KR102052226B1 - Silica sol dispersed in organic solvent, and method of manufacturing said silica sol dispersed in organic solvent - Google Patents

Abstract

Silica particle, the acidic phosphate ester represented by following formula (1), and an organic solvent are contained, and it is set as the organic-solvent dispersion silica sol whose dispersion particle diameter measured by the dynamic light scattering method of the said silica particle is 10-250 nm.
P = O ((OCH ₂ CH ₂ ) _n OR) _a (OH) _b (1)
(In formula, R represents a C1-C18 hydrocarbon group, n is an integer of 0-3, a is an integer of 1-2, b is 3-a)

Description

SILICA SOL DISPERSED IN ORGANIC SOLVENT, AND METHOD OF MANUFACTURING SAID SILICA SOL DISPERSED IN ORGANIC SOLVENT}

The present invention relates to an organic solvent dispersed silica sol in which silica particles are dispersed in an organic solvent and a method for producing an organic solvent dispersed silica sol.

An organic solvent dispersed silica sol in which colloidal silica particles of 1000 nm or less are dispersed in an organic solvent, for example, is added to a resin, a resin raw material, or a binder to be used for coating or nanocomposite, and to inhibit the transparency of the resin or the binder. It is widely used as a nanofiller which can improve the strength, hardness, heat resistance, insulation, and other characteristics, without using it. Such an organic solvent dispersion silica sol is manufactured by the method of replacing the dispersion medium (water) of the aqueous silica sol which makes water a dispersion medium, for example with an organic solvent. The manufacturing method by this solvent substitution takes time, and when replacing with the low boiling point organic solvent, it is necessary to use a large amount of organic solvent in order to dehydrate. Moreover, when substituting with a water-insoluble organic solvent, it is necessary to substitute via a water-soluble solvent dispersion sol, and it becomes a process which is troublesome.

Here, if the colloidal silica powder can be directly dispersed in an organic solvent, an organic solvent dispersed silica sol can be obtained simply. The general silica powder forms an aggregate, and it is necessary to perform some mechanical grinding. However, since the dispersion stability of the organic solvent dispersion silica sol obtained by such mechanical grinding | pulverization is bad in the organic solvent of a silica particle, when it is left to stand, there exists a problem that a silica particle will aggregate and a viscosity will rise. In addition, since the dispersion stability of the silica particles in the organic solvent before grinding is poor, in the step of grinding the raw material silica particles to a desired size at the time of manufacture, the silica particles agglomerate, the viscosity rises, and the grinding becomes difficult. . For example, silica particles obtained by a gas phase method of decomposing silicon chloride in a gas can be dispersed in a solvent under relatively mild conditions such as an ultrasonic disperser, but the viscosity tends to rise, and it is particularly difficult to disperse them at a high concentration. In addition, since silica particles obtained by the precipitation method of neutralizing and depositing water glass (sodium silicate) are easily precipitated in an organic solvent, pulverization using a media is preferable to disperse, but reaggregates during pulverization or after pulverization to provide a stable sol. It was difficult to obtain.

Moreover, the dispersion liquid which disperse | distributed the wet silica in polar solvent, The silica density in the dispersion liquid is 22 weight% or more, and the average particle diameter of a silica particle is less than 0.5 micrometer, and the pH of this dispersion liquid silica is the range of 3-5. A dispersion liquid is disclosed (refer patent document 1). However, since patent document 1 defines pH, it is a technique for the silica sol which uses water as a solvent instead of an organic solvent, and does not disperse a silica in an organic solvent.

Japanese Unexamined Patent Publication No. 2004-331479

An object of the present invention is to solve the problems of the prior art described above, and to provide an easy method for producing an organic solvent dispersed silica sol and an organic solvent dispersed silica sol having excellent dispersion stability.

The organic-solvent dispersion silica sol of this invention which solves the said subject contains a silica particle, the acidic phosphate ester represented by following formula (1), and an organic solvent, and the dispersion measured by the dynamic light scattering method of the said silica particle. It is characterized by the particle diameter of 10-250 nm.

P = O ((OCH ₂ CH ₂ ) _n OR) _a (OH) _b (1)

(In formula, R represents a C1-C18 hydrocarbon group, n is an integer of 0-3, a is an integer of 1-2, b is 3-a)

Moreover, at least 1 type of silicon organic group may couple | bond with the surface of the said silica particle.

Moreover, it is preferable that the said organic solvent is at least 1 sort (s) chosen from alcohol, a ketone, an ether, ester, and a hydrocarbon.

Another aspect of the present invention is a method for producing an organic solvent-dispersed silica sol comprising a step of grinding raw material silica particles in an organic solvent and a step of adding an acidic phosphate ester represented by the following formula (1).

P = O ((OCH ₂ CH ₂ ) _n OR) _a (OH) _b (1)

(In formula, R represents a C1-C18 hydrocarbon group, n is an integer of 0-3, a is an integer of 1-2, b is 3-a)

Moreover, you may have the process of adding an organosilicon compound.

