JP2001205132A - Method for crushing and/or kneading solid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for crushing and/or kneading solid using a dispersing medium free from problem of the depletion of ozone layer, nonflammable, high in stability, hardly imposing the problem of pressure tightness on a device and excellent in drying property. SOLUTION: The solid is crushed and/or kneaded under the presence of the dispersing medium containing the fluorine-containing hydrocarbon selected among decafluoropentane, heptafluorocyclopentane, perfluorohexane and perfluoroheptane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for pulverizing and / or kneading solids in a ball mill or the like in the presence of a dispersion medium.

[0002]

2. Description of the Related Art Pulverization and kneading of solids are performed by various methods in various industrial fields including cement, glass and ceramics, and one of them is a ball mill method. There are two types of ball milling methods, a wet method and a dry method. When it is desired to avoid agglomeration of solids to be ground or kneaded or to reduce the particle size, the wet method is often used. .

When grinding or kneading solids by a wet method, a dispersion medium is used to prevent agglomeration of the solids and to carry out grinding efficiently, and various dispersion media are used. It is used. Water is used as a typical example. JP-A-61-274399 also discloses a method of using alcohols, aromatics, and ketones as a dispersion medium in grinding.

Further, Japanese Patent Application Laid-Open No. 5-254918 discloses a method of using a mixed solvent of a solvent containing an elemental fluorine and an organic solvent when producing a slurry of an inorganic powder. As such a solvent containing elemental fluorine, dichlorotrifluoroethane, monochlorotetrafluoroethane, tetrafluoroethane, and dichlorofiflosfluoropropane are described.

[0005] Water as a dispersion medium in the pulverization and kneading of solids is nonflammable and has no effect on the solids. Further, the mixture of solids is subjected to drying and / or calcination steps after mixing. It often has excellent suitability as a dispersion medium because it does not remain and adversely affect the product. However, water has a boiling point of 10
0 ℃ and high latent heat of vaporization at boiling point 2264kJ
/ Kg, which is disadvantageous in that it requires time for drying and requires a lot of energy.

[0006] Further, when a water-soluble solid is contained in the solid to be pulverized and / or kneaded, the solid is dissolved in water, so that the supernatant cannot be removed and more drying is required. It takes a long time and energy.

[0007] Since the dispersion medium composed of the above-mentioned alcohols, aromatics, or ketones is flammable, the use of the dispersion medium must take measures to prevent ignition. Difficulties such as upsizing of the device are recognized.

Further, the solvent containing elemental fluorine described in the above-mentioned JP-A-5-254918 has the following problems when used alone.
It was not always practical. That is, dichlorotrifluoroethane and monochlorotetrafluoroethane have a boiling point of 28 ° C. and −12 ° C., respectively, and the pressure increases during pulverization or kneading performed at a temperature of several tens of degrees. This requires additional measures, such as an increase in equipment cost and an increase in the shape of the equipment.

Further, the above-mentioned dichlorofiflosfluoropropane (hereinafter, referred to as dichloropentafluoropropane, which is a more general name in the present invention) has a boiling point of 54 ° C., so that there is no need for the apparatus to withstand pressure. It is excellent and has a latent heat of vaporization at the boiling point of 147 kJ / kg, and the above-mentioned water (latent heat of vaporization at the boiling point: 2264 kJ / k)
It was confirmed by the present inventor that the present invention was superior in drying property to g). However, dichloropentafluoropropane is one of the ozone-depleting substances like dichlorotrifluoroethane and monochlorotetrafluoroethane described above.
Seed HCFC (Hydrochlorofluorocarbon)
Therefore, the abolition in 2020 has been decided according to the schedule of the Montreal Protocol for the purpose of protecting the ozone layer, and alternatives are being sought.

[0010] Further, the above-mentioned tetrafluoroethane is a high-pressure gas having a boiling point of -26 ° C, and requires a pressure-resistant device specified by the High Pressure Gas Safety Law, which increases the cost of the device and increases the size of the device.

[0011] As described above, the solvents containing elemental fluorine, which are conventionally known as dispersion media, have respective problems, and are never satisfactory as dispersion media.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide a non-flammable and non-flammable ozone layer when grinding and / or kneading at least one solid material.
An object of the present invention is to provide a pulverizing and / or kneading method using a dispersion medium having no influence on solids, high stability, little influence on pressure resistance of an apparatus, and excellent drying properties.

[0013]

Means for Solving the Problems The present inventor has repeatedly studied various substances to solve the above-mentioned problems, and as a result,
The present invention has been completed. That is, the present invention provides a method for pulverizing and / or kneading a solid in the presence of a dispersion medium, wherein the dispersion medium is a fluorocarbon selected from decafluoropentane, heptafluorocyclopentane, perfluorohexane and perfluoroheptane. The present invention relates to a method of pulverizing and / or kneading a solid, which is a composition containing at least one kind of hydrogen or the fluorine-containing hydrocarbon as a main component.

