JP6374696B2 - Method for producing surface-modified inorganic oxide particles and organic-inorganic composite particles - Google Patents

Description

  The present invention relates to surface-modified inorganic oxide particles and a method for producing organic-inorganic composite particles using the surface-modified inorganic oxide particles.

  Conventionally, attempts have been made to improve optical characteristics and control the refractive index by combining inorganic fine particles with a polymer. As a method of combining the inorganic fine particles and the polymer, a method of mixing an inorganic oxide and a polymer is generally used (see Patent Document 1). On the other hand, Patent Document 2 discloses a method for producing an organic-inorganic composite in which a polymerization initiating group is bonded to inorganic compound particles and a polymer is polymerized from the polymerization initiating group.

JP-A-11-326601 International Publication No. 2012-115057

  However, in the method of Patent Document 1, the inorganic fine particles are dispersed in the polymer, and when the coating agent is applied to the substrate and dried, the inorganic fine particles and the polymer become non-uniform, and the inorganic oxide and the polymer Depending on the ratio, a problem such as aggregation and turbidity of the inorganic fine particles may occur, and the target composite may not be obtained.

  When the organic-inorganic composite obtained by the method of Cited Document 2 is dispersed in a solvent or the like and used, sufficient dispersibility may not be obtained.

  Accordingly, an object of the present invention is to provide surface-modified inorganic oxide particles having excellent dispersibility and a method for producing organic-inorganic composite particles using the inorganic oxide particles.

［式（１）中、Ｒ_１及びＲ_２はそれぞれ独立に、無機酸化物粒子の表面と結合する単結合、水素原子又は炭素数１〜５のアルキル基を示し、Ｒ_３は−ＣＨ_２−、−Ｏ−、−ＮＨ−、−ＮＣＨ_３−又−ＮＣ_６Ｈ_５−を示し、Ｒ_４及びＲ_５はそれぞれ独立に、水素原子、炭素数１〜５のアルキル基又は炭素数６〜１２のアリール基を示し、Ｘはハロゲン原子を示し、ｎは１〜１０の整数を示す。］

［式（２）中、Ｒ_６は、前記一般式（１）で表される有機ケイ素基とは異なる有機ケイ素基を示し、ハロゲン原子を含んでいてもよい。］
［２］Ｒ_６が下記一般式（３）で表される有機ケイ素基である、［１］に記載の表面改質無機酸化物粒子。

［式（３）中、Ｒ_７、Ｒ_８及びＲ_９は各々独立に水素原子又は炭素数１〜５のアルキル基を示し、Ｒ_７、Ｒ_８及びＲ_９はのうち少なくとも一つは炭素数１〜５のアルキル基である。］
［３］無機酸化物粒子の単位面積当たりの一般式（１）で表される有機ケイ素基の修飾量が、０．００１〜０．５本／ｎｍ^２であり、一般式（２）で表される有機ケイ素基の修飾量が、１．５本／ｎｍ^２〜１０本／ｎｍ^２である、［１］又は［２］に記載の表面改質無機酸化物粒子。
［４］Ｒ_１及びＲ_２が、それぞれ独立に水素又は炭素数１〜５のアルキル基である、［１］〜［３］のいずれかに記載の表面改質無機酸化物粒子。
［５］無機酸化物粒子の粒径が１〜２００ｎｍである、［１］〜［４］のいずれかに記載の表面改質無機酸化物粒子。
［６］無機酸化物粒子が、酸化ケイ素、酸化チタン及び酸化ジルコニウムからなる群より選ばれる少なくとも１種を含む、［１］〜［５］のいずれかに記載の表面改質無機酸化物粒子。
［７］一般式（１）のＸが、臭素原子、塩素原子又はヨウ素原子である、［１］〜［６］のいずれかに記載の表面改質無機酸化物粒子。
［８］凝集度が５以下である、［１］〜［７］のいずれかに記載の表面改質無機酸化物粒子。
［９］［１］〜［８］のいずれかに記載の表面改質無機酸化物粒子と、重合性モノマーとを、触媒の存在下で重合する重合工程を備える、有機無機複合粒子の製造方法。
［１０］重合工程を溶媒の存在下で行う、［９］に記載の方法。
［１１］触媒が銅触媒である、［９］又は［１０］に記載の方法。
［１２］重合性モノマーが、アクリル酸エステル、メタクリル酸エステル及びスチレン類からなる群より選ばれる少なくとも１種を含む、［９］〜［１１］のいずれかに記載の方法。
［１３］［１］〜［８］のいずれかに記載の表面改質無機酸化物粒子と、［９］〜［１２］のいずれかに記載の方法により得られる有機無機複合粒子とを含む組成物。 The present invention relates to the following.
[1] Surface-modified inorganic oxide particles having an organosilicon group represented by the following general formula (1) and an organosilicon group represented by the following general formula (2) on the surface of the inorganic oxide particles .

[In Formula (1), R ₁ and R ₂ each independently represent a single bond, a hydrogen atom or an alkyl group having 1 to 5 carbon atoms bonded to the surface of the inorganic oxide particle, and R ₃ represents —CH ₂ —. , —O—, —NH—, —NCH ₃ — or —NC ₆ H ₅ —, wherein R ₄ and R ₅ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or 6 to 12 carbon atoms. X represents a halogen atom, and n represents an integer of 1 to 10. ]

[In Formula (2), R ₆ represents an organosilicon group different from the organosilicon group represented by Formula (1), and may contain a halogen atom. ]
[2] The surface-modified inorganic oxide particles according to [1], wherein R ₆ is an organosilicon group represented by the following general formula (3).