And it is preferable that the process of adding the acidic phosphate ester represented by said Formula (1) is performed before the process of grind | pulverizing the said raw material silica particle in an organic solvent is complete | finished.

Moreover, you may perform the process of adding the acidic phosphate ester represented by said Formula (1) after the process of grind | pulverizing the said raw material silica particle in an organic solvent.

According to this invention, the organic-solvent dispersion | distribution silica sol which was excellent in dispersion stability and suppressed aggregation of a silica particle can be provided. Moreover, the aggregation of the silica particle at the time of grinding | pulverization and the aggregation of the silica particle at the time of leaving the organic-solvent dispersing silica sol can be suppressed.

The organic-solvent-dispersed silica sol of this invention is a silica particle dispersion liquid of the sol state which disperse | distributed silica particle to the organic solvent, contains a silica particle, the acidic phosphate ester represented by said formula (1), and an organic solvent, and this silica The dispersed particle diameter measured by the dynamic light scattering method of particle | grains is characterized by being 10-250 nm.

There is no restriction | limiting in particular in the silica particle which an organic-solvent dispersion silica sol contains, The silica particle itself obtained by the wet method or the dry method may be sufficient, Moreover, this raw material silica particle is further made using the silica particle obtained by these wet method or the dry method as a raw material. It may be crushed. As a wet method, the precipitation method which neutralizes water glass (sodium silicate) with an acid etc. and precipitates a silica particle is mentioned. Moreover, as a dry method, the vapor-phase method of decomposing silicon chloride etc. in gas and obtaining a silica particle is mentioned. Commercially available products of silica particles obtained by the sedimentation method include SIPERNAT, CARPLEX manufactured by EVONIC, Tokusil manufactured by Tokuyama, Pine Yarn, Nip chamber manufactured by Toso Silica, Hi-Sil manufactured by PPG, and the like. Moreover, as a commercial item of the silica particle obtained by the vapor-phase method, Aerosil by EVONIC, Cab-O-Sil by Cabot, a rheosil by Tokuyama, etc. are mentioned. In addition, particles of a mixed oxide containing silica as a main component can also be used. Moreover, in order to improve affinity with an organic solvent, the organic particle | grains, such as a methyl group, an octyl group, a methacryl group, a phenyl group, an amino group, and the silicon organic group containing silicon are introduce | transduced, and the silica particle which has a lipophilic group is used, You may also

As for the particle diameter of the silica particle which the organic-solvent dispersion silica sol of this invention contains, the dispersed particle diameter (light intensity average diameter) by the dynamic light scattering method is 10-250 nm, for example.

Moreover, although the compounding ratio of a silica particle is not specifically limited, For example, it can be set as the organic-solvent dispersion silica sol whose solid content concentration (namely, silica particle concentration) is 5-50 mass%. Moreover, even if it is a high concentration organic-solvent dispersion silica sol whose solid content concentration is 5-50 mass%, it is excellent in dispersion stability in this invention.

In addition, acidic phosphate ester is phosphate monoester or phosphate diester. By adding the acidic phosphate ester represented by said formula (1), it becomes the organic-solvent dispersion silica sol excellent in dispersion stability. Since dispersion stability is excellent, aggregation of silica particles can be suppressed even if left to stand for a long time (for example, 1 month or longer) after production. Moreover, since aggregation of a silica particle is suppressed, this organic solvent dispersion | distribution silica sol becomes a filler and coating agents, such as a resin film with few aggregated particles and excellent transparency. Moreover, although mentioned later in detail, since the dispersion stability of a silica particle is excellent, since a rise of a viscosity is suppressed by suppressing the aggregation of the silica at the time of grinding | pulverization, a grinding | pulverization efficiency can be improved and an organic-solvent dispersion silica sol can be easily carried out. It can manufacture. Moreover, when phosphoric acid triester and phosphoric acid are used instead of the acidic phosphate ester represented by said Formula (1), as shown to the comparative example mentioned later, it is excellent in dispersion stability, and the effect of this invention that aggregation of a silica particle is suppressed. Can not exert.

By adding the acidic phosphate ester represented by the above formula (1) in this way, the dispersion stability of the organic solvent dispersed silica sol becomes good, that is, the reason why the dispersion stability of the silica particles in the organic solvent becomes good is unclear. The acidic phosphate ester represented by the above formula (1) is adsorbed to cation sites of impurities such as polyvalent metals that can be contained in the sol and become nuclei of the aggregation of silica particles, thereby preventing the impurities from becoming nuclei of the aggregation. It is assumed to be. In addition, these impurities originate from the raw material of a silica particle, and are presumed to mix in grinding media, a container, etc. at the time of grinding | pulverization. In addition, this impurity is not removed from the organic solvent dispersion silica sol by the acidic phosphate ester represented by said Formula (1), but it is contained.

In said Formula (1), R may be a linear hydrocarbon group or a branched hydrocarbon group may be sufficient as it. The number of ethylene oxide chains (OCH ₂ CH ₂ ), namely n, is 0 to 3 as described above, more preferably 0 to 1, and most preferably no ethylene oxide chain. Further, when the ethylene oxide chain is long, that is, when n is 4 or more, the dispersion stability is poor.

