH [III]
(where a is 1 to 3, b+d is 0 to 50 , and c is an integer of 1 to 6). The object of the present invention is to provide fluorine-silica composite particles having further improved water-repellent and lipophilic properties.

A second object of the present invention is to provide a method for producing such fluorine-containing silica composite particles.

A third object of the present invention is to provide a water-repellent and lipophilic agent containing such fluorine-containing silica composite particles as an active ingredient.

A first object of the present invention is to provide a fluorine-containing alcohol, a tetraalkoxysilane , and -CH ₂ CH , which is a group having at least one amino group and/or hydroxyl group in the molecule and not having a sulfo group. _{2CH2NH2 ,} -CH2CH2CH2OCH2CH ₍ OH _{) CH2OH} , -CH2CH2CH2NHCH2CH2NH2 or -CH2CH2CH2OCH2CH ( _{OH ) _} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _This is achieved by fluorine-containing silica composite particles comprising a condensate with silica particles surface-modified with CH2N ₌ C (NH2 ₎ NH(CH2 ) _3CH (NH2 ₎ COOH .

A second object of the present invention is the fluorine-containing alcohol , tetraalkoxysilane, and —CH ₂ CH , which is a group having at least one amino group and/or hydroxyl group in the molecule and no sulfo group. _{2CH2NH2 ,} -CH2CH2CH2OCH2CH ₍ OH _{) CH2OH ,} -CH2CH2CH2NHCH2CH2NH2 or -CH2CH2CH2OCH2CH ( _OH ) _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ _{_} _ Method for producing fluorine-containing silica composite particles by subjecting silica particles surface-modified with CH2N =C(NH2 ₎ NH(CH2 ₎ 3CH ₍ NH2 _{) COOH} to a condensation reaction using an alkaline or acidic catalyst achieved by

The third object of the present invention is achieved by a water-repellent and lipophilic agent containing such fluorine-containing silica composite particles as an active ingredient.

The fluorine-containing silica composite particles according to the present invention are dissolved in an organic solvent and applied to the surface of various substrates to form a thin film having water-repellent and lipophilic properties. Since this thin film exhibits selective adsorption of organic substances and can modify the substrate surface, it is effectively used for oil-water separation, especially for separation of fluorine-based compounds. Specifically, it enables effective recovery of water from an oil-water mixture in fields ranging from industrial use to general household use.

That is, when unmodified silane particles are used, when the obtained composite particles are dissolved in an organic solvent and applied to the substrate surface, a hydrophilic thin film is formed there (Comparative Examples 1 to 3 below). 2), and when modified silane particles are used, they exhibit water-repellent and lipophilic properties. In addition, since the adsorption rate of fluorine-substituted compounds is high and the adsorption rate of non-fluorine-substituted compounds is low, it is possible to selectively adsorb fluorine compounds.

This difference is due to the difference in the reactivity of the sol-gel reaction due to the difference in surface functional groups (presence or absence of hydrophilic acidic functional groups), and the morphology of the microsilica surface is different, so the corresponding silica composite particles are hydrophilic. will show

As a fluorine-containing alcohol, the general formula
HO( _CH2 ) _aCF ( _CF3 )[ _OCF2CF ( _CF3 )] _bO ( _{CF2 ) cO} [CF( _CF3 )CF2O] _dCF ( _CF3 )( _CH2 ) _aOH [III]
a: 1-3, 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 represented by is used.

Among the fluorine-containing alcohols represented by the general formula [III] , compounds in which a=1 are described in Patent Documents 3 and 4, and are synthesized through the following series of steps.
FOCRfCOF → _{H3 COOCRfCOOCH3} → _{HOCH2 RfCH2OH}
Rf: -C( _CF3 )[ _OCF2C ( _{CF3 )} ] _aO ( _CF2 ) _cO [CF( _CF3 )CF2O] _bCF ( _CF3 )-

These fluorine - containing alcohols, tetraalkoxysilanes , and silica particles whose surfaces are modified with a compound having at least one amino group and/or hydroxyl group in the molecule and no sulfo group are mixed with an alkaline or acidic solution. The reaction is carried out in the presence of a catalyst to form fluorine-containing silica composite particles as a condensate consisting of three components of fluorine-containing alcohol-tetraalkoxysilane-modified silica particles.

