JPS5819522B2 - Processing method to make powder denser - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a powder processing method for converting bulky powder into a dense powder, that is, a powder with a significantly reduced apparent volume, and more specifically, the present invention relates to a method for processing bulk powder into a dense powder, that is, a powder with a significantly reduced apparent volume. The present invention relates to a method for processing powder, which converts a bulky powder into a powder having a small bulk volume and improved dust scattering resistance in combination with an impact compaction operation using a pressurizing medium.

Inorganic or organic fillers, reinforcing agents, coloring agents, stabilizers, coloring agents, color developers, anti-sagging agents, which are incorporated into paints, inks, other coating or coating compositions, or molding compositions;
Compounding agents such as thickeners, matting agents, anti-blocking agents, etc.
In terms of dispersibility, it is required that the powder diameter be as fine as possible.

However, the atomization of these formulations simultaneously results in an increase in bulk volume, which not only leads to increases in transportation costs, packaging costs, and storage costs, but also tends to scatter dust, resulting in deterioration of the working environment and increased handling. resulting in operational difficulties.

The disadvantages of handling such bulky powders are often observed not only in the above-mentioned applications for compounding agents, but also in the fields of food, medicine, ceramics, chemical industry, agrochemicals, and the like.

Conventionally, so-called vacuum (reduced pressure) packaging techniques have been known in the field of food packaging.

According to this vacuum packaging technique, a flexible container is filled with solid foods, the space inside the container is evacuated, and then the container is sealed.

According to this packaging technique, it is possible to reduce the excess void volume of the package as a result of eliminating the space inside the container, but such packaging technique requires an expensive gas barrier container and furthermore, the packaging technique is The limitation is that the product is limited to solid articles that are non-flowable and have shape retention.

In other words, when filling a flexible container with gas barrier properties with fine powder and evacuating the inside of the container, suction of the gas contained in the powder and compression by atmospheric pressure applied to the powder through the container wall are performed. As a result of the interaction with the force, the powder fluidizes and spills out of the container.

Thus, traditional techniques for vacuum packaging powders, which use rigid containers such as cans or bottles, do not achieve the desired goal of producing dense (less bulky) powders from bulky powders. The goal will not be achieved.

Conventionally, as a method for reducing the bulk volume of powder packages,
Some attempts have been made to reduce the bulk of powder bagged products by applying pressure using a pressure device such as a hydraulic device, but this method of pressurization does not The bulk volume could only be reduced by about 5% at most, and the effect was still not fully satisfactory.

The present inventors installed a bulky powder in a sealable pressure-resistant container in a state in which it was filled in a support container that had a smaller volume than the pressure-resistant container and had a ventilation portion that communicated with the internal space of the pressure-resistant container. After the pressure container is sealed, the pressure container is degassed, and then air at atmospheric pressure is rapidly introduced into the deaerated pressure container under conditions that the air introduced into the pressure container can freely enter and exit the support container. When introduced, the powder mass can be converted into a dense powder mass with a significantly reduced bulk volume, and the powder mass whose bulk volume has been reduced by such means is When left in normal atmosphere for a long period of time,
It has also been found that even when this lump is crushed, it is always maintained in a dense state with a reduced bulk volume.

That is, an object of the present invention is to provide a powder processing method for turning bulky powder into dense powder, that is, powder with significantly reduced bulk volume.

Another object of the present invention is a powder processing method that converts a bulky powder into a powder having a small bulk volume and dust scattering resistance by a combination of a vacuum degassing operation and an impact compression operation using atmospheric air. is to provide.

According to the present invention, a bulky powder is loaded in a sealable pressure-resistant container in a state in which it is filled in a support container that has a smaller volume than the pressure-resistant container and has a ventilation portion that communicates with the internal space of the pressure-resistant container. After the pressure container is sealed, it is degassed, and then air at atmospheric pressure is introduced into the degassed container at 100 mmHf1/s.
Processing of powder characterized by reducing the bulk volume of the powder by rapidly introducing the air into the pressure container at a pressure increase rate equal to or higher than c and under conditions where air can freely enter and exit the support container. A method is provided.

The present inventors obtained the following interesting findings in the course of research that led to the present invention.

In other words, bulky powder (ultrafine silicic acid) is placed in the measuring cylinder.
The graduated cylinder filled with this powder is placed in a transparent pressure-resistant container, and then the inside of this pressure-resistant container is evacuated under reduced pressure, and the air contained in the powder is evacuated. However, it was observed that the bulk volume reduction rate in this case was only a few percent.

However, when air under atmospheric pressure is rapidly introduced into this pressure-resistant container, the ultrafine silicic acid in the graduated cylinder rapidly loses its shape while maintaining the external shape of the filling, that is, the shape of the graduated cylinder. This results in a very significant reduction in bulk volume.

The above-mentioned facts clearly suggest that the bulk volume reduction according to the present invention is brought about by the following mechanism.

In other words, bulky powder has a fine structure in which the particles are cross-linked (engaged) with each other in an extremely sparse manner, and therefore, although a relatively large amount of air is contained inside the powder, First, it is extremely difficult to destroy the aforementioned crosslinked structure simply by degassing this contained air.