The specific fluorine-containing hydrocarbon used as a dispersion medium in the present invention does not correspond to an ozone depleting substance and is nonflammable. Great stability. In addition, even in terms of boiling point, the pressure rise in the apparatus is small, the latent heat of vaporization is small, so the energy required for drying is small. It is a medium that sufficiently achieves the object of the present invention.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The specific fluorinated hydrocarbon used in the present invention is selected from decafluoropentane, heptafluorocyclopentane, perfluorohexane and perfluoroheptane. Decafluoropentane is
The boiling point is 55 ° C, and the latent heat of vaporization at the boiling point is 130 kJ / k.
g. Heptafluorocyclopentane has a boiling point of 8
2 ° C. and the latent heat of vaporization at the boiling point is 189 kJ / kg
It is. Perfluorohexane has a boiling point of 56 ° C., and the latent heat of vaporization at the boiling point is 92 kJ / kg. And perfluoroheptane has a boiling point of 80 ° C.,
The latent heat of vaporization at the boiling point is 80 kJ / kg. These are conventional dispersing media, for example, the boiling point of water is 100 ° C.
Has a latent heat of vaporization that is much smaller than the latent heat of vaporization of 2,264 kJ / kg, and is excellent in energy efficiency during drying. In addition, the effect of the pressure resistance on the pulverizing and / or kneading apparatus is small and excellent in terms of boiling point.

The above decafluoropentane has a molecular formula of C ₅
In the compounds represented by H ₂ F _10, 1,1,1,2,2,
3,4,5,5,5-decafluoropentane and 1,
There are isomers such as 1,1,2,2,3,3,5,5,5-decafluoropentane. In the present invention, such isomers can be used alone or as a mixture of two or more, but among them, 1,1,1,2,2,3,4,5,5,5
5-Decafluoropentane is preferred.

The above heptafluorocyclopentane is represented by the molecular formula C ₅ H ₃ F ₇ and comprises 1,1,2,2,3,3,
4-heptafluorocyclopentane and 1,1,2,2
There are isomers such as 2,3,4,5-heptafluorocyclopentane. In the present invention, even one of such isomers
Alternatively, it can be used as a mixture of two or more, and among them, 1,1,2,2,3,3,4-heptafluorocyclopentane is preferable.

The above perfluorohexane has a molecular formula of C ₆
A compound represented by F _14, there is a isomers such as n-perfluorohexane and iso perfluorohexane. In the present invention, such isomers can be used either alone or as a mixture of two or more, and among them, normal perfluorohexane is preferable.

The above perfluoroheptane has a molecular formula of C ₇
A compound represented by F _16, there is a isomers such as n-perfluoro-heptane and iso perfluoroheptane. In the present invention, one of such isomers or a mixture of two or more thereof can be used, and among them, normal perfluoroheptane is preferable.

The above-mentioned fluorinated hydrocarbon can be used alone, of course, but it can also be used as a composition containing the fluorinated hydrocarbon as a main component. When used also as a composition, it is preferable to use it together with at least one substance selected from alcohols, hydrocarbons (excluding the above-mentioned fluorine-containing hydrocarbons), ketones and ethers. As these alcohols, hydrocarbons, ketones and ethers, those having a boiling point of preferably 20 to 120 ° C, particularly preferably 20 to 100 ° C, are suitable. The amount of the substance to be used in combination is preferably 0.1 to 10 parts by mass, particularly preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the fluorinated hydrocarbon. The use amount outside the above range is not preferable because the advantage of the fluorine-containing hydrocarbon as the dispersion medium is impaired.

Preferred examples of the alcohol used above include lower alcohols having 1 to 3 carbon atoms, such as methanol, ethanol, 1-propanol and 2-propanol. Preferred examples of the hydrocarbon include
5 to 6 carbon atoms such as normal pentane, isopentane, cyclopentane, normal hexane, and cyclohexane
Lower hydrocarbons. Preferred examples of ketones include those having 3 carbon atoms such as acetone and methyl ethyl ketone.
To 5 ketones. Preferred examples of the ether include ethers having 4 to 6 carbon atoms, such as diethyl ether, diisopropyl ether, and dipropyl ether.

The dispersion medium used in the present invention may contain other substances as long as the object of the present invention is not impaired, and examples thereof include substances generally called "binders".

