WO2007110920A1

WO2007110920A1 - Hydrophobic silica

Info

Publication number: WO2007110920A1
Application number: PCT/JP2006/306224
Authority: WO
Inventors: Chonghui Wang; Tadakazu Motohashi
Original assignee: Hakuto Co., Ltd.
Priority date: 2006-03-28
Filing date: 2006-03-28
Publication date: 2007-10-04
Also published as: JPWO2007110920A1

Abstract

[PROBLEMS] To provide highly hydrophobic silica which can be used for improving anti-photoaging performance and water resistance/oil resistance in general coating materials, improving fouling (shell) attachment prevention performance in ship bottom paints, improving the surface slip properties and wearing resistance of rubbers and resins and enhancing the mechanical strength of these, improving toner flowability in electrostatic copiers, improving the antifoaming properties of antifoamers, and improving antiblocking properties in papermaking. [MEANS FOR SOLVING PROBLEMS] The hydrophobic silica is characterized by being obtained by treating hydrophilic silica with an aminoalkylsilane compound and then reacting the silica with one or more members selected among specific carboxylic acid compounds, alkylketene dimmers, and diisocyanate compounds.

Description

Specification

Hydrophobic silica Technical Field

[0001] The present invention relates to hydrophobic silica used in paints, rubbers, resins, agricultural chemicals, papers and the like.

Background art

[0002] Hydrophobic silica has made use of its hydrophobicity, and has traditionally been used as a general paint matting agent, photoaging inhibitor, water-proofing agent, oil-proofing agent, chemical-proofing agent and filler, ship bottom Antifouling additives for paint stains (shells), surface slipperiness improvers for rubber and resin, wear resistance improvers and mechanical strength reinforcing agents, fluidization of fine powders such as toner for electrostatic copying machines Hydrophobic silica is mainly used to make hydrophobic silica, which is used as a carrier for hydrophobic components of chemicals, pesticides, antifoam components, water repellents, oil repellents, and blocking agents for paper. Various methods have been proposed in the past. For example, a method of obtaining hydrophobic silica by reacting hydrophilic silica with methylchlorosilane or silane coupling agent, a method of hydrophobizing with hydrophilic silica and high molecular weight organopolysiloxane, hexamethyldisilazane (HMDS) And a method of hydrophobizing with onoreganopolysiloxane (for example, see Patent Document 1). The ability to easily obtain hydrophobic silica by these methods The modified hydrophobicity of the hydrophobic silica (see Patent Document 2) is limited to around 70%. Furthermore, in the case of hydrophilic silica and silane-powered primer and / or organopolysiloxane, the silane-powered primer and / or organopolysiloxane is only attached to the surface of the silica where it reacts with the silica surface. There is a disadvantage that separation of silane coupling agent from hydrophilic silica and Z or onoleganopolysiloxane occurs depending on the use environment. In recent years, there has been a demand for improvement in photoaging prevention performance and water resistance and oil resistance in general paints, and adhesion of dirt (shells) more suitable for the environment than using conventional organic lead compounds and organic tin compounds in ship bottom coatings. Requirement of prevention performance, improvement of surface slipperiness of rubber and resin, improvement of abrasion resistance and reinforcement of mechanical strength, improvement of toner fluidity in electrostatic copying machine, improvement of antifoaming agent performance, blocking of paper There is a demand for improved performance, and the method is higher. Hydrophobic silica is needed.

Therefore, as an improvement method to obtain highly hydrophobic silica, surface treatment of hydrophilic silica with polyethylene wax is used as an exuding agent for paints (see, for example, Patent Document 3), and hydrophilic silica is basic such as water vapor and ammonia A method of reacting with hexamethyldisilazane (H MDS) in the presence of gas has been proposed (for example, see Patent Document 4). However, satisfactory high hydrophobicity has not been achieved.

Patent Document 1: JP-A-5-97423

Patent Document 2: JP-A-8-259216

Patent Document 3: Japanese Patent Laid-Open No. 7-166091

Patent Document 4: JP-A-8-259216

Disclosure of the invention

Problems to be solved by the invention

[0003] The purpose of the present invention is to improve the photo-aging prevention performance of general paints, improve water resistance and oil resistance, improve the dirt (shell) adhesion prevention performance of ship bottom paint, and improve the surface slipperiness of rubber and resin. Hydrophobic silica with high hydrophobicity to improve wear and mechanical strength, improve toner fluidity in electrostatic copiers, improve defoaming performance of antifoaming agent, and improve blocking performance of paper Is to provide.