Specific examples of the acidic phosphate ester represented by the formula (1) include monomethyl phosphate, monoethyl phosphate, monoisopropyl phosphate, monobutyl phosphate, monohexyl phosphate, monooctyl phosphate, mono 2 ethylhexyl phosphate, and monodecyl phosphate. Monoalkyl phosphates such as monododecyl phosphate, monophenyl phosphate and monobenzyl phosphate, dimethyl phosphate, diethyl phosphate, diisopropyl phosphate, dibutyl phosphate, dihexyl phosphate, dioctyl phosphate, and diethylhexyl phosphate And dialkyl phosphates such as didecyl phosphate, didodecyl phosphate, diphenyl phosphate and dibenzyl phosphate.

Although one type may be sufficient as the acidic phosphate ester represented by said formula (1), you may mix and use 2 or more types. In general, commercially available acidic phosphate esters are often a mixture of monoalkyl phosphate and dialkyl phosphate for production reasons. Commercially available acidic phosphate esters represented by the above formula (1) include Phoslex A-1 (Methyl acid phosphate), A-2 (Ethyl acid phosphate), A-3 (Isopropyl acid phosphate) manufactured by SC Organic Chemical Co., Ltd. A-4 (Butyl acid phosphate), A-8 (2-Ethylhexyl acid phosphate), A-10 (Isodecyl acid phosphate), A-12 (Lauryl acid phosphate), A-13 (Tridecyl acid phosphate), A-18 (Stearyl acid phosphate), A-18D (Oleyl acid phosphate), A-180L (Isostearyl acid phosphate), A-208 (Di-2-ethylhexyl acid phosphate), alkyl phosphate esters manufactured by Toho Chemical SM-172 (alkyl group is C8 and branched), GF-339 (alkyl group is C6 to C10), GF-199 (alkyl group is C12), GF-185 (alkyl group is C13 and branched) And phosphanols such as panol ML-200 (alkyl group C12) and phosphanol ED-200 (alkyl group is C8, branched, and one ethylene oxide chain (OCH ₂ CH ₂ ) is attached).

Although the compounding ratio of the acidic phosphate ester represented by said Formula (1) is not specifically limited, For example, about 0.2-10 mass% is preferable with respect to the silica particle solid content which organic-solvent dispersion silica sol contains, More preferably, It is 0.5-5 mass%.

Moreover, the compounding ratio of the acidic phosphate ester represented by said Formula (1) can also be managed according to the pH of the liquid mixture which mixed and manufactured the water of the same mass as the organic-solvent dispersion silica sol. Specifically, when the organic solvent of the organic-solvent-dispersed silica sol is water-soluble, the above formula (1) in which the pH of the mixed solution prepared by mixing water of the same mass with the organic-solvent-dispersed silica sol is within the range of 3.0 to 6.5. It is preferable to mix | blend the acidic phosphate ester shown by). Moreover, when the organic solvent of an organic-solvent dispersion silica sol is water-insoluble, the said formula of the quantity whose pH of the mixed liquid manufactured by mixing the same mass of methanol and the same mass of water with the organic-solvent dispersion silica sol is in the range of 3.0-6.5. It is preferable to mix | blend the acidic phosphate ester shown by (1). Here, since the organic-solvent dispersion silica sol of this invention does not make water a dispersion medium, it does not contain water substantially. Specifically, even though the organic solvent-dispersed silica sol of the present invention contains water, the organic solvent dispersed silica sol is derived only from the water in the atmosphere to which the silica particles have adsorbed. For example, the moisture content is 5% by mass or less. Therefore, pH of the organic-solvent dispersion silica sol of this invention cannot be measured. Therefore, as described above, the pH of the mixed liquid prepared by mixing the same mass of water and the like is determined. In addition, the pH calculated | required by mixing the same mass water etc. with the organic solvent dispersion silica sol of this invention in this way is not naturally the pH of the organic solvent dispersion silica sol itself of this invention.

Examples of the organic solvent contained in the organic solvent-dispersed silica sol of the present invention include alcohols, ketones, ethers, esters and hydrocarbons. Alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 1-hexanol, 1-octanol, 2- Ethyl-1-hexanol, allyl alcohol, benzyl alcohol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2 -(Methoxyethoxy) ethanol, 1-methoxy 2-propanol, dipropylene glycol monomethyl ether, diacetone alcohol, ethyl carbitol, butyl carbitol and the like. Examples of the ketones include acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, methyl isobutyl ketone, 2-heptanone, 4-heptanone, diisobutyl ketone, cyclohexanone, and the like. Can be mentioned. Examples of the ether include diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, 1,4-dioxane, tetrahydrofuran, and 1,2-diethoxyethane. As ester, ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, hydroxyethyl methacrylate, hydroxyethyl acryl And γ-butyrolactone, methyl methacrylate, isobutyl acrylate, cyclohexyl acrylate, 2-ethoxyethyl acrylate, trifluoroethyl acrylate, and glycidyl methacrylate. As a hydrocarbon, halogenated hydrocarbons, such as n-hexane, cyclohexane, benzene, toluene, xylene, solvent naphtha, styrene, dichloromethane, and trichloroethylene, etc. are mentioned. Although one type may be sufficient as an organic solvent, you may use it in mixture of 2 or more type.

