JP2007270054A - Metal oxide fine particle-containing polysiloxane composition and method for producing the same - Google Patents

Abstract

A silicone material having various functions and excellent in heat resistance and moist heat resistance and a method for producing the same are provided.
In an organic solvent, in the presence of a basic compound, an acidic compound or a metal chelate compound, metal oxide fine particles and the following average composition formula (1) R ¹ _a SiO _b (OR ² ) _c (1) ( In the formula, R ¹ is a hydrogen atom or a monovalent hydrocarbon group having no oxyalkylene group, and when there are a plurality of R ^{1 s,} they may be the same or different, and R ² is a hydrogen atom Or an alkyl group, and when there are a plurality of R ^{2 s,} they may be the same or different from each other, a is greater than 0 and less than 2, b is greater than 0 and less than 2, and c is greater than 0 And a polysiloxane composition obtained by mixing a metal oxide fine particle dispersion mixed with a polyfunctional polysiloxane represented by the formula (a + b × 2 + c = 4) and silicone having a polydimethylsiloxane structure.
[Selection figure] None

Description

  The present invention relates to a polysiloxane composition containing metal oxide fine particles and a silicone having a polydimethylsiloxane structure, in which metal oxide fine particles are highly dispersed, and a metal material containing fine metal oxide particles.

  Conventionally, as a means for imparting various functions to a siloxane material having excellent durability, a composite of a binder having a siloxane skeleton (hereinafter also referred to as “siloxane binder”) and various metal oxides has been studied. Silicone is known as one of the siloxane-based binders. This silicone does not deteriorate unless it is usually at a high temperature of 200 ° C. or higher, is useful as a siloxane-based binder having excellent heat resistance and ultraviolet resistance, and is used for various applications in that it is excellent in flexibility. . However, when metal oxide fine particles are blended in order to impart various functions to silicone, there is a problem that the metal oxide fine particle-containing silicone material is inferior in heat resistance and moist heat resistance.

  Further, when silicone and metal oxide are combined, they are often prepared in the form of a dispersion. However, since silicone is difficult to dissolve in water, it is necessary to use an organic solvent as a dispersion medium. On the other hand, metal oxide fine particles tend to aggregate in an organic solvent and are therefore often dispersed in an aqueous medium. Therefore, in order to finely disperse the metal oxide fine particles in the organic solvent, phosphoric acid, sulfonic acid or carboxylic acid having an organic group having 6 or more carbon atoms (see Patent Document 1), an organic compound having an oxyalkylene group, It was necessary to use an ester such as phosphoric acid having an oxyalkylene group (see Patent Document 2) or a silane compound having an oxyalkylene group (see Patent Document 3).

However, when these compounds are used to finely disperse metal oxide fine particles in an organic solvent and the metal oxide fine particles and silicone are combined, the dispersibility of the dispersion is good. When a silicone material containing metal oxide fine particles is formed by removing the metal oxide, phosphoric acid having an organic group having 6 or more carbon atoms or a compound having an oxyalkylene group remains in the silicone material. Due to poor compatibility between the silicone and the silicone, phase separation occurs, and these compounds may be discolored (yellowed) or cracked under severe environments such as under UV irradiation or at a high temperature of 150 ° C or higher. It sometimes occurred.
JP 2004-283822 A JP 2005-185924 A JP 2004-99879 A

  The present invention is intended to solve the problems associated with the prior art as described above, and has various functions and is excellent in heat resistance and heat and moisture resistance, and such a silicone material is obtained. An object of the present invention is to provide a polysiloxane composition in which metal oxide fine particles are highly dispersed and a method for producing the same.

As a result of diligent research to solve the above problems, the present inventor, when holding a silicone material containing a silicone having a polydimethylsiloxane structure and metal oxide fine particles under high humidity, the silicone is decomposed and the silicone material We have found that degradation occurs. Although the details of this degradation mechanism are not clear, it was speculated that it was hydrolysis degradation of silicone. Further, it has been found that the smaller the primary particle diameter of the metal oxide fine particles, the easier the hydrolysis degradation of silicone occurs. Then, although the metal oxide fine particles were surface-treated with a silane coupling agent such as a silane monomer, the hydrolysis degradation of silicone could not be sufficiently suppressed.

  The present inventor previously treated metal oxide fine particles with polyfunctional polysiloxane in an organic solvent, and mixed the obtained metal oxide fine particle dispersion with silicone having a polydimethylsiloxane structure to decompose silicone. The present inventors have found that deterioration can be suppressed and have completed the present invention.

That is, the metal oxide fine particle-containing polysiloxane composition according to the present invention comprises a metal oxide fine particle and the following average composition formula (1) in the presence of a basic compound, an acidic compound or a metal chelate compound in an organic solvent.
R ¹ _a SiO _b (OR ² ) _c (1)
(In the formula, R ¹ is a monovalent hydrocarbon group having no hydrogen atom or oxyalkylene group;
When a plurality of R ¹ are present, they may be the same or different from each other, R ² is a hydrogen atom or an alkyl group, and when a plurality of R ² are present, they may be the same or different from each other. A is greater than 0 and less than 2, b is greater than 0 and less than 2, c is greater than 0 and less than 4, and a + b × 2 + c = 4)
A metal oxide fine particle dispersion obtained by mixing the polyfunctional polysiloxane represented by the formula (1) and dispersing the metal oxide fine particles in an organic solvent;
It is characterized by being mixed with silicone having a polydimethylsiloxane structure.

The water content of the metal oxide fine particle dispersion is preferably 5% by weight or less.
The metal oxide fine particles and the polyfunctional polysiloxane are preferably mixed in the presence of a basic compound.

The basic compound is preferably an organic amine compound.
The weight average molecular weight of the polyfunctional polysiloxane is preferably in the range of 1,000 to 100,000 in terms of polystyrene measured by gel permeation chromatography.