Means for solving the problem

[0004] In the present invention, after reacting hydrophilic silica and an aminoalkylsilane compound to introduce a reactive amino group on the surface of the hydrophilic silica, the amino group is further reacted with a specific compound. The resulting hydrophobic silica has high hydrophobicity.

That is, the invention according to claim 1 is characterized in that the hydrophilic silica is represented by the general formula (1) (wherein

R ² is independently an alkylene group having 1 to 4 carbon atoms, R ³ ,

R ⁵ is independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and n is an integer of 0 to 5. ) And an aminoalkylsilane compound represented by general formula (2) (wherein R ⁶ is a linear or branched alkyl group having 2 to 21 carbon atoms, and having 2 to 21 carbon atoms) A carboxylic acid compound represented by a straight or branched alkenyl group, X is a hydroxyl group, a chlorine atom, or a bromine atom), general formula (3) (wherein R ⁸ is a straight chain having 1 to 20 carbon atoms) Chain or branched chain An alkyl group, a linear or branched alkenyl group having 1 to 21 carbon atoms, and an alkylphenyl group having 6 to 24 carbon atoms. ) Alkylketene dimer represented by general formula (4) (wherein R 9 is an alkylene group having 6 to 24 carbon atoms and an alkylphenylene group having 6 to 24 carbon atoms). It is a hydrophobic silica obtained by reacting with a hydrophobizing agent containing one or more selected from cyanate compounds.

[0005] [Chemical 5]

H ₂ N- (R -NH) _n — R ² — S i-(R ³ ) (R ⁴ ) (R 1)

[0006] [Chemical 6]

R ⁶ — COX (2)

[0007] [Chemical 7]

R — CH ⁼ -* — CH— Tx

(3)

O― C O

[0008] [Chemical 8]

OCN— R ⁹ — N CO (4)

The invention according to claim 2 is the hydrophobic silica according to claim 1, wherein the aminoalkylsilane compound is 2-aminoethyltriethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) _ It is characterized by being one or more of 3-aminopropyltrimethoxysilane.

The invention according to claim 3 is the hydrophobic silica according to claim 1, wherein the hydrophobizing agent is decanoic acid, dodecanoic acid, stearic acid, decanoic acid chloride, dodecanoic acid chloride, stearic acid salt Hardened beef tallow alkyl (carbon number 14-18) ketene dimer, stearyl ketene dimer, beninole ketene dimer, 1,6-hexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate, It is one or more of xylylene diisocyanate and tolylene diisocyanate.

The invention according to claim 4 is the hydrophobic silica according to any one of claims 1 to 3, wherein the hydrophilic silica is treated with an aminoalkylsilane compound and then the hydrophobizing agent in the presence of a fluorosurfactant. Hydrophilic silica treated with an aminoalkylsilane compound is hydrophobized by the above.

The invention's effect

[0009] The hydrophobic silica of the present invention can obtain a higher water repellency than the hydrophobic silica produced by the conventional method, and can improve the anti-aging property and water resistance * oil resistance of general paints. Improves dirt (shell) adhesion prevention performance on ship bottom paint, improves surface slipperiness of rubber and resin, improves wear resistance and mechanical strength, improves fluidity of toner in electrostatic copier, It is possible to greatly contribute to improving the defoaming performance of the foaming agent and the blocking performance of the paper.

BEST MODE FOR CARRYING OUT THE INVENTION

[0010] In the present invention, hydrophilic silica and an aminoalkylsilane compound are reacted to introduce a hydrophobic group having a reactive amino group on the surface of the hydrophilic silica, and then the amino group and It is a hydrophobic silica having a high hydrophobicity obtained by reacting with one or more hydrophobizing agents selected from certain carboxylic acid compounds, alkyl ketene dimers or alkenyl ketene dimers, and diisocyanate compounds.

The hydrophilic silica used in the present invention is not particularly limited, and may be any of wet precipitation silica, wet gel silica, dry silica (including fumed silica produced by flame pyrolysis of chlorosilane), etc. These silicas may be used alone or in combination.