In the present invention, when pulverizing and / or kneading a solid using the above-mentioned dispersion medium, the method, means and apparatus are not limited, and various types can be used. For example, a ball mill or the like can be used for grinding and / or kneading. The amount of the dispersing medium used varies depending on the type of the target solid material and the purpose of pulverization, kneading, etc., but per 100 parts by mass of the solid material, preferably from 200 to 100 parts by mass.
500 parts by mass.

The dispersion medium of the present invention is particularly advantageously used for pulverization in a ball mill. In the case of such a ball mill, in order to prevent damage to the mill from balls violently moving in the mill, an impact is applied to the inner wall of the mill. An elastomer for absorption is coated. Such elastomers are susceptible to corrosion due to the harsh environment in the mill and, for example, in the case of the above-mentioned dichloropentafluoropropane, affect the elastomer and cause damage such as deformation and peeling. However, in the case of the dispersion medium of the present invention, there is also an advantage that such a bad influence is not caused because the corrosiveness to the elastomer is small.

In the present invention, the type of solid matter to be pulverized and / or kneaded is not limited, and may be any of inorganic or organic matter, low molecular weight or high molecular weight substance, natural substance and synthetic substance. You may. In addition, the particle size of the target solid is not limited, and can be applied to, for example, pulverization and / or kneading of a solid of several tens of microns to several tens of millimeters. In addition, the pulverization and kneading in the present invention are intended to cover all operations which are not necessarily expressed as such and substantially involve pulverization and / or kneading, such as crushing, mixing and stirring.

In the present invention, preferable representative solids are various minerals, oxides, hydroxides, carbonates, metals and the like required in the fields of cement, glass, ceramics and the like. is there. Among them, in the present invention, even when pulverizing and kneading a solid containing a water-soluble substance, which is a problem when water is used as a dispersion medium, drying with energy efficiency can be performed, which is extremely advantageous.

[0027]

EXAMPLES The present invention will be described in more detail with reference to examples below, but it should be understood that the present invention is not construed as being limited to these examples. Example 1
Examples 7 to 10, 10 to 16 and 19 are examples, and Example 8
-9, Examples 17-18, and Example 20 are comparative examples.

Example 1 A water-insoluble ball mill containing 50 g each of zinc oxide, aluminum oxide, barium carbonate and manganese dioxide was used as a dispersion medium in the form of 1,1,1,2,2. , 3,4,5,5,5
-Decafluoropentane (hereinafter referred to as medium A) by 3
00 g was charged. After crushing and kneading for 1 hour, the mixture was allowed to stand for 10 minutes, and then about 50 g of the supernatant was removed.
The mixture in the ball mill was transferred to a stainless steel vat having a size of m. The drying time measured by leaving the vat in a thermostat set at 60 ° C. and measuring the weight change is shown in Table 1.

Example 2 In Example 1, as a dispersion medium,
The same operation as in Example 1 was performed, except that the same amount of 1,1,2,2,3,3,4-heptafluorocyclopentane (hereinafter, referred to as medium B) was used instead of medium A, and measurement was performed. Table 1 shows the obtained drying times.

Example 3 In Example 1, the dispersion medium was
The same operation as in Example 1 was performed except that normal perfluorohexane (hereinafter, referred to as medium C) was used instead of medium A, and the measured drying times are shown in Table 1.

Example 4 In Example 1, the dispersion medium was:
Except that normal perfluoroheptane (hereinafter, referred to as medium D) was used instead of medium A, the same operation as in Example 1 was performed, and the measured drying time is shown in Table 1.

Example 5 In Example 1, the dispersion medium was:
Instead of medium A, 1,1,1,2,2,3,4,5
Except that the same amount of a mixture of 5,5-decafluoropentane / normal perfluorohexane = 50 parts by mass / 50 parts by mass (hereinafter, referred to as medium E) was used, the same operation as in Example 1 was performed, and the measurement was performed. Table 1 shows the drying time.

Example 6 In Example 1, the dispersion medium was:
Instead of medium A, 1,1,1,2,2,3,4,5
The same operation as in Example 1 was carried out except that the same amount of a mixture of 5,5-decafluoropentane / ethanol = 97 parts by mass / 3 parts by mass (hereinafter, referred to as medium F) was used. It is shown in FIG.

Example 7 In Example 1, the dispersion medium was:
Instead of medium A, 1,1,1,2,2,3,4,5
The same operation as in Example 1 except that the same amount of a mixture of 5,5-decafluoropentane / normal perfluorohexane / ethanol = 49 parts by mass / 48 parts by mass / 3 parts by mass (hereinafter, referred to as medium G) was used. Table 1 shows the measured drying times.

Example 8 In Example 1, the dispersion medium was:
Instead of the medium A, dichloropentafluoropropane (1,1-dichloro-2,2,3,3,3-pentafluoropropane / 1,3-dichloro-1,2,2,3,3
−pentafluoropropane = 50 parts by mass / 50 parts by mass)
(Hereinafter referred to as medium a.) The same operation as in Example 1 was performed except that the drying time was measured. Table 1 shows the measured drying times.

