JPS63139015A - Reforming powder - Google Patents

Abstract

PURPOSE:To obtain the title reforming powder useful for cosmetic, paint, ink, colors, catalyst, plating carriers, etc., by bringing the vaporized specified silicone compd. into contact with the powder having an active site on the surface, and then baking the material. CONSTITUTION:At least one kind among the silicone compds. shown by formula I is vaporized and brought into contact with the powder having an active site on the surface, the silicone compd. is polymerized substantially over the whole surface of the powder, and the material is baked to obtain the reforming powder. In formula I, R<1>, R<2>, and R<3> are respectively H or a 1-10C hydrocarbonic group which can be substituted by at least one halogen atom, R<1>, R<2>, and R<3> are not H at the same time, R<4>, R<5>, and R<6> are respectively H or a 1-10C hydrocarbonic group which can be substituted by at least one halogen atom, (a) is 0 or >=1 integer, (b) is 0 or >=1 integer, (c) is 0 or 2, however the sum of (a) and (b) is >=3 when (c) is 0.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a modified powder obtained by treating a powder having active sites on its surface with vapor of a specific silicone compound, and then performing step 1. Regarding powder. .

In this specification, "powder" means -r particle size]011
It means any object that is 1 meter or less (larger than 10 mm is also sometimes referred to as 1.). In the present specification, "(5) body" includes a pseudomorphous body, a molded body, and a shaped body made of a plurality of the above-mentioned powders.

Furthermore, in the present invention, the term "active site" refers to a site that can catalyze the polymerization of a silicone compound having a siloxane bond (Si-0-Si) or a hydrosilyl (SiH) group, such as an acid site or a basic site. , means oxidation point, reduction point.

The modified powder according to the present invention has a different surface layer depending on the degree of firing, and when the degree of firing is high, the modified powder supports an inorganic silica compound. Such modified powder has excellent water dispersibility and good wettability with water, which is effective when plating the powder surface. In this case, 9. There are cases where tJ synthesis occurs and catalytic action occurs.

In addition, when the firing temperature is relatively low or the firing degree is low (t
By taking advantage of the difference in thermal stability of the functional groups on the silicone resin, for example, only the 5i-It group can be eliminated, leaving 5i-CH3 and producing a silicone resin-coated powder with high L-bistable stability. Such a modified powder has very good slipperiness, and if used in a t+1 product, it can be used to produce a tA product with good usability.

As shown in ``2'', the present invention relates to cosmetics, 4 f'■, ink,
It can be used in fields such as paints, catalysts, and plating carriers.

[Conventional technology 1] Conventionally, when coating the surface of a powder with a silica compound, the powder was diluted in a solvent such as water, water glass was added, and then an acid was added to adjust the pH to 9 or less, and silica was coated on the surface of the powder. There are known ways to remove the.

[Problems to be solved by the invention] However, in these methods, the thickness of the silica becomes thick and it is difficult to coat L'I uniformly. Because it is unavoidable to smoke, it tends to clump during drying. When a pulverization step is included to loosen this agglomeration, silica often separates, and solution reactions do not solve these problems at all.

[Means for Solving the Problems] The above object is achieved by solving the general formula % () [wherein R1, R2 and R3 are each independently a hydrogen atom or at least one halogen atom] A hydrocarbon group having 1 to 10 carbon atoms that may be substituted, provided that R1, R2, and R3 are not hydrogen atoms at the same time, and R4, R5, and R6 are A hydrocarbon group having 1 to 10 carbon atoms which may be a hydrogen atom or substituted with at least one halogen atom, a is OpO or an integer of 1 or more, and b is 0 or an integer of 1 or more. is an integer, and C is 0 or 2, but if C is ○, the sum of a and b is 3.
It shall be an integer greater than or equal to 1. At least one of the silicone compounds represented by 1 is brought into contact with a powder having active sites on the surface in the form of vapor, and the silicone compound is polymerized on substantially the entire surface of the powder, and substantially This can be accomplished by obtaining a modified powder that carries a silicone polymer coating on its entire surface and then firing it.

The present invention will be explained in detail below.

As already mentioned, most conventional techniques require heat, catalysts, or crushing power when treating powder with silicone oil. This is because it is assumed that the powder used has no activity.