Examples of the tetraalkoxysilane include tetramethoxysilane and tetraethoxysilane. If tetraalkoxysilane is not used, the water-repellent and oleophilic properties are hardly exhibited.

Silica particles having an average particle size of about 50 to 200 μm, preferably about 50 to 100 μm are desirably used, and commercially available products such as Wako Pure Chemical Industries Wakogel C-500HG are used. If an average particle size outside this range is used, separation after adsorption of organic matter becomes difficult.

A group having at least one amino group and/or hydroxyl group in the molecule and not having a sulfo group may have at least one -O- bond or -NH- group in the molecule , specifically Examples of groups include the following groups.
-CH2CH2CH2NH2 _, -CH2CH2CH2OCH2CH _{( OH ) CH2OH , -CH2CH2CH2NHCH2CH2NH2 ,} _ _{_} _ _ _{_ _ _ _ _ _}
-CH2CH2CH2OCH2CH _{( OH} ) CH2N =C( _NH2 )NH _{( CH2} ) _{3CH ( NH2} ) _COOH

Each of these components is about 80 to 800 parts by weight, preferably about 100 to 500 parts by weight, of fluorine-containing alcohol, and about 100 to 600 parts by weight of tetraalkoxysilane, per 100 parts by weight of modified silica particles. It is preferably used in a proportion of about 200 to 500 parts by weight. If the proportion of the fluorine-containing alcohol used is less than this range, the water-repellency and lipophilicity will be low, while if the proportion is greater than this range, the dispersibility in the solvent will be poor. If the proportion of tetraalkoxysilane used is less than this range, the lipophilicity will be low, whereas if the proportion used is greater than this range, the dispersibility in the solvent will be poor.

The reaction between these components is carried out using a catalytic amount of an alkaline or acidic catalyst, such as aqueous ammonia or an aqueous solution of an alkali metal or alkaline earth metal hydroxide such as sodium hydroxide, potassium hydroxide, calcium hydroxide, or hydrochloric acid, The reaction is carried out in the presence of sulfuric acid or the like at a temperature of about 0 to 100° C., preferably about 10 to 30° C., for about 0.5 to 48 hours, preferably about 1 to 10 hours.

The fluorine-containing alcohol content in the obtained fluorine-containing composite particles is about 1-60 mol %, preferably about 5-30 mol %, and the composite particle diameter is about 50-200 μm.

The fluorine-containing silica composite particles, which are the reaction product, are thought to have functional groups that modify the silica particles, fluorine-containing alcohol, tetraalkoxysilane, and silica particles bound to the hydroxyl groups on the surface of the silica particles using siloxane bonds as spacers. Therefore, the chemical and thermal stability of silica and the excellent water repellency and antifouling properties of fluorine are effectively exhibited. A glass surface treated with fluorine-containing silica composite particles exhibits an effect such as good water-repellency and lipophilicity. The silica composite particles are formed as a reaction product of fluorine-containing alcohol, tetraalkoxysilane and modified silica particles, but other components may be mixed as long as the object of the present invention is not hindered.

The water-repellent and lipophilic agent containing such fluorine-containing silica composite particles as an active ingredient is prepared by diluting with an organic solvent so that the solid content concentration is about 0.01 to 30% by weight, preferably about 0.05 to 3% by weight. It is done by Examples of organic solvents that can be used include alcohols such as methanol, ethanol, n-propanol and isopropanol; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ethers such as diethyl ether, diisopropyl ether, dioxane and tetrahydrofuran; Esters such as butyl acetate, polyhydric alcohol derivatives such as methyl cellosolve, ethyl cellosolve, methyl carbitol, ethyl carbitol, carbon tetrachloride, methylene chloride, trichloroethylene, perchlorethylene, trichloroethane, trichlorofluoromethane, tetrachlorodifluoroethane , trichlorotrifluoroethane and other halogenated hydrocarbons, and preferably a fluorine-containing organic solvent is used.