However, if a pressurizing medium such as air is rapidly introduced into the bulky powder atmosphere after deaerating the atmosphere, the pressurizing medium will disperse into the powder before it can diffuse into the powder packing. An impact compression force comparable to the pressure difference between the inside and outside is applied to the surface forming the outer shape of the body filling (including the interface between the measuring cylinder and the powder filling), and this impact compression force is As the pressurizing medium is introduced, the pressure spreads from the outer surface to the center of the powder filling.

Thus, according to the present invention, it is possible to uniformly apply an impact compressive force from the outer surface of the powder filling toward the center, and as a result, the sparse crosslinking structure between individual particles of the bulky powder can be effectively improved. The estimation of the mechanism that is recognized to be capable of producing a powder in which the particles are broken into particles and are closely engaged with each other, that is, a powder with a reduced bulk volume, is based on the following unexpected method by the method of the present invention. It corresponds extremely well with the action and effect of .

First, in the present invention, by using a combination of a vacuum degassing operation and an impact compaction operation using a pressurizing medium, it is surprisingly possible to significantly reduce the bulk volume of bulky powders with virtually no generation of dust. It is.

That is, when pressurizing gas is rapidly introduced into a powder packing under reduced pressure, it is expected that powder particles will scatter, but in the present invention, such prediction is not possible. On the contrary, the generation of dust is completely suppressed.

This effect is due to the fact that the gas rapidly introduced into the pressure vessel
This is recognized to be due to the fact that the impact compressive force is uniformly applied to the outer surface of the powder filler before it diffuses into the powder filler.

In addition, the dense powder produced by the present invention retains its original bulk state even when it is left in atmospheric pressure for a long period of time, or when it is crushed into an appropriate size. does not return to normal, but remains stably in the dense state immediately after production, that is, in a state with a small bulk volume, that is, in a state with a small bulk volume,
Moreover, the dust scattering resistance is maintained stably over a long period of time.

The reason for this is that in the method of the present invention, bulky powder is destroyed into a sparse crosslinked structure between particles, and this is replaced with a stable and dense crosslinked structure between particles, resulting in a powder with reduced bulk density. It is thought that this is because the state of small bulk volume and low dust scattering is stably connected as long as the dense crosslinked structure between particles is not destroyed.

Moreover, in the dense powder according to the present invention, the particles are merely mechanically and densely cross-linked, so this powder can be used in paints, inks, other dispersing liquids, resins, etc. It is also surprising that when dispersed in the melt there are no particular disadvantages in terms of dispersibility.

On the contrary, the dense powder according to the present invention has the advantage that the amount of air enclosed therein is small, so that the dispersion operation is easy.

The invention will be explained in detail below.

In the present invention, a bulky powder is charged into a sealable pressure-resistant container in a state in which it is filled in a support container that has a smaller volume than the pressure-resistant container and has a ventilation portion that communicates with the internal space of the pressure-resistant container. After sealing the pressure vessel in this state, it is deaerated, and then air at atmospheric pressure is rapidly introduced into the pressure vessel and under conditions that allow the air introduced into the pressure vessel to freely enter and exit the support vessel. is important.

First, when a container other than a pressure-resistant container such as a flexible container is filled with powder, and then the outside of the container is maintained at atmospheric pressure and the inside is degassed, the pressure applied to the flammable container must be Because the powder leaks out of the container, it is impossible to densify the powder.

Of course, if a filter is installed at the deaeration port and only the atmosphere is sucked in, deaeration and compression operations are possible, but with this method, deaeration is performed through the filter, so there is no pressure drop. Not only does the degassing operation itself become inefficient due to clogging of the filter and filters, but also the reduction in bulk volume after treatment is still not fully satisfactory.

In other words, in the above method, the degassing operation proceeds with the internal pressure of the powder filling and the external pressure of the container in equilibrium, so it is highly unlikely that an impulsive compressive force will be applied to the degassed powder filling. It is extremely difficult to destroy the loosely cross-linked structure between particles in bulky powder.

On the other hand, according to the present invention, the powder is degassed while maintaining the above-mentioned loose cross-linked structure between the particles in the pressure container, so that the powder is not encapsulated in the powder filling. The air that is
The above-mentioned sparse cross-linked structure is created by highly effective degassing with relatively little pressure drop, and in this state, the pressurizing medium is passed through the pressure container and rapidly acts on the powder in the support container. destroy uniformly from the outer surface to the center,
This makes it possible to bring about a significant reduction in bulk volume.

In the present invention, as the pressure-resistant container, any rigid pressure-resistant container having a powder filling port, a deaeration port, and a pressurizing medium inlet that can be sealed with a lid or door is used.

The exhaust port of this pressure vessel can be an oil rotary pump, nutsch pump, piston pump, atmospheric leg, steam ejector,
water flow pump, roots pump, mercury nizhif coupon pump,
Oil ejector pump, oil diffusion ejector pump, mercury diffusion pump, molecular pump, sputter ion pump,
Connected to a vacuum pump consisting of one or a combination of two or more of sublimation pumps, cryopumps, etc., while the inlet is open to the atmosphere or connected to a pressurized medium storage tank or pressurizing device. has been done.