[0011] The aminoaminosilane compound used in the present invention is an aminoaminosilane compound represented by the general formula (1). In general formula (1),

R ² is an alkylene group having 1 to 4 carbon atoms such as methylene group, ethylene group, propylene group, isopropylene group, butylene. A len group and an isobutylene group. R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, such as a hydrogen atom, a methyl group, an ethyl group, or a propyl group. Group, isopropyl group, methoxy group, ethoxy group, propoxy group, isopropoxy group. n is an integer of 0-5. Specific aminoalkylsilane compounds include 2_aminoethyltrimethoxysilane, 2_aminoethyltriethoxysilane, 2-aminoethylethylethyloxysilane, 3-aminopropyltriethoxysilane, N- (2- Aminoethyl) 1-2-aminoethyltriethoxysilane, N- (2-aminoethyl) 1-2-aminoethylethylethyloxysilane, N- (2-aminoethyl) _3-aminopropylmethyldimethoxysilane, N— (2-aminoethyl) 1-3-aminopropyltrimethoxysilane, N— (2-aminoethyl) 1-3-aminopropyltriethoxysilane, N— (2-aminoethyl) 1-3-aminominopropyl Ethyl ethoxysilane, preferably 2_aminoethyltriethoxysilane, 3-aminopropyltriethoxysilane, N— (2-aminoethyl ) Is one 3- Aminopuro pills trimethoxysilane. These can be used alone or in combination of two or more.

The reaction between the hydrophilic silica and the aminoalkylsilane compound is not particularly limited and is performed according to a normal hydrophobizing reaction. The amount of aminoalkylsilane compound used can be calculated according to the following formula.

a = (b X c) / d

a: Weight of aminoalkylsilane compound (g)

b: Weight of hydrophilic silica (g)

c: Specific surface area of silica (m ² / g)

d: Minimum covering area of aminoalkylsilane compound (m ² / g)

Here, the minimum coverage is calculated from the Stuart-Briegleb molecular model.

The amount of aminoalkylsilane compound used is appropriately selected depending on the intended use of hydrophobic silica and the degree of hydrophobicity required, and is usually 2 to 20 wt% with respect to hydrophilic silica.

, Preferably 4 to 10 wt%. The amount of aminoalkylsilane compound used is 2wt of silica.

If it is less than or equal to%, the hydrophobization rate of the hydrophilic silica may be low, and the degree of hydrophobization of the produced hydrophobic silica may not be sufficiently high, which may be undesirable. Aminoa If the amount of the alkylsilan compound used is 20 wt% or more of the hydrophilic silica, the cost of the aminoalkylsilane compound used is high and uneconomical, and the produced hydrophobic silica tends to aggregate, resulting in dry dispersion. It may be difficult to do so and may not be preferable.

[0013] The aminoalkylsilane compound is used as it is, a method of using an aminoalkylsilane compound as it is, a method of preparing and using a dilute aqueous solution having a concentration of 0.5 to 2 wt%, and a solution in a water-soluble organic solvent. And a method of dissolving and using in a water-insoluble organic solvent, and any method may be used.

The method of adding the aminoalkylsilane compound to the hydrophilic silica is not particularly limited. Usually, the mixer is mixed with the hydrophilic silica in a blender, and the aminoalkylsilane compound is directly added while stirring. Alternatively, there is a method of spray-coating an aqueous solution of an aminoalkylsilane compound or a diluted organic solvent, and any of them may be used.

[0014] The reaction time between the hydrophilic silica and the aminoalkylsilane compound is appropriately selected depending on the intended use of the hydrophobic silica force and the required level of hydrophobicity, and cannot be determined uniformly, but is usually preferably 5 to 100 minutes. The reaction proceeds almost completely in 20 to 60 minutes, and the aminoalkylsilane compound reacts with the OH group on the hydrophilic silica surface with the reactive amino group facing outward and binds.

[0015] The carboxylic acid compound used in the hydrophobizing agent of the present invention is a carboxylic acid or a carboxylic acid halide represented by the general formula (2). R ^{6 in the} general formula (2) is a linear or branched alkyl group having 2 to 21 carbon atoms or a linear or branched alkenyl group having 2 to 21 carbon atoms, and X is a hydroxyl group or a chlorine atom. A bromine atom. Specific examples of the carboxylic acid include propionic acid, butanoic acid, hexanoic acid, decanoic acid, dodecanoic acid, myristic acid, isomyristic acid, palmitic acid, isopalmitic acid, stearic acid, isostearic acid, oleic acid, 1 2-hydroxystearic acid, behenylic acid and the like. Examples of the carboxylic acid halide having 3 to 22 carbon atoms include acid chlorides and acid bromides of the above carboxylic acids. Specifically, propionate chloride, propionate bromide, butanoic acid chloride, and hexanoic acid. Chloride, decanoic acid chloride, dodecanoic acid chloride, myristic acid chloride, isomyristic acid chloride, palmitic acid chloride, isopalmitic acid chloride, stearic acid salt, stearic acid bromide Products, isostearic acid chloride, isostearic acid bromide, oleic acid chloride, 12-hydroxystearic acid chloride, behenyl acid chloride and the like. These can be used alone or in combination of two or more.