[In the formula (3), R ₇ , R ₈ and R ₉ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and at least one of R ₇ , R ₈ and R ₉ is the number of carbon atoms. 1 to 5 alkyl groups. ]
[3] The modification amount of the organosilicon group represented by the general formula (1) per unit area of the inorganic oxide particles is 0.001 to 0.5 / nm ² , and is represented by the general formula (2). The surface-modified inorganic oxide particles according to [1] or [2], wherein the modified amount of the organosilicon group is 1.5 / nm ² to 10 / nm ² .
[4] The surface-modified inorganic oxide particles according to any one of [1] to [3], wherein R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 5 carbon atoms.
[5] The surface-modified inorganic oxide particles according to any one of [1] to [4], wherein the inorganic oxide particles have a particle size of 1 to 200 nm.
[6] The surface-modified inorganic oxide particles according to any one of [1] to [5], wherein the inorganic oxide particles include at least one selected from the group consisting of silicon oxide, titanium oxide, and zirconium oxide.
[7] The surface-modified inorganic oxide particle according to any one of [1] to [6], wherein X in the general formula (1) is a bromine atom, a chlorine atom, or an iodine atom.
[8] The surface-modified inorganic oxide particles according to any one of [1] to [7], wherein the degree of aggregation is 5 or less.
[9] A method for producing organic-inorganic composite particles, comprising a polymerization step of polymerizing the surface-modified inorganic oxide particles according to any one of [1] to [8] and a polymerizable monomer in the presence of a catalyst. .
[10] The method according to [9], wherein the polymerization step is performed in the presence of a solvent.
[11] The method according to [9] or [10], wherein the catalyst is a copper catalyst.
[12] The method according to any one of [9] to [11], wherein the polymerizable monomer includes at least one selected from the group consisting of acrylic acid esters, methacrylic acid esters, and styrenes.
[13] A composition comprising the surface-modified inorganic oxide particles according to any one of [1] to [8] and the organic-inorganic composite particles obtained by the method according to any one of [9] to [12]. object.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the organic-inorganic composite particle | grains using the inorganic oxide particle which is excellent in the dispersibility, and this inorganic oxide particle can be provided.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as the present embodiment) will be described in detail. In addition, this invention is not limited to this Embodiment, It can implement by changing variously within the range of the summary. In addition, it is to be understood that the terms used in the present specification are used in the meaning normally used in the art unless otherwise specified.

<Surface modified inorganic oxide particles>
The surface-modified inorganic particles of the present embodiment have an organosilicon group represented by the following general formula (1) and an organosilicon group represented by the following general formula (2) on the surface of the inorganic oxide particles.

式（１）中、Ｒ_１及びＲ_２は無機酸化物粒子表面と結合していてもよく、結合していなくてもよい。Ｒ_１及びＲ_２が無機酸化物粒子の表面と結合している場合、単結合を示し、無機酸化物粒子表面と結合していない場合、それぞれ独立に、水素原子又は炭素数１〜５のアルキル基を示す。Ｒ_３は−ＣＨ_２−、−Ｏ−、−ＮＨ−、−ＮＣＨ_３−又−ＮＣ_６Ｈ_５−を示し、Ｒ_４及びＲ_５はそれぞれ独立に、水素原子、炭素数１〜５のアルキル基又は炭素数６〜１２のアリール基を示す。Ｘはハロゲン原子を示し、ハロゲン原子としては、臭素原子、塩素原子及びヨウ素原子が挙げられる。ｎは１〜１０の整数を示す。

In formula (1), R ₁ and R ₂ may be bonded to the surface of the inorganic oxide particles or may not be bonded. When R ₁ and R ₂ are bonded to the surface of the inorganic oxide particles, they represent a single bond, and when not bonded to the surface of the inorganic oxide particles, each independently represents a hydrogen atom or an alkyl having 1 to 5 carbon atoms. Indicates a group. R ₃ represents —CH ₂ —, —O—, —NH—, —NCH ₃ — or —NC ₆ H ₅ —, wherein R ₄ and R ₅ each independently represent a hydrogen atom or an alkyl having 1 to 5 carbon atoms. Group or an aryl group having 6 to 12 carbon atoms. X represents a halogen atom, and examples of the halogen atom include a bromine atom, a chlorine atom, and an iodine atom. n shows the integer of 1-10.

式（２）中、Ｒ_６は、一般式（１）で表される有機ケイ素基とは異なる有機ケイ素基を示し、ハロゲン原子を含んでいてもよい。Ｒ_６は、下記一般式（３）で表される有機ケイ素基であることが好ましい。

In the formula (2), R ₆ represents an organosilicon group different from the organosilicon group represented by the general formula (1), and may contain a halogen atom. R ₆ is preferably an organosilicon group represented by the following general formula (3).

式（３）中、Ｒ_７、Ｒ_８及びＲ_９は各々独立に水素原子又は炭素数１〜５のアルキル基を示す、ただし、Ｒ_７、Ｒ_８及びＲ_９はのうち少なくとも一つは炭素数１〜５のアルキル基であり、炭素数１〜３のアルキル基であることが好ましい。また、アルキル基を構成する水素原子はハロゲン原子に置換されておいてもよい。

In formula (3), R ₇ , R ₈ and R ₉ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, provided that at least one of R ₇ , R ₈ and R ₉ is carbon. It is a C1-C5 alkyl group, and it is preferable that it is a C1-C3 alkyl group. Moreover, the hydrogen atom which comprises an alkyl group may be substituted by the halogen atom.