However, many powders have surface activity. This surface activity of the powder deteriorates used books, oil, medicines, etc. that coexist with the powder. The present inventors reversely utilized this surface activity to polymerize silicone compounds on the powder surface to modify the surface, for example to make it hydrophobic, and to burn out the surface activity of the powder to improve the stability of coexisting ingredients such as fragrances. He discovered an innovative method to do this.

The powder to be modified in the present invention is not particularly limited as long as the powder has surface activity. Typical examples of the powder include inorganic pigments, metal oxides, etc., which have active sites on the surface. material, metal hydroxide, organic face ¥) 11 pearlescent material,
Silicate minerals, porous materials, carbon, metals, mica
Two composite powders are placed on the base. These powders may be treated with one type or in combination of multiple types.

Furthermore, it is also possible to process one or more of these aggregate molded bodies or shaped bodies. These powders are
Before carrying out the modification treatment according to the invention (ie, before contacting the silicone compound), any conventional treatment can be carried out (eg, alkaline cleaning, pickling, washing, plasma treatment). If the powder has a large number of acid sites (for example, kaolinite, iron oxide, manganese violet), it is best to perform alkaline washing. This is because the present invention makes it easier to form a silicone polymer film (described later) containing the silicone compound. Furthermore, the powder treated in the present invention may contain other substances on or in it (eg, colorants, IJV absorbers, pharmaceuticals, various additives).

In the present invention, contact between the silicone compound of formula (1) in the above form and powder having active sites on the surface is carried out at 120°C.
Below, preferably at a temperature of 100°C or less, preferably at a temperature of 2
The process is carried out in a closed container under a pressure of 00 mmHg or less, more preferably 100 mmHg or less, so that the vapor of the silicone compound of formula (1) can be vapor-deposited on the surface of the powder in a molecular state. Alternatively, contact between the silicone compound of formula (1) in the above form and powder having active sites on the surface is carried out for 1
At a temperature of 20°C or lower, preferably 100°C or lower, the formula (1
) can be carried out by supplying a mixed gas of a silicone compound and a carrier gas to the powder.

The silicone compound of the formula (1) consists of two groups.

The first group corresponds to the case where C=O in the above formula (1), and has the general formula %) [wherein R1, R2, R3, a and b have the same meanings as above, Preferably, R1, R2 and R3 are each independently a lower alkyl group or an aryl group (for example, a phenyl group) having 1 to 4 carbon atoms which may be substituted with at least one halogen atom, and a and b The sum is 3 to 7] This is a cyclic silicone compound represented by: Representative examples of this compound are as follows.

(Hereinafter in the margin) (Hereinafter in the margin) The above compounds (A), (B) and (C) may be used individually or in the form of a mixture thereof.

In each of the above formulas, n (or a + b) is preferably 3-7. As the value of n decreases, the boiling point decreases, so the amount evaporated and adsorbed onto the powder increases. In particular, trimers and tetramers are particularly suitable because they are easily polymerized due to their steric properties. Furthermore, silicone compounds containing hydrogen atoms have high reactivity and are therefore suitable for surface treatment. Regarding the amount of treatment (or amount added), the present invention is a gas phase treatment, and volatilized gaseous molecular silicone compounds, such as cyclic organosiloxane, are adsorbed to the powder and then polymerized by the active sites of the powder. The amount of treatment is not fixed, and the end point is when the silicone polymer completely covers the active sites. Of course, depending on the purpose, it may not be completely covered.

Examples of the cyclic silicone compound of formula (11) include dihydrodiene hexamedylcyclotetrasiloxane, trihydrodienepentamethylcyclotetrasiloxane, tetrahydrodienetetramethylcyclotetrasiloxane, and dihydrodieneoctamethylcyclopentasiloxane. Mention may be made of the siloxanes trihydrogen butamethylcyclopentasiloxane, tetrahydrogenhexamethylcyclopentasiloxane and pentahydrogenpentamethylcyclopentasiloxane, hexamethylcyclotrisiloxane, occumedylcyclotetrasiloxane .

The second group of silicone compounds of formula (I) is represented by formula (I).
This corresponds to the case where c=2 in I), and the general formula % formula % () [wherein R1, R2, R3, R4, R5, R6, a and b have the same meanings as above, and C is 2 However, preferably R1 to R6 are each independently a lower alkyl group or aryl group having 1 to 4 carbon atoms (e.g., phenyl group), which may be substituted with at least one halogen atom;
The sum of a and b is 2 to 5]. Representative examples of this compound include compounds represented by the formula (wherein a is 2 to 5).