The organic-solvent dispersion silica sol of this invention may contain the organosilicon compound which reacts with a silica particle, in order to improve the affinity of a silica particle and an organic solvent. Examples of such compounds include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylpropoxysilane, phenyldimethylmethoxysilane, chloropropyldimethylmethoxysilane and phenyltrimethoxy Silane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimeth Methoxysilane, trifluoropropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxy Silane, 3-glycidoxypropylmethylditriethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxy Propyltrimethoxysilane, 3 -Methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N -2- (aminoethyl) -3-aminopropylmethyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyl Triethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, Alkoxysilanes, such as 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, and 3-isocyanate propyl triethoxysilane, hexamethyldisiloxane , 1,3-dibutyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, 1,3-divinyltetramethyldisil It may be an acid, such as hexamethyl disiloxane ethyl, 3-glycidoxypropyl pentamethyl disiloxane flow. When it contains such an organosilicon compound, what is necessary is just about 1-20 mass% with respect to solid content of the silica particle which an organic solvent dispersion silica sol contains, for example.

Moreover, the organic-solvent dispersion silica sol of this invention may contain various surfactant, alkoxysilanes, etc.

Such an organic solvent dispersion silica sol can be manufactured by the manufacturing method which has the process of grind | pulverizing raw material silica particle in an organic solvent, and the process of adding the acidic phosphate ester represented by said Formula (1), for example. Moreover, you may have the process of adding an organosilicon compound further.

Although the process of grind | pulverizing the said raw material silica particle in an organic solvent, and the process of adding the acidic phosphate ester represented by said Formula (1) may be performed in arbitrary order, More preferably, in the said manufacturing method, the said formula The process of adding the acidic phosphate ester represented by (1) can be manufactured by performing in the process of grind | pulverizing raw material silica particle in an organic solvent. Specifically, the raw material silica particles are pulverized in an organic solvent by using the silica particles obtained by a wet method or a dry method such as the precipitation method as raw material silica particles. And before the grinding | pulverization process is completed, the acidic phosphate ester represented by said Formula (1) is added.

The time for adding the acidic phosphate ester represented by the formula (1) is not particularly limited, and the acidic phosphate ester represented by the formula (1) and the raw material silica particles are simultaneously added to the organic solvent so as to be added before the grinding of the raw material silica particles. Or after adding in order, you may grind | pulverize raw material silica particle. In addition, the acidic phosphate ester represented by the formula (1) is added during the pulverization of the raw material silica particles, that is, the acidic phosphate ester represented by the formula (1) is added after the raw silica particles are pulverized to a certain degree to form a slurry. After that, the silica particles may be pulverized again. The viscosity which rose by grinding | pulverization can be reduced by adding the acidic phosphate ester represented by said Formula (1) in the middle of grinding | pulverization.

Here, when the raw silica particles are pulverized in an organic solvent without adding the acidic phosphate ester represented by the formula (1), impurities are mixed from the raw silica particles, the grinding media, the grinding vessel, or the like to become nuclei for aggregation, and usually grinding. Due to the collision energy, etc. generated, the silica particles agglomerate during the grinding, the viscosity is high, and the grinding is difficult to grind. In particular, this aggregation becomes remarkable when the silica particles are in high concentration. However, in the said manufacturing method, since the acidic phosphate ester represented by said formula (1) is added, aggregation of a silica particle is suppressed. Therefore, even if silica particle is high concentration, the increase of the viscosity during grinding | pulverization is suppressed, grinding | pulverization efficiency can be improved and it can be grind | pulverized easily.

Although the method of grinding | pulverizing a raw material silica particle is not specifically limited, For example, it can grind | pulverize with general grinders, such as a grinder using media, such as a bead mill, an ultrasonic dispersion, and a pressure homogenizer. In the case of grinding the raw silica particles obtained by wet methods such as the sedimentation method, it is preferable to use a grinder which grinds at high energy, such as a grinder using a media.

The pulverization may be a batch type in which a slurry is prepared by adding and mixing an organic solvent, an acidic phosphate ester represented by the formula (1) and raw material silica particles to a container, and then pulverizing with a pulverizer as described above. It may be a circulation type in which the organic solvent, the acidic phosphate ester represented by the formula (1), and the raw material silica particles are added to the pulverizer as described above and pulverized, and then slurryed.

Although the particle diameter and specific surface area of a raw material silica particle are not limited, For example, the specific surface area measured by nitrogen adsorption method or Sears titration method (Anal. Chem. Vol. 28, No. 12, 1956) is 30-500 m <2> / g Is preferably.