(Organosilicon base)
In this embodiment, the organosilicon group is a bonding group composed of an organic substance and silicon, and is present on the surface of the inorganic oxide particles. The surface of the inorganic oxide particle before the organosilicon group is bonded may be formed from the inorganic oxide itself or may be surface-treated. The surface treatment here is to modify the surface of the inorganic oxide particles with a functional group by chemical reaction, heat treatment, light irradiation, plasma irradiation, radiation irradiation or the like.

  The method for bonding the organic silicon group to the surface of the inorganic oxide particle is not particularly limited. For example, the method of reacting the hydroxyl group on the surface of the inorganic oxide particle with the organic silicon compound, or the surface of the inorganic oxide particle There is a method of reacting a functional group introduced by the surface treatment with an organosilicon compound. It is also possible to link a plurality of organosilicon groups by further reacting an organosilicon compound with the organosilicon groups bonded to the inorganic oxide particles. Further, depending on the type of the organosilicon compound, water or a catalyst may be used in combination.

  The number of functional groups that the organosilicon compound binds to the surface of the inorganic oxide particles is not particularly limited, but is preferably monofunctional. When two or more functional groups are present, a condensate (by-product) of the organosilicon compound is generated and tends to be difficult to remove. In addition, when the organic-inorganic composite particles using the surface-modified inorganic oxide particles are formed into a film shape, the functional groups of the unreacted organosilicon compound remain in the organic-inorganic composite particles, so heat drying and heat processing are performed. Depending on the process and the like, low-boiling components such as alcohol and water are generated, and the film tends to foam. Moreover, it can also become a factor which inorganic oxide particle aggregates.

  The organosilicon group preferably has a polymerization initiating group. The polymerization initiating group possessed by the organosilicon group is not particularly limited as long as it is a functional group having polymerization initiating ability. For example, the coupling group containing a halogen atom is mentioned. A polymerization method using an organic halogen compound as a polymerization radical initiator and a transition metal complex as a catalyst is referred to as atom transfer radical polymerization (hereinafter referred to as “ATRP”). The bond dissociation energy of the halogen atom in the organosilicon group is preferably low. The polymerization initiating group includes, for example, a halogen atom bonded to a tertiary carbon atom, a halogen atom bonded to a carbon atom adjacent to an unsaturated carbon-carbon bond such as a vinyl group, a vinylidene group, and a phenyl group, a carbonyl group, a cyano group, and A group in which a halogen atom bonded directly to a hetero atom-containing conjugated group such as a sulfonyl group or bonded to an atom adjacent thereto is introduced as a preferable structure. More specifically, an organic halide group represented by the following general formula (4) is suitable as the polymerization initiating group.

式（４）中、Ｒ_４、Ｒ_５及びＸは一般式（１）中のＲ_４、Ｒ_５及びＸと同義である。

Wherein _(4), R 4, _{R 5} and X are as in formula (1) the same meaning as _R 4, _{R 5} and X in.

Specific examples of the polymerization initiating group represented by the general formula (4) are shown in the following chemical formula.

  That is, the organosilicon group represented by the general formula (1) according to the present embodiment has an organic halide group represented by the general formula (4) as a polymerization initiating group.

Specific examples of the organosilicon compound having an organosilicon group represented by the general formula (1) include the following silane compounds.
3- (2-Bromoisobutyroxy) propyldimethylchlorosilane (Cas number: 370870-81-8)
Propionic acid, 2-bromo-2-methyl-, 3- (dichloromethylsilyl) propyl ester (Cas number: 1057260-39-5)
Propionic acid, 2-bromo-2-methyl-, 3- (trichlorosilyl) propyl ester (Cas number: 688359-84-4)
3- (methoxydimethylsilylpropyl) -2-bromo-2-methylpropionate (Cas number: 531505-27-8)
3- (Dimethoxymethylsilylpropyl) -2-bromo-2-methylpropionate (Cas number: 1186667-60-6)
3- (Trimethoxysilylpropyl) -2-bromo-2-methylpropionate (Cas number: 314021-97-1)
(3- (2-Bromoisobutyryl) propyl) dimethylethoxysilane (Cas number: 265119-86-6)
(3- (2-Bromoisobutyryl) propyl) methyldiethoxysilane (Cas number: 11866667-65-1)
Propionic acid, 2-bromo-2-methyl-, 3- (triethoxysilyl) propyl ester (Cas number: 880339-31-1)
Propionic acid, 2-bromo-, 3- (chlorodimethylsilyl) propyl ester (Cas number: 438001-36-6)
Propionic acid, 2-bromo-, 3- (trichlorosilyl) propyl ester (Cas number: 663174-64-9)
Propionic acid, 2-bromo-, 3- (methoxydimethylsilyl) propyl ester (Cas number: 861807-46-7)
(3- (2-Bromopropionyl) propyl) dimethylethoxysilane (Cas number: 265119-85-5)
(3- (2-Bromopropionyl) propyl) triethoxysilane (Cas number: 1233513-06-8)

Examples of the organosilicon compound that can form the organosilicon group represented by the general formula (2) on the surface of the inorganic oxide particles include compounds having the organosilicon group represented by the general formula (3). There are the following silane compounds.
Hexamethyldisilazane (Cas number: 999-97-3)
N, N-bis (trimethylsilyl) urea (Cas number: 18297-63-7)
N, O-bis (trimethylsilyl) trifluoroacetamide (Cas number: 25561-30-2)
Trimethylsilyl trifluoromethanesulfonate (Cas number: 27607-77-8)
Triethylsilane (Cas number: 617-86-7)
Trimethylsilyl acetylene (Cas number: 1066-54-2)
Hexamethyldisilane (Cas number: 1450-14-2)
Allyltrimethylsilane (Cas number: 762-72-1)
Trimethylvinylsilane (Cas number: 754-05-2)
・ Methyltrimethoxysilane (Cas number: 1185-55-3)
Dimethyldimethoxysilane (Cas number: 1112-39-6)
Phenyltrimethoxysilane (Cas number: 2996-92-1)
・ Methyltriethoxysilane (Cas number: 2031-67-6)
Dimethyldiethoxysilane (Cas number: 78-62-6)
Phenyltriethoxysilane (Cas number: 780-69-8)
・ Hexyltrimethoxysilane (Cas number: 3069-19-0)
-Hexyltriethoxysilane (Cas number: 18166-37-5)
Decyltrimethoxysilane (Cas number: 5575-48-4)