Examples of linear silicone compounds of formula (II[) include:
1.1,1,2,3,4,4,4-octamethyltetrasiloxane, 1,1,1.2,3,4,5,5.5-nonamethylpentasiloxane, and 1,1,1 ,2,3
, 4,5,0,6.6-tecamethylhexasiloxane.

There are two types of silicone polymer film structures that can be coated on the powder surface. That is, when polymerization occurs through siloxane bonds (-Si-0-Si-), the resulting silicone polymer has a straight-line structure containing one unit of 5i-0-Si, and preferably has a weight average molecular weight of ft20
Have more than 10,000.

On the other hand, if the polymerization occurs by dehydrogenation of the hydrosilyl bond (Si-H) in the presence of small or trace amounts of R or O,
Polymerization of the following parts: -0-3i-0- ■ □→ O+ 820 -0-Si-0- (blank below) ■ A network structure of b -0-Si-0 units, It will contain a silicone polymer.

Preferred network polymers are those in which 2096 or more of the total Si atoms are converted to the -0-Si-0-1i positions in the polymer coating. The content of this unit can be determined from the IR absorption of methyl groups in the polymer coating.

The silicone compound of formula (1) is added in an amount necessary and sufficient to qualitatively cover the front surface of the powder, although the (processing amount) is not specifically determined. According to the present invention, first, (1)
A silicone compound is deposited on the surface of the powder, and the silicone compound is polymerized due to the presence of active sites distributed over the entire surface of the powder. Accordingly, a uniform and thin polymer skin H is formed. After the thin layer of silicone polymer is formed, substantially no polymerization occurs thereon. Therefore, the thickness of the silicone polymer coating is generally between 3 and 30 thick. On the other hand, when thermal polymerization occurs, polymerization that forms a thin layer is impossible.

Furthermore, when polymerization is carried out in the presence of a catalyst, it is impossible to uniformly coat only the surface of the powder because the polymerization occurs at the rsItm of the catalyst.

According to a basic aspect of the invention, the powder and the silicone compound (e.g. cyclic organosiloxane) are placed in separate containers/2 in a sealed room (e.g. below 100° C.) with the top open. Just t5 is fine.

In this state, the silicone compound vaporizes under the partial pressure at that temperature, creating an adsorption equilibrium on the powder. If the powder is inactive when the treated powder is taken out of the tightly sealed room, the silicone compound will be desorbed and the powder will return to its original surface, but there will be active sites on the particle surface. In the case of a powder having a polymerization activity, the silicone compound polymerizes on the powder, and as a result, the partial pressure of the silicone compound on the surface of the powder decreases, so that it is volatilized from the silicone compound in the container and supplied. Since surface polymerization occurs in this order, the silicone compound is supplied in the required amount to the system, and there is no waste.

Since the present invention is based on such a simple principle, no special equipment is required. For example, any type of closed room (eg, a closed room that can be maintained at a constant temperature, such as a desiccator or a constant temperature) can be used. Moreover, a desiccator can be used for small-scale processing. However, ideally, a device that can degas after treatment is desirable, and a gas sterilization device is preferably used. Continuously muffle the powder in a closed room.
Intermittent stirring should be used to avoid unwanted contact between the powder and the silicone compound.

According to another aspect of the invention, 120°C or less, preferably 1
Only the powder is inserted in advance into a sealed room at a temperature of 00°C or lower, and the silicone compound is vaporized at a predetermined partial pressure in another sealed room at a temperature of 120°C or lower. The silicone compound vapor can be introduced therein, for example by means of a pipe. Although there is no particular restriction on the pressure of the above system, it is preferable to carry out the polymerization under a pressure of 200 mm (11 g) or less (preferably 100 mm) (1 g or less)↓
Yes. In either embodiment, the processing time is 30 minutes to 1
50 hours, after which unpolymerized silicone compounds are removed by degassing to obtain the desired product.

According to another aspect of the invention, the powder may be treated by contacting it with a silicone compound of formula (1) in the form of a gas mixture with a carrier gas (e.g. by supplying it to the powder surface). can. The silicone compound of formula (1) and the carrier gas are mixed into the silicone compound of formula (1) or onto the surface of the silicone compound until the vapor pressure of the silicone compound is 1 mm or more, preferably 100 mm or more. The feed rate of the carrier gas stream can be determined appropriately depending on, for example, the vapor pressure of the silicone compound of formula (1), the type and amount of powder, and the capacity of the processing container. It is possible. It is preferable to adjust the treatment so that it lasts for 30 minutes to 150 hours.