[0016] The alkyl ketene dimer used in the hydrophobizing agent of the present invention is an alkyl ketene dimer represented by the general formula (3). In the general formula (3), R ⁷ and R ⁸ are each a straight chain or branched chain alkyl group, alkenyl group, or alkylphenyl group having carbon numbers:! -20. For example, propylene group, butyl group, octyl group, 2_ethylhexyl group, decyl group, dodecyl group, cocoalkyl (10 to 12 carbon atoms) group, tetradodecyl group, stearyl group, isostearyl group, cured beef tallow alkyl (carbon Number 14-18) group, beef tallow alkyl (carbon number 14-18) group, oleyl group, behenyl group, ethylphenyl group, isopropylphenyl group, butylphenyl group, octylphenyl, noylphenyl, decylphenyl group, dodecylpheny group There are ru groups. Specific alkyl ketene dimers include propylene ketene dimer, butylene ketene dimer, octyl ketene dimer, 2-ethyl hexyl ketene dimer, decyl ketene dimer, dodecyl ketene dimer, coco alkyl (10 to 12 carbon atoms) ketene dimer, Tetradecyl ketene dimer, hexadecyl ketene dimer, stearyl ketene dimer, isostearino ketene dimer, vinyl ketene dimer, cured beef tallow alkyl (carbon number 14-18) ketene dimer, tallow alkyl (carbon number 14-18) ) Ketene dimer, oleyl ketene dimer, butyl phenyl ketene dimer, octyl phenyl ketene dimer, nonyl phenyl ketene dimer, dodecyl phenyl ketene dimer, and as a sizing agent in the paper industry. Alkyl (8-18 carbon atoms) ketene dimer (AKD). These can be used alone or in combination of two or more. An alkyl ketene dimer having less than 10 carbon atoms may not be sufficiently hydrophobized, and an alkyl ketene dimer having more than 48 carbon atoms may be difficult to obtain industrially.

[0017] The diisocyanate compound used in the hydrophobizing agent of the present invention is a diisocyanate compound represented by the general formula (4). In the general formula (4), R ⁹ is an alkylene group having 6 to 24 carbon atoms or an alkylphenylene group having 6 to 24 carbon atoms. Specifically, 1,6-hexamethylene diisocyanate, 2, 2, 4_trimethyltetramethylene of alkylene disiocyanates. Diisocyanate, 2, 4, 4-trimethyltetramethylene diisocyanate, methylenebis mono (4,1-cyclohexylene) diisocyanate, isophorone diisocyanate, norbornole

—Mixture of xylylene diisocyanate), 4,4′-diphenylmethane diisocyanate, alkyl diylene diisocyanate, tolylene diisocyanate (toluene-1,4-diisocyanate, toluene 1 2 , 6-diisocyanate mixtures). These can be used alone or in combination of two or more. Diisocyanate compounds may not be sufficiently hydrophobized when the number of carbon atoms is less than 6, and those with more than 24 carbon atoms may be difficult to obtain industrially.

Of these, decanoic acid, dodecanoic acid, stearic acid, decanoic acid chloride, dodecanoic acid chloride, stearic acid chloride, and cured beef tallow alkyl (carbon number 14 to 18) ketene are preferred as hydrophobizing agents. Dimer, stearinoreketene dimer, beheninoreketene dimer, 1,6_hexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, tolylene diisocyanate And stearic acid chloride, stearyl ketene dimer, and tolylene diisocyanate are more preferable. These can be used alone or in combination of two or more.

[0019] Further, dimethylpolysiloxane, a dimethylpolysiloxane having a terminal reactive hydroxyl group, hydrogenmethylpolysiloxane, trimethylchlorosilane which has been conventionally used as long as it does not interfere with the effects of the present invention. A silane coupling agent such as

[0020] When the hydrophilic silica is hydrophobized, the mixing ratio of the hydrophilic silica treated with the hydrophobizing agent and the aminoalkylsilane compound is determined based on the carboxylic acid compound, alkyl ketene dimer, diisocyanate compound that is the hydrophobizing agent. The ratio of the total number of moles of reactive functional groups to the number of moles of reactive amino groups in the aminoalkyl silane compound is 1 ::! To 2: 1, preferably 1.1: 1 to 1: 1.5: 1 It is. The number of moles of reactive functional groups per mole of carboxylic acid compound, alkyl ketene dimer, and diisocyanate compound is 1 mole for carboxylic acid compounds, 1 mole for alkyl ketene dimers, and diisocyanate. For compounds, it is 2 moles. Molar ratio power of reactive amino groups in aminoalkylsilane compounds Range of the ratio If it is smaller than 1, sufficient hydrophobicity cannot be obtained due to the amino group remaining in the reaction. In addition, even if the total number of moles of the hydrophobizing agent exceeds the range of the ratio, there is no economic merit that the hydrophobicity cannot be improved enough to meet the increase.

