JPS6163528A - Method for improving fluidity of lime powder - Google Patents

Abstract

PURPOSE:To improve the fluidity of lime powder, safely, easily, surely and economically, by treating lime powder with a specific amount of an organopolysiloxane represented by a specific general formula. CONSTITUTION:100pts.wt. of lime powder is treated with 0.02-1pt.wt. of an organopolysiloxane represented by the general formula (R3<3>SiO1/2)l(R2<2>SiO2/3)m(R<1>SiO-3/2)n(R<1>, R<2> and R<3> are same or different univalent hydrocarbon group; lis 0-35mol%, m is 35-95mol%; n is 5-30mol%; l+m+n=100%. The compound of the general formula is preferably a fluid methylpolysiloxane wherein R1. R2 and R3 are methyl, l is 2-30%, m is 40-93% and n is 5-25%. Preferably, lime powder finer than 10 mesh is added with the compound of formula in the absence of solvent, and mixed and stirred at room temperature-10 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION sitΔMori111 The present invention relates to a method for improving the fluidity of lime powder, and more specifically, a method for improving the fluidity of lime powder, which is operationally safe, simple and reliable. Concerning methods for improving liquidity.

BACKGROUND ART Lime powder, especially quicklime powder, has been effectively used in the manufacture of refractories, as a treatment agent for valves and paper, as a desulfurizing agent, etc. However, since quicklime powder has hygroscopic properties, it cannot be used as it is. This causes inconvenience in handling as it loses fluidity.

To this end, as a method to improve the fluidity of lime powder such as quicklime, lime powder has been treated with methylhydrodiene polysiloxane, trimethyldimethylsiloxane terminal, dimethylsiloxane terminal hydroxyl group, trimethylsiloxymethylmethoxypolysiloxane terminal, etc. A method of processing has been proposed (Japanese Patent Application Laid-Open Nos. 55-47223 and 1982-120).
No. 519, Special Publication No. 57-7085, Special Publication No. 5757-
7O87° However, in the method of using methylhydrodiene polysiloxane as a fluidity improver for lime powder, hydrogen gas is generated as the treatment progresses, creating a risk of explosion. For example, when 100 lime powder is treated with methylhydrogen polysiloxane (0.1'), the maximum amount is 361!
of hydrogen gas is generated. Therefore, when processing lime powder in a container or storing the processed product, hydrogen gas explosion V! To remove the surrounding area, use inert gas or nonflammable solvent (chlorinated solvent, etc.)
However, the dilution process is complicated, and especially when diluted with a nonflammable solvent, the solvent must be removed in the subsequent process. be. Furthermore, if the opening of the container is made large, there is a risk that the powder will scatter as the treatment progresses and the flowability of the lime powder increases.

In addition, when terminal trimethylsilyl or terminal *i; water Mu dimethyl polysiloxane is used as a fluidity improver, a long processing time is required, and a considerable amount of time is required until the fluidity improvement effect is fully realized. Moreover, strong stirring treatment is required, which poses a problem in processability.

Moreover, the process using terminal trimethylsilylmethylmethoxypolysiloxanes makes the compound itself complicated to produce and expensive.

11.'' In view of the above circumstances, the present inventors have conducted intensive studies on a method for improving the fluidity of lime powder that is safe to work with and has good workability.As a result, the following general formula % formula % (However, RL, R2, and R' are the same or different single-stroke hydrocarbon groups, J = 0 to 35 mol%, m = 3
5-95 mol%, n=5-30 mol%.

The organopolysiloxane represented by J+n++n=100 mol% has excellent properties as a lime powder fluidity improver. It has been found that the above object can be achieved by carrying out the treatment using 0.02 to 1 part.

That is, 5 to 30 mol% of R''; LO soil units as described above.
When lime powder is treated using a compound containing it, there is no generation of hydrogen gas, and there is little generation of flammable gases such as methyl alcohol, so the work can be done safely. Since there is little methyl alcohol generation, there is no need to dilute with inert gas or non-flammable solvents, work can be done at room temperature, strong stirring is not necessarily required, and it can be used in small amounts for lime powder. It has good workability and can easily and reliably improve the fluidity of lime powder, such as being able to impart a fluidity-improving effect in a relatively short time, and the above compound is relatively easy to produce and is inexpensive. Therefore, the present invention was realized based on the finding that the processing cost can be reduced.

The present invention will be explained in more detail below.

11.1 The method for improving the fluidity of lime powder of the present invention can be suitably employed to improve the fluidity of lime powder such as quicklime, slaked lime, calcium carbonate, etc., especially lime powder with a particle size finer than 100 mesh. Lime powder of the following general formula (I) (R; Sl +) λ (1, s; ox), (R1si'0
．． H), ... (, T) (However, R1, R2, R3 are mutually the same or different monovalent hydrocarbon groups, !=0 to 35 Tl-le%, m=
35-95 mol%, n=5-30 mol%.

It is characterized by being treated with one or more organopolysiloxanes represented by J + m + n = 100 mol %).