As the carrier gas, an inert gas such as nitrogen, argon, helium, etc. is preferable, but it is also possible to use a mixed gas in which water vapor, methanol vapor, or ethanol vapor is mixed in the state of gas molecules with air or the above-mentioned activating gas.

According to the present invention, a mixed gas containing the silicone compound of formula (1) is brought into contact with the powder to be modified. The mixed gas is expressed by the formula (1
) contains the silicone compound as saturated vapor, it is necessary to make the contact/reaction temperature the same as or higher than the temperature of the mixed gas. This is because if the contact/reaction temperature is lower than the temperature of the mixed gas, the silicone compound will condense and the powder will be easily processed in an unbalanced form.

When a powder with many strong active sites on its surface is treated with a mixed gas, the powder tends to become a slurry. In this case, it is recommended to lower the total pressure relative to the saturated vapor pressure of the silicone compound by raising the contact/reaction temperature to a temperature higher than that of the supplied mixed gas and simultaneously supplying a carrier gas that does not contain the silicone compound. .

It is also possible to introduce the silicone compound and the carrier gas separately and mix them in the reaction vessel.

As described above, in the present invention, by supplying a mixed gas of a silicone compound and a carrier gas to the surface of the body, molecules of the silicone compound are continuously adsorbed to the powder, and active points on the surface are utilized. and polymerize it.

In the present invention, it is particularly preferable to use gas phase treatment for ultrafine powders, porous materials, pearl pigments, organic pigments, and the like. When these powders are treated in a gas phase, ultra-thin layers of silicone polymers are formed and the overall ultra-fineness, porosity, and
The pearl effect etc. can be maintained.

The silicone resin-coated powder thus obtained is then subjected to a firing process to form a silica-based compound layer on the entire body.

The firing temperature is 300°C to 1100°C.

When the firing temperature is 300°C to 500°C, one silicon group (5i-, which is unstable over time, although some organic groups from resinous resin may remain) disappears, and a stable base material can be produced. .

When the firing temperature is 500°C to 1100°C, most of the organic groups disappear and a silica or silica-based compound layer is formed on the surface. For example, when a silicone resin is formed on iron oxide powder and fired, a composite oxide of Fe and Si is produced.

Firing time is 2 to 24 hours. The firing atmosphere is in the air.
In vacuum, in nitrogen stream, in ammonia stream, in hydrogen stream,
The purpose can be achieved in any atmosphere including inert gas.

If a third component is added during firing, a mixture with the third component can be prevented from being formed on the surface.

Examples of the third component include metal carbonates and phosphates, and organic substances such as amino acids.

Examples will be described below.

Example 1 10 kg of muscovite was placed in a rotating double cone type reaction tank (made of stainless steel, equipped with a heat insulation jacket) having a volume of 1,001 cm. 400 g of tetrahydrotetramethylcyclotetrasiloxane was put into a supply tank (made of stainless steel, with a heat insulation jacket) that was directly connected to this reaction tank with a stainless steel pipe, and the system was pumped to 100 g using a vacuum pump.
The pressure was reduced to mmHg. The temperature of the system was maintained at 90°C by supplying a heating medium heated to 90°C from a heating medium heating tank to the heat insulation jackets of the reaction tank and stock solution supply tank using a circulation pump. The reaction tank was rotated 3 times by a timer after being allowed to stand still for 10 minutes, and this rotation was repeated for 10 hours. While the rotation was repeated, the muscovite was mixed and stirred in the reaction tank, and then N2 gas was introduced into the system to return it to normal pressure, yielding 10.2 kg of coated mica.

Example 2 20 g of the treated muscovite of Example 1 was placed in a crucible and fired at 300° C. for 4 hours under electricity.

Example 3 It was baked at 500° C. for 6 hours in the same manner as in Example 2.

Example 4 It was baked at 700° C. for 2 hours in the same manner as in Example 2.

Example 5 It was baked at 900° C. for 4 hours in the same manner as in Example 2.

Infrared absorption spectra, water dispersibility, and alkali hydrogen generation measurements were performed on the samples of Examples 1 to 5.

(Measurement of infrared absorption spectrum) Infrared absorption spectrum was measured by Digilab fyll:'T-I
It was measured by the diffuse reflection method using RFTS-15C.