[0021] The method of using the hydrophobizing agent includes the method of using the hydrophobizing agent as it is, the method of using the hydrophobizing agent as a solution by dissolving it in an organic solvent or water-soluble organic solvent having a concentration of! Any method may be used. Examples of organic solvents or water-soluble organic solvents include toluene, xylene, methyl ethyl ketone, and butyl cellosolve.

The method for adding the hydrophobizing agent is not particularly limited. Usually, a method is used in which a hydrophilic silica treated with an aminoalkylsilane compound is placed in a mixer or a blender, and the hydrophobizing agent is directly added while stirring, or There is a method of spraying a solvent dilution of a hydrophobizing agent, and any method may be used.

The reaction time between the hydrophobizing agent and the hydrophilic silica treated with the aminoalkylsilane compound is appropriately selected depending on the intended use of the hydrophobic silica and the degree of hydrophobicity, but cannot be determined uniformly. ~: 120 minutes, preferably 30 to 90 minutes.

[0022] In the production of the hydrophobized silica of the present invention, there is a case where the hydrophobic silica fine particles are stored for a long time from the production to use, during which the aggregation of the hydrophobic silica powder occurs. There is a case. To prevent this, hydrophobic silica with excellent dispersibility can be obtained by adding a fluorosurfactant during the hydrophobization reaction between the hydrophobizing agent and hydrophilic silica treated with an aminoalkylsilane compound. . As the fluorine-based surfactant to be added, there are fluorine-based compounds represented by the general formulas (5) to (7). In the general formula (5), R ^1Q is a perfluoroalkyl group having 5 to 22 carbon atoms, X is COM, SO M group, M is Na, K, L

Three

i. In general formula (6), R ¹¹ is a perfluoroalkyl group having 5 to 22 carbon atoms, Y is H (hydrogen atom), -OPO (OH) (phosphoric acid residue), p is an integer of:! To 15 It is. In general formula (7)

2

R ¹² is a perfluoroalkyl group having 5 to 22 carbon atoms, Z is a chlorine atom, bromine atom, iodine atom, sulfuric acid residue, phosphoric acid residue, or a carboxylic acid residue having 1 to 6 carbon atoms. . When the number of carbon atoms is 4 or less, the surface tension of the fluorine compound is low and it volatilizes, making it difficult to handle immediately. In addition, when the number of carbon atoms exceeds 22, it becomes difficult to obtain industrially.

[0023] [Chemical 9] R ¹⁰ — X (5)

[0024] [Chemical 10]

R "-S0 ₂ N (C ₂ H ₅ ) (C _z H ₄ 0) _p Y (6)

[0025] [Chemical 11]

[R ¹² -S0 ₂ N HC ₃ H ₆ N ⁺ CCH ₃ ) ₃ ] Z- (7)

The addition amount of the fluorosurfactant represented by the general formulas (5) to (7) may be appropriately determined according to the degree of requirement for preventing aggregation of the hydrophobic silica powder. It is 0.01-2 wt% with respect to hydrophilic silica, Preferably it is 0.05-: 1.5 wt%. 0. If less than Olwt%, the aggregation preventing effect may not be sufficiently obtained. On the other hand, the effect of the present invention can be obtained even when the addition amount of the fluorosurfactant exceeds 2 wt%, but the improvement degree of the effect obtained for the addition amount may be small, which is not preferable.

[0026] Further, in order to improve the dispersibility of the hydrophobic silica within a range not impeding the effect of the present invention, a polyalkylene glycol-based nonionic surfactant and naphthalene sulfonate-based surfactant that have been used conventionally are used. Further, a high molecular weight anionic surfactant such as lignin sulfonate or maleic acid copolymer may be used in combination with silicone oil. Examples of silicone oils generally include non-reactive silicone oils having a linear siloxane structure, methylphenyl silicone oils, alkyl-modified silicone oils, polyether-modified silicones, and fatty acid ester-modified silicone oils. Its kinematic viscosity is usually 1 to 100,000 mm ² / s. The loading amount of the surfactant and the silicone oil is usually 0.5 to 5 wt% with respect to the hydrophilic silica treated with the aminoalkylsilane compound.