The metal oxide fine particles and the polyfunctional polysiloxane are preferably mixed by a bead mill.
It is preferable to mix 1 to 1000 parts by weight of the polyfunctional polysiloxane with respect to 100 parts by weight of the metal oxide fine particles in terms of complete hydrolysis condensate.

The metal oxide fine particle-containing silicone material according to the present invention is obtained from the metal oxide fine particle-containing polysiloxane composition.
The LED sealing material according to the present invention is obtained from the metal oxide fine particle-containing polysiloxane composition, and the metal oxide fine particles are phosphors.

The method for producing a metal oxide fine particle-containing polysiloxane composition according to the present invention comprises a metal oxide fine particle and the following average composition formula (1) in the presence of a basic compound, an acidic compound or a metal chelate compound in an organic solvent.
R ¹ _a SiO _b (OR ² ) _c (1)
(In the formula, R ¹ is a monovalent hydrocarbon group having no hydrogen atom or oxyalkylene group;
When a plurality of R ¹ are present, they may be the same or different from each other, R ² is a hydrogen atom or an alkyl group, and when a plurality of R ² are present, they may be the same or different from each other. A is greater than 0 and less than 2, b is greater than 0 and less than 2, c is greater than 0 and less than 4, and a + b × 2 + c = 4)
After mixing with the polyfunctional polysiloxane represented by the above, the metal oxide fine particles are dispersed in an organic solvent to prepare a metal oxide fine particle dispersion,
The metal oxide fine particle dispersion is mixed with silicone having a polydimethylsiloxane structure.

  The metal oxide fine particles and the polyfunctional polysiloxane are preferably mixed in the presence of a basic compound, and the metal oxide fine particles and the polyfunctional polysiloxane are preferably mixed by a bead mill.

  According to the present invention, metal oxide fine particles are highly developed in an organic solvent containing silicone having a polydimethylsiloxane structure without using phosphoric acid having an organic group having 6 or more carbon atoms or a compound having an oxyalkylene group. A dispersed composition is obtained. This composition is excellent in dispersion stability and can form a functional silicone material containing metal oxide fine particles and a silicone having a polydimethylsiloxane structure. This silicone material is excellent in heat resistance and moist heat resistance. In addition, since the silicone material does not substantially contain the above compound, problems such as discoloration (yellowing) and generation of cracks do not occur in a harsh environment. In particular, a functional silicone material using highly refractive metal oxide fine particles as metal oxide fine particles can be used as a sealing material for LED elements using blue LED elements or ultraviolet LED elements as light emitting elements. It is useful as a sealing material for high-brightness LED elements.

  The metal oxide fine particle-containing polysiloxane composition according to the present invention is an organic solvent containing polyfunctional polysiloxane without using phosphoric acid having an organic group having 6 or more carbon atoms or a compound having an oxyalkylene group. It can be obtained by mixing a metal oxide fine particle dispersion in which metal oxide fine particles are highly dispersed and silicone having a polydimethylsiloxane structure.

[Metal oxide fine particle dispersion]
The metal oxide fine particle dispersion used in the present invention comprises a metal oxide fine particle and a polyfunctional polysiloxane having a hydroxyl group and / or an alkoxy group (hereinafter simply referred to as “polyfunctional polysiloxane”) having 6 or more carbon atoms. Obtained by mixing and dispersing in an organic solvent in the presence of a basic compound, acidic compound or metal chelate compound without using phosphoric acid having an organic group or a compound having an oxyalkylene group. Can do. This fine particle dispersion is a dispersion in which metal oxide fine particles are dispersed with a high dispersion having a volume average dispersed particle diameter of 300 nm or less.

  The metal oxide fine particle dispersion preferably does not substantially contain water. Specifically, the water content is preferably 5% by weight or less, more preferably 3% by weight or less, and more preferably 1% by weight or less. Is particularly preferred.

(Metal oxide fine particles)
The metal oxide fine particles used in the present invention are not particularly limited as long as they are metal element oxide fine particles. For example, antimony oxide, zirconium oxide, anatase type titanium oxide, rutile type titanium oxide, brookite type titanium oxide. , Zinc oxide, tantalum oxide, indium oxide, hafnium oxide, tin oxide, niobium oxide, aluminum oxide, cerium oxide, scandium oxide, yttrium oxide, lanthanum oxide, praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, oxide Terbium, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide, lutetium oxide, calcium oxide, gallium oxide, lithium oxide, strontium oxide, tungsten oxide, oxide Potassium, magnesium oxide, and complexes thereof, and indium - include metal oxide particles such as oxides of the metal 2 or more complex, such as tin oxide.

In the present invention, the metal oxide fine particles may be used singly or in combination of two or more. The metal oxide fine particles can be appropriately selected according to the function to be imparted. For example, TiO ₂ fine particles and ZrO ₂ fine particles are preferable when imparting high refractive properties.

  Such oxide fine particles may be added in the form of a powder not dispersed in a solvent, or in the form of a dispersion dispersed in a polar solvent such as isopropyl alcohol or a nonpolar solvent such as toluene. Also good. The fine oxide particles before addition may be aggregated to form secondary particles. In the present invention, it is preferable to use a powder because an appropriate organic solvent can be appropriately selected in consideration of the solubility of polysiloxane. The production method of the present invention is particularly effective when added in the form of powder.

(Polyfunctional polysiloxane)
The polyfunctional polysiloxane has the following average composition formula (1)
R ¹ _a SiO _b (OR ² ) _c (1)
And a polyfunctional polysiloxane having a hydroxyl group and / or an alkoxy group, preferably having a three-dimensional crosslinked structure.

