JPS6163527A - Method for improving fluidity of lime powder - Google Patents

Abstract

PURPOSE:To improve the fluidity of lime powder, quickly, safely, easily, surely and economically, by adding a specific amount of organopolysiloxane or cyclic organopolysiloxane represented by a specific general formula to lime powder. CONSTITUTION:100pts.wt. of lime powder finer than 100 mesh is mixed with 0.01-1pt.wt. of one or more compounds selected from the organopolysiloxane of formula I; Ra<1>(R<2>O)bSi(4-a-b)/2 and having -OR<2> at the molecular terminal, and a cyclic organopolysiloxane of general formula II (R<1> and R<2> are same or different hydrocarbon group; 0<=a<4; 0<a+b<=4; n is 3-10), in the absence of solvent at room temperature-100 deg.C. The fluidity of lime powder can be improved safely, easily and surely by the above treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application The present invention relates to a method for improving the fluidity of lime powder, and more specifically, to a method for improving the fluidity of lime powder in an operationally safe, simple and reliable manner.
The present invention relates to a method for improving lime powder fluidity that can improve s properties.

Prior art and related technologies - 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 does not absorb moisture as it is. It becomes inconvenient to handle because it loses its fluidity.

To this end, a conventional method for improving the fluidity of lime powder such as quicklime is to treat lime powder with methylhydrodiene polysiloxane, terminal trimethyldimethylsiloxane, terminal hydroxyl dimethylsiloxane, terminal trimethylsiloxymethylmethoxypolysiloxane, etc. has been proposed (JP-A-55-47223@, JP-A-58-1205
No. 19, Special Publication No. 57-7085, Special Publication No. 57-708
No. 7).

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 0.19 methyl hydrodiene polysiloxane, up to 36 yl
of hydrogen gas is generated. Therefore, when processing lime powder or storing processed products in a container, it is necessary to dilute it with an inert gas or nonflammable solvent (chlorinated solvent, etc.) to keep it out of the explosion range of hydrogen gas, or to close the opening of the container. It is necessary to increase the
Dilution treatment is complicated, and especially when diluted with a nonflammable solvent, the solvent must be removed in a subsequent step, which is a hassle. 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 fluidity of the lime powder increases.

In addition, when terminal trimethylsilyl or terminal water B group dimethylpolysiloxane is used as a fluidity improving agent, a long treatment time is required, and a considerable amount of time is required for the fluidity improvement effect to appear. , it is necessary to carry out a strong stirring process, which poses a problem in processability.

Furthermore, is there a method using terminal trimethylsilylmethylmethoxypolysiloxane to produce this compound itself?
lJ, it is sloppy and expensive.

11 Sad 11 In view of the above circumstances, the present inventors have conducted extensive 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 % () Cyclic organopolysiloxane represented by an organo group having a molecular chain terminal of 10R2 (wherein, in the above formula, RL and R2 are mutually the same or different hydrocarbon groups, 0≦a<4.Q <b≦4゜Q<a+b≦4.n
= 3 to 10) has excellent properties as a lime powder fluidity improver, and this type of compound is added to 100 parts (parts by weight, the same hereinafter) of lime powder. It has been found that the above object can be achieved by using 0.01 to 1 part of the above object.

In other words, when lime powder is treated using the above compound, 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.
Moreover, since no hydrogen gas is generated and little methyl alcohol is generated, there is no need to dilute with inert gas or nonflammable solvent, and work can be done at air temperature, so strong stirring is not necessarily required. Furthermore, the fluidity improving effect of lime powder can be imparted to lime powder in a relatively short amount of time using only a small amount, and the above-mentioned compounds have good workability and can easily and reliably improve the fluidity of lime powder. Because it is relatively easy to manufacture and inexpensive, it is It was discovered that the cost could be reduced, and the present invention was developed.

The present invention will be explained in more detail below.

11 to 11 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 is combined with an organopolysiloxane represented by the following general formula (I) R1α (R20)b 5LOiii...(1), whose molecular chain ends are 10R2, and a cyclic organopolysiloxane represented by the following general formula (n). Polysiloxane (here, in the above formula, R1 and R2 are the same or different hydrocarbon groups, 0≦a<4.Q<b≦4゜Q<a+
5≦4. lI! with one or more compounds selected from n = 3 to 10). 11! l! It is characterized by:

Here, as for the compounds of the formula (I) and the formula (ff> having a terminal OR2 group, R1 and R2 are each a methyl group,
A lower alkyl group such as an ethyl group, particularly a methyl group, is preferably used.

Moreover, as a compound of the formula (I>) having a terminal OR2 group,
Those having a methoxy group content of 34 to 65% by weight are preferably used.

Furthermore, the above compound has a viscosity of 1 at 25°C.
~500 C81 Especially preferred is 1 to 100 cs.

In addition, the said compound can be manufactured by a well-known method.