Example EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Aminoalkylsilane compounds)

A-1: N- (2-Aminoethyl) _3-aminominovir trimethoxysilane [Toray Silicone SH6020 (trade name), manufactured by Toray Dow Co. Silicone Co., Ltd.]

A-2: 3-Aminopropyltriethoxysilane [Toray Silicone SS1040 (trade name), manufactured by Toray Dow Co., Ltd. Silicone Co., Ltd.]

A- 3-. 2-Aminoethyltriethoxysilane (Reagent, Tokyo Chemical Industry Co., Ltd.)

(Hydrophilic silica)

8: Hydrophilic silica ["2 £ 031 200" (trade name), manufactured by J. M. Huber Co., Ltd.]

(Hydrophobicizing agent)

C: Lauric acid (manufactured by Kao Corporation)

D: Stearic acid [Asahi Denka Kogyo Co., Ltd.]

E: Stearic acid emulsion (stearic acid: 20wt% concentration) [manufactured by Hakuto Co., Ltd.]

F: Alkyl ketene dimer (AKD) [manufactured by Suzhou Tianma Chemical Co., Ltd., China]

G: AKD emulsion (AKD20wt% concentration) [made by Hakuto Co., Ltd.]

H: Tolylene diisocyanate [Asahi Kasei Co., Ltd.]

1: 4, 4, Diphenylmethane diisocyanate (Asahi Kasei Co., Ltd.)

(Other)

J: Perfluorooctyl sulfonic acid fluoride C F SO F [China Wuhan Haitoku Chemical Co., Ltd.

8 17 2

Made)

K: Dimethylpolysiloxane ["SH200" (trade name), kinematic viscosity 1000mm ² Zs, manufactured by Toray Dowko Iyung Silicone Co., Ltd.]

L: methyl hydroxy polysiloxane [ "KF99" (trade name), kinematic viscosity of 20mm ² / s, Shin-Etsu Siri corn Co., Ltd.]

N: Silicone oil emulsion (dimethylpolysiloxane 10wt% concentration) (Hakuto Co., Ltd.) M: Sodium perfluorooctyl sulfonate C F SO Na

8 17 3

Made by Co., Ltd.) P: Silanolated dimethylpolysiloxane at both ends ["BY16-873" (trade name), manufactured by Toray Dow Cowing Silicone Co., Ltd.]

[0028] (Example 1)

To a 500 mL three-necked flask equipped with a stirrer, thermometer and condenser, add 100 mL of deionized water and N— (2-aminoethyl) -1-3-aminopropyltrimethoxysilane (A) lg. Slowly add 20 g of hydrophilic silica (B) and loosen it at room temperature for 30 minutes.

A hydration reaction was performed. After 30 minutes, filtration was performed to obtain an aminoalkylsilane-treated product of hydrophilic silica. Next, add 300 g of beaker, 0.8 g of lauric acid (C), 0.5 g of dimethyl silicone oil (K), and lOOmL of toluene, stir, mix, and add hydrophilic silica treated with aminoalkylsilane. The mixture was stirred and stirred for 2 hours, and then heated to 90 to 110 ° C. to remove toluene-water azeotropically to obtain hydrophobic silica 1.

[0029] (Example 2)

To a 500 mL three-necked flask equipped with a stirrer, thermometer and condenser, add 2.5 g of stearic acid (D), 0.5 g of dimethyl silicone oil (Κ), and lOOmL of toluene, and heat to 60 ° C with stirring. Dissolved. Next, hydrophilic silica treated with aminoalkylsilane prepared in the same manner as in Example 1 was added and azeotroped at 90 to 110 ° C. for 2 hours to obtain hydrophobic silica 2.

[0030] (Example 3)

In Example 2, 2.5 g of stearic acid (D) was replaced with 2.5 g of alkyl ketene dimer (F) and added, and hydrophobic silica 3 was obtained in the same manner as in Example 2.

[Example 4]

To a 500 mL three-necked flask equipped with a stirrer, thermometer, and condenser, add 100 mL of deionized water and 2 g of N— (2-aminoethyl) -1-3-aminopropyltrimethoxysilane (A). Silica (B) (20 g) was slowly added and treated with an aminoalkyl silane at room temperature for 30 minutes. After 30 minutes, 25 g of stearic acid emulsion (E), 10 g of silicone oil emulsion (L), and 5 OmL of deionized water were added to the flask, and the mixture was further stirred for 1 hour. Water was filtered off, and the resulting solid was dried at 110 ° C. to obtain hydrophobic silica 4.