A suitable example of the arrangement of such a pressure vessel and its accessories is shown in FIG. 1 of the accompanying drawings.

In the present invention, in order to uniformly perform the degassing operation and the introduction operation of the pressurizing medium throughout the entire inside of the pressure-resistant container, the degassing and inlet ports described above are provided with a valve for making the flow of gas uniform. It is desirable to provide a rectifying mechanism.

By providing such a rectification mechanism, it is possible to completely prevent the generation of dust during the degassing operation and the compression operation using the pressurizing medium.

Bulky powders suitable for the treatment of the present invention include those having a fine particle size (secondary particle size) and a wide particle size distribution.

Nine of the total particles have a particle size distribution of 20μ or less determined by the sedimentation method.
It can be particularly advantageously applied to inorganic or organic fine powders in which the proportion of 70% or more of the total weight is 0% by weight or more, particularly 10μ or less.

Such a powder with a fine particle size and a wide distribution is generally amorphous or microcrystalline, and although it varies depending on its composition, it is generally smaller than 1.1 cc/9, especially 0.1 cc/9.
It has a bulk volume of less than 5 cc/g.

According to the present invention, such bulky powder can be converted into powder with significantly reduced bulk volume.

Suitable examples of powders include, but are not limited to:
It is as follows.

Inorganic powders include ultrafine silicic acid, white carbon,
Synthetic calcium silicate, activated clay, acid clay, silicate for pressure-sensitive paper coloring agent, cement, bentonite, kaolin,
Natural, synthetic, or semi-synthetic silicic acid or silicates such as talc, diatomaceous earth, synthetic zeolite, etc. @carbonate nitripolyline such as solid or heavy calcium carbonate, magnesium carbonate, basic magnesium carbonate, soda ash, etc. Phosphates such as soda and calcium phosphate: Aluminum compounds such as finely divided alumina and aluminum hydroxide Chromates such as dichloride, strontium chromate and barium chromate Calcium compounds such as calcium dioxide and calcium hydroxide Magnesium dioxide and hydroxide Magnesium compounds such as magnesium:
Carbon such as carbon black, activated return powder, etc.: zinc dust,
Metal powders such as aluminum powder and magnesium powder: Other fillers, reinforcing agents, pigments, stabilizers, anti-sagging agents, thickeners, matting agents, anti-blocking agents, fluidity improvers, agricultural chemicals, pharmaceuticals, cosmetics, Fine powder of one or more inorganic materials used as food compounding agents, decolorizers, catalysts or carriers, abrasion reducers, abrasives, fillers, lubricants, insulation improvers, flame retardants, flame retardants, etc. can be mentioned.

Organic powders include grain powders such as wheat flour, buckwheat flour, rice flour, and starch; metal soaps or organic acid metal salts such as calcium nistearate, magnesium, zinc, lead, basic lead phthalate, and basic lead maleate; Organic dyes or pigments:
Examples include fine powders of one or more organic compounds such as pharmaceuticals, cosmetics, agricultural chemicals, various resins, and pastes.

These inorganic powders and organic powders may be a mixture of multiple types of powders, such as a one-package formulation or a molding compound.

In the present invention, these bulky powders are charged into a support container that has a smaller volume than the pressure container and has an opening that communicates with the pressure container.
A flexible packaging container is particularly preferably used as the supporting container.

The packaging container may be anything as long as it is flexible and has a ventilation part, especially paper, film bags, cloth, aluminum foil, etc.
Alternatively, a bag-shaped container made of a laminate of these materials is preferably used.

The ventilation portion of the container may be an opening in the bag, or may be provided in the wall of the container, such as in a paper bag, cloth bag, or perforated film bag.

When the powder filled in these packaging containers is subjected to the treatment of the present invention, it is convenient because the powder whose bulk volume has been reduced can be taken out directly in the form of a package.

In a preferred embodiment of the present invention, the biaxially stretched olefin L'
A heat-shrinkable film container such as a resin film, vinyl chloride resin film, polystyrene film, nylon film, or polyester film is used, and after the bulk volume reduction treatment described above is performed, the package is taken out from the pressure-resistant container and this packaging is removed. The surface of the body is treated at a temperature equal to or higher than the heat shrinkage temperature of the film.

By such treatment, the folds of the film that are formed on the surface of the package due to the reduction in the bulk volume of the powder can be eliminated by heat shrinkage, and the appearance characteristics of the formed package can be improved.

Furthermore, bulky powders can be stored in hard containers or frames that have an opening at least in part, such as plastic, metal, glass, etc.
After filling an open container or frame made of wire mesh, wood, etc., it can be charged into a pressure container.

Alternatively, these powders are filled into a suitable conveying member, such as a belt conveyor, case conveyor, packet conveyor, vibrating conveyor, cellular turntable or turret, and fed continuously or intermittently into a pressure container. be able to.

