JPH01153529A - Ultrafine particle of titanium oxide having modified surface - Google Patents

Abstract

PURPOSE:To enable improvement in dispersibility of ultrafine particles of titanium oxide into organic solvents and resins, by treating ultrafine particles of amorphous spherical titanium oxide with an organotitanium compound, anionic surfactant or organosilicon compound. CONSTITUTION:Ultrafine particles of amorphous spherical titanium which is subjected to surface modification with one or more selected from an organotitanium compound, anionic surfactant and an organosilicon compound and has 100-1,000Angstrom average particle diameter and 50-200m<2>/g specific surface area. An organotitanium compound (titanium coupling agent) containing -Ti-O- bond can be used as the organotitanium compound. The amount thereof used is preferably 5-20wt.% based on raw material titanium oxide (dried weight). An alkali salt of fatty acid is used as the anionic surfactant and the amount thereof used is preferably 5-20wt.% based on the raw material titanium oxide (dried weight). A silane coupling agent such as organosilicon compound having hydrolyzable group bonded to silicon atom may be cited as the organosilicon compound and the amount thereof used is preferably 5-40wt.%.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to surface-modified titanium oxide ultrafine particles,
More specifically, the present invention relates to surface-modified ultrafine titanium oxide particles useful in ultraviolet deterioration inhibitors, ultraviolet shielding sheets and films, sunscreen coatings, and the like.

[Problems to be solved by the prior art and the invention] Titanium oxide has excellent weather resistance and high I! ! Because of its shielding power, it is widely used in fields such as cosmetics and paints. However, titanium oxide fine particles have a problem in that they are not dispersed in organic solvents. Therefore, in the future, titanium oxide that can be surface-modified and easily dispersed in organic solvents and resins will be required in order to develop a wide range of scrap applications.

As a surface modification method, ■ After treating crystalline granular titanium oxide with a silane coupling agent having an amino group (e.g., aminoalkoxysilane, polyethyleneimine-containing silane, etc.), a hydrophobizing agent (e.g., silazane, lower alkyl alkoxysilane, etc.) is used. , silicone oil, hydrogenated silicone oil, etc.) (Japanese Unexamined Patent Publication No. 184505/1983); and (1) treatment of crystalline granular titanium oxide with hydroxylamine or cycloimine, followed by treatment with a hydrophobizing agent as described above. A method (such as Japanese Unexamined Patent Publication No. 137305/1983) has been proposed.

However, the conventional surface modification method as described above is unsuitable for the recently developed spherical ultrafine titanium oxide particles (Japanese Patent Application Laid-Open No. 61-201604). It turned out that it was not effective.

Therefore, the present inventors conducted extensive research in order to develop spherical ultrafine titanium oxide that is highly dispersible in organic solvents and resins and has a high specific surface area.

[Means for solving problems]

As a result, it was discovered that spherical non-grade titanium oxide ultrafine particles with a high specific surface area were used as a raw material and treated with a specific surface modifier, and the particles had the above-mentioned desired physical properties. . The present invention was completed based on the findings.

That is, the present invention provides particles with an average particle diameter of 100 ml that have been surface-modified with one or more compounds selected from the group consisting of organotitanium compounds, anionic surfactants, and organosilicon compounds.
1000 m/g and a specific surface area of 50 to 200 m/g.

The surface-modified titanium oxide ultrafine particles in the present invention are
It is spherical and has an average particle size of 100 to 1000 g and a specific surface area of 50 to 200 bo/g. Such surface-modified titanium oxide ultrafine particles are produced by using as a raw material spherical titanium oxide ultrafine particles having the same or slightly larger specific surface area as above and surface-treating them with the above-mentioned surface modifier. can get. Here, the ultrafine titanium oxide particles to be surface-modified can be manufactured by various methods, but preferably by the method disclosed in JP-A No. 61-201604. That is, titanium oxide before surface modification is obtained by vaporizing or atomizing a volatile titanium compound (for example, titanium tetraisopropoxide), decomposing it under heating to produce ultrafine titanium oxide particles, and immediately after the decomposition, the titanium oxide is Those manufactured by cooling the ultrafine particles to a temperature at which they do not coalesce again are suitable.