[Example 5] In Example 4, 25 g of stearic acid emulsion (E) was replaced with 30 g of AKD emulsion (G), and hydrophobic silica 5 was obtained in the same manner as in Example 4.

[0033] (Example 6)

In Example 4, 2 g of N— (2-aminoethyl) 1-3-aminopropyltrimethoxysilane (A) (0.4 g) (hydrophilic silica: 2 wt%), 5 g of stearic acid emulsion (E) 5 g, Hydrophobic silica 6 was obtained in the same manner as in Example 4 by adding 10 g of silicone oil emulsion (N) in place of 20 g.

[Example 7]

In Example 4, 2 g of N— (2-aminoethyl) 1-3-aminopropyltrimethoxysilane (A) (4 g) (hydrophilic silica: 20 wt%), 50 g of 25 g of stearic acid emulsion (E), silicone 10 g of oil emulsion (N) was added in place of 5 g, and hydrophobic silica 7 was obtained in the same manner as in Example 4.

[Example 8]

To a 500 mL three-necked flask equipped with a stirrer, thermometer and condenser, add 100 mL of deionized water and 2 g of N— (2 aminoethyl) 3 aminopropyltrimethoxysilane (A). B) 20 g was slowly added and stirred at room temperature for 30 minutes. Thereafter, the reaction product was filtered to obtain an aminosilane-treated product of hydrophilic silica. Next, to a 300 mL beaker, add 53 g of tolylene diisocyanate (H), 0.2 g of sodium perfluorooctyl sulfonate (Μ), lOOmL of toluene, mix with stirring, and treat with aminoalkylsilane. Hydrophilic silica was added and reacted at 50 ° C for 2 hours. Next

90 to: Heated at 110 ° C. for 2 hours, and water and toluene were distilled off azeotropically to obtain hydrophobic silica 8. The obtained hydrophobic silica 8 was put in a glass container and allowed to stand indoors at room temperature for 1 month. One month later, the glass container containing the hydrophobic silica 8 was shaken, and the aggregation state of the hydrophobic silica 8 was examined.

[Example 9]

Hydrophobic silica 9 was hydrophobized in the same manner as in Example 8 without adding sodium perfluorooctyl sulfonate (M) 0.2 in Example 8, to obtain hydrophobic silica 9 . The obtained hydrophobic silica 9 was placed in a glass container and allowed to stand indoors at room temperature for 1 month. 1 month Later, the glass container containing the hydrophobic silica 9 was shaken, and the aggregation state of the hydrophobic silica 9 was examined. As a result, several easily disintegrating lumps were observed.

[0037] (Example 10)

In Example 8, 2.25 g of diisocyanate 4,4-diphenylmethane (1) was added instead of tolylene diisocyanate (H) to obtain hydrophobic silica 10.

[0038] (Example 11)

In Example 1, N— (2-aminoethyl) 1-3-aminopropyltrimethoxysilane (A

— L) Replacing lg with 3-aminopropyltriethoxysilane (A-2) lg and adding, and the hydrophobic silica 11 was obtained in the same manner as in Example 1.

[Example 12]

In Example 1, N— (2-aminoethyl) 1-3-aminopropyltrimethoxysilane (A

— L) Replacing lg with 2-aminoethyltriethoxysilane (A-3) 0.93 g, and adding the mixture, hydrophobic silica 12 was obtained in the same manner as in Example 1.

[0040] (Comparative Example 1)

A 500 mL three-necked flask equipped with a stirrer, thermometer and condenser is charged with 20 g of hydrophilic silica (B) and 2 g of dimethylpolysiloxane (K) and heated to 150 ° C for 1 hour under a nitrogen atmosphere. Thereafter, the mixture was cooled to obtain hydrophobic silica 13.

[0041] (Comparative Example 2)

In Comparative Example 1, instead of dimethylpolysiloxane (K) 1 .2 g, methylhydroxypolysiloxane (L) 1 .2 g was used and heated to 150 ° C. for 1 hour in a nitrogen atmosphere, and then cooled. Hydrophobic silica 14 was obtained.

[0042] (Comparative Example 3)

In Comparative Example 1, instead of dimethylpolysiloxane (K) 1 .2 g, silanolated dimethylpolysiloxane (P) 1 .2 g at both ends was heated to 150 ° C. for 1 hour in a nitrogen atmosphere, and then cooled. Thus, hydrophobic silica 15 was obtained.

[0043] (Comparative Example 4)

In Comparative Example 1, instead of dimethylpolysiloxane (K) 1 .2 g, silanolated both ends dimethylpolysiloxane (P) 1 .2 g and triethylenetetramine 0. The mixture was heated to 150 ° C. for 1 hour under air, and then cooled to obtain hydrophobic silica 16.