Alternatively, the pressure container is provided with a frame for supporting a bulky powder filling, and a powder charging port is provided above the frame, and a compressed powder discharge port is provided below the frame. By processing, it can be compressed into a mass similar to the frame and having a volume smaller than that of the frame.

After charging the powder into the pressure container, the container is substantially sealed and the atmosphere of the powder is evacuated.

The degree of deaeration varies depending on the desired degree of bulk volume reduction and the type of powder, but is generally 660 mmHg.
(absolute) or less, especially -IJ (absolute) or less at 660 mm' is preferable, and for raw material powder with relatively large bulk volume, for example, Q, 2 cc/g or more powder, the degree of deaeration is below 660 mmHg (absolute), 0.5cc/
For powders weighing more than
(Absolute) It is desirable that it be less than or equal to:

In addition, in the case of extremely fine powder with fluidity, in order to prevent the fine powder from being discharged from the pressure container along with degassing, the degassing rate should be set to 50 mynHjj'/m1yt.
,, Id or less, preferably 20 mrrtHg/mVt or less.

In the present invention, the dog is placed in a pressure-tight container that is evacuated.

Rapidly introduce atmospheric air.

In the present invention, the pressurization speed of atmospheric pressure air is 100 m
mHg /sec or more, especially the initial pressure increase rate 1f5 60
It is important to rapidly introduce the powder at a rate of 0 mmm1 (/sec or more) in order to allow the atmospheric pressure air to directly act on the powder filling in the support container while significantly reducing the bulk volume.

In this specification, the initial pressure increase rate (VEP) is defined as the following formula, where ΔP is the pressure in the pressure vessel after introducing the pressurizing medium (P2 mmHg absolute) in the pressure one-hour curve,
It represents the difference (degassing pressure difference) (P2 PO) from the pressure in the reduced pressure container (P62 mmHg absolute), and T is the pressure one-hour curve, where Pl is the point △P/2 on the curve. , P of said curve.

The time corresponding to T. , T1 is the time corresponding to the point where the extension of the straight line connecting Po and Pl intersects with the straight line P2,
T1-To(represents the time equivalent to Se).

More specifically, it can be easily determined from the pressure one-hour curve shown in the explanatory diagram shown in FIG.

The curve shown in FIG. 2 was obtained by connecting a Bourdon tube pressure detector to an automatic recorder.

In the present invention, whether or not it is possible to effectively destroy the loosely cross-linked structure between particles in a bulky powder depends on whether or not it is possible to apply an impact compressive force to the deaerated powder filling. Ori,
This is related to both the pressure applied to the outer surface of the powder charge and the rate at which the pressurizing medium diffuses into the interior of the powder charge.

That is, the rate of increase in pressure (Vo) on the outer surface of the powder filling
is large, while the rate of pressure increase inside the powder packing (
Under conditions where Vi) is small, it becomes possible to effectively apply an impact compression force to the powder or granular material.

The pressure increase rate (V i ) inside the powder filling is also related to the pressure increase rate Vo at the outer surface of the powder filling, and under conditions where Vo is relatively small, Vi becomes approximately equal to Vo. On the other hand, under conditions where vo is relatively large, Vi
is a much smaller value than Vo.

In the present invention, it is desirable to select the degree of pressure reduction and the initial pressure increase rate so that the bulk volume contraction rate is less than 10%, preferably 20% or more.
It is even possible to obtain a volumetric shrinkage of more than %, even up to 60%.

The powder whose bulk volume has been reduced is taken out from the pressure container in the form of a lump or packed in a packaging container, and if it is a lump, it is crushed as necessary and processed as described above. It is filled into a packaging container to form a package.

In the present invention, compression by a press is performed simultaneously with or after the compression of the powder by introducing a pressurizing medium,
The bulk volume can be further reduced, and this pressing operation can be easily performed with a press provided inside or outside the pressure-resistant container.

In addition, if a bulky powder is packed into a pallet, then the pallet is packed into a pressure-resistant container and subjected to degassing and compression operations, or further press operations, the volume of the pallet package is reduced all at once. There are also benefits that can be obtained.

According to the present invention, there is an advantage that the transportation cost, packaging cost, or storage cost of bulky powder can be reduced, and troubles such as dust scattering and dust explosion can be solved.

Example 1 In this example, a case will be described in which ultrafine silicic acid powder is used as the bulky powder to produce dense ultrafine silicic acid powder with a reduced bulk volume.

As a sample, ultrafine powdered silicic acid for paint manufactured by Suikagaku Co., Ltd. (trade name Mizukasil P-526) was placed in a hopper in advance, and the volume was left until it decreased due to natural sedimentation and reached a constant volume.
00. Measure 5000ml into an Oml measuring cylinder (diameter 120ii x height 500mm).

This sample was stored in an iron cylindrical pressure-resistant container 1 (inner diameter 500 mv, height 10
Put it in 0100O.

A 3-inch ball valve 5 for increasing the pressure to human pressure after degassing and a 2-inch valve 6 for adjusting the initial pressure increase rate are attached to this pressure-resistant container through a three-way branch pipe 4.