The surface-modified titanium oxide ultrafine particles of the present invention are: - The above-mentioned non-quality spherical titanium oxide ultrafine particles are combined with an organic titanium compound,
The surface is treated using one or more compounds selected from the group consisting of anionic surfactants and organic silicon compounds as a surface modifier.

Here, examples of the organic titanium compound include titanium coupling agents 2, such as organic titanium compounds 2 having a -Ti-0- bond, such as isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris(dioctylpyrophosphate) thicnate, tetra Isopropyl bis(dioctyl phosphite) titanate, tetraoctyl bis(
ditridecyl phosphite) titanate, tetra(2,
2-diallyloxymethyl-1-butyl) bis(ditridecyl) phosphite titanate bis(dioctyl pyrophosphate) oxyacetate titanate, bis(
Dioctyl pyrophosphate) ethylene nathanate,
Isopropyl trioctanoyl titanate, isopropyl dimethacrylic isostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate,
Examples include dicumyl phenyloxyacetate titanate, diisostearoyl ethylene nathanate, and the like.

When using an organic titanium compound, it is usually 5% by weight or more, preferably 5 to 5% by weight of the raw material titanium oxide (dry weight).
Use at a ratio of 20% focus. If the amount of organic titanium compound used is too small, the effect of hydrophobization (lipophilization) will not appear,
On the other hand, if the amount is too large, the effect will be saturated, which is not economical.

In order to surface modify titanium oxide with an organic titanium compound, the organic titanium compound is added at a weight ratio of 0.5 to 1 to the compound.
After dissolving it in an organic solvent of 50%, it is mixed with titanium oxide at room temperature in the above ratio, and stirred for 5 to 60 minutes to obtain treated titanium oxide in the form of powder or slurry.
It may be dried at 0°C for 3 to 24 hours. Here, as the organic solvent, hexane, acetone, ethanol, toluene, etc. can be used.

The anionic surfactant used in the present invention is preferably a fatty acid alkali salt. Here, the fatty acid may have a straight chain or a branched chain, and may be a -basic acid or a polybasic acid higher than a dibasic acid. As the anionic surfactant, straight chain fatty acid alkali salts are preferred, and specific examples include sodium laurate and sodium myristate.

Examples include sodium palmitate and sodium stearate.

When an anionic surfactant is used, it is usually used in an amount of 5% by weight or more, preferably 5 to 20% by weight of the raw material titanium oxide (type N when dry). If the amount used is too small, the effect of hydrophobization (lipophilization) will not be achieved, and on the other hand, if the amount used is too large, the effect will be saturated, which is not economical.

When surface modification is performed using an anionic surfactant,
The surfactant is dissolved in water at a weight ratio of 0.5 to 50, stirred for 10 to 120 minutes, and then titanium oxide is mixed in the above ratio to form a powder or slurry. The treated titanium oxide may be obtained and dried at room temperature to 110°C for 3 to 24 hours.

Furthermore, the treated titanium oxide in the form of a slurry may be filtered by suction, washed with water in a weight ratio of 5 to 50 parts of titanium oxide, and dried at room temperature to 110°C for 3 to 24 hours.

The organosilicon compound used in the present invention includes a silane coupling agent, such as an organosilicon compound having a hydrolyzable group bonded to a silicon atom. Here, the hydrolyzable group includes, for example, chlorine, alkoxy group, or alkanoyl group.

Specific examples of organosilicon compounds that can be used in the present invention include the following compounds.