The modification amount of the organosilicon group represented by the general formula (1) in the surface-modified inorganic oxide particles is preferably 0.001 to 0.5 / nm ² per unit area of the inorganic oxide particles, More preferably, it is 0.005 to 0.3 / nm ² , and still more preferably 0.01 to 0.1 / nm ² . When the modification amount of the organosilicon group represented by the general formula (1) is within the above range, the dispersibility of the surface-modified inorganic oxide particles is improved, and the particles are less likely to aggregate.

The modification amount of the organosilicon group represented by the general formula (2) in the surface-modified inorganic oxide particles is preferably 1.5 to 10 / nm ² per unit area of the inorganic oxide particles. It is more preferably 5-7 lines / nm ² , and further preferably 1.5-5 lines / nm ² . When the modification amount of the organosilicon group represented by the general formula (2) is in the above range, the dispersibility of the surface-modified inorganic oxide particles is improved, and the particles are less likely to aggregate.

  When the organosilicon group represented by the general formula (1) or (2) contains a halogen atom, the modification amount of the organosilicon group is determined by the method of elemental analysis, fluorescent X-ray analysis (XFR) described later, or the like. It can be calculated by measuring the content. On the other hand, when the organosilicon group represented by the general formula (1) or (2) does not contain a halogen atom, the modification amount of the organosilicon group is modified by a method such as X-ray electron spectroscopy (XPS) described later. It can be calculated by measuring the carbon content in the porous inorganic oxide particles.

  The modification amount of the organosilicon group represented by the general formulas (1) and (2) is appropriately adjusted depending on the blending amount of the organosilicon compound, reaction conditions, and the like when the inorganic oxide particles and the organosilicon compound are reacted. be able to.

(Inorganic oxide particles)
In this specification, an inorganic oxide is an oxide composed of one kind of inorganic component and oxygen, or a composite oxide composed of two or more kinds of inorganic components and oxygen. Plural kinds of elements may be present uniformly or unevenly in the particle, and the surface of one element may be covered with a compound of another element. The inorganic component is a group 1 alkali metal, a group 2 alkaline earth metal, a group 3-12 transition metal, a group 13-15 typical metal, and a semimetal such as boron, silicon, germanium, and the like. Furthermore, in the composite oxide containing two or more kinds of inorganic components, for example, nonmetallic components such as sulfur, phosphorus, and chlorine may be contained. The inorganic oxide particle according to the present embodiment is not particularly limited as long as it is a particle formed from an inorganic oxide, but from the viewpoint of easy availability, silicon oxide, titanium oxide, or zirconium oxide. Are preferred, and silicon oxide is particularly preferred.

  The shape and crystal form of the inorganic oxide particles are not particularly limited. For example, various shapes such as spherical, crystalline, scale-like, columnar, tubular, fibrous, hollow, porous, beaded, etc. It may be. Among these, commercially available hollow, beaded, or spherical inorganic oxide particles can be suitably used.

  The particle size of the inorganic oxide particles is not particularly limited, but is preferably 1 to 200 nm. In the present specification, the particle diameter means an average value of the outer diameters of the particles. When used as an optical material application, when the particle size of the inorganic oxide particles is 200 nm or less, problems such as light scattering hardly occur, and when the particle size is 1 nm or more, it is specific to the substance constituting the inorganic oxide particles. The characteristics can be demonstrated. As an optical material application, the particle size of the inorganic oxide particles is more preferably 1 to 150 nm, and still more preferably 10 to 100 nm. In particular, when transparency is required for organic / inorganic double particles having high film formability, and coating films, molded products, optical materials and the like using the same, the size of the particles needs to be in the Rayleigh scattering region. Therefore, the average particle size of the inorganic oxide particles is more preferably 10 to 70 nm, and particularly preferably 10 to 60 nm. A method for measuring the average particle diameter of the inorganic oxide particles will be described in detail in Examples described later.

(Method for producing surface-modified inorganic oxide particles)
The method for producing the surface-modified inorganic oxide particles according to the present embodiment is not particularly limited, but the surface-modified inorganic oxide particles have, for example, a polymerization initiating group on the surface of the inorganic oxide particles. It can be obtained by a step of bonding an organosilicon compound and an organosilicon compound having no polymerization initiating group.

  Surface-modified inorganic oxide in which organic silicon groups represented by general formulas (1) and (2) are introduced on the surface of inorganic oxide particles by reacting inorganic oxide particles with a specific organosilicon compound Particles are obtained. The reaction between the inorganic oxide particles and the specific organosilicon compound can be performed in a reaction liquid in which they are dispersed or dissolved, and the reaction may be performed while heating.

The surface-modified inorganic oxide particles may be produced as follows.
(A) An organic silicon compound having a polymerization initiating group is added to the dispersion of inorganic oxide particles and reacted at a predetermined temperature, and then an organosilicon compound having no polymerization initiating group is added and reacted to cause surface modification. A dispersion of porous inorganic oxide particles is obtained.
(B) After cooling the dispersion to room temperature, it is washed with a predetermined solvent, and the solid content is separated and dried by centrifugation or the like to isolate the surface-modified inorganic oxide particles.