In formula (1), R ¹ is a monovalent hydrocarbon group having no hydrogen atom or an oxyalkylene group when R ¹ there are a plurality or different be the same as each other, R ² Is a hydrogen atom or an alkyl group, and when a plurality of R ² are present, they may be the same as or different from each other. a is greater than 0 and less than 2, b is greater than 0 and less than 2, c is greater than 0 and less than 4, and a + b × 2 + c = 4. When there are a plurality of R ¹ and R ² , a is the ratio of the hydrogen atom and the monovalent hydrocarbon group having no oxyalkylene group to the total silicon atom, and c is the relationship between the hydroxyl group and the alkoxy group. The ratio with respect to the total silicon atom is represented.

  The weight average molecular weight of the polyfunctional polysiloxane is a polystyrene conversion value measured by gel permeation chromatography, preferably 1,000 to 100,000, more preferably 1,000 to 80,000, particularly preferably 1, 500-70,000. When a polysiloxane having a weight average molecular weight in the above range is used, the surface of the metal oxide fine particles is sufficiently protected by the polyfunctional polysiloxane, and hydrolysis degradation of silicone can be suppressed.

  The monovalent hydrocarbon group is not particularly limited as long as it does not have an oxyalkylene group, and examples thereof include a substituted or unsubstituted monovalent hydrocarbon group. Examples of the monovalent unsubstituted hydrocarbon group include an alkyl group having 1 to 8 carbon atoms, a phenyl group, a benzyl group, and a tolyl group. Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, pentyl group, hexyl group, heptyl group, and octyl group. Examples of the monovalent substituted hydrocarbon group include substituted alkyl groups having 1 to 8 carbon atoms. Examples of the substituent of the substituted alkyl group include halogen, amino group, mercapto group, isocyanate group, glycidyl group, glycidoxy group, ureido group and the like.

Examples of the alkyl group represented by R ² include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group. Of these alkyl groups, a methyl group and an ethyl group are preferable.

This polyfunctional polysiloxane can be produced, for example, by hydrolyzing and condensing polyfunctional alkoxysilane or polyfunctional chlorosilane in an appropriate combination so as to satisfy the above average composition formula. However, hydrolysis / condensation with only tetraalkoxysilanes and hydrolysis / condensation with dialkoxysilanes only are excluded.

Examples of the polyfunctional alkoxysilane include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, and tetra-n-butoxysilane;
Methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, n- Butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, Phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane 3,3,3-trifluoropropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanate Propyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- Trialkoxysilanes such as (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane;
Dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-i-propyldimethoxysilane, di-i-propyldiethoxy Silane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-pentyldimethoxysilane, di-n-pentyldiethoxysilane, di-n-hexyldimethoxysilane, di-n-hexyldi Ethoxysilane, di-n-heptyldimethoxysilane, di-n-heptyldiethoxysilane, di-n-octyldimethoxysilane, di-n-octyldiethoxysilane, di-n-cyclohexyldimethoxysilane, di-n-cyclohexyl Diethoxysilane, diphenyl Silane, dialkoxy silanes such as diphenyl diethoxy silane. These alkoxysilanes can be used individually by 1 type or in mixture of 2 or more types.

  Moreover, in addition to polyfunctional alkoxysilane, monofunctional alkoxysilane can also be used together. Examples of monofunctional alkoxysilanes include trimethylmethoxysilane, trimethylethoxysilane, triethylmethoxysilane, and triethylethoxysilane. These monofunctional alkoxysilanes are desirably used in an amount of 10% by weight or less, preferably 7% by weight or less, more preferably 5% by weight or less based on the total amount of alkoxysilane used.

  Further, as alkoxy group-containing polysiloxane, X40-9220, X40-9225 (trade name) manufactured by Shin-Etsu Silicone Co., Ltd., XR31-B1410, XR31-B0270, XR31-B2733 (trade name, manufactured by GE Toshiba Silicone) ) And other commercially available siloxane polymers can also be used.

In the metal oxide fine particle dispersion of the present invention, the polyfunctional polysiloxane is preferably 1 to 1000 parts by weight in terms of complete hydrolysis condensate with respect to 100 parts by weight of the metal oxide fine particles,
The content is more preferably 5 to 900 parts by weight, and particularly preferably 10 to 800 parts by weight.

(Organic solvent)
Examples of the organic solvent include alcohols, aromatic hydrocarbons, ethers, ketones, esters, and the like. Examples of the alcohols include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, i-butyl alcohol, n-butyl alcohol, sec-butyl alcohol, t-butyl alcohol, n-hexyl alcohol, n-octyl alcohol, Examples include ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene monomethyl ether acetate, and diacetone alcohol. Aromatic hydrocarbons include benzene, toluene, xylene, etc., ethers include tetrahydrofuran, dioxane, etc., and ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone. Examples of esters include ethyl acetate, propyl acetate, butyl acetate, propylene carbonate, methyl lactate, ethyl lactate, normal propyl lactate, isopropyl lactate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, and the like. Can be mentioned. These organic solvents may be used individually by 1 type, or 2 or more types may be mixed and used for them. Of these organic solvents, organic solvents other than alcohols such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, toluene, xylene, ethyl acetate, butyl acetate and the like are preferable. Moreover, it is preferable to use these organic solvents in the state which gave the dehydration process previously and removed the water | moisture content.

  The amount of the organic solvent used is not particularly limited as long as the metal oxide fine particles can be uniformly dispersed, but the solid content concentration of the obtained metal oxide fine particle dispersion is preferably 5 to 80% by weight, more preferably. Is 7 to 70% by weight, particularly preferably 10 to 60% by weight.

(Basic compound)
Examples of the basic compound include ammonia (including ammonia aqueous solution), organic amine compounds, alkali metals such as sodium hydroxide and potassium hydroxide, hydroxides of alkaline earth metals, alkalis such as sodium methoxide and sodium ethoxide. Examples thereof include metal alkoxides. Of these, ammonia and organic amine compounds are preferred.

