JPS6157236A - Oil-containing inorganic wall microcapsule and its preparation - Google Patents

Abstract

PURPOSE:To suppress the voltatilization of a volatile substance, by forming a microcapsule wherein oil of which the solubility to water is 5% or less or an oily solution containing said oil as a solvent is included in the hollow part of an inorg. hollow body. CONSTITUTION:Oil or which the solubility to water is 5% or less or an oily solution containing said oil as a solvent is mixed with an aqueous solution containing a water soluble inorg. compound selected from an alkali metal salt, a salt of a metal belonging to the VIIa group of a Periodic Table or the like to prepare an O/W type emulsion. Subsequently, an org. solvent, of which the solubility to water is 5% or less, is mixed with this O/W type emulsion to prepare an O/W/O type emulsion while an aqueous solution containing a compound, which forms a water insoluble precipitate through the reaction with the aforementioned water soluble inorg. compound, such as alkaline earth metal halide is mixed with the O/W/O type emulsion. Next, the reaction product is filtered and dried to prepare an oil-containing inorg. type microcapsule.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to oil-containing mineral walled microcapsules. The microcapsules of the present invention have the unique effect of slowly releasing the oil or oily solution encapsulated in the hollow part of the porous inorganic wall, so they can be used as active ingredients in insecticides, pharmaceuticals, cosmetics, fragrances, etc. It is used by the government as a holding material.

Summary of the Invention The oil-containing microcapsule of the present invention is a novel microcapsule that has not yet been described in any literature.

The oil-containing microcapsules of the present invention are oil or oil-based microcapsules that have a solubility in water of 5% or less due to the inorganic wall material. I! It is surrounded by a spherical body and has a diameter of about 0.1 to 50 μm. The inorganic wall material is porous and has a large number of minute pores that do not allow the contained oil or oily solution to freely flow out, but allow gradual seepage over a long period of time under certain conditions.

Therefore, the microcapsules of the present invention exhibit the following protective ability and ability to change shape and properties against fleas containing inclusions.

(Protective function (1) It is possible to suppress the volatilization of volatile materials.

(2) By separately microencapsulating two or more substances that have high mutual reactivity, or two or more substances of non-A Wasumi @6, it is possible to It becomes possible to react by

(3) Be able to handle toxic substances safely.

(4) Taste, smell, etc. can be improved to 1ffi.

(5) The effects of light, oxygen, heat, moisture, etc. can be eliminated.

■ Change function (1) Liquid substances can be solidified.

(2) Oil-soluble gaseous substances can be solidified.

(3) It is possible to change the appearance of the inclusions and hide the color.

(4) The apparent solubility of inclusions can be changed.

(5) The apparent ratio m of the inclusions can be changed (6) The release conditions of the inclusions can be controlled by adjusting the m class, thickness, degree of porosity, etc. of the wall material. I can do it.

The inorganic wall of the microcapsule of the present invention is made of the following materials. In the specification of the present application, the term "periodic table" refers to the elements of the short-period element cumulative periodic table described in Iwanami Physical and Chemical Dictionary, 3rd edition, page 1484.

Silicates with alkaline earth gold 1j≦...magnesium silicate, calcium silicate, strontium silicate, silicon Q barium vine.

Alkaline earth metal oxides...magnenoum oxide, barium oxide, calcium oxide, strontium oxide, etc.

Carbonates and sulfates of alkaline earth metals...magnesium carbonate, rehydrated calcium, strontium carbonate,
Barium carbonate, magnesium sulfate, calcium sulfate, strontium sulfate, barium sulfate, etc.

Oxides and carbonates of Group A metals of the periodic table: manganese oxide, manganese carbonate, etc.

Oxides, carbonates, and hydroxides of metals from group II of the periodic table...
...Iron oxide, hydrated iron oxide, cobalt oxide, cobalt carbonate, nickel oxide, nickel carbonate, nickel hydrate, etc.

Others: Silica (anhydrous silicic acid), calcium tungstate, basic copper carbonate, cadmium sulfide, zinc sulfide, silver sulfide, lead 1-chloride, silver carbonate, aluminum hydroxide, titanium oxide, zirconium hydroxide , tin oxide, lead hydroxide, etc., which form as a water-insoluble precipitate in an aqueous reaction, and which do not react with the encapsulated substance can be used in a wide variety of ways.

As the oil to be encapsulated in the microcapsule (gI (this is referred to as an encapsulating substance)), use an oil with a solubility in water of 5% or less, or an oily substance using this oil as a solvent. These include natural and synthetic oils, fats and waxes,
For example, almond oil, olive oil, spermaceti, hydrogenated oil, sesame oil, cholesterol, safflower oil, silicone, soybean oil, blackberry oil, vitamin A oil, castor oil, miso wax,
Examples include mink oil, cottonseed oil, Japanese wax, lanolin, liquid lanolin, vaseline, kerosene, linseed oil, oleyl alcohol, isopropyl myristate, isopropyl palmitate, and in addition to these oils, vitamin A, vitamin D1 fragrance, and menthol oil. Oil-based solutions are also used as encapsulating substances to dissolve oil-soluble substances such as photosensitive dyes, R94 dyes, and natural pigments.