  The organosilicon compound having a polymerization initiating group includes an organosilicon compound having a group represented by the general formula (4), and the organosilicon compound having no polymerization initiating group is represented by the general formula (3). And an organosilicon compound having a group.

  The compounding amount of the organosilicon compound with respect to the inorganic oxide particles is not particularly limited, but the compounding amount of the organosilicon compound having an organosilicon group represented by the general formula (1) is 100 g of the inorganic oxide particle amount, 0.0005 mol-1 mol is preferable, 0.0005 mol-0.5 mol is more preferable, 0.001 mol-0.2 mol is still more preferable. If the compounding amount of the organosilicon compound having an organosilicon group represented by the general formula (1) is 0.0005 mol or more, it easily reacts efficiently with the surface of the inorganic oxide particles. It becomes easy to remove the unreacted organosilicon compound from.

  Although the compounding quantity of the organosilicon compound which can form the organosilicon group represented by General formula (2) on the surface of an inorganic oxide particle is not specifically limited, 0.01 mol-5 mol with respect to 100 g of inorganic oxide particle amounts Is preferable, 0.01 mol to 2 mol is more preferable, and 0.01 mol to 1 mol is still more preferable. If the compounding amount of the organosilicon compound capable of forming the organosilicon group represented by the general formula (2) on the surface of the inorganic oxide particles is 0.001 mol or more, it easily reacts efficiently with the surface of the inorganic oxide particles, If it is 5 mol or less, an unreacted organosilicon compound will hardly remain.

  Although the reaction proceeds between the inorganic oxide particles and the organosilicon compound at room temperature, the reaction proceeds, but from the viewpoint of efficiency, 40 ° C to 90 ° C is preferable, 50 ° C to 90 ° C is more preferable, and 60 ° C to 85 ° C is more preferable. Further preferred.

  The aggregation degree of the surface-modified inorganic oxide particles is preferably 5 or less. The degree of aggregation indicates the redispersibility of the surface-modified inorganic oxide particles in the solvent, and is preferably 4 or less, more preferably 3 or less, from the viewpoint of dispersibility when the inorganic oxide particles are used for organic-inorganic composite. preferable.

<Method for producing organic-inorganic composite particles>
The organic-inorganic composite particles according to the present embodiment can be produced by a method including a polymerization step in which the surface-modified inorganic oxide particles and the polymerizable monomer are polymerized in the presence of a catalyst.

  More specifically, after the surface-modified inorganic oxide particles are dispersed in a solvent, a polymerizable monomer and a catalyst are added, a polymerization reaction is performed under a predetermined condition, and the polymerizable monomer initiated by the polymerization initiating group is Organic radical composite particles can be obtained by forming a polymer bonded to inorganic oxide particles by living radical polymerization.

(Polymerizable monomer)
The polymerizable monomer is not particularly limited, but is preferably polymerizable by ATRP. A single monomer may be used alone, or two or more different monomers may be used.

  Examples of the monomer include ethylene, “dienes such as buta-1,3-diene, 2-methylbuta-1,3-diene, 2-chlorobuta-1,3-diene”, “styrene, α-methyl. Styrenes such as styrene, 4-methylstyrene, 4-hydroxystyrene, acetoxystyrene, 4-chloromethylstyrene 2,3,4,5,6-pentafluorostyrene, 4-aminostyrene "," methyl acrylate, acrylic Ethyl acid, n-butyl acrylate, tert-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, octadecyl acrylate, cyclohexyl acrylate, benzyl acrylate, trimethylsilyl acrylate, amide acrylate, acrylic Acid 2- (dimethylamino) ethyl, 2,2,2-trifluoroethyl laurate, 2,2,3,3-tetrafluoropropyl acrylate, 1,1,1,3,3,3-hexafluoroisopropyl acrylate, 1H, 1H acrylic acid , 2H, 2H-heptadecafluorodecyl, 1H, 1H, 3H-hexafluorobutyl acrylate, 1H, 1H, 5H-octafluoropentyl acrylate, 1H, 1H-heptafluorobutyl acrylate, 2-isocyanato acrylate Acrylic esters such as ethyl, 1,1- (bisacryloyloxymethyl) ethyl isocyanate ”,“ methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, isobutyl methacrylate, methacrylic acid 2 ” -Ethylhexyl, octyl methacrylate, methacryl Octadecyl acid, cyclohexyl methacrylate, benzyl methacrylate, trimethylsilyl methacrylate, methacrylic acid amide, 2- (dimethylamino) ethyl methacrylate, 2- (diethylamino) ethyl methacrylate, 2,2,2-trifluoroethyl methacrylate, 1H, 1H, 2H, 2H-heptadecafluorodecyl methacrylate, 1H, 1H, 3H-hexafluorobutyl methacrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 1H, 1H, 5H methacrylate Octafluoropentyl, 1H, 1H, 7H-dodecafluoropentyl methacrylate, 2-isocyanatoethyl methacrylate, 2- (0- [1′-methylpropylideneamino] carboxyamino) ethyl methacrylate, 2-[(3 , 5-Dimethylpyra Methacrylic acid esters such as “(yl) carbonylamino] ethyl methacrylate”, “2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxybutyl acrylate” 4-hydroxybutyl acrylate, 2-hydroxyhexyl acrylate, 6-hydroxyhexyl acrylate, 3-perfluorobutyl-2-hydroxypropyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, acrylic acid 3-perfluorooctyl-2-hydroxypropyl, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, meta 3-hydroxybutyl toluate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl methacrylate, cyclohexyl methacrylate, 3-perfluorobutyl-2-hydroxypropyl methacrylate, 3-perfluorohexyl-2-hydroxypropyl methacrylate , 3-perfluorooctyl-2-hydroxypropyl methacrylate, acrylamide, methacrylamide, N-cyclopropylacrylamide, N, N-dimethylacrylamide, N-hydroxymethylacrylamide, N-isopropylacrylamide, acrylonitrile, methacrylonitrile, etc. (Meth) acrylic acid derivatives ”,“ vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate ”,“ vinyl methyl ether, vinyl Vinyl ethers such as ethyl ether ”,“ N-vinyl compounds such as vinyl methyl ketone, vinyl hexyl ketone, vinyl ketones, N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone ”,“ allyl ” "Allyl compounds such as alcohol, allyl chloride, allyl acetate, vinyl chloride, vinylidene chloride", "compounds having a fluorine alkyl group such as vinyl fluoride, vinylidene fluoride", "glycidyl acrylate, glycidyl methacrylate, 4-glycidyl Functional monomers such as styrene ”,“ reactivity of allyl acrylate, allyl methacrylate, diacrylic anhydride, 1,2-ethanediyl diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, divinylbenzene, etc. Compounds having a double bond two or more ", and the like. Among these, when importance is attached to the transparency of the coating film or the molded product, it is preferable to select styrenes, acrylic esters or methacrylic esters.