Examples of the organic amine include alkylamine, alkoxyamine, alkanolamine, and arylamine.
Alkylamines include methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, N, N-dimethylamine, N, N-diethylamine, N, N-dipropylamine, N, N-dibutylamine, trimethylamine , Alkylamines having an alkyl group having 1 to 4 carbon atoms, such as triethylamine, tripropylamine, and tributylamine.

  Alkoxyamines include methoxymethylamine, methoxyethylamine, methoxypropylamine, methoxybutylamine, ethoxymethylamine, ethoxyethylamine, ethoxypropylamine, ethoxybutylamine, propoxymethylamine, propoxyethylamine, propoxypropylamine, propoxybutylamine, butoxymethylamine , Alkoxyamines having 1 to 4 carbon atoms such as butoxyethylamine, butoxypropylamine, and butoxybutylamine.

As alkanolamine, methanolamine, ethanolamine, propanolamine, butanolamine, N-methylmethanolamine, N-ethylmethanolamine, N-propylmethanolamine, N-butylmethanolamine, N-methylethanolamine, N-ethyl Ethanolamine, N-propylethanolamine, N-butylethanolamine, N-methylpropanolamine, N-ethylpropanolamine, N-propylpropanolamine, N-butylpropanolamine, N-methylbutanolamine, N-ethylbutanolamine N-propylbutanolamine, N-butylbutanolamine, N, N-dimethylmethanolamine, N, N-diethylmethanolamine, N, N-dipropylmethanolamine N, N-dibutylmethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dipropylethanolamine, N, N-dibutylethanolamine, N, N-dimethylpropanolamine, N, N-diethylpropanolamine, N, N-dipropylpropanolamine, N, N-dibutylpropanolamine, N, N-dimethylbutanolamine, N, N-diethylbutanolamine, N, N-dipropylbutanolamine, N, N-dibutylbutanolamine, N-methyldimethanolamine, N-ethyldimethanolamine, N-propyldimethanolamine, N-butyldimethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanol Min, N-butyldiethanolamine, N-methyldipropanolamine, N-ethyldipropanolamine, N-propyldipropanolamine, N-butyldipropanolamine, N-methyldibutanolamine, N-ethyldibutanolamine, N -Propyldibutanolamine, N-butyldibutanolamine, N- (aminomethyl) methanolamine, N- (aminomethyl) ethanolamine, N- (aminomethyl) propanolamine, N- (aminomethyl) butanolamine, N -(Aminoethyl) methanolamine, N- (aminoethyl) ethanolamine, N- (aminoethyl) propanolamine, N- (aminoethyl) butanolamine, N- (aminopropyl) methanolamine, N- (aminopropyl) Ethanor Ruamine, N- (aminopropyl) propanolamine, N- (aminopropyl) butanolamine, N- (aminobutyl) methanolamine, N- (aminobutyl) ethanolamine, N- (aminobutyl) propanolamine, N- ( Examples thereof include alkanolamines having an alkyl group having 1 to 4 carbon atoms such as (aminobutyl) butanolamine.

Examples of the arylamine include aniline and N-methylaniline.
Further, as organic amines other than the above, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide; tetramethylethylenediamine, tetraethylethylenediamine Tetraalkylethylenediamine such as tetrapropylethylenediamine and tetrabutylethylenediamine; methylaminomethylamine, methylaminoethylamine, methylaminopropylamine, methylaminobutylamine, ethylaminomethylamine, ethylaminoethylamine, ethylaminopropylamine, ethylaminobutylamine, Propylaminomethylamine, propylamino Alkylaminoalkylamines such as tilamine, propylaminopropylamine, propylaminobutylamine, butylaminomethylamine, butylaminoethylamine, butylaminopropylamine, butylaminobutylamine; pyridine, pyrrole, piperazine, pyrrolidine, piperidine, picoline, morpholine, methyl Also included are morpholine, diazabicycloocrane, diazabicyclononane, diazabicycloundecene and the like.

  Such basic compounds may be used alone or in combination of two or more. Of these, triethylamine, tetramethylammonium hydroxide, and pyridine are particularly preferable.

(Acidic compounds)
Examples of the acidic compound include organic acids and inorganic acids. Examples of the organic acid include acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic acid, maleic anhydride, methylmalonic acid, adipic acid, Sebacic acid, gallic acid, butyric acid, meritic acid, arachidonic acid, mikimic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, linoleic acid, linolenic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, p-toluenesulfone Examples include acid, benzenesulfonic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, formic acid, malonic acid, methanesulfonic acid, phthalic acid, fumaric acid, citric acid, and tartaric acid. Examples of the inorganic acid include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid.

Such acidic compounds may be used alone or in combination of two or more. Of these, maleic acid, maleic anhydride, methanesulfonic acid, and acetic acid are particularly preferred.
(Metal chelate compound)
Examples of the metal chelate compound include organometallic compounds and / or partial hydrolysates thereof (hereinafter, organometallic compounds and / or partial hydrolysates thereof are collectively referred to as “organometallic compounds”).

Examples of the organometallic compounds include the following formula (a):
M (OR ⁷ ) _r (R ⁸ COCHCOR ⁹ ) _s (a)
(In the formula, M represents at least one metal atom selected from the group consisting of zirconium, titanium and aluminum, and R ⁷ and R ⁸ are each independently a methyl group, an ethyl group, or an n-propyl group. , Monovalent hydrocarbon having 1 to 6 carbon atoms such as i-propyl group, n-butyl group, sec-butyl group, t-butyl group, n-pentyl group, n-hexyl group, cyclohexyl group and phenyl group R ⁹ represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, or
Alkoxy groups having 1 to 16 carbon atoms such as methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, sec-butoxy group, t-butoxy group, lauryloxy group, stearyloxy group, etc. And r and s are each independently an integer of 0 to 4, and satisfy the relationship of (r + s) = (valence of M))
(Hereinafter, referred to as “organometallic compound (a)”),
A tetravalent tin organometallic compound in which one or two alkyl groups having 1 to 10 carbon atoms are bonded to one tin atom (hereinafter referred to as “organotin compound”), or
These partial hydrolysates are exemplified.