The oil-containing inorganic wall microcapsules of the present invention are produced, for example, as follows.

First, 1-/O% of the encapsulated substance heavy phosphorus is added to the encapsulated substance made of the above-mentioned oil or oil a solution. ! Dissolve the emulsifier of ilB1m. As the emulsifier, a nonionic surfactant having an HLB in the range of 8 to 18 is preferred, such as nrubitan monolaurate (HLB = 8.6) and polyoxyethylene sorbitan monostearate (HLB = 9.6). Polyoxyethylene rubitan monooleate' (HLB=15.0)
, polyoxyethylene sorbitan monolaurate (HL
B=13.3), polymexyethyleneoxypropylene stearate (HLB=15.7), etc. are exemplified as typical examples.

On the other hand, silicates, carbonates, sulfates, tungsten NI salts, and halides of alkali metals; 2 sulfates, halides, and nitrates of metals from group Ⅰ of the periodic table; sulfates, halides, and nitrates of metals from group Ⅰ of the periodic table; nitrate.

and a water-soluble inorganic compound selected from the group consisting of halides of alkaline earth metals (hereinafter referred to as "compound I"), containing at least 1 fil (containing n degree 0.3 morph 1 to saturation concentration, preferably 0.5 to Approximately 3.0 mol/l of the aqueous solution [rJF4] is mixed with the emulsifier oil solution to prepare an O/W emulsion. At this time, the aqueous solution of compound 1 and the emulsifier oil solution are The mixing interval is not particularly limited as long as the emulsion obtained is of O/W type, but it is usually preferable that the former be about 0 to 500 parts by weight to the latter 0 to 500 parts by weight.

Next, an organic solvent having a solubility in water of 5% or less is added to the above O/W type emulsion and mixed to prepare a . Examples of organic solvents with solubility in water of 5% or less include aliphatic saturated hydrocarbons such as hexane, decane, hexadecane, inhexane, and isohebutane; and aliphatic unsaturated hydrocarbons such as hexene, octene, dimethylbutadiene, and heptyne. ; Aromatic hydrocarbons such as benzene, toluene, dodecylbenzene, cymene, and styrene; Alicyclic hydrocarbons such as cyclohexane, cyclohexene, and cyclononane; these may be used alone or in combination of two or more. Ru. There is no problem even if up to about 0% by weight of alcohol M is mixed in the solvent ζ. The purpose of using the organic solvent is that the milk solution obtained is O
/) There is no particular limitation as long as it is Y2O type, but it is usually at least 50% by weight of the emulsion, preferably from 70 to 80% by weight. The 8-viewing method should be according to the usual method, and the usual 1.
Stirring method, shaking method, etc. can be adopted. During emulsification, a known emulsifier can be added, although it is not particularly necessary. The emulsifier preferably has an HLB of 1.8 to 8.
Nonionic surfactants within the range of 6 can be used.

Typically, sorbicun triolate (HLB = 1.
8), Rubitan monoole) (HLB=4.3),
Sorbitan monostearate (HLB=4.7), Sorbitan monopalmite-1- (HLB=6.7), Sorbitan mo/Laulz-) (HLB=8.6) J
(7) Mixtures of IW or iz 2 ff1Ju may be mentioned, and two or more plates of each nonionic surfactant having any HLB value τ may be mixed to obtain an HLB of 1.8 to 8.
You may use it by adjusting it so that it becomes 6. This uniform emulsification can be used in an amount of 5.01% by weight or less, preferably 0.01 to 3.0% by weight, based on the energizing medium.

Then, the halides and nitrates of the alkaline earth gold layer =
Carbonate salts, nitrates, sulfates and halides of Alkalibo α genus, inorganic acids and their anthenium salts; and none, IXu
At least one compound (hereinafter referred to as "Compound ■") that is an isolated compound from the group consisting of Item 5 and is capable of producing a water-insoluble precipitate by an aqueous reaction with the above Compound I.
Prepare a 0 degree water ts solution containing a moderate amount, usually 0.05 mol/l or more, preferably about 0.1 to 2.0 mol/l, and add this and the above 0/W/O variable L1η Mix with Shin. The mixing ratio of the aqueous solution of the compound (1) and the O/W/O hole is at least 1 part/O0iQ part, preferably about 300 to 500 parts It is better to

Thus, oil-containing S-Tsukitora-walled microcapsules are formed as a reaction product. The desired product is prepared by passing, rinsing and drying according to the method.

Effects of the Invention According to the present invention, the protection function and the change function are shown as 1:
In addition to the general effects Iζ mentioned above, the following specific effects can be achieved in each field.

(a) In the field of pharmaceuticals, by selecting the wall material appropriately, the wall material can be dissolved in the body and exert a synergistic effect with the pharmaceutical ingredients in the encapsulated substance. For example, when the wall material is made of magnesium oxide, it is effective as an antacid, when it is made of calcium carbonate, it is effective as a calcium agent, and when it is made of iron oxide, it is effective as a blood thickener.