  Specific examples of preferable polymerizable monomers are shown below by chemical formulas.

メタクリル酸エステル

Methacrylic acid ester

アクリル酸エステル

Acrylic ester

スチレン類

Styrenes

  The polymerization form of the monomer is not particularly limited, and examples thereof include homopolymerization, block copolymerization, random copolymerization, gradient copolymerization, tapered copolymerization, and graft copolymerization. Among these, from the viewpoint of controlling physical properties such as Tg and refractive index, copolymerization is preferable, and graft copolymerization is more preferable.

  The method of radical polymerization is not particularly limited, and for example, a bulk polymerization method or a solution polymerization method can be selected. Furthermore, from the viewpoint of productivity and safety, methods such as suspension polymerization, emulsion polymerization, dispersion polymerization, and seed polymerization may be employed.

  The polymerization temperature is not particularly limited and can be appropriately selected according to the polymerization method and the monomer type. For example, in the case of ATRP, the polymerization temperature is preferably -50 ° C to 200 ° C, more preferably 0 ° C to 150 ° C, still more preferably 20 ° C to 130 ° C. When the monomer contains an acrylic ester and / or a methacrylic ester, when polymerization is carried out at 40 to 130 ° C., precise polymerization can be carried out in a relatively short time.

  The polymerization time is not particularly limited and can be appropriately selected depending on the polymerization method and the monomer type, and can be, for example, 1 to 32 hours. When the polymerization time is within this range, the content of the inorganic oxide particles in the organic-inorganic composite particles becomes preferable. From the same viewpoint, the polymerization time is more preferably 1.5 to 24 hours.

  The polymerization reaction may be performed without a solvent or in the presence of a solvent. When using a solvent, a solvent having good dispersibility of the surface-modified inorganic oxide particles and solubility of the polymerization catalyst is preferable. A solvent may be used independently or may be used in combination of multiple types.

  The type of the solvent is not particularly limited. For example, acetone, methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), anisole, toluene, xylene, tetrahydrofuran (THF), 1-propanol, 2-propanol, methanol , Ethanol, 1-butanol, t-butanol, acetonitrile, dimethylformamide (DMF), dimethylacetamide, dimethyl sulfoxide (DMSO), N-methylpyrrolidone, 1,4-dioxane, water and the like.

  Although the usage-amount of a solvent is not specifically limited, For example, 0-2000 mass parts is preferable with respect to 100 mass parts of monomers, More preferably, it is 0-1000 mass parts. If the amount of the solvent is small, the reaction rate tends to be large, which is advantageous, but depending on the monomer species and the polymerization conditions, the viscosity of the polymerization solution tends to increase. In addition, when the amount of the solvent is large, the viscosity of the polymerization solution is lowered, but the reaction rate is lowered.

The polymerization reaction may be performed without a catalyst or using a catalyst, but it is preferable to use a catalyst from the viewpoint of productivity. The type of the catalyst is not particularly limited, but any catalyst may be appropriately used depending on the polymerization method, the monomer type, and the like. For example, in the case of ATRP, the type of catalyst may be appropriately selected from various commonly known types according to the polymerization method and the like. Specifically, for example, a metal catalyst containing Cu (0), Cu ⁺ , Cu ²⁺ , Fe ⁺ , Fe ²⁺ , Fe ³⁺ , Ru ²⁺ or Ru ³⁺ can be used. Among these, in order to achieve a high degree of control of molecular weight and molecular weight distribution, a monovalent copper compound containing Cu ⁺ and zero-valent copper are particularly preferable. Specific examples thereof include copper catalysts such as Cu (0), CuCl, CuBr, CuBr ₂ , and Cu ₂ O. These may be used alone or in combination. The usage-amount of a catalyst is 0.01-100 mol normally with respect to 1 mol of polymerization start groups, Preferably it is 0.01-50 mol, More preferably, it is 0.01-10 mol.

<Composition>
The composition of the present embodiment is a mixture containing surface-modified inorganic particles and organic-inorganic composite particles, and may be dispersed in another resin, or may be dispersed in a solvent. It may be dissolved in the resin or solvent.

  When the surface-modified inorganic particles or organic-inorganic composite particles in the composition of the present embodiment are dissolved in a resin or a solvent, it is preferable in terms of uniformity in the composition. The composition may be in the form of a powder. When the composition is in a powder form, it is preferable in terms of storage stability.