Thus, by pulverizing raw material silica particle in the organic solvent which added the acidic phosphate ester represented by said Formula (1) before or during grinding | pulverization, grinding | pulverization efficiency is high and an organic-solvent dispersion silica sol can be obtained easily. And since the obtained organic-solvent dispersion silica sol is excellent in dispersion stability, aggregation of a silica particle is suppressed even if it is left to stand for a long time.

Moreover, you may manufacture the organic-solvent dispersion silica sol of this invention by the manufacturing method which performs the process of adding the acidic phosphate ester represented by said Formula (1) after the process of grind | pulverizing raw material silica particle in an organic solvent. The steps for pulverizing the raw silica particles in an organic solvent are the same as above, but when the acidic phosphate ester represented by the formula (1) is not added before or during the pulverization, the silica particles tend to agglomerate. It is necessary to respond such as lowering the concentration. And after the process of grind | pulverizing raw material silica particle, the acidic phosphate ester represented by said Formula (1) is added. Even if it adds the acidic phosphate ester represented by said Formula (1) after grinding | pulverization, dispersion stability of the organic-solvent dispersion silica sol obtained becomes favorable, and even if it is left to stand for a long time after that, aggregation of a silica particle can be suppressed.

In addition, the addition time of other additives, such as an organosilicon compound, is not specifically limited, It can add before grinding | pulverization or during grinding | pulverization.

Example

Hereinafter, although it demonstrates further in detail based on an Example, this invention is not limited at all by this Example.

Example 1

41.1 g of silica powder a obtained by the sedimentation method shown in Table 1 as raw material silica particles in a poly container having a capacity of 500 ml and a diameter of 70 mm, 150 g of 2-propanol (hereinafter also referred to as IPA) as an organic solvent, and acidic phosphoric acid 0.60 g of acidic phosphate ester P3-1 shown in Table 2 as an ester and 180 g of soda-lime glass beads having a diameter of 1 to 1.5 mm were used as the grinding media, and after pulverizing at 130 rpm for 72 hours, the beads were separated by filtration. An IPA dispersed silica sol (organic solvent dispersed silica sol) was obtained. The physical property of the used silica powder is shown in Table 1, the acidic phosphate ester used is shown in Table 2, and the compounding ratio of a silica sol is shown in Table 3.

In addition, in Table 1, solid content was calculated | required by baking a silica powder for 30 minutes at 800 degreeC. In addition, the specific surface area was calculated | required by the Sears titration method described below. Specifically, first, 1.50 g of powder was collected in a 200 ml beaker as a solid content, about 100 ml of pure water was added to make a slurry, and then 30 g of NaCl was added and dissolved. Next, 1N-HCl was added to adjust the pH of the slurry to about 3, and then pure water was added until the slurry became 150 ml. The slurry was titrated with 0.1 N-NaOH at 25 ° C., and the volume V (ml) of the 0.1 N-NaOH solution required to raise the pH from 4.00 to 9.00 was measured, and the following Sears formula (2) The specific surface area was obtained by.

Specific surface area (m 2 / g) = 32 x V (ml)-25. (2)

And the average particle diameter of silica powder was made into the median diameter measured with the laser diffraction type particle size distribution analyzer SALD-7000 by Shimadzu Corporation. Pure water was used for the dispersion medium, and the refractive index of the particle | grains was calculated | required using 1.45-0.10i. In addition, the pH of the silica powder was measured about the slurry manufactured by adding 9.0 times pure water with respect to a silica powder on the mass basis.

Moreover, all the acidic phosphoric acid ester of Table 2 is a mixture of the monophosphoric acid phosphate and phosphate diester which are compounds represented by said Formula (1), and R and n in Formula (1) are as showing in Table 2. . In addition, in Table 2, 1st acid value titrates the aqueous solution obtained by melt | dissolving the acidic phosphate ester ("sample" in following formula) of Table 2 in water by 1 / 10N NaOH, and the 1st equivalent amount of titration It calculated from the point by the following formula | equation.

1st acid value = 0.1N-NaOH solution (ml) / sample (g) x 56.1 / 10

The obtained IPA dispersed silica sol was calcined at 800 ° C. for 30 minutes, and the solid content obtained was 19.6 mass%, the moisture by Karl Fischer titration method was 1.7 mass%, and the viscosity at 20 ° C. measured by the B-type viscometer was 14.0 mPa · s. And the dispersed particle diameter by the dynamic light scattering method were 212 nm. In addition, the dispersed particle diameter by dynamic light scattering method is the average particle diameter (Z-Average) measured by Zetasizer Nano by Malvern Instruments by diluting a silica sol 100 times by volume basis with the same solvent as a dispersion medium. Moreover, pH was 3.5 when the solution produced by adding water to the obtained IPA dispersion silica sol so that it may become IPA dispersion silica sol: water = 1: 1 by mass ratio was measured with the pH meter.