Examples of the organometallic compound (a) include tetra-n-butoxyzirconium, tri-n-butoxyethylacetoacetatezirconium, di-n-butoxybis (ethylacetoacetate) zirconium, n-butoxytris (ethylacetate). Organic zirconium compounds such as acetate) zirconium, tetrakis (n-propylacetoacetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium;
Organic titanium compounds such as tetra-i-propoxy titanium, di-i-propoxy bis (ethylacetoacetate) titanium, di-i-propoxy bis (acetylacetate) titanium, di-i-propoxy bis (acetylacetone) titanium ;
Tri-i-propoxyaluminum, di-i-propoxyethyl acetoacetate aluminum, di-i-propoxy acetylacetonate aluminum, i-propoxy bis (ethylacetoacetate) aluminum, i-propoxy bis (acetylacetonate) And organoaluminum compounds such as aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonato) aluminum, monoacetylacetonatobis (ethylacetoacetate) aluminum.

  As an organic tin compound, for example,

Chloride-type organotin compounds such as;
Reaction of organotin oxides such as (C ₄ H ₉ ) ₂ SnO, (C ₈ H ₁₇ ) ₂ SnO, and ester compounds such as silicates, dimethyl maleate, diethyl maleate and dioctyl phthalate Product;
Etc.

  Such metal chelate compounds may be used singly or in combination of two or more. Of these, tri-n-butoxy ethyl acetoacetate zirconium, di-i-propoxy bis (acetylacetonate) titanium, di-i-propoxy ethyl acetoacetate aluminum, tris (ethyl acetoacetate) aluminum, or these The partial hydrolyzate is preferred.

  Of the basic compounds, acidic compounds and metal chelate compounds, basic compounds and acidic compounds are preferred, basic compounds are more preferred, organic amine compounds are more preferred, and triethylamine, tetramethylammonium hydroxide, and pyridine are particularly preferred.

  The basic compound, acidic compound or metal chelate compound is usually 0.001 to 20 parts by weight, preferably 0.005, based on 100 parts by weight of the metal oxide fine particles in the metal oxide fine particle dispersion of the present invention. 10 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, still more preferably 0.01 to 1 part by weight, particularly preferably 0.01 to 0.5 parts by weight.

(Preparation method of metal oxide fine particle dispersion)
The metal oxide fine particle dispersion is obtained by adding metal oxide fine particles, polyfunctional polysiloxane, a basic compound, an acidic compound, or a metal chelate compound to an organic solvent, and mixing them thoroughly to obtain metal oxide fine particles. It can be prepared by dispersing in an organic solvent. At this time, it is preferable to use a known disperser such as a ball mill, a sand mill (bead mill, high shear bead mill), a homogenizer, an ultrasonic homogenizer, a nanomizer, a propeller mixer, a high shear mixer, a paint shaker, and the like. A ball mill and a sand mill (bead mill, high shear bead mill) are preferably used. As described above, when the metal oxide fine particles and the polyfunctional polysiloxane are mixed in the presence of the basic compound, acidic compound or metal chelate compound, the metal oxide is produced by the catalytic action of the basic compound, acidic compound or metal chelate compound. It is estimated that the polyfunctional polysiloxane condensation reaction proceeds on the surface of the fine particles, the surface of the metal oxide fine particles becomes hydrophobic, and is easily finely dispersed in the organic solvent.

In the metal oxide fine particle dispersion thus prepared, the volume average dispersed particle size of the metal oxide fine particles is preferably 300 nm or less, more preferably 200 nm or less.
〔silicone〕
The silicone used in the present invention is not particularly limited as long as it has a polydimethylsiloxane structure. For example, the side chain or terminal may have a functional group such as hydrogen, amino group, carboxy group, carbinol group, vinyl group, methacryl group or mercapto group.

Examples of the silicone include dimethyl silicone oil (KF96, KF96SP manufactured by Shin-Etsu Chemical Co., Ltd.), methylphenyl silicone oil (KF50 manufactured by Shin-Etsu Chemical Co., Ltd.), methyl hydrogen silicone oil (Shin-Etsu Chemical Co., Ltd.). KF99), carboxyl-modified reactive silicone oil (X-22-162C, X-22-3710 manufactured by Shin-Etsu Chemical Co., Ltd.), carbinol-modified reactive silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd.) X-22-160AS, KF-6001, KF-6002, KF-6003), methacryl-modified reactive silicone oil (X-22-164A, X-22 manufactured by Shin-Etsu Chemical Co., Ltd.)
-164C), mercapto-modified reactive silicone oil (X-22-167B, KF-2001, KF-2004 manufactured by Shin-Etsu Chemical Co., Ltd.), amino-modified reactive silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd.) X-22-161A), a silicone encapsulant made of a mixture of polydimethylsiloxane having Si—H cured with a platinum catalyst and polydimethylsiloxane having a carbon-carbon double bond.

<Metal oxide fine particle-containing polysiloxane composition and use thereof>
The metal oxide fine particle-containing polysiloxane composition according to the present invention can be obtained by mixing the metal oxide fine particle dispersion and a silicone having a polydimethylsiloxane structure. In this composition, the metal oxide fine particles are uniformly dispersed, and the volume average dispersed particle size of the metal oxide fine particles is preferably 300 nm or less, and more preferably 200 nm or less.

  This composition contains metal oxide fine particles and silicone having a polydimethylsiloxane structure, but since the surface of the metal oxide fine particles is protected with the polyfunctional polysiloxane, the silicone is not hydrolyzed and deteriorated. For example, the metal oxide fine particle-containing silicone material formed by removing the solvent from the composition by drying or the like is excellent in heat resistance and moist heat resistance.