  Examples of the present embodiment will be described below more specifically. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

<Raw materials>
The contents of the raw materials used in the reference examples, examples and comparative examples are shown in (1) to (2).

(1) Inorganic oxide particle solution 20 nm spherical silica solution: manufactured by Nissan Chemical Industries, Ltd., trade name “MEK-ST”, SiO ₂ content 30 mass%, specific surface area 220 m ² / g (measured by BET method by nitrogen adsorption) )

(2) Organosilicon compound (2-1) (3- (2-bromoisobutyryl) propyl) dimethylethoxysilane (hereinafter referred to as BIDS)
BIDS represented by the following chemical formula (5) was synthesized according to a known method (Japanese Patent Laid-Open No. 2006-257308).

(2-2) 1,1,1,3,3,3-hexamethyldisilazane (hereinafter referred to as HMDS): manufactured by Tokyo Chemical Industry Co., Ltd.

[Synthesis of surface modified inorganic oxide particles]
( Reference Example 1)
A condenser tube was connected, and the inside of the two-necked flask containing the rotor was purged with nitrogen. Under nitrogen, 500 g of a 20 nm spherical silica solution was introduced into the flask, and 2.9 mL of BIDS was further introduced, and stirring was started. The flask was immersed in an 80 ° C. oil bath and reacted for 2 hours with stirring. After the reaction was cooled to room temperature, 43.0 mL of HMDS was introduced under nitrogen. After stirring at room temperature for 2 hours, the reaction was performed by stirring at 80 ° C. for 3 hours, and the reaction solution was cooled to room temperature. The reaction solution was poured into hexane, transferred to a centrifuge tube, and centrifuged at 10,000 rpm, 10 ° C. for 30 minutes using a centrifuge (Model: 7700, manufactured by Kubota Corporation). The precipitate in the centrifuge tube was dissolved in a small amount of THF, and further poured into hexane, followed by centrifugation. The precipitate in the centrifuge tube was dried under vacuum (5 kPa or less) at 60 ° C. for 24 hours using a vacuum dryer (Advantech DRV320DA) to obtain powdery surface-modified inorganic oxide particles.

( Reference Example 5, Examples 2 to 4, 6 to 7, Comparative Example 1)
Surface-modified inorganic oxide particles were obtained in the same manner as in Reference Example 1 except that the composition was changed to the composition shown in Table 1.

  The physical properties of the surface modified inorganic oxide particles were evaluated by the following procedure.

<Analysis of surface-modified inorganic oxide particles>
(Modification amount of organosilicon group represented by general formula (1))
The amount (% by mass) of halogen atoms in the surface-modified inorganic oxide particles was measured using a fluorescent X-ray analysis (XRF) apparatus (trade name “ZSX” manufactured by Rigaku Corporation), and the unit surface area of the inorganic oxide particles The amount of modification of the organosilicon group represented by the general formula (1) per hit was calculated from the following formula.
(1) Modification amount of the organosilicon group represented by the general formula (1) (present) = surface modified oxide particle amount (g) × (Br content in surface modified inorganic oxide particles (mass%) ÷ 100 ÷ 79.9 + Cl amount (mass%) in the surface-modified inorganic oxide particles ÷ 100 ÷ 35.5) × 6.022 × 10 ²³
(2) Surface area of inorganic oxide particles (nm ² ) = Amount of inorganic oxide particles (g) × Specific surface area of inorganic oxide particles (m ² / g) × 10 ¹⁸
(3) Modification amount of the organosilicon group represented by the general formula (1) per unit surface area of the inorganic oxide particles (lines / nm ² ) = (1) ÷ (2)

(Modification amount of organosilicon group represented by general formula (2))
The amount of C in the surface-modified inorganic oxide particles was measured using an X-ray photoelectron spectroscopic analysis (XPS) apparatus (Thermo Fisher Scientific Co., Ltd., trade name “ESCALAB250”). The number of organosilicon groups (lines / nm ² ) represented by the general formula (2) was calculated from the following formula.
(1) The amount of C derived from the organosilicon group represented by the general formula (2) (% by mass) = the total amount of C in the surface-modified inorganic oxide particles (% by mass) −the general formula (1) C amount derived from organosilicon group (mass%)
(2) Surface-modified inorganic oxide particles Number of organosilicon groups represented by general formula (2) per unit surface area (number) = surface-modified inorganic oxide particle amount (g) × (1) ÷ 100 ÷ 12 ÷ 3 × 6.022 × 10 ²³
(3) Surface area of inorganic oxide particles (nm ² ) = Amount of inorganic oxide particles (g) × Specific surface area of inorganic oxide particles (m ² / g) × 10 ¹⁸
(4) Number of organosilicon groups represented by the general formula (2) per unit surface area of the inorganic oxide particles (lines / nm ² ) = (2) ÷ (3)

(Dispersed particle size)
In a 20 cc glass bottle, 1 g of surface-modified inorganic oxide particles are added to 5.6 g of methyl ethyl ketone, mixed for 30 minutes with a magnetic stirrer, and then subjected to dynamic light scattering (concentrated particle size analyzer FPAR-1000). Was used to measure the dispersed particle size of the surface-modified inorganic oxide particles.

(Degree of aggregation)
After measuring the dispersed particle diameter (A) of the surface-modified inorganic oxide particles as described above, the surface-modified inorganic oxide particles once vacuum-dried at 60 ° C. for 24 hours were again converted to 5.6 g of methyl ethyl ketone. The dispersed particle diameter (B) after the dispersion was measured. The degree of aggregation is a value obtained by dividing the dispersed particle size (B) by the dispersed particle size (A).