Also, inside the pressure vessel, there is a rectifying plate 2 to prevent the sample in the pressure vessel from directly scattering due to the introduction of air into the pressure vessel at high speed when raising the pressure from a deaerated state to atmospheric pressure. Atmospheric pressure is applied to the entire area around the sample through this current plate.

Further, a vacuum pump 9 for deaerating the inside of the pressure container, a stop valve 7 between the pressure container and the vacuum pump, and a pressure gauge 8 for indicating the deaeration state in the pressure container are installed.

After sealing the flange 3 of the sample placed in the pressure container 1, the pulp 5 is fully closed and the valve 7 is fully opened, and the inside of the pressure container is evacuated by the pump 9. As the air existing in the gaps between the sample particles is removed. It comes out gradually.

After degassing until the pressure reaches -650 miHg using the pressure gauge 8, the valve 7 is fully opened, and the valve 5 is instantaneously fully opened.

The state of atmospheric pressure increase at this time is converted into a current signal by a Bourdon tube type pressure detector 10 attached to the pressure vessel 1, and is recorded as a pressure vs. time curve by an automatic recorder 11.

This pressure versus time curve is shown in FIG.

As a result, when △P-650Hg, △T20.5sec
That's what I find.

This becomes the initial pressure increase rate.

Thereafter, when the sample was taken out from the pressure container 1, the sample was shrunk into a block shape that was almost similar to a graduated cylinder.

If you break this block and measure the volume, it will be 20507r.
It was Ll.

The shrinkage rate at this time was calculated using the following formula: 59
%Met.

Table 1 below shows the results of measuring the bulk density, oil absorption, particle size distribution, and dispersibility of the samples before and after shrinkage.

Note that each performance was measured by the following method.

Method for Measuring Oil Absorption A sample was dried in advance at a constant temperature of 110° C. and ground in an agate mortar to the extent that it was loosened.

Place 1g of sample on a glass plate (approximately 250X250X5).
Drop a small amount of boiled linseed oil into the center of the sample from the billet, and mix thoroughly with a spatula each time.

The dropping and kneading operations are repeated, and the end point is when the whole becomes a hard putty-like mass that can be rolled up into a spiral shape with a steel spatula, and the amount of boiled linseed oil used up to that point is determined. , the oil absorption amount (y
d/100 g) Method of calculating G, i.e. JISK5
According to the method specified in No. 101.

Here H: Amount of linseed oil (7 rll) S: Weight of sample Ll? ) Measurement method of particle size distribution Hitachi optical scanning rapid particle size distribution measuring method PSA-2 model was used.

In this measurement method, particles are suspended in a liquid and stirred to uniformly disperse the particles.

The dispersed particles settle over time according to Stokes' law, and the difference in particle size creates a concentration distribution of particles in the liquid.

Utilizing this principle, this method optically measures the particle concentration distribution after a certain period of time and records the state by photoelectric conversion.

The measurement method is as follows.

A 20 m9 sample was placed in a test tube with a stopper (capacity: 10 TL), and 5 TL of 0.1% sodium hexametaphosphate solution was added to it.
throw into.

This test tube with a stopper is attached to a shaker and shaken for 30 minutes at approximately 60 reciprocations per minute to disperse the sample in the 0.11% sodium hexametaphosphate solution.

This dispersed sample was placed in a measurement cell (height 8.5 crfL
, Width 2.0 CrfL, Width 2.0 am, Activate.

Next, operate the device to draw a particle size distribution curve and check the shape of the curve and approximate measurement time.

This is done because unless water is added accurately up to a certain marked line, the top of the curve will sag and accurate values cannot be obtained.

If it is determined that a sufficient curve can be obtained, an automatic recorder is activated to draw a particle size distribution curve.

The density and viscosity of the solvent at this measurement time and liquid temperature are read from a pre-calculated table, and the particle diameter of the sample is calculated using a predetermined calculation sheet.

After that, the recorded curve is divided into equal parts by the particle diameter, the transmitted light intensity at the equal dividing points on the curve is read, and the logarithmic conversion scale is used to calculate the lo
Read gI.

From this, the particle size distribution is calculated using a predetermined calculation paper.

In addition, in this example, for example, 1 to 2 μ (0A means the weight ratio of particles exceeding 1 μ and 2 μ or less).

Dispersibility measurement method Sample 25 on 50g of nitrocellulose lacquer black enamel
．． Add 9 and use a small high-speed stirring type dispersion machine (commonly known as Disper).
Stir for 5 minutes at J, IS K54004・4・(
2) Using a crush cage according to JIS-K 540
The crush distribution before and after shrinkage was measured by the 0.4.5.1.A method to determine the dispersibility.

Method for Measuring Bulky Powder Generally, when extremely bulky powder is measured using a graduated cylinder, the air is trapped inside the powder and after the measurement, the air gradually escapes, resulting in a decrease in volume.

Therefore, in this example, we left it naturally for 30 minutes.
When the volume reached a certain level, 5000 ml was measured, and the weight at that time was also measured.The bulk density was determined as the weight per unit volume.