In addition, in order to confirm the storage stability of this IPA dispersion silica sol, the heating stimulation test which sealed the silica sol in the glass bottle and stopped still at 50 degreeC for 28 days was performed. As a result, sedimentation, viscosity increase, and the increase of the dispersed particle diameter were not confirmed in the IPA dispersion silica sol after stopping still for 28 days at 50 degreeC. Table 4 shows the viscosity and the dispersed particle diameter of the IPA dispersed silica sol after being stopped at 50 ° C. for 28 days.

EXAMPLES 2-9

The same operation as in Example 1 was carried out except that the kind and the blending ratio of the silica powder, the kind and the blending ratio of the acidic phosphate ester, and the kind and the blending ratio of the organic solvent were shown in Table 3. Was obtained, and the physical property measurement and the heating promotion test were done. In addition, about Examples 4-9, methyltrimethoxysilane was added in the compounding ratio shown in Table 3 before a grinding | pulverization process. In Examples and Comparative Examples to be described later, when methyl ethyl ketone (hereinafter also referred to as MEK) was used instead of IPA as an organic solvent, MEK dispersed silica sol, water of the same mass and methanol of the same mass were added. The pH of the solution was measured with a pH meter, and the results are shown in Table 4.

[Comparative Examples 1-2]

An organic solvent-dispersed silica was carried out in the same manner as in Example 1, except that the acid phosphate ester was not added and the type and blending ratio of the silica powder and the type and blending ratio of the organic solvent were shown in Table 3. The sol was obtained, the measurement of physical properties, and the heating promotion test were performed.

Example 10

100 ml of 0.2 mm diameter soda lime beads were charged to a bead mill (150 ml of Apex Mill 015 grinding chamber capacity manufactured by Kotobuki Kogyo Co., Ltd.) having a slurry tank, 508 g of methyl ethyl ketone was added thereto, and a grinder (beads 87 g of silica powder c was added for 2 minutes, circulating operation of wheat) at a circumferential speed of 6 m / s. Next, after adding 2.45 g of acidic phosphate ester P8-1, the silica powder c 87g is further added for 4 minutes, Then, 16.0g of methyl trimethoxysilanes are added, it raises to the circumferential speed of 8 m / s, and it is 180 minutes. It grind | pulverized and obtained the MEK dispersion silica sol (organic solvent dispersion silica sol). The physical property of the used silica powder is shown in Table 1, the acidic phosphate ester used is shown in Table 2, and the compounding ratio of a silica sol is shown in Table 3.

The obtained MEK dispersion silica sol was 24.2 mass% of solid content, 1.5 mass% of moisture, viscosity 5.1 mPa * s, pH 5.4, and dispersed particle diameter 123 nm. Moreover, after stopping this MEK dispersion silica sol still at 50 degreeC for 28 days, when it re-measured, the viscosity was 5.0 mPa * s and the dispersed particle diameter was 120 nm. In addition, the measurement of each value was performed by the method similar to Example 1.

Example 11

A slurry mill prepared with the same slurry tank as in Example 10 was charged with 100 ml of 0.2 mm soda lime beads, and a slurry prepared by mixing 332.7 g of silica powder b with 874.2 g of methyl ethyl ketone was added to this grinder (bead mill). It grind | pulverized at the circumferential speed of 8 m / s for 180 minutes, circulating, and obtained the MEK dispersion liquid. 1.00g of acidic dihydrogen phosphate dibutyl P4-1 was added to 200g of this MEK dispersion liquid, and the MEK dispersion silica sol (organic solvent dispersion silica sol) was obtained.

The obtained MEK dispersion silica sol was 22.5 mass% of solid content, 1.2 mass% of moisture, viscosity 18.6 mPa * s, pH 4.2, and dispersed particle diameter 140 nm. Moreover, even after stopping for 1 month at room temperature, this MEK dispersion | distribution sol did not change the viscosity and dispersed particle diameter. Table 4 shows the viscosity and the dispersed particle diameter after stopping for 1 month at room temperature. In addition, the measurement of each value was performed by the method similar to Example 1.

Example 12

100 ml of 0.2 mm soda-lime beads were filled in the bead mill in which the slurry tank similar to Example 10 was formed, 1353 g of methyl ethyl ketones were added to a grinder (bead mill), and it circulated operation at the circumferential speed of 6 m / s, 280 g of powder e were added over 5 minutes. Next, after adding 6.7g of acidic phosphate ester P8-2, 270g of silica powder e is further added over 30 minutes, Then, 40.0g of methyltrimethoxysilanes are added, and it raises to the circumferential speed 8m / s. It grind | pulverized for 360 minutes and obtained the MEK dispersion silica sol.

The obtained MEK dispersion silica sol was 27.2 mass% of solid content, 1.7 mass% of water, viscosity 6.7 mPa * s, pH 4.5, and dispersed particle diameter 118 nm. After stopping this MEK dispersion sol still for 28 days at 50 degreeC, as a result of reanalysis, the viscosity was 6.3 mPa * s and the dispersed particle diameter was 117 nm.