Further, in the above composition, the metal oxide fine particles are highly dispersed without using a phosphoric acid having an organic group having 6 or more carbon atoms or a compound having an oxyalkylene group. Even if exposed to the bottom, it does not deteriorate and can form a metal oxide fine particle-containing silicone material having excellent durability. Further, this silicone material has no carbon-carbon bond in the cross-linked structure and has excellent ultraviolet resistance. For example, the silicone material is 5000 mW / m ² , 20
No yellowing (yellowing) even after 0 hours of UV irradiation.

  In addition, the metal oxide fine particle-containing polysiloxane composition of the present invention can further contain a phosphor, and the metal oxide fine particle-containing silicone material obtained from the polysiloxane composition can be used as an LED sealing material.

The mixing method of the metal oxide fine particle dispersion and polydimethylsiloxane is not particularly limited, and may be stirred using a conventionally known mixing method, for example, a stirrer.
The compounding amount of the metal oxide fine particle dispersion is preferably 0.1 to 1000 parts by weight, more preferably 1 to 500 parts by weight, and more preferably 5 to 300 parts by weight in terms of metal oxide fines with respect to 100 parts by weight of polydimethylsiloxane. Part is particularly preferred. When the mixing ratio of the metal oxide fine particles and the polydimethylsiloxane is within the above range, various functions can be imparted to the polydimethylsiloxane, and decomposition degradation of the polydimethylsiloxane can be suppressed.

  Further, the metal oxide fine particle-containing polysiloxane composition of the present invention may contain glass fibers in order to reduce the shrinkage-expansion of the metal oxide fine particle-containing silicone material. When a composition containing glass fibers is used, a thick film functional silicone material can be formed.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited at all by this Example. In the examples and comparative examples, “parts” and “%” indicate “parts by weight” and “% by weight” unless otherwise specified. In addition, various measurements in Examples and Comparative Examples were performed by the following methods.

[GPC measurement]
The weight average molecular weight of siloxane was shown as a polystyrene conversion value measured under the following conditions by gel permeation chromatography.
Apparatus: HLC-8120C (manufactured by Tosoh Corporation)
Column: TSK-gel Multipore H _XL- M (manufactured by Tosoh Corporation)
Eluent: THF, flow rate 0.5 mL / min, load 5.0%, 100 μL
〔Heat-resistant〕
The silicone material was stored at 150 ° C. for 150 hours, the weight of the silicone material before and after storage was measured, and the weight retention rate was calculated by the following formula.

Weight retention (%) = weight of silicone material after storage / weight of silicone material before storage × 100
[Moisture and heat resistance]
The silicone material was stored at a temperature of 85 ° C. and a humidity of 85% RH for 150 hours, the weight of the silicone material before and after storage was measured, and the weight retention was calculated by the following formula.

Weight retention (%) = weight of silicone material after storage / weight of silicone material before storage × 100
[Preparation Example 1]
100 parts by weight of powdery rutile-type titanium oxide fine particles (primary average particle size: 30 nm) and a polyfunctional polysiloxane having an Mw = 1,000 alkoxy-terminated methyl silicone oligomer (manufactured by Shin-Etsu Chemical Co., Ltd., product) Name: X40-9220) 20 parts by weight, 0.1 part by weight of triethylamine and 480 parts by weight of methyl ethyl ketone are put in a container, 2000 parts by weight of 0.1 mm diameter zirconia beads are added to this mixture, and a bead mill is used. The mixture was stirred at 1500 rpm for 1 hour to disperse the fine particles to obtain a metal oxide fine particle dispersion (I) having a solid content concentration of 20% by weight.

[Preparation Example 2]
Metal oxide fine particles having a solid content concentration of 20% by weight in the same manner as in Preparation Example 1 except that 100 parts by weight of powdery zinc oxide fine particles (primary average particle size: 20 nm) were used instead of rutile type titanium oxide fine particles. Dispersion (II) was prepared.

[Preparation Example 3]
Metal oxide fine particles having a solid content concentration of 20% by weight in the same manner as in Preparation Example 1 except that 100 parts by weight of powdery zirconium oxide fine particles (primary average particle diameter: 20 nm) were used instead of rutile type titanium oxide fine particles. Dispersion (III) was prepared.

[Preparation Example 4]
Except for using 20 parts by weight of alkoxy-terminated silicone polymer (GE Toshiba Silicone Co., Ltd., trade name: XR31-B0270) instead of silicone oligomer (X40-9220) as the polyfunctional polysiloxane. In the same manner as in Preparation Example 3, a metal oxide fine particle dispersion (IV) having a solid concentration of 20% by weight was prepared.

[Preparation Example 5]
A metal oxide fine particle dispersion (V) having a solid content concentration of 20% by weight was prepared in the same manner as in Preparation Example 1, except that 0.1 part by weight of methanesulfonic acid was used instead of triethylamine.

[Preparation Example 6]
A metal oxide fine particle dispersion (i) having a solid content concentration of 20% by weight was prepared in the same manner as in Preparation Example 1, except that 20 parts by weight of methyltrimethoxysilane was used as the polyfunctional silane monomer instead of the polyfunctional polysiloxane. did.

[Preparation Example 7]
100 parts by weight of powdery rutile-type titanium oxide fine particles (primary average particle size: 30 nm) and a polyfunctional polysiloxane having an Mw = 1,000 alkoxy-terminated methyl silicone oligomer (manufactured by Shin-Etsu Chemical Co., Ltd., product) Name: X40-9220) 100 parts by weight, polyoxyethylene alkyl phosphate ester (manufactured by Enomoto Kasei Co., Ltd., trade name: PLAD ED151) 9 parts by weight, acetylacetone 5 parts by weight, and methyl ethyl ketone 700 parts by weight In this mixture, 2000 parts by weight of 0.1 mm diameter zirconia beads are added to this mixture, and the mixture is stirred for 1 hour at 1500 rpm using a bead mill to disperse the fine particles, and a metal oxide fine particle dispersion having a solid content concentration of 20% by weight. (Ii) was obtained.