(Solvent dispersibility)
In a 20 cc glass bottle weighed in advance, 0.5 g of surface-modified inorganic oxide particles were added to 2.0 g of methyl ethyl ketone, mixed for 30 minutes with a magnetic stirrer, allowed to stand for 1 hour, and precipitated. The presence or absence of objects was evaluated. If precipitation occurs, remove the supernatant with a Pasteur pipette, dry the glass 20cc vial with the precipitate remaining at 60 ° C for 1 hour, then weigh the vial. The weight of the precipitate was determined by subtracting from the measured weight of the vial. The case where there was no precipitate in the solvent was marked as ◯, the case where there was a precipitate and the weight of the precipitate being 0.15 g or less, Δ, and the case where the weight of the precipitate was heavier than 0.15 g, was marked as x.

[Production of organic-inorganic composite particles]
Acetone as a solvent, methyl methacrylate (hereinafter referred to as MMA) as a polymerizable monomer, and CuBr as a catalyst were prepared, and organic-inorganic composite particles were produced by the following procedure.
(1) Add 29 mg of CuBr to a Schlenk flask containing a rotor, vacuum the inside of the flask, and then replace with nitrogen three times to deoxygenate the flask, and then add acetone to 100 mL of nitrogen. Introduced and stirred.
(2) To the solution of (1), 30 mg of N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine (PMDETA, manufactured by Aldrich) was added and stirred to obtain a catalyst solution.
(3) Into another Schlenk flask containing a rotor, 5.0 g of surface-modified inorganic oxide particles were added, and then the inside of the flask was vacuumed and then purged with nitrogen three times. Deoxygenated.
(4) Into the flask in (3), 10 mL of acetone was introduced under nitrogen, and further 8 mL of MMA was introduced and stirred while heating in an oil bath at 50 ° C. Then, 10 mL of the catalyst solution prepared in (2) was added to nitrogen. The reaction solution was stirred and the polymerization reaction was carried out.
(5) After 1 hour, composition analysis in the reaction solution was performed by GC measurement to confirm whether MMA was consumed, polymerization proceeded, and preparation of organic-inorganic composite particles was judged.
MMA where the polymerization of MMA has progressed while the dispersibility of the surface-modified inorganic oxide particles is good, while the polymerization of MMA progresses, but the dispersibility of the surface-modified inorganic oxide particles becomes worse with polymerization Δ, where MMA polymerization did not proceed was marked as x.

Table 2 shows the evaluation results of the surface-modified inorganic oxide particles prepared in Reference Examples, Examples and Comparative Examples.

  From Table 2, it can be confirmed that the surface-modified inorganic oxide particles of the present invention have a low degree of aggregation and excellent dispersibility.

  According to the present invention, surface-modified inorganic oxide particles having excellent dispersibility can be obtained, and organic-inorganic composite particles in which a polymer is bonded to the surface-modified inorganic oxide particles can be produced. Moreover, the organic-inorganic composite particles can construct a photonic crystal that is promising as a nano-optical material in the future.

Claims (11)

The surface of the inorganic oxide particles has an organosilicon group represented by the following general formula (1) and an organosilicon group represented by the following general formula (2),
The modification amount of the organosilicon group represented by the general formula (1) per unit area of the inorganic oxide particles is 0.001 to 0.045 / nm ² and is represented by the general formula (2). Surface-modified inorganic oxide particles in which the amount of the modified organosilicon group is 1.5 / nm ² to 10 / nm ² .

[In Formula (1), R ₁ and R ₂ each independently represent a single bond, a hydrogen atom or an alkyl group having 1 to 5 carbon atoms bonded to the surface of the inorganic oxide particle, and R ₃ represents —CH ₂ —. , —O—, —NH—, —NCH ₃ — or —NC ₆ H ₅ —, wherein R ₄ and R ₅ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or 6 to 12 carbon atoms. X represents a halogen atom, and n represents an integer of 1 to 10. ]

[In Formula (2), R ₆ represents an organosilicon group different from the organosilicon group represented by Formula (1), and may contain a halogen atom. ] The surface-modified inorganic oxide particles according to claim 1, wherein R ₆ is an organosilicon group represented by the following general formula (3).

[In the formula (3), R ₇ , R ₈ and R ₉ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and at least one of R ₇ , R ₈ and R ₉ is the number of carbon atoms. 1 to 5 alkyl groups. ] The surface-modified inorganic oxide particles according to claim 1 or 2, wherein R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.   The surface-modified inorganic oxide particles according to any one of claims 1 to 3, wherein the inorganic oxide particles have a particle size of 1 to 200 nm.   The surface-modified inorganic oxide particles according to any one of claims 1 to 4, wherein the inorganic oxide particles include at least one selected from the group consisting of silicon oxide, titanium oxide, and zirconium oxide.   The surface-modified inorganic oxide particles according to claim 1, wherein X is a bromine atom, a chlorine atom, or an iodine atom.   The surface-modified inorganic oxide particles according to any one of claims 1 to 6, wherein the degree of aggregation is 5 or less.   The manufacturing method of organic-inorganic composite particle | grains provided with the superposition | polymerization process which superposes | polymerizes the surface-modified inorganic oxide particle of any one of Claims 1-7, and a polymerizable monomer in presence of a catalyst.   The method according to claim 8, wherein the polymerization step is performed in the presence of a solvent.   The method according to claim 8 or 9, wherein the catalyst is a copper catalyst.   The method according to any one of claims 8 to 10, wherein the polymerizable monomer includes at least one selected from the group consisting of acrylic acid esters, methacrylic acid esters, and styrenes.