In addition, to measure the volume after compression, in most cases the block is shaped similar to a graduated cylinder, but this block was appropriately broken and then measured using the same graduated cylinder.

From the above results, the illegally shrunk powder became extremely compact with no changes in oil content, particle size distribution, and dispersibility, and the cost of transportation and storage was reduced.

In addition, the sample after shrinkage generates far less dust during handling than the sample before shrinkage, making it very easy to work with.Moreover, when mixing and stirring into the paint, there is less dust being swallowed by the paint. It got better.

Further, there was almost no increase in volume after this shrunken sample was left as it was for 60 days, and even when it was placed in a polyethylene bag and shaken, almost no increase in volume was observed.

Example 2 A sample of 50007711 was weighed into a measuring cylinder in the same manner as in Example 1 using ultrafine powdered silicic acid for paint manufactured by Suikagaku Co., Ltd. (trade name Mizukasil P-526) as a bulky powder. The pressure after deaeration is -100, -200° -300, -400, -5, respectively.
00, -600.

-700mmHf! After degassing to a maximum temperature, the pressure was increased to atmospheric pressure at each initial pressure increase rate, and samples were taken out.

The volume of the shrunken paint was measured and the volumetric shrinkage rate was determined in the same manner as in Example 1. The results are shown in Table 2.

Further, the change in volume when this shrunken sample was left for 60 days was determined using the following formula.

Volume change rate after being left for 60 days = According to this result, the higher the vacuum pressure, the more the shrinkage effect.
Further, even after being left for 60 days, almost no increase in volume was observed, and the dispersibility in paint was no different from that of the sample before shrinkage.

As a reference example, Table 2, No. 6 shows the change in volume of a sample that was left to stand naturally for 60 days without vacuum compression.

Example 3 As samples, ultrafine silicic acid powder for paints (product name Mizukashiru P-526) manufactured by Suiko Kagaku, micropowder silicic acid for luminescent agent (product name Jiruton M), and fine powder silicic acid for anti-blocking agent (product name Jiruton A) manufactured by the same company were used. Commercially available kaolin powder (Jossia Kaolin: Sparse) was weighed into a 5000 Tll measuring cylinder in the same manner as in Example 1, placed in a pressure-resistant container 1 shown in FIG. 1, and degassed to -600 mmHg.

After that, the initial pressurization rate V EP = 800 mmHg/
sec to atmospheric pressure.

The properties before and after shrinkage are shown in Table 3 (Mizukasil P-526 is shown in Table 1).

Further, Table 4 shows the results of changing the initial pressurization rate VEP after degassing the same sample to -600 mmHg.

Example 4 Weighed 5000 ml of each of the powder samples listed in Table 5 in the same manner as in Example 1, placed them in the pressure container 1 shown in Figure 1, degassed to -600 miHg, and then increased the initial pressure to 800 mmHg. Atmospheric pressure was introduced at /Sec, and the shrinkage rate and bulk density of each volume were determined, and the results are shown in Table 5.

Example 5 As a sample, 5000 ml of ultrafine powder silicic acid for paint (trade name Mizukashiru P-526) manufactured by Suikagaku Kagaku was weighed in the same manner as in Example 1.

This sample was tested in the following three ways.

■ Polyethylene bag with sealable zipper (30 (
1771X 40CrIL), and then placed in a pressure container with a 5 mm length open at the end of the sealed part to allow air in the gaps between the powders to be removed.

■ Breathable kraft paper bags (3 ply 30cm)
A sample was placed in IrLX 40Cr/L) and placed in a pressure container with the inlet sealed*.

. ■ Place the mixture in a 5000ml graduated cylinder and put it in a pressure container.

Place the above sample in a pressure-resistant container 1 shown in FIG.
After degassing to mmHg and then introducing atmospheric pressure, the initial pressurization rate was varied and the relationship with shrinkage rate was determined.

The results are shown in Table 6. To determine the volume after shrinkage, samples (■) and (■) of the above three types were taken out of the bag and measured using a measuring cylinder.

Example 6 As a sample, fine silicic acid powder for color forming agent manufactured by Hyurikagaku Co., Ltd. (trade name: Jiruton) was coated with 3 layers of kraft paper 672myC1,
Fill a 590mm x 165mm bag with 25kg, 40
Pallet 140crf for transporting bags (total + oookg)
The volume dimensions when stacked on L x 120cIrL x 15cIrL are 140m x 120 excluding the pallet.
CrIL×180cIfL.

This sample 13 is contained in a steel pressure vessel 1 (diameter 3
1.5 m×depth 1.5 m) through a sealable front door 3, and degassed through an automatic valve 7 to -650 mmHg using a Natsch pump.

Thereafter, the automatic atmospheric pressure introduction valve 5 provided in the pressure vessel was opened, and the pressure was returned to atmospheric pressure at an initial pressure increase rate of 600 ytmH9/sec to perform vacuum compression.