In the water-repellent and lipophilic agent solution, if necessary, various surfactants such as ionic and nonionic surfactants that improve the wettability of the surface treatment agent, silicone oil and silicone oil that further improve the releasability and lubricity A varnish or the like can also be added.

Application of the water-repellent-lipophilic agent solution to the substrate can be carried out by any commonly used method such as dipping, spraying, brushing, aerosol spraying, and application with an impregnated cloth. Examples of the molding material to which the water-repellent and lipophilic agent is applied include resins such as polyurethane, polycarbonate, epoxy resin, phenol resin, polyimide resin, and vinyl chloride resin; rubbers such as natural rubber, chloroprene rubber, and fluororubber; Molded articles such as metal (oxide), ceramics, ceramics, and glass can be mentioned.

The invention will now be described with reference to examples.

Comparative Examples 1-4
Fluorine-containing alcohol was added to a reaction vessel with a capacity of 13.5 ml.
HO( _CH2 ) _CF ( _CF3 )[ _OCF2CF ( _CF3 )] _bO ( _{CF2 )} 2O[CF( _CF3 )CF2O] _dCF ( _CF3 )( _CH2 )OH
[OXF9PO-OH (b+d=7)]
After 100 mg was added to 5 ml of methanol, 0.25 ml of tetraethylorthosilicate (TEOS) was added with stirring. Then, 2 ml of a 25% by weight aqueous ammonia solution was added dropwise with stirring, 100 mg of (modified) SiO ₂ (Fuji Silysia Chemical, average particle size: 100 μm) was added, and the mixture was stirred for 5 hours.
Comparative Example 1: Unmodified SiO ₂ (CHROMATREX FL100D) (average pore diameter 120 Å)
Comparative Example 2: Unmodified SiO ₂ (CHROMATREX PSQ100B) (average pore diameter 70 Å)
Comparative _{Example 3 :} SiO2 modified with _{-CH2CH2CH2OCH2CH (} OH _{) CH2SO3H}
(CHROMATREX SO3H MB100-75/200)
Comparative Example 4 _{: SiO2 modified with} -CH2CH2CH2SH (SCAVENGER SH SILICA)

After that, the solvent was evaporated at 85° C. under reduced pressure to obtain a white powder. The powder was stirred overnight in methanol, then recovered by centrifugation and dried to obtain a composite powder.

3 ml of n-hexane was added to 100 mg of the obtained composite powder, and the mixture was stirred overnight with a magnetic stirrer. After dropping 0.3 ml of the resulting composite solution onto a glass plate, it was dried at normal temperature for one day and then under vacuum for one day.

For the composite particle methanol (sol) solution obtained in each of the above comparative examples, the droplet contact angle (unit: °) was measured.

Take 0.30 ml of this composite particle methanol (sol) solution with a micropipette, drop it onto a cover glass (borosilicate glass manufactured by Matsunami Glass Co., Ltd.; 18 x 18 mm), evaporate the solvent at room temperature, and place it under vacuum. dried for one day. 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 measure over time.

The measurement results obtained are shown in Table 1 below.
Table 1
n-dodecane water
Comparative example 0 minutes 30 seconds 0 minutes 30 seconds
1 12 0 21 0
2 20 0 64 0
3 25 0 40 0
4 25 0 100 0