CHz = CHS i Cl 3 CHz = CH3i (OCzHs): + CH2 = CHS i (○CH:1)3CHz = C
HS i(OCzH40CHx):+CH2=CCH
3COOC:l Hb S i (OCH3) zCH
2= C(CH3) COOC3Hb S i (OC
2H40CHs ) 3CI Cx Hb Si (
OCH3) 3H3C, +)IbSi(OCH3)z HS C:+H65i(OC2H4)3C5HsSi(
OCzHs):+ Aminoalkyl silicone aqueous lubricant modified aminosilane HzNC, +HbSi(OCH:+)3HzNC:+H
bSi(OCzHs)3Hz N Cz Ha N H
C:l Hb S i (OCH3) 3(HOCzH
4) zNC3H6Si(OC2H5)3CHz COO
Cz H4N HCz H4N HC:l Hb S
i (OCH3) :IHz N Cz H= N H
Cz H4N HCx H6S i (OCH3) 3
HzNCONHC:+H6Si(OCH3):+Cationic unsaturated silane polymer silane 0CNC3H6Si(OCzHs)z Cz Hs OCON HC3Hb Si (OCz
Hs) ICbHsCHzNHC3H6Si(OC
H3)z, HCln CeH+tSi(OC2H5)
3((CzHsO)+5iCzHa C6H5(CH
3) ÷1-34 polyalkylene oxide silane Antistatic silane CbHsNHC,+H65i(OCH3)3 When using an organosilicon compound, it is usually used in an amount of 5% by weight or more of the raw material titanium oxide (dry weight), preferably is added in an amount of 5 to 40% by weight. If the amount added is too small, hydrophobicity (
If the amount is too much, the effect will be saturated and it is not economical.

When surface-modifying with organosilicon compounds such as those mentioned above,
It may be operated in the same manner as when using an organic titanium compound.

The case where an organic titanium compound, an anionic surfactant or an organic silicon compound is used alone is as described above, but it is also possible to surface modify the titanium oxide using two or more of these. When surface modification treatment is performed using two or more types, the operation may be performed in accordance with the above-mentioned operation in the case of a single type.

[Examples] Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 1.4 g of bis(dioctylpyrophosphate)oxyacetate titanate was placed in a 200 ml beaker and dissolved in 35 ml of hexane. To this solution was added 7 g (dry basis) of spherical amorphous titanium oxide (unsurfaced titanium oxide) having an average particle size of 200 nf/g and a specific surface area of 130 nf/g, and the mixture was stirred at room temperature for 10 minutes.

The resulting slurry was transferred to a glass dish and dried in air at 110''C for 3 hours.

After drying, the lumped titanium oxide was crushed in a porcelain mortar to form a powder. When the obtained surface-modified titanium oxide was evaluated using the lipophilicity evaluation method described below, the lipophilicity was 52%.
The particles did not precipitate upon standing in toluene. The average particle size of titanium oxide after modification is 200, and the specific surface area is 90.
rrf/g.

In this experiment, the same titanium oxide was treated with various amounts of bis(dioctyl pyrophosphate) oxyacetate titanate (modifier) added, and the degree of lipophilization of the surface-modified titanium oxide obtained was measured. The relationship between the amount of modifier added and the degree of lipophilicity is shown in Figure 1.

Put 50 ml of distilled water into a 100 ml beaker, and then add 0.2 g of the lipophilic fine powder sample to be evaluated. If the sample is sufficiently lipophilic, it will completely float on the water surface. Methanol is dripped into the water on which the sample is floating, while stirring with a small magnetic cooler, from a billet with the tip submerged in water. As methanol is added, the sample powder floating on the water surface becomes wet and dispersed in the water. Read the amount of methanol added when there are no more floating samples and the sample is completely wet.

When the measured value is a ml, the degree of lipophilicity is defined by the following formula.

Therefore, the larger the value of the degree of lipophilicity, the higher the degree of lipophilicity since it will not get wet unless it becomes a highly concentrated methanol aqueous solution.

Example 2 Surface-modified titanium oxide was obtained in the same manner as in Example 1, except that hexane was used as 7d and the drying and pulverizing steps were omitted.

Its degree of lipophilization was 51%, and the particles did not precipitate even when left in toluene.

Example 3 70 ml of ion-exchanged water was placed in a 200 d beaker, and then 7 g of the titanium oxide used in Example 1 was dispersed by stirring with a stirrer. Next, 1.4g of sodium laurate
was added and stirred at room temperature for 30 minutes. Next, filter by suction,
After washing with water (70ml of ion-exchanged water, room temperature), 110°
It was dried at C for 3 hours.