For example, a dehydrochloric acid partial methoxylation hydrolysis method in which trichloromethylsilane is reacted with methyl alcohol and water, a method in which trichloromethylsilane is reacted with methyl alcohol to produce 1 q of chloromethoxymethylsilane, and this is reacted with hydrogen or ferric chloride. It can be produced using a method such as demethylchloride polymerization of partial methoxysilane in which demethylchloride is performed in the presence of methoxysilane.

The present invention is to treat lime powder using the above compound, but in this case, the amount of the above compound used is 0.01 to 1 part per 100 parts of lime powder, and the amount used is O, O.
When the amount is less than IJM, and when it is more than 1 part, the lime powder fluidity improving effect is not sufficiently exhibited. In addition, the preferred range of use of the above compound is 0.1 parts per 100 parts of lime powder.
~0.5 part.

As a method for treating lime powder with the above compound, a commonly adopted method can be used. For example, the above compound is added to lime powder, and the lime powder is treated using an appropriate stirring method such as shaking and stirring. A method may be adopted in which the above-mentioned compounds are uniformly mixed. 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 it can be sufficiently treated at room temperature, and according to the present invention, highly fluid lime powder can be reliably produced at 1η by mixing at ambient temperature. I can do it. Further, the treatment time is not limited, but 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, hydrogen gas is not generated and methyl alcohol is generated very little, so 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.

As mentioned above, the lime powder fluidity improvement method of the present invention uses a specific organopolysiloxane to eliminate hydrogen generation and reduce methyl alcohol generation, making it safe. It can be processed in a relatively short time at room temperature, and
It is possible to reliably produce lime powder with sufficiently high fluidity by using only a small amount of processing agent, and it is also inexpensive.

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.

[Example 1. Comparative Examples 1 and 2] Methylmethoxypolysiloxane (methoxy group-containing ff13
9.8%, viscosity 7C3) respectively 0.05 fang and 0.1
'), 0.310.52 was added, and the internal volume was 160c.
The mixture was placed in a glass bottle (c) and shaken for 2 hours using a horizontal shaker.

For comparison, methylhydrodiene siloxane endblocked with trimethylsilyl groups and having a viscosity of 20 cs at 25°C was used.
Similar treatment was carried out using Comparative Example 1) and dimethylsiloxane endblocked with trimethylsilyl groups.

Next, the angle of repose of the quicklime treated in the above manner was measured to evaluate its fluidity. The results are shown in Table 1. Note that the angle of repose of untreated quicklime was 53°.

Table 1 [Example 2] Contains methoxy groups per 100 parts of quicklime used in Example 1! 0.0 methoxy-terminated copolymer consisting of 21.3% dimethylsiloxy units and methylmethoxysiloxy units
5'), 0.1? , 0.3').

0.52 was added and the same treatment as in Example 1 was performed.

As a result, the treated quicklime all showed good fluidity, and their angle of repose was 41°.

The angles were 39', 36', and 36°.

[Comparative Example 3] 0.1 part of methyltrimethoxysilane was added to 100 parts of quicklime used in Example 1, and the same treatment as in Example 1 was performed, but the angle of repose of the treated quicklime was 4°. and
The fluidity improvement effect was not sufficiently observed.

[Example 3. Comparative Example 4] Methylmethoxypolysiloxane containing methoxy group ff142.2% was added to 100 parts of quicklime used in Example 1.
．． 1 part and 0.1 part of the methylhydrodienesiloxane used in Example 1 were added, and the same treatment as in Example 1 was carried out, and the atmospheric concentration of hydrogen and methyl alcohol generated in the container was measured by gas chromatography. It was measured.

As a result, in the case of methylmethoxypolysiloxane, 2
0.004 volume dan% at 5℃ treatment temperature, 60℃ treatment I! l
The temperature was 0.01% by volume, and this gate did not change even after 24 hours of contact.

On the other hand, in the case of methylhydrodiene polysiloxane, at a treatment temperature of 25°C, the volume reduction was 3.0% by volume after 1 hour, 5.3% by volume after 2 hours, and 9.5% by volume after 4 hours. .

Claims (1)

[Claims] 1. The following general formula (I) R^1a(R^2O)bSiO(4-a-b)/2...
・Organopolysiloxanes represented by (I) whose molecular chain ends are -OR^2 and cyclic organopolysiloxanes represented by the following general formula (II) ▲Mathical formulas, chemical formulas, tables, etc. are available▼...(II) Siloxane (here, in the above formula, R^1 and R^2 are the same or different hydrocarbon groups, 0≦a<4, 0<b≦4, 0<a+b
≦4, n=3 to 10) using 0.01 to 1 part by weight of one or more compounds selected from
A method for improving the fluidity of lime powder, which comprises treating the weight part. 2. Organopolysiloxane of formula (I) having terminal OR^2 groups and (II) in lime powder finer than 100 mesh.
) One or more compounds selected from the cyclic organopolysiloxanes of the formula are added in a solvent-free state, and the mixture is heated at room temperature to 10
The method according to claim 1, wherein the treatment is carried out by mixing and stirring at 0°C.