Examples 1-6
In Comparative Examples 1 to 4, the same amount (100 mg) of modified SiO ₂ (Fuji Silysia Chemical, average particle size 100 μm) was used instead of (modified) SiO ₂ .
Example ₁ : SiO2 _modified with _{-CH2CH2CH2NH2} and -OH ₍ CHROMATREX NH- _DM1020 )
Example ₂ : SiO2 modified _{with -CH2CH2CH2NH2} ( _CHROMATREX NH-DM1020SG _{)
Example 3 : SiO2} modified with -CH2CH2CH2OCH2CH ( OH _{) CH2OH}
(CHROMATREX DIOL MB100-75/200)
Example ₄ : SiO2 modified _{with -CH2CH2CH2NHCH2CH2NH2} ( _{CHROMATREX DNH MB100-75} / ₂₀₀ )
Example 5 : _SiO2 modified with -CH2CH2CH2OCH2CH (OH) _{CH2N =} C( _NH2 ) _NH ( _{CH2 ) 3CH ( NH2} )COOH
(CHROMATREX ARG MB100-75/200)
_Example 6 _: SiO2 _{modified with -CH2CH2CH2NHCH2NH2} (SCAVENGER _DIAMINE SILICA)

The measurement results obtained are shown in Table 2 below.

Table 2
n-dodecane water
Example 0 minutes 30 seconds 0 minutes 5 minutes 10 minutes 15 minutes 20 minutes 25 minutes 30 minutes
1 32 0 180 － － － － － －
2 31 0 180 － － － － － －
3 31 0 136 130 129 129 127 126 125
4 30 0 139 136 134 132 127 125 120
5 26 0 111 109 108 103 100 93 87
6 27 0 132 130 129 126 126 124 123

Examples 7-8
In Examples 1 and 2, the organic matter adsorption rate was measured. The measurement results obtained are shown in Table 3 below.
Organic adsorption rate: Dissolve organic compounds at a given concentration in a water-methanol (2:8) mixed solvent.
70 mg of the composite was added to 5 ml of the solution and stirred with a stirrer for one day.
The solution is then centrifuged for 30 minutes and the supernatant solution is attached to the cylinder.
The composite was removed by passing through a filter.
The absorbance (A) at the maximum absorption wavelength of the obtained solution was measured by UV-vis spectrum
was measured. The adsorption rate was calculated from the following formula. In the formula, A ₀ is before adsorption
is the absorbance of an organic compound solution of
Organic matter adsorption rate (%) = [(A ₀ - A) / A ₀ ] x 100

Table 3
Organic compound name Concentration (mmol/L) Example 7 Example 8
Bisphenol A 0.03 23 17
Bisphenol AF 0.03 66 59
Perfluorobiphenol 0.01 53 49
Biphenol 0.034 13 8.6
Octafluoro-4,4′-biphenol 0.02 61 63

Claims (4)

General formula
HO(CH2 ₎ aCF ₍ CF3 ₎ [OCF2CF ₍ CF3 ₎ ] _{bO (} CF2 ₎ cO _[ CF(CF3 ₎ CF2O ] dCF ₍ CF3 ₎ ( _CH2 ) _aOH [III]
(where a is 1 to 3, b+d is 0 to 50, and c is an integer of 1 to 6), a tetraalkoxysilane, and at least one amino group and/or or -CH ₂ CH ₂ CH ₂ NH ₂ , -CH ₂ CH _{2 CH 2 OCH 2 CH(OH)CH 2 OH, -CH 2 CH 2 CH 2} NHCH _, which _are groups having _a hydroxyl _group and _not having _a sulfo group _2CH2NH2 or -CH2CH2CH2OCH2CH ( _{OH )} CH2N = _C (NH2 ) _{NH (} CH2 ₎ 3CH ( _{NH2 )} COOH _surface - modified _{silica particles} A fluorine-containing silica composite particle comprising a condensate. 2. The fluorine-containing silica composite particles according to claim 1 , wherein modified silica particles having an average particle size of 50 to 200 μm are used. 3. A method for producing fluorine-containing silica composite particles, which comprises subjecting the fluorine-containing alcohol according to claim 1 or 2 , tetraalkoxysilane and silica particles to a condensation reaction using an alkaline or acidic catalyst. 3. A water-repellent and lipophilic agent comprising the fluorine-containing silica composite particles according to claim 1 or 2 as an active ingredient.