When we bottled this shrunken material and measured its volumetric dimensions, we found that
It was 120Crn×102Crn×140cIrL.

Furthermore, when this sample was mechanically compressed and shaped at the same time by using a hydraulic press device shown in Fig. 5, using a hydraulic cylinder 14 and a press plate 15 at a pressure of 10 tons (in Fig. 5, 13 indicates a bagged product). , 16 indicates a pallet) The volumetric dimensions are even smaller, 120CrrLX102CII
It became IX136cIrL.

Example 7 Ultrafine powder silicic acid for paint manufactured by Mizusawa Chemical Co., Ltd. (trade name Mizukasil P-5)
26) 130 cfr made of PVC resin and resin heat shrink film
A LX 90 cm bag weighing 0 kg and 0 kg was placed in the bag, and the entrance of the bag was partially opened to allow air permeability and the bag was sealed.

In Figures 6-A, 6-B and 6-C, 10
It is made of steel and has a frame 17 partitioned with a wire mesh with a size of 5cnL x 50CrfL x 45CIIl, and the size is 3 in diameter.
A pressure-resistant container 1 with a depth of 1.5 m and OmX was used, and one bag of this sample was loaded into each framework, and the air was degassed to -650 mmH9 using a Natsch pump.

Thereafter, atmospheric pressure was introduced at an initial pressurization rate of 600 HgAeC, and the sample taken out was shrunk to a size similar to the size of the frame, and compressed into a rectangular plate shape of 70 cm x 35.5 cIrL x 30 cm.

Furthermore, by treating the PVC heat-shrinkable film with about 8 cm of hot air or boiling water, the bag was shrunk and a compact rectangular package was obtained.

The shrinkage rate at this time was 57%, and transportation and storage costs were greatly reduced.

Example 8 As a sample, ultrafine powdered silicic acid for paint manufactured by Mizusawa Chemical Co., Ltd. (trade name: Mizukashiru) was weighed into a 5000 ml graduated cylinder using the method of Example 1, and placed in the pressure container shown in FIG.

Further, a container containing 5 kg/air of compressed air was connected to the end of the valve 6 of the pressure container 1 by piping.

. After the pressure vessel 1 was degassed to -650 mmHg, the valve 7 was fully closed, the valves 5 and 6 were immediately fully opened, and compressed air was introduced into the pressure vessel 1 at an initial pressure increase rate of 1200 mmHg/sec.

After that, the compressed air was gradually released, and the pressure was returned to atmospheric pressure, and the sample was then taken out.

The shrinkage rate of this sample was 65% and the bulk density increased to 0.165.

Further, the dispersibility of this sample in paint was good with no change at all compared to before shrinkage.

Example 9 As a sample, ultrafine silicic acid powder for paint manufactured by Mizusawa Chemical Co., Ltd. (trade name Mizukashiru P-526) was put into the raw material supply hopper 18 of the apparatus shown in FIG.
9 into the space inside the screen 22 in the pressure vessel 1.

At this time, the sealable discharge damper 20 at the bottom of the pressure container 1 is in a closed state.

It is detected that the sample has been supplied to the upper limit of the pressure container by the upper limit tuning fork type level meter 21 attached to the pressure container 1, the flow rate adjustment damper 19 is closed, and the gas is degassed from the deaeration lower connected to the Natshu pump. did.

After degassing to -600 mmHg, the atmosphere introduction valve 5 was opened, and atmospheric pressure was applied to the entire sample through the screen 22 at an initial pressure increase rate of 800 mvtH9/sec.

The sample had a cylindrical block shape similar to the screen wall.

By opening the dispensing valve 20 with the air cylinder 24, the block is increased to the lower dispensing part 23, and by operating the air cylinder 25, the block is loosened to an appropriate size with the cutter 26, and after being weighed with the weighing hopper 27. packaged.

Two of the above-mentioned devices were installed, and by alternately degassing and introducing atmospheric pressure, smooth and compact packaging was achieved.

Example 10 Finely powdered silicic acid for coloring agent manufactured by Suikagaku Kagaku (trade name: Jiruton M) was filled into a 3-ply bag made of kraft paper.

In the apparatus shown in Figures 8-A18-B and 8-C, the sample and the pressure-resistant container 1 (consisting of an upper part 1a and a lower part 1b that can be opened and closed in the vertical direction) are transported by a supply conveyor 31. supplied.

The pressure containers 1a and 1b have a mechanism in which the upper half 1a can be opened and closed by an air cylinder 24, and inside thereof is provided with a conveyor 31' that is connected to a supply conveyor 31 at a small interval and is interlocked with a photocell 32. Ori,
The bagged product 13 is delivered to the photocell 3 by the supply conveyor 31.
At step 2, the number of pieces is detected, and the conveyor 31 and the conveyor 31 are stopped at the same time as the number of pieces is fed to the conveyor 31' in the pressure-resistant container.

Thereafter, the pressure vessels 1a and 1b were sealed by an air cylinder 24, and degassed to -600 mrILH& by a degassing lower.