(b) When producing microcapsules whose walls are made of polymeric substances, formaldehyde is used as a hardening agent during wall formation, so these microcapsules can be used for pharmaceuticals, cosmetics, etc.
There are major restrictions on the use of microcapsules in the field of foods and the like. However, the microcapsules of the present invention have no such restrictions at all.

(c) Since the reaction proceeds in a constant voltage state without requiring high temperatures or pressures during microcapsule production, energy consumption is low.

EXAMPLES Hereinafter, examples will be shown to further clarify the features of the present invention.

Example 1 Polyoxyethylene sorbitan monooleate (HLB=
50y of linseed oil solution dissolving 2% by weight of
4 mol/l of sodium silica dissolved in ff/O0ml
Add and mix the ingredients (a) to prepare an O/W type breast-shaped hole.

Then sorbitan monostearate (HLB=4.7
) and polyoxyethylene sorbitan monoole) (I
ILB=15.0) 1:2 moderated product (jugaki ratio) for 3 m
Bk% melt D1! Add the above o to 500 m of benzene solution
7wPJl! Add iIL, mix by shaking, and add O/
W/O breast milk n dare trJ.

Then, a 1.5 mo//l aqueous solution of calcium chloride/O
0/O0Oζ The above 0/TV/O type emulsion was added with stirring and allowed to react.

After the reaction was completed, pale yellow calcium silicate type microcapsules/O5y containing linseed oil were obtained by filtration, washing with water, and drying with 245trJJ at room temperature.

The average particle diameter of the obtained microcapsules was 9.9 μm.
The presence of linseed oil was confirmed by infrared green absorption spectrum. The content of linseed oil is 43% by weight.
And one.

Example 2 1.5 mo//l of calcium chloride! Aqueous solution/O00m
1.5 mo of strontium chloride instead of /! The same operation as in Example 1 was performed except that //aqueous solution/O/O0O was used, and the average particle diameter/O. Strontium silicate wall microcapsule spheres containing 1 μm linseed oil were obtained.

Example 3 Polyoxyethylene rubicune monostearate (HL
B=9. Dispersed lanolin 6 liquid 50y 1ζ hydrium carbonate aqueous solution C3 mol/l containing 6% by weight of (3) f6 n”l
)/O0mI! was added and irradiated with ultrasonic waves for 1 minute to obtain a uniform 0
/ Obtain type W milk fluid.

Then sorbitan monostearate (HLB=4.7
The above O/W type emulsion was added to 400 mA' of a benzene solution dissolving 0.1% by weight of 0.1% by weight, and the O/W/O type emulsion was shaken to obtain an O/W/O type emulsion.

Next, a 0.2 mol/l aqueous solution of calcium chloride 180
Add the above 0/W/O type milk solution to 0 ml with stirring and allow to react.

After the reaction, the product was separated from P, washed with water, and dried at room temperature for 24 hours to obtain spherical calcium carbonate-walled microcapsules 81y containing lanolin f2.

The average particle size of the obtained microcapsules was 5.5 μm.
Lanolin content is 59FFFF1%.

'=A Example 4 30 y of camellia oil that dissolves sorbitan monolaurate (HLB=8.6) at 8%, 6 t of silicon Q sodium water
Fi-(concentration as S t O2 4 IT) at/l
) /O0mg (Add this and use a homogenizer to make a homogeneous /I'O/W type pore temperature liquid.

Then, nrubitan monooleate (HLB=4.3)
Hexane solution of < 219// ) 300111 lζ
Add 1 fill of the above 0/W mold and shake for 5 minutes to form the 0/W/O emulsion.

Next lζ, ammonium sulfate water r8W (1,5mo//
V)/O00m/lζ Stir and add the above 0/W/O type emulsion and allow to react.

After the reaction is completed, spherical silica-walled microcapsules 492 containing camellia oil are prepared by the same operation 1 as in Example 1.
I got it.

The average particle diameter of the microcapsules was 3.1 μm.

The camellia oil content is 59%.

(that's all)

Claims (2)

[Claims] (1) Oil-containing inorganic wall microcapsules in which an oil having a solubility in water of 5% or less or an oily solution using the oil as a solvent is encapsulated in the hollow part of an inorganic hollow body. (2) (i) Alkaline silicates, carbonates, sulfates,
Tungstates and halides; sulfates, halides and nitrates of metals of group VIIa of the periodic table; group VII of the periodic table
An aqueous solution containing at least one water-soluble inorganic compound selected from the group consisting of Group I metal sulfates, halides, and nitrates; and alkaline earth metal halides; (ii) Next, an organic solvent having a solubility in water of 5% or less is mixed with the above O/W emulsion to form an O/W emulsion. O
(iii) then an emulsion selected from the group consisting of alkaline earth metal halides and nitrates; alkali metal carbonates, nitrates, sulfates and halides; inorganic acids and their ammonium salts; and inorganic bases. (v) mixing the O/W/O emulsion with an aqueous solution containing at least one compound which is a compound capable of producing a water-insoluble precipitate by an aqueous reaction with the water-soluble inorganic compound; A method for producing oil-containing inorganic walled microcapsules, which comprises filtering, washing and drying the product.