Example 13

100 ml of 0.2 mm soda-lime beads were charged to the bead mill in which the slurry tank similar to Example 10 was formed, 400 g of methyl ethyl ketones were added to the grinder (bead mill), and it circulated operation at the circumferential speed of 8 m / s, 96.0 g of powder e were added over 30 minutes. Next, after 2.4 g of acidic phosphate ester P8-2 is added, 50 g of silica powder e is further added over 10 minutes, and then 14.0 g of methyltrimethoxysilane is added, and 46.0 g of silica powder e is further added. After adding over 14 minutes, it grind | pulverized for 160 minutes, and obtained the MEK dispersion silica sol.

Obtained MEK dispersion silica sol was 30.5 mass% of solid content, 1.3 mass% of moisture, viscosity 11.9 mPa * s, pH 4.7, and dispersed particle diameter 123 nm. After stopping this MEK dispersion sol still for 28 days at 50 degreeC, as a result of reanalysis, the viscosity was 11.2 mPa * s and the dispersed particle diameter was 122 nm.

Example 14

The acidic phosphate ester P8 shown in Table 2 as 28.1 g of silica particles (Aerosil® 130 manufactured by EVONIC) obtained by a gas phase method as a raw material silica particle, 187 g of MEK as an organic solvent, and an acidic phosphate ester in the poly container used in Example 1 0.36 g of -2, 2.87 g of methyltrimethoxysilane and 180 g of soda-lime glass beads having a diameter of 1 to 1.5 mm were used as the grinding media, and after crushing at 130 rpm for 72 hours, the beads were separated by filtration and dispersed in MEK. Silica sol (organic solvent dispersed silica sol) was obtained.

The obtained MEK dispersion silica sol was 16.4 mass% of solid content, 0.02 mass% of water, viscosity 8.5 mPa * s, pH 3.2, and dispersed particle diameter 160 nm. After stopping this MEK dispersion silica sol still for 28 days at 50 degreeC, as a result of reanalysis, the viscosity was 7.5 mPa * s and the dispersed particle diameter was 163 nm.

Comparative Example 3

When the pulverized MEK dispersion obtained in Example 11 was quenched at room temperature without addition of acidic phosphate ester, the viscosity increased to 2760 mPa · s after two weeks.

[Comparative Example 4]

Tributyl phosphate 1.0g was added to 200 g of the MEK dispersion liquid after grinding | pulverization obtained in Example 11. The pH of the solution obtained by adding the same mass of water and the same mass of methanol to the obtained tributyl phosphate-containing MEK dispersion was 7.4. Moreover, when the obtained tributyl phosphate addition MEK dispersion liquid was stopped still at room temperature, the viscosity increased to 2180 mPa * s after two weeks.

[Comparative Example 5]

As a result of adding 0.6 g of 85% phosphoric acid to 200 g of the pulverized MEK dispersion liquid obtained in Example 11, the viscosity increased immediately after addition to form a paste. In addition, pH of the solution obtained by adding the same mass of water and the same mass of methanol to the obtained phosphoric acid addition MEK dispersion liquid was 4.0.

Comparative Example 6

Into the poly container used in Example 1, 44.0 g of silica powder e, 145.3 g of IPA as an organic solvent, 0.7 g of a 10.0% hydrochloric acid aqueous solution and 180 g of soda-lime glass beads having a diameter of 1 to 1.5 mm as grinding media were placed, After pulverizing at 130 rpm for 72 hours, the beads were separated by filtration to obtain an IPA dispersed silica sol (organic solvent dispersed silica sol).

Obtained IPA dispersion silica sol was 21.2 mass% of solid content, 2.1 mass% of moisture, viscosity 38 mPa * s, pH 3.2, and dispersed particle diameter 220 nm. When this IPA dispersion sol was stopped still at 50 degreeC, a part of silica particle settled in the lower part of a container after 7 days, and it became unable to redistribute even if shaken. Moreover, after stopping still for 28 days, when a top part was collect | recovered and reanalyzed, the viscosity was 51 mPa * s and the dispersed particle diameter was 235 nm.

Comparative Example 7

A bead mill with the same slurry tank as in Example 10 was filled with 100 ml of soda lime beads having a diameter of 0.2 mm, 526.2 g of methyl ethyl ketone was added to a grinder (bead mill), and circulated at 8 m / s at a circumferential speed. 78.0 g of silica powder e was added over 16 minutes. Next, after 7.4 g of acidic phosphate ester P13-3 was added, additionally 70 g of silica powder e was added over 8 minutes. As a result, the viscosity of the slurry was significantly increased and the slurry could not be circulated. , Grinding was stopped. Solid content of the slurry at this time was 20.2 mass%, pH of the solution which added this slurry, the same mass of water, and the same mass of methanol was 3.5.

As a result, all of Examples 1-14 which added the acidic phosphate ester represented by said Formula (1) were excellent in dispersion stability, and sedimentation, a viscosity increase, and the rise of a dispersed particle diameter were not confirmed even after 28 days left. On the other hand, in Comparative Examples 1-3 which did not add the acidic phosphate ester represented by said Formula (1), Comparative Example 4 which added the triphosphate ester, Comparative Example 5 which added the phosphoric acid, and Comparative Example 6 which added hydrochloric acid, it is left to stand. The viscosity increased remarkably compared with the Example whether the silica particle was agglomerated, and the dispersion stability was poor.