After that, the initial pressure increase rate is 600 m through the atmospheric pressure introduction valve 5.
The pressure was returned to atmospheric pressure at mH9/sec, and then the upper half 1a of the pressure-resistant container was opened by an air cylinder, and the conveyor 31' started to operate, and the compacted bagged product was taken out through the dispensing conveyor 31''.

When the shrinkage rate of this product was measured, it was 25%.

Example If As a test sample, a matting ultrafine powder silicic acid for paint manufactured by Suikagaku Co., Ltd. (trade name Mizukashiru P-526) was compressed and packaged using the apparatus shown in Figure 9-B.

That is, a sample weighed in advance at tkg (17.4 A) was supplied from the powder supply nozzle 35 between two heat-shrinkable films 33 with pinholes that were supplied through the guide 34 .

The heat-shrinkable film was heat-sealed at the side edges by seal rollers 36 and 37, and the sample wrapped by the seal and cutter portion 38 was supplied to a pressure-resistant container 1 that can be opened upward and downward by an air cylinder 24. .

Next, the pressure container 1 (la, 1b) is connected to the air cylinder 24
-650mmH from the deaeration lower, ? Vacuum pump until degassed.

Next, the initial pressure increase rate is 800vanH from the atmospheric pressure introduction valve 5.
The heat-shrinkable film was shrunk by introducing atmospheric pressure at a rate of g/sec and then introducing hot air at 80° C. from a hot air force of 39, and the increased weight of the package became compact with a size of about 7.21 g/sec.

[Brief explanation of drawings]

FIG. 1 is a layout diagram of a pressure-resistant container and attached equipment that can be used in the present invention, FIG. 2 is an explanatory diagram showing how to determine the initial pressure increase rate, and FIG. Figure 4 is a layout diagram of the pressure vessel used in Example 6, Figure 5 is a layout diagram of the hydraulic press device used in Example 6, and Figure 6-A is a pressure vs. time curve. 6-B is a side view of the container shown in FIG. 5-A, and FIG. 6-C is a front view of the pressure-resistant container with the lid opened used in Example 7. FIG. 7 is a side view of the intermittent powder compaction device used in Example 9, and FIG. 8-A is a side view of the intermittent feed automatic powder compaction device used in Example 10. FIG. 8-B is a front view of the device of FIG. 8-A, and FIG. 8-C is a front view of the device of FIG.
The figure is a top view of the apparatus shown in FIG. 8-A, FIG. 9-A is a side layout view of the packaging powder compression apparatus used in Example 1, and FIG. 9-B is a top view of the apparatus shown in FIG. 9-A. FIG. 3 is a top view of the device in FIG. A; Reference number 1 is a pressure vessel, 2 is a rectifier plate, 3 is a sealable lid, 4 is a branch pipe, 5 and 6 are pressure increase valves, 7 is a deaeration valve, 8 is a pressure gauge, 9 is a vacuum pump, 10 11 is a Bourdon tube type pressure detector, 11 is an automatic recorder, 13 is a pouch filled with powder, 14 is a hydraulic cylinder, 15 is a press plate, 16 is a pallet, 17 is a frame, 18 is a raw material supply hopper, 19 is a 20 is a sealable supply damper, 20 is a sealable discharge damper, 21 is a level needle, 22 is a screen, 23 is a lower discharge part, 24 and 25 are air cylinders, 26 is a cutter, 27 is a metering hopper, 29 is an exhaust valve, 30 is a piston, 31 is a supply conveyor, 32 is a photocell, 33
is a heat-shrinkable film with pinholes, 34 is a guide, 35
(powder supply nozzle) L/, 36 and 3γ are seal rollers,
39 indicates the hot air supply ports - Bow - 8

Claims (1)

[Scope of Claims] 1 A sealable pressure-resistant container in which a bulky powder is filled into a support container that has a smaller volume than the pressure-resistant container and has a ventilation portion that communicates with the internal space of the pressure-resistant container. After charging and sealing the pressure container, the air is degassed, and then atmospheric pressure air is rapidly introduced into the pressure container at a pressure increase rate of 100 mmHg/sec or more. 1. A method for processing powder, characterized in that the bulk volume of the powder is reduced by introducing the powder into a support container under conditions that allow it to freely enter and exit the support container. 2. The method according to claim 1, which comprises degassing the atmosphere of the powder to a pressure of 660 mmHg (absolute) or less. 3. It consists of charging a bulky powder into a pressure-resistant container in a state in which it is filled in a flexible packaging container with a ventilation part, and taking out the powder whose bulk volume has been reduced from the pressure-resistant container as a package. A method according to claim 1. 4 Claim 3, wherein the packaging container is a bag-like container
The method described in section. 5. Claim 3, wherein the packaging container is a heat-shrinkable film container, and the surface of the packaging body taken out from the pressure-resistant container is heat-treated to form a shrunken packaging body.
The method described in section. 6. The support container is composed of a frame that supports a bulky powder filling placed in a pressure-resistant container, and by introducing the air, the support container has a similar shape to the frame and is reduced in size compared to the frame container. 2. A method as claimed in claim 1, comprising compressing into a solid mass.