[Reference Preparation Example 1]
Powdery rutile type titanium oxide fine particles were dispersed in methyl ethyl ketone in the same manner as in Preparation Example 1 except that triethylamine was not used, but the titanium oxide fine particles settled.

[Reference Preparation Example 2]
Powdered rutile type titanium oxide fine particles were dispersed in methyl ethyl ketone in the same manner as in Preparation Example 1 except that polyfunctional polysiloxane was not used, but the titanium oxide fine particles settled.

[Reference Preparation Example 3]
Instead of polyfunctional polysiloxane, polydimethylsiloxane that does not contain Si-OR bond (R is an alkyl group) or Si-OH bond and has methacrylic structures at both ends (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-22-164B) Except that it was used, powdery rutile type titanium oxide fine particles were dispersed in methyl ethyl ketone in the same manner as in Preparation Example 1, but the titanium oxide fine particles settled.

[Reference Preparation Example 4]
Titanium oxide fine particle aqueous dispersion in which anatase type titanium oxide fine particles are dispersed in water in advance (“STS-01” manufactured by Ishihara Sangyo Co., Ltd.), TiO ₂ concentration of 30% by weight, volume average dispersed particle size of titanium oxide fine particles: 60 nm, 300 parts by weight of an organic dispersant (0% by weight) is placed in a container, and 100 parts by weight of an alkoxy-terminated silicone polymer (trade name: XR31-B0270, manufactured by GE Toshiba Silicone Co., Ltd.) with Mw = 10,000. Then, 500 parts by weight of methyl ethyl ketone was added, and 2000 parts by weight of zirconia beads having a diameter of 0.1 mm were further added to this mixture, and the mixture was stirred at 1500 rpm for 1 hour using a bead mill to disperse the fine particles. Titanium fine particles settled.

[Reference Preparation Example 5]
300 parts by weight of a titanium oxide fine particle aqueous dispersion (“STS-01” manufactured by Ishihara Sangyo Co., Ltd.) is placed in a container, and a condensate of a tetrafunctional silane compound alone (manufactured by Colcoat Co., Ltd., trade name: ethyl silicate) 48) Add 200 parts by weight and 500 parts by weight of methyl ethyl ketone, and further add 2000 parts by weight of 0.1 mm diameter zirconia beads to this mixture and stir at 1500 rpm for 1 hour using a bead mill to disperse the fine particles. However, the titanium oxide fine particles settled.

[Preparation Example 8]
Titanium oxide fine particles were dispersed in the same manner as in Reference Preparation Example 5 except that methyl ethyl ketone was changed to 500 parts by weight of isopropyl alcohol to prepare a metal oxide fine particle dispersion (iii).

[Example 1]
100 parts by weight of hydroxy-terminated polydimethylsiloxane (GE Toshiba Silicone Co., Ltd., trade name: XF-3905), 500 parts by weight of the above metal oxide fine particle dispersion (I) (100 parts by weight in terms of solid content, metal oxidation) After adding 83.3 parts by weight in terms of product fine particles) and stirring sufficiently to prepare a polysiloxane composition containing metal oxide fine particles, weigh a predetermined amount (approximately 2 g to the last four digits) in an aluminum dish. Then, it was dried at 100 ° C. for 30 minutes and at 200 ° C. for 1 hour to produce metal oxide fine particle-containing silicone material (1). The weight retention after the heat resistance test and after the heat and humidity resistance test of this silicone material was measured. The results are shown in Table 2.

[Examples 2 to 5]
Instead of the metal oxide fine particle dispersion (I), 500 parts by weight of the metal oxide fine particle dispersions (II) to (V) (100 parts by weight in terms of solid content, 83.3 weights in terms of metal oxide fine particles). Part) Silicone materials (2) to (5) containing metal oxide fine particles were prepared in the same manner as in Example 1 except for adding. The weight retention of these silicone materials after the heat resistance test and after the heat and humidity resistance test was measured. The results are shown in Table 2.

[Example 6]
The amount of the metal oxide fine particle dispersion (IV) added is 1500 parts by weight (300 in terms of solid content).
A metal oxide fine particle-containing silicone material (6) was produced in the same manner as in Example 4 except that the weight was changed to 250 parts by weight in terms of metal oxide fine particles. The weight retention after the heat resistance test and after the heat and humidity resistance test of this silicone material was measured. The results are shown in Table 2.

[Comparative Example 1]
100 parts by weight of hydroxy-terminated polydimethylsiloxane (manufactured by GE Toshiba Silicone Co., Ltd., trade name: XF-3905), 83.3 parts by weight of powdery rutile titanium oxide fine particles (primary average particle size: 30 nm) and methyl ethyl ketone 416 7 parts by weight in a container, and sufficiently agitated to prepare a polysiloxane composition containing metal oxide fine particles, weigh a predetermined amount (about 2 g to the last four digits) in an aluminum dish, 100 ° C. For 30 minutes at 200 ° C. for 1 hour to produce metal oxide fine particle-containing silicone material (C1). The weight retention after the heat resistance test and after the heat and humidity resistance test of this silicone material was measured. The results are shown in Table 2.

[Comparative Example 2]
100 parts by weight of hydroxy-terminated polydimethylsiloxane (GE Toshiba Silicone Co., Ltd., trade name: XF-3905), 83.3 parts by weight of powdery rutile-type titanium oxide fine particles (primary average particle size: 30 nm), 16.7 parts by weight of Mw = 1,000 alkoxy-terminated methyl silicone oligomer (trade name: X40-9220, manufactured by Shin-Etsu Chemical Co., Ltd.) as trifunctional polysiloxane, 0.1 part by weight of triethylamine, and methyl ethyl ketone 416.7 parts by weight are put in a container and sufficiently stirred to prepare a polysiloxane composition containing metal oxide fine particles. Then, a predetermined amount (about 2 g, weighed to the last four digits) is weighed in an aluminum dish, and 100 It was dried and cured at 200 ° C. for 30 minutes and at 200 ° C. for 1 hour to produce a metal oxide fine particle-containing silicone material (C2). The weight retention after the heat resistance test and after the heat and humidity resistance test of this silicone material was measured. The results are shown in Table 2.