(Water dispersibility) Water dispersibility was determined by adding 5% powder to a 0.5% MgSO4 aqueous solution for several minutes, placing it in a 100 mN sedimentation tube, and observing the sedimentation volume after 1 hour and 1 day.

(Measurement of water production using hydrogen detection method) Attach a 50ml dropping funnel and a hydrogen detection tube (Kitazawa Sangyo Nigastech - Hydrogen) to a 100+nlj three-necked round bottom flask with a magnetic stirrer, connect the detection tube to a water pump, and measure the generated water. Gas was always drawn in at a constant pressure. The round bottom flask of this measuring device has V↓1. Og was added thereto, and 5 ml of methanol was poured into it to ensure uniform dispersion. Next, 2 tons of 3 mL of NaOH were added at once through the funnel, and the mixture was stirred using a magnetic stirrer. 5i
If there is a -H group, the hydrogen detector tube will turn black due to the hydrogen generated by the alkali.

-t~ 1 ++Furi l;71 "Conflict I, ±
-1, Infrared absorption spectrum result As a result of the infrared absorption spectrum of Example 1, in addition to the infrared absorption spectrum of muscovite itself, C-11 at 2980 cm-',
Absorption of methyl group appeared at 1261 cm-' and 2172 cm-', and absorption of 5i-H group appeared at 2170 cm=.

In Example 2, 2170 cm" was obtained by firing at 300°C.
d) The absorption of Si-tl disappeared, but the absorption of methyl group still remained. In Examples 3 to 5, 2960 cm-', 1261 cm-', 1272 cm
-' absorption completely disappeared, and it became clear that the methyl group also disappeared.

2. Results of evaluation of water dispersibility Untreated muscovite, Examples 4 and 5, were surface-sedimented, but Example 3 was free-sedimented. Samples Example 1 and Example 2 were water repellent and floated on water.

Table 1 shows the sedimentation Tt'i after 1 hour and 1 hour. In Example 2, the methyl group remains and is water repellent when fired at 300°C, but when fired at 500°C, moisture is removed. The properties are very good.In untreated Shirakumoke, surface sedimentation occurs,
In Example 3, free sedimentation occurred, indicating that the moisture 111 property was better than that of the untreated sample. However, if the firing temperature is raised higher than that, the surface will start to settle again. The reason for this is thought to be that silanol produced on the surface changes to siloxane at temperatures above 700°C.

(Margin below) Table-1 *Displayed as sedimentation product M.

(Margin below) 3. Hydrogen generation measurement Table 1 shows the results of the hydrogen generation test using alkali.

In Example 1, hydrogen was generated, but in Example 2, no hydrogen was generated. This result is in good agreement with the disappearance of the 5i-H group by IR firing at 300°C. In other words, Example 2, which was fired at 300%, exhibited water repellency;
Also, since it does not generate hydrogen even in systems where other components are present,
It can be used as a stable base material.

Example 6 20g of zinc white and 5g of hexamethylcyclotrisiloxane
and were placed in separate containers and left in a desiccator at 80°C. After 16 hours, the zinc white was taken out and weighed, and 20.4 g of treated zinc white was obtained. Then 500℃
I baked it for 4 hours. (1) Aqueous treated zinc white was obtained. This treated zinc white did not cause water sacs due to alkali, and untreated zinc white interacted with schisolin and changed to 78. shows no interaction L:.

[Effects of the Invention] Coating with the silica-based composite according to the present invention is very simple, and since the silicon film is coated uniformly, a thin and uniform film is produced. As a result, it is possible to produce a good silica-based coated powder that is free from f-attacks.

Claims (1)

[Claims] General formula (R^1HSiO)_a(R^2R^3SiO)_b(
R^4R^5R^6SiO_1_/_2)_c(I) [wherein R^1, R^2 and R^3 are each independently a hydrogen atom or substituted with at least one halogen atom A hydrocarbon group having 1 to 10 carbon atoms, provided that R^1, R^2, and R^3 are not hydrogen atoms at the same time, and R^4, R^5
and R^6 are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms that may be substituted with at least one halogen atom, and a is an integer of 0 or 1 or more; , b is an integer of 0 or 1 or more, and c
is 0 or 2, but if c is 0 then a
It is assumed that the sum of and b is an integer of 3 or more. ] At least one silicone compound represented by is brought into contact with a powder having active sites on the surface in the form of vapor, the silicone compound is polymerized on substantially the entire surface of the powder, and then baked. The resulting modified powder.