The dried material was pulverized to obtain surface-modified titanium oxide. Its degree of lipophilization was 59%, and the particles precipitated after standing.

Example 4 4 ml of ion exchange water was put into a 200 ml beaker, and then 0.185 g of sodium laurate was added and dissolved. Furthermore, 4 g of titanium oxide used in Example 1 was added and stirred for 10 minutes to obtain powdered treated titanium oxide. Next, it was dried in air at 110°C for 3 hours to obtain surface-modified titanium oxide. Its lipophilicity was 35%. This surface-modified titanium oxide had an average particle size of 200 particles and a specific surface area of 95 m/g.

Example 5 Surface-modified titanium oxide was obtained in the same manner as in Example 3, except that it was evaporated to dryness without suction filtration or washing with water. Its lipophilicity was 58%.

Example 6 The obtained 35 ml was placed in a 200 ml beaker, and 2.8 g of vinyltriethoxysilane was added and dissolved. The titanium oxide used in Example 1 was added to the solution, stirred at room temperature for 10 minutes, and then treated in the same manner as in Example 1.

Its lipophilicity was 27%. The surface-modified titanium oxide had an average particle size of 200 particles and a specific surface area of 80 m/g.

Comparative Example 1 The same procedure as in Example 3 was carried out, except that 1.4 g of polyoxyethylene sorbitan monostearate, a nonionic surfactant, was used instead of sodium laurate.
Surface modified titanium oxide was obtained.

Its lipophilicity was 0%. In addition, the average particle size of this surface-modified titanium oxide is 200 mm, and the specific surface area is 110 rrf/
It was g.

Application Example 1 To 90 parts by weight of polystyrene, 10 parts by weight of the surface-modified spherical non-quality titanium oxide ultrafine particles obtained in Example 1 were added, and the mixture was molded using a minimax molding machine at 250''C to 101 parts by weight.
A 0x40 test piece was prepared.

Furthermore, this test piece was molded into a sheet-like test piece with a thickness of 200 μm at 250° C. using a press molding machine. 50 of this test piece
The absorbance at 0 nm was 0.30.

Comparative Example 2 A test piece was prepared in the same manner as in Application Example 1, except that untreated spherical non-quality titanium oxide ultrafine particles were used instead of surface-modified spherical non-quality titanium oxide ultrafine particles, 500
When the absorbance at nm was measured, the absorbance was 0.40, and the transparency was lower than that of Application Example 1.

Comparative Example 3 Using crystalline rice granular titanium oxide (P-25 from Degussa), which is a mixture of anatase type and rutile type, as titanium oxide, it was treated with bis(dioctyl pyrophosphate) oxyacetate titanate in the same manner as in Example 1. A surface-modified titanium oxide was produced through treatment. A test piece was prepared in the same manner as in Application Example 1 except that the surface-modified granular titanium oxide produced in this manner was used, and the absorbance was measured to be 0.50, and the test piece was cloudy.

〔Effect of the invention〕

The surface-modified ultrafine titanium oxide particles of the present invention are non-porous, spherical, have a high specific surface area, and have high surface hydrophobicity. That is, according to the present invention, the surface modification shown in FIG. 1, in which the dispersibility in organic solvents and resins was significantly improved, is due to the difference between the amount of modifier added and the degree of lipophilicity of the surface-modified titanium oxide in Example 1. It is a graph showing a relationship.

Lipophilicity degree (%)

Claims (4)

[Claims] (1) Surface modified with one or more compounds selected from the group consisting of organotitanium compounds, anionic surfactants, and organosilicon compounds with an average particle size of 100 to 1000 Å
and amorphous spherical titanium oxide ultrafine particles having a specific surface area of 50 to 200 m^2/g. (2) The ultrafine particles according to claim 1, wherein the organic titanium compound is an organic titanium compound having a -Ti-O- bond. (3) The ultrafine particles according to claim 1, wherein the anionic surfactant is a fatty acid alkali salt. (4) The ultrafine particles according to claim 1, wherein the organosilicon compound is an organosilicon compound in which a hydrolyzable group is bonded to a silicon atom.