[0044] (Comparative Example 5)

In a 500 mL three-necked flask equipped with a stirrer, thermometer and condenser, hydrophilic silicic acid (B) 20 g, tolylene diisocyanate (H) 53 g, sodium perfluorooctyl sulfonate (M) 0. Add 2 g of toluene l OOmL and mix with stirring at 50 ° C.

The reaction was performed for 2 hours. Subsequently, the mixture was heated at 90 to 110 ° C. for 2 hours to distill off water and toluene by azeotropic distillation, and then cooled to obtain hydrophobic silica 17.

[0045] (Hydrophobicity evaluation test)

The hydrophobicity of hydrophobic silica was measured using the transmittance method described in JP-A-5-97423. Hydrophobic silica (lg) and water (lOOg) were placed in a 200mL separatory funnel, stirred for 5 minutes, and allowed to stand for 1 minute. 10 mL of suspended water was taken from the lower aqueous phase of the separatory funnel, and the transmittance at a wavelength of 550 nm was measured with an absorptiometer. The degree of hydrophobicity was determined by the following formula based on pure transmittance (100), and this value was used as the hydrophobicity of hydrophobic silica. The higher the degree of hydrophobicity, the higher the hydrophobicity.

(Hydrophobicity) (%) = (a / i3) X 100

a: Permeability (%) of aqueous phase in hydrophobic silica

β: Water permeability (%)

The results are shown in Table 1.

[0046] [Table 1]

Example No. Hydrophobicity (%)

1 9 6

2 9 4

3 9 5

4 9 7

5 9 6

6 9 0

Example

7 9 8

8 9 4

9 9 3

1 0 9 1

1 1 9 0

1 2 9 1

1 6 8

2 7 3

Comparative Example 3 3 1

4 5 8

5 4 6

It can be seen that the hydrophobic silica of the present invention exhibits superior hydrophobicity as compared with conventional hydrophobic silica. It can also be seen that using a fluorosurfactant at the time of hydrophobization is effective in preventing aggregation of hydrophobic silica.

Claims

Claims Hydrophilic silica is represented by the general formula (1) (wherein R1 is an alkylene group having 1 to 4 carbon atoms, R2 is an alkylene group having 1 to 4 carbon atoms, R3, R4 and R5 are each independently a hydrogen atom, Treatment with an aminoalkylsilane compound represented by general formula (2) (formula (2) (formula 2) R6 is a linear or branched alkyl group having 2 to 21 carbon atoms, a linear or branched alkenyl group having 2 to 21 carbon atoms, and X is a hydroxyl group, a chlorine atom, or a bromine atom. Carboxylic acid compound represented by the general formula (3) (wherein R7 and R7 are both linear or branched alkyl groups having 1 to 20 carbon atoms, linear or branched alkenyl groups having! An alkyl ketene dimer represented by the general formula (4) (wherein R9 is carbon). An alkylphenylene group having 6 to 24 carbon atoms and an alkylphenylene group having 6 to 24 carbon atoms.) Obtained by reacting with a hydrophobizing agent containing at least one selected from diisocyanate compounds represented by the following formula: Hydrophobic silica characterized by

[Chemical 1]

H ₂ N- (R ¹ -ΝΗ) _Π -R ² -S i-(R ³ ) (R ⁴ ) (R ⁵ ) (1)

[Chemical 2]

R ⁶ — COX (2)

[Chemical 3]

R — H ⁼ then H— r \

(3)

O— CO

[Chemical 4]

OCN— R ⁹ — NCO (4) [2] The hydrophobic group according to claim 1, wherein the aminoalkylsilane compound is at least one of 2-aminoethyltriethoxysilane, 3-aminopropynoletriethoxysilane, and N- (2aminoethyl) 3-aminopropyltrimethoxysilane. silica.

[3] Hydrophobizing agents are decanoic acid, dodecanoic acid, stearic acid, decanoic acid chloride, dodecanoic acid chloride, stearic acid salt, hardened tallow alkyl (carbon number 14-18) ketene dimer, stearyl ketene One or more of dimer, benzylketene dimer, 1,6-hexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, tolylene diisocyanate The hydrophobic shear force according to claim 1.

[4] The hydrophilic silica treated with an aminoalkylsilane compound is hydrophobized with a hydrophobizing agent in the presence of a fluorosurfactant after the hydrophilic silica is treated with the aminoaminosilane compound. 4. The hydrophobic silica according to any one of items 1 to 3.