Example 9 In Example 1, the dispersion medium was
The same operation as in Example 1 was performed except that water (hereinafter, referred to as medium b) was used instead of medium A, and the measured drying times are shown in Table 1.

[0037]

[Table 1] [Example 10] 300 g of medium A was used as a dispersion medium in a ball mill containing 50 g each of zinc oxide, aluminum oxide, barium carbonate and water-soluble potassium nitrate.
I put it in. After crushing and kneading for 1 hour, the mixture was allowed to stand for 10 minutes, then about 50 g of the supernatant was removed, and the mixture in a ball mill was transferred to a stainless steel vat having a size of 15 cm × 15 cm. Table 2 shows the drying time obtained by allowing this vat to stand in a thermostat set at 60 ° C. and measuring the change in weight.

Example 11 In Example 10, except that the same amount of medium B was used instead of medium A as the dispersion medium,
Operating as in Example 10, the measured drying times are shown in Table 2.

Example 12 In Example 10, except that the same amount of medium C was used instead of medium A as the dispersion medium,
Operating as in Example 10, the measured drying times are shown in Table 2. [Example 13]

In Example 10, medium A was used as the dispersion medium.
In place of the above, the same operation as in Example 10 was carried out except that the same amount of the medium D was used, and the measured drying times are shown in Table 2. [Example 14]

In Example 10, medium A was used as the dispersion medium.
In place of the above, the same operation as in Example 10 was carried out except that the same amount of the medium E was used, and the measured drying times are shown in Table 2. [Example 15]

In Example 10, medium A was used as the dispersion medium.
In place of the above, the same operation as in Example 10 was carried out except that the same amount of the medium F was used, and the measured drying times are shown in Table 2. [Example 16]

In Example 10, medium A was used as the dispersion medium.
In place of the above, the same operation as in Example 10 was carried out except that the same amount of the medium G was used, and the measured drying times are shown in Table 2. [Example 17]

In Example 10, medium A was used as the dispersion medium.
In place of the above, the same operation as in Example 10 was carried out except that the same amount of the medium a was used, and the measured drying times are shown in Table 2. [Example 18]

In Example 10, medium A was used as the dispersion medium.
Instead of using the same amount of medium b, and in order to avoid loss of water-soluble potassium nitrate, the same operation as in Example 10 was performed except that the supernatant was not removed after grinding and kneading. Table 2 shows the drying time.

[0046]

[Table 2]

Example 19 Various elastomers (shown in Table 3) coated on the inner wall of a ball mill were immersed in a dispersion medium set at a temperature of 50 ° C. for 3 days, and after immersion, the rate of weight change and dimensional change of the elastomers Was measured. Regarding the media A to G, both the weight change and the dimensional change were extremely small.

Example 20 The same procedure as in Example 19 was carried out except that the medium a was used in place of the mediums A to G. Table 3 shows the measured weight change rate and dimensional change rate of the elastomer. Show.

[0049]

[Table 3]

As a reference, the
Table 4 shows the ozone destruction coefficients of the media A to C, the media a, and tetrafluoroethane and whether or not the media A to C correspond to the greenhouse gas. The ozone depletion coefficient of CCl ₃ F is 1
It is.

[0051]

[Table 4]

[0052]

The dispersion medium used in the method for pulverizing and / or kneading solids of the present invention is not an ozone depleting substance,
Moreover, it is non-flammable, and has a high stability at ordinary temperatures during pulverization and kneading. In addition, since the boiling point is relatively large, the pressure rise in the apparatus is small, the energy required for drying is small because the latent heat of vaporization is small, and the solubility in solids is small, so that water-soluble solids are pulverized and kneaded. And the corrosiveness of the elastomer coated on the inner wall of the ball mill is small.

Claims (3)

[Claims] 1. A method for pulverizing and / or kneading a solid in the presence of a dispersion medium, wherein the dispersion medium is a fluorine-containing hydrocarbon selected from decafluoropentane, heptafluorocyclopentane, perfluorohexane and perfluoroheptane. A method of pulverizing and / or kneading a solid material, characterized in that it is at least one kind of the above or a composition containing the fluorine-containing hydrocarbon as a main component. 2. The pulverization and / or kneading of a solid material according to claim 1, wherein the dispersion medium contains at least one selected from alcohols, hydrocarbons (excluding the above-mentioned fluorine-containing hydrocarbons), ketones and ethers. Method. 3. The method for pulverizing and / or kneading a solid according to claim 1, wherein at least one kind of the solid is water-soluble.