JPS59228917A - Filter medium - Google Patents

Abstract

PURPOSE:To obtain the filtrate with high clarity in a short time by using fibrous magnesium oxysulfate as a filter medium. CONSTITUTION:The fibrous magnesium oxysulfate (MOS) is a synthetic inorganic compd. expressed as MgSO4.5MgO.8H2O or MgSO4.5Mg(OH)2.3H2O. The MOS, having 2.0-2.5 true sp.gr., 5-100mum fiber length, and 0.1-2mum fiber diameter, is a highly voluminous fibrous substance, and assumes the needle crystal structure as the general form. The medium is used solely or in combination with well-known filter mediums or filter aids. In the combined use, >=1wt% is prefferably added. The MOS can be molded with resins, etc. and used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to liquid filtration materials. More specifically, the present invention uses fibrous magnesium oxysulfate (hereinafter M
It is abbreviated as O8. ).

Asbestos and diatomaceous earth, which are fibrous or granular inorganic natural products, have traditionally been used as resiliency agents and filter aids (together referred to as filtration materials) in the manufacturing process of the chemical industry.

Acid clay, colloidal clay, china clay, zeolite, etc., as well as organic natural products such as anthracite, charcoal powder, and pulp.

Synthetic products such as alumina gel, diatom gel, metal oxide gel, and glass fiber are also used. Foods, pharmaceuticals, and agricultural chemicals that require even higher levels of clarity.

In the cosmetics field, membrane filter-1 metal sintered filters, ceramic filters, etc. have been used.

However, even when the above-mentioned known filtration materials are used, there are still disadvantages in that the clarification performance is insufficient depending on the liquid to be filtered, clogging occurs, and a long filtration time is required. In addition, attempts have been made to improve the filtration rate by using a filter aid and a high-performance filter, but this has not been sufficient.

As a result of nine various studies in order to obtain high clarity in a short time, the present invention has been developed by using MOS as a filter material.
The present invention was completed based on the discovery that the present invention can exhibit a filtration function that far exceeds that of conventional filtration materials.

That is, the present invention relates to a filtration material characterized by containing fibrous magnesium oxysulfate.

Used in the present invention. MOS is MPS04/5M20/8H
20 or MP8045MIF(OH)2・3H20”
? It is a synthetic inorganic compound represented by '. This MOS can be produced, for example, by dispersing magnesium oxide or magnesium hydroxide in an aqueous magnesium sulfate solution and subjecting it to a heating reaction, or by dispersing magnesium hydroxide in a sulfuric acid solution and subjecting it to a heating reaction ( (See Japanese Unexamined Patent Publication No. 149318/1983).

The general form of MOS is true specific gravity 2.0 to 2.5, fiber length) 5 to 100 μm, diameter (fiber diameter) 0.1 to 2 μm,
It can be described as an extremely bulky fibrous material with an acicular crystal structure having a bulk specific gravity of 0.05 to 0.2.

MOS can be used alone or in combination with known filtration materials and p-transactive agents. Known filtration materials have a weight factor of 1 or more, preferably 30 or more.

Furthermore, it is also possible to use a weight factor of 50 or more.

Further, the MOS or the filtration material containing MOS used in the present invention may be in a dry state or in a wet state with a liquid, but a wet state is more preferable.

The MOS or the filtration material containing MOS in the present invention may be used by either a precoat method or a body feed method, and the filtration function is further improved by a combination of both methods. Furthermore, a filter can be created and used by molding MOS or a filtration material containing MOS using resin or other materials.

Next, the present invention will be specifically explained using examples.

Reference Example (Manufacturing Example of MOS) 9 kg of magnesium sulfate heptahydrate was dissolved in 120 A of water, and in this solution were dispersed magnesium hydroxide 2]25 and 0.4 Kf of MOS as a seed crystal.

This dispersion was put into an autoclave with an internal volume of 1707,
The reaction was carried out at 170°C for 3 hours. The generated precipitate was taken out, washed with water, dried at 160'C, and MOEI
I got it. The following experiment was conducted using the MOS thus obtained.

The filtration method is as follows.

Pre-coating method: A method in which the filtration material is dispersed in advance in a dispersion medium used for the liquid to be filtered, and is fixed on a F bed such as P cloth or a perforated glass plate, followed by filtration.

Body feed method: A method in which a dispersion liquid in which an appropriate amount of filtration material is dispersed in a liquid to be filtered is supplied to a P bed such as P cloth or a glass porous plate for filtration.

Example 1 MOS2 manufactured by the method described above. Of toluene 200
Ultrasonic dispersion was carried out in m/m. This MO8 dispersion was
0 solution glass filter (Gi, pore size 100-150
The toluene was removed under reduced pressure to form a MO8P' bed previously impregnated with toluene.