[Comparative Examples 3 to 4]
Instead of the metal oxide fine particle dispersion (1), 500 parts by weight of the metal oxide fine particle dispersion (i) or (ii) (100 parts by weight in terms of solid content, 83.3 parts by weight in terms of metal oxide fine particles) ) A metal oxide fine particle-containing silicone material (C3) or (C4) was produced in the same manner as in Example 1 except that it was added. The weight retention of these silicone materials after the heat resistance test and after the heat and humidity resistance test was measured. The results are shown in Table 2. The silicone material (C4) colored yellow immediately after drying at 200 ° C., and the degree of yellow increased further when stored at 150 ° C.

[Comparative Example 5]
Instead of the metal oxide fine particle dispersion (1), the metal oxide fine particle dispersion (iii) is changed to 500
A silicone material containing metal oxide fine particles was prepared in the same manner as in Example 1 except that 100 parts by weight (100 parts by weight in terms of solid content and 83.3 parts by weight in terms of metal oxide fine particles) was added. Dimethylsiloxane was insolubilized and precipitated and separated and settled.

[Reference Example 1]
After preparing 100 parts by weight of hydroxy-terminated polydimethylsiloxane (GE Toshiba Silicone Co., Ltd., trade name: XF-3905) and 416.7 parts by weight of methyl ethyl ketone in a container and thoroughly stirring to prepare a polysiloxane composition A predetermined amount (weighed to the last four digits at about 2 g) was weighed in an aluminum dish, and dried and cured at 100 ° C. for 30 minutes and at 200 ° C. for 1 hour to produce a silicone material (R1). The weight retention after the heat resistance test and after the heat and humidity resistance test of this silicone material was measured. The results are shown in Table 2.

Claims (12)

In the presence of a basic compound, acidic compound or metal chelate compound in an organic solvent, the metal oxide fine particles and the following average composition formula (1)
R ¹ _a SiO _b (OR ² ) _c (1)
(In the formula, R ¹ is a monovalent hydrocarbon group having no hydrogen atom or oxyalkylene group;
When a plurality of R ¹ are present, they may be the same or different from each other, R ² is a hydrogen atom or an alkyl group, and when a plurality of R ² are present, they may be the same or different from each other. A is greater than 0 and less than 2, b is greater than 0 and less than 2, c is greater than 0 and less than 4, and a + b × 2 + c = 4)
A metal oxide fine particle dispersion obtained by mixing the polyfunctional polysiloxane represented by the formula (1) and dispersing the metal oxide fine particles in an organic solvent;
A metal oxide fine particle-containing polysiloxane composition obtained by mixing a silicone having a polydimethylsiloxane structure.   2. The metal oxide fine particle-containing polysiloxane composition according to claim 1, wherein the metal oxide fine particle dispersion has a water content of 5% by weight or less.   The metal oxide fine particle-containing polysiloxane composition according to claim 1 or 2, wherein the metal oxide fine particles and the polyfunctional polysiloxane are mixed in the presence of a basic compound.   4. The metal oxide fine particle-containing polysiloxane composition according to claim 3, wherein the basic compound is an organic amine compound.   5. The weight average molecular weight of the polyfunctional polysiloxane is in the range of 1,000 to 100,000 in terms of polystyrene measured by gel permeation chromatography. 6. Metal oxide fine particle-containing polysiloxane composition.   The metal oxide fine particle-containing polysiloxane composition according to any one of claims 1 to 5, wherein the metal oxide fine particles and the polyfunctional polysiloxane are mixed by a bead mill.   The metal oxidation according to any one of claims 1 to 6, wherein 1 to 1000 parts by weight of the polyfunctional polysiloxane in terms of complete hydrolysis condensate is mixed with 100 parts by weight of the metal oxide fine particles. Fine particle-containing polysiloxane composition.   A metal material containing fine metal oxide particles obtained from the polysiloxane composition containing fine metal oxide particles according to claim 1.   An LED encapsulant obtained from the metal oxide fine particle-containing polysiloxane composition according to claim 1, wherein the metal oxide fine particle is a phosphor. In the presence of a basic compound, acidic compound or metal chelate compound in an organic solvent, the metal oxide fine particles and the following average composition formula (1)
R ¹ _a SiO _b (OR ² ) _c (1)
(In the formula, R ¹ is a monovalent hydrocarbon group having no hydrogen atom or oxyalkylene group;
When a plurality of R ¹ are present, they may be the same or different from each other, R ² is a hydrogen atom or an alkyl group, and when a plurality of R ² are present, they may be the same or different from each other. A is greater than 0 and less than 2, b is greater than 0 and less than 2, c is greater than 0 and less than 4, and a + b × 2 + c = 4)
After mixing with the polyfunctional polysiloxane represented by the above, the metal oxide fine particles are dispersed in an organic solvent to prepare a metal oxide fine particle dispersion,
A method for producing a metal oxide fine particle-containing polysiloxane composition, comprising mixing the metal oxide fine particle dispersion and a silicone having a polydimethylsiloxane structure.   The method for producing a metal oxide fine particle-containing polysiloxane composition according to claim 10, wherein the metal oxide fine particles and the polyfunctional polysiloxane are mixed in the presence of a basic compound.   The method for producing a polysiloxane composition containing metal oxide fine particles according to claim 10 or 11, wherein the metal oxide fine particles and the polyfunctional polysiloxane are mixed by a bead mill.