Moreover, in Examples 1-10 and Examples 12-14 which grind | pulverized raw material silica particle in the organic solvent to which the acidic phosphate ester represented by said Formula (1) was added, the viscosity in grinding | pulverization rises compared with Comparative Examples 1-7. This was suppressed and it was easy to grind. Moreover, in the comparative example 7 which used the acidic phosphate ester with a long ethylene oxide chain, the stabilization effect of the slurry during grinding | pulverization is lacking, and manufacture of a sol was impossible.

Example 15

MEK dispersion silica sol (organic solvent dispersion silica sol) obtained in Example 12 was converted into silica solid content based on 100 parts by mass of pentaerythritol triacrylate (KAYARAD PET3A manufactured by Nippon Kayaku Co., Ltd.) which is a UV (ultraviolet) curable resin. 0 mass part, 25 mass parts, or 50 mass parts was mixed, and 5 mass parts of polymerization initiators (irgacure 184) were further mixed. The obtained mixture was applied to a PET (polyethylene terephthalate) film (A4100 manufactured by Toyobo Cosmoshine, 125 µm) with a wire bar # 9 (WET film thickness of 20.6 µm). This was dried for 10 minutes on a 50 degreeC hotplate, and it hardened by irradiating UV. The total light transmittance and haze of the obtained film were measured by TOKYO DENSHOKU, SPECTRAL HAZE METER, and TC-H3DPK-MKII. Moreover, the pencil hardness of the obtained film was measured. Moreover, the total light transmittance and the haze were measured also by the said method about the used PET film. The results are shown in Table 5.

Example 16

As UV curable resin, it carried out similarly to Example 15 except having used the solution which melt | dissolved 100 mass parts of UA-306H (made by Kyoeisha Chemical Co., Ltd., pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer) in 43 mass parts of MEK. The operation was performed.

As shown in Table 5, since the organic-solvent dispersion silica sol of this invention was excellent in dispersibility, Example 15 and 16 also had high transparency. Moreover, it had sufficient hardness as hard-coat agents, such as a film. In addition, when the organic-solvent dispersion silica sol of Comparative Examples 1-5 which does not add the acidic phosphate ester is used instead of Example 12, since the silica particle aggregates and the viscosity is high, the organic-solvent dispersion silica sol of Comparative Examples 1-5 is high. The thing which has high transparency like Examples 15-16 is not obtained.

Claims (8)

It contains the silica particle, the acidic phosphate ester represented by following formula (1), and an organic solvent, The diameter of the dispersed particle measured by the dynamic light scattering method of the said silica particle is 10-250 nm, The compounding of the said acidic phosphate ester The organic solvent dispersion silica sol of which ratio is 0.5-5 mass% with respect to the said silica particle solid content.
P = O ((OCH ₂ CH ₂ ) _n OR) _a (OH) _b (1)
(In formula, R represents a C1-C18 hydrocarbon group, n is an integer of 0-3, a is an integer of 1-2, b is 3-a) The method of claim 1,
At least 1 type of silicon organic group couple | bonded with the surface of the said silica particle, The organic-solvent dispersion silica sol characterized by the above-mentioned. The method according to claim 1 or 2,
Organic solvent dispersion silica sol, characterized in that the organic solvent is at least one selected from alcohols, ketones, ethers, esters and hydrocarbons. Organic solvent dispersion silica comprising the step of pulverizing the raw material silica particles in an organic solvent and adding the acidic phosphate ester represented by the following formula (1) so as to be 0.5 to 5% by mass relative to the raw material silica particle solid content. Method for the preparation of sol.
P = O ((OCH ₂ CH ₂ ) _n OR) _a (OH) _b (1)
(In formula, R represents a C1-C18 hydrocarbon group, n is an integer of 0-3, a is an integer of 1-2, b is 3-a) The method of claim 4, wherein
It has a process of adding an organosilicon compound, The manufacturing method of the organic-solvent dispersion silica sol characterized by the above-mentioned. The method of claim 4, wherein
The step of adding the acidic phosphate ester represented by the formula (1) so as to be 0.5 to 5% by mass based on the raw material silica particle solid content is carried out before the step of pulverizing the raw material silica particles in an organic solvent is completed. Method for producing an organic solvent dispersed silica sol. The method of claim 5,
The step of adding the acidic phosphate ester represented by the formula (1) so as to be 0.5 to 5% by mass based on the raw material silica particle solid content is carried out before the step of pulverizing the raw material silica particles in an organic solvent is completed. Method for producing an organic solvent dispersed silica sol. The method according to any one of claims 4 to 7,
Performing a step of grinding the raw material silica particles in an organic solvent, followed by adding the acidic phosphate ester represented by the formula (1) so as to be 0.5 to 5% by mass relative to the raw material silica particle solid content. Method for producing a dispersed silica sol.