As a sample for clarification, the particle size is 0.025-0. o4μm dioxazine pigment Trade name: (sumitone East V
ioletRLi (manufactured by Sumitomo Chemical ■) 0.59 was ultrasonically dispersed in toluene 100%. This 0,5 wt%
MO precoated with dioxazine dispersed toluene
A test was conducted on the filtration performance of S. Filtration was carried out under a constant reduced pressure of 12 mHf using a vacuum pump, and the filtration time and the absorbance (measured at maximum absorption wavelength, 600 cm) of liquid F were measured using pure toluene as a symmetry. The results are shown in Table 1.

Example 2 Pre-coated in the same manner as in Example 1, and
A bed was formed and a +0.5 wt% dioxazine dispersion was prepared. Further, MOS 0.59 was added to this dispersion liquid, and filtration was performed in the same manner as in Example 1, and the time required for filtration and the transmittance of the P liquid were measured. The results are shown in Table 1.

Comparative Examples 1 to 5 Diatom ± (Comparative Example 1) instead of MOS in Example 1,
Activated alumina (Comparative Example 2), crushed pulp (Comparative Example 6),
A membrane filter pre-coated with activated carbon (Comparative Example 4) and a membrane filter with a pore size of 0.1 mm (Comparative Example 5) were used in place of the glycated MOS. Other conditions are Example 1
Perform vacuum filtration in exactly the same manner as above to determine the filtration rate and F
The transmittance (600 .mu.) of the liquid was measured. The results are shown in Table 1.

Comparative Example 6 0.5 wt thidioxazine-dispersed toluene was prepared in the same manner as in Example 1, using a membrane filter with a pore size of 0.1 μm instead of the precoated MOS filter bed in Example 1. Furthermore, after adding diatom ±0.5 f as a filter aid to 0.5 wt% dioxazine-dispersed toluene,
Perform vacuum filtration to determine filtration time and tear fluid permeability (600
m) was measured. The results are shown in Table 1.

Comparative Example 7 A replacement for the pre-coated MOS filter bed in Example 1 was pre-coated with activated carbon, and the same K O,5w as in Example 1 was applied.
Prepare t% dioxazine-dispersed toluene.

Furthermore, 0.52% of activated carbon was added to this dispersion and dispersed.
Perform vacuum filtration to determine the filtration rate and permeability of the solution (600
mm) was measured. The results are shown in Table 1.

From the above experimental results, MOS is a membrane filter (porous film) that is another known filtration material.

It is clear that both filtration efficiency (filtration rate) and clarity (transmittance) are very superior compared to diatomaceous earth, alumina gel, and pulp. In addition, the filtration function can be further improved by using the body feed method in combination.

Example 6 In place of the 0.5 wt% dioxazine pigment-dispersed toluene in Example 1, Aerosil with an average particle size of 7 mμm [≠38
02 (manufactured by Nippon Aerosil ■)], and the other conditions were exactly the same as in Example 1. The filtration time and the clarity (transmittance by white light) of the F solution were measured. The results are shown in Table 2.

Comparative Examples 8 to 11 Pre-coated with diatomaceous earth (Comparative Example 8), activated alumina (Comparative Example 9), and crushed pulp (Comparative Example 1o) instead of pre-coated MOI 9 in Example B, and pore size 0
．． A 1 μm membrane filter (Comparative Example 11) was used. Vacuum filtration was performed under exactly the same conditions as in Example 1, and the filtration rate and the transmittance of liquid E (white light) were measured.

The results are shown in Table 2.

Example 4 0.5wt96 quinacridone pigment (0.5wt%) instead of toluene dispersed with 0.5wt%
A filtration test was conducted using a MO8F bed precoated in the same manner as in Example 1 using 1 to 0.6 μm of dispersion water. The filtration rate and the permeability (white light) of liquid F were measured to evaluate the filtration function. The results are shown in Table 2.

Comparative Examples 12 to 14 Diatomaceous earth was used to replace the MOS in Example 4 (Comparative Example 12)
, activated alumina (Comparative Example 13), crushed pulp (Comparative Example 1)
4) was precoated and 0.5 wt% quinacridone pigment dispersion water was used. It was filtered under reduced pressure in exactly the same manner as in Example 1, and the filtration rate and p-liquid permeability were measured. The results are shown in Table 2.

It is clear from the above results that MOS exhibits a filtration function that far exceeds that of conventional filtration materials as a filtration material for clarifying and filtrating liquids.

Claims (1)

[Claims] A filtration material comprising fibrous magnesium oxysulfate.