Here, as the organopolysiloxane of formula (I), one in which R1, R2 and R3 are each a lower alkyl group such as a methyl group or ethyl group is preferably used. In particular, R1, R2, and R3 are each methyl katsure, and! =2
~35 mol%, m = 4Q ~ 93 mol%, n = 5-2
Methylpolysiloxane with a content of 5 mole % is preferably used. In this case, in the above formula (I), the single acid unit on R3SgO is not required, but it is introduced to adjust the degree of polymerization, and its mol% is 35 mol% or less as described above,
In particular, it is preferably 2 to 35 mol%. Also, R1
5 iO± units are necessary to accelerate the onset of fluidity improvement effect when processing lime powder, and its mol% is 5 to 5 iO units.
30 mol%, particularly preferably 5 to 25 mol% as mentioned above, 5 mol? If it is less than 30 mol %, the fluidity improvement effect will be delayed, and if it is more than 30 mol %, it will be difficult to obtain a stable polysiloxane fluid, which is not preferable.

In addition, the above compound has a viscosity of 1 to 500 at 25°C.
cs, especially 1 to 100 cs is preferred.

The organopolysiloxane of the above formula (1) can be produced by a known method, and is generally a co-hydrolysis method of silanes having corresponding hydrolyzable groups (chlorine, etc.) (if necessary, toluene etc.) solvents may be used)
ll 5W is done. For this reason, polysiloxane fluids are generally produced containing several percent or less of water M1 groups or alkoxy groups. In this case, a method of polymerization using a catalyst such as activated clay or sulfuric acid may also be employed to adjust the viscosity.

In the present invention, lime powder is treated using the organopolysiloxane of formula (I), and in this case, the amount of the compound used is 0.02 to 1 part per 100 parts of lime powder. , when the amount used is less than 0.02 part and 1
In either case, the lime powder fluidity improving effect is not sufficiently exerted. In addition, the suitable usage-amount range of the said compound is 0.1-0.5 part with respect to 100 parts of lime powder.

As a method for treating lime powder with the above-mentioned compound, a commonly adopted method can be used. For example, the above-mentioned compound is added to lime powder, and the lime powder is processed using an appropriate Fft# method such as shaking and stirring. A method of uniformly mixing the above compounds can be adopted. In this case, stirring does not necessarily have to be strong stirring. The treatment temperature is not particularly limited and can be from room temperature to 100°C, but the treatment can be carried out sufficiently at room temperature, and according to the present invention, highly fluid lime powder can be reliably produced by mixing at ambient temperature. Further, although the treatment time is not limited, it is usually 10 minutes to 1 hour, and according to the present invention, the fluidity of lime powder can be improved with a relatively short treatment time.

In addition, in the present invention, since hydrogen gas is not generated and the amount of methyl alcohol generated is very small, there is no need to dilute with inert gas or nonflammable gas, and the treatment can be carried out in an air atmosphere. Can be processed in solvent.

Effects of the invention) As mentioned above, the method for improving the fluidity of lime powder of the present invention uses a specific amount of a specific organopolysiloxane, thereby eliminating the generation of hydrogen and reducing the generation of methyl alcohol, making it safe. It can be processed in a relatively short time when completely crushed, and it is possible to reliably obtain lime powder with sufficiently high fluidity by using only a small amount of processing agent, and it is also inexpensive in terms of cost. It is.

EXAMPLES Hereinafter, the present invention will be specifically explained by showing examples and comparative examples, but the present invention is not limited to the following examples.

[Examples, Comparative Examples] (CH3) s 5=CI, (CH3) 2 sa
C2°CH35LCj 3 was used in the proportions shown in Table 1, and hydrolysis was carried out according to a conventional method to obtain methylpolysiloxane.

Table 1 Next, 200 mesh buses (250 mesh buses 8%,
0.1 part and 0.3 parts of the above-mentioned methylpolysiloxane were added to 100 parts of quicklime in a 325 mesh bath (40%), placed in a 300CC round bottom flask equipped with a stirrer, and mixed and stirred for 1 hour at room temperature. Ta.

For comparison, dimethylsiloxane with a terminal trimethylsilyl group having a viscosity of 20C3 at 25°C (Comparative Example 1) and 2
A similar treatment was carried out using terminal hydroxyl group-containing dimethylsiloxane (Comparative Example 2) having a viscosity of 20C3 at 5°C.

The angle of repose of the quicklime treated using the above method was measured to evaluate its fluidity. The results are shown in Table 2. Note that the angle of repose of untreated quicklime was 53°.

From the results shown in Table 2, it was found that the fluidity of quicklime powder could be improved in a short time by using the present Bonmei organopolysiloxane.

Claims (1)

[Claims] 1. The following general formula (I) (R^3_3SiO_1_/_2)_l(R^2_2S
iO_2_/_2)_m(R^1SiO_3_/_2)
_n...(I) (However, R^1, R^2, R^3 are the same or different monovalent hydrocarbon groups, l = 0 to 35 mol%, m
=35-95 mol%, n=5-30 mol%, l+m+n
1. A method for improving the fluidity of lime powder, which comprises treating 100 parts by weight of lime powder with 0.02 to 1 part by weight of an organopolysiloxane represented by the formula (=100 mol%). 2. R^1, R^2, R as a compound of general formula (I)
^3 is each a methyl group, l = 2 to 35 mol%,
The method of claim 1 using a methylpolysiloxane fluid in which m=40-93 mol% and n=5-25 mol%. 3. General formula (I) for lime powder finer than 100 mesh
The method according to claim 1 or 2, wherein the treatment is carried out by adding the compound in a solvent-free state and mixing and stirring at room temperature to 100°C.